Imaging element

Abstract

To provide an imaging element capable of reading out a focus detection signal and an image signal at high read-out speed.SOLUTION: An imaging element 3 includes: a pixel part 100 in which an AF pixel (13a), an AF pixel (13b), an imaging pixel (for example, 10r), and an imaging pixel (for example, 10g) are arranged in a column direction; a first signal line VoutA which is connected to a first read-out part 40a; a second signal line VoutB which is connected to a second read-out part 40b; and a vertical control part 30 which performs first control and second control for controlling output of signals from pixels. In the first control, the AF pixel (13a) and the AF pixel (13b) are controlled so as to be output to one signal line out of the first signal line VoutA and the second signal line VoutB. In the second control, the imaging pixel (for example, 10r) and the imaging pixel (for example, 10g) are controlled so as to be output to a different signal line out of the first signal line VoutA and the second signal line VoutB.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Image sensors that read out focus detection signals and image signals are known (see, for example, Patent Document 1). In such image sensors, there is a demand for faster signal readout. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-34606 Summary of the Invention

[0004] According to a first aspect of the invention, an image sensor includes a pixel section in which a first pixel has a first photoelectric conversion unit that converts light transmitted through an optical system into an electric charge and outputs a first signal used for focus detection of the optical system, a second pixel has a second photoelectric conversion unit that converts light transmitted through the optical system into an electric charge and outputs a second signal used for focus detection of the optical system, a third pixel has a third photoelectric conversion unit that converts light transmitted through the optical system into an electric charge and outputs a third signal used for image generation, and a fourth pixel has a fourth photoelectric conversion unit that converts light transmitted through the optical system into an electric charge and outputs a fourth signal used for image generation, and the pixel section is arranged in a column direction; first signal lines electrically connectable to the first pixel, the second pixel, the third pixel, and the fourth pixel; a first readout unit that performs signal processing on a signal among the first signal, the second signal, the third signal, and the fourth signal that is output to the first signal line; a second readout unit that performs signal processing on a signal among the first signal, the second signal, the third signal, and the fourth signal that is output to the second signal line; and a vertical control unit that performs first control that controls the first pixel and the second pixel so that the first signal and the second signal are output to one of the first signal line and the second signal line, and second control that controls the third pixel and the fourth pixel so that the third signal and the fourth signal are output to a different signal line among the first signal line and the second signal line. [Brief explanation of the drawings]

[0005] [Figure 1] 1 is a block diagram showing a configuration of an imaging device according to a first embodiment. [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of an imaging element according to a first embodiment. [Figure 3] 1 is a diagram illustrating an example of the configuration of a pixel of an imaging element according to a first embodiment. [Figure 4] 1 is a diagram illustrating an example of the configuration of a portion of an imaging element according to a first embodiment. [Figure 5] 5 is a timing chart showing an example of the operation of the imaging element according to the first embodiment. [Figure 6] FIG. 2 is a diagram illustrating an example of the configuration of a portion of an imaging element according to the first embodiment. [Figure 7] 6 is a timing chart showing another example of operation of the imaging element according to the first embodiment. [Figure 8] 6 is a timing chart showing another example of operation of the imaging element according to the first embodiment. [Figure 9] FIG. 10 is a diagram illustrating an example of the configuration of a portion of an imaging element according to Modification 1. [Figure 10] 10 is a timing chart showing an example of the operation of the imaging element according to Modification 1. [Figure 11] FIG. 10 is a diagram illustrating an example of the configuration of a portion of an imaging element according to Modification 2. DETAILED DESCRIPTION OF THE INVENTION

[0006] (First embodiment) FIG. 1 is a block diagram showing the configuration of an imaging device according to the first embodiment. FIG. 1 shows an example of the configuration of a camera 1, which is an example of an imaging device according to the first embodiment. The camera 1 includes an imaging optical system (imaging optical system) 2, an imaging element 3, a control unit 4, a memory 5, a display unit 6, and an operation unit 7. The imaging optical system 2 has multiple lenses, including a focus adjustment lens (focus lens), and an aperture stop, and forms a subject image on the imaging element 3. The imaging optical system 2 may be detachable from the camera 1.

[0007] The image sensor 3 is, for example, a CMOS image sensor. The image sensor 3 receives a light beam that has passed through the exit pupil of the imaging optical system 2 and captures an image of a subject. The image sensor 3 has a plurality of pixels, each having a photoelectric conversion unit, arranged two-dimensionally (for example, in row and column directions). The photoelectric conversion unit is formed of, for example, a photodiode (PD). The image sensor 3 photoelectrically converts the received light to generate a signal, and outputs the generated signal to the control unit 4.

[0008] The image sensor 3 has imaging pixels and AF pixels (focus detection pixels). The imaging pixels output signals (imaging signals) used for image generation. The AF pixels output signals (focus detection signals) used for focus detection. As will be described later, the AF pixels are arranged to replace some of the imaging pixels, and are distributed over almost the entire imaging surface of the image sensor 3. In the following description, when simply referring to pixels, this refers to either or both of the imaging pixels and the AF pixels.

[0009] The memory 5 is a recording medium such as a memory card. Image data and the like are recorded in the memory 5. Writing data to the memory 5 and reading data from the memory 5 are performed by the control unit 4. The display unit 6 displays an image based on the image data, information related to shooting such as the shutter speed and aperture value, a menu screen, and the like. The operation unit 7 includes various setting switches such as a release button and a power switch, and outputs operation signals to the control unit 4 in response to each operation.

[0010] The control unit 4 is configured with a processor such as a CPU, FPGA, or ASIC, and memories such as ROM and RAM, and controls each unit of the camera 1 based on a control program. The control unit 4 has an image data generation unit 4a and a focus detection unit 4b. The image data generation unit 4a performs various image processing on the image signal output from the image sensor 3 to generate image data. The image processing includes well-known image processing such as tone conversion processing, color interpolation processing, and edge enhancement processing.

[0011] The focus detection unit 4b uses a known phase difference detection method to perform focus detection processing required for automatic focusing (AF) of the imaging optical system 2. Specifically, the focus detection unit 4b detects the in-focus position of the focus lens so that the image formed by the imaging optical system 2 is focused on the imaging surface of the imaging element 3. The focus detection unit 4b detects the amount of image shift between the first and second images based on a pair of focus detection signals output from the imaging element 3. Based on the detected amount of image shift, the focus detection unit 4b calculates the amount of shift (defocus amount) between the current position of the focus lens and the in-focus position. The focus lens is driven in accordance with the defocus amount, thereby automatically performing focus adjustment.

[0012] The control unit 4 controls the image sensor 3 to separately read out signals from pixel rows in which AF pixels are arranged (hereinafter referred to as AF pixel rows) and from pixel rows in which AF pixels are not arranged (hereinafter referred to as imaging pixel rows).The control unit 4 also performs a process of sequentially selecting all pixel rows and reading out signals from each pixel, without separately reading out signals from AF pixel rows and imaging pixel rows.

[0013] For example, when displaying a through image (live view image) of a subject on the display unit 6 or when shooting a moving image, the control unit 4 separately reads out the signals of each pixel in the AF pixel row and the signals of each pixel in the imaging pixel row. When shooting a high-resolution still image, the control unit 4 sequentially selects all pixel rows and performs a process of reading out the signals of each pixel.

[0014] FIG. 2 is a diagram showing an example of the configuration of an image sensor 3 according to the first embodiment. The image sensor 3 has a pixel section (pixel region) 100, a vertical control section 30, and a plurality of readout sections 40 (first readout section 40a, second readout section 40b) arranged above and below the pixel section 100. In the pixel section 100 of the image sensor 3, pixels are arranged two-dimensionally (in the row and column directions). Note that the number and arrangement of pixels arranged in the pixel section 100 are not limited to the example shown in the figure. The pixel section 100 may have, for example, several million to several hundred million pixels or more.

[0015] The pixel section 100 has a plurality of imaging pixels 10 and AF pixels 13 (13a, 13b). In FIG. 2, the pixel in the upper left corner is the imaging pixel 10(1,1) in the first row and first column, and the AF pixel in the lower right corner is the AF pixel 13b(16,8) in the 16th row and eighth column, showing 128 pixels from the imaging pixel 10(1,1) to the AF pixel 13b(16,8). Note that the 128 pixels, 8 pixels in the row direction and 16 pixels in the column direction shown in FIG. 2, represent a group of pixels arranged in an arbitrary region of the imaging surface of the image sensor 3, and the names 1st to 8th columns and 1st to 16th rows in FIG. 2 are also given to the 128 pixels. Therefore, in the image sensor 3, pixels may exist not only to the right of the pixel in the eighth column and below the pixel in the 16th row in FIG. 2, but also to the left of the pixel in the first column and above the pixel in the first row.

[0016] Each imaging pixel 10 is provided with one of three color filters 41 having different spectral characteristics, for example, R (red), G (green), or B (blue). The R color filter 41 transmits light mainly in the red wavelength range, the G color filter 41 transmits light mainly in the green wavelength range, and the B color filter 41 transmits light mainly in the blue wavelength range. The pixels have different spectral characteristics depending on the color filter 41 arranged therein. As a result, the imaging pixel 10 includes pixels having red (R) spectral characteristics (hereinafter referred to as R pixels), pixels having green (G) spectral characteristics (hereinafter referred to as G pixels), and pixels having blue (B) spectral characteristics (hereinafter referred to as B pixels). The R pixels, G pixels, and B pixels are arranged according to a Bayer array.

[0017] The first and second AF pixels 13a, 13b are arranged by replacing some of the R, G, and B imaging pixels 10 arranged in the Bayer array as described above. The first and second AF pixels 13a, 13b are provided with color filters 41 and light-shielding films 43. For example, a G color filter is arranged as the color filter 41 in the first and second AF pixels 13a, 13b. The positions of the light-shielding portions 43 of the first AF pixel 13a and the second AF pixel 13b are different. As a result, the photoelectric conversion unit of the first AF pixel 13a receives a light beam that has passed through a first region of the first and second regions of the exit pupil of the imaging optical system 2. The photoelectric conversion unit of the second AF pixel 13b receives a light beam that has passed through a second region of the first and second regions of the exit pupil of the imaging optical system 2.

[0018] 2, the image sensor 3 has a first imaging pixel row 401 in which R pixels 10r and G pixels 10g are arranged alternately in the left-right direction, i.e., the row direction, and a second imaging pixel row 402 in which G pixels 10g and B pixels 10b are arranged alternately in the row direction. The image sensor 3 also has a first AF pixel row 403a in which G pixels 10g and first AF pixels 13a are arranged alternately in the row direction, and a second AF pixel row 403b in which G pixels 10g and second AF pixels 13b are arranged alternately in the row direction.

[0019] The vertical control unit 30 is controlled by the control unit 4 of the camera 1, and supplies control signals to each pixel to control the operation of each pixel. The first readout unit 40a and the second readout unit 40b each include an analog-to-digital conversion unit (AD conversion unit). A pixel signal of the pixel unit 100 selected by the vertical control unit 30 is output to the first vertical signal line VoutA or the second vertical signal line VoutB connected to that pixel. The pixel signal output to the first vertical signal line VoutA is converted into a digital signal by the first readout unit 40a and then output to the control unit 4. The pixel signal output to the second vertical signal line VoutB is converted into a digital signal by the second readout unit 40b and then output to the control unit 4.

[0020] 3 is a diagram showing the configuration of pixels of the image sensor 3 according to the first embodiment. Each pixel (pixels 10a and 10b in FIG. 3) includes a photoelectric conversion unit 11 and a transfer unit 12. Pixel 10a has a photoelectric conversion unit 11a and a transfer unit 12a, and pixel 10b has a photoelectric conversion unit 11b and a transfer unit 12b. Photoelectric conversion unit 11 is a photodiode PD that converts incident light into electric charges and accumulates the photoelectrically converted electric charges.

[0021] Furthermore, the imaging element 3 according to this embodiment is configured such that two adjacent pixels share a floating diffusion (FD) 15, a reset unit 16, an amplifier unit 17, a first selection unit 18, and a second selection unit 19, as indicated by the dashed line 20.

[0022] The transfer unit 12a of the pixel 10a is composed of a transistor M1 controlled by a signal TX1, and transfers the charges photoelectrically converted by the photoelectric conversion unit 11a to the FD15. That is, the transfer unit 12a forms a charge transfer path between the photoelectric conversion unit 11a and the FD15. The transfer unit 12b of the pixel 10b is composed of a transistor M2 controlled by a signal TX2, and transfers the charges photoelectrically converted by the photoelectric conversion unit 11b to the FD15. That is, the transfer unit 12b forms a charge transfer path between the photoelectric conversion unit 11b and the FD15. The transistors M1 and M2 are each a transfer transistor. The capacitance C of the FD15 accumulates (holds) the charges transferred to the FD15 and converts them into a voltage divided by the capacitance value.

[0023] The amplifier 17 amplifies and outputs a signal due to the charge accumulated in the capacitance C of the FD 15. The amplifier 17 is configured with a transistor M5 whose drain (terminal) and gate (terminal) are connected to a power supply VDD and the FD 15, respectively. The source (terminal) of the transistor M5 is connected to a first vertical signal line VoutA via a first selector 18 and to a second vertical signal line VoutB via a second selector 19. The amplifier 17 functions as part of a source follower circuit, using current sources (current sources 25a and 25b in FIG. 4) described later as load current sources. The transistor M5 is an amplifying transistor.

[0024] The reset unit 16 is configured by a transistor M4 controlled by a signal RST, and resets the charge of the FD 15 and resets the voltage of the FD 15. The transistor M4 is a reset transistor.

[0025] The first selection unit 18 is composed of a transistor M6 controlled by a signal SELA, and electrically connects or disconnects the amplifier unit 17 and the first vertical signal line VoutA. When the transistor M6 of the first selection unit 18 is in the on state, it outputs a signal from the amplifier unit 17 to the first vertical signal line VoutA. The second selection unit 19 is composed of a transistor M7 controlled by a signal SELB, and electrically connects or disconnects the amplifier unit 17 and the second vertical signal line VoutB. When the transistor M7 of the second selection unit 19 is in the on state, it outputs a signal from the amplifier unit 17 to the second vertical signal line VoutB. The transistor M6 is a first selection transistor, and the transistor M7 is a second selection transistor.

[0026] As described above, the charges photoelectrically converted by the photoelectric conversion unit 11 are transferred to the FD 15 by the transfer unit 12. Then, a signal (pixel signal) corresponding to the charges transferred to the FD 15 is output to the first vertical signal line VoutA or the second vertical signal line VoutB. The pixel signal is an analog signal generated based on the charges photoelectrically converted by the photoelectric conversion unit 11. The pixel signal output from the imaging pixel 10 is subjected to signal processing by the readout unit 40 and then output to the control unit 4 as an imaging signal.

[0027] In the present embodiment, the circuit configurations of the first AF pixel 13a and the second AF pixel 13b are the same as the circuit configuration of the imaging pixel 10. The pixel signals output from the first AF pixel 13a and the second AF pixel 13b are subjected to signal processing by the readout unit 40, and then output to the control unit 4 as a pair of focus detection signals.

[0028] FIG. 4 is a diagram showing a partial configuration of an image sensor 3 according to the first embodiment. FIG. 4 shows a portion of one pixel column of a plurality of pixels arranged in a column direction (vertical direction), which is a first direction, and a row direction (horizontal direction), which is a second direction intersecting the first direction. The configuration of the other pixel columns is the same as the configuration of the pixel columns in FIG. 4. The image sensor 3 includes a vertical control unit 30 and a plurality of readout units 40 (first readout unit 40a, second readout unit 40b). The vertical control unit 30 is provided in common to the plurality of pixel columns.

[0029] Furthermore, the image sensor 3 is provided with a first vertical signal line VoutA and a second vertical signal line VoutB for each pixel column, which is a column of a plurality of pixels aligned in the column direction. A first current source 25a and a first readout unit 40a are provided for the first vertical signal line VoutA, and a second current source 25b and a second readout unit 40b are provided for the second vertical signal line VoutB. Note that, in the example shown in FIG. 4, for simplicity of explanation, only one pixel in the row direction and six pixels in the column direction are shown. Figure 4 illustrates, of the multiple pixels shown in Figure 2, G pixel 10g(1,2) in the first row, second column, B pixel 10b(2,2) in the second row, second column, G pixel 10g(3,2) in the third row, second column, B pixel 10b(4,2) in the fourth row, second column, G pixel 10g(5,2) in the fifth row, second column, and B pixel 10b(6,2) in the sixth row, second column.

[0030] The first current source 25a is connected to each pixel via a first vertical signal line VoutA, and the second current source 25b is connected to each pixel via a second vertical signal line VoutB. The first current source 25a and the second current source 25b generate currents for reading signals from each pixel. The first current source 25a supplies the generated current to the first vertical signal line VoutA and the first selection unit 18 and amplifier unit 17 of each pixel. Similarly, the second current source 25b supplies the generated current to the second vertical signal line VoutB and the second selection unit 19 and amplifier unit 17 of each pixel.

[0031] The first readout unit 40a includes an AD converter and converts analog signals input from each pixel via the first vertical signal line VoutA into digital signals. The second readout unit 40b includes an AD converter and converts analog signals input from each pixel via the second vertical signal line VoutB into digital signals.

[0032] The vertical control unit 30 supplies signals TX1, TX2, RST, SELA, and SELB to each pixel to control the operation of each pixel. Specifically, the vertical control unit 30 supplies signals to the gate of each transistor in the pixel to turn the transistor on (connected, conductive, or short-circuited) or off (disconnected, non-conductive, open, or blocked).

[0033] When the control unit 4 instructs the vertical control unit 30 to read out the signals of each pixel in the imaging pixel rows (the first imaging pixel row 401 and the second imaging pixel row 402 in Figure 2), the vertical control unit 30 performs a process (first read control) of selecting the imaging pixel rows in units of two rows and reading out the pixel signals. When the control unit 4 instructs the vertical control unit 30 to read out the signals of each pixel in the AF pixel rows (the first AF pixel row 403a and the second AF pixel row 403b in Figure 2), the vertical control unit 30 performs a process (second readout control) of selecting two AF pixel rows at a time and reading out the pixel signals. Furthermore, when reading out signals from AF pixel rows, the vertical control unit 30 can also perform processing (third readout control) of selecting the AF pixel rows one by one and reading out pixel signals.

[0034] As described above, the vertical control unit 30 according to this embodiment performs first readout control, second readout control, and third readout control. The control unit 4 of the camera 1 controls the vertical control unit 30 to switch the pixel signal readout method. The first readout control, second readout control, and third readout control will be described below.

[0035] First, the first readout control will be described with reference to Fig. 4. In the first readout control, the vertical control unit 30 selects every two imaging pixel rows of the image sensor 3 and sequentially reads out signals from the pixels. Below, the first readout control will be described using as an example a case where pixel signals are read out from B pixel 10b(2,2), G pixel 10g(3,2), B pixel 10b(4,2), and G pixel 10g(5,2).

[0036] The vertical control unit 30 turns on the second selection unit 19 of the B pixel 10b(2,2) in the second row, i.e., the second selection unit 19 shared by the G pixel 10g(1,2) in the first row and the B pixel 10b(2,2) in the second row. The vertical control unit 30 also turns off the first selection unit 18 of the B pixel 10b(2,2), i.e., the first selection unit 18 shared by the G pixel 10g(1,2) and the B pixel 10b(2,2). The vertical control unit 30 also turns on the first selection unit 18 of the G pixel 10g(3,2) in the third row, i.e., the first selection unit 18 shared by the G pixel 10g(3,2) in the third row and the B pixel 10b(4,2) in the fourth row. The vertical control unit 30 also turns off the second selection unit 19 of the G pixel 10g(3,2), i.e., the second selection unit 19 shared by the G pixel 10g(3,2) and the B pixel 10b(4,2). The vertical control unit 30 also turns off the first selection unit 18 and the second selection unit 19 of the pixels in rows other than the first, second, third, and fourth rows.

[0037] A pixel signal based on the charge generated by the photoelectric conversion unit 11b of the B pixel 10b(2,2) in the second row is output to the second vertical signal line VoutB via the second selection unit 19 of the B pixel 10b(2,2). Also, a pixel signal based on the charge generated by the photoelectric conversion unit 11a of the G pixel 10g(3,2) in the third row is output to the first vertical signal line VoutA via the first selection unit 18 of the G pixel 10g(3,2).

[0038] After reading out pixel signals from the pixels in the second and third rows, the vertical control unit 30 turns on the second selection unit 19 of the B pixel 10b(4,2), which is a pixel in the fourth row, and turns off the first selection unit 18 of the B pixel 10b(4,2). The vertical control unit 30 also turns on the first selection unit 18 of the G pixel 10g(5,2), which is a pixel in the fifth row, and turns off the second selection unit 19 of the G pixel 10g(5,2). The vertical control unit 30 turns off the first selection unit 18 and second selection unit 19 of the pixels in rows other than the third, fourth, fifth, and sixth rows.

[0039] The pixel signal of the B pixel 10b(4,2) in the fourth row is output to the second vertical signal line VoutB via the second selection unit 19 of the B pixel 10b(4,2). Similarly, the pixel signal of the G pixel 10g(5,2) in the fifth row is output to the first vertical signal line VoutA via the first selection unit 18 of the G pixel 10g(5,2). Similarly, in the image sensor 3, imaging pixel rows are selected two at a time from the sixth row onwards, and pixel signals are output.

[0040] In this way, in the case of the first readout control, imaging pixel rows are selected two at a time in the image sensor 3, and pixel signals are output from the imaging pixels in one row to the first vertical signal line VoutA. Simultaneously, pixel signals are output from the imaging pixels in the other row to the second vertical signal line VoutB. The pixel signals sequentially output to the first vertical signal line VoutA are input to the first readout unit 40a, and the pixel signals sequentially output to the second vertical signal line VoutB are input to the second readout unit 40b. This allows the pixel signals output to the first vertical signal line VoutA and the pixel signals output to the second vertical signal line VoutB to be processed simultaneously (in parallel). The pixel signals output from each imaging pixel 10 are converted into digital signals by the readout unit 40 and then output to the control unit 4 as imaging signals.

[0041] In this embodiment, pixel signals from multiple G pixels 10g in the same column (G pixel 10g(1,2), G pixel 10g(3,2), and G pixel 10g(5,2) in FIG. 4) are output to the same first vertical signal line VoutA and input to the same first readout unit 40a. The AD conversion unit of the first readout unit 40a converts the input pixel signals of each G pixel 10g into digital signals. The pixel signals of each G pixel 10g are processed by the same AD conversion unit. Furthermore, pixel signals from multiple B pixels 10b in the same column (B pixel 10b(2,2), B pixel 10b(4,2), and B pixel 10b(6,2) in FIG. 4) are output to the same second vertical signal line VoutB and input to the same second readout unit 40b for processing. In this manner, in this embodiment, pixel signals from imaging pixels 10 in the same column in which color filters 41 of the same color are arranged are input to the same readout section 40 and processed.

[0042] In readout units provided at positions apart from each other, there is a risk that the characteristics of each readout unit will vary due to manufacturing variations, etc. For example, the conversion gain (AD conversion gain) used when converting analog pixel signals into digital signals will differ from readout unit to readout unit. Therefore, when pixel signals of the same color pixels in the same column are input to different readout units, differences will occur in the converted digital pixel signals due to differences in AD conversion gain.

[0043] In contrast, in the image sensor 3 according to this embodiment, pixel signals from pixels of the same color in the same column are input to the same readout section 40, so it is possible to suppress differences in pixel signals due to variations in the characteristics of each readout section 40. For example, it is possible to suppress differences in pixel signals from each image pixel 10 due to differences in AD conversion gain. As a result, it is possible to prevent degradation in the quality of images generated using the image signals.

[0044] Fig. 5 is a timing chart showing an example of the first readout control of the image sensor 3 according to the first embodiment. In the timing chart shown in Fig. 5, the horizontal axis represents time, and shows control signals input to each unit of the image sensor 3 in Fig. 4 in the case of the first readout control. Also, in Fig. 5, a transistor to which a high-level (e.g., power supply potential) control signal is input is turned on, and a transistor to which a low-level (e.g., ground potential) control signal is input is turned off.

[0045] At time t1 shown in FIG. 5, the signal RST <0> and signal RST <1> The signal RST goes high. <0> becomes high level, turning on the transistor M4 of the reset unit 16 shared by the G pixel 10g(1,2) in the first row and the B pixel 10b(2,2) in the second row. This resets the charge on the capacitance C of the FD 15 shared by the G pixel 10g(1,2) and the B pixel 10b(2,2), and the potential of the FD 15 becomes the reset potential. Also, the signal RST <1> becomes high level, turning on transistor M4 of the reset unit 16 shared by the G pixel 10g(3,2) in the third row and the B pixel 10b(4,2) in the fourth row. This resets the charge on capacitance C of FD15 shared by the G pixel 10g(3,2) and B pixel 10b(4,2), and the potential of FD15 becomes the reset potential.

[0046] Also, at time t1, the signal SELB <0> and signal SELA <1> The signal SELB goes high. <0> When the signal FD15 of the B pixel 10b(2,2) goes high, a signal based on the reset potential of the B pixel 10b(2,2) is output to the second vertical signal line VoutB by the amplifier unit 17 and the second selector unit 19 of the B pixel 10b(2,2). That is, a signal (reset signal) obtained after the charge of the FD15 of the B pixel 10b(2,2) is reset is output to the second vertical signal line VoutB. Also, the signal SELA <1> When this signal goes high, the reset signal of the G pixel 10g(3,2) is output to the first vertical signal line VoutA by the amplifier 17 and first selector 18 of the G pixel 10g(3,2).

[0047] In this way, reset signals are simultaneously output from the G pixel 10g(3,2) in the third row and the B pixel 10b(2,2) in the second row to the first vertical signal line VoutA and the second vertical signal line VoutB, respectively. The reset signals output to the first vertical signal line VoutA and the second vertical signal line VoutB are input to the first readout unit 40a and the second readout unit 40b, respectively, and converted into digital signals.

[0048] At time t2, signal TX2 <0> and signal TX1 <1> becomes high level. Signal TX2 <0> When the signal TX1 goes high, the transistor M2 of the transfer unit 12b in the B pixel 10b(2,2) is turned on, and the charge photoelectrically converted by the photoelectric conversion unit 11b is transferred to the FD 15. <1> When the signal goes high, the transistor M1 of the transfer unit 12a in the G pixel 10g(3,2) is turned on, and the charge photoelectrically converted by the photoelectric conversion unit 11a is transferred to the FD15.

[0049] At time t2, the signal SELB <0> is at a high level, a pixel signal based on the charge generated by the photoelectric conversion unit 11b of the B pixel 10b(2,2) is output to the second vertical signal line VoutB by the amplifier 17 and the second selector 19. <1> is at a high level, the pixel signal of the G pixel 10g(3,2) is output to the first vertical signal line VoutA by the amplifier 17 and the first selector 18.

[0050] In this way, pixel signals are simultaneously output from the G pixel 10g(3,2) in the third row and the B pixel 10b(2,2) in the second row to the first vertical signal line VoutA and the second vertical signal line VoutB, respectively. The pixel signals output to the first vertical signal line VoutA and the second vertical signal line VoutB are input to the first readout unit 40a and the second readout unit 40b, respectively, and converted into digital signals. The reset signal and pixel signal converted into digital signals are input to a signal processing unit (not shown). The signal processing unit performs signal processing such as correlated double sampling, which processes the difference between the reset signal and the pixel signal, and then outputs the processed pixel signal to the control unit 4.

[0051] At time t3, the signal RST <1> and signal RST <2> The signal RST goes high. <1> When this signal goes high, the transistor M4 of the reset unit 16 shared by the G pixel 10g(3,2) in the third row and the B pixel 10b(4,2) in the fourth row is turned on. This resets the charge on the capacitor C of the FD 15 shared by the G pixel 10g(3,2) and the B pixel 10b(4,2). Also, the signal RST <2> When this signal goes high, the transistor M4 of the reset unit 16 shared by the G pixel 10g(5,2) in the fifth row and the B pixel 10b(6,2) in the sixth row is turned on. This resets the charge on the capacitor C of the FD 15 shared by the G pixel 10g(5,2) and the B pixel 10b(6,2).

[0052] Also, at time t3, the signal SELB <1> and signal SELA <2> The signal SELB goes high. <1> When the signal SELA goes high, the reset signal of the B pixel 10b(4,2) is output to the second vertical signal line VoutB by the amplifier 17 and the second selector 19. <2> When the reset signal from the G pixel 10g(5,2) goes high, the amplifier 17 and the first selector 18 output the reset signal from the G pixel 10g(5,2) to the first vertical signal line VoutA.

[0053] In this way, reset signals are simultaneously output from the G pixel 10g(5,2) in the fifth row and the B pixel 10b(4,2) in the fourth row to the first vertical signal line VoutA and the second vertical signal line VoutB, respectively. The reset signals output to the first vertical signal line VoutA and the second vertical signal line VoutB are input to the first readout unit 40a and the second readout unit 40b, respectively, and converted into digital signals.

[0054] At time t4, signal TX2 <1> and signal TX1 <2> becomes high level. Signal TX2 <1> When the signal TX1 goes high, the charge photoelectrically converted by the photoelectric conversion unit 11b in the B pixel 10b(4,2) is transferred to the FD 15. <2> When the signal SELB goes high, the charge photoelectrically converted by the photoelectric conversion unit 11a in the G pixel 10g(5,2) is transferred to the FD 15. Also, at time t4, the signal SELB <1> is at a high level, the pixel signal of the B pixel 10b(4,2) is output to the second vertical signal line VoutB by the amplifier 17 and the second selector 19. <2> is at a high level, the pixel signal of the G pixel 10g(5,2) is output to the first vertical signal line VoutA by the amplifier 17 and the first selector 18.

[0055] In this way, pixel signals are simultaneously output from the G pixel 10g(5,2) in the fifth row and the B pixel 10b(4,2) in the fourth row to the first vertical signal line VoutA and the second vertical signal line VoutB, respectively. The pixel signals output to the first vertical signal line VoutA and the second vertical signal line VoutB are input to the first readout unit 40a and the second readout unit 40b, respectively, and converted into digital signals. The reset signal and pixel signal converted into digital signals are input to a signal processing unit (not shown). The signal processing unit performs signal processing such as correlated double sampling, and then outputs the processed pixel signals to the control unit 4.

[0056] In the period after time t5, similarly to the period from time t1 to time t5, imaging pixel rows are selected two at a time, and reset signal readout and pixel signal readout are performed. In this way, with the first readout control shown in Fig. 5, imaging pixel rows are selected two at a time, and pixel signals can be read out from multiple rows simultaneously.

[0057] Next, the second readout control will be described with reference to Figures 6 and 7. To simplify the description, the example shown in Figure 6 illustrates only the G pixel 10g (7,2) in the seventh row and second column, the first AF pixel 13a (8,2) in the eighth row and second column, the G pixel 10g (15,2) in the fifteenth row and second column, and the second AF pixel 13b (16,2) in the sixteenth row and second column, from among the multiple pixels shown in Figure 2. In the second readout control, the vertical control unit 30 sequentially selects every two AF pixel rows of the image sensor 3 and sequentially reads out signals from the pixels.

[0058] The vertical control unit 30 turns on the first selection unit 18 of the first AF pixel 13a(8,2) in the eighth row, which is an AF pixel row, and turns off the second selection unit 19 of the first AF pixel 13a(8,2). The vertical control unit 30 also turns on the second selection unit 19 of the second AF pixel 13b(16,2) in the sixteenth row, which is an AF pixel row, and turns off the first selection unit 18 of the second AF pixel 13b(16,2). The vertical control unit 30 also turns off the first selection unit 18 and the second selection unit 19 of pixels in rows other than the seventh, eighth, fifteenth, and sixteenth rows. As a result, the pixel signal of the first AF pixel 13a(8,2) in the eighth row is output to the first vertical signal line VoutA via the first selection unit 18 of the first AF pixel 13a(8,2). Furthermore, the pixel signal of the second AF pixel 13b(16,2) in the 16th row is output to the second vertical signal line VoutB via the second selection unit 19 of the second AF pixel 13b(16,2). Similarly, in the image sensor 3, for the 17th and subsequent AF pixel rows, the AF pixel rows are sequentially selected two at a time, and pixel signals are output.

[0059] In this way, in the case of the second readout control, two AF pixel rows are selected at a time in the image sensor 3, and pixel signals are output from the AF pixels in one row to the first vertical signal line VoutA. At the same time, pixel signals are output from the AF pixels in the other row to the second vertical signal line VoutB. This allows signals to be read out quickly from each AF pixel 13 arranged in the image sensor 3. In other words, the image sensor 3 can shorten the time it takes to read out the signals from the AF pixels 13. This allows the control unit 4 to shorten the time required for focus detection and focus adjustment.

[0060] Furthermore, the pixel signals output to the first vertical signal line VoutA and the second vertical signal line VoutB are input to the first readout unit 40a and the second readout unit 40b, respectively, and converted into digital signals. Because the pixel signals of each AF pixel 13 are processed in parallel by the first and second readout units 40a and 40b, AD conversion processing for the pixel signals of each AF pixel can be performed at high speed. After being converted into digital signals by the readout unit 40, the pixel signals of the first AF pixel 13a and the second AF pixel 13b are output to the control unit 4 as a pair of focus detection signals.

[0061] Fig. 7 is a timing chart showing an example of the second readout control of the image sensor 3 according to the first embodiment. In the timing chart shown in Fig. 7, the horizontal axis represents time, and shows control signals input to each unit of the image sensor 3 in Fig. 6 in the case of the second readout control.

[0062] At time t1 shown in FIG. 7, the signal RST <3> and signal RST <4> The signal RST goes high. <3> When the signal RST goes high, the charge on the capacitance C of the FD 15 is reset in the G pixel 10g(7,2) in the seventh row and the first AF pixel 13a(8,2) in the eighth row. <4> When this signal goes high, the charge on the capacitance C of the FD 15 is reset in the G pixel 10g (15,2) on the 15th row and the second AF pixel 13b (16,2) on the 16th row.

[0063] Also, at time t1, the signal SELA <3> and signal SELB <4> The signal SELA becomes high level. <3> When the signal SELB becomes high level, the reset signal of the first AF pixel 13a(8,2) is output to the first vertical signal line VoutA by the amplifier 17 and the first selector 18. <4> When the signal VoutB becomes high level, the reset signal of the second AF pixel 13b(16,2) is output to the second vertical signal line VoutB by the amplifier 17 and the second selector 19.

[0064] In this way, reset signals are simultaneously output from the first AF pixel 13a (8,2) on the eighth row and the second AF pixel 13b (16,2) on the sixteenth row to the first vertical signal line VoutA and the second vertical signal line VoutB, respectively. The reset signals output to the first vertical signal line VoutA and the second vertical signal line VoutB, respectively, are input to the first readout unit 40a and the second readout unit 40b, and converted into digital signals.

[0065] At time t2, signal TX2 <3> and signal TX2 <4> becomes high level. Signal TX2 <3> When the signal TX2 goes high, the charge photoelectrically converted by the photoelectric conversion unit 11b in the first AF pixel 13a(8,2) in the eighth row is transferred to the FD 15. <4> When the signal CS1 goes high, the charge photoelectrically converted by the photoelectric conversion unit 11b in the second AF pixel 13b (16,2) on the 16th row is transferred to the FD 15. Also, at time t2, the signal SELA <3> is at a high level, the pixel signal of the first AF pixel 13a(8,2) is output to the first vertical signal line VoutA by the amplifier 17 and the first selector 18. <4> is at a high level, the pixel signal of the second AF pixel 13b(16,2) is output to the second vertical signal line VoutB by the amplifier 17 and the second selector 19.

[0066] In this way, pixel signals are simultaneously output to the first vertical signal line VoutA and the second vertical signal line VoutB from the first AF pixel 13a (8,2) in the eighth row and the second AF pixel 13b (16,2) in the sixteenth row. The pixel signals output to the first vertical signal line VoutA and the second vertical signal line VoutB are input to the first readout unit 40a and the second readout unit 40b, respectively, and converted into digital signals. The reset signal and pixel signal converted into digital signals are input to a signal processing unit (not shown). The signal processing unit performs signal processing such as correlated double sampling, which performs differential processing between the reset signal and the pixel signal, and then outputs the processed pixel signal to the control unit 4.

[0067] Next, the third readout control will be described with reference to Fig. 6 and Fig. 8. In the third readout control, the vertical control unit 30 sequentially selects the AF pixel rows of the image sensor 3 one by one, and sequentially reads out signals from the pixels.

[0068] The vertical control unit 30 turns on the first selection unit 18 of the first AF pixel 13a(8,2) in the eighth row, which is an AF pixel row, and turns off the second selection unit 19 of the first AF pixel 13a(8,2). The vertical control unit 30 also turns off the first selection unit 18 and the second selection unit 19 of pixels in rows other than the seventh and eighth rows. As a result, the pixel signal of the first AF pixel 13a(8,2) in the eighth row is output to the first vertical signal line VoutA via the first selection unit 18.

[0069] After reading out the pixel signal from the pixel in the eighth row, the vertical control unit 30 turns on the first selection unit 18 of the second AF pixel 13b(16,2) in the 16th row, which is an AF pixel row, and turns off the second selection unit 19 of the second AF pixel 13b(16,2). The vertical control unit 30 also turns off the first selection unit 18 and the second selection unit 19 of the pixels in rows other than the 15th and 16th rows. As a result, the pixel signal of the second AF pixel 13b(16,2) in the 16th row is output to the first vertical signal line VoutA via the first selection unit 18.

[0070] Although an example has been described in which the pixel signal of the AF pixel 13 is output to the first vertical signal line VoutA, if the first selection unit 18 is in the off state and the second selection unit 19 is in the on state, the pixel signal can be output from the AF pixel 13 to the second vertical signal line VoutB.

[0071] As described above, in the case of the third readout control, AF pixel rows are selected one by one in the image sensor 3, and pixel signals are output from each pixel in the AF pixel row to the first vertical signal line VoutA (or the second vertical signal line VoutB). The pixel signals of each AF pixel in the same column are input to the AD conversion unit of the same readout unit 40. This makes it possible to suppress differences in the pixel signals output from each AF pixel due to deviations in AD conversion gain. As a result, it is possible to prevent a decrease in the accuracy of focus detection using focus detection signals.

[0072] Fig. 8 is a timing chart showing an example of the third readout control of the image sensor 3 according to the first embodiment. In the timing chart shown in Fig. 8, the horizontal axis represents time, and shows control signals input to each unit of the image sensor 3 in Fig. 6 in the case of the third readout control.

[0073] At time t1 shown in FIG. <3> When the signal SELA becomes high level, the charge of the capacitance C of the FD 15 is reset in the G pixel 10g(7,2) in the seventh row and the first AF pixel 13a(8,2) in the eighth row. <3> When the signal VoutA becomes high level, the reset signal of the first AF pixel 13a(8,2) is output to the first vertical signal line VoutA.

[0074] At time t2, signal TX2 <3> When the signal SELA becomes high level, the charge photoelectrically converted by the photoelectric conversion unit 11b in the first AF pixel 13a(8,2) in the eighth row is transferred to the FD 15. Also, at time t2, the signal SELA <3> is at a high level, the pixel signal of the first AF pixel 13a(8,2) is output to the first vertical signal line VoutA.

[0075] At time t3, the signal RST <4> When the signal SELA goes high, the charge of the capacitance C of the FD 15 is reset in the G pixel 10g (15,2) in the 15th row and the second AF pixel 13b (16,2) in the 16th row. <4> When the signal VoutA becomes high level, the reset signal of the second AF pixel 13b(16,2) is output to the first vertical signal line VoutA.

[0076] At time t4, signal TX2 <4> When the signal SELA goes high, the charge photoelectrically converted by the photoelectric conversion unit 11b in the second AF pixel 13b (16,2) in the 16th row is transferred to the FD 15. Also, at time t4, the signal SELA <4> is at a high level, the pixel signal of the second AF pixel 13b(16,2) is output to the first vertical signal line VoutA.

[0077] The reset signal and pixel signal sequentially output to the first vertical signal line VoutA are converted into digital signals by the first readout unit 40a. The converted digital pixel signals are subjected to signal processing such as correlated double sampling and then output to the control unit 4.

[0078] As described above, the image sensor 3 according to this embodiment can perform the first readout control, the second readout control, and the third readout control. By performing the first readout control, the image sensor 3 can improve the accuracy of the signals from the imaging pixels. Furthermore, in the case of the second readout control, the image sensor 3 can improve the readout speed of the signals from the AF pixels, and in the case of the third readout control, the accuracy of the signals from the AF pixels.

[0079] According to the above-described embodiment, the following effects can be obtained. (1) The image sensor 3 includes a first pixel (AF pixel 13) and a second pixel (AF pixel 13) arranged in a first direction, each of which has a first photoelectric conversion unit (photoelectric conversion unit 11) that photoelectrically converts light to generate electric charges and a light-shielding unit 43 that blocks part of the light incident on the first photoelectric conversion unit, and outputs a signal based on the electric charges generated in the first photoelectric conversion unit; and a third pixel (imaging pixel 10) and a fourth pixel (AF pixel 13) arranged in the first direction, each of which has a second photoelectric conversion unit that photoelectrically converts light to generate electric charges and outputs a signal based on the electric charges generated in the second photoelectric conversion unit. The vertical control unit 30 includes a pixel (imaging pixel 10), a first signal line (first vertical signal line VoutA) and a second signal line (second vertical signal line VoutB) that are arranged in a first direction and output a signal from one of a first pixel, a second pixel, a third pixel, and a fourth pixel, and a control unit (vertical control unit 30) that performs first control (second readout control) to output the signal from the first pixel to the first signal line and the signal from the second pixel to the second signal line, and second control (first readout control) to output the signal from the third pixel and the signal from the fourth pixel to the first signal line or the second signal line. In this embodiment, the vertical control unit 30 performs the first control (second readout control) and the second control (first readout control). By performing the second control, the vertical control unit 30 can improve the accuracy of the signal from the imaging pixel, and by performing the first control, can improve the readout speed of the signal from the AF pixel.

[0080] (2) The control unit (vertical control unit 30) performs a third control (third readout control) that outputs the signal of the first pixel and the signal of the second pixel to the first signal line or the second signal line. In this embodiment, the vertical control unit 30 performs the third control (third readout control). By performing the third control, the vertical control unit 30 can improve the accuracy of the signal of the AF pixel.

[0081] The following modifications are also within the scope of the present invention, and one or more of the modifications may be combined with the above-described embodiment.

[0082] (Variation 1) FIG. 9 is a diagram showing a partial configuration of an image sensor according to Modification 1, and FIG. 10 is a timing chart showing an example of first readout control of the image sensor according to Modification 1. Note that, in the example shown in FIG. 9, for simplicity of explanation, only one pixel in the row direction and four pixels in the column direction are shown. Of the multiple pixels shown in FIG. 2, FIG. 9 shows a G pixel 10g(1,2) in the first row and second column, a B pixel 10b(2,2) in the second row and second column, a G pixel 10g(3,2) in the third row and second column, and a B pixel 10b(4,2) in the fourth row and second column. Hereinafter, the first readout control of the image sensor according to Modification 1 will be described with reference to FIGS. 9 and 10.

[0083] At time t1 shown in FIG. 10, the signal RST <0> and signal RST <1> The signal RST goes high. <0> When the signal goes high, the charge on the capacitance C of the FD 15 shared by the G pixel 10g(1,2) and the B pixel 10b(2,2) is reset. Also, the signal RST <1> When the signal goes high, the charge on the capacitance C of the FD 15 shared by the G pixel 10g(3,2) and the B pixel 10b(4,2) is reset.

[0084] Also, at time t1, the signal SELA <0> and signal SELB <1> The signal SELA becomes high level. <0> When this signal goes high, the reset signal of the G pixel 10g(1,2) is output to the first vertical signal line VoutA by the amplifier 17 and first selector 18 of the G pixel 10g(1,2). Also, the signal SELB <1> When the reset signal of the B pixel 10b(4,2) becomes high level, the reset signal of the B pixel 10b(4,2) is output to the second vertical signal line VoutB by the amplifier unit 17 and the second selector unit 19 of the B pixel 10b(4,2).

[0085] In this way, reset signals are simultaneously output from the G pixel 10g(1,2) in the first row and the B pixel 10b(4,2) in the fourth row to the first vertical signal line VoutA and the second vertical signal line VoutB, respectively. The reset signals output to the first vertical signal line VoutA and the second vertical signal line VoutB are input to the first readout unit 40a and the second readout unit 40b, respectively, and converted into digital signals.

[0086] At time t2, signal TX1 <0> and signal TX2 <1> becomes high level. Signal TX1 <0> When the signal TX2 goes high, the charge photoelectrically converted by the photoelectric conversion unit 11a in the G pixel 10g(1,2) is transferred to the FD 15. <1> When the signal CS goes high, the charge photoelectrically converted by the photoelectric conversion unit 11b in the B pixel 10b(4,2) is transferred to the FD 15. Also, at time t2, the signal SELA <0> is at a high level, the pixel signal of the G pixel 10g(1,2) is output to the first vertical signal line VoutA. <1> is at a high level, the pixel signal of the B pixel 10b(4,2) is output to the second vertical signal line VoutB.

[0087] In this way, pixel signals from the G pixel 10g(1,2) in the first row and the B pixel 10b(4,2) in the fourth row are simultaneously output to the first vertical signal line VoutA and the second vertical signal line VoutB, respectively. The pixel signals output to the first vertical signal line VoutA and the second vertical signal line VoutB are input to the first readout unit 40a and the second readout unit 40b, respectively, and converted into digital signals. The converted digital pixel signals are subjected to signal processing such as correlated double sampling, and then output to the control unit 4.

[0088] At time t3, the signal RST <0> and signal RST <1> The signal RST goes high. <0> When the signal goes high, the charge on the capacitance C of the FD 15 shared by the G pixel 10g(1,2) and the B pixel 10b(2,2) is reset. Also, the signal RST <1> When the signal goes high, the charge on the capacitance C of the FD 15 shared by the G pixel 10g(3,2) and the B pixel 10b(4,2) is reset.

[0089] Also, at time t3, the signal SELB <0> and signal SELA <1> The signal SELB goes high. <0> When the signal SELA becomes high level, the reset signal of the B pixel 10b(2,2) is output to the second vertical signal line VoutB. <1> When the signal VoutA becomes high level, the reset signal of the G pixel 10g(3,2) is output to the first vertical signal line VoutA.

[0090] In this way, reset signals are simultaneously output from the G pixel 10g(3,2) in the third row and the B pixel 10b(2,2) in the second row to the first vertical signal line VoutA and the second vertical signal line VoutB, respectively. The reset signals output to the first vertical signal line VoutA and the second vertical signal line VoutB are input to the first readout unit 40a and the second readout unit 40b, respectively, and converted into digital signals.

[0091] At time t4, signal TX2 <0> and signal TX1 <1> becomes high level. Signal TX2 <0> When the signal TX1 goes high, the charge photoelectrically converted by the photoelectric conversion unit 11b in the B pixel 10b(2,2) is transferred to the FD 15. <1> When the signal SELB goes high, the charge photoelectrically converted by the photoelectric conversion unit 11a in the G pixel 10g(3,2) is transferred to the FD 15. Also, at time t4, the signal SELB <0> is at a high level, the pixel signal of the B pixel 10b(2,2) is output to the second vertical signal line VoutB. <1> is at a high level, the pixel signal of the G pixel 10g(3,2) is output to the first vertical signal line VoutA.

[0092] In this way, pixel signals from the G pixel 10g(3,2) in the third row and the B pixel 10b(2,2) in the second row are simultaneously output to the first vertical signal line VoutA and the second vertical signal line VoutB, respectively. The pixel signals output to the first vertical signal line VoutA and the second vertical signal line VoutB are input to the first readout unit 40a and the second readout unit 40b, respectively, and converted into digital signals. The converted digital pixel signals are subjected to signal processing such as correlated double sampling, and then output to the control unit 4.

[0093] In the period after time t5, similarly to the period from time t1 to time t5, imaging pixel rows are selected two at a time, and reset signal readout and pixel signal readout are performed. Thus, in the first readout control according to Modification 1, similarly to the above-described embodiment, imaging pixel rows are selected two at a time, and pixel signals can be simultaneously read out in units of multiple rows. Furthermore, pixel signals of pixels of the same color in the same column can be read out to the same readout unit 40, thereby suppressing differences in pixel signals due to variations in the characteristics of each readout unit 40.

[0094] (Variation 2) In the first embodiment described above, an example has been described in which two adjacent pixels share the FD 15, etc., but the pixel configuration is not limited to this. For example, each of the multiple pixels provided in the image sensor 3 may be configured to have the FD 15, a reset unit 16, an amplifier unit 17, a first selection unit 18, and a second selection unit 19. Alternatively, three or more pixels may be configured to share the FD 15, etc. For example, four pixels may be configured to share the FD 15, etc.

[0095] Fig. 11 is a diagram showing an example of the configuration of an image sensor in which four pixels share an FD 15, etc. In Fig. 11, the pixel in the upper left corner is the imaging pixel 10(1,1) in the first row and first column, and the pixel in the lower right corner is the imaging pixel 10(8,3) in the eighth row and third column, and 24 pixels from imaging pixel 10(1,1) to imaging pixel 10(8,3) are shown.

[0096] 11, dotted lines 20 schematically indicate that four pixels share the FD 15, reset unit 16, amplifier unit 17, first selection unit 18, and second selection unit 19. The AF pixel 13 shown in Fig. 11 is the first AF pixel 13a or the second AF pixel 13b described above. AF pixel 13(2,2) shares the FD 15 and other elements with AF pixel 13(4,2), and AF pixel 13(6,2) shares the FD 15 and other elements with AF pixel 13(8,2).

[0097] In the third readout control, the vertical control unit 30 according to this modification sequentially selects, for example, the AF pixel 13(2,2), the AF pixel 13(4,2), the AF pixel 13(6,2), and the AF pixel 13(8,2) to read out the signal. In the second readout control, the vertical control unit 30 selects the AF pixel 13(2,2) or the AF pixel 13(4,2) to output the pixel signal to the first vertical signal line VoutA (or the second vertical signal line VoutB). Simultaneously with this readout, the vertical control unit 30 selects the AF pixel 13(6,2) or the AF pixel 13(8,2) to output the pixel signal to the second vertical signal line VoutB (or the first vertical signal line VoutA). Therefore, even when the FD 15 or the like is shared among multiple AF pixels, signals can be read out from each AF pixel 13 at high speed.

[0098] (Variation 3) In the above-described embodiment, an example in which the first vertical signal line VoutA and the second vertical signal line VoutB are arranged as vertical signal lines has been described, but this is not limiting. For example, three or more vertical signal lines may be arranged. Increasing the number of vertical signal lines allows pixel signals from the AF pixels 13 to be read out at even higher speeds.

[0099] (Variation 4) In the above-described embodiment, an example has been described in which a G color filter 41 is disposed in the AF pixel 13. However, the present invention is not limited to this. For example, a W (white) color filter or a B color filter may be disposed as the color filter 41 in the AF pixel 13.

[0100] (Modification 5) In the above embodiment, the case where primary color (RGB) color filters are used in the imaging element 3 has been described, but complementary color (CMY) color filters may also be used.

[0101] (Variation 6) In the above-described embodiment and modifications, the photodiode is used as the photoelectric conversion unit, but a photoelectric conversion film may be used as the photoelectric conversion unit.

[0102] (Variation 7) The imaging element 3 described in the above-mentioned embodiments and variations may be applied to cameras, smartphones, tablets, cameras built into PCs, in-vehicle cameras, cameras mounted on unmanned aerial vehicles (drones, radio-controlled aircraft, etc.), etc.

[0103] (Variation 8) The imaging elements described in the above-described embodiments and modifications may be applied to a stacked sensor (stacked-type imaging element) configured by stacking multiple substrates (for example, multiple semiconductor substrates). For example, the pixel section 100 is arranged on a first-layer substrate, the vertical control section 30 and readout section 40 are arranged on a second-layer substrate, and the vertical signal line Vout is arranged between the first-layer substrate and the second-layer substrate. The pixel section 100 and vertical control section 30 may also be arranged on the first-layer substrate, and the readout section 40 may be arranged on the second-layer substrate. The stacked sensor may also have three or more layers.

[0104] Although various embodiments and modifications have been described above, the present invention is not limited to these. Other embodiments that are conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention.

[0105] The disclosures of the following priority applications are incorporated herein by reference: Japanese Patent Application No. 2018-67700 (filed March 30, 2018) [Explanation of symbols]

[0106] 3 imaging element, 4 control unit, 10 imaging pixel, 13a first AF pixel, 13b second AF pixel, 30 vertical control unit, 40a first readout unit, 40b second readout unit

Claims

[Claim 1] a pixel section in which the following pixels are arranged along a column direction: a first pixel having a first photoelectric conversion unit that converts light transmitted through an optical system into an electric charge, and that outputs a first signal used for focus detection of the optical system; a second pixel having a second photoelectric conversion unit that converts light transmitted through the optical system into an electric charge, and that outputs a second signal used for focus detection of the optical system; a third pixel having a third photoelectric conversion unit that converts light transmitted through the optical system into an electric charge, and that outputs a third signal used for image generation; and a fourth pixel having a fourth photoelectric conversion unit that converts light transmitted through the optical system into an electric charge, and that outputs a fourth signal used for image generation; a first signal line electrically connectable to the first pixel, the second pixel, the third pixel, and the fourth pixel; a second signal line electrically connectable to the first pixel, the second pixel, the third pixel, and the fourth pixel; a first readout unit that performs signal processing on the signal output to the first signal line among the first signal, the second signal, the third signal, and the fourth signal; a second readout unit that performs signal processing on the signal output to the second signal line among the first signal, the second signal, the third signal, and the fourth signal; a vertical control unit that performs first control to control the first pixel and the second pixel so that the first signal and the second signal are output to one of the first signal line and the second signal line, and second control to control the third pixel and the fourth pixel so that the third signal and the fourth signal are output to different signal lines of the first signal line and the second signal line; An imaging element comprising:

Images