JP2018014658A - Imaging apparatus and control method of imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of capturing a still image on a suitable focus position even when performing imaging for ranging/photometry during continuous shooting.SOLUTION: An imaging apparatus includes: still image capturing means for storing electric charge for a still image and reading out the stored electric charge by an imaging unit; ranging/photometric imaging means for storing electric charge for ranging/photometry and reading out the stored electric charge by the imaging unit; continuous shooting means for alternately actuating still image capturing and ranging/photometric imaging; exposure determination means for determining an exposure control value of succeeding ranging/photometric imaging and an exposure control value for succeeding still image capturing on the basis of a photometric imaging result during storage of electric charge for the still image and reading of the stored electric charge; and focus control means, when the exposure control value for the succeeding ranging/photometric imaging is determined, for calculating start timing of the succeeding still image capture, and during reading of the stored electric charge for the still image, for controlling a focus lens on the basis of the ranging imaging result and the still image capture start timing during reading of the stored electric charge for the still image.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging apparatus and a method for controlling the imaging apparatus, and more particularly to an imaging apparatus capable of performing continuous shooting using distance measurement and photometry results by an imaging sensor, and control of the imaging apparatus.

  2. Description of the Related Art Conventionally, there has been provided an imaging apparatus that can continuously shoot while adjusting the focus and exposure according to the movement and change of a subject.

  In such an imaging device, during continuous shooting, in addition to still image imaging processing, distance measurement processing and photometry processing are performed, and focus lens driving and aperture driving are performed as needed using the results, thereby focusing and exposure. Are combined. As distance measurement and photometry methods, charge is accumulated and read out in a specific drive mode using a dedicated sensor such as a distance measurement sensor or photometry sensor, or an imaging sensor capable of phase difference AF. There is a method of measuring the distance and brightness of the subject based on the information obtained therefrom.

  The distance measurement method using this imaging sensor is different from contrast AF (a method that detects multiple edges while moving the focus lens and detects edges to adjust the focus), and completes the distance measurement with a single imaging process. Therefore, high-speed focusing is possible.

  Here, consider a case where continuous shooting is performed using the distance measurement and photometry results obtained by the image sensor described above. First, charge is stored and read out by driving a still image pickup sensor to obtain recording still image data. Next, the distance measurement / photometry data is obtained by accumulating and reading out charges by driving the distance measurement / photometry image sensor. Here, by performing predetermined calculation processing using the obtained information, the distance and brightness of the subject are obtained, and in order to acquire the next recording still image data, charge is accumulated by driving the still image sensor. I do.

  After that, during the still image data readout period, the focus lens is driven and focused according to the determined subject distance, and an appropriate exposure value is determined according to the determined subject brightness, and Drive the aperture to the original. After the readout of the still image data and the focus lens / aperture driving are completed, the operation returns to the above-described charge accumulation and readout processing by the distance measurement / photometry sensor drive, and these operations are repeated.

  According to the above-described method, it is possible to continuously shoot while adjusting the focus and exposure according to the movement and change of the subject, and to adjust the focus and exposure in parallel with the charge accumulation and readout period of the imaging sensor. Since this process is performed, continuous shooting can be performed at high speed.

  In Patent Document 1, in an imaging apparatus using an imaging sensor capable of phase difference AF, the distance and brightness of an object are obtained using data obtained by still image imaging processing, and further stored for still images. The focus lens and the aperture are driven during the charge readout period so that the continuous shooting speed is not slowed down.

Japanese Patent Laid-Open No. 2006-18033

  However, when continuous shooting is performed according to the above-described processing flow, since the distance measurement / photometry data acquisition process is performed after the focus lens is driven, still image shooting for recording is not performed immediately. Therefore, in the case of a moving subject, even if the focus lens is driven to the optimal focus position at the timing when the distance measurement data is acquired, time has passed at the timing of still image shooting and is not the optimal focus position. May have.

  In order to solve this, a method of storing a plurality of obtained distance measurement results, calculating the moving speed of the subject, and driving the focus lens by predicting the subject distance for the next still image shooting timing Can be considered. However, since the charge accumulation time by driving the distance measuring / photometric imaging sensor fluctuates, it is difficult to accurately know the next still image shooting timing when driving the focus lens.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an imaging apparatus capable of capturing a still image at an appropriate focus position even when performing distance measurement / photometry imaging during continuous imaging.

In order to achieve the above object, an imaging apparatus according to the present invention includes:
Still image pickup means for storing charge for still image and reading of stored charge by the image pickup section, and distance measurement / photometry image pickup means for storing charge for distance measurement / photometry and reading of the stored charge by the image pickup section And continuous shooting means that alternately operate the still image pickup and the distance measurement / photometry imaging, and the next distance measurement / photometry based on the result of the photometry image pickup while storing the charge for the still image and reading the stored charge In response to the determination of the exposure control value for imaging and the exposure control value for the next still image imaging, and the exposure control value for the next ranging / photometric imaging, the next still image imaging And a focus control means for controlling the focus lens based on the distance measurement imaging result and the still image imaging start timing during the readout of the stored charge for the still image.

  According to the present invention, it is possible to provide an imaging apparatus capable of capturing a still image at an appropriate focus position even when performing distance measurement / photometry imaging during continuous imaging.

It is a flowchart which shows operation | movement of the imaging device of a present Example. It is a block diagram which shows the imaging device of a present Example. 6 is a timing chart illustrating an operation of the imaging apparatus according to the present exemplary embodiment. 6 is a timing chart illustrating an operation of the imaging apparatus according to the present exemplary embodiment.

  Hereinafter, examples of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. The embodiments of the present invention show preferred modes of the invention and do not limit the scope of the invention.

[Example]
In this embodiment, an imaging apparatus capable of performing continuous shooting using distance measurement and photometry results obtained by an imaging sensor will be described.

  Hereinafter, the main configuration of the imaging apparatus 200 according to the present embodiment will be described with reference to FIG.

  In FIG. 2, reference numeral 200 denotes an imaging device. The system control unit 201 includes, for example, a CPU (MPU), a memory (DRAM, SRAM), and the like, executes various processes (programs) to control each block of the imaging apparatus 200, and transfers data between the blocks. To control. Further, the system control unit 201 controls each block of the imaging device 200 in accordance with an operation signal from the operation unit 202 that receives an operation from the user.

  The operation unit 202 includes switches for inputting various operations related to photographing such as a power button and a shutter button. Further, it includes a menu display button, a determination button, other cursor keys, a pointing device, a touch panel, and the like. When these keys and buttons are operated by the user, an operation signal is transmitted to the control unit 201.

  The focus lens 203 is a lens for adjusting the focus of the optical image formed on the image sensor 209. Upon receiving an instruction from the system control unit 201, the focus control unit 204 controls the focus lens 203 based on the subject distance information obtained by the distance measuring unit 212. The diaphragm 205 operates to adjust the amount of light taken into the image sensor 209 and acquire an image with appropriate exposure. In response to an instruction from the system control unit 201, the aperture control unit 206 controls the aperture 205 based on the brightness information of the subject obtained by the photometry unit 213.

  The shutter 207 operates to block light taken into the image sensor 209. A shutter control unit 208 controls the shutter 207 in response to an instruction from the system control unit 201. In the case of still image shooting, light is taken into the image sensor 209 and control is performed so that the shutter 207 is opened during a period during which charges are accumulated, and shutter 207 is controlled during a period during which accumulated charges are read out. Note that the stored charge is read by closing the shutter 207 or performing electronic shutter control while the shutter 207 is open.

  The image sensor 209 includes a CMOS sensor and its peripheral circuit, converts an optical image of a subject captured by the lens into an image signal, performs analog-digital conversion, and transmits the image signal to the image processing unit 211. The image sensor 209 has a plurality of driving methods. One is a still image sensor drive for capturing a recording still image in accordance with a shooting instruction from a user. Furthermore, there is a through-image sensor drive that continuously generates images at a predetermined frame rate in order to perform framing before shooting. The other is a distance measurement / photometry sensor drive that acquires evaluation values for measuring the distance and brightness of a subject.

  Each pixel of the image pickup device 209 includes two different microlenses of the image pickup optical system so that an image can be obtained by receiving the light flux that has passed through each of the microlenses. The focus shift amount can be detected from the shift amount of two images of each pixel, that is, an image obtained by passing through one microlens and an image obtained by passing through the other microlens. Thus, by driving the image sensor 209 for distance measurement, an evaluation value for measuring the distance of the subject can be acquired. In addition, the brightness of the subject can be measured simultaneously by driving the sensor at this time.

  Note that when the distance is measured by the image sensor 209, the distance measurement accuracy decreases as the aperture is narrowed down. Therefore, in order to obtain distance measurement accuracy, the aperture 205 needs to be opened to the open side with respect to a predetermined aperture value (for example, F8). The evaluation value obtained by driving the distance measuring / photometric sensor is transmitted to the distance measuring means 212 and the photometric means 213. The imaging control unit 210 controls the timing of switching the driving method of the imaging element 209, charge accumulation, reading, and the like.

  The image processing unit 211 performs image quality adjustment processing for adjusting white balance, color, brightness, and the like on the input digital signal based on setting values. The image signal processed by the image processing unit 211 is transmitted to the display unit 214 for display, or a compressed image signal is generated for recording and transmitted to the image memory 215. Furthermore, the image processing unit 211 can extract subject information in the image by performing predetermined image analysis processing on the input digital signal. For example, it is possible to determine whether there is a person (face) or an object in the image, and to determine in which position in the image the subject is present. The extracted subject information is transmitted to the system control unit 201.

  The distance measuring means 212 measures the distance of the subject based on the evaluation value obtained by driving the distance measuring / photometric sensor of the image sensor 209. Specifically, as described above, the focus shift amount is calculated from the shift amount of the two images obtained from the image sensor 209, and the distance of the subject is measured.

  The photometric unit 213 measures the brightness of the subject based on the evaluation value obtained by driving the distance measuring / photometric sensor of the image sensor 209. Specifically, the brightness of the subject is measured by obtaining the luminance in the whole or a predetermined area from the image signal obtained from the image sensor 209 using an integration circuit or the like.

  The display unit 214 displays an image based on the image signal transmitted from the image processing unit 211, an operation screen (menu screen) for operating the imaging apparatus 200, and the like. The display unit 214 may be any display device such as a liquid crystal display, an organic EL display, and electronic paper.

  The image memory 215 temporarily stores the compressed image signal encoded for recording and sequentially writes it out to the recording unit 216. The written image data is deleted from the image memory 215 so that the next image can be stored. The image memory 215 is composed of a DRAM or the like, and the larger the capacity, the larger the number of recording images that can be temporarily stored. Therefore, even when the writing time to the recording unit 216 takes a long time, continuous high-speed shooting is continuously performed. Will be able to.

  The recording unit 216 records the compressed image signal stored in the image memory 215 on a recording medium. The recording medium may be a recording medium built in the imaging apparatus or a removable recording medium as long as the compressed image signal generated by the imaging apparatus 200 and various data can be recorded. For example, the recording medium includes all types of recording media such as a hard disk, an optical disk, a magneto-optical disk, a CD-R, a DVD-R, a magnetic tape, a nonvolatile semiconductor memory, and a flash memory.

  Next, a characteristic operation of the imaging apparatus 200 of the present embodiment will be described.

  The imaging apparatus 200 according to the present exemplary embodiment can execute a characteristic operation of capturing a still image at an appropriate focus position even when performing distance measurement / photometry imaging during continuous shooting.

  Hereinafter, a first operation of the imaging apparatus 200 in continuous shooting according to the present embodiment will be described with reference to FIG.

  When a user presses a shutter button included in the operation unit 202, an instruction to start continuous shooting is transmitted to each block of the imaging apparatus 200.

  In step S100, the image sensor 209 is driven by driving the distance measurement / photometry sensor, and charges are accumulated to acquire evaluation values for distance measurement / photometry.

  In S101, the charge accumulated in the image sensor 209 is read, and an evaluation value for distance measurement / photometry is acquired. Here, reading is performed by electronic shutter control with the shutter 207 open. Note that reading may be performed by controlling the shutter 207 to be closed by the shutter control unit 208 instead of the electronic shutter control. In that case, control is performed so that the shutter 207 is opened after reading.

  In S102, using the obtained evaluation value for distance measurement / photometry, the distance measurement means 212 performs distance measurement calculation and the light measurement means 213 performs light measurement calculation. In the distance measurement calculation / photometry calculation performed here, optimal focus / exposure adjustment is performed on the position of the subject (person / face / object) detected based on the subject information extracted by the image processing unit 211. Perform the operation. For example, the distance measurement information is acquired by the above-described method to focus on the detected subject, and the weighting of the photometry is increased with respect to the subject position to be focused, and exposure is performed based on the photometry result. To control.

  In this way, by using the object detection result for both the distance measurement calculation and the photometry calculation at the same time, the position for focusing and the position for performing the exposure match, and an optimal image can be obtained. It should be noted that the photometric calculation here determines the accumulation time for taking the still image of the first frame and the accumulation time for acquiring the evaluation value for distance measurement / photometry performed after the still image shooting of the first frame.

  In S103, the amount of change in the subject distance at the timing of still image shooting for the first frame is predicted based on the distance information of the subject obtained by the distance measurement calculation. When shooting a moving subject, even if the optimum focus position is determined at the timing when the distance measurement information is acquired, a time elapses from when the focus control is performed until the still image is shot. Image data may not be obtained. Therefore, it is predicted how much the subject moves from when the distance measurement information is acquired to when the actual still image is taken, and the focus lens is driven in advance toward the predicted position.

  Before the start of continuous shooting, the imaging apparatus 200 periodically obtains an evaluation value for distance measurement / photometry, and the distance measurement result immediately before the start of continuous shooting is stored in the memory of the system control unit 201. . The stored distance measurement result a1, its acquisition time t1, and the distance measurement result a2 obtained in S102 and its acquisition time t2 are used to predict the amount of change in the subject distance.

  Specifically, the subject distance change speed (a2-a1) / (t2-t1) is obtained from the difference in subject distance (a2-a1) and the difference in acquisition time (t2-t1), and the processing time of S104 to be described later Can be used to predict the amount of change in the subject distance at the timing of still image shooting for the first frame.

  In step S104, the focus control unit 204 controls the focus lens 203 based on the distance measurement result obtained in step S102 and the subject distance change obtained in step S103. Align. Further, based on the brightness information of the subject obtained by the photometric calculation, the aperture control unit 206 controls the aperture 205 to perform appropriate exposure adjustment for still image shooting of the first frame. Note that the focus lens 203 may not be controlled when the focus lens 203 is already in the optimum focus position for taking a still image of the first frame.

  In addition, the aperture 205 is already at the optimal aperture position for the first frame still image shooting, and adjustment of various shooting parameters such as the shutter speed and sensor sensitivity allows optimal exposure without controlling the aperture 205. When photographing can be performed, the aperture 205 need not be controlled. As for the processing time of S104 required for the subject distance prediction described above, the control time of the focus lens 203 and the control time of the aperture 205 are parameterized according to the control amount, and the focus or focus is controlled based on the corresponding control amount. The longer one of the aperture control times is set as the processing time in S104.

  In S105, the image sensor 209 is driven by driving the still image sensor, and charges are accumulated for acquiring still image data.

  In S106, the amount of change in the subject distance at the timing of the still image shooting for the second frame is predicted based on the distance information of the subject obtained by the distance measurement calculation. Here, as with the subject distance change prediction in S103, the distance measurement result a1 immediately before the start of continuous shooting and its acquisition time t1, and the distance measurement result a2 obtained in S102 and its acquisition time t2 are used. Predict the amount of change in subject distance.

  Specifically, the change speed (a2-a1) / (t2-t1) of the subject distance is obtained from the difference in subject distance (a2-a1) and the difference in acquisition time (t2-t1). By multiplying the time until the shooting time, the amount of change in the subject distance at the timing of the still image shooting for the second frame can be predicted.

  Here, a method of calculating the time until the still image shooting time of the second frame will be described. The first frame still image shooting time is t, and the first frame still image storage time ta, its readout time tb, and the evaluation value for distance measurement / photometry performed after the first frame still image shooting is acquired. By using the time Δt1 obtained by adding the accumulation time tc and the read time td, the still image shooting time (t + Δt1) for the second frame can be calculated. The accumulation times ta and tc are determined by the photometric calculation in S102.

  The readout times tb and td are parameters that depend on the image sensor 209 and are fixed numerical values. Further, when controlling the diaphragm in S113 described later, the diaphragm control time is further added to Δt1. Whether or not the aperture needs to be controlled in S113 is also determined by the photometric calculation in S102. The imaging apparatus 200 also has a frame speed stabilization function for keeping the frame speed of continuous shooting constant even when the shooting conditions change. This is to prevent the second frame still image from being shot until the frame speed stabilization time Δt2 has elapsed from the first frame still image shooting time t. When Δt1> Δt2, the still image shooting time of the second frame is (t + Δt1), but when Δt1 <Δt2, the still image shooting time of the second frame is (t + Δt2). By using the time until the still image shooting time of the second frame calculated in this way, the subject distance change amount prediction in S106 is performed.

  In step S107, the shutter control unit 208 controls the shutter 207 to close, reads the charges accumulated in the image sensor 209, and acquires still image data. Further, during reading of the still image, the focus control unit 204 controls the focus lens 203 based on the distance measurement result obtained in S102 and the subject distance change obtained in S106, and the second frame. The camera focuses best for still image shooting. Further, during reading of a still image, the aperture 205 is controlled so as to obtain an optimum aperture value for obtaining the evaluation value in S109 based on the photometric result obtained in S102.

  Here, the optimum aperture value for obtaining the evaluation value satisfies the conditions necessary for imaging the subject by using the image sensor 209 for phase difference AF, and is as identical as possible when shooting a still image of the next frame. Aperture value. For example, when imaging an object using the image sensor 209 for phase difference AF, the aperture value of the aperture 205 needs to be opened to the open side (including F8) from F8 for the reason of providing distance measurement accuracy. Suppose there is.

  In this case, if the aperture value for proper exposure adjustment for still image shooting of the next frame is F4, it is closer to F4 than F8, so it may be limited to the same F4 as that for still image shooting ( This is called “aperture value suitable for still image acquisition”). If the aperture value for adjusting the exposure appropriate for still image shooting of the next frame is F11, it is on the smaller aperture side than F8, so here the limit aperture value for F for phase difference AF is set to F8. Aperture (referred to as “aperture value suitable for evaluation value calculation”).

  In S108, it is determined whether or not the continuous shooting is to be ended by checking whether or not the shutter button included in the operation unit 202 is continuously pressed by the user. If the continuous shooting is to be continued, the process proceeds to S109.

  In step S109, the image sensor 209 is driven by driving the distance measuring / photometric sensor, and charges are accumulated to acquire an evaluation value for distance measuring / photometric measurement.

  In S110, the charge accumulated in the image sensor 209 is read, and an evaluation value for distance measurement / photometry is acquired.

  In S <b> 111, a display image is generated by the image processing unit 211 from the read evaluation value data, and the display image is displayed by the display unit 214. By displaying the latest captured image here during continuous shooting, it becomes easier for the user to take a picture while checking the subject.

  In S112, it is determined whether or not the aperture value of the aperture 205 is the “aperture value suitable for still image acquisition” described above. If it is “aperture value suitable for still image acquisition”, the process proceeds to S114. If “aperture value suitable for evaluation value calculation”, the process proceeds to S113. In the case of the above-described example, if the aperture value for still images is F4, it is already “aperture value suitable for still image acquisition”, and if the aperture value for still images is F11, “appropriate for evaluation value calculation”. "Aperture value".

  In S113, control is performed so that the aperture value of the aperture 205, which is “aperture value suitable for evaluation value calculation”, becomes “aperture value suitable for still image acquisition”.

  In S114, as described above, it is determined whether or not the frame speed stabilization time Δt2 has elapsed from the previous frame shooting time t. If it is not the frame speed stabilization time, the process returns to S114 to determine the frame speed stabilization time and If yes, the process proceeds to S115.

  In S115, the image sensor 209 is driven by driving the still image sensor, and charges are accumulated for acquiring still image data. During accumulation of still images, the distance measurement unit 212 performs distance measurement calculation and the photometry unit 213 performs photometry calculation using the distance measurement / photometry evaluation value obtained in S110. If the aperture value is suitable for evaluation value calculation in S112, the distance measurement calculation and the photometry calculation are performed while performing aperture control to “aperture value suitable for still image acquisition” in S113. You may do it. In addition, by the photometric calculation here, the accumulation time for taking the still image of the next frame and the accumulation time for acquiring the next distance measurement / photometry evaluation value are determined.

  In S116, based on the distance information of the subject obtained by the distance measurement calculation, the amount of change in the subject distance at the still image shooting timing of the next frame is predicted. Here, as with the subject distance change prediction in S106, the distance measurement result a2 obtained in S115 and its acquisition time t2, and the distance measurement result a1 obtained by obtaining the previous evaluation value for distance measurement. And the change amount of the subject distance is predicted by using the acquisition time t1. Specifically, the subject distance change speed (a2-a1) / (t2-t1) is obtained from the subject distance difference (a2-a1) and the acquisition time difference (t2-t1), and the still image of the next frame is obtained. By multiplying the time until the shooting time, the amount of change in the subject distance at the timing of still image shooting of the next frame can be predicted.

  Here, a method of calculating the time until the still image shooting time of the next frame will be described. Assume that the n-th still image shooting time is t, the (n + 1) -th still image storage time ta, its readout time tb, and the evaluation value for distance measurement / photometry performed after the n-th frame still image shooting. By using the time Δt1 obtained by adding the accumulation time tc and the read time td, the still image shooting time (t + Δt1) of the (n + 1) th frame can be calculated. The accumulation times ta and tc are determined by the photometric calculation in S115. The readout times tb and td are parameters that depend on the image sensor 209 and are fixed numerical values.

  In addition, when the aperture is controlled in S113 before the (n + 1) -th frame still image shooting, the aperture control time is further added to Δt1. Whether or not the diaphragm needs to be controlled in S113 is also determined by the photometric calculation in S115. Further, due to the frame speed stabilization function, when Δt1> Δt2, the still image shooting time of the next frame is (t + Δt1), but when Δt1 <Δt2, the still image shooting time of the next frame is (t + Δt2). . By using the time until the still image shooting time of the next frame calculated in this way, the subject distance change amount prediction in S116 is performed.

  In step S117, the shutter control unit 208 controls the shutter 207 to close, reads the charges accumulated in the image sensor 209, and obtains still image data. Further, during reading of the still image, the focus control unit 204 controls the focus lens 203 based on the distance measurement result obtained in S115 and the subject distance change obtained in S116, and the next frame is read. The camera focuses best for still image shooting. During reading of a still image, the aperture 205 is controlled based on the photometric result obtained in S115 so as to obtain an optimum aperture value for obtaining the evaluation value in the next S109. Then, the process returns to S108.

  A specific operation example according to this embodiment will be described with reference to FIGS. In FIG. 3A, photometric calculation is performed during the n-th still image shooting period. At this time, the (n + 1) -th still image storage time is obtained and the n-th still image shooting is performed. The accumulation time tc for the evaluation value performed after is obtained. Therefore, (t + Δt1) calculated based on tc obtained here is used as the still image shooting time of the (n + 1) -th frame, and the subject distance change amount is predicted to drive the focus lens.

  Further, in FIG. 3B, the accumulation time tc for the evaluation value obtained after the n-th frame still image shooting is obtained in the same manner, and the calculated (n + 1) -th frame still image shooting time is calculated based on this. The frame speed stabilization time Δt2 is longer than the time Δt1. Therefore, here, (t + Δt2) is set as the still image shooting time of the (n + 1) -th frame, and the focus lens driving is performed by predicting the subject distance change amount.

  As described above, by calculating the still image shooting time of the next frame, predicting the subject distance change amount, and driving the focus lens, it is appropriate even when shooting for distance measurement and photometry during continuous shooting It is possible to shoot still images at a precise focus position.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

200 imaging device, 201 system control unit, 202 operation unit,
203 Focus lens, 204 Focus control means, 205 Aperture,
206 Aperture control means, 207 shutter, 208 shutter control means,
209 imaging device, 210 imaging control means, 211 image processing means, 212 distance measuring means,
213 Photometric means, 214 display unit, 215 image display memory, 216 recording unit

Claims (2)

Still image capturing means for storing charges for still images and reading out the stored charges by the imaging unit;
Ranging / photometric imaging means for accumulating charge for distance measurement / photometry and reading out the accumulated charge by the imaging unit;
Continuous shooting means for alternately operating still image shooting and distance measurement / photometry imaging;
During charge accumulation for still image and readout of accumulated charge, exposure determination for determining exposure control value for next distance measurement / photometry imaging and exposure control value for next still image imaging based on photometric imaging result Means,
In response to the determination of the exposure control value for the next distance measurement / photometry imaging, the next still image imaging start timing is calculated, and the distance measurement imaging result and the still image are read while the stored charge for the still image is being read. An imaging apparatus comprising: focus control means for controlling the focus lens based on imaging start timing. It further has a frame speed stabilization means for keeping the interval of each still image imaging start timing of continuous shooting constant, and in addition to the distance measurement imaging result and still image imaging start timing, the focus lens based on the frame speed stabilization timing The imaging apparatus according to claim 1, wherein the imaging apparatus is controlled.