JP2018014680A - Imaging apparatus, control method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus which is compatible with change of an imaging field angle and proper exposure control.SOLUTION: A camera 100 which is an imaging apparatus includes: a motion determination unit 115 for determining whether the camera 100 is searching for a subject on the basis of the movement of the imaging apparatus detected by a shake detection sensor 101; a zoom control unit 116 that performs control to change a field angle when the motion determination unit 115 determines that the subject is being searched for; and an evaluation value calculation unit 122 that performs exposure control by switching from a first mode to a second mode when the change of the field angle is started.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging apparatus, a control method, and a program.

In recent years, an increase in magnification of an imaging apparatus including an optical zoom for driving a zoom lens and an electronic zoom for enlarging a part of a captured image has been advanced. When a user zooms using such a high-magnification machine and images a subject in a telephoto state, it is difficult to operate the subject so that it is within the angle of view, so the subject is frequently framed in and out. Will occur.
In Patent Document 1, when it is determined that the user is performing an operation of searching for a subject based on the amount of movement of the imaging device, the shooting angle of view is zoomed out, and when it is determined that the user has recaptured the subject, A technique for zooming in the angle of view is disclosed.

JP2015-102853A

  However, when the imaging apparatus automatically changes the shooting angle of view as in the technique described in Patent Document 1, a subject (subject other than the main subject) not intended by the user is included in the angle of view. In this case, functions such as subject detection for detecting a person's face, scene detection for discriminating a shooting scene, and automatic exposure control operate on a subject not intended by the user, which is preferable for imaging the main subject. May not be set.

  It is an object of the present invention to provide an imaging apparatus that achieves both a change in shooting angle of view and appropriate exposure control.

  In order to solve the above problems, an imaging apparatus according to the present invention includes: a determination unit that determines whether or not the imaging device is searching for a subject based on the movement of the imaging device detected by the detection unit; When it is determined that the subject is being searched, zoom control means for performing control to change the angle of view, and when the change of the angle of view is started, the exposure control is switched from the first mode to the second mode. Exposure control means.

  According to the present invention, it is possible to provide an imaging apparatus that can simultaneously change the shooting angle of view and perform appropriate exposure control.

It is a block diagram showing an example of composition of an imaging device concerning a 1st embodiment. It is an image figure explaining FA zoom. It is a figure explaining the process of the evaluation value in an evaluation value calculation part. It is a flowchart figure explaining FA zoom operation | movement. It is a figure explaining FA zoom operation | movement. It is a flowchart explaining an exposure control operation. It is a flowchart explaining an exposure control operation. It is a block diagram which shows the structural example of the imaging device which concerns on 2nd Embodiment. It is a figure explaining exposure control mode. It is a flowchart which shows the transition of exposure control mode.

(First embodiment)
FIG. 1 is a block diagram showing a configuration of a digital camera (camera) 100 according to an imaging apparatus implementing the present invention. One or more of the functional blocks shown in FIG. 1 may be realized by hardware such as an ASIC or a programmable logic array (PLA), or may be realized by a programmable processor such as a CPU or MPU executing software. May be. Further, it may be realized by a combination of software and hardware. Therefore, in the following description, even when different functional blocks are described as the operation subject, the same hardware can be realized as the subject.

  A camera 100 illustrated in FIG. 1 has an automatic shooting angle of view change function (hereinafter referred to as an FA (framing assist) zoom function). Further, the camera 100 described in the present embodiment has a blur function, and calculates the amount of motion of the FA zoom imaging device using shake information of the imaging device detected for blur correction. However, a motion amount detection sensor dedicated to FA zoom may be provided, and it is not essential to provide a blur correction function in order to realize the FA zoom function.

First, a configuration related to the blur correction function will be described. A shake (motion) applied to the camera 100 is detected by a shake detection sensor 101. An example of the shake detection sensor 101 is an angular velocity sensor that detects a shake (motion) of the camera 100 as an angular velocity. The microcomputer (μCOM) 102 performs signal processing on the output of the shake detection sensor 101.
The μCOM 102 includes a shake correction amount calculation unit 103, a subtracter 104, a control filter 105, and a shift lens control unit 106. The shake correction amount calculation unit 103 calculates a shake correction amount based on the output of the shake detection sensor 101. The blur correction amount is a value that drives the blur correction mechanism 108 to cancel the blur of the captured image. The shake correction amount calculation unit 103 includes an integrator, and converts the angular velocity signal output from the shake detection sensor 101 into an angle and outputs it.

The subtractor 104 outputs deviation data obtained by subtracting position data of a shake correction mechanism 108 (to be described later) from the output of the shake correction amount calculation unit 103 to the control filter 105.
The control filter 105 performs signal processing using an amplifier and a phase compensation filter on the deviation data output from the subtractor 104 and outputs a motor control amount to the shift lens control unit 106.
The shift lens control unit 106 drives the motor 107 by modulating the motor control amount to a waveform (PWM waveform) that changes the duty ratio of the pulse wave.

  The motor 107 is, for example, a voice coil type motor. When the motor 107 is driven, the blur correction mechanism 108 is moved in a direction different from the optical axis. An example of the blur correction mechanism 108 is a lens unit (shift lens) that can move in a direction different from the optical axis. However, although the shake correction mechanism 108 and the image sensor 110 are described separately in FIG. 1, the shake correction mechanism 108 may have a structure in which the image sensor 110 is on a movable unit and can move in a direction different from the optical axis. .

  The position detection sensor 109 is composed of a magnet and a hall sensor provided at a position opposite to the magnet. The position detection sensor 109 detects a movement amount of the shake correction mechanism 108 in a direction perpendicular to the optical axis, and obtains position data of the shake correction mechanism 108. It supplies to the subtractor 104 mentioned above. As a result, a feedback control system is configured in which the movement amount in the direction different from the optical axis of the blur correction mechanism 108 is made to follow the output of the blur correction amount calculation unit 103. As a result of the movement of the shake correction mechanism 108 based on the shake correction amount, an image in which the vertical or horizontal shake of the subject on the imaging surface caused by the shake of the camera 100 is corrected is formed on the image sensor 110. The

The imaging element 110 includes a plurality of photoelectric conversion units, converts a subject image formed by an imaging optical system including the blur correction mechanism 108 into an electrical signal as a captured image signal, and supplies the electrical signal to the signal processing unit 111.
The signal processing unit 111 generates a video signal (video signal) based on, for example, the NTSC format from the signal obtained by the image sensor 110, and supplies the video signal to the image memory 112 that temporarily stores the video signal. The video signal output from the image memory 112 is supplied to the recording control unit 113. The recording control unit 113 outputs and records the video signal supplied from the image memory 112 to the recording medium 114 when recording of a video signal is instructed by an operation unit (not shown) used for recording start and end instructions. . The recording medium 114 is, for example, an information recording medium such as a semiconductor memory or a magnetic recording medium such as a hard disk, and may be an external recording medium.

Next, a configuration related to the FA zoom function will be described.
The output of the shake detection sensor 101 is also supplied to the motion determination unit 115. Based on the amount of movement of the camera 100 detected by the shake detection sensor 101, the movement determination unit 115 determines whether the photographer is moving to search for a subject (subject search is in progress). When the photographer loses sight of the subject, it is assumed that the camera 100 is moved greatly in order to search for the subject. When the amount of motion is equal to or greater than the motion determination threshold, the motion determination unit 115 searches for the subject ( It is determined that the subject is being searched. On the other hand, when the subject is stably captured, the amount of motion of the camera 100 is small. Therefore, when the amount of motion is less than the stillness determination threshold, the photographer is capturing the subject (not searching for the subject). ). Note that the amount of motion is at least one of angular velocity, acceleration, or an angle calculated by integrating the angular velocity by a motion determination unit. Further, as the threshold values for motion determination and stillness determination, the threshold values calculated by the motion determination threshold value calculation unit 120 described later are used.

  The zoom control unit 116 receives a determination result of the motion determination unit 115 and supplies a zoom-out or zoom-in driving signal to the zoom motor 117. The zoom motor 117 is, for example, a stepping motor. When the stepping motor rotates, the feed screw rotates, and the zoom lens 118 is driven in the optical axis direction. The zoom control unit 116 calculates a drive signal having the number of pulses necessary to move the zoom lens 118 to the target position and inputs the drive signal to the zoom motor 117.

  A position scale (not shown) is fixed to the holding frame of the zoom lens 118 in order to detect the position of the zoom lens. A position detection sensor 119 is fixed at a position facing a position scale of a lens barrel (not shown). A scale pattern such as a magnetic pattern and a light reflection pattern is generated in the optical axis direction on the position scale, and the zoom lens 118 is read by the position detection sensor 119 reading a magnetic signal, a light reflection signal, and the like corresponding to the position of the scale. The position in the optical axis direction can be detected. The detection signal of the position detection sensor 119 is input to the zoom control unit 116 and used for position control of the zoom lens.

  The motion determination threshold value calculation unit 120 calculates a motion determination threshold value based on the current zoom position information obtained from the zoom control unit 116. This is because, even when the amount of movement of the camera 100 is constant, it is easier to lose sight of the subject when the zoom position is on the telephoto side than when it is on the wide-angle side. Therefore, it is preferable to determine the determination threshold based on the zoom position. Because. Specifically, in the case of the telephoto side, the threshold value is decreased in order to easily determine that the subject is being searched for even with a smaller amount of movement. On the other hand, in the case of the wide angle side, the threshold value is increased in order to easily determine that the subject is captured even with a larger amount of movement.

Here, a specific example of the FA zoom will be described with reference to FIG. FIG. 2A illustrates the movement of the subject. The camera 100 is moved from the left to the right in the figure in an attempt to catch the ball 200 that is a moving subject.
FIG. 2B shows a captured image taken by the camera 100 at this time, and FIG. 2C shows the amount of movement of the camera 100 detected by the shake detection sensor 101.
Prior to time t1, the camera 100 is not moved and the amount of movement is a small value. When the ball is released at time 1, the photographer moves the camera 100 in an attempt to catch this, and the output of the shake detection sensor 101 begins to increase.

At time t2, the photographer continues to move the imaging device in an attempt to avoid the ball from coming out of the frame, and the amount of movement further increases. Here, at time t2, when the amount of motion detected by the shake detection sensor 101 is equal to or greater than the motion determination threshold value calculated by the motion determination threshold value calculation unit 120, the motion determination threshold value calculation unit 120 searches for a subject. Determined. In response to the determination by the movement determination threshold value calculation unit 120, the zoom control unit 116 performs zoom-out control. As a result, at a time after time t2, the shooting angle of view becomes wide and the subject can be easily captured. After capturing the ball, the movement of the imaging device by the photographer is stable and the amount of movement is small.
Then, at time t3, when the amount of motion calculated by the motion determination threshold value calculation unit 120 is less than the stillness determination threshold value and it is determined that the subject is captured, the zoom control unit 116 performs zoom-in control. Note that the FA zoom ON / OFF button (not shown) can be switched between a state in which FA zoom is enabled and a normal shooting state in which the zoom is not zoomed out even when the amount of movement is large.

Returning to the description of FIG. 1, a configuration relating to exposure control will be described.
The image signal output from the image sensor 110 is separated into a luminance signal and a color signal in the signal processing unit 111, and each signal is input to the evaluation value calculation unit 122. In the evaluation value calculation unit 122, exposure control is performed based on the input signal. Further, the evaluation value calculation unit 122 includes a subject detection function for detecting a specific subject such as a human face and a scene detection function for detecting a scene such as a sunset scene. In the shooting setting unit 123, a photographer performs various settings including a subject detection function and a scene detection function. The subject detection function and the scene detection function may be configured to detect a specific subject or scene by any known method.

The exposure control will be described with reference to FIG.
FIG. 3A is a diagram illustrating exposure control based on the subject detection function. When a person is present in the photographed image, a face evaluation value calculation frame 301 in which the vertical and horizontal sizes and positions can be freely changed is set in the face portion of the person. Then, using the evaluation value in the face evaluation value calculation frame 301, the aperture motor 127 is operated until the human face is properly exposed to control the aperture diameter of the aperture 128. By adjusting the aperture diameter of the stop 128, the amount of light received by the image sensor is adjusted to control the exposure. This is called face exposure control.
FIG. 3B is a diagram for explaining exposure control based on the scene detection function. If an evening scene exists in the image being shot, only the evaluation frames indicated by the diagonal lines recognized as empty portions are extracted from the divided evaluation frames 302 obtained by dividing the entire screen into a plurality of portions. Then, the aperture motor 127 is operated to control the aperture diameter of the aperture 128 so that the average value of the plurality of evaluation frames becomes a predetermined luminance value. This is called scene exposure control. In the above description, the face exposure control and the scene exposure control are executed by controlling the aperture diameter of the diaphragm 128. However, each exposure parameter (accumulation time and gain) other than the aperture diameter of the diaphragm is used. Exposure control may be executed.

If no person is present in the image being photographed or if no sunset scene is present in the image being photographed, subject detection and scene detection do not operate. Even when the subject detection function or scene detection function is stopped by the shooting setting unit 123, subject detection or scene detection does not operate. In that case, an evaluation value is calculated using an evaluation frame (area) obtained by dividing the entire image.
FIG. 3C is a diagram illustrating exposure control based on evaluation value calculation. The weighted average value of the exposure level is increased by increasing the weight ratio (degree of weighting for the photometry result) of the central evaluation frame 303 (center area) on the screen indicated by the diagonal lines and lowering the weight ratio of the other divided frames. calculate. The aperture motor 127 is operated to control the aperture diameter of the aperture 128 so that the weighted average value becomes a predetermined luminance value. As a result, it is possible to photograph the subject captured at the center of the screen with a more appropriate exposure. This is called center-weighted exposure control.

FA zoom control for automatically performing zoom-out when the photographer is searching for a subject (during subject search) will be described with reference to the flowchart of FIG. 4 and the operation diagram of FIG.
In step S400, the zoom control unit 116 holds the current zoom position as the reference zoom position f0. The reference zoom position is a zoom position that is a target when returning to the original zoom position after changing the zoom position. That is, the process of S400 is a process necessary to return to the original zoom position after executing zoom-out and zoom-in.
In step S401, the zoom control unit 116 calculates a target zoom position f1 to be zoomed out. As shown in FIG. 5, the target zoom position f1 is set on the wide angle side from the reference zoom position f0. For example, when the amount of zooming out to the wide angle side in FA zoom is a value such as 1 / α times in terms of focal length, the target zoom position f1 is f0 / α. The value α for calculating the target zoom position is a predetermined fixed value or a value that can be set by the photographer through a menu operation.

In step S402, the motion determination unit 115 determines whether or not the photographer is searching for a subject (whether or not the subject is being searched). When it is determined that the photographer is searching for a subject (subject search is in progress), the process proceeds to step S403, and when it is determined that the subject is captured (subject search is not in progress), FA zoom is performed. The process ends without activating.
In step S403, the zoom control unit 116 performs zoom-out control, drives the zoom lens 118 by the zoom motor 117, and executes zoom-out.
In step S404, the zoom control unit 116 determines whether the current zoom position has reached the target zoom position f1 based on the output from the position detection sensor 119. If the target zoom position has been reached, the process proceeds to step S405. If the target zoom position has not been reached, the process of step S403 is repeated until the target zoom position is reached.

In step S405, the motion determination unit 115 determines whether or not the photographer is capturing the subject. If it is determined that the photographer is capturing the subject, the process proceeds to S406. On the other hand, when it is determined that the subject is being searched, the camera waits until it is determined that the photographer is capturing the subject with the zoom position held at f1.
In step S406, the zoom control unit 116 performs zoom-in control, the zoom motor 117 drives the zoom lens 118 to the reference zoom position f0, and the FA process ends.

Next, exposure control during FA zoom control will be described with reference to the flowcharts of FIGS. First, with reference to FIG. 6, a flow based on the premise that the subject detection function and the scene detection function are disabled when the FA zoom control is executed will be described.
In step S600, the evaluation value calculation unit 122 determines whether a face is detected by subject detection or a scene is detected by scene detection. If it is determined that none has been detected, the process proceeds to S605, where the center-weighted exposure control is performed, and the process ends. If it is determined in step S600 that a face is detected or a scene is detected, the process proceeds to step S601.

In step S601, the evaluation value calculation unit 122 determines whether FA zoom control has been started. If FA zoom control has not been started, the process proceeds to S604, where face exposure control or scene exposure control is performed and the process ends. If FA zoom control is started, the process proceeds to step S602.
When FA zoom control is started, zoom-out is performed, and subjects other than the main subject intended by the photographer also enter the angle of view as shown in the captured image at time t3 in FIG. Come. At this time, when the subject detection function is executed, a subject unintended by the photographer may be detected, and exposure control may be performed based on the subject. If exposure control is performed based on an unintended subject, exposure of the subject being searched for becomes too low, making it difficult to search for the subject. Therefore, in step S602, the evaluation value calculation unit 122 temporarily stops the subject detection function for detecting a face and the scene detection function for detecting a scene.
In step S <b> 603, the evaluation value calculation unit 122 performs center-part weighted exposure control.

In step S606, the evaluation value calculation unit 122 monitors whether the FA zoom control is being performed after performing the center-part weighted exposure control in step 603. If FA zoom control is in progress, the process remains in step S606 and monitoring is continued. On the other hand, if the FA zoom control is not being performed, the process proceeds to step S607.
In step S607, the subject detection function for detecting the face temporarily stopped in step S602 and the scene detection function for detecting a scene are resumed, and the process ends.

Next, referring to FIG. 7, a flow based on the premise that the exposure control is switched while the subject detection function and the scene detection function are enabled will be described.
In step S710, the evaluation value calculation unit 122 determines whether FA zoom control is being performed. If FA zoom control is in progress, the process proceeds to step S711, where the center-weighted exposure control is performed, and the process ends. On the other hand, if the FA zoom control is not being performed, the process proceeds to step S712.

In step S712, the evaluation value calculation unit 122 determines whether a face is detected by subject detection or a scene is detected by scene detection. When it is determined that none is detected, the evaluation value calculation unit 122 performs the center-weighted exposure control and ends the processing. If it is determined in step S712 that a face has been detected or a scene has been detected, the process proceeds to step S714.
In step S714, the evaluation value calculation unit 122 performs center-part weighted exposure control and ends the process.

  As described above, in the present embodiment, exposure control that focuses on the center of the shooting screen during FA zoom control is performed, so that exposure control is not performed specifically for a specific subject. , Make it easier to find the subject.

(Second Embodiment)
In the second embodiment, FA zoom control and exposure control when a very dark subject is photographed will be described. For example, assume a case where an image of an animal sleeping in a very dark place is taken with a slow shutter. In order to capture a very dark subject, the user automatically changes the shooting mode to a slow shutter mode that automatically shifts to a slow shutter with a long accumulation time than 1/60 seconds, which is the standard shutter speed of NTSC. It is set. The advantage is that a subject with little movement can shoot brightly in a dark place while reducing noise. However, when an animal starts moving during shooting and the user automatically zooms out by searching for the subject, if the slow shutter is used, the subject has a tailed image, making it difficult to find the animal.

FIG. 8 is a block diagram illustrating a configuration of the imaging apparatus according to the second embodiment. Of the blocks shown in the block diagram of FIG. 8, blocks having the same functions as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
The difference from the first embodiment is an evaluation value calculation unit 800. The evaluation value calculation control executed by the evaluation value calculation unit 800 is substantially the same as the control of the first embodiment, but the exposure control method using each exposure parameter is different. In the first embodiment, the exposure is controlled mainly using the aperture value related to the aperture diameter of the aperture 128. However, in the second embodiment, the image sensor 110 including the aperture value of the aperture 128 and the gain 801 are combinedly controlled. doing. The image sensor 110 is controlled to control the accumulation time with an electronic shutter, and the gain 801 is controlled to electrically amplify the video level.

Here, the exposure control will be described with reference to FIG. FIG. 9 is a diagram for explaining control of the diaphragm 128, the electronic shutter, and the gain 801 based on the evaluation value calculated by the evaluation value calculation unit 122 according to the brightness of the subject.
First, normal exposure control will be described with reference to FIG. When the subject is dark, the aperture 128 is fixed at the open F1.6, and the gain 801 is fixed at 18 dB which is the maximum gain. The electronic shutter is automatically set between 1/15 seconds and 1/60 seconds. If the subject is very dark, the exposure time is 1/15 seconds, and the exposure cannot be controlled beyond that. If the subject becomes brighter, it works up to 1/60 second.
When it becomes brighter, the aperture 128 is fixed at the open F1.6, and the electronic shutter is fixed at 1/60 second. The gain is automatically set between 18 dB and 0 dB.
When it becomes brighter, the aperture 128 is automatically set between F1.6 and F8.0, and when it is brightest, the electronic shutter is automatically set from 1/60 second to 1/500 second.

  When photographing a very dark subject, the aperture control is F1.6, the electronic shutter is 1/15 second, and the gain 801 is 18 dB as exposure control. Here, the animal being photographed moves, and the user starts searching for a subject, and the FA zoom operation starts. The fact that the FA zoom operation starts also means that the user is moving the camera, so that the subject to be photographed is likely to have a tailed image due to the long accumulation time. In this state, it is difficult to find the subject no matter how much the FA zoom is operated to the wide angle side and the shooting angle of view becomes wide.

  Therefore, the camera 100 changes the exposure control to the gain expansion mode shown in FIG. In the gain expansion mode, first, the slow shutter mode is temporarily stopped. The electronic shutter is changed from 1/15 seconds to 1/60 seconds, and the state where the tail is pulled is eliminated. Furthermore, since the maximum gain that is the maximum value of the gain 801 is expanded from 18 dB to 30 dB, the brightness of the subject can be maintained. Here, since the two-stage spectral amount is reduced by the electronic shutter, the gain is increased by 12 dB (two stages) to compensate. This change in exposure control increases the noise, but makes it easier to find an animal because an image that does not have a tail while maintaining brightness is obtained. After that, when an animal is found and a subject is captured, the camera is zoomed in by the FA zoom operation. When the FA zoom operation is completed, the camera can be changed to the slow shutter mode again, and bright shooting with less noise can be continued.

Next, switching to the gain expansion mode will be described with reference to the flowchart of FIG.
In step S1000, the evaluation value calculation unit 800 determines whether shooting is performed in the slow shutter mode. If it is determined that the image is not shot in the slow shutter mode, the process is terminated. If it is determined that the image is shot in the slow shutter mode, the process proceeds to S1001.
In step S1001, the evaluation value calculation unit 800 determines whether the FA zoom operation has started. If it is determined that the FA zoom operation has not started, the process is terminated. If it is determined that the FA zoom operation has started, the process advances to step S1002.

In step S1002, the evaluation value calculation unit 800 switches the exposure control to the gain expansion mode. By switching to the gain expansion mode, it is possible to prevent a tailed image from being shot with an accumulation time longer than 1/60 seconds and to easily search for a subject. After switching, the process proceeds to step S1003.
In step S1003, the evaluation value calculation unit 800 determines whether or not the FA zoom operation has ended. If it is determined that the FA zoom operation has not ended, monitoring is continued until the FA zoom operation ends. On the other hand, if it is determined that the FA zoom operation has ended, the process proceeds to step S1004.

In step S1004, the exposure control is switched from the gain expansion mode to the slow shutter mode to reduce the amount of processing. Here, a bright image with less noise can be obtained again on the subject.
As described above, in the present embodiment, when the FA zoom control is performed in the slow shutter mode, the electronic shutter is switched to the gain expansion mode that prevents the electronic shutter from becoming the slow shutter. In gain expansion mode, the amount of light that has become darker is compensated by other exposure controls, so it is no longer a tailed image, and the brightness of the image can be maintained, making it easier to find the subject. .

  Although the present invention has been described in detail based on preferred embodiments thereof, the present invention is not limited to these specific embodiments, and various forms within the scope of the present invention are also included in the present invention. included. A part of the above-described embodiments may be appropriately combined. That is, the camera 100 does not necessarily have to be configured by a single mechanism. For example, the camera 100 is an interchangeable lens camera, and includes a configuration in which the μCOM 102, the shake detection sensor 101, the shake correction mechanism 108, and the zoom lens 118 are included in the interchangeable lens.

(Other examples)
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

  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. For example, in the above-described embodiment, a digital camera has been described as an example of an imaging apparatus that implements the present invention. However, the present invention is not limited to this. For example, a configuration in which an imaging device other than a digital camera, such as a portable device such as a digital video camera or a smartphone, a wearable terminal, or a security camera may be employed.

100 imaging device 101 shake detection sensor 102 μCOM
115 motion determination unit 116 zoom control unit 122 evaluation value calculation unit

Claims (15)

Determining means for determining whether the imaging device is searching for a subject based on the movement of the imaging device detected by the detecting means;
Zoom control means for performing control to change the angle of view when the determination means determines that the subject search is in progress;
And an exposure control means for performing exposure control by switching from the first mode to the second mode when the change of the angle of view is started.   The imaging apparatus according to claim 1, wherein the determination unit determines that the subject is being searched when a motion amount of the imaging apparatus is equal to or greater than a threshold value.   3. The imaging apparatus according to claim 1, wherein the zoom control unit performs zoom-out to change the angle of view to a wide angle side when the determination unit determines that the subject search is in progress. .   The first mode is a mode for performing exposure control based on a subject or a scene, and the second mode is a mode for performing exposure control with emphasis on a center portion of an image. Item 4. The imaging device according to any one of Items 1 to 3.   5. The first mode according to claim 1, wherein the first mode includes a mode in which an object being imaged is detected and exposure control is performed so that the object has an appropriate exposure. The imaging apparatus of Claim 1.   The imaging apparatus according to claim 1, wherein the first mode includes a mode in which a scene being imaged is detected and exposure control is performed in accordance with the scene.   In the second mode, an image is divided into a plurality of areas, a weighted average value of exposure levels is calculated with emphasis on the area at the center of the image, and the weighted average value is set to a predetermined luminance value. The image pickup apparatus according to any one of claims 1 to 6, wherein exposure control is performed so that The imaging device further includes an imaging element having a plurality of photoelectric conversion units;
A diaphragm for adjusting the amount of light received by the image sensor,
The imaging apparatus according to claim 1, wherein the exposure control unit performs the exposure control by controlling the diaphragm. The imaging device further includes an imaging element having a plurality of photoelectric conversion units;
A diaphragm for adjusting the amount of light received by the image sensor;
Gain means for amplifying the gain of the signal output from the imaging device,
4. The exposure control unit according to claim 1, wherein the exposure control unit performs the exposure control by controlling an accumulation time in the imaging device, the diaphragm, and the gain unit. 5. Imaging device.   The first mode is a slow shutter mode in which the accumulation time is long, and the second mode is an exposure control in which the maximum gain of the gain means is extended and the accumulation time is shorter than the slow shutter mode. The control device according to claim 9, wherein the control device is a mode for performing the following.   The zoom control unit changes the field angle to the telephoto side when the determination unit determines that the subject search is not being performed after the exposure control is switched from the first mode to the second mode. The image pickup apparatus according to claim 1, wherein zoom-in is performed.   The imaging apparatus according to claim 11, wherein the exposure control unit switches exposure control from the second mode to the first mode when the zoom-in is completed. The imaging device further includes detection means for detecting movement of the imaging device,
The imaging device according to any one of claims 1 to 12, wherein the detection unit is an angular velocity sensor that detects a motion of the imaging device as an angular velocity. A method for controlling an imaging apparatus,
A determination step of determining whether the imaging device is searching for a subject based on the movement of the imaging device detected by the detection unit;
A zoom control step for performing control to change the angle of view when it is determined in the determination step that the subject is being searched;
An exposure control step of performing exposure control by switching from the first mode to the second mode when the change of the angle of view is started.   A program that causes a computer to function as each unit included in the imaging apparatus according to any one of claims 1 to 13.

Images