JP2016085244A - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device capable of having a dust removing function and a shutter function while saving space and using a decreased number of components.SOLUTION: An imaging device having an imaging element comprises: an excitation member; an optical member arranged on a subject side of the imaging element, and receiving vibration of the excitation member to vibrate; a vibrator receiving vibration of the excitation member to vibrates; a control unit which controls the excitation member; and a moving member abutting on the vibrator and receiving motion of the vibrator to move. While the excitation member has one surface stuck on the optical member and the opposite surface stuck on the vibrator, a vibration member composed of the excitation member, optical member, and vibrator has a neutral plane of vibration bending arranged outside the excitation member, and the control unit controls a vibration mode of the excitation member so as to switch between a first mode in which the moving member is moved and a second mode in which foreign matter sticking on the optical member is removed by vibrating the optical member.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image pickup apparatus having a dust removing function for removing foreign matters such as dust attached to an optical member disposed on a subject side of an image pickup element, and a shutter function.

  Conventionally, in a camera, a mechanical shutter performs exposure adjustment by driving a front curtain and a rear curtain at high speed and high accuracy. In addition, when the captured image data is transferred, the charge transfer path is shielded to prevent noise from being generated in the image data.

  However, in a camera equipped with an electronic shutter, the mechanical shutter need not perform exposure adjustment. Therefore, this mechanical shutter does not need to be driven at high speed and with high accuracy, and can have a simple configuration (space saving and parts saving).

  Therefore, by using an ultrasonic motor using a piezoelectric element as disclosed in Patent Document 1 as a mechanical shutter drive source, the mechanical shutter can have a simple configuration.

  On the other hand, in a conventional digital camera, when a lens is exchanged, dust enters the camera body and adheres to the imaging element in the camera body, so that the acquired captured image may be deteriorated. In order to avoid such a phenomenon, a dustproof filter that transmits the photographic light beam is provided on the subject side of the image sensor, and this is vibrated by a piezoelectric element, thereby removing foreign matters such as dust adhering to the surface of the dustproof filter. Technology has been proposed.

  Further, Patent Document 2 discloses an apparatus in which a dust removing device having a dust removing function and a mechanical shutter described above are integrated as one device with the aim of saving the space of the camera and reducing the number of parts.

Japanese Patent No. 0421964 JP 2005-331829 A

  However, in the conventional technique disclosed in Patent Document 2, the mechanical shutter includes a drive source dedicated to driving the shutter, and the dust removing device includes a drive source dedicated to driving the dust removal. In other words, although the apparatus has an integral configuration, the drive source is provided with a separate one, and a space for holding each drive source is required, so the apparatus has a large configuration.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an imaging apparatus capable of realizing a dust removal function and a shutter function with a reduced space and a reduced number of parts.

In order to achieve the above object, the present invention provides:
In an imaging apparatus having an imaging device, a vibration member, an optical member that is disposed on a subject side of the imaging device and vibrates by receiving vibration of the vibration member, and vibrates by receiving vibration of the vibration member One surface of the vibration member, and a control unit that controls the vibration member, and a moving member that is in contact with the vibration element and moves by receiving the motion of the vibration element. Is affixed to the optical member, the opposite surface is affixed to the vibrator, and in the vibration member constituted by the vibration member, the optical member and the vibrator, the neutral surface of vibration bending is the vibration member A first mode in which the moving member is moved by controlling the vibration mode of the vibration member by the control unit, and the optical member is attached to the optical member by vibrating the optical member. To remove foreign matter And switches between modes.

  According to the present invention, it is possible to provide an imaging apparatus capable of realizing a dust removing function and a shutter function with a reduced space and a reduced number of parts.

It is a front side perspective view of the digital single-lens reflex camera which concerns on 1st Embodiment. It is a back side perspective view of the digital single-lens reflex camera concerning a 1st embodiment. It is a block diagram which shows the electric constitution of the digital single-lens reflex camera which concerns on 1st Embodiment. It is a disassembled perspective view which shows the structure of the imaging unit which concerns on 1st Embodiment. It is a disassembled perspective view which shows the structure of the vibration unit which concerns on 1st Embodiment. It is the figure which showed the relationship between the neutral surface of a vibration, and the thickness of each member. It is the figure which showed electrode arrangement | positioning of the piezoelectric element which concerns on 1st Embodiment. It is a disassembled perspective view which shows the structure of the shutter curtain unit which concerns on 1st Embodiment. It is a side view which shows the vibration shape of the vibration unit which concerns on 1st Embodiment. It is the figure which showed the shutter operation | movement which concerns on 1st Embodiment. It is the figure which showed the vibration shape excited by the vibration unit at the time of shutter operation | movement which concerns on 1st Embodiment. 5 is a flowchart of dust removal operation and shutter operation in the camera operation according to the first embodiment. It is a disassembled perspective view which shows the structure of the imaging unit which concerns on 2nd Embodiment. It is a disassembled perspective view which shows the structure of the vibration unit which concerns on 2nd Embodiment. It is a disassembled perspective view which shows the structure of the shutter curtain unit which concerns on 2nd Embodiment. It is a graph which shows the relationship between the frequency and amplitude of two vibration modes excited by the optical filter in 2nd Embodiment. It is a figure which shows the voltage applied to the m-th order and m + 1 order vibration mode shape in case m is odd number, and a piezoelectric element concerning 2nd Embodiment. It is a figure which shows the voltage applied to the m-th order and m + 1st order vibration mode shape in case m is an even number based on 2nd Embodiment, and a piezoelectric element. It is a figure for demonstrating the case where the 9th and 10th vibration modes are excited simultaneously with respect to the optical filter which concerns on 2nd Embodiment. It is a graph which shows the behavior in each time phase at the time of exciting simultaneously by shifting two vibration modes 90 degree in the optical filter which concerns on 2nd Embodiment. It is a graph which shows the behavior in each time phase at the time of exciting simultaneously by shifting two vibration modes 90 degree in the optical filter which concerns on 2nd Embodiment. It is a graph which shows the behavior in each time phase at the time of exciting simultaneously by shifting two vibration modes 90 degree in the optical filter which concerns on 2nd Embodiment. It is a graph which shows the behavior in each time phase at the time of exciting simultaneously by shifting two vibration modes 90 degree in the optical filter which concerns on 2nd Embodiment. It is the figure which showed the shutter operation | movement which concerns on 2nd Embodiment. It is the figure which showed the vibration shape excited by the vibration unit at the time of shutter operation | movement which concerns on 2nd Embodiment. It is the figure which showed the shutter operation | movement at the time of the multiple curtain structure which concerns on 2nd Embodiment. It is the figure which showed electrode arrangement | positioning of the piezoelectric element which concerns on 3rd Embodiment. It is a side view which shows the vibration shape of the vibration unit which concerns on 3rd Embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the present invention according to the claims, and all the combinations of features described in the present embodiments are not necessarily essential for solving the problems of the present invention. Absent.

[First Embodiment]
<Camera configuration>
1 and 2 are views showing the appearance of a digital single-lens reflex camera according to the present invention. Specifically, FIG. 1 is a perspective view of the camera body 1 as viewed from the front side, showing a state in which a photographing lens unit (not shown) is removed, and FIG. 2 is a perspective view of the camera body 1 as viewed from the back side. It is.

  Reference numeral 4 denotes a lens lock release button that is pushed in when removing the photographing lens unit. Reference numeral 5 denotes a mirror box disposed in the camera housing, and the photographic light flux that has passed through the photographic lens is guided here. A quick return mirror 6 is disposed inside the mirror box 5. The quick return mirror 6 is held at an angle of 45 ° with respect to the photographic optical axis in order to guide the photographic light flux toward the pentaprism 22 (see FIG. 3), and the image sensor 33 (see FIG. 3). Therefore, it is possible to take a state of being held at a position retracted from the photographing light flux.

  On the grip side of the upper part of the camera, a shutter button 7 as a start switch for starting shooting, a main operation dial 8 for setting a shutter speed and a lens aperture value according to an operation mode at the time of shooting, and an operation mode of the shooting system A setting button 10 is arranged. Some of the operation results of these operation members are displayed on the LCD display panel 9. The operation mode setting button 10 is used to set whether the continuous shooting or only one frame shooting is performed when the shutter button 7 is pressed once, the self shooting mode setting, and the like. 9 shows the setting status.

  The shutter button 7 is configured such that a switch SW1 (7a described later) is turned on by a first stroke (half-pressed), and a switch SW2 (7b described later) is turned on by a second stroke (full press).

  A flash unit 11 that pops up with respect to the camera body, a shoe groove 12 for attaching a flash, and a flash contact 13 are arranged at the upper center of the camera, and a shooting mode setting dial 14 is arranged at the upper right of the camera. An external terminal lid 15 that can be opened and closed is provided on the side opposite to the grip side. Inside the external terminal lid 15, a video signal output jack 16 and a USB output connector are provided as external interfaces. 17 is stored.

  In FIG. 2, a viewfinder eyepiece window 18 is provided on the back side of the camera, and a color liquid crystal monitor 19 capable of displaying an image is provided near the center of the back side. The sub operation dial 20 arranged beside the color liquid crystal monitor 19 plays an auxiliary role of the function of the main operation dial 8. For example, in the AE mode of the camera, the exposure correction amount for the appropriate exposure value calculated by the automatic exposure device is set. Used to set. Alternatively, in the manual mode in which each of the shutter speed and the lens aperture value is set according to the user's will, the shutter speed is set with the main operation dial 8 and the lens aperture value is set with the sub operation dial 20. The sub operation dial 20 is also used to select display of a captured image displayed on the color liquid crystal monitor 19.

  Reference numeral 43 denotes a main switch for starting or stopping the operation of the camera. Reference numeral 44 denotes a dust removal instruction operation member for executing a dust removal operation, which is for instructing an operation to screen off foreign matters such as dust attached on the optical filter. This dust removal operation will be described in detail later.

  FIG. 3 is a block diagram showing the main electrical configuration of the digital single-lens reflex camera according to the present invention. In addition, the part which is common in the above-mentioned drawing is shown with the same symbol. Reference numeral 100 denotes a central processing unit (hereinafter referred to as MPU) which is a microcomputer built in the camera body. The MPU 100 controls the operation of the camera, and executes various processes and instructions for each element. Reference numeral 100a denotes an EEPROM built in the MPU 100, which can store time information of the time measuring circuit 109 and other information.

  Connected to the MPU 100 are a mirror drive circuit 101, a focus detection circuit 102, a piezoelectric element drive circuit 103, a video signal processing circuit 104, a switch sense circuit 105, and a photometric circuit 106. An LCD drive circuit 107, a battery check circuit 108, a time measurement circuit 109, and a power supply circuit 110 are also connected. These circuits operate under the control of the MPU 100.

  Further, the MPU 100 communicates with the lens control circuit 201 disposed in the photographing lens unit via the mount contact 21. The mount contact 21 also has a function of transmitting a signal to the MPU 100 when the photographing lens unit is connected. Thereby, the lens control circuit 201 can communicate with the MPU 100 and drive the photographing lens 200 and the diaphragm 204 in the photographing lens unit via the AF driving circuit 202 and the diaphragm driving circuit 203. Become.

  In the present embodiment, the photographic lens 200 is shown as a single lens for convenience, but actually includes a large number of lens groups.

  The AF drive circuit 202 is configured by, for example, a stepping motor, and adjusts the imaging light flux to be focused on the image sensor 33 by changing the focus lens position in the imaging lens 200 under the control of the lens control circuit 201. Reference numeral 203 denotes an aperture drive circuit, which is configured by, for example, an auto iris or the like, and is configured to change the aperture 204 by the lens control circuit 201 to obtain an optical aperture value.

  The quick return mirror 6 guides the photographic light beam passing through the photographic lens 200 to the pentaprism 22 and transmits a part thereof to the sub mirror 30. The sub mirror 30 guides the transmitted photographic light beam to the focus detection sensor unit 31.

  The mirror driving circuit 101 is for driving the quick return mirror 6 to a position where the subject image can be observed by the finder and a position where the subject image is retracted from the photographing light flux. At the same time, the sub mirror 30 is driven to a position for guiding the photographing light flux to the focus detection sensor unit 31 and a position for retracting from the photographing light flux. Specifically, it is composed of, for example, a DC motor and a gear train.

  Reference numeral 31 denotes a known phase difference type focus detection sensor unit. The signal output from the focus detection sensor unit 31 is supplied to the focus detection circuit 102, converted into a subject image signal, and then transmitted to the MPU 100. The MPU 100 performs focus detection calculation by the phase difference detection method based on the subject image signal. Then, the defocus amount and the defocus direction are obtained, and based on this, the focus lens in the photographing lens 200 is driven to the in-focus position via the lens control circuit 201 and the AF drive circuit 202.

  Reference numeral 22 denotes a pentaprism, which is an optical member that converts and reflects the photographing light beam reflected by the quick return mirror 6 into an erect image. The user can observe the subject image from the viewfinder eyepiece window 18 through the viewfinder optical system. The pentaprism 22 guides part of the photographing light flux to the photometric sensor 37. The photometric circuit 106 obtains the output of the photometric sensor 37, converts it into a luminance signal of each area on the observation surface, and outputs it to the MPU 100. The MPU 100 calculates an exposure value from the obtained luminance signal.

  Reference numeral 32 denotes a shutter curtain, which blocks the photographing light flux when the user is observing the subject image with the viewfinder. Further, at the time of image capturing, the evacuation is performed from the front surface of the image sensor according to the release signal. The shutter curtain 32 is controlled by the piezoelectric element drive circuit 103 that has received a command from the MPU 100.

  Reference numeral 33 denotes an image pickup element, for example, a CMOS which is an image pickup device. There are various types of imaging devices such as a CCD type, a CMOS type, and a CID type, and any type of imaging device may be adopted. Further, the charge accumulation time is controlled by the MPU 100.

  Reference numeral 34 denotes a clamp / CDS (correlated double sampling) circuit, which performs basic analog processing before A / D conversion and can also change the clamp level. Reference numeral 35 denotes an AGC (automatic gain adjustment circuit) which performs basic analog processing before A / D conversion and can change the AGC basic level. Reference numeral 36 denotes an A / D converter that converts an analog output signal of the image sensor 33 into a digital signal.

  Reference numeral 410 denotes an optical filter, which is formed by laminating a plurality of birefringent plates and phase plates made of quartz or the like and laminating an infrared cut filter. In the present embodiment, the optical filter 410 is described as an integral configuration of an infrared cut filter or an optical low-pass filter using crystal or the like. However, the present invention is not limited to this, and a plurality of optical filters is used. The structure divided | segmented into an element member may be sufficient. In that case, an optical element disposed on the outermost surface constituting the sealed structure including the imaging element is vibrated by a piezoelectric element described later.

  Reference numeral 430 denotes a piezoelectric element that is vibrated by the piezoelectric element driving circuit 103 that receives a command from the MPU 100 and is configured to vibrate integrally with an optical filter 410 and a vibrating body 420 described later.

  Reference numeral 400 denotes an image pickup unit unitized with the optical filter 410, the piezoelectric element 430, the shutter curtain 32, the image pickup element 33, and other components to be described later. The shutter operation and dust removal are controlled by the MPU 100 and the piezoelectric element drive circuit 103. Perform the action. A detailed configuration will be described later.

  Reference numeral 104 denotes a video signal processing circuit, which performs overall hardware image processing such as gamma / knee processing, filter processing, and monitor display information synthesis processing on digitized image data. The image data for monitor display from the video signal processing circuit 104 is displayed on the color liquid crystal monitor 19 via the color liquid crystal drive circuit 112.

  Further, the video signal processing circuit 104 can also store image data in the buffer memory 37 through the memory controller 38 in accordance with an instruction from the MPU 100. Further, the video signal processing circuit 104 has a function of performing image data compression processing such as JPEG. When continuous shooting is performed, such as continuous shooting, image data can be temporarily stored in the buffer memory 37 and unprocessed image data can be sequentially read out through the memory controller 38. Thus, the video signal processing circuit 104 can sequentially perform image processing and compression processing regardless of the speed of the image data input from the A / D converter 36.

  The memory controller 38 has a function of storing image data input from the external interface 40 (corresponding to the video signal output jack 16 and the USB output connector 17 in FIG. 1) in the memory 39. In addition, it has a function of outputting image data stored in the memory 39 from the external interface 40. The memory 39 is a flash memory that can be attached to and detached from the camera body.

  Reference numeral 105 denotes a switch sense circuit, which transmits an input signal to the MPU 100 according to the operation state of each switch. 7a is a switch SW1 that is turned on by the first stroke (half-press) of the shutter button 7. Reference numeral 7b denotes a switch SW2 that is turned on by the second stroke (fully pressed) of the shutter button 7. When the switch SW2 is turned on, an instruction to start photographing is transmitted to the MPU 100. Further, the main operation dial 8, the sub operation dial 20, the photographing mode setting dial 14, the main switch 43, and the dust removal operation instruction operation member 44 are connected.

  A liquid crystal display driving circuit 107 drives the LCD display panel 9 and the in-finder liquid crystal display 41 in accordance with instructions from the MPU 100.

  A battery check circuit 108 performs a battery check for a predetermined time in accordance with a signal from the MPU 100 and sends the detection output to the MPU 100. A power supply unit 42 supplies necessary power to each element of the camera.

  Reference numeral 109 denotes a time measuring circuit that measures the time and date from when the main switch 43 is turned off to when it is turned on, and can send the measurement result to the MPU 100 in accordance with an instruction from the MPU 100.

<Configuration of imaging unit>
A detailed configuration of the imaging unit 400 will be described. FIG. 4 is an exploded perspective view showing the configuration of the imaging unit 400 according to the present embodiment. The imaging unit 400 is configured to restrict linear drive to the imaging element unit 500, the sealing member 450, the vibration unit 470, the urging member 490, the shutter curtain unit 440, the urging member 520, and the shutter curtain unit 440. The illustrated guide means is provided.

  The image sensor unit 500 includes an image sensor 33 and an image sensor holding member 510. The imaging element holding member 510 is provided with screw holes 510a, 510b, 510c, 510d, and 510e. The sealing member 450 is formed of an elastic body such as rubber or poron. The urging member 490 is formed of a material having a spring property such as metal, and is provided with screw holes 490a, 490b, 490c, and 490d. The urging member 520 is formed of a material having a spring property such as metal, and is provided with a screw hole 520a.

  The screw hole 490a of the biasing member 490 and the screw hole 510a of the image sensor holding member 510, the screw hole 490b and the screw hole 510b, the screw hole 490c and the screw hole 510c, and the screw hole 490d and the screw hole 510d are fixed with screws. As a result, the vibration unit 470 and the sealing member 450 are sandwiched between the image sensor unit 500 and the biasing member 490 and are held on the subject side of the image sensor unit 500. The subject side surface of the sealing member 450 contacts the vibration unit 470, and the photographer side surface contacts the image sensor 33.

  Since the vibration unit 470 is biased toward the imaging unit 500 by the spring property of the biasing member 490, the sealing member 450 and the vibration unit 470 are in close contact with each other with no gap, and the sealing member 450 and the image sensor 33 are also the same. It is in close contact with the gap. As a result, the space between the vibration unit 470 and the image sensor 33 is sealed by the sealing member 450 to form a sealed space that prevents entry of foreign matters such as dust.

  The screw hole 520a of the urging member 520 and the screw hole 510e of the image sensor holding member 510 are fixed with screws. As a result, the shutter curtain unit 440 is sandwiched between the urging member 520 and the vibration unit 470 and is held on the subject side of the vibration unit 470. Since the shutter curtain unit 440 is biased toward the imaging unit 500 by the spring property of the biasing member 520, the surface on the image pickup person side of the shutter curtain unit 440 and the surface on the subject side of the vibration unit 470 are subjected to pressure. It abuts in the generated state. Detailed configurations of the vibration unit 470 and the shutter curtain unit 440 will be described later.

<Configuration of vibration unit>
A detailed configuration of the vibration unit 470 will be described. FIG. 5 is an exploded perspective view showing the configuration of the vibration unit 470 according to the present embodiment. The vibration unit 470 includes an optical filter 410, a piezoelectric element 430, and a vibration body 420. The vibrating body 420 is made of a material such as a metal that easily transmits vibration, and has a protrusion 420a on the subject side. The protrusion 420a and the vibrating body 420 are integrated.

  The piezoelectric element 430 and the vibrating body 420 are disposed on one side of the optical filter 410 outside the effective imaging area 410a. One surface of the piezoelectric element 430 is bonded (adhered) to the optical filter 410, and the other surface is bonded (adhered) to the vibrating body 420, and receives the vibration of the piezoelectric element 430 as a vibration source, and receives the optical filter. 410 and the vibrating body 420 vibrate together.

  In this vibration unit 470, it is necessary to consider the neutral plane of vibration. The neutral plane of vibration is a boundary surface between a region where the vibration bending extends and a region where the vibration bending contracts. FIG. 6 is a side view of the vibration unit 470 showing a neutral plane of vibration. FIG. 6A is a diagram showing that a neutral surface exists in the piezoelectric element 430, and also shows the relationship among the thicknesses of the optical filter 410, the piezoelectric element 430, and the vibrating body 420 at that time.

If the neutral plane of vibration of the vibration unit 470 exists inside the piezoelectric element 430 that is a vibration source, the stretching force and the contracting force cancel each other, so the vibration becomes weak. FIG. 6B is a diagram showing that a neutral surface exists between the optical filter 410 and the piezoelectric element 430. The thickness of the optical filter 410, the piezoelectric element 430, and the vibrating body 420 at that time is shown in FIG. The relationship is also shown. By changing the thickness of each member constituting the vibration unit 470, the position of the neutral plane of vibration can be adjusted. Therefore, in the present embodiment, since the neutral plane of the vibration is disposed outside the piezoelectric element 430 that is the vibration source, the relationship between the thicknesses of the respective members is as follows.
The thickness of the vibrating body 420 + the thickness of the piezoelectric element 430 ≦ the thickness of the optical filter 410 The thickness of each member constituting the vibration unit 470 is set as described above, so that the vibration of the piezoelectric element 430 as a drive source is canceled out. It can be excited without causing it. More ideally, it is desirable to place the neutral surface as close as possible to the center of the thickness of the optical filter 410 that occupies most of the configuration of the vibration unit 470. By doing so, in the vibration of the optical filter 410, the displacement amount of the contracting region becomes equal to the displacement amount of the extending region, and stable vibration can be obtained.

  In this embodiment, since the neutral surface of the vibration is disposed on the optical filter 410 side, the relationship between the thicknesses of the respective members is as described above. However, the neutral surface of the vibration is disposed outside the piezoelectric element 430. If possible, it may be arranged on the vibrating body 420 side. In that case, the relationship between the thicknesses of the members may not be as described above.

<< Electrode layout of piezoelectric element >>
7 is a detailed view of the piezoelectric element 430 according to the present invention, FIG. 7 (b) is a side view of the piezoelectric element 430, and FIG. 7 (a) is a plan view of FIG. 7 (b) viewed from the left. FIG. 7C is a plan view of FIG. 7B viewed from the right side. As shown in FIG. 7C and FIG. 7A, the piezoelectric element 430 has electrodes arranged in three phases of A phase, B phase, and C phase. The A surface of the piezoelectric element 430 is bonded (adhered) to the optical filter 410, and the B surface is bonded (adhered) to the vibrating body 420.

<Configuration of shutter curtain unit>
A detailed configuration of the shutter curtain unit 440 will be described. FIG. 8 is an exploded perspective view showing the configuration of the shutter curtain unit 440 according to the present embodiment. The shutter curtain unit 440 includes a shutter curtain 32, an elastic member 460, and a moving body 480. The moving body 480 is made of metal or the like. The elastic member 460 is formed of an elastic member such as rubber. By this elastic member 460, an elastic characteristic and a damping function can be imparted to the contact portion between the moving body 480 and the protrusion 420a of the vibrating body 420. As a result, transient vibrations and audible sounds can be prevented from occurring in the shutter curtain unit 440, and a good driving state can be obtained. The shutter curtain 32, the elastic member 460, and the moving body 480 are bonded (attached).

<Dust removal mechanism>
The mechanism of the dust removal operation will be described. The piezoelectric element 430 is excited to vibrate and the optical filter 410 is vibrated, thereby removing dust and foreign matter adhering to the subject side of the optical filter 410. FIG. 9 is a side view of the optical filter 410, the piezoelectric element 430, and the vibrating body 420. When a voltage is applied to the piezoelectric element 430, state changes (vibration) of the optical filter 410, the piezoelectric element 430, and the vibrating body 420 are illustrated. Shape).

  An equal voltage in the same time phase is applied to the A phase and the B phase of the piezoelectric element 430 through a flexible printed circuit board for the piezoelectric element, and the C phase is set to the ground (0 [V]). Since the voltage is applied to the A phase and the B phase of the piezoelectric element 430 at the same time phase, the polarity of the applied voltage is switched in the same cycle. When the voltage applied to the A phase and the B phase is a positive value, the A phase and the B phase of the piezoelectric element 430 contract in the perpendicular direction and extend in the in-plane direction. Therefore, the optical filter 410 bonded to the piezoelectric element 430 receives a force for expanding the bonding surface in the surface direction from the piezoelectric element 430 and deforms so that the bonding surface side with the piezoelectric element 430 becomes convex. That is, when a positive voltage is applied to the A phase and the B phase, the optical filter 410 is bent and deformed as indicated by the solid line in FIG. Similarly, if the voltage applied to the A phase and the B phase is negative, the piezoelectric element 430 is deformed in the opposite direction of expansion and contraction with the aforementioned one, and the optical filter 410 is bent and deformed as shown by a two-dot chain line in FIG. Occurs.

  Therefore, by applying the same voltage at the same time phase to the A phase and the B phase while keeping the C phase at the ground, the polarity of the voltage applied in the same period is switched, and the unevenness of the optical filter 410 is periodically changed. Standing-wave vibration that causes switching occurs. By setting the frequency of the periodic voltage in the vicinity of the resonance frequency of the natural mode of the vibration unit 470, a large amplitude can be obtained even with a small applied voltage, and the efficiency is high. In addition, there are a plurality of resonance frequencies of the vibration unit 410. When a voltage is applied at each resonance frequency, the vibration unit 410 can be vibrated in vibration modes of different orders.

  Here, as shown in FIG. 9, in standing wave vibration, vibration nodes (d1, d2,..., D1, D2,...) And abdomen are alternately generated. The vibration node is a position where the amplitude is almost zero, and the vibration abdomen is a position where the amplitude is maximum between adjacent nodes. In order to remove dust attached to the surface of the optical filter 410, a force greater than the adhesive force, that is, acceleration must be applied to the dust. However, since the amplitude is almost zero at the vibration node, the acceleration is almost zero, and it is not possible to screen off dust or the like against the adhesive force. Therefore, when the optical filter 410 is vibrated only in one vibration mode, dust or the like remains on the vibration node.

  In order to improve this, after the optical filter 410 is vibrated in one vibration mode, the optical filter 410 is vibrated in another vibration mode. Thereby, dust remaining in the first vibration mode can be removed in another subsequent vibration mode. In this case, if a node in one vibration mode overlaps with a node in another vibration mode, dust on the overlapping node cannot be removed, so the nodes should not overlap. There must be. Therefore, it is desirable that the combinations of vibration modes to be used are even-numbered nodes (odd order) and odd-numbered nodes (even order). In the present embodiment, the eleventh vibration mode (section 12) and the twelfth vibration mode (section 13) are used in combination.

  The resonance frequency of the optical filter 410 varies depending on the shape, thickness, material, and the like of the optical filter 410, but it is preferable to select a resonance frequency that is outside the audible range in order to suppress generation of unpleasant sound.

  In this embodiment, an example in which vibration is excited in the eleventh vibration mode and the twelfth vibration mode has been described. However, the present invention is not limited to this, and vibration may be excited in other vibration modes. Three or more types of vibration modes may be used.

<Mechanism of shutter operation>
The shutter operation will be described. By exciting vibration in the piezoelectric element 430, an elliptical motion (circular motion) is generated at the tip of the protrusion 420a. The details of this elliptical motion (circular motion) are described in Japanese Patent No. 0261964, and are omitted here. The protrusion 420a2 point of the vibrating body 420 and the moving body 480 are in contact with each other in a state where pressure is generated by the biasing member 520. By the elliptical motion (circular motion) generated at the tip of the protrusion 420a, a friction driving force is generated on the contact surface between the moving body 480 and the protrusion 420a, and the moving body 480 moves. Since the moving body 480 is bonded (attached) to the elastic member 460 and the shutter curtain 32, the movable body 480 moves as a whole shutter curtain unit 440. FIG. 10 shows a state of the shutter operation according to the present embodiment, FIG. 10 (a) shows a state when the shutter curtain is opened, and FIG. 10 (b) shows a state when the shutter curtain is closed. It is.

  Next, a method for generating an elliptical motion (circular motion) at the tip of the protrusion 420a will be described. More specifically, the vibrator 420 is excited with two different vibration modes at one frequency by shifting the time phase, thereby generating an elliptical motion (circular motion) at the tip of the protrusion 420a.

  FIG. 11 is a diagram showing two vibration modes excited by the vibrating body 420 according to the present embodiment, and a dotted line in the figure indicates a vibration node. As shown in the figure, the long side direction of the optical filter 410 is X, the short side direction is Y, and the normal direction of the surface is Z. The vibration mode shown in FIG. 11A is a primary vibration mode in which a primary waveform is generated on the X- and Z-axis planes of the vibrating body 420, and the phase is the same for the A phase and the B phase of the piezoelectric element 430. The same voltage is applied and the C phase is grounded (0 [V]) to excite it. The vibration mode shown in FIG. 11B is a secondary vibration mode in which a secondary waveform is generated in the Y and Z planes of the vibrating body 420, and the time of the voltage applied to the A phase and the B phase of the piezoelectric element 430. The phase is shifted by 180 ° and the C phase is grounded (0 [V]) to excite it. By setting the frequency of the applied voltage in the vicinity of the resonance frequency of the natural mode of the vibration unit 470, a large amplitude can be obtained even with a small applied voltage, and the efficiency is high.

  In order to excite these two vibration modes at one frequency, the shapes of the piezoelectric element 430, the vibration body 420, and the optical filter 410 are designed so that the resonance frequencies substantially coincide. Further, as shown in FIG. 11B, the protrusion 420a is disposed near the node of the secondary vibration mode, and the tip of the protrusion 420a is displaced in the Y direction by this vibration. At the same time, as shown in FIG. 11A, the protrusion 420a is disposed in the vicinity of the antinode of the primary vibration mode, and the tip of the protrusion 420a is displaced in the Z direction by this vibration. By synthesizing these two different vibration modes with a time phase difference of 90 °, similar elliptical motion (circular motion) can be generated at the two points of the tip of the protrusion 420a.

  The moving direction of the shutter curtain unit 440 is switched by switching the rotational direction of the elliptical motion (circular motion) generated at the tip of the protrusion 420a. The resonance frequency of the vibration unit 470 varies depending on the shape, plate thickness, material, and the like of the piezoelectric element 430, the vibration body 420, and the optical filter 410, but the resonance frequency is outside the audible range in order to suppress generation of unpleasant sound. Is preferred.

  In this embodiment, the example in which the vibration body 420 excites the primary vibration mode and the secondary vibration mode has been described. However, the present invention is not limited to this, and other vibration modes may be excited. In addition, the number of the protrusions 420a provided on the vibrating body 420 has been described as two, but may be three or more.

<Operation control>
Control will be described. As described above, the vibration mode suitable for the shutter operation is excited to the vibration unit 470 when performing the shutter operation, and the vibration mode suitable for the dust removal operation is excited to the vibration unit 470 when performing the dust removal operation. There is a need to. By controlling the voltage, frequency, and time phase applied to the electrodes A phase, B phase, and C phase of the piezoelectric element 430 by the MPU 100 and the piezoelectric element driving circuit 103, the vibration mode excited to the vibration unit 470 is switched and the shutter operation is performed. And dust removal operation.

<Camera operation>
A dust removal operation and a shutter operation during camera operation will be described. FIG. 12 is a flowchart showing a dust removal operation and a shutter operation during camera operation. In step 1, it is determined whether or not the main switch 43 is turned on. When the power is turned on, in step 2, a process for starting the camera system is performed, the power supply circuit 110 is controlled to supply power to each circuit, the system is initialized, and the camera can be operated for shooting. The camera system ON operation is performed.

  Next, in step 3, it is determined whether or not the photographer has operated the dust removal instruction operation member 44. If it has been operated, the process proceeds to step 4, and if it has not been operated, the process proceeds to step 5. Although the dust removal instruction operation member 44 is provided in the present embodiment, the present invention is not limited to this. For example, the operation member for instructing the dust removal operation is not limited to a mechanical button, and may be an instruction from a menu displayed on the color liquid crystal monitor 19 using a cursor key, an instruction button, or the like. .

  In step 4, the camera body 1 is caused to perform a dust removal operation in response to a command to start the dust removal operation. First, the power supply circuit 110 supplies power necessary for the dust removal operation to each part of the camera body 1. In parallel with this, the remaining battery level of the power source 42 is detected, and the result is transmitted to the MPU 100. Upon receiving the dust removal operation start signal, the MPU 100 sends a drive signal to the piezoelectric element drive circuit 103. When the piezoelectric element driving circuit 103 receives a driving signal from the MPU 100, the piezoelectric element driving circuit 103 generates a voltage for exciting a vibration mode suitable for dust removal in the optical filter 410 and applies the voltage to the piezoelectric element 430. The piezoelectric element 430 expands and contracts in accordance with the applied voltage, and causes the optical filter 410 to excite a vibration mode suitable for dust removal. When the dust removing operation is completed, the process proceeds to Step 5.

  Next, in step 5, it is determined whether or not the photographer has operated SW2 (7b). If the SW2 (7b) has been operated, the process proceeds to step 6, and if not, the process proceeds to step 7.

  In step 6, the camera body 1 is caused to perform a shutter operation in response to a command for starting the shutter operation by SW2 (7b). The shutter operation means that the shutter curtain unit 440 is retracted from the front surface of the image sensor 33 (curtain opening operation) from the SW2 (7b) operation until the image sensor 33 starts exposure, and the shutter curtain unit 440 is moved to the image sensor after the exposure ends. (33) This is an operation of moving to the front (curtain closing operation).

First, the power supply circuit 110 supplies power necessary for the shutter operation to each part of the camera body 1. In parallel with this, the remaining battery level of the power source 42 is detected, and the result is transmitted to the MPU 100. Upon receiving the shutter operation start signal, the MPU 100 sends a drive signal to the piezoelectric element drive circuit 103. When the piezoelectric element driving circuit 103 receives a driving signal from the MPU 100, the piezoelectric element driving circuit 103 generates a voltage that causes an elliptical motion (circular motion) at the tip of the protrusion 420 a and applies the voltage to the piezoelectric element 430. The piezoelectric element 430 expands and contracts according to the applied voltage, and generates an elliptical motion (circular motion) at the tip of the protrusion 420a. Due to the elliptical motion (circular motion) generated at the tip of the protrusion 420a, a friction driving force is generated on the contact surface between the shutter curtain unit 440 and the protrusion 420a, and the shutter curtain unit 440 moves. When the shutter operation ends, the process proceeds to step 7.
Next, in step 7, it is determined whether the power is turned off by the main switch 43 when the camera is in a standby state. If turned off, the process proceeds to step 7, and if not turned off, the process returns to step 3.

  In step 8, after performing the same dust removal operation as in step 4, the process proceeds to step 9. Here, in the dust removal operation in step 8, parameters such as the drive frequency, drive time, and control method of the piezoelectric element 430 may be different from those in step 4 in consideration of the power consumption and operation time of the camera 1. Needless to say.

  In step 9, control for terminating each circuit is performed by controlling the MPU 100, necessary information and the like are stored in the EEPROM 100 a, and the power supply circuit 110 is controlled to turn off the power supply to each circuit. Do.

  As described above, the dust removal operation is performed not only at an arbitrary timing intended by the photographer but also when the power is turned off. That is, the camera system OFF operation is performed after the operation for removing the foreign matter adhering to the surface of the optical filter 410 is performed.

  In the present embodiment, the power OFF operation by the main switch 43 has been described. However, the camera system OFF operation similar to that at the time of power OFF may be executed after a predetermined time has elapsed in the power ON state. In this case, it goes without saying that the same effect can be obtained if the dust removing operation is performed in advance.

  As described above in detail, according to the present embodiment, by controlling the vibration mode excited to the vibration unit 470, the dust removal function and the shutter function can be realized with one drive source, and the number of parts can be saved. Can be provided.

[Second Embodiment]
A second embodiment will be described. In particular, the description will focus on the differences between the second embodiment of the present invention and the above-described first embodiment, and the description of the same (similar) parts as those of the above-described first embodiment will be omitted or simplified. Turn into.

<Configuration of imaging unit>
FIG. 13 is an exploded perspective view showing the configuration of the imaging unit 600 according to the present embodiment. The imaging unit 600 restricts linear drive to the imaging element unit 700, the sealing member 650, the vibration unit 670, the urging member 690, the shutter curtain unit 640, the urging members 720a and 720b, and the shutter curtain unit 640. And a guide means (not shown). The imaging element holding member 710 is provided with screw holes 710a, 710b, 710c, 710d, 710e, and 710f. The urging member 720a is provided with a screw hole 720c, and the urging member 720b is provided with a screw hole 720d.

  FIG. 14 is an exploded perspective view showing the configuration of the vibration unit 670 according to this embodiment. The vibration unit 670 includes an optical filter 610, piezoelectric elements 630a and 630b, and vibration bodies 620a and 620b. Piezoelectric elements 630a and 630b and vibrating bodies 620a and 620b are disposed on both sides of the optical filter 610 outside the effective imaging area 610a. The vibrating bodies 620a and 620b are provided with projections 620c and 620d on the subject side.

  FIG. 15 is an exploded perspective view showing the configuration of the shutter curtain unit 640 according to the present embodiment. The shutter curtain unit 640 includes moving bodies 680a and 680b, elastic bodies 660a and 660b, and a shutter curtain 632. The moving bodies 680a and 680b and the elastic bodies 660a and 660b are bonded (attached) to both sides of the shutter curtain 632 corresponding to the positions of the protrusions 620c and 620d of the vibrating bodies 620a and 620b. The screw hole 720c of the urging member 720a and the screw hole 710e, the screw hole 720d, and the screw hole 710f of the image sensor holding member 710 are fixed with screws. As a result, the shutter curtain unit 640 is sandwiched between the vibration unit 670 and the biasing member 720 and is held on the subject side of the vibration unit 670. The moving body 680a and the protrusion 620c of the vibrating body 620a are in contact with each other in a state where pressure is generated by the biasing member 720a, and the protrusion 620d of the moving body 680b and the vibrating body 620b is generated by the biasing member 720b. In contact.

<Dust removal mechanism>
The dust removal operation will be described. By exciting vibrations in the piezoelectric elements 630a and 630b, vibration (carrier wave) capable of transporting foreign matters such as dust is excited in the optical filter 610, and dust is removed. More specifically, the foreign matter is conveyed by exciting the optical filter 610 with two vibration modes having different orders at one frequency with different time phases. In order to focus on the explanation of the principle of the transport operation, the description will be made with the configuration of the optical filter 610, the piezoelectric elements 630a and 630b, and the vibrating bodies 620a and 620b, which are the minimum necessary configuration.

  FIG. 16 is a graph showing the relationship between the frequency and amplitude of two vibration modes excited by the optical filter 610 in this embodiment. As shown in FIG. 16, the mth order vibration mode is excited at the frequency indicated by f (m), and the m + 1st order vibration mode is excited at the frequency indicated by f (m + 1). Here, if the frequency f of the voltage applied to the piezoelectric elements 630a and 630b is set to f (m) <f <f (m + 1), the resonance of both the m-th order vibration mode and the m + 1-order vibration mode can be used. it can. If f is set to f <f (m), the m-th order resonance can be used, but it is difficult to increase the amplitude of the m + 1-order vibration mode because it is away from the f (m + 1) -order resonance point. Become. Further, when f (m + 1) <f, the amplitude is increased only in the m + 1st order vibration mode. In this embodiment, since both vibration modes are used, the frequency f is set in a range where f (m) <f <f (m + 1).

  17 (a) and 17 (b) are diagrams showing m-order and m + 1-order vibration mode shapes when m is an odd number, and voltages applied to the A-phase and B-phase of the piezoelectric elements 630a and 630b. . At this time, the C phase is ground (0 [V]).

  FIGS. 18A and 18B are diagrams showing m-order and m + 1-order vibration mode shapes when m is an even number, and voltages applied to the A-phase and B-phase of the piezoelectric elements 630a and 630b. is there. At this time, the C phase is ground (0 [V]).

  17A and 17B show a case where m = 9 as an example when m is an odd number. As shown in FIG. 17A, in each vibration mode, a plurality of nodes appear at equal intervals in the direction parallel to the longitudinal direction of the piezoelectric elements 630a and 630b (in the same direction). In FIG. 17B, the amplitude and time phase of the alternating voltage applied to the piezoelectric elements 630a and 630b in each vibration mode are represented by a real component and an imaginary component. (1) shows the m-order vibration mode, (2) shows the m + 1-order vibration mode, and (3) shows the alternating voltage, although the time phase of the m + 1-order vibration mode is shifted by 90 °. Here, in order to obtain the same amplitude in the two vibration modes, where the amplitude ratio of the m-th order vibration mode and the m + 1-order vibration mode with respect to an AC voltage of a certain frequency is A: 1, the voltage of each vibration mode is represented by m. Normalized by the amplitude of the next vibration mode. In order to simultaneously excite the mth-order vibration mode and the m + 1st-order vibration mode whose time phase is 90 ° in the optical filter 610, the AC voltages of (1) and (3) may be added. That is, an AC voltage as shown in (4) may be applied.

  Similarly, FIG. 18A and FIG. 18B show the vibration mode shape and the AC voltage applied to the piezoelectric elements 630a and 630b when m = 10 as an example when m is an even number. Indicates.

  In this embodiment, the time phase difference between the m-th order and m + 1-order vibration modes is set to 90 °. However, how to superimpose the two vibration modes by controlling the amplitude, time phase, and frequency of the AC voltage is as follows. It is possible to control arbitrarily.

  Next, the behavior of the optical filter 610 when the two vibration modes are excited simultaneously by the above control method will be described. As shown in FIG. 19, consider a case where the ninth and tenth vibration modes are excited simultaneously for the optical filter 610. A and B vibration mode shapes are indicated by A and B in the figure. The values from 0 to 360 are represented from the left end to the right end of the optical filter 610. Further, as shown in the figure, the long side direction of the optical filter 610 is X, the short side direction is Y, and the normal direction of the surface is Z.

  FIGS. 20 to 23 show the behavior of the optical filter 610 in each time phase when the above two vibration modes are excited simultaneously with the time phase shifted by 90 °. 20 to 23, C represents the ninth-order vibration mode waveform and D represents the tenth-order vibration mode waveform in each time phase in FIGS. E represents a waveform obtained by synthesizing two vibration modes, that is, an actual amplitude of the optical filter 610. F is the acceleration of the optical filter 610 in the Z direction.

  The foreign matter adhering to the surface of the optical filter 610 moves under the force in the normal direction as the optical filter 610 is deformed. That is, when the curve F indicating the acceleration in the Z direction takes a positive value, the foreign matter is pushed out of the plane and receives a force in the normal direction of the curve E indicating the displacement of the optical filter 610 in this time phase. In the section indicated by rn (n = 1, 2, 3,...) In the figure, the foreign substance receives a force in the right direction (positive direction in the X direction). In the section indicated by ln (n = 1, 2, 3,...) In the figure, the foreign matter receives a force in the left direction (negative direction in the X direction). As a result, the foreign matter moves to a location indicated by Xn (n = 1, 2, 3,...). In the present embodiment, this Xn (n = 1, 2, 3,...) Moves in the positive X direction as the time phase advances, so that the foreign matter moves in the positive X direction.

  In this embodiment, the time phase difference between the two vibration modes is set to 90 °. However, the present invention is not limited to this, and the time phase difference may be set larger than 0 ° and smaller than 180 °. Even in this case, since the portion corresponding to Xn moves in the positive direction in the X direction, the foreign matter can be conveyed in the positive direction in the X direction. Further, when the time phase difference between the two vibration modes is set larger than −180 ° and smaller than 0 °, the portion corresponding to the above Xn moves in the negative direction in the X direction. It is possible to transport foreign matter.

In addition, the foreign substance conveyance force is determined by the acceleration of the optical filter 610. The acceleration a of the optical filter 610 is expressed by the following equation, where f is the driving frequency, P is the amplitude, V is the driving voltage, and k1, k2 are proportional constants.
a = k ₁ P (2πf) ² = k ₂ V (2πf) ²
That is, the foreign substance conveyance force is proportional to the amplitude of the optical filter 610 and the square of the driving frequency. Therefore, the conveyance force can be increased by increasing the AC voltage V and the frequency f applied to the piezoelectric elements 630a and 630b.

<Mechanism of shutter operation>
The shutter operation will be described. By exciting vibrations in the piezoelectric elements 630a and 630b, elliptical motion (circular motion) is generated at the tips of the protrusions 620c and 620d. The protrusions 620c and 620d4 of the vibrating bodies 620a and 620b and the moving bodies 680a and 680b of the shutter curtain unit 640 are in contact with each other in a state where pressure is generated by the biasing members 720a and 720b. By the elliptical motion (circular motion) generated at the tips of the protrusions 620c and 620d, a frictional driving force is generated on the contact surfaces of the protrusions 620c and 620d and the moving bodies 680a and 680b, and the moving bodies 680a and 680b move. Since the moving bodies 680a and 680b are bonded (adhered) to the elastic members 660a and 660b and the shutter curtain 632, they move as a whole shutter curtain unit 640. FIG. 24 shows the shutter operation, FIG. 24 (a) shows a state when the shutter curtain is opened, and FIG. 24 (b) shows a state when the shutter curtain is closed.

  Next, a method for generating elliptical motion (circular motion) at the tips of the protrusions 620c and 620d of the vibrating bodies 620a and 620b will be described. Specifically, by causing the vibrators 620a and 620b to excite two different vibration modes at one frequency while shifting the time phase, elliptical motion (circular motion) is caused at the tips of the protrusions 620c and 620d. generate.

  FIG. 25 is a diagram illustrating two vibration modes excited by the vibrating bodies 620a and 620b according to the present embodiment, and the dotted line in the figure indicates a vibration node. As shown in the figure, the long side direction of the optical filter 610 is X, the short side direction is Y, and the normal direction of the surface is Z. The vibration mode shown in FIG. 25A is a primary vibration mode in which similar primary waveforms are generated on the X- and Z-axis planes of the vibrating bodies 620a and 620b. This primary vibration mode is excited by applying the same voltage in the same time phase to the A phase and B phase of the piezoelectric elements 630a and 630b and setting the C phase to ground (0 [V]).

  The vibration mode shown in FIG. 25B is a secondary vibration mode in which similar secondary waveforms are generated on the Y and Z planes of the vibrating bodies 620a and 620b. This secondary vibration mode is excited by shifting the time phase of the voltage applied to the A phase and B phase of the piezoelectric elements 630a and 630b by 180 ° and setting the C phase to ground (0 [V]). By setting the frequency of the voltage to be applied in the vicinity of the resonance frequency of the natural vibration mode of the vibration unit 670, a large amplitude can be obtained even with a small applied voltage, which is efficient.

  In order to excite these two vibration modes at one frequency, the shapes of the piezoelectric elements 630a and 630b, the vibrators 620a and 620b, and the optical filter 610 are designed so that the resonance frequencies substantially coincide. In addition, as shown in FIG. 25B, the protrusions 620c and 620d are arranged near the nodes of the secondary vibration mode, and the tip ends of the protrusions 620c and 620d are displaced in the Y direction by this vibration. At the same time, as shown in FIG. 25A, the protrusions 620c and 620d are arranged near the antinode of the primary vibration mode, and the tip of the protrusions 620c and 620d is displaced in the Z direction by this vibration. . By synthesizing these two different vibration modes with a time phase difference of 90 °, similar elliptical motion (circular motion) can be generated at the four points of the protrusions 620c and 620d of the vibrating bodies 620a and 620b.

  The moving direction of the shutter curtain unit 640 is switched by switching the rotational direction of the elliptical motion (circular motion) generated at the tips of the protrusions 620c and 620d. The resonance frequency of the vibration unit 670 varies depending on the shape, plate thickness, material, and the like of the piezoelectric elements 630a and 630b, the vibrating bodies 620a and 620b, and the optical filter 610, but is outside the audible range in order to suppress generation of unpleasant sound. It is preferable to select such a resonance frequency. In this embodiment, the example in which the first vibration mode and the second vibration mode are excited in the vibrating bodies 620a and 620b has been described. However, the present invention is not limited to this, and vibration modes of other orders may be excited. . Moreover, although the number of the protrusions 620c and 620d provided on the vibrating bodies 620a and 620b has been described as four, the number may be an even number of six or more.

  As described above in detail, according to the present embodiment, by controlling the vibration mode excited by the vibration unit 670, the dust removal function and the shutter function can be realized with one drive source, and the number of space-saving and parts-saving points can be achieved. Can be provided. In addition, since the piezoelectric elements 630 a and 630 b as vibration sources are provided on both sides of the optical filter 610, vibration larger than that in the first embodiment can be excited in the vibration unit 670. That is, the shutter curtain unit 640 can be moved at a higher speed than in the first embodiment, and the dust removal capability can be enhanced. Although the shutter curtain unit 640 of the present embodiment has been described as a single curtain, it may have a multiple curtain configuration as shown in FIG.

  FIG. 26A shows a state when the shutter curtain is opened in the two-screen structure, and FIG. 26B shows a state when the shutter curtain is closed in the two-screen structure. As shown in FIG. 26, in the case of the two-screen configuration, the shutter curtain unit is divided into left and right like 740a and 740b, and moves as separate bodies. The shutter curtain unit 740a and the protrusion 620c of the vibration unit 670 are in contact with each other in a state where pressure is generated by the biasing member 720a. Due to the elliptical motion (circular motion) of the tip of the protrusion 620c, a friction driving force is generated on the contact surface between the shutter curtain unit 740a and the protrusion 620c, and the shutter curtain unit 740a moves. The shutter curtain unit 740b and the protrusion 620d of the vibrating body 620b of the vibration unit 670 are in contact with each other in a state where pressure is generated by the biasing member 720b. Due to the elliptical motion (circular motion) of the tip of the protrusion 620d, a friction driving force is generated on the contact surface between the shutter curtain unit 740b and the protrusion 620d, and the shutter curtain unit 740b moves.

[Third Embodiment]
Third, an embodiment will be described. In particular, the difference between the third embodiment of the present invention and the second embodiment described above will be mainly described, and the description of the same (similar) parts as those of the second embodiment described above will be omitted or simplified. Turn into.

<< Electrode layout of piezoelectric element >>
FIG. 27 is a detailed view of the piezoelectric elements 830a and 830b according to the present invention. FIG. 27A shows the electrode arrangement of the piezoelectric element 830a. The piezoelectric element 830a includes three phases of A phase, B phase, and C phase. Electrodes are arranged. FIG. 27B shows the electrode arrangement of the piezoelectric element 830b, and the piezoelectric element 630b has three electrodes of D phase, E phase, and F phase. The A surface of the piezoelectric elements 830a and 830b is bonded (adhered) to the optical filter 810, and the B surface is bonded (adhered) to the vibrating bodies 820a and 820b.

<Dust removal mechanism>
By exciting vibrations in the piezoelectric elements 830a and 830b and vibrating the optical filter 810, dust and foreign matter adhering to the subject side of the optical filter 810 are removed. FIG. 28 is a side view of the optical filter 810, the piezoelectric elements 830a and 830b, and the vibrating bodies 820a and 820b. The state of the optical filter 810, the piezoelectric elements 830a and 830b, and the vibrating bodies 820a and 820b when a voltage is applied. This represents a change (vibration shape).

  The same voltage is applied to the A phase, the B phase, the D phase, and the E phase of the piezoelectric elements 830a and 830b in the same time phase, and the C phase and the F phase are set to the ground (0 [V]). Since the voltage is applied to the A phase, the B phase, the D phase, and the E phase at the same time phase, the polarity of the applied voltage is switched in the same cycle. When the voltage applied to the A phase, the B phase, the D phase, and the E phase is a positive value, the A phase, the B phase, the D phase, and the E phase of the piezoelectric elements 830a and 830b contract in the perpendicular direction, and the in-plane direction To grow. Therefore, the optical filter 810 bonded to the piezoelectric elements 830a and 830b receives a force for expanding the bonding surface in the surface direction from the piezoelectric elements 830a and 830b, and is deformed so that the bonding surface side with the piezoelectric elements 830a and 830b becomes convex. do. That is, when a positive voltage is applied to the A phase, the B phase, the D phase, and the E phase, the optical filter 810 undergoes bending deformation as indicated by the solid line of the 11th-order vibration mode in FIG.

  Similarly, if the voltages applied to the A phase, the B phase, the D phase, and the E phase are negative, the piezoelectric elements 830a and 830b are deformed in the opposite direction of expansion and contraction, and the optical filter 810 has the 11th order shown in FIG. Bending deformation occurs as shown by the two-dot chain line in the vibration mode. Accordingly, the 11th order vibration shown in FIG. 28 is applied to the optical filter 810 by applying equal voltages in the same time phase to the A phase, the B phase, the D phase, and the E phase while keeping the C phase and the F phase at the ground. It is possible to excite an odd-order standing wave oscillation such as a mode.

  Next, the same voltage in the same time phase is applied to the A phase and the B phase of the piezoelectric element 830a, and the D phase and the E phase of the piezoelectric element 830b are 180 ° in phase with the A phase and the B phase of the piezoelectric element 830a. The shifted voltage is applied, and the C phase and the F phase are set to the ground (0 [V]). That is, the time phase of the voltage applied to the piezoelectric element 830a and the voltage applied to the piezoelectric element 830b is shifted by 180 °. Therefore, the positive / negative of the voltage applied to the A phase and the B phase of the piezoelectric element 830a and the positive / negative of the voltage applied to the D phase and the E phase of the piezoelectric element 830b are always reversed.

  When the voltage applied to the A phase and the B phase of the piezoelectric element 830a is a positive value, the A phase and the B phase of the piezoelectric element 830a contract in the perpendicular direction and extend in the in-plane direction, thereby extending the optical filter 810 and the piezoelectric element. It deform | transforms so that the joint surface side with 830a may become convex. At this time, since a negative voltage is applied to the D phase and the E phase of the piezoelectric element 830b, the piezoelectric element 830b is deformed in the opposite direction of expansion and contraction with the piezoelectric element 830a, and the optical filter 810 and the piezoelectric element 830b The joint surface side is deformed so as to be concave. That is, the optical filter 810 is bent and deformed as shown by the solid line of the twelfth vibration mode in FIG.

  When the voltage applied to the A phase and the B phase of the piezoelectric element 830a is a negative value, the piezoelectric element 830a is deformed so that the joint surface side between the optical filter 810 and the piezoelectric element 830a is concave. At this time, since a positive voltage is applied to the D phase and the E phase of the piezoelectric element 830b, the piezoelectric element 830b is deformed so that the joint surface side between the optical filter 810 and the piezoelectric element 830b is convex. That is, the optical filter 810 is bent and deformed as shown by the two-dot chain line of the twelfth vibration mode in FIG.

  Therefore, the 12th order shown in FIG. 28 is added to the optical filter 810 by shifting the time phase of the voltage applied to the A phase and the B phase of the piezoelectric element 830a and the time phase of the voltage applied to the D phase and the E phase of the piezoelectric element 830b. It is possible to excite even-order standing wave vibrations such as

  As described above, the C-phase and F-phase of the piezoelectric elements 830a and 830b are grounded, and the voltage, time phase, and frequency applied to the A-phase, B-phase, D-phase, and E-phase are switched, so that the optical filter 810 has an 11th order. And the 12th vibration mode are excited. By exciting the two vibration modes in combination, foreign matters such as dust adhering to the surface of the optical filter 810 are removed.

  In this embodiment, an example in which vibration is excited in the eleventh vibration mode and the twelfth vibration mode has been described. However, the present invention is not limited to this, and vibration may be excited in other vibration modes. Three or more types of vibration modes may be used.

  As described above in detail, according to the present embodiment, by controlling the vibration mode excited by the vibration unit 870, the dust removal function and the shutter function can be realized with one drive source, and the number of parts can be saved. Can be provided. In addition, since the piezoelectric elements 830a and 830b as vibration sources are provided on both sides of the optical filter 810, vibration larger than that in the first embodiment can be excited in the vibration unit 870. That is, the shutter curtain unit 840 can be moved at a higher speed than in the first embodiment, and the dust removal capability can be enhanced.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

32 shutter curtain, 100 MPU, 103 piezoelectric element drive circuit,
400 imaging unit, 410 optical filter, 420 vibrator, 430 piezoelectric element,
440 shutter curtain unit, 470 vibration unit, 480 moving body,
520 Biasing member

Claims (5)

In the imaging apparatus having the imaging element (33),
A vibrating member (430);
An optical member (410) that is disposed on the subject side of the imaging element (33) and vibrates by receiving the vibration of the excitation member (430);
A vibrator (420) that vibrates by receiving the vibration of the vibrating member (430);
A control unit (100) for controlling the vibrating member (430);
A moving member (440) that is in contact with the vibrator (420) and moves by receiving the motion of the vibrator (420);
One surface of the excitation member (430) is attached to the optical member (410), and the opposite surface is attached to the vibrator (420).
In the vibration member (470) configured by the vibration member (430), the optical member (410), and the vibrator (420), a neutral plane of vibration bending is disposed outside the vibration member (430). And
By controlling the vibration mode of the vibrating member (430) by the control unit (100), the first mode for moving the moving member (440) and the optical member (410) are vibrated. An imaging apparatus characterized by switching between a second mode for removing foreign matter adhering to the optical member (410). The optical member is a plate-like rectangular member,
The vibrator and the vibration member are arranged on either side of the two sides facing the optical member,
2. The imaging apparatus according to claim 1, wherein during the second mode driving, the vibration mode in which the optical member has a plurality of nodes parallel to one side of the optical member is excited. The optical member is a plate-like rectangular member,
The vibrator and the vibration member are arranged in the vicinity of two opposite sides of the optical member,
2. The imaging apparatus according to claim 1, wherein during the second mode driving, the vibration mode in which the optical member has a plurality of nodes parallel to one side of the optical member is excited. The optical member is a plate-like rectangular member,
The vibrator and the vibration member are arranged in the vicinity of two opposite sides of the optical member,
When driving in the second mode, the two vibration modes of different orders are excited on the optical member by shifting the time phase by one frequency to excite vibration capable of transporting the foreign matter attached to the optical member. The imaging apparatus according to claim 1. The excitation member is a plate-like rectangular member,
The vibrator is provided with a protrusion (420a),
When driving in the first mode, a primary bending vibration mode is excited on the short side of the vibration member, and a secondary bending vibration mode is excited on the long side of the vibration member;
The primary bending vibration mode and the secondary bending vibration mode are excited with a time phase difference of 90 °,
The elliptical motion or the circular motion is generated in the protrusion by providing the protrusion at an abdomen in the primary bending vibration mode and a node in the secondary bending vibration mode. 5. The imaging device according to any one of 4.