JP4965810B2 - Imaging apparatus and control method thereof - Google Patents

Description

  The present invention relates to an imaging apparatus capable of capturing still images and moving images, and a control method thereof.

In the past, there were different categories of shooting for each product, such as taking still pictures with a digital still camera and moving pictures with a video camera. Recently, however, there are commercially available digital still cameras that can shoot moving images and video cameras that can shoot still images. If you want to shoot a still image in a state where you have already started moving image shooting in a product that has such a still image shooting and moving image shooting function and has only one image sensor, you must first take a moving image shooting. After interrupting and taking a still image, movie recording is started again. This is because the method of driving an image sensor such as a CCD or CMOS is completely different between still image shooting that requires high resolution and moving image shooting that requires a frame rate higher than the resolution. Therefore, still image shooting and moving image shooting cannot be performed at the same time, and the image sensor must be used exclusively for still image shooting and moving image shooting. For example, Patent Document 1 describes a digital camera that captures a still image by switching to the still image shooting mode only during still image shooting when the still image shooting mode is selected during moving image shooting in the moving image shooting mode. Has been.
JP 2004-186866 A

  However, when shooting the same subject, the optimal exposure conditions differ between moving image shooting and still image shooting. For example, in the case of movie shooting, even if it is better to squeeze the aperture to avoid image degradation due to the smear phenomenon, in order to prevent diffraction due to squeezing the aperture and camera shake due to a decrease in shutter speed, even when shooting a still image In some cases, it is better to open the aperture. Under these conditions, it is necessary to change the aperture when attempting to shoot a high-quality still image from the state where movie recording has already started, but in order to move the aperture to a predetermined aperture position It takes a certain amount of time and reduces the shooting response. However, if the aperture is not moved, as described above, there is a problem that the image quality of the captured still image is deteriorated, and further, the interruption time of moving image shooting becomes longer due to the decrease of the shutter speed.

  An object of the present invention is to solve the above-mentioned drawbacks of the prior art.

  The feature of the present invention is that, in still image shooting from a moving image shooting state, the time taken for still image shooting is shortened so that the interruption time of moving image shooting is not as long as possible.

An imaging device according to one embodiment of the present invention includes the following configuration. That is,
An imaging device capable of taking still images during movie shooting,
Imaging means for imaging a subject;
An aperture control means for controlling the amount of light incident on the imaging means by driving an aperture mechanism;
Exposure time control means for controlling the exposure time of the imaging means;
Luminance information acquisition means for acquiring luminance information of the subject;
Based on the luminance information acquired by the luminance information acquisition means, calculating means for calculating the aperture value of the aperture mechanism during still image shooting and the exposure time during still image shooting;
The (n + 1 ) aperture driving time and the (n + 1 ) aperture required to change the aperture mechanism from the aperture value at the time of moving image shooting to the (n + 1 ) aperture value calculated by the calculation means. wherein a first (n + 1) elapsed time which is the sum of the exposure time of the calculated by the calculating means in correspondence with the value (n + 1), the diaphragm mechanism from the aperture value at the time of moving image shooting the (n + 1 ) the (n + 2 ) th aperture driving time and the (n + 2 ) th aperture value required for changing to the (n + 2 ) th aperture value calculated by the calculation means that is further away from the aperture value. comparing means for comparing, and the elapsed time of the which is the sum of the exposure time of the (n + 2) which is calculated (n + 2) by said calculating means in correspondence,
When the (n + 1 ) elapsed time is shorter than the (n + 2 ) elapsed time based on the comparison result of the comparison means, the (n + 1 ) aperture value and the (n + 1 ) th are Setting means for setting the exposure time as the aperture value and the exposure time at the time of still image shooting ,
If the elapsed time of the first (n +1) is not shorter than the elapsed time of the first (n + 2), the initial value of the variable n as 0, elapsed time elapsed the (n + 1) -th of the first (n + 2) Every time the variable n is incremented by 1 until the time becomes shorter than the time, the (n + 1) th elapsed time and the (n + 2) elapsed time are compared, and the (n + 1) th elapsed time is becomes shorter than the elapsed time of the (n + 2), and sets as the first (n + 1) the aperture value and the exposure time at the time of still image shooting aperture value and the exposure time of the first (n + 1) of .

An imaging apparatus according to another aspect of the present invention has the following configuration. That is,
An imaging device capable of taking still images during movie shooting,
Imaging means for imaging a subject;
An aperture control means for controlling the amount of light incident on the imaging means by driving an aperture mechanism;
Exposure time control means for controlling the exposure time of the imaging means;
Luminance information acquisition means for acquiring luminance information of the subject;
Based on the luminance information acquired by the luminance information acquisition means, calculating means for calculating the aperture value of the aperture mechanism during still image shooting and the exposure time during still image shooting;
The aperture drive time required to change the aperture mechanism from the aperture value at the time of moving image shooting to the (n + 1 ) th aperture value calculated by the calculating means and the (n + 1 ) th aperture value for moving image shooting the (n the diaphragm driving time required to change the aperture value and is calculated by the calculating means in correspondence to the aperture value of the a diaphragm driving time of the (n + 1) obtained by adding the (n + 1) + and the (n + 1) elapsed time which is the sum of the exposure time of 1), computed by said computing means apart than the aperture value of the said diaphragm mechanism from the aperture value at the time of moving image shooting (n + 1) th The aperture drive time required to change to the (n + 2 ) th aperture value and the aperture drive time required to change from the (n + 2 ) th aperture value to the aperture value for moving image shooting are added. the (n + 2) of the diaphragm driving time and the Comparing means for (n + 2) aperture value in correspondence of the comparing, and the elapsed time of the which is the sum of the exposure time of the (n + 2) which is calculated (n + 2) by said calculating means,
When the (n + 1 ) elapsed time is shorter than the (n + 2 ) elapsed time based on the comparison result of the comparison means, the (n + 1 ) aperture value and the (n + 1 ) th are Setting means for setting the exposure time as the aperture value and the exposure time at the time of still image shooting ,
If the elapsed time of the first (n +1) is not shorter than the elapsed time of the first (n + 2), the initial value of the variable n as 0, elapsed time elapsed the (n + 1) -th of the first (n + 2) Every time the variable n is incremented by 1 until the time becomes shorter than the time, the (n + 1) th elapsed time and the (n + 2) elapsed time are compared, and the (n + 1) th elapsed time is becomes shorter than the elapsed time of the (n + 2), and sets as the first (n + 1) the aperture value and the exposure time at the time of still image shooting aperture value and the exposure time of the first (n + 1) of .

  The outline of the present invention does not enumerate all the features necessary for the present invention, and therefore a sub-combination of these feature groups can also be an invention.

According to the present invention, in the still image shooting from moving Well shadow state, shortening the time required for stationary Well shadow, it is possible to quickly resume the movie shooting.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the invention according to the claims, and all the combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. .

  FIG. 1 is a block diagram illustrating the overall configuration of an imaging apparatus (camera) according to an embodiment of the present invention.

  In the figure, outside light is collected by a lens 10. In FIG. 1, this lens 10 is represented as one lens, but it is also possible to mount a lens unit composed of a plurality of lenses. It is also possible to adjust the focal point and adjust the angle of view by moving the lens 10 back and forth along the optical axis. The amount of light passing through the lens 10 is adjusted by the diaphragm 12. The system control unit 100 controls the aperture amount of the aperture 12 by transmitting aperture control information to the aperture drive circuit 24. The system control unit 100 includes a CPU 1001, a program executed by the CPU 1001 (flowcharts in FIGS. 2 and 3) and various data, a ROM 1002, and a RAM 1003 that temporarily stores various data during processing by the CPU 1001. . Transmission of control information from the system control unit 100 to the aperture driving circuit 24 includes serial communication and a pulse signal, and a signal transmission / reception mode that matches the specifications of the aperture driving circuit 24 is employed. The diaphragm 12 includes an iris diaphragm composed of a plurality of wings, and a round diaphragm in which a plate is punched with various diameters in advance. The system control unit 100 uses the diaphragm 12 and the diaphragm drive circuit 24 to control the diaphragm 12 to reduce the amount of incident light when the luminance of the subject is high, and to control the diaphragm 12 when the luminance of the subject is low. Control is performed so that the amount of incident light is increased. Further, the system control unit 100 controls the shutter 11 by transmitting shutter control information to the shutter drive circuit 25. The exposure time when taking a still image is determined by the opening / closing time of the shutter 11. The opening / closing time is determined by the system control unit 100 determining an optimum time and issuing an instruction to the shutter drive circuit 25.

  The light that has passed through the lens 10, the shutter 11, and the diaphragm 12 is received by the image sensor 14. Here, the imaging device 14 is a CCD (Charge Coupled Devices) sensor, but a CMOS (Complementary Metal Oxide Semiconductor) sensor may be mounted. The system control unit 100 controls the image sensor 14 by transmitting a control signal of the image sensor to a timing generator (TG) 22. Transmission of control information from the system control unit 100 to the TG 22 includes serial communication and parallel bus communication, and is determined according to the specifications of the TG 22. The TG 22 drives the image sensor 14 based on the control information received from the system control unit 100. The image sensor 14 periodically performs exposure to the element and reading of the exposed data, and this work is performed with reference to a drive signal from the TG 22. The TG 22 can control the exposure time of the image sensor 14. This is made possible by outputting a drive signal from the TG 22 to the image sensor 14 so as to release the charge charged by the element 14 at an arbitrary timing.

  The image signal output from the image sensor 14 in this way passes through a CDS (Correlated Double Sampler) circuit 16. The CDS circuit 16 has a main role of removing noise components included in the image signal by a correlated double sampling method. Thereafter, the signal level of the image signal is amplified by a PGA (Programmable Gain Amplifier) circuit 18. The system control unit 100 transmits the amplification level to the PGA circuit 18 to control the amplification amount. Transmission of control information from the system control unit 100 to the PGA circuit 18 includes serial communication and parallel bus communication, and is determined according to the specifications of the PGA circuit 18.

  Usually, the exposure of the image sensor 14 is appropriately achieved by appropriately setting the exposure amount of the image sensor 14 with the aperture 12 and appropriately setting the exposure time of the image sensor 14 with the TG 22. At the same time, the image signal can be artificially changed by amplifying the image signal by the PGA circuit 18. For example, when the subject brightness is extremely low in the dark, the aperture 12 is opened to maximize the exposure amount, and the exposure time of the image sensor 14 is extended as much as possible to receive more light. To control. However, there is a limitation in the mechanism that the diaphragm 12 cannot be opened beyond a certain level, and there is a practical limit that if the exposure time of the image sensor 14 is extended, the update cycle of the image signal becomes longer. In this case, the signal level of the image signal becomes low, and a dark image is captured due to insufficient exposure. As a method of improving this phenomenon, the PGA circuit 18 amplifies the level of the image signal and controls so that the exposure of the image becomes appropriate.

  Thereafter, the image signal is converted from an analog signal to a digital signal by an A / D (Analog / Digital Converter) circuit 20. Depending on the type of camera, the bit width of this digital signal is 10 bits, 12 bits, 14 bits, etc., and the signal processing circuit 200 in the subsequent stage can handle image data of a plurality of types of bit widths.

  In FIG. 1, the CDS circuit 14, the PGA circuit 18, and the A / D circuit 20 are expressed as separate blocks, but it is also possible to adopt a circuit in which these functions are mounted in one IC package. is there.

  The digitized image data is input to the signal processing circuit 200. The signal processing circuit 200 is composed mainly of various image processing blocks for the purpose of improving the image quality. Among them, there is a Y separation block 202 that extracts luminance information Y from image data. The image sensor 14 has red (R), green (G), and blue (B), or yellow (Y), magenta (M), cyan (C), and green (G) colors on the front of the element. A filter is applied, and each pixel is filtered by each color. The Y separation block 202 excludes the color information from these pixel data and extracts only the luminance information Y. The luminance information Y thus extracted can be referred to from the system control unit 100, and is used as information for processing for making the exposure of the image sensor 14 appropriate.

  In the Y separation block 202, when extracting the luminance information Y, the image is divided into a plurality of areas, and the luminance information is extracted for each area.

  5 to 7 are conceptual diagrams of extraction of the luminance information.

  FIG. 5 shows the luminance distribution of an image obtained by dividing an entire image into 100 areas each consisting of 10 areas in the vertical and horizontal directions, and shooting a subject with a dark background and a bright person. From FIG. 5, it can be seen that the luminance level of the background is low and the luminance level of the person is high.

  FIG. 6 shows a state in which the luminance information of FIG. 5 is weighted. In FIG. 6, the largest weight is applied to the substantially central portion of the image.

  The camera provides various photometry methods depending on the shooting application, and it is possible to select in which mode the luminance is measured in which part of the image to be shot and in which mode. In this mode, the user can select an arbitrary mode by operating a switch of the operation unit 34.

  FIG. 7 is a diagram showing the luminance distribution after the weighting shown in FIG. 6 is performed on the luminance distribution of FIG.

  When the luminance distribution of the person in FIG. 5 is multiplied by weighting data in which the weight is placed at the center of the screen as shown in FIG. 6, it can be seen that more emphasis is placed on the area near the face of the person. The weighted luminance distribution in FIG. 7 is averaged over the entire image, and thus the subject luminance Y is calculated.

  5, 6, and 7 show the case where the entire image is divided into 10 × 10 = 100 areas. However, the size and number of division areas are not limited to this, and can be arbitrarily selected. Is possible.

  When the image data subjected to the image processing by the signal processing circuit 200 is output to the image display unit 32 such as an LCD, the image data is converted into analog data by the D / A converter (D / A) 30. In FIG. 1, the image is displayed on the image display unit 32 mounted on the camera body, but the video output terminal is mounted and an image is displayed on the external monitor by connecting the cable to an external monitor such as a television. It is also possible to output. Further, the image data subjected to the image processing by the signal processing circuit 200 can be recorded on the image storage medium 28 such as a nonvolatile memory or a magnetic tape. The image storage medium 28 can be configured to be detachable via the image storage medium I / F 26.

  The operation unit 34 includes a power on / off switch, a photographing start / end switch, a photometry mode selection switch, a photographing mode selection switch, a reproduction mode selection switch, and the like. When the user operates these switches, the system control unit 100 Can communicate information to Note that the shooting start / end switch can be prepared separately for a still image switch and a moving image switch, so that still image shooting can be started even during moving image shooting.

  The processing of the system control unit 100 for realizing continuous AE (AE: AutoExposure Control) during moving image shooting in the camera shown in FIG. 1 will be described.

  FIG. 2 is a flowchart for explaining a control process by the system control unit 100 of the camera according to the present embodiment. A program for executing this process is stored in the ROM 1002 and is executed under the control of the CPU 1001.

In this flowchart, it is assumed that the program diagram (FIG. 4) follows the “moving diagram” indicated by the solid line 400. In this program diagram, the horizontal axis represents the shutter speed Tv, the vertical axis represents the aperture Av and gain ΔGain, and the oblique axis represents the exposure value Ev. The relationship between the exposure value Ev, the aperture Av, the shutter speed Tv, and the gain ΔGain is
Ev = Av + Tv-ΔGain (1)
It is represented by

  The program diagram shows a predetermined combination of aperture Av, shutter speed Tv, and gain ΔGain that can be taken for each exposure value Ev.

The relationship between sensitivity Sv, brightness Bv and exposure value Ev is
Sv + Bv = Ev Equation (2)
It is expressed by

  In general, the image pickup device (CCD) 14 provides various drive modes. The image pickup device 14 adds a mode in which data accumulated in each pixel is output in units of one pixel, or RGB pixels of the same color. There is a mode to output together. At this time, depending on the presence or absence of this pixel addition, the data level differs between the former mode and the latter mode, which is expressed as sensitivity Sv.

  In FIG. 4, the sensitivity Sv at the time of moving image shooting is represented by Sv = 6, and the sensitivity Sv at the time of still image shooting is represented by Sv = 4. It can be seen that due to the difference in sensitivity, the exposure value Ev differs between moving image shooting and still image shooting even with the same subject brightness Bv. For example, when the brightness Bv = 5, the exposure value Ev = 11 when shooting a moving image, but Ev = 9 when shooting a still image. The exposure value (in the direction of the oblique axis) represented by a white circle 401 in FIG. 4 is an appropriate exposure at (Bv = 5) + (Sv = 6) during moving image shooting. At this time, the appropriate exposure value at the time of shooting a still image is (Bv = 5) + (Sv = 4), and any point on the line represented by the broken line 402 in the oblique axis direction may be used. . Note that the data of the moving image diagram in FIG. 4 is stored in the ROM 1002, for example.

  In the flowchart of FIG. 2, first, in step S102, the initial value Ev of the exposure value is determined, and the program diagram of FIG. 4 is drawn with this Ev. In step S104, the target aperture Av, shutter speed Tv, and gain ΔGain are obtained from the initial value Ev and the program diagram. If the initial exposure value Ev = 10, a point (Av = 5, Tv = 5, ΔGain = 0) is derived from the moving image diagram of FIG. Each device is controlled in the subsequent steps with the target values (Av = 5, Tv = 5, ΔGain = 0) obtained in step S104 (steps S106, S108, S110).

  When the device control is thus completed and the exposure is confirmed, the process proceeds to step S112, and the luminance Y of the subject is acquired. Here, the continuous AE is feedback control, and the difference from the target luminance YRef is brought closer to “0”. Therefore, first, in step S114, a difference ΔBv0 between the subject brightness Y and the reference (target) subject brightness YRef is calculated. In step S116, it is difficult to set the difference ΔBv0 to “0” depending on the resolution of the aperture Av, the shutter speed Tv, and the gain ΔGain. Therefore, it is determined whether the difference ΔBv0 is within a predetermined range. If it is within the predetermined range, it is determined that the feedback control has converged. The predetermined range is determined based on the resolution of the aperture Av, the shutter speed Tv, and the gain ΔGain, but can be determined dynamically.

  For example, as the shutter 11 becomes a high-speed shutter due to the nature of the device, the resolution decreases and the amount of change in one step increases. This means that if the shutter speed Tv is changed by one step, the change amount of the difference ΔBv0 also increases. Therefore, a method such as increasing the convergence range (the above-mentioned predetermined range) as the shutter speed increases is adopted. If the difference ΔBv0 is outside the predetermined range in step S116, it is determined that the difference has not yet converged, and the process proceeds to step S120. The process proceeds to the next feedback loop, and a convergence speed ( Control the time constant. Here, a method of simply obtaining a new difference ΔBv1 by multiplying the difference ΔBv0 by a feedback gain is employed. However, in addition to this, it is also possible to incorporate differential control that takes into account the amount of change from the previous difference ΔBv0 and integration control that takes into account the previous difference ΔBv0. In step S122, the aperture Av, shutter speed Tv, gain value ΔGain (Av = 5, Tv = 5, ΔGain = 0) acquired in steps S106, S108, and S110, and the new difference ΔBv1 obtained in step S120. Then, the next exposure value Ev is determined. Then, the process proceeds again to step S104, and the aperture Av, shutter speed Tv, and gain value ΔGain are acquired from the exposure value Ev and the program diagram of FIG. 4, and a loop is formed toward the convergence of the difference ΔBv0.

  On the other hand, if the difference ΔBv0 is within the convergence range (predetermined range) in step S116, the convergence is completed and the process proceeds to step S118 to enter a state where monitoring is continued at a constant time period. That is, after waiting for a certain time in step S118, the subject luminance Y is acquired in step S112, then the difference ΔBv0 is obtained in step S114, and it is checked in step S116 whether the difference ΔBv0 is within a predetermined range. If it is determined that this monitoring loop is outside the predetermined range, the process proceeds to a feedback loop after step S120.

  FIG. 3 is a flowchart for explaining processing when shooting a still image in a state where the continuous AE according to FIG. 2 is operated and shooting a moving image. A program for executing this processing is stored in the ROM 1002. It is stored and executed under the control of the CPU 1001.

First, in step S202, the current subject brightness Bv is determined. This subject brightness Bv is
Bv = effective aperture value Av + effective shutter speed Tv−effective gain ΔGain−sensitivity SvMov (= 6) during moving image shooting + difference ΔBv0 Equation (3)
Is required. Here, as the effective values of the aperture Av, the shutter speed Tv, and the gain ΔGain, values in a state that is already controlled during moving image shooting are used. Here, SvMov is the sensitivity during shooting of a moving image, and here, SvMov = 6 as described above with reference to FIG. The difference ΔBv0 uses the difference between the appropriate luminance acquired with effective Av, effective Tv, and effective ΔGain during moving image shooting and the luminance signal Y separated by the Y separation circuit 202. Here, the effective gain ΔGain may be omitted depending on the specifications of the camera. Further, the effective shutter speed Tv at the time of shooting a moving image is realized by changing the driving timing of the CCD 14 and the image data extraction timing by the TG 22 instead of actually operating the shutter mechanism as in the case of shooting a still image. is doing.

  In step S204, an exposure value Ev for taking a still image is obtained. This is obtained by the following equation (4).

Ev = Bv (subject brightness) + SvCapt (sensitivity during still image shooting) (4)
Here, SvCapt is the sensitivity at the time of shooting a still image, and here, SvCapt = Sv4 as described with reference to FIG.

  Further, in this step S204, each parameter value n, effective aperture value Av0, shutter speed Tv0 (Tv0 = Ev−Av0), and TimeSum0 (infinite) used in the following steps are set. In step S206, the shutter speed Tv1 is obtained by the following equation (5) from the exposure value Ev and the aperture value Av1 obtained by moving the effective aperture value Av0 (current aperture Av) by n steps.

Tv1 = Ev−Av1 (5)
In step S208, an aperture amount that must be moved for still image shooting is obtained from the effective aperture value Av (current aperture Av) and the aperture value Av1 moved by n steps. Further, the aperture drive time is calculated from the aperture amount and the aperture drive speed. Then, the exposure time is calculated from the shutter speed Tv1, and the switching time TimeSum1 required for switching for taking a still image is obtained by the following equation (6).

TimeSum1 = aperture driving time + exposure time (6)
In step S210, TimeSum1 obtained in step S208 is compared with TimeSum0. Here, since TimeSum0 has an initial value of infinity (∞), TimeSum1 is always smaller. Thereafter, the process proceeds to step S212 to enter a loop process, where the change of the sum of the aperture driving time and the exposure time is monitored by moving the aperture 12 (adding n), and the point where the sum of the times becomes the smallest is found. Thus, in step S210, the effective aperture value Av is moved by n steps, so that when TimeSum1> TimeSum0, the process proceeds to step S214, and it is determined that TimeSum0 has the smallest sum of time. Then, the aperture Av0 and shutter speed Tv0 at this time are determined as the aperture value and shutter speed for still image shooting. In step S216, the aperture 12 is controlled to the determined aperture Av0, and a still image is shot in step S218.

  Note that even when moving to movie shooting again after the still image shooting is completed, the time required to change to the aperture value during movie shooting is minimized by performing the above settings. it can. At this time, TimeSum2 obtained by the following equation (7) is used instead of the switching time TimeSum1.

TimeSum2 = Aperture drive time + Exposure time + Aperture drive time (7)
In addition, the aperture, shutter speed, and the like at the time of shooting a moving image immediately before switching to still image shooting are stored in the memory (RAM 1003) of the system control unit 100, and stored when moving to moving image shooting again. By reading out the aperture, shutter speed, etc., and using them for the aperture drive circuit 24 and shutter drive control, the time required for returning to the moving image shooting can be shortened.

  As described above, according to the present embodiment, by taking a still image using the aperture Av and the shutter speed Tv that minimize the sum of the aperture drive time and the exposure time, the shooting time lag is shortened and the moving image is interrupted. Can be shortened. As a result, it is possible to accurately capture a photo opportunity in shooting a still image. Note that the sum of the aperture driving time and the exposure time is not necessarily controlled to be minimum. For example, it may be configured to select either the aperture Av or the shutter speed Tv at which the sum of the aperture driving time and the exposure time is a predetermined value or less.

  Furthermore, it is possible to satisfy the user's request to continuously shoot moving images in a balanced manner.

It is a block diagram explaining the whole structure of the imaging device (camera) which concerns on embodiment of this invention. It is a flowchart explaining the control processing by the system control part of the camera which concerns on this Embodiment. FIG. 3 is a flowchart for explaining processing in the case of shooting a still image in a state in which the continuous AE according to FIG. 2 is operated and moving image shooting is performed. It is a program diagram showing the relationship between exposure value Ev, aperture stop Av, shutter speed Tv, and gain ΔGain. It is a figure which shows the luminance distribution when the whole screen is divided | segmented into a total of 100 area | region which consists of 10 areas each vertically and horizontally, and the back is dark and the subject image | photographs a bright subject. It is a figure which shows a mode that weighting was performed with respect to the luminance information of FIG. FIG. 7 is a diagram showing a luminance distribution after weighting shown in FIG. 6 is performed on the luminance distribution of FIG. 5.

Claims (4)

An imaging device capable of taking still images during movie shooting,
Imaging means for imaging a subject;
An aperture control means for controlling the amount of light incident on the imaging means by driving an aperture mechanism;
Exposure time control means for controlling the exposure time of the imaging means;
Luminance information acquisition means for acquiring luminance information of the subject;
Based on the luminance information acquired by the luminance information acquisition means, calculating means for calculating the aperture value of the aperture mechanism during still image shooting and the exposure time during still image shooting;
The (n + 1 ) aperture driving time and the (n + 1 ) aperture required to change the aperture mechanism from the aperture value at the time of moving image shooting to the (n + 1 ) aperture value calculated by the calculation means. wherein a first (n + 1) elapsed time which is the sum of the exposure time of the calculated by the calculating means in correspondence with the value (n + 1), the diaphragm mechanism from the aperture value at the time of moving image shooting the (n + 1 ) the (n + 2 ) th aperture driving time and the (n + 2 ) th aperture value required for changing to the (n + 2 ) th aperture value calculated by the calculation means that is further away from the aperture value. comparing means for comparing, and the elapsed time of the which is the sum of the exposure time of the (n + 2) which is calculated (n + 2) by said calculating means in correspondence,
When the (n + 1 ) elapsed time is shorter than the (n + 2 ) elapsed time based on the comparison result of the comparison means, the (n + 1 ) aperture value and the (n + 1 ) th are Setting means for setting the exposure time as the aperture value and the exposure time at the time of still image shooting ,
If the elapsed time of the first (n +1) is not shorter than the elapsed time of the first (n + 2), the initial value of the variable n as 0, elapsed time elapsed the (n + 1) -th of the first (n + 2) Every time the variable n is incremented by 1 until the time becomes shorter than the time, the (n + 1) th elapsed time and the (n + 2) elapsed time are compared, and the (n + 1) th elapsed time is becomes shorter than the elapsed time of the (n + 2), and sets as the first (n + 1) the aperture value and the exposure time at the time of still image shooting aperture value and the exposure time of the first (n + 1) of Imaging device. An imaging device capable of taking still images during movie shooting,
Imaging means for imaging a subject;
An aperture control means for controlling the amount of light incident on the imaging means by driving an aperture mechanism;
Exposure time control means for controlling the exposure time of the imaging means;
Luminance information acquisition means for acquiring luminance information of the subject;
Based on the luminance information acquired by the luminance information acquisition means, calculating means for calculating the aperture value of the aperture mechanism during still image shooting and the exposure time during still image shooting;
The aperture drive time required to change the aperture mechanism from the aperture value at the time of moving image shooting to the (n + 1 ) th aperture value calculated by the calculating means and the (n + 1 ) th aperture value for moving image shooting the (n the diaphragm driving time required to change the aperture value and is calculated by the calculating means in correspondence to the aperture value of the a diaphragm driving time of the (n + 1) obtained by adding the (n + 1) + and the (n + 1) elapsed time which is the sum of the exposure time of 1), computed by said computing means apart than the aperture value of the said diaphragm mechanism from the aperture value at the time of moving image shooting (n + 1) th The aperture drive time required to change to the (n + 2 ) th aperture value and the aperture drive time required to change from the (n + 2 ) th aperture value to the aperture value for moving image shooting are added. the (n + 2) of the diaphragm driving time and the Comparing means (n + 2) aperture value in correspondence of the comparing, and the elapsed time of the which is the sum of the exposure time of the (n + 2) which is calculated (n + 2) by said calculating means,
When the (n + 1 ) elapsed time is shorter than the (n + 2 ) elapsed time based on the comparison result of the comparison means, the (n + 1 ) aperture value and the (n + 1 ) th are Setting means for setting the exposure time as the aperture value and the exposure time at the time of still image shooting ,
If the elapsed time of the first (n +1) is not shorter than the elapsed time of the first (n + 2), the initial value of the variable n as 0, elapsed time elapsed the (n + 1) -th of the first (n + 2) Every time the variable n is incremented by 1 until the time becomes shorter than the time, the (n + 1) th elapsed time and the (n + 2) elapsed time are compared, and the (n + 1) th elapsed time is becomes shorter than the elapsed time of the (n + 2), and sets as the first (n + 1) the aperture value and the exposure time at the time of still image shooting aperture value and the exposure time of the first (n + 1) of Imaging device. An image capturing unit that captures an image of an object, an aperture control unit that controls an amount of light incident on the image capturing unit by driving an aperture mechanism, and an exposure time control unit that controls an exposure time of the image capturing unit. A method for controlling an image pickup apparatus capable of taking a still image,
A luminance information acquisition step for acquiring luminance information of the subject;
Based on the luminance information acquired in the luminance information acquisition step, a calculation step of calculating the aperture value of the aperture mechanism at the time of still image shooting and the exposure time at the time of still image shooting;
The (n + 1 ) aperture driving time and the (n + 1 ) aperture required to change the aperture mechanism from the aperture value at the time of moving image shooting to the (n + 1 ) aperture value calculated in the calculation step. wherein a first (n + 1) elapsed time which is the sum of the exposure time of the calculated in the calculating step to correspond to the value (n + 1), the diaphragm mechanism from the aperture value at the time of moving image shooting the (n + 1 ) the (n + 2 ) th aperture driving time and the (n + 2 ) th aperture value required to change to the (n + 2 ) th aperture value calculated in the calculation step that is further away from the aperture value. a comparison step of comparing, the elapsed time of the (n + 2) is the sum of the exposure time of the (n + 2) calculated in the calculating step to correspond,
Based on the comparison result of the comparison step, when the (n + 1 ) elapsed time is shorter than the (n + 2 ) elapsed time, the (n + 1 ) aperture value and the (n + 1 ) th time And setting the exposure time as the aperture value and the exposure time during still image shooting ,
If the elapsed time of the first (n +1) is not shorter than the elapsed time of the first (n + 2), the initial value of the variable n as 0, elapsed time elapsed the (n + 1) -th of the first (n + 2) Every time the variable n is incremented by 1 until the time becomes shorter than the time, the (n + 1) th elapsed time and the (n + 2) elapsed time are compared, and the (n + 1) th elapsed time is When the (n + 2) is shorter than the elapsed time, and setting an exposure time of the (n + 1) th aperture value and the second of (n + 1) as the aperture value and the exposure time at the time of still image shooting,
A method for controlling an imaging apparatus, comprising: An image capturing unit that captures an image of an object, an aperture control unit that controls an amount of light incident on the image capturing unit by driving an aperture mechanism, and an exposure time control unit that controls an exposure time of the image capturing unit. A method for controlling an image pickup apparatus capable of taking a still image,
A luminance information acquisition step for acquiring luminance information of the subject;
Based on the luminance information acquired in the luminance information acquisition step, a calculation step of calculating the aperture value of the aperture mechanism at the time of still image shooting and the exposure time at the time of still image shooting;
For the moving image from the aperture value of the diaphragm (n + 1) th aperture driving time required for changing the aperture value and said the mechanism from aperture for movie recording is calculated by the calculation step (n + 1) the (n the diaphragm driving time required to change the aperture value and is calculated by the calculating step in correspondence to the aperture value of the a diaphragm driving time of the (n + 1) obtained by adding the (n + 1) + and the (n + 1) elapsed time which is the sum of the exposure time of 1), is calculated by the calculating step away than the aperture value of the said diaphragm mechanism from the aperture value at the time of moving image shooting (n + 1) th The aperture drive time required to change to the (n + 2 ) th aperture value and the aperture drive time required to change from the (n + 2 ) th aperture value to the aperture value for moving image shooting are added. the (n + 2) of the diaphragm driving time and the A comparing step (n + 2) aperture value in correspondence of the comparing, and the elapsed time of the (n + 2) is the sum of the exposure time of the (n + 2) calculated in the calculating step,
Based on the comparison result of the comparison step, when the (n + 1 ) elapsed time is shorter than the (n + 2 ) elapsed time, the (n + 1 ) aperture value and the (n + 1 ) th time And setting the exposure time as the aperture value and the exposure time during still image shooting ,
If the elapsed time of the first (n +1) is not shorter than the elapsed time of the first (n + 2), the initial value of the variable n as 0, elapsed time elapsed the (n + 1) -th of the first (n + 2) Every time the variable n is incremented by 1 until the time becomes shorter than the time, the (n + 1) th elapsed time and the (n + 2) elapsed time are compared, and the (n + 1) th elapsed time is When the (n + 2) is shorter than the elapsed time, and setting an exposure time of the (n + 1) th aperture value and the second of (n + 1) as the aperture value and the exposure time at the time of still image shooting,
A method for controlling an imaging apparatus, comprising:

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