JP2004264691A - Electronic imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic imaging apparatus which can perform a proper dust removing operation corresponding to a selected picture quality, as an electronic imaging device capable of performing imaging with a plurality of kinds of picture quality. <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 formed by the photographic optical system 12a 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 a camera operating switch SW 152 which can set a plurality of recording modes concerned with picture quality. Moreover the computer 150 makes the filter 21 perform the dust removing operation by vibrating the filter 21 by being linked with the photographing operation by the device 27 when a high-quality recording 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 technology related to a dust-proof function of an optical device used in an electronic imaging device, a technology has been proposed in which dust attached to the dust-proof glass is wiped off by vibrating a protective glass (dust-proof glass) that protects an image sensor. Have been. 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 dustproof glass at one predetermined cycle.
[0003]
[Problems to be solved by the invention]
By the way, the electronic imaging device has an operation mode in which shooting can be performed with various image qualities (the number of recording pixels, the image compression ratio, and the like). The user can execute a photographing operation with a desired image quality according to uses such as printing, processing with a personal computer, and homepage. The user can obtain high-quality image data by removing dust from the dust-proof glass.
[0004]
However, when the user selects a low image quality that is hardly affected by dust, the dust removing operation is a useless operation. In a specific shooting situation, the user tries to secure the number of shots even if the image quality is lowered. In such a situation, it is not preferable to perform the dust removing operation for each photographing operation. This is because the electric energy of the battery that supplies power to the camera system is taken along with the dust removing operation, and the user cannot take a desired number of images.
[0005]
In other situations, the user may try to reduce the time for continuous shooting even if the image quality is reduced. By reducing the number of recording pixels, the access time to a medium for recording image data is reduced. The dust removing operation in such a situation causes an increase in the release time lag. As a result, the continuous shooting speed becomes slow and the user's intention is not achieved.
[0006]
The present invention has been made in view of such a problem, and an object of the present invention is to perform an appropriate dust removing operation according to a selected image quality in an electronic imaging device capable of imaging with a plurality of image qualities. It is an object of the present invention to provide an electronic imaging device capable of performing such operations.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a first aspect of the present invention is an electronic imaging apparatus capable of imaging with a plurality of types of image quality, comprising: an imaging optical system that forms an optical image of a subject; Imaging means including a photoelectric conversion element for converting the optical image thus converted into an electric signal, and disposed between the photographing optical system and the photoelectric conversion means to prevent dust or the like from adhering to the photoelectric conversion surface of the photoelectric conversion means. An optical element to prevent, a control means for causing the optical element to perform a dust removing operation by vibrating the optical element at a predetermined frequency, and a setting means capable of setting a plurality of recording modes related to image quality, When the high-quality recording mode is set by the setting unit, the control unit vibrates the optical element in conjunction with the imaging operation of the imaging unit, and causes the optical element to perform a dust removing operation.
[0008]
According to a second aspect, in the electronic imaging apparatus according to the first aspect, the high image quality recording mode is a recording mode having a large number of pixels.
[0009]
According to a third aspect, in the electronic imaging apparatus according to the first aspect, the high-quality recording mode is a recording mode having a low image compression ratio.
[0010]
According to a fourth aspect, in the electronic imaging device according to the first aspect, the control unit causes the optical element to vibrate for a predetermined time prior to an imaging operation.
[0011]
According to a fifth aspect of the present invention, there is provided an electronic imaging apparatus capable of imaging with a plurality of types of image quality, comprising: a photographic optical system for forming an optical image of a subject; and an optical signal formed by the photographic optical system. An imaging unit including a photoelectric conversion element that converts the light into an optical element disposed between the imaging optical system and the photoelectric conversion unit, for preventing dust and the like from adhering 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; a first image recording mode for acquiring a high-quality electronic image; and the first image recording mode Setting means for selectively setting a lower image quality second image recording mode, wherein the control means sets the first image recording mode when the setting means sets the first image recording mode. For imaging operation by imaging means Dynamic and by vibrating the optical element to perform the dust removal operation to the optical element.
[0012]
According to a sixth aspect, in the electronic imaging apparatus according to the fifth aspect, the first image recording mode has a larger number of pixels of the image acquired by the imaging means than the second image recording mode. .
[0013]
According to a seventh aspect, in the electronic imaging device according to the fifth aspect, the first image recording mode has a lower compression ratio of the image acquired by the imaging means than the second image recording mode. .
[0014]
According to an eighth aspect of the present invention, there is provided an electronic imaging apparatus capable of imaging with a plurality of types of image quality, comprising: a photographic optical system for forming an optical image of a subject; and an optical image formed by the photographic optical system. An imaging unit including a photoelectric conversion element that converts the light into an optical element disposed between the imaging optical system and the photoelectric conversion unit, for preventing dust and the like from adhering 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; a first image recording mode for acquiring a high-quality electronic image; and the first image recording mode Setting means capable of setting a second image recording mode of lower image quality, wherein the control means controls the optical element when the first image recording mode is set by the setting means. Allow dust removal operation and When two image recording mode has been set to prohibit dust removal operation of the optical element.
[0015]
According to a ninth aspect of the present invention, there is provided an electronic imaging apparatus capable of imaging with a plurality of image qualities, comprising: a photographic optical system for forming an optical image of a subject; and an optical signal formed by the photographic optical system. An imaging unit including a photoelectric conversion element that converts the light into an optical element disposed between the imaging optical system and the photoelectric conversion unit, for preventing dust and the like from adhering 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, and setting means capable of setting a plurality of recording modes related to image quality, wherein the control means The form of the dust removing operation of the optical element is changed according to the recording mode set by the setting unit.
[0016]
In a tenth aspect based on the electronic imaging apparatus according to the ninth aspect, the control unit changes the time of the dust removing operation of the optical element according to the recording mode set by the setting unit.
[0017]
According to an eleventh aspect, in the electronic imaging apparatus according to the tenth aspect, the control unit sets the operation time of the dust removing unit to the first recording mode when the first recording mode is set by the setting unit. When the second recording mode having higher image quality than the first recording mode is set, the second time is longer than the first time.
[0018]
In a twelfth aspect based on the ninth aspect, in the electronic imaging apparatus according to the ninth aspect, the control means permits or prohibits execution of the operation of the dust removing means according to a recording mode set by the setting means. .
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0020]
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.
[0021]
That is, FIG. 1 is a perspective view schematically showing an internal configuration of a camera body with a part thereof cut away.
[0022]
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.
[0023]
The lens unit 12 is configured to internally hold a photographing optical system 12a including a plurality of lenses and a driving mechanism thereof.
[0024]
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.
[0025]
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.
[0026]
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.
[0027]
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.
[0028]
Inside the camera body 11, various components such as a finder device 13 forming a so-called observation optical system and a shutter mechanism for controlling the irradiation time of the subject light beam to the photoelectric conversion surface of the image sensor and the like are provided. A shutter 14 provided, an image sensor (not shown) for obtaining an image signal corresponding to a subject image, and a shutter 14 disposed at a predetermined position on the front side of the photoelectric conversion surface of the image sensor to remove dust and the like on the photoelectric conversion surface. A plurality of circuit boards including an image pickup unit 15 including a dustproof filter (also referred to as dustproof glass) 21 which is a dustproof member for preventing adhesion, and a main circuit board 16 on which various electric members constituting an electric circuit are mounted. (Only the main circuit board 16 is shown) and the like are disposed at predetermined positions.
[0029]
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.
[0030]
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.
[0031]
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.
[0032]
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.
[0033]
Further, as the shutter 14, for example, a shutter mechanism of a focal plane system, a drive circuit thereof, and the like similar to those generally used in a conventional camera or the like are applied.
[0034]
FIG. 2 is a block diagram showing a system configuration of the camera according to one embodiment of the present invention.
[0035]
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.
[0036]
The lens unit 12 is controlled by a lens control microcomputer (hereinafter referred to as “Lucom”) 205.
[0037]
The control of the camera body 11 is performed by a body control microcomputer (hereinafter, referred to as Bucom) 150.
[0038]
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.
[0039]
In this case, the Lucom 205 operates as a camera system while subordinately cooperating with the Bucom 150.
[0040]
In the lens unit 12, a photographic optical system 12a and an aperture 203 are provided.
[0041]
The photographing optical system 12a is driven by a DC motor (not shown) in the lens driving mechanism 202.
[0042]
The aperture 203 is driven by a stepping motor (not shown) in the aperture drive mechanism 204.
[0043]
The Lucom 205 controls each of these motors according to a command from the Bucom 150.
[0044]
The following components are arranged in the camera body 11 as shown in the figure.
[0045]
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 114 An AF sensor unit 116 for receiving a light beam and automatically measuring a distance is provided.
[0046]
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.
[0047]
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.
[0048]
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.
[0049]
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.
[0050]
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.
[0051]
Note that a temperature measurement circuit 133 is provided near the dustproof filter 21 to measure the temperature around the image sensor 27.
[0052]
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.
[0053]
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.
[0054]
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.
[0055]
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.
[0056]
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.
[0057]
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.
[0058]
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.
[0059]
The user can check the captured image from the display image on the liquid crystal monitor 124.
[0060]
The SDRAM 125 is a memory for temporarily storing image data, and is used as a work area when the image data is converted.
[0061]
The image data is set to be stored in the recording medium 127 after being converted into JPEG data.
[0062]
The image sensor 27 is protected by the dust filter 21 made of a transparent glass member as described above.
[0063]
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.
[0064]
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.
[0065]
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.
[0066]
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.
[0067]
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.
[0068]
It is preferable that the temperature measurement point of the sensor is set very close to the vibration surface of the dustproof filter 21.
[0069]
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.
[0070]
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.
[0071]
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.
[0072]
Next, details of the imaging unit 15 in the camera 1 of the present embodiment will be described.
[0073]
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.
[0074]
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.
[0075]
Note that the imaging unit 15 of the camera 1 of the present embodiment is a unit constituted by a plurality of members including the shutter 14 as described above. However, in FIGS. The illustration of the shutter 14 is omitted.
[0076]
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.
[0077]
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.
[0078]
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.
[0079]
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.
[0080]
The image sensor 27 is mounted at a predetermined position on the main circuit board 16 via an image sensor fixing plate 28.
[0081]
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.
[0082]
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.
[0083]
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.
[0084]
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. .
[0085]
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.
[0086]
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.
[0087]
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.
[0088]
The airtightness between the optical LPF 25 and the image sensor 27 is maintained.
[0089]
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.
[0090]
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.
[0091]
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.
[0092]
Thus, the optical LPF 25 does not escape from the inside of the CCD case 24 toward the front side.
[0093]
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.
[0094]
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.
[0095]
The image sensor 27 is mounted on the main circuit board 16 with the image sensor fixing plate 28 interposed therebetween as described above.
[0096]
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.
[0097]
The main circuit board 16 is fixed to the image sensor fixing plate 28 by screws 16d via spacers 16c.
[0098]
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.
[0099]
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.
[0100]
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.
[0101]
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.
[0102]
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.
[0103]
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.
[0104]
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.
[0105]
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.
[0106]
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.
[0107]
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.
[0108]
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.
[0109]
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. .
[0110]
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.
[0111]
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.
[0112]
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.
[0113]
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.
[0114]
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.
[0115]
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.
[0116]
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.
[0117]
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.
[0118]
Thus, a predetermined gap 51a is formed in a space between the optical LPF 25 and the dustproof filter 21.
[0119]
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.
[0120]
The space 51b is a sealed space formed so as to protrude outside the optical LPF 25 (see FIGS. 4 and 5).
[0121]
The space 51b is set to be a space wider than the space 51a.
[0122]
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.
[0123]
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.
[0124]
The sealing structure is provided at a position outside the periphery of the optical LPF 25 or its vicinity.
[0125]
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.
[0126]
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.
[0127]
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.
[0128]
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.
[0129]
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.
[0130]
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.
[0131]
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.
[0132]
Thereby, the dust filter 21 can be efficiently supported without hindering the vibration of the dust filter 21.
[0133]
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.
[0134]
The resonance frequency at this time is determined by the shape, plate thickness, material and the like of the dustproof filter 21.
[0135]
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.
[0136]
FIG. 9 is a specific circuit diagram of the dustproof filter drive circuit 140 described above. FIG. 10 is a diagram showing waveforms of signals generated in the respective units in FIG.
[0137]
As illustrated in FIG. 9, the dustproof filter drive circuit 140 includes an N-ary counter 241, a 1/2 frequency divider 242, an inverter 243, a plurality of MOS transistors (Q00, Q01, Q02) 244a, 244b, 244c; It comprises a transformer 245 and a resistor (R00) 246.
[0138]
The transistor (Q01) 244b and the transistor (Q02) 244c connected to the primary side of the transformer 245 are turned on / off to generate a signal (Sig4) having a predetermined period on the secondary side of the transformer 245. The piezoelectric element 22 is driven based on the signal of the predetermined period, and the dustproof filter 21 resonates.
[0139]
The Bucom 150 controls the dust filter drive circuit 140 via two IO ports P_PwCont and D_NCnt provided as control ports and a clock generator 255 existing inside the Bucom 150 as follows. The clock generator 255 outputs a pulse signal (basic clock signal) to the N-ary counter 241 at a frequency sufficiently faster than the signal frequency applied to the piezoelectric element 22.
[0140]
This output signal is signal Sig1 having a waveform represented by the time chart in FIG. This basic clock signal is input to the N-ary counter 241.
[0141]
The N-ary counter 241 counts the pulse signal and outputs a count end pulse signal each time the pulse signal reaches a predetermined value “N”. That is, the basic clock signal is divided by 1 / N. This output signal is signal Sig2 having a waveform shown in the time chart of FIG.
[0142]
In the frequency-divided pulse signal, the duty ratio between High and Low is not 1: 1. Therefore, the duty ratio is converted to 1: 1 through the 1/2 frequency dividing circuit 242. The converted pulse signal corresponds to the signal Sig3 having the waveform shown in the time chart of FIG.
[0143]
In the High state of the converted pulse signal, the MOS transistor (Q01) 244b to which this signal has been input is turned on. On the other hand, the pulse signal is applied to the transistor (Q02) 244c via the inverter 243. Therefore, in a low state of the pulse signal, the transistor (Q02) 244c to which the signal is input is turned on. When the transistor (Q01) 244b and the transistor (Q02) 244c connected to the primary side of the transformer 245 are turned on alternately, a signal having a cycle like the signal Sig4 in FIG. 10 is generated on the secondary side.
[0144]
The winding ratio of the transformer 245 is determined from the output voltage of the unit of the power supply circuit 153 and the voltage required for driving the piezoelectric element 22. Note that the resistor (R00) 246 is provided to restrict an excessive current from flowing through the transformer 245.
[0145]
When driving the piezoelectric element 22, the transistor (Q00) 244a must be in the ON state, and a voltage must be applied from the power supply circuit 153 to the center tap of the transformer 245. In the figure, ON / O control of the transistor (Q00) 244a is performed via P_PwCont of the IO port. The set value “N” of the N-ary counter 241 can be set from the IO port D_NCnt. Therefore, the Bucom 150 can arbitrarily change the drive frequency of the piezoelectric element 22 by appropriately controlling the set value “N”.
[0146]
Here, the drive frequency can be calculated by the following equation.
[0147]
fdrv = fpls / 2N (Expression 1)
Here, N: set value to the counter,
fpls: frequency of the output pulse of the clock generator,
fdrv: frequency of a signal applied to the piezoelectric element,
The calculation based on the equation 1 is performed by the CPU (control means) of the Bucom 150.
[0148]
(1st Embodiment)
FIG. 11 is a flowchart for explaining the operation of the Bucom 150 in the camera system according to the first embodiment of the present invention.
[0149]
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.
[0150]
Step S101 is a step for detecting attachment / detachment of the lens unit 12 to / from the camera. In the attachment / detachment detection operation for detecting that the lens unit 12 is attached to the camera body 11, the attachment / detachment state of the lens unit 12 is checked by periodically communicating with the Lucom 205. In step S102, it is determined whether or not the lens unit 12 is mounted on the camera body 11, and when it is detected that the lens unit 12 is mounted on the camera body 11, the process proceeds from step S102 to step S103 to perform the dust removing operation. Is done. In step S103, the piezoelectric element 22 provided on the dustproof filter 21 is vibrated at the resonance frequency (f0) for a predetermined time (T0). The value set in the N-ary counter 241 for vibrating the piezoelectric element 22 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 dust removal operation is performed based on these data. When the lens unit 12 is replaced, the camera mount is exposed to the outside, and external air flows into the mirror box. At this time, dust enters and adheres to the dustproof filter 21. Therefore, a sufficient length is required for the drive time (T0). After execution of step S103, the process returns to step S101.
[0151]
On the other hand, if the attachment of the lens unit 12 to the camera body 11 is not detected in step S102, the process proceeds from step S102 to step S104. Step S104 is an operation step of periodically monitoring the state of the camera operation SW 152. In step S105, it is determined whether or not the image quality mode selection SW, which is one of the camera operation SWs 152, has been operated. If it is detected that the image quality mode selection SW has been operated, the process proceeds from step S105 to step S106.
[0152]
In step S106, by operating the image quality mode selection switch, the operation of selecting four types of image quality modes in still image shooting and the operation of selecting moving image shooting can be executed. Names of LAW, SHQ, HQ, and SQ are given to these four image quality modes, and a name of MOVIE is given to moving image shooting.
[0153]
In the LAW mode, image data read from the image sensor 27 is recorded without performing pixel number conversion or compression processing. Therefore, the LAW mode has the largest amount of information among the four modes.
[0154]
In the SHQ mode and the HQ mode, recording is performed without reducing the number of all pixels of the image sensor 27 provided in the electronic imaging device. However, there is a difference in the compression ratio. In the SHQ mode, the data amount of the image data is compressed to about 1/3, whereas in the HQ mode, the data amount of the image data is compressed to about 1/8. I do. Due to the difference in the data compression ratio, the image quality of the image recorded in the SHQ mode is better than the image recorded in the HQ mode. In the SQ mode, a compression operation is performed after reducing the number of pixels by converting the number of pixels. Therefore, good image quality is in the order of LAW, SHQ, HQ, and SQ. The magnitude of the information amount is also in the order of LAW, SHQ, HQ, and SQ.
[0155]
In the movie mode, the amount of information increases in order to shoot a moving image. Therefore, the number of pixels is greatly reduced as compared with a still image. The image quality is much worse than in the still image mode.
[0156]
Each time the image quality mode selection switch is operated, the image quality mode information changes as shown in FIG. For example, assume that SHQ is set in the image quality mode information. By operating the image quality mode selection switch in this state, HQ is set as the image quality mode information. After execution of step S106, the process returns to step S101.
[0157]
On the other hand, if the image quality mode selection switch is not operated in step S105, the process immediately proceeds to step S107. In step S107, the operation state of the first release SW, which is one of the camera operation switches 152, is determined. If the first release SW has been operated, the process proceeds to step S108, and if not, the process returns to step S101.
[0158]
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.
[0159]
In step S109, 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.
[0160]
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.
[0161]
On the other hand, if the shift amount calculated in step S110 is within the permitted range, 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 an operation of the second release SW is performed, the process proceeds to step S113, and when no operation is performed, the process proceeds to step S101.
[0162]
In step S113, the aperture of the taking lens in the taking optical system 12a is controlled based on the Av value calculated in step S108. In step S114, the quick return mirror 13b is driven to the UP position. When the quick return mirror 13b is driven, the air in the mirror box is agitated, and there is a high possibility that dust adheres to the dustproof filter 21, so that the dust removing operation is performed after the mirror UP.
[0163]
Next, in step S115, it is determined which mode is set based on the image quality mode information. When LAW or SHQ is set as the image quality mode information, the process proceeds from step S115 to step S116.
[0164]
In LAW and SHQ, high image quality is required. Therefore, dust is not allowed to adhere to the dust filter 21, and the dust must be surely removed here. Therefore, in step S116, the removal operation is performed under the same conditions as in step S103. Then, control goes to a step S118.
[0165]
When HQ is set as the image quality mode information in step S115, the process proceeds from step S115 to step S117. In step S117, the dustproof filter 21 is vibrated at the frequency (f0) for a predetermined time (T1). The driving frequency here is the same f0 as in step S116, but the driving time is different. HQ has inferior image quality as compared to LAW and SHQ. Therefore, there is no need to perform the same level of dust removal operation as the LAW and SHQ. Therefore, the operation time may be short. That is, T0> T1. Shortening the power consumption and the release time lag can be reduced. This driving time is stored in the nonvolatile memory 29. After execution of step S117, the process moves to step S118.
[0166]
If SQ or MOVIE is set as the image quality mode information in step S115, the process immediately proceeds from step S115 to step S118.
[0167]
In step S118, the shutter 14 is controlled to be open. In step S119, in the still image photographing operation, the image sensor 27 is exposed based on the Tv value calculated in step S108. When the moving image shooting operation is selected, moving image data is taken in from the image sensor 27 for a predetermined time. 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, the shutter 14 is charged. In step S122, the aperture of the taking lens in the taking optical system 12a is controlled. In step S123, the number of pixels read from the image sensor 27 is converted according to the image quality mode. In step S124, image data is compressed according to the image quality mode.
[0168]
In step S125, the created image data is stored in the recording medium 127.
[0169]
According to the above-described first embodiment, an electronic imaging device capable of performing an appropriate dust removing operation according to a selected image quality is provided.
[0170]
【The invention's effect】
According to the present invention, there is provided an electronic imaging apparatus capable of performing an appropriate dust removing operation according to a selected image quality.
[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.
9 is a circuit diagram schematically showing a configuration of a dust filter drive circuit 140 in the electronic imaging device 1 described in FIG.
10 is a time chart showing the form of each signal output from each component in the dustproof filter drive circuit 140 of FIG. 11;
FIG. 11 is a flowchart illustrating an operation of the Bucom 150 in the camera system according to the first embodiment of the present invention.
FIG. 12 is a diagram showing how image quality mode information changes each time an image quality mode selection switch is operated.
[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 ... Finder apparatus, 13a ... Penta prism, 13b ... Reflecting mirror, 13c ... Eyepiece, 14 ... Shutter, 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 (12)

An electronic imaging device capable of imaging with a plurality of image qualities,
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,
Setting means for setting a plurality of recording modes related to image quality;
With
The control means, when the high-quality recording mode is set by the setting means, vibrates the optical element in conjunction with an imaging operation by the imaging means, and causes the optical element to perform a dust removing operation. Electronic imaging device. 2. The electronic imaging apparatus according to claim 1, wherein the high image quality recording mode is a recording mode having a large number of pixels. 2. The electronic imaging apparatus according to claim 1, wherein the high image quality recording mode is a recording mode having a low image compression ratio. 2. The electronic imaging apparatus according to claim 1, wherein the control unit vibrates the optical element for a predetermined time prior to an imaging operation. An electronic imaging device capable of imaging with a plurality of image qualities,
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,
Setting means for selectively setting a first image recording mode for acquiring a high-quality electronic image, and a second image recording mode having a lower image quality than the first image recording mode;
With
When the first image recording mode is set by the setting unit, the control unit vibrates the optical element in conjunction with an imaging operation by the imaging unit, and causes the optical element to perform a dust removing operation. An electronic imaging device characterized by the above-mentioned. 6. The electronic imaging apparatus according to claim 5, wherein the first image recording mode has a larger number of pixels of the image acquired by the imaging means than the second image recording mode. 6. The electronic imaging apparatus according to claim 5, wherein the first image recording mode has a lower compression ratio of the image acquired by the imaging means than the second image recording mode. An electronic imaging device capable of imaging with a plurality of image qualities,
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,
Setting means for setting a first image recording mode for acquiring a high-quality electronic image, and a second image recording mode having a lower image quality than the first image recording mode;
With
The control unit permits the dust removal operation of the optical element when the first image recording mode is set by the setting unit, and the optical device performs the optical removal operation when the second image recording mode is set. An electronic imaging apparatus, wherein an operation of removing dust from an element is prohibited. An electronic imaging device capable of imaging with a plurality of image qualities,
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,
Setting means for setting a plurality of recording modes related to image quality;
With
The electronic imaging apparatus according to claim 1, wherein the control unit changes a form of the dust removing operation of the optical element according to a recording mode set by the setting unit. The electronic imaging apparatus according to claim 9, wherein the control unit changes a time of the dust removing operation of the optical element according to a recording mode set by the setting unit. When the first recording mode is set by the setting unit, the control unit sets the operation time of the dust removing unit to a first time, and sets a second image having higher image quality than the first recording mode. 11. The electronic imaging apparatus according to claim 10, wherein when the recording mode is set, the second time is longer than the first time. The electronic imaging apparatus according to claim 9, wherein the control unit permits or prohibits execution of the operation of the dust removing unit according to a recording mode set by the setting unit.

Images