JP2009130471A - Imaging apparatus and method of controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus with the long period exposure function of valve imaging or the like, which is capable of obtaining images of an appropriate exposure level, and to provide a method of controlling the imaging apparatus. <P>SOLUTION: The imaging apparatus includes an imaging unit 291 for repeatedly imaging an object image in a set cycle to output image data, an adding operation unit 292 for performing an adding operation with past image data every time the image data is output, an added image storage unit 293 for sequentially storing added images operated in the adding operation unit 292, and a selection unit 298 for selecting one of two or more pieces of added image data stored in the added image storage unit 293 after the end of an imaging operation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging device and a method for controlling the imaging device, and more particularly to an imaging device capable of displaying a subject image according to the degree of exposure in long-time shooting such as bulb shooting and a method for controlling the imaging device.

  In general, bulb photography is often used when photographing subjects such as the starry sky, fireworks, and night views. However, bulb exposure varies in the appropriate exposure time (time from shutter opening to shutter closing) depending on the object to be photographed and ambient conditions, and the photographer can determine the exposure time without looking at the finished image at his own discretion. Had to decide. Therefore, there is a problem that if the judgment is wrong, the exposure is unexpected and excessive.

Therefore, when a photographed image can be observed in accordance with exposure during bulb photographing or the like, the exposure level can be observed in real time, and the exposure time can be easily determined. For example, Patent Document 1 discloses an imaging apparatus that takes out pixel signals from an imaging element at a predetermined time interval (for example, 1/10 second) during an imaging operation and displays sequentially added images on a liquid crystal monitor. Yes.
JP 2005-117395 A

  According to the imaging apparatus described in Patent Document 1, since the progress of exposure can be confirmed, a large failure can be prevented even in bulb photography. However, the determination is not always appropriate, and a failure may be noticed when checking after shooting.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an imaging apparatus and an imaging apparatus control method capable of obtaining an image with an appropriate exposure level during long exposure such as bulb photography. To do.

  In order to achieve the above object, an imaging apparatus according to a first aspect of the present invention provides an imaging unit that repeatedly captures a subject image at a set period and outputs image data during bulb shooting, and the image data is output. Each time, an addition calculation unit that performs addition calculation with past image data, an addition image storage unit that sequentially stores the addition image calculated by the addition calculation unit, and the addition image storage after the bulb photographing operation ends A selection unit that selects any one of the plurality of addition image data stored in the unit.

According to a second aspect of the present invention, in the first aspect, the selection unit includes an operation member that can be manually operated, and thumbnail images corresponding to a plurality of addition image data stored in the addition image storage unit. A display unit that displays a list, and when one of the thumbnail images is selected by the operation of the operation member, any one of a plurality of addition image data stored in the addition image storage unit accordingly Select.
In the imaging device according to a third aspect of the present invention, in the first aspect, the period is variable and is set manually.
Further, an imaging apparatus according to a fourth aspect of the present invention includes a display unit that displays the added image calculated by the addition calculation unit every time the image data is output.
In the imaging apparatus according to a fifth aspect based on the first aspect, the imaging unit repeatedly captures the subject image in response to the first operation of the release button, and responds to the second operation of the release button. Then, the imaging is stopped.

An imaging apparatus according to a sixth aspect of the invention is an imaging unit that repeatedly captures a subject image at a set cycle and outputs image data during bulb photographing operation, the image data, and image data output in the past. An addition operation unit that performs the addition operation, an addition image storage unit that independently stores a plurality of addition images calculated by the addition operation unit, and the addition image storage unit after completion of the bulb photographing operation. A display unit that displays a plurality of stored addition images in a list display is provided.
An imaging apparatus according to a seventh aspect of the present invention includes a selection unit that selects any one of a plurality of addition images displayed on the display unit, and an image recording unit that records the addition image selected by the selection unit It comprises.

  According to an eighth aspect of the present invention, there is provided a control method for an image pickup apparatus, wherein during a bulb photographing operation, a subject image is repeatedly picked up at a set cycle to obtain image data, and each time the image data is output, past image data is output. Are added and stored in sequence, and after the bulb photographing operation is completed, one of the stored plurality of added image data is selected, and the selected added image data is recorded on a recording medium. .

  According to the present invention, it is possible to provide an imaging apparatus and an imaging apparatus control method capable of obtaining an image with an appropriate exposure level during long exposure such as bulb photography.

  Hereinafter, a preferred embodiment using a digital single lens reflex camera to which the present invention is applied will be described with reference to the drawings. FIG. 1 is an external perspective view of a digital single-lens reflex camera according to an embodiment of the present invention as seen from the back.

  This digital single-lens reflex camera is composed of a camera body 200 and an interchangeable lens 100. On the upper surface of the camera body 200, a release button 21, a shooting mode dial 22, an information setting dial 24, a strobe 50, 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 the camera is turned on, the camera executes a photographing operation for capturing image data of the subject image based on the output of the image sensor 221 (see FIG. 2).

  The shooting mode dial 22 is an operation member configured to be rotatable. By matching a picture display or a symbol representing the shooting mode provided on the shooting mode dial 22 with an index, the program shooting mode (P) and aperture priority are set. Each shooting mode such as shooting mode (A), shutter shooting priority mode (S), manual shooting mode (M), bulb mode (B), etc. can be selected.

  The information setting dial 24 is an operation member configured to be rotatable, and a desired setting value, mode, or the like can be selected by rotating the information setting dial 24 on an information display screen or the like. When the bulb mode is set, the update time of the image display during exposure can be set. The strobe 50 is a pop-up type auxiliary lighting device. By operating an operation button (not shown), the strobe 50 pops up and can irradiate the subject.

  On the back of the camera body 200, there are a liquid crystal monitor 26, a continuous / single shooting button 27, an AF lock button 28, an up cross button 30U, a down cross button 30D, a right cross button 30R, and a left cross button 30L (these buttons). The cross buttons 30U, 30D, 30R, and 30L are collectively referred to as a cross button 30), an OK button 31, a live view display button 33, an enlarge button 34, a menu button 37, and a playback button 38. . The liquid crystal monitor 26 is a display device that performs live view display, reproduces and displays a captured subject image, and displays shooting information and menus. At the time of bulb photographing, an image is displayed based on an image signal acquired by the image sensor 221 during the exposure operation. Any liquid crystal display can be used as long as it can perform these displays.

  The continuous shooting / single shooting button 27 is a continuous shooting mode in which continuous shooting is performed while the release button 21 is fully pressed, and a single shooting mode in which one frame is shot when the release button 21 is fully pressed. This is an operation member for switching. The AE lock button 28 is an operation member for fixing the photometric value. Thus, when the luminance of the object to be photographed is measured and then the AE lock button 28 is operated, the photometric value is retained even if the composition is changed, and photographing can be performed without changing the exposure level.

  The cross button 30 is an operation member for instructing the movement of the cursor in the two-dimensional direction of the X direction and the Y direction on the liquid crystal monitor 26. In addition, when reproducing and displaying the subject image recorded on the recording medium 277, It is also used to select a subject image. In addition to providing four buttons for up, down, left, and right, it is possible to replace with an operation member that can be operated in two dimensions, such as a switch that can detect the operation direction in two dimensions, such as a touch switch. It is. The OK button 31 is an operation member for confirming various items selected by the cross button 30, the control dial 24, or the like.

  The live view display button 33 is an operation button for switching from a display screen for information display or the like to a live view display, or from a live view display to a display screen for information display or the like. The live view display is a mode in which the subject image is displayed on the liquid crystal monitor 26 for observation based on the output of the image sensor 221 for recording the subject image, and the information display is set to display shooting information of the digital single lens reflex camera. Therefore, this mode is displayed on the liquid crystal monitor 26. The enlargement button 34 is an operation member for enlarging and displaying a part of the subject image on the liquid crystal monitor 26, and the enlargement position can be changed by operating the cross button 30 described above.

  The menu button 37 is an operation member for switching to a menu mode for setting various modes of the digital single-lens reflex camera. When the menu mode is selected by operating the menu button 37, a menu screen is displayed on the liquid crystal monitor 26. Is done. The menu screen has a plurality of hierarchical structures. Various items are selected with the cross-shaped button 30, and selection is determined by operating the OK button 31. The playback button 38 is an operation button for instructing the liquid crystal monitor 26 to display a subject image recorded after shooting. The image data of the subject stored in a later-described SDRAM (Synchronous Dynamic Random Access Memory) 267 and recording medium 277 in a compression mode such as JPEG is expanded and displayed.

  A recording medium storage lid 40 is attached to the side surface of the camera body 200 so as to be freely opened and closed. When the recording medium storage lid 40 is opened, a loading slot for the recording medium 277 is provided therein, and the recording medium 277 can be detachably loaded into the camera body 200.

  Next, the overall configuration of the digital single-lens reflex camera mainly including the electric system will be described with reference to FIG. In the present embodiment, the interchangeable lens 100 and the camera body 200 are configured separately and are electrically connected by the communication contact 300, but the interchangeable lens 100 and the camera body 200 can also be configured integrally. . The circuit block of the built-in strobe 50 is omitted in FIG.

  Inside the interchangeable lens 100, a photographing optical system 101 for focus adjustment and focal length adjustment, and a diaphragm 103 for adjusting the aperture amount are arranged. The photographing optical system 101 is driven by a lens driving mechanism 107, and the diaphragm 103 is connected to be driven by a diaphragm driving mechanism 109.

  The lens driving mechanism 107 and the aperture driving mechanism 109 are each connected to a lens CPU 111, and the lens CPU 111 is connected to a communication circuit 273 of the camera body 200 via a communication contact 300. The lens CPU 111 controls the inside of the interchangeable lens 100. The lens CPU 111 controls the lens driving mechanism 107 to perform focusing and zoom driving, and also controls the aperture driving mechanism 109 to perform aperture value control. Further, the lens CPU 111 transmits lens-specific information such as an open aperture value and focal length information of the interchangeable lens 100, and focal length and focal position information detected by an optical system position detection mechanism (not shown) to the camera body 200. To do.

  In the camera body 200, a position tilted by 45 degrees with respect to the optical axis of the lens (the lowered position, the subject image observation position) in order to reflect the subject image to the observation optical system, and a subject image to be guided to the image sensor 221. A movable mirror 201 that can be rotated between the jumped up position (the raised position and the retracted position) is provided. Above the movable mirror 201, a focusing screen 205 for forming a subject image is disposed, and above this focusing screen 205, a pentaprism 207 for horizontally reversing the subject image is disposed.

  An eyepiece lens (not shown) for observing the subject image is arranged on the emission side (right side in FIG. 2) of the pentaprism 207, and the photometric sensor 211 is arranged on the side of the pentaprism 207 so as not to interfere with the observation of the subject image. Has been. The photometric sensor 211 is connected to a photometric processing circuit 241, and the output of the photometric sensor 211 is subjected to processing such as amplification and analog-digital conversion by the photometric processing circuit 241.

  Near the center of the movable mirror 201 described above is a half mirror, and on the back surface of the movable mirror 201, a sub mirror 203 for reflecting subject light transmitted through the half mirror portion to the lower part of the camera body 200 is provided. ing. The sub mirror 203 is rotatable with respect to the movable mirror 201. When the movable mirror 201 is flipped up (the position indicated by a broken line in FIG. 2), the sub mirror 203 is rotated to a position that covers the half mirror portion. When in the observation position (lowering position), it is in an open position with respect to the movable mirror 201 as shown.

  This movable mirror 201 is driven by a movable mirror drive mechanism 239. A focus detection sensor 243 is disposed below the sub mirror 203, and an output of the focus detection sensor 243 is connected to a focus detection processing circuit 245. The focus detection sensor 243 is a known phase difference AF that separates the peripheral light beam of the photographic optical system 101 into two light beams in order to measure the defocus amount of the subject image formed by the photographic optical system 101. It consists of an optical system and a pair of sensors.

A focal plane type shutter 213 for controlling the exposure time is disposed behind the movable mirror 201, and this shutter 213 is driven and controlled by a shutter drive mechanism 237. An imaging element 221 is disposed behind the shutter 213 and photoelectrically converts a subject image formed by the photographing optical system 101 into an electrical signal. The imaging element 211 may be a CCD (Charge Coupled Devices) or a CMOS (Complementary).
Needless to say, a two-dimensional image sensor such as Metal Oxide Semiconductor can be used.

  Between the shutter 213 and the image sensor 221, an infrared cut filter / low pass filter 217, which is an optical filter for removing an infrared light component and a high frequency component from a subject light beam, is disposed.

  The image sensor 221 is connected to the image sensor drive circuit 223, and the image sensor drive circuit 223 reads an image signal from the image sensor 221. The image sensor driving circuit 223 is connected to an ADC (Analogue Digital Converter) 225 that performs analog-digital conversion of an image signal. The output of the ADC 225 is connected to the dark current removal circuit 227. The dark current removal circuit 227 is a circuit for removing dark current generated in the image sensor 221 and corrects image data representing the subject image using the dark current generated in the light-shielding region around the image sensor 221. To do.

The dark current removal circuit 227 is an ASIC (Application Specific
Integrated Circuit Application Specific Integrated Circuit) 250 is connected to a data bus 252 in the circuit. The data bus 252 includes a sequence controller (hereinafter referred to as “body CPU”) 251, an image processing circuit 257, a compression / decompression circuit 259, a video signal output circuit 261, an SDRAM control circuit 265, an input / output circuit 271, and a communication circuit 273. A recording medium control circuit 275, a flash memory control circuit 279, and a switch detection circuit 283 are connected.

  The body CPU 251 connected to the data bus 252 controls the operation of this digital single lens reflex camera. The image processing circuit 257 connected to the data bus 252 is a variety of images such as digital amplification (digital gain adjustment processing) of digital image data, color correction, gamma (γ) correction, contrast correction, and live view display image generation. Perform processing. The compression / decompression circuit 259 is a circuit for compressing the image data stored in the SDRAM 267 by a compression method such as JPEG or TIFF, and decompressing the compressed image data. Note that image compression is not limited to JPEG or TIFF, and other compression methods can be applied.

  The video signal output circuit 261 is connected to the liquid crystal monitor 26 via the liquid crystal monitor drive circuit 263. The video signal output circuit 261 is a circuit for converting the image data stored in the SDRAM 267 and the recording medium 277 into a video signal for display on the liquid crystal monitor 26. As shown in FIG. 1, the liquid crystal monitor 26 is disposed on the back surface of the camera body 200. However, the liquid crystal monitor 26 is not limited to the back surface as long as the photographer can observe the image. .

  The SDRAM 267 is connected to the data bus 252 via the SDRAM control circuit 265, and the SDRAM 267 temporarily stores the image data processed by the image processing circuit 257 or the image data compressed by the compression / decompression circuit 259. This is a buffer memory.

  The input / output circuit 271 connected to the image sensor driving circuit 223, the shutter driving mechanism 237, the movable mirror driving mechanism 239, the photometry processing circuit 241, and the focus detection processing circuit 245 is connected to each of the body CPU 251 and the like via the data bus 252. Controls circuit and data input / output.

  The communication circuit 273 connected to the lens CPU 111 via the communication contact 300 is connected to the data bus 252 and exchanges data and communicates control commands with the body CPU 251 and the like. A recording medium control circuit 275 connected to the data bus 252 is connected to the recording medium 277 and controls recording of image data and the like on the recording medium 277 and reading of the image data and the like.

  The recording medium 277 can be loaded with any rewritable recording medium such as an xD picture card (registered trademark), a compact flash (registered trademark), an SD memory card (registered trademark), or a memory stick (registered trademark). And is detachable from the camera body 200. In addition, the hard disk may be configured to be connectable via a communication contact.

  The flash memory control circuit 279 is connected to a flash memory 281, and the flash memory 281 stores a program for controlling the operation of the digital single lens reflex camera, and the body CPU 251 stores the program in the flash memory 281. The digital single lens reflex camera is controlled according to the stored program. Note that the flash memory 281 is an electrically rewritable nonvolatile memory.

  1R switch that detects the first stroke (half press) of the release button 21, 2R switch that detects the second stroke (full press), power switch, menu switch linked to the menu button 37, and linked to the shooting mode dial 22 Various switches 285 including a dial switch, a dial switch interlocked with the information setting dial 24, and various switches interlocked with other operation members are connected to the data bus 252 via the switch detection circuit 283.

  Next, a configuration related to image display during exposure in bulb photography will be described with reference to FIG. The control unit 297 includes a body CPU 251 that controls the entire digital single lens reflex camera. The imaging unit 291 includes an imaging element 221, an imaging element drive circuit 223, an ADC circuit 225, a dark current removal circuit 227, and the like, and outputs image data based on the image signal. The output of the imaging unit 291 is connected to the addition calculation unit 292.

  The addition operation unit 292 includes a body CPU 251 and an image processing circuit 257. The addition calculation unit 292 inputs image data from the imaging unit 291 and inputs previous addition image data stored in the storage area of the addition image storage unit 293. The two are added together to generate a new added image, which is output to the added image storage unit 293. The added image storage unit 293 is configured by a temporary storage device such as the SDRAM 267, and has a large number of storage areas divided from the storage area A to the storage area nn. Is remembered.

  That is, the first image data is stored in the storage area A, and then when the image data is output from the imaging unit 291, the addition operation between the image data and the immediately preceding added image data stored in the storage area A The value is performed, and new added image data is stored in the storage area B. As described above, every time image data is output from the imaging unit 291, the addition image storage unit 293 performs addition calculation and sequentially stores the image data in the storage area in accordance with the control of the control unit 297.

  The image display unit 296 includes the liquid crystal monitor 26, the liquid crystal monitor drive circuit 263, and the like, and displays the image read from the addition image storage unit 293. The selection unit 298 is configured by the cross button 30, the OK button 31, and the like, and selects an image to be finally recorded from a plurality of subject images captured at the time of bulb photographing. The image recording unit 295 is configured by the storage medium 277 and records the image selected by the selection unit 298.

  Since it is configured in this manner, the control unit 297 causes the imaging unit 291 to output image data at the set update time interval, and the addition operation unit 292 is stored in the image data and the added image storage unit 293. Addition operation is performed on the immediately preceding addition value. In each storage area of the addition image storage unit 293, the addition value of the image data until each image data is output is sequentially stored.

  An image based on the image data stored in the added image storage unit 293 is displayed on the image display unit 296. Since the image data stored in the storage area A is the first exposure, it is an underexposed image as shown in FIG. 8A, and the image stored in the storage area B is the first image stored next. Since the exposure image data is added, the image data becomes slightly brighter as shown in FIG. Sequentially, each time image data is accumulated, the image becomes a little brighter, the image in the storage area D becomes close to the appropriate exposure as shown in FIG. 8D, and if the image data continues to accumulate, it is stored in the storage area G. As shown in FIG. 8G, an overexposed image is obtained.

  When shooting is finished, the image display unit 296 displays a list of images based on the image data stored in each storage area in a thumbnail display as shown in FIG. In the case immediately after the end of bulb shooting, the selection frame 311 shows an image corresponding to the latest shooting. The photographer moves the selection frame 311 to an image according to the photographer's intention from among the images displayed in the list by operating the cross button 30, and if the image is satisfactory, selects the image with the OK button 31. When an image is selected, the image is recorded on the recording medium 277.

  Next, details of the operation of the digital single-lens reflex camera according to the embodiment of the present invention will be described with reference to the flowcharts shown in FIGS. FIG. 4 shows a power-on reset operation by the body CPU 251 on the camera body 200 side. When a battery is loaded in the camera body 200, this flow starts, and it is determined whether the power switch of the camera body 200 is on (# 1).

  If the result of the determination is that the power switch is off, it enters a sleep state that is a state of low power consumption (# 3). In this sleep state, interrupt processing is performed only when the power switch is turned on, and processing for turning on the power switch is performed in step # 5 and subsequent steps. Until the power switch is turned on, operations other than power switch interrupt processing are stopped to prevent the power battery from being consumed. In step # 1, if the power switch is on, or if the sleep state is canceled in step # 3, power supply is started (# 5).

  Next, if there is information such as the shooting mode set by the shooting mode dial 22, the ISO sensitivity set by the information setting dial 24, the manually set shutter speed or aperture value, those shooting conditions, and lens information Reading is performed (# 7). The lens information is read from the lens CPU 111 via the communication circuit 273 such as lens-specific information such as the full aperture value and focal length information of the interchangeable lens 100. In this step, if the valve mode is set, this information is read.

  Subsequently, it is determined whether or not the valve mode is set (# 9). Since the shooting mode is read in step # 7, it is determined whether or not the bulb mode is set as the read shooting mode. As a result of the determination, if the bulb mode is not set, photometry / exposure amount calculation is performed (# 11). In this step, the subject brightness is measured by the photometric sensor 211, an exposure amount is calculated, and exposure control values such as a shutter speed and an aperture value are calculated according to the shooting mode and shooting conditions using the exposure amount.

  If the valve mode is set as a result of the determination in step # 9, an update time (cycle for repeatedly outputting image data) is input (# 31). The input of the update time will be described later with reference to FIG. When the input of the update time is finished, the process jumps to step # 13. In the bulb mode, since the shutter 213 is opened and closed by a user operation regardless of photometry, the photometry / exposure amount calculation in step # 11 is not executed.

  Next, shooting information is displayed on the liquid crystal monitor 26 (# 13). The shooting information includes the shooting mode and shooting conditions read in step # 7, and the shutter speed and aperture value exposure control values calculated in step # 11. When the bulb mode is set as the shooting mode, as shown in FIG. 10, a valve mode display 301 and an update time display 302 are displayed on the liquid crystal monitor 26 together with other shooting information.

  Once the shooting information is displayed, it is next determined whether or not the playback switch linked to the playback button 38 is on (# 17). The reproduction mode is a mode in which image data recorded on the recording medium 277 is read and displayed on the liquid crystal monitor 26 when the reproduction button 38 is operated. If the result of determination is that the regeneration switch is on, regeneration operation is executed (# 33).

  If the result of determination in step # 17 is that the playback switch is not on, it is determined whether or not the menu switch linked to the menu button 37 is on (# 19). In this step, it is determined whether the menu button 37 is operated and the menu mode is set. If the result of determination is that the menu switch is on, a menu is displayed on the liquid crystal monitor 26 and menu setting operation is performed (# 35). Various setting operations such as AF mode, white balance, ISO sensitivity setting, and drive mode setting can be performed by the menu setting operation.

  If the result of determination in step # 19 is that the menu switch is not on, it is determined whether or not the release button 21 has been pressed halfway, that is, whether or not the 1R switch is on. If the result of determination is that the 1R switch is on, a shooting operation subroutine for shooting preparation and shooting is executed (# 37). Details of this subroutine will be described later with reference to FIG.

  If the result of determination in step # 21 is that the 1R switch is not on, it is determined whether or not the power switch is on as in step # 1 (# 23). If the result of determination is that the power switch is on, processing returns to step # 7 and the above operation is repeated. On the other hand, if the power switch is not on, the power supply is stopped (# 25), the process returns to step # 3, and the above-described sleep state is entered.

  Next, the update time input operation in step # 31 will be described with reference to FIG. When this subroutine is entered, it is first determined whether or not the information setting dial 24 has been operated in order to input the update time (# 45). If the result of determination is that the information setting dial 24 has not been operated, processing returns to the original routine. On the other hand, if the information setting dial 24 has been operated, the switch detection circuit 283 detects the rotation direction (# 47).

  Subsequently, it is determined whether or not the detected rotation direction is a direction for reducing the update time (# 49). As a result of the determination, if the rotation direction decreases the update time, it is determined whether or not the previous update time has reached the lower limit value (# 51). The lower limit value may be set as appropriate, but may be about 0.1 seconds, for example. If the result of determination is that the lower limit has not been reached, the update time is shortened in a predetermined step in order from the current setting state (# 53). As shown in FIG. 10, the update time is displayed as the update display 302 in the shooting information on the liquid crystal monitor 26. Each time the information setting dial 24 is rotated to shorten the update time, for example, If the current setting state is the initial value of 30 seconds, it gradually decreases in a predetermined step from (c) in FIG. 11 toward the lower limit value in (a). This step may be appropriately determined in consideration of usability. When the update time is shortened, the original routine is restored.

  If the result of determination in step # 49 is not decreasing, it is determined whether or not the previous update time has reached the upper limit (# 55). The upper limit value may be set as appropriate. For example, the upper limit value may be 9 minutes as a time period that is not affected by the dark current. If the result of determination is that the upper limit has not been reached, the update time is extended in a predetermined step (# 57). Each time the information setting dial 24 is rotated in a direction to increase the update time, the information setting dial 24 gradually increases in a predetermined step from the current state toward the upper limit value in FIG. When the update time extension ends, the process returns to the original routine. This update time interval is an example and can be changed as appropriate.

  Next, the photographing operation in step # 37 will be described with reference to FIG. This subroutine starts when the 1R switch is turned on. First, the photographing information displayed on the liquid crystal monitor 26 is turned off (# 61). Subsequently, a subroutine for phase difference AF control is executed (# 63). In this subroutine, the focus shift direction and the focus shift amount of the photographing optical system 101 are detected by a known phase difference AF, and the drive control of the optical system drive mechanism 107 is performed based on the focus shift direction and the focus shift amount. The system 101 is focused.

  When the phase difference AF is completed, it is determined whether or not the valve mode is set as in step # 9 (# 65). If the bulb mode is not set as a result of the determination, photometry / exposure amount calculation is performed to determine exposure control values such as shutter speed and aperture value (# 67). On the other hand, if the valve mode is set as a result of the determination, step # 67 is skipped and the process proceeds to step # 69. In the bulb mode, as described above, the opening / closing time of the shutter 213 is determined by the photographer, and photometry and exposure amount calculation are unnecessary.

  Subsequently, it is determined whether the shutter button 21 has been fully pressed, that is, whether the 2R switch is on (# 69). If the result of determination is that the 2R switch is not on, it is determined whether or not the 1R switch is on (# 87). If the result of determination is that the 1R switch is not on, the shooting operation is terminated and processing returns to the original routine. On the other hand, if the result of determination is that the 1R switch is on, processing returns to step # 69 and enters a standby state for detecting the state of the 1R switch and 2R switch.

  If the result of determination in step # 69 is that the 2R switch is turned on, the routine proceeds to step for shooting. First, the movable mirror 201 is retracted (moved to the raised position) (# 71). As a result, the subject light flux by the photographing optical system 101 is guided in the direction of the image sensor 221. Subsequently, the lens CPU 111 is instructed to perform a narrowing operation, and the narrowing operation of the diaphragm 103 is executed (# 73).

  Now that the preparation for entering the normal photographing operation or the bulb photographing operation is completed, the exposure operation is started (# 75). In the exposure, the traveling of the front curtain of the shutter 213 is started and the charge accumulation of the image sensor 221 is started. When the time corresponding to the shutter speed obtained in step # 67 or the shutter speed manually set by the photographer has elapsed, the running of the rear curtain of the shutter 213 is started and the charge accumulation of the image sensor 221 is ended.

  Here, when the bulb mode is set, the shutter 213 is opened while the release button 21 is fully pressed, and during this time, the image sensor 221 repeatedly acquires image data at update time intervals. The added image based on the image data is displayed on the liquid crystal monitor 26 while being updated. Details of this exposure operation will be described later with reference to FIG.

  When the exposure operation ends, an instruction to open the diaphragm 103 is output to the lens CPU 111, the diaphragm 103 is opened (# 77), and the movable mirror 201 is returned to the lowered position (# 79). Subsequently, as in step # 65, it is determined whether or not the valve mode is set (# 81). As a result of the determination, if the valve mode is not set, image processing is performed on the data of the normal image or the added image that is read from the image sensor 221 and temporarily stored in the SDRAM 267 (# 81). The image data subjected to the image processing is recorded in the recording medium 277 (# 83), and the display of the image displayed on the liquid crystal monitor 26 is stopped (# 85). When the image display is stopped, the original routine is restored.

  If the result of determination in step # 81 is valve mode, a list of all added images is displayed (# 89). That is, based on the image data stored in each storage area of the added image storage unit 293, a list is displayed in thumbnail display as shown in FIG. Then, the latest image, that is, the last image taken is selected and the selection frame 311 is displayed (# 91).

  Next, it is determined whether or not the cross button 30 has been operated (# 93). If the cross button 30 has not been operated, the process jumps to step # 97. The selection frame 311 is moved to switch the selected image (# 95). Subsequently, it is determined whether or not the OK button 31 has been operated (# 97). If it has not been operated, the process returns to step # 93 to execute the above-described processing. On the other hand, if the OK button 31 has been operated, the image data of the selected image is read from the added image storage unit 293 (# 99). When the reading is finished, the process proceeds to step # 83 described above to execute the process.

  Next, the exposure operation in step # 75 will be described with reference to FIG. When this subroutine is entered, first, as in step # 9, it is determined whether or not the valve mode is set (# 101). If the valve mode is not set as a result of the determination, a normal shooting mode such as a program shooting mode is executed.

  As a normal shooting mode, first, a timer for measuring the exposure time is started (# 103), and when the shutter 213 is opened, the image sensor 221 starts imaging (# 105). That is, photoelectric conversion of the subject image formed on the image sensor 221 is performed, and signal charge accumulation is started. It is determined whether the exposure time (set time) corresponding to the shutter speed calculated in step # 67 or manually set has elapsed (# 107). As a result of the determination, when the exposure time has elapsed, the shutter 213 is closed and the imaging with the image sensor 221 is stopped (# 109).

  Subsequently, the image signal is read from the image sensor 221 (# 111), and the read image signal is temporarily stored in the SDRAM 267 (# 113). Based on the temporarily stored image signal, the captured image is displayed on the liquid crystal monitor 26 (# 115).

  If the result of determination in step # 101 is that the valve mode has been set, first, all of the added image storage areas prepared in the added image storage unit 293 are cleared (# 119), and manual operation is performed in step # 31. The input update time is set (# 120). Subsequently, a timer for updating the display update time is started (# 121), and as in step # 105, the shutter 213 is opened and imaging is started (# 123). Subsequently, the update time measuring timer determines whether or not the update time set in step # 120 has elapsed (# 125).

  As a result of the determination, if the update time has not elapsed, it is determined whether or not the release button 21 has been fully pressed, that is, whether or not the 2R switch has been turned off (# 151). When the 2R switch is on and the update time has not elapsed, the process enters a standby state in which step # 125 and step # 151 are repeatedly determined.

  As a result of the determination in step # 125, when the update time has elapsed, similarly to step # 109 and step # 111, the imaging of the image sensor 221 is stopped while the shutter 213 is open, and the image signal is read (# 127, # 129). Subsequently, the timer for update time measurement is restarted (# 131), and the image sensor 221 is started to image (# 133).

  Next, the addition image data is read from the storage area stored immediately before in the addition image storage unit 293, and the addition operation of this image data and the image data read in step # 129 is performed (# 135). The image data of the added image obtained here is stored in a storage area adjacent to the storage area read immediately before by the added image storage unit 293 (# 137). Subsequently, the stored added image is displayed on the liquid crystal monitor 26 (# 139), and the process returns to step # 125 to execute the above-described steps.

  If the result of determination in step # 151 is that the release button 21 has been fully pressed, that is, if it is determined that the 2R switch has been turned off, the shutter 213 is closed and imaging is stopped, as in step # 127. (# 153). That is, the exposure operation is terminated, and then the original routine is returned to.

  Thus, every time the update time set in step # 31 (# 120) elapses (# 125 → Y), imaging with the image sensor 221 is stopped, and image data is output, which is added to this image data. An added image with the immediately preceding added image stored in the storage area of the image storage unit 293 is obtained and sequentially stored. The added image stored in each storage area is updated and displayed on the liquid crystal monitor 26 as shown in FIG. 8 every time the update time elapses. When the update time elapses for the first time, since the exposure time is short, the entire image is dark. However, every time the update time elapses, image data is cumulatively added, so that the image gradually becomes brighter.

  As described above, in the present embodiment, when the bulb mode is set, the imaging operation is repeated at the update time interval during the bulb photographing operation, and the obtained image data and the past added image data are added and calculated. The added image data is stored independently in the added image storage unit 293, and can be selected from a plurality of added images after photographing. For this reason, an image with an appropriate exposure level can be obtained after photographing.

  In the present embodiment, the added images are displayed as a list on the liquid crystal monitor 26. For this reason, it is possible to compare the individual added images and easily select an image in accordance with the photographer's intention. Furthermore, in the present embodiment, the cycle (update time) for repeatedly obtaining the imaging output from the imaging unit 291 is variable, and thus can be set to an optimum cycle according to the characteristics of the subject image. Further, in the present embodiment, since the added image is displayed in accordance with the progress of exposure during exposure, it is convenient to determine the timing for ending the shooting in bulb shooting.

  In the present embodiment, when the exposure operation is terminated, when imaging is stopped in step # 153 (FIG. 7), the process returns to the original routine. However, at this time, since the signal charge is accumulated in the image sensor 221, the image capturing unit 291 may read this signal, generate an added image, and display the added image.

  In the present embodiment, the addition image is generated when the valve mode is set. However, when the exposure is performed for a long time, for example, when the exposure is performed for a long time, the addition image is displayed. It may be generated and displayed.

  Further, in the present embodiment, when the valve mode is set, the release button 21 is fully pressed, and the shutter is opened until the full press is released, that is, while the 2R switch is on, and the imaging operation is performed. Had gone. However, other than this method, for example, the imaging operation is started when the release button 21 is fully pressed (first release operation), and the imaging operation is continued even when the release button 21 is fully released, and again. The imaging operation may be stopped when the release button 21 is fully pressed (second release operation performed after the first release operation).

  Furthermore, in the present embodiment, an added image is displayed to indicate the exposure level during exposure. However, if it is sufficient to use it for finally selecting an image, the added image during exposure is displayed. May be omitted. Furthermore, in this embodiment, the image selected in steps # 97 and # 99 is read. However, the selected image is not limited to one, and a plurality of added images may be read.

  Furthermore, in the present embodiment, the update time is set manually in step # 31. However, the update time is not limited to this. For example, when the brightness is high, the update time is shortened according to the brightness of the subject. On the contrary, when the luminance is low, it is of course possible to automatically set the update time, for example.

Furthermore, in the present embodiment, an example in which a single-lens reflex type is applied as a digital camera has been described. However, the present invention may be a digital camera such as a compact type other than a single-lens reflex type, and may be a mobile phone or a personal digital assistant (PDA). Personal
Of course, a camera built into Digital Assist) may be used. The present invention can be applied to any imaging apparatus capable of shooting in bulb mode or long time.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the gist thereof in the implementation stage. . In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, you may delete some components of all the components shown by embodiment.

It is the external appearance perspective view which looked at the digital single-lens reflex camera concerning one Embodiment of this invention from the back. 1 is a block diagram illustrating an overall configuration of an electric system of a digital single-lens reflex camera according to an embodiment of the present invention. In the digital single-lens reflex camera concerning one Embodiment of this invention, it is the block diagram which extracted and showed the structure relevant to imaging and display, such as a valve mode. It is a flowchart which shows the operation | movement of the power-on reset in one Embodiment of this invention. It is a flowchart which shows the operation | movement of the update time input in one Embodiment of this invention. It is a flowchart which shows the imaging | photography operation | movement in one Embodiment of this invention. It is a flowchart which shows the exposure operation | movement in one Embodiment of this invention. It is a figure which shows the display at the time of valve | bulb mode imaging | photography in one Embodiment of this invention, (a) to (g) shows the display which changes with progress of update time. It is a figure which shows the list display of the full addition image at the time of completion | finish of valve | bulb mode imaging | photography in one Embodiment of this invention, (a) is a list display immediately after completion | finish of imaging | photography, (b) is a list display at the time of selection. It is a figure which shows the imaging | photography information display of the digital single-lens reflex camera concerning one Embodiment of this invention. It is a figure which shows the update display of the digital single-lens reflex camera concerning one Embodiment of this invention, (a) to (e) shows the display of each different update time.

Explanation of symbols

21 ... Release button, 22 ... Shooting mode dial, 24 ... Information setting dial, 26 ... LCD monitor, 27 ... Continuous / single-shot button, 28 ... AF lock button, 30 ... Cross button, 30U ... Cross button for up, 30D ... Cross button for down, 30R ... Cross button for right, 30L ... Cross button for left, 31 ... OK button, 33 ..Live view display button 34... Enlarge button 37. Menu button 38. Play button 40. Media loading lid 50. Strobe 100. Interchangeable lens 101 ... Imaging optical system, 103. Diaphragm, 107... Optical system drive mechanism, 109... Diaphragm drive mechanism, 111. 203 ... submirror, 205 ... focusin Screen, 207... Pentaprism, 211... Photometric sensor, 213... Focal plane shutter, 217... Infrared cut filter / low pass filter, 221. Circuit, 225 ... ADC circuit, 227 ... dark current elimination circuit, 237 ... shutter drive mechanism, 239 ... movable mirror drive mechanism, 241 ... photometric processing circuit, 243 ... focus detection sensor 245: focus detection processing circuit, 250: ASIC, 251 ... sequence controller (body CPU), 252 ... data bus, 257 ... image processing circuit, 259 ... compression / decompression circuit, 261 ... Video signal output circuit, 263 ... Liquid crystal monitor drive circuit, 265 ... SDRAM detection circuit, 267 ... S RAM, 271 ... I / O circuit, 273 ... communication circuit, 275 ... recording medium control circuit, 277 ... recording medium, 279 ... flash memory control circuit, 281 ... flash memory, 283 ... switch detection circuit, 285 ... various switches, 291 ... imaging unit, 292 ... addition operation unit, 293 ... addition image storage unit, 295 ... image recording unit, 296 ... Image display unit, 297 ... control unit, 298 ... selection unit, 300 ... communication contact, 301 ... valve mode display, 302 ... update time display, 311 ... selection frame

Claims (8)

An imaging unit that repeatedly captures a subject image at a set period and outputs image data during bulb photographing operation;
Each time the image data is output, an addition operation unit that performs addition operation with past image data,
An addition image storage unit for sequentially storing the addition images calculated by the addition calculation unit;
A selection unit that selects one of a plurality of addition image data stored in the addition image storage unit after the bulb photographing operation is completed;
An image pickup apparatus comprising:   The selection unit includes an operation member that can be manually operated, and a display unit that displays a list of thumbnail images corresponding to a plurality of addition image data stored in the addition image storage unit. 2. The imaging apparatus according to claim 1, wherein when any one of the thumbnail images is selected, any one of a plurality of added image data stored in the added image storage unit is selected accordingly.   The imaging apparatus according to claim 1, wherein the period is variable and is manually set.   The imaging apparatus according to claim 1, further comprising a display unit that displays the addition image calculated by the addition calculation unit each time the image data is output.   The imaging unit according to claim 1, wherein the imaging unit repeatedly captures the subject image in response to a first operation of the release button, and stops the imaging in response to a second operation of the release button. Imaging device. An imaging unit that repeatedly captures a subject image at a set period and outputs image data during bulb photographing operation;
An addition operation unit for performing an addition operation of the image data and image data output in the past;
An addition image storage unit that independently stores a plurality of addition images calculated by the addition calculation unit;
A display unit for displaying a plurality of added images stored in the added image storage unit in a list display after the bulb photographing operation is completed;
An image pickup apparatus comprising: A selection unit that selects any one of the plurality of addition images displayed on the display unit;
An image recording unit for recording the added image selected by the selection unit;
The imaging apparatus according to claim 6, further comprising: During bulb shooting operation, the subject image is repeatedly taken at the set cycle to obtain image data,
Each time the image data is output, it is added to the past image data and sequentially stored,
After completion of the bulb photographing operation, select any one of the plurality of stored additional image data,
A method for controlling an imaging apparatus, wherein the selected addition image data is recorded on a recording medium.