JP2007295312A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital camera capable of displaying and recording an object image without noise by correcting defective pixels caused by through-image display for a long time even when the digital camera performs through-image display wherein moving pictures are consecutively displayed. <P>SOLUTION: A liquid crystal monitor 26 consecutively displays a through-image in a B mode on the basis of object image data acquired by an imaging section 311, and acquisition operations of post developed pixel defects information are performed in response to stop of the through-image display for switching to photographing information display or the like during the through-image display, a second storage section 236b stores the information, and a pixel defect correction section 317 corrects the pixel defects and outputs a result of the correction as image data. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a digital camera having a through image display function, and more specifically, a so-called through image display function (also referred to as a live view display function or an electronic viewfinder function) that displays an image repeatedly acquired by an image sensor as a moving image on a display device. The present invention relates to a digital camera having

In conventional cameras, the subject image is observed with an optical viewfinder. However, recent compact digital cameras abolish the viewfinder optical system together with the optical viewfinder, and continuously acquire images acquired by the image sensor. More and more, so-called through image display functions for displaying on a display device such as a liquid crystal monitor have been increasing.

As an example of such a through image display function installed in a digital camera, the optical viewfinder display mode and the electronic viewfinder display mode can be selected. When the electronic viewfinder display mode is selected, the movable mirror is retracted from the photographing optical path and focal There has been proposed a digital single-lens reflex camera in which a plain shutter is fully opened, a subject image is guided to an image sensor, and the subject image obtained thereby is continuously displayed on a liquid crystal monitor (Patent Document 1).
JP 2002-369042 A

Thus, although a digital camera having a through image display function has been proposed, noise due to pixel defects due to variations in output characteristics of each pixel is present in the image sensor used here. For this reason, if the output signal of the image sensor is used as it is, noise due to pixel defects is superimposed on an effective signal component, which causes deterioration of the image quality of the captured image. In particular, when the imaging operation is continued for a long time as in the case of a through image display, there is a problem that the temperature of the imaging device itself rises and pixel defects are extremely increased.

In order to remove these pixel defects, an electronic still camera having a noise reduction function has been proposed (Patent Document 2). In this noise reduction function, when an image is captured, the image sensor is first exposed with the shutter closed, and a dark image obtained thereby is recorded in a memory. Subsequently, the image sensor is exposed with the shutter opened, and the dark image stored in the memory is subtracted from the bright image signal obtained by this exposure. According to this method, since the noise component generated at the time of dark output is canceled by the difference, it is possible to remove pixel defects.
JP 2006-5912 A

However, Patent Document 2 only discloses how noise removal is performed when recording a still image. In a through image in which a moving image is continuously displayed, the image is displayed for a long time. Patent Document 2 does not disclose how to remove the noise that appears on the display screen when the operation is performed.

The present invention has been made in view of such circumstances, and provides a digital camera capable of correcting and correcting pixel defects caused by long-time through image display and displaying and recording a subject image without noise. For the purpose.

In order to achieve the above object, a digital camera according to a first aspect of the present invention includes an image pickup means for acquiring a subject image with an image pickup device, a pixel defect information storage means for storing pixel defect information of the image pickup means, and the pixel Based on the defect information, a pixel defect correction unit that performs pixel defect correction on the output of the imaging unit, a through image display unit that continuously displays the image data output from the imaging unit on a display device, and the through A subsequent pixel defect information acquisition unit that executes an operation of acquiring the subsequent pixel defect information in response to the cancellation of the image display, and a pixel defect information update that updates a storage content of the pixel defect information storage unit based on the subsequent pixel defect information Means.

According to a second aspect of the present invention, in the digital camera according to the first aspect, the subsequent pixel defect information acquisition means is configured to detect the subsequent pixel defect information according to switching from the through image display state to another display state. Execute the acquisition operation.
Further, in the digital camera according to the third invention, in the second invention, the other display state includes a display of shooting information or a setting menu display of camera operation.
The digital camera according to a fourth aspect of the present invention is the digital camera according to the first aspect, wherein the pixel defect information storage means includes first storage means for storing preceding pixel defect information stored at the time of factory shipment, Second storage means for storing pixel defect information is provided.
Furthermore, in the digital camera according to a fifth aspect based on the fourth aspect, the subsequent pixel defect information acquisition means acquires the subsequent pixel information based on the dark image of the imaging means and the preceding pixel defect information. To do.
Further, in the digital camera according to a sixth aspect based on the fifth aspect, the subsequent pixel defect information acquisition means acquires the subsequent pixel defect information after removing pixel information caused by a shutter error.

In order to achieve the above object, a digital camera according to a seventh aspect of the invention is an image pickup means for acquiring a subject image with an image pickup device, and a through image display for continuously displaying image data acquired by the image pickup means on a display device. Means, pixel defect information acquisition means for executing an operation of acquiring pixel defect information in response to the stop of the through image display, and output of the imaging means based on the pixel defect information acquired by the pixel defect information acquisition means On the other hand, pixel defect correction means for correcting pixel defects is provided, and the through image display means displays the image data corrected by the pixel defect correction means.
According to an eighth aspect of the present invention, there is provided a digital camera according to the seventh aspect, further comprising storage means for detecting and storing pixel defect information of the imaging means in advance prior to the through image display. The defect correction means corrects the pixel defect information stored in advance and the pixel defect information acquired by the pixel defect information acquisition means during the through image display.

In the digital camera of the present invention, the subsequent pixel defect information acquisition unit that executes the acquisition operation of the subsequent pixel defect information in response to the stop of the through image display, and the storage of the pixel defect information storage unit based on the subsequent pixel defect information Since the pixel defect information updating means for updating the contents is provided, it is possible to provide a digital camera capable of correcting a pixel defect and displaying a subject image without noise.

Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is an external perspective view of a digital single-lens reflex camera to which the present invention is applied. This single-lens reflex camera is composed of a camera body 20 and a lens barrel 10 as an interchangeable lens. The lens barrel 10 is detachably attached to the front mounting portion of the camera body 20. In the present embodiment, the lens barrel 10 and the camera body 20 are configured separately and are electrically connected via a communication contact (not shown). However, the lens barrel 10 and the camera body 20 are integrally configured. It is also possible to do.

On the upper surface of the camera body 20, a release button 21, a mode dial 22, a power switch lever 23, a control dial 24, and the like are arranged. The release button 21 has a first release switch that is turned on when the photographer is half-pressed and a second release switch that is turned on when the photographer is fully pressed. When the first release switch (hereinafter referred to as 1R) is turned on, the camera performs photographing preparation operations such as focus detection, focusing of the photographing lens, and photometry of the subject brightness, and the second release switch (hereinafter referred to as 2R). When it is turned on, a photographing operation for capturing image data of the subject image is executed based on the output of the image sensor.

The mode dial 22 is an operation member configured to be rotatable, and a program mode, an aperture priority mode, a shutter priority mode, a portrait by matching a symbol or picture display representing a shooting mode (not shown) on the mode dial with an index. Shooting modes such as mode and auto mode can be selected. The power switch lever 23 is an operation member for turning on / off the power of the digital single-lens reflex camera, and is configured to be rotatable at two positions, on and off. The control dial 24 is an operation member for setting photographing information such as a shutter speed, an aperture value, a sensitivity, and a correction value, and various setting values can be changed by a rotating operation.

A liquid crystal monitor 26, a playback button 27, a menu button 28, a cross key 30, an OK button 31, a viewfinder 33, a through image switching button 34, a display switching button 35, and a preview button 36 are disposed on the back of the camera body 20. . The playback button 27 is an operation button for instructing display of a subject image recorded on the liquid crystal monitor 26 after shooting. The subject image data stored in a later-described SDRAM 237 or recording medium 245 in a compression mode such as JPEG is expanded and displayed. The cross key 30 is an operation member for instructing movement of the cursor in the two-dimensional direction of the X direction and the Y direction on the liquid crystal monitor 26. The OK button 31 is an operation member for confirming various items selected by the cross key 30 or the like. The menu button 28 is a button for switching to the menu mode. When the menu mode is selected by operating the button 28, a menu screen is displayed on the liquid crystal monitor 26. The menu screen has a plurality of hierarchical structures, and various items are selected with the cross key 30 and the selection is determined by operating the OK button 31.

The display switching button 35 is an operation member for switching to a through image display for displaying a subject image on the liquid crystal monitor 26 based on the output of the image sensor. As will be described later in the through image display, the digital single-lens reflex camera of the present embodiment has two types of A mode display and B mode display, and the through image switching button 34 is an operation button for switching between these two mode displays. . The preview button 36 is an operation button for issuing a command for narrowing the aperture of the photographing lens from the open state in order to confirm the depth of focus when observing the subject image. These playback button 27, menu button 24, display switching button 35, and preview button 36 are all linked to an on / off switch, and a signal generated in response to the operation of the operation button is an ASIC (Application Specific Integrated Circuit) described later. To the application specific integrated circuit) 263. The liquid crystal monitor 26 is a display device for displaying a subject image as a through image for observation, reproducing and displaying a photographed subject image, and displaying camera information and menus. Any liquid crystal display can be used as long as it can perform these displays. Although not shown, the angle with respect to the camera body 20 can be freely changed. The eyepiece 33 is an eyepiece of the finder optical system, and the photographer can look into the eyepiece 33 and check the subject image.

FIG. 2 is a block diagram showing a schematic optical configuration of the digital single-lens reflex camera according to the embodiment of the present invention.
A first reflecting mirror 201 is disposed in the camera body 20 on the optical axis of the photographing lens 101 disposed in the lens barrel 10. The first reflecting mirror 201 captures a subject image at a position inclined by 45 degrees with respect to the optical axis of the photographic lens 101 in order to reflect the subject luminous flux to the finder optical system, and a subject image (a main CCD (Charge Coupled Device) described later). 221), it can be rotated to a position retracted from the photographing optical path. The rotation axis 201a of the first reflection mirror 201 is along the height direction of the camera body 20, and can be rotated around the symbol R. The first reflecting mirror 201 totally reflects the subject luminous flux to the right as viewed from the front surface of the camera body 20. In the present embodiment, the light is totally reflected to the right. However, the present invention is not limited to this, and the reflection direction of the subject light flux is most appropriate in terms of the arrangement of the mechanism members and optical members, both above and to the left of the camera body. You may choose to Moreover, although the movable mirror is used as the optical path changing member, the present invention is not limited to this, and any member that can change the optical path, such as a liquid crystal mirror that can be electrically switched between a transmission state and a reflection state, may be used.

A screen mat 205 is disposed on the reflection optical axis of the first reflection mirror 201, and a second reflection mirror 271 formed of a half mirror is disposed behind the screen mat 205. The screen mat 205 is a mat surface for forming an image of a subject light flux by the photographing lens 101, and is disposed at a position equivalent to the main CCD 221 (see FIG. 3) at a distance from the first reflection mirror 201. The second reflecting mirror 271 reflects a part of the subject luminous flux above the camera body 20, and the remaining subject luminous flux passes through the second reflecting mirror 271 and enters the photometric sensor 281 disposed behind. The photometric sensor 281 is a 7 × 7 divided photometric sensor for measuring subject luminance, and is connected to an input / output circuit 239 in the ASIC 263.

A third reflection mirror 273 is disposed on the reflection optical axis of the second reflection mirror 271, and the subject luminous flux is totally reflected by the third reflection mirror 273 on the upper left side of the camera body 20. A fourth reflection mirror 275 configured with a half mirror is disposed on the reflection optical axis of the third reflection mirror 273. On the transmission optical axis of the fourth reflection mirror 275, an imaging lens 277 and a CCD 279 in the finder as a two-dimensional imaging device are arranged. The in-viewfinder CCD 279 converts the subject image formed on the screen mat 205 into a photoelectric signal and outputs it to the CCD drive circuit 283 (FIG. 3). The fourth reflecting mirror 275 reflects the remaining subject light beam behind the camera body 20, and an eyepiece lens 209 is disposed on the reflected optical axis. The subject luminous flux reflected by the fourth reflecting mirror is observed as a subject image by the photographer E through the eyepiece 209 and the finder 33 (FIG. 1).

FIG. 3 is a block diagram showing the overall configuration of the digital single-lens reflex camera according to the present embodiment.
Inside the lens barrel 10, photographing lenses 101a and 101b for adjusting the focal length and adjusting the focal length, and a diaphragm 103 for adjusting the aperture amount are arranged. The lens 101 a and the lens 101 b are driven by the lens driving mechanism 107, and the diaphragm 103 is driven by the diaphragm driving mechanism 109. These lens driving mechanism 107 and diaphragm driving mechanism 109 are each connected to a lens CPU 111, and this lens CPU 111 is connected to the camera body 20 via a communication contact (not shown). The lens CPU 111 controls the lens barrel 10 and controls the lens driving mechanism 107 to perform focusing and zoom driving, and also controls the aperture driving mechanism 109 to control the aperture value.

The first reflection mirror 201 described above is disposed in the camera body 20, and on the right side of the first reflection mirror 201 (in FIG. 3, the drawing is above the first reflection mirror 201). The above-described screen mat 205 is arranged to form a subject image, and the second reflecting mirror 271, the third reflecting mirror 273, and the fourth reflecting mirror 275 are arranged behind the screen mat 205, and the second A photometric sensor 281 is disposed behind the reflection mirror 271, and an imaging lens 277 and a viewfinder CCD 279 (abbreviated as “F CCD” in FIG. 3) are disposed behind the fourth reflection mirror 275. An eyepiece lens 209 is disposed on the reflection optical axis of the fourth reflection mirror 275.

Near the center of the first reflection mirror 201 described above, a half mirror is formed, and on the back surface of the first reflection mirror 201, a sub mirror 203 for reflecting a subject light beam transmitted through the half mirror portion is provided. . The sub mirror 203 is rotatable with respect to the first reflecting mirror 201. When the first reflecting mirror 201 is retracted from the photographing optical path and the subject light flux is incident on the main CCD 221, the sub mirror 203 is positioned so as to cover the half mirror portion. When the first reflecting mirror 201 is in the subject image observation position as shown in the drawing, the first reflecting mirror 201 is in a position perpendicular to the first reflecting mirror 201. The first reflecting mirror 201 is driven by a mirror driving mechanism 219. Further, a TTL phase difference type distance measuring circuit 217 including a distance measuring sensor is disposed on the reflected optical path of the sub mirror 203, and this circuit controls the amount of focus deviation of the subject image formed by the lenses 101a and 101b. It is a circuit for detecting. The temperature detection circuit 216 is disposed in the vicinity of the main CCD 221, performs temperature detection using a known thermocouple, thermistor, resistance temperature detector, etc., and outputs the detection result to the input / output circuit 239.

A focal plane type shutter 213 for controlling the exposure time is disposed behind the first reflecting mirror 201, and the shutter 213 is driven and controlled by a shutter driving mechanism 215. A main CCD 221 serving as a two-dimensional imaging device is disposed behind the shutter 213, and subjects images formed by the lenses 101a and 101b are photoelectrically converted into electric signals. In the present embodiment, a CCD is used as an image sensor. However, the present invention is not limited to this, and a CMOS (Complementary Metal Oxide) is used.
Needless to say, a two-dimensional imaging device such as Semiconductor) can be used. The main CCD 221 is connected to a CCD drive circuit 223, and the analog / digital conversion (AD conversion) is performed by the CCD drive circuit 223. The CCD drive circuit 223 receives control from a later-described sequence controller (hereinafter referred to as “body CPU”) 229 via the input / output circuit 239, performs on / off control of the power of the main CCD 221, and performs imaging timing of the main CCD 221. To adjust the variation with the output of the CCD 279 in the finder, and amplify the photoelectric conversion signal (gain adjustment). A CCD drive circuit 283 described later has a similar function. The in-viewfinder CCD 279 is an image pickup device that photoelectrically converts a subject image formed on the screen mat 205, and may be an image pickup device such as a CMOS like the main CCD 221, and the number of pixels is only used for observation of the subject image. The number may be smaller than that of the main CCD 221. The in-finder CCD 279 is connected to a CCD drive circuit 283, and the CCD drive circuit 283 performs analog-digital conversion (AD conversion).

The CCD drive circuit 223 and the CCD drive circuit 283 are connected to a CCD switching circuit 285, and this CCD switching circuit 285 is controlled to selectively output any one of the CCDs by a switching control line from the input / output circuit 239. . The CCD switching circuit 285 is connected to the image processing circuit 227 via the CCD interface 225. The image processing circuit 227 performs various types of image processing such as color correction, gamma (γ) correction, contrast correction, monochrome / color mode processing, and through image processing. The image processing circuit 227 is connected to the data bus 261 in the ASIC 263. In addition to the image processing circuit 227, the data bus 261 includes a body CPU 229, a compression circuit 231, a flash memory control circuit 233, and an SDRAM (Synchronous Dynamic Random Access).
Memory) control circuit 236, input / output circuit 239, communication circuit 241, recording medium control circuit 243, video signal output circuit 247, and switch detection circuit 253 are connected.

The body CPU 229 connected to the data bus 261 controls the flow of the digital single lens reflex camera. A compression circuit 231 connected to the data bus 261 is a circuit for compressing image data or the like stored in an SDRAM 237 described later with JPEG. Note that image compression is not limited to JPEG, and other compression methods can be applied. The flash memory control circuit 233 connected to the data bus 261 is connected to the flash memory 235. The flash memory 235 stores a program for controlling the flow of the electronic camera, and the body CPU 229 The electronic camera is controlled according to the program stored in H.235. Note that the flash memory 235 is an electrically rewritable nonvolatile memory. In addition, a pixel defect storage unit 236 for storing pixel defect information is provided in the flash memory 235, and includes a first storage unit 236a and a second storage unit 236b as will be described later. (See FIG. 9). The SDRAM 237 is connected to the data bus 261 via the SDRAM control circuit 236, and the SDRAM 237 temporarily stores the image information processed by the image processing circuit 227 or the image information compressed by the compression circuit 231. It is a memory for.

The above-described shutter drive mechanism 215, temperature detection circuit 216, distance measurement circuit 217, mirror drive mechanism 219, CCD drive circuit 223, photometric sensor 281, CCD drive circuit 283, and input / output circuit 239 for connecting the CCD switching circuit 285 are data Data input / output with each circuit such as the body CPU 229 is controlled via the bus 261. A communication circuit 241 connected to the lens CPU 111 via a communication contact (not shown) is connected to the data bus 261 and exchanges data with the body CPU 229 and the like and communicates control commands. A recording medium control circuit 243 connected to the data bus 261 is connected to the recording medium 245 and controls recording of image data and the like on the recording medium 245. The recording medium 245 includes a rewritable recording medium such as an xD picture card (registered trademark), a compact flash (registered trademark), an SD memory card (registered trademark), a memory stick (registered trademark), or a hard disk drive (HD). The camera body 20 is detachable.

The video signal output circuit 247 connected to the data bus 261 is connected to the liquid crystal monitor 26 via the liquid crystal monitor drive circuit 249. The video signal output circuit 247 is a circuit for converting image data stored in the SDRAM 237 or the recording medium 245 into a video signal to be displayed on the liquid crystal monitor 26. The liquid crystal monitor 26 is arranged on the back surface of the camera body 20 as shown in FIG. 1, but it is not limited to the back surface as long as it can be observed by the photographer. . A switch for detecting the first stroke and the second stroke of the release button 21, a mode dial 22, a power switch 23, a control dial 24, a playback button 27, a menu button 28, a cross key 30, an OK button 31, and a through image switching button 34 Various switches 255 (abbreviated as various SWs in FIG. 3) including a preview button 36, an AF permission button 37, a lens detection switch <not shown> and the like are connected to the data bus 261 via the switch detection circuit 253.

Next, a hierarchical structure of display / operation modes of the digital single-lens reflex camera according to the present embodiment will be described with reference to FIG.
There are three main display / operation modes: information display M100, A mode display M200, and B mode display M300. The information display M100 is initially set in a state where the camera body 20 is turned on. In this information display mode, basic information is displayed for shooting by the camera, and an information display screen for shooting mode, shutter speed, aperture, AF mode, flash, pixel count, etc. is displayed on the liquid crystal monitor 26. Is displayed. Shooting modes such as a program mode and a shutter speed priority mode are set by rotating the mode dial 22. Further, items such as ISO sensitivity, shutter speed, aperture value, correction value, and number of pixels are selected by operating the cross key 30 on the information display screen, and numerical values are set by operating the control dial 24.

The A mode display M200 is a mode in which the subject image formed on the screen mat 205 is photoelectrically converted by the in-finder CCD 279 and the observation subject image is displayed on the liquid crystal monitor 26 based on the photoelectric conversion signal. In this mode, the subject luminous flux is guided to the distance measuring circuit 217 via the sub mirror 203 provided in the first reflecting mirror 201, so that the automatic focus detection operation can be performed together with the observation of the subject image. In the screen display on the liquid crystal monitor 26, as shown in FIG. 10A, “A” (see reference numeral 305) is displayed at the lower left of the screen to indicate the A mode display. In this mode, the AF frame 303 engraved on the screen mat 205 can also be visually recognized.

In the B mode display M300, the first reflecting mirror 201 is retracted from the photographing optical path, the shutter 213 is opened, the subject luminous flux is directly formed on the main CCD 221, and the subject image is converted into a photoelectric conversion signal. In this mode, an object image for observation is displayed on the liquid crystal monitor 26 based on the signal. In this mode, since the subject light flux is directly received by the main CCD 221 without using the half mirror in the finder optical system, the reduction in the amount of light reaching the CCD 221 can be prevented, and a subject image can be sufficiently obtained even for a low-luminance subject. Can be displayed. Note that, in the B mode display M300, the autofocus is essentially inoperative. That is, since the first reflecting mirror 201 is retracted, the automatic focus detection is not activated. In order to indicate the B mode display at the lower left of the screen of the liquid crystal monitor 26, “B” (see reference numeral 307) is displayed as shown in FIG. In this mode, since the distance measurement by the distance measurement circuit 217 is impossible, the AF frame is not displayed unlike the A mode display. Of course, the symbols for indicating the A mode display and the B mode display are not limited to “A” and “B”, but may be symbols, characters, pictograms, etc. such as “main CCD” and “in-finder CCD”.

As described above, when the camera body 20 is turned on, the information display M100 is initialized. Switching from the information display M100 to the A mode display M200 or the B mode display M300 is performed by operating the display switching button 35. In this case, when the display switching button 35 is operated, the display mode is switched to the A mode display M200 or the B mode display M300 set most recently. At the time of shipment from the factory, if the A mode display is set as a default value (of course, B mode display is also possible), when the display switching button 35 is first operated, the mode is switched to the A mode display M200 and displayed again. When the switch button 35 is operated, the display returns to the information display M100. When the through image display switching button 34 is operated when the A mode display M200 is set, the mode is switched to the B mode display M300. When the through image display switching button 34 is operated again in this state, the display returns to the A mode display M200. . When the display switching button 35 is operated in the B mode display M300, the display returns to the information display M100. That is, switching from the information display M100 to the A mode display M200 or the B mode display M300 is performed by operating the display switching button 35 to shift to the most recently set mode, and the A mode display M200 and the B mode display M300. Switching between them is performed by a through image display switching button 34.

Here, the fact that either the A mode display M200 or the B mode display M300 is set is stored in a non-illustrated nonvolatile memory, so that the memory is retained even if the power of the camera body 20 is turned off. Is done. However, it goes without saying that the display may be reset to either the A mode display or the B mode display in accordance with the power on. As a special case, when the lens detection switch (not shown) detects that the lens barrel 10 has been removed from the camera body 20, the B mode display M300 is switched to the information display M100.

As described above, in this embodiment, the light amount of the subject light flux is reduced, but the A mode display capable of performing the automatic focus adjustment and the automatic focus adjustment are disabled, but the light amount of the subject light flux is not reduced and is reduced. The B mode display capable of sufficiently displaying the subject image even with the brightness is switched by a simple operation.

Next, the lower hierarchy of the information display M100 will be described. When the preview button 36 is pressed on in the state of the information display M100, the preview C is executed (M110). When the preview button 36 is released and turned off, the display returns to the information display M100. In the information display M100, when the release button 21 is half-pressed (1R on), photographing preparation operations such as photometry and distance measurement are performed (M120), and when the release button 21 is fully pressed (2R on), the main The output of the CCD 221 is read, and the photographing operation C for recording the recording image data on the recording medium 245 is executed (M121). When the shooting operation is finished and the release button 21 is half-pressed (1R off), the display returns to the information display M100. When the menu button 28 is turned on, a menu screen for setting card setting, drive mode, flash correction, etc. appears (M130). It can be determined by operating the cross key 30 on this screen to move the cursor, select a desired item, and press the OK button 31 (M131). When menu button 28 or OK button 31 is turned on from menu display M130, it is possible to return to information display M100. Furthermore, on the screen of the information display M100, the mode dial 22, the control dial 24, and the cross key 30 can be operated to set the desired mode / value (M140).

Next, the process proceeds to the lower hierarchy of the A mode display M200. First, when the preview button 36 is pressed on in the A mode display M200, the preview A is executed (M210). The preview A is a mode in which the subject image is displayed on the liquid crystal monitor 26 based on the image signal from the main CCD 221 in a state where the aperture 103 is stopped down to a set aperture value. Release the preview button 36 and turn it off to cancel the preview mode and return to the A mode display M200. In the A mode display, when the release button 21 is pressed halfway and 1R is turned on, shooting preparation is performed in the same manner as the shooting preparation operation M120 (M220), and when the release button 21 is fully pressed and 2R is turned on, the shooting operation is performed. A is performed (M221). When the menu button 28 is turned on, a menu screen appears (M230). In this state, the cross key 30 is operated to move the cursor, select an item, determine a desired item with the OK button 31, and return to the menu display M230 (M231). When the menu button 28 or the OK button 31 is turned on in this display state, the screen returns to the A mode display M200.

Next, moving to the lower level of the B mode display M300, first, when the menu button 28 is pressed and turned on in the B mode display M300, the menu is displayed (M310). Here, when the cross key 30 is operated (M311) and the desired item is determined by the OK button 31, the display returns to the menu display M310. From the menu display, it is possible to return to the B mode display M300 by turning on the menu button 28 or the OK button 31. Even in the B mode display state, even if the release button 21 is half-pressed, the first reflecting mirror is in the retracted state and the shutter is in the open state. When turned on, the photographing operation B for recording the recording image data on the recording medium 245 is executed based on the image signal from the main CCD (M320). When the preview button 36 is turned on, a narrowing operation of the diaphragm 103 is performed, and a preview B for displaying a through image on the liquid crystal monitor 26 based on an image signal from the main CCD 221 is executed (M330). This preview B is a mode in which the subject image is displayed on the liquid crystal monitor 26 on the basis of the image signal from the main CCD 221 in a state where the aperture 103 is stopped down to the set aperture value, similarly to the preview A.

Next, the A mode display M200 shown in FIG. 4 will be described with reference to the flowchart shown in FIG.
When the display switching button 35 is turned on, an A mode display operation for displaying a subject image based on an output from the in-viewfinder CCD 279 is performed. First, in order to determine the driving condition of the in-viewfinder CCD 279, photometric / exposure amount calculation (that is, the subject luminance value, shutter speed and sensitivity) is performed based on the output of the photometric sensor 281 in step S1. Next, the CCD 279 in the finder is selected (S3), and power is supplied to it (S5). Subsequently, in order to set the electronic shutter speed and sensitivity conditions for driving the CCD, the through image condition setting 1 subroutine is executed using the photometry / exposure amount calculation result obtained in step S1 (S7). By executing this subroutine, an image with appropriate brightness (brightness) can be displayed on the liquid crystal monitor 26. Details of this subroutine will be described later with reference to FIG. When the through image condition setting 1 is completed, the A mode display is started (S9). The through image display operation is controlled by the image processing circuit 227 in response to the start instruction.

Next, similarly to step S2, photometry / exposure amount calculation is performed again (S11), and the calculated exposure amount is displayed (S13). Subsequently, in order to keep the brightness of the live view display on the liquid crystal monitor 26 appropriately, a live view condition setting 2 subroutine is executed (S15). Since the through image condition setting 1 in step S7 was before the through image display on the liquid crystal monitor 26, it was performed based on the output of the photometric sensor 281, but in the through image condition setting 2, the target brightness and the previous imaging The electronic shutter speed and sensitivity at the next imaging are determined from the screen brightness and the difference based on the result. Here, the brightness is a value corresponding to a weighted average value of each pixel output of the CCD, for example. Thereafter, it is determined whether or not the release button 21 is half-pressed, that is, whether 1R is turned on (S21).

If the result of determination is that 1R is on, photometry / exposure amount calculation for use in exposure control during shooting operation is performed (S23), and a ranging / focus adjustment subroutine is executed (S25). In the distance measurement / focus adjustment subroutine, the focus shift amount of the photographing lens 101 is calculated by the TTL phase difference method based on the output of the distance measurement circuit 217, the lens drive amount is calculated based on the focus shift amount, and the lens CPU 111 The lens driving mechanism 107 is driven via the lens to perform focusing. Subsequently, it is determined whether or not the release button 21 is fully pressed, that is, whether or not 2R is turned on. If it is off, it is determined whether or not the release button 21 is half-pressed (S29). In this case, a standby state in which steps S27 and S29 are repeatedly executed is entered. If the photographer's hand is released from the release button 21 in this state, step S29 is skipped with N, and the process proceeds to step S37. On the other hand, when the release button 21 is fully pressed, the process proceeds to step S31 to stop the A mode display, that is, stop displaying the live view on the liquid crystal monitor 26, and turn off the power of the CCD 279 in the finder. (S33), the operation proceeds to the photographing operation A (M221). In the photographing operation A, the first reflecting mirror 201 is retracted from the photographing optical path, the diaphragm 103 is narrowed down to a set value, the shutter 213 is opened, and after the photographing operation by the main CCD 221 is performed, the first reflecting mirror 201 is set to the reflecting position. A known operation of returning the aperture 103 and the shutter 213 to the initial position is performed. When the photographing operation A ends, the process returns to step S1 and the above steps are repeated.

Returning to step S21, if 1R is off, it is determined in step S41 whether the preview button 36 is on. If it is on, the A mode display is fixed, that is, the display subject image as a through image displayed on the liquid crystal monitor 26 is not updated but is maintained as it is (S43). This is because when the aperture 103 is narrowed down in the preview operation and the subject brightness is lowered, the through image condition setting cannot sufficiently follow, and the brightness of the image changes unnaturally. In order to prevent this unnatural change, the update of the through image is stopped until the image is stabilized. Thereafter, the process proceeds to preview A (M210), and the subject image is displayed on the liquid crystal monitor 26 as a through image based on the output of the main CCD 221 with the aperture 103 set to the set value. When preview A ends, the process returns to step S1 and the above steps are repeated.

Returning to step S41, if the preview button 36 is off, the process proceeds to step S45, where it is determined whether the display switching button 35 has been pressed, that is, whether it is on. If it is on, the A mode display M200 is terminated and the process proceeds to the information display M100. Returning to step S45, if the result of determination is that the display switching button 35 has not been pressed, that is, if it has been turned off, processing proceeds to step S47, whether the menu button 28 has been pressed, that is, whether it has been turned on. If it is ON, the process proceeds to the menu display M230 described with reference to FIG. If the menu button 28 is off, the process proceeds to step S49, and it is determined whether or not the through image switching button 34 is on (S49). If it is off, no button has been operated, so the process returns to step S11 and the above-described flow is repeated. When the live view display button 34 is operated in the state of the A mode display M200, the mode is switched to the B mode display M300 as described above. Therefore, if it is determined to be on in S49, the A mode display is fixed as in step S41, and then the process proceeds to the B mode display (M300).

Next, the flow of the B mode display M300 will be described with reference to FIG. When the B mode display is entered, first, the main CCD 221 is selected (S61), and supply of power to the main CCD 221 is started (S63). Next, as in step S1, photometric / exposure amount calculation is performed (S65), the first reflecting mirror 201 is rotated about the axis 201a, and retracted from the photographing optical path (S67). Subsequently, the focal plane shutter 213 is opened (S69), and a subject image is formed on the main CCD 221. As in step S7, a through image display condition setting 1 subroutine is executed (S71), and through image display in B mode display is started (S73). When the A mode display M200 is switched to the B mode display M300, the display on the liquid crystal monitor 26 is fixed from the A mode display fixed in step S51 to the start of the B mode display in step S73. The display is switched to B mode display, that is, through image display based on the image signal output from the main CCD 221. Next, in step S75, a timer is started and the process proceeds to step S81.

In step S81, it is determined whether the release button 21 is fully pressed, that is, whether 2R is on. First, the through image display displayed on the liquid crystal monitor 26 is stopped, that is, the B mode display is stopped (S83), and the focal plane shutter 213 and the first reflection mirror 201 are returned to the initial state (S85, S87). Thereafter, the process proceeds to the shooting operation B (M320), the shutter 213 is opened, and after the imaging operation by the main CCD 221 is performed, the aperture 103 and the shutter 213 are returned to the initial positions. When the photographing operation B is completed, the process returns to step 61 and the above-described steps are repeated. Returning to step S81, if 2R is off, the process proceeds to step S91 to determine whether the preview button 36 is on. If it is on, the preview operation is started and the B mode display is fixed (S93). This is to prevent the image brightness from unnaturally changing when narrowing down, as in the case of fixing the A mode display in step S43. Thereafter, the process proceeds to preview B (M330), and the subject image is displayed as a through image on the liquid crystal monitor 26 based on the output of the main CCD 221 in a state where the aperture 103 is reduced to the set value.

Returning to step S91, if the preview button 36 is off, it is determined in step S101 whether the display switching button 35 is on. If it is on, the process returns to the information display M100, but before that, a process for ending the B mode display is performed from S103 to S109. First, the B mode display is stopped (S103), the focal plane shutter 213 is closed, and the first reflecting mirror 201 is returned from the retracted position to a position where the light beam is reflected to the finder optical system (S107). Subsequently, a pixel defect detection subroutine is executed (S108). This subroutine is for detecting pixel defects when switching from the B mode display M300 to the information display M100, and will be described later in detail with reference to FIG. After returning from this subroutine, the power source of the main CCD 221 is turned off (S109), and the process proceeds to the information display M100.

Returning to step S101, if the display switching button 35 is off, the process proceeds to step S111 to determine whether the menu button 28 is on. If the result of determination is that it is on, menu display M310 is displayed, but before that, processing for stopping the live view display in B mode display is performed in steps S113 to S119. Since this process is the same as steps S103 to S109 described above, a description thereof will be omitted. Here again, a subroutine for pixel defect detection is executed (S118). This is to detect a pixel defect when switching from B mode display to M300 to menu display M310 (see FIG. 8).

Returning to step S111, if the result of determination is OFF, it is determined in step S121 whether or not the through image switching button 34 is ON. If the result of determination is that it is on, the B mode display M300 is switched to the A mode display M200, but before that, switching processing is performed in steps S123 to S129. First, in step S123, the B mode display is fixed. This is to prevent image distortion when switching the through image display mode, as in step S77. Subsequent steps S125 to S129 are the same as steps S105 to S109 described above, and a description thereof will be omitted. In this case as well, a pixel defect detection subroutine is executed (S128). This is to detect a pixel defect when switching from the B mode display to the A mode display M200 from the M300 (see FIG. 8).

Returning to step S121, if the result of determination is OFF, control proceeds to step S131, where it is determined whether or not the lens barrel 10 has been removed from the camera body 20 based on the output of a lens detection switch <not shown>. To do. When the determination result is Yes, that is, when the lens barrel 10 is removed, the information display M100 is performed. In the B mode display, the first reflecting mirror 201 is retracted from the photographing optical path, and the focal plane shutter 213 is open. For this reason, the main CCD 221 is directly exposed to the outside, and dust or the like may be attached. Therefore, by closing the B mode display M300, dust or the like is prevented from adhering to the imaging surface of the main CCD 221. In order to end the B mode display, processing is performed in steps S133 to S139. Since these steps are the same as steps S103 to S109 described above, description thereof will be omitted. In this case as well, a pixel defect detection subroutine is executed (S138). This is to detect pixel defects when switching from the B mode display to the information display M100 from M300 (see FIG. 8).

Returning to step S131, if the result of determination is No, the lens barrel 10 remains attached. In this case, whether or not pixel defect detection is subsequently required in step S140 and step S141. Make a decision. In general, an imaging device such as the main CCD 221 increases the dark current in the image sensor as the ambient temperature increases, and noise based on pixel defects becomes conspicuous. Therefore, in the present embodiment, pixel defects are detected when the temperature around the image sensor is equal to or higher than a predetermined value and when a predetermined time has elapsed. First, it is determined whether or not the temperature detected by the temperature detection circuit 216 is equal to or higher than a predetermined temperature. If the temperature is equal to or higher than the predetermined temperature, in step S141, the timer started in step S75 determines whether or not a predetermined time has elapsed. If the result of determination is Yes, the ambient temperature of the image sensor is equal to or higher than a predetermined value, and a predetermined time has elapsed since the start of B-mode display. In step S149, pixel defect detection is performed. I do. Since the steps up to the detection of the pixel defect are the same as steps S103 to S108 described above, description thereof will be omitted. When the pixel defect detection subroutine is completed, the process returns to step S65 to repeat the above steps. As described above, in the present embodiment, during live view display, in steps S140 and S141, it is predicted whether or not a subsequent pixel defect has occurred in the output of the main CCD 221, and a subsequent pixel defect has occurred in the subject image data. In step S149, the subsequent pixel defect information acquisition operation is executed.

If the answer is No in at least one of the steps S140 and S141, that is, if the temperature is equal to or lower than the predetermined temperature or the predetermined time has not elapsed, the through image display is performed as in step S15. After the through image condition setting 2 subroutine (S151) for adjusting the brightness of the image on the liquid crystal monitor 26 is executed, the process proceeds to step S81 described above.

In this embodiment, when the B mode display M300 is entered, when the initial settings from step S61 to S75 are completed, the loops of steps S81, S91, S101, S111, S121, S131, S140, S141, and S151 are sequentially processed. Become. When processing this loop, as described above, when the temperature around the imaging element is equal to or higher than a predetermined value and a predetermined time has elapsed, pixel defects are detected. Yes. The pixel defect detected here is used for image correction when a through image is displayed on the liquid crystal monitor 26, as will be described later. Therefore, even when the B mode display is performed for a long time or the ambient temperature rises, the through image display from which noise is removed can be performed. Further, even when the user exits the B mode display and shifts to the information display M100, the menu display M310, the preview B M330, and the A mode display M200, since the pixel defect is detected, by performing the B mode display, Even if noise is likely to occur, it is possible to display a through image with noise removed by correction. In particular, in order to switch to another display state (shooting information display, camera operation setting menu display, A mode display, etc.) with the stop of the live view display, it is necessary to perform an operation for switching. Since the pixel defect is detected by making good use of the switching time, the switching time can be effectively utilized.

Next, “through image condition setting 1” and “through image condition setting 2” will be described with reference to FIG. As described above, this subroutine is for adjusting the image brightness when displaying the subject image on the liquid crystal monitor 26. First, when the through image condition setting 1 subroutine is entered, in step S201, the electronic shutter speed TV1 and sensitivity SV1 at the time of next imaging are determined based on the output BVs of the photometric sensor 281. Since the aperture value when displaying a through image is an open aperture value, if this aperture value is AVs,
AVs + TV1 = BVs + SV1
There is a relationship
BVs-AVs = TV1-SV1
It becomes. Since the left side of this equation is a known value, TV1 and SV1 may be obtained from the value on the left side according to a program line or a table as appropriate. Thereafter, the determined electronic shutter speed TV1 and sensitivity SV1 are stored and set in the respective registers (S207). The CCD drive circuit 223 or the CCD drive circuit 283 performs drive control of the CCD 221 or 279 based on the TV1 and SV1 set and stored here, and reads out the photoelectric conversion signal. When the setting of TV1 and SV1 is completed in step S207, the process returns to the original flow.

Next, “through image condition setting 2” will be described. When the setting 2 subroutine is entered, first, a difference ΔEV between the target image brightness (predetermined value) and the image brightness at the time of previous imaging is calculated (S203). Subsequently, the electronic shutter speed TV1 and sensitivity SV1 at the next imaging are determined so that the image brightness is constant (S205). This decision is based on the following factors:
・ Aperture value AVs
-Electronic shutter speed TV0 at the time of previous imaging
・ Sensitivity SV0 at the time of previous imaging
The difference ΔEV between the target image brightness and the previous image brightness
First, as a basic expression of the exposure condition, AVs + TV0 = BV0 + SV0
It is.

Here, BV0 is the previous luminance, but the true value is not known and is a provisional value in the above basic formula. Since the true luminance value BV0 is different from the target, ie, ΔEV,
BV0 = AVs + TV0−SV0 + ΔEV
= AV1 + TV1-SV1
Thus, TV1 and SV1 are obtained from this relational expression. Here, the difference ΔEV may be obtained from, for example, the difference between the weighted average of the output of each pixel of the image sensor and the target value. When step S205 ends, the process proceeds to step S207 described above and returns to the original flow.

Next, a subroutine for pixel defect detection will be described with reference to FIG. An imaging element such as a CCD has fixed pattern noise caused by variations in output characteristics of each pixel. Therefore, if the output of the image sensor is used as it is, the noise is superimposed on an effective image signal component, and this causes deterioration of the image quality of the captured image. In particular, noise tends to increase when the temperature of the image sensor itself rises due to reasons such as displaying a through image for a long time. Such fixed pattern noise is formed by pixel defects of each pixel. As pixel defects, there are pixel defects existing in individual image pickup devices themselves (herein, referred to as “first pixel defects”), and through image display. There is a pixel defect (referred to herein as a “later pixel defect”) that occurs due to the continuous operation. In the present embodiment, the first pixel defect is detected in advance at the time of shipment from the factory, and this is written in the pixel defect storage unit 236 in the flash memory 235, and the second pixel defect is detected during the B mode display operation. The detected subsequent pixel defect is also written in the pixel defect storage unit 236 in the flash memory 235 to update the information.

When the pixel defect detection subroutine is entered, first a dark image is taken (S301). When performing pixel defect detection, the shutter 213 is closed in advance (S105, S115, S125, S135, S145), and the CCD 221 is shielded from light. In this dark image shooting, a photoelectric conversion signal (dark image signal) is read out by capturing an image for a predetermined time in a light-shielded state. The central average level is calculated using the read dark image signal (S303). Here, a predetermined range in the central portion of the image is selected, and an average value of digital values of photoelectric conversion signals in this range is calculated. Subsequently, it is determined whether or not the central average level is within a predetermined value (S305). The darker the level of the image signal is, the lower the level is, and the higher the level is brighter. Now, since the image is taken with the shutter 213 in the closed state, the image signal level of each pixel should be a minimum value. However, stray light is generated or the shutter malfunctions (hereinafter, “shutter error”). The level of the image signal becomes high. If pixel defect detection is performed based on a dark image signal obtained under such an adverse condition, noise cannot be removed correctly. Therefore, in this embodiment, when such a shutter malfunction occurs, that is, when the central average level is not within a predetermined value, the pixel defect is not detected and the process returns. . In this case, noise removal based on the subsequent pixel defect cannot be performed, but the subject image can be observed.

If the median average level is within the predetermined value in step S305, the process proceeds to step S307. In the present embodiment, pixel defect detection is performed at the factory shipment stage, and information indicating the coordinates of a pixel in which a pixel defect exists for each image sensor (starting pixel defect information) is the first in the pixel defect storage unit 236. It is written in the storage unit 236a (see FIG. 9). In step S307, the previous pixel defect information stored in the first storage unit 236 is read. Subsequently, the pixel defect of the dark image signal is corrected using the read out starting pixel defect information (S309). Of the image information based on the dark image signal, the image information corresponding to the coordinate position having the pixel defect is not used, and the defect is corrected by replacing it with the signal level corresponding to the dark time.

Thus, the subsequent pixel defect information is detected using the image information corrected using the previous pixel defect information. For this, first, pixel-by-pixel readout is performed from the corrected image information (S311). It is determined whether or not the read signal level for each pixel is equal to or higher than the defect determination level (S313). If there is a pixel defect, the black level is not reached. Therefore, if the signal level corresponds to a certain level of brightness or more, the process proceeds to step S315 because there is a defect, and the coordinates of the pixel in which the defect has occurred are set. The data is temporarily stored in the SDRAM 237. If it is not the defect determination level or higher in step S313, or if the temporary storage in the SDRAM is completed in step S315, the process proceeds to step S317 to determine whether there is a next pixel. If the result of determination is that reading of all pixels has not been completed and there is a next pixel, the process returns to step S311 to repeat the above steps.

Steps S311 to S315 are repeated, and when the defect level determination is completed for all the pixels of the image information based on dark image shooting, the process proceeds to step S319. In this step, since the coordinate information of the pixel that is the subsequent defect image is temporarily stored in the SDRAM 237, the stored subsequent defect coordinates (subsequent pixel defect information) are read. All the subsequent pixel defect information read out is stored in the second storage unit 236b in the flash memory 235 (S321), and the process returns to the original flow. Each time the pixel defect detection subroutine is executed, the subsequent pixel defect information is updated in the second storage unit 236b.

Next, a configuration for detecting the leading defect image information and the succeeding pixel defect information and correcting the through image will be described with reference to the block functional diagram shown in FIG. The imaging 311 including the main CCD 221 etc. outputs image information for each pixel. The output of the imaging unit 311 is output to the pixel defect detection unit 313 when detecting a pixel defect, and is output to the pixel defect correction unit 317 when performing normal B-mode display. The pixel defect detection unit 313 performs detection according to the flow shown in FIG. 8 described above, and is substantially executed by the body CPU 229 that is a sequence controller. The starting pixel defect information detected at the factory shipment stage is stored in the first storage unit 236a, and the subsequent pixel defect information detected in the aforementioned steps S108, S118, S128, S138, and S149 during the B mode display is the first information. 2 is stored in the storage unit 236b. In principle, the initial pixel defect information written in the first storage unit 236a at the factory shipment stage is not rewritten, but the subsequent pixel defect information written in the second storage unit 236b is detected every time a pixel defect is detected. The subsequent pixel defect information is updated.

The pixel defect correction unit 317 receives image information for each pixel from the imaging unit 311 and first and subsequent pixel defect information from the pixel defect information storage unit 236, and corrects the pixel defect. The function is carried. The pixel defect correction unit 317 performs pixel information on the image information corresponding to the pixel in which the pixel defect has occurred based on the previous and / or subsequent pixel defect information stored in the pixel defect information storage unit 236. Correction is performed using a known interpolation method using surrounding image information. The image information corrected by the pixel defect correction unit 317 is output as image data and displayed on the liquid crystal monitor 26. In the B mode display, if the predetermined time has not passed and the predetermined time has not elapsed, the pixel defect correction unit 317 corrects the image information based on the previous pixel defect information, and the predetermined time is exceeded by the predetermined temperature. When the time has elapsed, the pixel defect correction unit 317 corrects the image information based on both the preceding pixel defect information and the subsequent pixel defect information.

In this embodiment, the initial pixel defect information is written at the factory shipment stage. However, the present invention is not limited to this. For example, it may be performed when the camera body is reset, and if the performance of the image sensor can be ensured. It can be omitted. Further, the subsequent pixel defect information is detected only for the main CCD 221, and the image information is corrected in the case of the B mode display. However, the detection of the subsequent pixel defect information and the A mode are similarly performed for the CCD 279 in the finder. Of course, the image information in the case of display may be corrected. Further, in the embodiment, the detected subsequent pixel defect information is used for the through image display, but it is needless to say that it may be used for correction when recording a still image.

Next, the 1st modification of one Embodiment of this invention is demonstrated using FIG. In one embodiment, the subsequent pixel defect is detected when a predetermined temperature is exceeded and a predetermined time elapses. However, in this first modification, the subsequent pixel defect is detected only by whether or not the predetermined time has elapsed. Decided to do. As a configuration, the temperature detection circuit 216 is not necessary in the overall circuit block diagram shown in FIG. 3, and the present invention except that the determination whether the temperature is equal to or higher than a predetermined temperature (S140 in FIG. 6) is deleted as shown in FIG. Therefore, detailed description thereof is omitted.

Then, the 2nd modification of one Embodiment of this invention is demonstrated. In one embodiment, it is determined whether or not to detect the subsequent pixel defect with temperature and time, but in this second modification, the ISO sensitivity and time that have been set in the menu display are determined. Therefore, the subsequent pixel defect is detected. Therefore, step S140 in the flow shown in FIG. 6 may be replaced with “predetermined ISO or higher?”. As a result, when the B mode display is performed for a predetermined time or more with a predetermined ISO sensitivity, a subsequent pixel defect can be detected and the image information can be corrected. In general, pixel defects are more conspicuous as in the case of high ISO. According to the second modification, it is possible to perform a through image display in which noise is not conspicuous even when high ISO sensitivity is set.

In the above modification, one or a combination of the predetermined time, the predetermined temperature, and the predetermined ISO sensitivity is used, but various modifications can be obtained by combining these. For example, when the temperature is equal to or higher than the first predetermined temperature and the first predetermined time has elapsed, when the temperature is equal to or higher than the second predetermined temperature (> first predetermined temperature) and the second predetermined time (> first predetermined time) ), A combination of a predetermined time and a predetermined ISO sensitivity, three combinations, and the like are obtained.

As described above, in the embodiment of the present invention, when the B mode display is performed at a predetermined temperature for a predetermined time or more, pixel defect detection is performed in step S149, and the detected and written pixel defect information is based on the detected pixel defect information. The pixel defect correction unit 317 corrects the image information. For this reason, noise is removed from the subject image displayed on the liquid crystal monitor 26 as a through image, which makes it very easy to see. In addition, since the storage content of the second storage unit 326b that stores the subsequent pixel defect information is updated every time the pixel defect is detected, the image information can always be corrected based on the latest subsequent pixel defect information.

Further, in the embodiment of the present invention, pixel defect detection is performed when shifting from through display to another display mode (for example, display of shooting information or camera operation setting menu display), and subsequent pixel defects are generated. Even after easy through image display is completed, pixel defects can be corrected and noise can be removed. Further, in the present embodiment, since the subsequent pixel defect information is acquired using a dark image, it is possible to detect pixel defects that occur during B-mode display. Furthermore, in this embodiment, pixel defect detection is performed after checking in advance whether a shutter error has occurred, so that correct pixel defect information can be obtained.

In the description of the embodiments of the present invention, a digital single lens reflex camera is taken as an example. However, the present invention is not limited to this, and a digital camera that has an image sensor and can display a through image based on the output of the image sensor. Of course, the present invention can be applied to any electronic imaging device.

1 is an external perspective view of a digital single lens reflex camera according to an embodiment of the present invention. 1 is a block diagram showing a schematic optical configuration of a digital single-lens reflex camera according to an embodiment of the present invention. 1 is a block diagram illustrating an overall configuration of a digital single-lens reflex camera according to an embodiment of the present invention. It is a block diagram which shows the display mode of the digital single-lens reflex camera in one Embodiment of this invention, and the hierarchical structure of the operation mode menu. It is a flowchart of A mode display in one embodiment of the present invention. It is a flowchart of the B mode display in one Embodiment of this invention. 6 is a flowchart of through image condition setting 1 and through image condition setting 2 in an embodiment of the present invention. It is a flowchart of pixel defect detection in one embodiment of the present invention. FIG. 5 is a block diagram illustrating pixel defect detection and correction functions according to an embodiment of the present invention. FIG. 4 is a display screen of a through image display mode in the liquid crystal monitor of one embodiment of the present invention, where (A) shows an A mode display and (B) shows a B mode display. It is a flowchart of the B mode display in the modification of one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lens barrel 20 Camera main body 21 Release button 22 Mode dial 23 Power switch 24 Control switch 26 Liquid crystal monitor 27 Playback button 28 Menu button 30 Cross key 31 OK button 33 Viewfinder 34 Through image switching button 35 Display switching button 36 Preview button 213 Focal Plain shutter 221 Main CCD
229 Body CPU
235 Flash memory 236 Pixel defect storage unit 236a First storage unit 236b Second storage unit 279 CCD in viewfinder
227 Image processing circuit 285 CCD switching circuit 317 Pixel defect correction unit

Claims (8)

Imaging means for acquiring a subject image with an imaging element;
Pixel defect information storage means for storing pixel defect information of the imaging means;
Pixel defect correction means for performing pixel defect correction on the output of the imaging means based on the pixel defect information;
Through image display means for continuously displaying the image data output from the imaging means on a display device;
Subsequent pixel defect information acquisition means for performing an operation of acquiring the subsequent pixel defect information in response to the suspension of the through image display,
Pixel defect information updating means for updating the storage content of the pixel defect information storage means based on the subsequent pixel defect information;
A digital camera comprising: 2. The digital camera according to claim 1, wherein the subsequent pixel defect information acquiring unit executes an operation of acquiring the subsequent pixel defect information in response to switching from the through image display state to another display state. .   3. The digital camera according to claim 2, wherein the other display state includes a display of shooting information or a setting menu display of camera operation. The pixel defect information storage means includes first storage means for storing the preceding pixel defect information stored at the time of factory shipment, and second storage means for storing the subsequent pixel defect information. The digital camera according to claim 1, wherein the digital camera is a digital camera. The digital camera according to claim 4, wherein the subsequent pixel defect information acquisition unit acquires the subsequent pixel information based on a dark image of the imaging unit and the previous pixel defect information. 2. The digital camera according to claim 1, wherein the subsequent pixel defect information acquisition unit acquires the subsequent pixel defect information after removing pixel information caused by a shutter error. Imaging means for acquiring a subject image with an imaging element;
Through image display means for continuously displaying image data acquired by the imaging means on a display device;
Pixel defect information acquisition means for performing an operation of acquiring pixel defect information in response to the suspension of the through image display;
Pixel defect correction means for performing pixel defect correction on the output of the imaging means based on the pixel defect information acquired by the pixel defect information acquisition means;
Comprising
The digital image camera, wherein the through image display means displays the image data corrected by the pixel defect correction means. Prior to the through image display, the image pickup means has storage means for detecting and storing pixel defect information in advance, and the pixel defect correction means includes the pixel defect information stored in advance and the through image display. 8. The digital camera according to claim 7, wherein correction is performed using pixel defect information acquired by the pixel defect information acquiring means.