JP2009124238A - Imaging device and its flicker detecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging device capable of accurately detecting flickers in a short time independently of object status and photographic scenes. <P>SOLUTION: A signal of pixels undergoing rolling readout operation and a signal of pixels undergoing collective reset/collective transfer readout operation are obtained from a single photographic picture. The signal processing circuit 8 calculates a difference between the output of pixels undergone the collective reset/collective transfer readout operation on the left one column and the output of pixels that are adjoining to the pixels and undergone the rolling readout operation on each line. As the result of this subtraction, when there is a periodic difference of a prescribed threshold value or more in the vertical direction, the signal processing circuit 8 determines the image is affected by a flicker. When a flicker exists and a pixel signal has a readout time difference in each line, the flicker due to the time difference appears on the line. Contrarily, when the pixel signal has no readout time difference, no flicker appears on every line. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging apparatus that detects flicker in reading a signal from an image sensor during moving image shooting, and a flicker detection method thereof.

  In an imaging apparatus such as a digital camera, a CMOS image sensor is used as a solid-state imaging device in terms of low voltage, low power consumption, and the frequency of use thereof has increased in recent years.

  By the way, when there is a blinking light source such as a fluorescent lamp as the light source in the photographing environment, the photographed image of the imaging device is affected by flicker by the light source. In particular, in the CMOS image sensor, since pixel signals are sequentially read out for each scanning line, it is known that the reading start time is shifted for each scanning line and the exposure time is different.

  Therefore, when the scanning line is line by line, the flicker that occurs is a line flicker whose output changes in the vertical direction of the screen, as in the image shown in FIG. FIG. 5 is a diagram showing the occurrence of line flicker.

In order to remove or reduce the influence of such flicker, the following methods are known as methods for detecting and correcting flicker. For example, there has been proposed one that detects flicker by integrating pixel signal levels for each predetermined line in one frame and using the integration result of lines at the same position in a plurality of past frames (see Patent Document 1). . In addition, there has been proposed one that detects flicker by calculating the line brightness by integrating the pixel level for each line within one frame and detecting the fluctuation period in the vertical direction of the line brightness (see Patent Document 2). ).
Japanese Patent No. 3476400 JP 2004-260574 A

  However, in Patent Document 1, a captured image of at least two frames is necessary to detect flicker, and an integrated value of a plurality of frames is used for flicker detection. I was going to get it.

  In addition, since there is always a time difference between the shooting time of the image used for flicker detection and the actual captured image, if the flicker state changes during that time, the flicker pattern may not be correctly removed.

  Further, in Patent Document 2, when the subject is a “uniform luminance surface” as shown in FIG. 5, it is possible to detect the flicker pattern with high accuracy from the signal amplitude, but in reality, there are various in the shooting screen. It is very rare that there is a uniform subject and a “uniform luminance surface”. Therefore, it is usually difficult to detect the flicker pattern of the captured image.

  The present invention has been made in view of the above problems, and provides an imaging apparatus and a flicker detection method capable of detecting flicker more accurately in a short time regardless of the state of a subject and a shooting scene. With the goal.

  In order to achieve the above object, an imaging apparatus according to the present invention includes two pixel units each including a photoelectric conversion unit that generates and accumulates charges by photoelectric conversion and a floating diffusion unit that accumulates the generated charges. An image pickup apparatus using an image pickup device arranged in a dimension, wherein the photoelectric conversion unit of the pixel unit within a predetermined range consisting of some columns or rows among the plurality of pixel units arranged in two dimensions, and Batch reset means for collectively resetting the floating diffusion portion, and batch transferring the charges accumulated in the photoelectric conversion portion collectively to the floating diffusion portion after a predetermined time has elapsed since the batch reset. The transfer means and the photoelectric conversion units and the floating diffusion units of the plurality of pixel units arranged in a two-dimensional manner, excluding the pixel unit within a predetermined range made up of the partial columns or rows, sequentially in predetermined units. Sequential reset with reset And a sequential transfer means for sequentially transferring the electric charge accumulated in the photoelectric conversion unit to the floating diffusion unit for each predetermined unit after a predetermined time has elapsed since the sequential reset is performed. A detection unit that calculates difference information using the pixel signal of the pixel unit obtained and the pixel signal of the pixel unit obtained by the sequential transfer unit, and detects flicker based on the calculated difference information; It is characterized by having.

  According to the flicker detection method of the imaging apparatus of the present invention, a plurality of pixel units each including a photoelectric conversion unit that generates and accumulates charges by photoelectric conversion and a floating diffusion unit that accumulates the generated charges are two-dimensionally arranged. A flicker detection method for an image pickup apparatus using an image pickup device, wherein among the plurality of pixel portions arranged in two dimensions, the photoelectric conversion portion of a pixel portion within a predetermined range consisting of some columns or rows, and A batch reset step for collectively resetting the floating diffusion portion, and a batch for transferring charges accumulated in the photoelectric conversion portion to the floating diffusion portion after a predetermined time has elapsed since the batch reset was performed. The transfer step and the photoelectric conversion unit and the floating diffusion unit of the plurality of pixel units arranged in two dimensions, excluding the pixel unit within a predetermined range composed of the partial columns or rows, sequentially in predetermined units. reset A sequential reset step, a sequential transfer step of sequentially transferring the charge accumulated in the photoelectric conversion unit to the floating diffusion unit for each predetermined unit after a predetermined time has elapsed since the sequential reset is performed, and the batch transfer Detection that calculates difference information using the pixel signal of the pixel unit obtained in the step and the pixel signal of the pixel unit obtained in the sequential transfer step, and detects flicker based on the calculated difference information And a step.

  According to the imaging device of the first aspect of the present invention, the pixel signal of the pixel unit obtained by the batch transfer unit and the pixel signal of the pixel unit obtained by the sequential transfer unit are used for one photographed image. Thus, difference information is calculated, and flicker is detected based on the calculated difference information. Thereby, flicker can be detected more accurately in a short time regardless of the state of the subject and the shooting scene.

  According to the imaging device of the second aspect, flicker can be easily detected. According to the imaging apparatus of the third aspect, difference information necessary for flicker detection can be easily obtained by using an output between adjacent pixels. According to the imaging device of the fourth aspect, it is possible to detect flicker while ensuring an effective pixel area. According to the imaging device of the fifth aspect, the effective pixel area can be efficiently used, and it is not necessary to provide a pixel area that is reset and transferred in a batch separately from the effective pixel area.

  Embodiments of an imaging apparatus and a flicker detection method of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of an imaging apparatus according to an embodiment. The image pickup apparatus of the present embodiment is applied to a digital camera that can perform moving image / still image shooting.

  The imaging apparatus includes an optical system 1 including a lens and a diaphragm, a focal plane mechanical shutter (mechanical shutter) 2, and an imaging element 3. When the still image shooting mode is selected by a shooting mode switching SW (not shown) for switching between the moving image / still image shooting mode, the mechanical shutter 2 sets the exposure time to the image sensor due to the difference in travel time between the front curtain and the rear curtain. Control. When the moving image shooting mode is selected, the mechanical shutter 2 is fully opened and light is always guided to the image sensor 3.

  The imaging device 3 is a CMOS image sensor, and a part of pixels can be read out differently from other pixels. Specifically, in the present embodiment, the imaging device 3 includes a pixel unit that can perform rolling readout and a pixel unit that can perform batch reset batch transfer readout. Note that flicker detection described later can be detected based on pixel information obtained by this different readout method.

  The imaging apparatus also includes a CDS circuit 4 that performs analog signal processing, an A / D converter 5 that converts an analog signal into a digital signal, and a timing signal generation circuit 6. The timing signal generation circuit 6 generates a signal for operating the image sensor 3, the CDS circuit 4 and the A / D converter 5. In addition, the imaging apparatus includes an optical system 1, a mechanical shutter 2, a driving circuit 7 for the imaging device 3, a signal processing circuit 8 that performs signal processing necessary for captured image data, and an image memory that stores the signal processed image data. 9

  In addition, the imaging device includes an image recording medium 10 that is removable from the imaging device, a recording circuit 11 that records signal processed image data on the image recording medium 10, an image display device 12 that displays signal processed image data, and The image display device 12 includes a display circuit 13 that displays an image. The imaging apparatus also includes a system control unit 14 that controls the entire imaging apparatus, a nonvolatile memory (ROM) 15, and a volatile memory (RAM) 16.

  The nonvolatile memory (ROM) 15 stores a program describing a control method executed by the system control unit 14 and control data such as parameters and tables used when the program is executed. In the volatile memory (RAM) 16, the program, control data, and correction data stored in the nonvolatile memory 15 are transferred and stored. The volatile memory (RAM) 16 is used when the system control unit 14 controls the imaging apparatus.

  An operation when the moving image shooting mode is selected in the imaging apparatus having the above configuration will be described. Here, prior to the shooting operation, when the operation of the system control unit 14 is started, such as when the imaging apparatus is turned on, necessary programs and control data are transferred from the nonvolatile memory 15 to the volatile memory 16 and stored. I shall keep it. These programs and data are used when the system control unit 14 controls the imaging apparatus. Further, the system control unit 14 transfers additional programs and data from the nonvolatile memory 15 to the volatile memory 16 or directly reads and uses data in the nonvolatile memory 15 as necessary.

  First, the drive circuit 7 drives the optical system 1 including a diaphragm and a lens in accordance with a control signal from the system control unit 14 and fully opens the mechanical shutter 2. Then, the optical system 1 forms a subject image set to an appropriate brightness on the image sensor 3.

  The image pickup device 3 is driven by a drive pulse based on an operation pulse generated by the timing signal generation circuit 6 controlled by the system control unit 14, converts the subject image into an electrical signal by photoelectric conversion, and outputs it as an analog image signal. To do. A method for driving the image sensor 3 will be described later.

  The analog image signal output from the image pickup device 3 is subjected to clock synchronization noise removal by the CDS circuit 4 in accordance with an operation pulse generated by the timing signal generation circuit 6 controlled by the system control unit 14, and the A / D converter 5. Is converted into a digital image signal.

  Once the digital image is stored in the image memory 9, the signal processing circuit 8 controlled by the system control unit 14 performs image processing such as color conversion, white balance, gamma correction, and resolution conversion processing on the digital image signal. Then, image compression processing or the like is performed.

  The image memory 9 is used for temporarily storing a digital image signal during signal processing or for storing image data which is a digital image signal subjected to signal processing. The image data signal-processed by the signal processing circuit 8 and the image data stored in the image memory 9 are converted into data suitable for the image recording medium 10 (for example, file system data having a hierarchical structure) in the recording circuit 11. Is recorded on the image recording medium 10. After the resolution conversion process is performed by the signal processing circuit 8, the image data is converted into a signal suitable for the image display device 12 (for example, an NTSC analog signal) by the display circuit 13, and the image display device 12 performs the conversion. Is displayed.

  When requested by the system control unit 14, the signal processing circuit 8 outputs information on digital image signals and image data generated in the signal processing process to the system control unit 14. For example, information such as the spatial frequency of the image, the average value of the designated area, the data amount of the compressed image, or information extracted from the information is output. Further, the signal processing circuit 8 performs an operation from image signals obtained by different reading methods in the CMOS image sensor 3, and also generates flicker information. In addition, the signal processing circuit 8 performs image correction for each line based on the obtained flicker information, and also performs image processing for reducing the influence of flicker. When requested by the system control unit 14, the recording circuit 11 outputs information such as the type and free capacity of the image recording medium 10 to the system control unit 14.

  A reproduction operation when image data is recorded on the image recording medium 10 will be described. The recording circuit 11 reads image data from the image recording medium 10 in accordance with a control signal from the system control unit 14. Similarly, when the image data is a compressed image, the signal processing circuit 8 performs an image expansion process according to a control signal from the system control unit 14 and stores it in the image memory 9. The image data stored in the image memory 9 is subjected to resolution conversion processing in the signal processing circuit 8, converted into a signal suitable for the image display device 12 in the display circuit 13, and displayed on the image display device 12. .

  Next, the CMOS image sensor 3 and the driving method thereof in the present embodiment will be described in detail. FIG. 2 is a diagram showing a schematic configuration of the CMOS image sensor 3. For the sake of simplicity, FIG. 2 shows a pixel configuration in which unit pixels (pixel portions) 101 are arranged in only 3 rows × 3 columns. However, in reality, a large number of pixels are two-dimensionally arranged as a shooting screen. Has been.

  In the same figure, the pixels located in the left column are different from the other pixels in that the connection destinations of the gates of the transfer switch 103 and the reset switch 107 are the transfer pulse φTX0 and the reset pulse φRES0, respectively. Further, since the pixels in the left one column are not located in the region output as final image data, there is no problem due to the difference in driving method.

  The photodiode (PD) 102 converts light into electric charge as a photoelectric conversion unit. The transfer switch 103 transfers charges generated in the PD 102 to a storage area (floating diffusion: FD) 104 to be described later by a transfer pulse φTX0 for the pixels located in the left column and a transfer pulse φTX for the other pixels. . An accumulation region (FD) 104 that is a floating diffusion portion temporarily accumulates charges. The amplification MOS amplifier 105 functions as a source follower.

  The selection switch 106 selects a pixel by a selection pulse φSEL. The reset switch 107 removes the charge accumulated in the FD 104 by the reset pulse φRES0 for the pixels located in the left column and the reset pulse φRES for the other pixels.

  Here, the FD 104, the amplification MOS amplifier 105, and a constant current source 109, which will be 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. Is output. The constant current source 109 serves as a load for the amplification MOS amplifier 105.

  The column selection switch 110 is driven by the horizontal scanning circuit 114 and selects an output signal from the readout circuit 113. The output amplifier 111 outputs an output signal from the readout circuit 113 to the outside of the image sensor 3. The vertical scanning circuit (shift register) 112 is for selecting the switches 103, 106, and 107. The read circuit 113 temporarily holds the output signal generated on the signal output line 108. The horizontal scanning circuit 114 sequentially outputs pixel outputs that are output for each column of the readout circuit 113 to the output amplifier 111.

  For the pulse signals φTX, φRES, and φSEL, the pulse signals applied by, for example, the nth scan line selected by the vertical scanning circuit 112 are described as φTXn, φRESn, and φSELn, respectively. For the pulse signals φTX0 and φRES0, the same pulse signal is applied to each scan line regardless of the nth scan line.

  Next, the driving operation of the image sensor in the moving image shooting mode will be described. FIG. 3 is a timing chart showing the driving operation of the image sensor 3. In the present embodiment, the pixels in the CMOS image sensor 3 are driven to be divided into pixels for performing rolling readout and pixels for performing batch reset batch transfer readout in one frame, thereby obtaining an output obtained from a difference in driving method. Based on the result, flicker can be detected.

  First, driving of pixels other than the left one column in which rolling readout is performed will be described. The vertical scanning circuit 112 applies the reset pulse φRESn and the transfer pulse φTXn and turns on the transfer switch 103 and the reset switch 107 during the period from time t11 to t12 on the n line. Then, the vertical scanning circuit 112 performs a reset operation for sequentially removing unnecessary charges accumulated in the PD 102 and the FD 104 other than the first column on the left of the n line by every predetermined unit (for each line).

  When the transfer switch 103 is turned off at time t12, an accumulation operation for accumulating the photoelectric charge generated in the PD 102 for a predetermined time Tint1 is started. Here, the PD 102 for which the accumulation operation is started is located in a position other than the left one column, and the accumulation of the PD 102 located in the left one column is started at a timing described later.

  Next, the vertical scanning circuit 112 applies a transfer pulse φTXn at time t17 after a predetermined time, which is the predetermined time Tint1, turns on the transfer switch 103, and transfers the photocharge accumulated in the PD 102 to the FD 104. Perform the action.

  Prior to this transfer operation, the reset switch 107 needs to be turned off, and is turned off simultaneously with the transfer switch 103 at time t12. Here, for pixels other than the left one column, a predetermined time Tint1 from the reset operation end time t12 to the transfer end time t17 is the accumulation time.

  After completion of the n-line transfer operation, the vertical scanning circuit 112 applies the selection pulse φSELn at time t18 to turn on the selection switch 106, whereby the n-line charge held in the FD 104 is converted into a voltage and read. It is output to the circuit 113. The signals temporarily held in the readout circuit 113 are sequentially output from the time t19 by the horizontal scanning circuit (HSR) 114.

  After the reset pulse φTXn is applied to the n line, the same operation is performed on the n + 1 line which is the next row of the n line. That is, for the n + 1 line, at time t13 after a predetermined time, as with the n line, application of a pulse signal corresponding to each line is started, and charges are accumulated at a predetermined time Tint1 that is the same accumulation time as the n line. Thereafter, the signals are sequentially output and read. Further, for the n + 2 line which is the next row, the same operation as the n line and the n + 1 line is performed at time t15.

  On the other hand, the pixels in the left first column are read by batch reset batch transfer. The driving of pixels within a predetermined range located in the left column will be described. First, the reset operation is performed not only on a specific line but also on all lines at the same time.

  The vertical scanning circuit 112 applies the reset pulse φRES0 and the transfer pulse φTX0 during the period from time t15 to t16, and turns on the transfer switch 103 and the reset switch 107 of the pixels located in the left column. The vertical scanning circuit 112 performs a reset operation for removing unnecessary charges accumulated in the PD 102 and the FD 104. This reset operation is performed on all lines at the same time.

  When the transfer switch 103 is turned off at time t16, an accumulation operation for accumulating the photoelectric charge generated in the PD 102 for a predetermined time Tint0 is started.

  Next, the vertical scanning circuit 112 applies a transfer pulse φTX0 at time t17 after a predetermined time, which is a predetermined time Tint0, turns on the transfer switch 103, and transfers the photocharge accumulated in the PD 102 to the FD 104. Perform the action. This transfer operation is also performed on all lines at the same time.

  The end of the transfer operation performed on all the lines simultaneously and the timing of reading from each line are the same as those of the pixels on which the above-described rolling reading has been performed. That is, in each line, a pixel for which batch reset batch transfer is performed is once held in the FD 104 and then read from the FD 104 as a pixel signal on one line at the same timing as a pixel on which rolling reading is performed on the same line. Read out to the circuit 113. The pixel signal thus obtained is a pixel signal in which the readout time does not differ from line to line, and the accumulation time and the time are the same for all lines.

  By such a driving operation, a pixel signal that has been subjected to rolling readout from one photographed image and a pixel signal that has been subjected to batch reset batch transfer readout can be obtained.

  The signal processing circuit 8 performs arithmetic processing on the pixel signal read out in this way, and detects flicker information. That is, the signal processing circuit 8 outputs, in the above arithmetic processing, the output (pixel signal) of the pixel that has been subjected to batch reset batch transfer readout that is positioned in the left column and the pixel that has undergone rolling readout adjacent to that pixel. A subtraction process with the output (pixel signal) is performed for each line. As a result of the subtraction process, when there is a difference equal to or greater than a predetermined threshold value and this difference (difference information) has periodicity in the vertical direction with respect to the lines of the row to be sequentially transferred, the signal processing circuit 8 causes the flicker. It is determined that there is an influence by.

  In the case where there is flicker, in a pixel signal in which a difference occurs in readout time for each line, flicker due to the difference in the time is applied for each line. On the other hand, flicker is not applied to each line for pixel signals that have no difference in readout time for each line. Therefore, flicker can be detected by performing the above subtraction process and calculating the difference information. Further, difference information necessary for flicker detection can be easily obtained by using an output between adjacent pixels. In this way, flicker can be easily detected. Further, the influence of flicker can be removed by subtracting the detected amount of flicker from the pixel signal for each line.

  FIG. 4 is a flowchart showing a flicker information detection processing procedure in the signal processing circuit 8. First, the signal processing circuit 8 sets a value 1 to the variable n (step S1). Then, the signal processing circuit 8 reads an image on the nth line of the captured image stored in the image memory 9 (step S2).

  Then, the signal processing circuit 8 outputs, from the output of the pixel located in the left one column (pixel output of batch reset batch transfer readout) of the read n-th line image, the output of the pixel close to that pixel ( The pixel output of rolling readout) is subtracted (step S3). As a result of this subtraction, a difference value between the two pixel outputs is obtained and stored in the image memory 9.

  The signal processing circuit 8 determines whether or not the variable n has exceeded the total number of lines N (step S4). If the total number of lines N is not exceeded, the signal processing circuit 8 adds 1 to the variable n (step S5), returns to step S2, and performs the same processing.

  On the other hand, when the variable n exceeds the total number N of lines, the signal processing circuit 8 determines whether or not there is periodicity in the vertical direction of the image (step S6). That is, the signal processing circuit 8 refers to the difference value of each line stored in the image memory 9, and the difference value is a value equal to or larger than a predetermined threshold value, and is perpendicular to the line of the row to be sequentially transferred. It is determined whether or not there is periodicity in the direction.

  If the difference value has periodicity in the vertical direction of the image, the signal processing circuit 8 determines that flicker has occurred (step S7), and ends this processing. On the other hand, if the difference value does not have periodicity in the vertical direction of the image, the signal processing circuit 8 determines that no flicker has occurred (step S8), and ends this processing.

  In this way, by reading out the CMOS image sensor 3 with different pixel driving methods, the difference information of the pixel output obtained from the difference in the reading time of the pixels by the driving method can be obtained for one photographed image. Based on this, flicker information can be detected.

  In the above-described embodiment, the pixel column within a predetermined range in which batch reset batch transfer readout is performed is the left one column. However, the present invention is not limited to this. That is, it is only necessary to have a column of pixels other than the effective pixel region where light is guided, and the position and the number of columns of the pixel outside the effective pixel region are not particularly limited. Thereby, flicker can be detected with high accuracy while ensuring an effective pixel area.

  In addition, in the case of an imaging apparatus that performs image shooting by column thinning, a column to be thinned is a column of pixels for which batch reset batch transfer readout is performed, and a column that is not to be thinned is a column of pixels for which rolling readout is performed. Similarly, flicker can be detected in the same manner. Accordingly, the effective pixel area can be efficiently used, and it is not necessary to provide a pixel area where batch reset batch transfer reading is performed separately from the effective pixel area.

  Further, in the case of an imaging apparatus that performs image shooting by thinning out rows, a configuration in which thinned rows are rows of pixels that are subjected to batch reset batch transfer readout, and rows that are not thinned out are rows of pixels that are subjected to rolling readout Similarly, flicker can be detected in the same manner. In this case, the rows to be thinned out by the vertical scanning circuit can be realized by selecting them at the same timing at a time. Further, the reset pulse φRES0 and the transfer pulse φTX0 for reading the batch reset batch transfer are not necessary.

  According to the imaging apparatus of the present embodiment, rolling readout and batch reset batch transfer readout are performed on a single photographed image as a pixel readout method in the CMOS image sensor 3. Accordingly, flicker information can be detected based on the difference information of the pixel output obtained from the difference in the pixel readout time according to the driving method. In this way, flicker can be detected more accurately in a short time regardless of the state of the subject and the shooting scene. Therefore, it is possible to remove the influence of the detected flicker.

  The present invention is not limited to the configuration of the above-described embodiment, and any configuration can be used as long as the functions shown in the claims or the functions of the configuration of the present embodiment can be achieved. Is also applicable.

It is a block diagram which shows the structure of the imaging device in embodiment. 2 is a diagram showing a schematic configuration of a CMOS image sensor 3. FIG. 3 is a timing chart illustrating a driving operation of the image sensor 3. 6 is a flowchart showing a flicker information detection processing procedure in the signal processing circuit 8; It is a figure which shows generation | occurrence | production of a line flicker.

Explanation of symbols

3 CMOS image sensor (image sensor)
7 Driving Circuit 8 Signal Processing Circuit 101 Pixel Unit 102 Photodiode (PD)
103 Transfer switch 104 Storage area (FD)
107 Reset switch

Claims (6)

An imaging apparatus using an imaging device in which a plurality of pixel units each having a photoelectric conversion unit that generates and accumulates charges by photoelectric conversion and a floating diffusion unit that accumulates the generated charges are two-dimensionally arranged ,
Batch reset means for collectively resetting the photoelectric conversion unit and the floating diffusion unit of the pixel unit within a predetermined range consisting of some columns or rows among the plurality of pixel units arranged in two dimensions;
A batch transfer means for collectively transferring charges accumulated in the photoelectric conversion unit to the floating diffusion unit after a predetermined time has elapsed since the batch reset was performed;
Sequentially resets the photoelectric conversion units and the floating diffusion units of the plurality of two-dimensionally arranged pixel units excluding the pixel unit within a predetermined range composed of some of the columns or rows sequentially for each predetermined unit. Resetting means;
Sequential transfer means for sequentially transferring the charge accumulated in the photoelectric conversion unit to the floating diffusion unit for each predetermined unit after a predetermined time has elapsed since the sequential reset was performed;
The difference information is calculated using the pixel signal of the pixel unit obtained by the batch transfer unit and the pixel signal of the pixel unit obtained by the sequential transfer unit, and flicker is calculated based on the calculated difference information. An imaging apparatus comprising: a detecting means for detecting.   The detection means detects flicker when the difference information is equal to or greater than a predetermined threshold and has periodicity in a vertical direction with respect to a row or column line to be sequentially transferred. Item 2. The imaging device according to Item 1.   The detection unit uses the pixel signal of the pixel unit obtained by the batch transfer unit and the pixel signal of the pixel unit which is adjacent to the pixel unit and obtained by the sequential transfer unit to obtain difference information. The imaging device according to claim 1, wherein the imaging device is calculated.   2. The imaging according to claim 1, wherein a pixel portion within a predetermined range including a part of columns or rows from which a pixel signal is obtained by the batch transfer unit is located outside an effective pixel region of the imaging device. apparatus.   When an image is captured by performing a thinning operation on columns or rows, a pixel portion within a predetermined range consisting of the partial columns or rows is a pixel portion of a column or row thinned out by the thinning operation. The imaging apparatus according to claim 1, wherein: Flicker detection of an imaging apparatus using an imaging device in which a plurality of pixel units each having a photoelectric conversion unit that generates and accumulates charges by photoelectric conversion and a floating diffusion unit that accumulates the generated charges are arranged two-dimensionally A method,
A batch reset step for collectively resetting the photoelectric conversion unit and the floating diffusion unit of the pixel unit within a predetermined range consisting of some columns or rows among the plurality of pixel units arranged in two dimensions;
A batch transfer step of collectively transferring charges accumulated in the photoelectric conversion unit to the floating diffusion unit after a predetermined time has elapsed since the batch reset was performed;
Sequentially resets the photoelectric conversion units and the floating diffusion units of the plurality of two-dimensionally arranged pixel units excluding the pixel unit within a predetermined range composed of some of the columns or rows sequentially for each predetermined unit. A reset step,
A sequential transfer step of sequentially transferring the charge accumulated in the photoelectric conversion unit to the floating diffusion unit for each predetermined unit after a predetermined time has elapsed since the sequential reset was performed;
Difference information is calculated using the pixel signal of the pixel unit obtained in the batch transfer step and the pixel signal of the pixel unit obtained in the sequential transfer step, and flicker is calculated based on the calculated difference information. A flicker detection method for an image pickup apparatus, comprising: a detection step for detecting.