JP2005175031A - Imaging device and its driving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging device which saves on labor and promotes efficiency of processing, and also to provide its driving method. <P>SOLUTION: The imaging device comprises a plurality of photoelectric converter which convert photographed images into electric charges and accumulate them, a plurality of vertical transfer sections which transfer the electric charges vertically, a plurality of horizontal transfers which transfer the electric charges horizontally, and a plurality of read-out modes. The vertical transfer sections have a plurality of systems which can be driven independently for each of different read-out modes. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention generally relates to an imaging apparatus and a driving method thereof, and more particularly, to a process for reading an output signal from a pixel of a solid-state imaging device. The present invention is suitable for output signal readout processing for video cameras and digital still cameras, for example.

  In CCD (Charge Coupled Device) sensors as image pickup elements used in digital still cameras that have become widespread in recent years, there is an increasing demand for not only high resolution and small size but also labor saving and efficient processing.

  There are mainly a sequential scanning (progressive scanning or all-pixel reading) method and an interlaced scanning (interlace) method in which all pixels are read out in two steps. The sequential readout method is characterized in that it can obtain twice the resolution in a single readout compared to the interlace scanning method (for example, Patent Documents 1 and 2). Furthermore, some CCD sensors can perform vertical thinning readout by the configuration of a vertical transfer CCD. Thinning readout is not required to read out all the pixels in the image sensor by finder driving (EVF driving) or generating an image with a size smaller than the number of pixels, while the number of pixels of the CCD sensor is advancing due to technological advances. This is an effective means when it is necessary to read an image of one frame at a higher speed, such as in moving image shooting (for example, Patent Document 3).

  In the interline structure which is a typical structure, the photodiodes and the vertical transfer CCDs are alternately arranged in a pixel composed of a photodiode for storing signal charges and a vertical transfer CCD for transferring signal charges. Are arranged in a matrix, and a horizontal transfer CCD and an output amplifier are arranged below the pixels (see, for example, Patent Document 2).

In typical sequential scanning, every time one vertical transfer CCD is transferred, the horizontal transfer CCD is transferred by a number equal to or greater than the number of horizontal pixels (one line transfer). Is repeated by a number equal to or greater than the number of vertical pixels (one frame transfer). The output amplifier in the final stage converts the transferred charge into a voltage and outputs it to the outside of the image sensor. On the other hand, in a typical vertical thinning readout, the horizontal transfer CCD performs one line transfer each time the vertical transfer CCD is transferred, for example, in three stages. As a result, an image of one screen (one frame) can be obtained at a speed about three times that at the time of sequential scanning and reading. The vertical transfer CCD is wired so that all pixels can be read out during the exposure / focus control as in the electronic viewfinder drive.
JP 2000-023008 A JP 2000-050174 A JP 2003-333410 A

  However, in the conventional image sensor driving method, all the vertical transfer CCDs are required even if only a part of a range of pixels among all pixels such as thinning out or electronic zooming is required due to wiring. And unnecessary pixels (that is, discarded) are read out, leading to unnecessary power consumption due to unnecessary driving and discarding operations.

  Accordingly, an object of the present invention is to provide an imaging apparatus capable of achieving labor saving and processing efficiency and a driving method thereof.

  According to another aspect of the present invention, there is provided a driving method of an imaging apparatus, a plurality of photoelectric conversion units that convert captured images into charges, a plurality of vertical transfer units that transfer the charges in a vertical direction, and the charges. A driving method of an imaging apparatus having a plurality of horizontal transfer units that transfer in a horizontal direction and a plurality of readout modes, wherein the first readout mode among the plurality of readout modes includes the plurality of vertical transfer units. Among the plurality of vertical transfer units, the first vertical transfer unit is driven to read the first charge and the second read mode is different from the first read mode. And driving the second vertical transfer unit that does not completely match the vertical transfer unit to read out the second charge.

  For example, the first charge readout mode is horizontal thinning readout, and the first vertical transfer unit is a part of the plurality of vertical transfer units. The plurality of photoelectric conversion units may include a plurality of systems that can be driven independently, and in the first read mode, the plurality of systems may be driven at a predetermined cycle.

  Alternatively, the first readout mode may be vertical thinning readout, and some of the plurality of photoelectric conversion units may be driven in the first readout mode.

  In still another example, the plurality of readout modes include a vertical pixel addition readout mode, and the method includes the vertical transfer unit when reading from the vertical transfer unit to the horizontal transfer unit in the vertical pixel addition readout mode. May be sent in multiple stages.

  A driving apparatus according to another aspect of the present invention includes a plurality of photoelectric conversion units that convert a captured image into charges and accumulates, a plurality of vertical transfer units that transfer the charges in a vertical direction, and the charges in a horizontal direction. An image pickup apparatus having a plurality of horizontal transfer units that transfer data to and a plurality of readout modes, wherein the vertical transfer unit has a plurality of systems that can be driven independently for different readout modes. The plurality of vertical transfer units may repeatedly arrange the system. The photoelectric conversion unit may include a plurality of systems that can be driven independently.

  Further objects and other features of the present invention will become apparent from the preferred embodiments described below with reference to the accompanying drawings.

  According to the present invention, it is possible to provide an imaging apparatus capable of achieving labor saving and processing efficiency and a driving method thereof.

  Hereinafter, an imaging apparatus 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 9. Here, FIG. 1 is a schematic block diagram of the imaging apparatus 100. As shown in FIG. 1, the imaging device 100 forms an optical system (imaging lens) subject image on the imaging device to form an image of the subject to be photographed on the imaging device (CCD) 103. A lens 101, an optical filter 102, an image sensor 103 as a photoelectric conversion element, a timing generator (TG) 104 for driving the image sensor 103, and signal processing of analog image data from the image sensor An analog signal processing unit 105 configured by an electric circuit of A, a A / D conversion unit 106 for digitizing analog image data, a digital image processing unit 107 for image processing of digitized image data, An internal memory 108 used for processing in the image processing unit, and an external memory 10 for storing image processed image data With the door.

  The optical filter 102 mainly includes an optical LPF (Low Pass Filter) and an infrared (IR) cut filter. An image incident from the optical system 101 is formed by the image sensor 103, and the image is photoelectrically converted by the image sensor 103 and output. The output is subjected to A / D through an analog signal processing unit 105 such as correlated double sampling (CDS), AGC-AMP (gain control amplifier), clamp circuit, etc. for removing clock and noise from the CCD output signal. A conversion 106 converts the digital signal. The image data converted into the digital signal is subjected to preprocessing such as horizontal thinning and resizing in the digital image processing unit 107 and then subjected to signal processing of color and luminance signals to generate an image file such as RGB or YUV. The internal memory 108 is used to store a temporary image during the image processing, but is finally stored in the external memory 1009.

  Hereinafter, with reference to FIG. 2 to FIG. 5, a flow of reading until the charge is output from the photoelectric conversion unit 103 </ b> A of the first embodiment applicable to the imaging element 103 of the imaging device 100 will be described. Here, FIG. 2 is a schematic block diagram for explaining the horizontal thinning readout method. This embodiment uses a vertical three-phase six-electrode CCD sensor in which the vertical transfer CCD 202 is driven by φV1B, φV2B, and φV3B, and the vertical transfer CCD 204 is driven by φV1A, φV2A, and φV3A in order to perform thinning in the horizontal direction. . At the time of all pixel reading (not shown), φV1A = φV1B, φV2A = φV2B, φV3A = φV3B, and all the vertical transfer CCDs 202 and 204 are driven. Reference numerals 201 and 203 denote photodiodes (PD).

  Referring to FIG. 2, in the horizontal thinning readout, first, the vertical transfer pulse φV3B supplied by the TG 104 photoelectrically converts in the PD 201 and the accumulated (signal) charge is read to the vertical transfer CCD 202. At this time, by stopping the vertical transfer pulse φV3A, photoelectric conversion is performed in the PD 203, and the accumulated charge is not read out to the vertical transfer CCD 204. The vertical transfer CCD 202 transfers charges to the horizontal transfer CCD 205 in accordance with the vertical transfer pulses φV1B, φV2B, and φV3B supplied from the TG 104. The horizontal transfer CCD 205 is driven by horizontal transfer pulses φH 1 and φH 2 supplied from the TG 104 and transfers charges to the output amplifier 206. At this time, every time the vertical transfer CCD 202 is transferred by one stage, the horizontal transfer CCD 205 is transferred by the number of horizontal pixels or more (one line transfer). Such vertical transfer for one stage and horizontal transfer for one line is repeated as many times as the number of vertical pixels (one frame transfer). The output amplifier 206 in the final stage converts the transferred charge into a voltage and outputs it to the outside of the image sensor 103.

  FIG. 3 is a wiring diagram of electrodes for driving the vertical transfer CCDs 202 and 204 for achieving the charge transfer of FIG. In the present embodiment, each of the PDs 201 and 203 is provided with a color filter having a 2 × 2 pixel configuration of R, G1, G2, and B in order to perform color processing in the subsequent digital image processing unit 107. In the all pixel reading drive (not shown), reading is sequentially performed from all the PDs 201 and 203 existing in the image sensor. At the time of horizontal thinning readout shown in FIG. 2, data is transferred to and read from the vertical transfer CCDs 202 and 204 only from the PD hatched in FIG.

  202 shown in FIG. 2 corresponds to 304 to 306 shown in FIG. 3, and 204 shown in FIG. 2 corresponds to 301-303 shown in FIG. Vertical transfer operations are performed by applying vertical transfer pulses φV1A, φV2A, φV3A, φV1B, φV2B, and φV3B to the vertical transfer CCDs 301 to 306, respectively. Note that φV3A and φV3B also serve as a read operation from the PD 201.

  The operation of the vertical transfer CCD of the image sensor having a configuration incapable of vertical thinning readout will be described with reference to FIG. The charge first photoelectrically converted and stored in the PD 201 is read out to the vertical transfer CCDs 303 and 306 at the timing when φV3A = φV3B = M (middle level) becomes H (high level). Next, when φV3A = φV3B = H changes to M, the vertical transfer CCDs 303 and 306 hold the charges. Thereafter, charges are transferred from the vertical transfer CCDs 303 and 306 to the vertical transfer CCDs 301 and 304 at the timing when φV1A = φV1B = L (low level) becomes M, and the charges are transferred at the timing when φV3A = φV3B = M becomes L. , 304. After that, by sequentially driving φV2A = φV2B = M to φV3A = φV3B = M, then φV1A = φV1B = M..., Vertical transfer CCD 302, vertical transfer CCD 305 to vertical transfer CCD 303, vertical transfer CCD 306, then vertical Charges are transferred to the transfer CCD 301, the vertical transfer CCD 304,.

  Next, the horizontal thinning readout time shown in FIG. 2 will be described with reference to FIG. First, the photoelectric conversion is performed by the PD 201, and the accumulated charge is read out to the vertical transfer CCD 306 at the timing when φV3A = M is fixed and φV3B = M (middle level) becomes H (high level). Next, when φV3A = M is fixed and φV3B = H becomes M, the charge is held by the vertical transfer CCD 306. Thereafter, the charge is transferred from the vertical transfer CCD 306 to the vertical transfer CCD 304 when φV1A = L is fixed and φV1B = L (low level) is M, and the charge is vertically transferred when φV3A = M is fixed and φV3B = M is changed to L. The data is held in the transfer CCD 304. After that, with φV1A = φV2A = L fixed, φV3A = M fixed, and sequentially driving from φV2B = M to φV3B = M, then φV1B = M... Transfers charges with the CCD 304.

  FIG. 4 is a timing chart of vertical transfer pulses φV1A, φV2A, φV3A, φV1B, φV2B, and φV3B for realizing the reading method of FIGS. 2 and 3, and FIG. b) shows a timing chart at the time of horizontal thinning readout.

  In the figure, 401 is a pulse for reading charges from the PD to the vertical transfer CCD, 402 is a pulse for transferring the vertical transfer CCD in one stage, and 403 is a pulse for transferring the vertical transfer CCD in three stages. Note that 400 is a high-speed vertical transfer pulse for sweeping away unnecessary charges accumulated in the vertical transfer CCD immediately before reading, and is generally transferred by the number of stages equal to or more than the number of vertical pixels (number of lines). Reference numeral 404 denotes a cycle of one line (1H), and there are 404 periods corresponding to the number of vertical pixels (the number of lines) both at the time of all pixel readout and at the time of horizontal thinning readout. Although omitted in the figure, during the period 404 other than the period 402 (403), the number of all horizontal pixels (one line) is read when all the pixels are read, and the number of horizontal pixels read (horizontal pixel numbers in this description) when reading the horizontal thinning. / 3) signal (charge) is output. As described with reference to FIG. 3, the vertical transfer pulses φV1A, φV2A, and φV3A are fixed to φV1A = φV2A = L and φV3A = M during horizontal thinning readout.

FIGS. 5A to 5D are plan views showing a configuration example of one pixel for realizing the reading methods of FIGS. 2 to 4, respectively, AA ′ cross-sectional view of FIG. It is B 'sectional drawing and CC' sectional drawing. In FIG. 5A, H is the width of the vertical CCD, and constitutes the CCD in the vertical direction. The vertical transfer pulses φV1A = φV1B, φV2A = φV2B, and φV3A = φV3B correspond to the electrodes 501 to 503, respectively. Each wiring is connected to a vertically adjacent pixel, extends in the vertical direction, and continues for one column. In the region of H, an insulating layer 504 such as SiO ₂ is provided under the three electrodes 501 to 503, and constitutes a vertical transfer CCD together with the three electrodes. The thick insulating layer 505 has a function of isolating each electrode from the CCD. As a result, electrode wiring on the insulating layer 505 becomes possible.

  Hereinafter, with reference to FIGS. 6 to 9, the flow of reading until the charge is output from the photoelectric conversion unit 103 </ b> B of the second embodiment applicable to the image sensor 103 of the image capturing apparatus 100 will be described. Here, FIG. 6 is a schematic block diagram for explaining the horizontal / vertical thinning readout method. 211 and 213 are PDs, 222 and 214 are vertical transfer CCDs, 215 is a horizontal transfer CCD, and 216 is an output amplifier.

  In this embodiment, a CCD having a vertical three-phase seven-electrode configuration is used. In the operation, the vertical transfer CCDs 212 and 214 are transferred in one stage at the time of reading all pixels, that is, every time the charge for one line is transferred to the horizontal transfer CCD 215, the horizontal transfer CCD 215 is driven and output for one line. At the time of thinning readout, for example, in FIG. 6, the vertical transfer CCDs 212 and 214 are transferred in three stages, the horizontal transfer CCD 215 is driven, and one line is output. With this driving method, an image of one screen (one frame) can be obtained at a speed about three times as high as that when reading all pixels.

  FIG. 7 is a wiring diagram of electrodes for driving the vertical transfer CCDs 212 and 214 for achieving the charge transfer of FIG. In this embodiment, each of the PDs 211 and 213 is provided with a color filter having a 2 × 2 pixel configuration of R, G1, G2, and B in order to perform color processing in the subsequent digital image processing unit 107. In the all-pixel reading drive (not shown), reading is sequentially performed from all PDs 211 and 213 existing in the image sensor. At the time of horizontal / vertical thinning readout shown in FIG. 6, only the hatched PD in FIG. 7 is transferred to the vertical transfer CCDs 212 and 214 for reading.

  6 corresponds to 314 to 316 shown in FIG. 7, and 214 shown in FIG. 6 corresponds to 311 to 313 shown in FIG. Vertical transfer operations are performed by applying vertical transfer pulses of φV1A, φV2A, φV3A, φV1B, φV2B, φV3B, and φV3B ′ to the vertical transfer CCDs 311 to 317, respectively. Note that φV3A, φV3B, and φV3B ′ also serve as a reading operation from the PD 211, and in the case of an image sensor configuration that does not perform vertical thinning readout, φV3B = φV3B ′, and there is no need to provide φV3B ′ and increase the wiring.

  The operation of the vertical transfer CCD of the image pickup device having the configuration capable of vertical thinning and having φV3 ′ in FIG. 7 will be described. When all-pixel readout is performed in the image sensor 103B, driving of the image sensor having the above-described all-pixel readout configuration is performed by giving pulses of the same phase such as φV1A = φV1B, φV2A = φV2B, φV3A = φV3B = φV3B ′. The same drive is realized.

  When horizontal thinning is performed in FIG. 7, φV3B = φV3B ′, φV1A = φV2A = L fixed, and φV3A = M fixed, so that the same driving as the horizontal thinning readout of FIG.

  Finally, the horizontal / vertical thinning readout shown in FIG. 6 will be described with reference to FIG. In the vertical thinning readout drive, charges are read from the PD to the vertical transfer CCD 317 at the timing when M is set to H only for φV3B ′. Note that φV3A and φV3B at the same timing remain M, and charges are not read from the PD to the vertical transfer CCDs 313 and 316 but held in the PD. The operation after reading to the vertical transfer CCD 317 is similar to the driving of the image pickup device having the all-pixel reading configuration described above, φV3A = M fixed, φV3B = φV3B ′ = M to φV1A = M, φV1B = M to φV2A = M Fixed, φV2B = M to φV3A = M fixed, φV3B = φV3B ′ = M to φV1A = M fixed, φV1B = M, and so on to drive vertical transfer CCD 317 to vertical transfer CCD 314, then vertical transfer CCD 315, then Charges are transferred to the vertical transfer CCD 316 (317) and then to the vertical transfer CCDs 314. At this time, the vertical transfer CCDs 316 and 317 are different only in reading from the PD 211 to the vertical transfer CCD, and the transfer in the vertical transfer CCD is the same operation.

  FIG. 8 is a timing chart of vertical transfer pulses φV1A, φV2A, φV3A, φV1B, φV2B, φV3B, and φV3B ′ for realizing the reading method of FIGS. 6 and 7, and FIG. FIG. 8B shows a timing chart at the time of horizontal and vertical thinning readout.

  In the figure, 601 is a pulse for reading out charges from the PD to the vertical transfer CCD, 602 is a pulse for transferring the vertical transfer CCD in one stage, and 603 is a pulse for transferring the vertical transfer CCD in three stages. Note that 600 is a high-speed vertical transfer pulse for sweeping away unnecessary charges accumulated in the vertical transfer CCD immediately before reading, and is generally transferred by the number of stages equal to or more than the number of vertical pixels (number of lines). Reference numeral 604 denotes a cycle of one line (1H). The period 604 exists for the number of vertical pixels (for the number of lines) at the time of reading all pixels, and the number of lines to be read for the horizontal / vertical thinning-out reading (in this description, vertical pixels). Number / 3) exists. Although not shown, during the period other than the period 602 (603) of the period 604, the number of all horizontal pixels (one line) is read at the time of reading all pixels, and the number of horizontal pixels to be read at the time of horizontal / vertical thinning reading (this description) Then, a signal (charge) of horizontal pixel number / 3) is output. As described with reference to FIG. 6, the vertical transfer pulses φV1A, φV2A, and φV3A are fixed at φV1A = φV2A = L and φV3A = M at the time of horizontal thinning readout. In reading from the PD, only φV3B ′ is used, and there is no reading pulse from the φV3B PD (period in which φV3B = H).

  9 and 10 are configuration examples of one pixel for realizing the readout method shown in FIGS. FIG. 9 is a configuration example of pixels to be thinned out during horizontal / vertical thinning, and corresponds to the vertical transfer CCD 316 in FIG. 9A is a plan view, and FIGS. 9B to 9D are an A-A ′ sectional view, a B-B ′ sectional view, and a C-C ′ sectional view of FIG. 9A, respectively. FIG. 10 shows a configuration example of pixels read out during horizontal and vertical thinning, and corresponds to the vertical transfer CCD 317 in FIG. 10A is a plan view, and FIGS. 9B to 9D are A-A ′, B-B ′, and C-C ′ cross-sectional views of FIG. 9A, respectively.

In the figure, H is the width of the vertical CCD, and constitutes the CCD in the vertical direction. The vertical transfer pulses φV1A = φV1B, φV2A = φV2B, φV3A = φV3B, and φV3B ′ correspond to the electrodes 701 to 704, respectively. Each wiring is connected to vertical adjacent pixels and extends in the vertical direction, and continues for one column. In the region of H, an insulating layer 705 such as SiO ₂ is disposed under the four electrodes 701 to 704, and a CCD is configured with the four electrodes. Further, the thick insulating layer 705 serves to isolate each electrode from the CCD. As a result, electrode wiring on the insulating layer 705 becomes possible.

  Hereinafter, with reference to FIG. 11 and FIG. 12, a flow of reading until the charge is output from the photoelectric conversion unit 103 </ b> C of the third embodiment applicable to the image sensor 103 of the image capturing apparatus 100 will be described. Here, FIG. 11 is a schematic block diagram for explaining the horizontal thinning / vertical addition reading method. 221 and 223 are PDs, 222 and 224 are vertical transfer CCDs, 225 is a horizontal transfer CCD, and 226 is an output amplifier.

  In this embodiment, a CCD having a vertical three-phase seven-electrode configuration is used as in FIG. Similarly to the vertical thinning readout, the vertical transfer CCD 222 is transferred in three stages, and the horizontal transfer CCD 225 is driven to output one line. At this time, by transferring three stages, two pixels in the vertical direction can be added when transferring from the vertical transfer CCD 222 to the horizontal transfer CCD 225. In other words, vertical thinning in FIG. 6 and vertical addition in FIG. 11 can be realized by electrode wiring. With this driving method, an image of one screen (one frame) can be obtained at a speed about three times as high as that when reading all pixels. The advantage of performing the vertical addition is that the sensitivity is doubled by doubling the pixel (PD201) that receives light.

  FIG. 12 shows electrode wirings for realizing the drive of FIG. Pixels to be thinned when performing horizontal thinning are wired with φV1A, φV2A, and φV3A, and pixels read out during horizontal thinning are wired with φV1B, φV2B, and φV3B (φV3B ′). Further, the pixel read at the time of vertical addition reading is connected to φV3B ′, and the pixel to be thinned out is connected to φV3B.

  Although the present invention has been described with reference to three embodiments, the electrode configuration is not limited to three phases. Further, although the filter array is 2 × 2 RGB, it is not limited to this. Furthermore, although the embodiment has been described with sequential scanning (all pixel readout), the present invention is also effective during interlaced scanning.

  As described above, according to the present invention, driving and stopping for each column can be independently performed by the image pickup device in which the electrodes of the vertical transfer CCD are wired in the vertical direction and the driving method thereof. This eliminates the need for all pixels as in electronic viewfinder drive during exposure / focus control, so it can be read out by thinning out every few pixels in the horizontal and vertical directions, or part of all pixels during electronic zoom. If it is not necessary to move unnecessary vertical transfer CCDs that sequentially read out only the pixels in the range, and do not need to read peripheral pixels such as the left and right of the image, it becomes possible to stop the corresponding vertical transfer CCD, As a result, power saving can be realized.

1 is a schematic block diagram illustrating an overall configuration of an imaging apparatus according to an embodiment of the present invention. It is a schematic block diagram for demonstrating the read-out method from the image pick-up element of the 1st Example applicable to the imaging device shown in FIG. It is a schematic block diagram explaining the example of wiring of the image sensor shown in FIG. 4 is a timing chart of transfer pulses applicable to the wiring of FIG. FIG. 3 is a schematic plan view and a schematic cross-sectional view illustrating a configuration example of one pixel of the image sensor illustrated in FIG. 2. It is a schematic block diagram for demonstrating the read-out method from the image pick-up element of the 2nd Example applicable to the imaging device shown in FIG. It is a schematic block diagram explaining the example of wiring of the image sensor shown in FIG. It is a timing chart of the transfer pulse applicable to the wiring of FIG. It is the schematic plan view and schematic sectional drawing which show the structural example of one pixel of the image pick-up element shown in FIG. It is the schematic plan view and schematic sectional drawing which show the structural example of another pixel of the image pick-up element shown in FIG. It is a schematic block diagram for demonstrating the read-out method from the image pick-up element of the 3rd Example applicable to the imaging device shown in FIG. It is a schematic block diagram explaining the example of wiring of the image sensor shown in FIG.

Explanation of symbols

100 Imaging device 103, 103A-C Image sensor 104 Timing generator 201, 203, 211, 213, 221, 223 Photodiode 202, 204, 212, 214, 222, 224 Vertical transfer CCD
205, 215, 225 Horizontal transfer CCD
206, 216, 226 Output amplifier

Claims (8)

A plurality of photoelectric conversion units that convert and store captured images into charges, a plurality of vertical transfer units that transfer the charges in the vertical direction, a plurality of horizontal transfer units that transfer the charges in the horizontal direction, and a plurality of A driving method of an imaging apparatus having a readout mode,
In the first readout mode among the plurality of readout modes, a step of reading the first charge by driving a first vertical transfer unit among the plurality of vertical transfer units;
In a second read mode different from the first read mode, the second vertical transfer unit that does not completely match the first vertical transfer unit among the plurality of vertical transfer units is driven to perform the first read mode. Reading two charges.   2. The method according to claim 1, wherein the first charge readout mode is horizontal thinning readout, and the first vertical transfer unit is a part of the plurality of vertical transfer units. The plurality of photoelectric conversion units include a plurality of systems that can be driven independently,
3. The method according to claim 2, wherein, in the first read mode, the plurality of systems are driven at a predetermined cycle.   2. The method according to claim 1, wherein the first readout mode is vertical thinning readout, and a part of the plurality of photoelectric conversion units is driven in the first readout mode. . The plurality of readout modes include a vertical pixel addition readout mode,
2. The method according to claim 1, further comprising a step of sending the vertical transfer unit in a plurality of stages when reading from the vertical transfer unit to the horizontal transfer unit in the vertical pixel addition reading mode. A plurality of photoelectric conversion units for converting and storing the captured image into electric charge;
A plurality of vertical transfer units for transferring the charges in the vertical direction;
An imaging apparatus having a plurality of horizontal transfer units that transfer the charges in the horizontal direction and a plurality of readout modes,
The vertical transfer unit includes a plurality of systems that can be driven independently for different readout modes.   The apparatus according to claim 6, wherein the plurality of vertical transfer units repeatedly arrange the system.   The apparatus according to claim 6, wherein the photoelectric conversion unit includes a plurality of systems that can be driven independently.