JP2008236670A - Imaging apparatus, its control method, program, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrict wasteful consumption of electric power by effectively removing foreign matter such as dust adhering to an optical member disposed on an imaging optical axis. <P>SOLUTION: The imaging apparatus includes an imaging element for subjecting a subject image focused by an imaging lens to photoelectric conversion; a transparent optical member disposed between the imaging element and the imaging lens; a foreign matter removal device for removing foreign matter adhering to the optical member; a multi-division light measuring sensor for dividing an imaged screen to a plurality of regions to detect subject luminance in each region and outputting measured values; and a control part for controlling switching on whether the foreign matter removal device is controlled in a first operation mode or in a second operation mode different in operation state from the first operation mode, in response to the measured values by the multi-division light measuring sensor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for removing foreign matters such as dust attached to an optical member disposed on a photographing optical axis in an imaging apparatus such as a digital camera.

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

  In such an image pickup apparatus, an optical low-pass filter and an infrared cut filter are disposed on the subject side of the image pickup device, and when foreign matters such as dust adhere to the surface of these filters, the attached portion becomes a black dot. The image appears in the photographed image and the image looks poor.

In particular, in a single-lens reflex digital camera with interchangeable lenses, mechanical operation parts such as shutters and quick return mirrors are arranged in the vicinity of the image sensor, and foreign matters such as dust generated from these operation parts May adhere to the low-pass filter. In addition, when the lens is replaced, foreign matter such as dust may enter the camera body from the opening of the lens mount and adhere to it. In order to avoid such a phenomenon, as in Patent Document 1, a dust-proof curtain that transmits the photographic light flux is provided on the subject side of the image sensor, and this is vibrated by a piezoelectric element so that it adheres to the surface of the dust-proof curtain. Techniques for removing foreign substances such as dust have been proposed.
JP 2003-319222 A

  If an operation for removing foreign matter such as dust is performed every time a photographing operation is performed using the above-described method, photographing can be performed in a state where it is least affected by the foreign matter. However, performing a foreign matter removal operation or performing a foreign matter removal operation in an excessive amount of time in all photographing causes unnecessary power consumption.

  For example, when the user performs shooting in a situation where the user is hardly affected by foreign matter such as dust, the foreign matter removal operation is a useless operation. Such a useless operation causes problems such as depriving the electric energy of the battery that supplies power to the camera system and reducing the number of shots.

  Accordingly, the present invention has been made in view of the above-described problems, and an object of the present invention is to efficiently remove foreign matters such as dust adhering to an optical member disposed on a photographing optical axis, and waste power. Is to suppress unnecessary consumption.

  In order to solve the above-described problems and achieve the object, an imaging apparatus according to the present invention includes an imaging element that photoelectrically converts a subject image formed by a photographic lens, and is disposed between the imaging element and the photographic lens. The light-transmitting optical member, the foreign matter removing means for removing the foreign matter adhering to the optical member, and the photographing screen are divided into a plurality of areas, and the subject brightness in each area is detected and the photometric value is output. Multi-division photometry means for controlling the foreign matter removal means in a first operation mode according to a photometric value of the multi-division photometry means, or a second operation having an operation state different from the first operation mode. And control means for switching and controlling whether to control in the mode.

  The image pickup apparatus control method according to the present invention includes an image pickup device that photoelectrically converts a subject image formed by a photographing lens, and a light-transmissive optical member that is disposed between the image pickup device and the photographing lens. A foreign substance removing unit that removes the foreign substance attached to the optical member, and a multi-division photometric unit that divides the photographing screen into a plurality of areas, detects subject luminance in each area, and outputs a photometric value. A method for controlling an imaging apparatus, wherein the foreign matter removing means is controlled in a first operation mode according to a photometric value of the multi-division photometry means, or a different operation state from the first operation mode. And a control step of switching and controlling whether to control in the two operation modes.

  A program according to the present invention causes a computer to execute the above control method.

  A storage medium according to the present invention stores the above program.

  According to the present invention, it is possible to efficiently remove foreign matters such as dust adhering to the optical member disposed on the photographing optical axis, and it is possible to suppress wasteful consumption of electric power.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are not necessarily essential to the practice of the invention.

(First embodiment)
<Camera configuration>
Hereinafter, a single-lens reflex digital camera according to a first embodiment of the present invention will be described with reference to FIGS. 1, 2, and 3. FIG. The configuration of the single-lens reflex digital camera is common to other embodiments.

  1 and 2 are views showing the appearance of a single-lens reflex digital camera according to the present embodiment. Specifically, FIG. 1 is a perspective view seen from the front side of the camera, showing a state in which the taking lens unit is removed, and FIG. 2 is a perspective view seen from the back side of the camera.

  In FIG. 1, reference numeral 1 denotes a camera body, which is provided with a grip portion 1a that protrudes forward so that a user can easily hold the camera stably during shooting. Reference numeral 2 denotes a mount, which fixes a detachable taking lens unit 200a (see FIG. 3) to the camera body. The mount contact 21 has a function of transmitting a control signal, a status signal, a data signal, and the like between the camera body and the photographing lens unit and supplying power to the photographing lens unit. Further, the mount contact 21 may be configured not only for electrical communication but also for optical communication, voice communication, and the like.

  Reference numeral 4 denotes a lens lock release button that is pushed in when removing the photographing lens unit. Reference numeral 5 denotes a mirror box disposed in the camera housing, and the photographic light flux that has passed through the photographic lens is guided here. A quick return mirror 6 is disposed inside the mirror box 5. The quick return mirror 6 is held at an angle of 45 ° with respect to the photographing optical axis in order to guide the photographing light flux in the direction of the pentaprism 22 (see FIG. 3) and the direction of the image sensor 33 (see FIG. 3). In order to guide to the position, it is possible to take a state of being held at a position retracted from the photographing light flux.

  On the grip side of the upper part of the camera, a shutter button 7 as a start switch for starting shooting and a main operation dial 8 for setting a shutter speed and a lens aperture value according to an operation mode at the time of shooting are arranged. In addition, an operation mode setting button 10 for setting an operation mode of the photographing system is also arranged. Some of the operation results of these operation members are displayed on the LCD display panel 9.

  The shutter button 7 has a configuration in which a switch SW1 (7a described later) is turned on by a first stroke (half-pressed) and a switch SW2 (7b described later) is turned on by a second stroke (fully pressed).

  The operation mode setting button 10 is used to set whether the continuous shooting or only one frame shooting is performed when the shutter button 7 is pressed once, the self shooting mode setting, and the like. 9 shows the setting status.

  A flash unit 11 that pops up with respect to the camera body, a shoe groove 12 for mounting the flash, and a flash contact 13 are arranged at the upper center of the camera, and a shooting mode setting dial 14 is arranged at the upper right side of the camera.

  An external terminal lid 15 that can be opened and closed is provided on the side opposite to the grip. Inside the external terminal lid 15, a video signal output jack 16 and a USB output connector are provided as external interfaces. 17 is stored.

  In FIG. 2, a viewfinder eyepiece window 18 is provided on the back side of the camera, and a color liquid crystal monitor 19 capable of displaying an image is provided near the center of the back side. The sub operation dial 20 arranged beside the color liquid crystal monitor 19 plays an auxiliary role of the function of the main operation dial 8. For example, in the AE mode of the camera, the exposure correction amount for the appropriate exposure value calculated by the automatic exposure device is set. Used to set. Alternatively, in the manual mode in which each of the shutter speed and the lens aperture value is set according to the user's will, the shutter speed is set with the main operation dial 8 and the lens aperture value is set with the sub operation dial 20. The sub operation dial 20 is also used to select display of a captured image displayed on the color liquid crystal monitor 19.

  Reference numeral 43 denotes a main switch for starting or stopping the operation of the camera. Reference numeral 44 denotes a cleaning instruction operation member for operating the cleaning mode, which is for instructing an operation for removing dust attached to the optical low-pass filter.

  The cleaning mode can be arbitrarily operated using the cleaning mode instruction operation member 44, and can be automatically operated in consideration of the photographing scene based on the photometric distribution of the subject as will be described later.

  FIG. 3 is a block diagram showing the main electrical configuration of the single-lens reflex digital camera of the present embodiment. In addition, the part which is common in the above-mentioned drawing is shown with the same symbol.

  Reference numeral 100 denotes a central processing unit (hereinafter referred to as MPU) which is a microcomputer built in the camera body. The MPU 100 controls the operation of the camera, and executes various processes and instructions for each element.

  Reference numeral 100a denotes an EEPROM built in the MPU 100, which can store time information of the time measuring circuit 109 and other information.

  Connected to the MPU 100 are a mirror drive unit 101, a focus detection circuit 102, a shutter drive circuit 103, a video signal processing circuit 104, a switch sense circuit 105, and a photometric circuit 106. An LCD drive circuit 107, a battery check circuit 108, a time measurement circuit 109, a power supply circuit 110, and a piezoelectric element drive circuit 111 are also connected. These circuits operate under the control of the MPU.

  The MPU 100 communicates with the lens control circuit 201 disposed in the photographing lens unit 200 a via the mount contact 21. The mount contact 21 also has a function of transmitting a signal to the MPU 100 when the photographing lens unit 200a is connected. Accordingly, the lens control circuit 201 can communicate with the MPU 100 and drive the photographing lens 200 and the diaphragm 204 in the photographing lens unit 200a via the AF driving unit 202 and the diaphragm driving unit 203. It becomes. In the present embodiment, the photographic lens 200 is shown as a single lens for convenience, but is actually composed of a large number of lens groups.

  The AF driving unit 202 is configured by a stepping motor, for example, and adjusts the imaging light flux to be focused on the image sensor 33 by changing the position of the focus lens in the imaging lens 200 under the control of the lens control circuit 201.

  Reference numeral 203 denotes an aperture driving unit, which is configured by, for example, an auto iris or the like, and is configured to change the aperture diameter of the aperture 204 by the lens control circuit 201 to obtain an optical aperture value.

  The quick return mirror 6 guides the photographic light beam passing through the photographic lens 200 to the pentaprism 22 and transmits a part thereof to the sub mirror 30. The sub mirror 30 guides the photographing light flux that has passed through the quick return mirror 6 to the focus detection sensor unit 31.

  The mirror drive unit 101 is for driving the quick return mirror 6 to a position where the subject image can be observed by the viewfinder and a position where the subject image is retracted from the photographing light flux. At the same time, the sub mirror 30 is driven to a position for guiding the photographing light flux to the focus detection sensor unit 31 and a position for retracting from the photographing light flux. Specifically, it is composed of, for example, a DC motor and a gear train.

  Reference numeral 31 is a well-known focus detection using a phase difference detection system composed of a field lens, a reflecting mirror, a secondary imaging lens, a diaphragm, a line sensor composed of a plurality of CCDs, and the like arranged in the vicinity of an imaging surface (not shown). It is a sensor unit. The signal output from the focus detection sensor unit 31 is supplied to the focus detection circuit 102, converted into a subject image signal, and then transmitted to the MPU 100. The MPU 100 performs focus detection calculation by the phase difference detection method based on the subject image signal. Then, the defocus amount and the defocus direction are obtained, and based on this, the focus lens in the photographing lens 200 is driven to the in-focus position via the lens control circuit 201 and the AF drive unit 202.

  Reference numeral 22 denotes a pentaprism, which is an optical member that converts and reflects the photographing light beam reflected by the quick return mirror 6 into an erect image. The user can observe the subject image from the finder eyepiece window 18 via the finder optical system. The pentaprism 22 guides part of the photographing light flux to the photometric sensor 45. The photometric circuit 106 obtains the output of the photometric sensor 45, converts it into a luminance signal for each area on the observation surface, and outputs it to the MPU 100. The MPU 100 calculates a photometric value from the obtained luminance signal and determines an exposure value.

  Reference numeral 32 denotes a mechanical focal plane shutter. First, as shown in FIG. 4, when a user is observing a subject image with a viewfinder, the shutter front curtain 32a of the mechanical focal plane shutter 32 is in a light shielding position and after the shutter. The curtain 32b is at the exposure position. Next, at the time of shooting, as shown in FIG. 5, the shutter front curtain 32 a performs exposure travel in which the shutter front curtain 32 a moves from the light shielding position to the exposure position, passes light from the subject, and images are picked up by the image sensor 33. After the elapse of the desired shutter time, as shown in FIG. 6, the shutter rear curtain 32b travels from the exposure position to the light shielding position to complete the photographing. The mechanical focal plane shutter 32 is controlled by a shutter drive circuit 103 that has received a command from the MPU 100.

  Reference numeral 33 denotes an image sensor. In this embodiment, a CMOS sensor that is an image pickup device is used. However, there are various types of imaging devices such as a CCD type, a CMOS type, and a CID type, and any type of imaging device may be adopted.

  Reference numeral 34 denotes a clamp / CDS (correlated double sampling) circuit, which performs basic analog processing before A / D conversion and can also change the clamp level. Reference numeral 35 denotes an AGC circuit (automatic gain adjusting device) which performs basic analog processing before A / D conversion and can change the AGC basic level. Reference numeral 36 denotes an A / D converter that converts an analog output signal of the image sensor 33 into a digital signal.

  410 is an optical low-pass filter, which is formed by laminating and laminating a plurality of birefringent plates and phase plates made of quartz, and further laminating an infrared cut filter.

  A laminated piezoelectric element 430 is configured to be excited by the piezoelectric element driving circuit 111 that receives a command from the MPU 100 and to transmit the vibration to the optical low-pass filter 410.

  Reference numeral 400 denotes an image pickup unit in which the optical low-pass filter 410, the piezoelectric element 430, and the image pickup element 33 are unitized together with other components to be described later.

  Reference numeral 104 denotes a video signal processing circuit, which performs overall hardware image processing such as gamma / knee processing, filter processing, and monitor display information synthesis processing on digitized image data. The image data for monitor display from the video signal processing circuit 104 is displayed on the color liquid crystal monitor 19 via the color liquid crystal drive circuit 112. Further, the video signal processing circuit 104 can also store image data in the buffer memory 37 through the memory controller 38 in accordance with an instruction from the MPU 100. Further, the video signal processing circuit 104 has a function of performing image data compression processing such as JPEG. When continuous shooting is performed, such as continuous shooting, image data can be temporarily stored in the buffer memory 37 and unprocessed image data can be sequentially read out through the memory controller 38. Thus, the video signal processing circuit 104 can sequentially perform image processing and compression processing regardless of the speed of the image data input from the A / D converter 36.

  The memory controller 38 has a function of storing image data input from the external interface 40 (corresponding to the video signal output jack 16 and the USB output connector 17 in FIG. 1) in the memory 39. In addition, it has a function of outputting image data stored in the memory 39 from the external interface 40. The memory 39 is a flash memory that can be attached to and detached from the camera body.

  Reference numeral 105 denotes a switch sense circuit, which transmits an input signal to the MPU 100 according to the operation state of each switch. Reference numeral 7a denotes a switch SW1 that is turned on by the first stroke (half-pressed) of the release button 7. Reference numeral 7b denotes a switch SW2 that is turned on by the second stroke (full press) of the release button 7. When the switch SW2 is turned on, an instruction to start photographing is transmitted to the MPU 100.

  The MPU 100 is connected to a main operation dial 8, a sub operation dial 20, a shooting mode setting dial 14, a main switch 43, and a cleaning instruction operation member 44.

  Reference numeral 107 denotes an LCD drive circuit that drives the LCD display panel 9 and the in-finder liquid crystal display device 41 in accordance with instructions from the MPU 100.

  A battery check circuit 108 performs a battery check for a predetermined time in accordance with a signal from the MPU 100 and sends the detection output to the MPU 100.

  A power supply unit 42 supplies necessary power to each element of the camera.

  Reference numeral 109 denotes a time measuring circuit that measures the time and date from when the main switch 43 is turned off to when it is turned on, and can send the measurement result to the MPU 100 in accordance with an instruction from the MPU 100.

<Configuration of vibration device>
Next, a configuration for exciting the optical low-pass filter 410 in the present embodiment will be described with reference to FIG.

  FIG. 7 is an exploded perspective view showing a configuration around the optical low-pass filter and the image sensor.

  First, 420 is an optical low-pass filter holding member made of resin or metal. The piezoelectric element 430 is held so that the expansion / contraction direction due to voltage application is a direction orthogonal to the optical axis (camera top-to-bottom direction). The piezoelectric element 430 may or may not be bonded to the optical low-pass filter holding member 420, but is not bonded to the optical low-pass filter 410. One end of the optical low-pass filter 410 is in contact with the piezoelectric element 430, and the opposite end is in contact with the biasing member 440. The biasing member 440 biases the optical low-pass filter 410 in a direction substantially orthogonal to the optical axis with respect to the piezoelectric element 430 so that the movement of the optical low-pass filter 410 follows the expansion / contraction movement of the piezoelectric element 430. As long as the urging member 440 is an elastic body, a plate spring or a coil spring formed of metal may be used, or a polymer such as rubber or plastic may be used.

  Next, reference numeral 460 denotes a plate-like restricting member that restricts the position of the optical low-pass filter 410 so as to be sandwiched between the optical low-pass filter holding member 420 in the optical axis direction, and the periphery is hooked on the optical low-pass filter holding member 420. Fixed to. As described above, the optical low-pass filter 410 is held by the optical low-pass filter holding member 420 so as to be able to vibrate so as to be sandwiched between the piezoelectric element 430 and the biasing member 440. Further, the outer peripheral portion of the optical low-pass filter 410 is hermetically sealed with a frame-like elastic member 450, and the position of the optical low-pass filter 410 in the optical axis direction is restricted by the restriction member 460. With these configurations, the optical low-pass filter holding unit 470 is configured.

  The optical low-pass filter holding member 420 of the optical low-pass filter holding unit 470 is coupled to the image sensor holding member 510 of the image sensor holding unit 500 with a step screw 530 while sandwiching an elastic rubber sheet 520.

  Next, the operation of the vibration exciter configured as described above will be described.

  When the MPU 100 applies a predetermined periodic voltage to the piezoelectric element 430 housed in the optical low-pass filter holding member 420, the piezoelectric element 430 vibrates in a direction substantially perpendicular to the optical axis (the camera top-to-bottom direction). The optical low-pass filter 410 is disposed so as to be sandwiched between the piezoelectric element 430 and the biasing member 440 in substantially the same in-plane direction. Therefore, the optical low-pass filter 410 is held in close contact with the piezoelectric element 430, and is caused to vibrate in a direction substantially parallel to the vibration direction of the piezoelectric element 430 and in a direction substantially perpendicular to the optical axis by the vibration of the piezoelectric element 430. Excited.

  In the present embodiment, the gap between the optical low-pass filter holding member 420 and the image sensor 33 is sealed with the rubber sheet 520 as described above. Further, the optical low-pass filter 410 and the optical low-pass filter holding member 420 are sealed with the piezoelectric element 430 and the elastic member 450. Therefore, the space between the optical low-pass filter 410 and the image sensor 33 is a sealed space from which foreign matter such as dust does not enter.

  The vibration of the optical low-pass filter holding unit 470 is absorbed by the rubber sheet 520 and hardly transmitted to the image sensor 33. With this configuration, even if the piezoelectric element 430 vibrates, the imaging element 33 hardly vibrates, and only the optical low-pass filter 410 vibrates, so that the mass of the vibrating object can be reduced, and the optical low-pass filter 410 can be reduced with less energy. Can be vibrated.

<Camera operation>
Next, FIG. 8 is a flowchart showing the overall operation of the single-lens reflex digital camera of this embodiment.

  In FIG. 8, when the power of the single-lens reflex digital camera is turned on (YES in step S1), it is determined whether or not the optical viewfinder mode is set (step S2). When it is in the optical finder mode (YES in step S2), the processes of steps S3 to S17 described below are executed. The case of the electronic viewfinder mode (NO in step S2) will be described in detail later.

  In the optical finder mode, first, if SW1 is turned ON by the first stroke (half-pressed) of the shutter button 7 (step S3), the light from the subject is measured by the photometric sensor 45 (step S4). Then, the output voltage representing the photometric brightness value is converted into a digital signal, and the MPU 100 calculates the shutter speed and the aperture value of the aperture 204 (step S5).

  Next, the focus detection sensor is used to obtain the defocus amount and the defocus direction of the subject, and based on this, the focus lens in the photographing lens 200 is brought to the in-focus position via the lens control circuit 201 and the AF drive unit 202. Drive (step S6).

  It is determined whether or not SW2 is turned ON by the second stroke (full press) of the shutter button 7, that is, whether or not to start photographing (step S7). When starting, the process proceeds to step S9.

  In step S9, it is determined whether the camera is set to perform the foreign matter removal operation automatically or manually. If it is performed automatically, the process proceeds to step S10. If it is performed manually, step S11 is performed. Proceed to

  In step S10, a photographic scene is determined based on the photometric distribution of the subject, and a foreign matter removing operation is performed. Details of the determination method will be described later. Then, as shown in FIG. 5, the quick return mirror 6 is flipped up (step S11), and in the subsequent step S12, the image travels in the direction in which the shutter front curtain 32a is opened, and an image is picked up by the image sensor 33 (step S13). Then, after the shutter time has elapsed, as shown in FIG. 6, the shutter rear curtain 32b travels in the closing direction to block the light from the subject (step S14). Smearing can be prevented by running in the direction in which the shutter rear curtain 32b is closed. Thereafter, the quick return mirror 6 is lowered (step S15), and one shooting process is completed.

  Next, the diaphragm 204 is opened, and the image captured in step S13 is read, processed, recorded, and the captured still image is displayed on the color liquid crystal monitor 19 (step S16).

  Further, the shutter front curtain 32a is charged in the closing direction and the shutter rear curtain 32b is charged in the opening direction (step S17), and then the process returns to the processing after the optical finder mode selection in step S3.

  If the result of determination in step S7 is that shooting is not started, it is determined whether or not the optical finder mode is to be continued (step S8), and if so, the processing in steps S3 to S7 is repeated. On the other hand, as a result of the determination in step S8, when the optical finder mode is not continued, it is determined that the optical finder mode has been canceled, the processing returns to step S2, and the subsequent processing is repeated.

<Determination of foreign matter removal operation>
Next, the determination method of the foreign substance removal operation in step S10 in FIG. 8 will be described with reference to FIGS.

  FIG. 9 is a flowchart illustrating a method for determining a foreign substance removal operation, and FIG. 10 is a diagram illustrating a state in which the screen is divided into, for example, 45 photometric areas. The divided photometric areas correspond to the divided photometric areas of the multi-divided photometric sensor 45.

  The photometry circuit 106 converts the output value of the multi-division photometry sensor 45 into the luminance value of each photometry area 71 divided on the observation surface as shown in FIG. 10 and outputs it to the MPU 100. The MPU 100 calculates a photometric value from each luminance value, and stores 45 pieces of data under the name Ex (x = 1 to 45) in a RAM (random access memory) in the MPU 100 (step S4 in FIG. 8). In step S101 in FIG. 9, the MPU 100 calculates the average value AveE of the photometric values in each area as follows.

AveE = Ave (Ex) (x = 1 to 45)
Then, it is determined whether each photometric value Ex is larger than the average value AveE,
Ex> AveE (x = 1 to 45)
If the condition is satisfied, the process proceeds to step S102. Otherwise, the process proceeds to step S11. Although the average photometric value is used here, other values may be used. For example, the photometric value of the central area 71a of the divided photometric area 71, the photometric value of the main subject, or the photometric value of the photometric area corresponding to the focused distance measuring point may be used. A combination of these values may also be used. In addition, in a camera having a multi-point AF function having a plurality of ranging points, it is not necessary to compare all the metering values for each metering area. Photometric values in areas that are not recognized may be excluded from comparison targets. This is based on the idea that it is desirable to compare and discriminate the photometric value of the background, not the main subject.

  In step S102, it is determined whether or not the number of photometric areas satisfying the condition in step S101 is 10 and there are continuous areas. If there are 10 or more areas continuously, the process proceeds to step S103. If not, the process proceeds to step S11. In addition, this step S11 means step S11 in FIG.

  The number of areas being 10 or more means that a subject having a photometric value larger than the average photometric value occupies approximately ¼ or more in the screen. The number of areas as the threshold value may be larger or smaller than 10 depending on the number of divided photometric areas.

  In step S103, the photometric values Ex are compared in the number of photometric areas n satisfying the condition in step S101 (here, n is an integer of 10 or more because the threshold value is 10 as described above). And it is discriminate | determined as follows whether all those differences are below Ev2.

| Exi−Exj | ≦ Ev2 (i = 1 to n, j = 1 to n)
Here, Exi and Exj are distinguished by assigning numbers i and j to the photometric value Ex of each area.

  If these differences are all equal to or less than Ev2, the process proceeds to step S104, and otherwise, the process proceeds to step S11. In other words, it is determined whether each area satisfying the condition of step S102 has substantially the same luminance.

  In step S104, as described above, the optical low-pass filter 410 is vibrated to perform the foreign substance removal operation. Therefore, by taking the above steps, a foreign matter removing operation is performed when shooting a subject in which high-brightness areas having almost no brightness difference are continuously present.

  Specifically, as shown in FIG. 11, a part representing the “sky” of the landscape (in the thick frame line in the figure), or a part representing the “white wall of the house” in the background of the person as shown in FIG. If the subject is in the line), the condition for performing the foreign substance removal operation is satisfied, and the foreign substance removal operation is automatically performed. That is, at the time of photographing, the foreign matter removing operation is performed after the SW2 is turned on and before the photographing operation is performed.

  As described above, the foreign matter removal operation is automatically performed only when shooting an image in which foreign matter such as dust is conspicuous, that is, a high brightness and uniform image (for example, an empty landscape or a white wall). Can be taken without the influence of foreign matter.

<Operation in electronic viewfinder mode>
Next, the case of the electronic finder mode (NO in step S2) in the flowchart of FIG. 8 will be described in detail.

  FIG. 13 is a schematic sectional view showing an electronic viewfinder mode in the single-lens reflex digital camera of the present embodiment.

  The quick return mirror 6 is always at a position retracted from the photographic light beam in order to guide the photographic light beam in the direction of the image sensor 33, and both the shutter front curtain 32a and the shutter rear curtain 32b are in an open position, so that continuous imaging is performed. The electronic viewfinder display to be performed is performed.

  The user cannot observe the subject image from the viewfinder eyepiece window 18 through the viewfinder optical system.

  At the time of shooting, first, a light shielding charge is performed in which the shutter front curtain 32a moves from the open position to the closed position, and the shutter front curtain 32a travels again in the opening direction. 32b travels in the closing direction to complete the shooting. Then, for the next electronic finder operation, exposure charging is performed in which only the shutter rear curtain 32b is moved from the closed position to the opened position in order to always perform imaging.

  Next, the overall operation of the camera in the electronic viewfinder mode will be described with reference to the flowchart of FIG.

  As a result of the determination in step S2 in FIG. 8, when the mode is not the optical finder mode, that is, in the electronic finder mode, the processing in the electronic finder mode is executed by the processing in steps S18 to S35 in FIG.

  In the electronic viewfinder mode, first, the quick return mirror 6 is lifted (step S18), moved in a direction to open the shutter front curtain 32a, and then a still image is captured by the image sensor 33, and the shutter rear curtain 32b is closed. (Step S19).

  The image captured in step S19 is read out, processed, recorded, and the captured still image is displayed on the color liquid crystal monitor 19 for a predetermined time (step S20). As a result, the user can confirm the composition and the like. At this time, photometry is performed from the still image (step S21), and the MPU 100 calculates the shutter speed and the aperture value of the aperture 204 (step S22).

  Next, only the shutter rear curtain 32b is charged in the opening direction (step S23), and as shown in FIG. 13, the imaging device 33 always performs imaging and displays a moving image (step S24).

  In a succeeding step S25, it is determined whether or not the photographing is started. When the photographing is started, the process proceeds to a step S26.

  In step S26, it is determined whether the camera is set to perform the foreign matter removal operation automatically or manually. If it is performed automatically, the process proceeds to step S27. If it is performed manually, step S28 is performed. Proceed to

  In step S27, the photographic scene is determined based on the photometric distribution of the subject, and a foreign matter removing operation is performed. Details of the determination method will be described later.

  Thereafter, the shutter front curtain 32a is charged in the closing direction (step S28), the shutter front curtain 32a is moved in the opening direction (step S29), and a still image is captured by the image sensor 33 (step S30). Then, after the shutter time has elapsed, the shutter rear curtain 32b is caused to travel in the closing direction (step S31).

  The image captured in step S30 is read, processed, recorded, and the captured still image is displayed on the color liquid crystal monitor 19 for a predetermined time (step S32), and the process returns to step S23 and subsequent steps.

  If the result of determination in step S25 is that shooting is not started, it is determined whether or not the electronic viewfinder mode is to be continued (step S33). If so, the processing of steps S24 to S25 is repeated.

  If the electronic finder mode is not continued as a result of the determination in step S33, it is determined that the photographing mode by the electronic finder has been canceled. Then, after the quick return mirror 6 is lowered (step S34), the shutter front curtain 32a is charged in the closing direction (step S35), the processing returns to step S2 in FIG. 8, and the subsequent processing is repeated.

<Determination of foreign matter removal operation>
Next, with reference to FIG. 15, the determination method of the foreign substance removal operation in step S27 of FIG. 14 will be described. FIG. 15 is a flowchart showing a method for determining the foreign substance removal operation.

  The video signal processing circuit 104 outputs the digitized image signal obtained from the image sensor 33 through the processes of the clamp / CDS circuit 34, the AGC circuit 35, and the A / D converter 36 to the MPU 100.

  The MPU 100 divides the observation screen into 45 areas as shown in FIG. 10, for example, and converts the obtained image signal into luminance values of the divided areas 71. The MPU 100 calculates a photometric value from each luminance value, and stores 45 pieces of data under the name Ex (x = 1 to 45) in a RAM (random access memory) in the MPU 100 (step S21 in FIG. 14).

  Subsequent steps S111 to S114 performed by the MUP 100 are the same as steps S101 to S104 described so far. That is, in step S111, the average value AveE of the photometric values in each area is compared with each photometric value Ex. If the photometric value Ex is large, the process proceeds to step S112. Otherwise, the process proceeds to step S28. Although the average photometric value is used here, other values may be used. For example, the photometric value of the central area 71a of the divided area 71, the photometric value of the main subject, the photometric value of the area corresponding to the focused distance measuring point, or a combination of these values But you can. For cameras with multiple AF points that have multiple AF points, it is not necessary to compare all photometric values for each area, and it is recognized as infinity by ranging at other AF points. Photometric values in areas that are not used may be excluded from comparison targets.

  In step S112, it is determined whether or not the number of areas satisfying the condition in step S111 is 10 or more and the area exists continuously. If the condition is satisfied, the process proceeds to step S113. Otherwise, the process proceeds to FIG. Proceed to step S28.

  In step S113, the photometric values of all the areas satisfying the conditions in step S111 are compared. If all of the differences are equal to or less than Ev2, the process proceeds to step S114. Otherwise, the process proceeds to step S28.

  In step S114, the optical low-pass filter 410 described so far is vibrated to perform a foreign substance removal operation.

(Second Embodiment)
In the second embodiment, as described in the first embodiment, it is not determined whether or not to perform the foreign substance removing operation based on the photometric distribution, but the operation time of the foreign substance removing operation is set based on the photometric distribution. Change. Others are the same as in the first embodiment.

  FIG. 16 is a flowchart illustrating a method for determining a foreign matter removal operation according to the second embodiment.

  First, in steps S121 to S123, determinations similar to those in steps S101 to S103 in FIG. 9 or steps S111 to S113 in FIG. 15 are performed. If all the conditions are satisfied, the process proceeds to step S124. If the condition is not satisfied in each step, the process proceeds to step S125.

  In step S124, the foreign matter removing operation for vibrating the optical low-pass filter 410 described so far is performed for 1 second longer than the normal operation time.

  In step S125, the foreign matter removing operation is performed for 0.5 seconds, which is a normal operation time.

  After step S124 and step S125, the process proceeds to the photographing operation.

  In this way, by performing the foreign matter removal operation longer than usual only when photographing an image in which foreign matters such as dust are conspicuous, that is, a high brightness and uniform image (for example, an empty landscape or a white wall), It is possible to perform shooting without the influence of foreign matter without wasting power.

  Here, the normal operation time of the foreign matter removal operation is set to 0.5 seconds. However, if it is an optimum value considering the electric energy, the foreign matter removal rate, the foreign matter removal method, etc., it may be shorter or longer than 0.5 seconds. Also good. In addition, the operation time longer than normal for the foreign matter removal operation is set to be twice the normal operation time. However, if this is also an optimum value considering the electric energy, the foreign matter removal rate, the foreign matter removal method, etc. May be small. Further, in consideration of the fact that the higher the brightness of the image, the more likely the foreign matter becomes conspicuous with respect to the image, a step may be provided for the predetermined value (for example, the photometric average value) that is the threshold value in step S121. . That is, the larger the predetermined value, that is, the higher the brightness of the subject, the longer the foreign substance removal operation time may be set in steps.

  Further, the length of the foreign matter removal drive time has been described so far, but the number of foreign matter removal drive times may be increased more than usual when photographing foreign matters.

(Third embodiment)
In the third embodiment, as described in the first embodiment, it is not determined whether or not to perform the foreign substance removal operation based on the photometric distribution, but the foreign substance removal operation is performed based on the photographing scene and the photometric distribution. Determine whether to do it. Others are the same as in the first embodiment.

  FIG. 17 is a flowchart illustrating a method for determining a foreign matter removing operation according to the third embodiment.

  First, in step S135, the MPU 100 determines whether or not the photographing mode set by the photographing mode setting dial 14 is “landscape mode”. If the condition is satisfied, the process proceeds to step S131. Otherwise, the foreign substance removing operation is not performed. Start shooting. The “landscape mode” is a shooting mode used when shooting a wide landscape or night view.

  Steps S131 to S133 are the same as the determination of the photometric distribution described so far. If all the conditions are satisfied, the process proceeds to step S134. If the conditions are not satisfied in each step, the foreign substance removing operation is not performed and the photographing operation is performed. enter.

  In step S134, the foreign substance removing operation for vibrating the optical low-pass filter 410 described so far is performed.

  Here, the reason why “landscape mode” is taken up as a parameter for determining the shooting mode in step S135 is as follows.

  In other words, when shooting in the “landscape mode”, the subject often does not move. Therefore, even if a foreign object removal operation is performed during shooting, the shutter chance is not missed. It is because it is thought that it may go.

  On the other hand, from the opposite point of view, if the “sport mode” used when taking a picture capturing the moment of a fast-moving subject is set as the shooting mode, the foreign matter removal operation may not be performed. In other shooting modes, the foreign matter removal operation based on the photometric distribution described so far is performed. This is because when the “Sports Mode” is selected, it is better not to perform the foreign matter removal operation, because if the foreign matter removal operation is performed at the time of shooting, there is a risk of missing a photo opportunity. Because it is.

(Fourth embodiment)
In the fourth embodiment, as described in the second embodiment, the operation time of the foreign matter removal operation is not changed based on the photometric distribution, but the operation time of the foreign matter removal operation is set based on the photographing scene and the photometric distribution. Change. Others are the same as in the second embodiment.

  FIG. 18 is a flowchart illustrating a method for determining a foreign matter removal operation according to the fourth embodiment.

  First, in step S145, the MPU 100 determines whether or not the photographing mode set by the photographing mode setting dial 14 is “landscape mode”. If the condition is satisfied, the process proceeds to step S141. Otherwise, the process proceeds to step S146.

  Steps S141 to S143 are the same as the determination of the photometric distribution described so far. If all the conditions are satisfied, the process proceeds to step S144. If the conditions are not satisfied in each step, the process proceeds to step S146.

  In step S144, the foreign matter removal operation is performed for 1 second longer than the normal operation time, similar to the processing in step S124 of FIG.

  In step S146, similar to the processing in step S125 of FIG. 16, the foreign matter removing operation is performed for 0.5 seconds of the normal operation time. After step S144 and step S146, the operation proceeds to the photographing operation.

  By doing so, there are few situations in which a photo opportunity is missed when shooting in “landscape mode”, so it is possible to perform shooting with less influence of foreign matter by performing the foreign matter removal operation for a longer time than usual. .

  In addition, as described above, if “sport mode” is selected as the shooting mode instead of “landscape mode”, the foreign substance removal may be driven for a normal time from the viewpoint of severe photo opportunities. That is, the driving for a longer time than usual may not be performed.

(Fifth embodiment)
With reference to FIGS. 19 and 20, another embodiment of the apparatus for removing foreign matters such as dust adhering to the optical low-pass filter will be described.

  The imaging unit 600 includes a light-transmissive optical element 611, a holding member 612 that holds the optical element 611, and a light-transmissive cover member 613a that protects the solid-state imaging element 613b and the solid-state imaging element 613b. A solid-state imaging device 613. Further, a seal member 614 for sealing between the cover member 613 a of the solid-state imaging device 613 and the optical element 611 is provided. The optical element 611 is specifically an optical low-pass filter.

  Next, reference numeral 621 denotes a lever that is connected to a drive unit (not shown) and can run in the direction of arrow A in the drawing parallel to the surface of the optical element 611, and is an abrasion resistant fiber 622 (for example, Dyneema manufactured by Toyobo Co., Ltd.). Is provided. The abrasion-resistant fiber 622 is a cleaning brush. Reference numeral 623 denotes foreign matter adhering to the optical element 611. Here, the length of the abrasion-resistant fiber 622 is adjusted so as to contact the optical element 611.

  First, the lever 621 is positioned in the upper part of the figure, and when the foreign matter removal (cleaning mode) operation is started, the lever 621 is scanned downward, and the abrasion-resistant fiber 622 also travels downward. And the foreign material 623 adhering to the surface of the optical element 611 is wiped off by running downward while the abrasion-resistant fiber 622 is in contact. Then, after scanning the surface of the optical element 611 downward, it returns to the original position above.

(Sixth embodiment)
With reference to FIG. 21 and FIG. 22, another embodiment of the apparatus for removing foreign matters such as dust adhering to the optical low-pass filter will be described.

  The imaging unit 700 includes a light-transmitting optical element 711, a holding member 712 that holds the optical element 711, and a light-transmitting cover member 713a for protecting the solid-state imaging element 713b and the solid-state imaging element 713b. A solid-state imaging device 713. Further, a seal member 714 for sealing between the cover member 713a of the solid-state imaging device 713 and the optical element 711 is provided. The optical element 711 is specifically an optical low-pass filter.

  Next, 721 is an insulator such as polyimide that can run in the direction of the arrow A in the drawing parallel to the surface of the optical element 711, and is switched between a charged state and a charge-removed state by a coil (not shown). Reference numeral 723 denotes foreign matter adhering to the optical element 711.

  First, the insulator 721 is located in the upper part of the drawing, and when the operation in the cleaning mode is started, a predetermined voltage is applied to a coil (not shown) to charge the insulator 721 and scan downward. Then, since the insulator 721 is charged, if a charged foreign matter 723 is attached to the surface of the optical element 711, an electrostatic force is generated between the mutually charged foreign matter 723 and the insulator 721. To do. The foreign material 723 is attracted to the insulator 721 by this electrostatic force (electrostatic adsorption) against the adhesive force with the surface of the optical element 711. Then, the foreign material 723 attracted to the insulator 721 by electrostatic force remains on the surface of the insulator 721.

  When the insulator 721 finishes scanning downward, a voltage opposite to that when charged by a coil (not shown) is applied. Then, the insulator 721 is neutralized. By this static elimination operation, the foreign matter 723 attached to the surface of the insulator 721 due to electrostatic force is separated from the surface of the insulator 721 by gravity and falls. After that, the insulator 721 returns to the upper original position.

  In any of the embodiments described so far, the foreign matter removing operation is efficiently performed when photographing an image in which foreign matter such as dust is conspicuous, that is, a high-luminance and uniform image (for example, an empty landscape or a white wall). Can be done. Therefore, the user can perform shooting without the influence of foreign matter without wasting power.

(Other embodiments)
The object of each embodiment is also achieved by the following method. That is, a storage medium (or recording medium) in which a program code of software that realizes the functions of the above-described embodiments is recorded is supplied to the system or apparatus. Then, the computer (or CPU or MPU) of the system or apparatus reads and executes the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but the present invention includes the following cases. That is, based on the instruction of the program code, an operating system (OS) or the like running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  Furthermore, the following cases are also included in the present invention. That is, the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, a CPU or the like provided in the function expansion card or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  When the present invention is applied to the above storage medium, the storage medium stores program codes corresponding to the procedure described above.

1 is a front perspective view of a single-lens reflex digital camera according to a first embodiment of the present invention. 1 is a rear perspective view of a single-lens reflex digital camera according to a first embodiment of the present invention. It is a block diagram which shows the electrical constitution of a single-lens reflex digital camera. It is a schematic sectional drawing of a single-lens reflex digital camera, and is a figure showing the state before photography operation in optical finder mode. It is a schematic sectional drawing of a single-lens reflex digital camera, and is a figure showing the state under imaging in optical finder mode. It is a schematic sectional drawing of a single-lens reflex digital camera, and is a figure showing the state at the time of the end of imaging in optical finder mode. It is a disassembled perspective view which shows the structure around an optical low-pass filter and an image pick-up element. It is a flowchart of the imaging | photography process performed with a single-lens reflex digital camera. It is a flowchart which shows the determination method of the foreign material removal operation | movement in 1st Embodiment. It is a figure which shows a mode that the screen was divided | segmented into 45 photometry areas, for example. It is a figure which shows the specific example of the imaging | photography screen of foreign material removal operation | movement discrimination | determination based on photometric distribution. It is a figure which shows the specific example of the imaging | photography screen of foreign material removal operation | movement discrimination | determination based on photometric distribution. It is a schematic sectional drawing of a single-lens reflex digital camera, and is a figure showing the state before photography operation in electronic finder mode. It is a flowchart of the imaging | photography process using the electronic finder performed by the single-lens reflex digital camera. It is a flowchart which shows the determination method of foreign material removal operation | movement. It is a flowchart which shows the determination method of the foreign material removal operation | movement in 2nd Embodiment. It is a flowchart which shows the determination method of the foreign material removal operation | movement in 3rd Embodiment. It is a flowchart which shows the determination method of the foreign material removal operation | movement in 4th Embodiment. It is the schematic of another form of the apparatus which removes the foreign material adhering on an optical low-pass filter. It is the schematic of another form of the apparatus which removes the foreign material adhering on an optical low-pass filter. It is the schematic of another form of the apparatus which removes the foreign material adhering on an optical low-pass filter. It is the schematic of another form of the apparatus which removes the foreign material adhering on an optical low-pass filter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera body 1a Grip part 2 Mount part 4 Lens lock release button 5 Mirror box 6 Quick return mirror 7 Shutter button 8 Main operation dial 9 Liquid crystal display part 10 Operation mode setting button 11 Strobe unit 12 Shoe groove 13 Strobe contact 14 Shooting mode setting Dial 15 External terminal cover 16 Video signal output jack 17 USB output connector 18 Viewfinder eyepiece window 19 Color liquid crystal monitor 20 Sub operation dial 21 Mount contact 22 Penta prism 30 Sub mirror 31 Focus detection sensor unit 32 Mechanical focal plane shutter 33 Image sensor 34 Clamp / CDS (Correlated Double Sampling) Circuit 35 AGC Circuit (Automatic Gain Adjuster)
36 A / D converter 37 Buffer memory 38 Memory controller 39 Memory 40 External interface 41 Liquid crystal display device in the viewfinder 42 Power supply unit 43 Main switch 44 Cleaning instruction operation member 45 Photometric sensor 46 Eyepiece 47 Focusing screen 71 Photometric area 100 MPU
100a EEPROM
DESCRIPTION OF SYMBOLS 101 Mirror drive part 102 Focus detection circuit 103 Shutter drive circuit 104 Video signal processing circuit 105 Switch sense circuit 106 Photometry circuit 107 LCD drive circuit 108 Battery check circuit 109 Time measurement circuit 110 Power supply circuit 111 Piezoelectric element drive circuit 112 Color liquid crystal drive circuit DESCRIPTION OF SYMBOLS 200 Shooting lens 201 Lens control circuit 202 AF drive part 203 Diaphragm drive part 204 Diaphragm 300 Main body chassis 400 Imaging unit 410 Optical low-pass filter 420 Optical low-pass filter holding member 430 Piezoelectric element 440 Energizing member 450 Elastic member 460 Restriction member 470 Optical low-pass filter Holding unit 500 Imaging element holding unit 510 Imaging element holding member 520 Rubber sheet 530 Step screw

Claims (14)

An image sensor that photoelectrically converts a subject image formed by the photographing lens;
A light transmissive optical member disposed between the imaging element and the photographic lens;
Foreign matter removing means for removing foreign matter attached to the optical member;
A multi-division metering unit that divides the photographing screen into a plurality of areas, detects subject brightness in each area, and outputs a photometric value;
Depending on the photometric value of the multi-segment photometry means, the foreign matter removal means is switched between the first operation mode and the second operation mode, which is different from the first operation mode. Control means for controlling
An imaging apparatus comprising:   The image processing apparatus further includes a selection unit that selects a shooting mode of the imaging apparatus, and the control unit sets the foreign matter removal unit according to a shooting mode selected by the selection unit and a photometric value of the multi-segment photometry unit. 2. The imaging apparatus according to claim 1, wherein control is performed by switching between control in one operation mode and control in the second operation mode.   The control means compares the photometric value for each area of the multi-division photometry means with a predetermined value, and an area showing a photometric value larger than the predetermined value is predetermined in the photographing screen. 2. The imaging apparatus according to claim 1, wherein the foreign matter removing unit is controlled in the first operation mode when there are a plurality of continuous presences.   The first operation mode is an operation mode for controlling to drive the foreign matter removing means, and the second operation mode is an operation mode for controlling not to drive the foreign matter removing means. The imaging device according to any one of claims 1 to 3.   The second operation mode is an operation mode for driving the foreign matter removing means for a predetermined time, and the first operation mode is a time longer than the predetermined time for the foreign matter removing means. The imaging apparatus according to claim 1, wherein the imaging apparatus is an operation mode to be driven.   The image pickup apparatus further includes instruction means for instructing an image pickup operation of the image pickup device, and each time the instruction means is operated, the control means sets the first foreign substance removal means in accordance with the photometric value of the multi-division photometry means. The image pickup apparatus according to claim 1, wherein the image pickup apparatus controls whether to control in the second operation mode or in the second operation mode.   The imaging apparatus according to claim 1, wherein the multi-division photometry unit is a photometry unit that detects a subject brightness using a photometry sensor disposed outside the photographing optical axis.   The imaging apparatus according to claim 1, wherein the multi-division photometry unit is a photometry unit that detects subject luminance based on an image signal obtained from the imaging element.   The imaging apparatus according to claim 1, wherein the foreign matter removing unit removes the foreign matter attached to the optical member by vibrating the optical member.   The imaging apparatus according to claim 1, wherein the foreign matter removing unit removes foreign matter attached to the optical member by sweeping a surface of the optical member.   The imaging apparatus according to claim 1, wherein the foreign matter removing unit removes the foreign matter attached to the optical member by electrostatically attracting a surface of the optical member. An image sensor that photoelectrically converts a subject image formed by a photographic lens, a light-transmitting optical member that is disposed between the image sensor and the photographic lens, and a foreign material removal that removes foreign material attached to the optical member And a multi-division photometry unit that divides a photographing screen into a plurality of regions, detects subject luminance in each region, and outputs a photometric value.
Depending on the photometric value of the multi-segment photometry means, the foreign matter removal means is switched between the first operation mode and the second operation mode, which is different from the first operation mode. And a control process for controlling the imaging apparatus.   A program for causing a computer to execute the control method according to claim 12.   A computer-readable storage medium storing the program according to claim 13.

Images