JP2004264580A - Electronic imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic imaging apparatus which does not bring about a deterioration in picture quality and in which wasteful power consumption is eliminated. <P>SOLUTION: The electronic imaging apparatus is equipped with a photographic optical system 12a which forms the optical image of a subject, an imaging device 27 which converts the optical image into an electric signal, a dust-proof filter 21 which is arranged between the photographic optical system 12a and the imaging device 27 and which prevents dust or the like from being deposited on the photoelectric conversion surface of the imaging device 27 and a microcomputer 150 which makes the dust-proof filter 21 perform a dust removing operation by vibrating the filter 21 at prescribed frequencies and the computer 150 vibrates the filter 21 in a first vibration mode in timing corresponding to the start of an imaging operation and vibrates the filter 21 in a second vibration mode in timing corresponding to the exchanging of the photographic optical system 12a. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electronic imaging device, and more particularly, to an electronic imaging device having a dustproof function capable of removing dust attached to components such as a camera system.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as an example of a technique relating to a dustproof function of an optical device, a technique has been proposed in which a protective glass (dustproof glass) for protecting an image sensor is vibrated to remove dust adhering to the dustproof glass. For example, there is one disclosed in JP-A-2002-204379, in which a piezoelectric element is used as means for vibrating dustproof glass. The piezoelectric element expands and contracts in response to an applied voltage, and vibrates the attached dust-proof glass in one predetermined cycle. Japanese Patent Application No. 2002-142703 discloses that a dust removing operation is performed when a photographic lens is replaced.
[0003]
[Problems to be solved by the invention]
There are various situations where dust adheres to the dust-proof glass. When the photographic lens is replaced, the mirror box is exposed and dust may enter from outside the camera and adhere to the dustproof glass. The possibility that dust adheres to the dust-proof glass is even higher when the shutter is in the OPEN state without attaching an interchangeable lens (lens unit). Even in such a situation, if the shutter speed is high, the problem seems to be small.
[0004]
On the other hand, along with the improvement in the performance of the imaging device, some users have mounted a camera on a telescope and are taking astrophotography. In astrophotography, the shutter speed is long because the subject brightness is low. Therefore, there is a possibility that dust adheres during the OPEN of the shutter. In addition, telescopes are often larger than camera interchangeable lenses, and have poor airtightness. Therefore, the possibility that the dust-containing glass comes into contact with the air containing dust increases.
[0005]
The above-mentioned prior art does not show a method for coping with the problem that dust adheres during the OPEN of the shutter during such a long exposure time.
[0006]
The present invention has been made in view of such a problem, and an object thereof is to reduce deterioration in image quality by performing an appropriate dust removing operation, for example, during an imaging operation for performing long-time exposure. An object of the present invention is to provide an electronic imaging device that does not invite and eliminates unnecessary power consumption.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a first invention includes a photographing optical system that forms an optical image of a subject and a photoelectric conversion element that converts an optical image formed by the photographing optical system into an electric signal. An imaging unit, an optical element disposed between the imaging optical system and the photoelectric conversion unit, for preventing dust and the like from adhering to the photoelectric conversion surface of the photoelectric conversion unit, and oscillating the optical element at a predetermined frequency. Control means for causing the optical element to perform a dust removing operation, whereby the control means vibrates the optical element in a first vibration mode at a first timing related to an imaging operation by the imaging means. At the same time, the optical element is vibrated in the second vibration mode at a second timing excluding the imaging operation by the imaging means.
[0008]
According to a second invention, in the electronic imaging apparatus according to the first invention, the first timing is a timing corresponding to a start of an imaging operation by the imaging means, and the second timing is the imaging optical system. It is the timing according to the exchange of the.
[0009]
According to a third aspect, in the electronic imaging apparatus according to the first aspect, the electronic imaging apparatus has a mode for operating the vibrating means in response to a manual operation. The optical element is vibrated in the vibration mode 2.
[0010]
According to a fourth aspect, in the electronic imaging device according to the first or third aspect, the second vibration mode is a mode in which the optical element is vibrated at its resonance frequency.
[0011]
According to a fifth aspect, in the electronic imaging device according to the first aspect, the first vibration mode is a vibration mode in which the optical element is vibrated at a frequency other than its resonance frequency.
[0012]
According to a sixth aspect, in the electronic imaging device according to the first aspect, the first vibration mode is a vibration mode in which the optical element intermittently vibrates.
[0013]
According to a seventh aspect, in the electronic imaging device according to the first aspect, the first vibration mode is a vibration mode in which the optical element generates a bending vibration wave.
[0014]
According to an eighth aspect, in the electronic imaging apparatus according to the first aspect, the first vibration mode is executed during an imaging operation with a long exposure time or during bulb shooting.
[0015]
In a ninth aspect, in the electronic imaging device according to the first aspect, the first vibration mode is a vibration mode that consumes less power than the second vibration mode.
[0016]
According to a tenth aspect of the present invention, there is provided an imaging optical system for forming an optical image of a subject, an imaging unit including a photoelectric conversion element for converting an optical image formed by the imaging optical system into an electric signal, An optical element arranged between the system and the photoelectric conversion means for preventing dust or the like from adhering to the photoelectric conversion surface of the photoelectric conversion means, and a shutter time equal to or greater than a predetermined value or bulb photography is selected. In this case, there is provided control means for causing the optical element to perform a dust removing operation by vibrating the optical element in a predetermined vibration mode in association with an imaging operation by the imaging means.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0018]
FIG. 1 is a partially cutaway perspective view showing a schematic configuration of an embodiment when the present invention is applied to a digital camera.
[0019]
That is, FIG. 1 is a perspective view schematically showing an internal configuration of a camera body with a part thereof cut away.
[0020]
The camera 1 of the present embodiment includes a camera body 11 and a lens unit 12, each of which is configured separately, and both the camera body 11 and the lens unit 12 are configured to be detachable from each other. It is.
[0021]
The lens unit 12 is configured to internally hold a photographing optical system 12a including a plurality of lenses and a driving mechanism thereof.
[0022]
The photographing optical system 12a transmits a light beam from the subject so that an image of the subject formed by the subject light beam is formed at a predetermined position (on a photoelectric conversion surface of an image sensor described later). For example, it is constituted by a plurality of optical lenses and the like.
[0023]
The lens unit 12 is disposed so as to protrude toward the front of the camera body 11. The camera body 11 is provided with various constituent members and the like, and is a photographing optical member serving as a connecting member for detachably mounting a lens unit 12 holding a photographing optical system 12a. This is a so-called single-lens reflex camera having a system mounting portion 11a provided on the front surface thereof.
[0024]
That is, an exposure opening having a predetermined diameter capable of guiding a subject light beam into the camera body 11 is formed at a substantially central portion on the front side of the camera body 11, and the periphery of the exposure opening is formed. A photographing optical system mounting section 11a is formed in the section.
[0025]
In addition to the photographing optical system mounting portion 11a provided on the front surface of the camera body 11, various operation members for operating the camera body 11 at predetermined positions such as an upper surface portion and a rear surface portion are provided. For example, a release button 17 or the like for generating an instruction signal or the like for starting a photographing operation is provided.
[0026]
Inside the camera body 11, various components such as a finder device 13 constituting a so-called observation optical system and a shutter mechanism for controlling the irradiation time of a subject light beam on the photoelectric conversion surface of the image sensor, and the like are provided. A shutter unit 14 provided, an image pickup device (not shown) for obtaining an image signal corresponding to the subject image, and a predetermined position on the front side of the photoelectric conversion surface of the image pickup device. An image pickup unit 15 including a dustproof filter (also referred to as dustproof glass) 21 which is a dustproof member for preventing the adhesion of dust, and a plurality of circuits including a main circuit board 16 on which various electric members constituting an electric circuit are mounted. Substrates (only the main circuit board 16 is shown) and the like are disposed at predetermined positions.
[0027]
The finder device 13 includes a quick return mirror 13b configured to bend the optical axis of the subject light beam transmitted through the photographing optical system 12a and guide the light beam toward the observation optical system, and a light beam emitted from the quick return mirror 13b. It comprises a pentaprism 13a that receives and forms an erect erect image, an eyepiece 13c that forms an image in an optimal form for enlarging and observing the image formed by the pentaprism 13a, and the like.
[0028]
The quick return mirror 13b is configured to be movable between a position retracted from the optical axis of the imaging optical system 12a and a predetermined position on the optical axis. In a normal state, the quick return mirror 13b is positioned on the optical axis of the imaging optical system 12a. It is arranged at a predetermined angle with respect to the optical axis, for example, at an angle of 45 degrees.
[0029]
Accordingly, when the camera 1 is in the normal state, the optical axis of the subject light flux transmitted through the photographing optical system 12a is bent by the quick return mirror 13b, and the pentaprism is disposed above the quick return mirror 13b. 13a.
[0030]
On the other hand, while the camera 1 is performing a shooting operation, the quick return mirror 13b moves to a predetermined position retracted from the optical axis of the shooting optical system 12a, whereby the subject light flux is captured. It is led to the element side.
[0031]
Further, as the shutter unit 14, for example, a shutter mechanism of a focal plane system, a driving circuit thereof, and the like similar to those generally used in a conventional camera or the like are applied.
[0032]
FIG. 2 is a block diagram showing a system configuration of the camera according to one embodiment of the present invention.
[0033]
That is, the camera system of the present embodiment mainly includes a camera body 11 and a lens unit 12 as an interchangeable lens, and a desired lens unit 12 is detachably mounted on the front surface of the camera body 11. Have been.
[0034]
The lens unit 12 is controlled by a lens control microcomputer (hereinafter referred to as “Lucom”) 205.
[0035]
The control of the camera body 11 is performed by a body control microcomputer (hereinafter, referred to as Bucom) 150.
[0036]
The Lucom 205 and the Bucom 150 are electrically connected via the communication connector 206 so that they can communicate with each other at the time of combination.
[0037]
In this case, the Lucom 205 operates as a camera system while subordinately cooperating with the Bucom 150.
[0038]
In the lens unit 12, a photographic optical system 12a and an aperture 203 are provided.
[0039]
The photographing optical system 12a is driven by a DC motor (not shown) in the lens driving mechanism 202.
[0040]
The aperture 203 is driven by a stepping motor (not shown) in the aperture drive mechanism 204.
[0041]
The Lucom 205 controls each of these motors according to a command from the Bucom 150.
[0042]
The following components are arranged in the camera body 11 as shown in the figure.
[0043]
For example, single-lens reflex type components (pentaprism 13a, quick return mirror 13b, eyepiece 13c, sub-mirror 114) as an optical system, focal-plane shutter 115 on the optical axis, and reflection from sub-mirror 14 An AF sensor unit 116 for receiving a light beam and automatically measuring a distance is provided.
[0044]
Further, an AF sensor driving circuit 117 for driving and controlling the AF sensor unit 116, a mirror driving mechanism 118 for driving and controlling the quick return mirror 13b, and a spring force for driving a front curtain and a rear curtain of the shutter 115 are provided. A shutter charging mechanism 119 for charging, a shutter control circuit 120 for controlling the movement of the front curtain and the rear curtain, and a photometry circuit 121 for performing photometry processing based on the light beam from the pentaprism 13a are provided.
[0045]
On the optical axis, an image sensor 27 for photoelectrically converting a subject image passing through the optical system is provided as a photoelectric converter.
[0046]
In this case, the image sensor 27 is protected by a dust filter 21 made of a transparent glass member as an optical element disposed between the image sensor 27 and the photographing optical system 12a.
[0047]
For example, a piezoelectric element 22 is attached to the periphery of the dustproof filter 21 as a part of a vibration unit that vibrates the dustproof filter 21 at a predetermined frequency.
[0048]
The piezoelectric element 22 has two electrodes. The piezoelectric element 22 causes the dust-proof filter 21 to vibrate by the dust-proof filter driving circuit 140 as a part of the vibrating means. Is configured to be able to be removed.
[0049]
Note that a temperature measurement circuit 133 is provided near the dustproof filter 21 to measure the temperature around the image sensor 27.
[0050]
The camera system also includes an image processing controller that performs image processing using an interface circuit 123 connected to the image sensor 27, a liquid crystal monitor 124, an SDRAM 125 provided as a storage area, a FlashROM 126, a recording medium 127, and the like. 128 are provided so as to provide an electronic record display function together with an electronic imaging function.
[0051]
As another storage area, a non-volatile memory 129 made of, for example, an EEPROM is provided as a non-volatile storage unit for storing predetermined control parameters required for camera control, and is accessible from the Bucom 150.
[0052]
Further, the Bucom 150 is provided with an operation display LCD 151 for notifying the user of the operation state of the camera by a display output, and a camera operation switch (SW) 152.
[0053]
The camera operation SW 152 is, for example, a switch group including operation buttons required for operating the camera, such as a release SW, a mode change SW, and a power SW.
[0054]
Further, a battery 154 as a power supply and a power supply circuit 153 for converting the voltage of the power supply to a voltage required by each circuit unit constituting the camera system and supplying the converted voltage are provided.
[0055]
Next, the operation of the camera system configured as described above will be described. First, the image processing controller 128 controls the interface circuit 123 in accordance with a command from the Bucom 150 to capture image data from the image sensor 27.
[0056]
This image data is converted into a video signal by the image processing controller 128 and output and displayed on the liquid crystal monitor 124.
[0057]
The user can check the captured image from the display image on the liquid crystal monitor 124.
[0058]
The SDRAM 125 is a memory for temporarily storing image data, and is used as a work area when the image data is converted.
[0059]
The image data is set to be stored in the recording medium 127 after being converted into JPEG data.
[0060]
The image sensor 27 is protected by the dust filter 21 made of a transparent glass member as described above.
[0061]
A piezoelectric element 22 for vibrating the glass surface is arranged on the periphery of the dustproof filter 21. The piezoelectric element 22 is also used as a driving unit of the piezoelectric element 22 as described later in detail. It is driven by the working dust filter drive circuit 140.
[0062]
It is more preferable that the imaging element 27 and the piezoelectric element 22 are integrally housed in a case surrounded by a frame as shown by a broken line, with the dustproof filter 21 as one surface.
[0063]
Normally, temperature affects the elastic modulus of a glass material and is one of the factors that change its natural frequency. Therefore, it is necessary to measure the temperature during operation and consider the change in its natural frequency. No.
[0064]
It is better to measure the temperature change of the dustproof filter 21 provided to protect the front surface of the image sensor 27 whose temperature rises sharply during operation, and to estimate the natural frequency at that time.
[0065]
Therefore, in the case of this example, a sensor (not shown) connected to the temperature measuring circuit 133 is provided to measure the peripheral temperature of the image sensor 27.
[0066]
It is preferable that the temperature measurement point of the sensor is set very close to the vibration surface of the dustproof filter 21.
[0067]
The mirror driving mechanism 118 is a mechanism for driving the quick return mirror 13b to the UP position and the DOWN position. Is divided and guided to the pentaprism 13a side.
[0068]
The output from the AF sensor in the AF sensor unit 116 is transmitted to the Bucom 150 via the AF sensor drive circuit 117, and a known distance measurement process is performed.
[0069]
Further, while the user can view the subject from the eyepiece 13c adjacent to the pentaprism 13a, a part of the light beam passing through the pentaprism 13a is guided to a photosensor (not shown) in the photometric circuit 121, where it is detected. A well-known photometric process is performed based on the light amount thus obtained.
[0070]
Next, details of the imaging unit 15 in the camera 1 of the present embodiment will be described.
[0071]
FIGS. 3, 4, and 5 are views showing a part of the imaging unit 15 in the camera 1 of the present embodiment, and FIG. 3 is an exploded perspective view of a main part of the imaging unit in an exploded manner. is there.
[0072]
FIG. 4 is a perspective view showing a part of the assembled imaging unit in a cutaway view, and FIG. 5 is a cross-sectional view taken along a cut surface of FIG.
[0073]
Note that the imaging unit 15 of the camera 1 according to the present embodiment is a unit including a plurality of members including the shutter unit 14 as described above. However, in FIGS. The illustration of the shutter section 14 is omitted.
[0074]
In addition, in order to show the positional relationship between the constituent members, in FIGS. 3 to 5, it is provided in the vicinity of the image pickup unit 15 and the image pickup device 27 is mounted. The image pickup device 27 includes an image signal processing circuit and a work memory. FIG. 2 also shows a main circuit board 16 on which an electric circuit of an imaging system is mounted.
[0075]
Note that the details of the main circuit board 16 itself are applied to those generally used in conventional cameras and the like, and description thereof is omitted.
[0076]
The imaging unit 15 is composed of a CCD or the like, and transmits an image signal corresponding to the light irradiated on its own photoelectric conversion surface through the imaging optical system 12a, and a thin plate-shaped fixedly supporting the imaging element 27. An image sensor fixing plate 28 made of a member and an optical element arranged on the side of the photoelectric conversion surface of the image sensor 27 and formed to remove high frequency components from a subject light beam transmitted through the imaging optical system 12a and irradiated. An optical low-pass filter (hereinafter, referred to as an optical LPF) 25, and a low-pass filter receiving member that is disposed at a peripheral portion between the optical LPF 25 and the image sensor 27 and that is formed by a substantially frame-shaped elastic member or the like. The optical LPF 25 (optical element) is held in close contact with the peripheral portion or a portion in the vicinity thereof, and the image pickup device 27 is housed and fixedly held therein. An imaging element housing case member 24 (hereinafter, referred to as a CCD case 24) disposed so that a predetermined portion is in close contact with a dust-proof filter receiving member 23 to be described later; A dust-proof filter receiving member 23 that supports the filter 21 in close contact with its peripheral portion or a portion in the vicinity thereof; and a photoelectric conversion surface side of the image sensor 27 supported by the dust-proof filter receiving member 23 and a front side of the optical LPF 25. , A dust-proof filter 21 which is a dust-proof member opposed to a predetermined position having a predetermined interval between the optical LPFs 25, and a predetermined vibration which is provided on a peripheral portion of the dust-proof filter 21 and which has a predetermined vibration. And a piezoelectric element 22 composed of an electromechanical transducer or the like and a dustproof filter 21 It is constituted by a pressing member 20 made of an elastic body and the like for airtightly joining and fixing and holding the filter receiving member 23.
[0077]
The imaging element 27 receives the subject luminous flux transmitted through the imaging optical system 12a on its own photoelectric conversion surface and performs a photoelectric conversion process to obtain an image signal corresponding to the subject image formed on the photoelectric conversion surface. For example, a charge coupled device (CCD; Charge Coupled Device) is used.
[0078]
The image sensor 27 is mounted at a predetermined position on the main circuit board 16 via an image sensor fixing plate 28.
[0079]
The image signal processing circuit, the work memory, and the like are mounted on the main circuit board 16 as described above, and the signal output from the image sensor 27 is processed by these circuits.
[0080]
On the front side of the image pickup device 27, an optical LPF 25 is provided with a low-pass filter receiving member 26 interposed therebetween.
[0081]
A CCD case 24 is provided so as to cover the image sensor 27, the low-pass filter receiving member 26, and the optical LPF 25.
[0082]
That is, the CCD case 24 is provided with an opening 24c having a rectangular shape at a substantially central portion, and the optical LPF 25 and the image sensor 27 are arranged in the opening 24c from the rear side. .
[0083]
A step portion 24a having a substantially L-shaped cross section is formed on the inner peripheral edge portion on the rear side of the opening 24c, as shown in FIGS.
[0084]
As described above, the low-pass filter receiving member 26 made of an elastic member or the like is provided between the optical LPF 25 and the image sensor 27.
[0085]
The low-pass filter receiving member 26 is arranged at a position on the front edge of the imaging device 27 that avoids the effective range of the photoelectric conversion surface, and comes into contact with the vicinity of the rear edge of the optical LPF 25. I have.
[0086]
The airtightness between the optical LPF 25 and the image sensor 27 is maintained.
[0087]
As a result, an elastic force in the optical axis direction by the low-pass filter receiving member 26 acts on the optical LPF 25.
[0088]
Therefore, a low-pass filter that displaces the optical LPF 25 in the optical axis direction by arranging the peripheral portion on the front side of the optical LPF 25 so as to be substantially airtightly contacted with the step portion 24a of the CCD case 24. The position of the optical LPF 25 in the optical axis direction is regulated against the elastic force of the receiving member 26.
[0089]
In other words, the position of the optical LPF 25 inserted from the rear side into the opening 24 c of the CCD case 24 is regulated in the optical axis direction by the step portion 24 a of the CCD case 24.
[0090]
Thus, the optical LPF 25 does not escape from the inside of the CCD case 24 toward the front side.
[0091]
After the optical LPF 25 is inserted into the opening 24c of the CCD case 24 from the rear side in this way, the imaging element 27 is disposed on the rear side of the optical LPF 25.
[0092]
In this case, a low-pass filter receiving member 26 is sandwiched between the optical LPF 25 and the image sensor 27 at the peripheral edge.
[0093]
The image sensor 27 is mounted on the main circuit board 16 with the image sensor fixing plate 28 interposed therebetween as described above.
[0094]
The image sensor fixing plate 28 is fixed to the screw hole 24e from the rear side of the CCD case 24 by a screw 28b via a spacer 28a.
[0095]
The main circuit board 16 is fixed to the image sensor fixing plate 28 by screws 16d via spacers 16c.
[0096]
On the front side of the CCD case 24, a dust filter receiving member 23 is fixed to a screw hole 24b of the CCD case 24 by a screw 23b.
[0097]
In this case, a peripheral groove 24d is formed in a substantially annular shape at a predetermined position on the peripheral side of the CCD case 24 and on the front side, as shown in detail in FIGS.
[0098]
On the other hand, an annular convex portion 23d (not shown in FIG. 3) corresponding to the peripheral groove 24d of the CCD case 24 is entirely provided at a predetermined position on the peripheral side and the rear side of the dustproof filter receiving member 23. It is formed in a substantially annular shape over the circumference.
[0099]
Therefore, the CCD case 24 and the dust-proof filter receiving member 23 are formed in an annular region, that is, in a region where the peripheral groove 24d and the annular convex portion 23d are formed by fitting the annular convex portion 23d and the peripheral groove 24d. They are fitted with each other substantially airtightly.
[0100]
The dustproof filter 21 has a circular or polygonal plate shape as a whole, and at least an area having a predetermined spread in a radial direction from its own center forms a transparent portion, and this transparent portion is provided on a front side of the optical LPF 25. Are arranged facing each other with an interval of.
[0101]
A predetermined vibrating member for applying vibration to the dustproof filter 21 is provided on a peripheral portion of one surface (the rear side in the present embodiment) of the dustproof filter 21. The piezoelectric elements 22 to be formed are arranged so as to be integrated, for example, by means such as sticking with an adhesive.
[0102]
The piezoelectric element 22 is configured so that a predetermined vibration can be generated in the dustproof filter 21 by applying a predetermined driving voltage from the outside.
[0103]
The dust filter 21 is fixed and held by a pressing member 20 made of an elastic body such as a leaf spring so as to be airtightly joined to the dust filter receiving member 23.
[0104]
An opening 23f having a circular or polygonal shape is provided in the vicinity of a substantially central portion of the dustproof filter receiving member 23.
[0105]
The opening 23f is set to be large enough to allow the light beam of the subject transmitted through the imaging optical system 12a to pass therethrough and to irradiate the photoelectric conversion surface of the image sensor 27 disposed behind the light beam. ing.
[0106]
A wall portion 23e (see FIGS. 4 and 5) protruding toward the front side is formed in a substantially annular shape at a peripheral portion of the opening 23f, and the front end side of the wall portion 23e further faces the front side. A receiving portion 23c is formed so as to protrude.
[0107]
On the other hand, in the vicinity of the outer peripheral edge of the front side of the dust-proof filter receiving member 23, a plurality of (three in this embodiment) projections 23a are formed at predetermined positions so as to project toward the front side. .
[0108]
The protruding portion 23a is a portion formed for fixing the pressing member 20 for fixing and holding the dustproof filter 21, and the pressing member 20 is formed with a screw 20a or the like with respect to the tip of the protruding portion 23a. Are fixed by the fastening means.
[0109]
The pressing member 20 is a member formed of an elastic body such as a leaf spring as described above, and has a base end fixed to the protruding portion 23 a and a free end contacting the outer peripheral edge of the dustproof filter 21. By being in contact, the dustproof filter 21 is pressed toward the dustproof filter receiving member 23, that is, in the optical axis direction.
[0110]
In this case, when a predetermined portion of the piezoelectric element 22 disposed on the outer peripheral edge on the back side of the dustproof filter 21 contacts the receiving portion 23c, the position of the dustproof filter 21 and the piezoelectric element 22 in the optical axis direction is adjusted. Are being regulated.
[0111]
Thus, the dustproof filter 21 is fixedly held so as to be airtightly joined to the dustproof filter receiving member 23 via the piezoelectric element 22.
[0112]
In other words, the dust-proof filter receiving member 23 is configured to be airtightly joined to the dust-proof filter 21 and the piezoelectric element 22 by the urging force of the pressing member 20.
[0113]
As described above, the dust-proof filter receiving member 23 and the CCD case 24 are configured such that the circumferential groove 24d and the annular convex portion 23d (see FIGS. 4 and 5) are substantially airtightly fitted to each other. At the same time, the dust filter receiving member 23 and the dust filter 21 are hermetically joined via the piezoelectric element 22 by the urging force of the pressing member 20.
[0114]
The optical LPF 25 disposed in the CCD case 24 is disposed so as to be substantially airtight between the peripheral edge on the front side of the optical LPF 25 and the step 24a of the CCD case 24.
[0115]
Further, on the rear side of the optical LPF 25, an image sensor 27 is disposed via a low-pass filter receiving member 26, so that substantially airtightness is maintained between the optical LPF 25 and the image sensor 27. ing.
[0116]
Thus, a predetermined gap 51a is formed in a space between the optical LPF 25 and the dustproof filter 21.
[0117]
A space 51 b is formed by the peripheral side of the optical LPF 25, that is, the CCD case 24, the dust filter receiving member 23, and the dust filter 21.
[0118]
The space 51b is a sealed space formed so as to protrude outside the optical LPF 25 (see FIGS. 4 and 5).
[0119]
The space 51b is set to be a space wider than the space 51a.
[0120]
The space formed by the gap 51a and the space 51b is a sealed space 51 which is substantially airtightly sealed by the CCD case 24, the dust filter receiving member 23, the dust filter 21, and the optical LPF 25 as described above. ing.
[0121]
As described above, in the imaging unit 15 of the camera according to the present embodiment, the sealing structure that forms the substantially sealed space 51 that is formed around the optical LPF 25 and the dustproof filter 21 and that includes the gap 51 a is configured. I have.
[0122]
The sealing structure is provided at a position outside the periphery of the optical LPF 25 or its vicinity.
[0123]
Further, in the present embodiment, the dustproof filter receiving member 23 which is the first member for supporting the dustproof filter 21 in close contact with the peripheral portion or in the vicinity thereof, and the optical LPF 25 in close contact with the peripheral portion or in the vicinity thereof. The sealing structure is constituted by the CCD case 24 and the like, which is a second member disposed so as to be in close contact with the dust-proof filter receiving member 23 at a predetermined position of the self.
[0124]
In the camera according to the present embodiment configured as described above, the dustproof filter 21 is disposed at a predetermined position on the front side of the image pickup device 27 so as to be formed on the periphery of the photoelectric conversion surface of the image pickup device 27 and the dustproof filter 21. By sealing the sealing space 51 to be sealed, dust and the like are prevented from adhering to the photoelectric conversion surface of the image sensor 27.
[0125]
In this case, a periodic voltage is applied to the piezoelectric element 22 disposed integrally with the periphery of the dust-proof filter 21 for dust and the like adhering to the exposed surface on the front side of the dust-proof filter 21. Then, by applying a predetermined vibration to the dustproof filter 21, the dustproof filter 21 can be removed.
[0126]
FIG. 6 is a front view showing only the dustproof filter 21 and the piezoelectric element 22 provided integrally with the dustproof filter 21 of the imaging unit 15 of the camera 1.
[0127]
7 and 8 show the state change of the dust filter 21 and the piezoelectric element 22 when a drive voltage is applied to the piezoelectric element 22 of FIG. 6, and FIG. 7 is along the line AA of FIG. FIG. 8 is a sectional view taken along line BB of FIG.
[0128]
Here, for example, when a negative (minus; one) voltage is applied to the piezoelectric element 22, the dustproof filter 21 is deformed as shown by a solid line in FIGS. ; +) When a voltage is applied, the dustproof filter 21 is deformed as shown by a dotted line in FIG.
[0129]
In this case, the amplitude is substantially zero at the position of the node of the vibration as indicated by the reference numeral 21a in FIGS. 6 to 8, so that the receiving portion of the dustproof filter receiving member 23 is provided at a portion corresponding to the node 21a. 23c is set to abut.
[0130]
Thereby, the dust filter 21 can be efficiently supported without hindering the vibration of the dust filter 21.
[0131]
In this state, by controlling the dust-proof filter driving circuit 140 at a predetermined time and applying a periodic voltage to the piezoelectric element 22, the dust-proof filter 21 vibrates, and the surface of the dust-proof filter 21 The attached dust is removed.
[0132]
The resonance frequency at this time is determined by the shape, plate thickness, material and the like of the dustproof filter 21.
[0133]
In the examples shown in FIGS. 6 to 8 described above, the case where the primary vibration is generated is shown, but the present invention is not limited to this, and higher-order vibration may be generated.
[0134]
FIG. 9 is a diagram conceptually illustrating a configuration of a vibration unit that vibrates the dustproof filter 21 in the imaging unit of the electronic imaging apparatus.
[0135]
As shown in FIG. 9, the annular piezoelectric element 22 is polarized into 22a and 22b. In this case, the piezoelectric elements 22a and 22b are polarized in the plate thickness direction in eight circumferentially divided regions, and the polarization directions are indicated by plus (+) and minus (-), and the polarization directions are opposite. Are alternately arranged. Then, one piezoelectric element 22b is a quarter of the wavelength of vibration (here, one wavelength corresponds to the length of the plus (+) and minus (-) polarization regions) with respect to the other piezoelectric element 22a. They are arranged so as to be shifted by a wavelength (１ ／ λ).
[0136]
A voltage of a predetermined frequency is added to the piezoelectric elements 22a and 22b thus configured by the dustproof filter driving circuit 140 in the respective plate thickness directions.
[0137]
In this case, the frequency signal (first periodic voltage signal) output from the oscillator 34 of the dustproof filter drive circuit 140 is added to the piezoelectric element 22b as it is, while the dustproof filter drive circuit is A signal (second periodic voltage signal) whose phase is shifted by 90 ° by the 90 ° phase shifter 35 of 140 is applied.
[0138]
By applying such a signal to each of the piezoelectric elements 22a and 22b, the dustproof filter 21 is rotated in the rotational direction X about the center of the dustproof filter 21 as shown in FIG. 10 (only the dustproof filter 21 is shown). Bending wave vibrations (vibrations in which the peaks Y and the valleys T alternately occur at equal intervals and with the same amplitude) are generated.
[0139]
When the bending traveling wave uttered by the piezoelectric elements 22a and 22b is viewed at an arbitrary time, it has a substantially symmetrical shape with respect to the center (optical axis) of the dustproof filter 21.
[0140]
FIG. 11 is a circuit diagram schematically showing the configuration of the dustproof filter drive circuit 140 in the electronic imaging device 1 described with reference to FIG. FIG. 12 is a time chart showing the form of each signal output from each component in the dustproof filter drive circuit 140 of FIG.
[0141]
A clock generator 255 is provided inside the body control microcomputer 41. The clock generator 255 generates a pulse signal (basic clock) at a frequency sufficiently higher than a signal frequency to be applied to the piezoelectric elements 22a and 22b. (See Sig1 shown in FIG. 12). This basic clock signal is input to the N-ary counter 241 of the dust filter driving circuit 140. The N-ary counter 241 counts the pulse signal, and outputs a count end pulse signal every time the predetermined value = N is reached. That is, the basic clock signal is divided by 1 / N (see Sig2 shown in FIG. 12).
[0142]
Since the duty ratio of High and Low is not 1: 1 for the frequency-divided pulse signal, the duty ratio is converted to 1: 1 via the first 1/2 frequency dividing circuit 242-1. At this time, the frequency is halved (see Sig3 shown in FIG. 12). The output signal from the first 1/2 frequency dividing circuit 242-1 is output to the second 1/2 frequency dividing circuit 242-2 and the exclusive OR (ExOR) circuit 247. The pulse signal input to the second 1/2 frequency dividing circuit 242-2 is further output at a half frequency (see Sig4 shown in FIG. 12).
[0143]
Here, when the pulse signal Sig4 is in a high state, the MOS transistor Q01 (244b1) is turned on. Further, the pulse signal Sig4 is applied to the MOS transistor Q02 (244c1) via the first inverter 243-1. In this case, when the pulse signal Sig4 is in a low state, the MOS transistor Q02 (244c1) is turned on.
[0144]
In this way, when the two MOS transistors Q01 (244b1) and Q02 (244c1) connected to the primary side of the transformer A (245-1) are turned on alternately, the two MOS transistors Q01 (244b1) are turned on. On the next side, a Sig5 signal shown in FIG. 12 is generated. In this case, the turns ratio of the transformer A (245-1) is determined by the output voltage of the power supply circuit 153 and the voltage required to drive one of the piezoelectric elements 22a.
[0145]
The resistor R00 (246-1) is provided to restrict an excessive current from flowing through the transformer A (245-1).
[0146]
When driving the piezoelectric element 22a, it is necessary that Q00 (244a1) is in the ON state (ON) and that a voltage is applied from the power supply circuit 153 to the center tap of the transformer A (245-1). In this case, on / off control of Q00 (244a1) is performed from P_PwContA of the body control microcomputer 150.
[0147]
The set value of the N-ary counter 241 = N is set from the port of the body control microcomputer 150 = D_NCnt. That is, the body control microcomputer 150 can arbitrarily change the drive frequency of the piezoelectric elements 22a and 22b by controlling the set value = N.
[0148]
The calculation of the driving frequency is based on the following equation (1).
[0149]
fdrv = fpls / 4N (1)
Here, N: the set value to the N-ary counter 241
fpls: frequency of output pulse of clock generator 255
fdrv: frequency of the signal applied to the piezoelectric element 22a
Thus, the drive signal (Sig5) of a predetermined voltage is applied to the piezoelectric element 22a.
[0150]
On the other hand, the output signal Sig3 of the first 1/2 frequency dividing circuit 242-1 is output to the third 1/2 frequency dividing circuit 242-2 via the exclusive OR (ExOR) circuit 247. In this case, when the port P_θCont of the body control microcomputer 150 is in a high state, the pulse signal Sig3 is inverted. Thereafter, the signal is output to the third 1/2 frequency dividing circuit 243-2.
[0151]
When the port P_θCont is in a low (Low) state, the pulse signal Sig3 is output to the third 分 frequency dividing circuit 242-2 as it is (see Sig6 in FIG. 12). This pulse signal Sig6 is output after being further halved in frequency by the third 1/2 frequency dividing circuit 242-3 (see Sig7 shown in FIG. 12). As a result, the second inverter 243-2, Q11 (244b2), Q12 (244c2), and the transformer B (245-2) are driven, and a drive signal (Sig8) of a predetermined voltage is applied to the piezoelectric element 22b.
[0152]
The functions of the second inverter 243-2, Q11 (244b2), Q12 (244c2), transformer B (245-2), and resistor R10 are the same as those of the above-described first inverter 243-1, Q01 (244b1), Q02. (244c1), the transformer A (245-1), and the resistor R00 (246-1).
[0153]
In each of the first to third 1/2 frequency dividing circuits 242-1, 222-2, and 242-3, the frequency dividing operation is performed in response to the rising edge of the input pulse signal. ing.
[0154]
Then, even if the frequency of the pulse signal is the same, when the signal is inverted, the second 1/2 frequency dividing circuit 242-2 and the third 1/2 frequency dividing circuit 242-3 output respectively. A pulse signal having a phase difference occurs. The phase difference in this case is 90 °.
[0155]
Accordingly, a phase difference of 90 ° occurs between the signal Sig5 applied to the piezoelectric element 22a and the signal Sig8 applied to the piezoelectric element 22b. The phase difference can be controlled by the port P_θCont of the body control microcomputer 150. For example, when the port P_θCont is in a high state, a phase difference of 90 ° occurs, and when the port P_θCont is in a low state, no phase difference occurs. That is, by controlling the port P_θCont, different forms of vibration can be applied to the dustproof filter 21.
[0156]
(1st Embodiment)
FIG. 13 is a flowchart for explaining the operation of the Bucom 150 in the camera system according to the first embodiment of the present invention.
[0157]
The Bucom 150 starts operating when the power switch of the camera is turned on. In step S100, a process for activating the camera system is executed. The power supply circuit 153 is controlled to supply power to each circuit unit constituting the camera system. In addition, initialization of each circuit is performed.
[0158]
Step S101 is an operation step for detecting the state of the lens unit 12 by performing a communication operation with the Lucom 205, and is periodically executed. When it is detected in step S102 that the lens unit 12 is attached to the camera body 11, the process proceeds from step S102 to step S103. In step S103, the two piezoelectric elements 22a and 22b provided on the dustproof filter 21 are driven at the resonance frequency (f0) in phase for a predetermined time (T0). The value set in the N-ary counter 241 to vibrate the two piezoelectric elements 22a and 22b is stored in the nonvolatile memory 129. The non-volatile memory 129 also stores the time (T0) at which the dust filter 21 is vibrated in order to remove dust adhering to the dust filter 21. A dustproof operation is performed based on these data. The dust filter 21 vibrates as shown in FIGS. 7 and 8, and dust is removed.
[0159]
On the other hand, if it is not detected in step S102 that the lens unit 12 has been attached to the camera body 11, the process proceeds from step S102 to step S104. Step S104 is a processing step of periodically detecting the state of the camera operation SW 152. In step S105, the state of CleanUpSW, one of the camera operation SWs 152, is determined. Here, when the CleanUpSW is operated, the process proceeds to step S106, and the subroutine “CleanUp operation” is executed. The details of the subroutine "CleanUp operation" will be described later.
[0160]
On the other hand, if the CleanUpSW is not operated in step S105, the process proceeds to step S107. In step S107, the state of the first release switch, which is one of the camera operation switches 152, is determined. If the first release SW is ON, the process proceeds to step S108, and if it is OFF, the process proceeds to step S101.
[0161]
In step S108, luminance information of the subject is obtained from the photometry circuit 121. From this information, the exposure time (Tv value) of the image sensor 27 and the aperture setting value (Av value) of the lens unit 12 are calculated.
[0162]
In the next step S109, the detection data of the AF sensor unit 116 is obtained via the AF sensor drive circuit 117. The Bucom 150 calculates the amount of defocus based on this data. In step S110, it is determined whether or not the calculated shift amount is within the permitted range. If not, drive control of the photographing lens in the photographing optical system 12a is performed in step S111, and the process returns to step S101.
[0163]
On the other hand, if the deviation amount is within the permitted range in step S110, the process proceeds to step S112. In step S112, the operation state of the second release switch, which is one of the camera operation switches 152, is determined. When the operation of the camera operation SW 152 is performed, the process proceeds to step S113, and when there is no operation, the process proceeds to step S101.
[0164]
In step S113, the aperture of the taking lens in the taking optical system 12a is set based on the Av value calculated in step S105. In step S114, the quick return mirror 13b is driven to the UP position.
[0165]
In the following steps S115 to S117, a dustproof permission flag is set. The dustproof permission flag is a flag for instructing whether or not to execute the dust removal operation in parallel with the imaging operation. When the dustproof permission flag is cleared ("0"), the dust removal operation is prohibited, and when the dustproof permission flag is set ("1"), the dust removal operation is permitted. The dustproof permission flag is set when the shutter time is longer than a predetermined time. If the shutter time is long, the time during which the dustproof filter 21 contacts the outside air becomes long, and dust may adhere to the dustproof filter 21 during exposure.
[0166]
In addition, when the valve shooting is selected, the shutter 14 is kept in the open state while the user turns on the release SW, so that dust may adhere. Also, in bulb shooting, the Open time of the shutter 14 cannot be predicted (the exposure time intended by the user cannot be detected by the camera). Therefore, it is necessary to always perform the dust removing operation during bulb photography.
[0167]
Although not particularly mentioned in the present embodiment, it may be determined whether or not to perform the dust removing operation according to the shooting mode. This is because the shooting mode includes an operation mode in which the shutter time is long (such as a night scene shooting mode).
[0168]
First, in step S115, it is determined whether or not the shutter speed is greater than a predetermined value. If the value is equal to or more than the predetermined value, the process proceeds to step S117 to set a dustproof permission flag. If the value is equal to or less than the predetermined value, the process proceeds to step S116 to clear the dustproof permission flag.
[0169]
In step S115, it is also determined whether or not bulb photography has been selected. If the bulb shooting has been selected, step S117 is executed to set the dustproof permission flag. If the bulb shooting has not been selected, step S116 is executed to clear the dustproof flag. After execution of step S116 or step S117, the process proceeds to step S118.
[0170]
In step S118, the shutter 14 is OPEN-controlled. In step S119, a subroutine "imaging operation" is executed. The detailed operation of the subroutine "imaging operation" will be described later. In step S120, the shutter 14 is subjected to CLOSE control. In step S121, the quick return mirror 13b is driven to the Down position. Further, in step S122, the shutter 14 is charged. In step S123, the aperture of the taking lens in the taking optical system 12a is driven to the open position. In step S124, the image data is fetched from the image sensor 27, converted into a predetermined format, and stored in a recording medium.
[0171]
FIG. 14 is a diagram for explaining the details of the subroutine "CleanUp operation" (step S106) described in FIG. When the user turns on CleanUpSW, this subroutine is executed. The dust removal operation is automatically performed by the camera as needed. However, it is convenient if the dust removal operation can be executed by the user separately from the dust removal operation automatically performed by the camera.
[0172]
Further, in the camera manufacturing process, in order to perform an operation test, it is necessary to be able to arbitrarily perform a dust removing operation by a manual operation. This subroutine exists to respond to these requests. In this routine, the quick return mirror 13b is fixed at the UP position, and the shutter 14 is also in the OPEN state, so that the state of the dustproof filter 21 during vibration can be observed. When large dust adheres, it is not preferable to remove it between the dustproof filter 21 and the shutter 14. By using the dust removing operation of this routine, dust can be excluded to the outside of the camera.
[0173]
First, in step S150, the quick return mirror 13b is moved to the Up state. In step S151, the shutter 14 is set to the OPEN state. In step S152, driving of the two piezoelectric elements 22a and 22b at the frequency f0 and in the same phase is started. This causes the dust filter 21 to start vibrating as shown in FIGS.
[0174]
In step S153, the state of the CleanUpSW is detected, and the process waits in step S153 until the CleanUpSW is turned off. While the CleanUpSW is ON, the vibrating operation of the dustproof filter 21 is continued. The user only needs to keep CleanUpSW in the ON state for a necessary time. When the CleanUpSW is turned off, the process shifts to step S154 to stop driving the piezoelectric elements 22a and 22b provided in the dustproof filter 21. After that, the procedure moves to step S155.
[0175]
In step S155, the shutter 14 is set to the Close state. In step S156, the quick return mirror 13b is driven to the Down position. In step S157, a charging operation of the shutter 14 is performed. And return.
[0176]
FIG. 15 is a diagram for explaining the details of the subroutine “imaging operation” (step S119) described in FIG. In step S200, the state of the dustproof permission flag is determined. If the dust-proof permission flag is "1", the process proceeds to step S201 to start the vibration operation of the dust-proof filter 21, and if the dust-proof permission flag is "0", the process proceeds to step S202. In step S201, a drive signal having the frequency (f0 + Δf) and the same phase is applied to the two piezoelectric elements 22a and 22b. f0 is a resonance frequency, and Δf is a shift amount described later.
[0177]
The resonance frequency f0 is determined by the material and shape of the dust filter 21. When the dustproof filter 21 is driven at the resonance frequency f0, the amplitude of the dustproof filter 21 becomes maximum as shown in FIG. As the amplitude of the dust filter 21 increases, the ability to remove dust increases. However, at the resonance frequency f0, the impedance required for driving the dustproof filter 21 increases because the impedance of the piezoelectric elements 22a and 22b decreases. In addition, if the dustproof filter 21 is greatly deformed, aberrations generated by the dustproof filter 21 increase, which may cause image degradation.
[0178]
Therefore, in the present embodiment, in consideration of these problems, the driving frequency of the dustproof filter 21 during the imaging operation is intentionally shifted from the resonance frequency f0. The shift amount (Δf) is stored in the nonvolatile memory 129. When the dustproof filter 21 is driven at a frequency other than the resonance frequency f0, the amplitude of the dustproof filter 21 decreases. However, if the purpose is not to remove dust that has already adhered but to prevent dust from adhering, A slight reduction in amplitude is not a major problem.
[0179]
In the next step S202, the image processing controller 128 is instructed to start an imaging operation. In step S203, it is determined whether or not bulb shooting is being performed. If the bulb shooting is being performed, the process proceeds to step S204. In step S204, the process waits until the release switch is turned off. When the release SW is turned off, the process proceeds to step S206.
[0180]
On the other hand, if it is determined in step S203 that bulb shooting is not being performed, the process proceeds from step S203 to step S205. In step S205, the timer counter is operated to wait for the shutter time determined in step S108. Thereafter, the process proceeds to step S206.
[0181]
In step S206, an instruction to stop the imaging operation is sent to the image processing controller 128. In step S207, the state of the image stabilization permission flag is determined. If the anti-vibration flag is "1", the vibration control of the anti-dust filter 21 is stopped in step S208, and the process returns to the main routine. If the image stabilization permission flag is "0", the process immediately returns to the main routine.
[0182]
According to the first embodiment described above, in a camera system having a function of removing dust by vibrating the dust filter, the dust filter 21 is set at the resonance frequency of the dust filter 21 when the taking lens is replaced or when the CleanUpSW is operated. In addition to vibrating, the dustproof filter 21 is vibrated at a frequency (f0 + Δf) shifted from the resonance frequency f0 by Δf during an imaging operation for performing long-time exposure or during bulb shooting, so that image quality deteriorates. There is provided an electronic imaging apparatus that eliminates unnecessary and unnecessary power consumption.
[0183]
(2nd Embodiment)
FIG. 17 is a flowchart for explaining the operation of the Bucom 150 in the camera system according to the second embodiment of the present invention. The second embodiment is characterized in that the dustproof filter 21 is intermittently driven in the subroutine "imaging operation" (step S119 in FIG. 13) described in the first embodiment. Other steps are the same as in the first embodiment.
[0184]
First, in step S400, the state of the dustproof permission flag is detected. If the dustproof permission flag is “1”, the process proceeds to step S401 to start the vibration operation of the dustproof filter 21. In step S401, a predetermined drive signal is applied to the piezoelectric elements 22a and 22b that vibrate the dust filter 21. After that, it moves to step S402.
[0185]
On the other hand, if the dustproof permission flag is “0” in step S400, the process immediately proceeds to step S402. In step S402, the image processing controller 128 is instructed to start an imaging operation. In step S403, it is determined whether or not bulb shooting is being performed. If it is the bulb shooting, the flow shifts to step S405 to detect the state of the release SW. If the release SW is detected to be OFF, the process proceeds to step S406, and if the release SW is ON, the process proceeds to step S4050. In step S4050, the vibration operation of the dustproof filter 21 is stopped for a predetermined time. Then, the vibration operation is restarted. In step S4051, the process waits for a predetermined time to continue the vibration operation. The dust removal operation during bulb shooting is performed intermittently by the operation of step S4050 and step S4051. The bulb photographing operation is used when photographing a low-luminance subject such as a celestial body. Therefore, the exposure time may be very long. Therefore, it is desired to reduce the power required for the dust removing operation as much as possible. Therefore, the driving power of the dustproof filter 21 is suppressed by making the driving operation intermittent.
[0186]
On the other hand, if the bulb shooting is not being performed in step S403, the process proceeds to step S404. In step S404, the timer counter is operated to wait for the shutter time determined in step S108. Then, control goes to a step S406.
[0187]
In step S406, a stop instruction for the imaging operation is sent to the image processing controller 128. In step S407, the state of the image stabilization permission flag is determined. If the anti-vibration flag is "1", the flow returns to the main routine after stopping the vibration operation of the anti-dust filter 21 in step S408. If the defense permission flag is "0", the routine immediately returns to the main routine.
[0188]
According to the second embodiment described above, in a camera system having a function of removing dust by vibrating a dustproof filter, the dustproof filter 21 is set at the resonance frequency of the dustproof filter 21 when the taking lens is replaced or when the CleanUpSW is operated. In addition to the vibration, the dustproof filter 21 is intermittently vibrated at the time of an imaging operation for performing long-time exposure or at the time of bulb photography, thereby providing an electronic imaging apparatus that eliminates unnecessary power consumption.
[0189]
(Third embodiment)
FIG. 18 is a flowchart for explaining the operation of the Bucom 150 in the camera system according to the third embodiment of the present invention. The third embodiment is characterized in that in the subroutine "imaging operation" described in the first embodiment (step S119 in FIG. 13), the dust-proof filter 21 is driven by using a bending traveling wave. Other steps are the same as in the first embodiment.
[0190]
First, in step S300, the state of the dustproof permission flag is determined. If the flag is “1”, the process proceeds to step S301 to start the vibration operation of the dustproof filter 21. In step S301, a driving signal having a frequency (fs) and a phase of 90 ° is applied to the two piezoelectric elements 22a and 22b. By this operation, a bending traveling wave as shown in FIG. By selecting a driving method in which the amount of deformation of the dustproof filter 21 is small, it is possible to suppress an increase in aberration generated by the dustproof filter 21. After step S301, the process moves to step S302.
[0191]
On the other hand, if the flag is “0” in step S300, the process immediately proceeds to step S302. In step S302, the image processing controller 128 is instructed to start an imaging operation. In step S303, it is determined whether or not bulb shooting is being performed. If the bulb shooting is being performed, the process proceeds to step S304. In step S304, the process waits until the release switch is turned off. When the release SW is turned off, the process proceeds to step S306.
[0192]
On the other hand, if it is determined in step S303 that bulb shooting is not being performed, the process proceeds from step S303 to step S305, in which the timer counter is operated to wait for the shutter time determined in step S108. After step S305, the process proceeds to step S306.
[0193]
In step S306, an instruction to stop the imaging operation is sent to the image processing controller 128. In step S307, the state of the image stabilization permission flag is determined. If the flag is "1", the flow returns to the main routine after stopping the vibration operation of the dustproof filter 21 in step S308. If the flag is "0", the process immediately returns to the main routine.
[0194]
According to the third embodiment, in a camera system having a function of removing dust by vibrating a dust filter, the resonance frequency (non-bending traveling wave) of the dust filter 21 when the taking lens is replaced or when the CleanUpSW is operated. Then, the dust-proof filter 21 is vibrated, and the dust-proof filter 21 is driven so that a bending traveling wave is generated at the time of an imaging operation for performing long-time exposure or at the time of bulb shooting. There is provided an electronic imaging device without any problem.
[0195]
(Note)
1. A shooting optical system for forming an optical image of a subject,
Imaging means including a photoelectric conversion element for converting an optical image formed by the imaging optical system into an electric signal,
An optical element disposed between the imaging optical system and the photoelectric conversion unit, for preventing adhesion of dust and the like to a photoelectric conversion surface of the photoelectric conversion unit;
When the shutter time is equal to or greater than a predetermined value or when valve shooting is selected, the optical element is vibrated in a predetermined vibration mode in association with an imaging operation by the imaging unit, thereby performing a dust removing operation on the optical element. Control means to be performed;
An electronic imaging device comprising:
[0196]
2. The control means vibrates the optical element at a frequency shifted from a resonance frequency of the optical element. An electronic imaging device according to item 1.
[0197]
3. The control means vibrates the optical element intermittently. An electronic imaging device according to item 1.
[0198]
4. The control means vibrates the optical element in such a manner that a bending traveling wave is generated in the optical element. An electronic imaging device according to item 1.
[0199]
【The invention's effect】
According to the present invention, for example, an appropriate dust removing operation is performed during an imaging operation in which long-time exposure is performed, so that an electronic imaging device that does not cause deterioration in image quality and eliminates unnecessary power consumption is provided. Is done.
[Brief description of the drawings]
FIG. 1 is a partially cutaway perspective view showing a schematic configuration of an embodiment when the present invention is applied to a digital camera.
FIG. 2 is a block diagram illustrating a system configuration of a camera according to an embodiment of the present invention.
FIG. 3 is an exploded perspective view of a main part of the camera 1 according to the embodiment, in which a part of the imaging unit 15 is taken out and is shown.
FIG. 4 is a perspective view showing a part of the imaging unit 15 in the camera 1 according to the embodiment, which is taken out and partially cut away in a state where the imaging unit is assembled.
FIG. 5 is a view showing a part of the image pickup unit 15 in the camera 1 of the present embodiment, and is a cross-sectional view along a cut surface in FIG. 4;
FIG. 6 is a front view showing only a dustproof filter 21 and a piezoelectric element 22 provided integrally with the dustproof filter 21 of the image pickup unit 15 of the camera 1;
7 is a cross-sectional view taken along the line AA of FIG. 6, showing a change in state of the dustproof filter 21 and the piezoelectric element 22 when a drive voltage is applied to the piezoelectric element 22 of FIG.
FIG. 8 is a cross-sectional view taken along the line BB of FIG. 6, showing a state change of the dust filter 21 and the piezoelectric element 22 when a driving voltage is applied to the piezoelectric element 22 of FIG.
FIG. 9 is a diagram conceptually showing a configuration of a vibrating unit that vibrates the dustproof filter 21 in the image pickup unit in the electronic image pickup apparatus.
FIG. 10 is a diagram showing a state in which a bending traveling wave vibration that proceeds in the rotation direction X about the center of the dustproof filter 21 is generated.
11 is a circuit diagram schematically illustrating a configuration of a dust filter driving circuit 140 in the electronic imaging device 1 described in FIG.
12 is a time chart showing the form of each signal output from each component in the dustproof filter drive circuit 140 of FIG.
FIG. 13 is a flowchart illustrating an operation of the Bucom 150 in the camera system according to the first embodiment of the present invention.
FIG. 14 is a diagram for explaining details of a subroutine “CleanUp operation” (step S106) described in FIG. 13;
FIG. 15 is a diagram for explaining details of a subroutine “imaging operation” described in FIG. 13;
FIG. 16 is a diagram showing the relationship between the amplitude of dustproof glass and the driving frequency.
FIG. 17 is a flowchart illustrating an operation of the Bucom 150 in the camera system according to the second embodiment of the present invention.
FIG. 18 is a flowchart illustrating an operation of a Bucom 150 in a camera system according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Camera, 11 ... Camera main body, 11a ... Photographing optical system mounting part, 12 ... Lens unit, 12a ... Photographing optical system, 13 ... Viewfinder device, 13a ... Penta prism, 13b ... Reflecting mirror, 13c ... Eyepiece, 14 ... Shutter unit, 15 imaging unit, 16 main circuit board, 17 release button, 21 dustproof filter, 27 imaging device, 28 image processing controller, 140 dustproof filter drive circuit, 150 microcomputer for body control ( Bucom), 205: microcomputer for lens control (Lucom).

Claims (10)

A shooting optical system for forming an optical image of a subject,
Imaging means including a photoelectric conversion element for converting an optical image formed by the imaging optical system into an electric signal,
An optical element disposed between the imaging optical system and the photoelectric conversion unit, for preventing adhesion of dust and the like to a photoelectric conversion surface of the photoelectric conversion unit;
Control means for causing the optical element to perform a dust removing operation by vibrating the optical element at a predetermined frequency,
With
The control means vibrates the optical element in a first vibration mode at a first timing related to an imaging operation by the imaging means, and a second vibration at a second timing excluding the imaging operation by the imaging means. An electronic imaging device, wherein the optical element is vibrated in a form. 2. The electronic device according to claim 1, wherein the first timing is a timing according to a start of an imaging operation by the imaging unit, and the second timing is a timing according to replacement of the imaging optical system. Imaging device. 2. The electronic imaging apparatus according to claim 1, wherein the electronic imaging device has a mode in which the vibration unit is operated in response to a manual operation, and in the mode, the optical element is vibrated in the second vibration mode. An electronic imaging device according to claim 1. 4. The electronic imaging apparatus according to claim 1, wherein the second vibration mode is a vibration mode in which the optical element is vibrated at its resonance frequency. 2. The electronic imaging apparatus according to claim 1, wherein the first vibration mode is a vibration mode in which the optical element is vibrated at a frequency other than its resonance frequency. 2. The electronic imaging apparatus according to claim 1, wherein the first vibration mode is a vibration mode that intermittently vibrates the optical element. The electronic imaging device according to claim 1, wherein the first vibration mode is a vibration mode in which a bending vibration wave is generated in the optical element. 2. The electronic imaging apparatus according to claim 1, wherein the first vibration mode is executed during an imaging operation with a long exposure time or during bulb shooting. 3. The electronic imaging device according to claim 1, wherein the first vibration mode is a vibration mode that consumes less power than the second vibration mode. A shooting optical system for forming an optical image of a subject,
Imaging means including a photoelectric conversion element for converting an optical image formed by the imaging optical system into an electric signal,
An optical element disposed between the imaging optical system and the photoelectric conversion unit, for preventing adhesion of dust and the like to a photoelectric conversion surface of the photoelectric conversion unit;
When the shutter time is equal to or greater than a predetermined value or when valve shooting is selected, the optical element is vibrated in a predetermined vibration mode in association with an imaging operation by the imaging unit, thereby performing a dust removing operation on the optical element. Control means to be performed;
An electronic imaging device comprising:

Images