Imaging device, control method thereof, and program

Abstract

To allow photographing with high consecutive shooting speed, while reducing the influence of flicker on a photographed image.SOLUTION: An imaging apparatus has: an image pick-up device; setting means that sets a photographing control value; control means that controls the drive of the image pick-up device; and flicker detection means that detects flicker on the basis of a signal output from the image pick-up device. When causing the image pick-up device to output a signal for flicker detection, the control means controls to drive the image pick-up device with n (n is a natural number of 3 or more) different frame rates. The control means executes, according to the photographing control value, first control of performing detection processing with the n different frame rates in a divided manner over a plurality of frames of imaging performed by the image pick-up device to acquire an image for recording, or second control of performing detection processing with the n different frame rates between frames of the imaging performed by the image pick-up device to acquire the image for recording.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an imaging device and a control method and program thereof, and more particularly to a technique for capturing an image while reducing the influence of periodic changes in the amount of light (called flicker) from a subject. [Background technology]

[0002] In recent years, the sensitivity of image sensors in imaging devices such as digital cameras and mobile phones has been increasing. As a result, it has become possible to capture bright images with reduced subject blur by setting a high shutter speed (short exposure time) to capture a subject in a relatively dark environment, such as indoors, compared to outdoor scenes during the day.

[0003] Furthermore, fluorescent lights, which are widely used as indoor light sources, are known to cause flicker, a phenomenon in which the illumination light periodically fluctuates due to the influence of commercial power supply frequencies. Shooting with a high shutter speed under a light source that causes such flicker (hereinafter referred to as a flickering light source) can result in uneven exposure and color within a single image (frame). Also, there is a risk of variations in exposure and color temperature occurring among multiple images captured in succession.

[0004] In recent years, the use of light-emitting diodes (hereinafter referred to as LEDs) as light sources has been increasing. LEDs use a different current supply method than fluorescent lamps, with the drive current controlled by a rectifier circuit, causing them to flicker at a different cycle and waveform than the power supply frequency. LEDs also flicker at a faster cycle than fluorescent lamps (hereinafter referred to as high-frequency flicker light sources). A method has been disclosed that can automatically detect the frequency of such high-frequency flicker and reduce its impact on images.

[0005] For example, Patent Document 1 proposes a method for capturing moving images with fewer dropped frames while suppressing flicker caused by fluorescent lights by alternately switching between different shutter speeds for each predetermined line of the image sensor between capturing moving images to detect flicker.

[0006] Furthermore, Patent Document 2 discloses a flicker detection method in which, in order to automatically detect the blinking cycle of a high-frequency flicker light source, an image sensor is driven at n frame rates, where n is a natural number greater than or equal to 3. In this way, a method is disclosed that can automatically detect the frequency of flicker occurring in a subject and reduce its impact on an image. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-98416 [Patent Document 2] Japanese Patent Publication No. 2022-130277 Summary of the Invention [Problem to be solved by the invention]

[0008] However, since the frequency of a high-frequency flickering light source changes depending on the color of the light source, etc., there are cases where the flicker frequency changes during shooting. In Patent Document 1, flicker detection is performed at two types of shutter speed, so the detectable flicker frequency is limited. Furthermore, when performing flicker detection for each shot in continuous shooting, as in Patent Document 2, the image sensor is driven at three or more frame rates, which takes time for processing between shots (hereinafter referred to as between frames), and there is a risk that the speed of continuous shooting of still images will slow down.

[0009] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide an imaging device that enables high-speed continuous shooting while reducing the effect of flicker on still image capture. [Means for solving the problem]

[0010] In order to achieve the above object, an imaging device according to the present invention comprises an imaging element, setting means for setting shooting control values, control means for controlling the driving of the imaging element, and flicker detection means for detecting flicker based on a signal output from the imaging element, wherein the control means controls the imaging element to drive at n different frame rates, where n is a natural number greater than or equal to 3, when causing the imaging element to output a flicker detection signal, and the control means executes, in accordance with the shooting control values, a first control for dividing and performing detection processing at the n different frame rates across a plurality of frames of imaging in which the imaging element acquires images for recording, or a second control for performing detection processing at the n different frame rates across frames of imaging in which the imaging element acquires images for recording, and the flicker detection means detects flicker based on the flicker detection signal acquired for each of the n frame rates. [Effects of the Invention]

[0011] According to the present invention, by changing the flicker detection method depending on the shooting interval in a flickering environment such as an LED, it is possible to provide an imaging device that reduces the effects of flicker while enabling high-speed continuous shooting. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram showing a system configuration of a digital mirrorless camera according to an embodiment of the present invention. [Figure 2] 1 is a flowchart of high-frequency flicker-free imaging according to the first embodiment of the present invention. [Figure 3] 10 is a drive pattern determination table for detecting flicker between frames in the first and second embodiments of the present invention. [Figure 4] 10 shows a flicker detection sequence according to frame speed in the first and second embodiments of the present invention. [Figure 5] 10 is a flowchart of flicker-free photography in the second embodiment of the present invention. [Figure 6]10 is a flowchart of flicker-free photography in a third embodiment of the present invention. [Figure 7] 10 is a drive pattern determination table for detecting flicker between frames in the third embodiment of the present invention. [Figure 8] 10 is a sequence of detecting flicker according to a frame speed in the third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0014] Although the present embodiment will be described using a digital mirrorless camera as an example, the present invention can be applied to various electronic devices that have a live view image display and video recording function, such as smartphones, camcorders, and camera-equipped game consoles.

[0015] First Embodiment FIG. 1 shows the system configuration of a digital mirrorless camera according to an embodiment of the present invention, primarily including a camera body 100 and a photographing lens 200. In the camera body 100, reference numeral 101 denotes an image sensor such as a CCD or CMOS sensor including an infrared cut filter, a low-pass filter, etc., and an image of a subject is formed on a light receiving surface by the photographing lens 200. The image sensor 101 photoelectrically converts the image of the subject received by light, and the resulting electrical signal is used as various image signals, such as a live view display or a captured image for recording. Since the electrical signal obtained by the image sensor 101 is an analog value, it also has a function for converting it into a digital value. An evaluation value (photometric value) of the brightness of the subject can be detected based on the image signal output from the image sensor 101. The exposure time of the image sensor 101 can be controlled according to a shutter speed that can be set as an exposure control value for the image sensor 101.

[0016] The shutter 102 is a light-oblique device that can travel in a direction parallel to the signal scanning direction of the image sensor 101. The exposure time of the image sensor 101 can be controlled by adjusting an exposure opening formed by, for example, multiple shutter blades of a mechanical shutter in accordance with the shutter speed described above. The exposure time adjustment according to the present invention can be achieved by utilizing a so-called electronic shutter that adjusts the signal reset and readout timing of the image sensor 101 and the shutter 102, or by using both of them.

[0017] The display unit 103 is configured, for example, with a TFT liquid crystal panel. During framing, images acquired by the image sensor 101 and various shooting setting information are displayed in real time to provide a live view (LV). Images captured in response to user operations are also displayed, allowing the user to review them. The display unit 103 of this embodiment includes a resistive or capacitive thin-film element known as a touch panel, and doubles as an operation unit that can be touched by the user. The touch panel detects a user's touch on an icon or the like displayed on the display unit 103, enabling the operation of a function linked to the display of the touched position. For example, icons related to shooting settings and modes can be displayed on the touch panel, allowing the user to set the settings by touching the panel.

[0018] The CPU 104 is a control means capable of comprehensively controlling each part of the camera body 100 and the accessories attached to the camera body 100. A ROM (read only memory) and a RAM (random access memory) are connected to the CPU 103. The ROM (not shown) is a non-volatile storage element that stores programs for operating the CPU 104, various adjustment parameters, and the like. Programs read from the ROM are expanded into volatile RAM (not shown) and executed. Generally, RAM is a slower, lower-capacity element than frame memory (not shown).

[0019] The CPU 104 also performs calculations related to flicker detection based on the image captured by the image sensor 101. The calculations related to flicker detection include determining whether flicker has occurred and determining the frequency of the flicker light source and the peak timing of the flicker light intensity.

[0020] The camera body 100 can operate in a drive mode (continuous shooting mode) in which continuous shooting is performed while an operating member (not shown) that commands the start of shooting is pressed. The number of continuous shots per unit time in drive mode can be set by the user. The number of continuous shots per unit time in drive mode is called the frame rate or continuous shooting speed. For example, the continuous shooting speed is set for each mode setting, such as 3 fps (low-speed drive mode), 30 fps (high-speed drive mode), and 40 fps (high-speed + drive mode). In this embodiment, the user is assumed to be able to select each of the above modes. The continuous shooting speed can be assigned to each drive mode from 40 fps, 30 fps, 20 fps, 15 fps, 12 fps, 10 fps, 7.5 fps, 5 fps, 3 fps, 2 fps, and 1 fps. For example, the user can change the drive mode even during shooting by operating the display unit 102.

[0021] Next, the photographic lens 200 will be described.

[0022] Reference numeral 201 denotes a lens group including a focus lens, and focus can be adjusted by driving the focus lens. In FIG. 1, lens group 201 is represented by a single lens, but in reality it is made up of multiple lenses. Reference numeral 202 denotes an aperture, which adjusts the amount of light entering the camera. Reference numeral 203 denotes a CPU (hereinafter also referred to as "LPU") that controls each part of the photographing lens 200. In addition to controlling lens group 201 and aperture 202, LPU 203 communicates with CPU 104 on the camera body 100 side, so that it can exchange information such as focus position and aperture, as well as information during image stabilization, with the camera body 100.

[0023] Next, continuous shooting in the first embodiment will be described with reference to the flowchart shown in Fig. 2. In the following description, a method for acquiring a signal for detecting flicker (hereinafter referred to as a "flicker detection signal") and a flicker calculation method for detecting flicker from the flicker detection signal can be performed using known techniques, so description thereof will be omitted. In this embodiment, the imaging cycle for flicker detection (hereinafter referred to as flicker detection drive) is set to three types: 159 fps, 200 fps, and 252 fps. In the flicker detection process in this embodiment, the CPU 104 changes the imaging cycle of the image sensor 101 to the imaging cycle (frame rate) for flicker detection, and causes the image sensor 101 to acquire a predetermined number of images for each flicker detection drive.

[0024] First, in S100, when the power of the camera body 100 is turned on, the CPU 104 uses the image sensor 101 to accumulate charge for flicker detection and obtain a flicker detection signal. The CPU 104 then performs a flicker calculation to detect flicker information using the obtained flicker detection signal. The flicker calculation determines whether flicker is occurring, and if flicker is occurring, detects the flicker frequency and flicker peak timing. Once the above detection process is complete, the process proceeds to S101.

[0025] In S101, the CPU 104 checks whether a user has performed a shooting instruction operation, such as pressing a shutter release button. If a shooting instruction operation has been performed, the process proceeds to S102, and if a shooting instruction operation has not been performed, S101 is repeated. Note that if a shooting instruction operation has not been performed, the process may return to S100 and execute the flicker detection process again.

[0026] In S102, the CPU 104 performs flicker detection processing for capturing the first image. The details of the detection processing are the same as in S100, and therefore will not be described. When the flicker detection processing is completed, the process proceeds to S103.

[0027] In S103, the CPU 104 changes (determines) the shooting control values ​​for capturing the first still image. The shooting control values ​​include the shutter speed, aperture value, ISO sensitivity, etc., and may be automatically set by the camera body 100 or may be arbitrarily set by the user. The CPU 104 changes the shooting control values ​​to those that can minimize flicker based on the flicker frequency and shooting settings identified in S100 or S102. For example, if the identified flicker frequency is 540.0 Hz, the CPU 104 sets the shutter speed to 1 / 540.0, changes the aperture value and ISO sensitivity to match the shutter speed, and changes the shooting control values ​​so that the still image is captured with appropriate exposure. Note that if the CPU 104 determines that there is no flicker as a result of the flicker detection process in S100 or S102, it does not change the shooting control values. Once the changing (determination) of the shooting control values ​​for capturing the first still image is complete, the process proceeds to S104.

[0028] In S104, the CPU 104 controls the image sensor 101 and the shutter 102 based on the shooting control values ​​determined in S103, and performs shooting (recording) of a still image.

[0029] In S105, the CPU 104 checks whether the user is continuing the shooting operation. If the shooting operation is to be continued, the process proceeds to S106. If the shooting operation is not being continued, the shooting ends.

[0030] In S106, the CPU 104 acquires information on the frame rate for still image shooting as one of the shooting control values ​​from the current shooting settings, and proceeds to S107. Here, the shooting settings refer to information such as the shooting mode set in the camera body 100, and include information on the number of continuous shots (frame rate).

[0031] In S107, the CPU 104 references the frame rate information acquired in S106 and acquires information on the number of images required for flicker detection drive between frames and the type of flicker detection drive by referencing the frame rate determination table shown in FIG. 3. For example, if the frame rate is set to 30 fps in the high-speed drive mode, the number of images required for flicker detection drive is three and the type of flicker detection drive is one. Also, if the frame rate is set to 3 fps in the low-speed drive mode, the number of images required for flicker detection drive is ten and the type of flicker detection drive is three. It is known that the more images required for flicker detection drive, the better the flicker detection performance. Therefore, if the set frame rate is long, the CPU 104 controls the number of images required for flicker detection drive to be increased in order to improve flicker detection performance. For example, if three types of flicker detection drive are performed simultaneously between frames, the flicker frequency is identified between frames, and the next still image is captured according to the flicker frequency. Furthermore, when one or two types of flicker detection drive are performed between frames, the flicker detection process is divided, so the flicker detection result from the previous frame or the previous two frames is also used to identify the flicker frequency, and the next still image is shot according to the flicker frequency.

[0032] The flow from S108 to S110 will be described with reference to the flicker detection sequence according to the frame speed in FIG.

[0033] In S108, the CPU 104 performs flicker detection processing based on the inter-frame detection drive pattern determined in S107.

[0034] For example, when the frame rate is 30 fps, there is only one type of flicker detection drive between frames, so a sequence is executed to detect flicker by dividing it among multiple frames as shown in FIG. 4(a).

[0035] The processing for each frame for capturing the Nth still image will be described with reference to Figure 4(a). First, after capturing the (N-3)th still image, the CPU 104 acquires three images at a flicker detection drive speed of 159 fps and analyzes the flicker frequency. Next, after capturing the (N-2)th still image, the CPU 104 acquires three images at a flicker detection drive speed of 200 fps and analyzes the flicker frequency. Next, after capturing the (N-1)th still image, the CPU 104 acquires three images at a flicker detection drive speed of 252 fps and analyzes the flicker frequency. Once the analysis results of the flicker frequency for the three types of flicker detection drive are available, the CPU 104 determines the flicker frequency for capturing the Nth still image.

[0036] In other words, different flicker detection driving is performed between the frame after the N-3th still image is taken and the frame after the N-2th still image is taken, between the frame after the N-2th still image is taken and the frame after the N-1th still image is taken, and between the frame after the N-1th still image is taken and the frame after the N-1th still image is taken and the Nth still image.

[0037] Furthermore, when the frame rate is set to 3 fps, there are three types of flicker detection drive between frames, resulting in a sequence in which flicker is detected continuously (all at once) between frames, as shown in Figure 4(b).

[0038] The processing performed between frames for capturing the Nth still image will be explained with reference to Figure 4(b). First, after capturing the (N-1)th still image, 10 images are captured with a flicker detection drive of 159 fps and the flicker frequency is analyzed. Next, 10 images are captured with a flicker detection drive of 200 fps and the flicker frequency is analyzed. Next, 10 images are captured with a flicker detection drive of 252 fps and the flicker frequency is analyzed. Once the analysis results for the three types of flicker detection drive are available, the flicker frequency for capturing the Nth still image is determined.

[0039] That is, the three types of flicker detection driving required in this embodiment are performed continuously (all at once) between the frames after the (N-1)th still image is captured and the Nth still image is captured.

[0040] In the above example where the frame rates are 30 fps and 3 fps, the order of flicker drive is 159 fps, 200 fps, and 252 fps, but the order of the imaging cycles may be changed. Also, the frequencies used for flicker detection drive are not limited to these.

[0041] In S109, the CPU 104 performs the same process as in S103, and changes the shooting control values ​​for shooting the second still image.

[0042] In S110, the CPU 104 controls the image sensor 101 and the shutter 102 in the same manner as in S104, and captures (records) a still image.

[0043] As described above, according to the flowchart shown in Fig. 2, when the shooting setting is a frame speed faster than a predetermined value (equal to or greater than the predetermined value), the types of flicker detection drive and the number of images are limited, making it possible to shoot at a high frame speed while reducing flicker. Also, when the shooting setting is a frame speed slower than the predetermined value, the types of flicker detection drive and the number of images are increased, making it possible to maintain the frame speed set by the user while improving flicker detection accuracy.

[0044] As described above, according to the first embodiment, by changing the type of flicker detection drive performed between frames and the number of images used for flicker detection depending on the shooting settings, it is possible to maintain the frame rate and reduce flicker at the same time.

[0045] <Second embodiment> Next, high-frequency flicker-free imaging in a second embodiment of the present invention will be described with reference to the flowchart shown in Fig. 5. However, since the processes from S101 to S110 in Fig. 2 are the same as those in Fig. 2 for the first embodiment, their description will be omitted. In this embodiment, processes from S201 to S202 are further added after S106.

[0046] In the first embodiment, the CPU 104 checks (acquires) information about the frame rate for still images from the current shooting settings (drive mode and continuous shooting speed) in S106 of Fig. 2. However, the actual frame rate may be slower than the frame rate set by the user due to factors such as the live view update rate being slowed down by other shooting settings or external light, or the aperture moving to track exposure.

[0047] Therefore, in this embodiment, after S106, the process proceeds to S201, where the CPU 104 checks the shooting control time required to shoot at a shooting interval based on the frame rate acquired in S106. The shooting control time here refers to the cumulative control time for each control that must be performed until the next shooting, such as the live view update time, the time required to detect the subject, and the drive time for the aperture and focus lens. Note that the elements that make up the shooting control time are not limited to the above items, and are acquired by the CPU 104 according to the required shooting control.

[0048] In S202, the CPU 104 compares the shooting interval time based on the shooting setting frame speed confirmed in S106 with the shooting control time confirmed in S201, and sets the longer time as the shooting frame speed.

[0049] In step S107, CPU 104 refers to the frame-to-frame flicker detection drive pattern determination table of FIG. 3, and acquires the number of images and type of flicker detection drive during frame-to-frame flicker detection drive according to the frame speed determined in step S202.

[0050] As described above, in this embodiment, if the actual frame speed becomes slower than the set frame speed, the flicker detection drive pattern is changed, thereby improving the accuracy of flicker detection in a situation that corresponds to the actual frame speed.

[0051] <Third embodiment> Next, flicker-free shooting in a third embodiment of the present invention will be described with reference to the flowchart shown in Fig. 6. However, since the processing of steps S101 to S110 in Fig. 2 is the same as that in Fig. 2 of the first embodiment, a description thereof will be omitted. In this embodiment, processing related to S301 and S302 after branching is further added after S108.

[0052] In the first and second embodiments described above, three types of flicker detection drive (drive corresponding to three frequencies) were described to detect high-frequency flicker. Note that it is possible to increase the number of types of flicker detection drive to more than three depending on the range of frequencies to be detected. In this example, a low-frequency flicker detection drive (600 fps) for detecting low-frequency flicker of 100 Hz or 120 Hz is added to the high-frequency flicker, making a total of four types.

[0053] In step S107, the CPU 104 refers to the inter-frame flicker detection drive pattern determination table of FIG. 7 to obtain the number of images and type of flicker detection drive during inter-frame flicker detection drive according to the frame speed.

[0054] Subsequently, in step S108, the CPU 104 performs flicker detection processing based on the inter-frame detection drive pattern determined in step S107.

[0055] As shown in the sequences of FIGS. 8(a) and 8(b), flicker detection driving for detecting high-frequency flicker and flicker detection driving for detecting low-frequency flicker are performed during still image exposure.

[0056] For example, when the frame rate is 20 fps, there are two types of flicker detection drive between frames, so a sequence is executed to detect flicker by dividing it among multiple frames as shown in FIG. 8(a).

[0057] The processing for each frame for capturing the Nth still image will be described with reference to FIG. 8(a). First, after capturing the (N-3)th still image, the CPU 104 acquires three images at a flicker detection drive speed of 159 fps and six images at a flicker detection drive speed of 600 fps, and analyzes the flicker frequency. Next, after capturing the (N-2)th still image, the CPU 104 acquires three images at a flicker detection drive speed of 200 fps and six images at a flicker detection drive speed of 600 fps, and analyzes the flicker frequency. Next, after capturing the (N-1)th still image, the CPU 104 acquires three images at a flicker detection drive speed of 252 fps and six images at a flicker detection drive speed of 600 fps, and analyzes the flicker frequency. Once the analysis results of the flicker frequency for the four types of flicker detection drive speeds are available, the CPU 104 determines the flicker frequency for capturing the Nth still image.

[0058] That is, one of the three types of high-frequency flicker detection drive and low-frequency flicker detection drive are executed between the frames after the (N-3)th still image is shot and the (N-2)th still image is shot. Then, between the frames after the (N-2)th still image is shot and the (N-1)th still image, one of the three types of high-frequency flicker detection drive that have not yet been executed and low-frequency flicker detection drive are executed. Then, between the frames after the (N-1)th still image is shot and the Nth still image, the remaining high-frequency flicker detection drive and low-frequency flicker detection drive are executed.

[0059] Furthermore, when the frame rate is set to 3 fps, there are four types of flicker detection drive between frames, resulting in a sequence in which flicker is detected continuously between frames as shown in FIG. 8(b).

[0060] The processing for each frame between the Nth still images will be explained with reference to Figure 8(b). First, after capturing the (N-1)th still image, 10 images are captured with a flicker detection drive of 159 fps and the flicker frequency is analyzed. Next, 10 images are captured with a flicker detection drive of 200 fps and the flicker frequency is analyzed. Next, 10 images are captured with a flicker detection drive of 252 fps and the flicker frequency is analyzed. Next, 6 images are captured with a flicker detection drive of 600 fps and the flicker frequency is analyzed. Once the analysis results for the four types of flicker detection drive are available, the flicker frequency for capturing the Nth still image is determined.

[0061] That is, three types of high frequency flicker detection driving and low frequency flicker detection driving are performed continuously (all at once) between the frames after capturing the (N-1)th still image and the Nth still image.

[0062] In the above example where the frame rates are 20 fps and 3 fps, the order of flicker drive is 159 fps, 200 fps, and 252 fps, but the order of the imaging cycles may be changed. Also, the frequencies used for flicker detection drive are not limited to these.

[0063] In step S301, CPU 104 determines whether there is 100 Hz or 120 Hz flicker based on the results of the inter-frame flicker detection process in step S108. If there is no 100 Hz or 120 Hz flicker, the process proceeds to step S109. If there is 100 Hz or 120 Hz flicker, the process proceeds to step S302.

[0064] In step S302, the CPU 104 controls the image sensor 101 and the shutter 102 to perform still image exposure at a timing that coincides with the peak timing of the flicker. Then, still image shooting is performed in accordance with the peak timing of the flicker so that variations in exposure and color temperature do not occur among multiple images.

[0065] As described above, even when the detection range of the flicker frequency is wide, the flowchart shown in FIG. 6 makes it possible to perform imaging with reduced flicker by increasing the number of types of flicker detection driving.

[0066] (Other embodiments) In the above embodiment, the control during continuous shooting of still images has been described, but it may also be applied to control during video shooting. In that case, the continuous shooting speed can be replaced with the frame rate for control, and the exposure for a still image becomes the exposure for each frame of the video.

[0067] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0068] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0069] 100 camera body 101 Image sensor 102 Display Unit 103 CPU 200 Photographic Lenses 201 Focusing Lens 202 Aperture 203 LPU

Claims

1. An imaging element; a setting means for setting a shooting control value; a control means for controlling the driving of the imaging element; a flicker detection means for detecting flicker based on a signal output from the imaging element; and the control means controls the image sensor to be driven at n different frame rates, n being a natural number equal to or greater than 3, when causing the image sensor to output a flicker detection signal; a first control in which the control means divides and performs the detection process at the n different frame rates over a plurality of frames of imaging in which the imaging element acquires images for recording; or a second control for performing detection processing at the n different frame rates between frames in which the image sensor acquires images for recording, in accordance with the photographing control value; The imaging device is characterized in that the flicker detection means detects flicker based on a flicker detection signal obtained for each of the n frame rates.

2. 2. The imaging apparatus according to claim 1, wherein the photographing control values ​​include information about a frame rate at which the imaging element captures an image for recording.

3. 3. The image pickup apparatus according to claim 2, wherein said control means controls said image pickup element in said first control mode when said frame speed is equal to or greater than a predetermined value.

4. 2. The imaging device according to claim 1, wherein the setting means changes the shooting control value based on the detected flicker.

5. 2. The imaging device according to claim 1, wherein at least one of the n different frame rates is a frame rate used for detecting high-frequency flicker.

6. 2. The imaging device according to claim 1, wherein at least one of the n different frame rates is a frame rate set to detect flicker of 100 Hz or 120 Hz.

7. The imaging device according to claim 6, characterized in that, when the control means executes the first control, the image sensor is controlled so that detection processing at a frame rate set to detect flicker of 100 Hz or 120 Hz among the n different frame rates is always performed between each of the plurality of frames.

8. a setting step in which a setting means sets a shooting control value; a control step in which a control means controls driving of the imaging element; a flicker detection step in which a flicker detection means detects flicker based on a signal output from the imaging element; and In the control step, when a signal for detecting flicker is output from the image sensor, the control means controls the image sensor to be driven at n different frame rates, where n is a natural number equal to or greater than 3; In the control step, a first control is executed in which detection processing is divided and performed at the n different frame rates over a plurality of frames of imaging in which the imaging element acquires images for recording, or a second control is executed in which detection processing is performed at the n different frame rates over a plurality of frames of imaging in which the imaging element acquires images for recording, in accordance with the shooting control value; The method for controlling an imaging device, wherein in the flicker detection step, the flicker detection means detects flicker based on a flicker detection signal acquired for each of the n frame rates.

9. A program for causing a computer to function as each of the means of the imaging device according to any one of claims 1 to 7.

10. A computer-readable storage medium storing the program according to claim 9.

Images