Patent Description:
In the past, an imaging device such as a camera used as a monitoring device is required to always clear a field of view thereof. In particular, there have been proposed various mechanisms for removing water droplets such as raindrops, for cameras used outdoors, such as in an on-vehicle use. <CIT> discloses a liquid droplet removing device in which a piezoelectric element is attached to a drip-proof cover disposed in front of an imaging element. By vibrating the drip-proof cover, droplets in a field of view of an imaging element are removed. The drip-proof cover is held by a support frame. The imaging element is disposed in an internal space formed by the drip-proof cover and the support frame.

In the liquid droplet removing device described in <CIT>, the piezoelectric element is directly attached to the drip-proof cover. Thus, in the drip-proof cover, even a portion of the imaging element outside the field of view is vibrated, and there is a possibility that a vibration efficiency is greatly deteriorated. Further, the portion of the drip-proof cover outside the field of view is held by the support frame. Thus, when temperature changes or when external force is applied, there is a possibility that a stress is applied to the drip-proof cover or the piezoelectric element in a vibrator, and vibration is inhibited. Thus, it becomes difficult to obtain desired performance.

<CIT> teaches an apparatus for mitigating contamination of an optical device, which comprises an open-topped, closed-sided and closed-bottomed housing cup partially defining a protected volume to enclose the optical device. The housing cup includes a top collar having an open central aperture, wherein a top cover laterally spans the central aperture of the top collar. The top cover comprises a cylindrical annular ultrasonic transducer, such as a piezoelectric cylinder.

<CIT> discloses an image pick-up device with a dust preventing member. A dust-proofing filter comprising a piezoelectric element is arranged in front of a charged coupled device, CCD, case. A dust-proofing filter supporting member is fixed to the CCD case and the dust-proofing filter is fixed to projecting portions of the supporting member by pressing members comprising an elastic member which airtightly joints the dust-proofing filter to the dust-proofing filter supporting member.

<CIT> discloses a vibratory assembly having a housing. A transducer is operably coupled with the housing and has a substantially cylindrical shape. An isolator is at least partially disposed between the housing and the transducer. A lens cover is operably coupled with the transducer. A power source includes contacts operably coupled with the transducer. The power source supplies power to the transducer at various frequencies swept around a resonance harmonic to account for mass changes resulting from debris accumulation on the lens cover.

An object of the present invention is to provide a vibration device and an optical detection device capable of suppressing influence of a stress applied to a vibrator, and capable of effectively vibrating a cover to which water droplets or the like are attached.

This object is achieved by a vibration device according to claim <NUM>. Further developments of the invention are defined in the dependent claims. Any embodiments and examples of the description not falling within the scope of the claims do not form part of the invention and are provided for illustrative purposes only.

An optical detection device according to the present invention includes a vibration device configured according to the present invention, and an optical detection element disposed so that a detection region is included in the light-transmissive cover.

Other features, elements, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings.

Hereinafter, the present invention will be disclosed, with reference to the accompanying drawings, and by describing specific embodiments of the present invention.

Note that, the embodiments described in the present specification are illustrative, and that partial substitutions or combinations of configurations are possible between different embodiments.

<FIG> is a schematic elevational sectional view of a vibration device according to a first comparative example. <FIG> is an exploded perspective view of the vibration device according to the first comparative example.

A vibration device <NUM> illustrated in <FIG> is a vibration device that removes water droplets or foreign matter from within a field of view of an imaging element, by moving the water droplets or foreign matter with vibration, or atomizing the water droplets or the like. The vibration device <NUM> has a vibrator <NUM> and a case member <NUM>. The vibrator <NUM> includes a light-transmissive cover <NUM>, a piezoelectric element <NUM>, and a cylinder <NUM>. Here, when a direction in which the cylinder <NUM> extends is defined as an axial direction Z, the vibrator <NUM> of the vibration device <NUM> has an opening end portion 2A positioned closer to the cylinder <NUM> than the light-transmissive cover <NUM> in the axial direction Z. The vibration device <NUM> has an elastic member <NUM> provided between the opening end portion 2A of the vibrator <NUM> and the case member <NUM> of the vibrator <NUM>.

The light-transmissive cover <NUM>, the piezoelectric element <NUM>, the cylinder <NUM>, the elastic member <NUM>, and the case member <NUM> form an internal space. An optical detection element such as an imaging element is disposed in the internal space. Note that, in the present specification, the internal space is not limited to a hermetically sealed space, and a space partially open to the exterior is also defined as an internal space.

Hereinafter, a configuration of the vibration device <NUM> will be described in detail.

The light-transmissive cover <NUM> has a dome-like shape. The light-transmissive cover <NUM> has a substantially circular shape in a plan view. The light-transmissive cover <NUM> has a bottom surface 3c. The bottom surface 3c is positioned on a side of the cylinder <NUM> in the vibrator <NUM>. The light-transmissive cover <NUM> has a flange portion 3a provided in a vicinity of the bottom surface 3c. The flange portion 3a has a first surface 3b and a second surface that is on the opposite side of the first surface 3b. In the present comparative example, the second surface of the flange portion 3a is included in the bottom surface 3c. Note that, the shape of the light-transmissive cover <NUM> is not limited to the above, and may be flat plate-like, for example. A shape in a plan view of the light-transmissive cover <NUM>, may be, for example, a polygon. The light-transmissive cover <NUM> need not have the flange portion 3a. In the present specification, "in a plan view" refers to viewing from an upside in the axial direction Z. The upside in the axial direction Z corresponds to an upside in <FIG>.

As a material of the light-transmissive cover <NUM>, for example, a light-transmissive plastic, a glass such as quartz or boron acid, a light-transmissive ceramic, or the like may be used. Light-transmissive in the present specification refers to transmittance with which at least an energy line or light having a wave length to be detected by an optical detection element such as the above imaging element is transmitted.

As illustrated in <FIG>, the piezoelectric element <NUM> is attached to the bottom surface 3c of the light-transmissive cover <NUM>. The piezoelectric element <NUM> has a substantially annular piezoelectric body <NUM>. As a material of the piezoelectric body <NUM>, for example, a suitable piezoelectric ceramics such as PZT or (K, Na)NbO<NUM> or a suitable piezoelectric single crystal such as LiTaO<NUM> or LiNbO<NUM> may be used. The shape of the piezoelectric body <NUM> is not limited to the above.

The piezoelectric element <NUM> includes a first electrode 6a provided on one main surface of the piezoelectric body <NUM>, and a second electrode 6b provided on the other main surface. The first electrode 6a and the second electrode 6b are each substantially annular, and are provided on the opposite sides of the piezoelectric body <NUM>. The first electrode 6a and the second electrode 6b are each made of suitable metal. The first electrode 6a and the second electrode 6b may be, for example, Ni electrodes, or may be electrodes each made of a metal thin film such as Ag or Au formed by a sputtering method or the like.

Note that, in the present comparative example, one piezoelectric element <NUM> that is substantially annular is provided, but the present comparative example is not limited thereto. For example, a plurality of substantially rectangular plate-like piezoelectric elements may be provided along an outer peripheral edge of the light-transmissive cover <NUM>.

The first electrode 6a of the piezoelectric element <NUM> is attached to the light-transmissive cover <NUM>. On the other hand, the cylinder <NUM> is attached to the second electrode 6b of the piezoelectric element <NUM>. The cylinder <NUM> has an opening 7a. In the present comparative example, the light-transmissive cover <NUM> is indirectly coupled to the cylinder <NUM> with the piezoelectric element <NUM> interposed therebetween, so as to cover the opening 7a of the cylinder <NUM>. Note that, the cylinder <NUM> is substantially cylindrical. However, the shape of the cylinder <NUM> is not limited to the substantially cylindrical shape, and may be, for example, a rectangular cylindrical shape or the like.

The cylinder <NUM> has a first opening end face 7b and a second opening end face 7c that is on the opposite side of the first opening end face 7b. The first opening end face 7b, of the first opening end face 7b and the second opening end face 7c is positioned closer to the light-transmissive cover <NUM>. The piezoelectric element <NUM> is attached to the first opening end face 7b.

A direction connecting the first opening end face 7b and the second opening end face 7c that is a direction in which the cylinder <NUM> extends is the axial direction Z. A direction orthogonal to the axial direction Z is defined as a radial direction X. Note that, in the present specification, the radial direction X may be described as a direction X orthogonal to the axial direction Z. The cylinder <NUM> has an outer surface 7d positioned outside in the radial direction X, and an inner surface 7e positioned inside in the radial direction X.

Here, the vibrator <NUM> has an opening end face not sealed by the light-transmissive cover <NUM>, and an outer surface and an inner surface that are connected to the opening end face. In the present comparative example, the opening end face of the vibrator <NUM> is the second opening end face 7c of the cylinder <NUM>. The outer surface 7d of the cylinder <NUM> constitutes a part of the outer surface of the vibrator <NUM>. The inner surface 7e of the cylinder <NUM> constitutes a part of the inner surface of the vibrator <NUM>. In the vibration device <NUM>, the above opening end portion 2A of the vibrator <NUM> includes the second opening end face 7c of the cylinder <NUM>, and includes respective portions near the second opening end face 7c, of the outer surface 7d and the inner surface 7e.

The cylinder <NUM> is made of suitable metal. Note that, the material of the cylinder <NUM> is not limited to the above, and may be an appropriate ceramic or the like. As in the present comparative example, when the cylinder <NUM> is made of metal, the cylinder <NUM> may be used as a second electrode of the piezoelectric element <NUM>. In this case, the second electrode 6b of the piezoelectric element <NUM> illustrated in <FIG> need not be provided.

As illustrated in <FIG>, the vibration device <NUM> includes the case member <NUM>. The case member <NUM> includes a bottom plate portion 9c, and a side wall portion 9d provided on the bottom plate portion 9c. The case member <NUM> has a substantially circular shape in a plan view. Note that, the shape of the case member <NUM> is not limited to the above, and, in a plan view, for example, may have a shape such as a substantially rectangular shape. In the present comparative example, the case member <NUM> is made of suitable resin.

The elastic member <NUM> is provided on the bottom plate portion 9c of the case member <NUM>. The elastic member <NUM> of the vibration device <NUM> is an elastic sheet having a substantially annular shape, and a sheet-like shape. However, the shape of the elastic sheet is not limited to the substantially annular shape. The elastic sheet is made of, for example, rubber or the like.

The elastic member <NUM> is provided between the opening end portion 2A of the vibrator <NUM> and the bottom plate portion 9c of the case member <NUM>. More specifically, the elastic member <NUM> is provided between the second opening end face 7c of the cylinder <NUM> and the bottom plate portion 9c of the case member <NUM>. In this way, the elastic member <NUM> holds the vibrator <NUM>. In a plan view, an entirety of the elastic member <NUM> overlaps with the cylinder <NUM>. However, the disposition of the elastic member <NUM> is not limited to the above. The elastic member <NUM> is not limited to the elastic sheet. An elastic modulus of the elastic member <NUM> is preferably larger than an elastic modulus of the cylinder <NUM>.

A feature of the present comparative example is that the vibrator <NUM> is held by the elastic member <NUM>. Thereby, influence of a stress applied to the vibrator <NUM> can be suppressed, and the light-transmissive cover <NUM> to which water droplets or the like are attached can be efficiently vibrated. This will be described below by comparing the present comparative example with a second comparative example.

A vibration device of the second comparative example that is different from the first comparative example in that an elastic member is not included, and the vibration device having the configuration of the first comparative example were prepared. Note that, a case member having an opening at a center portion thereof was used as a case member of the vibration device in the present comparative example.

<FIG> is a diagram illustrating thermal stress distribution at -<NUM> with reference to <NUM> standards in a second comparative example. <FIG> is a diagram illustrating thermal stress distribution at -<NUM> with reference to <NUM> standards in the first comparative example. Note that, <FIG> each illustrates a part corresponding to half a section illustrated in <FIG>. Stress distribution diagrams other than <FIG> may also illustrate a part corresponding to half a section along an axial direction of the vibration device. In <FIG>, a positive value indicates a tensile stress, and a negative value indicates a compressive stress.

As illustrated in <FIG>, it may be understood that, in the second comparative example, since the case member <NUM> contracts when being cooled, a large compressive stress is applied to the cylinder <NUM> of the vibrator <NUM> from the case member <NUM>. As described above, when a large stress is applied to the vibrator <NUM>, vibration of the vibrator <NUM> is inhibited. Thus, vibration efficiency of the light-transmissive cover <NUM> to which water droplets or the like are attached is also reduced.

Compared to this, <FIG> illustrates that, in the first comparative example, although the case member <NUM> contracts, a stress applied to the vibrator <NUM> from the case member <NUM> is reduced by the elastic member <NUM>. Thereby, influence of a stress applied to the vibrator <NUM> can be suppressed, and the light-transmissive cover <NUM> to which water droplets or the like are attached can be efficiently vibrated.

In addition, since the elastic member <NUM> is provided, outward leakage of vibration from the vibrator <NUM> can also be reduced. In this way, the leakage of vibration can also be reduced, by a configuration other than strictly optimizing a dimension of each part of the vibrator <NUM>. Thus, a management range of the dimension of the each part of the vibrator <NUM> can be widened, and a degree of freedom in design can be enhanced.

<FIG> is a schematic elevational sectional view of a vibration device according to a modification example of the first comparative example.

A light-transmissive cover <NUM> of the present modification example does not have a flange portion. The light-transmissive cover <NUM> is directly coupled to the first opening end face 7b of the cylinder <NUM>. The piezoelectric element <NUM> is provided on the second opening end face 7c of the cylinder <NUM>. The piezoelectric element <NUM> is positioned at an opening end portion 12A of a vibrator <NUM>. The elastic member <NUM> is provided between the piezoelectric element <NUM> and the bottom plate portion 9c of the case member <NUM>. In a plan view, the elastic member <NUM> has a portion positioned outside the vibrator <NUM>. In the case of the present modification example as well, as in the first comparative example, it is possible to suppress influence of a stress applied to the vibrator <NUM>, and to effectively vibrate the light-transmissive cover <NUM> to which water droplets or the like are attached.

<FIG> is a schematic elevational sectional view of a vibration device according to a third comparative example. <FIG> is an exploded perspective view of the vibration device according to the third comparative example.

As illustrated in <FIG> and <FIG>, a vibration device <NUM> of the present comparative example is different from the first comparative example in that an elastic member is not included, a projection portion <NUM> is provided on a case member <NUM>, and the projecting portion <NUM> holds the vibrator <NUM>. In other respects than the above, the vibration device <NUM> according to the present comparative example has a similar configuration to that of the vibration device <NUM> according to the first comparative example.

The projecting portion <NUM> is provided on the bottom plate portion 9c of the case member <NUM>. In the present comparative example, one projecting portion <NUM> that is substantially annular is provided. Note that, a plurality of projecting portions may be provided along a circumferential direction. In the present specification, the circumferential direction is a circumferential direction about an axis extending in the above axial direction Z. In addition, when a thickness along the direction X orthogonal to the axial direction Z is defined as a radial thickness, it is desirable that a radial thickness of the projecting portion <NUM> is equal to or less than half a radial thickness of the opening end portion 2A of the vibrator <NUM>. Thereby, the vibrator <NUM> can be vibrated more efficiently.

As illustrated in <FIG>, a section along the axial direction Z of the projecting portion <NUM> has a substantially rectangular shape. Note that, the projecting portion <NUM> may have a shape of a section such as a trapezoidal shape, a triangular shape, or a substantially semicircular shape, in which a side closer to the vibrator <NUM> is convex.

The projecting portion <NUM> is provided integrally with the bottom plate portion 9c, and is made of, for example, resin or the like. Note that, the projecting portion <NUM> may be provided as a different body from the bottom plate portion 9c. In this case, a material different from that of the case member <NUM> may be used for the projecting portion <NUM>, or for example, the projecting portion <NUM> may be made of metal or the like.

In the present comparative example, the vibrator <NUM> is held by the projecting portion <NUM>. Thereby, influence of a stress applied to the vibrator <NUM> can be suppressed, and the light-transmissive cover <NUM> to which water droplets or the like are attached can be efficiently vibrated.

<FIG> is a diagram illustrating thermal stress distribution at -<NUM> with reference to <NUM> standards in the third comparative example. Note that, the case member having the opening at the center portion was used as the case member of the vibration device in which the thermal stress distribution was determined.

<FIG> illustrates that, in the third comparative example, although the case member <NUM> contracts, a stress applied to the vibrator <NUM> from the case member <NUM> is reduced by the projecting portion <NUM>. Thereby, influence of a stress applied to the vibrator <NUM> can be suppressed, and the light-transmissive cover <NUM> to which water droplets or the like are attached can be efficiently vibrated.

<FIG> is a schematic elevational sectional view of a vibration device according to a first embodiment. <FIG> is an exploded perspective view of the vibration device according to the first embodiment, from which the side wall portion of a case member is omitted. <FIG> is an enlarged view of <FIG>.

As illustrated in <FIG>, the present embodiment is different from the first comparative example in that an elastic member <NUM> is a leaf spring, and is different in a shape of a case member <NUM>. In other respects than the above, the vibration device <NUM> according to the present embodiment has a similar configuration to that of the vibration device <NUM> according to the first comparative example.

More specifically, as illustrated in <FIG>, the case member <NUM> has a substantially rectangular shape in a plan view. A bottom plate portion 39c of the case member <NUM> is provided with an opening 39a. The bottom plate portion 39c has a side surface 39e that connects both main surfaces of the bottom plate portion 39c to each other in the opening 39a.

In the present embodiment, a plurality of the elastic members <NUM> provided along a circumferential direction holds the vibrator <NUM>. However, one elastic member made of a leaf spring having an annular shape in a plan view may be provided.

As illustrated in <FIG>, the elastic member <NUM> has a first connection portion <NUM> connected to the opening end portion 2A of the vibrator <NUM>, and a second connection portion <NUM> connected to the case member <NUM>. In the present embodiment, a section along the axial direction Z of the first connection portion <NUM> has a substantially L-shaped shape. The first connection portion <NUM> is connected to the second opening end face 7c and the outer surface 7d of the cylinder <NUM> in the vibrator <NUM>. By fitting the first connection portion <NUM> of the elastic member <NUM> to the cylinder <NUM>, the first connection portion <NUM> and the cylindrical member <NUM> are connected to each other. Note that, the method of connecting the first connection portion <NUM> and the cylinder <NUM> is not limited to the above, and connection may be performed by, for example, a conductive adhesive, solder, welding, or the like.

The second connection portion <NUM> extends parallel to the bottom plate portion 39c of the case member <NUM>. More specifically, the second connection portion <NUM> extends from an outside to an inside in the direction X orthogonal to the axial direction Z. The second connection portion <NUM> is connected to the bottom plate portion 39c. A method for connecting the second connection portion <NUM> to the case member <NUM> is not particularly limited, but connection may be performed by, for example, an adhesive, screwing, or the like. When the second connection portion <NUM> is screwed, the second connection part <NUM> may have a through-hole for the screwing.

In the present embodiment as well, as in the first comparative example, it is possible to suppress influence of a stress applied to the vibrator <NUM>, and to effectively vibrate the light-transmissive cover <NUM> to which water droplets or the like are attached. This will be described below by comparing the present embodiment with a fourth comparative example.

A vibration device of the fourth comparative example that is different from the first embodiment in that an elastic member is not included, and the vibration device having the configuration of the first embodiment were prepared. In each of the vibration devices described above, a displacement amount was obtained, respectively, while changing temperature. A rate of change in the displacement amount was calculated with reference to <NUM> standards as a normal temperature.

<FIG> is a diagram illustrating a rate of change in a displacement amount in each of the vibration device according to the first embodiment and the vibration device according to the fourth comparative example, with reference to the normal temperature. In <FIG>, a solid line indicates a result of the first embodiment, and a broken line indicates a result of the fourth comparative example.

<FIG> illustrates that, in the fourth comparative example, when a temperature is lower than <NUM> as the normal temperature, the rate of change in the displacement amount is about -<NUM>% to about -<NUM>%, and the amount of displacement is small. This is because vibration is inhibited by a stress applied to the vibrator from the case member.

Compared to this, in the first embodiment, an absolute value of the rate of change in the displacement amount is less than about <NUM>% irrespective of temperature, and it can be seen that the vibration is stable. As described above, in the first embodiment, it is possible to suppress the influence of the stress applied to the vibrator <NUM> due to temperature, and it is possible to efficiently vibrate the light-transmissive cover <NUM> to which water droplets or the like are attached.

In addition, as in the first embodiment, when the elastic member <NUM> is the leaf spring, an elastic constant can be easily adjusted, and spring performance can be easily adjusted. Thus, design in consideration of stress when a temperature change occurs or when external force is applied can be easily achieved, and a degree of freedom in design can be enhanced.

As in the first embodiment, it is preferable to partially hold the vibrator <NUM> by the plurality of elastic members <NUM>. Thereby, the stress applied to the vibrator <NUM> can be further reduced, and the vibration is further unlikely to be inhibited.

In the first embodiment, the four elastic members <NUM> are provided every about <NUM>° in the circumferential direction, and are disposed so as to be <NUM>-fold rotationally symmetric. As described above, by disposing the plurality of elastic members <NUM> so as to be rotationally symmetric, bias unlikely occurs in holding the vibrator <NUM>, and it is possible to suitably hold the vibrator <NUM>. Further, in addition to physical holding stability, stability of a vibration mode of the vibration device <NUM> is obtained. Note that, the number of elastic members <NUM> is not limited to the above, and for example, the three elastic members <NUM> may be provided about every <NUM>° in the circumferential direction, and may be disposed so as to be <NUM>-fold rotationally symmetric. However, the plurality of elastic members <NUM> may not necessarily be disposed so as to be rotationally symmetric.

Hereinafter, first to fourth modification examples of the first embodiment will be described. In the first to fourth modification examples as well, as in the first embodiment, it is possible to suppress influence of a stress applied to the vibrator <NUM>, and to effectively vibrate the light-transmissive cover <NUM> to which water droplets or the like are attached.

In the first modification example illustrated in <FIG>, a second connection portion 37A of an elastic member 38A extends from an inside to an outside in the direction X orthogonal to the axial direction Z.

In the second modification example illustrated in <FIG>, a first groove portion 47f is provided in a second opening end face 47c of a cylinder <NUM> of a vibrator. The first groove portion 47f is provided in a substantially annular shape. On the other hand, a section along the axial direction Z of a first connection portion 36B of an elastic member 38B has a substantially U-shaped shape. The first groove portion 47f of the cylinder <NUM> is fitted with the first connection portion 36B of the elastic member 38B, and the first connection portion 36B is connected to an inside of the first groove portion 47f. Note that, a plurality of the first groove portions may be provided along a circumferential direction, in the second opening end face 47c of the cylinder. The first connection portion 36B of each the elastic member 38B may be connected to an inside of each the first groove.

A vibration device of the third modification example illustrated in <FIG> is configured similarly to the vibration device of the second modification example except for a second connection portion 37C of an elastic member 38C. The second connection portion 37C of the elastic member 38C reaches the side surface 39e from a main surface of the bottom plate portion 39c of the case member <NUM>, on a side of a vibrator. The second connection portion 37C is connected to the main surface and the side surface 39e.

In the fourth modification example illustrated in <FIG>, a first connection portion 36D of an elastic member 38D is connected to the second opening end face 7c of the cylinder <NUM> of a vibrator. A second connection portion 37D of the elastic member 38D has a portion extending in parallel to a main surface of a bottom plate portion 49c of a case member <NUM>, on a side of a vibrator, and from an inside to an outside in the direction X orthogonal to the axial direction Z. The portion extending in the direction X of the second connection portion 37D is connected to the main surface of the bottom plate portion 49c on the side of the vibrator.

The second connection portion 37D has a portion having a substantially U-shaped section along the axial direction Z. The portion having the substantially U-shaped section is connected to an end portion on an outside in the direction X of the portion extending in the direction X. On the other hand, a second groove portion 49f is provided in a main surface of the bottom plate portion 49c of the case member <NUM>, on the side of the vibrator. The second groove portion 49f is provided in a substantially annular shape. The second groove portion 49f of the case member <NUM> is fitted with the second connection portion 37D of the elastic member 38D, and the second connection portion 37D is connected to an inside of the second groove portion 49f.

In the present modification example, the second groove portion 49f is provided so as to be in contact with the side wall portion 9d. The case member <NUM> does not have a step portion between the second groove portion 49f and the side wall portion 9d. The portion of the elastic member 38D having the substantially U-shaped section reaches the side wall portion 9d from the inside of the second groove portion 49f, and is also connected to the side wall portion 9d. Note that, the position of the second groove portion 49f is not limited to the above. Alternatively, a plurality of the second grooves may be provided along a circumferential direction, in the bottom plate portion 49c of the case member <NUM>. The second connection portion 37D of each of the elastic members 38D may be connected to an inside of each of the second grooves.

<FIG> is a schematic elevational sectional view of a vibration device according to a second embodiment. <FIG> is an enlarged view of <FIG>.

As illustrated in <FIG>, the present embodiment is different from the first embodiment in a configuration of a case member <NUM> and a configuration of a leaf spring serving as an elastic member <NUM>. In other respects than the above, the vibration device according to the present embodiment has a similar configuration to that of the vibration device <NUM> according to the first embodiment.

More specifically, as illustrated in <FIG>, the case member <NUM> includes a holding portion <NUM> that extends inward from the side wall portion 9d in the direction X, is connected to the elastic member <NUM>, and holds the vibrator <NUM> with the elastic member <NUM> interposed therebetween. The holding portion <NUM> includes a first surface <NUM> positioned on a side closer to the vibrator <NUM>, a second surface 59i that is on the opposite side of the first surface <NUM>, and a side surface 59e connecting the first surface <NUM> and the second surface 59i to each other. Note that, as illustrated in <FIG>, in the present embodiment, the bottom plate portion 9c of the case member <NUM> does not have an opening.

Referring back to <FIG>, a first connection portion <NUM> of the elastic member <NUM> is connected to the inner surface 7e and the second opening end face 7c of the cylinder <NUM> of the vibrator <NUM>. A second connection portion <NUM> is connected to the side surface 59e and the second surface 59i of the holding portion <NUM> of the case member <NUM>.

In the present embodiment as well, as in the first embodiment, it is possible to suppress influence of a stress applied to the vibrator <NUM>, and to effectively vibrate the light-transmissive cover <NUM> to which water droplets or the like are attached.

<FIG> is a schematic elevational sectional view illustrating a vicinity of an elastic member in a vibration device according to a third embodiment.

The present embodiment is different from the second embodiment in that the side surface 59e of a holding portion <NUM> of a case member <NUM> includes a step portion 69j, and is different in a configuration of an elastic member <NUM>. In other respects than the above, the vibration device according to the present embodiment has a similar configuration to that of the second embodiment.

More specifically, the first connection portion <NUM> of the elastic member <NUM> is connected to the outer surface 7d and the second opening end face 7c of the vibrator <NUM>. A second connection portion <NUM> is connected to the side surface 59e of the holding portion <NUM> of the case member <NUM>, and an end portion of the second connection portion <NUM> abuts on the step portion 69j. Thus, the elastic member <NUM> and the vibrator <NUM> can be held more reliably by the holding portion <NUM>.

In addition, since the end portion of the second connection portion <NUM> abuts on the step portion 69j, a first opposing portion 65a does not come into contact with the first surface <NUM>. Accordingly, an elastic constant of the elastic member <NUM> can be increased. Thus, it is possible to further suppress influence of a stress applied to the vibrator <NUM> without increasing in size, and it is possible to more efficiently vibrate the light-transmissive cover <NUM> to which water droplets or the like are attached.

<FIG> is a schematic elevational sectional view illustrating a vicinity of an elastic member in a vibration device according to a modification example of the third embodiment.

The case member <NUM> according to the present modification example is configured similarly to the second embodiment. An elastic member 68A has the first connection portion <NUM> and the first opposing portion 65a similar to those of the third embodiment. On the other hand, the elastic member 68A has a second opposing portion 65b, that is a portion opposed to the side surface 59e of the holding portion <NUM> of the case member <NUM> with a gap therebetween. A second connection portion 67A of the elastic member 68A is connected to the second surface 59i of the holding portion <NUM>. Since the first opposing portion 65a and the second opposing portion 65b are provided, it is possible to effectively increase an elastic constant of the elastic member 68A without increasing the size. Thus, it is possible to further effectively suppress influence of a stress applied to the vibrator <NUM> without increasing the size, and it is possible to more efficiently vibrate the light-transmissive cover <NUM> to which water droplets or the like are attached.

<FIG> is a plan view of an elastic member in a vibration device according to a fourth embodiment.

The present embodiment is different from the first embodiment in a configuration of an elastic member <NUM>. In other respects than the above, the vibration device according to the present embodiment has a similar configuration to that of the vibration device <NUM> according to the first embodiment.

More specifically, the elastic member <NUM> includes a plurality of spring portions 78a disposed along a circumferential direction, and a frame-like portion 78b connecting the spring portions 78a to each other. Each of the spring portions 78a includes the first connection portion <NUM> connected to the vibrator <NUM>.

The elastic member <NUM> has a plurality of second connection portions <NUM> that are disposed along the circumferential direction, are connected to each other by the frame-like portion 78b, and are connected to the case member <NUM>. The second connection portion <NUM> has a through-hole 57a. At the through-hole 57a, the second connection portion <NUM> is connected to and fixed to the case member <NUM> by a screw, a projection, or the like. However, when the second connection portion <NUM> is connected to the case member <NUM> by an adhesive or the like, the second connection portion <NUM> need not have the through-hole 57a. The frame-like portion 78b is substantially annular. Note that, the shape of the frame-like portion 78b is not limited to the above.

In the present embodiment, the four spring portions 78a are disposed so as to be <NUM>-fold rotationally symmetric in the circumferential direction. Similarly, the four second connection portions <NUM> are disposed so as to be <NUM>-fold rotationally symmetric in the circumferential direction. The plurality of second connection portions <NUM> and the plurality of spring portions 78a are disposed so as not to overlap with each other in a plan view. More specifically, the spring portions 78a and the second connection portions <NUM> are alternately disposed about every <NUM>° in the circumferential direction. Accordingly, the elastic member <NUM> is <NUM>-fold rotationally symmetric as a whole. By disposing the plurality of spring portions 78a and the plurality of second connection portions <NUM> so as to be rotationally symmetric as described above, bias unlikely occurs during holding the vibrator <NUM>, and it is possible to suitably hold the vibrator <NUM>.

Note that, the respective numbers of pieces of the plurality of spring portions 78a and the plurality of second connection portions <NUM> are not limited to the above. For example, the three spring portions 78a and the three second connection portions <NUM> may be disposed so as to be <NUM>-fold rotationally symmetric, respectively. The positional relationship between the plurality of spring portions 78a and the plurality of second connection portions <NUM> is not limited to the above, and disposition may not necessarily be performed so that an entirety of the elastic member <NUM> is rotationally symmetric. The plurality of spring portions 78a and the plurality of second connection portions <NUM> may not necessarily be disposed so as to be rotationally symmetric, respectively.

In the present embodiment, in a plan view, the plurality of spring portions 78a and the plurality of second connection portions <NUM> do not overlap with each other. Note that, in a plan view, the plurality of spring portions 78a and the plurality of second connection portions <NUM> may overlap with each other.

<FIG> is a schematic elevational sectional view of a vibration device according to a fifth embodiment. <FIG> is an enlarged view of <FIG>.

As illustrated in <FIG>, the present embodiment is different from the first embodiment in that a first support body <NUM> that extends in the axial direction Z and supports the vibrator <NUM> is provided. The present embodiment is also different from the first embodiment in that the elastic member 38D and the case member <NUM> as in the fourth modification example of the first embodiment are included. In other respects than the above, the vibration device according to the present embodiment has a similar configuration to that of the vibration device <NUM> according to the first embodiment.

As illustrated in <FIG>, the first support body <NUM> includes a third connection portion 83a connected between the piezoelectric element <NUM> and the light-transmissive cover <NUM>, and a first bottom portion 83c fixed to the case member <NUM>. The first support body <NUM> has a first coupling portion 83b extending in the axial direction Z, and coupling the third connection portion 83a and the first bottom portion 83c to each other. The third connection portion 83a is substantially annular. The first coupling portion 83b and the first bottom portion 83c each have a substantially cylindrical shape extending in the axial direction Z. Note that, the shapes of the respective portions of the first support body <NUM> are not limited to the above. The first coupling portion 83b may have a frame-like shape other than an annular shape, for example. The first coupling portion 83b and the first bottom portion 83c may each have, for example, a shape such as a rectangular cylindrical shape.

A section along the axial direction Z of the first support body <NUM> has a substantially L-shaped shape. More specifically, when a thickness along the direction X orthogonal to the axial direction Z is defined as a radial thickness, a radial thickness of the first bottom portion 83c is larger than a radial thickness of the first coupling portion 83b in the first support body <NUM>. Thereby, the first coupling portion 83b is more easily deformed than the first bottom portion 83c, and a spring property is excellent. Note that, the radial thickness of the first bottom portion 83c of the first support body <NUM> is increased from a side of the first coupling portion 83b toward an outside in the radial direction X.

The first bottom portion 83c of the first support body <NUM> and the case member <NUM> are directly connected to each other. The above method of connection is not particularly limited, and the connection may be performed by, for example, an adhesive or screwing.

In the present embodiment, the first support body <NUM> is made of suitable metal. When the first support body <NUM> is made of metal, the first support body <NUM> may be used as a first electrode of the piezoelectric element <NUM>. In this case, the first electrode 6a of the piezoelectric element <NUM> illustrated in <FIG> need not be provided. In the present embodiment, routing of electrical connection between the piezoelectric element <NUM> and the exterior can be easily carried out. Thus, productivity can be enhanced. When the cylinder <NUM> is also made of metal, the routing of the electric connection between the piezoelectric element <NUM> and the exterior can be more easily carried out, so that the productivity can be further enhanced.

Note that, the material of the first support body <NUM> is not limited to the above, and may be an appropriate ceramic or the like. The first support body <NUM> may be formed integrally, or each part thereof may be formed as a separate body. In this case, the respective parts of the first support body may be joined by a method such as welding. For example, a configuration may be adopted in which rigidity of a material of the first bottom portion 83c may be higher than rigidity of a material of the first coupling portion 83b.

As described above, the third connection portion 83a of the first support body <NUM> is connected between the piezoelectric element <NUM> and the light-transmissive cover <NUM>. Note that, the piezoelectric element <NUM> may be positioned at the opening end portion 2A of the vibrator <NUM>, and the third connection portion 83a may be connected between the cylinder <NUM> and the light-transmissive cover <NUM>.

In the first support body <NUM>, vibration can be absorbed due to a spring property of the first coupling portion 83b. Note that, the absorption of vibration by the first coupling portion 83b refers to conversion of a vibration propagated from the vibrator <NUM> through the third connection portion 83a into a vibration in the first coupling portion 83b. This makes the leakage of the vibration harder to reach the first bottom portion 83c. Thus, leakage and damping of vibration to the case member <NUM> can be suppressed, and the vibrator <NUM> can be supported more securely.

The vibrator <NUM> is, in addition to being held by the elastic member 38D, supported by the first support body <NUM>. Thus, it is possible to further suppress influence of a stress applied to the vibrator <NUM>, and it is possible to more efficiently vibrate the light-transmissive cover <NUM> to which water droplets or the like are attached. Further, durability against vibration shock can be enhanced, and reliability can be enhanced.

In the present embodiment as well, an optical detection element such as an imaging element is disposed in an internal space formed by the vibrator <NUM>, the elastic member 38D, and the case member <NUM>. In addition, the piezoelectric element <NUM> of the vibrator <NUM> and the elastic member 38D are covered with the first support body <NUM>, the light-transmissive cover <NUM> of the vibrator <NUM>, and the case member <NUM>. Thereby, waterproof performance can be enhanced.

Although the first bottom portion 83c of the first support body <NUM> and the case member <NUM> are directly connected to each other by an adhesive, screwing, or the like, the present embodiment is not limited thereto, and the first bottom portion 83c and the case member <NUM> may be indirectly connected to each other. In a modification example of the fifth embodiment illustrated in <FIG>, a fixing member 85A is provided on the side wall portion 9d of the case member <NUM>, so as to grip the first bottom portion 83c, together with the case member <NUM>. A section along the axial direction Z of the fixing member 85A has a substantially L-shaped shape. The fixing member 85A can be fixed on the side wall portion 9d by, for example, screwing, or the like. In this manner, the first bottom portion 83c of the first support body <NUM> may be indirectly connected to the case member <NUM> by using the fixing member 85A, or the like.

<FIG> is an enlarged schematic elevational sectional view of a vibration device according to an sixth embodiment.

The present embodiment is different from the fifth embodiment in that a second support body <NUM> that extends in the axial direction Z and supports the vibrator <NUM> is provided, and that a fixing member 85B for fixing the first support body <NUM> and the second support body <NUM> is provided. In other respects than the above, the vibration device according to the present embodiment has a similar configuration to that of the vibration device according to the fifth embodiment.

The second support body <NUM> has a shape similar to that of the first support body <NUM>. More specifically, the second support body <NUM> has a fourth connection portion 84a connected to the first surface 3b in the flange portion 3a of the light-transmissive cover <NUM>, and a second bottom portion 84c fixed to the first bottom portion 83c of the first support body <NUM>. The second support body <NUM> includes a second coupling portion 84b extending in the axial direction Z, and coupling the fourth connection portion 84a and the second bottom portion 84c to each other. The fourth connection portion 84a is substantially annular. The second coupling portion 84b and the second bottom portion 84c each have a substantially cylindrical shape extending in the axial direction Z. Note that, the shapes of the respective portions of the second support body <NUM> are not limited to the above. The second coupling portion 84b may have a frame-like shape other than an annular shape, for example. The second coupling portion 84b and the second bottom portion 84c may each have, for example, a rectangular cylindrical shape.

A section along the axial direction Z of the second support body <NUM> has a substantially L-shaped shape. More specifically, in the second support body <NUM>, a radial thickness of the second bottom portion 84c is larger than a radial thickness of the second coupling portion 84b. Thereby, the second coupling portion 84b is more easily deformed than the second bottom portion 84c, and a spring property is excellent. Note that, the radial thickness of the second bottom portion 84c of the second support body <NUM> is increased from a side of the second coupling portion 84b toward an outside in the radial direction X.

In the present embodiment, the second support body <NUM> is made of suitable metal. Note that, the second support body <NUM> may be made of a suitable ceramic or the like.

The second bottom portion 84c of the second support body <NUM> is provided on the first bottom portion 83c of the first support body <NUM>. The fixing member 85B is provided on the second bottom portion 84c. The fixing member 85B is substantially annular, and is made of suitable resin or the like. Note that, the shape of the fixing member 85B is not limited to the above. The first bottom portion 83c and the second bottom portion 84c are fixed to the side wall portion 9d of the case member <NUM> from a side of the fixing member 85B by a screw <NUM>.

In the second support body <NUM>, vibration can be absorbed due to a spring property of the second coupling portion 84b. This makes the leakage of the vibration harder to reach the second bottom portion 84c. Thus, leakage and damping of vibration to the case member <NUM> can be suppressed, and the vibrator <NUM> can be supported more securely.

The vibrator <NUM> is, in addition to being held by the elastic member 38D and being supported by the first support body <NUM>, supported by the second support body <NUM>. Thus, it is possible to further suppress influence of a stress applied to the vibrator <NUM>, and it is possible to more efficiently vibrate the light-transmissive cover <NUM> to which water droplets or the like are attached. Further, durability against vibration shock can be effectively enhanced, and reliability can be effectively enhanced. In addition, since the flange portion 3a of the light-transmissive cover <NUM> is gripped by the first support body <NUM> and the second support body <NUM>, the light-transmissive cover <NUM> is unlikely to fall off the vibrator <NUM>. Thus, the reliability can be further enhanced.

In the present embodiment as well, an optical detection element such as an imaging element is disposed in an internal space formed by the vibrator <NUM>, the elastic member 38D, and the case member <NUM>. Further, the piezoelectric element <NUM> of the vibrator <NUM> and the elastic member 38D are covered with the first support body <NUM>, the light-transmissive cover <NUM> of the vibrator <NUM>, and the case member <NUM>. In addition, the first coupling portion 83b of the first support member <NUM> is covered with the second support body <NUM>. Thereby, waterproof performance can be further enhanced.

The configuration for fixing the first support body <NUM> and the second support body <NUM> is not limited to the above. In the following, first and second modification examples of the sixth embodiment will be described, that are different from the sixth embodiment in a configuration for fixing the first support body <NUM> and the second support body <NUM>. In the first and second modification examples as well, as in the sixth embodiment, influence of a stress applied to a vibrator can be suppressed, a light-transmissive cover to which water droplets or the like are attached can be efficiently vibrated, and the light-transmissive cover <NUM> is unlikely to fall off from the vibrator <NUM>.

As illustrated in <FIG>, in the first modification example, the fixing member 85A as in the fifth embodiment is used. The fixing member 85A is disposed so as to grip, together with the case member <NUM>, a portion where the first bottom portion 83c of the first support body <NUM> and the second bottom portion 84c of the second support body <NUM> are stacked. The fixing member 85A is fixed to the side wall portion 9d of the case member <NUM> by screwing. The first support body <NUM> and the second support body <NUM> are indirectly fixed to the case member <NUM> by using the fixing member 85A.

As illustrated in <FIG>, in the second modification example as well, the fixing member 85A as in the fifth embodiment is used. The fixing member 85A is disposed so as to grip, together with the case member <NUM>, the first bottom portion 83c of the first support body <NUM>. The fixing member 85A is fixed to the side wall portion 9d of the case member <NUM> by screwing. The first support body <NUM> is indirectly fixed to the case member <NUM> by using the fixing member 85A. The method for fixing the case member <NUM> and the fixing member 85A is not limited to the screwing. Fixing by welding, or by using other mechanical structure such as snap-fitting may be used.

On the other hand, the second bottom portion 84c of the second support body <NUM> is provided on the fixing member 85A. The second bottom portion 84c is fixed to the case member <NUM> with the fixing member 85A interposed therebetween, by the screw <NUM> that fixes the fixing member 85A. The second support body <NUM> is also fixed to the first bottom portion 83c of the first support body <NUM> with the fixing member 85A interposed therebetween. In this manner, the fixing member 85A made of resin or the like is positioned between the first support body <NUM> and the second support body <NUM>.

As described above, when the first support body <NUM> is made of metal, the first support body <NUM> is electrically connected to the piezoelectric element <NUM>. On the other hand, in the present modification example, the first support body <NUM> and the second support body <NUM> are electrically insulated from each other by the fixing member 85A. Thus, the second support body <NUM> not electrically connected to the piezoelectric element <NUM> is positioned outermost with respect to the vibration device. Thus, safety can be more reliably enhanced.

In the sixth embodiment, one second support body <NUM> is provided, the fourth connection portion 84a is frame-like, and the second coupling portion 84b and the second bottom portion 84c are each substantially cylindrical. Note that, the configuration of the second support body <NUM> is not limited thereto. In the following, third to sixth modification examples of the sixth embodiment each having a different configuration of the second support body will be described. In the third to sixth modification examples as well, as in the sixth embodiment, influence of a stress applied to a vibrator can be suppressed, a light-transmissive cover to which water droplets or the like are attached can be efficiently vibrated, and the light-transmissive cover <NUM> is unlikely to fall off from the vibrator <NUM>.

As illustrated in <FIG>, in the third modification example, a second support body 86C includes a plurality of fourth connection portions 86a and a plurality of second coupling portions 86b disposed along a circumferential direction. Each of the fourth connection portions 86a and the second coupling portions 86b is substantially rectangular plate-like. The plurality of second coupling portions 86b are connected to each other by the second bottom portion 84c.

In the present modification example, the second support body 86C supports a part of the light-transmissive cover <NUM> in the circumferential direction. Thereby, a vibration of the vibrator <NUM> is unlikely to be inhibited, and a vibration efficiency can be enhanced.

As illustrated in <FIG>, in the fourth modification example, a second support body 86D includes, similarly to the third modification example, the plurality of fourth connection portions 86a and the plurality of second coupling portions 86b. The second support body 86D includes the plurality of second coupling portions 86b, and includes an outer wall portion 87A provided along the circumferential direction. A shape of the outer wall portion 87A of the present modification example is substantially cylindrical, similar to the shape of the second coupling portion 84b in the sixth embodiment. Accordingly, when a configuration is adopted where the first support body <NUM> and the second support body 86D are electrically insulated from each other, safety can be more reliably enhanced, and a vibration of the vibrator <NUM> is unlikely to be inhibited.

Note that, the outer wall portion 87A may be provided with a cutout portion. In this case, even when foreign matter such as water, mud, or the like enters between the light-transmissive cover <NUM> and the second support body 86D, the water, mud, or the like, can be removed from the cutout portion.

As illustrated in <FIG>, in the fifth modification example, a second support body 86E includes, similarly to the third modification example, the plurality of fourth connection portions 86a and the plurality of second coupling portions 86b. The second support body 86E includes the plurality of second coupling portions 86b, and includes a plurality of outer wall portions 87B provided along a circumferential direction. Note that, in the present modification example, the outer wall portion 87B corresponding to the second coupling portion 86b and the outer wall portion 87B not including the second coupling portion 86b are provided. However, at least one outer wall portion 87B that includes the second coupling portion 86b and extends in the circumferential direction may be provided.

The outer wall portions 87B are connected to each other by the second bottom portion 84c, and are opposed to each other in the circumferential direction with respective gaps interposed therebetween. Thus, even when foreign matter such as water, mud, or the like enters between the light-transmissive cover <NUM> and the second support body 86E, the water, mud, or the like can be removed from the above gap portion. In addition, as in the fourth modification example, safety can be more reliably enhanced, and a vibration of the vibrator <NUM> is unlikely to be inhibited.

As illustrated in <FIG>, in the sixth modification example, a plurality of second support bodies 86F is provided. Each of the second support bodies 86F includes the fourth connection portion 86a, the second coupling portion 86b, and a second bottom portion 86c. Similarly to the third modification example, the fourth connection portion 86a and the second coupling portion 86b are each substantially rectangular plate-like. The second bottom portion 86c has a substantially rectangular parallelepiped shape.

<FIG> is an exploded perspective view illustrating a vibration device according to a seventh embodiment of the present invention. <FIG> is a schematic sectional view illustrating an elastic member and a case member of a vibration device according to the seventh embodiment.

As illustrated in <FIG> and <FIG>, the present embodiment is different from the fourth embodiment in that an elastic member <NUM> and a case member <NUM> are insert molded bodies. The present embodiment is also different from the fourth embodiment in that the first support body <NUM> is connected to the case member <NUM> by using the fixing member 85A, as in the modification example of the fifth embodiment illustrated in <FIG>, and different in an arrangement of the spring portion 78a and the second connection portion <NUM>. In other respects than the above, the vibration device according to the present embodiment has a similar configuration to the vibration device of the fourth embodiment.

In the elastic member <NUM>, the three spring portions 78a and the three second connection portions <NUM> are disposed so as to be <NUM>-fold rotationally symmetric, respectively. The second connection portion <NUM> is insert molded so as to be positioned inside the case member <NUM>. In this way, since the elastic member <NUM> and the case member <NUM> are integrated as an insert molded body, the configuration of the vibration device can be simplified. Thus, productivity can be enhanced. In addition, as in the fourth embodiment, it is possible to suppress influence of a stress applied to the vibrator <NUM>, and to effectively vibrate the light-transmissive cover <NUM> to which water droplets or the like are attached.

<FIG> is a schematic elevational sectional view of an imaging device according to a eighth embodiment.

An imaging device <NUM> as an optical detection device includes the vibration device <NUM> according to the first embodiment, and an imaging element <NUM> as an optical detection element. The imaging element <NUM> is disposed in an internal space of the vibration device <NUM> configured with the vibrator <NUM>, the elastic member <NUM>, and the case member <NUM>. Note that, although not illustrated in the figure, the imaging element <NUM> can be supported by using an appropriate member or the like.

A circuit board <NUM> is provided in the internal space. Although an arrangement of the circuit board <NUM> is not particularly limited, in the present embodiment, the circuit board <NUM> is provided on a portion on a side of the bottom plate portion 39c of the case member <NUM> in the imaging element <NUM>. The circuit board <NUM> includes a piezoelectric element control circuit for driving the piezoelectric element <NUM> in a resonance state or the like, and an imaging element control circuit for driving the imaging element <NUM>. The imaging device <NUM> may include a heater for heating the vibrator <NUM>. Thereby, moisture can be efficiently removed. In this case, the circuit board <NUM> may include a heater control circuit for driving the heater.

Note that, the vibration device <NUM> or the imaging device <NUM> may not necessarily have the circuit board <NUM>. When the circuit board <NUM> is not provided, it is sufficient that the imaging element <NUM> and the piezoelectric element <NUM> are controlled by signals from an outside.

Examples of the imaging element <NUM> include, for example, a CMOS, a CCD, a bolometer, a thermopile, and the like, for receiving light of a wave length in any from a visible region to a far infrared region. Examples of the imaging device <NUM> include, for example, a camera, a radar, a LIDAR device, and the like.

Note that, an optical detection element for optically detecting an energy ray, other than the imaging element <NUM> may be disposed in the internal space of the vibration device <NUM>. An energy ray to be detected may be, for example, an active energy ray such as an electromagnetic wave, an infrared ray, or the like. A detection region of the optical detection element is included in the light-transmissive cover <NUM>. In the imaging device <NUM>, a field of view of the imaging element <NUM> as the detection region is included in the light-transmissive cover <NUM>.

Since the imaging device <NUM> includes the vibration device <NUM> according to the first embodiment, it is possible to suppress influence of a stress applied to the vibrator <NUM>, and it is possible to effectively vibrate the light-transmissive cover <NUM> to which water droplets or the like are attached.

In the present embodiment, although the example using the vibration device <NUM> according to the first embodiment has been described, the vibration devices according to the present invention such as the second to seventh embodiments may be used for imaging devices. For example, when the vibration device according to the seventh embodiment is used, the light-transmissive cover <NUM> can be efficiently vibrated, and additionally, productivity can be enhanced, and further, the reduction in size can be achieved.

Claim 1:
A vibration device (<NUM>) comprising:
a vibrator (<NUM>) including a cylinder (<NUM>) having an opening (7a) in an axial direction (Z) of the cylinder (<NUM>) between a first opening end face (7b) of the cylinder (<NUM>) and a second opening end face (7c) of the cylinder (<NUM>) on an opposite side of the first opening end face (7b), a light-transmissive cover (<NUM>) coupled to the cylinder (<NUM>) on the side of the first opening end face (7b) so as to cover the opening (7a) of the cylinder (<NUM>), and a piezoelectric element (<NUM>) between the first opening end face (7b) of the cylinder (<NUM>) and the light-transmissive cover (<NUM>) for vibrating the light-transmissive cover (<NUM>), the vibrator (<NUM>) having an opening end portion (2A) including the second opening end face (7c);
an elastic member (<NUM>, <NUM>, 38A - 38D, <NUM>, <NUM>, 68A, <NUM>, <NUM>) for holding the opening end portion (2A) of the vibrator (<NUM>); and
a case member (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) connected to the elastic member (<NUM>, <NUM>, 38A - 38D, <NUM>, <NUM>, 68A, <NUM>, <NUM>),
characterized in that the elastic member (<NUM>, 38A - 38D, <NUM>, <NUM>, 68A, <NUM>) is a leaf spring having a first connection portion (<NUM>, 36B, 36D, <NUM>) connected to the vibrator (<NUM>), and a second connection portion (<NUM>, 37A, 37C, 37D, <NUM>, <NUM>, 67A) connected to the case member (<NUM>, 38A - 38D, <NUM>, <NUM>, 68A, <NUM>, <NUM>).