Imaging element and imaging device

Abstract

This imaging element comprises: a first pixel that is provided with a first photoelectric conversion unit and that outputs a first signal used for image generation on the basis of charge generated by the first photoelectric conversion unit; a second pixel that is provided with a second photoelectric conversion unit and that outputs a second signal used to control the first pixel on the basis of charge generated by the second photoelectric conversion unit; a first signal line from which the first signal is output; and a second signal line from which the second signal is output. The second signal is used to control a frame rate for reading the first signal from the first pixel.

Description

Image sensor and image pickup device

[0001] The present invention relates to an imaging element and an imaging device.

[0002] 2. Description of the Related Art When shooting moving images, there is a demand for an imaging device that can capture a desired moment of a subject at a high frame rate (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2003-87630

[0004] According to a first aspect of the disclosure, an imaging element includes a first pixel having a first photoelectric conversion unit and outputting a first signal used for image generation based on charges generated by the first photoelectric conversion unit, a second pixel having a second photoelectric conversion unit and outputting a second signal used for controlling the first pixel based on charges generated by the second photoelectric conversion unit, a first signal line from which the first signal is output, and a second signal line from which the second signal is output, and the second signal is used to control a frame rate for reading out the first signal from the first pixel.

[0005] According to a second aspect of the disclosure, the imaging device includes the above-mentioned imaging element, a detection unit that detects the movement of a subject based on the second signal, and a control unit that controls the frame rate for reading out the first signal from the first pixel based on the detection result of the detection unit.

[0006] According to a third aspect of the disclosure, an imaging device includes an imaging unit that images a subject, a detection unit that detects movement of the subject, and a control unit that, when a first detection result is output from the detection unit, controls the frame rate of the imaging unit to a first frame rate, and, when the detection result of the detection unit changes from the first detection result to a second detection result, controls the frame rate of the imaging unit to a second frame rate that is equal to or higher than the first frame rate.

[0007] According to a fourth aspect of the disclosure, an imaging device includes an imaging unit that images a subject, a detection unit that detects movement of the subject, and a recording unit that, when the detection result of the detection unit changes from a first detection result to a second detection result, records image data output from the imaging unit after the first detection result is output.

[0008] The configurations of the embodiments described below may be modified as appropriate, and at least a portion of the configuration may be replaced with other components. Furthermore, components that are not particularly limited in terms of their placement may be placed in any position that can achieve their function, not limited to the placement disclosed in the embodiments.

[0009] FIG. 1 is a diagram schematically illustrating an example configuration of a digital camera including an image sensor according to a first embodiment. FIG. 2 is a diagram illustrating an example arrangement of pixels in the image sensor according to the first embodiment. FIG. 3 is a diagram illustrating a schematic configuration of the image sensor according to the first embodiment. FIGS. 4A and 4B are circuit diagrams showing the configurations of imaging pixels and detection pixels, respectively. FIG. 5 is a flowchart illustrating an example of processing executed by the body control unit according to the first embodiment. FIG. 6 is a timing chart for describing processing executed by the body control unit according to the first embodiment. FIG. 7 is a flowchart for describing an example of processing executed by the body control unit according to a second embodiment. FIG. 8 is a flowchart showing details of frame rate control processing 1. FIG. 9 is a flowchart showing details of frame rate control processing 2. FIG. 10 is a flowchart showing details of frame rate control processing 3. FIG. 11 is a timing chart for describing processing executed by the body control unit according to the second embodiment.

[0010] First Embodiment A digital camera 1 (hereinafter referred to as camera 1), which is an example of an imaging device according to a first embodiment, will be described below with reference to FIGS. 1 to 6. Note that, in the drawings shown below, an XYZ Cartesian coordinate system is appropriately provided for ease of explanation and understanding. In this coordinate system, the direction from the subject toward the camera body 2 at a camera position (hereinafter referred to as the normal position) when a photographer takes a landscape image with the optical axis OA horizontal is defined as the +Z direction. Furthermore, the direction toward the right as viewed from the camera body 2 at the normal position is defined as the +X direction. Furthermore, the direction toward the upper side at the normal position is defined as the +Y direction. Note that the scales of the shapes, lengths, thicknesses, etc. of the various parts shown in the embodiments do not necessarily correspond to the actual objects, and some elements may be omitted from the drawings to facilitate understanding.

[0011] 1 is a diagram schematically illustrating an example configuration of a digital camera 1 (hereinafter referred to as camera 1) equipped with an image sensor 21 according to the first embodiment. The camera 1 includes an interchangeable lens 3 and a camera body 2. The interchangeable lens 3 is attached to the camera body 2 via a lens mount (not shown). Note that the camera 1 may also be configured as an integrated lens camera rather than an interchangeable lens camera.

[0012] The interchangeable lens 3 includes an imaging optical system 31 including, for example, a zoom lens, a focus lens, an aperture, an anti-vibration lens, etc., and a lens control unit 32. The lens control unit 32 includes peripheral components such as a CPU (Central Processing Unit) and memory. The lens control unit 32 performs drive control of the focus lens and aperture, detects the positions of the zoom lens and focus lens, sends lens information to the camera body 2, and receives camera information from the camera body 2.

[0013] The camera body 2 includes, for example, an image sensor 21 , an image processing unit 22 , a body control unit 23 , a display unit 24 , an operation unit 25 , and a recording unit 26 .

[0014] The operation unit 25 includes a shutter button, operation members for various settings, etc. The display unit 24 is, for example, a liquid crystal monitor (also called a rear monitor) mounted on the rear surface of the camera body 2.

[0015] The body control unit 23 includes a CPU and peripheral components such as memory. The body control unit 23 controls the operation of the camera 1, such as driving and controlling the image sensor 21, reading pixel signals from the image sensor 21, performing focus detection calculations and focusing the interchangeable lens 3, and displaying and recording image data. The body control unit 23 also communicates with the lens control unit 32, receiving lens information and sending camera information (such as defocus amount and aperture value).

[0016] The body control unit 23 also includes a detection unit 231 and a frame rate control unit 232. The detection unit 231 detects the movement of the subject within the angle of view (the state of the subject) based on detection image data output from a second image processing unit 22B (described later). The detection unit 231 also detects the presence or absence of a subject within the angle of view based on moving image data output from a first image processing unit 22A (described later).

[0017] The frame rate control unit 232 controls the frame rate, which defines the time interval for reading out pixel signals from the imaging pixels 51 a included in the imaging element 21 , based on the detection result of the detection unit 231 .

[0018] The recording unit 26 has a card slot into which a nonvolatile recording medium such as a memory card can be inserted, and also has a volatile memory such as a RAM (Random Access Memory).

[0019] The recording unit 26 stores the image data and various data generated in the image processing unit 22 in a recording medium attached to the card slot. The recording unit 26 also stores the image data and various data generated in the image processing unit 22 in volatile memory. The recording unit 26 also stores the image data and various data stored in the volatile memory in a non-volatile recording medium. The recording unit 26 may have an internal memory. In this case, the recording unit 26 can also record the image data and various data generated in the image processing unit 22 in the internal memory. The volatile memory may be configured as part of the body control unit 23.

[0020] The image processing unit 22 is an image processing engine that performs various image processes on the pixel data input from the imaging element 21. In this embodiment, the image processing unit 22 includes a first image processing unit 22A and a second image processing unit 22B.

[0021] The first image processing unit 22A performs various image processes on the pixel data input from the image sensor 21 to generate image data (moving image data) to be stored in a recording medium such as a memory card. The generated image data is stored by the recording unit 26 in a volatile memory such as a RAM or a non-volatile recording medium such as a memory card under the control of the body control unit 23.

[0022] The second image processing unit 22B generates detection image data for detecting the movement of the subject (the state of the subject) within the angle of view, using the pixel data input from the image sensor 21. The generated detection image data is input to the detection unit 231 of the body control unit 23.

[0023] The first image processing unit 22A and the second image processing unit 22B can execute processes independently (asynchronously).

[0024] The image sensor 21 is disposed on the intended imaging plane (intended focal plane) of the interchangeable lens 3, and photoelectrically converts the subject image formed by the interchangeable lens 3. The image sensor 21 according to this embodiment is a stacked image sensor. Specifically, the image sensor 21 includes an image sensor chip that outputs pixel signals corresponding to incident light, a signal processing chip that processes the pixel signals, and a memory chip that stores the pixel signals. The image sensor chip, signal processing chip, and memory chip are stacked and electrically connected to one another by conductive bumps such as Cu.

[0025] 2 is a diagram showing an example of the arrangement of pixels in the image sensor 21 according to this embodiment. The image sensor 21 includes a pixel array 50 including imaging pixels 51a that perform photoelectric conversion on received light in their photoelectric conversion units and output signals used to generate images, and detection pixels 51b that perform photoelectric conversion on received light in their photoelectric conversion units and output signals used to control the imaging pixels 51a.

[0026] The imaging pixels 51a include pixels (hereinafter referred to as R pixels) that have filters with spectral characteristics that separate light in a first wavelength range (red (R) light) from the incident light, pixels (hereinafter referred to as G pixels) that have filters with spectral characteristics that separate light in a second wavelength range (green (G) light) from the incident light, and pixels (hereinafter referred to as B pixels) that have filters with spectral characteristics that separate light in a third wavelength range (blue (B) light) from the incident light.

[0027] The pixel array 50 includes a first pixel group 400 and a second pixel group 400'. The first pixel group 400 includes a first pixel group 401 in which R pixels 51a and G pixels 51a are alternately arranged in the ±X directions, i.e., the row direction, and a second pixel group 402 in which G pixels 51a and B pixels 51a are alternately arranged in the row direction. A plurality of first pixel groups 400 are arranged consecutively in the ±Y directions, i.e., the column direction. As a result, the first pixel group 401 and the second pixel group 402 are alternately arranged in the ±Y directions, i.e., the column direction. The imaging pixels 51a are arranged according to a Bayer array.

[0028] The second pixel group 400′ includes the first pixel group 401 and a third pixel group 403 in which a plurality of detection pixels 51b (D pixels) are arranged in the row direction. In the example of FIG. 2 , two first pixel groups 400 are provided between the second pixel groups 400′ in the Y direction. Note that the number of first pixel groups 400 provided between the second pixel groups 400′ is not limited to two and may be one, three, or more. In this embodiment, a D pixel that is different from any of the R, G, and B pixels is provided as the plurality of detection pixels 51b, and is configured to receive light in a wavelength range wider than any of the first, second, and third wavelength ranges. In this embodiment, the second pixel set 400′ is arranged such that the second pixel group 402 of the first pixel group 401 and the second pixel group 402 included in the first pixel set 400 is replaced with D pixels, but the first pixel group 401 may also be replaced with D pixels. Also, instead of the D pixels, R pixels, G pixels, and B pixels may be arranged in a Bayer array and used as the detection pixels 51b.

[0029] Fig. 3 is a diagram illustrating a schematic configuration of the image sensor 21 according to this embodiment. Fig. 4A and Fig. 4B are circuit diagrams illustrating the configurations of the image pickup pixels 51a and the detection pixels 51b, respectively.

[0030] As shown in FIG. 3, the imaging element 21 includes a pixel array 50, a vertical drive unit 42, a drive control unit 43, a horizontal drive unit 44, a signal processing unit 45, and a memory unit 46.

[0031] As shown in FIGS. 4A and 4B, the imaging pixel 51a and the detection pixel 51b each have a photoelectric conversion unit 62 such as a photodiode (PD) and a readout unit 60.

[0032] The photoelectric conversion unit 62 has a function of converting incident light into electric charges and storing the photoelectrically converted electric charges. The readout unit 60 includes a transfer unit 63, a discharge unit 64, a floating diffusion (FD) 65, an amplifier unit 66, and a selection switch unit 67.

[0033] As shown in Fig. 4A, in the imaging pixel 51a, the transfer unit 63 is controlled by a signal Tx_a and transfers the charge photoelectrically converted by the photoelectric conversion unit 62 to the floating diffusion 65. Also, as shown in Fig. 4B, in the detection pixel 51b, the transfer unit 63 is controlled by a signal Tx_b and transfers the charge photoelectrically converted by the photoelectric conversion unit 62 to the floating diffusion 65. In other words, the transfer unit 63 forms a charge transfer path between the photoelectric conversion unit 62 and the floating diffusion 65. The floating diffusion 65 holds (accumulates) the charge.

[0034] The amplifier 66 amplifies and outputs a signal generated by the charge held in the floating diffusion 65. As shown in Fig. 4A, in the imaging pixel 51a, the amplifier 66 is connected to the first vertical signal line 52A via the selection switch unit 67. As shown in Fig. 4B, in the detection pixel 51b, the amplifier 66 is connected to the second vertical signal line 52B via the selection switch unit 67.

[0035] 4A, in the imaging pixel 51a, the discharge unit (reset unit) 64 is controlled by a signal Rst_a to discharge the charge of the floating diffusion 65 and reset the potential of the floating diffusion 65 to a reset potential (reference potential). Also, as shown in FIG. 4B, in the detection pixel 51b, the discharge unit (reset unit) 64 is controlled by a signal Rst_b to discharge the charge of the floating diffusion 65 and reset the potential of the floating diffusion 65 to the reset potential (reference potential).

[0036] 4A, in the imaging pixel 51a, the selection switch unit 67 is controlled by a signal Sel_a to output the signal from the amplifier unit 66 to a first vertical signal line 52A. Also, as shown in FIG. 4B, in the detection pixel 51b, the selection switch unit 67 is controlled by a signal Sel_b to output the signal from the amplifier unit 66 to a second vertical signal line 52B.

[0037] The transfer unit 63, the discharge unit 64, the amplifier unit 66, and the selection switch unit 67 are each configured by, for example, a transistor M1, a transistor M2, a transistor M3, and a transistor M4, respectively.

[0038] In the imaging pixel 51 a, the readout unit 60 reads out a signal (noise signal) generated when the potential of the floating diffusion 65 is reset to the reset potential by the discharge unit 64 to the first vertical signal line 52A via the selection switch unit 67. In addition, in the imaging pixel 51 a, the readout unit 60 reads out a signal (photoelectric conversion signal) corresponding to the charge transferred from the photoelectric conversion unit 62 to the floating diffusion 65 by the transfer unit 63 to the first vertical signal line 52A via the selection switch unit 67.

[0039] In the detection pixel 51b, the readout unit 60 reads out a signal (noise signal) when the potential of the floating diffusion 65 is reset to the reset potential by the discharge unit 64 to the second vertical signal line 52B via the selection switch unit 67. In addition, in the detection pixel 51b, the readout unit 60 reads out a signal (photoelectric conversion signal) corresponding to the charge transferred from the photoelectric conversion unit 62 to the floating diffusion 65 by the transfer unit 63 to the second vertical signal line 52B via the selection switch unit 67.

[0040] In this way, since the imaging pixel 51a is connected to the first vertical signal line 52A and the detection pixel 51b is connected to the second vertical signal line 52B, it is possible to simultaneously read out the signal from the imaging pixel 51a and the signal from the detection pixel 51b.

[0041] Returning to Figure 3, the drive control unit 43 generates clock signals and control signals that serve as the basis for the operation of the vertical drive unit 42, signal processing unit 45, memory unit 46, horizontal drive unit 44, etc., based on a master clock input from outside and a control signal input from the body control unit 23, and provides these signals to the vertical drive unit 42, signal processing unit 45, memory unit 46, horizontal drive unit 44, etc.

[0042] The vertical drive unit 42 supplies control signals such as signal Rst_a, signal Tx_a, and signal Sel_a to the imaging pixels 51 a to control the operation of each imaging pixel 51 a. The vertical drive unit 42 also supplies control signals such as signal Rst_b, signal Tx_b, and signal Sel_b to the detection pixels 51 b to control the operation of each detection pixel 51 b. Note that in Figure 3, "(n)" in signal Rst_a(n), signal Tx_a(n), signal Sel_a(n), signal Rst_b(n), signal Tx_b(n), and signal Sel_b(n) represents the row number.

[0043] The signal processing unit 45 includes analog-to-digital conversion units (ADCs) 451a1 to 451am and 451b1 to 451bm and correlated double sampling units (CDSs) 452a1 to 452am and 452b1 to 452bm. The ADCs 451a1 to 451am convert noise signals and photoelectric conversion signals input via the first vertical signal lines 52A(1) to 52A(m) into digital signals and output the digital signals to the CDSs 452a1 to 452am, respectively. The ADCs 451b1 to 451bm convert noise signals and photoelectric conversion signals input via the second vertical signal lines 52B(1) to 52B(m) into digital signals and output the digital signals to the CDSs 452b1 to 452bm, respectively. In FIG. 3, "(m)" in the first vertical signal line 52A(m) and the second vertical signal line 52B(m) represents the column number.

[0044] CDS 452a1 to CDS 452am and 452b1 to CDS 452bm perform correlated double sampling on the input digital signal, remove noise from the digital signal based on the input noise signal, and output the noise-removed digital signal (hereinafter referred to as pixel signal) to memory unit 46.

[0045] The memory unit 46 includes memories 461a1 to 461am and 461b1 to 461bm. The memories 461a1 to 461am store the pixel signals output from the CDSs 452a1 to 452am, respectively, and the memories 461b1 to 461bm store the pixel signals output from the CDSs 452b1 to 452bm, respectively.

[0046] The horizontal drive unit 44 outputs a set of pixel signals stored in memories 461a1 to 461am as captured pixel data to the first image processing unit 22A in response to a scanning signal from the drive control unit 43. Furthermore, the horizontal drive unit 44 outputs a set of pixel signals stored in memories 461b1 to 461bm as detected pixel data to the second image processing unit 22B in response to a scanning signal from the drive control unit 43.

[0047] The pixel signals stored in the memories 461a1 to 461am and the pixel signals stored in the memories 461b1 to 461bm can be output asynchronously. The pixel signals stored in the memories 461a1 to 461am and the pixel signals stored in the memories 461b1 to 461bm can be output simultaneously or at different timings.

[0048] Next, the processing executed by the body control unit 23 according to the first embodiment will be described. Fig. 5 is a flowchart showing an example of the processing executed by the body control unit 23 according to the first embodiment. Fig. 6 is a timing chart for explaining the processing of the body control unit 23 according to the first embodiment.

[0049] 5 is initiated, for example, when a command to shoot a video is issued (for example, when the video shooting button is pressed). First, the frame rate control unit 232 of the body control unit 23 sets the frame rate that defines the time interval for reading out signals from the imaging pixels 51a to frame rate R1 (step S11). Here, the user may set frame rate R1 via the operation unit 25, or the body control unit 23 may set frame rate R1 automatically. The value of frame rate R1 may be set within a range of 3 to 120 fps, for example, and preferably within a range of 15 to 60 fps.

[0050] 6, signals are read from the imaging pixels 51a at time intervals T1, and imaging pixel data (e.g., MI1) is output to the first image processing unit 22A. That is, the time interval T1 corresponds to the set frame rate R1. The first image processing unit 22A generates moving image data (MI1) based on the imaging pixel data (MI1). The generated moving image data (e.g., MI1) is recorded on a non-volatile recording medium via the recording unit 26 under the control of the body control unit 23, and is also displayed on the display unit 24.

[0051] On the other hand, signals are read out from the detection pixels 51b at time intervals T3, for example, and detection pixel data (e.g., DI1) is output to the second image processing unit 22B. Here, the time interval T3 is set in advance and is set, for example, as a time interval corresponding to a frame rate R2, which will be described later. The second image processing unit 22B generates detection image data (DI1) for detecting the state (movement) of a subject within the angle of view, based on the detection pixel data (DI1).

[0052] 5, the detection unit 231 of the body control unit 23 obtains a motion vector from the difference (inter-frame difference) between two consecutive detection image data input from the second image processing unit 22B, and determines whether the calculated motion vector is equal to or greater than a threshold value TVa (step S13). Note that if only one detection image data is input from the second image processing unit 22B, the determination in step S13 is negative, and step S13 is executed again.

[0053] For example, suppose a user wants to capture the moment of a lightning strike at a high frame rate. The user adjusts the position and orientation of the camera 1 so that a thundercloud is included in the angle of view, and starts video capture at a frame rate R1 (step S11). If the entire sky flashes for a moment due to a lightning strike, the motion vector obtained from the difference between two consecutive detection image data (inter-frame difference) becomes equal to or greater than the threshold TVa, and the determination in step S13 is affirmative. That is, in step S13, the detection unit 231 detects the movement of the subject (the state of the subject) within the angle of view. In the following description, the process performed by the detection unit 231 will be referred to as a subject state detection process.

[0054] While the motion vector is less than the threshold value TVa (step S13 / NO), the process of step S13 is repeated.

[0055] Then, when the motion vector becomes equal to or greater than the threshold value TVa (step S13 / YES), the frame rate control unit 232 sets the frame rate, which defines the time interval for reading out signals from the imaging pixels 51a, to a frame rate R2 higher than the frame rate R1 (step S15). Here, the user may set the frame rate R2 via the operation unit 25, or the body control unit 23 may automatically set the frame rate R2. The value of the frame rate R2 may be, for example, within a range of 120 to 2000 fps, and preferably within a range of 480 to 960 fps.

[0056] For example, in FIG. 6, suppose that the motion vector is equal to or greater than the threshold value TVa in the subject state detection process DP12 (shown by hatching) using the detection image data DI11 and DI12 generated by the second image processing unit 22B (step S13 / YES). In this case, the frame rate control unit 232 sets the frame rate to frame rate R2 at time t1 when the next moving image vertical synchronization signal is output (step S15). As a result, signals are read out from the imaging pixels 51a at time intervals T2, which are shorter than time interval T1. In other words, moving images are captured at a frame rate R2, which is higher than frame rate R1.

[0057] The first image processing unit 22A generates moving image data based on the captured pixel data. The generated moving image data is recorded on a non-volatile recording medium via the recording unit 26 under the control of the body control unit 23, and is also displayed on the display unit 24. In this way, when the motion vector becomes equal to or greater than the threshold value TVa, the frame rate is set to frame rate R2, which is higher than frame rate R1, so that changes in the state of the subject occurring within the angle of view (such as the occurrence of a lightning strike) can be captured at a high frame rate.

[0058] Since the frame rate is changed based on the inter-frame difference (motion vector) of the detection image data generated based on the signal output from the detection pixel 51 b, it can be said that the signal output from the detection pixel 51 b is used to control the frame rate for reading out signals from the imaging pixel 51 a. Furthermore, since the movement of the subject (the state of the subject) is detected based on the inter-frame difference (motion vector) of the detection image data generated based on the signal output from the detection pixel 51 b, it can also be said that the signal output from the detection pixel 51 b is used to detect the movement of the subject (the state of the subject).

[0059] 5, when the frame rate is set to frame rate R2, the detection unit 231 determines whether the motion vector is equal to or greater than the threshold value TVa (step S17). In step S17, for example, it determines whether the lightning strike is continuing. If the lightning strike has ended, the motion vector will be less than the threshold value TVa.

[0060] The process of step S17 is repeatedly executed until the motion vector becomes less than the threshold value TVa (step S17 / YES). When the motion vector becomes less than the threshold value TVa (step S17 / NO), the frame rate control unit 232 sets the frame rate to frame rate R1, which is lower than frame rate R2 (step S19), and returns to step S13. The process of FIG. 5 is repeatedly executed until the video shooting is completed.

[0061] For example, in FIG. 6 , assume that the motion vector is equal to or greater than the threshold value TVa in the subject state detection processes DP13 to DP32 (step S17 / YES), and then becomes less than the threshold value TVa in the subject state detection process DP33 (shown by cross-hatching) (step S17 / YES). In this case, the body control unit 23 sets the frame rate to frame rate R1 from time t2 when the next vertical synchronization signal is output. This causes signals from the imaging pixels 51a to be read at a time interval T1 longer than time interval T2. In this way, video can be captured at a high frame rate (frame rate R2) from the time when the motion vector is equal to or greater than the threshold value TVa until it becomes less than the threshold value TVa, allowing the desired moment to be captured at a high frame rate. Furthermore, because video is captured at a frame rate R1 lower than frame rate R2 at times other than the desired moment, the amount of video data stored on the recording medium can be reduced compared to when video is captured at frame rate R2 even at times other than the desired moment.

[0062] As described above in detail, according to the first embodiment, the image sensor 21 includes the image sensor 51a, each of which includes a photoelectric conversion unit 62 and outputs a signal used for image generation based on the charge generated by the photoelectric conversion unit 62; the detection pixel 51b, each of which includes the photoelectric conversion unit 62 and outputs a signal used for controlling the image sensor 51a based on the charge generated by the photoelectric conversion unit 62; the first vertical signal line 52A through which the signal from the image sensor 51a is output; and the second vertical signal line 52B through which the signal from the detection pixel 51b is output. The signal from the detection pixel 51b is used to control the frame rate for reading out the signal from the image sensor 51a. This enables a transition from a normal frame rate to a high-speed frame rate at a more appropriate timing, leading to optimization of memory capacity. The camera 1 includes the image sensor 21, the detection unit 231 that detects the movement of a subject within the field of view (the state of the subject) based on the signal from the detection pixel 51b, and the frame rate control unit 232 that controls the frame rate for reading out the signal from the image sensor 51a based on the detection result of the detection unit 231. This makes it possible to control the frame rate when capturing a desired moment of the subject in accordance with the movement (state) of the subject.

[0063] In the first embodiment, the output of signals from the imaging pixels 51 a and the output of signals from the detection pixels 51 b are executed in parallel, thereby enabling the generation of moving image data based on the signals from the imaging pixels 51 a and the generation of detection image data based on the signals from the detection pixels 51 b to be executed in parallel.

[0064] Furthermore, in the first embodiment, when the motion vector obtained from the inter-frame difference of the detection image data becomes equal to or greater than the threshold value TVa (FIG. 5: step S13 / YES), the frame rate control unit 232 controls the frame rate to frame rate R2 (FIG. 5: step S15). As a result, from the moment a change occurs in the state of the subject within the angle of view (the moment a lightning strike occurs), video can be captured at frame rate R2, which is higher than the frame rate R1 that was set before the change in the state of the subject (before the lightning strike occurred).

[0065] Furthermore, in the first embodiment, when the motion vector acquired from the inter-frame difference of the detection image data becomes equal to or greater than the threshold value TVa and then becomes less than the threshold value TVa (FIG. 5: step S17 / YES), the frame rate control unit 232 controls the frame rate to frame rate R1, which is lower than frame rate R2 (step S19). As a result, after the desired moment has ended, the video is captured at a lower frame rate, thereby reducing the amount of video data stored on the recording medium.

[0066] Second Embodiment The second embodiment differs from the first embodiment in the processing executed by the body control unit 23. In the second embodiment, the timing of changing the frame rate differs from the first embodiment in order to avoid missing the initial movement of the desired moment. For example, if you want to capture the moment an insect walking on a plant takes flight, changing the frame rate from frame rate R1 to frame rate R2 (>frame rate R1) upon detecting the movement of its wings as it takes flight will only change the frame rate after the moment the insect actually starts moving its wings. Therefore, it is not possible to capture the moment the insect spreads its wings at frame rate R2. In order to capture the moment the insect spreads its wings at frame rate R2, it is desirable, for example, to capture the insect at frame rate R2 even while the insect is moving.

[0067] Therefore, in the second embodiment, two thresholds are used for the motion vector to control the timing for changing the frame rate, so as not to miss the initial movement at the moment of capture.

[0068] 7 to 10 are flowcharts showing an example of processing executed by the body control unit 23 according to the second embodiment. Fig. 11 is a timing chart for explaining processing executed by the body control unit 23 according to the second embodiment.

[0069] 7 starts, for example, when video shooting starts. First, the frame rate control unit 232 of the body control unit 23 sets the frame rate that defines the time interval for reading out signals from the imaging pixels 51a to frame rate R1 (step S51).

[0070] Next, the body control unit 23 checks the video shooting settings set in the camera body 2 (step S53). The video shooting settings are made by the user via the operation unit 25. Note that the video shooting setting method of this embodiment is one example and is not limited to the setting method of this embodiment.

[0071] If the video shooting setting is a setting (setting 1) for not missing the initial movement of a second movement of a subject already present within the field of view when that subject makes a first movement and then a second movement, the body control unit 23 executes frame rate control process 1 (step S100). For example, suppose an insect is already present within the field of view and you want to capture a video of the insect taking off. In this case, if you do not start shooting when the insect is moving slowly (for example, walking), you will miss the moment when the insect begins to take off. Setting 1 is applied in such cases.

[0072] 8 is a flowchart showing the details of frame rate control process 1 (step S100). When frame rate control process 1 starts, the detection unit 231 determines whether the motion vector obtained from the inter-frame difference of the detection image data is equal to or greater than a threshold value TVb (step S101). The threshold value TVb is set to a relatively small value because it is used to detect small movements of the subject.

[0073] The process of step S101 is repeated until the motion vector becomes equal to or greater than the threshold value TVb (step S101 / NO).The moving image data shot at the frame rate R1 is stored in a non-volatile recording medium.

[0074] When the motion vector becomes equal to or greater than the threshold value TVb (step S101 / YES), the frame rate control unit 232 sets the frame rate, which defines the time interval for reading signals from the imaging pixels 51a, to frame rate R2, which is higher than frame rate R1 (step S103). Under the control of the body control unit 23, the recording unit 26 starts storing the video data captured at frame rate R2 in RAM (volatile memory) (step S105). At this time, the body control unit 23 stops storing the video data in the non-volatile recording medium.

[0075] 11, assume that the motion vector is equal to or greater than the threshold value TVb in the subject state detection process DP4 (step S101 / YES). In this case, the frame rate control unit 232 changes the frame rate from frame rate R1 to frame rate R2 (>frame rate R1) at time t11 when the next moving image vertical synchronization signal is output (step S103). Since the moving image data captured at frame rate R2 is temporarily stored in RAM, moving image data MI2 to MI4 are stored in RAM.

[0076] 8 , the detection unit 231 determines whether the motion vector is equal to or greater than the threshold TVb (step S107). If the motion vector is equal to or greater than the threshold TVb (step S107 / YES), the detection unit 231 determines whether the motion vector is equal to or greater than the threshold TVc (step S109). In setting 1, the threshold TVc is set to a value greater than the threshold TVb. This makes it possible to determine, for example, whether an insect, which is the subject of the photograph, has moved from a walking state (a state in which the motion vector is equal to or greater than the threshold TVb) to a movement in which it spreads its wings to take flight (whether the motion vector has become equal to or greater than the threshold TVc).

[0077] If the motion vector is less than the threshold TVc (step S109 / NO), the process returns to step S107. If the motion vector is less than the threshold TVb in step S107 (step S107 / NO), it can be determined that the subject has stopped, for example. That is, it can be determined that an insect has stopped moving from a walking state without spreading its wings to take off. In this case, under the control of the body control unit 23, the recording unit 26 thins out the video data captured at the frame rate R2 and stored in RAM, and stores the data in a non-volatile recording medium (step S119). The video data thinning process may involve, for example, thinning out some frames. Thereafter, the frame rate control unit 232 returns the frame rate to frame rate R1 (step S117) and the process returns to step S101. If the motion vector remains less than the threshold TVb for a long period of time in step S107, older data may be deleted depending on the RAM capacity.

[0078] For example, in FIG. 11, suppose that in subject state detection process DP4 the motion vector is greater than or equal to threshold value TVb (step S101 / YES), in subject state detection processes DP5 and DP6 the motion vector is greater than or equal to threshold value TVb (step S107 / YES) but less than threshold value TVc (step S109 / NO), and in subject state detection process DP7 the motion vector is less than threshold value TVb (step S107 / NO).

[0079] In this case, the recording unit 26 stores, for example, the moving image data MI3 out of the moving image data MI2 to MI4 captured at the frame rate R2 and stored in the RAM, in a non-volatile recording medium (step S119).The frame rate control unit 232 also changes the frame rate from the frame rate R2 to the frame rate R1 at time t12 when the next moving image vertical synchronization signal is output (step S117).

[0080] 8 , when the motion vector is equal to or greater than the threshold value TVc (step S109 / YES), the frame rate control unit 232 sets the frame rate to a frame rate R3 that is equal to or greater than the frame rate R2 (step S111). The frame rate R3 may be higher than the frame rate R2 or may be the same as the frame rate R2. The frame rate control unit 232 may also leave the frame rate at the frame rate R2.

[0081] Then, under the control of the body control unit 23, the recording unit 26 starts storing the moving image stored in the RAM in a non-volatile recording medium (step S113), thereby making it possible to store a moving image captured at a high frame rate, including the moment when the insect, which is the subject, takes flight, in the non-volatile recording medium.

[0082] For example, in FIG. 11, when the motion vector becomes equal to or greater than the threshold value TVb in the subject state detection process DP17 (step S101 / YES), the frame rate control unit 232 changes the frame rate from frame rate R1 to frame rate R2 (>frame rate R1) at time t13 when the next vertical synchronization signal for moving images is output (step S103).

[0083] In the subject state detection processes DP18 to DP23, the motion vector is equal to or greater than the threshold value TVb (step S107 / YES) but less than the threshold value TVc (step S109 / NO), and in the subject state detection process DP24, the motion vector becomes equal to or greater than the threshold value TVc (step S109 / YES).

[0084] In this case, the body control unit 23 sets the frame rate to frame rate R3, which is equal to or higher than frame rate R2, at time t14 when the next vertical synchronization signal for moving images is output (step S111).

[0085] Furthermore, from time t14, the recording unit 26 starts storing the moving image data stored in the RAM onto the recording medium (step S113).

[0086] 8, after the frame rate is set to frame rate R3 and the moving image data stored in the RAM is started to be stored in the recording medium, the detection unit 231 determines whether the motion vector is equal to or greater than a threshold value TVc (step S115). In step S115, for example, it is determined whether the insect, which is the subject, continues to take off.

[0087] The process of step S115 is repeated until the motion vector becomes less than the threshold TVc (step S115 / YES). Then, when the motion vector becomes less than the threshold TVc (step S115 / NO), the frame rate control unit 232 returns the frame rate to frame rate R1 (step S117) and returns to step S101. The process of step S100 is repeatedly executed until the video capture is completed. Here, when the motion vector becomes less than the threshold TVc, the storage of the video in RAM and the storage of the video data stored in RAM in the recording medium may be terminated.

[0088] 11, for example, suppose that the motion vector was equal to or greater than the threshold value TVc in the subject state detection processes DP25 to DP31 (YES in step S115), but became less than the threshold value TVc in the subject state detection process DP32 (NO in step S115). In this case, at time t15 when the next moving image vertical signal is output, the frame rate control unit 232 changes the frame rate to frame rate R1 (step S117). As a result, moving images will be captured at frame rate R1 from time t15 onwards.

[0089] In this way, the frame rate control process 1 makes it possible to capture the moment when the subject's movement transitions from the first movement to the second movement at a high frame rate.

[0090] Returning to Figure 7, if the video shooting setting is, for example, a setting (setting 2) for capturing the moment when a subject (e.g., a bird) enters the field of view at a high frame rate, the body control unit 23 executes frame rate control process 2 (step S200).

[0091] 9 is a flowchart showing the details of frame rate control process 2. When frame rate control process 2 is started, the detection unit 231 determines whether the motion vector obtained from the inter-frame difference of the detection image data is equal to or greater than a threshold value TVd (step S201). The threshold value TVd at this time is a threshold value for determining whether a subject has entered the angle of view, and is set to a relatively large value.

[0092] The process of step S201 is repeated until the motion vector becomes equal to or greater than the threshold value TVd (step S201 / NO).

[0093] When the motion vector becomes equal to or greater than the threshold value TVd (step S201 / YES), the frame rate control unit 232 sets the frame rate, which defines the time interval for reading pixel signals from the imaging pixels 51a, to frame rate R2, which is higher than frame rate R1 (step S203). Under the control of the body control unit 23, the recording unit 26 starts saving the video data captured at frame rate R2 to RAM (step S205). At this time, the recording unit 26 stops storing the video data in the non-volatile recording medium.

[0094] Next, the detection unit 231 determines whether the motion vector is equal to or greater than a threshold TVd (step S207). The process of step S207 is repeated until the motion vector becomes less than the threshold TVd (step S207 / YES). Step S207 determines whether the movement of the subject that has entered the angle of view is sufficient to allow the subject to be recognized. If the movement of the subject is sufficient to allow the subject to be recognized, the motion vector is less than the threshold TVd.

[0095] If the motion vector is less than the threshold value TVd (step S207 / NO), the detection unit 231 determines whether the motion vector is equal to or greater than the threshold value TVe (step S209). In setting 2, the threshold value TVe is set to a value smaller than the threshold value TVd. This makes it possible to determine, for example, whether a subject that has suddenly entered the field of view is still present within the field of view and is moving.

[0096] If the motion vector is equal to or greater than the threshold value TVe (step S209 / YES), the detection unit 231 determines whether or not a subject (e.g., a bird) can be recognized (step S211). The detection unit 231 determines whether or not the subject can be recognized, for example, by using video data captured at a frame rate R2. In this embodiment, subject recognition is performed using video data captured at a frame rate R2, but this is not limited thereto, and subject recognition may also be performed using other video data.

[0097] If the motion vector is less than the threshold value TVe (step S209 / NO), or if the subject cannot be recognized (step S211 / NO), the recording unit 26 thins out the video data captured at the frame rate R2 and stored in the RAM, and stores the thinned data in a non-volatile recording medium (step S221). Then, the frame rate control unit 232 sets the frame rate to frame rate R1 (step S219). After setting the frame rate to frame rate R1, the process returns to step S201.

[0098] For example, if a subject that enters the angle of view from outside the angle of view does not stop within the angle of view but continues to move out of the angle of view, the motion vector will be less than the threshold TVe, and the determination in step S209 will be negative. Also, if a subject (e.g., a bird) that enters the angle of view from outside the angle of view stops once within the angle of view (perches on a tree) and then flies away to the outside of the angle of view, the motion vector will be greater than or equal to the threshold TVe due to the swaying of the tree (step S209 / YES), but the subject (bird) cannot be recognized, and the determination in step S211 will be negative. In this way, when a subject is no longer present within the angle of view, the determinations in steps S209 and S211 are executed to switch the frame rate to frame rate R1, which is lower than frame rate R2.

[0099] 11, for example, suppose that the motion vector is equal to or greater than the threshold value TVd in the subject state detection process DP4 (step S201 / YES). In this case, the frame rate control unit 232 changes the frame rate from frame rate R1 to frame rate R2 (>frame rate R1) at time t11 when the next moving image vertical synchronization signal is output (step S203). Since the moving image data captured at frame rate R2 is temporarily stored in RAM, moving image data MI2 to MI4 are stored in RAM.

[0100] Subsequently, suppose that the motion vector is equal to or greater than the threshold value TVd in the subject state detection processes DP5 and DP6 (YES in step S207), and that the motion vector is less than the threshold value TVd (NO in step S207) and less than the threshold value TVe (NO in step S209) in the subject state detection process DP7. Alternatively, suppose that the motion vector is less than the threshold value TVd (NO in step S207) and greater than or equal to the threshold value TVe (YES in step S209) in the subject state detection process DP7, but the subject is not recognized (NO in step S211). In this case, the recording unit 26 stores, for example, the video data MI3 from the video data MI2 to MI4 captured at the frame rate R2 and stored in RAM on a non-volatile recording medium (step S221). Furthermore, the frame rate control unit 232 sets the frame rate to frame rate R1 at time t12, when the next video vertical synchronization signal is output (step S219).

[0101] 9 , if the subject is recognized (step S211 / YES), the frame rate control unit 232 sets the frame rate to frame rate R3, which is equal to or higher than frame rate R2 (step S213). The frame rate control unit 232 may leave the frame rate at frame rate R2. In other words, as long as the subject is present within the angle of view, the subject continues to be captured at a frame rate equal to or higher than frame rate R2.

[0102] Then, the recording unit 26 starts storing the moving image data stored in the RAM in a non-volatile recording medium (step S215). This allows a moving image captured at a high frame rate at the moment when the subject enters the angle of view to be stored in the non-volatile recording medium.

[0103] Next, the body control unit 23 determines whether or not the subject has been recognized (step S217). While the subject has been recognized, the process of step S217 is repeated (step S217 / YES). When the subject cannot be recognized (step S217 / NO), the frame rate control unit 232 returns the frame rate to frame rate R1 (step S219) and returns to step S201. The process of step S200 is repeatedly executed until the video capture is completed.

[0104] For example, in FIG. 11, when the motion vector becomes equal to or greater than the threshold value TVd in the subject state detection process DP17 (step S201 / YES), the frame rate control unit 232 changes the frame rate from frame rate R1 to frame rate R2 at time t13 when the next vertical synchronization signal for moving images is output (step S203).

[0105] In the subject state detection processes DP18 to DP23, the motion vector is greater than or equal to the threshold value TVd (step S207 / YES), and in the subject state detection process DP24, the motion vector is less than the threshold value TVd (step S207 / NO) and greater than or equal to the threshold value TVe (step S209 / YES), and the subject is recognized (step S211 / YES).

[0106] In this case, the frame rate control unit 232 sets the frame rate to frame rate R3, which is equal to or higher than frame rate R2, at time t14 when the next vertical synchronization signal for moving images is output (step S213).

[0107] Furthermore, from time t14, the recording unit 26 starts storing the moving image data stored in the RAM onto the recording medium (step S215).

[0108] Then, if a subject is recognized in the subject state detection processes DP25 to DP31 (YES in step S217) but is no longer recognized in the subject state detection process DP32 (NO in step S217), the frame rate control unit 232 changes the frame rate to frame rate R1 at time t15 when the next moving image vertical signal is output (step S219). As a result, moving images are shot at frame rate R1 from time t15 onwards.

[0109] In this way, according to the frame rate control process 2, the subject can be photographed at a high frame rate from the moment the subject enters the angle of view until the subject moves out of the angle of view.

[0110] Returning to FIG. 7, if the video shooting setting is, for example, a setting (setting 3) for capturing the moment when a specified event (e.g., lightning) occurs within the field of view at a high frame rate, as described in the first embodiment, the body control unit 23 executes frame rate control process 3 (step S300).

[0111] Fig. 10 is a flowchart showing an example of frame rate control process 3. The process in Fig. 10 is almost the same as the process in Fig. 5, so the same processes are denoted by the same reference numerals and detailed description will be omitted. The process in step S300 is repeatedly executed until the video capture is completed.

[0112] As described above in detail, according to the second embodiment, in the frame rate control process 1, when the motion vector obtained from the inter-frame difference of the detection image data changes from a state in which it is equal to or greater than the threshold value TVb to a threshold value TVc that is greater than the threshold value TVb (step S109 / YES in FIG. 8 ), the frame rate control unit 232 controls the frame rate to a frame rate R3 that is equal to or greater than the frame rate R2 (time t14 in FIG. 11 ). This makes it possible to capture the moment when the subject begins a predetermined movement at a frame rate R2 that is higher than the normal frame rate R1, even before the subject begins the predetermined movement. This makes it possible to prevent missing the initial movement of the moment you want to capture. Furthermore, in frame rate control process 2, when the motion vector acquired from the inter-frame difference of the detection image data is equal to or greater than the threshold TVd, and the motion vector becomes less than the threshold TVd but equal to or greater than the threshold TVe (<threshold TVd) (NO in step S207 and YES in step S209), the frame rate control unit 232 controls the frame rate to frame rate R3, which is equal to or greater than the frame rate R2 (time t14 in FIG. 11 ). This makes it possible to capture, for example, the moment a subject enters the angle of view at frame rate R2, which is higher than the normal frame rate R1.

[0113] Furthermore, in the second embodiment, for example, in frame rate control process 1, when the motion vector changes from a state in which it is equal to or greater than threshold value TVb to a threshold value TVc that is greater than threshold value TVb (step S109 / YES in FIG. 8 ), the recording unit 26 records, on a non-volatile recording medium, image data (moving image data) generated based on signals output from the imaging pixels 51 a after the motion vector became equal to or greater than threshold value TVb. More specifically, the recording unit 26 records, on a non-volatile recording medium, image data that was generated based on signals output from the imaging pixels 51 a after the motion vector became equal to or greater than threshold value TVb and that was stored in RAM. This allows a moving image captured at a high frame rate at a desired moment to be recorded on a non-volatile recording medium.

[0114] Furthermore, in the second embodiment, for example, in frame rate control process 1, when the motion vector becomes equal to or greater than threshold value TVb (YES in step S101) and then falls below threshold value TVb (YES in step S107), the recording unit 26 thins out the moving image data stored in RAM and records the thinned data on a non-volatile recording medium (step S119). That is, the recording unit 26 records a portion (MI3) of the image data (MI2 to MI4 in FIG. 11) generated based on the signals output from the imaging pixels 51a after the motion vector becomes equal to or greater than threshold value TVb. This reduces the amount of data for moving images that do not include the desired moment.

[0115] In the second embodiment, when the motion vector becomes equal to or greater than the threshold value TVb and then falls below the threshold value TVb in the frame rate control process 1, the moving image data stored in the RAM is thinned out and recorded on a non-volatile recording medium (step S119), but this is not limiting. For example, when the motion vector becomes equal to or greater than the threshold value TVb and then falls below the threshold value TVb, the moving image data stored in the RAM may not be stored on a non-volatile recording medium, i.e., may be discarded.

[0116] In the first and second embodiments, the interchangeable lens 3 is a zoom lens with a variable focal length, but the interchangeable lens 3 may be a fixed focal length lens.

[0117] Furthermore, in the first and second embodiments, the frame rate control unit 232 controls the frame rate based on a motion vector, but this is not limiting. In addition to the frame rate, the body control unit 23 may control at least one of the exposure time (the time it takes for charge to accumulate in the photoelectric conversion unit) and ISO sensitivity of the imaging pixels 51 a. In other words, the signal from the detection pixel 51 b may be used to control the shooting conditions (settings during shooting) for moving images.

[0118] In the first and second embodiments, moving images shot at frame rate R1 are stored in a nonvolatile storage medium, but this is not limiting. For example, moving images shot at frame rate R1 may not be stored in a nonvolatile storage medium, and only moving images shot at frame rates R2 and R3, which are higher than frame rate R1, may be stored in a nonvolatile storage medium. This reduces the amount of moving image data stored in a nonvolatile storage medium.

[0119] The above-described embodiment is not limited to this, and various modifications can be made without departing from the spirit and scope of the invention.

[0120] REFERENCE SIGNS LIST 1 camera 2 camera body 3 interchangeable lens 21 imaging element 23 body control unit 22 image processing unit 26 recording unit 51a imaging pixel 51b detection pixel 52A first vertical signal line 52B second vertical signal line 62 photoelectric conversion unit 231 detection unit 232 frame rate control unit

Claims

1. An imaging element comprising: a first pixel having a first photoelectric conversion unit, the first pixel outputting a first signal used for image generation based on charges generated by the first photoelectric conversion unit; a second pixel having a second photoelectric conversion unit, the second pixel outputting a second signal used for controlling the first pixel based on charges generated by the second photoelectric conversion unit; a first signal line through which the first signal is output; and a second signal line through which the second signal is output, wherein the second signal is used to control a frame rate for reading out the first signal from the first pixel.

2. The imaging device according to claim 1, wherein the output of the first signal from the first pixel and the output of the second signal from the second pixel are performed in parallel.

3. An imaging device comprising: an imaging element according to claim 1 or claim 2; a detection unit that detects the movement of a subject based on the second signal; and a control unit that controls the frame rate for reading out the first signal from the first pixel based on the detection result of the detection unit.

4. The imaging device according to claim 3, wherein the control unit controls the frame rate to a first frame rate when a first detection result is output from the detection unit.

5. The imaging device according to claim 4, wherein the control unit controls the frame rate to a second frame rate equal to or higher than the first frame rate when the detection result of the detection unit changes from the first detection result to a second detection result.

6. The imaging device according to claim 5, wherein the control unit controls the frame rate to a third frame rate lower than the first frame rate when the detection result of the detection unit changes from the first detection result to a third detection result different from the second detection result.

7. An imaging device according to claim 5 or claim 6, further comprising a recording unit that, when the detection result of the detection unit changes from the first detection result to the second detection result, records an image generated based on the first signal output from the first pixel after the first detection result is output from the detection unit.

8. The imaging device of claim 7, wherein, when the detection result of the detection unit changes from the first detection result to a third detection result different from the second detection result, the recording unit records a part of an image generated based on the first signal output from the first pixel after the first detection result is output from the detection unit, or does not record an image generated based on the first signal output from the first pixel after the first detection result is output from the detection unit.

9. An imaging device according to any one of claims 5 to 8, wherein the first detection result indicates a first movement of the subject, and the second detection result indicates a second movement of the subject that is different from the first movement.

10. An imaging device according to any one of claims 4 to 9, wherein the first frame rate is higher than the frame rate before the first detection result is output from the detection section.

11. An imaging device comprising: an imaging unit that images a subject; a detection unit that detects movement of the subject; and a control unit that, when a first detection result is output from the detection unit, controls the frame rate of the imaging unit to a first frame rate, and, when the detection result of the detection unit changes from the first detection result to a second detection result, controls the frame rate of the imaging unit to a second frame rate that is equal to or higher than the first frame rate.

12. The imaging device described in claim 11, wherein the control unit controls the frame rate of the imaging unit to a third frame rate lower than the first frame rate when the detection result of the detection unit changes from the first detection result to a third detection result different from the second detection result.

13. An imaging device comprising: an imaging unit that images a subject; a detection unit that detects movement of the subject; and a recording unit that, when the detection result of the detection unit changes from a first detection result to a second detection result, records image data output from the imaging unit after the first detection result is output in non-volatile memory.

14. The imaging device described in claim 13, wherein the recording unit starts recording the image data output from the imaging unit in volatile memory when the detection unit outputs the first detection result, and starts recording the image data stored in the volatile memory in the non-volatile memory when the detection result of the detection unit changes from the first detection result to the second detection result.

Images