JP4719705B2 - Imaging device and imaging unit - Google Patents

Description

  The present invention relates to an imaging device and an imaging unit incorporated in the imaging device, and more particularly to a technique for removing foreign matters such as dust adhering to the surface of an optical member disposed on a photographing optical axis.

  In an imaging apparatus such as a digital camera that captures an image by converting an image signal into an electrical signal, an imaging light beam is received by an imaging element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). Then, the photoelectric conversion signal output from the image sensor is converted into image data and recorded on a recording medium such as a memory card. In such an imaging apparatus, an optical low-pass filter and an infrared cut filter are arranged in front of the imaging element (subject side).

  In this type of image pickup apparatus, when foreign matter such as dust adheres to the cover glass of the image pickup element or the surface of these filters, the foreign matter becomes a black dot and appears in the photographed image, resulting in a deterioration in the appearance of the image.

  Especially in digital SLR cameras with interchangeable lenses, mechanical operation parts such as shutters and quick return mirrors are arranged in the vicinity of the image sensor, and foreign matters such as dust generated from these operation parts are covered by the cover of the image sensor. May adhere to glass or filter surfaces. In addition, when the lens is replaced, foreign matter such as dust may enter the camera body from the opening of the lens mount and adhere to it.

  Therefore, in Patent Document 1, a dustproof screen that transmits a photographic light beam is provided on the subject side of an image sensor, and this is vibrated by a piezoelectric element, thereby removing foreign matters such as dust attached to the surface of the dustproof screen. Proposed.

JP 2003-348403 A

  According to Patent Document 1, a voltage is applied to the piezoelectric element joined to the dust screen to remove the foreign matter adhering to the surface of the dust screen, and the dust screen is displaced in the optical axis direction by driving the piezoelectric element. The curtain vibration is generated. In such a configuration, the periphery of the dust screen is pressed by an annular part or a plurality of parts, and the dust screen is fixedly held.

  However, when the fixing and holding member of the dust screen is in an annular shape, the area in contact with the dust screen becomes large, and vibration of the dust screen is suppressed. Further, the vibration of the dustproof curtain is transmitted to the fixed holding member, and it vibrates in a plurality of natural modes of the fixed holding member, and an unpleasant sound is generated by the low order natural mode. Furthermore, when the fixed holding member of the dustproof curtain is composed of a plurality of parts, the assembly workability is lowered.

  The present invention has been made in view of the above problems, and in the configuration for removing foreign matters such as dust adhering to the surface of an optical member disposed on the photographing optical axis by vibration, the generation of unpleasant sound. In addition to eliminating the vibration, the object is to prevent vibration from being suppressed and to further improve the assemblability.

An image pickup apparatus according to the present invention includes an image pickup element that converts an optical image of a subject into an electric signal, an optical member that is disposed in front of the image pickup element and on a photographing optical axis, and that adds vibration to the optical member. And a frame-shaped holding member that holds the optical member and applies an urging force. The corner of the optical member is fixed to a corner of the holding member, and the holding member has at least one side. The portion is formed as a single part bent so as to extend in the photographing optical axis direction.
An image pickup unit of the present invention is an image pickup unit incorporated in an image pickup apparatus, and includes an image pickup element that converts an optical image of a subject into an electrical signal, and an optical element that is disposed in front of the image pickup element and on a photographing optical axis. A member, a vibration means for causing bending deformation in which unevenness of the optical member is switched, and a frame-shaped holding member that holds and biases the optical member, and a corner of the optical member is provided at a corner of the holding member. The holding member is formed as a single part bent so that at least one side extends in the direction of the photographing optical axis.

  According to the present invention, in the configuration that removes foreign matter such as dust attached to the surface of the optical member disposed on the photographing optical axis by vibration, generation of unpleasant sound is prevented and vibration is not suppressed, Further, the assembling property can be improved.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
1 and 2 are external views of a digital single-lens reflex camera according to the present embodiment. FIG. 1 is a front perspective view of the camera as viewed from the subject side, and shows a state in which the taking lens unit is removed. FIG. 2 is a rear perspective view of the camera as seen from the photographer side.

  As shown in FIG. 1, the camera body 1 is provided with a grip portion 1 a that protrudes toward the subject side so that the photographer can stably grip the camera body during shooting.

  A photographic lens unit (not shown in FIGS. 1 and 2) is detachably fixed to the mount portion 2 of the camera body 1. The mount contact 21 enables communication of a control signal, a status signal, a data signal, and the like between the camera body 1 and the photographing lens unit and supplies power to the photographing lens unit. The mount contact 21 may be configured not only for electrical communication but also for optical communication, voice communication, and the like. A lens lock release button 4 that is pushed in when removing the taking lens unit is disposed beside the mount unit 2.

  In the camera body 1, there is provided a mirror box 5 that guides a photographing light beam that has passed through the photographing lens, and a main mirror (quick return mirror) 6 is disposed in the mirror box 5. The main mirror 6 is held at an angle of 45 ° with respect to the photographing optical axis in order to guide the photographing light flux toward the penta roof mirror 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 1a on the upper side of the camera, a release button 7 as a start switch for 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 upper surface of the shooting system An operation mode setting button 10 is arranged. Some of the operation results of these operation members are displayed on the LCD display panel 9. The release button 7 is configured such that SW1 (7a in FIG. 3) is turned on in the first stroke and SW2 (7b in FIG. 3) is turned on in the second stroke. The top operation mode setting button 10 is used for setting whether the release button 7 is pressed once for continuous shooting or shooting for only one frame, setting for the self-shooting mode, and the like. The setting status is displayed on the LCD display panel 9.

  A flash unit 11 that pops up with respect to the camera body 1, a shoe groove 12 for attaching a flash, and a flash contact 13 are provided in the center of the upper part of the camera.

  A shooting mode setting dial 14 is arranged on the right above the camera.

  An external terminal lid 15 that can be opened and closed is provided on the side surface opposite to the grip 1a of the camera. Inside the external terminal lid 15, a video signal output jack 16 and a USB output connector 17 are housed as external interfaces.

  As shown in FIG. 2, a finder eyepiece window 18 is provided above the back of the camera. In addition, a color liquid crystal monitor 19 capable of displaying an image is provided near the center of the back of the camera.

  A sub operation dial 20 is arranged beside the color liquid crystal monitor 19. The sub operation dial 20 plays an auxiliary role in the function of the main operation dial 8. For example, in the AE mode of the camera, it is used to set an exposure correction amount for the appropriate exposure value calculated by the automatic exposure device. 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 photographed image displayed on the color liquid crystal monitor 19.

  Further, a main switch 43 for starting or stopping the operation of the camera and a cleaning instruction operation member 44 for operating the cleaning mode are arranged on the back of the camera. As will be described in detail later, the cleaning instruction operation member 44 is for instructing an operation to screen off foreign matters such as dust adhering to the surface of the low-pass filter.

  FIG. 3 is a block diagram showing the main electrical configuration of the digital single-lens reflex camera according to the present embodiment. In addition, the same code | symbol is attached | subjected to the part which is common in FIG. A central processing unit (hereinafter, referred to as “MPU”) 100 formed of a microcomputer built in the camera body 1 controls operation of the camera, and executes various processes and instructions for each element. The EEPROM 101a built in the MPU 100 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 shutter drive circuit 103, a video signal processing circuit 104, a switch sense circuit 105, and a photometric circuit 106. Further, an LCD drive circuit 107, a battery check circuit 108, a time measurement circuit 109, a power supply circuit 110, and a piezoelectric element drive circuit 111 are connected. These circuits operate under the control of the MPU 100.

  The MPU 100 communicates with the lens control circuit 201 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. Accordingly, the lens control circuit 201 communicates with the MPU 100 and drives 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. In FIG. 3, only one photographing lens is shown for the sake of convenience, but actually, it is constituted by a large number of lens groups.

  The AF driving circuit 202 is configured by, for example, a stepping motor, and changes the focus lens position in the photographing lens 200 under the control of the lens control circuit 201 so as to adjust the photographing light beam to be focused on the image sensor 33. The aperture driving circuit 203 is configured by, for example, an auto iris or the like, and changes the aperture 204 under the control of the lens control circuit 201 to obtain an optical aperture value.

  The main mirror 6 guides the photographic light beam passing through the photographic lens 200 to the penta roof mirror 22 and transmits a part thereof while being held at an angle of 45 ° with respect to the photographic optical axis shown in FIG. Guide to submirror 30. The sub mirror 30 guides the photographing light beam transmitted through the main mirror 6 to the focus detection sensor unit 31.

  The mirror drive circuit 101 is composed of, for example, a DC motor and a gear train, and drives the main 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 beam. When the main mirror 6 is driven, the sub mirror 30 is simultaneously moved to a position for guiding the imaging light flux to the focus detection sensor unit 31 and a position for retracting from the imaging light flux.

  The focus detection sensor unit 31 includes a field lens, a reflection mirror, a secondary imaging lens, a diaphragm, a line sensor including a plurality of CCDs, and the like that are arranged in the vicinity of an imaging surface (not shown). Perform detection. A 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.

  The penta roof mirror 22 converts and reflects the photographing light beam reflected by the main mirror 6 into an erect image. The photographer can observe the subject image from the viewfinder eyepiece window 18 through the viewfinder optical system. The penta roof mirror 22 also guides a part of the photographic light beam to the photometric sensor 23. The photometric circuit 106 obtains the output of the photometric sensor 23, converts it into a luminance signal for each area on the observation surface, and outputs it to the MPU 100. The MPU 100 calculates an exposure value based on the luminance signal.

  The shutter unit (mechanical focal plane shutter) 32 is in a state of blocking the photographing light beam during imaging standby, that is, when the photographer is observing the subject image with the viewfinder. At the time of imaging, a desired exposure time is obtained by a time difference between a front blade group and a rear blade group (not shown) according to a release signal. The shutter unit 32 is controlled by the shutter drive circuit 103 that has received an instruction from the MPU 100.

  In the imaging unit 400, the infrared cut filter 410, the optical low-pass filter 420, the piezoelectric element 430, and the imaging element 33 are unitized together with other components described later. The detailed configuration will be described later.

  The infrared cut filter 410 removes a high spatial frequency, and its surface is coated with a conductive substance in order to prevent adhesion of foreign matters. In the present embodiment, the infrared cut filter 410 corresponds to an optical member disposed on the imaging optical axis in front of the image sensor 33.

  The optical low-pass filter 420 is formed by laminating a plurality of birefringent plates and phase plates made of, for example, quartz. The optical low-pass filter 420 separates the light beam incident on the image sensor 33 into a plurality of light beams, and effectively reduces the generation of false resolution signals and false color signals.

  The piezoelectric element 430 is driven by the piezoelectric element drive circuit 111 that has received an instruction from the MPU 100, and is configured to vibrate integrally with the infrared cut filter 410. In the present embodiment, the piezoelectric element 430 corresponds to an excitation unit that applies vibration to the optical member (infrared cut filter 410) in the present invention.

  The image sensor 33 converts an optical image of a subject into an electrical signal. In this embodiment, a CMOS type imaging device is used, but there are various other types such as a CCD type, and any type of imaging device may be adopted.

  The clamp / CDS (correlated double sampling) circuit 34 performs basic analog processing before A / D conversion, and the clamp level can be changed. The AGC (automatic gain adjusting device) 35 performs basic analog processing before A / D conversion, and can change the AGC basic level. The A / D converter 36 converts the analog output signal of the image sensor 33 into a digital signal.

  The video signal processing circuit 104 performs overall image processing by hardware such as gamma / knee processing, filter processing, and information composition processing for monitor display on the 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. 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 can also perform 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. Thereby, 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 the image data input from the external interface 40 in the memory 39 and outputting the image data stored in the memory 39 from the external interface 40. The external interface 40 corresponds to the video signal output jack 16 and the USB output connector 17 in FIG. As the memory 39, a flash memory that can be attached to and detached from the camera body is used.

  The switch sense circuit 105 transmits an input signal to the MPU 100 according to the operation state of each switch. The switch SW1 (7a) is turned on by the first stroke of the release button 7. The switch SW2 (7b) is turned on by the second stroke of the release button 7. When the switch SW2 (7b) 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 cleaning instruction operation member 44 are connected.

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

  The battery check circuit 108 performs a battery check according to an instruction from the MPU 100 and transmits the detection result to the MPU 100. The power supply unit 42 supplies power to each element of the camera.

  The time measuring circuit 109 measures the time and date from when the main switch 43 is turned off to when it is turned on, and transmits the measurement result to the MPU 100 in accordance with an instruction from the MPU 100.

  Hereinafter, the imaging unit 400 will be described with reference to FIGS. FIG. 4 is an exploded perspective view showing a schematic configuration inside the camera for explaining the peripheral structure of the imaging unit 400. A mirror box 5 and a shutter unit 32 are arranged in this order from the subject side on the subject side of the main body chassis 300 that is the skeleton of the camera body. An imaging unit 400 is disposed on the photographer side of the main body chassis 300. The image pickup unit 400 is adjusted and fixed so that the image pickup surface of the image pickup element 33 is spaced a predetermined distance from and parallel to the attachment surface of the mount unit 2 that serves as a reference to which the photographing lens unit is attached.

  FIG. 5 is an exploded perspective view showing the configuration of the imaging unit 400. The imaging unit 400 includes a vibration unit 470 including an infrared cut filter 410, a frame member 450, and an imaging element unit 500 including an imaging element 33.

  First, the image sensor unit 500 will be described with reference to FIGS. The image sensor unit 500 includes an image sensor 33, an image sensor holding member 510 that holds the image sensor 33, a circuit board 520, a shield case 530, a light shielding member 540, an optical low-pass filter 420, and an optical low-pass filter holding member 550.

  The imaging element holding member 510 is made of metal or the like, and includes left and right positioning pins 510a for positioning with the holding member 460 of the vibration unit 470, and screw holes 510b for fixing the circuit board 520 and the shield case 530 with screws. Left and right screw holes 510c for fixing the holding member 460 of the vibration unit 470 with screws are provided.

  An electric circuit of an imaging system is mounted on the circuit board 520, and a screw escape hole 520a is provided. The shield case 530 is formed of metal or the like and is provided with a screw hole 530a. The circuit board 520 and the shield case 530 are secured to the image sensor holding member 510 with screws using screw escape holes 520a, screw holes 530a, and screw holes 510b. The shield case 530 is connected to a ground potential on the circuit in order to protect the electric circuit from static electricity.

  The light shielding member 540 has an opening corresponding to the effective area of the photoelectric conversion surface of the image sensor 33, and a double-sided tape is fixed to the subject side and the photographer side. The optical low-pass filter holding member 550 is fixed to the cover glass 33 a of the image sensor 33 by the double-sided tape of the light shielding member 540. The optical low-pass filter 420 is positioned at the opening of the optical low-pass filter holding member 550, and is fixed and held on the light shielding member 540 with double-sided tape.

  6 is a cross-sectional view taken along line AA in FIG. The surface on the subject side of the light shielding member 540 is in contact with the optical low-pass filter 420, and the surface on the photographer side is in contact with the cover glass 33 c of the image sensor 33. Double-sided tape is fixed to the object side and the photographer side of the light shielding member 540, and the optical low-pass filter 420 is fixed and held on the cover glass 33c of the image sensor 33 by the double-sided tape of the light shielding member 540. As a result, the space between the optical low-pass filter 420 and the cover glass 33a of the image sensor 33 is sealed by the light shielding member 540, thereby forming a sealed space that prevents entry of foreign matters such as dust.

  Next, the vibration unit 470 will be described with reference to FIGS. The vibration unit 470 includes an infrared cut filter 410, a piezoelectric element 430, and a holding member 460.

  The holding member 460 is formed as a single part from a material (conductive member) having a spring property (elasticity) such as metal, and positioning holes 460a and screw holes 460b are provided in the left and right arms. The four corners of the infrared cut filter 410 (the corners of the four corners) are fixed to the four corners of the holding member 460 with a conductive adhesive. In this case, as will be described later, at the four corners of the holding member 460, locations near the four corners of the infrared cut filter 410 and including vibration nodes are fixed. The upper and lower sides 460c of the holding member 460 are bent so as to extend in the direction of the photographing optical axis so as to connect the fixing portions. In other words, the holding member 460 is formed from a single plate material, the portion fixed to the infrared cut filter 410 has a surface that is perpendicular to the imaging optical axis, and the surfaces of the upper and lower side portions 460c are captured. It can be said that it is bent so as to be parallel to the optical axis. The holding member 460 is a frame-like holding member that holds the optical member (infrared cut filter 410) in the present invention and applies an urging force. The urging force acts so that the infrared cut filter 410 is urged toward the image sensor unit 500. Further, the bent upper and lower sides 460c are arranged with a gap from the infrared cut filter 410 so as not to generate a sound by shaking directly during vibration.

  The vibration unit 470 is positioned with respect to the image sensor unit 500 using the positioning holes 460a of the holding member 460 and the positioning pins 510a of the image sensor holding member 510. In this state, the vibration unit 470 is locked to the image sensor unit 500 with screws using the screw holes 460b and the screw holes 510c so as to sandwich the frame member 450. As a result, the electricity charged on the surface of the infrared cut filter 410 coated with the conductive material can be released from the holding member 410 to the circuit board 520 via the imaging element holding member 510 and the shield case 530, and foreign matter adheres. Can be prevented.

  The frame member 450 is formed of a soft material such as rubber and serves as a vibration absorbing material for the infrared cut filter 410 and forms a sealed space between the infrared cut filter 410 and the optical low-pass filter 420. Note that the frame member 450 is preferably formed of a thick member or a member having low hardness, and abuts on a vibration node of the infrared cut filter 410 described later in order to increase the vibration absorption of the infrared cut filter 410. .

  Further, the surface of the frame member 450 on the subject side is in contact with the infrared cut filter 410, and the surface on the photographer side is in contact with the optical low-pass filter 420. Since the infrared cut filter 410 is biased toward the image sensor unit 500 by the spring property of the holding member 460, the infrared cut filter 410 is in close contact with the frame member 450 without any gap. In close contact. As a result, the space between the infrared cut filter 410 and the optical low-pass filter 420 is sealed by the frame member 450, and a sealed space that prevents entry of foreign matters such as dust is formed.

  As shown in FIG. 7, the piezoelectric element 430 is fixed to the end portion of the rectangular infrared cut filter 410 with an adhesive or the like. In the present embodiment, a total of two identically shaped piezoelectric elements 430 are fixed to both ends of the infrared cut filter 410.

  FIG. 8 is a diagram for explaining the piezoelectric element 430. As shown in the figure, the A surface of the piezoelectric element 430 is divided into a + phase for exciting the infrared cut filter 410 to bend and a G phase. Further, the B surface of the piezoelectric element 430 is electrically connected to the G phase of the A surface by a conductive material (not shown) or the like, and is kept at the same potential as the G phase. A conductive connecting member such as a flexible print (not shown) is fixed to the A surface by adhesion or the like, and a predetermined voltage can be independently applied to the + phase and the G phase. The B surface is fixed to the infrared cut filter 410 by bonding or the like, and the piezoelectric element 430 and the infrared cut filter 410 are configured to move integrally.

  Next, with reference to FIG. 9, the mechanism in which the infrared cut filter 410 vibrates and its vibration shape will be described. First, deformation of the piezoelectric element 430 when a positive voltage is applied to the + phase of the piezoelectric element 430 through the conductive connecting member and the G phase is set to the ground (0 V) will be described.

  FIG. 9 is a side view showing the vibration shape of the infrared cut filter 410. When the voltage described above is applied, the + phase of the piezoelectric element 430 contracts in the perpendicular direction and extends in the in-plane direction. Therefore, the infrared cut 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. Therefore, when the voltage described above is applied to the + phase, the infrared cut filter 410 undergoes bending deformation as shown by the solid line in FIG. Similarly, if the voltage applied to the + phase is negative, the piezoelectric element 430 deforms in the opposite direction of expansion and contraction as described above, and the infrared cut filter 410 exhibits bending deformation as indicated by the broken line in FIG.

  When positive and negative voltages are applied to the + phases of the two piezoelectric elements 430 at the same phase frequency, an even-order mode (for example, an 18th-order mode shown in FIG. 9A) is generated. Further, when positive and negative voltages are applied to the + phases of the two piezoelectric elements 430 at a frequency shifted in phase by a half wavelength, an odd-order mode (for example, a 19th-order mode shown in FIG. 9B) is generated. Then, as shown in FIG. 9, in the bending vibration, vibration nodes (for example, d1, d2, D1, and D2) are generated, and the amplitude of the vibration nodes is substantially zero.

  That is, when the voltage applied to the + phase of the piezoelectric element 430 is periodically switched between positive and negative while the potential of the B-phase electrode is kept at the ground, the infrared cut filter 410 generates bending vibration in which irregularities are periodically switched to a wave shape. Arise. By setting the frequency of the periodic voltage in the vicinity of the resonance frequency of the natural mode of the infrared cut filter 410, a large amplitude can be obtained with a smaller voltage. The resonance frequency of the eigenmode of the infrared cut filter 410 varies depending on the shape, plate thickness, material, etc. of the infrared cut filter 410, but the eigenmode is selected so that the resonance frequency is outside the audible range so as not to generate unpleasant sound. It is preferable.

  In addition, in this embodiment, although demonstrated as a structure which generate | occur | produces the vibration of 18th-order mode or 19th-order mode, you may make it generate | occur | produce not only this but vibration other than this, and three or more types of vibration A mode may be used.

  FIGS. 10A and 10B are front views showing the vibration shape of the vibration unit 470, where FIG. 10A shows a state in which vibrations in the 18th order mode and FIG. Each dotted line extending up and down represents a vibration node (for example, d1, d2, D1, and D2). As shown in FIGS. 10A and 10B, the infrared cut filter 410 is fixed to the holding member 460 at a location including a vibration node. Since the vibration of the node is substantially zero and the amplitude is small in the vicinity thereof, the attenuation of the vibration of the infrared cut filter 410 can be reduced.

  Further, in the infrared cut filter 410, a range for generating a large amplitude and removing a foreign substance is a range (effective range) through which a light beam incident on the effective region of the image sensor 33 passes. The holding member 460 is fixed in the vicinity of the four corners that are outside the effective range of the infrared cut filter 410. Thereby, dust can be efficiently removed without impeding the vibration for removing the foreign matter adhering to the effective range.

  The upper and lower sides 460c of the holding member 460 are bent so as to extend in the photographing optical axis direction. As a result, the strength of the holding member 460 in the direction of the photographing optical axis is increased, and the dimensional accuracy can be maintained without being bent by mistake during assembly, and can be formed as a single component. Therefore, the assemblability is improved as compared with the case of handling a plurality of parts. Further, the vibration transmitted to the side portion 460c is the horizontal plane direction (photographing optical axis direction) indicated by the arrow A. The horizontal plane direction has higher rigidity than the vertical direction, and the vibration amplitude is very small and unique. The resonant frequency of the mode is outside the audible range, and no unpleasant sound is generated.

  Next, an operation for removing foreign matters such as dust attached to the surface of the infrared cut filter 410 in the present embodiment will be described. When the cleaning instruction operation member 44 is operated, the camera body 1 is shifted to the cleaning mode in response to the instruction to start the cleaning mode. In the present embodiment, the cleaning instruction operation member 44 is provided, but the present invention is not limited to this. For example, the cleaning instruction operation member 44 is not limited to a mechanical button, but may be an instruction using a cursor key, an instruction button, or the like on a menu screen displayed on the color liquid crystal monitor 19.

  Further, the transition to the cleaning mode may be performed automatically during a normal camera sequence such as when the power is turned on, or may be performed based on the number of times of shooting, the date, and the like. .

  The power supply circuit 110 supplies power necessary for the cleaning mode to each part of the camera body 1 as necessary. 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 cleaning mode start signal, the MPU 100 sends a drive signal to the piezoelectric element drive circuit 111. When receiving the drive signal from the MPU 100, the piezoelectric element drive circuit 111 generates a periodic voltage that excites bending vibration of the infrared cut filter 410 and applies it to the piezoelectric element 430. The piezoelectric element 430 expands and contracts according to the applied voltage, and the infrared cut filter 410 performs bending vibration.

  As mentioned above, although this invention was demonstrated with various embodiment, this invention is not limited only to these embodiment, A change etc. are possible within the scope of the present invention. For example, in the above embodiment, the infrared cut filter 410 is configured to excite bending vibration, but the optical member referred to in the present invention is not limited to the infrared cut filter 410. A filter having a substantially rectangular shape and modulating an incident light beam into a desired light beam, for example, an optical low-pass filter or a birefringent plate formed by bonding a birefringent plate, a phase plate and an infrared cut filter 410 The phase plate alone may be configured to excite bending vibration.

  In the above-described embodiment, the infrared cut filter 410 is fixed to the holding member 460 with a conductive adhesive, and the holding member 460 and the surface of the infrared cut filter 410 are electrically connected. However, the present invention has such a configuration. It is not limited to. That is, as the conductive fixing means referred to in the present invention, for example, as shown in FIG. 11, the infrared cut filter 410 may be fixed to the holding member 460 by the conductive double-sided tape 440. In this case, the conductive double-sided tape 440 has a function of absorbing vibration and has an effect of not transmitting vibration to the holding member 460. That is, the vibration of the infrared cut filter 410 can be generated more efficiently.

1 is a front perspective view of a digital single-lens reflex camera according to an embodiment of the present invention. It is a back side perspective view of the digital single-lens reflex camera which concerns on embodiment of this invention. 1 is a block diagram showing an electrical configuration of a digital single-lens reflex camera according to an embodiment of the present invention. It is a disassembled perspective view which shows schematic structure inside the camera for demonstrating the periphery structure of an imaging unit. It is a disassembled perspective view which shows the structure of an imaging unit. It is sectional drawing which follows the AA line of FIG. It is a perspective view of a vibration unit. It is a figure for demonstrating a piezoelectric element. It is a side view which shows the vibration shape when an infrared cut filter vibrates, (a) is a figure which shows the state of 18th-order mode, (b) is a figure which shows the state of 19th-order mode. It is a front perspective view when an infrared cut filter vibrates, (a) is a figure which shows the state of 18th-order mode, (b) is a figure which shows the state of 19th-order mode. It is a disassembled perspective view which shows the structure of the vibration unit in other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera body 2 Mount part 33 Image pick-up element 400 Image pick-up unit 410 Infrared cut filter 430 Piezoelectric element 450 Frame member 460 Holding member 460a Positioning hole 460b Screw hole 460c Side part 470 Vibration unit 500 Image pick-up element unit 510 Image pick-up element holding member 520 Circuit board 530 Shield case 540 Shading member 550 Optical low-pass filter holding member

Claims (8)

An image sensor that converts an optical image of a subject into an electrical signal;
An optical member disposed on the imaging optical axis in front of the imaging element;
Excitation means for applying vibration to the optical member;
A frame-shaped holding member that holds the optical member and applies an urging force;
The corner portion of the optical member is fixed to the corner of the holding member, and the holding member is formed as a single part bent so that at least one side portion extends in the photographing optical axis direction. An imaging apparatus characterized by the above.   The imaging apparatus according to claim 1, wherein the vibration member causes the optical member to be bent and deformed so that the corrugations are changed into a wave shape.   The imaging apparatus according to claim 1, wherein a corner portion of the optical member is fixed to a corner of the holding member by a conductive fixing means.   The imaging apparatus according to claim 1, wherein the holding member is a conductive member.   The imaging apparatus according to claim 1, wherein a surface of the optical member is coated with a conductive substance.   The imaging apparatus according to claim 1, wherein the optical member has a rectangular shape and modulates an incident light beam and emits the light beam.   The imaging apparatus according to claim 1, wherein the optical member is an infrared cut filter. An imaging unit incorporated in an imaging device,
An image sensor that converts an optical image of a subject into an electrical signal;
An optical member disposed on the imaging optical axis in front of the imaging element;
Vibration means for causing bending deformation in which the unevenness of the optical member is switched;
A frame-shaped holding member that holds and urges the optical member;
The corner portion of the optical member is fixed to the corner of the holding member, and the holding member is formed as a single part bent so that at least one side portion extends in the photographing optical axis direction. An imaging unit characterized by.

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