JP2020074548A - Image sensor and imaging apparatus - Google Patents

Abstract

To provide an image sensor which can read a signal for use in focus detection and a signal for use in image generation at high speed.SOLUTION: An image sensor 212 includes: a pixel array part 40 having a first pixel group where first pixels generating a plurality of first analog signals corresponding to the amount of incident light are arranged in a first direction, a plurality of first pixel groups being arranged in a second direction crossing the first direction; a row scanning circuit 41 for scanning the plurality of first pixel groups in the second direction in the pixel array part; a column AD converter 42 for converting the plurality of first analog signals in parallel into a plurality of first digital signals; a column digital adder circuit 46 for adding the plurality of first digital signals; a second horizontal output circuit 45 for outputting the plurality of first digital signals to the outside; and a first horizontal output circuit 49 for outputting an added digital signal obtained by adding the plurality of first digital signals by the column digital adder circuit.SELECTED DRAWING: Figure 10

Description

  The present invention relates to an image pickup device and an image pickup apparatus.

  An image pickup device, in which focus detection pixels composed of a microlens and a pair of photoelectric conversion units arranged behind the microlens, are arranged on the planned focal plane of the photographing lens, thereby forming a pair of focus detection light beams passing through the optical system. A pair of image signals corresponding to the pair of images are generated as analog signals in the pair of photoelectric conversion units, and the pair of analog signals are independently read from the image sensor to determine the image shift amount (phase difference) between the pair of image signals. The focus adjustment state (defocus amount) of the taking lens is detected by detecting, and the analog signals generated by the pair of photoelectric conversion units of the focus detection pixel are analog-added in the focus detection pixel, and the analog after addition is added. 2. Description of the Related Art There is known an image pickup apparatus that reads out a signal as an image signal from an image pickup element to generate image information (see, for example, Patent Document 1).

JP, 2001-83407, A

  In the image pickup apparatus as described above, since a pair of analog signals are analog-added in the focus detection pixel, the pair of analog signals are independently read from the image pickup element during focus detection, and the image pickup element is generated during image information generation. Therefore, it is necessary to add a pair of analog signals and read out, and there is a problem that focus detection and image information generation cannot be performed at the same time in signal reading out for one frame from the image sensor.

The image sensor according to the first aspect of the present invention converts light into electric charge, and has a first pixel having a first photoelectric conversion unit and a second photoelectric conversion unit which are provided in a first direction, and light to charge. Converted into a second pixel having a third photoelectric conversion part and a fourth photoelectric conversion part provided in a second direction intersecting the first direction, and converted by the first photoelectric conversion part. A first signal line that outputs a signal based on charges, a second signal line that outputs a signal based on charges converted by the second photoelectric conversion unit, and a signal converted by the third photoelectric conversion unit A third signal line that outputs a signal based on electric charge, a fourth signal line that outputs a signal based on electric charge converted by the fourth photoelectric conversion unit, and a signal output from the first signal line And a signal output from the second signal line are added, and a signal output from the third signal line and the fourth signal line are added. An adder for adding a signal output on a signal line, a signal output on the first signal line, a signal output on the second signal line, and a signal output on the third signal line And a first output line that outputs at least one of the signals output from the fourth signal line, and a second output line that outputs the signal added by the adder.
An image sensor according to a second aspect of the present invention converts light into electric charges, converts a light into electric charges in a first pixel having a first photoelectric conversion unit and a second photoelectric conversion unit, and converts the light into electric charges. A second pixel having a photoelectric conversion unit, a first signal line for outputting a signal based on the charges converted by the first photoelectric conversion unit, and the charges converted by the second photoelectric conversion unit. A second signal line for outputting a signal based on the charges, a third signal line for outputting a signal based on the charges converted by the third photoelectric conversion unit, a signal output on the first signal line, and An adding unit for adding the signal output from the second signal line, and a first output unit that outputs at least one of the signal output from the first signal line and the signal output from the second signal line. Output line, and at least the signal added by the adder and the signal output by the third signal line. Comprising a second output line for outputting the One, the.
An image pickup apparatus according to a third aspect of the present invention includes the image pickup element according to the first or second aspect, and a generation unit that generates image data based on the signal added by the addition unit.

  According to the present invention, for example, a signal used for focus detection and a signal used for image generation can be read at high speed.

FIG. 3 is a transverse cross-sectional view showing the configuration of a lens-interchangeable digital still camera equipped with the image sensor of one embodiment. It is a figure which shows the focus detection position on the imaging screen of an interchangeable lens. It is a front view which shows the detailed structure of an image sensor. It is a front view which shows the detailed structure of an image sensor. It is a figure which shows the spectral sensitivity characteristic of each color filter. It is a figure which shows the structure of a focus detection pixel. It is sectional drawing of a focus detection pixel. It is a figure which shows the structure of the focus detection optical system of a pupil division type phase difference detection system. It is a block diagram which shows in detail the relationship between an image sensor and a body drive control device. It is a block diagram which shows the structure of an image sensor. 7 is a timing chart in the case where the individual read operation of the output signals of the pair of photoelectric conversion units of the focus detection pixel and the read operation of the added signal obtained by adding the output signals of the pair of photoelectric conversion units are performed in parallel during one frame period. .. 7 is a timing chart in the case where the individual read operation of the output signals of the pair of photoelectric conversion units of the focus detection pixel and the read operation of the added signal obtained by adding the output signals of the pair of photoelectric conversion units are performed in parallel during one frame period. .. 7 is an operation flowchart of a focus detection CPUa of the body drive control device included in the digital still camera. 7 is an operation flowchart of a CPUb for image processing of the body drive control device included in the digital still camera. It is a figure which shows the correlation calculation result of a pair of data string. It is a timing chart at the time of performing row partial read. It is a figure which shows the structure of a focus detection pixel. It is a front view which shows the detailed structure of an image sensor. It is a block diagram which shows the structure of an image sensor. It is a front view which shows the detailed structure of an image sensor. It is a front view which shows the detailed structure of an image sensor. It is a figure which shows the structure of an imaging pixel. It is sectional drawing of an imaging pixel. It is a figure for explaining the mode of a photography light flux. It is a front view which shows the detailed structure of an image sensor. It is a block diagram which shows the structure of an image sensor. It is a figure explaining the selection operation of the switch provided in the pixel column of two adjacent columns. It is a figure explaining the selection operation of the switch provided in the pixel column of two adjacent columns. FIG. 6 is a timing chart in the case where an individual read operation of output signals of a pair of photoelectric conversion units of a focus detection pixel and an output signal read operation of an output signal of an imaging pixel are performed in parallel during one frame period. It is a timing chart at the time of performing row partial read. It is a block diagram which shows the structure of an image sensor. It is a figure explaining the selection operation of the switch provided in the pixel column of two adjacent columns. It is a front view which shows the detailed structure of an image sensor. It is a block diagram which shows the structure of an image sensor. It is a block diagram which shows the structure of an image sensor. It is a front view which shows the detailed structure of an image sensor. It is a front view which shows the detailed structure of an image sensor. It is a block diagram which shows the structure of an image sensor. It is a front view which shows the detailed structure of an image sensor. It is a block diagram which shows the structure of an image sensor.

<First Embodiment>
An image pickup device and an image pickup apparatus according to an embodiment of the present invention will be described. FIG. 1 is a cross-sectional view showing the configuration of a lens-interchangeable digital still camera equipped with an image sensor according to an embodiment. A digital still camera 201 according to an embodiment includes an interchangeable lens 202 and a camera body 203, and various interchangeable lenses 202 are mounted on the camera body 203 via a mount section 204.

  The interchangeable lens 202 includes a lens 209, a zooming lens 208, a focusing lens 210, a diaphragm 211, a lens drive control device 206, and the like. The lens drive control device 206 is composed of a microcomputer, a memory, a drive control circuit, and the like (not shown). The lens drive control device 206 controls the focus of the focusing lens 210 and the aperture diameter of the diaphragm 211, the zooming lens 208, and the focusing lens. In addition to detecting the states of the lens 210 and the diaphragm 211, lens information is transmitted and camera information is received by communication with a body drive control device 214 described later. The diaphragm 211 forms an aperture with a variable aperture diameter at the center of the optical axis for adjusting the amount of light and the amount of blur.

  The camera body 203 includes an image pickup element 212, a body drive control device 214, a liquid crystal display element drive circuit 215, a liquid crystal display element 216, an eyepiece lens 217, a memory card 219, and the like. In the image pickup element 212, pixels that function as image pickup pixels and focus detection pixels are two-dimensionally arranged. Details of the image sensor 212 will be described later.

  The body drive control device 214 is composed of a microcomputer, a memory, a drive control circuit, and the like, and controls the drive of the image sensor 212, reads an output signal from the image sensor 212, performs focus detection calculation based on the output signal, and replaces the interchangeable lens 202. The focus adjustment is repeatedly performed, and image processing calculation and recording based on the output signal and operation control of the camera are performed. Further, the body drive control device 214 communicates with the lens drive control device 206 via the electric contact 213, and receives lens information and camera information (defocus amount, aperture value, etc.).

  The liquid crystal display element 216 functions as an electronic view finder (EVF). The liquid crystal display element drive circuit 215 displays a through image by the image pickup element 212 on the liquid crystal display element 216, and the photographer can observe the through image through the eyepiece lens 217. The memory card 219 is an image storage that stores an image captured by the image sensor 212.

  The light flux that has passed through the interchangeable lens 202 forms a subject image on the light receiving surface of the image sensor 212. This subject image is photoelectrically converted by each pixel of the image pickup element 212, and the output signal of each pixel is sent to the body drive control device 214.

  The body drive control device 214 calculates the defocus amount based on the output signal from each pixel of the image sensor 212, and sends the defocus amount to the lens drive control device 206. Further, the body drive control device 214 processes the output signal from each pixel of the image sensor 212 to generate image data, stores the image data in the memory card 219, and drives the liquid crystal display device to drive the through image signal from the image sensor 212. It is sent to the circuit 215 and the through image is displayed on the liquid crystal display element 216. Further, the body drive control device 214 sends aperture control information to the lens drive control device 206 to control the aperture of the aperture 211.

  The lens drive control device 206 updates the lens information according to the focusing state, zooming state, aperture setting state, aperture open F value, and the like. Specifically, the positions of the zooming lens 208 and the focusing lens 210 and the aperture value of the aperture 211 are detected, lens information is calculated according to these lens positions and aperture values, or a lookup prepared in advance is performed. Lens information corresponding to the lens position and the aperture value is selected from the table.

  The lens drive control device 206 calculates the lens drive amount based on the received defocus amount, and drives the focusing lens 210 to the in-focus position according to the lens drive amount. Further, the lens drive controller 206 drives the diaphragm 211 according to the received diaphragm value.

  FIG. 2 is a diagram showing a focus detection position (set by the user by operating an operation member not shown in FIG. 1) on the shooting screen of the interchangeable lens 202. An example of an area (focus detection area, focus detection position) in which an image is sampled on a shooting screen at the time of detection is shown. In this example, the focus detection area 101 is arranged at the center of the rectangular photographing screen 100. The focus detection area 101 shown by a rectangle extends in the horizontal direction on the photographing screen 100, and the output signals of pixels linearly arranged along the longitudinal direction of the focus detection area 101 are used for focus detection.

  3 and 4 are front views showing the detailed configuration of the image pickup element 212, which is an enlarged view of the vicinity of the focus detection area 101 on the image pickup element 212. FIG. 3 is a diagram showing a layout of a pixel 311 (hereinafter referred to as a focus detection pixel 311) that serves as an image pickup pixel and a focus detection pixel. The focus detection pixel 311 has a row direction (horizontal direction light) and a column direction (vertical direction). Are densely arranged in a two-dimensional square lattice at. FIG. 4 is a diagram showing an array of color filters in the array of focus detection pixels 311 shown in FIG. 3, in which color filters (R: red filter, G: green filter, B: blue filter) is arranged, and the spectral sensitivity of each color filter has the characteristics shown in FIG.

  As shown in FIG. 6, the focus detection pixel 311 is composed of a rectangular microlens 10 and a pair of photoelectric conversion units 13 and 14 divided into two by an element isolation region 15 extending in the vertical direction. When the pair of photoelectric conversion units 13 and 14 are integrated, the size becomes equivalent to that of a photoelectric conversion unit of a normal image pickup pixel. For simplicity, the color filters are not shown in FIG. When the outputs of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 are added, the width of the element isolation region 15 is set so that the added output becomes equal to the output of the photoelectric conversion unit of the normal imaging pixel. Is preferably as narrow as possible so that the pair of photoelectric conversion units 13 and 14 are close to each other.

  FIG. 7 is a cross-sectional view of the focus detection pixel 311 shown in FIG. 6, in which the light shielding mask 30 is formed close to the photoelectric conversion units 13 and 14, and the light passing through the opening 30d of the light shielding mask 30 is detected. The photoelectric conversion units 13 and 14 receive light. A flattening layer 31 is formed on the light shielding mask 30, and a color filter 38 is formed thereon. The flattening layer 32 is formed on the color filter 38, and the microlens 10 is formed thereon. The shapes of the photoelectric conversion units 13 and 14 limited to the opening 30d by the microlens 10 are projected forward to form a pair of distance measurement pupils. The photoelectric conversion units 13 and 14 are formed on the semiconductor circuit board 29. An element isolation region 15 is formed to isolate the photoelectric conversion units 13 and 14. With the configuration described above, the photoelectric conversion units 13 and 14 respectively receive a pair of focus detection light fluxes that pass through a pair of distance measurement pupils of the exit pupil of the interchangeable lens.

  FIG. 8 shows the structure of a focus detection optical system of a pupil division type phase difference detection system using a microlens. A part of the focus detection pixel array in the focus detection area 101 is shown enlarged. In FIG. 8, the exit pupil 90 is set at a position of a distance d in front of the microlens 10 arranged on the planned image forming plane of the interchangeable lens 202 (see FIG. 1). The distance d is a distance that is determined according to the curvature of the microlens 10, the refractive index, the distance between the microlens 10 and the photoelectric conversion units 13 and 14, and is referred to as a distance-measuring pupil distance in this specification. In addition, FIG. 11 shows the optical axis 91 of the interchangeable lens, the microlens 10, the photoelectric conversion units 13 and 14, the focus detection pixel 311, and the focus detection light fluxes 73 and 74.

  The distance measuring pupil 93 is formed by projecting the photoelectric conversion unit 13 limited by the opening 30d by the microlens 10. Similarly, the distance measuring pupil 94 is the one in which the photoelectric conversion unit 14 limited by the opening 30d is projected by the microlens 10. The distance-measuring pupils 93 and 94 are different partial regions of the exit pupil 90, are arranged in the horizontal direction, and are line-symmetrical with respect to a vertical line passing through the optical axis 91.

  In FIG. 8, five adjacent focus detection pixels 311 in the focus detection area 101 near the photographing optical axis 91 are schematically illustrated, but also in the focus detection pixels 311 arranged in the periphery of the screen, each photoelectric conversion unit. Are configured to receive the luminous fluxes arriving at the respective microlenses from the corresponding distance measuring pupils 93 and 94. Due to the microlens 10, the pair of photoelectric conversion units 13 and 14 and the above-described partial regions different from each other, that is, the pair of distance measurement pupils 93 and 94, have a conjugate relationship with each other.

  With the above-described configuration, the photoelectric conversion unit 13 outputs a signal corresponding to the intensity of the image formed on the microlens 10 by the light flux 73 passing through the distance measurement pupil 93 and traveling toward the microlens 10 of the focus detection pixel 311. To do. Further, the photoelectric conversion unit 14 outputs a signal corresponding to the intensity of the image formed on the microlens 10 by the light flux 74 which passes through the distance measuring pupil 94 and is directed to the microlens 10 of the focus detection pixel 311.

  By combining the outputs of the photoelectric conversion units 13 and 14 of the plurality of focus detection pixels 311 arranged in the focus detection area 101 in the horizontal direction into the output groups corresponding to the distance measurement pupil 93 and the distance measurement pupil 94, the distance measurement pupil Information about the intensity distribution of a pair of images formed on the array of the focus detection pixels 311 by the focus detection light fluxes 73 and 74 passing through the focus detection pixels 94 and 93 is obtained. By performing image shift detection calculation processing (correlation calculation processing, phase difference detection processing) described later on this information, the image shift amount of the pair of images is detected by a so-called pupil division type phase difference detection method. Further, a conversion calculation is performed according to the image shift amount in accordance with the proportional relationship between the distance between the center of gravity of the pair of distance measurement pupils 93 and 94 and the distance between the distance measurement pupils, so that the current image formation surface (planned image formation surface) The deviation (defocus amount) of the image plane) at the focus detection position corresponding to the position of the upper microlens array is calculated. Specifically, by multiplying the image shift amount (the amount in the plane perpendicular to the optical axis 91) by a predetermined conversion coefficient (a value obtained by dividing the distance measuring pupil distance d by the distance between the centers of gravity of the distance measuring pupils 93 and 94). The defocus amount (deviation between the image plane on the optical axis 91 and the planned image plane) is calculated.

  Further, by obtaining the output signal obtained by adding the outputs of the photoelectric conversion units 13 and 14 of each focus detection pixel 311 on the entire screen, it is possible to obtain an image signal equivalent to the case where the normal image pickup pixels are arranged in the Bayer array.

  FIG. 9 is a block diagram showing in detail the relationship between the image pickup device 212 and the body drive control device 214 in the part related to the present invention. In the body drive control device 214, the image pickup device control unit 220 and the buffer memory 221 are provided. , CPUa (microcomputer) 222 and CPUb (microcomputer) 223 are housed. The image sensor 212 performs charge accumulation control (charge accumulation time and charge accumulation timing) and signal output control of the focus detection pixels 311 under the control of the image sensor control unit 220. As will be described later, the image pickup device 212 AD-converts the output signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 and outputs it as digital data (data for focus detection) from the channel 1 and at the same time of the focus detection pixel 311. Digital data obtained by digitally adding the digital data of the pair of photoelectric conversion units 13 and 14 (a signal equivalent to the output signal of a normal image pickup pixel) is output from channel 2 as digital data. The digital data output from channel 1 and channel 2 is temporarily stored in the buffer memory 221 as digital data for one frame. The CPUa 222 performs the process described below on the digital data (data for focus detection) of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 of the focus detection area stored in the buffer memory 221, thereby performing focus detection. The CPUb 223 performs well-known image processing on the digital data (image data) for one frame stored in the buffer memory 221, and performs image display and image recording.

  As described above, the digital data for focus detection and the digital data for image are output from the image pickup element 212 via the different channels while temporally overlapping each other. Further, since the focus detection digital data and the image digital data are processed by the individual CPUs 222 and 223, it is not necessary to separate the focus detection processing and the image processing temporally, and they can be performed independently at the same time.

  Next, digital data obtained by digitally adding digital data of a pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 and digital data of a pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 from two channels at the same time (normal A configuration of the image pickup element 212 capable of outputting a signal equivalent to the output signal of the image pickup pixel will be described with reference to FIG.

  FIG. 10 is a block diagram showing the configuration of the image sensor 212 (CMOS image sensor). The image sensor 212 includes a row scanning circuit 41 and a column AD conversion in addition to the pixel array section 40 in which a large number of focus detection pixels 311 including a pair of photoelectric conversion sections 13 and 14 are two-dimensionally arranged in a matrix. Device 42, second line memory 44, second column scanning circuit 51, second horizontal output circuit 45, column digital adding device 46, first line memory 48, first column scanning circuit 52, first horizontal output circuit 49 and timing It has a configuration including a control circuit 50.

  In this system configuration, the timing control circuit 50 includes a row scanning circuit 41, a column AD conversion device 42, and a column digital addition device 46 based on a master clock input from the outside and a control signal input from the image sensor control unit 220. , The first line memory 48, the second line memory 44, the first column scanning circuit 52, the second column scanning circuit 51, and the like to generate clock signals and control signals that serve as a reference for the operation, and the row scanning circuit 41 and the column AD. It is given to the conversion device 42, the column digital addition device 46, the first line memory 48, the second line memory 44, the first column scanning circuit 52, the second column scanning circuit 51, and the like.

  Further, a peripheral drive system and a signal processing system for driving and controlling each focus detection pixel 311 of the pixel array section 40, that is, a row scanning circuit 41, a column AD conversion device 42, a column digital addition device 46, a first line memory 48, a first line memory 48, The 2-line memory 44, the first column scanning circuit 52, the second column scanning circuit 51, the first horizontal output circuit 49, the second horizontal output circuit 45, the timing control circuit 50, and the like are the same chip (semiconductor) as the pixel array section 40. Integrated on the substrate). The chip on which these are integrated is stacked on the chip of the pixel array section 40.

  Although not shown here, the focus detection pixel 311 is obtained by photoelectric conversion in the photoelectric conversion units 13 and 14 in addition to the pair of photoelectric conversion element units 13 and 14 (for example, photodiodes). A three-transistor configuration having a transfer transistor that transfers electric charge to an FD (floating diffusion) portion, a reset transistor that controls the potential of the FD portion, and an amplification transistor that outputs a signal according to the potential of the FD portion, Further, a 4-transistor structure having a separate selection transistor for selecting a pixel can be used.

  In the pixel array section 40, focus detection pixels 311 are two-dimensionally arranged by 2N rows and 2M columns. In other words, the pixel array unit 40 has a focus detection pixel group in which 2M focus detection pixels 311 are arranged in the horizontal direction in each row, and the focus detection pixel group has 2N rows in the vertical direction that intersect the horizontal direction. Will be placed. In FIG. 10, the focus detection pixel 311 in the upper left is the pixel in the first row and the first column, and a green filter of Bayer array is arranged in this pixel, and the focus detection pixel 311 is arranged as a pixel group in the first row. Has a green filter and a blue filter. One system of row control lines 21 (21 (1) to 21 (2N)) is provided for each row with respect to the pixel arrangement of 2N rows and 2M columns, and two column signal lines (22 (1)) are provided for each column. a, 22 (1) b to 22 (2M) a, 22 (2M) b) are wired. One end of each row control line 21 (21 (1) to 21 (2N)) is connected to each output end corresponding to each row of the row scanning circuit 41, and each row control line 21 has control signals R (1) to R (R). (2N) is output. The row scanning circuit 41 is composed of a shift register or the like, and controls the row address and row scanning of the pixel array section 40 via the row control lines 21 (21 (1) to 21 (2N)).

  The pair of photoelectric conversion units 13 and 14 of each focus detection pixel 311 in the same row are connected to the row scanning circuit 41 by the same row control line 21, and control signals R (1), ..., R (L). , ..., R (2N) are simultaneously subjected to charge accumulation control and signal readout control. Further, one photoelectric conversion unit 13 of the pair of photoelectric conversion units 13 and 14 of each focus detection pixel 311 is connected to one column signal line 22 (m) b of two column signal lines provided for each column, The output signal (analog signal) of the photoelectric conversion unit 13 is output to the column signal line 22 (m) b. The other photoelectric conversion unit 14 of the pair of photoelectric conversion units 13 and 14 of each focus detection pixel 311 is connected to the other column signal line 22 (m) a of the two column signal lines provided for each column, The output signal (analog signal) of the photoelectric conversion unit 14 is output to the column signal line 22 (m) a. For example, when the focus detection pixels 311 forming the focus detection pixel group of the Lth row of the pixel array section 40 are selected by the control signal R (L) given from the row scanning circuit 41, the focus detection pixels of the Lth row are selected. The output signals of the pair of photoelectric conversion units 13 and 14 of 311 are output to the column signal lines (22 (1) a, 22 (1) b to 22 (2M) a, 22 (2M) b).

  The column AD converter 42 is provided for each of the column signal lines 22 (1) a, 22 (1) b to 22 (2M) a, 22 (2M) b provided corresponding to the pixel columns of the pixel array section 40. Each of the focus detection pixels 311 of the pixel array section 40 having a corresponding ADC (analog-digital conversion circuit) 23 (1) a, 23 (1) b to 23 (2M) a, 23 (2M) b. The pair of analog signals output to the H.V. signal are converted into H-bit digital signals and output according to the control signal TA1 provided from the timing control circuit 50. “H bit” represents the number of bits, and is, for example, 10 bits, 12 bits, 14 bits or the like.

  The second line memory 44 is a memory (25 provided for each ADC (23 (1) a, 23 (1) b to 23 (2M) a, 23 (2M) b) that constitutes the column AD converter 42. (1) a, 25 (1) b to 25 (2M) a, 25 (2M) b), and ADCs (23 (1) a, 23 (1) b to 23 (2M) a, 23 (2M) ) The digital signal output for each b) is stored as an H-bit digital signal according to the control signal TM2 given from the timing control circuit 50. Here, each memory (25 (1) a, 25 (1) b to 25 (2M) a, 25 (2M) b) of the second line memory 44 has a pair of photoelectric conversion units for one row of focus detection pixels. The output signals of 13 and 14 are stored as digital signals.

  The column digital adder 46 is provided for each of a pair of ADCs ((23 (1) a, 23 (1) b) to (23 (2M) a, 23 (2M) b)) that constitute the column AD converter 42. And a pair of ADCs ((23 (1) a, 23 (1) b) to (23 (2M) a, 23 (2M) b). )) Is added according to the control signal TD1 given from the timing control circuit 50, and is output as an H-bit addition digital signal.

  The first line memory 48 has a memory (28 (1) to 28 (2M)) provided for each of the digital adding circuits (26 (1) to 26 (2M)) configuring the column digital adding device 46. The added digital signal output from each of the digital addition circuits (26 (1) to 26 (2M)) is stored as an H-bit digital signal in accordance with the control signal TM1 given from the timing control circuit 50. Here, in each memory (28 (1) to 28 (2M)) of the first line memory 48, an addition signal obtained by adding the output signals of the pair of photoelectric conversion units 13 and 14 for the focus detection pixels for one row (imaging pixel (Corresponding to the output signal of) is stored as a digital signal.

  The second column scanning circuit 51 is composed of a shift register or the like, and under the control of the timing control circuit 50, the memory (25 (1) a, 25 (1) b to 25 (2M) a in the second line memory 44. , 25 (2M) b) and column scanning and column scanning are controlled. The second line memory 44 operates according to the scanning signal TS2 provided from the second column scanning circuit 51, and the memories (25 (1) a, 25 (1) b to 25 (2M) a, 25 (2M) b). The H-bit digital signals stored in each of the above are sequentially read out to the second horizontal output circuit 45, and output signals of the pair of photoelectric conversion units 13 and 14 for focus detection via the second horizontal output circuit 45. Serially output as a (digital signal).

  The first column scanning circuit 52 is configured by a shift register or the like, and under the control of the timing control circuit 50, the column addresses and column scanning of the memories (28 (1) to 28 (2M)) in the first line memory 48 are performed. Take control. The first line memory 48 operates according to the scanning signal TS1 given from the first column scanning circuit 52, and the H-bit added digital signals stored in each of the memories (28 (1) to 28 (2M)) are sequentially arranged. The signal is read out to the first horizontal output circuit 49, and serially output to the outside as an output signal (digital signal) equivalent to the output signal of the imaging pixel via the first horizontal output circuit 49.

  Next, in the configuration of the image sensor shown in FIG. 10, an individual read operation of the output signals of the pair of photoelectric conversion units of the focus detection pixel and the addition signal of the output signals of the pair of photoelectric conversion units are added during one frame period. A case where the reading operations are performed in parallel will be described with reference to timing charts in FIGS. In FIGS. 11 and 12, VS is a vertical synchronizing signal indicating one frame period, and HS is a horizontal synchronizing signal indicating one horizontal scanning period.

  In the operation shown in FIG. 11, the control signals R (1), R (2), R (3) to R (2n + 1), R (2n + 2) are transmitted from the row scanning circuit 41 to the pixel array section 40 in synchronization with the horizontal synchronization signal HS. ), R (2n + 3) to R (N) are sequentially issued, and control signals R (1), R (2), R (3) to R (2n + 1), R (2n + 2), R (2n + 3) to R ( N), the analog signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 for one line of the row are column signal lines (22 (1) a, 22 (1) b to 22 (2M) a, 22 (2M) b).

  FIG. 12 is an enlarged view of the operation parts of the (2n + 1) th row, the (2n + 2) th row, and the (2n + 3) th row in FIG. When the (2n + 1) th row of the pixel array unit 40 is selected by the control signal R (2n + 1), the analog signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 for one line of the (2n + 1) th row are column signals. It is output to the lines (22 (1) a, 22 (1) b to 22 (2M) a, 22 (2M) b). A pair of photoelectric conversions of the focus detection pixels 311 for one line of (2n + 1) rows output to the column signal lines (22 (1) a, 22 (1) b to 22 (2M) a, 22 (2M) b). The analog signals of the units 13 and 14 of the column AD conversion device 42 connected to the column signal lines 22 (1) a, 22 (1) b to 22 (2M) a, 22 (2M) according to the control signal TA1. It is converted into a digital signal by the ADC (23 (1) a, 23 (1) b to 23 (2M) a, 23 (2M) b).

The digital signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 for one line of the (2n + 1) th row that have been digitally converted are ADC (23 (1)) of the column AD conversion device 42 according to the control signal TM2. a, 23 (1) b to 23 (2M) a, 23 (2M) b) connected to the second line memory 44 (25 (1) a, 25 (1) b to 25 (2M) a, 25 (2M) b).

  At the same time, the digital signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 for one line of (2n + 1) rows which are digitally converted are paired to form the column AD conversion device 42 according to the control signal TD1. Digital adder circuits (26 (1) to (26 (1) to) of the column digital adder 46 provided for each ADC ((23 (1) a, 23 (1) b) to (23 (2M) a, 23 (2M) b)). 26 (2M)).

  The added digital signal of the focus detection pixel 311 for one line of the (2n + 1) th row, to which the output signals of the pair of photoelectric conversion units 13 and 14 are added, is a digital addition circuit of the column digital addition device 46 according to the control signal TM1. It is stored in the memory ((28 (1) to 28 (2M)) of the first line memory 48 connected to (26 (1) to 26 (2M)).

  Of the focus detection pixels 311 for one line of (2n + 1) rows stored in the memories (25 (1) a, 25 (1) b to 25 (2M) a, 25 (2M) b) of the second line memory 44. The digital signals of the pair of photoelectric conversion units 13 and 14 are sequentially serially output from the second horizontal output circuit 45 to the outside during the period until the next horizontal synchronizing signal HS is generated, according to the scanning signal TS2. Based on the digital signal output from the second horizontal output circuit 45, the CPUa 222 for focus detection of the body drive control device 214 detects the focus state of the interchangeable lens 202 (optical system) as shown in FIG. , Adjust its focus condition.

  Similarly, the focus detection for one line of the (2n + 1) th row in which the output signals of the pair of photoelectric conversion units 13 and 14 stored in the memories ((28 (1) to 28 (2M)) of the first line memory 48 are added. The added digital signal of the pixel 311 is sequentially serially output from the first horizontal output circuit 49 to the outside during the period until the next horizontal synchronizing signal HS is generated, according to the scanning signal TS1. Based on the output added digital signal, the CPUb 223 for image processing of the body drive control device 214 generates image data as shown in FIG. 14 described later.

  When the control signal R (2n + 2) is issued in synchronization with the next horizontal synchronization signal HS and the (2n + 2) row of the pixel array section 40 is selected, a pair of focus detection pixels 311 for one line of the (2n + 2) row. The processes are repeated by the same operation for the analog signals of the photoelectric conversion units 13 and 14. Further, similar processing is repeated under the control signal R (2n + 3) synchronized with the next horizontal synchronization signal HS.

  13 and 14 are flowcharts showing the operation of the digital still camera (image pickup apparatus) 201 according to the embodiment. The processes according to these flowcharts are performed in parallel. FIG. 13 is an operation flowchart of the CPUa 222 for focus detection of the body drive control device 214. When the power of the digital still camera 201 is turned on in step S100, the focus detection operation in step S110 and subsequent steps is started. In step S110, the data of the pair of photoelectric conversion units of the focus detection pixels arranged in the focus detection area selected in frame synchronization is read. The data of the pair of photoelectric conversion units is a digital signal output from the second horizontal output circuit 45 described above. In a succeeding step S120, an image shift detection calculation process (correlation calculation process, phase difference detection process) described later is performed based on the data of the focus detection pixel to calculate the image shift amount. It should be noted that the position of the focus detection area is assumed to have been previously selected by the photographer using an operation member (not shown).

  In step S130, the image shift amount is converted into a defocus amount.

  In step S140, it is detected whether or not the focus state of the interchangeable lens 202 (optical system) is near the in-focus state, that is, whether or not the absolute value of the calculated defocus amount is within a predetermined value. When it is determined that it is not in the vicinity of the in-focus state, the process proceeds to step S150, the defocus amount is transmitted to the lens drive control device 206, and the focusing lens 210 of the interchangeable lens 202 is driven to the in-focus position. ) Focus condition.

  Even when the focus cannot be detected, the process branches to this step, the scan drive command is transmitted to the lens drive control device 206, and the focusing lens 210 of the interchangeable lens 202 is scan driven from infinity to the close range. Then, it progresses to step S160.

  When it is determined in step S140 that it is in the vicinity of the in-focus state, the process proceeds to step S160, and it is determined whether or not the shutter release is performed by operating a shutter button (not shown). If it is determined that the shutter release has not been made, the process returns to step S110 and the above-described operation is repeated. On the other hand, if it is determined that the shutter release has been performed, the process proceeds to step S170, and waits until the shooting operation according to the shutter release ends, and when the shooting operation ends, the process returns to step S110 and the above-described operations are repeated.

  Details of the image shift detection calculation processing (correlation calculation processing, phase difference detection processing) in steps S120 and S130 of FIG. 13 will be described below. The pair of data of the focus detection pixels 311 are separated for each color of the same color in the Bayer array.

The pair of images detected by the focus detection pixel 311 may have the light amount balance broken due to the distance measuring pupils 93 and 94 being eclipsed by the aperture opening of the lens. Therefore, the image shift detection accuracy with respect to the light amount balance is maintained. Perform possible types of correlation operations. _Let A1 _n (A1 ₁ , ..., A1 _j : j) be the number of data) and A2 _n (A2 ₁ , ..., A2 _j ) be a pair of data strings read from the array of focus detection pixels 311. In general terms, without distinguishing due to color differences, a pair of data strings is subjected to the following correlation calculation formula (1) disclosed in Japanese Unexamined Patent Publication No. 2007-333720 for A1 _n and A2 _n , and the correlation amount is calculated. Calculate C (k).
C (k) = Σ | A1 _n · A2 _{n + 1 + k} −A2 _{n + k} · A1 _{n + 1} | (1)

In the equation (1), the Σ operation is accumulated for n. The range of _n is limited to the range in which the data of A1 _n , A1 _{n + 1} , A2 _{n + k} , and A2 _{n + 1 + k} exists according to the image shift amount k. The shift amount k is an integer, and is a relative shift amount with the data interval of the data string as a unit. As shown in FIG. 15A, the calculation result of the equation (1) shows that the correlation amount C (k) is minimal in the shift amount in which the pair of data has a high correlation (k = kj = 2 in FIG. 15A). (The smaller the value, the higher the correlation).

Next, the shift amount X that gives the minimum value C (X) for the continuous correlation amount is obtained by using the three-point interpolation method of the formulas (2) to (5).
X = kj + D / SLOP (2)
C (X) = C (kj)-| D | ... (3)
D = {C (kj-1) -C (kj + 1)} / 2 (4)
SLOP = MAX {C (kj + 1) -C (kj), C (kj-1) -C (kj)}
... (5)

  Whether or not the shift amount X calculated by the equation (2) is reliable is determined as follows. As shown in FIG. 15B, when the correlation between the pair of data is low, the minimum value C (X) of the interpolated correlation amount is large. Therefore, when C (X) is greater than or equal to the predetermined threshold value, it is determined that the calculated shift amount is unreliable, and the calculated shift amount X is canceled. Alternatively, in order to standardize C (X) with the contrast of data, if the value obtained by dividing C (X) by SLOP, which is a value proportional to the contrast, is equal to or greater than a predetermined value, the reliability of the calculated shift amount Is determined to be low, and the calculated shift amount X is canceled. Alternatively, if the SLOP that is a value proportional to the contrast is less than or equal to a predetermined value, it is determined that the subject has low contrast and the calculated shift amount is unreliable, and the calculated shift amount X is canceled.

As shown in FIG. 15 (c), low level of correlation between the pair of data when there is no drop in correlation quantity C (k) between the shift range _k min _{to k max} is for a local minimum C (X) In such a case, it is determined that focus detection is impossible.

When it is determined that the calculated shift amount X is reliable, it is converted into the image shift amount shft by the equation (6).
shft = PY · X (6)

  In Expression (6), PY has a value twice the pixel pitch of the focus detection pixels 311 (pixel pitch of focus detection pixels of the same color).

The image shift amount shft calculated by the equation (6) is multiplied by a predetermined conversion coefficient k to be converted into the defocus amount def.
def = k · shft1 (7)

  In the equation (7), the conversion coefficient k is a conversion coefficient according to the proportional relationship between the distance between the centers of gravity of the pair of distance measuring pupils 93 and 94 and the distance between the distance measuring pupils, and changes according to the aperture F value of the optical system. ..

  In this way, three defocus amounts are calculated for the three colors of the Bayer array, so averaging processing such as simple averaging or weighted averaging is performed to determine the final defocus amount in the selected focus detection area. Is calculated.

  FIG. 14 is an operation flowchart of the image processing CPU b 223 of the body drive control device 214. When the power of the digital still camera 201 is turned on in step S200, the image processing operation of step S210 and subsequent steps is started. In step S210, the added digital data (corresponding to the data of the image pickup pixel) obtained by adding the output data of the pair of photoelectric conversion units of the focus detection pixel in frame synchronization is read, and the image processing for display is performed on the data. From the electronic viewfinder. The added digital data read in step S210 is the added digital signal output from the above-described first horizontal output circuit 49.

  In step S220, it is determined whether or not shutter release has been performed by operating a shutter button (not shown). If it is determined that the shutter release has not been made, the process returns to step S210 and the above-described operation is repeated. On the other hand, if it is determined that the shutter release has been performed, the process proceeds to step S230, and a shooting operation according to the shutter release is performed. First, an aperture adjustment command is transmitted to the lens drive controller 206, and the aperture value of the interchangeable lens 202 is set to the control F value (F value set by the photographer or automatically). At the time when the aperture control is completed, the added digital data (corresponding to the data of the image pickup pixels arranged in the Bayer array) obtained by adding the output data of the pair of photoelectric conversion units of the focus detection pixel is read out and well known to the added digital data. Image processing (demosaic processing, noise processing, gradation processing, white balance processing, etc.) is performed to generate image data, and the image data is stored in the memory card in step S240. When the series of shooting operations is completed, the process returns to step S210 and the above-described operations are repeated.

  In the above-described first embodiment, the focus detection is performed only in the selected focus detection area. However, since the focus detection data of the entire screen is stored in the buffer memory, the focus detection CPUa 222 operates as follows. If the processing capability is high, focus detection may be performed in a plurality of focus detection areas on the entire screen, and the focus adjustment of the lens may be performed according to the result.

  In the above-described first embodiment, the description has been made assuming that the data obtained by adding the data of the pair of photoelectric conversion units of the focus detection pixels for the image is read out for every frame, but the thinning-out reading is performed instead of reading all the data. A circuit configuration for (row / column) or pixel addition reading (row / column) may be added to the configuration of the present invention, and the read image data may be used for display or the like.

  In the above-described first embodiment, the description has been made assuming that the data of the pair of photoelectric conversion units of the all-focus detection pixel for focus detection is read out for each frame, but of the pair of photoelectric conversion units of the all-focus detection pixel. Since reading data is a heavy load and requires a large memory capacity for storing data, frame thinning (reading once every several frames) / row thinning (reading one row every few lines) / row Partial reading (reading only some rows) / column thinning (reading one column in several rows) / column partial reading (reading only some columns) may be performed.

  FIG. 16 is a timing chart corresponding to FIG. 12 in the case of performing row partial reading (reading the data of the pair of photoelectric conversion units of the focus detection pixel only in the (2n + 2) th row), and is the (2n + 1) row in FIG. 11. , (2n + 2) rows and (2n + 3) rows are enlarged views.

  The operation when the (2n + 2) row of the pixel array section 40 is selected by the control signal R (2n + 2) is the same as that in FIG. On the other hand, when the row other than the (2n + 2) row is selected (the operation according to the control signal R (2n + 1) and the control signal R (2n + 3) in FIG. 16), the control signal TM2 is not generated, and the column AD converter 42 does not generate. A pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 for one line converted into a digital signal by the ADC (23 (1) a, 23 (1) b to 23 (2M) a, 23 (2M) b). Of the second line memory 44 connected to the ADCs (23 (1) a, 23 (1) b-23 (2M) a, 23 (2M) b) of the column AD converter 42. (1) a, 25 (1) b to 25 (2M) a, 25 (2M) b). Further, since the scanning signal TS2 is not generated, serial output is not sequentially performed from the second horizontal output circuit 45 to the outside until the next horizontal synchronizing signal HS is generated.

  The row to be partially read out and the column to be partially read out can be changed by sending information from the body drive control device 214 to the image pickup device 212 according to the position of the selected focus detection area.

  In the first embodiment described above, the column AD conversion device 42 having the number of ADCs corresponding to the number of the pair of photoelectric conversion units of the focus detection pixels for one row is provided, and the digital output signals of the pair of ADCs are provided. Since the column digital adder 46 having the number of the focus detection pixels for one row is provided with the digital addition circuit 26 for performing digital addition, the output signals of the pair of photoelectric conversion units of the focus detection pixels are output during one frame period. It is possible to perform the individual read operation and the read operation of the added signal (corresponding to the output signal of the imaging pixel) obtained by adding the output signals of the pair of photoelectric conversion units in parallel. As a result, the problem of the conventional technology (providing an analog adder for each focus detection pixel) (individual read operation of the output signals of the pair of photoelectric conversion units of the focus detection pixel and the output signal of the pair of photoelectric conversion units during one frame period) It is possible to solve the problem that the read operation of the added signal (corresponding to the output signal of the image pickup pixel) obtained by adding is not performed in parallel.

  Further, as a method for solving the problems of the conventional technique, output data of a pair of photoelectric conversion units of all focus detection pixels are individually read from an image sensor during one frame period, temporarily stored in an external buffer memory, and then the buffer is stored. It is conceivable to perform addition processing on the output data of the pair of photoelectric conversion units stored in the memory, but in that case, the processing time increases by the addition processing time and the external processing load also increases. I will end up. According to the configuration and the operation of the image sensor of the present application, the readout / image processing of image data can be handled in the same manner as a normal image sensor. In addition, since the output data of the pair of photoelectric conversion units of the focus detection pixels can be individually read out, the load of the reading process can be reduced and the capacity of the buffer memory for data storage can be saved.

  Further, as a method for solving the problems of the conventional technology, a second horizontal output circuit is used when the output data of the pair of photoelectric conversion units of the focus detection pixels are horizontally scanned and serially output instead of providing the column digital adder 46. A data holding memory (which holds data delayed by one data output time) and a digital addition circuit are provided in parallel at the output terminal of 45, and output data of a pair of photoelectric conversion units of focus detection pixels are added in synchronization with individual data output. It is also possible to generate and output the addition data after that, but the data transfer rate becomes slower by the addition processing time (addition time for one focus detection pixel x total focus detection pixels), and high-speed data reading is possible. become unable. Since the image pickup device 212 of the present application is provided with the column digital adder 46 and the addition processing is performed simultaneously for each column independently, it is possible to perform high-speed reading at almost the same data transfer rate as an image pickup device including only normal image pickup pixels. become.

<Second Embodiment>
In the first embodiment, the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 are arranged side by side in the horizontal direction (row direction), but the direction in which the pair of photoelectric conversion units of the focus detection pixel are arranged side by side is horizontal. By using a direction other than the direction (row direction), image shift detection can be performed in directions other than the horizontal direction. FIG. 17 is a diagram showing a focus detection pixel 312 configured by rotating the focus detection pixel 311 shown in FIG. 6 by 90 degrees. The focus detection pixel 312 is a rectangular microlens 10 and an element isolation region extending in the horizontal direction. It is composed of a pair of photoelectric conversion units 16 and 17 divided into two by 18. When the pair of photoelectric conversion units 16 and 17 are integrated, the size becomes equivalent to that of a photoelectric conversion unit of a normal image pickup pixel.

  FIG. 18 is a diagram corresponding to the pixel layout diagram of FIG. 3 (the filter array corresponds to FIG. 4) and shows a detailed configuration of the image sensor 212 in which the focus detection pixels 311 and 312 are arranged. FIG. 3 is a front view showing the vicinity of the focus detection area 101 on the image sensor 212 in an enlarged manner. The focus detection pixels 311 and the focus detection pixels 312 are alternately arranged in every other row.

  FIG. 19 is a block diagram showing the configuration of the image sensor 212 having the pixel layout shown in FIG. 18. The description of the same parts as those of FIG. 10 will be omitted, and only the characteristic parts will be described. The difference between the pixel array section 40 and FIG. 10 is that the focus detection pixels 312 including the pair of photoelectric conversion sections 16 and 17 separated in the vertical direction are arranged in the even-numbered rows.

  The pair of photoelectric conversion units 16 and 17 of each focus detection pixel 312 arranged in an even row are connected to the row scanning circuit 41 by the same row control line 21, and a control signal R (L) (L is an even number). Accordingly, charge accumulation control and signal read control are simultaneously performed. Further, one photoelectric conversion unit 16 of the pair of photoelectric conversion units 16 and 17 of each focus detection pixel 312 arranged in an even-numbered row is one column signal line 22 (m) of two column signal lines provided for each column. ) A, the output signal (analog signal) of the photoelectric conversion unit 16 is output to the column signal line 22 (m) a. The other photoelectric conversion unit 17 of the pair of photoelectric conversion units 16 and 17 of each focus detection pixel 312 is connected to the other column signal line 22 (m) b of the two column signal lines provided for each column, The output signal (analog signal) of the photoelectric conversion unit 17 is output to the column signal line 22 (m) b. For example, when the focus detection pixel 312 in the Lth row of the pixel array unit 40 is selected by the control signal R (L) given from the row scanning circuit 41, the pair of photoelectric conversion units of the focus detection pixel 312 in the Lth row. The output signals of 16 and 17 are output to the column signal lines (22 (1) a, 22 (1) b to 22 (2M) a, 22 (2M) b).

  When the image sensor 212 having the above configuration is used, the data of the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 of the same color arranged in odd rows are grouped horizontally for each photoelectric conversion unit. Phase difference detection can be performed on a subject image having a horizontal contrast change by using the paired data, and the pair of photoelectric conversion units 16 of the focus detection pixels 312 of the same color arranged in even rows. , 17 data are grouped in the vertical direction for each photoelectric conversion unit, it is possible to detect a phase difference with respect to a subject image having a contrast change in the vertical direction.

  20 is a modification of FIG. 18, in which focus detection pixels 311 and focus detection pixels 312 are alternately arranged in every other column. When the image sensor 212 having such a configuration is used, the data of the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 of the same color arranged in the odd columns are grouped in the horizontal direction for each photoelectric conversion unit. It becomes possible to detect a phase difference with respect to a subject image having a horizontal contrast change by using the paired data, and the pair of photoelectric conversion units 16 of the focus detection pixels 312 of the same color arranged in even columns. By using a pair of data obtained by grouping 17 pieces of data in the vertical direction for each photoelectric conversion unit, it is possible to detect a phase difference with respect to a subject image having a contrast change in the vertical direction.

  FIG. 21 is a modification of FIG. 18, in which focus detection pixels 311 and focus detection pixels 312 are alternately arranged in a staggered pattern. That is, the focus detection pixels 311 are arranged at the positions of (odd rows and odd columns) or (even rows and even columns), and the focus detection pixels 311 are arranged at (odd rows and even columns) or (even rows and odd columns). 312 is arranged. From the viewpoint of the Bayer array color filter, the focus detection pixel 311 is provided with a green filter, and the focus detection pixel 312 is provided with a red filter or a blue filter.

  When the image pickup device 212 having such a configuration is used, the pair of photoelectric conversion units 13 of the focus detection pixel 311 provided with the green filter arranged in the odd-numbered row of the odd-numbered row or the even-numbered row of the even-numbered row, It becomes possible to detect a phase difference with respect to a subject image having a horizontal contrast change by using a pair of data obtained by grouping the data of 14 in the horizontal direction for each photoelectric conversion unit, and to the odd-numbered even-numbered columns. The data of the pair of photoelectric conversion units 16 and 17 of the focus detection pixels 312 having the arranged blue filters or the focus detection pixels 312 having the red filters arranged in the even-numbered rows and the odd-numbered columns are arranged for each photoelectric conversion unit. By using a pair of data grouped in the vertical direction, it is possible to detect a phase difference for a subject image having a contrast change in the vertical direction.

<Third Embodiment>
In the first embodiment, all the pixels are configured by the focus detection pixels, but by mixing the normal image pickup pixel in which the photoelectric conversion unit is not divided and the focus detection pixel in which the photoelectric conversion unit is divided, , The number of focus detection pixels in the entire image sensor is reduced to simplify the structure of the image sensor, and the number of focus detection data externally output from the image sensor is reduced to perform image processing on the data transfer rate of the focus detection data. It becomes possible to make the data transfer rate of the data for use almost the same.

  As shown in FIG. 22, the image pickup pixel 310 has a rectangular microlens 10 and a photoelectric conversion unit 11 whose light receiving area is limited by a light-shielding mask described later.

  FIG. 23 is a sectional view of the image pickup pixel 310 shown in FIG. In the image pickup pixel 310, the light shielding mask 30 is formed close to the photoelectric conversion unit 11 for image pickup, and the photoelectric conversion unit 11 receives the light passing through the opening 30 a of the light shielding mask 30. A flattening layer 31 is formed on the light shielding mask 30, and a color filter 38 is formed thereon. The flattening layer 32 is formed on the color filter 38, and the microlens 10 is formed thereon. The shape of the opening 30a is projected forward by the microlens 10. The photoelectric conversion unit 11 is formed on the semiconductor circuit board 29.

  FIG. 24 is a diagram for explaining the state of the imaging light flux received by the imaging pixel 310 shown in FIG. 22 in comparison with FIG. 8, and the description of the portions overlapping with FIG. 8 will be omitted.

  The imaging pixel 310 is composed of the microlens 10 and the photoelectric conversion unit 11 arranged behind it, and the shape of the opening 30a (see FIG. 23) arranged in the vicinity of the photoelectric conversion unit 11 is measured from the microlens 10. It is projected on the exit pupil 90 which is separated by the distance pupil distance d, and the projected shape thereof forms a region 95 which is substantially circumscribed with the distance pupils 93 and 94.

  The photoelectric conversion unit 11 outputs a signal corresponding to the intensity of the image formed on the microlens 11 by the imaging light flux 71 passing through the area 95 and traveling toward the microlens 10.

  FIG. 25 is a diagram corresponding to the pixel layout diagram of FIG. 3 (the filter array corresponds to FIG. 4), and the imaging pixels 310 and the focus detection pixels 311 are alternately arranged in a staggered pattern. That is, the focus detection pixel 311 is arranged at the position of (odd row and odd column) or (even row and even column), and the imaging pixel 310 is arranged at (odd row and even column) or (odd row and even column). Are placed. From the viewpoint of a Bayer array color filter, the focus detection pixel 311 is provided with a green filter, and the imaging pixel 310 is provided with a red filter or a blue filter. In terms of focus detection performance, the spectral sensitivity characteristic of the green filter is located between the spectral sensitivity characteristic of the red filter and the spectral sensitivity characteristic of the blue filter, as shown in FIG. Is preferably provided. As shown in FIGS. 6 and 22, the sum of the surface areas of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 is the surface area of the photoelectric conversion unit 11 of the imaging pixel 310 because the element isolation region 15 exists. Smaller than. Therefore, in terms of imaging performance, the sum of the photoelectric conversion signal values output by the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 is smaller than the photoelectric conversion signal value of the photoelectric conversion unit 11 of the imaging pixel 310. It is preferable that the focus detection pixel 311 is provided with a green filter that is arranged more than the red filter and the blue filter.

  FIG. 26 is a block diagram showing the configuration of the image sensor 212 having the pixel layout shown in FIG. 25. The description of the same parts as those of FIG. 10 will be omitted, and only the characteristic parts will be described. The main difference from FIG. 10 is that a memory constituting the second line memory 44 by providing the second column switch device 43 in the middle of the column AD conversion device 42, the second line memory 44, and the column digital addition device 46. And the number of digital adder circuits constituting the column digital adder 46 are reduced.

  The image sensor 212 includes a row scanning circuit 41 and a column AD conversion in addition to the pixel array section 40 in which a large number of focus detection pixels 311 including a pair of photoelectric conversion sections 13 and 14 are two-dimensionally arranged in a matrix. Device 42, second column switch device 43, second line memory 44, second column scanning circuit 51, second horizontal output circuit 45, column digital adder device 46, first column switch device 47, first line memory 48, It has a configuration including a one-column scanning circuit 52, a first horizontal output circuit 49, and a timing control circuit 50.

  In this system configuration, the timing control circuit 50 includes the row scanning circuit 41, the column AD conversion device 42, and the first column switching device based on a master clock input from the outside and a control signal input from the image sensor control unit 220. 47, the second column switch device 43, the column digital adder device 46, the first line memory 48, the first line memory 44, the first column scanning circuit 52, the second column scanning circuit 51, etc. A control signal or the like is generated, and the row scanning circuit 41, the column AD conversion device 42, the first column switching device 47, the second column switching device 43, the column digital adding device 46, the first line memory 48, the first line memory 44, It is given to the first column scanning circuit 52, the second column scanning circuit 51, and the like.

  In the pixel array section 40, image pickup pixels 310 and focus detection pixels 311 are two-dimensionally arranged by 2N rows and 2M columns. In FIG. 26, the focus detection pixel 311 at the upper left is the pixel in the first row and the first column, and the green filter of the Bayer array is arranged in this pixel. A row control line 21 (21 (1) to 21 (2N)) is provided for each row with respect to the pixel arrangement of 2N rows and 2M columns, and two column signal lines (22 (1) a, 22) are provided for each column. (1) b to 22 (2M) a and 22 (2M) b) are wired. The total number of row control lines is 2N, and the total number of column signal lines is 4M. One end of each row control line 21 (21 (1) to 21 (2N)) is connected to each output end corresponding to each row of the row scanning circuit 41, and each row control line 21 has control signals R (1) to R (R). (2N) is output.

  The photoelectric conversion units of the imaging pixels 310 and the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 arranged in the same row are connected to the row scanning circuit 41 by the same row control line 21, and the control signal R (L ), Charge accumulation control and signal readout control are simultaneously performed. The photoelectric conversion unit 11 of the imaging pixel 310 is connected to one column signal line 22 (m) a of two column signal lines provided for each column, and the output signal (analog signal) of the photoelectric conversion unit 11 is a column signal. Output to line 22 (m) a. Also, one photoelectric conversion unit 13 of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 is connected to one column signal line 22 (m) b of two column signal lines provided for each column, and The output signal (analog signal) of the conversion unit 13 is output to the column signal line 22 (m) b. The other photoelectric conversion unit 14 of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 is connected to the other column signal line 22 (m) a of the two column signal lines provided for each column. The output signal (analog signal) of the conversion unit 14 is output to the column signal line 22 (m) a. For example, when the Lth row of the pixel array section 40 is selected by the control signal R (L) given from the row scanning circuit 41, the output signal of the photoelectric conversion section 11 of the imaging pixel 310 of the Lth row is the column signal line. (22 (1) a to 22 (2M) a) and the output signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 in the L-th row are column signal lines (22 (1) a and 22 (1). ) B to 22 (2M) a, 22 (2M) b). At this time, when L is an odd number, the image pickup pixels 310 are arranged in the even columns of this row, so the signal on the column signal line 22 (2m) b corresponding to the even column becomes an invalid signal. When L is an even number, the imaging pixels 310 are arranged in the odd columns of this row, so the signal on the column signal line 22 (2m + 1) b corresponding to the odd column becomes an invalid signal.

  The column AD converter 42 is provided for each of the column signal lines 22 (1) a, 22 (1) b to 22 (2M) a, 22 (2M) b provided corresponding to the pixel columns of the pixel array section 40. 4M ADCs (analog-digital conversion circuits) 23 (1) a, 23 (1) b to 23 (2M) a, 23 (2M) b are provided, and each pixel from the pixel array unit 40 is arranged in each column. To the H-bit digital signals (S (1) a, S (1) b to S (2M) a, S (2M)) according to the control signal TA1 given from the timing control circuit 50. b) and output.

  The second column switch device 43 has M switches 24 (1, 2) to 24 (2M-1, 2M) provided for each of two adjacent pixel columns, and the ADC (23 (1) a , 23 (1) b to 23 (2M) a, 23 (2M) b) are selected and output according to the control signal TW2 provided from the timing control circuit 50.

  FIGS. 27A and 27B are views for explaining the selection operation of the switches 24 (2m + 1, 2m + 2) provided in two adjacent pixel rows ((2m + 1) row and (2m + 2) row). The switch 24 (2m + 1, 2m + 2) has four ADCs (23 (2m + 1) a, 23 (2m + 1) b, 23 (2m + 2) a) corresponding to two pixel columns ((2m + 1) column and (2m + 2) column). , 23 (2m + 2) b), four digital signals S (2m + 1) a, S (2m + 1) b, S (2m + 2) a, S (2m + 2) b are input. The switch 24 (2m + 1, 2m + 2) has a multiple of 2, for example, a multiple of 4 corresponding to a pixel column of 4 columns ((2m + 1) column, (2m + 2) column, (2m + 3) column, (2m + 4) column), for example, Eight ADCs (23 (2m + 1) a, 23 (2m + 1) b, 23 (2m + 2) a, 23 (2m + 2) b, 23 (2m + 3) a, 23 (2m + 3) b, 23 (2m + 4) a, 23 (2m + 4) ) B) to a multiple of 4, for example, eight digital signals S (2m + 1) a, S (2m + 1) b, S (2m + 2) a, S (2m + 2) b, S (2m + 3) a, S (2m + 3) b. , S (2m + 4) a, S (2m + 4) b may be input. In that case, for example, the focus detection pixels 311 are arranged in the (2m + 1) th column, and the image pickup element 310 is arranged in each of the (2m + 2) th column, the (2m + 3) th column, and the (2m + 4) th column.

  FIG. 27A shows a selection operation of the switch 24 (2m + 1, 2m + 2) when the row scanning circuit 41 selects an odd row of the pixel array section 40. The switch 24 (2m + 1, 2m + 2) has an odd row. Of the four digital signals S (2m + 1) a, S (2m + 1) b, S (2m + 2) a, S corresponding to the imaging pixels 310 arranged in the even-numbered columns and the focus detection pixels 311 in the odd-numbered rows. (2m + 2) b is input. Of these, the signal S (2m + 2) b becomes an invalid signal.

  The switch 24 (2m + 1, 2m + 2) has a pair of signals (Q (2m + 1, 2m + 2) a for digital addition, according to a control signal TW2 (identification information of odd-numbered row or even-numbered row) input to the second column switch device 43. As Q (2m + 1, 2m + 2) b), digital signals S (2m + 1) a and S (2m + 1) b corresponding to the pair of photoelectric conversion units of the focus detection pixel 311 are selected and output.

  FIG. 27B shows a selection operation of the switch 24 (2m + 1, 2m + 2) when the row scanning circuit 41 selects an even row of the pixel array section 40. The switch 24 (2m + 1, 2m + 2) has an even row. Of the four digital signals S (2m + 1) a, S (2m + 1) b, S (2m + 2) a, S corresponding to the imaging pixels 310 arranged in the odd-numbered columns and the focus detection pixels 311 in the even-numbered rows. (2m + 2) b is input. Of these, the signal S (2m + 1) b becomes an invalid signal.

  The switch 24 (2m + 1, 2m + 2) corresponds to the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 according to the control signal TW2 (identification information of odd row or even row) input to the second column switch device 43. As the pair of signals (Q (2m + 1, 2m + 2) a, Q (2m + 1, 2m + 2) b), digital signals S (2m + 2) a, S (2m + 2) b corresponding to the pair of photoelectric conversion units of the focus detection pixel 311 are selected. And output.

  The second line memory 44 includes a total of 2M memories (25 (1, 2) provided in pairs for each of the M switches 24 (1, 2) to 24 (2M-1, 2M) of the second column switch device 43. ) A, 25 (1, 2) b to 25 (2M-1, 2M) a, 25 (2M-1, 2M) b), and M switches 24 (1, 2) to 24 (2M-). 1, 2M) and a pair of digital signals (Q (1,2) a, Q (1,2) b to Q (2M−) corresponding to the pair of photoelectric conversion units 13, 14 of the focus detection pixel 311). 1, 2M) a, Q (2M-1, 2M) b) are stored as H-bit digital signals according to the control signal TM2 given from the timing control circuit 50. Here, each memory (25 (1, 2) a, 25 (1, 2) b to 25 (22M-1, 2M) a, 25 (22M-1, 2M) b) of the second line memory 44 has 1 The output signals of the pair of photoelectric conversion units 13 and 14 for M focus detection pixels for the rows are stored as digital signals.

  The column digital adder 46 includes a total of M digital adder circuits (26 (1 ,, 2) provided for each of the M switches 24 (1, 2) to 24 (2M-1, 2M) of the second column switch device 43. 2) to 26 (2M-1, 2M)), and a pair of photoelectric conversion units of the focus detection pixel 311 which are output for each of the M switches 24 (1, 2) to 24 (2M-1, 2M). Timing of a pair of digital signals (Q (1,2) a, Q (1,2) b to Q (2M-1,2M) a, Q (2M-1,2M) b) corresponding to 13 and 14) The signals are added according to the control signal TD1 given from the control circuit 50 and output as H-bit addition digital signals (P (1, 2) to P (2M-1, 2M)).

  The first column switch device 47 has M switches 27 (1, 2) to 27 (2M-1, 2M) provided for every two adjacent pixel columns, and has 2M ADCs (23 ( 1) a to 23 (2M) a) digital signals (S (1) a, S (2) a to S (2M-1) a, S (2M) a) and M digital signals. The timing control circuit 50 outputs the addition digital signals (P (1,2) to P (2M-1,2M)) output for each of the addition circuits (26 (1,2) to 26 (2M-1,2M)). It is selected and output according to the control signal TW1 (identification information of odd-numbered row or even-numbered row) given from.

  28A and 28B are views for explaining the selection operation of the switch 27 (2m + 1, 2m + 2) provided in the adjacent two pixel columns ((2m + 1) column and (2m + 2) column). The switch 27 (2m + 1, 2m + 2) outputs two digital signals from two ADCs (23 (2m + 1) a, 23 (2m + 2) a) corresponding to two pixel columns ((2m + 1) column and (2m + 2) column). S (2m + 1) a and S (2m + 2) a are input, and one addition digital signal P (2m + 1, 2m + 2) is input from the digital addition circuit 26 (2m + 1, 2m + 2).

  FIG. 28A shows a selection operation of the switch 27 (2m + 1, 2m + 2) when the row scanning circuit 41 selects an odd row of the pixel array section 40. The switch 27 (2m + 1, 2m + 2) has an odd row. One digital signal S (2m + 2) a corresponding to the photoelectric conversion unit 11 of the imaging pixel 310 arranged in the even-numbered column and the photoelectric conversion unit 14 of the focus detection pixel 311 arranged in the odd-numbered column of the odd-numbered row. It corresponds to one corresponding digital signal S (2m + 1) a and the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 arranged in the odd-numbered row and odd-numbered column from the digital addition circuit 26 (2m + 1, 2m + 2). An addition digital signal P (2m + 1, 2m + 2) (corresponding to a signal of an image pickup pixel) obtained by adding a pair of signals S (2m + 1) a and (2m + 1) b is input. Of these, the signal S (2m + 1) a input from the ADC 23 (2m + 1) a does not correspond to the signal of the image pickup pixel.

  The switch 27 (2m + 1, 2m + 2) corresponds to a signal of a virtual imaging pixel arranged in an odd column according to a control signal TW1 (identification information of an odd row or an even row) input to the first column switch device 47. As the signal U (2m + 1) to be output, the digital addition signal P (2m + 1, 2m + 2) obtained by adding the digital signals corresponding to the pair of photoelectric conversion units of the focus detection pixel 311 is selected and output, and is arranged in the even-numbered column. As the signal U (2m + 1) of the image pickup pixel, the digital signal S (2m + 2) a corresponding to the image pickup pixel 310 is selected and output.

  FIG. 28B shows a selection operation of the switch 27 (2m + 1, 2m + 2) when the row scanning circuit 41 selects an even row of the pixel array section 40. The switch 27 (2m + 1, 2m + 2) has an even row. One digital signal S (2m + 1) a corresponding to the photoelectric conversion unit 11 of the imaging pixel 310 arranged in the odd-numbered column and the photoelectric conversion unit 14 of the focus detection pixel 311 arranged in the even-numbered even column Corresponding to one corresponding digital signal S (2m + 2) a and the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 arranged in the even-numbered row and even-numbered column from the digital addition circuit 26 (2m + 1, 2m + 2). An addition digital signal P (2m + 1, 2m + 2) (corresponding to a signal of an image pickup pixel) obtained by adding a pair of signals S (2m + 2) a and (2m + 2) b is input. Of these, the signal S (2m + 2) a does not correspond to the signal of the image pickup pixel.

  The switch 27 (2m + 1, 2m + 2) corresponds to a signal of a virtual imaging pixel arranged in an even column according to a control signal TW1 (identification information of an odd row or an even row) input to the first column switch device 47. As the signal U (2m + 2) to be output, the digital addition signal P (2m + 1, 2m + 2) obtained by adding the digital signals corresponding to the pair of photoelectric conversion units of the focus detection pixel 311 is selected and output, and is arranged in the odd column. As the signal U (2m + 1) of the image pickup pixel, the digital signal S (2m + 1) a corresponding to the image pickup pixel 310 is selected and output.

  The first line memory 48 includes 2M memories (28 (1)) provided in pairs for each of the M switches (27 (1,2) to 27 (2M-1,2M)) that configure the column switch device 47. .About.28 (2M)) and outputs a pair of digital signals for each switch (27 (1,2) to 27 (2M-1,2M)) according to the control signal TM1 given from the timing control circuit 50. And stores it as an H-bit digital signal. Here, in each memory (28 (1) to 28 (2M)) of the first line memory 48, an addition signal obtained by adding the output signals of the pair of photoelectric conversion units 13 and 14 for the focus detection pixels for one row (imaging pixel (Corresponding to the output signal of 1) and the output signal of the photoelectric conversion unit of the image pickup pixel are stored as digital signals according to the arrangement order of the focus detection pixels of the image pickup pixel.

  The second column scanning circuit 51 is composed of a shift register or the like, and under the control of the timing control circuit 50, the memory (25 (1) a, 25 (1) b to 25 (2M) a in the second line memory 44. , 25 (2M) b) and column scanning and column scanning are controlled. The second line memory 44 operates according to the scanning signal TS2 given from the second column scanning circuit 51, and the memories (25 (1,2) a, 25 (1,2) b to 25 (2M-1,2M)). a, 25 (2M-1, 2M) b), the H-bit digital signal stored in each of them is sequentially read out to the second horizontal output circuit 45, and for focus detection via the second horizontal output circuit 45. Are serially output (the number of data is 2M) as output signals (digital signals) of the pair of photoelectric conversion units 13 and 14.

  The first column scanning circuit 52 is configured by a shift register or the like, and under the control of the timing control circuit 50, the column addresses and column scanning of the memories (28 (1) to 28 (2M)) in the first line memory 48 are performed. Take control. The first line memory 48 operates according to the scanning signal TS1 provided from the first column scanning circuit 52, and the H-bit digital signal and the addition digital signal stored in each of the memories (28 (1) to 28 (2M)). The signals are sequentially read by the first horizontal output circuit 49, and serially output as an output signal (digital signal) equivalent to the output signal of the image pickup pixel array via the first horizontal output circuit 49.

  Next, in the configuration of the image sensor shown in FIG. 26, it corresponds to the individual read operation of the output signals (the signals for focus detection) of the pair of photoelectric conversion units of the focus detection pixel and the output signal of the image pixel in one frame period. A case where the reading operation of the output signal (signal for image processing) is performed in parallel will be described with reference to the timing chart of FIG.

  In the configuration of the image sensor shown in FIG. 26, the outline of the row scanning selection operation by the row scanning circuit 41 is the same as the operation shown in FIG.

  FIG. 29 is an enlarged view of the operation parts of the (2n + 1) th row, the (2n + 2) th row, and the (2n + 3) th row in FIG. When the (2n + 1) th row of the pixel array section 40 is selected by the control signal R (2n + 1), the analog signals of the focus detection pixels 311 and the imaging pixels 310 for one line of the (2n + 1) th row are changed to the column signal line (22 (1 ) A, 22 (1) b to 22 (2M) a, 22 (2M) b). Focus detection pixels arranged in odd columns for one line of (2n + 1) rows output to the column signal lines (22 (1) a, 22 (1) b to 22 (2M) a, 22 (2M) b) The analog signals of the pair of photoelectric conversion units 13 and 14 of 311 and the analog signals of the photoelectric conversion unit 11 of the image pickup signal 310 arranged in even columns are corresponding to the column signal lines 22 (1) a and 22 () according to the control signal TA1. 1) b to 22 (2M) a, ADC of the column AD converter 42 connected to 22 (2M) (23 (1) a, 23 (1) b to 23 (2M) a, 23 (2M) b) Is converted into a digital signal by.

  The digital signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 and the even columns which are input from the column AD conversion device 42 to the second column switching device 43 and arranged in the odd columns for one line of (2n + 1) rows The digital signal of the photoelectric conversion unit 11 of the image pickup signal 310 arranged in the second column switch device 43 (24 (1, 2) to 24 (2M-1, 2M)) is an odd-numbered column according to the control signal TW2. The digital signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 arranged at are selected and output.

  The digital signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 arranged in odd columns output from the second column switch device 43 (24 (1, 2) to 24 (2M-1, 2M)) are , 2M memories (25 (1, 2) a, 25 (1, 2) b to 25 (2M-1, 2M) a, 25 (2M-1) of the second line memory 44 according to the control signal TM2. 2M) b).

  At the same time, the digital signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 arranged in the odd-numbered columns are M digital adder circuits (26 (1 ,,) of the column digital adder 46 according to the control signal TD1. 2) to 26 (2M-1, 2M)) and output.

  The photoelectric signals of the digital signals corresponding to one of the photoelectric conversion units 14 of the pair of photoelectric conversion units of the focus detection pixels 311 arranged in the odd columns input to the first column switch device 47 and the photoelectric signals of the imaging signals 310 arranged in the even columns are input. The added digital signal obtained by adding the digital signal of the conversion unit 11 and the digital signal corresponding to the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 arranged in odd columns is the first column switch according to the control signal TW1. The devices 47 (27 (1, 2) to 27 (2M-1, 2M)) arrange the digital signals added by the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 arranged in odd columns and the even columns. The digital signal of the photoelectric conversion unit 11 of the imaging signal 310 is selected, and the pair of photoelectric conversion units 13 of the focus detection pixels 311 arranged in the odd columns as output signals of the imaging pixels in the odd columns. 14 adds the digital signal output of the digital signal of the photoelectric conversion unit 11 of the image signal 310 which is arranged into even columns as output signal of the imaging pixel in the even-numbered columns are output.

  The added digital signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 arranged in the odd-numbered columns selectively output by the first column switch device 47 and the photoelectric conversion units 11 of the image pickup signals 310 arranged in the even-numbered columns. The digital signal is stored in the memory ((28 (1) to 28 (2M)) of the first line memory 48 according to the control signal TM1.

  It is stored in the 2M memories (25 (1,2) a, 25 (1,2) b to 25 (2M-1,2M) a, 25 (2M-1,2M) b) of the second line memory 44. The digital signals of the pair of photoelectric conversion units 13 and 14 of the M focus detection pixels 311 arranged in odd columns of (2n + 1) rows are generated until the next horizontal synchronization signal HS is generated according to the scanning signal TS2. During the period, the second horizontal output circuit 45 sequentially outputs serially to the outside.

  Similarly, 2M digital signals corresponding to the output signals of the imaging pixels of (2n + 1) rows stored in the memories ((28 (1) to 28 (2M)) of the first line memory 48 (focuses arranged in odd columns The added digital signal of the pair of photoelectric conversion units 13 and 14 of the detection pixel 311 and the digital signal of the photoelectric conversion unit 11 of the image pickup signal 310 arranged in an even column) are the next horizontal synchronization signal HS according to the scanning signal TS1. Is serially output to the outside from the first horizontal output circuit 49 in the period until the occurrence of.

  When the control signal R (2n + 2) is issued in synchronization with the next horizontal synchronization signal HS and the (2n + 2) row of the pixel array section 40 is selected, the focus detection pixels 311 for one line of the (2n + 2) row and the imaging are performed. The analog signal of the pixel 310 is output to the column signal lines (22 (1) a, 22 (1) b to 22 (2M) a, 22 (2M) b). Focus detection pixels arranged in even columns for one line of (2n + 2) rows output to the column signal lines (22 (1) a, 22 (1) b to 22 (2M) a, 22 (2M) b) The analog signals of the pair of photoelectric conversion units 13 and 14 of 311 and the analog signals of the photoelectric conversion unit 11 of the image pickup signal 310 arranged in odd columns correspond to the column signal lines 22 (1) a and 22 (in accordance with the control signal TA1. 1) b to 22 (2M) a, ADC of the column AD converter 42 connected to 22 (2M) (23 (1) a, 23 (1) b to 23 (2M) a, 23 (2M) b) Is converted into a digital signal by.

  Digital signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 and odd columns which are input from the column AD converter 42 to the second column switch device 43 and arranged in even columns for one line of (2n + 2) rows. The digital signal of the photoelectric conversion unit 11 of the image pickup signal 310 arranged in the second column switch device 43 (24 (1, 2) to 24 (2M-1, 2M)) is even-numbered columns according to the control signal TW2. The digital signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 arranged at are selected and output.

  The digital signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 arranged in even columns output from the second column switch device 43 (24 (1, 2) to 24 (2M-1, 2M)) are , 2M memories (25 (1, 2) a, 25 (1, 2) b to 25 (2M-1, 2M) a, 25 (2M-1) of the second line memory 44 according to the control signal TM2. 2M) b).

  At the same time, the digital signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 arranged in the even-numbered columns correspond to the control signal TD1 and the M digital addition circuits (26 (1, 2) to 26 (2M-1, 2M)) and output.

  The photoelectric signals of the digital signals corresponding to one of the photoelectric conversion units 14 of the pair of photoelectric conversion units of the focus detection pixels 311 arranged in even columns input to the first column switch device 47 and the photoelectric signals of the imaging signals 310 arranged in odd columns are input. The added digital signal obtained by adding the digital signal of the conversion unit 11 and the digital signal corresponding to the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 arranged in the even columns to the first column switch according to the control signal TW1. The devices 47 (27 (1, 2) to 27 (2M-1, 2M)) are arranged in even columns and added digital signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 and arranged in odd columns. The digital signal of the photoelectric conversion unit 11 of the image pickup signal 310 is selected, and the pair of photoelectric conversion units 13 of the focus detection pixels 311 arranged in even columns as output signals of the image pickup pixels in even columns. 14 adds the digital signal is outputted, the digital signal of the photoelectric conversion unit 11 of the image signal 310 which is arranged to the odd column as an output signal of the imaging pixel in the odd-numbered columns are output.

  The added digital signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 arranged in even columns, which are selectively output by the first column switch device 47, and the photoelectric conversion units 11 of the image pickup signals 310 arranged in odd columns, The digital signal is stored in the memory ((28 (1) to 28 (2M)) of the first line memory 48 according to the control signal TM1.

  It is stored in the 2M memories (25 (1,2) a, 25 (1,2) b to 25 (2M-1,2M) a, 25 (2M-1,2M) b) of the second line memory 44. The digital signals of the pair of photoelectric conversion units 13 and 14 of the M focus detection pixels 311 arranged in the even columns of (2n + 2) rows are generated until the next horizontal synchronization signal HS is generated according to the scanning signal TS2. During the period, the second horizontal output circuit 45 sequentially outputs serially to the outside. Based on the digital signal output from the second horizontal output circuit 45, the CPUa 222 for focus detection of the body drive control device 214 detects the focus state of the interchangeable lens 202 (optical system) as shown in FIG. Adjust the focus condition.

  Similarly, 2M digital signals corresponding to the output signals of the imaging pixels of (2n + 2) rows stored in the memories of the first line memory 48 ((28 (1) to 28 (2M)) (focuses arranged in even columns). The added digital signal of the pair of photoelectric conversion units 13 and 14 of the detection pixel 311 and the digital signal of the photoelectric conversion unit 11 of the image pickup pixel 310 arranged in the odd-numbered column are the next horizontal synchronization signal HS according to the scanning signal TS1. In the period until the occurrence of the, the first horizontal output circuit 49 sequentially outputs serially to the outside.2M digital signals output from the first horizontal output circuit 49 (a pair of photoelectric conversions of the focus detection pixels 311 in even columns). Based on the added digital signals of the units 13 and 14 and the digital signal of the photoelectric conversion unit 11 of the imaging pixels 310 in the odd columns, the CPUb 223 for image processing of the body drive control device 214 14, image data is generated, but in the present embodiment, 2M digital signals (focus detection pixels in even columns) output from the first horizontal output circuit 49 in step S210 of FIG. The data of the added digital signal of the pair of photoelectric conversion units 13 and 14 of 311 and the digital signal of the photoelectric conversion unit 11 of the image pickup pixel 310 of the odd-numbered column is read, and an image for display is read with respect to the read data. After the processing is performed, the image is displayed on the electronic viewfinder.In addition, in step S230 of Fig. 14, 2M digital signals (a pair of the even-numbered focus detection pixels 311 of the even-numbered columns) output from the first horizontal output circuit 49 are output. The data of the added digital signals of the photoelectric conversion units 13 and 14 and the data of the photoelectric conversion unit 11 of the image pickup pixels 310 in the odd-numbered columns are read out, and Known image processing on the read data (demosaicing, noise processing, gradation processing, and white balance processing) is is applied image data is generated.

  When the control signal R (2n + 3) is issued in synchronization with the next horizontal synchronizing signal HS and the (2n + 3) row of the pixel array section 40 is selected, the focus detection pixels 311 for one line of the (2n + 3) row and the imaging are performed. The process is repeated for the pixel 310 by the same operation as in the case of the control signal R (2n + 1).

  As described above, in the third embodiment, the image pickup pixels 310 of the pixel array section 40 and the focus detection pixels 311 are mixed, the focus detection pixels 311 are arranged at the positions of the green filters in the Bayer array, and the positions of the red filters and the blue filters are arranged. The image pickup pixels 310 are arranged, and the selection processing of the first column switch device 47 and the second column switch device 43 is switched depending on whether the row scanning circuit 41 scans an odd row or an even row of the pixel array section 40. Therefore, as compared with the configuration of the image sensor of FIG. 10, the number of digital circuits configuring the column digital adder 46 having a larger circuit scale than the switch circuit can be reduced (reduced from 2M to M). The number of memories forming the second line memory 44 having a larger circuit scale than the switch circuit is reduced (from 4M to 2). Pieces) can, it is possible to simplify the configuration of the imaging device. At the same time, the number of data output from the second horizontal output circuit 45 during the horizontal scanning period is halved (reduced from 4M to 2M) as compared with the configuration of the image sensor of FIG. 10, and the horizontal from the first horizontal output circuit 49. It becomes the same as the number of data output during the scanning period, and the data transfer rate can be reduced. Further, the focus detection data read from the second horizontal output circuit 45 is unified into the data of the focus detection pixels including the green filter, which is convenient for focus detection (in nature, there are many subjects having a green contrast). , In general, when there is chromatic aberration in the taking lens, the focus position for green is taken as the focus position).

  In the third embodiment described above, the number of pieces of focus detection data corresponding to the horizontal scanning of the second column scanning circuit 51 in one row and the number of pieces of image data corresponding to the horizontal scanning of the first column scanning circuit 52 Since the numbers are the same, the second column scanning circuit 51 and the first column scanning circuit 52 are shared (for example, the scanning signal TS1 of the first column scanning circuit 52 is used as the scanning signal TS2 of the second line memory 44). By doing so, it is possible to further simplify the configuration of the image sensor.

  In the third embodiment described above, the description has been made assuming that the data of the pair of photoelectric conversion units of all the focus detection pixels is read out for each frame for focus detection, but all of the pair of photoelectric conversion units of the focus detection pixels are read. Since reading of the data is heavy and requires a large memory capacity for storing data, frame thinning (reading once every few frames) / row thinning (reading one line every few lines) / Partial row reading (reading only some rows) / column thinning (reading one row in several rows) / column partial reading (reading only some columns) may be performed.

  FIG. 30 is a timing chart corresponding to FIG. 29 in the case of performing row partial reading (reading the data of the pair of photoelectric conversion units of the focus detection pixel only in the (2n + 2) th row). The operation when the (2n + 2) row of the pixel array section 40 is selected by the control signal R (2n + 2) is the same as that in FIG. On the other hand, when the row other than the (2n + 2) row is selected (the operation according to the control signal R (2n + 1) and the control signal R (2n + 3) in FIG. 30), the control signal TM2 is not generated, and the second line memory 44 is not stored. The memories (25 (1, 2) a, 25 (1, 2) b to 25 (2M-1, 2M) a, 25 (2M-1, 2M) b) have a pair of photoelectric conversion units of focus detection pixels. No data is stored. Further, since the scanning signal TS2 is not generated, serial output is not sequentially performed from the second horizontal output circuit 45 to the outside until the next horizontal synchronizing signal HS is generated.

  The row to be partially read out and the column to be partially read out can be changed by sending information from the body drive control device 214 to the image pickup device 212 according to the position of the selected focus detection area.

  In the third embodiment described above, as for each switch constituting the first column switch device 47, as shown in FIG. 28, the row scanning circuit 41 selects an odd row or an even row of the pixel array section 40. The two signals corresponding to the output signals of the imaging pixels are selected, and the pixels in the selected row and the two signals selected so as to be matched are sorted and stored in the memory of the first line memory 48. ((28 (1) to 28 (2M)) are stored, but the two selected signals are fixed without being distributed so as to match the pixel arrangement order in the selected row. Memory ((28 (1) to 28 (2M)), and the first column scanning circuit 52 stores the memory of the first line memory 48 ((28 (1) to 28 (2M)). 2M)) is supplied to the row scanning circuit 41 so as to match the pixel arrangement order in the selected row depending on whether the row scanning circuit 41 selects an odd row or an even row of the pixel array section 40. The scan signal TS1 may be changed to scan the memories ((28 (1) to 28 (2M)) of the first line memory 48.

<Fourth Embodiment>
The fourth embodiment is a modification of the third embodiment, and in the configuration of the image sensor 212 of the fourth embodiment shown in FIG. 31, the description of the same portions as the configurations of FIG. Only will be described. The difference between the pixel array section 40 and FIG. 26 is that in the pixel array section 40, two column signal lines (22 (1) a, 22 (1) b to 22 (2M) a, 22 (2M) b) and the number of column signal lines was 4M in total, while in FIG. 31, the number of column signal lines was reduced to one in the even columns, The number of column signal lines is reduced to 3M in total by sharing the column signal lines. In the fourth embodiment, by reducing the number of column signal lines, it is possible to alleviate the overcrowded state of the wiring layout in the pixel array section 40 and increase the area of the photoelectric conversion section, thereby obtaining a higher quality image and higher image quality. It enables accurate focus detection.

  Further, in the fourth embodiment, as the number of column signal lines decreases, the number of ADCs forming the column AD converter 42 can be reduced (4M to 3M), and the configuration of the image sensor can be simplified. ..

  31, one end of each row control line 21 (21 (1) to 21 (2N)) is connected to each output terminal corresponding to each row of the row scanning circuit 41, and each row control line 21 has a control signal R ( 1) to R (2N) are output.

  The photoelectric conversion units of the imaging pixels 310 and the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 arranged in the same row are connected to the row scanning circuit 41 by the same row control line 21, and the control signal R (L ), Charge accumulation control and signal readout control are simultaneously performed. In the pixel array section 40, two column signal lines 22 (2m + 1) a and 22 (2m + 1) b are arranged in odd columns, and one column signal line 22 (2m + 2) a is arranged in even columns. The photoelectric conversion units 11 of the imaging pixels 310 provided in the odd columns and the photoelectric conversion units 14 of the focus detection pixels 311 provided in the odd columns are one column signal line 22 of the two column signal lines provided in the odd columns. The photoelectric conversion units 13 of the focus detection pixels 311 connected to (2m + 1) a and provided in odd columns are connected to the other column signal line 22 (2m + 1) b provided in odd columns. Further, the photoelectric conversion units 11 of the imaging pixels 310 provided in the even columns and the photoelectric conversion units 14 of the focus detection pixels 311 provided in the even columns are connected to the column signal lines 22 (2m + 2) a provided in the even columns, The photoelectric conversion units 13 of the focus detection pixels 311 provided in the even-numbered columns are connected to the column signal lines 22 (2m + 1) b provided in the odd-numbered columns.

  For example, when the row scanning circuit 41 selects an odd-numbered row of the pixel array section 40, the output signal of the photoelectric conversion section 11 of the imaging pixel 310 of the odd-numbered row is output to the column signal line 22 (2m + 2) a, The output signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 in the odd rows are output to the column signal lines 22 (2m + 1) a and 22 (2m + 1) b. When the row scanning circuit 41 selects the even-numbered row of the pixel array section 40, the output signal of the photoelectric conversion section 11 of the even-numbered row imaging pixel 310 is output to the column signal line 22 (2m + 1) a, The output signal of the photoelectric conversion unit 14 of the even-numbered focus detection pixel 311 is output to the column signal line 22 (2m + 2) a, and the output signal of the photoelectric conversion unit 13 of the even-numbered focus detection pixel 311 is the column signal line 22. It will be output to (2m + 1) b.

  The column AD conversion device 42 is provided for each of the 3M column signal lines 22 (1) a and 22 (1) b to 22 (2M) a provided corresponding to the pixel columns of the pixel array section 40. Has a number of ADCs (analog-digital conversion circuits) 23 (1) a and 23 (1) b to 23 (2M) a, and outputs an analog signal output from each pixel of the pixel array section 40 for each column. In accordance with the control signal TA1 given from the control circuit 50, it is converted into an H-bit digital signal (S (1) a, S (1) b to S (2M) a) and output.

  The second column switch device 43 has M switches 24 (1, 2) to 24 (2M-1, 2M) provided for each of two adjacent pixel columns, and the ADC (23 (1) a , 23 (1) b to 23 (2M) a) are selected and output according to the control signal TW2 provided from the timing control circuit 50.

  32A and 32B are views for explaining the selecting operation of the switches 24 (2m + 1, 2m + 2) provided in the adjacent two pixel columns ((2m + 1) column and (2m + 2) column). , The switch 24 (2m + 1, 2m + 2) has two ADCs (23 (2m + 1) a, 23 (2m + 1) b) corresponding to odd columns (2m + 1) and one ADC corresponding to even columns (2m + 2). Three digital signals S (2m + 1) a, S (2m + 1) b, and S (2m + 2) a are input from (23 (2m + 2) a).

  FIG. 32A shows a selection operation of the switch 24 (2m + 1, 2m + 2) when the row scanning circuit 41 selects an odd row of the pixel array section 40. The switch 24 (2m + 1, 2m + 2) has an odd row. The three digital signals S (2m + 1) a, S (2m + 1) b, and S (2m + 2) a corresponding to the focus detection pixels 311 on the odd-numbered rows and the imaging pixels 310 arranged on the even-numbered columns are input. To be done.

  The switch 24 (2m + 1, 2m + 2) is responsive to a control signal TW2 (indicating an odd row) input to the second column switch device 43 to generate a pair of signals (Q (2m + 1, 2m + 2) a, Q (2m + 1) for digital addition. 2m + 2) b), the digital signals S (2m + 1) a and S (2m + 1) b corresponding to the pair of photoelectric conversion units of the focus detection pixel 311 are selected and output.

  FIG. 32B shows a selection operation of the switch 24 (2m + 1, 2m + 2) when the row scanning circuit 41 selects an even row of the pixel array section 40. The switch 24 (2m + 1, 2m + 2) has an even row. The three digital signals S (2m + 1) a, S (2m + 1) b, and S (2m + 2) a corresponding to the focus detection pixels 311 in the even-numbered rows and the imaging pixels 310 arranged in the odd-numbered columns To be done.

  The switch 24 (2m + 1, 2m + 2) is a pair of signals corresponding to the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 according to the control signal TW2 (indicating an even row) input to the second column switch device 43. As (Q (2m + 1, 2m + 2) a, Q (2m + 1, 2m + 2) b), digital signals S (2m + 2) a, S (2m + 1) b corresponding to the pair of photoelectric conversion units of the focus detection pixel 311 are selected and output. To do.

<Fifth Embodiment>
The fifth embodiment is a modification of the configuration of the focus detection pixels of the pixel array section in the third embodiment. FIG. 33 is a diagram corresponding to the pixel layout diagram of FIG. 25 (the filter array corresponds to FIG. 4), in which the focus detection images 311 arranged in the even rows of FIG. 25 are juxtaposed in the vertical direction. It is replaced with a focus detection pixel 312 having a pair of photoelectric conversion units 16 and 17.

  That is, in the odd rows, the focus detection pixels 311 are arranged in the odd columns, and the imaging pixels 310 are arranged in the even rows, and in the even rows, the imaging pixels 310 are arranged in the odd columns and the focus detection pixels 312 are arranged in the even rows. From the viewpoint of the Bayer array color filter, the focus detection pixel 311 and the focus detection pixel 312 are provided with a green filter, and the imaging pixel 310 is provided with a red filter or a blue filter.

  FIG. 34 is a block diagram showing the configuration of the image sensor 212 having the pixel layout shown in FIG. 33. The description of the same parts as those of FIG. 26 will be omitted, and only the characteristic parts will be described. The difference between the pixel array section 40 and FIG. 26 is that the focus detection pixel 312 including the pair of photoelectric conversion sections 16 and 17 separated in the vertical direction is arranged in the even row and the even column.

  The pair of photoelectric conversion units 16 and 17 of each focus detection pixel 312 arranged in even rows and even columns are connected to the row scanning circuit 41 by the same row control line 21, and a control signal R (L) (L is The charge accumulation control and the signal reading control are simultaneously performed according to the (even number). Further, one photoelectric conversion unit 16 of the pair of photoelectric conversion units 16 and 17 of each focus detection pixel 312 in the even-numbered rows and even-numbered columns is one column signal line 22 (2m + 2) of two column signal lines provided for each column. ) A, the output signal (analog signal) of the photoelectric conversion unit 16 is output to the column signal line 22 (2m + 2) a. The other photoelectric conversion unit 17 of the pair of photoelectric conversion units 16 and 17 of each focus detection pixel 312 is connected to the other column signal line 22 (2m + 2) b of the two column signal lines provided for each column, The output signal (analog signal) of the photoelectric conversion unit 17 is output to the column signal line 22 (2m + 2) b.

  When the image sensor 212 having the above-described configuration is used, the data of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 provided with the green filters arranged in the odd rows and the even columns is photoelectrically converted in the horizontal direction. Using a pair of data grouped for each conversion unit, it is possible to detect a phase difference for a subject image with a horizontal contrast change, and a focus with green filters arranged in even rows and even columns. Using the pair of data obtained by grouping the data of the pair of photoelectric conversion units 16 and 17 of the detection pixel 312 in the vertical direction for each photoelectric conversion unit, it is possible to detect the phase difference with respect to the subject image having the contrast change in the vertical direction. Become.

<Sixth Embodiment>
The sixth embodiment is a modification of the configuration of the focus detection pixels of the pixel array section in the fourth embodiment. The pixel layout in the sixth embodiment is the same as that in FIG. 33, and the focus detection pixel has a pair of photoelectric conversion units 16 and 17 in which the focus detection images 311 arranged in the even rows of FIG. 25 are juxtaposed in the vertical direction. 312.

  That is, in the odd rows, the focus detection pixels 311 are arranged in the odd columns, and the imaging pixels 310 are arranged in the even rows, and in the even rows, the imaging pixels 310 are arranged in the odd columns and the focus detection pixels 312 are arranged in the even rows. From the viewpoint of the Bayer array color filter, the focus detection pixel 311 and the focus detection pixel 312 are provided with a green filter, and the imaging pixel 310 is provided with a red filter or a blue filter.

  FIG. 35 is a block diagram showing the configuration of the image sensor 212 having the pixel layout shown in FIG. 33. The description of the same parts as those of FIG. 31 will be omitted, and only the characteristic parts will be described. The pixel array unit 40 is different from FIG. 31 in that the focus detection pixels 312 including the pair of photoelectric conversion units 16 and 17 separated in the vertical direction are arranged in the even-numbered rows and the even-numbered columns.

  The pair of photoelectric conversion units 16 and 17 of each focus detection pixel 312 arranged in even rows and even columns are connected to the row scanning circuit 41 by the same row control line 21, and a control signal R (L) (L is The charge accumulation control and the signal reading control are simultaneously performed according to the (even number). Further, one photoelectric conversion unit 16 of the pair of photoelectric conversion units 16 and 17 of each focus detection pixel 312 is connected to one column signal line 22 (2m + 2) a of one column signal line provided in an even column, The output signal (analog signal) of the photoelectric conversion unit 16 is output to the column signal line 22 (2m + 2) a. The other photoelectric conversion unit 17 of the pair of photoelectric conversion units 16 and 17 of each focus detection pixel 312 is connected to one column signal line 22 (2m + 1) b of the two column signal lines provided in the odd columns. The output signal (analog signal) of the photoelectric conversion unit 17 that is connected is output to the column signal line 22 (2m + 1) b.

  When the image sensor 212 having the above-described configuration is used, the data of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 provided with the green filters arranged in the odd rows and the even columns is photoelectrically converted in the horizontal direction. Using a pair of data grouped for each conversion unit, it is possible to detect a phase difference for a subject image with a horizontal contrast change, and a focus with green filters arranged in even rows and even columns. Using the pair of data obtained by grouping the data of the pair of photoelectric conversion units 16 and 17 of the detection pixel 312 in the vertical direction for each photoelectric conversion unit, it is possible to detect the phase difference with respect to the subject image having the contrast change in the vertical direction. Become.

<Seventh Embodiment>
In the first to sixth embodiments, the pixels (focus detection pixels, image pickup pixels) are arranged in the pixel array unit 40 in a square lattice shape, but the pixels are arranged in a pixel arrangement other than the square lattice pixel arrangement. The invention can be applied.

  FIG. 36 shows a so-called honeycomb array, which is a pixel array obtained by rotating a square lattice array by 45 degrees. Further, FIG. 37 shows a filter array corresponding to the pixel layout of FIG. The filter array shown in FIG. 37 is a Bayer array inclined by 45 degrees. In the honeycomb array shown in FIGS. 36 and 37, the focus detection pixels 411 in which a pair of photoelectric conversion units 33 and 34 are arranged side by side in the horizontal direction are arrayed.

  The matrix in such a honeycomb arrangement is defined as follows. That is, the horizontal pixel array in which the green filter is arranged is an odd row, the horizontal pixel array in which the red filter or the blue filter is arranged is in an even row, and the vertical pixel array in which the green filter is arranged is an odd row. A vertical pixel array in which columns, red filters, or blue filters are arranged is an even column.

  38 is a block diagram showing a configuration of an image pickup device 212 having the pixel layout (2N rows and 2M columns) of the honeycomb arrangement shown in FIG. 36, and is arranged in the pixel array section 40 in the configuration of the image pickup device shown in FIG. The focus detection pixels 311 are thinned out every other pixel and replaced with the focus detection pixels 411. That is, the focus detection pixels 411 are arranged only in the odd columns in the odd rows, and the focus detection pixels 411 are arranged only in the even columns in the even rows.

  The focus detection pixels 411 are two-dimensionally arranged in the pixel array unit 40 by 2N rows and 2M columns. In FIG. 38, the focus detection pixel 411 at the upper left is the pixel in the first row and the first column, and a green filter is arranged in this pixel. Row control lines 21 (21 (1) to 21 (2N)) are laid out for each row with respect to the pixel arrangement of 2N rows and 2M columns, and two column signal lines (22 (1) a, 22) are provided in odd columns. (1) b to 22 (2M-1) a and 22 (2M-1) b) are wired. One end of each row control line 21 (21 (1) to 21 (2N)) is connected to each output end corresponding to each row of the row scanning circuit 41, and each row control line 21 has control signals R (1) to R (R). (2N) is output.

  The pair of photoelectric conversion units 33 and 34 of each focus detection pixel 411 are connected to the row scanning circuit 41 by the same row control line 21, and charge accumulation control and signal reading control are simultaneously performed according to the control signal R (L). Done. Further, one photoelectric conversion unit 33 of the pair of photoelectric conversion units 33, 34 of the focus detection pixel 411 arranged in the odd-numbered row and odd-numbered column (2m + 1 column) has two column signals provided in the odd-numbered column (2m + 1 column). One of the lines is connected to the column signal line 22 (2m + 1) b, and the output signal (analog signal) of the photoelectric conversion unit 33 is output to the column signal line 22 (2m + 1) b. The other photoelectric conversion unit 34 of the pair of photoelectric conversion units 33 and 34 of each focus detection pixel 411 is the other column signal line 22 (2m + 1) a of the two column signal lines provided in the odd column (2m + 1 column). , And the output signal (analog signal) of the photoelectric conversion unit 34 is output to the column signal line 22 (2m + 1) a.

  Further, one photoelectric conversion unit 33 of the pair of photoelectric conversion units 33 and 34 of the focus detection pixel 411 arranged in the even-numbered rows and the even-numbered columns (2m + 2 columns) has two column signals provided in the odd-numbered columns (2m + 1 columns). One of the lines is connected to the column signal line 22 (2m + 1) b, and the output signal (analog signal) of the photoelectric conversion unit 33 is output to the column signal line 22 (2m + 1) b. The other photoelectric conversion unit 34 of the pair of photoelectric conversion units 33 and 34 of each focus detection pixel 411 is the other column signal line 22 (2m + 1) a of the two column signal lines provided in the odd column (2m + 1 column). , And the output signal (analog signal) of the photoelectric conversion unit 34 is output to the column signal line 22 (2m + 1) a.

  The column AD conversion device 42 includes column signal lines 22 (1) a, 22 (1) b to 22 (2M-1) a, 22 (2M-1) provided corresponding to the pixel columns of the pixel array section 40. The ADC (analog-digital conversion circuit) 23 (1) a, 23 (1) b to 23 (2M-1) a, 23 (2M-1) b provided for each b is included in the pixel array section 40. A pair of analog signals output from each focus detection pixel 411 for each column are converted into H-bit digital signals and output according to a control signal TA1 provided from the timing control circuit 50.

  The second line memory 44 is provided for each ADC (23 (1) a, 23 (1) b to 23 (2M-1) a, 23 (2M-1) b) that configures the column AD converter 42. Memory (25 (1) a, 25 (1) b to 25 (2M-1) a, 25 (2M-1) b), and an ADC (23 (1) a, 23 (1) b to 23 (1) b-23). The digital signal output every (2M-1) a, 23 (2M-1) b) is stored as an H-bit digital signal according to the control signal TM2 given from the timing control circuit 50. Here, each memory (25 (1) a, 25 (1) b to 25 (2M-1) a, 25 (2M-1) b) of the second line memory 44 has a pair of focus detection pixels for one row. The output signals of the photoelectric conversion units 33 and 34 are stored as digital signals.

  The column digital adder 46 is a pair of ADCs ((23 (1) a, 23 (1) b) to (23 (2M-1) a, 23 (2M-1) b)) that constitute the column AD converter 42. ) Is provided for each digital adder circuit (26 (1) to 26 (2M-1)), and a pair of ADCs ((23 (1) a, 23 (1) b) to (23 (2M-1)). ) A, 23 (2M-1) b)) are added according to the control signal TD1 given from the timing control circuit 50, and output as an H-bit addition digital signal.

  The first line memory 48 is a memory (28 (1) to 28 (2M-1)) provided for each of the digital adding circuits (26 (1) to 26 (2M-1)) included in the column digital adding device 46. ), And outputs an addition digital signal output from each of the digital addition circuits (26 (1) to 26 (2M-1)) in accordance with the control signal TM1 provided from the timing control circuit 50. Memorize as. Here, in each of the memories (28 (1) to 28 (2M-1)) of the first line memory 48, an addition signal (a signal obtained by adding the output signals of the pair of photoelectric conversion units 33 and 34 for one row of focus detection pixels (Corresponding to the output signal of the imaging pixel) will be stored as a digital signal.

  The second line memory 44 operates according to the scanning signal TS2 provided from the second column scanning circuit 51, and the memories (25 (1) a, 25 (1) b to 25 (2M-1) a, 25 (2M- 1) The H-bit digital signal stored in each of b) is sequentially read to the second horizontal output circuit 45, and passes through the second horizontal output circuit 45, and a pair of photoelectric conversion units 33 for focus detection, It is serially output to the outside as an output signal (digital signal) of 34.

  The first line memory 48 operates according to the scanning signal TS1 provided from the first column scanning circuit 52, and the H-bit addition digital signal stored in each of the memories (28 (1) to 28 (2M-1)). Are sequentially read by the first horizontal output circuit 49, and serially output as an output signal (digital signal) equivalent to the output signal of the image pickup pixel via the first horizontal output circuit 49.

<Eighth Embodiment>
The eighth embodiment is a modification of the configuration of the focus detection pixels of the pixel array section in the seventh embodiment. FIG. 39 is a diagram corresponding to the pixel layout diagram of FIG. 36 (the filter array corresponds to FIG. 37), and the focus detection images 411 arranged in the even-numbered rows of FIG. 36 are juxtaposed in the vertical direction. It is replaced with a focus detection pixel 412 having a pair of photoelectric conversion units 36 and 37.

  That is, the focus detection pixels 411 are arranged in the odd columns in the odd rows, and the focus detection pixels 412 are arranged in the even columns in the even rows.

  FIG. 40 is a block diagram showing the configuration of the image sensor 212 having the pixel layout shown in FIG. 39. The description of the same parts as those of FIG. 38 will be omitted, and only the characteristic parts will be described. The difference between the pixel array section 40 and FIG. 38 is that the focus detection pixels 412 including the pair of photoelectric conversion sections 36 and 37 separated in the vertical direction are arranged in the even-numbered rows and the even-numbered columns.

  The pair of photoelectric conversion units 36 and 37 of each focus detection pixel 412 arranged in the even-numbered rows and the even-numbered columns (2m + 2 columns) are connected to the row scanning circuit 41 by the same row control line 21, and the control signal R (L ) (L is an even number), charge accumulation control and signal read control are simultaneously performed. Further, one photoelectric conversion unit 36 of the pair of photoelectric conversion units 36 and 37 of each focus detection pixel 412 is one column signal line 22 (2m + 1) a of two column signal lines provided in an odd number column (2m + 1 column). , And the output signal (analog signal) of the photoelectric conversion unit 36 is output to the column signal line 22 (2m + 1) a. The other photoelectric conversion unit 37 of the pair of photoelectric conversion units 36 and 37 of each focus detection pixel 412 is the other column signal line 22 (2m + 1) b of the two column signal lines provided in the odd column (2m + 1 column). And the output signal (analog signal) of the photoelectric conversion unit 37 is output to the column signal line 22 (2m + 1) b.

  When the image sensor 212 having the above-described configuration is used, the data of the pair of photoelectric conversion units 33 and 34 of the focus detection pixel 411 provided with the green filters arranged in odd rows and odd columns are photoelectrically converted in the horizontal direction. Using a pair of data grouped for each conversion unit, it becomes possible to detect a phase difference for a subject image that has a horizontal contrast change, and the red and blue filters arranged in the even rows and even columns are used. The data of the pair of photoelectric conversion units 36 and 37 of the provided focus detection pixel 412 is grouped in the vertical direction for each photoelectric conversion unit, and a pair of data of the same color is used to position the object image with a contrast change in the vertical direction. Phase difference detection is possible.

<Other embodiments>
In the present invention, the number of photoelectric conversion units in the focus detection pixel is not limited to two, and the present invention can be applied to a configuration in which the focus detection pixel includes two or more photoelectric conversion units. For example, the focus detection pixel 311 shown in FIG. 6 includes two photoelectric conversion units 13 and 14 obtained by dividing a square into two equal parts in the horizontal direction, but the two photoelectric conversion units 13 and 14 are further divided into two equal parts in the vertical direction. The present invention can be applied to a configuration including a focus detection pixel including four photoelectric conversion units. For example, an ADC that provides four column signal lines in each column to independently read the analog signals of the four photoelectric conversion units and outputs the analog signals output from the four photoelectric conversion units as digital signals for AD conversion individually 10 is provided by providing a column AD converter including the column AD converter and a digital adder circuit that digitally adds the digital signals of the four photoelectric conversion units output from the column AD converter. The same effect as can be obtained.

  Further, instead of providing four column signal lines corresponding to the four photoelectric conversion units, two photoelectric conversion units of the four photoelectric conversion units and the other two photoelectric conversion units are arranged in two adjacent virtual rows. It is also possible to reduce the number of column signal lines to two by configuring the image sensor as a photoelectric conversion unit of the focus detection pixel. For example, when four photoelectric conversion units are arranged in two stages in each focus detection pixel 311, two photoelectric conversion units in the upper stage and two photoelectric conversion units in the lower stage are virtually adjacent to each other in two rows. The number of column signal lines is reduced to two, which is regarded as the photoelectric conversion unit of the focus detection pixel.

  In the image pickup device of the above-mentioned embodiment, an example is shown in which one data output channel for focus detection and one data output channel for image are provided for the entire image array section, but the read speed is increased. Therefore, it is possible to divide the image array unit into a plurality of regions and to provide one data output channel for focus detection and one data output channel for image for each region.

  In the image sensor 212 of the above-described embodiment, the CPUa 222 of the body drive control device 214 controls the interchangeable lens 202 (optical system) based on the digital signal obtained by the column AD conversion device 42 converting the pair of analog signals. Detect focus condition. However, a digital signal obtained by the column AD converter 42 converting a pair of analog signals may be used as a signal for a 3D camera.

  Further, the present invention is not limited to the image pickup device of the type in which the wiring layer is present between the microlens and the photoelectric conversion unit as shown in FIG. 7, but the wiring layer is not present between the microlens and the photoelectric conversion unit. It is also applicable to a backside illumination type image pickup device in which a wiring layer is arranged on the side opposite to the direction of the microlens with respect to the portion. An image pickup device such as the image pickup device according to the present invention that requires the column signal line 22 is provided with more wiring layers than the conventional image pickup device. In the back-illuminated type image pickup device, the wiring layer can be arranged without being limited by the layout of the photoelectric conversion unit, and thus the flexibility with respect to the increase in the number of column signal lines is improved.

  In the image pickup device 212 in the above-described embodiment, an example in which the image pickup pixels are provided with the Bayer array color filters has been shown, but the configuration and arrangement of the color filters are not limited to this, and complementary color filters (green: G, yellow). The present invention can be applied to arrangements other than the Bayer arrangement and the arrangement of: Ye, magenta: Mg, cyan: Cy). It can also be applied to a monochrome image sensor.

  The image sensor 212 in the above-described embodiment has the pixel array section 40 and the other part. Although the pixel array section 40 and the other portion are provided on different substrates and the different substrates are laminated on each other, the pixel array section 40 and the other portion are provided on the same substrate. Good.

  The image pickup apparatus is not limited to the digital still camera having the above-described camera body in which the interchangeable lens is mounted. For example, the present invention can be applied to a lens-integrated digital still camera or video camera. Further, it can be applied to a small camera module built in a mobile phone, a surveillance camera, a visual recognition device for a robot, an in-vehicle camera, and the like.

10 microlenses,
11, 13, 14, 16, 17, 33, 34, 36, 37 photoelectric conversion unit,
15, 18 element isolation region, 21 row control line, 22 column signal line,
23 ADC (analog-digital conversion circuit), 24, 27 switch,
25, 28 memory, 26 digital adder circuit,
29 semiconductor substrate, 30 light shielding mask, 31, 32 flattening layer, 38 color filter,
40 pixel array section, 41 row scanning circuit, 42 column AD converter,
43 second column switch device, 44 second line memory, 45 second horizontal output circuit,
46 column digital adder circuit, 47 first column switch device,
48 first line memory, 49 first horizontal output circuit, 50 timing control circuit,
51 second column scanning circuit, 52 first column scanning circuit,
71 shooting light flux, 73, 74 focus detection light flux, 90 exit pupil, 91 optical axis,
93,94 distance-measuring pupil, 95 area, 100 shooting screen, 101 focus detection area,
201 digital still camera, 202 interchangeable lens, 203 camera body,
204 mount unit, 206 lens drive control device,
208 zooming lens, 209 lens, 210 focusing lens,
211 diaphragm, 212 image sensor, 213 electrical contact, 214 body drive control device,
215 liquid crystal display element drive circuit, 216 liquid crystal display element, 217 eyepiece lens,
219 memory card, 220 image sensor control unit, 221 buffer memory,
222 CPUa, 223 CPUb,
310 image pickup pixels, 311, 312, 411, 412 focus detection pixels

Claims (9)

A first pixel which converts light into an electric charge and has a first photoelectric conversion portion and a second photoelectric conversion portion which are provided in a first direction;
A second pixel which converts light into an electric charge and which has a third photoelectric conversion part and a fourth photoelectric conversion part which are provided in a second direction intersecting the first direction;
A first signal line that outputs a signal based on the charges converted by the first photoelectric conversion unit;
A second signal line that outputs a signal based on the charges converted by the second photoelectric conversion unit;
A third signal line that outputs a signal based on the charges converted by the third photoelectric conversion unit;
A fourth signal line for outputting a signal based on the charges converted by the fourth photoelectric conversion unit;
The signal output from the first signal line and the signal output from the second signal line are added, and the signal output from the third signal line and the signal output from the fourth signal line are added. An adder for adding the signal and
At least one of the signal output from the first signal line, the signal output from the second signal line, the signal output from the third signal line, and the signal output from the fourth signal line. A first output line for outputting one
A second output line for outputting the signals added by the adder;
An image pickup device including. The image sensor according to claim 1,
The addition unit adds a signal output from the first signal line and a signal output from the second signal line, and a signal output from the third signal line. A second adder for adding the signal output from the fourth signal line,
The second output line is an image sensor that outputs at least one of the signal added by the first adder and the signal added by the second adder. The image sensor according to claim 1 or 2,
The signal output from the first signal line, the signal output from the second signal line, the signal output from the third signal line, and the signal output from the fourth signal line are digital signals. Equipped with an A / D converter that converts to
The addition unit adds the signals converted into digital signals by the A / D conversion unit,
The first output line outputs a signal converted into a digital signal by the A / D converter,
The second output line is an image sensor that outputs the digital signal added by the adder. The image sensor according to claim 3,
The A / D conversion unit converts a signal output from the first signal line into a digital signal, and a signal output from the second signal line into a digital signal. A second A / D conversion unit for converting, a third A / D conversion unit for converting the signal output on the third signal line into a digital signal, and a signal output on the fourth signal line And a fourth A / D conversion unit that converts the signal into a digital signal. The image sensor according to any one of claims 1 to 4,
An image pickup device in which the first signal line, the second signal line, the third signal line, and the fourth signal line are wired in the first direction. A first pixel that converts light into an electric charge and has a first photoelectric conversion unit and a second photoelectric conversion unit;
A second pixel that converts light into an electric charge and has a third photoelectric conversion unit;
A first signal line that outputs a signal based on the charges converted by the first photoelectric conversion unit;
A second signal line that outputs a signal based on the charges converted by the second photoelectric conversion unit;
A third signal line that outputs a signal based on the charges converted by the third photoelectric conversion unit;
An adding unit that adds the signal output from the first signal line and the signal output from the second signal line;
A first output line that outputs at least one of the signal output from the first signal line and the signal output from the second signal line;
A second output line that outputs at least one of the signal added by the adder and the signal output by the third signal line;
An image pickup device including. The image sensor according to claim 6,
An A / D converter that converts the signal output from the first signal line, the signal output from the second signal line, and the signal output from the third signal line into a digital signal,
The addition unit adds the signals converted into digital signals by the A / D conversion unit,
The first output line and the second output line are image pickup elements that output signals converted into digital signals by an A / D conversion unit. The image sensor according to claim 7,
The A / D conversion unit converts a signal output from the first signal line into a digital signal, and a signal output from the second signal line into a digital signal. An imaging device having a second A / D conversion unit for conversion and a third A / D conversion unit for converting the signal output from the third signal line into a digital signal. An image pickup device according to any one of claims 1 to 8,
An image pickup apparatus comprising: a generation unit that generates image data based on the signals added by the addition unit.

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