JP5484084B2 - Imaging unit and imaging apparatus - Google Patents

Description

  The present invention relates to an image pickup unit and an image pickup apparatus that hold an optical member and an image pickup element disposed on an optical axis with a holding member.

  In an imaging device such as a digital camera that captures a subject image by converting it into an electrical signal, the imaging light beam is received by the imaging device, a photoelectric conversion signal output from the imaging device is converted into image data, and a memory card, etc. Record on a recording medium. As the imaging element, a CCD (Charge Coupled Device), a CMOS sensor (Complementary Metal Oxide Semiconductor), or the like is used.

  In such an image pickup apparatus, an optical low-pass filter and an infrared absorption filter are arranged on the subject side of the image pickup element. When foreign matter such as dust adheres to the surface of these filters, the attached portion becomes a black dot. The image appears in the photographed image, and the image looks poor.

  In particular, in a digital single lens reflex camera 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 captured by the image sensor and filter. May adhere to the surface of 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.

  In order to avoid such a phenomenon, Patent Document 1 proposes a technique for removing foreign matters such as dust attached to the surface of the optical element by vibrating the optical element on the subject side of the image pickup element with a piezoelectric element. Has been. Here, the optical element unit and the imaging element unit are sealed with a double-sided adhesive rubber sheet.

JP 2008-26564 A

  However, in the method of Patent Document 1, since the image sensor is attached to the image sensor holding member supported by the mirror box by a leaf spring, there is a problem that the number of parts is large and the number of assembly steps is increased. Yes.

  In addition, since the optical element unit and the imaging element unit are sealed with a double-sided adhesive rubber sheet, there is a problem that it is difficult to peel off the double-sided adhesive during rework.

  The present invention has been made in view of the above points, and an object of the present invention is to reduce the number of parts and the number of assembly steps, and to improve reworkability.

Imaging unit of the present invention, an imaging element, an imaging element holding member for holding the image pickup element, and the optical engine member, the first face the image pickup element holding member is fixed, the rear surface of the first surface An optical member holding member that holds the optical member on the second surface, and the imaging element holding member that is formed on the first surface of the optical member holding member and holds the imaging element. A first sealing portion that forms a first sealed space between the imaging element and the optical member holding member when fixed to the first surface; and the second surface of the optical member holding member. A second sealing portion that is formed and forms a second sealed space between the optical member and the optical member holding member when the optical member is held on the second surface; The first sealing portion and the second sealing portion may be in an optical axis direction or a direction perpendicular to the optical axis. So as not to overlap the stomach, characterized in that it is integrally formed on the optical member holding member are separated from each other.

  According to the present invention, the number of parts and the number of assembly steps can be reduced, and the reworkability can be improved.

It is a front side perspective view of the digital single-lens reflex camera concerning this embodiment. It is a back side perspective view of the digital single-lens reflex camera concerning this embodiment. It is a block diagram which shows the electrical constitution of the digital single-lens reflex camera which concerns on this embodiment. It is a disassembled perspective view which shows schematic structure inside a camera for showing the surrounding structure of an imaging unit. It is a disassembled perspective view which shows the structure of an imaging unit. It is a figure for demonstrating the detail of a piezoelectric element. It is a figure which shows the structure of a holding member and a sealing part. It is the perspective view which decomposed | disassembled the image pick-up element unit from the image pick-up unit. It is the perspective view which decomposed | disassembled the optical low-pass filter from the imaging unit. It is a flowchart for demonstrating the operation | movement which removes foreign materials, such as dust adhering to the surface of an optical low-pass filter.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
<1. Overall schematic configuration of the camera (FIGS. 1 to 3)>
(1-1. Mechanical configuration (FIGS. 1 and 2))
In the present embodiment, the following digital single-lens reflex camera can be configured by applying the present invention. First, a mechanical configuration of the overall schematic configuration of the camera will be described.

  FIG. 1 is an external view of a digital single-lens reflex camera according to the present embodiment, and is a perspective view of the camera as viewed from the front side (subject side), showing a state in which the taking lens unit is removed. 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 (200a) (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 so that not only electrical communication but also optical communication, voice communication, and the like are possible. 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 upper right side of 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.

  FIG. 2 is an external view of the digital single-lens reflex camera according to the present embodiment, and is a perspective view of the camera viewed from the photographer side (back side). 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 optical low-pass filter 410. The cleaning mode can be arbitrarily operated using the cleaning instruction operation member 44, and can be automatically operated when the main switch 43 is turned on, turned off, or both.

(1-2. Electrical configuration (Fig. 3))
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 100a 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 sensor circuit 105, and a photometric circuit 106. In addition, 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 200a 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 200a 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 200a via the AF driving circuit 202 and the diaphragm driving circuit 203. In FIG. 3, only one photographing lens 200 is shown for convenience, but in actuality, it is constituted by a large number of lens groups.

  The AF drive circuit 202 is constituted by, for example, a stepping motor, and adjusts the focus of the photographing light flux to the imaging element 33 by changing the focus lens position in the photographing lens 200 under the control of the lens control circuit 201. 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 photographic 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 photographing light beam to the focus detection sensor unit 31 and a position for retracting from the photographing light beam.

  The focus detection sensor unit 31 is composed of a field lens, a reflection mirror, a secondary imaging lens, a diaphragm, a line sensor composed of a plurality of CCDs, etc. arranged in the vicinity of an imaging surface (not shown), and a phase difference type focus detection. I do. 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 has a shutter front curtain in a light shielding position and a shutter rear curtain in an exposure position when a photographer observes a subject image with a finder. Next, at the time of shooting, the shutter front curtain travels from the light shielding position to the exposure position, passes light from the subject, and the image sensor 33 captures an image. After the elapse of a desired shutter time, the shutter trailing curtain moves from the exposure position to the light shielding position, and the photographing is completed. The shutter unit 32 is controlled by the shutter drive circuit 103 that has received a command from the MPU 100.

  The imaging unit 400 is obtained by unitizing an imaging element unit 33a that is an imaging means including an optical low-pass filter 410, a piezoelectric element 430, and an imaging element 33 together with other components to be described later.

  The image sensor 33 photoelectrically converts a subject image. In this embodiment, a CMOS sensor is used, but there are various other types such as a CCD type, a CMOS type, and a CID type. A device may be adopted. The optical low-pass filter 410 disposed in front of the image sensor unit 33a is a single birefringent plate made of quartz and has a rectangular shape. The piezoelectric element 430 is a single-plate piezoelectric element (piezo element), and is configured to vibrate by the piezoelectric element driving circuit 111 in response to an instruction from the MPU 100 and transmit the vibration to the optical low-pass filter 410.

  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 sensor 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 (half press) of the release button 7. The switch SW2 (7b) is turned on by the second stroke (full press) 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 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.

<2. Specific Configuration of Imaging Unit (FIGS. 4 to 9)>
(2-1. Schematic configuration of imaging unit inside camera (FIG. 4))
Next, a schematic configuration of the imaging unit 400 in the present embodiment will be described. As shown in FIG. 4, the mirror box 5 and the 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 parallel to the attachment surface of the mount portion 2 as a reference to which the photographing lens unit is attached with a predetermined distance.

(2-2. Configuration of Imaging Unit (FIG. 5))
5A is a perspective view of the imaging unit 400 as viewed from the subject side, and FIG. 5B is a perspective view as viewed from the photographer side. As shown in FIGS. 5A and 5B, the optical low-pass filter 410 is a single birefringent plate made of quartz and has a rectangular shape. The optical low-pass filter 410 corresponds to the optical member referred to in the present invention. The optical low-pass filter 410 has a peripheral portion 410b in which the piezoelectric element 430 is disposed on one side of the effective imaging area 410a, and the direction orthogonal to the imaging optical axis center (camera horizontal direction) is asymmetric. An optical coating is applied to the surface of the optical low-pass filter 410 as described above.

  The piezoelectric element 430 has a single-plate rectangular strip shape, and is arranged so that the long side of the piezoelectric element 430 is parallel to the short side (side) of the optical low-pass filter 410 at the peripheral portion 410 b of the optical low-pass filter 410. To be adhered and held (attached). This piezoelectric element 430 corresponds to the vibration means in the present invention. The piezoelectric element 430 is attached in parallel to one of the four sides on the optical low-pass filter 410 and vibrates the optical low-pass filter 410 in a wave shape so as to have a plurality of nodes parallel to the one side.

  Reference numeral 610 denotes a resin or metal optical member holding member which is a first holding member, which has a substantially rectangular opening 610a and holds the optical low-pass filter 410 and the optical member 460. The optical member holding member 610 is integrally molded with a first sealing portion 620 on the photographer side and a second sealing portion 630 on the subject side. These sealing portions 620 and 630 are elastic members, and may be rubber or elastomer, or may be a polymer such as urethane foam or plastic as long as it is an elastic body. In addition, the optical member holding member 610 and the sealing portions 620 and 630 have been described as being integrally molded, but may be separated.

  The optical member 460 is an optical member in which a phase plate (depolarization plate), an infrared cut filter, and a birefringent plate having a refractive direction different by 90 ° with respect to the optical low-pass filter 410 are bonded together so as to block the opening 610a. It is bonded and fixed to the optical member holding member 610.

  An imaging element holding member 710 as a second holding member has a substantially rectangular opening 710a, holds the imaging element unit 33a on the photographer side, and holds the optical member holding member 610 on the subject side. To do. The image sensor unit 33 a is fixed to the image sensor holding member 710 with screws 500. The material of the image sensor holding member 710 may be resin or metal. However, if the image sensor holding member 710 is made of metal, the effect of releasing the heat of the image sensor 33 is increased, which is effective in preventing image deterioration due to heat generation of the image sensor 33.

  Reference numeral 440 denotes an urging member that abuts on the optical low-pass filter 410 at four locations outside the effective imaging area 410a of the optical low-pass filter 410 and urges the photographer side in the optical axis direction. The urging member 440 and the optical member holding member 610 are fixed to the image sensor holding member 710 with screws 510. The optical member holding member 610 is also fixed to the image sensor holding member 710 with screws 520. In this way, the optical low-pass filter 410 is held in close contact with the optical member holding member 610 by the second sealing portion 630, and the imaging element unit 33 a is attached to the first sealing portion 620 of the optical member holding member 610. In close contact.

  By adopting the above configuration, the optical low-pass filter 410 is sandwiched between the biasing member 440 and the second sealing portion 630 and is supported so as to freely vibrate.

  Reference numeral 470 denotes a piezoelectric element flexible printed circuit board for applying a voltage to the piezoelectric element 430, and is bonded and fixed to the piezoelectric element 430. The piezoelectric element 430 mainly expands and contracts in a direction orthogonal to the optical axis by applying a voltage, and resonates (vibrates) the optical low-pass filter 410. Thereby, the foreign material adhering to the surface of the optical low-pass filter 410 can be eliminated.

(2-3. Configuration of piezoelectric element (FIG. 6))
As shown in FIG. 6, the B surface of the piezoelectric element 430 is divided into a + phase for exciting standing wave vibration in the optical low-pass filter 410 and a G phase. In addition, the C surface of the piezoelectric element 430 is electrically connected by a conductive material (not shown) or the like and is kept at the same potential as the G phase of the B surface. A flexible printed circuit board 470 for piezoelectric elements is fixed to the B surface by bonding or the like, and a predetermined voltage can be independently applied to the + phase and the G phase. The C surface is fixed to the optical low-pass filter 410 by bonding or the like, and the piezoelectric element 430 and the optical low-pass filter 410 are configured to move integrally.

(2-4. Configuration of sealing portion (FIG. 7))
Next, the configuration of the optical member holding member 610 and the sealing portions 620 and 630 will be described in detail with reference to FIG. 7 is a cross-sectional view taken along line AA in FIG.

  The first sealing portion 620 is disposed so as to surround the opening 610a of the optical member holding member 610 on the photographer side. The first sealing portion 620 is integrated with the optical member holding member 610 by integral molding, and the surface on the photographer side comes into contact with the image sensor unit 33a. The first sealing portion 620 is an elastic member such as rubber or elastomer, and can be integrated with the optical member holding member 610 by two-color molding.

  In the image sensor unit 33 a, a screw fastening portion 33 b is fixed to the image sensor holding member 710 with a screw 500. The first sealing portion 620 is elastically deformed until the optical member holding member 610 and the imaging element unit 33a are at a predetermined interval by screwing the imaging element unit 33a to the imaging element holding member 710, It is possible to seal the space on the image sensor unit 33a side. The contact portion of the first sealing portion 620 with the image sensor unit 33a is formed in a convex shape having a cross section of one or more peaks. Further, the optical member 460 is held by being bonded to the outer periphery of a predetermined holding portion of the optical member holding member 610. As a result, the space surrounded by the optical member holding member 610, the imaging element unit 33a, the first sealing portion 620, and the optical member 460 is sealed, and a sealed space that prevents entry of foreign matters such as dust is formed.

  On the other hand, the second sealing portion 630 is disposed so as to surround the opening 610a of the optical member holding member 610 on the subject side. The second sealing portion 630 is arranged offset with respect to the first sealing portion 620 in the direction away from the optical axis (outward direction). The second sealing portion 630 is also integrated with the optical member holding member 610 by integral molding, and the surface on the subject side comes into contact with the optical low-pass filter 410. Since the optical low-pass filter 410 is urged toward the image sensor unit 33 a by the elasticity of the urging member 440, the second sealing portion 630 is elastically deformed, and the optical low-pass filter 410 and the optical member holding member 610 are deformed. And adheres without gaps. As a result, the space surrounded by the optical low-pass filter 410, the optical member holding member 610, the second sealing portion 630, and the optical member 460 is sealed, and a sealed space that prevents entry of foreign matters such as dust is formed.

  The optical low-pass filter 410 and the second sealing portion 630 also serve as a vibration transmission member when the piezoelectric element 430 applies vibrations, and removes foreign matters attached to the surface of the optical low-pass filter 410.

(2-5. Disassembly and assembly of the imaging unit (FIGS. 8 and 9))
By the way, although the optical member holding member 610 and the plurality of optical members 410 and 460 or the imaging element unit 33a form a sealed space with the above-described configuration, foreign matter may inevitably be mixed in the assembly process. For this reason, when foreign matter intrusion is found by inspection in the completion process of the imaging unit 400, it is required to disassemble the imaging unit 400, clean the foreign matter, and reassemble.

  Disassembly and assembly of the imaging unit in the present embodiment will be described. 8A and 8B, reference numeral 810 denotes a unit obtained by removing the imaging element unit 33a from the imaging unit 400. By forming a sealed space with the first sealing portion 620, the image sensor unit 33a can be removed simply by removing the screw 500. Furthermore, it can be reassembled using screws 500. When the image pickup element unit and the optical element unit are closely fixed with an adhesive sheet or the like as in the prior art, there are many problems such as damage to the member when peeled off during rework and the adhesive sheet cannot be reused. Compared with the prior art, by applying the present invention, the steps of disassembly, foreign matter cleaning, and assembly can be easily performed.

  9A and 9B, reference numeral 820 denotes a unit obtained by removing the biasing member 440, the optical low-pass filter 410, the piezoelectric element 430, and the piezoelectric element flexible printed circuit board 470 from the imaging unit 400. Even when foreign matter intrusion in the second sealing portion 630 and the optical low-pass filter 410 is confirmed, it is possible to clean the inside of the sealed space again by removing the screw 510 and the biasing member 440.

  As described above, the first sealing portion 620 and the second sealing portion 630 are integrally molded as a configuration in which the optical member holding member 610 holds the plurality of optical members 410 and 460 and the imaging element unit 33a. It is possible to reduce the number of parts and assembly man-hours. In addition, even when foreign matter is confirmed to enter the sealed space during the assembly process, as described above, it can be easily disassembled, cleaned, and assembled, thereby improving workability.

<3. Foreign matter removal operation (FIG. 10)>
Next, with reference to FIG. 10, an operation for removing foreign matters such as dust attached to the surface of the optical low-pass filter 410 will be described. First, in step S1, 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 cleaning instruction operation member 44 has been operated by the photographer. 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 cleaning 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 shift to the cleaning mode is not limited to a mechanical button, but is an instruction from a menu displayed on the color liquid crystal monitor 19 using a cursor key, an instruction button, or the like. Also good.

  Next, in step 4, in response to a command to start the cleaning mode, the camera body 1 is shifted to the cleaning mode. First, the power supply circuit 110 supplies power necessary for the cleaning mode 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 cleaning mode start signal, the MPU 100 sends a drive signal to the piezoelectric element drive circuit 111. When the piezoelectric element drive circuit 111 receives a drive signal from the MPU 100, the piezoelectric element drive circuit 111 generates a periodic voltage that excites the standing wave vibration of the optical low-pass filter 410 and applies it to the piezoelectric element 430. The periodic voltage is sequentially changed within a certain range of frequencies including the frequency for exciting the standing wave oscillation. The piezoelectric element 430 expands and contracts according to the applied voltage, and causes the optical low-pass filter 410 to generate standing wave vibration.

  When the cleaning mode ends, the process proceeds to step 5. In step 5, the camera operation is performed by receiving signals from the switch SW1 (7a), the switch SW2 (7b), the main operation dial 8, the sub operation dial 20, the shooting mode setting dial 14, and other switches. The camera operation is a generally known mode for taking and setting a camera, and a detailed description thereof is omitted here.

  Next, in step 6, 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. If not turned off, the process returns to step 3.

  Next, in step 7, after executing the same cleaning mode as in step 4, the process proceeds to step 8. Here, in the cleaning mode in Step 7, parameters such as the driving frequency, driving 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. There is no.

  In step 8, the MPU 100 controls to terminate each circuit, stores necessary information in the EEPROM 100a, and controls the power supply circuit 110 to turn off the power supply to each circuit. Do.

  As described above, the cleaning mode is executed 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 of removing the foreign matter adhering to the surface of the optical low-pass filter 410 is performed.

  Here, there are various kinds of foreign matters attached to the surface of the optical low-pass filter 410, but generally, if left for a long time with foreign matters attached, it may be difficult to remove even if vibration is applied in the cleaning mode. Elucidated experimentally. This is thought to be due to increased adhesion of liquid bridging force due to condensation due to changes in the environment (temperature and humidity), and adhesion due to repeated swelling and drying of dust due to environmental changes. It is done. In addition, in an elastic material such as rubber, oil and fat contained in the rubber bleeds and adheres over time. Therefore, if the cleaning mode is executed at the timing of power-off operation, which is likely to be unused for a long period of time, it is highly likely that it is difficult to remove foreign substances. It is more efficient and effective than the operation timing.

  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 cleaning mode is performed in advance.

  The optical member referred to in the present invention is not limited to the optical low-pass filter 410. For example, the material of the birefringent plate may be lithium niobate instead of quartz. Further, an optical low-pass filter constituted by bonding a birefringent plate, a phase plate, and an infrared absorption filter, or an infrared absorption filter alone may be vibrated. Moreover, you may make it the structure which vibrates to the glass plate single-piece | unit arrange | positioned in front of the birefringent plate.

  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.

33: Image sensor, 33a: Image sensor unit, 400: Image sensor unit, 410: Optical low-pass filter, 430: Piezoelectric element, 460: Optical member, 470: Flexible printed circuit board for piezoelectric element, 500: Screw, 610: Holding optical member Member, 710: imaging element holding member, 620: first sealing portion, 630: second sealing portion

Claims (4)

An image sensor ;
An image sensor holding member for holding the image sensor;
And the light faculty member,
The image sensor holding member is fixed to the first surface, and the optical member holding member that holds the optical member on the second surface which is the back surface of the first surface;
The imaging element holding member formed on the first surface of the optical member holding member and holding the imaging element is fixed between the imaging element and the optical member holding member when the imaging element holding member is fixed to the first surface. A first sealing portion forming a first sealed space in
Formed on the second surface of the optical member holding member, and when the optical member is held on the second surface, a second sealed space is formed between the optical member and the optical member holding member. A second sealing portion to be
The first sealing portion and the second sealing portion are separated from each other and formed integrally with the optical member holding member so as not to overlap each other in the optical axis direction and the direction perpendicular to the optical axis. An imaging unit characterized by that. The image pickup unit according to claim 1, wherein the image pickup element is fixed to the image pickup element holding member with a screw. The imaging unit according to claim 1, wherein the imaging element holding member is made of metal.   An imaging apparatus comprising the imaging unit according to claim 1.

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