JP4464289B2 - Imaging apparatus and control method thereof - Google Patents

Description

  The present invention relates to an imaging apparatus such as a digital still camera having a noise reduction function and a control method thereof.

  In recent years, digital still cameras (hereinafter referred to as “digital cameras”) having an image pickup device typified by a CCD or CMOS sensor are generally known to have a noise reduction (NR) processing mode. .

  This NR processing mode refers to the real image shooting in which the image sensor is not exposed for the same time as the exposure time of the main image shooting immediately after the exposure shooting processing for shooting (hereinafter referred to as “main image shooting”). An image (hereinafter referred to as “NR image capturing”) obtained by the same processing is acquired, and an image (hereinafter referred to as “main image”) obtained at the time of actual image capturing is obtained at the time of NR image capturing (hereinafter referred to as “main image”). By subtracting “NR image”, the fixed pattern noise caused by the pixel defect of the image sensor and the dark current noise generated by the heat generation of the image sensor and the increase of the environmental temperature are canceled out. An image is provided. An image acquired by subtracting the NR image from the main image is hereinafter referred to as a “final image”.

  The fixed pattern noise and dark current depend on the accumulation time of the image sensor, and the longer the accumulation time, the greater the adverse effect on the image quality. Therefore, the NR processing mode is a particularly effective function in shooting when the shooting time that affects the above is long.

  In the case of not in the NR processing mode, for example, the main image is corrected with a correction value prepared in advance in the camera, or is sufficiently short when the image sensor is not exposed when the camera is turned on or immediately before or after the main image is captured. There is known a method of acquiring a final image by subtracting an image obtained by photographing for a predetermined time from a main image.

  In the NR processing mode described above, since the NR image acquired by the NR image shooting at the same time as the main image shooting is subtracted from the main image, the total shooting time is about twice the main image shooting time, resulting in high image quality. While it is possible to obtain an image, there is a drawback that the photographer waits longer and feels stressed when shooting at a long time.

  Furthermore, some common digital cameras automatically display captured images on a display device provided in the camera immediately after the end of the capturing process. In the NR processing mode, the image display immediately after capturing is also captured. There is a problem that a person has to wait for display of an image until the image processing is completed.

  In order to solve the above problem, the present applicant ends the NR processing after the main image shooting is completed in the shooting sequence performed in the order of the main image shooting, the NR image shooting, and the NR processing in which the NR image is differentially processed from the main image. In the period up to this time, while taking the NR image, the main image itself or a display means is used to generate a display image and display it on the display device (hereinafter referred to as “temporary display”). By displaying a display image generated based on the final image subjected to NR processing after the NR processing is completed (hereinafter referred to as “main display”), a high-quality recorded image is obtained and photographed. It is disclosed that the entire image is quickly transmitted to the person to shorten the waiting time until the image is displayed and the stress until the photographer's image is output is eliminated (see Patent Document 1).

JP 2003-325494 A

  However, the invention described in Patent Document 1 is mainly based on radiography, and most of the imaging conditions (for example, the imaging time and the imaging interval) to the imaging object are constant, but in digital cameras, imaging is performed. The shooting conditions such as the shooting time and the shooting interval are not always constant depending on the shooting environment for each person.

  In the digital camera, when the shooting time is sufficiently long, the time required from the end of the main image shooting to the end of the NR processing is sufficiently longer than the time required to generate the temporary display image. Since the display period is sufficient, it is a very effective means. However, if the shooting time is relatively short and the time required from the end of the main image shooting to the end of the NR processing is approximately the same as the time required to generate the temporary display image, the main display is started from the start of the temporary display. Since the period until the start of image display is very short, there is a possibility that the photographer may feel uncomfortable by switching the display image during the short period.

  Furthermore, if the time required from the end of the main image capturing to the end of the NR processing is shorter than the time required for the temporary display image generation processing, the temporary image is displayed until the final image is displayed. It takes time.

  Also, in such a digital camera, while the temporary display on the display device is being performed, the NR image is being captured or the NR process is being performed, but the state of the camera viewed from the photographer is that the image is only displayed on the display device. Only it is. For this reason, even though the next shooting cannot be performed during this period, the photographer feels that the next shooting is possible.

  In addition, in a digital camera having an NR processing mode so far, the photographer can shoot the NR image by performing a temporary display on the display device, and the photographer can check the entire image even during the NR process. It was possible to confirm the satisfaction of the composition with respect to the image and whether the image was a failed work, but even if the photographer was able to confirm that the composition was unsuccessful or failed, the image could be erased. Or the current shooting cannot be forcibly stopped, and it is necessary to continue to wait until all shooting operations are completed, or to reset the camera by removing the camera's battery and then take the troublesome operation of shooting again. The configuration was very poor in operability.

The present invention has been made in view of the above problems, the imaging apparatus of the present invention converts a subject optical image into electric charges, and an imaging device for outputting an image signal, and display means, the image pickup element EXPOSURE from the first image signal obtained by, by subtracting the second image signal obtained by accumulating to electric load of the image sensor in a non-exposure state, a noise reduction means for generating a third image signal, the exposure the time required is determined whether shorter than a preset threshold, if not shorter, the period from the first image signal to generate an image signal of the temporary, the third image signal is generated , an image signal of the temporary displaying said third image signal from the display on the display means, when short, the generation of the third image signal an image signal of the provisional without displaying on the display means the waiting, the display means said third image signal after generating And a that control means to control so as to display.

Further, an imaging device that outputs an image signal by converting a subject optical image into a charge, the control method of the present invention of an imaging device having a display unit obtains a first image signal by exposure light to the image sensor a first imaging step, by subtracting the second image capturing step of obtaining a second image signal to accumulate to electric load of the image sensor in a non-exposure state, the second image signal from the first image signal a noise reduction step of generating a third image signal, a determining step of time required for the exposure to determine whether shorter than a preset threshold, the time required for the exposure than a preset threshold If not shorter, from said first image signal to generate an image signal of a temporary, until the third image signal is generated, the third image an image signal of the provisional from the display on the display means A first display step for displaying the signal and the previous If time required for exposure is shorter than a preset threshold, waiting for generation of the third image signal an image signal of the provisional without displaying on the display means, the said third image signal after generation A second display step of displaying on the display means.

  According to the present invention, it is possible to further reduce stress on a photographer when performing automatic reproduction of an image captured immediately after shooting in an imaging process involving NR processing using an NR image.

  Even during the NR process, the NR process can be interrupted with good operability when it is desired to abandon the captured image and perform the next shooting.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings. However, the dimensions, shapes, relative arrangements, and the like of the components exemplified in the present embodiment should be changed as appropriate according to the configuration of the apparatus to which the present invention is applied and various conditions. It is not limited to.

<Embodiment 1>
FIG. 1 is a block diagram illustrating a configuration of a digital camera according to the first embodiment.

  In FIG. 1, reference numeral 1 denotes an optical system that includes a plurality of lenses and forms an optical image of a subject to be photographed on an image plane of an image sensor 3 described later. Reference numeral 2 denotes a shutter for controlling the exposure amount to the image sensor 3. Reference numeral 3 denotes an image sensor that is a photoelectric conversion element such as a CCD or CMOS sensor for converting a subject optical image to be photographed into an electrical signal, and is composed of a plurality of pixels. Reference numeral 4 denotes an A / D converter for A / D converting the electrical signal output from the image sensor 3. Reference numeral 5 denotes a microcomputer including an image processing unit, which controls operation of each part of the camera and performs image processing on a digital signal from the A / D conversion unit 4 and records an image processed image on a recording medium 7 to be described later. The image at the time of shooting is reproduced on the display unit 8, and the image recorded on the recording medium 7 is reproduced and displayed. Reference numeral 6 denotes a memory, which is a place for temporarily storing photographed images. The main image is temporarily stored in the memory 6 at the time of NR processing, and after acquiring the NR image, the main image temporarily stored in the memory 6 is used. The final image is acquired by subtracting the acquired NR image.

  Reference numeral 7 denotes a recording medium for recording a photographed image converted into a predetermined format by the microcomputer 5, and for example, a nonvolatile memory such as a flash memory is used. The recording medium 7 is generally of a type that can be attached to and detached from a dedicated slot (not shown) configured in the camera, but may be built in the camera. Reference numeral 8 denotes a display unit that reproduces and displays captured images and images recorded on the recording medium 7, displays a camera shooting menu, displays warnings, and the like.

  Reference numeral 9 denotes an operation unit composed of a plurality of operation members. The operation unit 9 performs an operation for setting the NR shooting mode according to the first embodiment, and the microcomputer 5 controls the operation of the camera according to the state of the operation unit 9. I do. The operation member constituting the operation unit 9 is a button switch, a dial type switch, a touch panel type switch that also has a display unit 8 or other switch operation, and any device that can transmit the state to the microcomputer 5. But you can. Considering operability, the operation units 9 are scattered in the camera as shown in FIG.

  In FIG. 2, 9a is a release switch for instructing execution of a shooting sequence, 9b is a menu switch for displaying a camera setting menu screen on the display unit 8, and 9c is a dial switch. The dial switch 9c is composed of a dial switch part and a push button switch part (hatching part in the figure), and the menu screen item displayed on the display part 8 is scrolled with the dial switch part to select a desired menu. Then, the menu hierarchy selected by the push button switch section is opened or the menu is confirmed. Reference numeral 9d denotes a reproduction switch. When the reproduction switch 9d is pressed, an image recorded on the recording medium 7 is reproduced and displayed on the display unit 8. Reference numeral 9e denotes an erasure switch. When the erasure switch 9e is pressed, the image displayed on the display unit 8 is erased from the recording medium 7.

  FIG. 3 is a flowchart for explaining a photographing sequence in the first embodiment.

  First, when the photographer presses the release switch 9a of the operation unit 9, photographing under predetermined photographing conditions is started (step S201), and main image photographing is performed in step S202. In this image shooting, the microcomputer 5 performs exposure control such as the aperture amount of the optical system 1, the focal position, the exposure time of the shutter 2, the charge accumulation time of the image sensor 3 in accordance with predetermined shooting conditions, and the incident subject optical An output obtained by photoelectrically converting the image by the image sensor 3 is A / D converted by the A / D converter 4, and the A / D converted digital signal is stored in the memory 6 via the microcomputer 5.

  In step S203, the setting state of the NR processing mode is determined. The photographer can select ON / OFF in advance in the NR shooting mode, and this setting method is performed as follows, for example. First, the camera setting menu is displayed on the display unit 8 by pressing the menu switch 9b. An ON / OFF selection item of the NR shooting mode, which is one of the setting menus, is selected using the dial switch portion of the dial switch 9d, and further ON / OFF is determined by pressing the push button switch portion. . Note that the NR shooting mode setting method is not limited to this, and for example, an NR shooting mode dedicated ON / OFF switch may be provided.

  If it is not in the NR processing mode, the process proceeds to step S213, the digital signal stored in the memory 6 is subjected to predetermined correction and compression, and the image for recording and the image for display are generated and generated. The display image is displayed on the display unit 8 in step S211, the recording image is recorded on the recording medium 7 in step S212, and the photographing operation is terminated. Note that the predetermined correction includes correction data for canceling dark shading prepared in advance in the camera, dark image data prepared in advance, or dark captured in a sufficiently short time in the non-exposure state during actual image shooting. There is correction for reducing fixed pattern noise and dark shading components by subtracting an image from a digital signal of the main image (hereinafter referred to as “main image data”).

  On the other hand, if the NR shooting mode is set in step S203, the process proceeds to step S204 to start NR image shooting. In NR image capturing, charge accumulation of the image sensor 3 is performed in an unexposed state, and an electric signal is output. The charge accumulation time is the same as or substantially the same as the charge accumulation time in the exposed state during actual image capturing.

  In step 205, the shooting time at the time of actual image shooting is determined, and a provisional display method on the display unit 8 is determined according to the shooting time. If the shooting time is longer than the predetermined value, a sufficient time is required until the actual display. Therefore, a temporary image for temporary display is generated in step S206.

  In step S206, the microcomputer 5 reads out the main image data temporarily stored in the memory 6 and corrects the main image data with the correction value prepared in advance or corrects the main image data. Temporary display image data is created from the unfinished image data. The primary purpose of temporary display is to transmit the entire picture taken to the photographer as soon as possible. However, in order to display the image with the best possible image quality, the temporary display is performed from the original image that has been subjected to the predetermined correction. It is preferable to create an image. As the correction value prepared in advance, a correction value that cancels the dark shading amount, a black image with a different shooting time, or a black image that has been left at the previous NR shooting is used. Of course, the correction values are not limited to these.

  When the generation of the temporary image is completed, temporary display on the display unit 8 is performed in step S207. Here, in the temporary display on the display unit 8, the generated temporary image generated in step S206 and the character information that informs the photographer that the current display is the temporary display are displayed.

  4A to 4C are display examples of temporary display (provisional display 1) on the display unit 8 in step S207. Along with the display of the temporary image, “NR processing” and “End” are displayed in the upper right part of the screen. Character information such as “10 seconds until” and “temporarily displayed” are displayed. When the remaining time is displayed, the remaining time until the end of shooting is counted down and displayed. Although an example of displaying character information has been described here, it is not limited to character information. For example, when displaying the remaining time, simple image information indicating the degree of progress such as a clock or a bar is used. Any display form may be used. In addition, instead of displaying information indicating that it is a temporary display on the display unit 8, for example, a display member such as an LED is provided outside the display unit 8 and flashed to notify the photographer. You may make it do.

  In this way, by displaying the information indicating the temporary display, the photographer can recognize that the currently displayed image is a temporary image and misunderstand that the next shooting is possible. Can be prevented.

  On the other hand, if the shooting time is shorter than the predetermined value in step S205, the photographer does not wait for a long time until the final image is displayed. Even if the temporary image is temporarily displayed, the final image is displayed after the temporary display. The time until the image is displayed is too short, and the photographer may feel uncomfortable in switching the display screen from the temporary display to the final image display.

  Further, if the required time from the end of the main image capturing (step S202) to the end of the final image generation (step S210) is shorter than the time required for the temporary display image generation processing, the temporary image is temporarily displayed. On the other hand, since it may take time, the temporary image is not displayed in such a case. However, although it is a short time until the final image is displayed on the display unit 8, in the first embodiment, information indicating that the NR process is being performed is temporarily displayed in step S208. In this way, by notifying the photographer that the NR process is being performed, it is possible to prevent a mistaken shift to the next photographing. Since the time until the final image is displayed is sufficiently short, the provisional display process in step S208 may not be performed.

  FIGS. 5A and 5B are display examples of temporary display (temporary display 2) on the display unit 8 in step S208, and the center of the black screen (or fixed color display screen) on which no temporary image is displayed. Character information such as “processing in progress” and “10 seconds until completion” is displayed in the part. Here, as in step S207, it is needless to say that provisional display in various forms such as using image information or LEDs is possible, not limited to character information.

  In step S209, waiting for completion of NR image shooting, and when shooting is completed, the A / D conversion unit 4 performs A / D conversion on the output photoelectrically converted by the image sensor 3 obtained in the non-exposure state by NR image shooting. A / D converted digital signal (hereinafter referred to as “NR image data”) is generated. In step S210, the microcomputer 5 reads the main image data from the memory 6 and subtracts the NR image data, thereby removing fixed pattern noise and dark current noise and generating a final image that has been subjected to NR processing. In step S210, the final image is further compressed to generate image data for recording and main display. In step S211, the final image generated in step S210 is displayed on the display unit 8 instead of the temporary image. In step S212, the recording image is recorded on the recording medium 7, and the photographing operation is terminated.

  As described above, in the first embodiment, in the NR processing shooting mode, by changing the temporary display method on the display unit 8 according to the shooting time, if the shooting time is sufficiently long, even during NR shooting. Since the temporary image is temporarily displayed, the photographer can quickly confirm the image. In addition, when the shooting time is sufficiently short, the temporary image is not displayed, and the temporary image is not switched to the final image at an inadvertent timing, so that the photographer confirms the image without feeling uncomfortable. be able to. Further, by displaying information indicating the temporary display together with the temporary image, it is possible to notify the photographer that the photographing is being performed and to prevent the photographer from erroneously shifting to the next photographing operation. .

<Modification of Embodiment 1>
Next, a modified example of the first embodiment will be described.

  Some digital camera display devices have a function for permitting / prohibiting automatic playback immediately after shooting. This is a function that can be set by the photographer with the operation switch, and is set by the photographer's intention. If the automatic playback function is “prohibited”, the image is not displayed, but the NR Without letting the photographer know that the process is in progress, the photographer is very difficult to know when the next shot will be possible.

  Therefore, in the modification of the first embodiment, when the photographer prohibits the automatic playback function immediately after shooting, only the information indicating that NR processing is being performed is displayed on the display unit 8 regardless of the length of the shooting time. To display.

  FIG. 6 is a flowchart showing a shooting sequence in a modification of the first embodiment. Compared to FIG. 3, it is determined whether or not the automatic playback function immediately after shooting is prohibited in step S301. If it is prohibited, the process proceeds to step S208, and the above-described FIGS. 5A and 5B are performed. The difference is that the photographer temporarily displays information that can be understood by the photographer, such as “NR processing in progress” or “10 seconds until completion”. Except for the above, the processing is the same as that shown in FIG.

  As described above, according to the modification of the first embodiment, even when the photographer prohibits automatic reproduction immediately after shooting, only the information by characters is temporarily displayed, so that the photographer can The state can be grasped.

<Embodiment 2>
Next, Embodiment 2 of the present invention will be described.

  In the first embodiment, provisional display is performed on the display unit 8 in a form corresponding to the shooting time. In particular, when the shooting time is longer than the predetermined time, the shot temporary image is temporarily displayed on the display unit 8 during the shooting of the NR image, so that the photographer can quickly confirm the entire shot image. However, even if this photographed image is a failed work, the photographer must wait until the entire photographing operation is completed. In order to carry out the operation, it is necessary to wait until the entire photographing operation is completed, so that there is a case where the occasional photo opportunity is missed.

  These problems can be dealt with by the photographer resetting the camera by inserting and removing the battery of the camera, but the operability is poor and is not a preferable way.

  In order to solve such a problem, in the second embodiment, a case will be described in which a digital camera is provided with means for forcibly terminating the shooting operation during temporary display in the NR shooting mode.

  Since the configuration of the digital camera in the second embodiment is the same as that described with reference to FIGS. 1 and 2 in the first embodiment, the description thereof will be omitted. In the second embodiment, the erasing switch 9e has an NR process. An operation function is provided to cancel the operation. Note that the operation switch for canceling the NR process is not limited to the erasing switch 9e, and a dedicated switch for canceling the NR process may be provided even if it is a switch of the other operation unit 9. .

  FIG. 7 is a flowchart illustrating a shooting sequence according to the second embodiment. In FIG. 7, processes similar to those described in FIG. 3 of the first embodiment are denoted by the same step numbers and description thereof is omitted.

  In the second embodiment, after the temporary image as shown in FIG. 4 is displayed in step S207, for example, it is determined whether or not the erasure switch 9e is operated in step S401 and the photographer instructs to stop the NR process.

  Here, for example, when the photographer presses the erasure switch 9e during temporary display on the display unit 8, "shooting stop" and "shooting" as shown in FIGS. 8A and 8C at the bottom of the temporarily displayed image. The text of the “Back” selection menu is displayed. Here, when the shooting switch is selected by the dial switch portion of the dial switch 9c and the push button switch portion is pressed and confirmed, the photographing operation is forcibly terminated, and when “Back” is selected and confirmed, the selection menu is canceled (ie, , NR processing is continued). Note that these “shooting stop” and “return” display forms are displayed in different forms such that, for example, any character is displayed in white so that selection / non-selection can be identified. In the second embodiment, immediately after the erasure switch 9e is pressed during temporary display, the default display of “shooting stop” and “return” displayed on the display unit 8 is “return”. The default display in the present embodiment is the state shown in FIG. 8A. In this state, when the push button switch portion (center hatched portion) of the center portion of 9c is pressed without turning the dial portion of the switch 9c, “ “Return” is confirmed.

  In the default state shown in FIG. 8A, when the photographer wants to forcibly terminate the NR process, the dial switch 9c is rotated in the direction of the arrow in FIG. Select “Cancel” (the word “Cancel” changes from white to black). Next, the forced termination of the NR process is confirmed by pressing the push button switch at the center of the dial switch 9c shown in FIG.

  When the forced termination of the NR process is instructed as described above, the process proceeds to step S405, where the NR process is forcibly terminated, the temporary display of the temporary image displayed on the display unit 8 is turned off, and FIG. As shown in (), a display is made to notify the photographer that the NR process has been forcibly terminated, and the photographing operation is terminated. The end of the display in FIG. 8E is performed by operating an arbitrary operation switch of the operation unit 9, or is automatically executed after a predetermined time has elapsed.

  On the other hand, when the photographer presses the erasure switch 9e during the temporary display on the display unit 8 to display “Cancel shooting” and “Return”, the erasure switch 9e is pressed during the temporary display or when the photographing operation is to be continued. If it has been accidentally pressed, “return” is confirmed by pressing the push button portion of the dial switch 9c in the state of FIG. 8A (that is, NO in step S401), and the photographing operation is continued.

  When the display state of the display unit 8 is as shown in FIGS. 8A and 8C, the selection menu (shooting stop or return) is in an unconfirmed state unless the push button switch unit of the dial switch 9c is pressed. The display state of the display unit 8 is held as it is until the photographer confirms the selection menu.

  In step S401, if the photographer does not press the delete switch 9e, or if the photographer presses the delete switch 9e and confirms “Return” in the selection menu, the selection is made by pressing the delete switch 9e. If the menu is not confirmed, the state of NR image shooting is confirmed in step S402. If not completed, the process returns to step S401. If completed, the main image data is read from the memory 6 in step S403 and the NR image is read. By subtracting the data, fixed pattern noise and dark current noise are removed, and a final image subjected to NR processing is generated. In step S403, the final image is further subjected to compression processing to generate image data for recording and main display. Although not shown, the photographer presses the delete switch 9e in step S401 to display the selection menu for forcibly terminating the NR process on the display unit 8, but the process in step S403 is still in the unconfirmed selection menu. If “shooting stop” is selected and determined during generation of the final image, the process may proceed to step S401 at that time.

  When the final image is generated in step S403, it is determined in step S404 whether the photographer has forcibly terminated the NR process. In step S404, the photographer presses the erasure switch 9e in step S401 to display the selection menu for forcibly ending the NR process on the display unit 8. However, when the selection menu is unconfirmed even after the NR process is completed. Only need to be executed. In other words, if the “erasure stop” in the selection menu is confirmed by pressing the erase switch 9e, the process proceeds to step S405 at that time, so that the process does not proceed to step S404, and the photographer presses the erase switch 9e during temporary display. The determination of this step is unnecessary even when the button is not pressed or when the “return” of the selection menu is confirmed by pressing the erase switch 9e. In that case, the display image of the final image is displayed on the display unit 8 in step S211, the recording image is recorded on the recording medium 7 in step S212, and the photographing operation is terminated.

  If “shooting stop” and “return” are not confirmed in step S404, the selection menu is continuously displayed on the display unit 8 until one of the selection menus is confirmed. If the selection menu “cancel photography” is confirmed, the process proceeds to step S405 to forcibly terminate the NR process, and the display unit 8 is displayed on the display unit 8 to notify the photographer that the photographing operation has been forcibly terminated as described above. End the operation. If the selection menu “return” is confirmed, the display image of the final image is displayed on the display unit 8 in step S211, the recording image is recorded on the recording medium 7 in step S211, and the photographing operation is terminated. .

  In the above description, when “shooting stop” and “return” are not confirmed in step S404, the selection menu continues to be displayed on the display unit 8 until any of the selection menus is confirmed. If it is determined in advance and the predetermined time has not yet been determined, the selection menu display may be terminated from the display unit 8 and steps S211 and S212 may be executed.

  As described above, according to the second embodiment, when provisional display is performed at the time of NR processing, by providing means for forcibly terminating the NR processing, the photographed image is a failed work or the highest during temporary display. When a shooting opportunity has arrived, it is possible to immediately start the next shooting without waiting for the completion of all processing of the shooting operation.

<Other embodiments>
An object of the present invention is to supply a storage medium (or recording medium) in which a program code of software for realizing the functions of the above-described embodiments is recorded to a system or apparatus, and a computer (or CPU or MPU) of the system or apparatus. Needless to say, this can also be achieved by reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included. Examples of the storage medium for storing the program code include a flexible disk, hard disk, ROM, RAM, magnetic tape, nonvolatile memory card, CD-ROM, CD-R, DVD, optical disk, magneto-optical disk, MO, and the like. Can be considered. Also, a computer network such as a LAN (Local Area Network) or a WAN (Wide Area Network) can be used to supply the program code.

  Furthermore, after the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer, the function is determined based on the instruction of the program code. It goes without saying that the CPU or the like provided in the expansion card or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

It is a block diagram which shows the structure of the digital camera concerning Embodiment 1 of this invention. It is the schematic external view which looked at the digital camera concerning Embodiment 1 of this invention from the back surface. It is the flowchart explaining the imaging | photography sequence in Embodiment 1 of this invention. It is a figure which shows the example of a display form at the time of the temporary display in Embodiment 1 of this invention. It is a figure which shows the example of a display form at the time of the temporary display in the modification of Embodiment 1 and Embodiment 1 of this invention. It is the flowchart explaining the imaging | photography sequence in the modification of Embodiment 1 of this invention. It is the flowchart explaining the imaging | photography sequence in Embodiment 2 of this invention. It is a figure which shows the example of a display form at the time of the temporary display in Embodiment 2 of this invention.

Explanation of symbols

1: Optical system 2: Shutter 3: Image sensor 4: A / D conversion unit 5: Microcomputer 6: Memory 7: Recording medium 8: Display unit 9: Operation unit 9a: Release switch 9b: Menu switch 9c: Dial switch 9d: Playback switch 9e: Erase switch

Claims (12)

An image sensor that converts an optical image of a subject into an electric charge and outputs an image signal;
Display means;
Wherein the imaging element from the first image signal obtained by exposure light, by subtracting the second image signal obtained by accumulating to electric load of the image sensor in a non-exposure state, noise reduction to generate a third image signal Means,
Determining whether the or the time required for exposure is shorter than a preset threshold, if not shorter generates image signals of provisional from the first image signal, said third image signal is generated until, the image signal of the temporary displaying said third image signal from the display on the display means, is shorter, the third image an image signal of the provisional without displaying on the display means It waits for generation of the signal, the image pickup apparatus, wherein said third image signal after generating to have a control to that control unit to display on the display means. If time required for the exposure is shorter than the preset threshold, the previous SL control means until said third image signal is generated, information indicating the state of operation of the noise reduction means 2. The imaging apparatus according to claim 1, wherein control is performed to display at least one of information indicating time taken until the end of generation of the third image signal. If time required for the exposure is not shorter than the preset threshold, pre SL control means, information indicating that the image being displayed is the image signal of the temporary operation of the noise reduction means claim information indicating the state, or at least one of the third information indicating the time it takes generation completion of the image signal, and controlling to display so together with the image signal of the provisional 1 Or the imaging device of 2. Immediately after shooting an image, further comprising a setting means for switching the permission and prohibition of an operation for automatically displaying an image the captured on the display means,
If it is set to prohibited by the setting means, regardless of the time required for the exposure, while generating the third image signal, information indicating the state of operation of the noise reduction means or said first, 3 image signal capturing apparatus according to any one of claims 1 to 3, characterized in that displaying the at least one of information indicating the time it takes generation end of. Further comprising instruction means for instructing stop of generation of the third image signal,
5. The noise reduction unit stops processing related to generation of the third image signal when the instruction unit instructs to stop generation of the third image signal. The imaging device according to any one of the above. An image signal of the provisional image pickup apparatus according to any one of claims 1 to 5, characterized in that to produce after a predetermined correction to the first image signal. Said predetermined correction value used for correction of the obtained accumulated only charge time shorter than the time it took the imaging element to the exposure in the non-exposure state, a black image prepared in advance The imaging apparatus according to claim 6.   The imaging apparatus according to claim 6, wherein the correction value used for the predetermined correction is a correction value prepared in advance for canceling shading.   The imaging apparatus according to claim 6, wherein the correction value used for the predetermined correction is a second image signal obtained at the previous photographing. An imaging device control method comprising: an imaging device that converts an optical image of an object into an electric charge and outputs an image signal; and a display means,
A first imaging step of acquiring a first image signal and the dew light an imaging element,
A second imaging step of obtaining a second image signal to accumulate to electric load of the image sensor in a non-exposure state,
A noise reduction step of generating a third image signal by subtracting the second image signal from the first image signal;
A determination step of determining whether the time required for the exposure is shorter than a preset threshold;
If time required for the exposure is not shorter than the preset threshold, to generate an image signal of the provisional from the first image signal, until the third image signal is generated, the temporary A first display step of displaying the third image signal after displaying the image signal on the display means;
If time required for the exposure is shorter than the preset threshold value, it waits for the generation of the third image signal an image signal of the provisional without displaying on the display unit, the later generation third image signal And a second display step of displaying on the display means. The computer program of the order to execute the steps of the control method according to claim 1 0. A computer- readable storage medium storing the program according to claim 11 .

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