JP2010016614A - Image capturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of determining a composition that eliminates as much as possible the influence of foreign matter adhering to the vicinity of an imaging element on a captured image without missing a photo opportunity.
A viewfinder includes a first display area in which a subject image can be observed as an optical image and a second display area in which an electronic image displayed by the display means can be observed, which can be simultaneously observed through an eyepiece window. Provide. Then, there is provided display means for displaying the position information of the foreign matter detected by the foreign matter information detection means on the second display area so as to be superimposed on the already captured image.
[Selection] FIG.

Description

  The present invention relates to an imaging apparatus that captures an electronic image.

  2. Description of the Related Art Conventionally, a camera that can switch between an optical viewfinder and an electronic viewfinder and facilitates a confirmation operation of a reproduced image without changing the shooting posture is known as this type of imaging device (see Patent Document 1). This camera has a first finder system that optically guides an object image that has passed through a photographing lens to a finder, and a second finder system that electronically guides the object image to the finder via an image sensor and a display device. The camera also has a finder switching unit that switches between the valid states of both finder systems. In addition, the camera includes a mode switching unit that switches between a recording mode that is recorded in the storage unit and a reproduction mode that is read from the storage unit and displayed on the display device, and a control unit that switches between these modes.

  In this camera, when the control unit switches from the recording mode to the playback mode, the finder switching unit forcibly switches the finder system to the valid state of the second finder system. When the control unit switches back to the recording mode again, the finder switching unit automatically returns to the finder system that has been enabled in the original recording mode.

  Also, in an imaging device such as a digital camera, an imaging device protective glass fixed to the imaging device, an optical device disposed in front of the imaging device, or an optical system (hereinafter collectively referred to as imaging device optical system components) Foreign matter such as dust and dust (hereinafter simply referred to as foreign matter) may adhere. Thus, when a foreign substance adheres to an image pick-up element optical system component, there existed a problem that the quality of the image | photographed image fell, such as light being interrupted by the foreign substance and the part not being image | photographed.

To solve this problem, a white wall or the like is photographed with the lens aperture closed, and an image showing only the foreign matter on the image sensor is prepared in advance and used in combination with a normal photographed image. There is known a method for making the image inconspicuous (see Patent Document 2).
JP 2004-357123 A JP 2002-204379 A

  When the user wants to check the foreign matter information at the time of shooting, it is necessary to display the foreign matter information as disclosed in Patent Document 2 as electronic information. Display on the second finder system disclosed in FIG. However, in such a configuration, since it cannot be observed simultaneously with the subject optical image, the composition cannot be determined so that the main subject does not overlap the position where the foreign object exists. In particular, when an attempt was made to alternately check the liquid crystal display unit and the optical subject image, there was a risk of missing a photo opportunity.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide an imaging apparatus capable of determining a composition in which the influence of a foreign object is eliminated as much as possible without missing a photo opportunity. .

  In order to achieve the above object, an image pickup apparatus of the present invention includes an image pickup element that photoelectrically converts a subject image formed by a photographing lens, a first display region in which the subject image is observed as an optical image, and display means. Based on the finder means capable of simultaneously observing through the eyepiece window the second display area in which the electronic image photoelectrically converted by the image sensor displayed by the image sensor is based on the photoelectric conversion signal of the image sensor Foreign matter information detection means for detecting foreign matter information, which is information relating to at least the position of the foreign matter attached to the optical element arranged in front of the image sensor, and the position information of the foreign matter detected by the foreign matter information detection means in a captured image. And a display means for superimposing and displaying in the second display area.

  According to the present invention, since it is possible to check foreign object information while enabling observation of an optical object image without taking an eye off the viewfinder, a composition that eliminates the influence of foreign objects as much as possible without missing a photo opportunity. I can decide.

  An embodiment of an imaging device of the present invention will be described with reference to the drawings. The imaging apparatus of this embodiment is applied to a digital single lens reflex camera.

[First Embodiment]
The digital single-lens reflex camera of this embodiment is a still camera that captures an object image (subject image) with an image sensor such as a CMOS or a CCD. In this digital single-lens reflex camera, a release button for instructing the start of an imaging operation is provided on the exterior housing of the camera. Further, this camera has a continuous imaging mode (continuous shooting mode) in which the imaging operation is repeated while the release button is kept pressed as an imaging mode. While the release button is operated with the continuous shooting mode selected, the camera retracts the object image observation movable mirror out of the imaging optical path and performs photoelectric conversion of the object image (subject image) into an electronic image. The operation is repeated.

  FIG. 1 is a diagram illustrating a schematic configuration of an electric circuit of the digital single-lens reflex camera according to the first embodiment. The digital single-lens reflex camera 50 includes a CPU 141 that controls an operation sequence of the entire camera, an illumination unit 101, a photographing lens 120, a movable mirror 124, a shutter 126, and an image sensor 127. The imaging element 127 has a rectangular imaging unit with an aspect ratio of 3: 2.

  The digital single-lens reflex camera 50 includes a finder device 130, a focus detection device 139, a built-in printer 160, a zoom / focus / anti-vibration drive circuit 134, an aperture drive circuit 135, a mirror drive circuit 136, and an AF sensor drive circuit 137.

  The digital single-lens reflex camera 50 includes a shutter drive circuit 138, a dust removal mechanism drive circuit 169, a printer control circuit 161, an image sensor stabilization control circuit 172, a GPS circuit 162, a wireless communication circuit 163, and a digital TV tuner 164. The printer control circuit 161 controls the built-in printer 160. The image sensor stabilization control circuit 172 moves the position of the image sensor 127 to stop image blur. The GPS circuit 162 measures the position of the camera.

  The digital single-lens reflex camera 50 includes an infrared communication circuit 170, an audio processing circuit 165, and an image alteration detection data processing circuit 166. The infrared communication circuit 170 performs communication with a relatively small amount of data with a mobile phone or the like. The sound processing circuit 165 includes a microphone and a speaker.

  The digital single-lens reflex camera 50 includes a switch input unit 142, an EEPROM 143, a signal processing circuit 145, an illumination control circuit 146, an EPROM 147, an SDRAM 148, and a flash memory 150.

  The taking lens 120 has an optical axis of 120a and is attached to the lens mount 120b. The photographing lens 120 includes a plurality of lens groups 121, 167, and 123, and a diaphragm mechanism 122 is provided between these lens groups. The lens groups 121, 167, and 123 are driven by a zoom / focus / anti-vibration driving circuit 134. The aperture mechanism (simply referred to as aperture) 122 is driven by an aperture drive circuit 135.

  A movable mirror 124 is provided behind the lens groups 121, 167, and 123. The movable mirror 124 includes a half mirror and a holding mechanism thereof, and is movable to a mirror down position as a first position and a mirror up position as a second position. The movable mirror 124 jumps from the first position toward the focusing screen 131 to the second position, which is the mirror-up position, while rotating around the fixed shaft 124a during exposure (during imaging), and the imaging optical path Evacuate from. Further, a sub mirror 125 formed of a concave mirror is provided on the back of the central portion of the movable mirror 124 so as to reflect object light downward in the drawing.

  A re-imaging optical system 128 that separates an image with two lenses is provided below the reflected optical axis of the sub-mirror 125. Further, an AF sensor 129 is provided at an object image formation position by the re-imaging optical system 128. Is provided. An AF sensor driving circuit 137 is connected to the AF sensor 129.

  The sub mirror 125, the re-imaging optical system 128, and the AF sensor 129 constitute a focus detection device 139. The focus detection device 139 detects the imaging state of the object at a plurality of positions on the image sensor 127 by a known phase difference detection method.

  The zoom / focus / anti-vibration drive circuit 134 includes a drive source such as a known electromagnetic motor and an ultrasonic motor, a driver circuit for controlling these drive sources, an encoder device for detecting the position of the lens pupil, and the like. In zoom control and focus control, the positions of the lens groups 121, 167, and 123 in the direction of the optical axis 120a are controlled. In the image stabilization control, the position of the lens group 167 in the direction orthogonal to the optical axis 120a is controlled.

  A finder optical system is provided on the reflected light path of the movable mirror 124. The finder optical system includes a focusing screen 131, a pentaprism 132 made of optical glass, an eyepiece 133, and the like. The finder device 130 has a configuration in which a liquid crystal display 108, a prism 154, a photometric lens 155, a photometric sensor 156, and the like are added to the finder optical system.

  Object light (incident light) that has passed through the lens groups 121, 167, and 123 of the photographic lens 120 is reflected by the movable mirror 124 and imaged on the focusing screen 131. The observer visually recognizes the optical object image (optical image) formed on the focusing screen 131 through the single eyepiece window 168 via the pentaprism 132 and the eyepiece lens 133. The advantage of observing the optical image is that there is virtually no time delay.

  The photometric sensor 156 is a sensor for measuring the brightness of the object image on the focusing screen 131 via the photometric lens 155. The photometric sensor 156 is provided in the finder device 130 together with the photometric lens 155 at a position on the photometric axis that is decentered from the observation optical axis of the eyepiece lens 133. The photometric sensor 156 is formed of a photodiode having a light receiving surface divided into a plurality of parts. The CPU 141 performs a calculation according to the distance measurement position on the focusing screen 131 by the focus detection device 139 with respect to the luminance output individually output from the photodiode of the photometric sensor 156. Then, the CPU 141 obtains object luminance information (BV value) for performing exposure control from this calculation result.

  Behind the movable mirror 124, a shutter 126, a dust removing mechanism 169, and an image sensor 127 such as a CCD or a CMOS imager are provided.

  The shutter 126 is driven by the shutter drive circuit 138 and is opened for a predetermined time, and guides the object image to the light receiving surface of the image sensor 127. The movable mirror 124 is driven by the mirror drive circuit 136 and is raised to the second position in order to retract from the optical axis of the photographing lens 120, and the shutter 126 is driven by the shutter drive circuit 138 to be in the open state. As a result, an object image is guided to the light receiving surface of the image sensor 127, and an imaging operation is performed. At this time, the image sensor anti-vibration mechanism 171 connected to the image sensor anti-vibration control circuit 172 shifts and rotates the image sensor 127 in a direction to cancel the image blur, and the image flows and the sense of resolution is lost. prevent.

  Note that since the image sensor vibration isolating mechanism 171 is located closer to the image sensor 127 than the position where the optical path to the viewfinder device 130 is divided, the finder device 130 cannot confirm the composition change due to the shift or rotation of the image sensor 127. .

  The dust removing mechanism 169 mechanically vibrates optical elements such as an optical low-pass filter and an infrared cut filter, applies acceleration to the foreign matter attached thereto, and shakes off the foreign matter with the generated force.

  A zoom / focus / anti-vibration drive circuit 134, an aperture drive circuit 135, a mirror drive circuit 136, an AF sensor drive circuit 137, and a dust removal mechanism drive circuit 169 are connected to the CPU 141 constituted by a microprocessor via a data bus 152. Has been. The CPU 141 also includes a shutter drive circuit 138, a printer control circuit 161, an image sensor image stabilization control circuit 172, a GPS circuit 162, a wireless communication circuit 163, a digital TV tuner 164, and an infrared communication circuit 170 via the data bus 152. It is connected. The CPU 141 is also connected to the above-described audio processing circuit 165, image alteration detection signal processing circuit 166, and illumination control circuit 146 via the data bus 152. The CPU 141 is connected to a switch input unit 142 and an EEPROM 143 that is a nonvolatile memory via a data bus 152. Furthermore, the CPU 141 includes a foreign object detection unit 1001 described later.

  The switch input unit 142 is linked to a first release switch that is turned on in response to a half-pressing operation of a release button (not shown) provided on the exterior casing of the camera, and a deep-pressing operation of the release button. A second release switch that is turned on; In addition, the switch input unit 142 includes a plurality of switches such as a switch interlocking with a power switch of the camera and a mode switch interlocking with various mode buttons in the camera. The switch input unit 142 supplies an operation signal based on any switch operation to the CPU 141.

  The EEPROM 143 is a nonvolatile semiconductor memory. The EEPROM 143 stores adjustment values for each camera that are necessary for shipping in a production process while suppressing variations in individual cameras. The EEPROM 143 stores a coefficient indicating the relationship between the BV value and the backlight light amount for the CPU 141 to define the light amount of the backlight 108b, which will be described later, based on the output from the photometric sensor 156.

  When the first release switch is turned on, the CPU 141 controls the AF sensor driving circuit 137, calculates the distance between the two images on the AF sensor 129, and controls the zoom / focus / anti-vibration driving circuit 134 from the distance data. Then, the focus of the photographic lens 120 is adjusted.

  In addition, when the second release switch is turned on, the CPU 141 controls the mirror driving circuit 136 to retract the movable mirror 124 from the optical axis to the second position. The CPU 141 calculates an appropriate aperture value, shutter speed, and image sensor sensitivity based on the object luminance information based on the output of the photometric sensor 156 along with the retraction control. The CPU 141 drives the aperture mechanism 122 via the aperture drive circuit 135 with the obtained aperture value. The CPU 141 drives the shutter 126 via the shutter driving circuit 138 at the determined shutter time.

  Further, the CPU 141 refers to a coefficient indicating the relationship between the BV value stored in the EEPROM 143 and the backlight light amount, determines the amount of current to be supplied to the backlight 108b, and obtains a light amount appropriate for visual recognition.

  When the object image is formed on the light receiving surface of the image sensor 127 by the opening operation of the shutter 126, the object image is converted into an analog image signal, and further converted into a digital image signal in the signal processing circuit 145.

  The signal processing circuit 145 includes a RISC processor, a color processor, and a JPEG processor, and performs image processing such as digital image signal compression / expansion processing, white balance processing, and edge enhancement processing. Further, the signal processing circuit 145 performs a conversion process to a composite signal (luminance signal, color difference signal) output to the liquid crystal display 108.

  The CPU 141 and the signal processing circuit 145 are connected by a communication line 153. Via this communication line 153, control signals such as image signal capture timing and data are transmitted and received.

  The composite signal generated by the signal processing circuit 145 is output to the liquid crystal display 108 in the finder apparatus 130, and an electronic object image is displayed. The liquid crystal display 108 is provided between the pentaprism 132 and the eyepiece 133. The liquid crystal display 108 includes an LCD (liquid crystal display element) 108a that is a display element for displaying a color image, and a backlight 108b for illuminating the display surface of the LCD 108a from the rear. For the backlight 108b, for example, a white LED is used.

  The pentaprism 132 has a surface 154b obtained by extending the third reflecting surface 132a (see FIG. 3), and a prism 154 having the same refractive index as that of the pentaprism 132 is fixed by using an index matching adhesive. ing. The light beam emitted from the liquid crystal display 108 is reflected twice inside the prism 154 and guided toward the eyepiece lens 133. At this time, the display surface of the LCD 108a of the liquid crystal display 108 is in an optically equivalent position to the focusing screen 131 due to the curvature of the surface 154a. The image displayed on the LCD 108 a can be observed through the eyepiece window 168 regardless of whether the movable mirror 124 is in the first position or the second position. The brightness of the image displayed on the LCD 108a is adjusted to an appropriate brightness by changing the current supply amount of the white LED that is the backlight 108b.

  The signal processing circuit 145 is connected to the EPROM 147, the SDRAM (Synchronous Dynamic Random Access Memory) 148, and the flash memory 150 via the data bus 151.

  The EPROM 147 stores a program to be processed by a processor (CPU) included in the signal processing circuit 145. The SDRAM 148 is a volatile memory that temporarily stores image data before image processing and image data during image processing. The flash memory 150 is a non-volatile memory that stores finally finalized image data. The SDRAM 148 can perform high-speed operation, but when the power supply is stopped, the stored contents disappear. On the other hand, the flash memory 150 operates at a low speed, but the stored contents are preserved even when the camera is turned off.

  The lighting unit 101 includes a light-emitting panel 103, a reflector 118, and high-brightness LEDs 119 for each color of RGB. The light emitted from the high-intensity LED is reflected directly or by the reflector 118, passes through the light-emitting panel 103, and is irradiated toward the object. Even if the illumination unit 101 is removed from the camera body, the wireless communication circuit functions by a built-in battery (not shown). In other words, the illumination unit 101 is configured to communicate with the camera body (camera 50) via the wireless communication circuit 163 according to the UWB standard, for example, and can be remotely operated from the camera body side. The illumination control circuit 146 determines the light quantity balance of each RGB color under the control of the CPU 141, and controls the light emission instruction to the high brightness LED 119.

  FIG. 2 is a block diagram showing the configuration of the electric circuit of the signal processing circuit 145 and peripheral circuits connected thereto. The signal processing circuit 145 includes a CPU 500 serving as a control circuit that controls the signal processing operation, and a plurality of circuits that are connected to the CPU 500 and operate according to control signals from the CPU 500. The CPU 500 is connected to the camera sequence control CPU 141 via the communication line 153, and controls each circuit in the signal processing circuit 145 in accordance with a control signal transmitted from the CPU 141. In the signal processing circuit 145, a first image processing circuit 501, a thinning / extraction processing circuit 502, a second image processing circuit 506, and a third image processing circuit 503 are provided as a plurality of circuits. In the signal processing circuit 145, a video decoder 504, a white balance processing circuit 505, and a JPEG compression / decompression processing circuit 507 are provided.

  The first image processing circuit 501 drives the image sensor 127 according to the drive conditions set by the CPU 500, and performs pre-processing for generating a digital image signal by A / D converting the analog image signal output from the image sensor 127 Circuit. Further, the first image processing circuit 501 corrects the digital image signal based on the pixel signal of the light shielding portion of the image sensor 127.

  The thinning / extraction processing circuit 502 performs thinning processing on the digital image signal output from the first image processing circuit 501 and outputs the thinned image to the second image processing circuit 506 and the third image processing circuit 503. Here, the thinning-out process is a process for reducing the resolution. Note that the digital image signal output to the third image processing circuit 503 is a signal of an electronic object image displayed on the liquid crystal display 108.

  Here, the degree of thinning of the digital image signal output to the second image processing circuit 506 is instructed by the CPU 500 according to the resolution set by the user. Further, the degree of thinning of the digital image signal output to the third image processing circuit 503 is instructed by the CPU 500 so that the resolution is suitable for image display.

  The thinning / extraction processing circuit 502 extracts a part of the digital image signal and outputs it to a white balance processing circuit (hereinafter referred to as a WB processing circuit) 505. A method of extracting the digital image signal is instructed by the CPU 141.

  The WB processing circuit 505 is a circuit that outputs white balance information (WB information) for adjusting the color balance (white balance) of an image. This WB information is sent directly to the third image processing circuit 503, and is sent to the second image processing circuit 506 via the CPU 141.

  The third image processing circuit 503 is a circuit that generates a display image of the liquid crystal display 108. The third image processing circuit 503 is a simple post-processing circuit, and is a known post-processing circuit such as γ correction, reduction in the number of data bits, color adjustment based on WB information, conversion from RGB signals to YCbCr signals, and the like. Process. In general, when the captured image is repeatedly displayed on the liquid crystal display 108, the speed by software processing is often not in time. Accordingly, all the image processing for display is processed by hardware by the third image processing circuit 503.

  The video decoder 504 converts the YCbCr signal constituting the digital image signal into an NTSC signal to form an electronic object image, and displays the electronic object image on the LCD 108 a of the liquid crystal display 108. Note that the display surface of the LCD 108a is illuminated from behind by the backlight 108b with the amount of light defined by the CPU 141.

  The second image processing circuit 506 is a circuit that generates the digital image signal to be stored in the flash memory 150. The second image processing circuit 506 is, as a subsequent processing circuit, γ correction, reduction of the number of data bits of the digital image signal, color adjustment based on WB information, conversion from RGB signal to YCbCr signal, defective pixel of the image sensor 127 A known process such as correction, smear correction, hue or chromaticity is performed.

  The JPEG compression / decompression processing circuit 507 performs JPEG compression processing when the digital image signal processed by the second image processing circuit 506 is stored in the flash memory 150. The JPEG compression / decompression processing circuit 507 reads and decompresses the JPEG image stored in the flash memory 150.

  A foreign substance information display unit 1004 described later is provided in the CPU 500, and displays foreign substance information on the LCD 108a based on the number, size, position information, and the like of foreign substances input from the CPU 141. The image signal of the CPU 500 is output to the CPU 141 for determining the number, size, and position of foreign matter. Further, the CPU 500 outputs, to the CPU 141, a control signal for controlling the display state of the area in which the optical image is displayed within the viewfinder field, based on the calculation result of the CPU 500.

  FIG. 3 is a cross-sectional view showing the configuration of the finder device 130. FIG. 4 is a side view showing the configuration of the viewfinder device 130 when viewed from the direction of arrow A in FIG. A focusing screen 131, a condenser lens 180, and a pentaprism 132 are provided on the optical path reflected and branched by the movable mirror 124 shown in FIG. Object light imaged on the focusing screen 131 by the lens groups 121, 167, and 123 of the photographing lens 120 is transmitted through the condenser lens 180 and the pentaprism 132, and is directed from the surface 132b to the eyepiece window 168 surrounded by the eye cup 186. To inject. At this time, the object light passes through the dichroic mirror 182 and passes through the eyepiece lens 133 including the three lenses 133a, 133b, and 133c, and is observed by the eye of the observer looking through the eyepiece window 168 while being protected by the eyecup 186. Reach and re-image on the retina.

  The dichroic mirror 182 emits the organic EL display element 185 and reflects the light transmitted through the mirror 184 and the diopter matching lens 183 toward the eyepiece window 168. The field mask 179 has a rectangular opening indicating an object image range imaged by the image sensor 127. The finder observer can see the distance measuring point position information 197 (see FIG. 8) of the focus detection device 139 shown on the organic EL display element 185 superimposed on the object image in the field mask 179.

  FIG. 5 is a diagram showing a screen of the LCD 108 a of the liquid crystal display 108. The LCD 108a of the liquid crystal display 108 has a color display unit 108c having an aspect ratio of 4: 3. The display unit 108c provides an LCD display area 108d and a flat horizontally long LCD display area 108e having the same 3: 2 aspect ratio as the image sensor 127 for displaying electronic images within the viewfinder field.

  The light beam 193 emitted from the LCD display area 108d of the LCD 108a enters the pentaprism 132 from the surface 132b of the pentaprism 132. A light beam incident on the pentaprism 132 is a light beam 192. The light beam 192 that has been refracted and changed in direction then enters the surface 132a. Silver vapor deposition is performed on the surface 132a. The light beam 192 is reflected here and enters the prism 154 fixed to the pentaprism 132 by adhesion. The light beam 192 is reflected again by the silver-deposited surface 154a, and is further reflected back to the silver-deposited surface 154b of the prism 154 that is continuous with the surface 132a of the pentaprism 132. The light beam 192 is emitted from the surface 132 b of the pentaprism 132 toward the eyepiece window 168.

  In this way, by configuring the reflection optical path in the prism 154, the optical path length from the eyepiece lens 133 to the LCD display area 108d becomes close to the optical path length from the eyepiece lens 133 to the focusing screen 131. The diopter of the LCD display area 108d and the diopter of the focusing screen 131 substantially match.

  Furthermore, by giving a curvature to the surface 154a of the prism 154, the diopter of the LCD display area 108d and the diopter of the focusing screen 131 can be matched more accurately. At this time, even if the surface 154a is a flat surface, the diopters of both surfaces are close to each other so that the curvature of the surface 154a may be very weak. Further, although the reflection optical path of the surface 154a is an eccentric system, the deterioration of various optical aberrations is negligible.

FIG. 6 is a diagram showing the incident state of light rays on the pentaprism 132. Of the light beam 193 emitted the LCD display area 108d of the LCD 108a, the green light 193g is the angle theta ₁ is obliquely incident on the surface 132b of the pentagonal prism 132 is refracted at the interface between air and glass, angle theta ₂ To go inside the pentaprism 132. Since the relationship between the angle θ ₁ and the angle θ ₂ varies depending on the wavelength of light due to the chromatic dispersion of the refractive index of the glass, when the LCD display area 108d is used for electronic image display, the color blur in the vertical direction is maintained. Occurs, resulting in an image with poor resolution. Therefore, the electronic image displayed in the LCD display area 108d is previously shifted from the RGB image by the amount of positional deviation caused by chromatic dispersion.

  FIG. 7 is a diagram showing a positional shift state of the electronic image displayed in the LCD display area 108d. In the LCD display area 108d, a red electronic image 194r, a green electronic image 194g, and a blue electronic image 194b are vertically shifted in position. As a result, one light beam 193r, 193g, 193b emitted from the corresponding position of the red electronic image 194r, the green electronic image 194g, and the blue electronic image 194b is formed inside the pentaprism 132 as shown in FIG. The light beam 192 proceeds. Then, the light beam 192 finally reaches the eyes of the observer in a state where the color blur is almost eliminated.

  A light beam 194 (see FIG. 3) emitted from the display area 108e of the LCD 108a enters the pentaprism 132 from the bottom surface of the pentaprism 132 through the light guide prism 181 and is reflected inside the pentaprism 132 in the same manner as the object light. And it injects from the surface 132b.

  FIG. 8 is a diagram showing a display in the viewfinder field. The display in the viewfinder field includes a first display area 191, a second display area 190d, a third display area 190e, and distance measuring point position information 197. The first display area 191 shows an optical image of the object defined by the opening of the field mask 179. The second display area 190d is located above the first display area 191 and displays information by an image based on the LCD display area 108d of the LCD 108a. The third display area 190e is below the first display area 191, and displays information using character strings and icons based on the LCD display area 108e of the LCD 108a. The distance measuring point position information 197 is inside the first display area 191 and is indicated by the organic EL display element 185. At this time, the display luminances of the second display area 190d, the third display area 190e, and the distance measuring point position information 197 are all values suitable for visual recognition based on the output of the photometric device including the photometric sensor 156 and the photometric lens 155. To be controlled.

  The electronic image displayed in the second display area 190d in FIG. 8 is an image taken last time as one of information displays. According to this electronic image, it can be visually recognized that the black spot 195 exists due to the appearance of the foreign matter adhering to the optical low-pass filter. However, the black dots displayed in this way may be relatively small and overlooked. Therefore, in the present embodiment, this foreign matter display is performed in a superimposed manner as described later.

  Also, it can be seen that the image sensor image stabilization mechanism 171 has actuated, resulting in an object image with an unintentional composition with the upper portion of the subject missing. Furthermore, it can be seen that an appropriate white balance is set, the image is not blurred, and the focus is on the object.

  Furthermore, by displaying a predetermined mark corresponding to the attribute of the image at the same time as the image, information added to the image can be expressed. For example, a diamond-shaped mark 196 shown in FIG. 8 indicates that the tampering detection data processing circuit 166 has appropriately added tampering detection data to the previously captured image. In addition, when an image captured by another camera is displayed, the tampering detection determination result may be indicated by another mark.

  In the present embodiment, the liquid crystal display 108 is used, but an organic EL display may be used instead. In this case, the backlight 108b is not necessary.

  In the digital single-lens reflex camera having the above configuration, an operation sequence of the CPU 141 is shown. FIG. 9 is a flowchart showing an imaging operation procedure executed after a half-press operation (first release on operation) of the release button of the switch input unit 142 with a digital single-lens reflex camera. This flowchart is a subroutine called in the main flowchart of the CPU 141. In addition, since the main flowchart of CPU141 is a conventionally well-known technique, description here is abbreviate | omitted.

  First, the CPU 141 drives the photometric sensor 156 via the photometric lens 155, performs photometry, and measures the luminance of the object using the output from the photometric sensor 156 (step S1). The CPU 141 calculates the exposure amount (the aperture amount of the aperture mechanism 122, the shutter speed of the shutter 126, and the image sensor sensitivity) from the luminance information according to a predetermined arithmetic program.

  The CPU 141 reads the previously written image data (digital image signal) from the flash memory 150, and sends a control signal to the signal processing circuit 145 to instruct the electronic image to be displayed in the second display area 190d of the finder device 130. It is sent out (step S2). Upon receiving this control signal, the signal processing circuit 145 temporarily stores the digital image signal in the SDRAM 148 and performs processing for converting the image data into a composite signal. The signal processing circuit 145 supplies the composite signal to the liquid crystal display 108, and displays the captured electronic image on the LCD 108a. As a result, the previously captured electronic image is displayed in the second display area 190d of the viewfinder device 130. If an electronic image has already been displayed, the signal processing circuit 145 continues the display as it is.

  CPU141 adjusts the light quantity of the backlight 108b by changing the electric current supply amount to white LED which comprises the backlight 108b. The CPU 141 illuminates the electronic object image displayed on the LCD 108a with an appropriate amount of light based on the object luminance (luminance information) measured before imaging.

  Next, in step S3, the CPU 141 reads out the foreign substance information acquired by the foreign substance detection unit, and sends a control signal to the signal processing circuit 145 so as to be superimposed and displayed on the second display area 190d on the electronic image in step S2. Upon receiving this control signal, the signal processing circuit 145 supplies the foreign substance information to the liquid crystal display 108 and displays it superimposed on the electronic image. As a result, the foreign substance information is displayed as an electronic image in the second display area 190d of the finder apparatus 130. Details of step S3 will be described later.

  The CPU 141 drives the AF sensor 129 via the AF sensor driving circuit 137, and measures the defocus amount (ranging value) of the imaging lens 120 (step S4). Further, the CPU 141 performs the focusing operation of the lens groups 121, 167, and 123 based on the distance measurement value.

  Thereafter, the CPU 141 determines whether or not the release button is pressed down by the camera operator, that is, whether or not the second release switch connected to the switch input unit 142 is turned on (step S5).

  When the second release switch is not turned on, the CPU 141 determines whether or not the release button is half-pressed by the camera operator, that is, whether or not the first release switch is turned on (step S16). . If the first release switch is on, the CPU 141 determines that the release button is half-pressed, and returns to the process of step S1. On the other hand, when the first release switch is not turned on, it is considered that the camera operator has released his / her finger from the release button, so the CPU 141 returns to the main routine shown in the main flowchart as it is.

  On the other hand, if the second release switch is turned on in step S4, the CPU 141 determines that the release button has been pressed down and moves the movable mirror 124 from the first position to the second position via the mirror drive circuit 136. Is retracted out of the imaging optical path at the position (step S6). After performing the mirror up in step S5, the CPU 141 performs the aperture operation of the aperture mechanism 122 via the aperture drive circuit 135 based on the aperture amount calculated in step S1 (step S7).

  The CPU 141 sends a signal instructing the start of imaging to the signal processing circuit 145 (step S8). Upon receiving this signal, the signal processing circuit 145 starts the charge accumulation operation of the image sensor 127. The CPU 141 opens and closes the shutter 126 based on the shutter speed calculated in step S1 (step S9).

  After closing the shutter 126, the CPU 141 sends a signal instructing to stop imaging to the signal processing circuit 145 (step S10). Upon receiving this signal, the signal processing circuit 145 ends the charge accumulation operation in the image sensor 127. Further, the signal processing circuit 145 reads out an image signal from the image sensor 127, performs analog-digital (A / D) conversion, converts it into a digital image signal, and executes image processing associated therewith.

  The CPU 141 sends a control signal for instructing storage and display of the digital image signal to the signal processing circuit 145 (step S11). Upon receiving this signal, the signal processing circuit 145 temporarily stores the digital image signal in the continuous shooting data storage area of the SDRAM 148 in order and converts the data into a composite signal. The signal processing circuit 145 supplies the composite signal to the liquid crystal display 108 and displays an electronic image captured on the LCD 108a. As a result, the electronic image is displayed in the second display area 190d of the finder apparatus 130. At this time, the CPU 141 adjusts the amount of light of the backlight 108b by changing the amount of current supplied to the white LED constituting the backlight 108b. Then, the CPU 141 illuminates the electronic object image displayed on the LCD 108a with an appropriate amount of light based on the object brightness measured before imaging.

  The CPU 141 returns the aperture mechanism 122 from the aperture state to the open state via the aperture drive circuit 135 (step S12). The CPU 141 returns the movable mirror 124 to the imaging optical path as the first position via the mirror driving circuit 136 (step S13, mirror down).

  The CPU 141 determines whether or not the second release switch is off (step S14). If the second release switch is not off, the CPU 141 returns to the process of step S1, and repeats the processes from step S1 to step S12 until the second release switch is turned off. That is, if the second release switch is not turned off at this time, continuous shooting is continued. Then, the electronic object image captured immediately before is sequentially displayed on the finder device 130 like a moving image.

  On the other hand, if the second release switch is off in step S13, it is determined that the camera operator is about to end the continuous shooting. In this case, the CPU 141 instructs the signal processing circuit 145 to store the continuous shot image temporarily stored in the SDRAM 148 in a predetermined storage area of the flash memory 150 (step S15). Thereafter, the CPU 141 returns to the main routine.

  FIG. 10 is a timing chart showing the camera operation based on the operation sequence of the CPU 141. In the figure, after the release button is half-pressed, three shots are taken by pressing the release button deeply, and then the half-press operation of the release button is continued for a while. ing.

  First, when the first release switch is switched from OFF to ON at time T1, photometry and exposure amount calculation are performed immediately. Thereafter, the previously captured image S and foreign matter information X are displayed in the second display area 190 d of the viewfinder device 130.

  When the second release switch is switched from OFF to ON at time T2, the movable mirror 124 moves to the up position and the diaphragm 122 of the photographing lens 120 is narrowed.

  At time T3, the charge accumulation operation of the image sensor 127 for the image A is started, and the shutter 126 is opened and closed during that time. When the shutter 126 is closed, the charge accumulation operation of the image sensor 127 is stopped, and reading of the image signal of the image A and A / D conversion are started. Further, the opening operation of the diaphragm 122 and the moving operation of the movable mirror 124 to the down position are performed.

  When the reading of the image signal of the image A and the A / D conversion are completed, the digital image signal is temporarily stored in the continuous shooting data storage area of the SDRAM 148 in order. This image data is converted into a composite signal. When this composite signal is supplied to the liquid crystal display 108, the image A taken is displayed on the LCD 108a and can be viewed in the second display area 190d in the viewfinder device 130. It becomes. Note that the image S is continuously displayed from the time T1 in the second display area 190d of the finder apparatus 130 until an electronic image display update instruction for the image A is issued.

  Even at time T4, when the release button continues to be pressed deeply and the second release switch is on, the movable mirror 124 moves to the up position again, and the diaphragm 122 of the photographing lens 120 is narrowed.

  At time T5, the charge accumulation operation of the image sensor 127 for capturing the image B is started, and the shutter 126 is opened and closed during that time. When the shutter 126 is closed, the charge accumulation operation of the image sensor 127 is stopped, and reading of the image signal of the image B and A / D conversion are started. Further, the opening operation of the diaphragm 122 and the moving operation of the movable mirror 124 to the down position are performed.

  When the reading of the image signal of the image B and the A / D conversion are completed, the digital image signal is temporarily stored in the continuous shooting data storage area of the SDRAM 148 in order. This image data is converted into a composite signal. When this composite signal is supplied to the liquid crystal display 108, the image B is displayed on the LCD 108a and can be viewed in the second display area 190d in the viewfinder device 130. It becomes. Note that the image A is displayed in the second display area 190d of the viewfinder device 130 until an electronic image display update instruction for the image B is issued.

  Even at time T6, when the release button continues to be pressed deeply and the second release switch is on, the same operation as at times T4 and T5 is repeated, and the image C imaging operation is performed. Note that the image B is displayed in the second display area 190d of the finder apparatus 130 until an electronic image display update instruction for the image C is issued.

  At time T7, when the release button is fully pressed and the second release switch is turned off, the continuous shooting ends. However, reading of the image signal of the image C and A / D conversion are performed, and the display update operation to the image C is continuously performed.

  When the half-press operation of the release button is completed at time T8 and the first release switch is turned off, the electronic image display in the second display area 190d of the finder device 130 is stopped.

  In the above operation sequence, reading of the image signal, A / D conversion, storing of the image data in the memory (SDRAM 148), opening of the diaphragm 122, and return of the movable mirror 124 to the first position (down position) are performed. This is the shooting preparation operation for the next frame. The electronic image displayed in the second display area 190d is updated in synchronization with this shooting preparation operation.

  Next, a method for displaying foreign matter attached on the optical low-pass filter will be described.

  Foreign matter adhering to the optical low-pass filter cannot be seen through the optical viewfinder. That is, it cannot be observed as an optical image. Therefore, when taking an image in consideration of reflection of the foreign object on the subject, for example, information on the foreign object must be confirmed on a liquid crystal display on the back of the body. For this reason, there are problems that the photo opportunity is missed and the composition cannot be determined accurately so that the foreign object does not overlap the main subject.

  In the present embodiment, in order to deal with such problems, the captured image and the foreign substance information are displayed in the second display area 190d in the finder apparatus 130 so as to be superimposed on the captured image. Thereby, since the information on the foreign matter can be confirmed without taking a look away from the viewfinder eyepiece window 168, a composition in which the influence of the foreign matter is reduced can be determined without missing a photo opportunity.

  As a configuration for that purpose, as shown in FIG. 11, a foreign object detection unit 1001 provided in the CPU 141 that detects the state of the foreign object in the imaging screen of the image sensor 127 is provided. Also, a lens information acquisition unit that acquires lens information of a lens used when photographing a subject obtained from a lens drive target value of the CPU 141 or a zoom / focus / anti-vibration drive circuit 134 or a lens pupil position detection unit (not shown). 1003.

  Further, it has a foreign matter information display unit 1004 for displaying the state of the foreign matter detected by the foreign matter detection unit 1001 as foreign matter information in the second display area 190d based on the lens information acquired by the lens information acquisition unit 1003.

  The foreign object detection unit 1001 detects the state of the foreign object from the photoelectric conversion signal obtained by the image sensor 127 through the signal processing circuit 145 and the communication line 153. A foreign matter information recording unit 1002 (hereinafter also referred to as foreign matter information memory) for recording it as foreign matter information is included. Information recorded in the foreign matter information recording unit 1002 includes the number, position, and size of the detected foreign matter, and lens information used when the foreign matter is detected, such as a lens aperture value and a lens pupil position.

  The foreign matter information display unit 1004 is a control unit that controls the display state of the second display region 190d, and a second display region display control unit 1005 and a first display that controls the display state of the first display region that displays an optical image. An area display control unit 1006 is provided. The first display area display control unit 1006 can control the display state of the first display area according to the state of the foreign object detected by the foreign object information detection unit 1001. Specific display control will be described later. Similarly, the second display region display control unit 1005 can control the display state of the second display region according to the state of the foreign matter detected by the foreign matter information detection unit 1001.

  Next, details of foreign object detection will be described.

  FIG. 12 is a flowchart for explaining foreign object detection processing (detection processing of a pixel position where an image defect is caused by a foreign object) in the digital camera according to the present embodiment. This processing is performed by the CPU 141 executing a foreign object detection processing program.

  The foreign object detection process is a process for detecting the position, size, etc. of the shadow of the foreign object attached to the surface of the optical low-pass filter disposed in front of the image sensor 127 that is reflected in the image.

  The foreign object detection process is performed by capturing a foreign object detection image. When performing the foreign object detection processing, the camera is set so that the photographing light 120a of the photographing lens 120 is directed to a surface having a uniform luminance pattern, such as an emission surface of a surface light source device or a white wall, and preparation for foreign object detection is performed. Alternatively, a light unit for detecting foreign matter (a small point light source device attached in place of the lens) is attached to the lens mount 120b to prepare for foreign matter detection. The light source of the light unit may be a white LED, for example, and it is desirable to adjust the size of the light emitting surface so that it corresponds to a predetermined aperture value (for example, F64 in this embodiment).

  In the present embodiment, a case where a normal photographing optical system is used will be described. However, the light unit may be attached to the lens mount 120b to detect foreign matter. Thus, in the present embodiment, the foreign object detection image is an image having a uniform color.

  After the preparation is completed, for example, when an instruction to start the foreign object detection process is given from a switch button (not shown) on the back of the camera, the CPU 141 first sets the aperture. The foreign object in the vicinity of the image sensor (in front of the image sensor) changes its imaging state depending on the aperture value of the lens and changes its position depending on the pupil position of the lens. Therefore, in addition to the position and size of the foreign matter, the foreign matter information memory 1002 records the aperture value at the time of detection and the pupil position of the lens. In the stage of detecting the state of a foreign object, when allowing a plurality of lenses to be used or appropriately changing the aperture value to be narrowed down, it is necessary to record the aperture value at the time of detection and the pupil position of the lens in the foreign object information memory 1002. It can be said that there is. Here, the pupil position refers to the distance from the imaging plane (focal plane) of the exit pupil.

  The flowchart will be specifically described below.

  First, when the foreign object detection process is started, the aperture value of the taking lens 120 is designated. Here, for example, F16 is designated (step S21).

  Next, the CPU 141 causes the diaphragm drive circuit 135 to perform diaphragm blade control of the photographic lens 120, and sets the diaphragm to the diaphragm value designated in step S21 (step S22). Further, the focus position is set to infinity (step S23).

  When the aperture value and focus position of the photographing lens 120 are set, photographing in the foreign object detection mode is executed (step S24). Details of the uniform luminance photographing routine performed in step S24 will be described later with reference to FIG. The photographed image data is stored in the SDRAM 148 as foreign matter detection image data.

  When shooting is completed, the foreign object detection unit 1001 acquires the aperture value and lens pupil position at the time of shooting using the lens information acquisition unit 1003 (step S25).

  Next, the foreign matter detection unit 1001 acquires data corresponding to each pixel of the foreign matter detection image data stored in the SDRAM 148 read by the signal processing circuit 145 via the communication line 153 (step S26).

  The foreign object detection unit 1001 performs the process shown in FIG. 16 and acquires the position and size of the pixel where the foreign object exists (step S27).

  Then, the position and size of the pixel where the foreign object exists acquired in step S27, and the aperture value and lens pupil position information acquired in step S25 are recorded in the foreign object information memory 1002 (step S28). Here, when the light unit described above is used, lens information cannot be acquired. Therefore, when the lens information cannot be acquired, it is determined that the light unit is used, and the lens aperture position information determined in advance and the converted aperture value calculated from the light source diameter of the light unit are recorded.

  Here, in step S28, the position of the defective pixel (pixel defect) from the time of manufacture recorded in the pixel defect position memory in advance is compared with the position of the read pixel data to check whether the pixel defect is present. Then, the position may be recorded in the foreign matter information memory 1002 only in an area determined not to be due to a pixel defect.

  An example of the data format of the foreign substance information recorded in the foreign substance information memory 1002 is shown in FIG. As shown in FIG. 13, the foreign object information memory 1002 records lens information and information on the number, position, and size of foreign objects at the time of capturing image data for detecting foreign objects. Furthermore, as will be described later, the shape of the foreign matter may be recorded.

  Specifically, the actual aperture value (F value) at the time of capturing the foreign matter detection image data and the lens pupil position at that time are stored as lens information at the time of capturing the foreign matter detection image data. Subsequently, the number of detected foreign substance areas (integer value) is stored in the storage area, and subsequently, the specific parameters of the specific foreign substance areas are repeatedly stored by the number of foreign substance areas. The parameter of the foreign substance area is a set of three numerical values including the radius of the foreign substance (for example, 2 bytes), the x coordinate (for example, 2 bytes) of the center in the effective image area, and the y coordinate (for example, 2 bytes) of the center.

  When the data size of the foreign matter information is limited due to the size of the foreign matter information memory 1002 or the like, the data is stored with priority from the top of the foreign matter area obtained in step S27. This is because the foreign substance areas are sorted in the order of conspicuous foreign substances as will be described later in the foreign substance area acquisition routine of step S27.

  Next, the details of the foreign substance region acquisition routine performed in step S27 will be described with reference to FIGS.

  As shown in FIG. 14, the called foreign object detection image data is developed on a memory and processed in units of predetermined blocks. This is to cope with peripheral dimming caused by lens and sensor characteristics. Peripheral dimming is a phenomenon in which the luminance at the peripheral portion is lower than that at the central portion of the lens, and it is known that it is reduced to some extent by reducing the aperture of the lens. However, there is a problem that even if the aperture position is reduced, if the position of a foreign object is determined with a predetermined threshold value for a captured image, the foreign object in the peripheral portion cannot be detected accurately depending on the lens. Therefore, the image is divided into blocks to reduce the influence of peripheral dimming.

  If the blocks are simply divided, there is a problem that the detection result of the foreign matter straddling the blocks is shifted when the threshold values are different between the blocks. Therefore, the blocks are overlapped, and a pixel determined as a foreign object in any of the blocks constituting the overlap area is treated as a foreign object area.

  The foreign substance area determination in the block is performed according to the process flow shown in FIG. First, the maximum luminance Lmax and the average luminance Lave in the block are calculated, and the threshold value T1 in the block is calculated using the following equation.

T1 = Lave × 0.6 + Lmax × 0.4
Next, a pixel that does not exceed the threshold value is set as a foreign pixel (step S61), and an isolated region constituted by the foreign pixel is set as one foreign region di (i = 0, 1,..., N) (step S62). . As shown in FIG. 15, the maximum value Xmax and the minimum value Xmin of the horizontal coordinate of the pixel constituting the foreign object region are obtained for each foreign material region, and the maximum value Ymax and the minimum value Ymin of the vertical coordinate are obtained. A radius ri representing the size is calculated by the following equation (step S63).

ri = √ [{(Xmax−Xmin) / 2} ² + {(Ymax−Ymin) / 2} ² ]
FIG. 15 shows the relationship between Xmax, Xmin, Ymax, Ymin and ri.

  Thereafter, in step S64, an average luminance value for each foreign substance region is calculated.

  There is a case where the data size of the foreign matter information is restricted due to the restriction due to the size of the foreign matter information memory 1002 or the like. In order to cope with such a case, the foreign substance position information is sorted by size and average luminance value of the foreign substance area (step S65). In this embodiment, sorting is performed in descending order of ri. When ri is equal, the sort is performed in ascending order of the average luminance value. By doing in this way, it is possible to record the foreign matter information with priority on the noticeable foreign matter. The sorted foreign substance region is Di, and the radius of the foreign substance region Di is Ri.

  If there is a foreign substance area larger than a predetermined size, it may be excluded from sorting and placed at the end of the sorted foreign substance area list. This is because, for a large foreign substance region, image quality may be deteriorated if interpolation processing is performed later, and it is desirable to treat the priority as the lowest priority for correction.

  Next, details of the uniform luminance imaging routine performed in step S24 of FIG. 12 will be described using the flowchart shown in FIG. This uniform luminance imaging routine is implemented by the foreign object detection unit 1001 executing a uniform luminance imaging program.

  When this uniform luminance photographing routine is executed, in step S201, the CPU 141 operates the quick return mirror 124 shown in FIG. 1, performs so-called mirror up, and retracts the quick return mirror 124 outside the photographing optical path.

  Next, in step S202, charge accumulation in the image sensor 127 is started, and in the next step S203, exposure is performed by running the front curtain and rear curtain (not shown) of the shutter 126, respectively. Then, in step S204, the charge accumulation of the image sensor is terminated, and in the next step S205, the image processing circuit 145 reads image data from the image sensor 127, performs A / D conversion, and primarily stores it in the SDRAM 148.

  When reading of all image data from the image sensor 127 is completed in the next step S206, the quick return mirror 124 is mirrored down in step S207, the quick return mirror is returned to the oblique position, and a series of imaging operations is completed.

  Next, details of a normal shooting routine that is a mode for shooting a normal subject will be described with reference to a flowchart shown in FIG. Shooting other than the uniform luminance shooting mode corresponds to this normal shooting routine. This processing is performed by the foreign object detection unit 1001 executing a normal imaging program.

  When this normal photographing routine is executed, in step S401, the CPU 141 operates the quick return mirror 124 shown in FIG. 1, performs so-called mirror up, and retracts the quick return mirror 124 outside the photographing optical path.

  Next, in step S402, charge accumulation in the image sensor 127 is started, and in the next step S403, exposure is performed by running the front curtain and rear curtain (not shown) of the shutter 126, respectively. Then, in step S404, the charge accumulation of the image sensor 127 is terminated, and in the next step S405, the signal processing circuit 145 reads image data from the image sensor 127, performs A / D conversion, and primarily stores it in the SDRAM 148.

  When reading of all image data from the image sensor 127 is completed in the next step S406, the quick return mirror 124 is mirrored down in step S407, the quick return mirror is returned to the oblique position, and a series of imaging operations is completed.

  In step S300, the foreign substance information is updated based on the image data read in step S406. Since the foreign substance area can be known from the foreign substance information already stored in the foreign substance position memory 1002, it is confirmed whether or not the foreign substance shadow is reflected in the foreign substance area of the image data read in step S406. If the shadow of the foreign object is not shown, it is determined that the foreign object has already disappeared, and the foreign object information is deleted.

  For example, the case where the image data read in step S406 is an image as shown in FIG. 19 will be described as an example. Assume that the i-th foreign substance region 1100 obtained from the foreign substance information is an empty part of the image of FIG. Since the sky is a bright and almost uniform image, if a foreign object actually exists, the shadow of the foreign object should be clearly reflected. Nevertheless, if there is no foreign object shadow in the i-th foreign object area 1100, it is highly likely that the foreign object has moved or has been removed, so the i-th foreign object information is stored in the foreign object information memory 1002. And delete foreign material information.

  In this way, it is possible to increase the reliability of the foreign matter information by updating the foreign matter information based on the image data obtained by normal imaging. In particular, in the imaging apparatus according to the present embodiment having the dust prevention mechanism 169 that removes the foreign matter interposed between the photographic lens 120 and the image pickup device 127, there is a possibility that the foreign matter may move or fall after obtaining a uniform luminance image. high. For this reason, it is effective to update the foreign substance information based on a normal captured image as in the present embodiment. Further, in the imaging apparatus of the present embodiment, foreign object information is automatically updated in the imaging apparatus, so there is no need for the user to specify unnecessary foreign object information, and the user is not forced to perform troublesome work. .

  The foreign matter information update routine in step S300 will be described in more detail later.

  In step S408, the foreign substance information (data updated in step S300) shown in FIG. 13 is recorded in the flash memory 150 in association with the image data together with the camera setting value at the time of shooting.

  Specifically, for example, the association can be realized by adding foreign substance information to the Exif area which is a header area of an image file in which camera setting values at the time of shooting are recorded. Alternatively, the association can be realized by recording the foreign object information independently as a file and recording only the link information to the foreign object information file in the image data. However, if the image file and the foreign object information file are recorded separately, the link relationship may be lost when the image file is moved. Therefore, it is desirable to hold the foreign object information integrally with the image data.

  Next, the foreign matter information update routine executed in step S300 of FIG. 18 will be described using FIG.

  When the foreign matter information update routine of step S300 in FIG. 18 is executed, first, foreign matter information is acquired in step S301. Foreign matter information already stored in the foreign matter position memory 1002 is extracted.

  Next, the coordinate sequence Di (i = 1, 2,... N), the radius sequence Ri (i = 1, 2,..., N), the aperture value f1, and the lens pupil position L1 are obtained from the foreign substance information extracted in step S301. (Step S302). Here, Ri is the size of the foreign substance at the coordinate Di calculated in step S65 of FIG.

  In step S303, the aperture value f2 and the lens pupil position L2 at the time of shooting of the normally shot image are acquired, and in step S304, Di is converted by the following equation. Here, d is a distance from the center of the image to the coordinate Di, and H is a distance between the surface of the image sensor 127 and a foreign object. The coordinate Di ′ after conversion and the radius Ri ′ after conversion are defined by the following equation, for example.

Di ′ (x, y) = (L2 × (L1−H) × d / ((L2−H) × L1)) × Di (x, y)
Ri ′ = (Ri × f1 / f2 + 3) (1)
The unit here is a pixel, and “+3” for Ri ′ is a margin amount.

  In step S305, the output in the range of the foreign object coordinates Di (x, y) and the radius Ri ′ converted in step S304 in the image data is read.

In step S306, it is determined whether or not there is a foreign object shadow in the area read in step S305. The presence / absence of a foreign object shadow is determined by determining that there is no foreign object shadow when all of the following conditions are satisfied, and that there is a foreign object shadow when none of the following conditions are satisfied.
(1) The average luminance Yave of the pixels included in the center coordinates Di ′ and radius Ri ′ (Di ′, Ri ′ obtained by Expression (1)) calculated in step S304 in FIG. 20 is greater than a certain threshold Y0. .

Yave> Y0
(2) All the luminances Y of the pixels included in the center coordinate Di ′ and the radius Ri ′ (Di ′, Ri ′ obtained by the expression (1)) fall within the following range.

K1 × Yave <Y <K2 × Yave Here, K1 and K2 are proportional constants (3) center coordinates Di ′ and radius Ri ′ calculated in step S304 of FIG. 20 (Di ′, Ri determined by Expression (1)) Using the average luminance Yave and the maximum luminance Ymax of the pixels included in '), there is no region darker than the threshold value T3 obtained by the following equation.

T3 = Yave × 0.6 + Ymax × 0.4
By checking whether the average luminance Yave is larger than the threshold Y0 in (1) and checking whether the luminance Y is within a certain range in (2), the region defined by the central coordinate Di ′ and the radius Ri ′ is It is checked whether it is a uniform image area. Further, by checking whether or not there is a foreign object shadow in (3), it is determined whether or not there is a foreign object shadow in the region defined by the center coordinate Di ′ and the radius Ri ′.

  In (1), by examining whether the average luminance Yave is greater than the threshold Y0, the following effects can be obtained. That is, since the light does not reach the region defined by the center coordinate Di ′ and the radius Ri ′, it is determined that the foreign object is not reflected and the foreign object is removed despite the presence of the foreign object. Can be prevented.

  Further, in (2), by checking whether the luminance Y is within a certain range, the region defined by the center coordinate Di ′ and the radius Ri ′ has no fine pattern, and it is possible to reliably determine the presence or absence of a foreign object shadow. It is judged whether it is a pattern that can be performed. For example, if K1 = 0.8 and K2 = 1.2, it is determined whether or not the average luminance Yave is within a range of ± 20%. As a result, it is possible to prevent erroneous determination of the presence or absence of foreign matter.

  In (3), by confirming again whether or not there is an area darker than the threshold value T3, a final confirmation is made as to whether or not the shadow of the foreign object has really disappeared.

  By narrowing down with the AND conditions of the plurality of determination formulas (1) to (3), the risk of erroneously deleting the foreign substance information at that position even though the foreign substance remains attached is reduced.

  If there is no foreign object shadow in the i-th foreign substance area read in step S305, the reliability parameter Ri is incremented (step S307). The reliability Ri is a parameter indicating the reliability of the i-th foreign substance region. The initial value is “0” and is incremented by 1 every time it is determined that there is no foreign substance in the foreign substance presence determination. When the uniform luminance image is acquired, the reliability Ri is reset to the initial value “0”. In other words, the smaller this value, the more reliable the data.

  Next, it is determined whether or not the reliability Ri is greater than a certain threshold value R0 (step S308). If it is larger than the threshold value R0, it is determined that the foreign object has moved from the area or that the foreign object has been removed, and the foreign object information in the i-th foreign object area is deleted.

  As described above, the foreign substance area where it is apparent that no foreign substance is present can be deleted from the foreign substance information memory 1002 to increase the reliability of the foreign substance information. As a result, when the foreign object information is displayed during the subsequent photographing, it is possible to prevent unnecessary foreign object information from being displayed for the removed foreign object, and the reliability of the foreign object information display can be increased.

  If it is determined in step S306 that there is a shadow of foreign matter, the reliability Ri is smaller than the threshold value R0 in step S308, or the i-th foreign matter area data is deleted in step S309, the i-th is the final n It is determined whether it is the second (step S310). If it is not yet final, i is incremented by one, and the process proceeds to the next foreign object region determination. In the final case, the foreign matter information update routine is terminated.

  In the above description, the foreign object information is updated based on the image information of one photographed image. However, the change of the foreign object position is detected based on a plurality of pieces of image information, and the foreign object information is updated. By doing so, the accuracy can be further improved.

  In the present embodiment, the foreign object information update in step S300 is executed every time normal photographing is performed. Thus, it is confirmed whether or not a foreign substance really exists in the foreign substance area stored in the foreign substance information memory 1002. This increases the reliability of foreign matter information and reduces the risk of incorrect foreign matter information being displayed.

  The position and state of the foreign matter detected in this manner are displayed in the second display area 190d as information display by an electronic image. FIG. 21 is a diagram illustrating a relationship between an image observed in the first display area 191 as an optical image and an electronic image on which foreign substance information is superimposed and displayed.

  Reference numeral 602 denotes a foreign object display that is highlighted so that the presence of a foreign object is visually recognized at a corresponding position in the captured image based on the detected and converted position information of the foreign object. In this way, the foreign object information is converted into graphic information and superimposed on the captured image so that it can be easily viewed. Therefore, it is easier to see than a black dot as a shadow of a foreign object reflected in an actual image. Note that the highlighting may be performed so as to change the relative size based on the size information of each foreign object acquired when the foreign object is detected.

  Reference numeral 602a denotes a portion of the optical image observed in the first display area corresponding to the position of the foreign matter. As shown in the drawing, no foreign matter is observed in this region.

  Next, the details of the method for displaying foreign matter information will be described with reference to FIG. FIG. 22 shows details of the foreign substance information display in step S3 in FIG.

  First, in step S501, it is determined whether the foreign object display mode is set.

  If the foreign object display mode is set, the process advances to step S502 to acquire foreign object information from the foreign object information memory 1002. If not in the foreign object display mode, return.

  In step S502, after the acquisition of foreign object information from the foreign object information memory 1002 is completed, the process proceeds to step S503, where the photographing lens aperture value f2 and the photographing lens pupil position L2 are obtained as photographing lens information.

  In step S504, the same conversion as in step S304 described above is performed.

  In step S505, a circular foreign object image 602 represented by Ri ″ obtained by multiplying the radius Ri ′ calculated by the equation (1) by a constant magnification 50 is superimposed and displayed with a predetermined contrast. Thus, visibility is ensured by multiplying by a fixed magnification.

  Further, in order to improve the visibility, the display may be performed after setting the contrast higher than the contrast corresponding to the actual foreign object reflection.

  Further, although the constant magnification is 50, it may be set to an optimum value according to the state of the foreign matter. Here, the foreign object display 602 is displayed in a circle, but if the shape of the foreign object is known, the shape may be enlarged and displayed in a conspicuous color so that it can be easily recognized. You may let them.

  If there are many foreign objects, displaying all foreign object images makes it difficult to see because the individual foreign object displays approach each other. For this reason, only a certain number of foreign objects having a certain size or larger or a larger number of foreign objects may be displayed in order from the largest. The foreign object information memory 1002 records the foreign objects in a state of being sorted in descending order of the foreign object radius Ri when the foreign object is detected. Accordingly, it is possible to obtain a certain number from the foreign matter information memory 1002 or until the radius Ri becomes a constant value, and display the foreign matter display 602 for the obtained amount.

  In step S506, it is determined whether or not the aperture value of the photographing lens and the photographing lens pupil position have changed. This is because, when the user changes the aperture value or the photographing lens pupil position, the degree of reflection of the foreign object image changes. This is because the foreign object display 602 is also changed correspondingly. If there is no change in the aperture value of the photographing lens information or the photographing lens pupil position, the process returns.

  If there is a change in the photographic lens information in step S506, the process returns to step S503 to acquire the photographic lens information again.

  Here, the captured image captured last time is displayed as the background image on which the foreign substance information is superimposed, but the present invention is not limited to this. For example, if the movable mirror 124 is configured by a half mirror, and the subject image obtained by the imaging device is sequentially displayed in the second display area 190d while observing the subject image as an optical image by the finder device 130, Foreign object information can be superimposed on the same subject image. Further, if only the foreign object information is displayed on the black display without temporarily displaying the photographed image, it becomes easy to instantly confirm the presence of the foreign object information.

  As described above, according to the present embodiment, it is possible to observe an optical image of an object without looking away from the viewfinder, while confirming the reflection of a foreign matter attached on the optical low-pass filter by using an electronic image. Shooting was possible. Accordingly, since the composition can be determined so that the foreign object does not appear on the main subject while looking through the viewfinder, it is possible to shoot without missing a photo opportunity.

[Second Embodiment]
Since the configuration of the camera in the second embodiment is the same as that of the first embodiment described above, description thereof is omitted. The second embodiment is different from the first embodiment in that detailed information on the foreign matter is displayed in characters when the foreign matter information display mode is set.

  FIG. 23 is a diagram illustrating a relationship between an image observed in the first display area 191 as an optical image and an electronic image on which foreign substance information is superimposed and displayed. Here, as shown in the figure, in addition to the display of the foreign matter, the size of the foreign matter and the aperture value that is expected to affect the reflection are displayed as a character display 602b.

  The aperture value that affects the reflected image is an aperture value when the foreign object image captured in the captured image exceeds a predetermined contrast value, and is set in advance according to the size of the foreign object.

  Here, the brightness of the captured image is reduced and displayed. This is because if the background luminance is displayed at the same level as usual, the foreign object information display overlaps and it is difficult to recognize the foreign object information.

  As described above, according to the present embodiment, the foreign object information can be grasped in detail, so that it is possible to photograph while flexibly dealing with the reflection of the foreign object as reference information for composition change.

[Third Embodiment]
Since the configuration of the camera in the third embodiment is the same as that of the first embodiment, the description thereof is omitted. The third embodiment is different from the first embodiment in that the display is changed according to the state of the foreign matter when the foreign matter information display mode is set.

  FIG. 24 is a diagram illustrating a relationship between an image observed in the first display area 191 as an optical image and an electronic image on which foreign substance information is superimposed and displayed. Here, as shown in the figure, the display color of the foreign matter is changed or blinked depending on the state of the foreign matter. Specifically, the foreign objects 602d and 602e in which the degree of reflection of foreign objects is greater than a certain level are displayed in red, and the other foreign objects 602c are displayed in black. Further, the foreign object 602e whose degree of reflection remains larger than a certain level even when the aperture of the photographing lens is brought close to the full open value is displayed blinking. That is, the display state is changed according to the currently set shooting conditions.

  Here, the fact that the degree of reflection is greater than a certain level means that the shadow of a foreign object exceeds a predetermined contrast when actually captured. Since the contrast is mainly determined by the aperture value of the photographic lens being used and the size of the foreign matter, a combination of the aperture value and the size of the foreign matter that increase the degree of reflection is set in advance. Based on this, the degree of reflection is determined for all foreign matter information, and display control is executed.

  In the foreign matter images 602d and 602e displayed in red, the ones 602e that are blinked and the ones 602d that are not blinked are distinguished from each other because the foreign matter image 602e that affects the transfer even if the aperture is brought close to the full open value. This is to enable discrimination of the foreign object image 602d not to be performed.

  The display colors are red and black, but are not particularly limited. A gradation display may be used so that the degree of reflection of foreign matter can be determined in detail. Furthermore, for the same reason, the blinking cycle may be displayed in several patterns according to the degree of reflection.

  In addition to changing the display of the foreign object image, when the character information related to the foreign object information is displayed in a superimposed manner, the character information may be similarly changed according to the state of the foreign object.

  As described above, according to the present embodiment, since the display of the foreign object image changes depending on the state of the foreign object, the user can easily grasp the reflection of the foreign object. Accordingly, it is possible to pay more attention to the appearance of foreign matter, such as changing the shooting parameters as appropriate during shooting.

[Fourth Embodiment]
Since the configuration of the camera in the fourth embodiment is the same as that of the first embodiment, the description thereof is omitted. In the fourth embodiment, when the number of foreign objects having a certain size or more exceeds a certain number in the foreign object information detailed display mode, the display of the superimposed electronic image and the display of the foreign object image are changed. This is different from the first embodiment.

  FIG. 25 is a diagram illustrating a relationship between an image observed in the first display area 191 as an optical image and an electronic image on which foreign substance information is superimposed and displayed. Here, as shown in the figure, when the number of foreign objects having a certain size or more exceeds a certain number, the display of the photographed image that becomes the background of the foreign object image is blacked out and displayed. The foreign object image 602f blinks in white display. As a result, it is possible to urge the user to note that many foreign objects appear in the captured image.

  As described above, according to the present embodiment, when the number of foreign objects of a certain size or more exceeds a certain number, the foreign object image and the captured image displayed in a superimposed manner change, so the user is warned about the reflection of foreign objects. be able to.

[Fifth Embodiment]
Since the configuration of the camera in the fifth embodiment is the same as that of the first embodiment, the description thereof is omitted. The fifth embodiment is different from the first embodiment in that the display state of the first display area 191 that is an optical image is changed when the foreign substance information detailed display mode is set.

  FIG. 26 is a diagram illustrating a relationship between an image observed in the first display area 191 as an optical image and an electronic image on which foreign substance information is superimposed and displayed. Here, as shown in the figure, the first display area 191 is darkened when the number of foreign objects having a size larger than a certain value exceeds a predetermined value. Specifically, this is realized by the CPU 141 narrowing down the aperture of the photographing lens or giving a control instruction to hold the movable mirror 124 in the up state for a certain period of time. Thereby, the visibility of the second display area 190d can be relatively improved, and the user can be alerted to the effect that it is predicted that many foreign objects will appear in the captured image.

It is a figure which shows schematic structure of the electric circuit of the digital single-lens reflex camera in 1st Embodiment. It is a block diagram which shows the structure of the electric circuit of the signal processing circuit 145, and the peripheral circuit connected to it. It is sectional drawing which shows the structure of the finder apparatus 130. FIG. It is a side view which shows the structure of the finder apparatus 130 at the time of seeing from the arrow A direction of FIG. It is a figure which shows the screen of LCD108a of the liquid crystal display. It is a figure which shows the incident state of the light ray to the pentaprism 132. FIG. It is a figure which shows the position shift state of the electronic image displayed on LCD display area 108d. It is a figure which shows the display in a finder visual field. It is a flowchart which shows the imaging operation procedure of the digital single-lens reflex camera in 1st Embodiment. It is a timing chart based on an operation sequence. It is a block diagram which shows the structure in connection with the foreign material display of the digital single-lens reflex camera in 1st Embodiment. It is a flowchart for demonstrating a foreign material detection process. It is a figure which shows the example of a data format of the foreign material information recorded on a foreign material information memory. It is the figure which showed a mode that the foreign material area | region acquisition process was performed per block. It is the figure which showed the relationship between Xmax, Xmin, Ymax, Ymin, and ri of a foreign material area | region. It is a flowchart for demonstrating a foreign material area | region acquisition routine. It is a flowchart for demonstrating a uniform luminance imaging | photography routine. 6 is a flowchart for explaining a normal photographing routine. It is a figure which shows the example of the image data for demonstrating the concept of a foreign material information update. It is a flowchart for demonstrating a foreign material information update routine. It is a figure which shows the relationship between the image observed in a 1st display area as an optical image in 1st Embodiment, and the electronic image on which the foreign material information was superimposed and displayed. It is a flowchart which shows the procedure of the foreign material information display in 1st Embodiment. It is a figure which shows the relationship between the image observed in a 1st display area as an optical image in 2nd Embodiment, and the electronic image on which the foreign material information was superimposed and displayed. It is a figure which shows the relationship between the image observed in a 1st display area as an optical image in 3rd Embodiment, and the electronic image on which the foreign material information was superimposed and displayed. It is a figure which shows the relationship between the image observed in a 1st display area as an optical image in 4th Embodiment, and the electronic image on which the foreign material information was superimposed and displayed. It is a figure which shows the relationship between the image observed in a 1st display area as an optical image in 5th Embodiment, and the electronic image on which the foreign material information was superimposed and displayed.

Explanation of symbols

50 Digital SLR Camera 127 Image Sensor 130 Finder Device 141 CPU
145 Image processing circuit 168 Eyepiece window 190d Second display area 191 First display area

Claims (5)

An image sensor that photoelectrically converts a subject image formed by the photographing lens;
A first display area in which the subject image is observed as an optical image and a second display area in which an electronic image photoelectrically converted by at least the image sensor displayed by the display means can be observed simultaneously through an eyepiece window The finder means,
Foreign matter information detection means for detecting foreign matter information, which is information related to at least the position of the foreign matter attached to the optical element disposed in front of the image pickup device, based on the photoelectric conversion signal of the image pickup device;
An image pickup apparatus comprising: display means for displaying the position information of the foreign matter detected by the foreign matter information detection means on the second display area so as to be superimposed on the captured image.   The imaging apparatus according to claim 1, wherein the display unit changes a display state according to a set shooting condition.   The imaging apparatus according to claim 1, wherein the display unit changes a display state in accordance with the number of foreign matters detected by the foreign matter information detection unit.   The imaging apparatus according to claim 1, wherein the display unit changes a display state in accordance with a size of the foreign matter detected by the foreign matter information detection unit.   The imaging apparatus according to claim 1, further comprising a control unit that darkens an optical image displayed in the first display area when the display unit displays position information of a foreign object in the second display area.

Images