JP2008270987A - Image pickup device and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably acquire an image which is appropriately bright in the case of taking a photograph by using a flash by an image pickup device using an image pickup element. <P>SOLUTION: This image pickup device (100) for performing image pickup by using a flash (400) is provided with: an image pickup element (14) for converting incident rays of light into an electric signal, and for outputting image data; photometric means (7, 14, 16, 20); a system controller (50) for obtaining emitted light quantity by which the flash is made to emit the rays of light according to the photometric result of the photometric means; and an image processing circuit (20) for correcting the luminance level of image data acquired by the image pickup element by making the flash emit the rays of light so that a difference between actual emitted light quantity in the case of making the flash emit the rays of light based on the emitted light quantity obtained by the system controller and the emitted light quantity obtained by the system controller can be compensated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging apparatus and a control method thereof, and more particularly to an imaging apparatus capable of performing flash photography and a control method thereof.

  In recent years, digital cameras using an image sensor such as a CCD or CMOS sensor have been widely used as image recording means instead of silver salt films. Since these image sensors have a characteristic that the latitude is narrower than that of a silver salt film, particularly a negative film, exposure control with higher accuracy is required.

  The accuracy of this exposure control is determined according to factors such as the accuracy of metering control of the metering system for metering subject brightness, the accuracy of shutter control for controlling exposure time, and the accuracy of aperture control for controlling the amount of light. It is what is done.

  On the other hand, the accuracy of exposure control in the case of flash photography is determined including the controllability of the flash. As an example of the flash control method, Patent Document 1 discloses the following method. First, during pre-emission, an integrated value of the light emission amount of the xenon tube is obtained, and the reflected light from the subject that is pre-emission is measured to determine whether the appropriate amount of light is excessive or insufficient. At the time of the main light emission, when the integral value obtained by adding the integral value at the time of the pre-light emission and the excess / deficiency amount with the appropriate light amount is reached, the light emission of the xenon tube is stopped to obtain an image with the appropriate light emission amount.

Japanese Patent Laid-Open No. 09-061898

  However, in the above-described flash control method, the exposure during flash shooting is caused by overshoot until the xenon tube stops emitting light after the xenon tube stops emitting light after the desired amount of light is emitted during the main flash. Variation in quantity occurs. As a result, there has been a problem in that the brightness of images taken with flash varies. In particular, in a digital camera, since the latitude of the image sensor is narrow as described above, this slight variation in the amount of emitted light also becomes a problem.

  The present invention has been made in view of the above problems, and an imaging apparatus of the present invention capable of imaging using a light-emitting device includes an imaging unit that converts incident light into an electrical signal and outputs image data, and photometry Means for calculating the amount of light emitted by the light-emitting device according to the photometric result of the light-measuring means, and actual light emission when the light-emitting device is caused to emit light based on the light-emission amount obtained by the calculating means. Correction means for correcting the luminance level of the image data obtained from the imaging means by causing the light emitting device to emit light so as to compensate for the difference between the light emission quantity and the light emission quantity obtained by the calculation means;

  Further, the control method of the present invention for an imaging device that can be imaged using a light emitting device, converts incident light into an electrical signal, and outputs image data, and a photometric unit, includes the photometric unit. A calculation step of obtaining a light emission amount to be emitted to the light emitting device according to a photometric result by the imaging step, and an imaging step of performing imaging by the imaging unit while causing the light emission device to emit light based on the light emission amount obtained in the calculation step And a calculation step for measuring an actual light emission amount of the light emitting device in the imaging step, and a calculation for calculating a difference between the actual light emission amount measured in the measurement step and the light emission amount obtained in the calculation step And a correction step of correcting the luminance level of the image data obtained by imaging in the imaging step so as to compensate for the difference obtained in the calculation step and the calculation step.

  When an image capturing apparatus using an image sensor is used to capture an image using a light emitting device, an image with appropriate brightness can be stably acquired.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram illustrating a configuration of an imaging system according to an embodiment of the present invention.

  As shown in FIG. 1, the imaging system of the present embodiment mainly includes a camera body 100, an interchangeable lens type lens unit 200, and an external flash 400 that is a light emitting device. It is possible to capture images.

  First, the configuration of the camera body 100 will be described.

  In the figure, reference numeral 1 denotes a main mirror, which is obliquely installed in the photographing optical path in the viewfinder observation state and retracts out of the photographing optical path in the photographing state. Further, the main mirror 1 is a half mirror, and when it is obliquely arranged in the photographing optical path, it transmits about half of the light beam from the subject to the focus detection unit 8 described later.

  2 is a focusing plate disposed on a planned imaging surface of a focus lens 201, which will be described later, constituting a finder optical system, 3 is a sub-mirror, and is obliquely installed in the photographing optical path together with the main mirror 1 in the finder observation state. In the photographing state, the evacuation is out of the photographing optical path. The sub-mirror 3 bends the light beam transmitted through the oblique main mirror 1 downward and guides it toward a focus detection unit 8 described later.

  Reference numeral 4 denotes a pentaprism for changing the finder optical path. Reference numeral 5 denotes an eyepiece, and the photographer can confirm the photographing screen by observing the focus plate 2 from the eyepiece 5. This state is referred to as an optical viewfinder mode (OVF mode). Reference numerals 6 and 7 are an imaging lens for measuring the luminance of the object in the viewfinder observation screen and a photometric sensor which is an example of a photometric means, and has a known logarithmic compression circuit inside, and its output is logarithmically compressed. It will be a thing.

  A focus detection unit 8 detects a focus adjustment state of the lens unit 200 by a known so-called phase difference detection method.

  Reference numeral 9 denotes a focal plane shutter, and reference numeral 14 denotes an imaging device such as a CCD or CMOS sensor, which is an example of an imaging unit that converts incident light into an electrical signal and outputs image data.

  Reference numeral 16 denotes an A / D converter that converts an analog signal output from the image sensor 14 into a digital signal. A timing generation circuit 18 supplies a clock signal and a control signal to the image sensor 14, the A / D converter 16, and the D / A converter 26, respectively, and is controlled by the memory control circuit 22 and the system controller 50.

  An image processing circuit 20 performs predetermined pixel interpolation processing, color conversion processing, and luminance level conversion processing on the data from the A / D converter 16 or the data from the memory control circuit 22. In addition, the image processing circuit 20 performs predetermined calculation processing using the image data output from the A / D converter 16, and also performs TTL auto white balance (AWB) processing based on the obtained calculation result. ing.

  A memory control circuit 22 controls the A / D converter 16, the timing generation circuit 18, the image processing circuit 20, the image display memory 24, the D / A converter 26, the memory 30, and the compression / decompression circuit 32. Image data output from the A / D converter 16 is written into the image display memory 24 or the memory 30 via the image processing circuit 20, the memory control circuit 22, or only through the memory control circuit 22.

  Reference numeral 24 denotes an image display memory, 26 denotes a D / A converter, and 28 denotes an image display unit made up of a TFT type LCD or the like. Display image data written in the image display memory 24 is stored in the D / A converter 26. Via the image display unit 28. An electronic viewfinder (EVF) function can be realized by sequentially displaying the captured image data using the image display unit 28 with the main mirror 1 and the sub mirror 3 up and the shutter 9 opened. . Hereinafter, this state is referred to as an electronic viewfinder mode (EVF mode).

  Reference numeral 30 denotes a memory for storing captured still images and moving images, and has a storage capacity sufficient to store a predetermined number of still images and a moving image for a predetermined time. This makes it possible to write a large amount of images to the memory 30 at high speed even in continuous shooting or panoramic shooting in which a plurality of still images are continuously shot. The memory 30 can also be used as a work area for the system controller 50.

  A compression / decompression circuit 32 compresses / decompresses image data using a known compression method such as adaptive discrete cosine transform (ADCT). The compression / decompression circuit 32 reads an image stored in the memory 30, performs a compression process or an expansion process, and writes the processed data to the memory 30 again.

  A shutter control unit 40 controls the focal plane shutter 9 and controls the shutter 9 in cooperation with a diaphragm control unit 205 that controls the diaphragm 204 based on photometric information from the photometric sensor 7. A mirror control unit 41 includes a motor and a drive circuit for moving the main mirror 1 up and down.

  Reference numeral 50 denotes a system controller that controls the entire camera body 100 and incorporates a known CPU and the like. A memory 52 stores constants, variables, programs, and the like for operating the system controller 50.

  Reference numeral 54 denotes a notification unit for notifying the outside of an operation state, a message, and the like using characters, images, sounds, and the like in accordance with execution of a program by the system controller 50. As the notification unit 54, for example, a display unit that performs visual display using an LCD, an LED, or the like, or a sound generation element that performs voice notification, etc., is used, and the notification unit 54 is configured by a combination of one or more of these. In particular, in the case of the display unit, it is installed at one or a plurality of locations near the operation unit 70 of the camera body 100 that are easy to see. In addition, the notification unit 54 has a part of the function installed in the lower part of the focus plate 2.

  Among the display contents of the notification unit 54, the following are displayed on the LCD or the like. First, there are displays relating to shooting modes such as single-shot / continuous-shot shooting display and self-timer display. In addition, there are displays relating to recording such as compression rate display, recording pixel number display, recording number display, and remaining image number display. In addition, there are displays relating to shooting conditions such as shutter speed display, aperture value display, exposure correction display, flash display, and red-eye reduction display. In addition, there are a macro shooting display, a buzzer setting display, a clock battery remaining amount display, a battery remaining amount display, an error display, an information display with a multi-digit number, and a recording medium 120 attachment / detachment state display. Furthermore, the attachment / detachment state display of the lens unit 200, the communication I / F operation display, the date / time display, the display indicating the connection state with the external computer, and the like are also performed.

  In addition, among the display contents of the notification unit 54, examples of what is displayed below the focus plate 2 include the following. In-focus display, photographing preparation completion display, camera shake warning display, flash charge display, flash charge completion display, shutter speed display, aperture value display, exposure correction display, recording medium writing operation display, and the like.

  Further, among the display contents of the notification unit 54, examples of what is displayed by an LED or the like include the following. In-focus display, shooting preparation completion display, camera shake warning display, flash charge display, flash charge completion display, recording medium writing operation display, macro shooting setting notification display, secondary battery charge display, and the like.

  Further, among the display contents of the notification unit 54, what is displayed on the lamp or the like includes, for example, a self-timer notification lamp. This self-timer notification lamp may be shared with the AF auxiliary light.

  Reference numeral 56 denotes an electrically erasable / recordable non-volatile memory in which programs and the like to be described later are stored. For example, an EEPROM or the like is used.

  Reference numerals 60, 62, 64, 66, 68, and 70 are operation means for inputting various operation instructions of the system controller 50. One or a plurality of switches, dials, touch panels, pointing by line-of-sight detection, voice recognition devices, or the like. Consists of

  Here, a specific description of these operating means will be given.

  Reference numeral 60 denotes a mode dial switch, which can switch and set each function mode such as power-off, shooting mode (still image shooting mode, moving image shooting mode), playback mode, erase mode, PC connection mode, and the like.

  Reference numeral 62 denotes a shutter switch SW1, which is turned on during the operation of a shutter button (not shown) (for example, half-pressed), and instructs to start operations such as AF processing and AE processing.

  A shutter switch SW2 64 is turned on when a shutter button (not shown) is completed (for example, fully pressed), and instructs the start of a series of processes including exposure processing, development processing, and recording processing. First, in the exposure process, the signal read from the image sensor 14 is written into the memory 30 via the A / D converter 16 and the memory control circuit 22, and further the calculation in the image processing circuit 20 and the memory control circuit 22 is performed. Development processing using is performed. Further, in the recording process, the image data is read from the memory 30, compressed by the compression / decompression circuit 32, and written to the recording medium 120.

  Reference numeral 66 denotes a finder mode setting switch, which selects either the OVF mode or the EVF mode at the time of shooting. When the EVF mode is set, the main mirror 1 and the sub mirror 3 are retracted from the photographing optical path, the shutter 9 is opened, and images picked up by the image pickup device 14 are sequentially displayed on the image display unit 28.

  Reference numeral 68 denotes a quick review ON / OFF switch, which sets ON / OFF of a so-called “quick review” function for automatically reproducing image data taken immediately after photographing for a predetermined time. In the present embodiment, it is assumed that a function for setting a quick review function when the image display unit 28 is turned on is provided.

  An operation unit 70 includes various buttons and a touch panel. For example, the menu button, set button, macro button, multi-screen playback pagination button, flash setting button, single shooting / continuous shooting / self-timer switching button, menu movement + (plus) button, menu movement-(minus) button Including. Further, a playback image movement + (plus) button, a playback image movement-(minus) button, a shooting image quality selection button, an exposure correction button, a date / time setting button, and the like are also included. The functions of the plus button and the minus button can be selected more easily with numerical values and functions by providing a rotary dial switch. Also included is an ISO sensitivity setting button that can set the ISO sensitivity by changing the gain setting in the image sensor 14 or the image processing circuit 20.

  Reference numeral 80 denotes a power control unit, which includes a battery detection circuit, a DC-DC converter, a switch circuit that switches a block to be energized, and the like. The power supply control unit 80 detects the presence / absence of a battery, the type of battery, the remaining battery level, controls the DC-DC converter based on the detection result and an instruction from the system controller 50, and supplies a necessary voltage for a necessary period. , And supplied to each unit including the recording medium.

  Reference numerals 82 and 84 denote connectors, 86 denotes a primary battery such as an alkaline battery or lithium battery, a secondary battery such as a NiCd battery, NiMH battery, Li-ion battery, or Li polymer battery, an AC adapter, or the like.

  Reference numeral 90 denotes an interface with a recording medium such as a memory card or hard disk, and reference numeral 92 denotes a connector for connecting to a recording medium such as a memory card or hard disk. A recording medium attachment / detachment detection circuit 98 detects whether or not the recording medium 120 is attached to the connector 92.

  Although the present embodiment has been described as having one interface and connector for attaching the recording medium, the interface and connector for attaching the recording medium may have a single or plural number of systems. . Moreover, it is good also as a structure provided with combining the interface and connector of a different standard.

  As the interface and the connector, it is possible to configure using interfaces that comply with various storage medium standards. For example, a PCMCIA (Personal Computer Memory Card International Association) card, a CF (Compact Flash (registered trademark)) card, an SD card, or the like. When the interfaces 90 and 94 and the connectors 92 and 96 are configured using a standard conforming to a PCMCIA card, a CF (registered trademark) card, or the like, various communication cards can be connected. Communication cards include LAN cards, modem cards, USB (Universal Serial Bus) cards, and IEEE (Institute of Electrical and Electronic Engineers) 1394 cards. In addition, there are P1284 card, SCSI (Small Computer System Interface) card, PHS, and the like. By connecting these various communication cards, image data and management information attached to the image data can be transferred to and from other computers and peripheral devices such as a printer.

  A communication unit 72 has various communication functions such as RS232C, USB, IEEE1394, P1284, SCSI, modem, LAN, and wireless communication. Reference numeral 73 denotes a connector for connecting the camera body 100 to another device by the communication unit 72 or an antenna in the case of wireless communication.

  Reference numeral 120 denotes a recording medium such as a memory card or a hard disk. The recording medium 120 includes a recording unit 122 composed of a semiconductor memory, a magnetic disk, or the like, an interface 124 with the camera body 100, and a connector 126 for connecting with the camera body 100.

  As the recording medium 120, a memory card such as a PCMCIA card or compact flash (registered trademark), a hard disk, or the like can be used. Of course, it may be constituted by a micro DAT, a magneto-optical disk, an optical disk such as CD-R or CD-WR, a phase change optical disk such as DVD, or the like.

  399 is a communication line group that communicates between a lens unit 200 described later and the system controller 50 of the camera body 100, and 499 is a communication line group that communicates between an external flash 400 described later and the system controller 50 of the camera body 100. It is.

  Next, the configuration of the lens unit 200 will be described.

  A focus lens 201 forms a subject image on the image sensor 14 and performs focus adjustment, and a focus drive actuator 202 drives the focus lens 201 in the optical axis direction to focus. A focus control unit 211 controls the focus driving actuator 202 based on a command from the lens control microcomputer 206.

  A distance detection unit 203 includes an encoder for detecting a subject distance from the position of the focus lens 201, a diaphragm 204 for adjusting the amount of light during photographing, and a diaphragm drive actuator 250. A diaphragm control unit 205 controls the diaphragm drive actuator 250 based on a command from the lens control microcomputer 206.

  Reference numeral 207 denotes a zooming lens for adjusting the focal length for zooming. Reference numeral 208 denotes a zoom drive actuator for adjusting the focal length by driving the zooming lens 207 in the optical axis direction. A zoom control unit 212 controls the zoom drive actuator 208.

  Reference numeral 206 denotes a lens control microcomputer that controls the above-described focus drive, aperture drive, and the like, and controls communication with the system controller 50 on the camera body 100 side.

  The lens unit 200 is detachably attached to the camera body 100 via a lens mount 209, and is electrically connected to the camera body 100 by a connector 210 including a serial communication line and a power source.

  In the above description, the lens interchangeable single-lens reflex digital camera is described. However, a so-called digital compact camera in which a lens and a lens barrel are integrated with the main body may be used.

  Next, the configuration of the flash 400 of the present invention will be described with reference to FIG. The flash 400 is connected to the camera body at the contact point between the hot shoes 450 and 451.

  In FIG. 2, 401 is a power source battery, 402 is a DC / DC converter, and boosts the battery voltage to several hundred volts. Reference numeral 403 denotes a main capacitor for accumulating light emission energy. Reference numerals 404 and 405 denote resistors, which divide the voltage of the main capacitor 403 into a predetermined ratio. Reference numeral 406 denotes a coil for limiting the light emission current, reference numeral 407 denotes a diode for absorbing a counter electromotive voltage generated when light emission is stopped, and reference numeral 410 denotes a xenon (Xe) tube used as a light emitting element. Reference numeral 411 denotes a trigger generation circuit, and 412 denotes a light emission control circuit such as an IGBT (insulated gate bipolar transistor).

  A data selector 430 selects one of D0, D1, and D2 and outputs it to Y by a combination of two types of inputs Y0 and Y1. Reference numeral 431 denotes a light emission level control comparator for flat light emission, and reference numeral 432 denotes a light emission amount control comparator for flash light emission.

  A photodiode 435 is a light receiving sensor for controlling flat light emission, and photoelectrically converts light from the xenon tube 410. Reference numeral 434 denotes a photometric circuit that amplifies the photoelectrically converted minute current flowing through the photodiode 435 and converts the photocurrent into a voltage.

  A photodiode 438 is a light receiving sensor for controlling flash emission, and photoelectrically converts light from the xenon tube 410. Reference numeral 436 denotes an integral photometry circuit for logarithmically compressing the photoelectrically converted photocurrent flowing through the photodiode 438 and compressing and integrating the light emission amount of the xenon tube 410.

  Reference numeral 440 denotes a flash control microcomputer that controls the operation of the flash 400 as a whole, and reference numeral 411 denotes a contact group provided on the hot shoe to communicate with the camera body 100.

  Next, each terminal of the flash control microcomputer 440 will be described. CNT is a control output terminal for controlling charging of the DC / DC converter 402, and CLK is an input terminal for a synchronous clock for serial communication with the camera body 100. DO is a serial output terminal for transferring serial data from the flash 400 to the camera body 100 in synchronization with the synchronization clock. DI is a serial data input terminal for transferring serial data from the camera body 100 to the flash 400 in synchronization with the synchronization clock. CHG is an output terminal for transmitting whether or not the xenon tube 410 can emit light from the flash 400 to the camera body 100, and X is an input terminal to which a flash emission command from the camera body 100 is input.

  INT is an integration control output terminal of the integral photometry circuit 436, AD0 is an A / D conversion input terminal for reading an integral voltage indicating the light emission amount from the integral photometry circuit 436, and DA0 outputs a comparator voltage of the comparators 431 and 432. This is a D / A output terminal.

  Y0 and Y1 are output terminals in a selected state of the data selector 430, and TRIG is an output terminal of a light emission trigger.

  In the above description, the flash 400 has been described as being externally attached, but may be configured to be integrated with the main body.

<First Embodiment>
Next, operations in the first embodiment of the imaging apparatus having the above configuration will be described with reference to FIGS.

  3 and 4 are flowcharts of the main routine of the camera body 100 in the first embodiment. The operation of the system controller 50 will be described below with reference to FIG.

  In FIG. 3, the system controller 50 initializes a flag, a control variable, etc. by power-on such as battery replacement (step S101), and initializes the image display of the image display unit 28 to an OFF state (step S102). In step S103, the system controller 50 determines the set position of the mode dial 60. If the mode dial 60 is set to power OFF, the system controller 50 changes the display of each display unit to the end state, and sets necessary parameters, setting values, and setting modes including flags and control variables to nonvolatile. Record in memory 56. Further, the system controller 50 performs a predetermined end process such as shutting off unnecessary power of each part of the camera body 100 including the image display unit 28 by the power control unit 80 (step S105), and then returns to step S103.

  If the mode dial 60 is set to the shooting mode in step S103, the process proceeds to step S106.

  If the mode dial 60 is set to another mode in step S103, the system controller 50 executes processing according to the selected mode (step S104), and returns to step S103 when the processing is completed. .

  In step S <b> 106, the system controller 50 determines whether there is a problem in the operation of the camera body 100 due to the remaining capacity and operation status of the power supply 86 configured by a battery or the like by the power supply control unit 80. If there is a problem (NO in step S106), a predetermined warning is given by image or sound using the notification unit 54 (step S108), and the process returns to step S103.

  On the other hand, if there is no problem with the power supply 86 (YES in step S106), the system controller 50 determines whether the operation state of the recording medium 120 is a problem with the operation of the camera body 100, particularly with respect to the recording / reproducing operation of the image data with respect to the recording medium 120. Judge whether or not. If there is a problem (NO in step S107), a predetermined warning is given by image or sound using the notification unit 54 (step S108), and the process returns to step S103.

  If there is no problem in the operation state of the recording medium 120 (YES in step S107), the notification unit 54 is used to notify various setting states of the camera body 100 using images and sounds (step S109). The image display of the image display unit 28 may be turned on, and the image display unit 28 may also be used to notify various setting states of the camera body 100 using images and sounds.

  Next, the system controller 50 checks the setting state of the quick review ON / OFF switch 68 (step S110). If the quick review flag is set to ON, the quick review flag is set (step S111). If the quick review flag is set to OFF, the quick review flag is canceled (step S112). The state of the quick review flag is stored in the internal memory of the system controller 50 or the memory 52.

  Subsequently, the system controller 50 checks the setting state of the finder mode setting switch 66 (step S113). If the EVF mode has been set, the EVF flag is set (step S114), and EVF is started (step S115). At this time, when the EVF mode is not set, that is, when the main mirror 1 and the sub mirror 3 are down and the shutter 9 is closed, the main mirror 1 and the sub mirror 3 are driven up via the mirror control unit 41. Further, the shutter control unit 40 is controlled to open the shutter 9 to form a subject image incident on the image sensor 14 via the lens unit 200, and the image display of the image display unit 28 is set to the ON state. Furthermore, the captured image data is set to a through display state in which the image data is sequentially displayed (step S116), and the process proceeds to step S119 in FIG. In the through display state, the data sequentially written in the image display memory 24 via the image sensor 14, the A / D converter 16, the image processing circuit 20, and the memory control circuit 22 are transferred to the memory control circuit 22, D The images are sequentially displayed by the image display unit 28 via the / A converter 26. In this way, the EVF function is realized.

  On the other hand, if the viewfinder mode setting switch 66 is set to the OVF mode in step S113, the EVF flag is canceled (step S117), and OVF is started (step S118). If the OVF mode is not set at this time, that is, if the main mirror 1 and the sub mirror 3 are up and the shutter 9 is open, the main mirror 1 is driven down via the mirror control unit 41. Further, the shutter control unit 40 is controlled to close the shutter 9 and set to function as an optical viewfinder, the image display of the image display unit 28 is turned off, and the process proceeds to step S119 in FIG. As described above, when the OVF mode is set, shooting is performed using the optical viewfinder without using the EVF function of the image display unit 28.

  The state of the EVF flag set in step S114 or S117 is stored in the internal memory of the system controller 50 or the memory 52.

  If the shutter switch SW1 is not pressed in step S119, the process returns to step S103. If the shutter switch SW1 is pressed, the system controller 50 determines the state of the EVF flag stored in the internal memory or the memory 52 (step S120). If the EVF flag is set, the display state of the image display unit 28 is set to a freeze display state (step S121), and the process proceeds to step S122.

  In the freeze display state, rewriting of image data in the image display memory 24 via the image sensor 14, A / D converter 16, image processing circuit 20, and memory control circuit 22 is prohibited. The image data written last is displayed on the image display unit 28 via the memory control circuit 22 and the D / A converter 26, thereby displaying the frozen video.

  On the other hand, if the EVF flag has been canceled in step S120, the process proceeds directly to step S122.

  In step S122, focus adjustment processing is performed to focus the focus lens 201 on the subject, and photometry processing is performed to determine the aperture value and shutter speed. As a result of photometry, if necessary, the flash flag is set and the flash is set. Details of the focus adjustment / photometry processing performed in step S122 will be described later with reference to FIG.

  When the focus adjustment / photometry process (step S122) is completed, the system controller 50 determines the state of the EVF flag stored in the internal memory or the memory 52 (step S123). If the EVF flag is set, the display state of the image display unit 28 is set to the through display state (step S124), and the process proceeds to step S125. Note that the through display state in step S124 is the same operating state as the through state in step S116.

  On the other hand, if the EVF flag has been canceled in step S123, the process proceeds directly to step S125.

  If the shutter switch SW2 is not pressed (OFF in step S125) and the shutter switch SW1 is also released (OFF in step S126), the process returns to step S103.

  If the shutter switch SW2 is pressed (ON in step S125), the system controller 50 determines the state of the EVF flag stored in the internal memory of the system controller 50 or the memory 52 (step S127). If the EVF flag is set, the display state of the image display unit 28 is set to the fixed color display state (step S128), and the process proceeds to step S129.

  In the fixed color display state, the image data written in the image display memory 24 via the image sensor 14, the A / D converter 16, the image processing circuit 20, and the memory control circuit 22 is replaced with fixed color image data. The replaced fixed color image data is displayed on the image display unit 28 via the memory control circuit 22 and the D / A converter 26, thereby displaying a fixed color video.

  On the other hand, if the EVF flag has been canceled in step S127, the process proceeds directly to step S129.

  In step S129, the system controller 50 executes a photographing process including an exposure process and a development process. In the exposure process, the image was taken in the memory 30 via the image sensor 14, the A / D converter 16, the image processing circuit 20, the memory control circuit 22, or directly from the A / D converter 16 via the memory control circuit 22. Write image data. In the development process, the image data written in the memory 30 is read out and various processes are performed using the memory control circuit 22 and, if necessary, the image processing circuit 20. Details of the photographing process in step S129 will be described later with reference to FIGS.

  When the photographing process ends, the process proceeds to step S130, and the system controller 50 determines the state of the quick review flag stored in the internal memory or the memory 52 (step S130). If the quick review flag is set, a quick review display is performed (step S133). If the image display unit 28 is OFF prior to the quick review display, the display is performed after the image display unit 28 is turned ON (step S131).

  On the other hand, if the quick review flag has been canceled (OFF in step S130), the process proceeds directly to step S134.

  In step S134, the system controller 50 reads the image data written in the memory 30, and performs various image processing using the memory control circuit 22 and, if necessary, the image processing circuit 20. Further, after performing image compression processing according to the mode set using the compression / decompression circuit 32, recording processing for writing image data to the recording medium 120 is executed.

  When the recording process (step S134) ends, the system controller 50 determines the state of the shutter switch SW2. If the shutter switch SW2 has been pressed (ON in step S135), the system controller 50 determines the state of the continuous shooting flag stored in the internal memory of the system controller 50 or the memory 52 (step S136). If the continuous shooting flag has been set, the flow returns to step S129 to perform continuous shooting, and the next shooting is performed. If the continuous shooting flag is not set (NO in step S136), the process returns to step S135, and the current processing is repeated until the shutter switch SW2 is released.

  If the shutter switch SW2 is released, the process proceeds to step S138 after a predetermined minimum review time has elapsed in step S137.

  In step S138, the system controller 50 determines the state of the EVF flag stored in the internal memory or the memory 52. If the EVF flag has been set, the display state of the image display unit 28 is set to the through display state (step S139), and the process proceeds to step S141. In this case, after confirming the captured image by the quick review display on the image display unit 28, it is possible to enter a through display state in which image data captured for the next imaging is sequentially displayed.

  On the other hand, if the EVF flag has been canceled (OFF in step S138), the image display of the image display unit 28 is set to the OFF state (step S140), and the process proceeds to step S141. In this case, after confirming the captured image by the quick review display on the image display unit 28, the functions of the image display unit 28, the D / A converter 26, and the like that consume a large amount of power are stopped, thereby reducing power consumption. It becomes possible to do.

  In step S141, the state of the shutter switch SW1 is checked. If the shutter switch SW1 is ON, the system controller 50 returns to step S125 to prepare for the next shooting. If the shutter switch SW1 is OFF, the system controller 50 ends a series of shooting operations and returns to step S103.

  FIG. 5 shows a detailed flowchart of the focus adjustment / photometry process in step S122 of FIG.

  In step S200, the system controller 50 determines the state of the EVF flag stored in the internal memory or the memory 52. If the EVF flag has been set, the process proceeds to step S201, and if it has been canceled, the process proceeds to step S210.

  In step S201, a charge signal is read from the image sensor 14, and image data is sequentially read into the image processing circuit 20 via the A / D converter 16 (step S201). Using the sequentially read image data, the image processing circuit 20 performs a predetermined calculation used for TTL AE processing and AF processing. Note that this TTL AE process constitutes another example of photometric means.

  The system controller 50 performs AE control by combining the aperture control unit 205 and the electronic shutter of the image sensor 14 until the exposure (AE) is determined to be appropriate using the calculation result in the image processing circuit 20 (step S202). This is performed (step S203). A diaphragm drive command to the lens unit 200 is commanded by a known serial communication via the communication line 399 between the camera body 100 and the lens unit 200. In step S204, the system controller 50 determines whether flash is necessary using measurement data (photometry result) obtained by AE control. If the flash is necessary (YES in step S204), the flash flag is set and the flash 400 is charged (step S205).

  If it is determined that the exposure (AE) is appropriate (YES in step S202), the measurement data and / or setting parameters are stored in the internal memory or the memory 52 of the system controller 50.

  Next, the system controller 50 determines whether the white balance (AWB) is appropriate using the calculation result in the image processing circuit 20 and the measurement data obtained by the AE control. Until it is determined to be appropriate (until YES in step S206), the image processing circuit 20 is used to adjust color processing parameters and perform AWB control (step S207).

  If it is determined that the AWB is appropriate (YES in step S206), the measurement data and / or setting parameters are stored in the internal memory or the memory 52 of the system controller 50.

  Next, the system controller 50 performs focus adjustment (AF) using the calculation result in the image processing circuit 20 and the measurement data obtained by the AE control and the AWB control. Until the result is determined to be in focus (during NO in step S208), the lens unit 200 is instructed to drive the focus lens 201 via the communication line 399, and AF control is performed (step S209). At this time, the lens control microcomputer 206 controls the focus control unit 211 according to the focus drive amount or the focus drive speed commanded from the camera body 100 to drive the focus lens 201 in the optical axis direction.

  The focus determination in the EVF mode uses so-called contrast AF in which the focus lens 201 is driven in the optical axis direction to determine the position where the high-frequency component in the AF area of the image is the highest as the focus position.

  If it is determined that the in-focus state is obtained as a result of the focus adjustment (AF) (YES in step S208), the measurement data and / or setting parameters are stored in the internal memory of the system controller 50 or the memory 52, and the focus adjustment / photometry processing routine ( Step S122) is terminated.

  Next, when it is determined in step S200 that the EVF flag is not set, that is, in the case of the OVF mode, the process proceeds from step S200 to step S210, and photometry is performed by the photometric sensor 7. Then, the exposure value (EV) is calculated according to the photometric result of the photometric sensor 7 and the set ISO sensitivity, and the shutter speed (TV) and aperture value (AV) are obtained according to a predetermined shooting program diagram. (Step S211). In step S212, the system controller 50 determines whether or not flashing is necessary using the obtained exposure value (EV). If flash is necessary (YES in step S212), the flash flag is set and the flash 400 is charged (step S213).

  Next, if the focus shift amount detected by the known TTL phase difference type focus detection unit 8 is within the in-focus range (YES in step S214), the focus adjustment / photometry processing is terminated. On the other hand, if it is out of focus range (NO in step S214), the focus lens 201 is driven to perform AF control (step S215), and the process returns to step S214 to perform focus determination.

  When the series of processes is completed, the focus adjustment / ranging process in step S122 is terminated.

  6 and 7 show a detailed flowchart of the photographing process in step S129 of FIG. FIG. 8 shows a light emission waveform of the flash 400 at the time of flash photography and a waveform corresponding to the output of the integral photometry circuit 436.

  The system controller 50 determines the state of the EVF flag stored in the internal memory or the memory 52 in step S300. If the EVF flag has been set (EVF mode), the process proceeds to step S301. If the EVF flag has not been set (OVF mode), the process proceeds to step S321.

  First, the case of the EVF mode will be described.

In step S301, it is determined whether a flash flag is set. If it is set, the process proceeds to step S302, where an image of the subject is picked up by stationary light before pre-emission by the image sensor 14, and subject luminance (steady light) is obtained from the image information. The flash 400 does not emit light when imaging with steady light. Here, the exposure value EV is determined from the shutter time (charge accumulation time: TV) and the set aperture value (AV) (photometry by steady light). Next, the subject brightness level is obtained from the following formula (1) from the preset image brightness level LVL0 at appropriate exposure and the image brightness level LVL1 of the imaged subject.
LVLt = log2 (LVL1 / LVL0) (1)

Next, during the focus adjustment / photometry process (FIG. 5), the external light luminance BV is obtained by the following equation (2) using the exposure value EV (AV + TV) obtained in step S203 and the ISO sensitivity SV.
BV = EV−SV + LVLt (2)

  Next, the flash 400 is pre-flashed with a substantially constant light amount with a predetermined light emission amount and a predetermined light emission time (step S303). This pre-flash command is commanded from the system controller 50 on the camera body 100 side to the flash control microcomputer 440 by known serial communication between the flash 400 and the camera body 100 via the communication line 499. At this time, in the flash control microcomputer 440, the power supply SW (not shown) is turned on, and the voltage of the power supply 401 is boosted by the DC / DC converter 402. For this reason, when a pre-emission command is received, the emission control circuit 412 is controlled to illuminate the xenon tube 410 and perform pre-emission for a predetermined amount of light and a predetermined emission time.

  The pre-light emission operation will be described with reference to the circuit diagram shown in FIG.

  The flash control microcomputer 440 outputs a control voltage corresponding to the light emission amount instructed by the system controller 50 of the camera body 100 to the DA0 terminal.

  Next, Hi and Lo are output to Y1 and Y0, respectively, and the input D2 is selected. At this time, since the xenon tube 410 has not yet emitted light, almost no photocurrent flows through the photodiode 435, and no output voltage of the photometric circuit 434 input to the inverting input terminal of the comparator 431 is generated. On the other hand, since the output of the comparator 431 is Hi, the light emission control circuit 412 becomes conductive.

  Next, when a trigger signal is output from the TRIG terminal, the trigger circuit 411 generates a high voltage, excites the xenon tube 410, and light emission is started.

  On the other hand, the flash control microcomputer 440 instructs the integration photometry circuit 436 to start integration, and the integration photometry circuit 436 starts integrating the logarithmically compressed photoelectric output of the light quantity integration photodiode 438 (FIG. 8A). (T0 of “Output of integral photometry circuit”). At the same time, a timer for counting the light emission time designated by the system controller 50 of the camera body 100 is started.

  When pre-emission is started, the photocurrent from the light emission level control photodiode 435 for flat emission increases, and the output of the photometry circuit 434 increases. When the output of the photometry circuit 434 becomes higher than a predetermined comparator voltage set to the non-inverting input of the comparator 431, the output of the comparator 431 is inverted to Lo, and the light emission control circuit 412 changes the light emission current of the xenon tube 410. Cut off. As a result, the discharge loop is interrupted, but a recirculation loop is formed by the diode 409 and the coil 406, and the light emission current gradually decreases after the overshoot due to the delay of the circuit is settled.

  As the light emission current decreases, the light emission level decreases, so the photocurrent of the photodiode 435 decreases and the output of the photometry circuit 434 also decreases. When the voltage falls below a predetermined comparator level, the output of the comparator 431 is inverted again to Hi, the light emission control circuit 412 is turned on again, a discharge loop of the xenon tube 410 is formed, the light emission current increases, and the light emission level. Will also increase.

  As described above, the comparator 431 repeatedly increases and decreases the light emission level in a short period around the predetermined comparator voltage set to DA0, and as a result, the flat light continues to emit light at a desired substantially constant light emission level. Light emission is controlled.

  When a predetermined light emission time elapses due to the above-described timer count, the flash control microcomputer 440 sets the Y1 and Y0 terminals to Lo and Lo, respectively. As a result, the input of the data selector 430 is selected as D0, that is, the Lo level input, the output is forcibly set to the Lo level, and the light emission control circuit 412 cuts off the discharge loop of the xenon tube 410. In this manner, pre-light emission with a predetermined luminance and a predetermined light emission amount is performed.

  The above operation corresponds to the pre-light emission period from t0 to t1 in FIG.

  Note that pre-light emission may be performed by general flash light emission instead of the above-described flat light emission. The operation in that case will be described below.

  The flash control microcomputer 440 outputs a control voltage corresponding to the light emission amount instructed by the system controller 50 of the camera body 100 to the DA0 terminal.

  Next, Lo and Hi are output to Y1 and Y0, respectively, and the input D1 is selected. At this time, since the xenon tube 410 has not yet emitted light, almost no photocurrent flows through the photodiode 438, and the integration photometry circuit 436 input to the inverting input terminal of the comparator 432 has not started the integration operation. Therefore, since the output of the comparator 432 is Hi, the light emission control circuit 412 becomes conductive.

  Next, when a trigger signal is output from the TRIG terminal, the trigger circuit 411 generates a high voltage, excites the xenon tube 410, and light emission is started.

  On the other hand, the flash control microcomputer 440 instructs the integration photometry circuit 436 to start integration, and the integration photometry circuit 436 starts integrating the logarithmically compressed photoelectric output of the light quantity integration photodiode 438 (FIG. 8A). (T0 of “Output of integral photometry circuit”).

  When the pre-flash is started, the output of the integrating photometry circuit 436 increases according to the light emission amount, and when the pre-flash becomes higher than a predetermined comparator voltage set as the non-inverting input of the comparator 432, the output of the comparator 432 becomes Lo. Invert. Thereby, the light emission control circuit 412 cuts off the light emission current of the xenon tube 410. As a result, the discharge loop is interrupted, the light emission of the xenon tube 410 is terminated, and the pre-light emission with a predetermined light emission amount is performed.

  In step S304, the subject image is captured by the image sensor 14 while the flash 400 is performing pre-flash as described above (photometry during pre-flash).

  Next, only the subject reflected light component due to the pre-emission is extracted by subtracting the imaging data at the time of stationary light obtained in step S302 from the imaging data at the time of pre-emission captured in step S304. The main light emission amount is obtained from the difference between the pre-light-emitting subject reflected light component and the appropriate amount of light received by the image sensor 14 (step S305). Since this process is performed by the system controller 50, the system controller 50 operates as a calculation unit.

  Next, in preparation for shooting, the shutter in the open state is once closed (step S306), the shutter controller 40 is controlled again to open the front curtain of the shutter 9 (step S307), and the image sensor 14 Exposure is started (step S308). Next, if the flash flag is set (YES in step S309), the main light emission amount obtained in step S305 is instructed to the flash 400, and the flash 400 performs main light emission with the instructed light emission amount (step S310). . This operation corresponds to the period from t2 to t3 in FIG. After the predetermined exposure time, the rear curtain of the shutter 9 is closed (step S311), the accumulation of the image sensor 14 is terminated, and the actual captured image is sequentially read from the pixels on the image sensor 14 (step S312).

  In the first embodiment, as described in step S307, step S308, and step S311, the exposure control for the main photographing is performed by the mechanical shutter 9 instead of the electronic shutter. This is to prevent the image quality from being degraded due to the above.

  On the other hand, if it is not the EVF mode, that is, if it is the OVF mode (NO in step S300), the process proceeds to step S321, and it is determined whether or not the flash flag is set. If it is set (YES in step S321), the subject image is measured by the photometric sensor 7 before the pre-emission (step S322). In the photometry using the steady light, the flash 400 is not emitted. Here, the subject image is formed on the focusing plate 2 through the photographing lens 301, the image is formed on the photometric sensor 7 through the photometric lens 6, and this subject image is photoelectrically converted by the photometric sensor 7 and integrated for a predetermined time. Then, photometry of the subject in the steady light is performed.

  Next, in step S323, similarly to step S303, the flash 400 is pre-flashed with a predetermined light emission amount, and the reflected light from the subject that is pre-flashing is measured with the photometric sensor 7 in step S324.

  Next, by subtracting the photometry data at the time of stationary light obtained at step S322 from the photometry data at the time of pre-light emission obtained at step S324, only the subject reflected light component by the pre-light emission is extracted. The main light emission amount is obtained from the difference between the subject luminance by the subject reflected light component and the exposure value EV (AV + TV) obtained in step S211 during the focus adjustment / photometry process (FIG. 5) (step S325). Since this process is performed by the system controller 50, the system controller 50 operates as a calculation unit.

  Next, when preparation for photographing is completed, the system controller 50 raises the main mirror 1 and the sub mirror 3 and retracts them from the optical axis. Further, as described above, the lens unit 200 is instructed to narrow down to a predetermined aperture value via the communication line 399 between the camera body 100 and the lens unit 200. In response to this, the lens control microcomputer 206 controls the aperture controller 205 to limit the aperture 204 to a predetermined aperture value (step S326). Next, the shutter control unit 40 is controlled to open the front curtain of the shutter 9 (step S327), and exposure of the image sensor 14 is started (step S328). If the flash flag is set (YES in step S329), the main light emission amount obtained in step S325 is instructed to the flash 400, and the flash 400 performs main light emission with the instructed light emission amount (step S330). . After the predetermined exposure time, the rear curtain of the shutter 9 is closed (step S331), the accumulation of the image sensor 14 is terminated, and the exposure is terminated (step S332). Then, the main mirror 1 and the sub mirror 3 retracted from the optical axis in step S326 are returned to their original positions, and the diaphragm 204 is driven to open as in step S326 (step S333).

  After the processing in step S312 or S333, the process proceeds to step S340 in FIG. In step S340, the flash control microcomputer 440 sets the output value of the output terminal DA0, which is the light emission stop level, set at the time of light emission control, and the integrated voltage read from the input terminal AD0 when the integrated photometry circuit 436 at the completion of light emission is read. The difference, that is, the light emission excess / deficiency is calculated.

  Details will be described with reference to FIG. FIG. 8B is an enlarged view of the light emission waveform of FIG. 8A and the output of the integral light metering circuit 436 during the main light emission.

  As described above, when the xenon tube 410 performs pre-emission from time t0 to t1, an integrated value of the light emission amount of the xenon tube 410 is obtained by integrating the photocurrent of the photodiode 438 by the integrating photometry circuit 436. It is done. As described above, this integral value is controlled to stop the main light emission at the light emission stop level DA0 corresponding to the main light emission amount obtained in step S305 or step S325. However, since the remaining light emission indicated by A is performed from the xenon tube 410 even after the light emission is stopped, the integrated voltage increases until the light emission is completed, and even after the complete light emission is stopped, the light is emitted by the integral amount indicated by B. Will be.

  Normally, this value becomes over because the remaining light emission is added, but becomes under when the subject is far from the dimmable range, or when the voltage of the main capacitor 403 that accumulates the light emission is low. This overexposure / underexposure data is sent to the camera body 100 via the serial communication line between the flash 400 and the camera body 100 described above.

  Next, the charge signal is read out from the image sensor 14, and the memory is sent via the A / D converter 16, the image processing circuit 20, the memory control circuit 22, or directly from the A / D converter 16 via the memory control circuit 22. Data of the photographed image is written in 30 (step S341). Next, the system controller 50 reads the image data written in the memory 30 using the memory control circuit 22 and the image processing circuit 20 as necessary. Then, based on the overexposure / underexposure data acquired from the flash 400 in step S340, image brightness level correction, specifically, digital gain correction for correcting the brightness level by digital processing in the image processing circuit 20 of FIG. S342) is performed.

  As a specific digital gain correction method, assuming that the amount of overexposure represented by C in FIG. 8 is one exposure, the gain is corrected by minus one step as the gain. Is compensated. Conversely, if the exposure is insufficient, the underexposure is compensated by performing positive gain correction to fill the shortage. Thus, in this digital gain correction, correction is performed using the gain value determined so as to compensate for the overexposure / underexposure amount. In other words, the image processing circuit serves as a correction unit.

  After that, color processing for generating all RGB color data is performed for each pixel from the RGB pixels arranged in the Bayer array of the image sensor 14 (step S343). Then, the processed image data is written in the memory 30, and the display image data is transferred to the image display memory 24 via the memory control circuit 22 (step S344).

  When the series of processing is finished, the photographing processing routine (step S129) is finished.

  As described above, according to the first embodiment, when the luminance level of the captured image is corrected based on the measurement result of the actual flash amount of the flash, the actual flash amount of the flash varies. However, an image with an appropriate luminance level can be acquired.

<Second Embodiment>
Next, a second embodiment of the present invention will be described.

  In the second embodiment, a case will be described in which a correction amount for performing digital gain correction is determined based on the actual light emission amount of the flash 400 described in the first embodiment in accordance with the brightness of external light. This is because, when the contribution ratio of external light is high (for example, bright), if the digital gain correction is performed according to the actual light emission amount of the strobe, the luminance level of the portion corresponding to the external light may change. That is, if digital gain correction is performed, the entire screen is corrected, and it is considered that the image quality of a subject having a low contribution rate when determining a gain correction value is deteriorated. In the second embodiment, the digital gain correction amount is limited according to the external light luminance.

  The second embodiment is different from the processing described in the first embodiment only in the processing described with reference to FIG. 7, and will be described with reference to FIG. 9 instead of FIG. 7. Processes similar to those in FIG. Note that the processing in FIG. 9 is performed after step S312 or step S333 in FIG. 6, as in the first embodiment.

  In step S340, the flash control microcomputer 440 sets the output value of the output terminal DA0, which is the light emission stop level, set at the time of light emission control, and the integrated voltage read from the input terminal AD0 as the integrated voltage of the integral photometry circuit 436 at the end of light emission. The difference, that is, the light emission excess / deficiency is calculated.

  As described above, this value is usually over because the remaining light emission is added, but it is under if the subject is farther than the dimmable range or the voltage of the main capacitor 403 that accumulates the light emission charge is low. It becomes. This overexposure / underexposure data is sent to the camera body 100 via the serial communication line between the flash 400 and the camera body 100 described above.

Next, from the external light luminance BV obtained in step S302 or S322 in FIG. 6, the exposure value EV (AV + TV) and ISO sensitivity SV obtained in step S203 or step S211 in FIG. The deficiency is obtained by the following equation (3).
External light excess / deficiency = BV + SV− (TV + AV) (3)

  The maximum value of the image luminance correction amount is obtained from the table shown in FIG. Processing for obtaining the maximum value of the image luminance correction amount, that is, processing for limiting the correction amount of the luminance level gain correction by the image processing circuit 20 described later is performed by the system controller 50. Therefore, the system controller 50 realizes the function of the limiting means.

  Next, the charge signal is read out from the image sensor 14, and the memory is sent via the A / D converter 16, the image processing circuit 20, the memory control circuit 22, or directly from the A / D converter 16 via the memory control circuit 22. Data of the photographed image is written in 30 (step S341). Next, the system controller 50 reads the image data written in the memory 30 using the memory control circuit 22 and the image processing circuit 20 as necessary. Then, based on the overexposure / underexposure data acquired from the flash in step S340 and the maximum value of the luminance correction amount obtained in step S441, the image luminance level correction is performed within the range of the correction amount limited by the maximum value. This is performed (step S442). Here, specifically, the image processing circuit 20 performs digital gain correction for correcting the luminance level by digital processing. The specific processing method for digital gain correction is the same as the method described in the first embodiment.

  After that, color processing for generating all RGB color data is performed for each pixel from the RGB pixels arranged in the Bayer array of the image sensor 14 (step S343). Then, the processed image data is written in the memory 30, and the display image data is transferred to the image display memory 24 via the memory control circuit 22 (step S344).

  When the series of processing is finished, the photographing processing routine (step S129) is finished.

  As described above, according to the second embodiment, the correction of the luminance level of the photographed image based on the measurement result of the actual light emission amount of the flash is limited according to the luminance of the external light. As a result, even when the actual light emission amount of the flash varies, it is possible to correct the brightness level in a balanced manner with the external light without excessive correction.

  In the first and second embodiments, the case where the flash control microcomputer 440 obtains the excess or shortage of light emission has been described. However, the present invention is not limited to this. For example, you may comprise as follows. The integrated voltage of the integral photometry circuit 436 at the completion of light emission from the flash 400 is transmitted to the system controller 50 of the camera body 100, and the system controller 50 takes the difference from the main light emission amount commanded to the flash 400 in step S310.

It is a block diagram which shows the structure of the imaging system in embodiment of this invention. It is a block diagram which shows the structure of the flash concerning embodiment of this invention. It is a flowchart which shows a part of main routine in the 1st Embodiment of this invention. It is a flowchart which shows a part of main routine in the 1st Embodiment of this invention. It is a flowchart of the focus adjustment and photometry routine in the first embodiment of the present invention. It is a flowchart which shows a part of imaging | photography routine in the 1st Embodiment of this invention. It is a flowchart which shows a part of imaging | photography routine in the 1st Embodiment of this invention. It is a figure which shows the light emission waveform and integrated photometry result in the 1st Embodiment of this invention. It is a flowchart which shows a part of imaging | photography routine in the 2nd Embodiment of this invention. It is a table | surface which shows the maximum value of the image brightness correction amount in the 2nd Embodiment of this invention.

Explanation of symbols

1: Main mirror, 2: Focus plate, 3: Sub mirror, 4: Penta prism, 5: Eyepiece, 6: Imaging lens, 7: Photometric sensor, 8: Focus detection unit, 9: Shutter, 14: Image sensor, 16 : A / D converter, 18: Timing generation circuit, 20: Image processing circuit, 22: Memory control circuit, 24: Image display memory, 26: D / A converter, 28: Image display unit, 30: Memory, 32 : Compression / decompression circuit, 40: Shutter control unit, 41: Mirror control unit, 50: System controller, 52: Memory, 54: Notification unit, 56: Non-volatile memory, 60: Mode dial switch, 62: Shutter switch SW1, 64: Shutter switch SW2, 66: Viewfinder mode setting switch, 68: Quick review ON / OFF switch, 70: Operation unit, 72: Communication 73: Connector (or antenna), 80: Power supply control unit, 82, 84: Connector, 86: Power supply, 90: I / F, 92: Connector, 98: Recording medium attachment / detachment detection unit, 100: Camera body, 120: Recording Medium: 122: Recording unit, 124: I / F, 126: Connector, 200: Lens unit, 201: Focus lens, 204: Aperture, 205: Aperture control unit, 207: Zoom lens, 400: Flash

Claims (7)

An imaging device capable of imaging using a light emitting device,
Imaging means for converting incident light into an electrical signal and outputting image data;
Photometric means;
In accordance with a photometric result by the photometric means, a calculation means for obtaining a light emission amount to be emitted by the light emitting device;
The light emitting device emits light so as to compensate for the difference between the actual light emission amount when the light emitting device emits light based on the light emission amount obtained by the computing means and the light emission amount obtained by the computing means. And a correction unit that corrects the luminance level of the image data obtained from the imaging unit. In accordance with a photometric result obtained by performing photometry with the photometric means without performing light emission by the light emitting device, the electronic apparatus further includes a limiting unit that limits the correction amount of the luminance level.
The imaging apparatus according to claim 1, wherein the correction unit corrects the luminance level of the image data within a correction amount range limited by the limitation unit.   The imaging apparatus according to claim 1, wherein the light emitting device includes a measuring unit that measures an actual light emission amount when the light emitting device emits light.   When the light emitting device causes the light emitting device to emit light based on the light emission amount obtained by the computing means, the actual light emission amount measured by the measuring means, and the light emission amount obtained by the computing means The imaging apparatus according to claim 3, further comprising a calculating unit that calculates a difference between the two.   When the light emitting device is caused to emit light based on the light emission amount obtained by the calculating means, a difference between the actual light emission amount measured by the measuring means and the light emission amount obtained by the calculating means is calculated. The imaging apparatus according to claim 3, further comprising a calculation unit. An imaging device control method comprising: an imaging unit capable of imaging using a light emitting device, converting incident light into an electrical signal, and outputting image data; and a photometric unit,
In accordance with a photometric result by the photometric means, a calculation step for obtaining a light emission amount to be emitted by the light emitting device;
An imaging step of performing imaging by the imaging unit while causing the light emitting device to emit light based on the light emission amount obtained in the calculation step;
A measurement step of measuring an actual light emission amount of the light emitting device in the imaging step;
The calculation step for calculating the difference between the actual light emission amount measured in the measurement step and the light emission amount obtained in the calculation step, and the image pickup in the imaging step so as to compensate the difference obtained in the calculation step And a correction step of correcting the luminance level of the image data obtained as described above. In accordance with the photometric result obtained by performing photometry with the photometry means without performing light emission by the light emitting device, the method further includes a limiting step of limiting the correction amount of the luminance level,
The control method according to claim 6, wherein in the correction step, the luminance level of the image data is corrected within a correction amount range limited in the limitation step.

Images