Imaging apparatus

Abstract

To correct a PLS signal component.SOLUTION: An imaging apparatus comprises: an image pick-up device in which a first photoelectric conversion part that converts a light into an electric charge, a first pixel that contains a first charge holding part that holds the electric charge transferred from the first photoelectric conversion part, and a first output part that outputs a first signal based on the electric charge held by the first charge holding part, a second photoelectric conversion part that converts the light into the electric charge, and a second pixel that contains the second charge holding part holding the electric charge transferred from the second photoelectric conversion part and a second output part that outputs a second signal based on the electric charge held by the second charge holding part; and a correction part that corrects the second signal output from the second output part from a time until the first photoelectric conversion part is saturated, a charge holding time when the second charge holding part holds the electric charge, and information in regard to a parasitic reception photosensitivity.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an imaging device. [Background technology]

[0002] Image sensors having a memory in each pixel are known (see, for example, Patent Document 1). Conventionally, noise generated in pixels has been a problem. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-188410 A Summary of the Invention

[0004] The imaging device of the disclosed technique includes an imaging element having a first pixel including a first photoelectric conversion unit that converts light into an electric charge, a first charge holding unit that holds the electric charge transferred from the first photoelectric conversion unit, and a first output unit that outputs a first signal based on the electric charge held in the first charge holding unit, and a second pixel including a second photoelectric conversion unit that converts light into an electric charge, a second charge holding unit that holds the electric charge transferred from the second photoelectric conversion unit, and a second output unit that outputs a second signal based on the electric charge held in the second charge holding unit, and a correction unit that corrects the second signal output from the second output unit based on the time until the first photoelectric conversion unit becomes saturated, the charge holding time during which the second charge holding unit holds the electric charge, and information regarding parasitic light receiving sensitivity. [Brief description of the drawings]

[0005] [Figure 1] FIG. 1 is a block diagram illustrating an example of the configuration of an imaging apparatus according to the first embodiment. [Diagram 2] FIG. 2 is an explanatory diagram illustrating an example of the configuration of a pixel in a global shutter system according to the first embodiment. [Diagram 3]FIG. 3 is a graph showing the change over time in the exposure dose and PLS signal of a pixel according to the first embodiment. [Figure 4] FIG. 4 is an explanatory diagram showing a first example of photographing a subject having relatively varying light intensities according to the first embodiment. [Diagram 5] FIG. 5 is an explanatory diagram showing a second example of actual photography of a subject having relatively varying light intensities according to the first embodiment. [Figure 6] FIG. 6 is an explanatory diagram showing an example of acquisition of non-saturation data during exposure by the AF pixel according to the first embodiment. [Figure 7] FIG. 7 is an explanatory diagram showing a change over time in the amount of accumulated charge in the AF pixel according to the first embodiment. [Figure 8] FIG. 8 is an explanatory diagram showing a detailed concrete example of the amount of accumulated charge of the AF pixel and the change over time of the PLS signal according to the first embodiment. [Figure 9] FIG. 9 is an explanatory diagram showing an example of acquisition of non-saturation data during exposure by flicker detection according to the first embodiment. [Figure 10] FIG. 10 is an explanatory diagram showing the amount of accumulated charge in a normal pixel during exposure with flicker detection according to the first embodiment. [Figure 11] FIG. 11 is an explanatory diagram showing a detailed concrete example of the amount of accumulated charge of a normal pixel and the change over time in a PLS signal during exposure by flicker detection according to the first embodiment. [Figure 12] FIG. 12 is a flowchart illustrating an example of an imaging process procedure performed by the imaging device according to the first embodiment. [Figure 13] FIG. 13 is a flowchart illustrating an example of a PLS signal correction process procedure performed by the imaging device according to the first embodiment. [Figure 14] FIG. 14 is an explanatory diagram showing a detailed example of the amount of accumulated charge of a normal pixel and the change over time of a PLS signal according to the second embodiment. [Figure 15] FIG. 15 is an explanatory diagram showing a detailed concrete example of the amount of accumulated charge of a normal pixel and the change over time in a PLS signal during exposure by flicker detection according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] [Embodiment 1] <Configuration example of imaging device> Fig. 1 is a block diagram showing an example of the configuration of an imaging device according to the first embodiment. The imaging device 100 is a device capable of capturing still images and moving images, and specifically includes, for example, a digital camera, a digital video camera, a smartphone, a tablet, a personal computer, and a game machine. In Fig. 1, a digital camera is taken as an example of an imaging device to explain the configuration.

[0007] The imaging device 100 includes an optical system 101, an imaging element 102, an image processing unit 103, a rear monitor 104, a memory 105, an EVF (Electronic View Finder) 106, a camera control unit 107, and a flash 108.

[0008] The optical system 101 includes a plurality of lenses and a diaphragm arranged in the optical axis direction. The optical system 101 collects subject light and outputs the collected light to the image sensor 102.

[0009] The image sensor 102 receives subject light from the optical system 101 and converts it into an electrical signal. The image sensor 102 may be, for example, an XY address type solid-state image sensor (for example, a CMOS (Complementary Metal-Oxide Semiconductor) sensor) or a sequential scan type solid-state image sensor (for example, a CCD (Charge Coupled Device)).

[0010] A plurality of pixels are arranged in a matrix on the light receiving surface of the image sensor 102. A plurality of types of color filters, each of which transmits light of a different color component, are arranged in a predetermined color array (for example, a Bayer array) on the pixels of the image sensor 102. Therefore, each pixel of the image sensor 102 outputs an analog electrical signal corresponding to each color component by color separation by the color filter, and the analog electrical signal is converted into a digital signal and output to the image processing unit 103.

[0011] The image processing unit 103 executes image processing on the image data output from the imaging element 102. Specifically, for example, the image processing unit 103 executes, on the image data from the imaging element 102, image processing such as color interpolation, white balance adjustment, contour emphasis, gamma correction, and gradation conversion, as well as specific processing such as encoding processing, decoding processing, and compression / expansion processing.

[0012] The image processing unit 103 also includes a correction unit 130. The correction unit 130 executes correction for removing PLS signals from the image data obtained by the actual shooting.

[0013] Specifically, the image processing unit 103 is realized by a PLD (Programmable Logic Device) such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). The image processing unit 103 may also be configured by a processor that executes programs related to the above-mentioned image processing, encoding processing, decoding processing, and compression / decompression processing, and a memory 105 that stores the programs.

[0014] The rear monitor 104 is a monitor disposed on the opposite side to the optical system 101 , and displays an image based on the image data processed by the image processor 103 .

[0015] The memory 105 is a non-transient or temporary recording medium that stores image data processed by the image processing unit 103. The memory 105 may also store various programs and data. The memory 105 is, for example, a read only memory (ROM), a random access memory (RAM), a hard disk drive (HDD), or a flash memory. A plurality of memories 105 may be implemented in the imaging device 100, and at least one of the memories 105 may be detachable from the imaging device 100.

[0016] The EVF 106 is a finder that displays an image based on the image data processed by the image processing unit 103 .

[0017] The camera control unit 107 controls the optical system 101 and the image sensor 102. The camera control unit 107 has an exposure control unit 171, an AF control unit 172, and a light adjustment unit 173.

[0018] The exposure control unit 171 controls the exposure time of the image sensor 102. The AF control unit 172 determines whether the lens in the optical system 101 is in focus based on a phase difference obtained by a phase difference detection element inside or outside the image sensor 102, and drives and controls the lens in the focusing direction. The phase difference detection element in the image sensor 102 is referred to as an AF pixel. The light adjustment unit 173 controls the amount of light emitted by the flash 108, the emission timing, and the blinking interval.

[0019] The flash 108 emits light under the control of the light control unit 173. The flash 108 may be built into the imaging device 100, or may be detachable.

[0020] <Pixel configuration example> 2 is an explanatory diagram showing an example of the configuration of a pixel in the global shutter system according to the first embodiment. (A) shows an example of a circuit diagram in a pixel 200. (B) shows an example of a potential distribution in the pixel 200. The vertical direction indicates the potential, and the horizontal direction indicates the position in the pixel 200. The pixels 200 are photoelectric conversion elements arranged in the row and column directions in the image sensor 102. The pixels 200 include a photoelectric conversion unit 201 and a readout unit 210.

[0021] The photoelectric conversion unit 201 has a photoelectric conversion function of converting light 202 into electric charge 203. The photoelectric conversion unit 201 accumulates the photoelectrically converted electric charge 203. The photoelectric conversion unit 201 is formed of, for example, a photodiode.

[0022] The readout unit 210 has a discharge unit 211, a first transfer unit 212, a holding unit 213, a second transfer unit 214, an FD (floating diffusion) 215, a reset unit 216, and a pixel output unit 217. The readout unit 210 reads out a pixel signal based on the charge 203 converted by the photoelectric conversion unit 201 to a signal line 220. The readout unit 210 will be described as an N-channel type FET, but the type of transistor is not limited to this.

[0023] The discharge unit 211 discharges the charge 203 accumulated in the photoelectric conversion unit 201. For example, the discharge unit 211 transfers the charge 203 accumulated in the photoelectric conversion unit 201 to the holding unit 213 in a lump, and then discharges the charge 203. The discharge unit 211 controls the connection between the photoelectric conversion unit 201 and a power supply wiring. When a discharge control signal is input to the gate terminal of the discharge unit 211 (1), the discharge unit 211 discharges the charge 203 accumulated in the photoelectric conversion unit 201 to a power supply wiring to which a power supply voltage VDD is supplied. The discharge unit 211 is formed of, for example, a transistor. The discharge unit 211 may also be an element that has at least a gate terminal and constitutes a part of a transistor having a source terminal as a part of the photoelectric conversion unit 201 and a drain terminal as a part of a diffusion region connected to the power supply wiring.

[0024] (2) When a transfer control signal is input to the gate terminal of the first transfer unit 212, the first transfer unit 212 transfers the charge 203 accumulated in the photoelectric conversion unit 201 to the holding unit 213. The first transfer unit 212 is composed of a transistor. In the global shutter system, each pixel 200 transfers the charge 203 accumulated in the photoelectric conversion unit 201 to the holding unit 213 all at once.

[0025] The holding unit 213 holds the electric charge 203 of the photoelectric conversion unit 201. The holding unit 213 is configured by, for example, a capacitor, but may be something else that can hold an electric charge.

[0026] The second transfer unit 214 transfers the charge 203 in the holding unit 213 to the FD 215. The second transfer unit 214 controls an electrical connection between the holding unit 213 and the FD 215. (3) When a transfer control signal is input to a gate terminal of the second transfer unit 214, the second transfer unit 214 reads out the charge 203 held in the holding unit 213 and transfers it to the FD 215. The second transfer unit 214 is constituted of, for example, a transistor.

[0027] The reset unit 216 discharges the charge 203 accumulated in the FD 215 to a power supply wiring to which a power supply voltage VDD is supplied. The reset unit 216 controls an electrical connection between the FD 215 and the power supply wiring. When a reset control signal is input to the gate terminal of the reset unit 216, the reset unit 216 resets the potential of the FD 215 to the power supply voltage VDD, which is a reference potential. The reset unit 216 is, for example, configured by a transistor. The reset unit 216 may also be an element that has at least a gate terminal and configures a part of a transistor with a part of the FD 215 as a source terminal and a part of a diffusion region connected to the power supply wiring as a drain terminal.

[0028] The pixel output unit 217 (4) outputs a pixel signal based on the potential of the FD 215 to a signal line 220. The pixel output unit 217 has an amplifier unit 218 and a selection unit 219. The amplifier unit 218 is configured with a transistor. A gate terminal of the amplifier unit 218 is connected to the FD 215. A drain terminal of the amplifier unit 218 is connected to a power supply wiring to which a power supply voltage VDD is supplied. A source terminal of the amplifier unit 218 is connected to a drain terminal of the selection unit 219.

[0029] The selection unit 219 controls the electrical connection between the pixel 200 and the signal line 220. When a selection control signal is input to a gate terminal of the selection unit 219, the selection unit 219 electrically connects the pixel 200 and the signal line 220 and outputs a pixel signal from the pixel 200 to the signal line 220. The selection unit 219 is formed of, for example, a transistor. The selection unit 219 may also be an element that has at least a gate terminal and forms part of a transistor with a part of the amplifier unit 218 as a source terminal and a part of a diffusion region connected to the signal line 220 as a drain terminal.

[0030] The holding unit 213, the second transfer unit 214, the FD 215, the reset unit 216, and the pixel output unit 217, which are parts of the pixel 200, are covered with a light-shielding film 204. When light 202 is incident on the pixel 200, the photoelectric conversion unit 201 converts the light 202 into electric charge 203, which is accumulated in the holding unit 213 by the batch transfer of (2).

[0031] That is, in the global shutter type image sensor 102, when strong light enters, the photoelectric conversion unit 201 becomes saturated, causing the charge 203 to leak into the holding unit 213, generating a PLS (Parasitic Light Sensitivity) signal that includes a first PLS signal component C1, and a second PLS signal component C2, in which the light 202 transmits through the light-shielding film 204 and generates the charge 203 inside the holding unit 213. When there is no need to distinguish between the first PLS signal component C1 and the second PLS signal component C2, they are referred to as PLS signal components C.

[0032] The PLS signal is a false signal indicating parasitic light sensitivity, and it is known that false images occur near an object image that emits strong light. For example, if an object that emits strong light moves after exposure, the photoelectric conversion unit 201 starts accumulating charges again, and a PLS signal is generated in the pixel that becomes saturated.

[0033] In the first embodiment, the imaging device 100 obtains a non-saturated output by short-second exposure, calculates the PLS signal component C based on the time until saturation of the pixels exposed to strong light and the time elapsed since saturation, and corrects the image data obtained by the actual shooting.

[0034] <Changes in exposure dose and PLS signal of pixel 200 over time> 3 is a graph showing changes over time in the amount of exposure and the PLS signal of the pixel 200 according to the first embodiment. The horizontal axis indicates time, and the vertical axis indicates the amount of charge generated in the photoelectric conversion unit 201 or the holding unit 213. Times Taf, Tfl, Ts, and Tp on the horizontal axis indicate the elapsed time from time T0. Therefore, the times Taf, Tfl, Ts, and Tp may also be expressed as times Taf, Tfl, Ts, and Tp.

[0035] On the horizontal axis, T0 is the charge accumulation start time.

[0036] Taf is the AF pixel exposure time. The AF pixel exposure time Taf is a non-saturation time during which the charge 203 is accumulated in the AF pixel 200. The exposure of the AF pixel 200 ends at time Taf. The AF pixel exposure time Taf is set by the exposure control unit 171.

[0037] Tfl is the exposure time for flicker detection. The exposure time Tfl for flicker detection is the non-saturation time during which the charge 203 is accumulated in the pixel 200 while the flicker is occurring. When there is no distinction between the AF pixel exposure time Taf and the exposure time Tfl for flicker detection, they are referred to as the non-saturation time Tun.

[0038] Ts is the saturation exposure time. The saturation exposure time Ts is the exposure time at which the photoelectric conversion unit 201 is saturated.

[0039] Tp is the charge accumulation end time. The accumulation of the charge 203 in the pixel 200 ends at the charge accumulation end time Tp. The time Tp is set by the exposure control unit 171. The normal pixel 200 of the image sensor 102 may be saturated at the charge accumulation end time Tp.

[0040] A part of the photoelectric conversion unit 201 of the AF pixel 200 is covered with a light-shielding film (not shown) different from the light-shielding film 204. Therefore, the AF pixel 200 is a pixel 200 that is less likely to become saturated than the normal pixel 200.

[0041] Tt is the batch transfer time required to transfer the electric charge 203 from the photoelectric conversion unit 201 of each pixel 200 to the holding unit 213 .

[0042] Next, the vertical axis will be described. Spls is the PLS signal output. The PLS signal output Spls is the amount of exposure of the PLS signal at time Tp, that is, the amount of accumulated charge generated in the holding unit 213 as the PLS signal.

[0043] Saf is the AF pixel output. The AF pixel output Saf is a non-saturation output that indicates the amount of exposure during the AF pixel exposure time Taf, that is, the amount of charge 203 accumulated in the AF pixel 200.

[0044] Sfl is an output for flicker detection. The output Sfl for flicker detection is a non-saturated output that is the amount of charge 203 accumulated in the normal pixel 200 by exposure during the exposure time Tfl for flicker detection. When there is no distinction between the AF pixel output Saf and the output Sfl for flicker detection, it is referred to as a non-saturated output Sun.

[0045] Ss is the saturation output. The saturation output Ss is the amount of charge 203 accumulated in the normal pixel 200 by exposure during the saturation exposure time Ts. The saturation output Ss is held, for example, in the memory 105 as a value specific to the image sensor 102. Both the AF pixel output Saf and the output Sfl for flicker detection are detected at a timing different from the charge accumulation of the photoelectric conversion unit 201, but FIG. 3 shows that the non-saturation output Sun is less than the saturation output Ss.

[0046] A waveform 301 indicates a change in the amount of exposure when the normal pixel 200 is exposed to such strong light that the photoelectric conversion unit 201 is saturated within the charge accumulation end time Tp.

[0047] A waveform 302 indicates a PLS signal (hereinafter, referred to as a PLS signal 302) resulting from the charge 203 generated in the holding unit 213 after the photoelectric conversion unit 201 is saturated (at time Ts).

[0048] After the saturation exposure time Ts has elapsed, the total exposure amount of the waveform 301 and the waveform 302 is output from the pixel 200 .

[0049] If the slope 310 of the waveform 301 in the AF pixel exposure time Taf or the exposure time Tfl for flicker detection is known, the saturation exposure time Ts until the photoelectric conversion unit 201 is saturated can be specified. This enables the imaging device 100 to calculate the time when the first PLS signal component C1 occurs, that is, the time T from time Ts to time Tp.

[0050] Specifically, for example, in the case of exposure using the AF pixel 200, when light from a high-luminance subject is incident on the selected AF pixel 200, proper exposure is achieved and a non-saturated output Sun(Saf) is obtained. In the case of exposure for flicker detection, the image capture device 100 performs exposure for an exposure time Tfl to obtain the blinking cycle of the light source in the subject scene by multiple short-second exposures, that is, to detect flicker, and obtains a non-saturated output Sun(Sfl).

[0051] Since the non-saturation time Tun and the non-saturation output Sun are known, the saturation exposure time Ts is expressed by the following formula (F1).

[0052] Ts = Tun × Ss / Sun (F1)

[0053] The PLS signal 302 includes a first PLS signal component C1 due to the charge 203 overflowing from the photoelectric conversion unit 201 leaking into the holding unit 213 after the saturation exposure time Ts has elapsed, and increases over time as shown in the waveform 302. On the other hand, the elapsed time T obtained by subtracting the saturation exposure time Ts from the charge accumulation end time Tp during the main exposure is expressed by the following formula (F2).

[0054] T = Tp - Ts (F2)

[0055] Since the gradient g (the increase in the amount of charge per unit time) of the PLS signal 302 is known, the PLS signal output Spls is calculated by the following formula (F3).

[0056] Spls = g × (T + Tt) (F3)

[0057] The gradient g of the PLS signal 302 is stored in the memory 105, for example, as an example of information related to the parasitic light receiving sensitivity.

[0058] <Example of actual photography of a subject with relatively strong and weak light> Next, we will explain actual shooting examples of subjects with relatively strong and weak light. In such actual shooting examples, there are cases where the light of the moving main subject is stronger than the light of the background, and cases where the light of the background is stronger than the light of the moving main subject.

[0059] Fig. 4 is an explanatory diagram showing Example 1 of Main Shooting of a subject with varying light intensity according to the embodiment 1. Fig. 4 shows an example of main shooting in which the light of a moving main subject is stronger than the light of the background.

[0060] (A) shows an imaging surface 400 which is the imaging range of the image sensor 102 during actual shooting (when the shooting button is pressed). Actual shooting is not live view, but shooting by pressing the shooting button, etc. The imaging surface 400 includes, as subjects, a main subject 401 and a background 402. Area 403 is a pixel area including the main subject 401. Area 403 includes, for example, an AF pixel area. The AF pixel area is a collection of AF pixels 200.

[0061] Region 403 is a region for detecting PLS components, and a region for detecting the luminance difference between main subject 401, which is a high-luminance subject, and its surrounding region. Region 403 may be a region of a predetermined size that includes main subject 401. It may be determined in consideration of the motion vector of main subject 403. A divided region for AE (auto exposure) may be used.

[0062] The light of the main subject 401 is stronger than the light of the background 402, and the pixel area receiving the light from the main subject 401 is a high-luminance subject with a saturation output Ss. A high-luminance subject is a subject that is brighter than a predetermined luminance, for example, the average luminance within the shooting range. The main subject 401 is a moving subject, for example, the headlight of a motorcycle moving from left to right on the imaging surface 400. The background 402 is a low-luminance subject whose pixel area does not reach the saturation output Ss and has a lower luminance than the main subject 401, for example, a night scene. Specifically, for example, a subject with a luminance equal to or lower than the average luminance within the entire effective pixel area of ​​the imaging surface 400 of the image sensor 102 is considered to be a low-luminance subject.

[0063] (B) shows imaging surface 400 during batch transfer and readout after actual shooting in (A). Specifically, for example, (B) shows a state in which main subject 401 has moved after actual shooting has been performed by pressing the shooting button. Batch transfer is the transfer of each pixel 200 to holding unit 213 in (2) shown in FIG. 2. Readout is the output of pixel signals by (3) and (4) shown in FIG. 2. v1 is the motion vector of main subject 401.

[0064] (C) is ideal image data 410 that would be captured in the actual shooting of (A), and the composition and brightness of the imaging surface 400 of (A) should be the image data 410 as is.

[0065] (D) is image data 420 that is actually captured in the actual capture of (A). Due to the movement of main subject 401 in (B), the area indicated by diagonal lines on the right side of main subject 401, which should actually be background 402, becomes PLS signal component 404 and becomes an area brighter than background 402. The area where PLS signal component 404 occurs is determined by the size of main subject 401 and the direction and length of motion vector v1. The luminance of PLS ​​signal component 404 is determined by the amount of charge of PLS ​​signal 302. Specifically, for example, a PLS signal component occurs when main subject 401, which is a light source that emits strong light, moves to a position corresponding to an area that should actually be low luminance in captured image data 420 after capture, and this generates a false image (PLS signal component 404) and appears in image data 420.

[0066] The imaging device 100 corrects the PLS signal component 404 and outputs corrected image data 410 .

[0067] Fig. 5 is an explanatory diagram showing a second actual photographing example of a subject with relatively varying light intensity according to the first embodiment. Fig. 5 shows an actual photographing example in which the light in the background is stronger than the light of the moving main subject.

[0068] 4A shows the imaging surface 400 of the image sensor 102 during actual shooting (when the shooting button is pressed). The imaging surface 400 includes a first main subject 501, a second main subject 502, and a background 503 as subjects. The first main subject 501 is located further back than the second main subject 502 when viewed from the imaging device 100. The light from the first main subject 501 is stronger than the light from the second main subject 502, and it is a high-luminance subject in which the pixel region at the corresponding position has a saturation output Ss. The first main subject 501 is, for example, the sun.

[0069] As seen from imaging device 100, second main subject 502 is photographed in backlight, so the pixel area receiving light from second main subject 502 does not reach saturation output Ss, and second main subject 502 is a low-luminance subject with relatively lower luminance than first main subject 501. Second main subject 502 is, for example, an airplane moving from the lower left to the upper right of imaging plane 400.

[0070] Region 505 is a region for detecting PLS components, and a region for detecting the luminance difference between first main subject 501, which is a high-luminance subject, and its surrounding region. Region 505 may be a region of a predetermined size including first main subject 501. It may be determined taking into consideration the motion vector of second main subject 502. A divided region for AE may be used. Region 505 may be the second main subject 502, and the luminance difference between it and first main subject 501 may be detected.

[0071] (B) shows the imaging surface 400 during the batch memory transfer and reading after the actual shooting in (A). Specifically, for example, (B) shows the state where the second main subject 502 has moved after the actual shooting by pressing the shooting button. v2 is the motion vector of the second main subject 502.

[0072] (C) is the ideal image data 510 that is originally intended to be captured in the actual shooting in (A), and the composition and luminance of the imaging surface 400 in (A) should directly become the image data 510.

[0073] (D) is the ideal image data 520 that is actually captured in the actual shooting in (A). Due to the movement of the second main subject 502 in (B), it is affected by the PLS signal 302, and the central region of the second main subject 502 becomes the PLS signal component 504 indicated by the slanted lines and is brighter than the background 402. The generation region of the PLS signal component 504 is the overlapping region between the first main subject 501 and the second main subject 502. The luminance of the PLS signal component 504 is determined by the charge amount of the PLS signal 302.

[0074] After shooting, at a position corresponding to the region that is originally of low luminance in the captured image data 520, the appearance of a light source (in this example, the first main subject 501) that emits strong light causes the generation of a PLS signal component, which appears as an artifact (PLS signal component 504) in the image data 520.

[0075] <Detection Example of PLS Signal Component> Next, the detection of the PLS signal components 404 and 504 will be specifically described separately for the case of exposure by the AF pixels 200 (Figs. 6 to 8) and the case of exposure by flicker detection (Figs. 9 to 11).

[0076] [Exposure by AF Pixels 200] 6 is an explanatory diagram showing an example of acquisition of non-saturated data during exposure by the AF pixel 200 according to the first embodiment. A live view frame LV and a frame Faf of the AF pixel area are generated as non-saturated data at the timing of a vertical synchronization signal before actual shooting. Each pulse interval of the vertical synchronization signal is a short-second exposure time that is shorter than the period from the charge accumulation start time T0 to the charge accumulation end time Tp, that is, the AF pixel exposure time Taf.

[0077] In the case of exposure by the AF pixel 200, the AF pixel 200 is exposed for a period (Taf) shorter than the main exposure, and a part of the photoelectric conversion unit 201 of the AF pixel 200 is shielded from light by a shielding film (not shown) separate from the light shielding film 204. Therefore, even if light from a subject that emits strong light is incident on the AF pixel 200, the AF pixel 200 is unlikely to become saturated.

[0078] S1 indicates the start of AF. S2 is when the release button is pressed, that is, the start time T0 of the actual shooting. Frames LV and Faf are generated within the LV period from S1 to S2. During this LV period, the AF control unit 172 executes AF control. Then, after the LV period has elapsed, the actual shooting is executed. The generation time of each of the frames LV and Faf is the short-second exposure time, which is shorter than the period from the charge accumulation start time T0 to the charge accumulation end time Tp. The short-second exposure time of the frame LV and the short-second exposure time of the frame Faf may be the same time or may be different times.

[0079] It should be noted that the motion vectors v1 and v2 shown in FIGS. 4 and 5 are calculated based on the consecutive frames LV (or frames Faf).

[0080] Fig. 7 is an explanatory diagram showing a change over time in the amount of accumulated charge of the AF pixel 200 according to the first embodiment. Before charge accumulation start time T0, a frame Faf of the AF pixel region is generated. For ease of explanation, a live view frame LV is omitted in Fig. 7. The imaging device 100 detects an AF pixel output Saf of the frame Faf of the AF pixel region.

[0081] Specifically, for example, the imaging device 100 detects an AF pixel output Saf for any one of the frames Faf of the multiple AF pixel regions. In the example of Fig. 4, the AF pixel region is present within the region 403 and is located at a position corresponding to a high-luminance subject.

[0082] As a method for identifying the AF pixel that detects the AF pixel output Saf, for example, there is a method in which a motion vector of a subject that emits strong light (for example, a high-brightness subject such as the main subject 401 or the first main subject 501) is calculated from a live view image prior to the timing S2 at which the user presses the shooting button, and based on the calculated motion vector, the AF pixel 200 at a position that receives light from the subject that emits strong light in the frame Faf is predicted and determined as the AF pixel 200 that detects the AF pixel output Saf.

[0083] The frame Faf to be detected may be a frame Faf at any timing, but a frame Faf at a timing close to the start time T0 of the main shooting is appropriate.

[0084] Because the timing S2 at which the user presses the capture button is arbitrary, the image capture device 100 detects in advance, for example, the AF pixel output Saf of one or more frames Faf from the current time point to the previous time point S2 before the capture button is pressed. Then, when the capture button is pressed, the image capture device 100 selects the AF pixel output Saf of the frame Faf at the timing closest to the start time T0 of the actual capture (i.e., the timing S2 at which the capture button is pressed).

[0085] Furthermore, the image capturing apparatus 100 may calculate a statistical value of the AF pixel output Saf of the one or more frames Faf. The statistical value may be, for example, any one of an average value, a maximum value, a minimum value, and a mode value.

[0086] In this way, the image capturing apparatus 100 can acquire the AF pixel output Saf of the frame Faf and the AF pixel exposure time Taf that is set in advance, and can substitute these values ​​for Sun and Tun in the above formula (F1).

[0087] 8 is an explanatory diagram showing a detailed specific example of the amount of accumulated charge and the change over time of the PLS signal in the normal pixel 200 according to the first embodiment. (A) is a timing chart showing the change over time of the amount of charge accumulated in the pixel 200 of the image sensor 102. (B) is a timing chart showing the change over time of the amount of charge accumulated in the holding unit 213 of the pixel 200.

[0088] In Fig. 4A, pixel 200 in Fig. 8A is located within region 403. When main subject 401 moves in Fig. 4B, pixel 200 in Fig. 8A is assumed to be located within main subject 401.

[0089] In Fig. 5A, pixel 200 in Fig. 8A is located inside second main subject 502. When second main subject 502 moves in Fig. 5B, pixel 200 in Fig. 8A is located inside first main subject 501 but outside second main subject 502.

[0090] 8, the horizontal axes of (A) and (B) represent time, and the vertical axes of (A) and (B) represent the amount of charge generated in the photoelectric conversion unit 201 of the pixel 200 (represented as "PD charge amount") and the amount of charge accumulated in the holding unit 213 of the pixel 200 (represented as "memory charge amount"), respectively.

[0091] When the user presses the capture button (S2), the imaging apparatus 100 acquires the AF pixel output Saf and the AF pixel exposure time Taf for the frame Faf of the AF pixel area.

[0092] 8A starts main exposure at time T0, which is timing S2 when the shooting button is pressed, and generates electric charge Q1, and electric charge 203 (Q1) is transferred from pixel 200 to holding unit 213 during batch transfer time Tt from time Tms to time Tme. After that, at time T1, a high-luminance subject emitting strong light moves to a position corresponding to pixel 200, and passes pixel 200 at time T2. Therefore, photoelectric conversion unit 201 of pixel 200 starts generating electric charge again at time T1, and reaches saturation output Ss at time TS.

[0093] Note that the period from time Tme to time T1 is very short, and therefore the charge generated during this period need not be considered. Furthermore, imaging device 100 controls the timing Tme to Tfds at which pixels 200 are transferred to FD 215 for each row. Furthermore, imaging device 100 generates a motion vector of a high-luminance subject (for example, a high-luminance subject such as main subject 401 or first main subject 501) from an LV image or the like. Thus, imaging device 100 can calculate the period T1 to T2 during which the high-luminance subject passes through pixels 200 (a PLS signal is generated) during the period Tme to Tfds after shooting.

[0094] Here, time Tme is the end time of the batch transfer time Tt. Time T1 is the time when strong light 202 is incident after the batch transfer and the photoelectric conversion unit 201 starts generating charges again. Time Tfds is the time when the transfer control signal of the second transfer unit 214 starts transferring the charges 203 from the holding unit 213 to the FD 215, and time Tfde is the end time. In other words, the period from time Tfds to Tfde is the charge transfer period of (3) in FIG. 2.

[0095] 8B shows the change over time in the amount of charge in the holding unit 213 of the pixel 200. The charge 203 (Q1) is transferred in a batch from the photoelectric conversion unit 201 of the pixel 200 to the holding unit 213 during a batch transfer time Tt from time Tms to Tme after the main exposure period Tms.

[0096] Furthermore, between time T1 and time T2, the incidence of light 202 from the main subject 401 saturates the photoelectric conversion unit 201 of the pixel 200 at time TS, and the charge 203 (C1) of the first PLS signal component C1 leaks into the holding unit 213 of the pixel 200. Then, at time Tfds, the first PLS signal component C1 and the charge Q1 generated in the photoelectric conversion unit 201 during the main exposure period are read out to the FD 215. In this way, the PLS components 404 and 504 shown in FIGS. 4 and 5 are generated as false images.

[0097] A function or a table indicating the relationship between the period during which light 202 from a high-luminance subject having different luminance is received and the amount of charge 203 generated in the pixel 200 is stored in the memory 105 as information related to the parasitic light receiving sensitivity. Specifically, for example, a first function or a first table defining the first PLS signal component C1 is stored in the memory 105.

[0098] Therefore, the imaging device 100 can calculate the charge amount of the first PLS signal component C1 in the first light-receiving period, for example, by calculating the first light-receiving period from time TS to time T2 and substituting it into the above-mentioned first function or by referring to the first table. As described above, the first light-receiving period from time TS to time T2 is the period obtained by subtracting the period from time T1 to time TS (i.e., the period from when charge accumulation starts again until the photoelectric conversion unit 201 becomes saturated) from the period from time T1 to time T2. The period from time T1 to time TS is equal to the time Ts in the above formula (F1).

[0099] The correction section 130 may remove the first PLS signal component C1 from the image data of the main imaging. The first function may be a linear function or a non-linear function.

[0100] [Exposure with Flicker Detection] 9 is an explanatory diagram showing an example of acquisition of non-saturated data in exposure with flicker detection according to embodiment 1. In exposure with flicker detection, a short-second exposure is performed to detect the blinking cycle and peaks of a light source such as a fluorescent lamp or LED lighting, making it possible to acquire non-saturated data.

[0101] Specifically, for example, from timing S2 when the release button is pressed, the image capturing apparatus 100 repeats short-second exposure by detecting flicker, and detects the cycle and phase of the blinking of the light source. After detecting flicker, the image capturing apparatus 100 performs actual shooting.

[0102] It should be noted that the motion vectors v1 and v2 shown in FIGS. 4 and 5 are calculated based on the consecutive frames LV (or frames Faf).

[0103] Fig. 10 is an explanatory diagram showing the amount of accumulated charge in the normal pixel 200 during exposure for flicker detection according to embodiment 1. The difference from Fig. 7 is that in Fig. 7, the imaging device 100 detects the AF pixel output Saf of the frame Faf in the AF pixel area, whereas in Fig. 10, the imaging device 100 detects the output Sfl of the frame FL for flicker detection.

[0104] The imaging device 100 detects flicker that becomes the blinking cycle of the light source after the timing S2 when the capture button is pressed. Specifically, for example, the imaging device 100 detects an output Sfl during an exposure time Tfl for flicker detection for any one of the multiple flicker detection frames FL.

[0105] The imaging device 100 may determine the exposure time Tfl of the flicker detection frame FL based on, for example, the AF pixel exposure time Taf (see FIG. 7) detected during the live view period. The flicker detection frame FL to be detected may be a flicker detection frame FL at any timing, but a flicker detection frame FL at a timing close to the timing T0 at which the actual shooting starts is appropriate. The imaging device 100 may also calculate a statistical value of the output Sfl of one or more flicker detection frames FL. The statistical value may be, for example, an average value, a maximum value, a minimum value, or a mode value.

[0106] In this way, the imaging device 100 can obtain the output Sfl for flicker detection of the flicker detection frame FL and the exposure time Tfl for flicker detection, which can be substituted for Sun and Tun in the above formula (F1).

[0107] Fig. 11 is an explanatory diagram showing a detailed concrete example of the amount of accumulated charge of the normal pixel 200 and the change over time of the PLS signal during exposure for flicker detection according to the first embodiment. The difference from Fig. 8 is that the output Sfl for flicker detection of the flicker detection frame FL is detected during the exposure time Tfl for flicker detection. The rest is the same as the content shown in Fig. 8.

[0108] <Imaging process procedure> 12 is a flowchart showing an example of an imaging process procedure by the imaging device 100 according to embodiment 1. When the imaging device 100 is powered on, the imaging process starts (step S1200).

[0109] The image capturing apparatus 100 executes camera initial setting (step S1201). The camera initial setting is a process of reading and reflecting camera setting information such as ISO sensitivity.

[0110] The imaging device 100 executes imaging drive setting (step S1202). Specifically, for example, the imaging device 100 sets the gain of the imaging element 102 in accordance with the ISO sensitivity set in the camera initial setting, and sets the horizontal synchronization signal, vertical synchronization signal, and other settings related to the driving of the imaging element 102 in accordance with the set exposure time.

[0111] The image capturing apparatus 100 acquires a live view frame LV before actual shooting and a frame Faf of the AF pixel area (step S1203).

[0112] The imaging device 100 determines the brightness of the subject using the exposure control unit 171, automatically sets the short-second exposure time for live view and the charge accumulation end time Tp, and executes autofocus using the AF control unit 172 (step S1204).

[0113] The imaging device 100 causes the image processing unit 103 to perform image processing on the frame acquired in step S1203 (step S1205).

[0114] If pressing of the capture button is not detected (step S1206: No), the process returns to step S1203. If pressing of the capture button is detected (step S1206: Yes), the imaging device 100 acquires the flicker detection frame FL and then acquires image data of the actual capture (step S1207).

[0115] Then, the imaging device 100 performs image processing on the image data of the main shooting (step S1208), and records the image data of the main shooting after the image processing in the memory 105 (step S1209).

[0116] If the power-off operation has not been detected (step S1210: No), the process returns to step S1202. When the power-off operation is detected (step S1201: Yes), the power of the imaging device 100 is turned off, and the imaging process ends (step S1211).

[0117] <PLS Signal Correction Processing Procedure> FIG. 13 is a flowchart showing an example of the PLS signal correction processing procedure by the imaging device 100 according to Embodiment 1. The PLS signal correction processing is executed in the main shooting image processing (step S1208) of FIG. 12 after the main shooting.

[0118] [S1301] The correction unit 130 determines whether a high-luminance subject exists in the pre-frame and whether it is unsaturated in a short-exposure (step S1301). The pre-frame is a frame acquired before the main shooting. Specifically, for example, in the case of exposure by the AF pixel 200 (FIGS. 6 to 8), they are the frames Faf and LV of the AF pixel region, and in the case of exposure for flicker detection (FIGS. 9 to 11), it is the flicker detection frame FL.

[0119] In the case of exposure by the AF pixel 200 (FIGS. 6 to 8), the correction unit 130 judges whether or not a high-luminance object is present in the frame LV. The AF pixel output Saf and the AF pixel exposure time Taf are acquired for the frame Faf of the AF pixel region, and it is judged whether or not the AF pixel output Saf at the AF pixel exposure time Taf is less than the saturation output Ss. If a high-luminance object is present in the frame LV and the AF pixel output Saf at the AF pixel exposure time Taf is less than the threshold value (step S1301: Yes), a high-luminance object is present and the AF pixel output Saf of the frame Faf of the AF pixel region is a non-saturated output, so the process proceeds to step S1302. On the other hand, if a high-luminance object is not present in the frame LV or the AF pixel output Saf at the AF pixel exposure time Taf is the saturation output Ss (step S1301: No), the PLS signal correction process ends.

[0120] In the case of exposure by flicker detection (FIGS. 9 to 11), the correction unit 130 determines the exposure time Tfl for flicker detection based on the frame Faf or the frame LV of the AF pixel area, obtains the output Sfl for flicker detection in the exposure time Tfl for flicker detection, and judges whether the output Sfl for flicker detection is less than the saturation output Ss. Also, it judges whether a high-luminance object is present in the flicker detection frame FL.

[0121] If a high-luminance object is present and is less than the threshold (step S1301: Yes), the process proceeds to step S1302 because a high-luminance object is present and the output Sfl for flicker detection in the flicker detection frame FL is a non-saturated output. On the other hand, if a high-luminance object is not present or the output Sfl for flicker detection in the exposure time Tfl for flicker detection is a saturated output Ss (step S1301: No), the correction unit 130 ends the PLS signal correction process.

[0122] [S1302] The correction unit 130 judges whether the luminance level of the PLS-inducing region is equal to or lower than the threshold value (step S1302). The PLS-inducing region is a pixel region that induces the generation of a PLS signal, and is region 403 in the example of FIG. 4, and is region 503 or second main subject 502 in the example of FIG.

[0123] The luminance level of the PLS-inducing region is a statistical value based on the luminance value of each pixel in the PLS-inducing region. The statistical value is, for example, the sum, average, or mode of the luminance values ​​of each pixel in the PLS-inducing region. The threshold value is the average luminance in the entire effective pixel region of the imaging surface 400 of the image sensor 102 at the timing S2 when the shooting button is pressed to define a low-luminance subject.

[0124] If the brightness level of the PLS-inducing region excluding the high-brightness subject region is equal to or lower than the threshold (step S1302: Yes), the process proceeds to step S1303, and if the brightness level of the PLS-inducing region is not equal to or lower than the threshold (step S1302: No), the correction unit 130 ends the PLS signal correction process. Note that if step S1302: No, the correction unit 130 does not perform correction because artifacts due to the PLS signal are not noticeable.

[0125] [S1303] The correction unit 130 determines whether the subject with the saturation output Ss has moved (step S1303). The subject with the saturation output Ss is a subject whose statistical value (total, average, mode) based on the luminance value of each pixel in the pixel region is the saturation output Ss, that is, a high-luminance subject. In the example of FIG. 4, the subject with the saturation output Ss is the main subject 401.

[0126] If motion vector v1 of main subject 401 is detected, correction unit 130 determines that main subject 401 has moved (step S1303: Yes), and proceeds to step S1304. In the example of Fig. 5, the subject with saturation output Ss is first main subject 501. Because the motion vector of first main subject 501 is not detected, correction unit 130 determines that first main subject 501 has not moved (step S1303: No), and proceeds to step S1306.

[0127] [S1304] The correction unit 130 calculates the first PLS signal output Spls (step S1304). Specifically, for example, the correction unit 130 calculates the first PLS signal output Spls for the image data obtained by the main shooting using the above formulas (F1) to (F3).

[0128] [S1305] The correction unit 130 executes PLS correction on the pixel region in the direction of the motion vector v1 (step S1305). The pixel region in the direction of the motion vector v1 is specifically, for example, the region in which the PLS signal component 404 shown in FIG. 4 occurs. The correction unit 130 performs correction by subtracting the PLS signal output Spls calculated in step S1304 from the pixel signals from each pixel 200 in the region in which the PLS signal component 404 occurs. The correction unit 130 can also calculate the pixel region in the direction of the motion vector v1 from the shape of the high-luminance subject and the motion vector v1.

[0129] As a result, the image processing unit 103 generates image data 410, 510 from which the PLS signal component 404 shown in Fig. 4D and the PLS signal component 504 shown in Fig. 5D have been removed, based on the pixel signal after subtraction of the PLS signal output Spls. Then, the correction unit 130 ends the PLS signal correction process.

[0130] [S1306] Correction unit 130 determines whether the second main subject has moved and whether the second main subject overlaps with the first main subject (step S1305). Specifically, for example, correction unit 130 detects the motion vector of the second main subject, determines whether the second main subject has moved and was in a position overlapping the position of the first main subject during the actual shooting, and if the second main subject has moved and was in a position overlapping the position of the first main subject during the actual shooting (step S1306: Yes), proceeds to step S1307. On the other hand, if the motion vector of the second main subject is not detected, correction unit 130 determines that the second main subject has not moved (step S1306: No), and correction unit 130 ends the PLS signal correction process.

[0131] In the example of FIG. 5, correction section 130 determines that second main subject 502 has moved because motion vector v2 of second main subject 502 has been detected, and proceeds to step S1307.

[0132] [S1307] The correction unit 130 calculates the first PLS signal output Spls (step S1307). Specifically, for example, the correction unit 130 calculates the first PLS signal output Spls for the image data obtained by the main shooting using the above formulas (F1) to (F3).

[0133] [S1308] Correction unit 130 executes PLS correction on the induced region during shooting (step S1308). This is second main subject 502 shown in Fig. 5. Correction unit 130 performs correction on pixel signals from each pixel 200 in the region corresponding to second main subject 502 by subtracting the first PLS signal output Spls calculated in step S1307.

[0134] As a result, the image processing unit 103 generates image data 410, 510 from which the PLS signal component 404 shown in Fig. 4D and the PLS signal component 504 shown in Fig. 5D have been removed, based on the pixel signal after subtraction of the first PLS signal output Spls. Then, the correction unit 130 ends the PLS signal correction process.

[0135] In this way, according to the first embodiment, it is possible to remove the first PLS signal component C1 that occurs near a high-luminance subject in the image data.

[0136] [Embodiment 2] Next, a description will be given of embodiment 2. In embodiment 2, in addition to the first PLS component in embodiment 1, the second PLS signal component generated from the charge generation start time T1 is also corrected. In embodiment 2, the differences from embodiment 1 will be mainly described, so that the same components as those in embodiment 1 are denoted by the same reference numerals and description will be omitted.

[0137] FIG. 14 is an explanatory diagram showing a detailed example of the amount of accumulated charge and the change over time of the PLS signal in the normal pixel 200 according to the second embodiment.

[0138] 14B, similarly to FIG. 8B, during a batch transfer time Tt from time Tms to time Tme after the main exposure period Tms, the charges 203 (Q1) are transferred in a batch from the photoelectric conversion unit 201 of the pixel 200 to the holding unit 213. In the second embodiment, when light 202 from a high-luminance subject is incident on the image sensor 102 after the end of this batch transfer time Tt (time T1), the light passes through the light-shielding film 204 and generates a charge 203 of the second PLS signal component C2 in the holding unit 213.

[0139] Furthermore, after the end of the batch transfer time Tt (time Tme), when strong light enters, for example, when light 202 from the main subject 401 is incident on the photoelectric conversion unit 201 of the pixel 200 (Figure 4 (B)), the charge 203 of the second PLS signal component C2 is accumulated in the holding unit 213 of the pixel 200.

[0140] Also in the second embodiment, similarly to the first embodiment, a function or a table indicating the relationship between the period during which light 202 from a high-luminance subject having different luminance is received and the amount of charge 203 generated in the pixel 200 is stored in the memory 105 as information related to the parasitic light receiving sensitivity.

[0141] Therefore, the imaging device 100 can calculate the amount of charge of the second PLS signal component C2 in the second light receiving period, for example, by calculating the light receiving period from time T1 to T2 and substituting it into the second function or by referring to the second table.

[0142] In the second embodiment, the correction section 130 may remove the first PLS signal component C1 from the image data of the main imaging, may remove only the second PLS signal component C2 from the image data of the main imaging, or may remove the PLS signal 302 which is a composite component of the first PLS signal component C1 and the second PLS signal component C2. The second function may be a linear function or a nonlinear function.

[0143] Fig. 15 is an explanatory diagram showing a detailed concrete example of the amount of accumulated charge of the normal pixel 200 and the change over time of the PLS signal during exposure for flicker detection according to the second embodiment. The difference from Fig. 14 is that the output Sfl for flicker detection of the flicker detection frame FL is detected during the exposure time Tfl for flicker detection. The rest is the same as the content shown in Fig. 14.

[0144] In this way, according to the second embodiment, it is possible to remove the first PLS signal component C1, the second PLS signal component C2, or the PLS signal 302, which is a composite component of the first PLS signal component C1 and the second PLS signal component C2, that occurs near a high-brightness subject in the image data.

[0145] Although the above-described imaging device 100 has an imaging element 102, an image processing unit 103 including a correction unit 130, and a camera control unit 107 including an exposure control unit 171, the correction unit 130 and the exposure control unit 171 may be implemented inside the imaging element 102. In this case, the imaging element 102 has a layered structure and is composed of a layer in which the pixels 200 are arranged, a layer in which the exposure control unit 171 is arranged, and a layer in which the correction unit 130 is arranged.

[0146] Furthermore, the detection of the PLS signal component C by the imaging device 100 can be performed in two cases: exposure by the AF pixel 200 (FIGS. 6 to 8, and FIG. 14) and exposure for flicker detection (FIGS. 9 to 11, and FIG. 15). The imaging device 100 may be set to detect either of the PLS signal components C in response to a user selection operation.

[0147] The present invention is not limited to the above, and may be implemented by any combination of the above. In addition, other embodiments that are conceivable within the scope of the technical concept of the present invention are also included in the scope of the present invention. [Explanation of symbols]

[0148] 100 imaging device, 101 optical system, 102 imaging element, 103 image processing unit, 104 rear monitor, 105 memory, 107 camera control unit, 108 flash, 130 correction unit, 171 exposure control unit, 172 AF control unit, 173 dimming unit, 200 pixel, 201 photoelectric conversion unit, 202 light, 203 charge, 204 light shielding film, 210 readout unit, 211 discharge unit, 212 first transfer unit, 213 holding unit, 214 second transfer unit, 216 reset unit, 217 pixel output unit, 218 amplifier unit, 219 selection unit, 220 signal line, 302 PLS signal

Claims

1. an imaging element having a first pixel including a first photoelectric conversion unit that converts light into an electric charge, a first charge holding unit that holds the electric charge transferred from the first photoelectric conversion unit, and a first output unit that outputs a first signal based on the electric charge held in the first charge holding unit, and a second pixel including a second photoelectric conversion unit that converts light into an electric charge, a second charge holding unit that holds the electric charge transferred from the second photoelectric conversion unit, and a second output unit that outputs a second signal based on the electric charge held in the second charge holding unit; a correction unit that corrects a second signal output from the second output unit based on a time until the first photoelectric conversion unit becomes saturated, a charge retention time during which the second charge retention unit retains charges, and information regarding parasitic light receiving sensitivity; An imaging device having the above configuration.

2. 2. The imaging device according to claim 1, an acquisition unit that acquires a time until the first photoelectric conversion unit is saturated from a first signal based on charges converted in the first photoelectric conversion unit during a first charge accumulation time; An imaging device having the above configuration.

3. 3. The imaging device according to claim 2, An imaging device, wherein the acquisition unit acquires the time until the first photoelectric conversion unit becomes saturated from the first signal based on the charge converted in the first photoelectric conversion unit during the first charge accumulation time for focus detection.

4. 3. The imaging device according to claim 2, An imaging device, wherein the acquisition unit acquires the time until the first photoelectric conversion unit becomes saturated from the first signal based on the charge converted in the first photoelectric conversion unit during the first charge accumulation time for detecting flicker.

5. 3. The imaging device according to claim 2, An imaging device having a setting unit that can select either a first setting that obtains the time until the first photoelectric conversion unit becomes saturated from the first signal based on the charges converted in the first photoelectric conversion unit during the first charge accumulation time for focus detection, and a second setting that obtains the time until the first photoelectric conversion unit becomes saturated from the first signal based on the charges converted in the first photoelectric conversion unit during the first charge accumulation time for detecting flicker.

6. 3. The imaging device according to claim 2, The correction unit corrects the second signal when the first photoelectric conversion unit is not saturated during a first charge accumulation time.

7. 2. The imaging device according to claim 1, The correction unit corrects the second signal when a first region having a luminance value equal to or greater than a first luminance exists within an imaging range.

8. 8. The imaging device according to claim 7, An imaging device, wherein the first pixel is a pixel that corresponds to the first region during imaging.

9. 8. The imaging device according to claim 7, The correction unit corrects the second signal when a second region having a luminance value equal to or lower than the second luminance is present around the bright subject.

10. 10. The imaging device according to claim 9, the first pixel is a pixel corresponding to the first region at the time of shooting, An imaging device, wherein the second pixel is a pixel corresponding to the second region during imaging.

11. The imaging device according to any one of claims 7 to 10, The correction unit corrects the second signal based on the presence or absence of movement of the first area within the imaging range.

12. The imaging device according to claim 11, The correction unit corrects the second signal based on a movement vector of the first region when the first region moves within the imaging range.

13. 11. The imaging device according to claim 9, The correction unit corrects the second signal based on whether or not the second area moves within an imaging range when the first area does not move within an imaging range.

Images