Vibration device and vibration control method

Abstract

The vibration device of the present invention comprises a light-transmitting body and a light-transmitting body having a diameter of 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 The vibration control method of the present invention is a vibration control method of a vibration device comprising a light-transmitting body and a vibration unit for vibrating the light-transmitting body, wherein the vibration control method includes using the vibration unit to vibrate the light-transmitting body at a speed of 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 The following are the steps for vibration acceleration vibration.

Description

Technical Field

[0001] The present invention relates to a vibration device and a vibration control method for removing liquid droplets and the like by vibration. Background Art

[0002] Patent Document 1 discloses an in-vehicle optical sensor cover for removing debris from a lens. The in-vehicle optical sensor cover described in Patent Document 1 includes an ultrasonic vibration component that ultrasonically vibrates the lens or glass cover. The ultrasonic vibration component ultrasonically vibrates the lens or glass cover during or after cleaning by a cleaning nozzle.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-244417 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] The device of Patent Document 1 still has room for improvement in terms of enhancing the performance of removing liquid droplets.

[0008] Solutions for solving problems

[0009] A vibration device according to one embodiment of the present invention includes:

[0010] a light-transmitting body; and

[0011] The vibration part causes the light-transmitting body to vibrate at a speed of 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 Vibrates at the following vibration accelerations.

[0012] One embodiment of the present invention provides a vibration control method for a vibration device including a light-transmitting body and a vibration unit for vibrating the light-transmitting body, wherein the vibration control method includes vibrating the light-transmitting body at a speed of 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 The following are the steps for vibration acceleration vibration.

[0013] Effects of the Invention

[0014] According to the present invention, a vibration device and a vibration control method that improve the performance of removing liquid droplets can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic perspective view showing an example of an imaging unit including the vibration device according to the first embodiment of the present invention.

[0016] Figure 2 yes Figure 1 A schematic cross-sectional view of the camera unit.

[0017] Figure 3 This is a schematic perspective view of an example of a vibration device according to Embodiment 1 of the present invention.

[0018] Figure 4 yes Figure 3 Exploded perspective view of the vibration device.

[0019] Figure 5 yes Figure 3 A schematic cross-sectional view of a vibration device.

[0020] Figure 6 This is a block diagram of an example of the vibration device according to the first embodiment of the present invention.

[0021] Figure 7 This is a schematic diagram illustrating an example of the relationship between the slip angle and the adhesion energy.

[0022] Figure 8 This is a schematic diagram showing an example of the relationship between the sliding angle and the acceleration.

[0023] Figure 9 This is a schematic diagram showing an example of the relationship between the slide angle and the applied voltage.

[0024] Figure 10 This is a flowchart of an example of the vibration control method according to the first embodiment of the present invention.

[0025] Figure 11 This is a schematic diagram showing an example of the operation of the vibration device according to the first embodiment of the present invention.

[0026] Figure 12 This is a schematic cross-sectional view of an example of the vibration device according to the first embodiment of the present invention.

[0027] Figure 13 It is a schematic cross-sectional view of a vibration device according to a modified example of the first embodiment of the present invention.

[0028] Figure 14 This is a schematic perspective view showing an example of an imaging unit including a vibration device according to a second embodiment of the present invention.

[0029] Figure 15 yes Figure 14 A schematic cross-sectional view of the camera unit.

[0030] Figure 16 This is a block diagram of an example of a vibration device according to Embodiment 2 of the present invention.

[0031] Figure 17 This is a flowchart of an example of a vibration control method according to Embodiment 2 of the present invention.

[0032] Figure 18 This is a schematic diagram showing an example of the operation of the vibration device according to the second embodiment of the present invention.

[0033] Figure 19 This is a schematic cross-sectional view showing an example of an imaging unit including a vibration device according to a third embodiment of the present invention.

[0034] Figure 20 This is a block diagram of an example of a vibration device according to Embodiment 3 of the present invention.

[0035] Figure 21 This is a flowchart of an example of a vibration control method according to Embodiment 3 of the present invention.

[0036] Figure 22 This is a schematic diagram showing an example of the operation of the vibration device according to the third embodiment of the present invention.

[0037] Figure 23 It is a schematic cross-sectional view of an example of a vibration device according to a fourth embodiment of the present invention.

[0038] Figure 24 This is a schematic diagram of an example of a water-repellent coating.

[0039] Figure 25 This is a schematic cross-sectional view of an example of a vibration device according to Embodiment 5 of the present invention.

[0040] Figure 26 This is a block diagram of an example of a vibration device according to Embodiment 5 of the present invention.

[0041] Figure 27 This is a flowchart of an example of a vibration control method according to the fifth embodiment of the present invention.

[0042] Figure 28 This is a schematic diagram showing an example of the operation of the vibration device according to the fifth embodiment of the present invention.

[0043] Figure 29 This is a flowchart of an example of a vibration control method according to a modification of the fifth embodiment of the present invention.

[0044] Figure 30 This is a flowchart of an example of a vibration control method according to the sixth embodiment of the present invention.

[0045] Figure 31This is a schematic diagram showing an example of the operation of the vibration device according to the sixth embodiment of the present invention.

[0046] Figure 32 Yes Figure 30 A schematic diagram of an example of the vibration control method for the motion of a droplet.

[0047] Figure 33 Yes Figure 30 A schematic diagram of an example of the vibration control method for the motion of a droplet.

[0048] Figure 34 This is a schematic diagram showing an example of the relationship between the sliding angle and the acceleration.

[0049] Figure 35 This is a schematic diagram showing an example of the relationship between the slide angle and the applied voltage.

[0050] Figure 36 This is a flowchart of an example of a vibration control method according to a modification of the sixth embodiment of the present invention.

[0051] Figure 37 This is a graph showing the coating wear time of Example 1 and Comparative Example 1.

[0052] Figure 38 This is a graph showing the muddy water removal rates of Example 2 and Comparative Example 2.

[0053] Figure 39 This is a graph showing the usage amounts of the cleaning liquids in Example 3 and Comparative Example 3.

[0054] Figure 40 This is a schematic perspective view showing an example of an imaging unit including a vibration device according to a seventh embodiment of the present invention.

[0055] Figure 41 yes Figure 40 Exploded perspective view of the camera unit.

[0056] Figure 42 yes Figure 40 A schematic cross-sectional view of the camera unit.

[0057] Figure 43 This is a diagram showing an example of simulation results of vibration analysis of the imaging unit according to the seventh embodiment of the present invention.

[0058] Figure 44 This is a schematic cross-sectional view of an example of a vibration device.

[0059] Figure 45 This is a schematic cross-sectional view of another example of the vibration device.

[0060] Figure 46It is a schematic cross-sectional view of a vibration device according to a modified example of the seventh embodiment of the present invention.

[0061] Figure 47 Yes Figure 46 FIG. 1 is a diagram showing an example of simulation results of vibration analysis of a vibration device. DETAILED DESCRIPTION

[0062] (Background of the Invention)

[0063] The in-vehicle optical sensor cover described in Patent Document 1 includes a vibration mechanism comprising a piezoelectric element and electrodes within the camera cover housing that vibrates the glass cover by generating ultrasonic or low-frequency sound waves. The in-vehicle optical sensor cover described in Patent Document 1 vibrates the glass cover using the vibration mechanism while washer fluid is being sprayed from the washer nozzle's spray port onto the glass surface of the glass cover or after it has been sprayed.

[0064] However, the in-vehicle optical sensor cover described in Patent Document 1 still has room for improvement in terms of droplet removal. In the in-vehicle optical sensor cover described in Patent Document 1, when the light-transmitting body (the glass cover to which the droplets adhere) is vibrated, the droplets may remain on the light-transmitting body due to the vibration. Consequently, the in-vehicle optical sensor cover described in Patent Document 1 presents a problem of difficulty in removing the droplets adhered to the light-transmitting body.

[0065] Furthermore, the in-vehicle optical sensor cover described in Patent Document 1 has difficulty removing droplets containing foreign matter adhering to the translucent body. Droplets containing foreign matter are, for example, muddy water. Muddy water is more likely to remain on the translucent body than droplets such as rainwater, which are less likely to contain foreign matter. Therefore, even after cleaning the translucent body with a cleaning fluid, it is difficult to remove the muddy water from the body.

[0066] These problems are new problems discovered by the inventors of the present invention.

[0067] The inventors of the present invention conducted intensive studies to solve these problems and found that when the vibration acceleration of the light-transmitting body is changed, the sliding angle of the liquid droplets attached to the light-transmitting body changes.

[0068] Therefore, the inventors of the present invention have discovered a structure for controlling the vibration acceleration of the light-transmitting body, and have completed the following invention.

[0069] A vibration device according to one embodiment of the present invention includes:

[0070] a light-transmitting body; and

[0071] The vibration part causes the light-transmitting body to vibrate at a speed of 1.5×10 5 m / s 2 Above and 8.0×10 5m / s 2 Vibrates at the following vibration accelerations.

[0072] According to such a structure, the performance of removing liquid droplets can be improved.

[0073] Alternatively, the vibration portion may cause the light-transmitting body to move at a speed of 3.5×10 5 m / s 2 Above and 5.5×10 5 m / s 2 Vibrates at the following vibration accelerations.

[0074] According to such a structure, the performance of removing liquid droplets can be further improved.

[0075] Alternatively, the vibration device may further include:

[0076] A control unit controls the vibration acceleration of the vibration unit.

[0077] According to such a configuration, vibration acceleration can be easily controlled.

[0078] Alternatively, the vibration portion may include a piezoelectric element.

[0079] The control unit controls the value of the voltage applied to the piezoelectric element to be greater than or equal to 2 Vp-p and less than or equal to 15 Vp-p.

[0080] According to such a structure, vibration acceleration can be controlled more easily.

[0081] Alternatively, the vibration portion may include a vibration body disposed between the piezoelectric element and the light-transmitting body.

[0082] The piezoelectric element has a circular plate shape,

[0083] The vibrating body has a cylindrical shape,

[0084] The light-transmitting body has a circular plate shape or a dome shape.

[0085] According to such a structure, the performance of removing liquid droplets can be further improved.

[0086] Alternatively, the control unit may include:

[0087] The light-transmitting body is 8.1×10 5 m / s 2 Above and 1.7×10 6 m / s 2 The first vibration mode of vibration with the following vibration acceleration; and

[0088] The light-transmitting body is 1.5×10 5 m / s 2Above and 8.0×10 5 m / s 2 The following vibration acceleration vibration second vibration mode,

[0089] The control unit controls the vibration unit so as to execute the second vibration pattern after executing the first vibration pattern.

[0090] According to such a structure, the performance of removing liquid droplets can be further improved.

[0091] Alternatively, the vibration portion may include a piezoelectric element.

[0092] The control unit controls the value of the voltage applied to the piezoelectric element to be greater than or equal to 16 Vp-p and less than or equal to 60 Vp-p in the first vibration mode.

[0093] Furthermore, in the second vibration mode, the value of the voltage applied to the piezoelectric element is controlled to be greater than or equal to 2 Vp-p and less than or equal to 15 Vp-p.

[0094] According to such a structure, vibration acceleration can be controlled more easily.

[0095] Alternatively, the vibration device may further include:

[0096] a displacement detection sensor that detects information related to the displacement amount of the light-transmitting body and transmits the information to the control unit,

[0097] The control unit controls the vibration acceleration of the vibration unit based on the information.

[0098] According to such a configuration, the vibration acceleration of the vibration portion can be controlled based on information on the displacement amount of the light-transmitting body.

[0099] Alternatively, the vibration device may further include:

[0100] A fan device is used to spray gas toward the surface of the light-transmitting body.

[0101] According to such a structure, the performance of removing liquid droplets can be further improved.

[0102] Alternatively, the vibration device may further include:

[0103] A spraying device sprays liquid onto the surface of the light-transmitting body.

[0104] According to such a configuration, the liquid can be ejected toward the surface of the light-transmitting body, and the ejected liquid can be removed from the surface of the light-transmitting body.

[0105] Alternatively, a waterproof coating may be formed on the surface of the light-transmitting body.

[0106] According to such a structure, the performance of removing liquid droplets can be further improved.

[0107] One embodiment of the present invention provides a vibration control method for a vibration device including a light-transmitting body and a vibration unit for vibrating the light-transmitting body, wherein the vibration control method includes vibrating the light-transmitting body at a speed of 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 The following are the steps for vibration acceleration vibration.

[0108] According to such a structure, the performance of removing liquid droplets can be improved.

[0109] Alternatively, the vibrating step includes: vibrating the light-transmitting body at a speed of 3.5×10 5 m / s 2 Above and 5.5×10 5 m / s 2 Vibrates at the following vibration accelerations.

[0110] According to such a structure, the performance of removing liquid droplets can be further improved.

[0111] Alternatively, the vibration portion may include a piezoelectric element.

[0112] The vibrating step includes controlling, by a control unit, a voltage applied to the piezoelectric element to a value greater than or equal to 2 Vp-p and less than or equal to 15 Vp-p.

[0113] According to such a configuration, vibration acceleration can be easily controlled.

[0114] Alternatively, the vibration portion may include a piezoelectric element.

[0115] The vibrating step includes:

[0116] The light-transmitting body is made to 5 m / s 2 Above and 1.7×10 6 m / s 2 vibrate in a first vibration mode at the following vibration acceleration; and

[0117] The light-transmitting body is made to 5 m / s 2 Above and 8.0×10 5 m / s 2 The following vibration acceleration vibrates in the second vibration mode,

[0118] After the step of vibrating the light-transmitting body in the first vibration mode is performed, the step of vibrating the light-transmitting body in the second vibration mode is performed.

[0119] According to such a structure, the performance of removing liquid droplets can be further improved.

[0120] Alternatively, vibrating the light-transmitting body in the first vibration mode includes controlling, by the control unit, a voltage applied to the piezoelectric element to a value not less than 16 Vp-p and not more than 60 Vp-p,

[0121] Vibrating the light-transmitting body in the second vibration mode includes controlling, by the control unit, a value of a voltage applied to the piezoelectric element to be greater than or equal to 2 Vp-p and less than or equal to 15 Vp-p.

[0122] According to such a structure, vibration acceleration can be controlled more easily.

[0123] Alternatively, the vibration control method further includes the step of detecting information related to the displacement of the light-transmitting body.

[0124] The vibrating step includes controlling the vibration acceleration of the vibrating portion based on the information using a control portion.

[0125] According to such a configuration, the vibration acceleration of the vibration portion can be controlled based on information on the displacement amount of the light-transmitting body.

[0126] Alternatively, the vibration control method further includes the step of using a blower device to spray gas toward the surface of the light-transmitting body.

[0127] According to such a structure, the performance of removing liquid droplets can be further improved.

[0128] Alternatively, the vibration control method includes the step of using a spraying device to spray liquid onto the surface of the light-transmitting body.

[0129] According to such a configuration, the liquid can be ejected toward the surface of the light-transmitting body, and the ejected liquid can be removed from the surface of the light-transmitting body.

[0130] An embodiment of the present invention is described below with reference to the accompanying drawings. The following description is merely illustrative in nature and is not intended to limit the present disclosure, its applications, or uses. Furthermore, the drawings are schematic, and the proportions of various dimensions and the like may not necessarily correspond to actual proportions and the like.

[0131] (Implementation 1)

[0132] The vibration device of Embodiment 1 of the present invention is applied to a vehicle-mounted camera unit. Therefore, Embodiment 1 will be described using the vibration device applied to a camera unit as an example. Furthermore, the vibration device is not limited to vehicle-mounted camera units. For example, the vibration device can also be applied to security surveillance cameras, drone camera units, and the like.

[0133] [Camera Unit]

[0134] Figure 1 This is a schematic perspective view showing an example of the imaging unit 100 including the vibration device 200 according to the first embodiment of the present invention. Figure 2 yes Figure 1 1 is a schematic cross-sectional view of the imaging unit 100. In addition, the X, Y, and Z directions in the figure represent the longitudinal direction, the lateral direction, and the height direction of the imaging unit 100, respectively.

[0135] like Figure 1 and Figure 2 As shown, the imaging unit 100 includes a housing 11 , an imaging section 12 , and a vibration device 200 .

[0136] The housing 11 houses the vibration device 200 and the camera unit 12. For example, the housing 11 is formed into a cylindrical shape and is made of metal or synthetic resin. Figure 1 As shown, the housing 11 is formed into a square tube shape, but may also be other shapes such as a cylinder. A bottom plate 11a is fixed to one end of the housing 11, and the light-transmitting body 2 of the vibration device 200 is disposed on the other end so as to be exposed to the outside.

[0137] like Figure 2 As shown, the imaging unit 12 is supported by a main body member 12a and fixed to a base plate 11a, and the base plate 11a is fixed to the housing 11. In addition, a circuit including an imaging element (not shown) is built into the imaging unit 12. As the imaging element, for example, a CMOS, a CCD, a radiation thermometer or a thermopile that receives light of any wavelength from the visible region to the far infrared region can be listed. In addition, a lens unit including a plurality of lenses (not shown) can also be fixed in the imaging direction of the imaging unit 12. In addition, the structure of the imaging unit 12 is not particularly limited as long as it can capture the object located in front of the lens.

[0138] The vibration device 200 is mounted on the housing 11 so that the light-transmitting body 2 is exposed. The vibration device 200 is arranged on the optical path of the imaging unit 12. In the first embodiment, the vibration device 200 is arranged so that the surface of the light-transmitting body 2 is along the height direction (Z direction) of the imaging unit 100.

[0139] [Vibration device]

[0140] Next, the vibration device 200 will be described in detail.

[0141] Figure 3 It is a schematic perspective view of an example of the vibration device 200 according to the first embodiment of the present invention. Figure 4 yes Figure 3 An exploded perspective view of the vibration device 200. Figure 5 yes Figure 3 Schematic cross-sectional view of the vibration device 200. Figure 6 1 is a block diagram of an example of the vibration device 200 according to Embodiment 1 of the present invention. In addition, the X, Y, and Z directions in the figure represent the lateral direction, the thickness direction, and the longitudinal direction of the vibration device 200, respectively.

[0142] like Figures 1 to 6 As shown, the vibration device 200 includes a light-transmitting body 2, a vibration unit 3, a control unit 4, and a power supply conductor 5. In addition, the control unit 4 and the power supply conductor 5 are not essential components of the vibration device 200.

[0143] <Translucent Body>

[0144] The light-transmitting body 2 has light transmittance sufficient to transmit energy rays or light of a wavelength detected by an optical detection element, such as an imaging element, included in the imaging unit 12. In the first embodiment, the light-transmitting body 2 serves as a cover for protecting the imaging unit 12 from foreign matter. The imaging unit 12 is disposed within the light-transmitting body 2 and captures an image of an object outside the imaging unit 100 through the light-transmitting body 2.

[0145] Examples of materials for forming the light-transmitting body 2 include light-transmitting plastic, glass such as quartz or borosilicate, light-transmitting ceramics, and synthetic resins. For example, forming the light-transmitting body 2 from reinforced glass can increase the strength of the light-transmitting body 2 .

[0146] The light-transmitting body 2 has a disc shape. Specifically, when viewed in the thickness direction (Y direction) of the vibration device 200, the light-transmitting body 2 is formed into a circular shape. The shape of the light-transmitting body 2 is not limited to this. For example, when viewed in the thickness direction (Y direction) of the vibration device 200, the light-transmitting body 2 may also have a polygonal, elliptical, or triangular shape.

[0147] The outer peripheral edge of the light-transmitting body 2 is bonded to the vibration part 3. The light-transmitting body 2 and the vibration part 3 can be bonded using, for example, an adhesive or a solder material. Alternatively, thermocompression bonding or anodic bonding can be used.

[0148] In Embodiment 1, the light-transmitting body 2 has a disk shape with an outer diameter of 20 mm and a thickness of 2 mm. Furthermore, the light-transmitting body 2 is formed of light-transmitting glass.

[0149] <Vibration Section>

[0150] The vibrating portion 3 is a component that vibrates the light-transmitting body 2. The vibrating portion 3 vibrates the light-transmitting body 2 in the thickness direction (Y direction) of the vibration device 200. The vibrating portion 3 is configured to vibrate the light-transmitting body 2 at a predetermined vibration acceleration. The predetermined vibration acceleration is preferably 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 More preferably, the predetermined vibration acceleration is 3.5×10 5 m / s 2 Above and 5.5×10 5 m / s 2 the following.

[0151] The vibrating portion 3 has a cylindrical shape. In the first embodiment, the vibrating portion 3 has a cylindrical shape with an inner diameter of 16 mm, an outer diameter of 20 mm, and a height of 11 mm. Alternatively, the vibrating portion 3 may have a cylindrical shape with an inner diameter of 16 mm to 36 mm, an outer diameter of 22 mm to 40 mm, and a height of 9 mm to 40 mm.

[0152] The vibration unit 3 includes a piezoelectric element 6 and a vibrating body 7 .

[0153] The piezoelectric element 6 vibrates the light-transmitting body 2 via the vibrator 7. The piezoelectric element 6 is connected to the power supply conductor 5. The piezoelectric element 6 vibrates when it is supplied with power from the power supply conductor 5. In other words, the piezoelectric element 6 vibrates when a voltage is applied from the power supply conductor 5.

[0154] For example, the piezoelectric element 6 has an annular plate shape. The annular plate shape means that a plate-like member is formed into an annular shape.

[0155] The piezoelectric element 6 includes a piezoelectric body and an electrode connected to the power supply conductor 5. Examples of materials that can be used to form the piezoelectric body include barium titanate (BaTiO3), lead zirconate titanate (PZT: PbTiO3·PbZrO3), lead titanate (PbTiO3), lead metaniobate (PbNb2O6), bismuth titanate (Bi4Ti3O 12 ), (K,Na)NbO3 or suitable piezoelectric ceramics, such as LiTaO3 or LiNbO3, or suitable piezoelectric single crystals. The electrodes may be, for example, Ni electrodes. Alternatively, the electrodes may be formed by sputtering using a thin metal film such as Ag or Au. Alternatively, in addition to sputtering, the electrodes may be formed by plating or vapor deposition.

[0156] In Embodiment 1, the piezoelectric element 6 has an annular plate shape with an outer diameter of 22 mm, an inner diameter of 16 mm, and a thickness of 1 mm. The piezoelectric body forming the piezoelectric element 6 is made of lead zirconate titanate (PZT: Pb(Zr,Ti)O3).

[0157] The vibrating body 7 is disposed between the piezoelectric element 6 and the light-transmitting body 2 . The vibrating body 7 is bonded to the piezoelectric element 6 and the light-transmitting body 2 with, for example, an adhesive. The vibrating body 7 amplifies the vibration of the piezoelectric element 6 and transmits it to the light-transmitting body 2 .

[0158] For example, the vibrator 7 has a cylindrical shape extending in the thickness direction (Y direction) of the vibrating device 200. Specifically, the vibrator 7 has a circular cylindrical body 7a and an annular plate portion 7b provided at the end connected to the light-transmitting body 2.

[0159] The cylindrical body 7a has a thin portion 7c. The thin portion 7c is provided between the end of the cylindrical body 7a connected to the light-transmitting body 2 and the end connected to the piezoelectric element 6. This allows the vibration of the piezoelectric element 6 to be efficiently transmitted to the light-transmitting body 2.

[0160] The annular plate portion 7b is a plate-shaped member extending toward the center of the cylindrical body 7a. The light-transmitting body 2 is joined to the annular plate portion 7b. For example, the thickness of the annular plate portion 7b is smaller than that of the cylindrical body 7a and is approximately the same as that of the thin-walled portion 7c.

[0161] For example, the vibrating body 7 is formed of metal. Examples of the metal forming the vibrating body 7 include stainless steel, 42 alloy, 50 alloy, Invar, Super Invar, Kovar, aluminum, and duralumin. Alternatively, the vibrating body 7 may be formed of ceramics such as alumina and zirconia. The vibrating body 7 may also be formed of a semiconductor such as Si. The vibrating body 7 may also be covered with an insulating material.

[0162] In Embodiment 1, the vibrating body 7 has a cylindrical shape with an inner diameter of 16 mm, an outer diameter of 22 mm, and a height of 8 mm. The vibrating body 7 is made of stainless steel (SUS303).

[0163] <Control Unit>

[0164] The control unit 4 controls the vibration acceleration of the vibration unit 3. The control unit 4 is connected to the piezoelectric element 6 of the vibration unit 3 via the power supply conductor 5. The control unit 4 includes a power supply circuit and supplies power to the piezoelectric element 6 via the power supply conductor 5. In other words, the control unit 4 applies a voltage to the piezoelectric element 6 via the power supply conductor 5. Thus, the control unit 4 controls the vibration of the vibration unit 3.

[0165] In the first embodiment, the control unit 4 controls the voltage value applied to the piezoelectric element 6 to be greater than 2 Vp-p and less than 15 Vp-p. Thus, the control unit 4 can control the magnitude of the vibration of the vibration unit 3, thereby controlling the vibration acceleration of the light-transmitting body 2 to be less than 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 the following.

[0166] Preferably, the control unit 4 controls the voltage value applied to the piezoelectric element 6 to be greater than 5Vp-p and less than 8Vp-p. Thus, the control unit 4 can control the magnitude of the vibration of the vibration unit 3, thereby controlling the vibration acceleration of the light-transmitting body 2 to be within 3.5×10 5 m / s 2 Above and 5.5×10 5 m / s 2 the following.

[0167] The control unit 4 is composed of a CPU (Central Processing Unit) serving as the control center. It also includes a ROM (Read Only Memory) that stores programs and control data for CPU operation, a RAM (Ramdom Access Memory) that functions as the CPU's work area, and input / output interfaces for maintaining signal compatibility with peripheral devices.

[0168] <Power Supply Conductor>

[0169] The power supply conductor 5 connects the control unit 4 and the piezoelectric element 6. The power supply conductor 5 is connected to a power supply circuit included in the control unit 4, and the piezoelectric element 6 is supplied with power by the power supply circuit.

[0170] The power supply conductor 5 is formed of a conductive material, such as stainless steel, beryllium copper, nickel silver, or copper.

[0171] [Relationship between slip angle and adhesion energy]

[0172] Next, the relationship between the sliding angle and the adhesion energy will be described.

[0173] The sliding angle refers to the angle between the horizontal plane and the solid surface at which a droplet begins to slide downward when the droplet is attached to a horizontal solid surface and the solid surface is gradually tilted from the horizontal. Figure 7 This is a schematic diagram illustrating an example of the relationship between the slip angle and the adhesion energy. Figure 7 The relationship shown can be expressed using the calculation formula for adhesion energy proposed by Wolfram.

[0174] [Formula 1]

[0175]

[0176] E represents the adhesion energy, r represents the contact radius, m represents the droplet mass, g represents the gravitational acceleration, and θ represents the sliding angle. The above formula is based on experimental findings that the sliding angle θ of water and paraffin wax is proportional to the radius r of the contact surface between the droplet 50 and the solid 51. It assumes that at the sliding angle θ, the oblique component of the gravity of the droplet 50 and the adhesion force acting on the contact circumference are balanced. Furthermore, this indicator is experimentally unaffected by factors such as the liquid volume and the tilt angle; it is a unique evaluation indicator determined solely by the combination of the liquid and the solid.

[0177] As can be seen from the above formula, when the sliding angle θ decreases, the adhesion energy E decreases. In other words, when the sliding angle θ decreases, the droplet 50 is less likely to adhere to the solid surface.

[0178] The vibration device 200 vibrates the light-transmitting body 2 at a predetermined vibration acceleration to reduce the roll-off angle θ, thereby reducing the adhesion energy E required for the droplets to settle on the surface of the light-transmitting body 2. This makes it easier to remove the droplets adhered to the light-transmitting body 2.

[0179] [Relationship between sliding angle and vibration acceleration]

[0180] Figure 8 This is a schematic diagram showing an example of the relationship between the sliding angle and the vibration acceleration. Figure 8 The change in the fall angle relative to the change in the vibration acceleration is shown in FIG.

[0181] A power supply (Keysight Technologies: E26104A) and a function generator (Tektronix: AGF1022) were used to supply a signal to the piezoelectric element 6 of the vibration unit 3, which had a resonant frequency of approximately 60 kHz, to excite vibration. The displacement of the light-transmitting body 2, excited by the vibration of the vibration unit 3, was detected using a laser displacement meter (Olympus: BX51M). This displacement was measured using a multimeter (Keysight Technologies: 2110) and an oscilloscope (Tektronix: TBS1104). The vibration acceleration was denoted by α, the frequency by f, and the amplitude (displacement) by A. The equation α = (2πf) was used to represent the displacement of the light-transmitting body 2. 2 A is used to calculate the vibration acceleration.

[0182] like Figure 8 As shown, when the vibration acceleration α is 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 When the sliding angle θ is less than 40 degrees (refer to Figure 8When the sliding angle θ is less than 40 degrees, the droplet's adhesion energy E is smaller than the force of sliding off the surface of the light-transmitting body 2. Therefore, the droplet is less likely to remain on the light-transmitting body 2 and flows toward the outside of the body 2. This improves droplet removal performance.

[0183] In addition, when the vibration acceleration α is 3.5×10 5 m / s 2 Above and 5.5×10 5 m / s 2 When the sliding angle θ is less than 22 degrees (refer to Figure 8 When the sliding angle θ becomes less than 22 degrees, the adhesion energy E of the droplet is further reduced. Therefore, the droplet easily flows to the outside of the light-transmitting body 2, and the droplet removal performance is improved.

[0184] When the vibration acceleration α is greater than 1.5×10 5 m / s 2 Smaller or smaller than 8.0×10 5 m / s 2 When the sliding angle θ is larger than 40 degrees, the droplet adhesion energy E is greater than the force of sliding from the surface of the light-transmitting body 2 to the outside. Therefore, the vibration acceleration α is 3.5×10 5 m / s 2 Above and 5.5×10 5 m / s 2 Compared with the following, the droplets are difficult to slide down.

[0185] Therefore, the vibration acceleration α is preferably 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 More preferably, the vibration acceleration α is 3.5×10 5 m / s 2 Above and 5.5×10 5 m / s 2 By controlling the vibration acceleration α within the predetermined range, the sliding property of the liquid droplets attached to the surface of the light-transmitting body 2 is improved compared with other ranges.

[0186] In the first embodiment, the control unit 4 controls the vibration acceleration α by controlling the voltage value applied to the piezoelectric element 6 of the vibrating unit 3. Specifically, the control unit 4 applies the voltage to the piezoelectric element 6 via the power supply conductor 5. The control unit 4 controls the peak-to-peak value (Vp-p) of the AC voltage applied to the piezoelectric element 6.

[0187] Figure 9 This is a schematic diagram showing an example of the relationship between the sliding angle and the applied voltage. Figure 9 As shown, the control unit 4 controls the voltage applied to the piezoelectric element 6 to be greater than 2 Vp-p and less than 15 Vp-p, thereby making the vibration acceleration α 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 This makes it possible to reduce the sliding angle θ to 40 degrees or less (see Figure 9 "B1" in the image).

[0188] Furthermore, the control unit 4 can control the voltage applied to the piezoelectric element 6 to be greater than or equal to 5 Vp-p and less than or equal to 8 Vp-p, thereby making the vibration acceleration α 3.5×10 5 m / s 2 Above and 5.5×10 5 m / s 2 This makes it possible to reduce the sliding angle θ to 22 degrees or less (see Figure 9 "B2").

[0189] [action]

[0190] An example of an operation of the vibration device 200 , that is, an example of a vibration control method will be described. The vibration control method is a method of controlling the vibration device 200 .

[0191] Figure 10 This is a flowchart of an example of the vibration control method according to the first embodiment of the present invention. Figure 11 This is a schematic diagram showing an example of the operation of the vibration device 200 according to the first embodiment of the present invention.

[0192] like Figure 10 As shown, in step ST10, the light-transmitting body 2 is vibrated at a predetermined vibration acceleration by the vibration unit 3. The predetermined vibration acceleration is preferably 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 More preferably, the predetermined vibration acceleration is 3.5×10 5 m / s 2 Above and 5.5×10 5 m / s 2 the following.

[0193] like Figure 11 As shown, the light-transmitting body 2 vibrates at a predetermined vibration acceleration in the thickness direction (Y direction) of the light-transmitting body 2 . As a result, the liquid droplets 60 adhering to the surface of the light-transmitting body 2 slide down and are removed from the surface of the light-transmitting body 2 .

[0194] return Figure 10In the first embodiment, step ST10 includes step ST11 of controlling the voltage value applied to the piezoelectric element 6 of the vibration unit 3 by the control unit 4 .

[0195] In step ST11, the control unit 4 controls the voltage value applied to the piezoelectric element 6 to be greater than or equal to 2 Vp-p and less than or equal to 15 Vp-p. Preferably, the control unit 4 controls the voltage value applied to the piezoelectric element 6 to be greater than or equal to 5 Vp-p and less than or equal to 8 Vp-p.

[0196] As described above, in the vibration control method of the first embodiment, by executing steps ST10 and ST11 , the light-transmitting body 2 can be vibrated, thereby removing the liquid droplets adhering to the light-transmitting body 2 .

[0197] [Effect]

[0198] According to the vibration device 200 and the vibration control method of the first embodiment, the following effects can be achieved.

[0199] The vibration device 200 includes a light-transmitting body 2 and a vibration part 3. The vibration part 3 is configured so that the light-transmitting body is 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 The following vibration acceleration vibration. This structure can improve the performance of removing droplets adhered to the light-transmitting body 2. Specifically, by reducing the sliding angle of droplets adhered to the light-transmitting body 2, the droplet adhesion energy can be reduced. This makes it easier for the droplets to slide off the surface of the light-transmitting body 2, making it easier to remove the droplets from the surface of the light-transmitting body 2.

[0200] The vibration part 3 is preferably such that the light-transmitting body 2 is 3.5×10 5 m / s 2 Above and 5.5×10 5 m / s 2 The following vibration acceleration vibration. This structure can further improve droplet removal performance. Specifically, by further reducing the sliding angle, the droplet adhesion energy can be further reduced. This makes it easier for the droplet to slide off the surface of the light-transmitting body 2, making it easier to remove the droplet from the surface of the light-transmitting body 2.

[0201] The vibration device 200 further includes a control unit 4 that controls the vibration acceleration of the vibration unit 3. With such a configuration, the vibration acceleration of the vibration unit 3 can be easily controlled.

[0202] The vibration part 3 has a piezoelectric element 6. The control part 4 controls the value of the voltage applied to the piezoelectric element 6 to be greater than 2 Vp-p and less than 15 Vp-p. With such a structure, the vibration acceleration can be easily controlled to be within 1.5×10 5 m / s2 Above and 8.0×10 5 m / s 2 the following.

[0203] The vibrating portion 3 includes a vibrating body 7 disposed between the piezoelectric element 6 and the light-transmitting body 2. The piezoelectric element 6 has an annular plate shape. The vibrating body 7 has a cylindrical shape. The light-transmitting body 2 has a disk shape. This structure can further improve the droplet removal performance.

[0204] The vibration control method is a vibration control method for a vibration device 200 including a light-transmitting body 2 and a vibration unit 3 for vibrating the light-transmitting body, wherein the vibration control method includes vibrating the light-transmitting body 2 at a speed of 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 The following is step ST10 of vibration acceleration vibration. This structure can improve the performance of removing droplets adhered to the light-transmitting body 2. Specifically, by reducing the sliding angle of droplets adhered to the light-transmitting body 2, the droplet adhesion energy can be reduced. This makes it easier for the droplets to slide off the surface of the light-transmitting body 2, making it easier to remove the droplets from the surface of the light-transmitting body 2.

[0205] The vibration step ST10 includes vibrating the light-transmitting body 2 at a speed of 3.5×10 5 m / s 2 Above and 5.5×10 5 m / s 2 The following vibration acceleration vibration. According to such a structure, the droplet removal performance can be further improved.

[0206] The vibration part 3 has a piezoelectric element 6, and the vibration step ST10 includes a step ST11 of controlling the value of the voltage applied to the piezoelectric element 6 to be greater than 2 Vp-p and less than 15 Vp-p. With such a structure, the vibration acceleration can be easily controlled to be within 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 the following.

[0207] Furthermore, in the first embodiment, an example of the vibration device 200 being applied to the imaging unit 100 has been described, but the present invention is not limited thereto. Figure 12 FIG is a diagram schematically showing the vibration device 200 according to the first embodiment. Figure 12 As shown, the vibration device 200 can also be used alone. Alternatively, the vibration device 200 can also be applied to a unit including an optical detection element other than an imaging element.

[0208] In Embodiment 1, the light-transmitting body 2 is described as a disk-shaped example, but the present invention is not limited thereto. The light-transmitting body 2 may be in any shape other than a plate. For example, when viewed in the thickness direction (Y direction) of the vibration device 200, the shape of the light-transmitting body 2 may be polygonal, elliptical, or triangular.

[0209] Figure 13 1 is a schematic cross-sectional view of a vibration device 201 according to a modified example of embodiment 1 of the present invention. Figure 13 As shown, vibration device 201 includes a translucent body 2a and a vibrating unit 3. In vibration device 201, translucent body 2 is formed into a dome shape. A dome shape refers to a plate-like member formed into a hemispherical shape. Even with this structure, the same effects as vibration device 200 are achieved. Furthermore, in the imaging unit, the dome-shaped translucent body 2a can expand the field of view of imaging unit 12.

[0210] While the first embodiment describes an example in which the vibration unit 3 includes the vibrator 7, the present invention is not limited thereto. The vibrator 7 is not a required structure. The vibration unit 3 only needs to include an element that vibrates the light-transmitting body 2. For example, the vibration unit 3 may include only the piezoelectric element 6.

[0211] In the first embodiment, the example in which the vibration device 200 includes the control unit 4 is described, but the present invention is not limited thereto. For example, the control unit 4 may be included in a device separate from the vibration device 200 .

[0212] In the first embodiment, the vibration control method is described as including steps ST10 and ST11, but the present invention is not limited thereto. For example, Figure 10 Steps ST10 and ST11 shown can also be combined or divided. Alternatively, Figure 10 The flowchart shown may include additional steps. For example, a step of acquiring trigger information for starting vibration may be added. In this case, step ST10 may also start vibration generated by the vibration unit 3 based on the trigger information.

[0213] In the first embodiment, the light-transmitting body 2 is described as an example of a light-transmitting cover, but the present invention is not limited thereto. For example, the light-transmitting body 2 may be a lens.

[0214] (Implementation Method 2)

[0215] A vibration device according to a second embodiment of the present invention is described. In this second embodiment, the differences from the first embodiment are mainly described. In this second embodiment, the same or equivalent structures as those in the first embodiment are denoted by the same reference numerals for description. In this second embodiment, overlapping descriptions with those in the first embodiment are omitted.

[0216] Figure 14This is a schematic perspective view showing an example of the imaging unit 101 including the vibration device 202 according to the second embodiment of the present invention. Figure 15 yes Figure 14 Schematic cross-sectional view of the imaging unit 101. Figure 16 This is a block diagram of an example of the vibration device 202 according to the second embodiment of the present invention.

[0217] The second embodiment is different from the first embodiment in that a fan device 8 is provided.

[0218] like Figures 14 to 16 As shown, the vibration device 202 includes a fan device 8 in addition to the configuration of the vibration device 200 of the first embodiment.

[0219] <Blower unit>

[0220] The blower device 8 sprays gas toward the surface of the light-transmitting body 2. The blower device 8 is disposed on the upper surface of the housing 11. The blower device 8 includes a pipe 81, a blower head 82 disposed at the front end of the pipe 81, and a pump 83 that supplies gas to the pipe 81. A flow path 84 through which gas flows is formed within the pipe 81 and the blower head 82.

[0221] The gas ejected from the blower device 8 is, for example, air.

[0222] The pipe 81 is disposed on the upper surface of the housing 11 and extends toward the light-transmitting body 2. In the second embodiment, the pipe 81 extends in the thickness direction (Y direction) of the vibration device 202. The pipe 81 is connected to a pump 83.

[0223] The blower head 82 is provided at the front end of the pipe 81 and defines the direction of the injected gas. The blower head 82 is disposed toward the light-transmitting body 2. In the second embodiment, the blower head 82 is oriented in the longitudinal direction (Z direction) of the vibrating device 202. For example, the blower head 82 may be oriented in the direction of gravity.

[0224] The pump 83 is connected to the pipe 81 and supplies gas to a flow path 84 provided inside the pipe 81 and the blower head 82 .

[0225] In the second embodiment, the blower device 8 is controlled by the control unit 4. Specifically, the control unit 4 controls the injection of gas from the blower head 82 by controlling the pump 83.

[0226] [action]

[0227] An example of the operation of the vibration device 202 , that is, an example of a vibration control method will be described. The vibration control method is a method of controlling the vibration device 202 .

[0228] Figure 17 This is a flowchart of an example of a vibration control method according to Embodiment 2 of the present invention. Figure 17 Steps ST10 and ST11 shown in FIG. 1 are the same as those in the first embodiment. Figure 10 Steps ST10 and ST11 shown are the same, so detailed description is omitted. Figure 18 This is a schematic diagram showing an example of the operation of the vibration device 202 according to the second embodiment of the present invention.

[0229] like Figure 17 As shown, in step ST20, the blower device 8 sprays gas toward the surface of the translucent body 2. Specifically, in step ST20, the controller 4 controls the pump 83 to supply gas to the pipe 81. The gas supplied from the pump 83 is sprayed from the blower head 82 via the flow path 84 provided within the pipe 81. The blower head 82 is positioned toward the surface of the translucent body 2. Therefore, the gas is sprayed from the blower head 82 toward the surface of the translucent body 2. The wind pressure of the gas sprayed from the blower head 82 promotes the sliding off of liquid droplets adhering to the surface of the translucent body 2.

[0230] like Figure 18 As shown, when the blower device 8 sprays gas onto the surface of the light-transmitting body 2, the liquid droplets 60 adhering to the surface of the light-transmitting body 2 easily slide off. Specifically, the vibration of the vibrating portion 3 reduces the sliding angle θ of the liquid droplets 60, so the droplets 60 are easily slid off by the flow of gas. This makes it easier to remove the liquid droplets 60 from the surface of the light-transmitting body 2.

[0231] [Effect]

[0232] According to the vibration device 202 and the vibration control method of the second embodiment, the following effects can be achieved.

[0233] The vibration device 202 includes a blower device 8 that sprays gas toward the surface of the light-transmitting body 2. With this configuration, the gas sprayed from the blower device 8 can easily remove liquid droplets adhering to the surface of the light-transmitting body 2. Specifically, the vibration generated by the vibrating unit 3 reduces the sliding angle θ of the liquid droplets 60 adhering to the surface of the light-transmitting body 2, thereby creating a state in which the liquid droplets 60 easily slide off. In this state, spraying gas toward the surface of the light-transmitting body 2 facilitates the liquid droplets' sliding off the surface of the light-transmitting body 2. As a result, the droplet removal performance can be further improved.

[0234] According to the vibration device 202 , the liquid droplets adhering to the surface of the light-transmitting body 2 can be removed in a shorter time by the vibration generated by the vibration portion 3 and the gas jet by the blower device 8 .

[0235] Furthermore, according to the vibration device 203 , the vibration generated by the vibration portion 3 makes it easier for the droplets to slide down, so that the output of the pump 83 can be reduced, and cost reduction and low power consumption can be achieved.

[0236] The vibration control method of the second embodiment includes step ST20 of spraying gas onto the surface of the light-transmitting body 2. With this configuration, liquid droplets adhering to the surface of the light-transmitting body 2 can be easily removed by the gas sprayed from the blower device 8.

[0237] In addition, in Embodiment 2, the piping 81 of the fan device 8 is described as being arranged on the upper surface of the housing 11, but the present invention is not limited thereto. The piping 81 of the fan device 8 may be arranged inside the housing 11 or on the side or bottom surface of the housing 11.

[0238] In the second embodiment, the blower device 8 is described as including the pump 83 , but the present invention is not limited thereto. The blower device 8 only needs to include a device that can be controlled by the controller 4 and can supply gas.

[0239] In Embodiment 2, the blower head 82 is oriented in the longitudinal direction (Z direction) of the vibrating device 202, but the present invention is not limited thereto. The blower head 82 can be oriented in any direction as long as it can spray gas toward the surface of the light-transmitting body 2. For example, the blower head 82 can also be arranged in a direction inclined relative to the surface of the light-transmitting body 2.

[0240] In the second embodiment, the vibration control method is described as including steps ST10, ST11, and ST20, but the present invention is not limited thereto. Figure 17 Steps ST10, ST11 and ST20 shown can also be combined or divided. Figure 17 The flowcharts shown may also include additional steps.

[0241] (Implementation 3)

[0242] A vibration device according to a third embodiment of the present invention will be described. In this third embodiment, the differences from the first embodiment will be mainly described. In this third embodiment, components identical or equivalent to those in the first embodiment are denoted by the same reference numerals for description. In this third embodiment, overlapping descriptions with those in the first embodiment are omitted.

[0243] Figure 19 This is a schematic cross-sectional view showing an example of the imaging unit 102 including the vibration device 203 according to the third embodiment of the present invention. Figure 20 This is a block diagram of an example of the vibration device 203 according to the third embodiment of the present invention.

[0244] The third embodiment is different from the first embodiment in that a discharge device 9 is provided.

[0245] like Figure 19 and Figure 20As shown, the vibration device 203 includes a discharge device 9 in addition to the configuration of the vibration device 200 of the first embodiment.

[0246] <Dispensing device>

[0247] The ejection device 9 ejects liquid onto the surface of the light-transmitting body 2. The ejection device 9 is disposed on the upper surface of the housing 11. The ejection device 9 includes a pipe 91, an ejection head 92 provided at the front end of the pipe 91, and a pump 93 for supplying liquid to the pipe 91. A flow path 94 through which the liquid flows is formed within the pipe 91 and the ejection head 92.

[0248] For example, the liquid ejected from the ejection device 9 is cleaning liquid.

[0249] The pipe 91 is disposed on the upper surface of the housing 11 and extends toward the light-transmitting body 2. In the third embodiment, the pipe 91 extends in the thickness direction (Y direction) of the vibrating device 203. The pipe 91 is connected to a pump 93.

[0250] The ejection head 92 is provided at the front end of the pipe 91 and defines the direction of the ejected liquid. The ejection head 92 is disposed toward the light-transmitting body 2. In the third embodiment, the ejection head 92 is oriented in the longitudinal direction (Z direction) of the vibrating device 203. For example, the ejection head 92 may be oriented in the direction of gravity.

[0251] The pump 93 is connected to the pipe 91 and supplies liquid to a flow path 94 provided inside the pipe 91 and the discharge head 92 .

[0252] In the third embodiment, the discharge device 9 is controlled by the control unit 4 . Specifically, the control unit 4 controls the discharge of the liquid from the discharge head 92 by controlling the pump 93 .

[0253] [action]

[0254] An example of the operation of the vibration device 203 , that is, an example of a vibration control method will be described. The vibration control method is a method of controlling the vibration device 203 .

[0255] Figure 21 This is a flowchart of an example of a vibration control method according to Embodiment 3 of the present invention. Figure 21 Steps ST10 and ST11 shown in FIG. 1 are the same as those in the first embodiment. Figure 10 Steps ST10 and ST11 shown are the same, so detailed description is omitted. Figure 22 This is a schematic diagram showing an example of the operation of the vibration device 203 according to the third embodiment of the present invention.

[0256] like Figure 21As shown, in step ST30, the liquid is ejected onto the surface of the translucent body 2 by the ejection device 9. Specifically, in step ST30, the controller 4 controls the pump 93 to supply the liquid to the pipe 91. The gas supplied from the pump 93 is ejected from the ejection head 92 via the flow path 94 provided within the pipe 91. The ejection head 92 is positioned facing the surface of the translucent body 2. Therefore, the liquid is ejected from the ejection head 92 toward the surface of the translucent body 2.

[0257] like Figure 22 As shown, the ejection device 9 ejects a liquid 61 toward the surface of the light-transmitting body 2. When the liquid 61 is a cleaning liquid, foreign matter 62 such as dirt attached to the surface of the light-transmitting body 2 is removed by the liquid 61.

[0258] By performing steps ST10 and ST11 after the liquid 61 is ejected onto the surface of the light-transmitting body 2 , the liquid droplets 60 adhering to the surface of the light-transmitting body 2 are removed.

[0259] [Effect]

[0260] According to the vibration device 203 and the vibration control method of the third embodiment, the following effects can be achieved.

[0261] The vibration device 203 includes a discharge device 9 for discharging the liquid 61 onto the surface of the light-transmitting body 2. With this structure, the liquid 61 can be discharged onto the surface of the light-transmitting body 2. In addition, after the liquid 61 is discharged onto the surface of the light-transmitting body 2, the vibration generated by the vibration part 3 can remove the liquid droplets 60 attached to the surface of the light-transmitting body 2.

[0262] According to the vibration device 203 , the droplets 60 are easily slid down by the vibration generated by the vibration unit 3 , so that the output of the pump 93 can be reduced, and cost reduction and power consumption can be achieved.

[0263] For example, when the liquid 61 ejected from the ejection device 9 is a cleaning liquid, the surface of the light-transmitting body 2 can be cleaned with the liquid 61. This allows removal of foreign matter 62 such as dirt adhering to the surface of the light-transmitting body 2. After the surface of the light-transmitting body 2 is cleaned with the liquid 61, the vibration generated by the vibrating portion 3 can be used to easily remove the liquid droplets 60 from the surface of the light-transmitting body 2.

[0264] The vibration control method of Embodiment 3 includes step ST30 of ejecting liquid 61 onto the surface of the light-transmitting body 2. With this configuration, the liquid 61 can be ejected onto the surface of the light-transmitting body 2. Furthermore, after the liquid 61 is ejected onto the surface of the light-transmitting body 2, the vibration generated by the vibrating unit 3 can be used to remove the liquid droplets 60 adhering to the surface of the light-transmitting body 2.

[0265] In addition, in Embodiment 3, the piping 91 of the ejection device 9 is described as being arranged on the upper surface of the housing 11, but the present invention is not limited thereto. The piping 91 of the ejection device 9 may be arranged inside the housing 11 or on the side or bottom surface of the housing 11.

[0266] In the third embodiment, the discharge device 9 is described as including the pump 93 , but the present invention is not limited thereto. The discharge device 9 only needs to include a device that can be controlled by the control unit 4 and can supply liquid.

[0267] In Embodiment 3, the discharge head 92 is oriented in the longitudinal direction (Z direction) of the vibrating device 203, but the present invention is not limited thereto. The discharge head 92 only needs to be oriented in a direction in which the liquid 61 can be discharged toward the surface of the light-transmitting body 2. For example, the discharge head 92 may be arranged in a direction inclined relative to the surface of the light-transmitting body 2.

[0268] In the third embodiment, the liquid 61 ejected from the ejection device 9 is described as a cleaning liquid, but the present invention is not limited thereto. For example, the liquid 61 ejected from the ejection device 9 may be a coating material.

[0269] In the third embodiment, the vibration device 203 is described as executing the vibration generated by the vibration unit 3 after the liquid 61 is ejected by the ejection device 9. However, the present invention is not limited to this embodiment. For example, the vibration device 203 may execute the ejection of the liquid 61 by the ejection device 9 and the vibration generated by the vibration unit 3 in parallel. Alternatively, the vibration device 203 may execute the ejection of the liquid 61 by the ejection device 9 while the vibration generated by the vibration unit 3 is in progress.

[0270] In the third embodiment, the vibration control method is described as including steps ST10, ST11, and ST30, but the present invention is not limited thereto. Figure 21 Steps ST10, ST11 and ST30 shown may be combined or divided. Alternatively, Figure 21 The flowcharts shown may also include additional steps.

[0271] In the third embodiment, steps ST10 and ST11 are executed after step ST30, but the present invention is not limited thereto. For example, steps ST10 and ST11 may be executed in parallel with step ST30 or before step ST30.

[0272] (Implementation 4)

[0273] A vibration device according to a fourth embodiment of the present invention will be described. In this fourth embodiment, the differences from the first embodiment will be mainly described. In this fourth embodiment, components identical or equivalent to those in the first embodiment are denoted by the same reference numerals for description. Details overlapping with those in the first embodiment will be omitted in this fourth embodiment.

[0274] Figure 23 It is a partially enlarged cross-sectional view of an example of the vibration device 204 according to the fourth embodiment of the present invention.

[0275] The fourth embodiment is different from the first embodiment in that a waterproof coating layer 20 is provided.

[0276] like Figure 23 As shown, in the vibration device 204 , a waterproof coating 20 is formed on the surface of the light-transmitting body 2 .

[0277] <Waterproof coating>

[0278] The water-repellent coating 20 is a layer that repels liquids. For example, the water-repellent coating 20 is formed of a member having a larger contact angle than the surface of the light-transmitting body 2. In the fourth embodiment, the water-repellent coating 20 is formed on the entire surface of the light-transmitting body 2.

[0279] The waterproof coating 20 can be formed by applying a fluorine-based coating material or a silicone-based coating material to the surface of the light-transmitting cover 2. Examples of fluorine-based coating materials include materials having a compound having a perfluoroalkyl group as a main component, or materials having a compound having a perfluoroalkyl group (a material in which H of the alkyl group is replaced by F) as a main component. Specific examples of fluorine-based coating materials include fluorine-based polymers and polytetrafluoroethylene (PTFE). Examples of silicone-based coating materials include materials having a main chain portion composed of a direct bond of silicon (Si) and oxygen (O), and silicone oil is one example of such a material.

[0280] [Effect]

[0281] According to the vibration device 204 of the fourth embodiment, the following effects can be achieved.

[0282] In the vibrating device 204, a water-repellent coating 20 is formed on the surface of the light-transmitting body 2. This structure facilitates the removal of liquid droplets adhering to the surface of the light-transmitting body 2. Specifically, the water-repellent coating 20 enables a larger contact angle than the surface of the light-transmitting body 2. This reduces the adhesion energy of the liquid droplets, making it easier to remove the liquid droplets from the surface of the light-transmitting body 2.

[0283] In addition, the liquid droplets can be removed from the surface of the light-transmitting body 2 in a shorter time.

[0284] Furthermore, the water-repellent coating layer 20 can also suppress the adhesion of liquid droplets to the surface of the light-transmitting body 2 .

[0285] In addition, in the fourth embodiment, the waterproof coating 20 is formed on the entire surface of the light-transmitting body 2 , but the present invention is not limited thereto. For example, the waterproof coating 20 may be formed on a portion of the surface of the light-transmitting body 2 .

[0286] In the fourth embodiment, the water-repellent coating layer 20 is described as being formed of a fluorine-based coating material or a silicone-based coating material, but the present invention is not limited thereto. For example, the water-repellent coating layer 20 may have a structure that utilizes concavities and convexities to repel liquid.

[0287] Figure 24 2 is a schematic diagram of an example of a waterproof coating 20a. Figure 24 As shown, the waterproof coating 20a includes a plurality of protrusions 21. The protrusions 21 have, for example, a cylindrical shape. The protrusions 21 are arranged with intervals therebetween. The size (e.g., diameter or length of one side) and the arrangement interval of the protrusions 21 can be less than 500 nm.

[0288] The plurality of protrusions 21 can be formed, for example, by spin-coating a solution containing silica nanoparticles with a particle diameter of approximately 40 nm to 100 nm onto the surface of the light-transmitting body 2 and subjecting the solution to a sol-gel reaction. Alternatively, the protrusions 21 can be formed by transferring the shape of a finely contoured pattern onto the surface of the light-transmitting body 2 using a mold having a finely contoured pattern on its surface.

[0289] (Implementation 5)

[0290] A vibration device according to a fifth embodiment of the present invention will be described. In this fifth embodiment, the differences from the first embodiment will be mainly described. In this fifth embodiment, components identical or equivalent to those in the first embodiment are denoted by the same reference numerals for description. Details overlapping with those in the first embodiment will be omitted in this fifth embodiment.

[0291] Figure 25 This is a schematic cross-sectional view showing an example of a vibration device 205 according to Embodiment 5 of the present invention. Figure 26 This is a block diagram of an example of the vibration device 205 according to the fifth embodiment of the present invention.

[0292] The fifth embodiment is different from the first embodiment in that a displacement detection sensor 10 is provided.

[0293] like Figure 25 and Figure 26 As shown, the vibration device 205 includes the displacement detection sensor 10 in addition to the configuration of the vibration device 200 according to the first embodiment.

[0294] <Displacement Detection Sensor>

[0295] The displacement detection sensor 10 detects information related to the displacement of the transparent body 2. This information is information that allows calculation of the displacement of the transparent body 2 in the thickness direction. In Embodiment 5, the displacement detection sensor 10 is a laser Doppler displacement meter, and the information related to the displacement is a voltage value. The displacement detection sensor 10 irradiates the back surface of the transparent body 2 with laser light from the inside of the vibrating device 204, utilizing the laser's Doppler effect to acquire information related to the displacement in a non-contact manner.

[0296] The displacement detection sensor 10 is not limited to a laser Doppler displacement meter; any sensor capable of acquiring information related to the displacement of the transparent body 2 may be used. For example, the displacement detection sensor 10 may be an ultrasonic sensor, a microphone, or a laser sensor. Furthermore, the information related to the displacement is not limited to a voltage value; any information capable of calculating the displacement of the transparent body 2 may be used. Alternatively, the information related to the displacement may be the displacement of the transparent body 2 itself.

[0297] The displacement detection sensor 10 transmits the detected information to the control unit 4 .

[0298] The control unit 4 receives information related to the displacement amount from the displacement detection sensor 10 and controls the vibration acceleration of the vibration unit 3 based on the received information. Specifically, the control unit 4 calculates the displacement amount of the light-transmitting body 2 based on the received information. The control unit 4 controls the vibration acceleration of the vibration unit 3 based on the calculated displacement amount.

[0299] [action]

[0300] An example of the vibration control method, which is an example of the operation of the vibration device 205 , will be described. The vibration control method is a method of controlling the vibration device 205 .

[0301] Figure 27 This is a flowchart of an example of a vibration control method according to the fifth embodiment of the present invention. Figure 27 Step ST44 shown is the same as that of the first embodiment. Figure 10 Step ST10 shown is the same, so detailed description is omitted. Figure 28 This is a schematic diagram showing an example of the operation of the vibration device 205 according to the fifth embodiment of the present invention. Figure 28 (a) shows an example of a temporal change in the displacement of the light-transmitting body 2 . Figure 28 (b) shows an example of a temporal change in the vibration acceleration of the vibration unit 3 . Figure 28 (c) shows an example of the operation of the vibration device 205 at each time.

[0302] like Figure 27 and Figure 28As shown, in step ST40, the vibrating unit 3 is used to vibrate the light-transmitting body 2 in the detection vibration mode. The detection vibration mode is a mode in which the light-transmitting body 2 is vibrated in order to detect the displacement of the light-transmitting body 2. In the detection vibration mode, the control unit 4 controls the vibrating unit 3 to vibrate the light-transmitting body 2 at a detection vibration acceleration α. a Vibration. Detection vibration acceleration α a The value is set to a value that enables the displacement detection sensor 10 to detect a change in the displacement amount of the light-transmitting body 2. a For example, if it is set to less than 1.5×10 5 m / s 2 In this case, the light-transmitting body 2 is displaced by less than 1 μm in the thickness direction.

[0303] In step ST41, the displacement detection sensor 10 detects information related to the displacement amount of the light-transmitting body 2. In the fifth embodiment, the displacement detection sensor 10 is a laser Doppler displacement meter, and thus obtains information on a voltage value as information related to the displacement amount.

[0304] In step ST42, the displacement detection sensor 10 transmits information on the displacement amount to the control unit 4. The control unit 4 receives the information on the displacement amount from the displacement detection sensor 10 and calculates the displacement amount of the light-transmitting body 2 based on the received information.

[0305] like Figure 28 As shown, when no droplets adhere to the transparent body 2 in the vibration detection mode (t = t0), the displacement of the transparent body 2 is approximately constant. When droplets adhere to the transparent body 2 (t = t1), the displacement of the transparent body 2 decreases. In other words, as the amount of droplets adhered to the transparent body 2 increases, the displacement of the transparent body 2 decreases. Thus, the amount of droplets adhered to the transparent body 2 and the displacement of the transparent body 2 are inversely proportional. Therefore, the control unit 4 can estimate the amount of droplets adhered to the transparent body 2 based on the displacement of the transparent body 2.

[0306] In step ST43, the control unit 4 determines whether the displacement of the light-transmitting body 2 is smaller than the threshold value S1. If the displacement is greater than the threshold value S1, the process returns to step ST41. If the displacement is smaller than the threshold value S1, the process proceeds to ST44.

[0307] In step ST44, the vibrating unit 3 vibrates the light-transmitting body 2 in the droplet removal vibration mode. Step ST44 is the same as step ST10 in embodiment 1. After executing step ST44 for a predetermined time, the control unit 4 ends step ST44. By vibrating the light-transmitting body 2 in the droplet removal vibration mode, droplets are removed from the surface of the light-transmitting body 2. The droplet removal vibration mode is a mode in which the vibration described in step ST10 in embodiment 1 is generated, and the light-transmitting body 2 is vibrated at a predetermined vibration acceleration of 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 Vibrates at the following vibration accelerations.

[0308] like Figure 28 As shown, when the light-transmitting body 2 vibrates in the droplet removal vibration mode (t=t2), the droplets attached to the light-transmitting body 2 slide off. When the droplet removal vibration mode is executed for a predetermined time (t=t3), most of the droplets attached to the light-transmitting body 2 slide off. Thereafter, the control unit 4 returns to the detection vibration mode.

[0309] As described above, in the vibration device 205 according to the fifth embodiment, the vibration acceleration of the light-transmitting body 2 is controlled based on the displacement amount of the light-transmitting body 2 .

[0310] [Effect]

[0311] According to the vibration device 205 of the fifth embodiment, the following effects can be achieved.

[0312] The vibration device 205 includes a displacement detection sensor 10 that detects information on the displacement amount of the light-transmitting body 2 and transmits the detected information to the control unit 4. The control unit 4 controls the vibration acceleration of the vibration unit 3 based on the received information.

[0313] The vibration control method includes step ST41 of detecting information related to the displacement of the light-transmitting body 2. The vibration step includes steps ST42 to ST44 of controlling the vibration acceleration of the vibration unit 3 based on the detected information by the control unit 4. With this configuration, the vibration acceleration of the vibration unit 3 can be controlled based on the information related to the displacement of the light-transmitting body 2.

[0314] According to this structure, the vibration acceleration of the vibrating portion 3 can be controlled based on information related to the displacement of the light-transmitting body 2. As a result, the light-transmitting body 2 can be vibrated at a predetermined acceleration of 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 Vibrates at the following vibration accelerations.

[0315] In the fifth embodiment, the detection vibration acceleration α a Set to less than 1.5×10 5 m / s 2 The example of α is described, but the present invention is not limited to this. a It is sufficient that the vibration acceleration be set to be able to detect a change in the displacement amount of the light-transmitting body 2 .

[0316] In Embodiment 5, the control unit 4 terminates the droplet removal mode after executing step ST44 for a predetermined time. However, the present invention is not limited to this embodiment. For example, the control unit 4 may determine the end time of the droplet removal mode based on the displacement of the light-transmitting body 2. Alternatively, the vibration detection mode may be initiated after step ST44. The vibration detection mode may be performed continuously or periodically.

[0317] Figure 30 FIG. 1 is a flow chart of an example of a vibration control method according to a modification of Embodiment 5 of the present invention. Figure 30 As shown, the vibration control method of the modified example further includes steps ST45 to ST47.

[0318] In step ST45 , similarly to step ST41 , information on the displacement amount of the light-transmitting body 2 is detected by the displacement detection sensor 10 .

[0319] In step ST46, similarly to step ST42, the displacement sensor 10 transmits information on the displacement amount to the control unit 4. The control unit 4 receives the information on the displacement amount from the displacement sensor 10 and calculates the displacement amount of the light-transmitting body 2 based on the received information.

[0320] In step ST47, the control unit 4 determines whether the displacement of the light-transmitting body 2 is greater than or equal to the threshold value S2. If the displacement is less than the threshold value S2 in step ST47, the process returns to step ST44. The vibration in the droplet removal vibration mode in step ST44 is then continued. If the displacement is greater than or equal to the threshold value S2, the process ends. The vibration in the droplet removal vibration mode in step ST44 is thus terminated.

[0321] In this way, the end of the vibration in the droplet removal vibration mode is determined based on the displacement amount of the light-transmitting body 2 , so that the vibration for removing the droplets can be ended at a more appropriate timing.

[0322] (Implementation 6)

[0323] A vibration device according to a sixth embodiment of the present invention will be described. In this sixth embodiment, the differences from the fifth embodiment will be mainly described. In this sixth embodiment, components identical or equivalent to those in the fifth embodiment are denoted by the same reference numerals for description. Details overlapping with those in the fifth embodiment will be omitted in this sixth embodiment.

[0324] Figure 30 This is a flowchart of an example of a vibration control method according to the sixth embodiment of the present invention. Figure 30 Steps ST50 to ST53 and ST55 shown in FIG5 are the same as those in the fifth embodiment. Figure 27 Steps ST40 to ST44 shown are the same, so detailed descriptions are omitted. Figure 31 This is a schematic diagram showing an example of the operation of the vibration device according to the sixth embodiment of the present invention. Figure 31 (a) shows an example of a temporal change in the displacement of the light-transmitting body 2 . Figure 31 (b) shows an example of a temporal change in the vibration acceleration of the vibration unit 3 . Figure 31 (c) shows an example of the operation of the vibration device at each time.

[0325] The sixth embodiment differs from the fifth embodiment in that, in the vibration control method, the first vibration mode is executed and then the second vibration mode is switched. The second vibration mode corresponds to the droplet removal vibration mode of the fifth embodiment.

[0326] In the vibration device of the sixth embodiment, the control unit 4 has a first vibration mode and a second vibration mode. The rest of the configuration of the vibration device of the sixth embodiment is the same as that of the vibration device 205 of the fifth embodiment.

[0327] The first vibration mode is to make the light-transmitting body 2 vibrate at 8.1×10 5 m / s 2 Above and 1.7×10 6 m / s 2 The second vibration mode is a vibration mode in which the light-transmitting body 2 is vibrated at a vibration acceleration of 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 The following vibration acceleration vibration modes are provided: The control unit 4 executes the second vibration mode after executing the first vibration mode.

[0328] [action]

[0329] An example of the operation of the vibration device according to the sixth embodiment, that is, an example of a vibration control method will be described.

[0330] like Figure 30 and Figure 31As shown, in step ST50 , the light-transmitting body 2 is vibrated in the detection vibration mode by the vibration unit 3 .

[0331] In step ST51, the displacement detection sensor 10 detects information related to the displacement amount of the light-transmitting body 2. In the fifth embodiment, the displacement detection sensor 10 is a laser Doppler displacement meter, and thus obtains voltage value information as information related to the displacement amount.

[0332] In step ST52 , the displacement detection sensor 10 transmits information on the displacement amount to the control unit 4 .

[0333] In step ST53, the control unit 4 determines whether the displacement of the light-transmitting body 2 is smaller than the threshold value S1. In step ST53, if the displacement is greater than the threshold value S1, the process returns to step ST51. If the displacement is smaller than the threshold value S1, the process proceeds to ST54.

[0334] In step ST54, the vibrating unit 3 is used to vibrate the light-transmitting body 2 in the first vibration mode. The first vibration mode is a vibration mode in which droplets gather on the surface of the light-transmitting body 2. In the first vibration mode, the control unit 4 controls the vibrating unit 3 so that the light-transmitting body 2 vibrates at a speed of 8.1×10 5 m / s 2 Above and 1.7×10 6 m / s 2 The following first vibration acceleration α c vibration.

[0335] Step ST54 includes step ST54a of controlling the voltage applied to the piezoelectric element 6 by the control unit 4. In step ST54a, the voltage applied to the piezoelectric element 6 is controlled by the control unit 4 to be greater than or equal to 16 Vp-p and less than or equal to 60 Vp-p. 5 m / s 2 Above and 1.7×10 6 m / s 2 The following first vibration acceleration α c vibration.

[0336] like Figure 31 As shown, droplets sometimes adhere to the surface of the translucent body 2 in a dispersed manner (t = t1). In the first vibration mode, the droplets dispersed on the surface of the translucent body 2 are caused to aggregate at the portion of the translucent body 2 where the displacement is greatest (t = t2b). In the sixth embodiment, the translucent body 2 has a circular plate shape and vibrates while being supported at its outer edge. Therefore, the portion of the translucent body 2 where the displacement is greatest is the center of the translucent body 2.

[0337] After vibrating the light-transmitting body 2 in the first vibration mode for a predetermined period of time, the control unit 4 switches the vibration mode to the second vibration mode. The period during which the first vibration mode is implemented is shorter than the period during which the second vibration mode is implemented. Furthermore, the period during which the first vibration mode is implemented can be set arbitrarily. For example, if liquid droplets frequently adhere to the light-transmitting body 2, the period during which the first vibration mode is implemented can be extended. If liquid droplets rarely adhere to the light-transmitting body 2, the period during which the first vibration mode is implemented can be shortened.

[0338] In step ST55, the vibrating unit 3 is used to vibrate the light-transmitting body 2 in the second vibration mode. The second vibration mode is the droplet removal vibration mode of embodiment 5, which is a vibration mode for causing the droplets attached to the surface of the light-transmitting body 2 to slide off. In the second vibration mode, the control unit 4 controls the vibrating unit 3 so that the light-transmitting body 2 vibrates at a speed of 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 The following second vibration acceleration α b vibration.

[0339] Step ST55 includes step ST55a of controlling the voltage applied to the piezoelectric element 6 by the control unit 4. In step ST55a, the voltage applied to the piezoelectric element 6 is controlled by the control unit 4 to be greater than or equal to 2 Vp-p and less than or equal to 15 Vp-p. 5 m / s 2 Above and 8.0×10 5 m / s 2 The following second vibration acceleration α b vibration.

[0340] Figure 32 and Figure 33 Yes Figure 30 A schematic diagram showing an example of the motion of a droplet in the vibration control method. Figure 32 express Figure 30 This is an example of the movement of the droplet in step ST54. Figure 33 express Figure 30 An example of the movement of the droplet in step ST55. Figure 32 As shown, in step ST54, the light-transmitting body 2 is vibrated in the first vibration mode, so that the plurality of droplets 60 scattered on the surface of the light-transmitting body 2 are gathered in the center of the light-transmitting body 2. As a result, the plurality of droplets 60 are gathered to form a larger droplet 60a. Since the droplet 60a is heavier than the droplet 60, it is easy to slide down in the direction of gravity. Then, as shown in FIG. Figure 33 As shown, in step ST55 , the light-transmitting body 2 is vibrated in the second vibration mode, so that the droplet 60 a gathered at the center of the light-transmitting body 2 slides down in the direction of gravity.

[0341] As described above, in the vibration control method of the sixth embodiment, the liquid droplets 60 are collected on the surface of the light-transmitting body 2 in the first vibration mode, and the collected liquid droplets 60 a are caused to slide down from the light-transmitting body 2 in the second vibration mode.

[0342] [Relationship between sliding angle and vibration acceleration]

[0343] Figure 34 This is a schematic diagram showing an example of the relationship between the sliding angle and the vibration acceleration. Figure 34 The change in the fall angle relative to the change in the vibration acceleration is shown in FIG.

[0344] A power supply (Keysight Technologies: E26104A) and a function generator (Tektronix: AGF1022) were used to supply a signal to the piezoelectric element 6 of the vibration unit 3, which had a resonant frequency of approximately 60 kHz, to excite vibration. The displacement of the light-transmitting body 2, excited by the vibration of the vibration unit 3, was detected using a laser displacement meter (Olympus: BX51M). This displacement was measured using a multimeter (Keysight Technologies: 2110) and an oscilloscope (Tektronix: TBS1104). The vibration acceleration was denoted by α, the frequency by f, and the amplitude (displacement) by A. The equation α = (2πf) was used to represent the displacement of the light-transmitting body 2. 2 A is used to calculate the vibration acceleration.

[0345] As described in Embodiment 1, when the sliding angle θ is larger than 40 degrees, the adhesion energy E of the droplet is larger than the force of sliding from the surface of the light-transmitting body 2 to the outside. Therefore, the droplet gathers at the part of the light-transmitting body 2 where the displacement is the largest, that is, the center of the light-transmitting body 2. Figure 34 , when the vibration acceleration α is 8.1×10 5 m / s 2 When the vibration acceleration α is greater than 1.7×10 6 m / s 2 When the drop angle θ is large, it is around 90 degrees. When the drop angle is around 90 degrees, the droplet shows a motion close to vertical falling. Even if the drop angle is further increased, the motion of the droplet does not change. In other words, when the drop angle is around 90 degrees, the motion of the droplet is saturated. In addition, when the vibration acceleration α is too large, the load applied to the vibration device itself increases. Therefore, the drop angle that saturates the motion of the droplet is set to 1.7×10 6 m / s 2 Set to the maximum value of vibration acceleration.

[0346] Therefore, in the first vibration mode, the vibration acceleration α is preferably 8.1×10 5 m / s2 Above and 1.7×10 6 m / s 2 The following (refer to Figure 34 By controlling the vibration acceleration α within the predetermined range, the liquid droplets adhering to the surface of the light-transmitting body 2 can be aggregated.

[0347] In the sixth embodiment, the control unit 4 controls the vibration acceleration α by controlling the voltage value applied to the piezoelectric element 6 of the vibration unit 3. Specifically, the control unit 4 applies the voltage to the piezoelectric element 6 via the power supply conductor 5. The control unit 4 controls the peak-to-peak value (Vp-p) of the AC voltage applied to the piezoelectric element 6.

[0348] Figure 35 This is a schematic diagram showing an example of the relationship between the sliding angle and the applied voltage. Figure 35 As shown, the control unit 4 controls the voltage applied to the piezoelectric element 6 to be greater than 16 Vp-p and less than 60 Vp-p, thereby making the vibration acceleration α 8.1×10 5 m / s 2 Above and 1.7×10 6 m / s 2 The following (refer to Figure 35 "D1" in the image).

[0349] [Effect]

[0350] According to the vibration device and vibration control method of the sixth embodiment, the following effects can be achieved.

[0351] The control unit 4 of the sixth embodiment has a first vibration mode and a second vibration mode. The first vibration mode causes the light-transmitting body 2 to vibrate at 8.1×10 5 m / s 2 Above and 1.7×10 6 m / s 2 The second vibration mode causes the light-transmitting body 2 to vibrate at 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 The control unit 4 controls the vibration unit 3 so that the second vibration mode is executed after the first vibration mode. Specifically, the control unit 4 controls the voltage applied to the piezoelectric element 6 to a value of not less than 16 Vp-p and not more than 60 Vp-p in the first vibration mode, and controls the voltage applied to the piezoelectric element 6 to a value of not less than 2 Vp-p and not more than 15 Vp-p in the second vibration mode.

[0352] In the vibration control method of Embodiment 6, the vibrating step includes step ST54 of vibrating the light-transmitting body 2 in the first vibration mode and step ST55 of vibrating the light-transmitting body 2 in the second vibration mode. Step ST54 of vibrating the light-transmitting body 2 in the second vibration mode is performed after the step of vibrating the light-transmitting body 2 in the first vibration mode is performed. Specifically, step ST54 includes step ST54a of controlling the voltage applied to the piezoelectric element 6 to a value between 16 Vp-p and 60 Vp-p by the control unit 4, and step ST55 includes step ST55a of controlling the voltage applied to the piezoelectric element 6 to a value between 2 Vp-p and 15 Vp-p by the control unit 4.

[0353] According to such a structure, the performance of removing droplets can be further improved. In embodiment 6, by executing the first vibration mode, the droplets can be gathered on the surface of the light-transmitting body 2. By gathering the droplets, a plurality of droplets are combined. The weight of the combined droplets increases, and therefore it is easy to slide down in the direction of gravity. In this way, in embodiment 6, after the droplets are gathered on the surface of the light-transmitting body 2 in the first vibration mode, the gathered droplets can be made to slide down from the surface of the light-transmitting body 2 in the second vibration mode. Thus, compared with the case where the droplets are made to slide down in a state where the droplets are dispersed on the surface of the light-transmitting body 2, the performance of removing droplets can be improved in embodiment 6. In other words, in embodiment 6, the droplets attached to the light-transmitting body 2 can be removed more easily, and the droplets can be removed in a shorter time.

[0354] Furthermore, in Embodiment 6, even if droplets containing foreign matter adhere to the light-transmitting body 2, they can be easily removed without the use of a cleaning solution. For example, droplets containing solids, such as muddy water, tend to be less likely to slide off due to vibration than droplets containing less solids, such as rainwater. In Embodiment 6, even if droplets containing foreign matter, such as muddy water, adhere to the surface of the light-transmitting body 2, they can be removed without the use of a cleaning solution.

[0355] In addition, in Embodiment 6, a waterproof coating 20 may be formed on the surface of the light-transmitting body 2, as in Embodiment 4. Even if droplets of liquid containing foreign matter, such as muddy water, adhere to the light-transmitting body 2, the droplets can be removed quickly, thereby suppressing abrasion of the waterproof coating 20 caused by the droplets. This can extend the coating life of the waterproof coating 20.

[0356] Furthermore, in the sixth embodiment, an example in which the vibration control method includes steps ST50 to ST53 has been described, but the present invention is not limited thereto. Figure 36 FIG. 1 is a flow chart of an example of a vibration control method according to a modification of the sixth embodiment of the present invention. Figure 36As shown, the vibration control method of embodiment 6 only needs to include steps ST54 and ST55 and may not include steps ST50 to ST53. In this case, steps ST54 and ST55 may be executed periodically or based on user input information.

[0357] (Example)

[0358] As an example, the vibration device and vibration control method of Embodiment 6 were used to conduct performance evaluations, measuring coating wear time, mud and water removal rate, and cleaning fluid usage. Furthermore, as a comparative example, a vibration device without vibration acceleration control was used to conduct the same performance evaluations as in the example, measuring coating wear time, mud and water removal rate, and cleaning fluid usage. The comparative example was identical to the vibration device of the example, except for the lack of vibration acceleration control and the use of cleaning fluid.

[0359] The performance evaluation of Examples and Comparative Examples was carried out by performing the following steps (1) to (9).

[0360] (1) Rain X sold by Nishiki no Do Co., Ltd. was applied as a waterproof coating 20 to the surface of the light-transmitting body 2 of the vibration device used for performance evaluation.

[0361] (2) Measurement of the initial contact angle of the light-transmitting body 2. Regarding the contact angle, an image of the light-transmitting body 2 with a water droplet applied thereto was read by a computer, and the contact angle of the water droplet with respect to the surface of the light-transmitting body 2 was measured.

[0362] (3) The displacement of the light-transmitting body 2 is monitored using a laser Doppler displacement meter (manufactured by Ono Sakuki: LaserVibrometer LV-1800).

[0363] (4) Apply 10 μl of muddy water on the surface of the light-transmitting body 2 .

[0364] (5) Driving the vibration device. In the comparative example, since it is difficult to remove muddy water by vibration, the cleaning liquid is sprayed onto the surface of the light-transmitting body 2. In the comparative example, the cleaning liquid sprayed onto the light-transmitting body 2 is collected in a measuring cup.

[0365] (6) After driving the driving device for 20 seconds, stop the vibration device.

[0366] (7) The coating wear time of the waterproof coating 20 is calculated by measuring the contact angle and calculating the rate of decrease of the contact angle. Specifically, the amount of decrease in the contact angle and the time taken for the decrease are measured to calculate the rate of decrease of the contact angle. The coating wear time is calculated by calculating the time until the contact angle reaches the original contact angle of the light-transmitting body 2 from the rate of decrease of the contact angle.

[0367] (8) The muddy water remaining in the light-transmitting body 2 is recovered to calculate the muddy water removal rate.

[0368] (9) The amount of cleaning fluid used is quantified by measuring the weight of the cleaning fluid collected in the measuring cup.

[0369] In the examples, the evaluation results obtained through steps (7) to (9) of the performance evaluation are designated as Examples 1, 2, and 3, respectively. In the comparative examples, the evaluation results obtained through steps (7) to (9) of the performance evaluation are designated as Comparative Examples 1, 2, and 3, respectively.

[0370] Figure 37 1 is a graph showing the coating wear time of Example 1 and Comparative Example 1. The coating wear time refers to the time until the waterproof coating 20 peels off, that is, the life of the waterproof coating 20. Figure 37 As shown, the coating wear time in Comparative Example 1 was 4 minutes, while the coating wear time in Example 1 was 25 minutes. In Example 1, the coating wear time was extended by 6.2 times compared to Comparative Example 1. This shows that the life of the waterproof coating 20 in Example 1 was extended compared to Comparative Example 1.

[0371] Figure 38 : is a graph showing the muddy water removal rate of Example 2 and Comparative Example 2. Figure 38 As shown, the muddy water removal rate in Comparative Example 2 is 53%, while that in Example 2 is 98%. In Example 2, the muddy water removal rate is increased by 1.8 times compared to Comparative Example 2. This shows that the muddy water removal efficiency in Example 2 is improved compared to Comparative Example 2.

[0372] Figure 39 : is a graph showing the usage of the cleaning solution of Example 3 and Comparative Example 3. Figure 39 As shown, the amount of cleaning liquid used in Comparative Example 3 is 3.0 mL. In Example 3, no cleaning liquid is used, so the amount of cleaning liquid used is 0 mL. This shows that in Example 3, even without using a cleaning liquid as in Comparative Example 3, muddy water adhering to the light-transmitting body 2 can be removed.

[0373] (Implementation 7)

[0374] A vibration device according to a seventh embodiment of the present invention will be described. In this seventh embodiment, the differences from the first embodiment will be mainly described. In this seventh embodiment, components identical or equivalent to those in the first embodiment are denoted by the same reference numerals for description. Details overlapping with those in the first embodiment will be omitted in this seventh embodiment.

[0375] Figure 40This is a schematic perspective view showing an example of the imaging unit 104 including the vibration device 206 according to the seventh embodiment of the present invention. Figure 41 yes Figure 40 Exploded perspective view of the camera unit 104. Figure 42 yes Figure 40 Schematic cross-sectional view of the imaging unit 104.

[0376] The seventh embodiment differs from the first embodiment in that the vibration device 206 includes an inner lens 30 and an inner lens barrel 31. The seventh embodiment also differs from the first embodiment in that the light-transmitting body 2b is a lens.

[0377] like Figures 40 to 42 As shown, the imaging unit 104 includes a housing 11A, an imaging section 12 , and a vibration device 206 .

[0378] The housing 11A houses the imaging unit 12. For example, the housing 11A has a cylindrical shape with an open end, and is formed of metal, synthetic resin, etc. In the seventh embodiment, the housing 11A is formed into a square cylindrical shape, but may also be other shapes such as a cylindrical shape.

[0379] The imaging unit 12 is disposed on a bottom plate 11a fixed within the housing 11A. Furthermore, a circuit (not shown) including an imaging element is built into the imaging unit 12. The imaging element may be, for example, a CMOS, CCD, bolometer, or thermopile that receives light of any wavelength from the visible region to the far infrared region.

[0380] The vibrating device 206 is fixed to the end of the housing 11A. The vibrating device 206 is exposed from the housing 11A and is arranged on the optical path of the imaging unit 12. The vibrating device 206 includes a light-transmitting body 2b, a vibrating unit 3A, a fixing unit 13, an inner lens 30, and an inner barrel 31.

[0381] The light-transmitting body 2b is a lens disposed in the outermost layer. In Embodiment 7, the light-transmitting body 2b is a lens having a dome shape with a continuous curved surface. Furthermore, various lenses can be used as the light-transmitting body 2b. For example, the light-transmitting body 2b is a glass lens.

[0382] The vibration section 3A vibrates the light-transmitting body 2b. The vibration section 3A includes a piezoelectric element 6, a vibrating body 7, and a fixed portion 13. The piezoelectric element 6 and the vibrating body 7 are the same as those in the first embodiment, and therefore their description is omitted.

[0383] The fixing portion 13 is a member that fixes the vibrating portion 3A to the inner barrel 31. The fixing portion 13 is connected to the inner barrel 31 at a position that includes at least one vibration node of a resonant frequency in the vibrating device 206. In this specification, a "vibration node" refers to a portion that is 1 / 100 or less of the maximum amplitude of the light-transmitting body 2b.

[0384] For example, the fixing portion 13 has a cylindrical shape. Specifically, the fixing portion 13 includes a cylindrical fixing body 13a and a leaf spring portion 13b.

[0385] The cylindrical fixing body 13a has a cylindrical shape and is fixed to the inner lens barrel 31. For example, the cylindrical fixing body 13a is connected to the inner lens barrel 31 via a first connecting portion 14. The first connecting portion 14 will be described later. Alternatively, the cylindrical fixing body 13a may be directly connected to the inner lens barrel 31.

[0386] The leaf spring portion 13b extends from the cylindrical fixed body 13a toward the side where the light-transmitting body 2b is disposed, and is connected to the vibrating body 7. The leaf spring portion 13b extends from the outer surface of the vibrating body 7 in the Z direction and bends in the Y direction on the side of the housing 11A. The thickness of the leaf spring portion 13b is smaller than the thickness (dimension in the Z direction) of the cylindrical fixed body 13a. The leaf spring portion 13b absorbs the vibration of the vibrating body 7 and suppresses the transmission of the vibration to the cylindrical fixed body 13a. Specifically, when the leaf spring portion 13b receives vibration from the vibrating body 7, it absorbs the vibration by elastic deformation.

[0387] In the seventh embodiment, the fixing portion 13 is formed integrally with the vibrating body 7. Alternatively, the fixing portion 13 may not be formed integrally with the vibrating body 7, but may be formed as a member separate from the vibrating body 7.

[0388] The inner lens 30 is composed of a plurality of lenses disposed inside the vibration device 206. The inner lens 30 is disposed inside the vibration unit 3A and on the optical path between the light-transmitting body 2b and the imaging unit 12. The inner lens 30 is held by the inner lens barrel 31.

[0389] The inner lens barrel 31 is a member that holds the inner lens 30. The inner lens barrel 31 includes a lens holding portion 31a and a flange portion 31b. The inner lens barrel 31 is formed of, for example, metal.

[0390] The lens holder 31a is a cylindrical member that holds the inner lens 30. For example, the lens holder 31a has a cylindrical shape with one end and another end. The side where the light-transmitting body 2b is located is the one end of the lens holder 31a, and the side where the imaging unit 12 is located is the other end of the lens holder 31a. Protrusions are provided on the inner walls of the lens holder 31a at one end and the other end, respectively. These protrusions help hold the inner lens 30 housed within the lens holder 31a.

[0391] Flange 31b is a plate-shaped member extending outward from the other end of lens holder 31a. Flange 31b has, for example, a circular plate shape. Flange 31b is connected to vibrating unit 3A and housing 11A at a location in vibrating device 206 that includes at least one vibration node of a resonant frequency.

[0392] The flange portion 31b is connected to the cylindrical fixing body 13a of the fixing portion 13 at its upper surface via the first joining portion 14. Furthermore, the flange portion 31b is connected to the outer surface of the housing 11A at its lower surface via the second joining portion 15. Furthermore, the first joining portion 14 and the second joining portion 15 overlap when viewed from the Y direction. The upper surface of the flange portion 31b refers to the side on which the light-transmitting body 2b is disposed, and the lower surface of the flange portion 31b refers to the side on which the housing 11A is disposed.

[0393] In the seventh embodiment, first joining portion 14 and second joining portion 15 are provided at positions "that include at least one vibration node of a resonant frequency in vibration device 206." Therefore, the vibration of vibrating portion 3A is less likely to be transmitted to vibration device 206 at first joining portion 14 and second joining portion 15.

[0394] The first joint portion 14 and the second joint portion 15 are formed of a bonding material such as, for example, a UV-curing epoxy adhesive, a heat-curing epoxy adhesive, a two-liquid mixed curing epoxy adhesive, an acrylic adhesive, a polyurethane adhesive, or glass frit. The first joint portion 14 and the second joint portion 15 are formed, for example, in a ring shape. In addition, a notch may be provided in a part of the first joint portion 14 and the second joint portion 15. The notch can be used to pass electrical wiring connected to the piezoelectric element 6. Alternatively, the first joint portion 14 and the second joint portion 15 may be formed, for example, by a waterproof member.

[0395] The first and second joints 14, 15 may also be used to adjust the alignment of the inner lens barrel 31. Specifically, the position of the inner lens barrel 31 can be adjusted by adjusting the thickness (length in the Z direction) of the first and second joints 14, 15. By adjusting the position of the inner lens barrel 31, the position of the inner lens 30 relative to the light-transmitting body 2b can be adjusted.

[0396] The first joint 14 and the second joint 15 are preferably formed from a bonding material having a Young's modulus of 1 GPa or greater. In Embodiment 7, the first joint 14 and the second joint 15 are formed, for example, from a UV-curable epoxy adhesive having a Young's modulus of 1 GPa or greater. This allows for both suppressing the transmission of vibration from the vibrating portion 3A and achieving high-precision alignment between the light-transmitting body 2b and the inner lens barrel 31. For example, if the first joint 14 and the second joint 15 are formed from a vibration-absorbing member such as rubber, while the transmission of vibration can be suppressed, achieving high-precision alignment between the light-transmitting body 2b and the inner lens barrel 31 is difficult. On the other hand, if the first joint 14 and the second joint 15 are formed from a relatively hard member, while high-precision alignment adjustment is possible, suppressing the transmission of vibration is difficult.

[0397] [About vibration analysis]

[0398] Figure 43 This is a diagram showing an example of the simulation results of the vibration analysis of the camera unit 104 according to the seventh embodiment of the present invention. In addition, the vibration analysis was performed using Femtet manufactured by Murata Software Co., Ltd. to perform piezoelectric analysis (resonance analysis). The voltage applied to the piezoelectric element 6 was 20V. As the boundary conditions of the piezoelectric element 6, one end was set to 20V and the other end was set to 0V. In addition, Figure 43 The magnitude of the vibration amplitude is represented by the shades of white and black, indicating that the closer the color is to white, the greater the vibration, and the closer the color is to black, the smaller the vibration amplitude.

[0399] like Figure 43 As shown, in the vibration device 206, the amplitude of the light-transmitting body 2b, the piezoelectric element 6, and the vibrating body 7 is large, indicating that they are vibrating. On the other hand, the amplitude of the inner lens 30, the inner lens barrel 31, and the housing 11A is small compared to the light-transmitting body 2b, the piezoelectric element 6, and the vibrating body 7, indicating that they are hardly vibrating.

[0400] When focusing on the vicinity of the fixing portion 13, it can be seen that the leaf spring portion 13b absorbs vibration, making it difficult for vibration to be transmitted to the cylindrical fixing body 13a. Furthermore, it can be seen that at a location including a vibration node of the resonant frequency in the vibration device 206, the cylindrical fixing body 13a is connected to the inner lens barrel 31 via the first joint 14, and the inner lens barrel 31 is connected to the housing 11A via the second joint 15.

[0401] [Effect]

[0402] According to the vibration device and the imaging unit of the seventh embodiment, the following effects can be achieved.

[0403] The vibration device 206 of embodiment 7 includes a light-transmitting body 2b, a vibrating unit 3A, an inner lens 30, and an inner lens barrel 31. The light-transmitting body 2b is composed of a lens arranged as the outermost layer. The vibrating unit 3A vibrates the light-transmitting body 2b. The vibrating unit 3A includes a piezoelectric element 6, a vibrating body 7, and a fixing unit 13. The piezoelectric element 6 vibrates when a voltage is applied. The vibrating body 7 is arranged on the piezoelectric element 6, amplifies the vibration of the piezoelectric element 6, and transmits it to the light-transmitting body 2b. The fixing unit 13 is connected to the vibrating body 7 and to the inner lens barrel 31. The inner lens 30 is arranged in the optical path of the light-transmitting body 2b and is held by the inner lens barrel 31. The inner lens barrel 31 holds the inner lens 30 and is connected to the fixing unit 13. The fixing unit 13 and the inner lens barrel 31 are connected at a location in the vibration device 206 that includes at least one vibration node of a resonant frequency.

[0404] This structure can vibrate the translucent body 2b while suppressing the vibration of the inner lens 30. That is, when removing droplets adhering to the translucent body 2b, which is the outermost lens, the translucent body 2b can be vibrated while suppressing the vibration of the inner lens 30.

[0405] The fixing portion 13 and the inner lens barrel 31 are connected via the first joint portion 14. With this structure, the position of the inner lens 30 relative to the light-transmitting body 2b can be adjusted by adjusting the thickness of the first joint portion 14 formed between the fixing portion 13 and the inner lens barrel 31. This improves the alignment accuracy between the light-transmitting body 2b and the inner lens 30.

[0406] The first bonding portion 14 is made of a bonding material having a Young's modulus of 1 GPa or more. With such a structure, it is possible to achieve both improvement in the alignment accuracy between the light-transmitting body 2 b and the inner lens 30 and suppression of vibration.

[0407] The fixed portion 13 includes a cylindrical fixed body 13a and a leaf spring portion 13b. The cylindrical fixed body 13a is connected to the inner lens barrel 31. The leaf spring portion 13b extends from the cylindrical fixed body 13a toward the side where the light-transmitting body 2b is disposed and is connected to the vibrating body 7. The thickness of the leaf spring portion 13b is smaller than the thickness (length in the Z direction) of the cylindrical fixed body 13a. With such a structure, the leaf spring portion 13b absorbs the vibration of the vibrating body 7, thereby suppressing the vibration of the vibrating body 7 from being transmitted to the cylindrical fixed body 13a. In addition, vibration nodes are easily formed near the cylindrical fixed body 13a.

[0408] The imaging unit 104 includes a housing 11A, an imaging unit 12, and a vibrating device 206. The housing 11A has a cylindrical shape with an end portion, and the imaging unit 12 is housed within the housing 11A. The vibrating device 206 is connected to the end portion of the housing 11A. The vibrating device 206 is connected to the housing 11A at a location where the vibrating device 206 includes at least one vibration node of a resonant frequency. This configuration achieves the same effect as the vibrating device 206 described above, while simultaneously suppressing vibration of the inner lens 30 while vibrating the light-transmitting body 2b.

[0409] The fixing portion 13 of the vibrating device 206 is connected to the housing 11A via the second joint portion 15. With this structure, the position of the imaging unit 12 relative to the inner lens 30 can be adjusted by adjusting the thickness of the second joint portion 15 formed between the fixing portion 13 and the housing 11A. This improves the alignment accuracy between the inner lens 30 and the imaging unit 12.

[0410] The first joining portion 14 and / or the second joining portion 15 are formed of a waterproof member. With such a structure, waterproofness can be ensured.

[0411] The fixing portion 13 and the inner barrel 31 are formed of metal. With such a structure, the efficiency of the excitation can be improved.

[0412] The light-transmitting body 2b is formed of a glass lens. With such a structure, the efficiency of excitation can be improved.

[0413] Furthermore, in Embodiment 7, an example is described in which the first joining portion 14 includes at least one vibration node of a resonant frequency in the vibration device 206 , but the present invention is not limited thereto. For example, the first joining portion 14 may include a plurality of vibration nodes of a resonant frequency in the vibration device 206 .

[0414] In the seventh embodiment, the second joining portion 15 includes at least one vibration node of a resonant frequency in the vibration device 206 . However, the present invention is not limited thereto. For example, the second joining portion 15 may include a plurality of vibration nodes of a resonant frequency in the vibration device 206 .

[0415] In Embodiment 7, an example in which the first joint portion 14 is formed of a joint material is described, but the present invention is not limited to this. The first joint portion 14 may also be a structure that allows the fixing portion 13 and the inner lens barrel 31 to be directly connected. For example, the first joint portion 14 may be implemented by connecting the fixing portion 13 and the inner lens barrel 31 using a mechanism such as screws. In this case, an internal thread may be provided on the inner side of the cylindrical fixing body 13a of the fixing portion 13, and an external thread may be provided on the outer periphery of the inner lens barrel 31. With such a structure, the connection between the fixing portion 13 and the inner lens barrel 31 becomes easier, and the alignment and adjustment of the inner lens 30 and the light-transmitting body 2b also becomes easier.

[0416] While the seventh embodiment describes an example in which the second joint portion 15 is formed of a joint material, the present invention is not limited thereto. The second joint portion 15 may also be configured to directly connect the inner lens barrel 31 and the housing 11A. For example, the second joint portion 15 may be implemented by connecting the inner lens barrel 31 and the housing 11A using a mechanism such as screws. In this case, the inner side of the cylindrical housing 11A may be provided with an internal thread, and the outer periphery of the inner lens barrel 31 may be provided with an external thread. This configuration facilitates connection between the inner lens barrel 31 and the housing 11A, and also facilitates alignment and adjustment between the inner lens 30 and the imaging unit 12.

[0417] In the seventh embodiment, the example in which the vibrating portion 3A and the inner lens barrel 31 are separate bodies is described, but the present invention is not limited thereto. The vibrating portion 3A and the inner lens barrel 31 may be formed integrally. In this way, precision can be improved by integral molding.

[0418] In Embodiment 7, the light-transmitting body 2b is described as an example of a dome-shaped lens having a continuous curved surface, but the present invention is not limited thereto. The light-transmitting body 2b may also be a lens having a curved surface in at least a portion. Alternatively, the light-transmitting body 2b may be a lens having a flat surface.

[0419] In the seventh embodiment, an example in which the imaging unit 104 is connected to the vibration device 206 has been described, but the present invention is not limited thereto. Figure 44 2 is a schematic cross-sectional view of an example of the vibration device 206. Figure 44 As shown, the vibration device 206 can also be implemented independently. For example, the vibration device 206 can also be manufactured and sold independently. In addition, the vibration device 206 can also be used in devices other than the camera unit 104.

[0420] In the seventh embodiment, the vibration device 206 is described as including the inner lens 30 and the inner barrel 31 , but the present invention is not limited thereto. The vibration device 206 does not necessarily need to include the inner lens 30 and the inner barrel 31 . Figure 45 FIG. 1 is a schematic cross-sectional view of another example of a vibration device. Figure 45 As shown, the vibration device 207 may not include the inner lens 30 and the inner lens barrel 31 .

[0421] In the seventh embodiment, the fixing portion 13 is connected to the flange portion 31 b of the inner barrel 31 , but the present invention is not limited thereto. For example, the fixing portion 13 may be connected to the lens holding portion 31 a of the inner barrel 31 .

[0422] (Variation)

[0423] Figure 46 : is a schematic cross-sectional view of a vibration device 208 according to a modified example of embodiment 7 of the present invention. Figure 46 As shown, the vibration device 208 differs from the vibration device 206 of the seventh embodiment in that the fixing portion 13A is connected to the lens holding portion 31a of the inner lens barrel 31. The vibration device 208 also differs from the vibration device 206 of the seventh embodiment in that the inner lens barrel 31 does not include the flange portion 31b.

[0424] In the vibration device 208, the vibrating body 7A constituting the vibrating portion 3B is provided with a connecting portion 7d connected to the fixed portion 13A. The connecting portion 7d is provided between the cylindrical body 7a and the annular plate-shaped portion 7b. The connecting portion 7d has a cylindrical shape. The thickness (length in the Z direction) of the connecting portion 7d is smaller than the thickness (length in the Z direction) of the cylindrical body 7a. In the vibration device 208, a vibration node of a resonant frequency is formed near the connecting portion 7d.

[0425] The fixing portion 13A includes a first fixing body 13c and a second fixing body 13d.

[0426] The first fixed body 13c extends from the inner side of the connecting portion 7d of the vibrating portion 3B toward the lens holding portion 31a of the inner lens barrel 31 and is connected to the inner lens barrel 31. The first fixed body 13c is formed in the shape of an annular plate. The first fixed body 13c is formed integrally with the vibrating portion 3B and the inner lens barrel 31.

[0427] In the vibration device 208 , the first fixed body 13 c is connected to the inner barrel 31 in the vicinity of the connection portion 7 d where a vibration node of a resonant frequency is formed.

[0428] The second fixed body 13d is a member that extends outward from the connection portion 7d of the vibrating portion 3B and is bent toward the housing 11A. The second fixed body 13d is cylindrical and connected to the housing 11A. The second fixed body 13d is integrally formed with the vibrating portion 3B. Furthermore, the second fixed body 13d is connected to the housing 11A via a second joint 15.

[0429] The vibration device 208 includes a plurality of vibration nodes of resonance frequency. Specifically, the vibration device 208 has vibration nodes formed near the connection portion 7d between the light-transmitting body 2b and the piezoelectric element 6 and at the connection position between the fixing portion 13A and the housing 11A.

[0430] In the vibration device 208, the first fixed body 13c is connected to the inner barrel 31 at the location of a vibration node of the resonant frequency of the vibration device 208. This prevents the vibration of the vibration unit 3B from being transmitted to the inner barrel 31. Furthermore, in the vibration device 208, the second fixed body 13d is connected to the housing 11A at the location of a vibration node of the resonant frequency of the vibration device 208. This prevents the vibration of the vibration unit 3B from being transmitted to the housing 11A.

[0431] Figure 47 Yes Figure 46 Graph showing an example of simulation results of vibration analysis of the vibration device 208. In addition, the vibration analysis was performed using Femtet manufactured by Murata Software Co., Ltd. to perform piezoelectric analysis (resonance analysis). The voltage applied to the piezoelectric element 6 was 20V. As boundary conditions of the piezoelectric element 6, one end was set to 20V and the other end was set to 0V. In addition, Figure 47 The magnitude of the vibration amplitude is represented by the shades of white and black, indicating that the closer the color is to white, the greater the vibration, and the closer the color is to black, the smaller the vibration amplitude.

[0432] like Figure 47As shown, in the vibration device 208, the amplitude of the light-transmitting body 2b, the piezoelectric element 6, and the vibrating body 7A (excluding the connecting portion 7d) is large, indicating that they are vibrating. On the other hand, the connecting portion 7d, the inner lens 30, and the inner lens barrel 31 have a smaller amplitude than the light-transmitting body 2b, the piezoelectric element 6, and the vibrating body 7A (excluding the connecting portion 7d), indicating that they are hardly vibrating.

[0433] It can also be seen that the first fixed body 13 c is connected to the inner barrel 31 at a position where a vibration node of a resonant frequency is formed in the vibration device 208 .

[0434] Furthermore, in the vibration device 208, an example in which the first fixed body 13c and the inner lens barrel 31 are integrally formed has been described, but this is not limiting. The first fixed body 13c and the inner lens barrel 31 may also be connected via the first joint 14. For example, the first joint 14 may have a structure that connects the first fixed body 13c and the inner lens barrel 31 using a mechanism such as screws. In this case, an internal thread may be provided at the end of the first fixed body 13c, and an external thread may be provided on the outer periphery of the lens holding portion 31a of the inner lens barrel 31. This structure allows the inner lens barrel 31 to be adjusted relative to the first fixed body 13c in the Y direction, thereby easily adjusting the position of the inner lens 30 relative to the light-transmitting body 2b. This improves the alignment accuracy between the light-transmitting body 2b and the inner lens 30.

[0435] Although the present invention has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various modifications and variations will be apparent to those skilled in the art and should be understood to be included in the present invention as long as they do not depart from the scope of the invention as defined by the claims.

[0436] Industrial applicability

[0437] The vibration device and vibration control method of the present invention can be applied to vehicle-mounted cameras, surveillance cameras, or optical sensors such as LiDAR used outdoors.

[0438] Description of Reference Numerals

[0439] 2. 2a, 2b, light-transmitting body; 3. 3A, 3B, vibrating portion; 4. control portion; 5. power supply conductor; 6. piezoelectric element; 7. 7A, vibrating body; 7a, cylindrical body; 7b, annular plate portion; 7c, thin-walled portion; 7d, connecting portion; 8. blower device; 9. ejection device; 10, displacement detection sensor; 11. 11A, housing; 11a, bottom plate; 12. camera portion; 12a, main body member; 13. 13A, fixing portion; 13a, cylindrical fixing body; 13b, leaf spring portion; 13c, first fixing body; 13d, second fixing body; 14, first joint portion; 15, second Joint; 20, 20a, waterproof coating; 21, protrusion; 30, inner lens; 31, inner barrel; 31a, lens holding portion; 31b, flange; 50, droplet; 51, solid; 60, 60a, droplet; 61, liquid; 62, foreign matter; 81, piping; 82, blower head; 83, pump; 84, flow path; 91, piping; 92, ejection head; 93, pump; 94, flow path; 100, 101, 102, 103, 104, camera unit; 200, 201, 202, 203, 204, 205, 206, 207, 208, vibration device.

Claims

1. A vibration device, wherein: The vibration device has: Translucent body; The vibration part causes the light-transmitting body to vibrate at a speed of 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 The following vibration acceleration vibration; a control unit configured to control the vibration acceleration of the vibration unit; as well as a displacement detection sensor that detects information related to the displacement amount of the light-transmitting body and transmits the information to the control unit, The control unit controls the vibration acceleration of the vibration unit based on the information.

2. The vibration device according to claim 1, wherein The vibration part causes the light-transmitting body to move at a speed of 3.5×10 5 m / s 2 Above and 5.5×10 5 m / s 2 Vibrates at the following vibration accelerations.

3. The vibration device according to claim 1 or 2, wherein The vibration part has a piezoelectric element, The control unit controls the value of the voltage applied to the piezoelectric element to be greater than or equal to 2 Vp-p and less than or equal to 15 Vp-p.

4. The vibration device according to claim 3, wherein The vibration unit includes a vibration body disposed between the piezoelectric element and the light-transmitting body. The piezoelectric element has a circular plate shape, The vibrating body has a cylindrical shape, The light-transmitting body has a circular plate shape or a dome shape.

5. The vibration device according to claim 1 or 2, wherein The control unit has: The light-transmitting body is 8.1×10 5 m / s 2 Above and 1.7×10 6 m / s 2 The first vibration mode of vibration with the following vibration acceleration; and The light-transmitting body is 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 The following vibration acceleration vibration second vibration mode, The control unit controls the vibration unit so as to execute the second vibration pattern after executing the first vibration pattern.

6. The vibration device according to claim 5, wherein The vibration part has a piezoelectric element, The control unit controls the value of the voltage applied to the piezoelectric element to be greater than or equal to 16 Vp-p and less than or equal to 60 Vp-p in the first vibration mode. Furthermore, in the second vibration mode, the value of the voltage applied to the piezoelectric element is controlled to be greater than or equal to 2 Vp-p and less than or equal to 15 Vp-p.

7. The vibration device according to claim 1 or 2, wherein: The vibration device also has: A fan device is used to spray gas toward the surface of the light-transmitting body.

8. The vibration device according to claim 1 or 2, wherein: The vibration device also has: A spraying device sprays liquid onto the surface of the light-transmitting body.

9. The vibration device according to claim 1 or 2, wherein: A waterproof coating is formed on the surface of the light-transmitting body.

10. A vibration control method for a vibration device comprising a light-transmitting body and a vibration unit for vibrating the light-transmitting body, wherein: The vibration control method includes using the vibration part to make the light-transmitting body move at a speed of 1.5×10 5 m / s 2 Above and 8.0×10 5 m / s 2 The following steps are for vibration acceleration vibration; as well as a step of detecting information related to the displacement amount of the light-transmitting body, The vibrating step includes controlling the vibration acceleration of the vibrating portion based on the information using a control portion.

11. The vibration control method according to claim 10, wherein: The vibration step includes: making the light-transmitting body vibrate at a speed of 3.5×10 5 m / s 2 Above and 5.5×10 5 m / s 2 Vibrates at the following vibration accelerations.

12. The vibration control method according to claim 10 or 11, wherein: The vibration part has a piezoelectric element, The vibrating step includes controlling, by a control unit, a voltage applied to the piezoelectric element to a value greater than or equal to 2 Vp-p and less than or equal to 15 Vp-p.

13. The vibration control method according to claim 10 or 11, wherein: The vibration part has a piezoelectric element, The vibrating step includes: The light-transmitting body is made to 5 m / s 2 Above and 1.7×10 6 m / s 2 vibrate in a first vibration mode at the following vibration acceleration; and The light-transmitting body is made to 5 m / s 2 Above and 8.0×10 5 m / s 2 The following vibration acceleration vibrates in the second vibration mode, After the step of vibrating the light-transmitting body in the first vibration mode is performed, the step of vibrating the light-transmitting body in the second vibration mode is performed.

14. The vibration control method according to claim 13, wherein: Vibrating the light-transmitting body in the first vibration mode includes: controlling the value of the voltage applied to the piezoelectric element to be greater than or equal to 16 Vp-p and less than or equal to 60 Vp-p by a control unit; Vibrating the light-transmitting body in the second vibration mode includes controlling, by the control unit, a value of a voltage applied to the piezoelectric element to be greater than or equal to 2 Vp-p and less than or equal to 15 Vp-p.

15. The vibration control method according to claim 10 or 11, wherein: The vibration control method further includes the step of using a fan device to spray gas toward the surface of the light-transmitting body.

16. The vibration control method according to claim 10 or 11, wherein: The vibration control method further includes the step of using a spraying device to spray liquid onto the surface of the light-transmitting body.

Images