Imaging device and control method thereof

Abstract

To provide an imaging device that can capture still images with reduced flicker effects using a setting method that specifies a number of stops of 1 / 3 or more as the setting interval, which is a common method for setting the Tv of imaging devices. [Solution] An imaging device comprising: an image sensor for capturing an image; a detection means for detecting the period of brightness change of a light source from the image; a setting means for setting the exposure time of the image sensor; and a calculation means for calculating one or more candidate exposure times that reduce the effect of the brightness change of the light source based on the detection of the period of brightness change of the light source, wherein the setting means can set the exposure time from any of the set values ​​of a first setting interval, and the setting means controls so that when the candidate exposure times are converted using the setting interval, candidates for exposure times that do not satisfy predetermined conditions cannot be selected.

Description

Technical Field

[0001] The present invention relates to a method for setting the exposure time of an imaging device, and particularly to a method for setting the exposure time when shooting while reducing the influence of flicker.

Background Art

[0002] In recent years, the sensitivity of imaging devices such as digital cameras and mobile phones has been increasing. Therefore, even in a relatively dark environment such as indoors, it has become possible to obtain a bright image with reduced blur by shooting with a high shutter speed (short exposure time).

[0003] Light-emitting diodes (hereinafter referred to as LEDs), which are becoming popular as indoor light sources, control the drive current with a rectifier circuit, and flicker occurs, which is a phenomenon in which the illumination light fluctuates periodically. When shooting with a high shutter speed under a light source that causes such flicker (hereinafter referred to as a flicker light source), uneven exposure or color unevenness may occur within one image, or variations in exposure or color temperature may occur between a plurality of continuously shot images.

[0004] An LED is generally a light source that turns on and off at a faster cycle than a fluorescent lamp and is a light source that generates high-frequency flicker (high-frequency flicker light source). As a means for suppressing the influence of high-frequency flicker, a method of setting the shutter speed in accordance with the on / off cycle of the high-frequency flicker light source is known, and a method for detecting the on / off cycle of the high-frequency flicker light source is disclosed in, for example, Patent Document 1.

[0005] In addition, Patent Document 2 provides a first shutter speed series and a second shutter speed series finer than the first shutter speed series in the selection of the shutter speed. Each series can set the shutter speed at different intervals. An imaging device is disclosed that is characterized in that a shutter speed close to the on / off cycle is set within the second shutter speed series and can be changed for every integral multiple of the shutter speed.

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-130277 [Patent Document 2] Japanese Patent Publication No. 2019-161499 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, when changing the shutter speed (hereinafter referred to as Tv value) in integer multiples using the prior art disclosed in Patent Document 2 mentioned above, the setting method differs from that of a typical imaging device, which uses a specified number of stops (usually 1 / 3 stop or 1 / 2 stop) as the interval for setting Tv. In other words, the user needs to be aware of the difference in the Tv setting method.

[0008] In view of the above issues, in one embodiment of the present invention, there is an imaging device that can capture still images with reduced flicker effects using a setting method in which a specified number of stops of 1 / 3 or more is set as the setting interval, which is a common method for setting the Tv of an imaging device. [Means for solving the problem]

[0009] To achieve the above objective, an imaging device in one aspect of the present invention comprises an image sensor for capturing an image, a detection means for detecting the period of brightness change of a light source from the image, a setting means for setting the exposure time of the image sensor, and a calculation means for calculating one or more candidates for exposure time that reduce the influence of the brightness change of the light source based on the detection of the period of brightness change of the light source, wherein the setting means can set the exposure time from any of the set values ​​of a first setting interval, and the setting means controls so that when the candidates for exposure time are converted using the setting interval, candidates for exposure time that do not satisfy predetermined conditions cannot be selected. [Effects of the Invention]

[0010] According to one aspect of the present invention, it is possible to provide an imaging device that can capture still images with reduced flicker effects using a setting method that is a common method for setting the Tv of an imaging device, where the setting interval is a specified number of stops of 1 / 3 or more. [Brief explanation of the drawing]

[0011] [Figure 1] A block diagram illustrating the outline of the imaging system according to the first embodiment. [Figure 2] A block diagram illustrating the details of the imaging system according to the first embodiment. [Figure 3] A flowchart illustrating the flow of flicker detection, TV settings, and still image capture during live view according to the first embodiment. [Figure 4] A flowchart showing the flow of the TV setting method according to the first embodiment. [Figure 5] The TV settings screen when flicker is not detected according to the first embodiment. [Figure 6] This diagram shows the relationship between the setting Tv and the exposure time range when the setting interval is 1 / 3 stop. [Figure 7] This figure shows the relationship between the exposure time required to mitigate the effects of detected flicker and the Tv setting converted at 1 / 3 stop intervals. [Figure 8] The TV setting screen for TV setting method A (which prevents the selection of TV values ​​affected by flicker) according to this embodiment. [Figure 9] A flowchart showing the TV setting process for the second, third, and fourth embodiments. [Modes for carrying out the invention]

[0012] The present invention will be described in detail below with reference to the attached drawings, based on exemplary embodiments thereof. Note that the following embodiments do not limit the invention to the claims. Furthermore, while multiple features are described in the embodiments, not all of them are essential to the invention, and the multiple features may be combined arbitrarily. In addition, in the attached drawings, the same or similar configurations are given the same reference numeral, and redundant descriptions are omitted.

[0013] In the following embodiments, the present invention will be described with respect to the case where it is implemented in an imaging device that is a digital camera or a digital video camera. However, the present invention can be implemented in any electronic device having an imaging function. Such electronic devices include computer devices (personal computers, tablet computers, media players, PDAs, etc.), mobile phones, smartphones, game machines, robots, drones, drive recorders, and the like. Note that these are examples, and the present invention can also be implemented in other electronic devices.

[0014] (First Embodiment) FIG. 1 is a block diagram exemplarily explaining the outline of an imaging device according to the first embodiment of the present invention. Further, FIG. 2 is a block diagram explaining the details of the imaging device according to the first embodiment of the present invention. Hereinafter, an imaging system including a camera body 100 and a photographing lens 200, which is the first embodiment of the imaging device according to the present invention, will be described with reference to FIGS. 1 and 2.

[0015] Note that one or more of the functional blocks shown in FIGS. 1 and 2 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 an MPU executing software. 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 operating entity, the same hardware can be realized as the main body.

[0016] The camera body 100 of the digital camera is the imaging device according to this embodiment. The imaging element 101 is a charge accumulation type solid-state imaging element such as a CCD or a CMOS that includes an infrared cut filter, a low-pass filter, etc., and an optical image corresponding to the light beam of the subject guided by the photographing lens 200 is formed. By imaging the subject using this imaging element 101 and sequentially displaying the obtained image on the display unit 103 described later, the so-called live view function is realized. Note that the image obtained by the imaging element 101 is also used as the image for flicker detection and recording described later.

[0017] The shutter 102 is a light shielding member disposed in front of the imaging element 101 on the optical path of the light beam guided from the lens group 201. The shutter 102 includes a blade member, and in the deployed state of this blade member, the light beam from the subject can be blocked, and in the folded state of the blade member, the optical image corresponding to the light beam from the subject that forms an image on the imaging element 101 can be formed on the imaging element 101. In the camera body 100, it is possible to adjust the amount of light incident on the imaging element 101 according to the running speed of the shutter 102. Then, by changing the shutter speed, which is an exposure condition based on the running speed of the shutter 102 and the exposure time of the imaging element 101, the brightness of the image signal can be adjusted. Note that a configuration may be adopted in which a so-called electronic shutter that performs the same configuration as the operation of the shutter 102 is used for the accumulation control in the imaging element 101.

[0018] The display unit 103 is a display means (display portion) composed of a TFT type LCD (thin film transistor drive type liquid crystal display) or the like. The display unit 103 can display information regarding photographing parameters such as exposure when imaging the subject, and a display image based on the image obtained using the imaging element 101, and a live view (display) for sequentially displaying this display image is possible. The display control of the display unit 103 is realized by the control of the system control unit 104 described later.

[0019] The display unit 103 may also be a so-called touch panel that also serves as an operating means that allows user touch operation, and in this embodiment it also functions as a capacitive touch panel. The configuration of the display unit 103 that enables touch operation is not limited to detecting capacitance, and any known method may be adopted.

[0020] The system control unit 104 is a control means that comprehensively controls each part of the camera body 100 and the camera accessories attached to the camera body 100. The control contents performed by the system control unit 104 will be explained in detail in the description of various operations below. The system control unit 104 can realize various functions related to the camera body 100 by reading a program from the ROM of the setting value holding unit 113 (described later), loading it into RAM, and executing it.

[0021] The photographic lens 200 is an optical device that guides a light beam corresponding to the optical image of the subject into the camera body 100. The lens group 201 of the photographic lens 200 is an optical system equipped with various lenses such as focusing lenses, zoom lenses, and shift lenses. The aperture 202 is a light intensity adjustment member that can adjust the amount of light incident into the camera body 100 by adjusting the aperture diameter.

[0022] Furthermore, the photographic lens 200 is equipped with a lens control unit (LPU 203), which is a control means for the photographic lens. The LPU 203 controls the lens position of the lens group 201 and the aperture diameter of the aperture 202, and is also a communication control means that controls communication with the system control unit 104 of the camera body 100.

[0023] The aperture drive unit 205 is configured to drive the aperture 202 of the photographic lens 200, and can drive the aperture 202 to the aperture position indicated by the LPU 203, and adjust the opening of the aperture 202 to an opening amount corresponding to the aperture value. The lens drive unit 204 is configured to drive the lens group 201 of the photographic lens 200 to a predetermined position, and can drive the lens group 201 to the position indicated by the LPU 203.

[0024] The shutter control unit 105 is configured to control the opening and closing state of the shutter 102, and by controlling the movement of the shutter 102 at a time specified by the system control unit 104, it can control the shutter speed when imaging a subject.

[0025] The signal processing unit 106 is configured to perform various processes on the image signal output from the image sensor 101, including predetermined image interpolation, resizing such as reduction, color conversion, and calculation of the number of pixel data such as saturated pixels and blacked-out pixels on the digital image data. The signal processing unit 106 also plays the role of a detection means that detects the flicker frequency of a flicker light source from the image signal output from the image sensor 101.

[0026] The recording unit 112 is a recording medium for recording image signals obtained by imaging, and is capable of recording image signals acquired using the image sensor 101 as still image data or video data.

[0027] The setting value holding unit 113 holds setting values ​​related to the operation of the imaging system, centered on the camera body 100. In this embodiment, it is equipped with a ROM area that can be used as non-volatile memory and a RAM area that can be used as volatile memory.

[0028] The imaging instruction unit 110 is, for example, a shutter button. The imaging instruction unit 110 is electrically connected to the system control unit 104, and when pressed down by the user's manual operation, the signal becomes active, instructing the camera to prepare for imaging and to start imaging. In all other states, the signal is deactivated. The imaging instruction unit 110 can transition between two pressed states, and the CPU 104 recognizes the half-pressed state of the imaging instruction unit 110 as the imaging standby state and instructs each part of the camera body 100 to perform imaging preparation operations. The system control unit 104 then recognizes the fully pressed state of the imaging instruction unit 110 as the imaging state and instructs each part of the imaging system to perform imaging operations. In other words, the imaging instruction unit 110 is an operating means that allows the user to manually instruct the camera to prepare for imaging and to initiate imaging.

[0029] The operation unit 111 is an information input means that can be used to set various modes and functions on the camera body 100. In this embodiment, the operation unit 111 includes a rotary dial, a cross key, a select button, a reset button, etc., but the mechanism used for information input is not limited to these. Typical modes and functions that can be set using the operation unit 111 include metering mode, shooting mode, continuous shooting function, flickerless shooting function (described later), and various settings related to live view. By operating the operation unit 111, a graphical user interface (GUI) and function icons related to these functions are displayed on the display unit 103.

[0030] (Flicker detection and flicker-free shooting function) The operation of the camera body 100 during live view will be described below with reference to Figure 3. Figure 3 is a flowchart showing the flow of flicker detection, Tv setting, and still image shooting during live view according to the first embodiment of the present invention. This flow is realized when the system control unit 104 reads a program from the ROM of the setting value holding unit 113, expands it into RAM, and executes it. The following explanation will use as an example the case in which live view is started when the power switch (not shown) of the camera body 100 is turned on, with the flickerless shooting function already turned on.

[0031] When the power switch of the camera body 100 is turned on, in step S301 the system control unit 104 reads various setting values ​​from the ROM area of ​​the setting value holding unit 113 and writes them to the RAM area, making the setting values ​​accessible in subsequent steps. Among the setting values ​​is the "flicker detection setting," which is set to either "automatic" or "manual." In the case of "manual," flicker is detected in response to user operation, while in the case of "automatic," flicker is detected periodically even without explicit user operation. For example, in the case of "manual," the system may be configured so that flicker detection is performed by operating the flicker detection button corresponding to the operation unit 111 at the timing desired by the user. The steps for actually detecting flicker will be described later.

[0032] Next, in step S302, the system control unit 104 reads the "flicker detection setting" from the RAM area of ​​the setting value holding unit 113. If it is "automatic", proceed to step S303; otherwise, proceed to step S304.

[0033] In step S303, the signal processing unit 106 determines the flicker frequency by performing flicker detection processing on the image signal output from the image sensor 101. The specific method for detecting the frequency is omitted. For example, a detection method such as that described in Patent Document 1 (Japanese Patent Application Publication No. 2022-130277) can be used, and the flicker frequency can be determined by detecting periodic changes in brightness.

[0034] In step S304, the system control unit 104 determines whether or not a manual flicker detection operation has been performed at the operation unit 111. If a manual detection operation has been performed, the system proceeds to step S303; otherwise, the system proceeds to step S305.

[0035] In step S305, the system control unit 104 determines whether or not a TV setting operation has been performed on the operation unit 111. If the operation has been performed, the process proceeds to step S306; otherwise, the process proceeds to step S307.

[0036] In step S306, the system control unit 104 sets the Tv (Tv setting) based on the operation on the operation unit 111. The flow of setting the Tv in this embodiment will be described later using Figures 4 to 8.

[0037] In step S307, the system control unit 104 controls the image sensor 101, signal processing unit 106, and display unit 103 to perform live view display. At this time, the effect of flicker in live view display can be reduced by setting the exposure time to an integer multiple of the flicker period. The system control unit 104 also controls the camera body 100 to periodically perform photometering of the subject based on the image captured for live view during live view display, and exposure control is performed based on this photometering result.

[0038] In step S308, the system control unit 104 determines whether or not an imaging operation (imaging instruction) has been performed by the imaging instruction unit 110. If it is determined that an imaging operation has been performed, the system proceeds to step S309; ​​otherwise, it proceeds to step S310.

[0039] In step S309, based on the imaging instruction given to the imaging instruction unit 110, the system control unit 104 performs imaging with an exposure time that reduces the effect of flicker (flickerless imaging). In this embodiment, the exposure time is determined based on the idea that the effect of flicker can be reduced when the exposure time is an integer multiple of the flicker period. The method for determining the exposure time will be explained using Figures 5 and 6.

[0040] Figure 5 shows the relationship between the set Tv and the exposure time range when the Tv setting interval is 1 / 3 stop. For example, when the set Tv is 1 / 1000, the exposure time range has a width of 1 / 3 stop centered around 2 to the power of -10 [seconds], so it ranges from 2 to the power of (-10 - 1 / 6) [seconds] to 2 to the power of (-10 + 1 / 6) [seconds], which calculates to 0.87 [ms] to 1.10 [ms]. Figure 5 also shows the exposure time range calculated similarly for Tv settings other than 1 / 1000.

[0041] Next, Figure 6 shows the relationship between the exposure time that reduces the effect of flicker based on the detected flicker period and the set Tv converted at 1 / 3 stop intervals. Figure 7 shows an example where the detected flicker period is 1 ms (= frequency 1000 Hz). That is, integer multiples of 1 ms, such as 1, 2, 3, 4, 5, 6, 7, ... ms, are candidate exposure times that reduce the effect of flicker. The system control unit 104 can calculate the exposure time that reduces the effect of flicker based on the detected flicker period.

[0042] The setting Tv for each exposure time in Figure 6, compared to the exposure time range in Figure 5, is shown in the lower row under "Setting Tv converted in 1 / 3 stop intervals". In the Tv setting of step S108 described later, one of the setting Tv in the lower row under "Setting Tv converted in 1 / 3 stop intervals" in Figure 6 is selected, so the corresponding exposure time in the upper row is adopted as the exposure time for shooting.

[0043] In step S310, the system control unit 104 determines whether or not the operation to turn off the power of the camera body 100 (power off operation) has been performed at the operation unit 111. If the power off operation has been performed, the process proceeds to step S311, and under the control of the system control unit 104, the live view is interrupted and the power of the camera body 100 is turned off. If the operation has not been performed, the process returns to step S302.

[0044] Next, we will explain the flow of TV settings performed in step S306 using Figures 4 to 8.

[0045] In this embodiment, the Tv setting is performed using a Tv setting method (hereinafter referred to as "Tv setting method A") that prevents the selection of Tv values ​​that may cause flicker. The specific method will be explained using Figures 5 to 8.

[0046] Figures 4(a) and 4(b) show the Tv setting screen when flicker is not detected, respectively. Figure 4(a) is an example of the GUI screen display when Tv=1 / 500, and is displayed, for example, superimposed on the live view display of display unit 103.

[0047] The Tv setting display frame 401 displays the currently set Tv value. The slider 402 is a slider-like display that shows the configurable Tv values, and the central indicator 403 shows the currently set Tv value. In Figure 4(a), indicator 403 corresponds to the position of the number 500, indicating to the user that Tv = 1 / 500 is set. Markers 404 or 405 are displayed on the slider 402 at intervals of 1 / 3 of a setting width, indicating the configurable Tv values. In Figure 4(a), for a typical Tv value (e.g., 1 / 500), marker 404 is displayed at the numerical position corresponding to the interval of one step. Markers 405 are also displayed between markers 404, corresponding to intervals of 1 / 3 of a step. To make it easier to visually understand that the intervals are different, Figure 4(a) shows an example where the display forms of markers 404 and 405 are different. Note that the display forms of markers 404 and 405 are not limited to these. For example, it is preferable that they have a distinguishable shape, such as color, thickness, or shape.

[0048] The shaded area in 406 indicates that the maximum Tv setting that can be set with slider 502 is 1 / 2000.

[0049] For example, if you operate the dial on the control unit 111 or the directional keys to change the Tv to the slower side once from the state shown in Figure 4(a), the set Tv will be set from 1 / 500 to 1 / 400, which is 1 / 3 of a stop slower. The display at this time is shown in Figure 4(b). At this time, the Tv displayed in the Tv setting display frame 401 is changed to Tv=1 / 400, and the slider 402 is slid to the left corresponding to 1 / 3 of a stop of Tv.

[0050] Figures 5 to 7 show the Tv setting screen when flicker detection is performed. As mentioned above, Figure 5 shows the relationship between the set Tv and the exposure time range when the Tv setting range is 1 / 3 stop intervals, and Figure 6 shows the relationship between the exposure time that reduces the effect of the detected flicker and the set Tv converted to 1 / 3 stop intervals.

[0051] In Tv setting method A, only the setting values ​​shown in Figure 6 are presented to the user as configurable. A specific GUI screen is shown in Figure 7. Of the Tv settings in Figure 5, 1 / 800, 1 / 640, and 1 / 400 are not among the Tv settings converted in 1 / 3 stop intervals in Figure 6, so these Tv settings are not configurable. To indicate to the user that these Tv settings are not configurable, the markers for the corresponding Tv positions are not displayed in Figure 7, preventing the user from setting them. For example, if the Tv is changed once to a higher speed from the state in Figure 8, it will not be set to 1 / 640 or 1 / 800, but to 1 / 1000. Also, the maximum Tv is 1 / 1000, which is indicated to the user in the shaded area of ​​506. With the above Tv setting method, the exposure time that reduces the effect of flicker can be set in 1 / 3 stop intervals.

[0052] With the configuration described above, it is possible to provide an imaging device that can capture still images with reduced flicker effects using the Tv setting method, which is a common method for general imaging devices, where the setting interval is a specified number of stops of 1 / 3 or more. In this embodiment, the setting of Tv at 1 / 3 stop intervals was described, but it is not limited to this, and it is also possible to implement this even when the Tv setting range is 1 / 2 stop or more, such as 1 / 3 stop intervals.

[0053] (Second Embodiment) In the first embodiment, the Tv setting method A shown in Figure 7 may result in the unsettable Tv changing when the flicker period changes. In the second embodiment, a Tv setting method that can solve this problem will be described. The basic functional configuration is the same as in the first embodiment, so the explanation will be omitted.

[0054] In this embodiment, for Tv speeds higher than a specific Tv, the setting range is changed from that of the lower-speed side to set the Tv (hereinafter referred to as "Tv setting method B"). The specific method will be explained using Figure 9.

[0055] In Figure 9, the setting interval for Tv on the faster side of 1 / 125 is changed from 1 / 3 step intervals to 1 step intervals. Therefore, marker 505, which was displayed in Figure 4(a), is not displayed in Figure 10. The above Tv setting method results in Tv values ​​that cannot be set at 1 / 3 step intervals, but this can be resolved by changing the Tv setting interval to 1 step intervals as shown above.

[0056] In this embodiment, the setting range for Tv on the faster side of 1 / 125 is set to one step interval, but the threshold can be set to other Tv values. In particular, setting the threshold to a Tv value equivalent to, for example, -2 steps from the flicker frequency to be detected is preferable because it makes it easier to prevent the occurrence of Tv values ​​that cannot be set.

[0057] (Third embodiment) To take advantage of the strengths of both the Tv setting method A of the first embodiment and the Tv setting method B of the second embodiment, a method of switching the Tv setting method according to the flicker detection setting is effective. In the third embodiment, an example of an imaging device that switches the Tv setting method according to the flicker detection setting will be described. The basic functional configuration of this embodiment is the same as that of the first embodiment, so the explanation will be omitted.

[0058] The third embodiment will be described below with reference to Figure 8(a).

[0059] First, in step S801, the system control unit 104 reads the "flicker detection setting" from the RAM area of ​​the setting value holding unit 113. The flicker detection setting can be set by the user from the menu setting screen displayed on the operation unit 111 or the display unit 103. If the flicker detection setting is "automatic", the system proceeds to step S802; if it is "manual", the system proceeds to step S803.

[0060] The process in step S802 is the same as the method for setting Tv in the second embodiment, and the process in step S803 is the same as the method for setting Tv in the first embodiment, so their explanations will be omitted.

[0061] With the configuration described above, when flicker detection is performed automatically, it prevents the creation of unconfigurable Tv values, while when flicker detection is performed manually, the Tv value can be set in increments of 1 / 3 of a step.

[0062] (Fourth Embodiment) In the third embodiment, switching between TV setting method A and TV setting method B was performed solely by the flicker detection setting. In this embodiment, even when the "flicker detection setting" is set to "automatic," TV setting method A is adopted if no flicker is detected. This allows TV settings to be adjusted in 1 / 3 increments until flicker is detected. The basic functional configuration of this embodiment is the same as that of the first embodiment, so a detailed explanation is omitted.

[0063] The fourth embodiment will be described below with reference to Figure 8(b).

[0064] First, in step S804, the system control unit 104 reads the "flicker detection setting" from the RAM area of ​​the setting value holding unit 113. The flicker detection setting can be set by the user from the menu setting screen displayed on the operation unit 111 or the display unit 103. If the flicker detection setting is "automatic", proceed to step S805; otherwise, proceed to step S807.

[0065] In step S805, the system control unit 104 determines whether flicker has been detected at least once since the camera body 100 was powered on. If flicker has been detected at least once, the system proceeds to step S806; otherwise, it proceeds to step S807.

[0066] Step S806 is the same process as step S802 in the third embodiment, and step S807 is the same process as step S803 in the third embodiment, so their explanations will be omitted.

[0067] In the configuration described above, even when the "Flicker Detection Setting" is set to "Automatic," if no flicker is detected, the TV setting can be adjusted in increments of 1 / 3 until flicker is detected. In this embodiment, the branching decision in step S806 was made based on "if flicker has been detected at least once since the camera body 100 was powered on," but it could also be made based on "whether flicker is currently detected."

[0068] According to the configuration described above, even when the "Flicker Detection Setting" is set to "Automatic," if no flicker is detected, the TV setting can be adjusted in 1 / 3 increments until flicker is detected. Furthermore, if flicker is detected, the TV setting can be adjusted by changing the setting increment.

[0069] (Other embodiments) The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0070] This embodiment includes the following imaging device and control method for the imaging device.

[0071] (Composition 1) An imaging device comprising: an image sensor for capturing an image; a detection means for detecting the period of brightness change of a light source from the image; a setting means for setting the exposure time of the image sensor; and a calculation means for calculating one or more candidate exposure times that reduce the effect of the brightness change of the light source based on the detection of the period of brightness change of the light source, wherein the setting means can set the exposure time from any of the set values ​​of a first setting interval, and the setting means controls so that when the candidate exposure times are converted using the setting interval, candidates for exposure times that do not satisfy predetermined conditions cannot be selected.

[0072] (Configuration 2) The imaging apparatus according to configuration 1, characterized in that the first setting interval is an interval of 1 / 3 stop or more.

[0073] (Composition 3) The imaging apparatus according to configuration 1 or 2, characterized in that the predetermined conditions correspond to an integer multiple of the period for the candidate exposure time.

[0074] (Composition 4) The imaging apparatus according to any one of configurations 1 to 3, characterized in that, if the set exposure time is shorter than the first time, the setting means causes the exposure time to be set at a larger setting interval than when the set exposure time is the first time.

[0075] (Composition 5) The imaging apparatus according to any one of configurations 1 to 3, characterized in that when the set exposure time is shorter than the first time, the setting means sets the exposure time in one-step setting intervals, and when the exposure time is the first time, it sets the exposure time in 1 / 3 step or 1 / 2 step setting intervals.

[0076] (Composition 6) The imaging apparatus according to any one of configurations 1 to 5, characterized in that when the detection means automatically detects the period of change in brightness of the light source, the exposure time is set at a larger set interval compared to when the detection means does not automatically detect the period of change in brightness of the light source.

[0077] (Composition 7) The imaging apparatus according to any one of configurations 1 to 6, further comprising a display control means for displaying the exposure time setting on a display unit, wherein the display control means controls the display unit not to display any of the exposure time candidates that do not satisfy the predetermined conditions.

[0078] (Composition 8) The imaging apparatus according to any one of configurations 1 to 6, further comprising a display control means for displaying the exposure time setting on a display unit, wherein the display control means controls the display unit to display a message indicating that an exposure time candidate that does not satisfy the predetermined conditions cannot be selected.

[0079] (Control method 1) A control method for an imaging device, comprising: an imaging step of capturing an image; a detection step of detecting the period of brightness change of a light source from the image; a setting step of setting the exposure time of the image sensor; and a calculation step of calculating one or more candidate exposure times that reduce the effect of the brightness change of the light source based on the detection of the period of brightness change of the light source, wherein in the setting step, the exposure time can be set from any of the set values ​​of a first setting interval, and in the setting step, candidates for exposure times that do not satisfy predetermined conditions when the candidate exposure times are converted to the setting interval cannot be selected. [Explanation of Symbols]

[0080] 100 Camera Body 101 Image sensor 104 System Control Unit (CPU) 106 Signal Processing Unit 110 Imaging instruction unit 111 Operation section 112 Records Department 113 Setting value retention unit 200 shooting lenses 203 Lens Control Unit (LPU)

Claims

1. An image sensor that captures an image, A detection means for detecting the period of change in the brightness of the light source from the aforementioned image, A setting means for setting the exposure time of the image sensor, The system includes a calculation means for calculating one or more candidate exposure times that reduce the effect of changes in the brightness of the light source, based on the detection of the period of changes in the brightness of the light source. In the setting means, the exposure time can be set from any of the setting values ​​of the first setting interval. The imaging apparatus is characterized in that the setting means controls the system so that when the candidate exposure times are converted using the setting interval, candidates for exposure times that do not satisfy predetermined conditions cannot be selected.

2. The imaging apparatus according to claim 1, characterized in that the first setting interval is an interval of 1 / 3 stop or more.

3. The imaging apparatus according to claim 1, characterized in that the predetermined conditions correspond to an integer multiple of the period for the candidate exposure time.

4. The imaging apparatus according to claim 1, characterized in that, if the set exposure time is shorter than the first time, the setting means causes the exposure time to be set at a larger setting interval than when the set exposure time is the first time.

5. The imaging apparatus according to claim 1, characterized in that, if the set exposure time is shorter than the first time, the setting means sets the exposure time in one-stop intervals, and if the exposure time is the first time, it sets the exposure time in one-third-stop or one-half-stop intervals.

6. The imaging apparatus according to claim 1, characterized in that when the detection means automatically detects the period of change in brightness of the light source, the exposure time is set at a larger set interval compared to when the detection means does not automatically detect the period of change in brightness of the light source.

7. The system further includes a display control means that displays the exposure time setting on the display unit, The imaging apparatus according to claim 1, characterized in that the display control means controls the display unit not to display any of the exposure time candidates that do not satisfy the predetermined conditions.

8. The system further includes a display control means that displays the exposure time setting on the display unit, The imaging apparatus according to claim 1, characterized in that the display control means controls the display unit to display a message indicating that a candidate exposure time that does not satisfy the predetermined conditions cannot be selected.

9. Image acquisition step and A detection step to detect the period of change in the brightness of the light source from the aforementioned image, A setting step for setting the exposure time of the image sensor, The method includes a calculation step of calculating one or more candidate exposure times that reduce the effect of the brightness change of the light source based on the detection of the period of brightness change of the light source, In the setting step, the exposure time can be set from any of the set values ​​of the first setting interval. A control method for an imaging device, characterized in that, in the setting step, when the candidate exposure time is converted using the setting interval, candidates for exposure time that do not satisfy predetermined conditions cannot be selected.

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