JP2006033381A - Imaging device and control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To expand dynamic range, when photographing a moving image. <P>SOLUTION: The imaging device has a CMOS sensor (69) in which pixels are arranged two-dimensionally, control means (71, 74) which read out pixel signals for one screen from the CMOS sensor, by executing the scanning for reading out the pixel signals at least every other line a plurality of times to the CMOS sensor when photographing a moving image, scan different lines for each scanning, and drive and control the CMOS sensor so that an electric charge storage times become different; an image memory (72) for storing the pixel signals read out for each scanning; and dynamic range expanding means (73, 74) for expanding the dynamic range by using the pixel signals stored in the image memory. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to signal readout at the time of moving image shooting of a CMOS sensor as a solid-state imaging device in a digital camera or the like, and more particularly to expansion of a dynamic range at the time of moving image shooting.

  2. Description of the Related Art Conventionally, some imaging devices use a CMOS sensor as a solid-state imaging device (see, for example, Patent Documents 1 and 2). When the imaging device has a mechanical shutter that is a mechanical light shielding member, the CMOS sensor is shielded from light by the mechanical shutter during still image shooting, and the shutter is set so that an appropriate exposure amount is obtained after resetting all pixels in the shielded state. Is opened, the CMOS sensor is exposed, the signal is read after the shutter is closed after a predetermined time, and a still image can be taken. However, since the driving speed of the mechanical shutter is limited, when performing exposure at a shorter time, it is realized by using the electronic shutter function without using the mechanical shutter. At that time, the mechanical shutter is opened so that the CMOS sensor is always exposed.

  First, a scan for removing unnecessary charges accumulated in the pixels, that is, a reset scan is executed for each pixel or line, and then a scan for reading out signal charges is performed for each pixel or line after a predetermined time elapses. Thus, an electronic shutter operation can be realized. Such an electronic shutter is hereinafter referred to as a “rolling electronic shutter”.

  FIG. 7 is a circuit diagram showing a schematic configuration example of a CMOS sensor employing a conventional XY address type scanning method, and FIG. 8 is a timing chart showing a CMOS sensor driving method for realizing a conventional electronic shutter.

  FIG. 7 shows the configuration of an image sensor that employs an XY address type scanning method. In FIG. 7, reference numeral 101 denotes a unit pixel. In FIG. 7, for simplification of the drawing, only the pixels 101 are shown in 4 rows × 4 columns, but actually, a very large number (for example, several millions) of pixels 101 are two-dimensionally arranged. Yes. Reference numeral 102 denotes a photodiode (PD) that converts light into electric charges, reference numeral 103 denotes a transfer switch that transfers electric charges generated in the PD 102 to a storage area (floating diffusion: FD), which will be described later, by a transfer pulse φTX, and reference numeral 104 temporarily transfers the electric charges. An accumulation region (FD) for accumulating the signal and 105 is an amplification MOS amplifier functioning as a source follower. Reference numeral 106 denotes a selection switch that selects a pixel by a selection pulse φSEL, and reference numeral 107 denotes a reset switch that removes charges accumulated in the FD 104 by a reset pulse φRES. The FD 104, the amplification MOS amplifier 105, and a constant current source 109 described later constitute a floating diffusion amplifier, and the signal charge of the pixel selected by the selection switch 106 is converted into a voltage, which is output to the readout circuit 113 via the signal output line 108. Is done. Reference numeral 109 denotes a constant current source serving as a load for the amplification MOS amplifier 105. Reference numeral 110 denotes a selection switch that selects an output signal from the readout circuit 113 and is driven by the horizontal scanning circuit 114. Reference numeral 111 denotes an output amplifier for outputting a signal to the outside of the image sensor. Reference numeral 112 denotes a vertical scanning circuit (shift register) for selecting the switches 103, 106, and 107.

  For each of the pulse signals φTX, φRES, and φSEL, pulse signals that are selected by the vertical scanning circuit 112 and applied to, for example, the nth scan line are described as φTXn, φRESn, and φSELn.

  FIG. 8 shows a driving pulse and an operation sequence in the rolling electronic shutter operation. In FIG. 8, for the sake of simplicity, the drive control for four rows from the n line to the n + 3 line selected by the vertical scanning circuit 112 will be described.

In the n line, first, φRESn and φTXn are applied during a period from time t31 to t32, the transfer switch 103 and the reset switch 107 are turned on, and a reset operation for removing unnecessary charges accumulated in the PD 102 and the FD 104 on the n line. I do. At time t32, the transfer switch 103 is turned off, and an accumulation operation for accumulating the photocharge generated in the PD 102 is started. Next, at time t <b> 34, φTXn is applied to turn on the transfer switch 103, and a transfer operation for transferring the photocharge accumulated in the PD 102 to the FD 104 is performed. The reset switch 107 needs to be turned off prior to this transfer operation, and in the drive control shown in FIG. 8, it is turned off simultaneously with the transfer switch 103 at time t32. As described above, the accumulation time is from the time t32 when the reset operation ends to the time t35 when the transfer ends.
After the transfer operation for the nth line is completed, φSELn is applied to turn on the selection switch 106, whereby the charge held in the FD 104 is converted into a voltage and output to the reading circuit 113. The signals temporarily held by the readout circuit 113 are sequentially output from the time t36 by the horizontal scanning circuit 112. The time from the start of transfer at time t34 to the end of reading at time t37 is T3read, and the time from time t31 to time t33 is T3wait. Similarly, in other lines, the time from the start of transfer to the end of reading is T3read, and the time from the start of resetting of one line to the start of resetting of the next line is T3wait.

  Although a still image can be taken with the rolling electronic shutter according to the driving method described above, as shown in FIG. 9, after the second application of φTXn + 3 and φSELn + 3 following reset, φTXn to φTXn + 3, φSELn to φSELn + 3 without resetting. By repeatedly applying the above signal, it is possible to obtain a moving image signal whose signal reading interval is the accumulation time Tint.

  Other documents on the configuration / driving method of the CMOS sensor include Patent Documents 1 and 2.

  On the other hand, the imaging device has a high resolution mode and a normal mode. In the high resolution mode, a progressive scan is performed to read out all pixels, and in a normal mode, an interlaced scan is performed to obtain a real-time video signal by pixel addition or pixel decimation. There has been proposed an imaging apparatus that enables output (see, for example, Patent Document 3).

  In addition, proposals have been made to prevent false signals from being generated even when reading is performed at such a relatively high frame rate (see, for example, Patent Document 4).

JP 2000-201300 A JP 2002-209144 A JP 7-298111 A JP 2000-134550 A

  However, in the rolling electronic shutter, the accumulation time Tint of one frame at the time of moving image shooting is the signal reading interval as described above, and is fixed regardless of the luminance of the subject, so that the appropriate exposure range is narrowed. Therefore, there is a signal reading method called a slit rolling shutter that can control the accumulation time by resetting the pixels once before the signal reading. This timing chart is shown in FIG. As shown in FIG. 10, after the accumulated signal is read out, the signal is once reset after a predetermined time, so that the accumulation time Tint can be made shorter than the readout interval. This is an effective exposure control when the subject brightness is high because the accumulation time of one frame can be controlled in units of one horizontal line scanning time.

  However, the slit rolling shutter can handle exposure when the entire screen is uniform and the subject brightness is bright, but when a dark portion and a bright portion are mixed in one screen, for example, the main subject is properly exposed. Even if it can be controlled, there is a problem that others are saturated or darkened.

  The present invention has been made in view of the above problems, and an object of the present invention is to expand the dynamic range at the time of moving image shooting.

  The imaging apparatus according to the present invention includes: an imaging unit in which pixels are arranged two-dimensionally; and at the time of moving image shooting, the imaging unit performs a scan for reading out a pixel signal at least every other row a plurality of times, so that 1 Reads out pixel signals for the screen, scans different rows for each scan, and controls the drive of the imaging means so that the charge accumulation time differs, and the pixel signals read for each scan And a dynamic range expansion unit that expands the dynamic range using the pixel signal stored in the storage unit.

  Further, the control method of the present invention of the image pickup apparatus having the image pickup means in which the pixels are two-dimensionally arranged performs a plurality of scans for reading out the pixel signal at least every other row of the image pickup means at the time of moving image shooting. Reads out pixel signals for one screen from the image pickup means, scans different rows for each scan, and controls the drive of the image pickup means so that the charge accumulation time is different, and reads for each scan. A storage step of storing the output pixel signal, and a dynamic range expansion step of expanding the dynamic range using the pixel signal stored in the storage means.

  According to the present invention, the dynamic range during moving image shooting can be expanded.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.

<First Embodiment>
(Configuration of imaging device)
FIG. 1 shows a schematic configuration of the imaging apparatus according to the first embodiment of the present invention.

  In FIG. 1, 73 is a signal processing circuit which is a main calculation module, 72 is an image memory having a capacity capable of storing imaging signals of a plurality of frames, and 74 is a CPU, which controls the signal processing circuit 73 and controls the timing generation circuit 71. The imaging sequence is controlled.

  Reference numeral 68 denotes a photographing optical system, and 69 denotes a CMOS sensor which is an image sensor. In the first embodiment, a CMOS sensor having the same configuration as that shown in FIG. 7 is used as the CMOS sensor 69, and the description thereof is omitted here. However, as described with reference to FIG. 7, only 4 rows × 4 columns are shown for easy understanding, but actually, a very large number (for example, several millions) of pixels 101 are two-dimensional. Is arranged. Reference numeral 70 denotes a preprocessing circuit that performs A / D conversion on the output of the CMOS sensor 69 and performs correction processing such as fixed pattern noise of the CMOS sensor 69. The drive timing of the CMOS sensor 69 is generated by the timing generation circuit 71.

  Reference numeral 75 denotes a moving image / still image switching switch (SW) for switching between the moving image shooting mode and the still image shooting mode, and 76 denotes a shooting start switch (SW) for instructing start of shooting. When the shooting start SW 76 is operated again after the start of shooting, the shooting is terminated. 77 and 78 are dynamic range switching selection SWs, which are selected according to shooting such as daytime, night view, and indoor. For example, when indoor shooting is selected, a combination of charge accumulation times is described as will be described later. Is set so that the dynamic range is expanded. Note that the switching of the dynamic range may be interlocked with the switching of the white balance.

(Reading control of CMOS sensor)
Next, overall processing for exposure and readout control by the imaging apparatus having the above-described configuration in the first embodiment will be described with reference to FIG.

  First, in step S11, the CPU 74 confirms the state of the moving image / still image switching switch SW75. If it is a still image, the process proceeds to step S19.

  In the case of a moving image, the process proceeds to step S12, and the CPU 74 determines whether or not dynamic range expansion is selected by operating the dynamic range changeover switch 77 and / or 78. If the dynamic range expansion is not selected, the process proceeds to step S16. If the dynamic range expansion is selected, the process proceeds to step S13.

  In each of steps S13, S16, and S19, it is determined whether or not the shooting start SW 76 has been turned on. If turned on, the process proceeds to steps S15, S18, and S21, respectively. In step S15, a moving image with an expanded dynamic range is shot by changing the accumulation time for each frame, which is a feature of the first embodiment of the present invention. In step S18, a moving image is shot by a normal slot rolling shutter method. In step S21, a still image is shot by known exposure / readout control.

  On the other hand, if the shooting start SW 76 is not turned on in S13, S16, and S19, the process proceeds to steps S14, S17, and S20, respectively, and it is determined whether or not the other switches 75, 77, and 78 are operated. For example, the process of returning to steps S13, S16, and S19 is repeated, and the process waits for the imaging start SW 76 to be turned on. Further, when the switches 75, 77, and 78 are operated, the process is terminated, and the process from step S11 is started again.

  Next, exposure and readout control for capturing a moving image with an expanded dynamic range in the first embodiment of the present invention performed in step S15 will be described. In the first embodiment, reading is performed by the slot rolling shutter method, even-numbered rows and odd-numbered rows are alternately read for each frame, and the charge accumulation time is different between even-numbered rows and odd-numbered rows. Realize the expansion of the dynamic range. Hereinafter, a driving method of the CMOS sensor for that purpose will be described in detail with reference to FIGS.

  First, on the n line, during the period from time t11 to t12, φRESn and φTXn are applied, the transfer switch 103 and the reset switch 107 are turned on, and reset for removing unnecessary charges accumulated in the PD102 and the FD104 on the nth line. Perform the action. When the transfer switch 103 is turned off at time t12, an accumulation operation for accumulating the photocharge generated in the PD 102 is started. Next, φTXn is applied at time t14 after the elapse of the predetermined time Tint1, the transfer switch 103 is turned on, and a transfer operation for transferring the photocharge accumulated in the PD 102 to the FD 104 is performed. The reset switch 107 needs to be turned off prior to this transfer operation, and in the drive control shown in FIG. 3, it is turned off simultaneously with the transfer switch 103 at time t12. As described above, the accumulation time is from the time t12 when the reset operation ends to the time t15 when the transfer ends.

  After the transfer operation for the nth line is completed, φSELn is applied to turn on the selection switch 106, whereby the charge held in the FD 104 is converted into a voltage and output to the reading circuit 113. The signals temporarily held by the readout circuit 113 are sequentially output from the time t16 by the horizontal scanning circuit 112.

  On the other hand, after applying φTXn, a reset operation is performed to remove unnecessary charges accumulated in PD102 and FD104 of the n + 1 line by applying φRESn + 1 and φTXn + 1 to the n + 1 line of the next row after a predetermined time t13. I do. When φTXn + 1 becomes low and the transfer switch 103 is turned off, the accumulation operation in the PD 102 of the (n + 1) th line is started.

  On the n-th line, after the predetermined time Tint1 has elapsed, the transfer switch 103 is turned on to transfer the accumulated photocharge to the FD 104. However, since the signal on the n + 1-th line is not read out in the first frame, φTXn + 1 and φSELn + 1 are kept low. , Neither transfer to the FD 104 nor transfer to the reading circuit 113 is performed.

  Similarly, after the application of φTXn + 2, φTXn + 2 is applied after a predetermined time, and φTXn + 3 is applied after a predetermined time. However, since the n + 2 line is read, φTXn + 2 and φSELn + 2 are further applied after the predetermined time Tint1, and horizontal transfer is performed. Since the line is not read, φTXn + 3 and φSELn + 3 are not applied.

  By the above control, the signals of the odd lines can be read out with a predetermined accumulation time (accurately, the time corresponding to the pulse width of φSEL is different, but is described as Tint1 for convenience).

  Next, even line signals are read out. After the application of φRESn + 3 in the previous frame, φRESn to n + 3 and φTXn to n + 3 are sequentially output again every predetermined time, and the reset operation for each row is performed. In this frame, since reading of the n-th row is not performed, after application of φRESn + 1 and φTXn + 1, φTXn + 1 is applied again after a lapse of a predetermined time Tint2 shorter than Tint1 to turn on the transfer switch 103, and the light accumulated in the PD102 A transfer operation for transferring charges to the FD 104 is performed.

  After the transfer operation for the (n + 1) th line is completed, φSELn + 1 is applied to turn on the selection switch 106, whereby the charge held in the FD 104 is converted into a voltage and output to the reading circuit 113. The signals temporarily held by the readout circuit 113 are sequentially output from the time t16 by the horizontal scanning circuit 112.

  Hereinafter, the charge on the n + 2 line is not read, but the charge on the n + 3 line is read.

  By the above control, the signals of the even lines can be read out with an accumulation time shorter than the accumulation time Tint1 (accurately, the time is equal to the pulse width of φSEL, but is denoted as Tint2 for convenience).

(Dynamic range expansion processing)
The odd line signal and the even line signal acquired as described above are temporarily stored in the image memory 72 after being processed by the preprocessing circuit 70, and the signal processing circuit 73 performs dynamic range expansion processing using these signals. Do. FIG. 4 is a diagram showing the concept of the dynamic range expansion process.

First, a signal exceeding a predetermined value Ths is detected from signals of odd lines exposed at the accumulation time Tint1. The predetermined value Ths is a signal value corresponding to the charge when the charge is saturated during charge accumulation, but may be set slightly lower. When there is no signal exceeding the predetermined value Ths, the odd line signal is read twice (that is, the odd line signal is used as a signal for two rows). When there is a signal exceeding the predetermined value Ths (S ₁₂ and S _{34 in} FIG. 4A), the signal value S of the pixel corresponding to that pixel is read out of the signals of the even lines (FIG. 4 ( In a), S ₂₂ and S ₄₄ ), the signal value S is amplified by the following equation. Samp is a signal value after amplification.
Samp = S × (Tint1 / Tint2)

  For example, when Tint2 has an accumulation time that is half that of Tint1, the signal value S is doubled.

  The signal value Samp amplified in this way is replaced with a signal value S exceeding a predetermined value Ths (FIG. 4B), and the signals of the odd lines after the replacement are read out twice, and two rows worth are read out. A signal is assumed (FIG. 4C).

  By doing so, the resolution in the vertical direction is lowered, but the dynamic range can be expanded even when reading is performed by the slit rolling shutter method. In recent years, the number of pixels of the sensor tends to increase greatly, so that even if the vertical resolution is halved, a sufficient resolution can be obtained.

  In the above example, a case has been described in which signals in the same row are read twice to obtain signals for two rows, but may be read once depending on the resolution of the output destination.

<Second Embodiment>
Next, a second embodiment of the present invention will be described.

  The second embodiment is different from the first embodiment in the moving image shooting method at the time of dynamic range expansion processing. Hereinafter, a moving image shooting method at the time of dynamic range expansion processing according to the second embodiment will be described. The imaging apparatus in the second embodiment has the same configuration as that shown in FIG. 1, and the CMOS sensor 69 is also the same as that shown in FIG.

  The mechanism of CMOS slit rolling shutter readout in the second embodiment will be described with reference to FIG.

  First, the read line will be described. The upper three waveforms represent a selection signal SEL, a reset signal RS, and a transfer signal TX, respectively. Each signal may be considered as a gate signal of each of the nMOS transistors 4, 5, and 2.

  The figure below it shows the operation of the pixel 101 for each row on the time axis. 59 represents a line at the top of the screen, and 60 represents a line at the bottom of the screen. At the timing of 61, TX and RS are simultaneously turned on in pulses, whereby PD and FD are collectively reset, and the photographing operation is started. A hatched line 62 represents a reading operation from the upper part to the lower part of the screen. Reference numeral 65 denotes a pixel reset operation for resetting PD and FD performed in advance before reading in reading out one horizontal line. This timing is performed for the second selected row during the read operation of the selected row. The horizontal length from the reset operation to the read operation is called the accumulation time Tint.

  Next, thinning out will be described. Since thinning-out only resets PD and FD as described above, TX and RS are only turned on at the same time as 55. At the same time, the pixel portions of PD and FD are reset by turning on RS and TX in the second selected row. Scan reading of the row is not performed.

  By repeating scanning for all rows in this way, one frame is read out.

  Since the slit rolling shutter reads out as described above, the accumulation period cannot be inserted between the readings as in the rolling shutter. Changing the reset timing for each frame is the same as reading out a combination of frames with the same thinning-out frame as in the above-described rolling shutter.

  By changing the thinning-out for each frame, it becomes possible to set the second PD and FD reset between the frames of the same previous thinning-out as shown in FIG. It is also possible to set an accumulation time that exceeds.

  The present invention changes the thinning line selected by the vertical shift register for each frame in the slit rolling shutter.

  With this alone, the storage time is determined by the second PD, FD reset and reading as described above. Although the accumulation time is the maximum reading time, if the PD and FD reset of the thinning row are not performed in the selected row sequentially selected by the vertical shift register, the current frame is changed from the second PD and FD reset of the previous frame. The accumulation time until reading is the accumulation time, and the accumulation time exceeding the frame rate can be set. In this case, since the accumulation of the next frame has started before the reading of the previous frame, there is also an effect that the image connection between frames is improved.

  In addition, according to the said 1st and 2nd embodiment, although the case where it has a structure shown in FIG. 7 as the CMOS sensor 69 was demonstrated, it cannot be overemphasized that it is not restricted to this. For example, a capacitor CTN for holding a reset level (noise component) for each vertical readout line and a capacitor CTS for predicting a signal read from each pixel may be provided. In this case, the reset level is held in the capacitor CTN prior to signal reading of each pixel, the read signal is once held in the capacitor CTS, and the noise component is obtained by taking the difference between the signal component and the reset level. It is possible to obtain each pixel signal in which variation based on the characteristics of each pixel is reduced and the variation is reduced.

  In the first and second embodiments, the row from which a signal is read is alternately changed to an odd row and an even row for each frame. However, the present invention is not limited to this. For example, 1, 4, 7 ... rows are read in the first frame, 2, 5, 8 ... rows are read in the second frame, 3, 6, 9 ... rows are read in the third frame, etc. Needless to say, every other row may be read in one frame, such as reading. In that case, it is possible to perform control so as to have three different times for each frame, similarly to the control described in the first and second embodiments. However, readout of one frame requires that the readout row and the thinning-out row be performed with the pixel unit that can obtain at least information for color reproduction as a minimum unit.

  As described above, according to the first and second embodiments, the dynamic range at the time of moving image shooting can be expanded.

  Further, if the entire screen is read out with a plurality of thinning patterns, it is possible to eliminate the lack of information in the screen.

  Furthermore, the dynamic range can be expanded by the slit rolling shutter method without changing the frame rate.

1 is a block diagram illustrating a schematic configuration of an imaging apparatus according to an embodiment of the present invention. It is a flowchart which shows the whole process of the imaging device in embodiment of this invention. It is a timing chart for demonstrating the video recording process accompanying the dynamic range expansion in the 1st Embodiment of this invention. It is a figure which shows the concept of the dynamic range expansion process in the 1st Embodiment of this invention. It is a timing chart for demonstrating the concept of the video recording process accompanied by the dynamic range expansion in the 2nd Embodiment of this invention. It is a timing chart for demonstrating the concept of the video recording process accompanying the dynamic range expansion in the 2nd Embodiment of this invention. It is a circuit diagram which shows the example of schematic structure of the CMOS sensor which takes the scanning method of XY address type. It is a timing chart which shows the drive pulse and operation sequence at the time of still image photography in the conventional rolling electronic shutter operation. It is a timing chart which shows the drive pulse and operation | movement sequence at the time of the video recording in the conventional rolling electronic shutter operation | movement. It is a timing chart which shows the drive pulse and operation | movement sequence at the time of the moving image photography in the conventional slit rolling electronic shutter operation | movement.

Explanation of symbols

68 Imaging Optical System 69 CMOS Sensor 70 Preprocessing Circuit 71 Timing Generation Circuit 72 Image Memory 73 Signal Processing Circuit 74 CPU
75 Movie / still image switch 76 Shooting start switch 77, 78 Dynamic range switch SW

Claims (11)

Imaging means in which pixels are arranged two-dimensionally;
At the time of moving image shooting, the image pickup means reads a pixel signal for one screen from the image pickup means by scanning a pixel signal at least every other row a plurality of times, and scans a different row for each scan, And control means for driving and controlling the imaging means so that the charge accumulation times are different;
Storage means for storing pixel signals read for each of the scans;
An image pickup apparatus comprising: a dynamic range expansion unit that expands a dynamic range using a pixel signal stored in the storage unit.   The imaging apparatus according to claim 1, wherein the imaging unit is a CMOS sensor, and the control unit drives and controls the CMOS sensor by a slit rolling shutter system. The dynamic range expansion means is
Detecting means for comparing a pixel signal obtained by scanning a predetermined time with a predetermined threshold value among pixel signals for one screen stored in the storage means, and detecting a pixel having a pixel signal exceeding the threshold value; ,
When a pixel signal exceeding the threshold is detected, an alternative pixel signal used in place of the image signal that is adjacent to the detected pixel and obtained by a different scan is used instead of the image signal exceeding the threshold. Computing means for computing;
Replacement means for replacing a pixel signal exceeding the threshold with a substitute pixel signal obtained by the calculation means,
The imaging apparatus according to claim 1, wherein the threshold value is a value that is smaller by a predetermined value than a pixel signal value obtained in a state where the pixel is saturated.   The imaging apparatus according to claim 3, further comprising: an output unit that outputs the pixel signal obtained by the predetermined scanning after the pixel signal is replaced by the replacement unit a plurality of times.   The control unit scans twice every other row, and the predetermined scan is a scan with a longer charge accumulation time, and the calculation unit is adjacent to the detected pixel and is in a different scan. The imaging apparatus according to claim 3, wherein the pixel signal value is calculated by amplifying the obtained pixel signal according to the charge accumulation time. The control means performs scanning three times every two rows, the predetermined scan is a scan with an intermediate charge accumulation time, and the detection means further includes a predetermined second threshold value and the predetermined scan. Comparing the obtained pixel signal to detect a pixel signal value lower than the second threshold,
When the pixel signal value exceeding the threshold is detected, the arithmetic means amplifies a pixel signal obtained by scanning adjacent to the detected pixel and having a short charge accumulation time according to the charge accumulation time. Thus, when the pixel signal value that is lower than the second threshold is detected, the pixel that is adjacent to the detected pixel and obtained by scanning with a long charge accumulation time is calculated. 4. The imaging apparatus according to claim 3, wherein the substitute pixel signal value is calculated by reducing the signal according to the charge accumulation time. A setting unit for setting a first mode for capturing a moving image by expanding the dynamic range and a second mode for capturing a moving image without expanding the dynamic range;
The imaging apparatus according to claim 1, wherein when the first mode is set, the control unit, the storage unit, and the dynamic range control unit are operated.   The imaging apparatus according to claim 2, wherein pixel reset by a slit rolling shutter method is performed in all frames. A method for controlling an imaging apparatus having imaging means in which pixels are arranged two-dimensionally,
At the time of moving image shooting, the image pickup means reads a pixel signal for one screen from the image pickup means by scanning a pixel signal at least every other row a plurality of times, and scans a different row for each scan, And a control step of driving and controlling the imaging means so that the charge accumulation times are different;
A storage step of storing the pixel signal read for each scan;
And a dynamic range expansion step of expanding a dynamic range using the pixel signal stored in the storage means.   A program executable by an information processing apparatus, comprising program code for realizing the control method according to claim 9.   A storage medium readable by an information processing apparatus, wherein the program according to claim 10 is stored.

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