JP6157291B2 - IMAGING DEVICE AND ITS CONTROL METHOD, IMAGING SYSTEM, PROGRAM, AND STORAGE MEDIUM - Google Patents

Description

  The present invention relates to an imaging apparatus, and more particularly, to an imaging apparatus that corrects image data using correction data generated based on data acquired from an imaging element during moving image shooting.

  In general, in an imaging apparatus such as a digital camera or a digital video camera, correction data for correcting the output of an image sensor is stored in advance, and image data is corrected using the correction data to obtain a good image. . However, for example, when the temperature of the image sensor rises and the characteristics of the image sensor change as the environmental temperature rises, there is a problem that good correction cannot be performed with the correction data held in advance.

  In order to solve the above problems, Patent Document 1 discloses an imaging apparatus that regenerates correction data when conditions such as temperature change during imaging.

JP 2006-121358 A

  However, the imaging device described in Patent Document 1 has the following problems.

  For example, when acquiring image data continuously like a moving image with an image sensor that outputs multiple types of data, such as focus detection pixel data and imaging pixel data, when the shooting conditions at the focus detection pixel are changed Needs to interrupt the acquisition of image data. For this reason, there is a problem that the image is interrupted when the correction data is regenerated.

  The present invention provides an imaging apparatus capable of regenerating correction data without interrupting acquisition of image data, a control method therefor, an imaging system, a program, and a storage medium.

  An imaging apparatus according to an aspect of the present invention includes an imaging element having a unit pixel including a first photoelectric conversion unit and a second photoelectric conversion unit, and the first photoelectric conversion unit or the second photoelectric conversion. A first correction signal for correcting a focus detection signal is read from a focus detection pixel composed of a unit, and the first photoelectric conversion unit is captured from an imaging pixel composed of the first photoelectric conversion unit and the second photoelectric conversion unit. And a first read mode for reading a second correction signal for correcting an image signal obtained by adding the signals of the second photoelectric conversion unit, the focus detection signal is read from the focus detection pixel, and the image pickup pixel is read. Switching control is performed between a second reading mode for reading the image signal and a third reading mode for reading the first correction signal from the focus detection pixel and reading the image signal from the imaging pixel. It comprises a control means, wherein the third read mode, characterized in that it is set when the read condition of the focus detection pixels are changed.

  According to the present invention, correction data can be regenerated without interrupting acquisition of image data.

It is a figure which shows the structure of the imaging device which concerns on 1st, 2nd embodiment of this invention. It is a figure which shows the structure of the image pick-up element which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the image correction part which concerns on 1st, 2nd embodiment of this invention. It is a figure which shows the 1st, 2nd focus detection method of this invention. 3 is a flowchart illustrating an operation of the imaging apparatus according to the first embodiment of the present invention. It is a figure which shows operation | movement of the imaging device which concerns on 1st, 2nd embodiment of this invention. It is a figure which shows operation | movement of the image pick-up element which concerns on the 1st Embodiment of this invention. It is a figure which shows operation | movement of the image pick-up element which concerns on the 1st Embodiment of this invention. It is a figure which shows operation | movement of the image pick-up element which concerns on the 1st Embodiment of this invention. It is a figure which shows operation | movement of the image pick-up element which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the image pick-up element which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the imaging device which concerns on the 2nd Embodiment of this invention. It is a figure which shows operation | movement of the image pick-up element which concerns on the 2nd Embodiment of this invention. It is a figure which shows operation | movement of the image pick-up element which concerns on the 2nd Embodiment of this invention. It is a figure which shows operation | movement of the image pick-up element which concerns on the 2nd Embodiment of this invention. It is a figure which shows operation | movement of the image pick-up element which concerns on the 2nd Embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing a configuration of an imaging apparatus according to the first embodiment of the present invention. Although FIG. 1 shows an imaging apparatus in which an imaging apparatus body (camera body) and an imaging lens (imaging optical system) are integrated, the present invention is not limited to this, and the imaging lens captures an image. The present invention can also be applied to an imaging system that is replaceably attached to the apparatus main body.

  Referring to FIG. 1, the imaging apparatus of the present invention includes an imaging element 100 and has a function of capturing a moving image or a still image. The image sensor 100 converts an optical image formed by an imaging optical system disposed on the subject side into an electrical signal (an analog signal, that is, an image signal). The analog signal output from the image sensor 100 is adjusted in gain by an analog front end (AFE) 102 and converted into a digital signal (image data) according to a predetermined quantization bit. Note that the drive timing of the image sensor 100 and the AFE 102 is controlled by a timing generator (TG) 101. Here, the analog signal output from the image sensor 100 is converted into a digital signal by the AFE 102, but this is not restrictive. The digital signal may be output from the image sensor 100. Here, the TG 101 outside the image sensor 100 controls the drive timing with respect to the image sensor 100, but the TG inside the image sensor 100 may control the drive timing.

  A RAM 107 is a memory (image memory) for storing image data output from the AFE 102 and image data processed by an image processing unit 108 (to be described later), and the RAM 107 is also used as a work memory by the CPU 103 (to be described later). . Here, the RAM 107 is used as the image memory and the work memory, but other memories may be used as long as the access speed is at a level that does not cause a problem.

  The ROM 105 stores a program that operates on the CPU 103. In the example shown in the figure, a flash ROM is used as the ROM 105, but a memory other than the flash ROM may be used as long as the memory does not have a problem with the access speed.

  The CPU 103 has a function as a control unit that comprehensively controls the imaging apparatus. The image processing unit 108 performs processing such as correction and compression of image data obtained as a result of shooting. The image processing unit 108 includes an image correction unit 300 described later.

  The recording unit 109 is, for example, a nonvolatile memory or a hard disk. For example, still image data and moving image data are recorded in the recording unit 109.

  In FIG. 1, the recording unit 109 is described as being included in the imaging apparatus, but the recording unit 109 may be a recording medium such as a non-volatile memory or a hard disk that can be attached and detached via a connector.

  The operation unit 104 is used when setting shooting commands, imaging conditions, and the like to the CPU 103. The display unit 106 displays a still image, a moving image, a menu, and the like obtained as a result of shooting under the control of the CPU 103.

  Reference numeral 110 denotes an AF calculation unit, which performs focus detection by processing described later based on image data output from the AFE 102.

  Reference numeral 119 denotes a first lens group disposed at the tip of the imaging optical system (imaging optical system), which is held so as to be able to advance and retract in the optical axis direction. A diaphragm 118 adjusts the light amount at the time of photographing by adjusting the aperture diameter. Reference numeral 117 denotes a second lens group. In this embodiment, the diaphragm 118 and the second lens group 117 are integrally moved forward and backward in the optical axis direction, and have a zooming function (zoom function) in conjunction with the forward and backward movement of the first lens group 119.

  Reference numeral 116 denotes a third lens group (focus lens) that performs focus adjustment by advancing and retreating in the optical axis direction.

  Reference numeral 111 denotes a focal plane shutter that adjusts the exposure time during still image shooting. In this embodiment, the exposure time of the image sensor 100 is adjusted by a focal plane shutter, but this is not a limitation. The imaging device 100 may have an electronic shutter function and adjust the exposure time with a control pulse.

  Reference numeral 112 denotes a focus drive circuit that controls the focus actuator 114 based on the focus detection result of the AF calculation unit 110 and performs focus adjustment by driving the third lens group 116 back and forth in the optical axis direction. Reference numeral 113 denotes an aperture drive circuit that controls the aperture of the aperture 118 by drivingly controlling the aperture actuator 115.

  Next, the configuration of the image sensor 100 shown in FIG. 1 will be described in detail with reference to FIGS. 2 (a) and 2 (b).

  FIG. 2A is a circuit diagram showing the unit pixel 200 of the image sensor 100 according to the present invention. As shown in FIG. 2A, the unit pixel 200 includes a first photodiode (photoelectric conversion unit) 201a, a second photodiode (photoelectric conversion unit) 201b, a first transfer switch 202a, and a second transfer. A switch 202b is included. Further, the unit pixel 200 includes a floating diffusion 203, an amplification unit 204, a reset switch 205, and a selection switch 206.

  As described above, the image sensor 100 according to the present invention includes a unit pixel including the first photoelectric conversion unit and the second photoelectric conversion unit. However, the number of photoelectric conversion units provided in each unit pixel is not limited to two shown in FIG. 2 and may be two or more (for example, four). In the present invention, the first photoelectric conversion unit or the second photoelectric conversion unit functions as a focus detection pixel, as will be described later. In addition, the first photoelectric conversion unit and the second photoelectric conversion unit function as imaging pixels, as will be described later.

  The photodiodes 201a and 201b function as a photoelectric conversion unit that receives light that has passed through the same microlens and generates signal charges corresponding to the amount of light received.

  The transfer switches 202a and 202b transfer charges generated in the photodiodes 201a and 201b to the common floating diffusion region 203, respectively. The transfer switches 202a and 202b are controlled by transfer pulse signals TX_A and TX_B, respectively.

  The floating diffusion 203 functions as a charge-voltage converter that temporarily holds the charges transferred from the photodiodes 201a and 201b and converts the held charges into a voltage signal.

  The amplifying unit 204 is a source follower MOS transistor, amplifies a voltage signal based on the charge held in the floating diffusion 203, and outputs it as a pixel signal.

  The reset switch 205 is controlled by a reset pulse signal RES, and resets the potential of the floating diffusion 203 to the reference potential VDD.

  The selection switch 206 is controlled by the vertical selection pulse signal SEL, and outputs the pixel signal amplified by the amplification unit 204 to the vertical output line 207.

  A common power source 208 supplies the reference potential VDD.

  FIG. 2B is a diagram illustrating a readout circuit of the image sensor 100 according to the present invention.

  Reference numeral 234 denotes a pixel region, in which a plurality of unit pixels 200 are arranged in a matrix. In the present embodiment, in order to simplify the description, n + 1 pixels are arranged in the horizontal direction and 4 pixels are arranged in the vertical direction, but the actual number of pixels in the vertical direction is even larger. Further, the unit pixel 200 is provided with any one of a plurality of color filters (in this embodiment, three colors of red, green, and blue). In FIG. 2B, a red color filter is provided, a pixel that captures red light is provided as an R pixel, a green color filter is provided, a pixel that captures green light is provided as a G pixel, and a blue color filter is provided. A pixel that captures the image is denoted as a B pixel. Each pixel having three color filters is arranged according to a Bayer array.

  Reference numeral 209 denotes a vertical shift register, which transmits a drive pulse through a common drive signal line 210 for each pixel in each row. For simplicity, one drive signal line 210 is shown for each row, but actually, a plurality of drive signal lines are connected to each row.

  The unit pixels 200 in the same column are connected to a common vertical output line 207, and a signal from each pixel is input to the common readout circuit 212 via the vertical output line 207. The signals processed by the reading circuit 212 are sequentially output to the output amplifier 233 by the horizontal shift register 232. Reference numeral 211 denotes a current source load connected to the vertical output line 207.

  Next, a specific circuit configuration of the reading circuit 212 will be described.

  213 is a clamp capacitor C0, 214 is a feedback capacitor Cf, 215 is an operational amplifier, 216 is a reference voltage source for supplying a reference voltage Vref, and 229 is a switch for short-circuiting both ends of the feedback capacitor Cf. The switch 229 is controlled by a RES_C signal. Reference numerals 217 and 219 denote capacitors for holding a signal voltage (S signal), and reference numerals 218 and 220 denote capacitors for holding noise (N signal). Reference numeral 217 denotes a capacity S signal holding capacity AB, 219 denotes a capacity S signal holding capacity A, 218 and 220 as a capacity N signal holding capacity.

  Reference numerals 221, 222, 223, and 224 denote switches that control writing to the capacitor. The switch 221 is controlled by the TS_AB signal, and the switch 223 is controlled by the TS_A signal. The switches 222 and 224 are controlled by a TN signal. Reference numerals 225, 226, 227, and 228 are switches for receiving a signal from the horizontal shift register 232 and outputting a signal to the output amplifier 233. The switches 225 and 226 are controlled by the HAB (m) signal of the horizontal shift register 232, and the switches 227 and 228 are controlled by the HA (m) signal. Here, m represents the column number of the readout circuit to which the control signal line is connected. The signals written in the capacitor S signal holding capacitor AB217 and the capacitor S signal holding capacitor A219 are output via the common output line 230, and the signals written in the capacitor N signal holding capacitors 218 and 220 are output via the common output line 231. It is output to the amplifier 233.

  Next, image data output from the image sensor 100 will be described.

  FIG. 4A and FIG. 4B show the relationship between the focus state and the phase difference in the image sensor 100.

  Reference numeral 404 denotes a cross section of the pixel array. Reference numeral 400 denotes a microlens provided for each unit pixel. As described above, the photodiodes 201a and 201b are configured to receive light that has passed through the same microlens. Since another image having a phase difference is incident on the photodiode 201a and the photodiode 201b according to the configuration described later, the photodiode 201a is an A image pixel and the photodiode 201b is a B image pixel. In the drawing, the A image pixel is indicated by A, and the B image pixel is indicated by B. In this embodiment, two photodiodes are arranged for one microlens, but this is not restrictive. The present invention can be applied to a configuration in which a plurality of photodiodes are arranged vertically or horizontally with respect to one microlens.

  Reference numeral 401 denotes a photographing lens that is considered as one lens by combining the first lens group 119, the second lens group 117, and the third lens group 116 shown in FIG.

  The light emitted from the subject 402 passes through each region of the photographing lens 401 with the optical axis 403 as the center, and forms an image on the image sensor. Here, the exit pupil and the center of the taking lens are the same.

  According to such a configuration, the case where the imaging optical system is viewed from the A image pixel and the case where the imaging optical system is viewed from the B image pixel is equivalent to the symmetrical division of the pupil of the imaging optical system. In other words, the light beam from the imaging optical system is so-called pupil-divided into two light beams, and the respective divided light beams (first light beam and second light beam) are incident on the A image pixel and the B image pixel. In this way, each of the A image pixel and the B image pixel receives light (photoelectric conversion) that has passed through different pupil regions of the exit pupil of the imaging optical system, and as described later, the focus detection pixel. Can function as. In addition, the A image pixel and the B image pixel can function as an imaging pixel as described later because the image formed by the light flux from the imaging optical system can be photoelectrically converted by adding the signals of each other. .

  The light beam from a specific point on the subject 402 passes through the divided pupil corresponding to the A image pixel A and enters the A image pixel A and the divided pupil corresponding to the B image pixel B. It is divided into a light beam ΦLb incident on the B image pixel B. Since these two light beams are incident from the same point on the subject 402, when the imaging optical system is in focus, the imaging element passes through the same microlens as shown in FIG. Reach the top point. Accordingly, the image signals obtained from the A image pixel A and the B image pixel B are identical to each other.

  However, as shown in FIG. 4B, in a state where the focus is shifted by Y in the optical axis direction, the arrival positions of the two light beams ΦLa and ΦLb are equal to the change in the incident angle of the light beams ΦLa and ΦLb to the microlens. Deviation from each other. Therefore, there is a phase difference between the image signals obtained from the A image pixel A and the B image pixel B, respectively.

  Each of the A image pixel A and the B image pixel B (that is, the focus detection pixel) is obtained by photoelectrically converting two subject images (A image and B image) having a phase difference, and obtained by the photoelectric conversion. The signal is output to the outside of the image sensor 100 and used for an AF operation described later.

  Reading of the image sensor 100 is performed by first reading out only the signal of the A image pixel A (hereinafter also referred to as a focus detection signal) by the operation described later, and the signals of the A image pixel A and the B image pixel B. A second reading for reading the added signal (hereinafter also referred to as an image signal) is performed. Thereafter, the A signal obtained by converting the signal of the A image pixel A into a digital signal by the AFE 102 and the signal obtained by adding the signals of the A image pixel A and the B image pixel B converted to a digital signal by the AFE 102 Is an AB image.

  The A image and the AB image are input to the AF calculation unit 110 after being applied with correction described later by the image correction unit 300 included in the image processing unit 108. The AF calculation unit 110 subtracts the A image from the AB image, and generates a B image that is image data photoelectrically converted by only the B image pixel B.

  Next, a focus detection operation performed in the AF calculation unit 110 will be described. FIG. 4C shows an A image and a B image in the case of FIG. The horizontal axis represents the pixel position, and the vertical axis represents the output. When the image is in focus, the A and B images match. FIG. 4D is an A image and a B image in the case of FIG. At this time, the A image and the B image have a phase difference depending on the state described above, and the pixel position is shifted by the shift amount X. The AF calculation unit 110 calculates the shift amount X for each frame to calculate the focus shift amount, that is, the Y value in FIG. 4B. The AF calculation unit 110 transfers the calculated Y value to the focus drive circuit 112.

  The focus drive circuit 112 calculates the amount of movement of the third lens group 116 based on the Y value acquired from the AF calculation unit 110 and outputs a drive command to the focus actuator 114. The third lens group 116 is moved to a focus position by the focus actuator 114 and is brought into focus by the image sensor 100.

  FIG. 3 is a block diagram showing an example of the configuration of the image correction unit 300 included in the image processing unit 108 shown in FIG.

  The image position information generation circuit 304 counts the number of input data, and based on the image size (number of columns / number of rows) set by the CPU 103, an image position indicating which position of the image the input data is. Calculate information. At the same time, based on the A image area set by the CPU 103 and the image position information, A image area information indicating that the input data is an A image is output. Further, based on the AB image area set by the CPU 103 and the image position information, AB image area information indicating that the input data is an AB image is output.

  The correction data generation circuit 301 refers to the image position information and the calculation area set by the CPU 103, and functions as generation means for generating correction data for each column using the image data in the calculation area. In this embodiment, the correction data is obtained by calculating the average value of image data for a predetermined number of pixels for each column. Further, data in the calculation process until the image data for a predetermined number of pixels is averaged is stored in the memory 305 for each column and used for generating correction data. The finally calculated correction data for each column of the A image or AB image is stored in the memory (storage means) 305.

  Based on the A image area information and the AB image area information output from the image position information generation circuit 304, the memory control unit 303 calculates an address for storing correction data for each column of each of the A image and the AB image. An address is output to 305. When generating correction data, a write signal for storing calculation process data and generated correction data in the memory 305 is output.

  Correction data stored at an input address is output from the memory 305 and input to a correction circuit (correction means) 302. The correction circuit 302 corrects input data (for example, image data of A image corresponding to the focus detection signal and image data of AB image corresponding to the image signal) using the correction data, and outputs the data. In the correction in the present embodiment, the correction data for each column is subtracted from the image data to correct the offset for each column.

  In this embodiment, the average value for each column of image data is calculated, and the image data is corrected by subtracting it from the corresponding column of image data. However, this is not restrictive.

Next, the operation of the image pickup apparatus in the present embodiment will be described using the flowchart shown in FIG.
When a moving image shooting switch included in the operation unit 104 is pressed, shooting of a moving image is started. In step S <b> 100, the CPU 103 sets a horizontal position for reading the A image with respect to the image sensor 100. The A image readout position is set to a region including a preset focus detection region. Here, the reading position of the A image, that is, the first focus detection area is assumed to be the ith to i-th columns.

  Next, in step S101, the CPU 103 sets the reading mode of the A image and the AB image to the correction data generation signal output mode (first reading mode) for the TG 101. With this setting, correction data generation signals are output for the A and AB images at the time of reading, and are input to the image correction unit 300 as correction data generation data converted into digital signals by the AFE 102.

  In step S <b> 102, the CPU 103 performs setting for generating correction data for the A image and the AB image in the image correction unit 300. The image correction unit 300 generates each correction data from the correction data generation data of the A image and the AB image according to the setting here.

  Thereafter, in step S103, correction data generation signals for the A and AB images are read. Hereinafter, reading of the correction data generation signals for the A and AB images will be described with reference to FIG. 7A. FIG. 7A is a diagram illustrating the readout timing of one row of the correction data generation signals for the A and AB images. At time a1, TX_A and TX_B which are control signals of the transfer switches 202a and 202b are set to H. When TX_A and TX_B become H, the charges accumulated in the photodiodes 201a and 201b are transferred to the gate of the amplification unit 204 via the first transfer switch 202a and the second transfer switch 202b, and the photodiodes 201a and 201b are transferred. Is reset. At time a2, TX_A and TX_B are set to L, and photocharges are started to be accumulated in the photodiodes 201a and 201b.

  After accumulating the necessary time, SEL, which is the control signal of the selection switch 206, is set to H at time a3, and the amplifying unit 204 is turned on. At time a4, RES, which is a control signal of the reset switch 205, is set to L to release the reset of the floating diffusion region 203. At this time, the potential of the floating diffusion region 203 is read as a reset signal level to the vertical output line 207 via the amplifier 204 and is input to the reading circuit 212.

  Thereafter, when RES_C is set to L at time a5, a difference between the reset signal level read to the vertical output line 207 and the reference voltage Vref is output from the operational amplifier 215. At time a6, TN is set to H, the switches 222 and 224 are turned on, and at time a7, TN is set to L and the switches 222 and 224 are turned off, whereby the output of the operational amplifier 215 is written into the capacitor N signal holding capacitors 218 and 220.

  Next, at time a8, in order to write the output of the operational amplifier 215 at this time to the capacitor S signal holding capacitor A219, TS_A is set to H, the switch 223 is turned on, TS_A is set to L, and the switch 223 is turned off at time a9. Exit.

  Subsequently, at time a10, in order to write the output of the operational amplifier 215 at this time to the capacitor S signal holding capacitor AB217, TS_AB is set to H, the switch 221 is turned on, TS_AB is set to L at time a11, the switch 221 is turned off, and writing is performed. finish.

  With this operation, the noise component of the readout circuit 212 can be obtained by taking the voltage difference between the capacitor S signal holding capacitor AB217 and the capacitor N signal holding capacitor 218. That is, the reset potential readout signal of the pixel is an AB image correction data generation signal (second correction signal). Further, the noise component of the reading circuit 212 can be obtained by taking the voltage difference between the capacitor S signal holding capacitor A219 and the capacitor N signal holding capacitor 220. In other words, the readout signal of the reset potential of the pixel becomes the A image correction data generation signal (first correction signal).

  Next, at time a12, RES is set to H, and the floating diffusion region 203 is reset.

  Thereafter, between times a13 to a14, the drive pulse HA (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 227 and 228 are changed from OFF to ON to OFF. The signals held in the capacitor S signal holding capacitor A 219 and the capacitor N signal holding capacitor 220 in the column where the switches 227 and 228 are changed from OFF → ON → OFF are read to the common output lines 230 and 231, respectively, and output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes a correction data generation signal for the A image.

  Here, according to the setting in step S100, the pixel column in which the drive pulse HA (m) of the horizontal shift register 232 changes from L → H → L is the ith column as shown in the drive timing of FIG. Otherwise, it always remains at the L level. Therefore, the pixel column from which the correction data generation signal for the A image is read is the h-th column.

  Next, during time a14 to a15, the drive pulse HAB (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 225 and 226 are changed from OFF to ON to OFF. . The signals held in the capacitor S signal holding capacitor AB 217 and the capacitor N signal holding capacitor 218 in the column in which the switches 225 and 226 are changed from OFF → ON → OFF are read to the common output lines 230 and 231, respectively, and output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes an AB image correction data generation signal. Here, the drive pulse HAB (m) sequentially changes from L to H to L in all the 0th to nth columns as shown in the drive timing of FIG. 7A. Therefore, AB image correction data generation signals are read from all columns.

  The above operation is sequentially performed for each row, and the reading of the correction data generation signals for the A and AB images is completed. The output signal is converted into a digital signal by the AFE 102.

  In this way, correction data generation data for the A and AB images can be obtained as described at the time of startup in FIG. This data is input to the image correction unit 300. In the image correction unit 300, the input data is averaged for each column, and the first correction data for each of the hth to ith columns of the A image and the columns of the 0th to nth columns of the AB image are performed by the above-described processing. Second correction data is generated for each and stored as described at the time of activation in FIG.

  In step S104, the CPU 103 determines whether the generation of correction data for the A image and the AB image has been completed. In this embodiment, since the generation of correction data is completed with the correction data generation data for one frame, the process proceeds to step S105. If correction data generation data for a plurality of frames is required, the process returns to step S103, and reading is repeated until the generation of correction data is completed.

  In step S105, the CPU 103 sets the read mode of the A image and the AB image to the image signal output mode (second read mode) for the TG 101. With this setting, during readout, the A and AB images are output as light component signals photoelectrically converted by the photodiodes 201a and 201b and input to the image correction unit 300 as image data converted into digital signals by the AFE 102. The

  In step S <b> 106, the CPU 103 performs setting for correcting the A image and the AB image in the image correction unit 300. The image correction unit 300 corrects the image data of the A image and the AB image according to the setting here.

  In step S107, the image signals of the A image and the AB image are read out. Hereinafter, reading of image signals of the A image and the AB image will be described with reference to FIG. 7B.

  FIG. 7B is a diagram illustrating the readout timing of one row of the image signals of the A image and the AB image. At time b1, TX_A and TX_B which are control signals of the transfer switches 202a and 202b are set to H. When TX_A and TX_B become H, the charges accumulated in the photodiodes 201a and 201b are transferred to the gate of the amplification unit 204 via the first transfer switch 202a and the second transfer switch 202b, and the photodiodes 201a and 201b are transferred. Is reset. At time b2, TX_A and TX_B are set to L, and photocharges are started to be accumulated in the photodiodes 201a and 201b.

  After accumulating the necessary time, SEL, which is a control signal of the selection switch 206, is set to H at time b3, and the amplifying unit 204 is turned on. The reset of the floating diffusion region 203 is canceled by setting RES, which is a control signal of the reset switch 205, to L at time b4. At this time, the potential of the floating diffusion region 203 is read as a reset signal level to the vertical output line 207 via the amplifier 204 and is input to the reading circuit 212.

  Thereafter, when RES_C is set to L at time b5, the difference between the reset signal level read to the vertical output line 207 and the reference voltage Vref is output from the operational amplifier 215. At time b6, TN is set to H, the switches 222 and 224 are turned on, and at time b7, TN is set to L and the switches 222 and 224 are turned off, whereby the output of the operational amplifier 215 is written into the capacitor N signal holding capacitors 218 and 220.

  Next, TX_A is set to H at time b8, the photocharge of the photodiode 201a is transferred to the floating diffusion region 203, and TX_A is set to L at time b9. By this operation, the charge accumulated in the photodiode 201 a is read out to the floating diffusion region 203. Then, an output corresponding to the change is supplied to the readout circuit 212 via the amplification unit 204 and the vertical output line 207.

  In the readout circuit 212, an inversion gain is applied to the voltage change at the ratio of the clamp capacitor C0 of 213 and the feedback capacitor Cf of 214, and output.

  To write this voltage to the capacitor S signal holding capacitor A219, TS_A is switched from L to H at time b10, switch 223 is turned on, TS_A is switched from H to L at time b11, switch 223 is turned off, and writing is completed. To do.

  Next, TX_A is set to H again at time b12, and TX_B is also set to H at the same time. With this operation, the photocharges of both the photodiodes 201a and 201b can be simultaneously read out to the floating diffusion region 203. The read charge is supplied to the read circuit 212 in the same manner as when only the photodiode 201 a is read, and is output via the operational amplifier 215.

  In order to write this voltage to the capacitor S signal holding capacitor AB217, TS_AB is switched from L to H at time b14, switch 221 is turned on, TS_AB is switched from H to L at time b15, switch 221 is turned off, and writing is completed. To do.

  With this operation, by taking the voltage difference between the capacitor S signal holding capacitor AB217 and the capacitor N signal holding capacitor 218, an image signal of AB image that is the sum of the output signals from the photodiodes 201a and 201b is obtained. This AB image signal becomes a captured image. Further, by taking the differential voltage between the capacitor S signal holding capacitor A219 and the capacitor N signal holding capacitor 220, an image signal (focus detection signal) of A image which is an output signal from the photodiode 201a is obtained.

  Next, at time b16, RES is set to H, and the floating diffusion region 203 is reset.

  Thereafter, during time b17 to b18, the drive pulse HA (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 227 and 228 are changed from OFF to ON to OFF. The signals held in the capacitor S signal holding capacitor A 219 and the capacitor N signal holding capacitor 220 in the column where the switches 227 and 228 are changed from OFF → ON → OFF are read to the common output lines 230 and 231, respectively, and output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes an image signal of the A image.

  Here, according to the setting in step S100, the pixel column in which the drive pulse HA (m) is L → H → L is the h-th column as shown in the drive timing of FIG. Remains. Therefore, the pixel column from which the A image signal is read is the h-th to i-th columns.

  Next, during time b18 to b19, the drive pulse HAB (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 225 and 226 are changed from OFF to ON to OFF. . The signals held in the capacitor S signal holding capacitor AB 217 and the capacitor N signal holding capacitor 218 in the column in which the switches 225 and 226 are changed from OFF → ON → OFF are read to the common output lines 230 and 231, respectively, and output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes an image signal of the AB image. Here, the drive pulse HAB (m) sequentially changes from L to H to L in all the 0th to nth columns as shown in the drive timing of FIG. 7B. Therefore, the image signal of the AB image is read from all columns.

  The above operation is sequentially performed for each row, and reading of the image signals of the A image and the AB image is completed. The output signal is converted into a digital signal by the AFE 102.

  In this way, image data of the A image and the AB image is obtained as described in the first frame of FIG. This data is input to the image correction unit 300. In the image correction unit 300, the correction data for each of the columns h to i of the A image and the columns 0 to n of the AB image stored in the memory 305 is output from the memory 305 in accordance with the column correspondence of the input data. The offset correction for each column is performed.

  The corrected A image and AB image are input to the AF calculation unit 110, and an AF operation is performed by the processing described above. The image data of the AB image is stored in the RAM 107. The CPU 103 transfers the image data of the AB image stored in the RAM 107 to the image processing unit 108, and the image processing unit 108 compresses the image data. Thereafter, it is recorded in the recording unit 109 as moving image data.

  In step S108, the CPU 103 determines whether the moving image shooting switch of the operation unit 104 is pressed again and shooting is finished. If the photographing is finished, the photographing operation is finished as it is. If not, the process proceeds to step S109.

  In step S109, the CPU 103 determines whether the position of the focus detection area (that is, the read position of the focus detection pixel) has been changed. If the position of the focus detection area has not been changed, the process returns to step S107, and the operations from step S107 to step S108 described above are repeated (FIG. 6A).

  If the position of the focus detection area has been changed (or if the readout condition of the focus detection pixel of the image sensor has been changed), the process proceeds to step S110. In step S110, the CPU 103 sets a horizontal position for reading the A image to the image sensor 100 in accordance with the position of the focus detection area after the change. Here, the reading position of the A image, that is, the second focus detection area is assumed to be the jth to kth columns. Here, a focus detection area before the focus detection area is changed is a first focus detection area, and a focus detection area after the focus detection area is changed is a second focus detection area.

  In step S111, the CPU 103 sets the A image readout mode to the correction data generation signal output mode and the AB image readout mode to the image signal output mode (third readout mode) for the TG 101. With this setting, at the time of reading, a correction data generation signal is output for the A image, and an image signal is output for the AB image.

  In step S <b> 112, the CPU 103 performs setting for generating correction data for the A image and setting for correcting the AB image in the image correction unit 300. The image correction unit 300 generates A image correction data from the A image correction data generation data according to the setting here, and corrects the AB image data.

  Thereafter, in step S113, the correction signal generation signal for the A image and the image signal for the AB image are read out. The readout of the A image correction data generation signal and the AB image signal will be described below with reference to FIG. 7C.

  FIG. 7C is a diagram illustrating the readout timing of one row of the A image correction data generation signal and the AB image signal. At time c1, TX_A and TX_B which are control signals of the transfer switches 202a and 202b are set to H. When TX_A and TX_B become H, the charges accumulated in the photodiodes 201a and 201b are transferred to the gate of the amplification unit 204 via the first transfer switch 202a and the second transfer switch 202b, and the photodiodes 201a and 201b are transferred. Is reset. At time c2, TX_A and TX_B are set to L, and photocharges are started to be accumulated in the photodiodes 201a and 201b.

  After accumulating the necessary time, SEL, which is a control signal of the selection switch 206, is set to H at time c3, and the amplifying unit 204 is turned on. The reset of the floating diffusion region 203 is canceled by setting RES, which is a control signal of the reset switch 205, to L at time c4. At this time, the potential of the floating diffusion region 203 is read as a reset signal level to the vertical output line 207 via the amplifier 204 and is input to the reading circuit 212.

  Thereafter, when RES_C is set to L at time c5, the difference between the reset signal level read to the vertical output line 207 and the reference voltage Vref is output from the operational amplifier 215. At time c6, TN is set to H, the switches 222 and 224 are turned ON, and at time c7, TN is set to L and the switches 222 and 224 are turned OFF, whereby the output of the operational amplifier 215 is written into the capacitor N signal holding capacitors 218 and 220.

  Next, at time c8, in order to write the output of the operational amplifier 215 at this time to the capacitor S signal holding capacitor A219, TS_A is set to H, the switch 223 is turned ON, TS_A is set to L, and the switch 223 is turned OFF at time c9. Exit.

  Next, TX_A is set to H again at time c10, and TX_B is also set to H at the same time. With this operation, the photocharges of both the photodiodes 201a and 201b can be simultaneously read out to the floating diffusion region 203. The read charge is supplied to the read circuit 212 and output via the operational amplifier 215.

  In order to write this voltage to the capacitor S signal holding capacitor AB217, TS_AB is switched from L to H at time c12, switch 221 is turned on, TS_AB is switched from H to L at time c13, switch 221 is turned off, and writing is completed. To do.

  With this operation, by taking the voltage difference between the capacitor S signal holding capacitor AB217 and the capacitor N signal holding capacitor 218, an image signal of AB image that is the sum of the output signals from the photodiodes 201a and 201b is obtained. This AB image signal becomes a captured image. Further, the noise component of the reading circuit 212 can be obtained by taking the voltage difference between the capacitor S signal holding capacitor A219 and the capacitor N signal holding capacitor 220. This signal becomes a correction data generation signal (first correction signal) for the A image.

  Next, at time c14, RES is set to H, and the floating diffusion region 203 is reset.

  Thereafter, during time c15 to c16, the drive pulse HA (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 227 and 228 are turned from OFF to ON to OFF. The signals held in the capacitor S signal holding capacitor A 219 and the capacitor N signal holding capacitor 220 in the column where the switches 227 and 228 are changed from OFF → ON → OFF are read to the common output lines 230 and 231, respectively, and output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes a correction data generation signal for the A image.

  Here, according to the setting in step S110, the pixel column in which the drive pulse HA (m) changes from L → H → L is the jth to kth columns as shown in the drive timing of FIG. Remains. Accordingly, the pixel column from which the A image signal is read out is the jth to kth columns.

  Next, during time c16 to c17, the drive pulse HAB (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 225 and 226 are changed from OFF to ON to OFF. . The signals held in the capacitor S signal holding capacitor AB 217 and the capacitor N signal holding capacitor 218 in the column in which the switches 225 and 226 are changed from OFF → ON → OFF are read to the common output lines 230 and 231, respectively, and output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes an image signal of the AB image. Here, the drive pulse HAB (m) sequentially changes from L to H to L in all columns 0 to n as shown in the drive timing of FIG. 7C. Therefore, the image signal of the AB image is read from all columns.

  The above operation is sequentially performed for each row, and the reading of the A image correction data generation signal and the AB image signal is completed. The output signal is converted into a digital signal by the AFE 102.

  In this way, the correction data generation data for the A image and the image data for the AB image are obtained as described in the p-th frame of FIG. 6B. This data is input to the image correction unit 300. The image correction unit 300 averages the input data for each column, generates correction data for each column of the jth to kth columns of the A image by the above-described processing, and describes it in the p frame in FIG. 6B. Store like this. Here, the memory 305 updates the correction data before the focus detection area is changed to the correction data after the focus detection area is changed. In other words, the first correction data corresponding to the first focus detection area is stored before the focus detection area is changed, and the second correction data corresponding to the second focus detection area is stored after the focus detection area is changed. Correction data is stored. Accordingly, the memory 305 only needs to hold one of the first correction data and the second correction data, and is not necessary to hold correction data corresponding to all focus detection areas. Memory capacity can be reduced. Thereby, an imaging device can be reduced in size. Further, correction data for each of the 0th to n-th columns of the AB image is output from the memory 305 in accordance with the column correspondence of the input data, and offset correction is performed for each column.

  The corrected image data of the AB image is stored in the RAM 107. The CPU 103 transfers the image data of the AB image stored in the RAM 107 to the image processing unit 108, and the image processing unit 108 compresses the image data. Thereafter, it is recorded in the recording unit 109 as moving image data.

  In step S114, the CPU 103 determines whether the generation of the correction data for the A image has been completed. In this embodiment, since the generation of correction data is completed with the correction data generation data for one frame, the process proceeds to step S105. If correction data generation data for a plurality of frames is required, the process returns to step S113 to repeat reading until the generation of correction data is completed.

  In subsequent step S105, the CPU 103 sets the readout mode of the A image and the AB image to the image signal output mode (second readout mode) for the TG 101. With this setting, during readout, the A and AB images are output as light component signals photoelectrically converted by the photodiodes 201a and 201b and input to the image correction unit 300 as image data converted into digital signals by the AFE 102. The

  In step S <b> 106, the CPU 103 performs setting for correcting the A image and the AB image in the image correction unit 300. The image correction unit 300 corrects the image data of the A image and the AB image according to the setting here.

  In step S107, the image signals of the A image and the AB image are read out. Hereinafter, reading of image signals of the A image and the AB image will be described with reference to FIG. 7D.

  FIG. 7D is a diagram illustrating the readout timing of one row of the image signals of the A image and the AB image. The operation from time d1 to d16 is the same as the operation from time b1 to b16 shown in FIG. During times d17 to d18, the drive pulse HA (m) of the horizontal shift register 232 is sequentially changed from L → H → L for each readout circuit, and accordingly, the switches 227 and 228 are changed from OFF → ON → OFF. The signals held in the capacitor S signal holding capacitor A 219 and the capacitor N signal holding capacitor 220 in the column where the switches 227 and 228 are changed from OFF → ON → OFF are read to the common output lines 230 and 231, respectively, and output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes an image signal (focus detection signal) of the A image.

  Here, according to the setting in step S110, the pixel column in which the drive pulse HA (m) changes from L → H → L is the jth to kth columns as shown in the drive timing of FIG. Remains. Accordingly, the pixel column from which the A image signal is read out is the jth to kth columns.

  Next, during time d18 to d19, the drive pulse HAB (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 225 and 226 are changed from OFF to ON to OFF. . The signals held in the capacitor S signal holding capacitor AB 217 and the capacitor N signal holding capacitor 218 in the column in which the switches 225 and 226 are changed from OFF → ON → OFF are read to the common output lines 230 and 231, respectively, and output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes an image signal of the AB image. Here, the drive pulse HAB (m) sequentially changes from L to H to L in all the 0th to nth columns as shown in the drive timing of FIG. 7D. Therefore, the image signal of the AB image is read from all columns.

  The above operation is sequentially performed for each row, and reading of the image signals of the A image and the AB image is completed. The output signal is converted into a digital signal by the AFE 102.

  In this way, image data of A image and AB image is obtained as described in the (p + 1) th frame of FIG. 6B. This data is input to the image correction unit 300. In the image correction unit 300, the correction data for each of the jth to kth columns of the A image and the 0th to nth columns of the AB image stored in the memory 305 is output from the memory 305 according to the column correspondence of the input data. The offset correction for each column is performed.

  The corrected A image and AB image are input to the AF calculation unit 110, and an AF operation is performed by the processing described above. The image data of the AB image is stored in the RAM 107. The CPU 103 transfers the image data of the AB image stored in the RAM 107 to the image processing unit 108, and the image processing unit 108 compresses the image data. Thereafter, it is recorded in the recording unit 109 as moving image data.

  Thereafter, the operations after step S108 are performed in the same manner as described above, and the AF operation and moving image recording are continued.

  As described above, even when the reading position of data (A image) used for focus detection in moving image shooting is changed, the offset correction for each column of the A image is applied by regenerating the correction data of the A image. Can do. Further, when the A image correction data is regenerated, the A image can output correction data generation data, and the AB image can output image data, so that the frame rate is maintained without missing the frame data of the moving image. The focus detection position can be changed. Therefore, according to the present invention, the correction data of the focus detection pixel at the new position can be regenerated without interrupting the acquisition of the image data.

  In the present embodiment, the correction data generation signal can be output using the same pixel as the pixel that outputs the image signal, so that it is not necessary to provide a special pixel in the image sensor.

  In this embodiment, the correction data is regenerated when the focus detection position is changed. However, the present invention is not limited to this. For example, when the shooting conditions (shooting sensitivity, etc.), pixel addition cycle (addition rate), pixel skipping cycle (readout skipping rate), etc., of the A image (focus detection pixel) are changed. Can also be applied.

  In this embodiment, the correction data generation circuit 301 is configured to generate correction data, but this is not restrictive. A configuration in which correction data update data is read above the image data when the image data is read, and the correction data in the memory is updated using the correction data update data can also be applied.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  The configuration of the imaging apparatus according to the second embodiment of the present invention is the same as the configuration shown in FIG.

  In this embodiment, the configuration of the readout circuit of the image sensor 100 is different from that of the first embodiment. FIG. 8A is a diagram illustrating the readout circuit 500 of the image sensor in the present embodiment. Components having the same reference numerals as those in FIG. 2B have the same functions as those in FIG.

  Hereinafter, a specific circuit configuration of the read circuit 500 of this embodiment will be described.

  Reference numeral 501 denotes a clamp capacitor C0, 502 a feedback capacitor Cf, 503 an operational amplifier, 504 a reference voltage source for supplying a reference voltage Vref, and 517 a switch for short-circuiting both ends of the feedback capacitor Cf. The switch 517 is controlled by a RES_C signal. Reference numerals 505, 506, 507, and 508 denote first capacitors for holding a signal voltage. 505 is a capacitor S signal holding capacitor 1AB, 507 is a capacitor S signal holding capacitor 1A, and 506 is a capacitor N signal holding capacitor 1AB, 508. Is expressed as a capacitor N signal holding capacitor 1A.

  Reference numerals 509, 510, 511, and 512 denote switches that control writing to the first capacitor. The switch 509 is controlled by the TS1_AB signal, and the switch 511 is controlled by the TS1_A signal. The switch 510 is controlled by a TN_AB signal, and the switch 512 is controlled by a TN_A signal.

  Reference numerals 526, 527, 528, and 529 denote second capacitors for holding a signal voltage. 526 is a capacitor S signal holding capacitor 2AB, 528 is a capacitor S signal holding capacitor 2A, and 527 is a capacitor N signal holding capacitor 2AB, 529. Is represented as a capacitor N signal holding capacitor 2A. Reference numerals 522, 523, 524, and 525 denote switches that control writing to the second capacitor. The switches 522 and 523 are controlled by the TS2_AB signal, and the switches 524 and 525 are controlled by the TS2_A signal. Reference numerals 518, 519, 520, and 521 denote buffers for writing to the second capacitor, and reference numerals 513, 514, 515, and 516 denote switches for receiving a signal from the horizontal shift register 232 and outputting the signal to the output amplifier 233. is there. The switches 513 and 514 are controlled by the HAB (m) signal of the horizontal shift register 232, and the switches 515 and 516 are controlled by the HA (m) signal. Here, m represents the column number of the readout circuit to which the control signal line is connected. The signals written in the capacitor S signal holding capacitor 2AB526 and the capacitor S signal holding capacitor 2A528 are output to the output amplifier 233 via the common output line 230. Signals written in the capacitor N signal holding capacitor 2AB527 and the capacitor N signal holding capacitor 2A529 are output to the output amplifier 233 via the common output line 231.

  Further, the image sensor 100 according to the present embodiment has a light shielding region (OB) in which the upper part of the photodiode is shielded as shown in FIG. 8B. In this embodiment, correction data is generated using the output data of the OB area. In the present embodiment, OB is used, but this is not restrictive. A configuration using a dummy pixel having no photodiode in the pixel is also possible.

  Next, the operation of the imaging apparatus in the present embodiment will be described using the flowchart shown in FIG.

  When a moving image shooting switch included in the operation unit 104 is pressed, shooting of a moving image is started. In step S <b> 200, the CPU 103 sets a horizontal position for reading the A image with respect to the image sensor 100. The A image readout position is set to a region including a preset focus detection region. Here, the reading position of the A image is assumed to be the ith to i-th columns.

  Next, in step S <b> 201, the CPU 103 sets the reading mode of the A image and the AB image to the correction data generation signal output mode (first reading mode) for the TG 101. With this setting, correction data generation signals are output for the A and AB images at the time of reading, and are input to the image correction unit 300 as correction data generation data converted into digital signals by the AFE 102.

  In step S <b> 202, the CPU 103 sets the image correction unit 300 to generate correction data for the A image and the AB image. The image correction unit 300 generates each correction data from the correction data generation data of the A image and the AB image according to the setting here.

  Thereafter, in step S203, signals for generating correction data for the A and AB images are read. Hereinafter, reading of the correction data generation signals for the A and AB images will be described with reference to FIG. 10A.

  FIG. 10A is a diagram showing the readout timing of the first row of the correction data generation signals for the A and AB images. The first line is an OB area as shown in FIG. 8B, and the signal of the light-shielded photodiode is read out.

  At time e1, TX_A and TX_B which are control signals of the transfer switches 202a and 202b are set to H. When TX_A and TX_B become H, the charges accumulated in the photodiodes 201a and 201b are transferred to the gate of the amplification unit 204 via the first transfer switch 202a and the second transfer switch 202b, and the photodiodes 201a and 201b are transferred. Is reset. At time e2, TX_A and TX_B are set to L, and photocharges are started to be accumulated in the photodiodes 201a and 201b.

  After accumulating the necessary time, SEL, which is a control signal for the selection switch 206, is set to H at time e3, and the amplifying unit 204 is turned on. At time e4, the reset of the floating diffusion region 203 is released by setting RES, which is a control signal of the reset switch 205, to L. At this time, the potential of the floating diffusion region 203 is read as a reset signal level to the vertical output line 207 via the amplifier 204 and is input to the reading circuit 500.

  Thereafter, when RES_C is set to L at time e <b> 5, a difference between the reset signal level read to the vertical output line 207 and the reference voltage Vref is output from the operational amplifier 503. At time e6, TN_AB and TN_A are set to H and switches 510 and 512 are turned ON, and at time e7, TN_AB and TN_A are set to L and switches 510 and 512 are turned OFF, whereby the output of the operational amplifier 503 is transferred to the capacitor N signal holding capacitors 1AB506 and 1A508. Write.

  Next, TX_A is set to H at time e8, the photocharge of the photodiode 201a is transferred to the floating diffusion region 203, and TX_A is set to L at time e9. By this operation, the charge accumulated in the photodiode 201 a is read out to the floating diffusion region 203. Then, an output corresponding to the change is supplied to the reading circuit 500 via the amplifying unit 204 and the vertical output line 207.

  In the readout circuit 500, an inversion gain is applied to the voltage change at the ratio of the clamp capacitor C0 of 501 and the feedback capacitor Cf of 502, and output.

  In order to write this voltage to the capacitor S signal holding capacitor 1A507, TS1_A is switched from L to H at time e10, switch 511 is turned on, TS1_A is switched from H to L at time e11, switch 511 is turned off, and writing is completed. To do.

  Subsequently, TS2_A is switched from L to H at time e12 in order to write the signals written in the capacitor S signal holding capacitor 1A507 and the capacitor N signal holding capacitor 1A508 to the capacitor S signal holding capacitor 2A528 and the capacitor N signal holding capacitor 2A529. . By switching TS2_A from L to H, the switches 524 and 525 are turned on. At time e13, TS2_A is switched from H to L and the switches 524 and 525 are turned off to complete the writing.

  With this operation, a difference voltage between the capacitor S signal holding capacitor 2A528 and the capacitor N signal holding capacitor 2A529 is obtained, whereby a signal for generating correction data for A image, which is an output signal from the light-shielded photodiode 201a, is obtained.

  Thereafter, output of the signals held in the capacitor S signal holding capacitor 2A528 and the capacitor N signal holding capacitor 2A529 is started at time e14. The drive pulse HA (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 515 and 516 are turned from OFF to ON to OFF. The signals held in the capacitor S signal holding capacitor 2A 528 and the capacitor N signal holding capacitor 2A 529 in the column in which the switches 515 and 516 are changed from OFF → ON → OFF are read to the common output lines 230 and 231, respectively, and output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes a correction data generation signal for the A image.

  Here, according to the setting in step S200, the pixel column in which the drive pulse HA (m) is L → H → L is the h-th column as shown in the drive timing of FIG. Remains. Therefore, the pixel column from which the correction data generation signal for the A image is read is the h-th column.

  Next, TX_A is set to H again at time e15, and TX_B is set to H at the same time. With this operation, the photocharges of both the photodiodes 201a and 201b can be simultaneously read out to the floating diffusion region 203. The read charge is supplied to the read circuit 500 and output through the operational amplifier 503 in the same manner as when only the photodiode 201 a is read.

  In order to write this voltage to the capacitor S signal holding capacitor 1AB505, TS1_AB is switched from L to H at time e17, switch 509 is turned on, TS1_AB is switched from H to L at time e18, switch 509 is turned off, and writing is completed. To do.

  Next, at time e19, RES is set to H, and the floating diffusion region 203 is reset.

  Subsequently, TS2_AB is switched from L to H at time e20 in order to write the signals written in the capacitor S signal holding capacitor 1AB505 and the capacitor N signal holding capacitor 1AB506 to the capacitor S signal holding capacitor 2AB526 and the capacitor N signal holding capacitor 2AB527. . By switching TS2_AB from L to H, the switches 522 and 523 are turned ON, and at time e21, TS2_AB is switched from H to L and the switches 522 and 523 are turned OFF to complete the writing.

  By this operation, by taking the voltage difference between the capacitor S signal holding capacitor 2AB526 and the capacitor N signal holding capacitor 2AB527, the correction data generation signal for the AB image, which is the sum of the output signals from the light-shielded photodiodes 201a and 201b, is obtained. can get.

  Next, during time e22 to e23, the drive pulse HAB (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 513 and 514 are turned from OFF to ON to OFF. . Signals held in the capacitor S signal holding capacitor 2AB526 and the capacitor N signal holding capacitor 2AB527 in the column in which the switches 513 and 514 are changed from OFF → ON → OFF are read to the common output lines 230 and 231 respectively, and are output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes an AB image correction data generation signal. Here, the drive pulse HAB (m) sequentially changes from L to H to L in all columns 0 to n as shown in the drive timing of FIG. 10A. Therefore, AB image correction data generation signals are read from all columns.

  Next, the read timing for the second and subsequent rows in reading the correction data generation signals for the A and AB images will be described.

  FIG. 10B is a diagram illustrating the readout timing of the second row of the correction data generation signal for the A image and the AB image.

  At time f1, TX_A and TX_B which are control signals of the transfer switches 202a and 202b are set to H. When TX_A and TX_B become H, the charges accumulated in the photodiodes 201a and 201b are transferred to the gate of the amplification unit 204 via the first transfer switch 202a and the second transfer switch 202b, and the photodiodes 201a and 201b are transferred. Is reset. At time f2, TX_A and TX_B are set to L, and photocharges are started to be accumulated in the photodiodes 201a and 201b.

  After accumulating the necessary time, SEL, which is a control signal of the selection switch 206, is set to H at time f3, and the amplifying unit 204 is turned on. The reset of the floating diffusion region 203 is canceled by setting RES, which is a control signal of the reset switch 205, to L at time f4. At this time, the potential of the floating diffusion region 203 is read as a reset signal level to the vertical output line 207 via the amplifier 204 and is input to the reading circuit 500.

  Thereafter, RES_C is set to L at time f5.

  Subsequently, TS2_A is switched from L to H at time f6 in order to write the signals written in the capacitor S signal holding capacitor 1A507 and the capacitor N signal holding capacitor 1A508 to the capacitor S signal holding capacitor 2A528 and the capacitor N signal holding capacitor 2A529. . By switching TS2_A from L to H, the switches 524 and 525 are turned on. At time f7, TS2_A is switched from H to L and the switches 524 and 525 are turned off to complete the writing.

  Then, by this operation, the voltage difference between the capacitor S signal holding capacitor 2A528 and the capacitor N signal holding capacitor 2A529 is taken. As a result, the output signal from the light-shielded photodiode 201a stored in the capacitor S signal holding capacitor 1A507 and the capacitor N signal holding capacitor 1A508 is read again by reading the first row, and the correction data generation of the A image is performed. A signal is obtained.

  Thereafter, output of the signals held in the capacitor S signal holding capacitor 2A528 and the capacitor N signal holding capacitor 2A529 is started at time f8. The drive pulse HA (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 515 and 516 are turned from OFF to ON to OFF. The signals held in the capacitor S signal holding capacitor 2A 528 and the capacitor N signal holding capacitor 2A 529 in the column in which the switches 515 and 516 are changed from OFF → ON → OFF are read to the common output lines 230 and 231, respectively, and output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes a correction data generation signal for the A image.

  Here, according to the setting in step S200, the pixel column in which the drive pulse HA (m) is L → H → L is the h-th column as shown in the drive timing of FIG. 10B, and the other pixel levels are always at the L level. Remains. Therefore, the pixel column from which the correction data generation signal for the A image is read is the h-th column.

  Next, at time f9, RES is set to H, and the floating diffusion region 203 is reset.

  Subsequently, the signals written in the capacitor S signal holding capacitor 1AB505 and the capacitor N signal holding capacitor 1AB506 in the reading of the first row are written in the capacitor S signal holding capacitor 2AB526 and the capacitor N signal holding capacitor 2AB527. By switching TS2_AB from L to H at time f10, the switches 522 and 523 are turned ON, and by switching TS2_AB from H to L at time f11, the switches 522 and 523 are turned OFF and the writing ends.

  Then, the voltage difference between the capacitor S signal holding capacitor 2AB526 and the capacitor N signal holding capacitor 2AB527 is taken. By this operation, correction data for the AB image, which is the sum of output signals from the light-shielded photodiodes 201a and 201b stored in the capacitor S signal holding capacitor 1AB505 and the capacitor N signal holding capacitor 1AB506 in the first row reading, is generated. A signal is obtained.

  Next, during time f12 to f13, the drive pulse HAB (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 513 and 514 are turned from OFF to ON to OFF. . Signals held in the capacitor S signal holding capacitor 2AB526 and the capacitor N signal holding capacitor 2AB527 in the column in which the switches 513 and 514 are changed from OFF → ON → OFF are read to the common output lines 230 and 231 respectively, and are output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes an AB image correction data generation signal. Here, the drive pulse HAB (m) sequentially changes from L to H to L in all the 0th to nth columns as shown in the drive timing of FIG. 10B. Therefore, AB image correction data generation signals are read from all columns.

  The above operation is sequentially performed for each row, and the reading of the correction data generation signals for the A and AB images is completed. The output signal is converted into a digital signal by the AFE 102.

  In this way, correction data generation data for the A and AB images can be obtained as described at the time of startup in FIG. This data is input to the image correction unit 300. In the image correction unit 300, the input data is averaged for each column, and the correction data for the columns h to i of the A image and the columns 0 to n of the AB image are generated by the above-described processing. It is stored as described at the time of startup in FIG.

  In step S204, the CPU 103 determines whether the generation of correction data for the A image and the AB image has been completed. In this embodiment, since the generation of correction data is completed with the correction data generation data for one frame, the process proceeds to step S205. If correction data generation data for a plurality of frames is required, the process returns to step S203 to repeat reading until the correction data generation ends.

  In step S205, the CPU 103 sets the read mode of the A image and the AB image to the image signal output mode (second read mode) for the TG 101. With this setting, during readout, the A and AB images are output as light component signals photoelectrically converted by the photodiodes 201a and 201b and input to the image correction unit 300 as image data converted into digital signals by the AFE 102. The

  In step S <b> 206, the CPU 103 performs settings for correcting the A image and the AB image in the image correction unit 300. The image correction unit 300 corrects the image data of the A image and the AB image according to the setting here.

  Thereafter, in step S207, the image signals of the A image and the AB image are read out. Reading one line of the image signal is performed at the same reading timing as in FIG. 10A described above. The readout operation illustrated in FIG. 10A is sequentially performed for each row, and the readout of the image signals of the A image and the AB image is completed. The output signal is converted into a digital signal by the AFE 102.

  In this way, image data of the A image and the AB image is obtained as described in the first frame of FIG. This data is input to the image correction unit 300. In the image correction unit 300, the correction data for each of the columns h to i of the A image and the columns 0 to n of the AB image stored in the memory 305 is output from the memory 305 in accordance with the column correspondence of the input data. The offset correction for each column is performed.

  The corrected A image and AB image are input to the AF calculation unit 110, and an AF operation is performed by the processing described above. The image data of the AB image is stored in the RAM 107. The CPU 103 transfers the image data of the AB image stored in the RAM 107 to the image processing unit 108, and the image processing unit 108 compresses the image data. Thereafter, it is recorded in the recording unit 109 as moving image data.

  In step S208, the CPU 103 determines whether the moving image shooting switch of the operation unit 104 is pressed again to end shooting. If the photographing is finished, the photographing operation is finished as it is. If not, the process proceeds to step S209.

  In step S209, the CPU 103 determines whether the position of the focus detection area has been changed. If the position of the focus detection area has not been changed, the process returns to step S207, and the operations from step S207 to step S208 described above are repeated (FIG. 6A).

  If the position of the focus detection area has been changed, the process proceeds to step S210. In step S210, the CPU 103 sets a horizontal position for reading the A image to the image sensor 100 in accordance with the position of the focus detection area after the change. Here, the reading position of the A image is assumed to be the jth to kth columns.

  In step S211, the CPU 103 sets the A image readout mode to the correction data generation signal output mode and the AB image readout mode to the image signal output mode (third readout mode) for the TG 101. With this setting, at the time of reading, a correction data generation signal is output for the A image, and an image signal is output for the AB image.

  In step S <b> 212, the CPU 103 performs settings for generating correction data for the A image and settings for correcting the AB image in the image correction unit 300. The image correction unit 300 generates A image correction data from the A image correction data generation data according to the setting here, and corrects the AB image data.

  Thereafter, in step S213, the A image correction data generation signal and the AB image signal are read out. The readout of the A image correction data generation signal and the AB image signal will be described below with reference to FIG. 10C.

  FIG. 10C is a diagram illustrating the readout timing of the first row of the correction data generation signal for the A image and the image signal for the AB image. The first line is an OB area as shown in FIG. 8B, and the signal of the light-shielded photodiode is read out. The operation up to time g13 is the same as the operation up to time e13 in FIG.

  Output of the signals held in the capacitor S signal holding capacitor 2A528 and the capacitor N signal holding capacitor 2A529 is started at time g14. The drive pulse HA (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 515 and 516 are turned from OFF to ON to OFF. The signals held in the capacitor S signal holding capacitor 2A 528 and the capacitor N signal holding capacitor 2A 529 in the column in which the switches 515 and 516 are changed from OFF → ON → OFF are read to the common output lines 230 and 231, respectively, and output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes a correction data generation signal for the A image.

  Here, according to the setting in step S210, the pixel column in which the drive pulse HA (m) is L → H → L is the jth to kth columns as shown in the drive timing of FIG. Remains. Accordingly, the pixel column from which the A image signal is read out is the jth to kth columns.

  Thereafter, the operation after time g15 is the same as the operation after time e15 in FIG.

  Next, the readout timing for the second and subsequent rows in the readout of the A image correction data generation signal and the AB image signal will be described.

  FIG. 10D is a diagram illustrating the readout timing of the second row of the A image correction data generation signal and the AB image signal.

  The operation up to time h5 is the same as the operation up to time f5 in FIG.

  At time h6, in order to write the output of the operational amplifier 503 to the capacitor N signal holding capacitor 1AB506, TN_AB is set to H and the switch 510 is turned ON. At time h7, TN_AB is set to L and the switch 510 is turned OFF to complete the writing.

  Subsequently, TS2_A is switched from L to H at time h8 in order to write the signals written in the capacitor S signal holding capacitor 1A507 and the capacitor N signal holding capacitor 1A508 to the capacitor S signal holding capacitor 2A528 and the capacitor N signal holding capacitor 2A529. . By switching TS2_A from L to H, the switches 524 and 525 are turned on. At time h9, TS2_A is switched from H to L and the switches 524 and 525 are turned off to complete the writing.

  Then, the voltage difference between the capacitor S signal holding capacitor 2A528 and the capacitor N signal holding capacitor 2A529 is taken. By this operation, the output signal from the light-shielded photodiode 201a stored in the capacitor S signal holding capacitor 1A507 and the capacitor N signal holding capacitor 1A508 is read again in the first row reading, and the correction data of the A image A signal for generation is obtained.

  Thereafter, output of the signals held in the capacitor S signal holding capacitor 2A528 and the capacitor N signal holding capacitor 2A529 is started at time h10. The drive pulse HA (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 515 and 516 are turned from OFF to ON to OFF. The signals held in the capacitor S signal holding capacitor 2A 528 and the capacitor N signal holding capacitor 2A 529 in the column in which the switches 515 and 516 are changed from OFF → ON → OFF are read to the common output lines 230 and 231, respectively, and output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes a correction data generation signal for the A image.

  Here, according to the setting in step S210, the pixel column in which the drive pulse HA (m) changes from L → H → L is the jth to kth columns as shown in the drive timing of FIG. Remains. Accordingly, the pixel column from which the A image signal is read out is the jth to kth columns.

  Next, TX_A is set to H again at time h11, and TX_B is also set to H at the same time. With this operation, the photocharges of both the photodiodes 201a and 201b can be simultaneously read out to the floating diffusion region 203. The read charge is supplied to the read circuit 500 and output through the operational amplifier 503 in the same manner as when only the photodiode 201 a is read.

  In order to write this voltage to the capacitor S signal holding capacitor 1AB505, TS1_AB is switched from L to H at time h13, switch 509 is turned on, TS1_AB is switched from H to L at time h14, switch 509 is turned off, and writing is completed. To do.

  Next, at time h15, RES is set to H, and the floating diffusion region 203 is reset.

  Subsequently, TS2_AB is switched from L to H at time h16 in order to write the signals written in the capacitor S signal holding capacitor 1AB505 and the capacitor N signal holding capacitor 1AB506 to the capacitor S signal holding capacitor 2AB526 and the capacitor N signal holding capacitor 2AB527. . TS2_AB is switched from L to H, switches 522 and 523 are turned on, TS2_AB is switched from H to L at time h17, switches 522 and 523 are turned off, and writing is completed.

  With this operation, by taking the voltage difference between the capacitor S signal holding capacitor 2AB526 and the capacitor N signal holding capacitor 2AB527, an image signal of an AB image that is the sum of the output signals from the photodiodes 201a and 201b is obtained.

  Next, during time h18 to h19, the drive pulse HAB (m) of the horizontal shift register 232 is sequentially changed from L to H to L for each readout circuit, and accordingly, the switches 513 and 514 are turned from OFF to ON to OFF. . Signals held in the capacitor S signal holding capacitor 2AB526 and the capacitor N signal holding capacitor 2AB527 in the column in which the switches 513 and 514 are changed from OFF → ON → OFF are read to the common output lines 230 and 231 respectively, and are output by the output amplifier 233. Output as a differential voltage. This difference voltage becomes an image signal of the AB image. Here, the drive pulse HAB (m) is sequentially changed from L → H → L in all the 0th to nth columns as shown in the drive timing of FIG. 10D. Therefore, the image signal of the AB image is read from all columns.

  The above operation is sequentially performed for each row, and the reading of the A image correction data generation signal and the AB image signal is completed. The output signal is converted into a digital signal by the AFE 102.

  In this way, the correction data generation data for the A image and the image data for the AB image are obtained as described in the p-th frame of FIG. 6B. This data is input to the image correction unit 300. The image correction unit 300 averages the input data, and stores the correction data for each of the j-th to k-th columns of the A image as described in the p-th frame in FIG. . Further, correction data for each of the 0th to n-th columns of the AB image is output from the memory 305 in accordance with the column correspondence of the input data, and offset correction is performed for each column.

  The corrected image data of the AB image is stored in the RAM 107. The CPU 103 transfers the image data of the AB image stored in the RAM 107 to the image processing unit 108, and the image processing unit 108 compresses the image data. Thereafter, it is recorded in the recording unit 109 as moving image data.

  In step S214, the CPU 103 determines whether the generation of the correction data for the A image has been completed. In this embodiment, since the generation of correction data is completed with the correction data generation data for one frame, the process proceeds to step S205. If correction data generation data for a plurality of frames is required, the process returns to step S213 to repeat reading until the correction data generation is completed.

  In subsequent step S <b> 205, the CPU 103 sets the read mode of the A image and the AB image to the image signal output mode (second read mode) for the TG 101. With this setting, during readout, the A and AB images are output as light component signals photoelectrically converted by the photodiodes 201a and 201b and input to the image correction unit 300 as image data converted into digital signals by the AFE 102. The

  In step S <b> 206, the CPU 103 performs settings for correcting the A image and the AB image in the image correction unit 300. The image correction unit 300 corrects the image data of the A image and the AB image according to the setting here.

  Thereafter, in step S207, the image signals of the A image and the AB image are read out. The reading of the image signals of the A image and the AB image is the same as the reading operation of FIG. The readout operation of FIG. 10C is sequentially performed for each row, and the readout of the image signals of the A image and the AB image is completed. The output signal is converted into a digital signal by the AFE 102.

  In this way, image data of A image and AB image is obtained as described in the (p + 1) th frame of FIG. 6B. This data is input to the image correction unit 300. In the image correction unit 300, the correction data for each of the jth to kth columns of the A image and the 0th to nth columns of the AB image stored in the memory 305 is output from the memory 305 according to the column correspondence of the input data. The offset correction for each column is performed.

  The corrected A image and AB image are input to the AF calculation unit 110, and an AF operation is performed by the processing described above. The image data of the AB image is stored in the RAM 107. The CPU 103 transfers the image data of the AB image stored in the RAM 107 to the image processing unit 108, and the image processing unit 108 compresses the image data. Thereafter, it is recorded in the recording unit 109 as moving image data.

  Thereafter, the operations after step S208 are performed in the same manner as described above, and the AF operation and moving image recording are continued.

  As described above, even when the readout position of data (A image) used for focus detection in moving image shooting is changed, it is possible to apply correction for each column of A image by regenerating A image correction data. it can. Further, when the A image correction data is regenerated, the A image can output correction data generation data, and the AB image can output image data, so that the frame rate is maintained without missing the frame data of the moving image. The focus detection position can be changed. Therefore, according to the present invention, the correction data of the focus detection pixel at the new position can be regenerated without interrupting the acquisition of the image data.

  Further, in this embodiment, a signal obtained by repeatedly reading out a pixel signal is used as a correction data generation signal, so that correction including the fixed pattern noise for each column of the pixel portion can be performed.

  In this embodiment, the correction data is regenerated when the focus detection position is changed. However, the present invention is not limited to this. For example, when the shooting conditions (shooting sensitivity, etc.), pixel addition cycle (addition rate), pixel skipping cycle (readout skipping rate), etc., of the A image (focus detection pixel) are changed. Can also be applied.

  In this embodiment, the correction data generation circuit 301 is configured to generate correction data, but this is not restrictive. A configuration in which correction data update data is read above the image data when the image data is read, and the correction data in the memory is updated using the correction data update data can also be applied.

As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.
(Other embodiments)
The object of the present invention can also be achieved as follows. That is, a storage medium in which a program code of software describing a procedure for realizing the functions of the above-described embodiments is recorded is supplied to an apparatus (for example, an imaging apparatus). The computer (or CPU, MPU, etc.) of the device reads out and executes the program code stored in the storage medium.

  In this case, the program code itself read from the storage medium realizes the novel function of the present invention, and the storage medium and program storing the program code constitute the present invention.

  Examples of the storage medium for supplying the program code include a flexible disk, a hard disk, an optical disk, and a magneto-optical disk. Further, a CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD-R, magnetic tape, nonvolatile memory card, ROM, or the like can also be used.

  Moreover, the function of the above-described embodiment is realized by making the program code read by the computer executable. Further, based on the instruction of the program code, an OS (operating system) or the like running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments may be realized by the processing. included.

  Furthermore, the following cases are also included. First, the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing.

  The present invention can be suitably used for camera systems such as compact digital cameras, single-lens reflex cameras, and video cameras.

100 Image sensor 103 CPU (control means)

Claims (15)

An image pickup device having a unit pixel including a first photoelectric conversion unit and a second photoelectric conversion unit;
A first correction signal for correcting a focus detection signal is read out from a focus detection pixel including the first photoelectric conversion unit or the second photoelectric conversion unit, and the first photoelectric conversion unit and the second photoelectric conversion unit are read out. A first reading mode for reading a second correction signal for correcting an image signal obtained by adding the signals of the first photoelectric conversion unit and the second photoelectric conversion unit from an imaging pixel formed of a conversion unit;
A second readout mode for reading out the focus detection signal from the focus detection pixel and reading out the image signal from the imaging pixel;
Control means for switching and controlling a third readout mode for reading out the first correction signal from the focus detection pixel and reading out the image signal from the imaging pixel;
Have
The image pickup apparatus, wherein the third readout mode is set when a readout condition of the focus detection pixel is changed.   The imaging apparatus according to claim 1, wherein the reading condition is changed when a focus detection area of the imaging element is changed.   The imaging apparatus according to claim 1, wherein the reading condition is changed when a photographing sensitivity of the focus detection signal is changed.   The imaging apparatus according to claim 1, wherein the readout condition is changed when a readout thinning rate of the focus detection signal is changed.   The imaging apparatus according to claim 1, wherein the readout condition is changed when an addition rate of the focus detection signal is changed.   The control means sets the first readout mode when shooting is started, then switches to the second readout mode, and switches to the third readout mode when the readout conditions are changed. Thereafter, the imaging device is switched to the second readout mode, and the imaging apparatus according to any one of claims 1 to 5. Generating means for generating correction data for correcting the focus detection signal from the first correction signal;
Storage means for storing the correction data,
7. The storage unit according to claim 1, wherein the storage unit updates the correction data before the read condition is changed to the correction data after the read condition is changed. 8. Imaging device. Generating means for generating first correction data for correcting the focus detection signal from the first correction signal, and generating second correction data for correcting the image signal from the second correction signal;
Correction means for correcting the focus detection signal based on the first correction data and correcting the image signal based on the second correction data;
The control means causes the generation means to generate the first correction data from the first correction signal read in the third read mode when the read condition is changed, and the correction means The imaging apparatus according to claim 1, wherein the image signal read in the third readout mode is corrected based on the second correction data.   9. The imaging apparatus according to claim 1, wherein the first correction signal or the second correction signal is a readout signal of a reset potential of a pixel.   The imaging apparatus according to claim 1, wherein the first correction signal or the second correction signal is a signal from a dummy pixel that does not have the photoelectric conversion unit.   The imaging device according to claim 1, wherein the first correction signal or the second correction signal is a signal from a pixel provided in a light shielding region. An imaging device according to any one of claims 1 to 11,
An imaging system comprising: an imaging lens that is detachable from the imaging device. A method for controlling an imaging device including an imaging device having a unit pixel including a first photoelectric conversion unit and a second photoelectric conversion unit,
A first correction signal for correcting a focus detection signal is read out from a focus detection pixel including the first photoelectric conversion unit or the second photoelectric conversion unit, and the first photoelectric conversion unit and the second photoelectric conversion unit are read out. A step of executing a first readout mode for reading out a second correction signal for correcting an image signal obtained by adding the signals of the first photoelectric conversion unit and the second photoelectric conversion unit from an imaging pixel including a conversion unit. When,
Reading the focus detection signal from the focus detection pixel and executing a second read mode for reading the image signal from the imaging pixel;
Executing a third readout mode of reading out the first correction signal from the focus detection pixel and reading out the image signal from the imaging pixel when a readout condition of the focus detection pixel is changed;
A method for controlling an imaging apparatus, comprising:   A computer-executable program in which a procedure of a control method for an imaging apparatus according to claim 13 is described. A computer-readable storage medium storing a program for causing a computer to execute the steps of the imaging apparatus control method according to claim 13.