JP2006060428A - Electronic camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remove a foreign matter stuck to a transparent plate arranged at the front face of an imaging element easily and surely. <P>SOLUTION: Driving force of a motor 50 is transmitted through a gear 52 to a screw shaft 42 to rotate the screw shaft 42. Through the rotation of the screw shaft 42, an electrical charging member 46 shifts right and left(in direction of arrow X), namely the electrical charging member 46 scans the front face of a cover glass 24. Each frictional charging member 48 is provided on both end sides of the cover glass 24, and put in contact with the electrical charging member 46 during the scanning of the electrical charging member 46, and thereby the electrical charging member 46 is frictionally charged. When the electrical charging member 46 charged by frictional charge scans the front face of the cover glass 24, the foreign matter, such as dust, stuck to the cover glass 24 is removed through electrostatic adsorption of the electrical charging member 46. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electronic camera.

  In recent years, many digital cameras using an image sensor such as a CCD have been put on the market. Such a digital camera has a problem that if a foreign object such as dust unrelated to the subject adheres to a cover glass or the like disposed in front of an image sensor such as a CCD, the foreign object also appears in the captured image. is there.

  In addition, even with a camera using a conventional silver salt film, if a foreign object adheres to the film, it will be reflected, but in the case of a film, since the film moves every frame, the same foreign object is reflected in all the frames. It is very rare to enter. However, in the case of an image sensor such as a CCD, since it does not move after photographing, the foreign matter appears on many frames once the foreign matter adheres. In addition, foreign substances gradually accumulate on the cover glass.

  Therefore, the photographer always has to be very careful about adhesion of foreign matter to the cover glass of the image pickup device such as CCD, and much labor has been spent on checking and cleaning the foreign matter. In particular, a digital camera capable of exchanging lenses has a great influence because dust enters from the outside during lens exchange. Furthermore, since the image sensor is disposed relatively deep inside the digital camera, it is not easy to check whether the cleaning operation or foreign matter has been removed.

  For this reason, when the dust mode is set, after the foreign matter near the CCD is confirmed by the image display means, the cleaning mode is immediately set on the screen of the dust mode, and a complicated menu selection operation is not required and the cleaning is performed in a short time. A configuration has been proposed that moves to work and facilitates maintenance. (For example, refer to Patent Document 1).

  Alternatively, a configuration has been proposed in which the imaging unit is brought close to the opening of the camera body to facilitate cleaning work and facilitate confirmation of dust removal. (For example, refer to Patent Document 2).

In addition, a configuration has been proposed in which charges generated in an image pickup device and the like are neutralized to suppress the adhesion of dust and facilitate removal. (For example, refer to Patent Document 3).
Japanese Patent Laid-Open No. 2001-157087 JP 2004-40652 A JP 2000-29132 A

  However, the cleaning operation is performed by removing the lens unit from the camera body and blowing it away by blowing a gas such as air using a blower or spray jet type gas cylinder, or by wiping with a volatile solvent such as alcohol. The cover glass of the element is cleaned. Such a cleaning method has various problems such as incomplete cleaning, solvent bleed, or damage due to cleaning work. Even if the gas is wiped off, dust may drift in the camera body and reattach. Alternatively, since the cleaning operation is performed with the lens unit removed, new dust may adhere. Furthermore, since the user himself cleans, it also depends on the user's judgment and cleaning skills.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an electronic camera that easily and reliably removes foreign matters adhering to a light-transmitting plate disposed in front of an image sensor.

  The electronic camera according to claim 1, a lens, an image sensor that converts a subject image formed by the lens into an electrical signal, a light-transmitting plate disposed in front of the image sensor, and the light-transmitting plate An electronic camera comprising: a charging member that scans a front surface by a scanning unit; and a charging unit that charges the charging member.

  In the electronic camera according to the first aspect, the imaging element converts the subject image formed by the lens into an electric signal. A translucent plate is disposed on the front surface of the image sensor. The scanning member scans the charging member charged by the charging unit on the front surface of the translucent plate. Then, foreign matters such as dust adhering to the light transmitting plate are electrostatically adsorbed and removed by the charged charging member. Accordingly, it is possible to prevent foreign matters such as dust adhering to the translucent plate from appearing in the photographed image.

  According to a second aspect of the present invention, in the configuration of the first aspect, the electronic camera is a frictional charging member that contacts the charging member scanned by the scanning unit and charges the charging member by frictional charging. Yes.

  In the electronic camera according to the second aspect, the charging member scanned by the scanning unit comes into contact with the friction charging member, and the charging member is charged by friction charging. Therefore, the charging member is charged with a simple and inexpensive configuration.

  According to a third aspect of the present invention, in the electronic camera according to the first aspect, the charging unit includes a contact charging member that contacts the charging member to give a charge, and a voltage application that applies a voltage to the contact charging member. It is characterized by being means.

  In the electronic camera according to the third aspect, the contact charging member to which the voltage is applied by the voltage applying means and the charging member come into contact with each other, and the charging member is charged by being charged. Therefore, a high charge amount can be reliably imparted to the charging member. Therefore, the charging force by which the charging member electrostatically attracts the foreign matter is high.

  The electronic camera according to claim 4, a lens, an image sensor that converts a subject image formed by the lens into an electrical signal, a light-transmitting plate disposed in front of the image sensor, and the light-transmitting plate And an electret member that scans the front surface by a scanning unit and retains a charge semipermanently.

  In the electronic camera according to the fourth aspect, the image sensor converts the subject image formed by the lens into an electric signal. A translucent plate is disposed on the front surface of the image sensor. The electret member that is charged and charged semipermanently on the front surface of the light transmitting plate is scanned by the scanning means. Then, foreign matters such as dust adhering to the translucent plate are electrostatically attracted to the electret member and removed. Accordingly, it is possible to prevent foreign matters such as dust adhering to the translucent plate from appearing in the photographed image. In addition, since the electret member holds the charge semi-permanently, no charging means for charging the electret member is required. Therefore, it is an inexpensive and simple configuration.

  The electronic camera according to claim 5, a lens, an image sensor that converts a subject image formed by the lens into an electric signal, a light-transmitting plate disposed in front of the image sensor, and the light-transmitting plate An electrode member that scans the front surface by a scanning unit and a voltage applying unit that sets the electrode member to a predetermined potential are provided.

  In the electronic camera according to the fifth aspect, the imaging element converts the subject image formed by the lens into an electric signal. A translucent plate is disposed on the front surface of the image sensor. The scanning member scans the electrode member whose front surface of the translucent plate is brought to a predetermined potential by the voltage applying unit. Then, foreign matters such as dust adhering to the translucent plate are electrostatically attracted to the electrode member and removed. Accordingly, it is possible to prevent foreign matters such as dust adhering to the translucent plate from appearing in the photographed image.

  The electronic camera according to claim 6 is the configuration according to any one of claims 1 to 5, wherein a shutter is disposed in front of the light-transmitting plate, and the shutter includes the charging member and the electret. Any one of a member and the electrode member is attached and serves as the scanning means.

  In the electronic camera according to the sixth aspect, the image sensor converts the subject image formed by the lens into an electric signal. A translucent plate is disposed on the front surface of the image sensor. Any one of a charging member, an electret member, and an electrode member is attached to a shutter disposed on the front surface of the translucent plate. Then, by opening and closing the shutter, the charging member, electret member, and electrode member are scanned on the front surface of the translucent plate, and foreign matters such as dust adhering to the translucent plate are electrostatically adsorbed and removed. Accordingly, it is possible to prevent foreign matters such as dust adhering to the translucent plate from appearing in the photographed image. In addition, since no separate scanning means is required, the structure is inexpensive and simple.

  According to a seventh aspect of the present invention, in the configuration of any one of the first to sixth aspects, the electronic camera includes a foreign matter detection unit that detects a foreign matter attached to the translucent plate, and the foreign matter detection unit includes: When the foreign matter is detected, the scanning unit operates.

  The electronic camera according to claim 7 includes foreign matter detection means for detecting foreign matter attached to the translucent plate. When the foreign matter detection means detects the foreign matter, the scanning means operates to remove the foreign matter attached to the transparent plate. To do. Therefore, it is possible to perform photographing in a state where foreign matters such as dust are not attached to the light transmitting plate.

  According to an eighth aspect of the present invention, there is provided the electronic camera according to the eighth aspect, wherein the foreign matter detecting means detects the attachment of the foreign matter when the power is turned on.

  In the electronic camera according to the eighth aspect, when the power is turned on, the foreign matter detection means detects the attachment of the foreign matter. Therefore, every time the power is turned on, in other words, the foreign matter detection means always detects the foreign matter before the start of photographing, and when the foreign matter detection means detects the foreign matter, the scanning means operates to remove the foreign matter attached to the light transmitting plate. Therefore, it is possible to take an image in a state where no foreign matter such as dust adheres to the light transmitting plate.

  According to a ninth aspect of the present invention, in the electronic camera according to any one of the first to eighth aspects, the lens unit including the lens and a camera body that mounts the lens unit interchangeably. It is composed.

  In the electronic camera according to the ninth aspect, a lens unit including a lens is mounted on the camera body in a replaceable manner. When the lens unit is replaced, foreign matter such as dust enters and adheres to the translucent plate. However, since the charging member, electret member, and electrode member are scanned and electrostatically adsorbed on the front surface of the translucent plate, foreign matter such as dust attached to the translucent plate is prevented from appearing in the photographed image.

  According to a tenth aspect of the present invention, in the configuration according to the ninth aspect, the electronic camera includes a lens unit detection unit that detects attachment / detachment of the lens unit, and when the lens unit detection unit detects attachment / detachment of the lens unit, The scanning means operates.

  In the electronic camera according to the tenth aspect, when the lens unit detection unit detects attachment / detachment of the lens unit, the scanning unit operates to remove the foreign matter attached to the light transmitting plate. Therefore, when the lens unit is replaced, even if foreign matter such as dust enters, the cleaning operation is automatically performed after the lens unit is attached, so there is always no foreign matter such as dust attached to the translucent plate. You can shoot with.

  As described above, according to the present invention, foreign matters such as dust adhering to the translucent plate are electrostatically adsorbed and removed by the charging member, electret member, and electrode member. Accordingly, it is possible to prevent foreign matters such as dust adhering to the translucent plate from appearing in the photographed image.

  A digital camera according to a first embodiment of the present invention will be described.

  As shown in FIG. 1, the digital camera 10 is a single-lens reflex digital camera that mainly captures still images. As shown in FIG. 1 and FIG. 2, the digital camera 10 includes a lens mount 14 on the front (front) portion of the camera body 12, and a lens including a plurality of lenses 300 and the like via the lens mount 14. The unit 16 is mounted so as to be replaceable. That is, the lens unit 16 can be replaced. Further, the shutter button 18 is disposed at the upper left portion toward the front.

  As shown in FIG. 3, an optical viewfinder 60, a display panel 62, a liquid crystal monitor 64, a cross button 66, a menu / execution button 67, a back button 68, a function button 63 and the like are provided on the rear exterior portion of the digital camera 10. ing.

  The liquid crystal monitor 64 can display a subject image and a reproduced image of a recorded image. In addition, information on the currently set mode, image compression rate information, date / time information, frame number, and the like are also displayed. Furthermore, it is also used as a user interface display screen when the user performs various setting operations, and menu information such as setting items is displayed as necessary.

  The optical viewfinder 60 can see the subject image from the lens unit 16 (see FIG. 1) as it is.

  As shown in FIG. 4, a quick return mirror 203 is provided in the photographing optical path inside the camera body 12. The quick return mirror 203 moves between a position for guiding subject light from the lens unit 16 to the optical path system to the optical viewfinder 60 (an oblique position) and a position for retracting outside the photographing optical path (a retracted position). (So-called mirror down and mirror up). In FIG. 4, the quick return mirror 203 is in an oblique position where the mirror is lowered. The alternate long and short dash line indicates the optical axis 201.

  Above the quick return mirror 203, a focus plate 204 on which subject light guided to the optical viewfinder 60 forms an image is disposed. A condenser lens 205 for improving the visibility of the optical viewfinder 60 is provided above the focus plate 204. Then, the pentagonal roof prism 206 guides the subject light passing through the focusing plate 204 and the condenser lens 205 to the eyepiece 208 for the optical viewfinder 60.

  On the other hand, behind the quick return mirror 203, there is disposed a fall-plane shutter type shutter mechanism 30 in which the shutter 32 opens and closes in the vertical direction (the arrow Y direction in FIG. 5B). In FIG. 3, the shutter 32 is open. A CCD 22 that is an image sensor is disposed behind the shutter mechanism 30, and the front surface of the CCD 22 is protected by a cover glass 24. The CCD 22 has a large number of photodiodes (not shown) arranged in a plane and has a honeycomb arrangement, a Bayer arrangement, and other predetermined color filter arrangement structures. Note that the cover glass 24 includes various optical filters arranged on the front surface of the image sensor, for example, a low-pass filter for reducing moire.

  A cleaning mechanism 40 that removes foreign matters such as dust attached to the surface of the cover glass 24 is disposed between the cover glass 24 and the shutter mechanism 30. Details of the cleaning mechanism 40 will be described later.

  Then, after the quick return mirror 203 is mirrored up to a position where the quick return mirror 203 is retracted out of the photographing optical path (retracted position), the shutter 32 is opened and charges are accumulated in the CCD 22. Then, the image data is recorded on the recording medium 120 (see FIG. 6).

  Next, the cleaning mechanism 40 will be described.

  As shown in FIG. 5, the screw shaft 42 and the shaft 44 are arranged in parallel above and below the photographing optical path, and are fixed to, for example, a housing. The upper screw shaft 42 is fixed rotatably. For example, a rod-shaped charging member 46 made of ebonite is passed through the screw shaft 42 and the shaft 44. A screw is formed on the inner peripheral surface of the hole 46 </ b> A of the charging member 46 through which the screw shaft 42 is passed, and is screwed into the screw shaft 42. The charging member 46 is disposed with a predetermined distance from the cover glass 24.

  A motor 50 is disposed on one end side of the screw shaft 42, and the driving force of the motor 50 is transmitted to the screw shaft 42 via the gear 52, so that the screw shaft 42 rotates. Further, the motor 50 rotates in both forward and reverse directions. Then, as the screw shaft 42 rotates, the charging member 46 moves left and right (arrow X direction). That is, the charging member 46 scans the front surface of the cover glass 24.

  Frictional charging members 48 are disposed on both ends of the cover glass 24, and come into contact with the charging member 46 as the charging member 46 scans to frictionally charge the charging member 46. (Refer to the charging member 46 shown by the one-dot chain line in FIG. 5B).

  When the frictionally charged charging member 46 scans the front surface of the cover glass 24, foreign matters such as dust adhering to the cover glass 24 are electrostatically adsorbed on the charging member 46 and removed.

  Now, triboelectric charging is a combination of materials that rub and determines which is positive (+) and which is negative (-). An arrangement in which substances that rub against each other and are easily charged positively (+) and substances that are easily charged negatively (−) is referred to as a charge column (charging sequence). In other words, the charged column is a sequence of those that easily emit electrons or those that easily receive electrons. A substance having a close positional relationship in the charge train has a small charge amount due to friction, and becomes larger as the distance increases.

  Therefore, the charging member 46 is positively (+) charged if the material of the friction charging member 48 is on the negative (−) side from ebonite, and the charging member 46 is negative if it is on the positive (+) side from ebonite. Charges to (-). In addition, if a material whose charging train is separated from ebonite is selected, the charging amount of the charging member 46 is increased.

  The charging member 46 that scans the front surface of the cover glass 24 may be a material other than ebonite. However, a conductive material such as a metal rod is not suitable.

  Further, the combination of the material of the charging member 46 and the frictional charging member 48 may be determined depending on whether the charge amount is positive or negative.

  Further, the form of the frictional charging member 48 is not particularly limited. However, even if the frictional charging member 48 comes into contact with the charging member 46 and rubs, there is no waste or dust. For example, a nonwoven fabric or felt is preferable.

  FIG. 6 is a block diagram showing the internal configuration of the digital camera 10 (camera body 12 and lens unit 16). The lens unit 16 includes a diaphragm mechanism 80 and a plurality of lenses 300 such as a focusing lens 82, and also drives an iris motor 83 and a driving circuit (motor driver) 84 as a means for driving the diaphragm mechanism 80 and the focusing lens 82. An AF motor 86 and its driving circuit (motor driver) 87, a central processing unit for control (hereinafter referred to as a lens CPU) 88, a ROM 89 storing various data, and the like are incorporated.

  The ROM 89, which is a nonvolatile storage means, may be rewritable or may be rewritable like an EEPROM. The ROM 89 stores the model name of the lens unit 16, focal length, F-number, and other information related to lens performance (hereinafter referred to as “lens information”).

  When the lens unit 16 is attached to the lens mount 14 of the camera body 12 (see FIGS. 1 and 2), the electrical contact 14A provided on the lens mount 14 and the electrical contact 16A of the lens unit 16 are connected. The lens unit 16 and the camera body 12 are electrically connected to each other, and signals can be transferred between a CPU (hereinafter referred to as camera CPU) 90 in the digital camera 10 and the lens CPU 88.

  The camera CPU 90 functions as a control unit that performs overall control of the camera system according to a predetermined program, and also functions as a calculation unit that performs various calculations such as an AE / AF calculation. A ROM 91 connected to the camera CPU 90 stores programs executed by the camera CPU 90 and various data necessary for control. The RAM 92 is used as a work area for the camera CPU 90. The ROM 91 which is a nonvolatile storage means may be non-rewritable, or may be rewritable like an EEPROM.

  The camera CPU 90 controls the operation of each circuit in the digital camera 10 based on instruction signals from the power switch 93, the mode selection switch 94, the release detection switch 95, and other operation units 96 provided in the camera body 12. . The operation unit 96 is a block including various operation means such as the cross button 66, the menu / execution button 67, the back button 68, and the function button 63 described with reference to FIG.

  The power switch 93 is an operation means for turning on / off the main power of the digital camera 10. The camera CPU 90 monitors the state of the power switch 93 and controls the power circuit 97 according to the state. That is, when the closed (ON) state of the power switch 93 is detected, the camera CPU 90 gives a start command signal to the power circuit 97 to start the power circuit 97.

  The power supply circuit 97 includes a DC / DC converter. The power supplied from the battery 98 loaded in the digital camera 10 is converted into a required voltage by the DC / DC converter of the power supply circuit 97 and then supplied from the power supply circuit 97 to each circuit block in the digital camera 10. The When the open (OFF) state of the power switch 93 is detected, the camera CPU 90 gives a stop command signal to the power circuit 97 to stop the power supply from the power circuit 97. Note that the main power ON / OFF is not limited to the operation of the power switch 93, but the auto power ON function (function to turn on power at a set time) and the auto power OFF function (no operation state for a certain period of time). There is also a mode of switching according to a case or a function of automatically turning off power at a set time.

  The camera CPU 90 can detect attachment / detachment of the lens unit 16 based on an electrical signal transmitted via the electrical contact portion 14 </ b> A, and can acquire lens information from the attached lens unit 16. The acquired lens information is stored in an EEPROM (nonvolatile storage means) 99 of the digital camera 10, and the information content is retained even when the power is turned off. The camera CPU 90 determines whether or not the lens has been exchanged by comparing the data held in the EEPROM 99 with the lens information newly acquired from the lens unit 16 when the power is turned on.

  The mode selection switch 94 is a means for setting the operation mode of the digital camera 10, and by operating this mode changeover switch, a "shooting mode" (shooting mode) or a "playback mode" (a mode for playing back recorded images). ) And other modes. The release detection switch 95 is a detection switch disposed inside the shutter button 18 (see FIG. 1), and includes an S1 switch that is turned on when the shutter button 18 is half-pressed and an S2 switch that is turned on when the shutter button 18 is fully pressed. .

  When the “shooting mode” is selected by the mode selection switch 94, the digital camera 10 is ready for shooting. When the camera CPU 90 detects that the shutter button 18 is half-pressed (S1 = ON), it performs AE and AF processing, and when it detects that the shutter button 18 is fully pressed (S2 = ON), it captures an image for recording. The CCD exposure and readout control is started.

  The AE function mounted on the digital camera 10 is a TTL type AE. Inside the digital camera 10, an AE sensor (light receiving element) 100 as a detection system and the transmitted light from the photographing lens are branched to reach the AE sensor 100. An optical system (not shown) that forms a detection optical path is provided. The AF function of the digital camera 10 is a TTL phase difference AF, and the digital camera 10 includes an AF module 101 that is a detection system of the phase difference AF and an optical system (not shown) necessary for forming a detection optical path. Are arranged. The arrangement structure of the AE sensor 100 and the AF module 101, the configuration of the optical system, and the like are not particularly limited in the implementation of the present invention, and various modes known in the field of single-lens reflex cameras can be applied. Further, means for realizing the AE / AF function is not limited to the above example, and other AE / AF methods may be used.

  When the shutter button 18 is “half-pressed” (S 1 = ON), the camera CPU 90 determines the focus state based on the detection signal from the AF module 101 and generates a movement control signal for the focusing lens 82. This movement control signal is sent to the lens CPU 88. The lens CPU 88 controls the motor driver 87 based on the signal from the camera CPU 90 to operate the AF motor 86 and move the focusing lens 82 to the in-focus position.

  Further, the camera CPU 90 performs AE calculation based on the detection signal from the AE sensor 100 to calculate an aperture value and a shutter speed. A diaphragm control signal generated by the camera CPU 90 is sent to the lens CPU 88. The lens CPU 88 controls the motor driver 84 based on the signal from the camera CPU 90 to operate the iris motor 83, thereby opening the aperture mechanism 80 to a required opening.

  When the shutter button 18 is “fully pressed” (S2 = ON), the camera CPU 90 controls the shutter mechanism 30 (see FIG. 4) based on the result of the AE calculation, and opens and closes the shutter 32 of the shutter mechanism 30. At the same time, the charge accumulation time of the CCD 22 is controlled.

  The optical image of the subject imaged on the CCD 22 via the lens unit 16 is photoelectrically converted by the CCD 22.

  The signal charges accumulated in each photodiode (not shown) of the CCD 22 are sequentially read out as voltage signals (imaging signals) corresponding to the signal charges based on the pulses supplied from the timing generator (TG) 103. The signal output from the CCD 22 is sent to the analog processing unit 104, where required processing such as correlated double sampling (CDS) processing, color separation, and gain adjustment is performed. The image signal generated by the analog processing unit 104 is converted into a digital signal by the A / D converter 106 and then stored in the memory 110 via the image input controller 108. The timing generator 103 gives a timing signal to the CCD 22, the analog processing unit 104, and the A / D converter 106 in accordance with a command from the camera CPU 90, and the circuits are synchronized by this timing signal.

  Data stored in the memory 110 is sent to the image signal processing circuit 114 via the bus 112. The image signal processing circuit 114 is an image processing unit including a luminance / color difference signal generation circuit, a gamma correction circuit, a sharpness correction circuit, a white balance correction circuit, and the like, and processes an image signal in accordance with a command from the camera CPU 90.

  The image data input to the image signal processing circuit 114 is converted into a luminance signal (Y signal) and a color difference signal (Cr, Cb signal) and subjected to predetermined processing such as gamma correction. The image data generated by the image signal processing circuit 114 is sent to the compression / decompression circuit 116 and compressed according to a predetermined format such as JPEG. The compressed image data is recorded on the recording medium 120 via the media controller 118.

  The compression format is not limited to JPEG, and MPEG and other methods may be adopted. The means for storing image data is not limited to a semiconductor memory represented by a memory card, and various media such as a magnetic disk, an optical disk, and a magneto-optical disk can be used. Further, the recording medium (such as an internal memory) built in the digital camera 10 is not limited to a removable medium.

When “reproduction mode” is selected by the mode selection switch 94, an image file is read from the recording medium 120. The read image data is decompressed by the compression / decompression circuit 116 and sent to the VRAM 122. The data stored in the VRAM 122 is
The video encoder 124 converts the signal into a predetermined display signal (for example, an NTSC color composite video signal) and then supplies the signal to the liquid crystal monitor 64. In this way, the image stored in the recording medium 120 is displayed on the liquid crystal monitor 64.

  The camera CPU 90 also controls the operation of the cleaning mechanism 40 shown in FIG. That is, the rotation of the motor 50 is controlled, the charging member 46 is scanned left and right, and the removal of foreign matters such as dust adhering to the cover glass 24 is controlled.

  Next, the operation of the first embodiment will be described.

  In the digital camera 10, the lens unit 16 is replaced as necessary by the user. At that time, foreign matter such as external dust enters the inside of the camera body 12 from the opening 17 (see FIG. 2) of the camera body 12.

  Alternatively, foreign matter such as dust mixed during production and foreign matter such as friction powder generated from a drive portion (for example, the shutter mechanism 30) inside the camera body 12 are also present inside the camera body 12.

  If such foreign matter adheres to the cover glass 24, it will appear in the photographed image. Therefore, as shown in FIG. 5, the camera CPU 90 of the digital camera 10 controls the cleaning mechanism 40 to automatically scan the charging member 46 on the front surface of the cover glass 24 at a predetermined timing and adhere to the cover glass 24. Foreign matter is removed by electrostatic adsorption on the charging member 46. Hereinafter, the operation of removing the foreign matter adhering to the cover glass 24 by electrostatic adsorption to the charging member 46 will be referred to as “cleaning operation”.

Next, a predetermined timing for performing the cleaning operation will be described. The timing of the first cleaning operation is as shown in FIG. 7 after the lens unit 16 has been replaced, which is most likely to cause foreign matter to enter.

  As described above, the camera CPU 90 can detect the attachment / detachment of the lens unit 16 based on the electrical signal transmitted via the electrical contact portion 14A. Therefore, when the camera CPU 90 detects that the lens unit 16 has been replaced, the camera CPU 90 performs a cleaning operation.

  Note that it is only necessary to determine whether or not there is a possibility that the lens unit 16 is removed from the lens mount portion 14 and dust is mixed therein. Therefore, whether or not the lens unit 16 is actually replaced (that is, different lens units). It is not necessary to determine whether or not the is attached. That is, it is only necessary to determine whether or not to perform the cleaning operation by detecting whether or not the lens unit 16 is removed and attached.

  As shown in FIG. 8, the timing of the second cleaning operation is to detect whether or not foreign matter has adhered to the cover glass 24 after the main power is turned on, and foreign matter that has an influence on photographing has adhered. If so, the cleaning operation is performed. Then, after cleaning, if it is determined that foreign matter is attached or has a size that affects photographing, the cleaning operation is performed again. After cleaning, if it is determined that there is no foreign matter attached or the size does not affect the photographing, the mode is shifted to the normal mode.

  That is, every time the main power is turned on, in other words, before the start of photographing, the attachment of foreign matter is always detected, and if necessary, a cleaning operation is performed.

  The turning on of the main power supply includes not only the operation of the power switch 93 but also the case where the main power supply is turned on by an auto power ON function (function to turn on power at a set time).

  An example of a method for detecting whether or not foreign matter is attached to the cover glass 24 will be described below.

  By operating the focusing lens 82 to the infinity end so that the subject image is not formed on the CCD 22 that is the image pickup device, only the foreign matter adhering to the cover glass 24 arranged in front of the CCD 22 can be imaged. Then, when the camera CPU 90 determines that the captured foreign object is larger than a predetermined size and affects the shooting, the camera CPU 90 performs a cleaning operation.

  In this way, even if foreign matter such as dust adheres to the cover glass 24 arranged on the front surface of the CCD 22 arranged relatively deep inside the digital camera 10, it can be easily removed.

  In addition, since the foreign matter is electrostatically adsorbed, dust does not drift inside and reattach to the cover glass 24 as in the case of removing by wiping with air. Alternatively, the solvent bleed does not remain as in the case where the solvent is wiped away.

  Furthermore, since the lens unit 16 is automatically cleaned without removing the lens unit 16, no new dust is attached, and the quick return mirror 203 and the shutter mechanism 30 are not accidentally damaged by the user during the cleaning operation. .

  In addition, since the cleaning operation is automatically performed at a predetermined timing, it is possible to perform shooting in a state where foreign matter such as dust is not always attached to the cover glass 24.

  Further, the charged charging member 46 is brought into contact with the friction charging member 48 to be frictionally charged. That is, the charging member 46 is charged with an inexpensive and simple configuration.

  Note that the timing for cleaning may be other than the first and second timings. For example, the cleaning operation may be performed automatically after the photographing is completed, or the cleaning operation may be performed after detecting the presence or absence of foreign matter at the first timing. Further, dust may be generated when the movable mechanism is operated, such as opening / closing of the shutter 32 and rotation of the quick return mirror 203. Therefore, the cleaning operation may be performed after such a movable operation. Alternatively, the user may perform the cleaning operation at an arbitrary timing by operating the cross button 66, the menu / execution button 67, and the like.

  However, the camera CPU 90 controls so that the cleaning operation is not performed during photographing, particularly during the accumulation of charges in the CCD 22.

  Next, a second embodiment will be described. In addition, the same code | symbol is attached | subjected to the member same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 9, unlike the first embodiment, the cleaning mechanism 40 (see FIG. 5C) is not disposed between the cover glass 24 and the shutter mechanism 330.

  However, a plate-shaped charging member 334 made of ebonite, for example, is attached to the end of the shutter 332 on the cover glass 24 side. The charging member 334 and the cover glass 24 have a predetermined interval.

  A friction charging member 338 is attached to the upper part of the shutter mechanism 330. Then, as shown in FIGS. 9B and 9C, when the shutter 332 is closed, the charging member 334 comes into contact with the friction charging member 338, and the charging member 334 is frictionally charged.

  When the charging member 334 that is frictionally charged scans the front surface of the cover glass 24 with the opening and closing of the shutter 332 (see FIGS. 9A and 9B), dust or the like adhering to the cover glass 24 is detected. The foreign matter is electrostatically attracted to the charging member 334 and removed.

  Next, the operation of the second embodiment will be described.

  As in the first embodiment, the shutter 332 is opened and closed at a predetermined timing, whereby foreign matters such as dust adhering to the cover glass 24 are electrostatically adsorbed to the charging member 334 and removed. Further, every time the shutter 332 is opened and closed for photographing, the charging member 334 is automatically electrostatically attracted and removed.

  Further, since a separate mechanism for scanning the charging member 334 on the front surface of the cover glass 24 is not required, the cost and space can be saved.

  In both the first and second embodiments, the charging members 46 and 334 are charged using frictional charging. However, the present invention is not limited to this. The charging members 46 and 334 may be charged by other methods.

  For example, the charging members 46 and 334 may be electrically charged as in the following modification.

  First, the configuration of a modification of the first embodiment will be described.

  As shown in FIG. 10, contact charging portions 750 are disposed on both ends of the cover glass 24. The contact charging unit 750 has a configuration in which a fur brush 748 in which conductive fibers are formed in a brush shape is attached to a sheet metal 749 with a conductive adhesive. Then, a high voltage is applied to the sheet metal 749 from the power supply circuit 97.

  In a state where a high voltage is applied to the contact charging member 750, as the charging member 46 is scanned, the charging member 46 comes into contact with the fur brush 748 of the contact charging unit 750 to be charged, and the charging member 46 is charged.

  Next, a configuration of a modification of the second embodiment will be described.

  As shown in FIG. 11, a contact charging unit 850 is disposed on the shutter mechanism 830. The contact charging unit 850 has a configuration in which a conductive brush is formed in a brush shape, and a fur brush 848 is attached to a sheet metal 849 with a conductive adhesive. Then, a high voltage is applied to the sheet metal 849 from the power supply circuit 97.

  When the shutter 332 is closed in a state where a high voltage is applied to the contact charging unit 850, the charging member 334 comes into contact with the fur brush 848 of the contact charging member 850 to be charged, and the charging member 334 is charged.

  Next, the operation of the modified example of the first and second embodiments will be described.

  In a state where a high voltage is applied to the fur brushes 748 and 848 of the contact charging members 750 and 850 from the power supply circuit 97, the charging members 46 and 334 come into contact with the fur brushes 748 and 848 to be charged and charged. Therefore, a high charge amount can be reliably applied to the charging members 46 and 334. Therefore, the charging members 46 and 334 have a high attraction force for electrostatically adsorbing foreign matter.

  Next, third and fourth embodiments will be described. In addition, the same code | symbol is attached | subjected to the member same as 1st and 2nd embodiment, and the overlapping description is abbreviate | omitted.

  First, the configuration of the third embodiment will be described.

  As shown in FIG. 12, the cleaning mechanism 440 includes a scanning member 446 that scans the surface of the cover glass 24. The scanning member 446 includes a prism portion 448 and an electret sheet 450 attached to the cover glass 24 side of the prism portion 448. Unlike the first embodiment, the friction charging member 48 (see FIG. 5) for friction charging is not provided.

  Next, the configuration of the fourth embodiment will be described.

  As shown in FIG. 13, an electret sheet 434 is pasted on the cover glass 24 side of the front end portion of the shutter 332. Unlike the second embodiment, the friction charging member 338 (see FIG. 9) for friction charging is not provided.

  The electret sheets 450 and 434 used in the third and fourth embodiments are non-woven fabrics that are made of electret fibers and do not have yarn waste.

  In addition, an electret is what a electric charge is hold | maintained semipermanently in an insulating substance body. As a manufacturing method, for example, a polymer material having excellent insulating properties (for example, Teflon (registered trademark), polypropylene, Mylar, etc.) is heated and melted and solidified between the electrodes while applying a high DC voltage. After removing the electrode, the surface in contact with the electrode is positively or negatively charged, and this polarization (a state divided into positive and negative electricity) is maintained semipermanently, so that there is a method of making an electret . Alternatively, there are a method in which a DC high voltage is applied to a needle electrode to generate ions in the atmosphere and this is applied to the sample, and a method in which the sample is applied to the sample by pulse discharge.

  The electret sheets 450 and 434 are made of the electroletized fibers in this way.

  Next, the operation of the third and fourth embodiments will be described.

  Since the electret sheets 450 and 434 are charged semi-permanently, when the front surface of the cover glass 24 is scanned as in the first and second embodiments, foreign matter such as dust attached to the cover glass 24 is removed. , 434 are electrostatically adsorbed and removed.

  Further, as described above, since the electret sheets 450 and 434 are semi-permanently charged, charging means (the friction charging members 48 and 338 for friction charging in the first and second embodiments) is not necessary. . Therefore, it is low cost and space saving.

  Next, fifth and sixth embodiments will be described. In addition, the same code | symbol is attached | subjected to the member same as 1st to 4th embodiment, and the overlapping description is abbreviate | omitted.

  First, the configuration of the fifth embodiment will be described.

  As shown in FIG. 14, the cleaning mechanism 540 includes a scanning member 546 that scans the front surface of the cover glass 24. The scanning member 546 includes a prism portion 548 and an electrode plate 550 attached to the prism glass portion 548 on the cover glass 24 side. The electrode plate 550 is applied with a high voltage from the power supply circuit 97. Note that the wire 552 connecting the electrode plate 550 and the power supply circuit 97 follows the scanning operation of the scanning member 546 so as not to disturb the scanning of the scanning member 546, and does not enter the imaging optical path even if it is bent. It is attached so that there is no.

  Next, the configuration of the sixth embodiment will be described.

  As shown in FIG. 15, an electrode plate 634 is attached to the end of the shutter 632 on the cover glass 24 side. As shown in FIGS. 15C and 15D, a conductive film 640 is formed on a part of the surface of the shutter 632, and the electrode plate 634 is supplied with power through the conductive film 640 and the wire 650. A high voltage is applied from circuit 97.

  Next, the operation of the fifth and sixth embodiments will be described.

  When a high voltage is applied to the electrode plates 550 and 634 and the front surface of the cover glass 24 is scanned in the same manner as in the first and second embodiments, foreign matters such as dust attached to the cover glass 24 are applied to the electrode plates 550 and 634. It is removed by electrostatic adsorption. In addition, since a high voltage is applied to the electrode plates 550 and 634 and electrostatic adsorption is performed, the adsorption force is large.

  In addition, this invention is not limited to said embodiment.

  For example, in the above embodiment, a single-lens reflex digital camera that mainly captures still images has been described as an example, but the present invention is not limited to this. The present invention can be applied to various electronic cameras such as a digital video camera and a DVD camera that mainly shoot moving images. Further, the present invention is not limited to the single lens reflex type, and can be similarly applied to other types of interchangeable lens type electronic cameras. Furthermore, the present invention can also be applied to a lens-fixed type electronic camera (for example, a compact type digital camera) that cannot exchange lenses. In the lens-fixed electronic camera, dust does not enter when the lens is replaced. However, dust mixed during production, friction powder generated from the drive part, and the like may adhere to the cover glass and cannot be removed by the user himself. Therefore, it is effective to apply the present invention.

1 is a perspective view showing a digital camera according to a first embodiment of the present invention. 1 is a perspective view of a digital camera according to a first embodiment of the present invention with a lens unit removed. It is a figure which shows the back surface of the digital camera which concerns on the 1st Embodiment of this invention. It is a figure which shows typically the inside of the digital camera which concerns on the 1st Embodiment of this invention. 1A and 1B show a cleaning mechanism for a digital camera according to a first embodiment of the present invention, in which FIG. 1A is a front view, FIG. 1B is a cross-sectional view taken along the line B-B in FIG. It is sectional drawing of -C cross section. It is a block diagram which shows the internal structure of the digital camera which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the timing of a 1st cleaning operation | movement. It is a flowchart which shows the timing of 2nd cleaning operation | movement. The shutter mechanism of the digital camera which concerns on the 2nd Embodiment of this invention is shown, (A) is sectional drawing which shows the state which the shutter closed, (B) is sectional drawing which shows the state which opened the shutter, (C) is It is an enlarged view of H part of (B). 2A and 2B show a digital camera cleaning mechanism according to a modification of the first embodiment of the present invention, in which FIG. 1A is a front view, FIG. 1B is a cross-sectional view taken along the line BB in FIG. It is sectional drawing of CC cross section of). The shutter mechanism of the digital camera which concerns on the modification of the 2nd Embodiment of this invention is shown, (A) is sectional drawing which shows the state which the shutter closed, (B) is sectional drawing which shows the state which the shutter opened, ( C) is an enlarged view of the H portion of (B). The cleaning mechanism of the digital camera which concerns on the 3rd Embodiment of this invention is shown, (A) is a front view, (B) is sectional drawing of the BB cross section of (A), (C) is C of (A). It is sectional drawing of -C cross section. The shutter mechanism of the digital camera which concerns on the 4th Embodiment of this invention is shown, (A) is sectional drawing which shows the state which the shutter closed, (B) is sectional drawing which shows the state which the shutter opened. FIG. 7 shows a cleaning mechanism of a digital camera according to a fifth embodiment of the present invention, in which (A) is a front view, (B) is a sectional view taken along the line BB of (A), and (C) is C of (A). It is sectional drawing of -C cross section. The shutter mechanism of the digital camera which concerns on the 6th Embodiment of this invention is shown, (A) is sectional drawing which shows the state which the shutter closed, (B) is sectional drawing which shows the state which opened the shutter, (C) is A rear view of a state where the shutter is closed, (D) is an enlarged view of a D portion of (A).

Explanation of symbols

10 Digital camera (electronic camera)
12 camera body 14A electrical contact (lens unit detection means)
16 Lens unit 22 CCD (Image sensor)
24 Cover glass (translucent plate)
42 Screw shaft (scanning means)
44 Shaft (scanning means)
46 Charging member 48 Friction charging member 50 Motor (scanning means)
52 Gear (scanning means)
82 Focusing lens (lens, foreign matter detection means)
90 Camera CPU (foreign matter detection means, lens unit detection means)
97 Power supply circuit (voltage application means)
300 Lens 332 Shutter 334 Charging Member 338 Friction Charging Member 434 Electret Sheet (Electret Member)
450 Electret sheet (Electret member)
550 Electrode plate (electrode member)
632 Shutter 634 Electrode plate (electrode member)
748 Fur brush (contact charging member)
848 Fur Brush (Contact Charging Member)

Claims (10)

A lens,
An image sensor that converts an object image formed by the lens into an electrical signal;
A translucent plate disposed in front of the imaging device;
A charging member that scans the front surface of the translucent plate by a scanning means;
Charging means for charging the charging member;
With electronic camera.   The electronic camera according to claim 1, wherein the charging unit is a friction charging member that contacts the charging member scanned by the scanning unit and charges the charging member by friction charging. The charging means includes
A contact charging member that contacts the charging member to give a charge;
Voltage applying means for applying a voltage to the contact charging member;
The electronic camera according to claim 1, wherein: A lens,
An image sensor that converts an object image formed by the lens into an electrical signal;
A translucent plate disposed in front of the imaging device;
An electret member that scans the front surface of the translucent plate by a scanning means and holds a charge semipermanently;
An electronic camera comprising: A lens,
An image sensor that converts an object image formed by the lens into an electrical signal;
A translucent plate disposed in front of the imaging device;
An electrode member that scans the front surface of the translucent plate by a scanning means;
Voltage applying means for setting the electrode member to a predetermined potential;
An electronic camera comprising: A shutter is disposed on the front surface of the translucent plate,
6. The electron according to claim 1, wherein any one of the charging member, the electret member, and the electrode member is attached to the shutter, and also serves as the scanning unit. camera. Foreign matter detecting means for detecting foreign matter attached to the translucent plate,
The electronic camera according to any one of claims 1 to 6, wherein the scanning unit operates when the foreign matter detection unit detects the foreign matter.   The electronic camera according to claim 7, wherein the foreign matter detection unit detects the attachment of foreign matter when the power is turned on. A lens unit comprising the lens;
A camera body for mounting the lens unit interchangeably;
The electronic camera according to claim 1, wherein the electronic camera is configured as follows. Comprising lens unit detection means for detecting attachment and detachment of the lens unit;
The electronic camera according to claim 9, wherein the scanning unit operates when the lens unit detection unit detects attachment / detachment of the lens unit.

Images