JP2004253873A - Electronic imaging unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic imaging unit capable of carrying out a dust-proof operation without a user for hearing a sound produced from a camera when a silent operation mode is set. <P>SOLUTION: The electronic imaging unit having the silent operation mode wherein production of sound related to imaging operations is suppressed, includes: an imaging optical system 12a for forming the optical image of an object; an imaging element 27 for converting the optical image formed by the imaging optical system 12a into an electric signal; a dust-proof filter 21 located between the imaging optical system 12a and the imaging element 27 to prevent dust or the like from depositing onto the photoelectric conversion face of the imaging element 27; and a body control microcomputer 150 for vibrating the dust-proof filter 21 at a prescribed frequency to make the dust-proof filter 21 perform dust removal operations, and the microcomputer 150 vibrates the dust-proof filter 21 depending on a different vibration form in accordance with a state as to whether or not the quiet sound operating mode is set. <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 related to a dustproof function of an optical device, a technique is known in which a protective glass (dustproof glass) for protecting an image sensor is vibrated to remove dust adhering to the protective glass. For example, Japanese Patent Application Laid-Open No. 2002-204379 discloses that a piezoelectric element is used as means for vibrating the protective glass. This piezoelectric element expands and contracts in response to an applied voltage and vibrates the protective glass in one predetermined cycle.
[0003]
[Problems to be solved by the invention]
By the way, there are various shooting modes in a camera, but there is a need to suppress as much as possible the sound generated by the camera with each imaging operation. In order to respond to such needs, a camera system having an operation mode (hereinafter, referred to as a silent operation mode) capable of performing an imaging operation quietly has been proposed.
[0004]
In the silent operation mode, the user is not notified by sound. In addition, consideration is given to driving the mechanical members of the camera so as not to generate mechanical noise.
[0005]
By the way, if the dust-proof glass is vibrated to remove dust, sound is generated due to the vibration of the air. If the frequency of the sound generated during the excitation is in the audible band, the user will hear this sound. It is undesirable that such a sound is generated when the silent operation mode is set.
[0006]
The present invention has been made in view of such a problem, and an object of the present invention is to perform an imaging operation without being heard by a user when a silent operation mode is set. In particular, it is an object of the present invention to provide an electronic imaging apparatus capable of performing a dustproof operation without being heard by a user when a silent operation mode is set.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a first invention is an electronic imaging apparatus having a silent operation mode for suppressing generation of sound related to an imaging operation, and an imaging optical system that forms an optical image of a subject. A photoelectric conversion unit that converts an optical image formed by the imaging optical system into an electric signal, and dust disposed between the imaging optical system and the photoelectric conversion unit, and dust on a photoelectric conversion surface of the photoelectric conversion unit. And a control means for causing the dust filter to perform a dust removal operation by vibrating the dust filter at a predetermined frequency, wherein the silent operation mode is selected. The dust filter is vibrated in different vibration modes depending on whether or not the filter is selected.
[0008]
According to a second aspect, in the electronic imaging device according to the first aspect, the control unit vibrates the dustproof filter at a different driving frequency depending on whether the silent operation mode is selected.
[0009]
According to a third aspect, in the electronic imaging apparatus according to the second aspect, the control means is higher when the silent operation mode is selected than when the silent operation mode is not selected. The dust filter is vibrated at a driving frequency.
[0010]
According to a fourth aspect, in the electronic imaging apparatus according to the third aspect, the control unit vibrates the dustproof filter at a drive frequency that does not generate an audible sound when the silent operation mode is selected. .
[0011]
According to a fifth aspect, in the electronic imaging apparatus according to the first aspect, the control means generates a traveling wave in the dust-proof filter according to whether the silent operation mode is selected. And generating a standing wave in the dustproof filter.
[0012]
According to a sixth aspect, in the electronic imaging apparatus according to the fifth aspect, the dustproof filter includes a plurality of piezoelectric elements, and the control unit controls the plurality of the plurality of piezoelectric elements when the silent operation mode is selected. A drive voltage having a different phase is applied to the piezoelectric elements, and when the silent operation mode is not selected, a drive voltage having the same phase is applied to the plurality of piezoelectric elements.
[0013]
According to a seventh aspect of the invention, there is provided an electronic imaging apparatus having a silent operation mode for suppressing generation of sound related to an imaging operation, wherein the imaging optical system forms an optical image of a subject, and the imaging optical system forms the optical image. A photoelectric conversion unit that converts an imaged optical image into an electric signal; and a dustproof device that is disposed between the imaging optical system and the photoelectric conversion unit and that prevents dust and the like from adhering to a photoelectric conversion surface of the photoelectric conversion unit. A filter, and control means for causing the dustproof filter to perform a dust removing operation by vibrating the dustproof filter at a predetermined frequency, wherein the control means determines whether or not the silent operation mode is selected. Accordingly, one of performing the dust removing operation of the dustproof filter and prohibiting the dust removing operation of the dustproof filter is performed.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
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.
[0016]
That is, FIG. 1 is a perspective view schematically showing an internal configuration of a camera body with a part thereof cut away.
[0017]
The camera 1 of the present embodiment includes a camera body 11 and a lens barrel 12 which are separately formed, and both the camera body 11 and the lens barrel 12 are configured to be detachable from each other. It becomes.
[0018]
The lens barrel 12 is configured to hold therein a photographing optical system 12a including a plurality of lenses and a driving mechanism thereof.
[0019]
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.
[0020]
The lens barrel 12 is provided so as to protrude toward the front of the camera body 11.
[0021]
The camera body 11 is provided with various constituent members and the like, and is a connecting member for detachably mounting a lens barrel 12 holding a shooting optical system 12a. This is a so-called single-lens reflex camera having an optical system mounting portion 11a on its front surface.
[0022]
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.
[0023]
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 for generating an instruction signal or the like for starting an imaging operation is provided.
[0024]
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.
[0025]
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.
[0026]
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.
[0027]
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.
[0028]
On the other hand, while the camera 1 is performing the imaging operation, the quick return mirror 13b moves to a predetermined position retracted from the optical axis of the imaging optical system 12a. It is led to the element side.
[0029]
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.
[0030]
FIG. 2 is a block diagram showing a system configuration of the camera according to the embodiment of the present invention.
[0031]
That is, the camera system of this embodiment mainly includes a camera body 11 and a lens barrel 12 as an interchangeable lens, and a desired lens barrel 12 is detachably attached to the front surface of the camera body 11. It is attached to.
[0032]
The lens barrel 12 is controlled by a lens control microcomputer (hereinafter referred to as “Lucom”) 205.
[0033]
The control of the camera body 11 is performed by a body control microcomputer (hereinafter, referred to as Bucom) 150.
[0034]
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.
[0035]
In this case, the Lucom 205 operates as a camera system while subordinately cooperating with the Bucom 150.
[0036]
In the lens barrel 12, an imaging optical system 12a and an aperture 203 are provided.
[0037]
The photographing optical system 12a is driven by a DC motor (not shown) in the lens driving mechanism 202.
[0038]
The aperture 203 is driven by a stepping motor (not shown) in the aperture drive mechanism 204.
[0039]
The Lucom 205 controls each of these motors according to a command from the Bucom 150.
[0040]
The following components are arranged in the camera body 11 as shown in the figure.
[0041]
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.
[0042]
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.
[0043]
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.
[0044]
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.
[0045]
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.
[0046]
Further, the piezoelectric element 22 has two electrodes, and the piezoelectric element 22 vibrates the dustproof filter 21 by a dustproof filter driving circuit 140 as a part of the vibrating means, and the dust adhering to the glass surface thereof. Is configured to be able to be removed.
[0047]
Note that a temperature measurement circuit 133 is provided near the dustproof filter 21 to measure the temperature around the image sensor 27.
[0048]
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.
[0049]
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.
[0050]
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.
[0051]
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.
[0052]
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.
[0053]
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.
[0054]
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.
[0055]
The user can check the captured image from the display image on the liquid crystal monitor 124.
[0056]
The SDRAM 125 is a memory for temporarily storing image data, and is used as a work area when the image data is converted.
[0057]
The image data is set to be stored in the recording medium 127 after being converted into JPEG data.
[0058]
The image sensor 27 is protected by the dust filter 21 made of a transparent glass member as described above.
[0059]
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.
[0060]
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.
[0061]
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.
[0062]
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.
[0063]
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.
[0064]
It is preferable that the temperature measurement point of the sensor is set very close to the vibration surface of the dustproof filter 21.
[0065]
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.
[0066]
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.
[0067]
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.
[0068]
Next, details of the imaging unit 15 in the camera 1 of the present embodiment will be described.
[0069]
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.
[0070]
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.
[0071]
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.
[0072]
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.
[0073]
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.
[0074]
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.
[0075]
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.
[0076]
The image sensor 27 is mounted at a predetermined position on the main circuit board 16 via an image sensor fixing plate 28.
[0077]
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.
[0078]
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.
[0079]
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.
[0080]
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. .
[0081]
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.
[0082]
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.
[0083]
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.
[0084]
The airtightness between the optical LPF 25 and the image sensor 27 is maintained.
[0085]
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.
[0086]
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.
[0087]
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.
[0088]
Thus, the optical LPF 25 does not escape from the inside of the CCD case 24 toward the front side.
[0089]
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.
[0090]
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.
[0091]
The image sensor 27 is mounted on the main circuit board 16 with the image sensor fixing plate 28 interposed therebetween as described above.
[0092]
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.
[0093]
The main circuit board 16 is fixed to the image sensor fixing plate 28 by screws 16d via spacers 16c.
[0094]
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.
[0095]
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.
[0096]
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.
[0097]
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.
[0098]
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.
[0099]
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.
[0100]
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.
[0101]
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.
[0102]
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.
[0103]
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.
[0104]
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.
[0105]
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. .
[0106]
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.
[0107]
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 abutting on the outer peripheral edge of the dustproof filter 21. Thus, the dustproof filter 21 is pressed toward the dustproof filter receiving member 23, that is, in the optical axis direction.
[0108]
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.
[0109]
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.
[0110]
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.
[0111]
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.
[0112]
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.
[0113]
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.
[0114]
Thus, a predetermined gap 51a is formed in a space between the optical LPF 25 and the dustproof filter 21.
[0115]
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.
[0116]
The space 51b is a sealed space formed so as to protrude outside the optical LPF 25 (see FIGS. 4 and 5).
[0117]
The space 51b is set to be a space wider than the space 51a.
[0118]
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.
[0119]
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.
[0120]
The sealing structure is provided at a position outside the periphery of the optical LPF 25 or its vicinity.
[0121]
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.
[0122]
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.
[0123]
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.
[0124]
Here, the vibration as the dust removing operation of the dustproof filter 21 will be described. FIG. 6 is a front view showing only the dustproof filter 21 and the piezoelectric element 22 provided integrally with the dustproof filter 21 in the image pickup unit 15 of the camera 1.
[0125]
7 and 8 show the state change of the dustproof filter 21 and the piezoelectric element 22 when a periodic drive voltage is applied to the piezoelectric element 22 of FIG. 6, and FIG. FIG. 8 is a cross-sectional view taken along line BB of FIG. 6.
[0126]
For example, when a negative (minus;-) voltage is applied to the piezoelectric element 22, the dustproof filter 21 is deformed as shown by a solid line in FIGS. 7 and 8, while a positive (plus; +) voltage is applied to the piezoelectric element 22. Is applied, the dustproof filter 21 is deformed as shown by a dotted line in FIG.
[0127]
In this case, the amplitude is substantially zero at the position of the vibration node indicated by the reference numeral 21a in FIGS. 6 to 8, so that the receiving portion 23c of the dustproof filter receiving member 23 is provided at a portion corresponding to the node 21a. Is set to abut. Thereby, the dustproof filter 21 can be efficiently supported without hindering the vibration. In this state, the dust filter 21 vibrates by applying a periodic voltage to the piezoelectric element 22, and dust and the like attached to the surface of the dust filter 21 are removed.
[0128]
The resonance frequency at this time is determined by the shape, plate thickness, material and the like of the dustproof filter 21. The examples shown in FIGS. 6 to 8 described above show the case where the primary vibration is generated.
[0129]
Another example shown in FIGS. 9 to 11 shows a state in which secondary vibration is generated in a dustproof filter having the same configuration as the examples shown in FIGS. 6 to 8.
[0130]
In this case, FIG. 9 is a front view showing only the dustproof filter 21 and the piezoelectric element 22 provided integrally with the dustproof filter 21 in the imaging unit 15 of the camera 1 as in FIG.
[0131]
10 and 11 show a state change of the dustproof filter 21 and the piezoelectric element 22 when a periodic voltage for generating secondary vibration is applied to the piezoelectric element 22 of FIG. 9, and FIG. 9 is a cross-sectional view taken along line AA of FIG. 9, and FIG. 11 is a cross-sectional view taken along line BB of FIG.
[0132]
For example, when a negative (minus;-) voltage is applied to the piezoelectric element 22, the dustproof filter 21 deforms as shown by a solid line in FIGS. 10 and 11, while a positive (plus; +) voltage is applied to the piezoelectric element 22. Is applied, the dustproof filter 21 is deformed as shown by a dotted line in FIG.
[0133]
In this case, as shown by reference numerals 21a and 21b shown in FIGS. 9 to 11, two pairs of nodes exist in this vibration, but the receiving portion of the dustproof filter receiving member 23 is provided at a portion corresponding to the node 21a. By setting so that 23c is brought into contact, the dustproof filter 21 can be efficiently supported without obstructing the vibration, similarly to the examples shown in FIGS. 6 to 8 described above.
[0134]
Therefore, in such a dustproof mechanism, the dustproof filter 21 vibrates by applying a periodic voltage to the piezoelectric element 22 at a predetermined time, and dust and the like attached to the surface of the dustproof filter 21 can be removed.
[0135]
FIG. 12 is a diagram conceptually illustrating a configuration of a vibration unit that vibrates a dustproof filter in an imaging unit in the electronic imaging apparatus.
[0136]
As shown in FIG. 12, the ring-shaped 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).
[0137]
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.
[0138]
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 (a second periodic voltage signal) having a phase shifted by 90 ° is applied by 48 90 ° phase shifters 35.
[0139]
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. 13 (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.
[0140]
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.
[0141]
FIG. 14 is a circuit diagram schematically illustrating the configuration of the dust filter drive circuit 140 in the electronic imaging device 1 described with reference to FIG. FIG. 15 is a time chart showing the form of each signal output from each component in the dustproof filter drive circuit 140 of FIG.
[0142]
A clock generator 255 is provided inside the body control microcomputer 150. 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. 15). 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. 15).
[0143]
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. 15). 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. 15).
[0144]
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.
[0145]
When the two MOS transistors Q01 (244b1) and Q02 (244c1) connected to the primary side of the transformer A (245-1) are alternately turned on in this manner, the two MOS transistors Q01 (244b1) are turned on. On the next side, a signal of Sig5 shown in FIG. 15 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.
[0146]
The resistor R00 (246-1) is provided to restrict an excessive current from flowing through the transformer A (245-1).
[0147]
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.
[0148]
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.
[0149]
The calculation of the driving frequency is based on the following equation (1).
[0150]
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.
[0151]
On the other hand, the output signal Sig3 of the first 分 frequency dividing circuit 242-1 is outputted to the third 分 frequency dividing circuit 242-3 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 243-3.
[0152]
When the port P_θCont is in a low state, the pulse signal Sig3 is output to the third 周 frequency divider 242-3 as it is (see Sig6 in FIG. 15). The pulse signal Sig6 is further output after being halved by the third 1/2 frequency divider 242-3 (see Sig7 shown in FIG. 15). 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.
[0153]
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).
[0154]
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.
[0155]
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 °.
[0156]
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.
[0157]
(1st Embodiment)
FIG. 16 is a flowchart for explaining the operation of the Bucom 150 in the camera system according to the first embodiment of the present invention.
[0158]
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.
[0159]
Next, as shown in step S101, step S102, and step S103, an operation of removing dust when the power is turned on is executed. This is because dust may adhere to the dustproof filter 21 for some reason (for example, the user has exchanged the taking lens) while the power is off.
[0160]
In step S101, the state of the silent operation mode selection switch, which is one of the camera operation switches 152, is determined. If the silent operation mode selection switch is ON, the silent operation mode is selected, and various sounds generated in connection with the imaging operation must be suppressed. Therefore, here, even if the imaging operation is delayed, the operating speed of the actuator is reduced to suppress mechanical noise. In addition, notification display by sound (warning when the battery is low, a pseudo release sound for clearly indicating the imaging operation, a notification sound at the end of the focus adjustment operation, and the like) is prohibited. In the silent operation mode, the noise generated by the dustproof filter 21 due to the dustproof operation must also be suppressed.
[0161]
If the silent operation mode has not been selected in step S101, the process proceeds from step S101 to step S102, and the dustproof operation for the dustproof filter 21 is performed. The value set in the N-ary counter 241 to vibrate the dustproof filter 21 at the resonance frequency (f0) is stored in the nonvolatile memory 129. The time (T0) for exciting the dustproof filter 21 to remove dust is also stored in the nonvolatile memory 129. In step S102, a sound dustproof operation is performed based on these data. Here, the two piezoelectric elements 22a and 22b are driven at the frequency f0 in the same phase for the time T0. When the dust filter 21 is vibrated at the frequency f0, the dust filter 21 vibrates as shown in FIGS. The dust filter 21 vibrates in the same phase as a whole. Therefore, if f0 is an audible frequency, a sound that can be detected by a person is generated. Since the operation mode is not the silent operation mode, the generation of the sound is convenient for notifying the user of the dustproof operation.
[0162]
On the other hand, when the silent operation mode is selected in step S101, the process proceeds from step S101 to step S103. Here, the dustproof operation for the dustproof filter 21 is performed in the same manner as the operation in step S102. The two control parameters (f1, T1) are read from the nonvolatile memory 129. Here, f1 is a frequency different from (higher than) f0 described above. However, when the driving frequency is high, the vibration width of the filter becomes small. Therefore, it is necessary to set the driving time T1 at the frequency f1 longer than the driving time T0 at the frequency f0 in order to completely remove the attached dust and the like. In step S103, the dustproof filter 21 is vibrated based on these control parameters, and a silent dustproof operation is performed. When the dustproof filter 21 is vibrated at f1, the dustproof filter 21 vibrates in a form different from the vibration forms shown in FIGS. 7 and 8, as shown in FIGS. The dust filter 21 does not vibrate in the same phase as a whole. As can be seen from the figure, the phase of the shift of the central portion and the shift of the peripheral portion are shifted by 180 °. Therefore, the sound generated by the shift of the central portion and the sound generated by the shift of the peripheral portion are also out of phase and canceled. Therefore, even if f1 is an audible frequency, the user does not hear the sound associated with the dustproof operation. There are many vibration modes of the circular glass plate constituting the dustproof filter 21. In vibration modes other than those shown in FIGS. 7 and 8, sound cannot be radiated efficiently because the entire dustproof filter 21 does not vibrate in phase. Therefore, in the silent operation mode, it is not necessary to stick to the frequency f1 if the entire dustproof filter 21 is driven at a frequency that does not vibrate in phase.
[0163]
After execution of step S102 or step S103, the process proceeds to step S104. In step S104, the state of the first release SW, which is one of the camera operation switches 152, is determined. It waits in step S104 until the operation of the first release SW is detected. When the first release SW is operated, the process moves from step S104 to step S105. In step S105, the luminance information of the subject is obtained from the photometry circuit 121. The exposure time (Tv value) of the imaging unit 15 and the aperture setting value (Av value) of the lens unit 12 are calculated from this information.
[0164]
In step S106, detection data of the AF sensor unit 116 is obtained via the AF sensor drive circuit 117. The amount of defocus is calculated based on this data.
[0165]
In step S107, it is determined whether or not the calculated shift amount is within the permitted range. If not, drive control of the photographic lens in the photographic optical system 12a is performed in step S108, and the process returns to step S104.
[0166]
On the other hand, if it is determined in step S107 that the deviation amount is within the permitted range, the process proceeds to step S109. In step S109, the operation state of the second release switch, which is one of the camera operation switches 152, is determined. When the operation of the SW is performed, the process proceeds to step S110, and when the operation of the SW is not performed, the process proceeds to step S104.
[0167]
In step S110, the state of the silent operation mode setting SW is detected. If the operation mode is not the silent operation mode, a soundproof dustproof operation is started in step S111 prior to the imaging operation. This operation is the same as step S102 described above. The dustproof operation is performed in parallel with a preparation operation (steps S113 and S114) necessary for the imaging operation, which will be described later.
[0168]
On the other hand, when the operation mode is the silent operation mode in step S110, a silent dustproof operation is started in step S112. This operation is the same operation as step S103.
[0169]
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.
[0170]
In step S114, the quick return mirror 13b is driven to the UP position.
[0171]
In step S115, the drive of the dustproof filter 21 is stopped by stopping the drive of the piezoelectric element 22 to end the dustproof operation.
[0172]
In step S116, the shutter 14 is OPEN-controlled. In step S117, an imaging operation is performed by exposing the imaging device 27 based on the Tv value calculated in step S105.
[0173]
In step S118, the shutter 14 is subjected to CLOSE control. In step S119, the quick return mirror 13b is driven to the Down position and the shutter 14 is charged.
[0174]
In step S120, the aperture of the taking lens in the taking optical system 12a is driven to the open position. In step S121, image data is read from the image sensor 27, converted into a predetermined format, and stored in a recording medium.
[0175]
According to the above-described first embodiment, since the silent dustproof operation is performed when the silent operation mode is set, the dustproof operation can be performed without the user hearing the sound generated by the camera.
[0176]
(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.
[0177]
The Bucom 150 starts operating when the power switch of the camera is turned on. In step S200, 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.
[0178]
Next, as shown in step S201, step S202, and step S203, an operation for removing dust at the time of power-on is executed. This is because dust may adhere to the dustproof filter 21 for some reason (for example, the user has exchanged the taking lens) while the power is off.
[0179]
In step S201, the state of the silent operation mode selection switch, which is one of the camera operation switches 152, is determined. When the silent operation mode selection switch is ON, the silent operation mode is selected, and various sounds generated in connection with the imaging operation must be suppressed. Therefore, here, mechanical noise that reduces the operation speed of the actuator even if the imaging operation is delayed is suppressed. In addition, notification display by sound (a warning when the battery is low, a pseudo release sound for clearly indicating the imaging operation, a notification sound at the end of the focus adjustment operation, and the like) is prohibited. In the silent operation mode, the noise generated by the dustproof filter 21 due to the dustproof operation must also be suppressed.
[0180]
If the silent operation mode is not selected in step S201, the process proceeds from step S201 to step S202. In step S202, a dustproof operation is performed on the dustproof filter 21. The value set in the N-ary counter 241 to vibrate the dustproof filter 21 at the resonance frequency (f0) is stored in the nonvolatile memory 129. The time (T0) for exciting the dustproof filter 21 to remove dust is also stored in the nonvolatile memory 129. In step S202, a sound dustproof operation is executed based on these data. Here, the two piezoelectric elements 22a and 22b are driven at the frequency f0 in the same phase for the time T0. When the dust filter 21 is vibrated at the frequency f0, the dust filter 21 vibrates as shown in FIGS. The dustproof filter 21 vibrates in the same phase as a whole. Therefore, if f0 is an audible frequency, a sound that can be detected by a person is generated. Since the operation mode is not the silent operation mode, the generation of the sound is convenient for notifying the user of the dustproof operation.
[0181]
On the other hand, when the silent operation mode is selected in step S201, the process proceeds from step S201 to step S203. Here, the dustproof operation for the dustproof filter 21 is performed in the same manner as the operation in step S202. The two control parameters (fs, Ts) are read from the nonvolatile memory 129. Here, fs is a driving frequency, and Ts is a driving time. When a drive signal having a phase shift of 90 ° is applied to the two piezoelectric elements 22a and 22b based on these parameters, the dust filter 21 vibrates as shown in FIG. In this case, a traveling wave is generated in the dustproof filter 21, but no sound can be radiated because the entire dustproof filter 21 does not vibrate in phase. Therefore, the dustproof operation is performed in a silent state.
[0182]
After the execution of step S202 or step S203, the process proceeds to step S204. In step S204, the state of the first release SW, which is one of the camera operation SWs 152, is determined. The process waits in step S204 until the operation of the first release SW is detected. When the first release SW is operated, the process moves from step S204 to step S205. In step S205, the luminance information of the subject is obtained from the photometry circuit 121. The exposure time (Tv value) of the imaging unit 15 and the aperture setting value (Av value) of the lens unit 12 are calculated from this information.
[0183]
In step S206, detection data of the AF sensor unit 116 is obtained via the AF sensor drive circuit 117. The amount of defocus is calculated based on this data.
[0184]
In step S207, 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 S208, and the process returns to step S204.
[0185]
On the other hand, if the deviation amount is within the permitted range in step S207, the process proceeds to step S209. In step S209, the operation state of the second release switch, which is one of the camera operation switches 152, is determined. If the second release SW has been operated, the flow shifts to step S210; otherwise, the flow shifts to step S204.
[0186]
In step S210, the state of the silent operation mode setting SW is detected. When the operation is not in the silent operation mode, a sound dustproof operation is started in step S211 prior to the imaging operation. This operation is the same as step S202 described above. The dustproof operation is executed in parallel with the preparation operation (step S213, step S214) necessary for the imaging operation.
[0187]
On the other hand, when the operation mode is the silent operation mode in step S210, the process proceeds from step S210 to step S212 to start the dust-proof operation by the bending traveling wave. This operation is the same as step S203.
[0188]
In step S213, the aperture of the taking lens in the taking optical system 12a is set based on the Av value calculated in step S205.
[0189]
In step S214, the quick return mirror 13b is driven to the UP position.
[0190]
In step S215, driving of the dustproof filter 21 is stopped by stopping driving of the piezoelectric element 22 to end the dustproof operation.
[0191]
In step S216, the shutter 14 is OPEN-controlled. In step S217, the image pickup device 27 is exposed based on the Tv value calculated in step S205 to perform an image pickup operation.
[0192]
In step S218, the shutter 14 is subjected to CLOSE control. In step S219, the quick return mirror 13b is driven to the Down position. Further, the shutter 14 is charged. In step S220, the aperture of the taking lens in the taking optical system 12a is driven to the open position. In step S221, image data is read from the image sensor 27, converted into a predetermined format, and stored in a recording medium.
[0193]
According to the above-described second embodiment, when the silent operation mode is set, the dustproof operation is performed by the bending traveling wave, so that the user can perform the dustproof operation without being heard by the camera. it can.
[0194]
(Third embodiment)
In the first and second embodiments described above, when the silent operation mode is selected, the dustproof filter 21 is driven in such a manner as not to generate a sound that can be heard by a person, so that the silent operation mode is selected. Even if there is, the dustproof operation itself is not stopped. However, in the third embodiment, when the silent operation mode is set, the operation of the dustproof operation itself is prohibited. With the prohibition of the dustproof operation, the quick return mirror 13b is moved to the UP position in order to reduce the probability that dust adheres to the dustproof filter 21.
[0195]
Normally, the quick return mirror 13b is UP / Down driven in conjunction with the exposure operation, but here, when the silent operation mode is set, the quick return mirror 13b is fixed at the UP position. By fixing the quick return mirror 13b, the air in the mirror box is not stirred. Therefore, the possibility that dust existing in the mirror box is wound up and adheres to the dustproof filter 21 is reduced. Further, the mechanical noise generated by the UP / Down of the quick return mirror 13b is also eliminated, which is more consistent with the purpose of the silent operation mode.
[0196]
Hereinafter, the operation of the Bucom 150 in the camera system according to the third embodiment of the present invention will be described with reference to the flowchart in FIG. The Bucom 150 starts operating when the power switch of the camera is turned on. In step S300, a process for activating the camera system is performed. 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.
[0197]
In step S301, the state of the silent operation mode selection switch, which is one of the camera operation switches 152, is determined. When the silent operation mode selection switch is ON, it indicates that the silent operation mode has been selected. If the silent operation mode selection switch is ON in step S301, the process proceeds from step S301 to step S302. In step S302, the position of the quick return mirror 13b is detected. If the quick return mirror 13b is at the Down position, it indicates that immediately after the silent operation mode selection SW is turned on. Then, the process shifts from step S302 to step S303 to drive the quick return mirror 13b to the UP position. When the quick return mirror 13b is set to the UP position, the finder enters a black out state, and the user cannot observe the subject using the finder. In this situation, it is necessary to use the liquid crystal monitor 124 to observe the subject.
[0198]
Therefore, the shutter 14 is set to the OPEN state, the image data is read from the image sensor 27, and a video signal is created. Then, the subject image is displayed on the liquid crystal monitor 124 by the video signal. A detailed description of this operation is omitted.
[0199]
In the next step S304, a dustproof operation is performed under predetermined conditions. The dustproof operation in step S304 is the same as step S102 (FIG. 16). Although a noise is generated with the dustproof operation, there is no problem since the dustproof operation is not performed during the silent operation mode. Here, the reason why the silent dust proof operation described in the first and second embodiments is not performed in the dust proof operation is that the user is shifted to the silent operation mode by using the sound by performing the sound dust proof operation. To announce that.
[0200]
If the silent operation mode has already been set and the quick return mirror 13b is at the UP position, the operations in steps S303 and S304 are not required. At this time, the process moves from step S302 to step S307.
[0201]
On the other hand, when the silent operation mode selection switch is OFF in step S301, the position of the quick return mirror 13b is detected in step S305. When the quick return mirror is in the UP position, it indicates that immediately after the silent operation mode selection SW is turned off. If the quick return mirror 13b is in the UP position in step S305, the quick return mirror 13b is returned to the Down position in step S306. With the quick return mirror 13b set to the Down position, the blackout state of the finder is released. The user can observe the subject through the finder. Next, the process proceeds to step S307.
[0202]
In step S307, the state of the first release SW, which is one of the camera operation SWs 152, is determined. When the first release SW is turned on, the process proceeds from step S307 to step S308, and when the first release SW is off, the process proceeds to step S301. In step S308, the state of the silent operation mode selection SW is detected. If the silent operation mode selection switch is OFF, the process proceeds to step S309.
[0203]
In step S309, the 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. In step S310, a well-known phase difference type focus adjustment operation is performed. That is, the detection data of the AF sensor unit 116 is obtained via the AF sensor drive circuit 117. The amount of defocus is calculated based on the data, and the photographic lens in the photographic optical system 12a is driven based on the amount of defocus. Thereafter, the process proceeds to step S313.
[0204]
On the other hand, when the operation mode is the silent operation mode in step S308, the process proceeds from step S308 to step S311. In step S311, subject brightness information is detected based on the output of the imaging element 27. Then, the exposure time (Tv value) of the imaging element 27 and the aperture setting value (Av value) of the lens unit 12 are calculated. Since the quick return mirror 13b is at the UP position, it is not possible to obtain the subject brightness information using the photometric circuit 121 arranged in the finder optical system.
[0205]
In step S312, a well-known contrast-type focus adjustment operation is performed. That is, the position of the taking lens is adjusted so that the contrast of the image data read from the image sensor 27 is maximized.
[0206]
In step S313, the operation state of the second release switch, which is one of the camera operation switches 152, is determined. If the second release SW has been operated, the flow shifts to step S314; otherwise, the flow shifts to step S301.
[0207]
In step S314, the aperture of the taking lens in the taking optical system 12a is controlled based on the Av value already calculated. In step S315, it is determined whether or not the silent operation mode is set. If the silent operation mode is set, there is no need to drive the quick return mirror 13b. Dustproof operation is also prohibited. Therefore, in this case, the process moves from step S315 to step S318.
[0208]
On the other hand, when the silent operation mode is not set in step S315, the quick return mirror 13b is driven to the UP position in step S316. Further, in step S317, a dustproof operation is performed. The dustproof operation here is the same as the dustproof operation in step S304.
[0209]
In step S318, the shutter 14 is OPEN-controlled. In step S319, the image sensor 27 is exposed based on the already calculated Tv value. In step S320, the shutter 14 is subjected to CLOSE control.
[0210]
In step S321, it is determined whether the silent operation mode is set. If it is in the silent operation mode, there is no need to make the quick return mirror 13b down, so the process immediately proceeds to step S323. If the silent operation mode has not been set, the quick return mirror 13b is driven to the Down position in step S322, and the process proceeds to step S323. In step S323, the shutter 14 is charged.
[0211]
In the next step S324, the aperture of the taking lens in the taking optical system 12a is driven to the open position. In step S325, the image data is read from the image sensor 27, converted into a predetermined format, and stored in a recording medium.
[0212]
According to the above-described third embodiment, the dustproof operation is not performed when the silent operation mode is set, so that the imaging operation can be performed without the user hearing the sound generated by the camera.
[0213]
(Note)
1. A shooting optical system for forming an optical image of a subject,
Photoelectric conversion means for converting the optical image into an electric signal,
A dustproof filter disposed between the imaging optical system and the photoelectric conversion unit and capable of vibrating at a set cycle;
Has,
An electronic imaging apparatus, wherein the dust filter is capable of vibrating in a first vibration mode in which an audible sound is generated when vibrated, and in a second vibration mode in which the audible sound is smaller than the first vibration mode.
[0214]
2. The first vibration mode is a vibration mode in which the dustproof filter generates a standing wave, and the second vibration mode is a vibration mode in which the dustproof filter generates a traveling wave. An electronic imaging device according to item 1.
[0215]
3. In the first vibration mode, the dust filter is vibrated at a first frequency, and in the second vibration mode, the dust filter is vibrated at a second frequency higher than the first frequency. 1. An electronic imaging device according to item 1.
[0216]
4. The second vibration mode is a vibration mode executed when the electronic imaging apparatus is set to a silent mode. An electronic imaging device according to item 1.
[0219]
5. A shooting optical system for forming an optical image of a subject,
Photoelectric conversion means for converting the optical image into an electric signal,
Dustproof glass disposed between the imaging optical system and the photoelectric conversion means,
A plurality of piezoelectric elements arranged on the periphery of the dust-proof glass,
A drive control unit that applies a periodic drive voltage to the plurality of piezoelectric elements, and generates a vibration wave on the dust-proof glass by the vibration of the piezoelectric elements generated thereby,
Has,
The drive control means is capable of driving the plurality of piezoelectric elements at a first frequency at which the dustproof glass vibrates while emitting an audible sound and at a second frequency at which the dustproof glass does not emit an audible sound. Electronic imaging device characterized by the following.
[0218]
6. 4. The electronic imaging apparatus has a silent operation mode, and the drive control means drives the plurality of piezoelectric elements at the second frequency in the silent operation mode. An electronic imaging device according to item 1.
[0219]
7. 5. The second frequency is higher than the first frequency. An electronic imaging device according to item 1.
[0220]
8. A shooting optical system for forming an optical image of a subject,
Photoelectric conversion means for converting the optical image into an electric signal,
Dustproof glass disposed between the imaging optical system and the photoelectric conversion means,
A plurality of piezoelectric elements arranged on the periphery of the dust-proof glass,
Drive control means for applying a periodic drive piezoelectric to the plurality of piezoelectric elements, and generating vibration waves on the dust-proof glass by the vibration of the piezoelectric elements generated thereby;
Setting means for selectively setting the normal operation mode and the silent operation mode,
Has,
An electronic imaging apparatus, wherein the drive control means generates a standing wave on the dust-proof glass in the normal operation mode, and generates a traveling wave on the dust-proof glass in the silent operation mode.
[0221]
9. The drive control unit applies a drive voltage having the same phase to the plurality of piezoelectric elements in the normal operation mode, and applies a drive voltage having a different phase to the plurality of piezoelectric elements in the silent operation mode. Do 8 An electronic imaging device according to item 1.
[0222]
10. A shooting optical system for forming an optical image of a subject,
Photoelectric conversion means for converting the optical image into an electric signal,
A dustproof filter disposed between the imaging optical system and the photoelectric conversion unit and capable of vibrating at a set cycle;
Vibration control means for vibrating the dustproof filter at a timing prior to an imaging operation,
Setting means for selectively setting the normal operation mode and the silent operation mode,
Has,
An electronic imaging apparatus, wherein the vibration operation of the dustproof filter is prohibited when the silent operation mode is set.
[0223]
【The invention's effect】
According to the present invention, when the silent operation mode is set, it is possible to perform an imaging operation without being heard by the user the sound generated by the camera, particularly when the silent operation mode is set, The dustproof operation can be performed without the user hearing the sound generated by the camera.
[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 shown.
FIG. 4 is a perspective view showing a part of the imaging unit 15 of 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 taken along a cut surface in FIG.
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 shows a state change of the dustproof filter 21 and the piezoelectric element 22 when a periodic drive voltage is applied to the piezoelectric element 22 of FIG. 6, and is a cross-sectional view taken along line AA of FIG. is there.
8 shows a state change of the dustproof filter 21 and the piezoelectric element 22 when a periodic drive voltage is applied to the piezoelectric element 22 of FIG. 6, and is a cross-sectional view taken along line BB of FIG. is there.
9 is a front view showing only a dustproof filter 21 and a piezoelectric element 22 provided integrally with the dustproof filter 21 in the image pickup unit 15 of the camera 1 as in FIG.
10 shows a state change of the dustproof filter 21 and the piezoelectric element 22 when a periodic voltage for generating secondary vibration is applied to the piezoelectric element 22 of FIG. 9, and FIG. It is sectional drawing which follows the A line.
11 shows a state change of the dust filter 21 and the piezoelectric element 22 when a periodic voltage for generating secondary vibration is applied to the piezoelectric element 22 of FIG. 9, and FIG. It is sectional drawing which follows the B line.
FIG. 12 is a diagram conceptually showing a configuration of a vibrating means for vibrating a dustproof filter in an imaging unit in the electronic imaging apparatus.
FIG. 13 is a diagram showing a state of a bending traveling wave vibration (a vibration in which peaks Y and valleys T alternately occur at equal intervals and with equal amplitude) generated in the dustproof filter 21.
14 is a circuit diagram schematically showing a configuration of a dust filter driving circuit 140 in the electronic imaging device 1 described in FIG.
FIG. 15 is a time chart showing a form of each signal output from each component in the dustproof filter drive circuit 140 of FIG. 14;
FIG. 16 is a flowchart illustrating an operation of the Bucom 150 in the camera system according to the first embodiment of the present invention.
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 (7)

An electronic imaging apparatus having a silent operation mode that suppresses generation of sound related to an imaging operation,
A shooting optical system for forming an optical image of a subject,
Photoelectric conversion means for converting an optical image formed by the imaging optical system into an electric signal,
A dustproof filter 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 dustproof filter to perform a dust removing operation by vibrating the dustproof filter at a predetermined frequency;
With
The electronic imaging apparatus according to claim 1, wherein the control unit vibrates the dustproof filter in a different vibration mode depending on whether the silent operation mode is selected. 2. The electronic imaging apparatus according to claim 1, wherein the control unit vibrates the dustproof filter at a different drive frequency depending on whether the silent operation mode is selected. 3. 3. The control device according to claim 2, wherein the control unit vibrates the dustproof filter at a higher drive frequency when the silent operation mode is selected than when the silent operation mode is not selected. 4. Electronic imaging device. The electronic imaging apparatus according to claim 3, wherein the control unit vibrates the dustproof filter at a drive frequency that does not generate an audible sound when the silent operation mode is selected. The control means performs either one of generating a traveling wave in the dustproof filter and generating a standing wave in the dustproof filter according to whether the silent operation mode is selected. The electronic imaging device according to claim 1, wherein: The dustproof filter includes a plurality of piezoelectric elements, and the control unit applies drive voltages having different phases to the plurality of piezoelectric elements when the silent operation mode is selected, and the silent operation mode is selected. 6. The electronic imaging apparatus according to claim 5, wherein the driving voltage having the same phase is applied to the plurality of piezoelectric elements when the driving is not performed. An electronic imaging apparatus having a silent operation mode that suppresses generation of sound related to an imaging operation,
A shooting optical system for forming an optical image of a subject,
Photoelectric conversion means for converting an optical image formed by the imaging optical system into an electric signal,
A dustproof filter 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 dustproof filter to perform a dust removing operation by vibrating the dustproof filter at a predetermined frequency;
With
The control unit performs one of performing the dust removing operation of the dustproof filter and prohibiting the dust removing operation of the dustproof filter according to whether the silent operation mode is selected. The electronic imaging device according to claim 1, wherein:

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