JP2023156291A - Imaging element and imaging device - Google Patents

Abstract

To provide an imaging element with which it is possible to read out a signal used for focus detection and a signal used for image formation at high speed.SOLUTION: An imaging element 212 comprises: a first photoelectric conversion unit 14 and a second photoelectric conversion unit 13 that photoelectrically convert light having passed through a first micro-lens to generate an electric charge; a first signal line 22a that outputs a signal based on the electric charge generated by the first photoelectric conversion unit 14; a second signal line 22b that outputs a signal based on the electric charge generated by the second photoelectric conversion unit 13; and a first A/D conversion unit 23a that is electrically connected to the first signal line 22a, and converts an analog signal based on the electric charge generated by the first photoelectric conversion unit 14 into a first digital signal; a second A/D conversion unit 23b that is electrically connected to the second signal line 22b, and converts an analog signal based on the electric charge generated by the second photoelectric conversion unit 13 into a second digital signal; and a digital addition circuit 26 that adds up the first and second digital signals.SELECTED DRAWING: Figure 10

Description

The present invention relates to an imaging device and an imaging device.

An imaging device with an array of focus detection pixels consisting of a microlens and a pair of photoelectric conversion units placed behind it is placed on the planned focal plane of the photographic lens, thereby forming a pair of focus detection light fluxes that pass through the optical system. A pair of image signals corresponding to the pair of images are generated as analog signals in a pair of photoelectric conversion units, and the pair of analog signals are independently read out from the image sensor to calculate the amount of image shift (phase difference) between the pair of image signals. By this detection, the focus adjustment state (defocus amount) of the photographic lens is detected, and the analog signals generated by the pair of photoelectric conversion units of the focus detection pixel are added in analog form within the focus detection pixel, and the analog signal after addition is 2. Description of the Related Art An imaging device that generates image information by reading a signal as an image signal from an image sensor is known (for example, see Patent Document 1).

Japanese Patent Application Publication No. 2001-83407

In the above-mentioned imaging device, analog addition processing of a pair of analog signals is performed within the focus detection pixel, so when detecting focus, the pair of analog signals are read out independently from the image sensor, and when generating image information, the pair of analog signals are read out independently from the image sensor. It is necessary to add and read out a pair of analog signals from the image sensor, and there is a problem that focus detection and image information generation cannot be performed simultaneously when reading out signals for one frame from the image sensor.

An image sensor according to a first aspect of the present invention includes a first photoelectric conversion section and a second photoelectric conversion section that photoelectrically convert light transmitted through a first microlens to generate charges, and a first photoelectric conversion section that generates charges. a first signal line that outputs a signal based on the charge generated by the conversion unit; a second signal line that outputs a signal based on the charge generated by the second photoelectric conversion unit; and the first signal line. a first A/D conversion section that is electrically connected to the line and converts an analog signal based on the charge generated by the first photoelectric conversion section into a first digital signal; and the second signal line. a second A/D converter that is electrically connected and converts an analog signal based on the charge generated by the second photoelectric converter into a second digital signal; and a first adding section that adds the two digital signals.
An image sensor according to a second aspect of the present invention includes the above-described image element and a generation section that generates image data based on the signals added by the addition section.

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

FIG. 1 is a cross-sectional view showing the configuration of an interchangeable lens digital still camera equipped with an image sensor according to an embodiment. FIG. 3 is a diagram showing a focus detection position on a photographic screen of an interchangeable lens. FIG. 2 is a front view showing the detailed configuration of an image sensor. FIG. 2 is a front view showing the detailed configuration of an image sensor. FIG. 3 is a diagram showing spectral sensitivity characteristics of each color filter. FIG. 3 is a diagram showing the configuration of a focus detection pixel. FIG. 3 is a cross-sectional view of a focus detection pixel. FIG. 2 is a diagram showing the configuration of a focus detection optical system using a pupil division type phase difference detection method. FIG. 2 is a block diagram showing in detail the relationship between an image sensor and a body drive control device. FIG. 2 is a block diagram showing the configuration of an image sensor. 12 is a timing chart when an individual readout operation of the output signals of a pair of photoelectric conversion units of a focus detection pixel and a readout operation of an added signal obtained by adding the output signals of the pair of photoelectric conversion units of a focus detection pixel are performed in parallel during one frame period. . 12 is a timing chart when an individual readout operation of the output signals of a pair of photoelectric conversion units of a focus detection pixel and a readout operation of an added signal obtained by adding the output signals of the pair of photoelectric conversion units of a focus detection pixel are performed in parallel during one frame period. . It is an operation flowchart of the CPUa for focus detection of the body drive control device included in the digital still camera. 2 is an operation flowchart of a CPU for image processing of a body drive control device included in a digital still camera. FIG. 3 is a diagram showing a correlation calculation result for a pair of data strings. 3 is a timing chart when performing partial row reading. FIG. 3 is a diagram showing the configuration of a focus detection pixel. FIG. 2 is a front view showing the detailed configuration of an image sensor. FIG. 2 is a block diagram showing the configuration of an image sensor. FIG. 2 is a front view showing the detailed configuration of an image sensor. FIG. 2 is a front view showing the detailed configuration of an image sensor. FIG. 3 is a diagram showing the configuration of an imaging pixel. FIG. 3 is a cross-sectional view of an imaging pixel. FIG. 3 is a diagram for explaining the state of a photographing light flux. FIG. 2 is a front view showing the detailed configuration of an image sensor. FIG. 2 is a block diagram showing the configuration of an image sensor. FIG. 6 is a diagram illustrating a selection operation of switches provided in two adjacent pixel columns. FIG. 6 is a diagram illustrating a selection operation of switches provided in two adjacent pixel columns. 12 is a timing chart when an individual readout operation of output signals of a pair of photoelectric conversion units of a focus detection pixel and a readout operation of an output signal corresponding to an output signal of an imaging pixel are performed in parallel during one frame period. 3 is a timing chart when performing partial row reading. FIG. 2 is a block diagram showing the configuration of an image sensor. FIG. 6 is a diagram illustrating a selection operation of switches provided in two adjacent pixel columns. FIG. 2 is a front view showing the detailed configuration of an image sensor. FIG. 2 is a block diagram showing the configuration of an image sensor. FIG. 2 is a block diagram showing the configuration of an image sensor. FIG. 2 is a front view showing the detailed configuration of an image sensor. FIG. 2 is a front view showing the detailed configuration of an image sensor. FIG. 2 is a block diagram showing the configuration of an image sensor. FIG. 2 is a front view showing the detailed configuration of an image sensor. FIG. 2 is a block diagram showing the configuration of an image sensor.

<First embodiment>
An imaging element and an imaging device according to an embodiment of the present invention will be described. FIG. 1 is a cross-sectional view showing the configuration of an interchangeable lens digital still camera equipped with an image sensor according to an embodiment. A digital still camera 201 according to one embodiment includes an interchangeable lens 202 and a camera body 203, and various interchangeable lenses 202 are attached to 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, an aperture 211, a lens drive control device 206, and the like. The lens drive control device 206 is composed of a microcomputer (not shown), a memory, a drive control circuit, etc., and performs drive control for adjusting the focus of the focusing lens 210 and the aperture diameter of the diaphragm 211, as well as controlling the zooming lens 208 and the focusing lens. In addition to detecting the states of the lens 210 and the aperture 211, it also transmits lens information and receives camera information through communication with a body drive control device 214, which will be described later. The diaphragm 211 forms an aperture with a variable aperture diameter centered on the optical axis in order to adjust the amount of light and the amount of blur.

The camera body 203 includes an image sensor 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 sensor 212, pixels that function as both image capture pixels and focus detection pixels are arranged in a two-dimensional manner. The image sensor 212 will be described in detail later.

The body drive control device 214 is composed of a microcomputer, memory, drive control circuit, etc., and performs drive control of the image sensor 212, reading of an output signal from the image sensor 212, focus detection calculation based on the output signal, and control of the interchangeable lens 202. In addition to repeatedly performing focus adjustment, image processing calculations and recording based on the output signal, camera operation control, etc. are performed. Further, the body drive control device 214 communicates with the lens drive control device 206 via the electrical contact 213, and receives lens information and transmits 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 the through image captured by the image sensor 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 images captured by the image sensor 212.

A subject image is formed on the light-receiving surface of the image sensor 212 by the light beam that has passed through the interchangeable lens 202 . This subject image is photoelectrically converted by each pixel of the image sensor 212, and an output signal from each pixel is sent to the body drive control device 214.

The body drive control device 214 calculates a defocus amount based on the output signal from each pixel of the image sensor 212, and sends this 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 it in the memory card 219, and uses the through image signal from the image sensor 212 to drive the liquid crystal display element. It is sent to a circuit 215 and the through image is displayed on a 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 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, and lens information is calculated according to these lens positions and aperture value, or a lookup prepared in advance is performed. Select lens information according to the lens position and aperture value from the table.

The lens drive control device 206 calculates a 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 control device 206 drives the aperture 211 according to the received aperture value.

FIG. 2 is a diagram showing the focus detection position (set by the user by operating an operating member not shown in FIG. 1) on the photographing screen of the interchangeable lens 202, and the pixel row on the image sensor 212, which will be described later, is in focus. An example of an area (focus detection area, focus detection position) in which an image is sampled on the photographic screen during detection is shown. In this example, a focus detection area 101 is arranged at the center of a rectangular photographing screen 100. A focus detection area 101 indicated by a rectangle extends horizontally in the photographing screen 100, and output signals of pixels arranged linearly 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 sensor 212, and show the vicinity of the focus detection area 101 on the image sensor 212 in an enlarged manner. FIG. 3 is a diagram showing the layout of a pixel 311 (hereinafter referred to as focus detection pixel 311) that serves as an imaging pixel and focus detection pixel, and the focus detection pixel 311 is arranged in a row direction (horizontal direction) and a column direction (vertical direction). are densely arranged in a two-dimensional square grid. FIG. 4 is a diagram showing an arrangement of color filters in the arrangement of focus detection pixels 311 shown in FIG. 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 sections 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 the same as that of the photoelectric conversion unit of a normal imaging pixel. Note that color filters are not shown in FIG. 6 for the sake of brevity. Note that when the outputs of the pair of photoelectric converters 13 and 14 of the focus detection pixel 311 are added, the width of the element isolation region 15 is adjusted so that the added output is equal to the output of the photoelectric converter of a normal imaging pixel. It is desirable to make the space as narrow as possible and to place the pair of photoelectric conversion units 13 and 14 close to each other.

FIG. 7 is a cross-sectional view of the focus detection pixel 311 shown in FIG. The photoelectric conversion units 13 and 14 receive light. A planarization layer 31 is formed on the light-shielding mask 30, and a color filter 38 is formed thereon. A planarization layer 32 is formed on the color filter 38, and a microlens 10 is formed thereon. The shapes of the photoelectric conversion units 13 and 14, which are limited by the aperture 30d by the microlens 10, are projected forward to form a pair of distance measuring pupils. The photoelectric conversion sections 13 and 14 are formed on a semiconductor circuit board 29. Further, an element isolation region 15 is formed to isolate the photoelectric conversion sections 13 and 14. With the above configuration, the photoelectric conversion units 13 and 14 each receive a pair of focus detection light fluxes that pass through a pair of distance measuring pupils of the interchangeable lens.

FIG. 8 shows the configuration of a focus detection optical system using a pupil division type phase difference detection method using microlenses. Note that a portion of the focus detection pixel array in the focus detection area 101 is shown in an enlarged manner. In FIG. 8, the exit pupil 90 is set at a distance d forward from the microlens 10, which is placed on the intended imaging plane of the interchangeable lens 202 (see FIG. 1). This distance d is determined depending on the curvature and refractive index of the microlens 10, the distance between the microlens 10 and the photoelectric conversion units 13 and 14, and is referred to as a distance measurement pupil distance in this specification. FIG. 11 also shows an optical axis 91 of the interchangeable lens, a microlens 10, photoelectric conversion units 13 and 14, a focus detection pixel 311, and focus detection light beams 73 and 74.

The distance measuring pupil 93 is a projection of the photoelectric conversion unit 13 limited by the aperture 30d by the microlens 10. Similarly, the distance measuring pupil 94 is a projection of the photoelectric conversion unit 14 limited by the aperture 30d using the microlens 10. The distance measuring pupils 93 and 94 are mutually different partial regions of the exit pupil 90, are lined up in the horizontal direction, and have a shape that is axisymmetric with respect to a vertical line passing through the optical axis 91.

Although FIG. 8 schematically illustrates five adjacent focus detection pixels 311 in the focus detection area 101 near the imaging optical axis 91, each photoelectric conversion unit are configured to receive light beams arriving at each microlens from corresponding distance measuring pupils 93 and 94, respectively. Due to the microlens 10, the pair of photoelectric conversion units 13 and 14 and the above-mentioned mutually different partial regions, that is, the pair of distance measuring pupils 93 and 94 are in a conjugate relationship with each other.

With the above configuration, the photoelectric conversion unit 13 outputs a signal corresponding to the intensity of the image formed on the microlens 10 by the light beam 73 passing through the distance measurement pupil 93 and directed toward the microlens 10 from the focus detection pixel 311. 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 beam 74 passing through the distance measuring pupil 94 and directed toward 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 horizontally in the focus detection area 101 described above into output groups corresponding to the distance measurement pupils 93 and 94, the distance measurement pupils Information regarding the intensity distribution of a pair of images formed on the array of focus detection pixels 311 by focus detection light beams 73 and 74 passing through focus detection pupil 93 and distance measurement pupil 94, respectively, can be obtained. By performing image shift detection calculation processing (correlation calculation processing, phase difference detection processing) to be described later on this information, the amount of image shift between the pair of images is detected using a so-called pupil division type phase difference detection method. Furthermore, by performing a conversion calculation 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 measuring pupil distance, the amount of image shift is calculated based on the current image forming plane (planned image forming plane) with respect to the planned image forming plane. The deviation (defocus amount) of the image forming plane at the focus detection position corresponding to the position of the upper microlens array is calculated. Specifically, by multiplying the amount of image shift (the amount in the plane perpendicular to the optical axis 91) by a predetermined conversion coefficient (the value obtained by dividing the distance measurement pupil distance d by the distance between the centers of gravity of the distance measurement pupils 93 and 94). The amount of defocus (deviation between the imaging plane and the planned imaging plane in the direction of the optical axis 91) is calculated.

Furthermore, by obtaining an 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 that obtained when normal imaging pixels are arranged in a Bayer array.

FIG. 9 is a block diagram showing in detail the relationship between the image sensor 212 and the body drive control device 214, which are related to the present invention. , a CPUa (microcomputer) 222, and a CPUb (microcomputer) 223 are housed. The image sensor 212 performs charge accumulation control (charge accumulation time and charge accumulation timing) of the focus detection pixel 311 and signal output control under the control of the image sensor control unit 220. As described later, the image sensor 212 performs AD conversion on the output signals of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311, and outputs them from channel 1 as digital data (data for focus detection). Digital data (a signal equivalent to the output signal of a normal imaging pixel) obtained by digitally adding the digital data of the pair of photoelectric conversion units 13 and 14 is output from channel 2 as digital data. The digital data output from channel 1 and channel 2 is temporarily stored in buffer memory 221 as one frame of digital data. The CPUa 222 performs focus detection by performing processing to be described later on the digital data (data for focus detection) of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 in the focus detection area stored in the buffer memory 221. The CPUb 223 performs well-known image processing on one frame of digital data (image data) 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 images are output from the image sensor 212 through different channels in a temporally overlapping manner. Furthermore, since the digital data for focus detection and the digital data for images are processed in separate CPUs 222 and 223, there is no need to temporally separate focus detection processing and image processing, and they can be performed simultaneously and independently.

Next, digital data (normal The configuration of the image sensor 212 that can output a signal (equivalent to the output signal of an image sensor) will be described using FIG. 10.

FIG. 10 is a block diagram showing the configuration of the image sensor 212 (CMOS image sensor). The image sensor 212 includes a 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, a row scanning circuit 41, and a column AD conversion circuit. device 42, second line memory 44, second column scanning circuit 51, second horizontal output circuit 45, column digital addition device 46, first line memory 48, first column scanning circuit 52, first horizontal output circuit 49 and timing The configuration includes a control circuit 50.

In this system configuration, the timing control circuit 50 controls the row scanning circuit 41, the column AD converter 42, and the column digital adder 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, etc. It is applied to the conversion device 42, column digital addition device 46, first line memory 48, second line memory 44, first column scanning circuit 52, second column scanning circuit 51, etc.

Further, peripheral drive systems and signal processing systems that drive and control each focus detection pixel 311 of the pixel array section 40, that is, a row scanning circuit 41, a column AD converter 42, a column digital adder 46, a first line memory 48, a first 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, etc. are built on the same chip (semiconductor) as the pixel array section 40. (substrate). The chip in which these are integrated is stacked on the chip of the pixel array section 40.

As the focus detection pixel 311, although not shown here, in addition to the pair of photoelectric conversion elements 13 and 14 (for example, a photodiode), the focus detection pixel 311 is obtained by photoelectric conversion in the photoelectric conversion elements 13 and 14, for example. A three-transistor configuration including a transfer transistor that transfers charge to an FD (floating diffusion) section, a reset transistor that controls the potential of the FD section, and an amplification transistor that outputs a signal according to the potential of the FD section; Furthermore, a four-transistor structure having an additional selection transistor for pixel selection can be used.

In the pixel array section 40, focus detection pixels 311 are two-dimensionally arranged in 2N rows and 2M columns. In other words, the pixel array unit 40 has a focus detection pixel group in each row in which 2M focus detection pixels 311 are arranged in the horizontal direction, and the focus detection pixel group is arranged in 2N rows in the vertical direction intersecting the horizontal direction. Placed. In FIG. 10, the focus detection pixel 311 on the upper left is the pixel in the first row and first column, and a green filter of Bayer array is arranged in this pixel, and the focus detection pixel 311 arranged as a pixel group in the first row has a green filter and a blue filter. For this pixel arrangement of 2N rows and 2M columns, one system of row control lines 21 (21(1) to 21(2N)) is wired for each row, and two column signal lines (22(1) 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 terminal corresponding to each row of the row scanning circuit 41, and each row control line 21 receives control signals R(1) to R. (2N) is output. The row scanning circuit 41 is constituted by 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)).

A pair of photoelectric conversion units 13 and 14 of each focus detection pixel 311 in the same row is connected to the row scanning circuit 41 by the same row control line 21, and receives control signals R(1), . . . , R(L). , . . . , R(2N), charge accumulation control and signal readout control are simultaneously performed. 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 section 13 is output to the column signal line 22(m)b. Further, 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 section 14 is output to the column signal line 22(m)a. For example, when the focus detection pixel 311 constituting the L-th row focus detection pixel group of the pixel array section 40 is selected by the control signal R (L) given from the row scanning circuit 41, the L-th focus detection pixel Output signals from the pair of photoelectric conversion units 13 and 14 of 311 are output to 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 column signal line 22(1)a, 22(1)b to 22(2M)a, 22(2M)b provided corresponding to a pixel column of the pixel array section 40. ADCs (Analog-to-Digital Conversion Circuits) 23(1)a, 23(1)b to 23(2M)a, 23(2M)b are provided. A pair of analog signals output from the timing control circuit 50 is converted into an H-bit digital signal and output according to a control signal TA1 given from the timing control circuit 50. "H bit" represents the number of bits, such as 10 bits, 12 bits, 14 bits, etc.

The second line memory 44 is a memory (25 (1)a, 25(1)b to 25(2M)a, 25(2M)b), and ADC(23(1)a, 23(1)b to 23(2M)a, 23(2M) ) The digital signal output in each step b) is stored as an H-bit digital signal in accordance with 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 will be stored as digital signals.

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

The first line memory 48 includes memories (28(1) to 28(2M)) provided for each digital addition circuit (26(1) to 26(2M)) constituting the column digital addition device 46. , the added digital signal output from each digital addition circuit (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, each memory (28(1) to 28(2M)) of the first line memory 48 contains an addition signal (imaging pixel ) will be stored as a digital signal.

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

The first column scanning circuit 52 is configured with a shift register or the like, and controls the column addresses of the memories (28(1) to 28(2M)) in the first line memory 48 and column scanning under the control of the timing control circuit 50. 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 addition digital signals stored in each of the memories (28(1) to 28(2M)) are sequentially The signal is read out to the first horizontal output circuit 49, and serially outputted 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, the individual readout operation of the output signals of the pair of photoelectric conversion units of the focus detection pixel and the addition signal obtained by adding the output signals of the pair of photoelectric conversion units of the focus detection pixel during one frame period are performed. A case where read operations are performed in parallel will be explained using timing charts shown in FIGS. 11 and 12. In FIGS. 11 and 12, VS is a vertical synchronization signal indicating one frame period, and HS is a horizontal synchronization signal indicating one horizontal scanning period.

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

FIG. 12 is an enlarged view of the operating portions of rows (2n+1), (2n+2), and (2n+3) in FIG. 11. When the (2n+1) row of the pixel array unit 40 is selected by the control signal R(2n+1), the analog signal of the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 for one line of the (2n+1) row becomes a column signal. It is output to the lines (22(1)a, 22(1)b to 22(2M)a, 22(2M)b). Photoelectric conversion of a pair of focus detection pixels 311 for one line of (2n+1) rows output to column signal lines (22(1)a, 22(1)b to 22(2M)a, 22(2M)b) The analog signals of the sections 13 and 14 are transmitted to the column AD converter 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 digitally converted digital signals of the pair of photoelectric converters 13 and 14 of the focus detection pixel 311 of the (2n+1) row are converted to the ADC (23(1)) of the column AD converter 42 in accordance with the control signal TM2. a, 23(1)b to 23(2M)a, 23(2M)b) of 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 converters 13 and 14 of the focus detection pixels 311 of the (2n+1) row, which are digitally converted, are converted into digital signals of the pair of photoelectric converters 13 and 14 of the focus detection pixel 311 of the (2n+1) row, which are converted into digital signals of the pair of photoelectric converters 13 and 14 of the focus detection pixel 311 of the (2n+1) row, in accordance with the control signal TD1. The digital addition circuit (26(1) to 26(2M)).

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

One line of focus detection pixels 311 in (2n+1) rows stored in the second line memory 44 (25(1)a, 25(1)b to 25(2M)a, 25(2M)b) The digital signals of the pair of photoelectric converters 13 and 14 are serially output from the second horizontal output circuit 45 to the outside in response to the scanning signal TS2 until the next horizontal synchronization signal HS is generated. Based on the digital signal output from the second horizontal output circuit 45, the focus detection CPUa 222 of the body drive control device 214 detects the focus state of the interchangeable lens 202 (optical system) as shown in FIG. 13, which will be described later. , adjust its focus state.

Focus detection for one line of (2n+1) rows to which the output signals of the pair of photoelectric conversion units 13 and 14 stored in the memory ((28(1) to 28(2M)) of the first line memory 48 are added. The added digital signals of the pixels 311 are serially output from the first horizontal output circuit 49 to the outside in response to the scanning signal TS1 until the next horizontal synchronization signal HS is generated. 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, which will be described later.

When the control signal R(2n+2) is emitted 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 Similar processing is repeated for the analog signals of the photoelectric conversion units 13 and 14. Furthermore, 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 (imaging device) 201 according to one embodiment. Processing according to these flowcharts is performed in parallel. FIG. 13 is an operation flowchart of the focus detection CPUa 222 of the body drive control device 214. When the power of the digital still camera 201 is turned on in step S100, focus detection operations starting from step S110 are started. In step S110, data of a pair of photoelectric conversion units of focus detection pixels arranged in the selected focus detection area in frame synchronization is read out. The data of this pair of photoelectric conversion sections is a digital signal output from the second horizontal output circuit 45 mentioned above. In the subsequent step S120, image shift detection calculation processing (correlation calculation processing, phase difference detection processing), which will be described later, is performed based on the data of the focus detection pixels to calculate the amount of image shift. It is assumed that the position of the focus detection area is selected in advance 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 the focus state of the interchangeable lens 202 (optical system) is close to in-focus, that is, whether the absolute value of the calculated defocus amount is within a predetermined value. If it is determined that the focus is not near the focus, the process advances to step S150, where the defocus amount is sent to the lens drive control device 206, and the focus lens 210 of the interchangeable lens 202 is driven to the in-focus position. ).

Note that if the focus cannot be detected, the process also branches to this step, and sends a scan drive command to the lens drive control device 206 to scan and drive the focusing lens 210 of the interchangeable lens 202 from infinity to close range. After that, the process advances to step S160.

If it is determined in step S140 that the focus is near, the process advances to step S160, and it is determined whether or not the shutter release has been performed by operating a shutter button (not shown). If it is determined that the shutter release has not been performed, 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 advances to step S170 and waits for the photographing operation corresponding to the shutter release to be completed. When the photographing operation is completed, the process returns to step S110 and the above-described operation is repeated.

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

The pair of images detected by the focus detection pixel 311 may have an imbalance in light quantity due to the distance measurement pupils 93 and 94 being eclipsed by the aperture aperture of the lens, so image shift detection accuracy is maintained with respect to the balance in light quantity. Perform the type of correlation operation that can be performed. A pair of data strings read out from the array of focus detection pixels 311 are defined as A1n (A11, . . . , A1j:j) is the number of data) and A2n (A21, . To generalize the data strings A1n and A2n, the following correlation calculation formula (1) disclosed in Japanese Unexamined Patent Application Publication No. 2007-333720 is applied to calculate the correlation amount C(k).
C(k)=Σ|A1n・A2n+1+k−A2n+k・A1n+1| ...(1)

In equation (1), the Σ operations are accumulated over n. The range of n is limited to the range in which data A1n, A1n+1, A2n+k, and A2n+1+k exist depending on the image shift amount k. The shift amount k is an integer, and is a relative shift amount using the data interval of the data string as a unit. As shown in FIG. 15(a), the calculation result of equation (1) shows that the correlation amount C(k) is minimal at the shift amount where the correlation between a pair of data is high (k=kj=2 in FIG. 15(a)).・The smaller BR>I, the higher the correlation.)

Next, using the three-point interpolation method of equations (2) to (5), the shift amount X that gives the minimum value C(X) for the continuous correlation amount is determined.
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 using equation (2) is reliable is determined as follows. As shown in FIG. 15(b), when the degree of correlation between a pair of data is low, the minimum value C(X) of the interpolated correlation amount becomes large. Therefore, if C(X) is greater than or equal to a predetermined threshold, it is determined that the reliability of the calculated shift amount is low, and the calculated shift amount X is canceled. Alternatively, in order to normalize C(X) by the contrast of the data, if the value obtained by dividing C(X) by SLOP, which is a value proportional to the contrast, is greater than a predetermined value, the reliability of the calculated shift amount is is determined to be low, and the calculated shift amount X is canceled. Alternatively, if SLOP, which is a value proportional to contrast, is less than a predetermined value, it is determined that the object has low contrast and the reliability of the calculated shift amount is low, and the calculated shift amount X is canceled.

As shown in FIG. 15(c), if the degree of correlation between a pair of data is low and there is no drop in the correlation amount C(k) within the shift range kmin to kmax, it is not possible to find the minimum value C(X). In such a case, it is determined that focus cannot be detected.

If it is determined that the calculated shift amount X is reliable, it is converted into an image shift amount shft using equation (6).
shft=PY・X...(6)

In equation (6), PY is 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 equation (6) is multiplied by a predetermined conversion coefficient k to convert it into a defocus amount def.
def=k・shft1...(7)

In 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 measuring pupil distance, 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 a simple average or a weighted average is performed to obtain the final defocus amount in the selected focus detection area. is calculated.

FIG. 14 is an operation flowchart of the CPUb 223 for image processing of the body drive control device 214. When the power of the digital still camera 201 is turned on in step S200, image processing operations starting from step S210 are started. In step S210, the summed digital data (corresponding to the data of the imaging pixel) obtained by adding the output data of the photoelectric conversion unit of the pair of focus detection pixels in frame synchronization is read out, and image processing for display is performed on the data. to be displayed on the electronic viewfinder. The added digital data read out in step S210 is the added digital signal output from the first horizontal output circuit 49 described above.

In step S220, it is determined whether the shutter release is performed by operating a shutter button (not shown). If it is determined that the shutter release has not been performed, 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 advances to step S230, and a photographing operation corresponding to the shutter release is performed. First, an aperture adjustment command is sent to the lens drive control device 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). When the aperture control is completed, the added digital data (corresponding to the data of the Bayer-arranged imaging pixels) obtained by adding the output data of the photoelectric conversion unit of the pair of focus detection pixels is read out, and the added digital data is known. 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 photographing operations is completed, the process returns to step S210 and the above-described operations are repeated.

In the first embodiment described above, the focus detection is performed only in the selected focus detection area, but since the focus detection data for the entire screen is stored in the buffer memory, the focus detection CPUa 222 If the processing capacity is high, focus detection may be performed in a plurality of focus detection areas on the entire screen, and the focus of the lens may be adjusted according to the results.

In the first embodiment described above, it has been explained that the data obtained by adding the data of the photoelectric conversion unit of a pair of focus detection pixels for images is read out for each frame, but instead of reading out all data, thinning reading is performed. (row/column) or pixel addition/readout (row/column) may be further added to the configuration of the present invention, and the read image data may be used for display or the like.

In the first embodiment described above, the data of the photoelectric conversion unit of the pair of all focus detection pixels for focus detection is read out for each frame, but the data of the photoelectric conversion unit of the pair of all focus detection pixels Reading data is a heavy load and requires a large amount of memory capacity for data storage, so frame thinning (reading once every few frames) / line thinning (reading one line every few lines) / row Partial reading (reading only some rows)/column thinning (reading one column every few columns)/partial column reading (reading only some columns) may be used.

FIG. 16 is a timing chart corresponding to FIG. 12 when performing row partial readout (reading data of a pair of photoelectric conversion units of focus detection pixels only in the (2n+2)th row), and is a timing chart corresponding to the (2n+1) row in FIG. , (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. 12. On the other hand, when a row other than the (2n+2) row is selected (operation according to the control signal R(2n+1) and control signal R(2n+3) in FIG. 16), the control signal TM2 is not generated and the column AD converter 42 is activated. A pair of photoelectric conversion units 13 and 14 of one line of focus detection pixels 311 converted into digital signals by ADC (23(1)a, 23(1)b to 23(2M)a, 23(2M)b) The digital signal is sent to the memory (25 (1)a, 25(1)b to 25(2M)a, 25(2M)b). Furthermore, since the scanning signal TS2 is not generated, the second horizontal output circuit 45 is not serially output to the outside during the period until the next horizontal synchronizing signal HS is generated.

The row for partial readout and the column for partial readout can be changed by sending information from the body drive control device 214 to the image sensor 212, depending on the position of the selected focus detection area.

In the first embodiment described above, the column AD converter 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 Since the column digital addition device 46 is provided, in which the number of digital addition circuits 26 for performing digital addition is equal to the number of focus detection pixels in one row, the output signals of the photoelectric conversion units of a pair of focus detection pixels during one frame period are It becomes possible to perform the individual readout operation and the readout operation of the summed signal (corresponding to the output signal of the imaging pixel) obtained by adding the output signals of the pair of photoelectric conversion sections in parallel. This solves the problems of the conventional technology (where an analog addition device is provided for each focus detection pixel) (individual readout of the output signals of the pair of photoelectric conversion units of the focus detection pixel during one frame period and the output signal of the pair of photoelectric conversion units of the focus detection pixel). It is possible to solve the problem that the reading operation of the summed signal (corresponding to the output signal of the imaging pixel) cannot be performed in parallel.

In addition, as a method to solve the problems of the conventional technology, the output data of a pair of photoelectric conversion units of all focus detection pixels is individually read out from the image sensor during one frame period, and temporarily stored in an external buffer memory. It may be possible to perform addition processing on the output data of a pair of photoelectric conversion units stored in memory, but in that case, the processing time would increase by the amount of addition processing time, and the external processing load would also increase. Put it away. According to the configuration and operation of the image sensor of the present application, image data reading/image processing can be handled in the same way as a normal image sensor. In addition, it is also possible to partially read out the output data of a pair of photoelectric conversion units of the focus detection pixel individually, so that the load of the readout process can be reduced and the capacity of the buffer memory for data storage can also be saved.

In addition, as a method for solving the problems of the conventional technology, instead of providing the column digital adder 46, when horizontally scanning the output data of the pair of photoelectric conversion units of the focus detection pixel and sequentially outputting it serially, a second horizontal output circuit is provided. A data holding memory (to hold data with a delay of one data output time) and a digital addition circuit are installed in parallel at the output terminal of 45, and the output data of a pair of photoelectric conversion units of focus detection pixels are added in synchronization with the individual data output. It is also possible to generate and output added data by doing this, but the data transfer rate will be slowed down by the addition processing time (addition time for one focus detection pixel x total number of focus detection pixels), making it difficult to read out the data at high speed. become unable. The image sensor 212 of the present application is provided with a column digital adder 46, and addition processing is performed independently and simultaneously for each column, so high-speed readout is possible at almost the same data transfer rate as an image sensor consisting only of normal imaging pixels. become.

<Second embodiment>
In the first embodiment, the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 were 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 311 are arranged horizontally is By selecting a direction other than the row direction, image shift detection can be performed in a direction 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. It is composed of a pair of photoelectric conversion sections 16 and 17 divided into two by 18. When the pair of photoelectric conversion units 16 and 17 are integrated, the size becomes the same as that of the photoelectric conversion unit of a normal imaging pixel.

FIG. 18 is a diagram corresponding to the pixel layout diagram of FIG. 3 (the filter arrangement corresponds to FIG. 4), and shows the detailed configuration of the image sensor 212 in which the focus detection pixel 311 and the focus detection pixel 312 are arranged. FIG. 2 is a front view showing the vicinity of the focus detection area 101 on the image sensor 212 in an enlarged manner. Focus detection pixels 311 and focus detection pixels 312 are arranged alternately 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. Description of parts that are the same as the configuration of FIG. 10 will be omitted, and only characteristic parts will be described. The difference between the pixel array section 40 and FIG. 10 is that a focus detection pixel 312 including a pair of photoelectric conversion sections 16 and 17 separated in the vertical direction is arranged in the even-numbered rows.

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

When using the image sensor 212 having the above configuration, 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-numbered rows are grouped horizontally for each photoelectric conversion unit. Using a pair of converted data, it is possible to detect a phase difference for a subject image with a contrast change in the horizontal direction. , 17 are grouped in the vertical direction for each photoelectric conversion unit, and phase difference detection can be performed for a subject image whose contrast changes in the vertical direction.

FIG. 20 is a modification of FIG. 18, in which focus detection pixels 311 and focus detection pixels 312 are arranged alternately in every other column. When using the image sensor 212 with such a configuration, 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-numbered columns are grouped horizontally for each photoelectric conversion unit. Using this pair of data, it becomes possible to detect a phase difference for a subject image with a contrast change in the horizontal direction, and a pair of photoelectric conversion units 16, Using a pair of data obtained by grouping the 17 data in the vertical direction for each photoelectric conversion unit, it is possible to detect a phase difference for a subject image with 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 manner. That is, the focus detection pixel 311 is arranged at the position (odd row and odd column) or (even row and even column), and the focus detection pixel 311 is arranged at the position (odd row and even column) or (even row and odd column). 312 is placed. In terms of the Bayer array color filters, the focus detection pixel 311 is equipped with a green filter, and the focus detection pixel 312 is equipped with a red filter or a blue filter.

When using the image sensor 212 having such a configuration, a pair of photoelectric conversion units 13 of the focus detection pixel 311 including a green filter arranged in an odd numbered row and an odd numbered column or an even numbered row and an even numbered column, Using a pair of data obtained by grouping 14 data horizontally for each photoelectric conversion unit, phase difference detection is possible for subject images with contrast changes in the horizontal direction. The data of the pair of photoelectric conversion units 16 and 17 of the focus detection pixel 312 with blue filters arranged or the focus detection pixel 312 with red filters arranged in even rows and odd columns is collected for each photoelectric conversion unit. By using a pair of vertically grouped data, it is possible to detect a phase difference for a subject image with a contrast change in the vertical direction.

<Third embodiment>
In the first embodiment, all pixels were made up of focus detection pixels, but by mixing normal imaging pixels in which the photoelectric conversion section is not divided and focus detection pixels in which the photoelectric conversion section is divided, By reducing the number of focus detection pixels in the entire image sensor and simplifying the configuration of the image sensor, and reducing the number of focus detection data externally output from the image sensor, the data transfer rate of focus detection data can be improved through image processing. This makes it possible to achieve a data transfer rate comparable to that of other data.

As shown in FIG. 22, the imaging pixel 310 includes a rectangular microlens 10 and a photoelectric conversion section 11 whose light receiving area is limited by a light-shielding mask, which will be described later.

FIG. 23 is a cross-sectional view of the imaging pixel 310 shown in FIG. 22. In the imaging pixel 310, a light-shielding mask 30 is formed close to the photoelectric conversion section 11 for imaging, and the photoelectric conversion section 11 receives the light that has passed through the opening 30a of the light-shielding mask 30. A planarization layer 31 is formed on the light-shielding mask 30, and a color filter 38 is formed thereon. A planarization layer 32 is formed on the color filter 38, and a microlens 10 is formed thereon. The shape of the opening 30a is projected forward by the microlens 10. Photoelectric conversion section 11 is formed on semiconductor circuit board 29 .

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

The imaging pixel 310 is composed of a microlens 10 and a photoelectric conversion section 11 placed behind it, and the shape of an aperture 30a (see FIG. 23) placed close to the photoelectric conversion section 11 is measured from the microlens 10. It is projected onto the exit pupil 90 which is spaced apart by the distance pupil distance d, and its projected shape forms a region 95 that is approximately circumscribed to the distance measuring pupils 93 and 94.

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

FIG. 25 is a diagram corresponding to the pixel layout diagram of FIG. 3 (the filter arrangement corresponds to FIG. 4), and the imaging pixels 310 and focus detection pixels 311 are alternately arranged in a staggered manner. That is, the focus detection pixel 311 is arranged at the position (odd row and odd column) or (even row and even column), and the imaging pixel 310 is arranged at the position (odd row and even column) or (odd row and even column). is placed. From the perspective of the Bayer array color filters, the focus detection pixel 311 is equipped with a green filter, and the imaging pixel 310 is equipped with a red filter or a blue filter. In terms of focus detection performance, the spectral sensitivity characteristics of the green filter are located between the spectral sensitivity characteristics of the red filter and the spectral sensitivity characteristics of the blue filter, as shown in FIG. is preferably provided. Further, as shown in FIGS. 6 and 22, since the element isolation region 15 exists, 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. 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 more green filters than red filters and blue filters.

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

The image sensor 212 includes a 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, a row scanning circuit 41, and a column AD conversion circuit. device 42, second column switch device 43, second line memory 44, second column scanning circuit 51, second horizontal output circuit 45, column digital addition device 46, first column switch device 47, first line memory 48, The configuration includes 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 controls the row scanning circuit 41, the column AD converter 42, and the first column switch device based on a master clock input from the outside and a control signal input from the image sensor control unit 220. 47, a clock signal that serves as a reference for the operation of the second column switch device 43, column digital addition device 46, first line memory 48, first line memory 44, first column scanning circuit 52, second column scanning circuit 51, etc. Generates control signals and the like, and includes a row scanning circuit 41, a column AD converter 42, a first column switch device 47, a second column switch device 43, a column digital adder 46, a first line memory 48, a first line memory 44, It is applied to the first column scanning circuit 52, the second column scanning circuit 51, etc.

In the pixel array section 40, imaging pixels 310 and focus detection pixels 311 are two-dimensionally arranged in 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 first column, and a green filter in a Bayer array is arranged at this pixel. For this pixel arrangement of 2N rows and 2M columns, row control lines 21 (21(1) to 21(2N)) are wired for each row, and two column signal lines (22(1)a, 22(22N)) are wired for each column. (1)b to 22(2M)a, 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 terminal corresponding to each row of the row scanning circuit 41, and each row control line 21 receives control signals R(1) to R. (2N) is output.

The photoelectric conversion unit of the imaging pixel 310 and the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 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 performed at the same time. 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. It is output to line 22(m)a. Further, 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 converter 13 is output to the column signal line 22(m)b. Further, 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, and 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 converter 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 transmitted to 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 L-th focus detection pixel 311 are output to the column signal lines (22(1)a, 22(1M)a). )b to 22(2M)a, 22(2M)b). If L is an odd number at this time, since the imaging pixels 310 are arranged in even columns of this row, the signal on the column signal line 22 (2m)b corresponding to the even columns becomes an invalid signal. Further, when L is an even number, since the imaging pixels 310 are arranged in the odd columns of this row, 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 column signal line 22(1)a, 22(1)b to 22(2M)a, 22(2M)b provided corresponding to a pixel column of the pixel array section 40. It has 4M ADCs (Analog-to-Digital Conversion Circuits) 23(1)a, 23(1)b to 23(2M)a, 23(2M)b, which are connected to each column from each pixel of the pixel array section 40. According to the control signal TA1 given from the timing control circuit 50, the analog signal output to 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 has an ADC (23 (1) a , 23(1)b to 23(2M)a, 23(2M)b) are selected and outputted according to the control signal TW2 given from the timing control circuit 50.

FIGS. 27(a) and 27(b) are diagrams illustrating the selection operation of the switches 24 (2m+1, 2m+2) provided in two adjacent pixel columns ((2m+1) column and (2m+2) column), 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, and S(2m+2)b are input. The switch 24 (2m+1, 2m+2) has multiples of 2 columns, for example, multiples of 4 corresponding to 4 pixel columns ((2m+1) column, (2m+2) column, (2m+3) column, (2m+4) column), for example. 8 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), multiples of 4, for example, 8 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, and S(2m+4)b may be input. In that case, for example, the focus detection pixel 311 is arranged in the (2m+1) column, and the image sensor 310 is arranged in the (2m+2) column, the (2m+3) column, and the (2m+4) column.

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

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

The switches 24 (2m+1, 2m+2) correspond to the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 311 according to the control signal TW2 (identification information for odd or even rows) 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 and S(2m+2)b corresponding to the pair of photoelectric conversion units of the focus detection pixel 311 are selected. and output it.

The second line memory 44 includes a total of 2M memories (25 (1, 2 )a, 25(1,2)b~25(2M-1,2M)a, 25(2M-1,2M)b), and M switches 24(1,2)~24(2M- A pair of digital signals (Q(1,2)a, Q(1,2)b to Q(2M- 1, 2M)a, Q(2M-1, 2M)b) are stored as H-bit digital signals in accordance with 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 one The output signals of the pair of photoelectric conversion units 13 and 14 for the M focus detection pixels of the row are stored as digital signals.

The column digital adder 46 includes a total of M digital adder circuits (26(1, 2), 2) to 26 (2M-1, 2M)), and a pair of photoelectric conversion units of the focus detection pixels 311 are output for each of the M switches 24 (1, 2) to 24 (2M-1, 2M). 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 They are added in accordance with the control signal TD1 given from the control circuit 50 and output as an H-bit addition digital signal (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 each of two adjacent pixel columns, and 2M ADCs (23 ( 1) Digital signals (S(1)a, S(2)a to S(2M-1)a, S(2M)a) output for each a to 23(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 from each addition circuit (26(1, 2) to 26(2M-1, 2M)). It selects and outputs according to the control signal TW1 (identification information of odd-numbered or even-numbered rows) given from .

FIGS. 28(a) and 28(b) are diagrams illustrating the selection operation of the switches 27 (2m+1, 2m+2) provided in two adjacent pixel columns ((2m+1) column and (2m+2) column), The switch 27 (2m+1, 2m+2) receives 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. 28(a) shows the selection operation of the switches 27 (2m+1, 2m+2) when the odd-numbered row of the pixel array section 40 is selected by the row scanning circuit 41. 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 Corresponding one digital signal S(2m+1)a and a 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 added digital signal P(2m+1, 2m+2) (corresponding to a signal of an imaging 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 imaging pixel.

The switches 27 (2m+1, 2m+2) correspond to signals of virtual imaging pixels arranged in odd-numbered columns in accordance with the control signal TW1 (identification information of odd-numbered or even-numbered rows) input to the first column switch device 47. As the signal U(2m+1), a digital sum 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 an even numbered column. The digital signal S(2m+2)a corresponding to the imaging pixel 310 is selected and output as the imaging pixel signal U(2m+1).

FIG. 28(b) shows the selection operation of the switches 27 (2m+1, 2m+2) when the even-numbered rows of the pixel array section 40 are selected by the row scanning circuit 41. 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 column of the even-numbered row Corresponding one digital signal S(2m+2)a and a pair of photoelectric conversion units 13 and 14 of the focus detection pixels 311 arranged in even-numbered rows and even-numbered columns from the digital addition circuit 26 (2m+1, 2m+2) An added digital signal P(2m+1, 2m+2) (corresponding to a signal of an imaging 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 imaging pixel.

The switches 27 (2m+1, 2m+2) correspond to signals of virtual imaging pixels arranged in even-numbered columns in accordance with the control signal TW1 (identification information of odd-numbered or even-numbered rows) input to the first column switch device 47. As the signal U(2m+2), a digital sum 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 an odd-numbered column. The digital signal S(2m+1)a corresponding to the imaging pixel 310 is selected and output as the imaging pixel signal U(2m+1).

The first line memory 48 includes a pair of 2M memories (28(1) 28 (2M)), and outputs a pair of digital signals for each switch (27 (1, 2) to 27 (2M-1, 2M)) in accordance with the control signal TM1 given from the timing control circuit 50. and stored as an H-bit digital signal. Here, each memory (28(1) to 28(2M)) of the first line memory 48 contains an addition signal (imaging pixel ) and the output signal of the photoelectric conversion section of the imaging pixel are stored as digital signals according to the order in which the focus detection pixels are arranged.

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

The first column scanning circuit 52 is configured with a shift register or the like, and controls the column addresses of the memories (28(1) to 28(2M)) in the first line memory 48 and column scanning under the control of the timing control circuit 50. Take control. The first line memory 48 operates in response to the scanning signal TS1 given from the first column scanning circuit 52, and includes the H-bit digital signal stored in each of the memories (28(1) to 28(2M)) and the addition digital signal. The signals are sequentially 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 array via the first horizontal output circuit 49.

Next, in the configuration of the image sensor shown in FIG. 26, this corresponds to the individual readout operation of the output signals (signals for focus detection) of the pair of photoelectric conversion units of the focus detection pixel and the output signal of the imaging pixel during one frame period. A case where readout operations of output signals (signals for image processing) are performed in parallel will be described using the timing chart of FIG. 29.

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 operating portions of rows (2n+1), (2n+2), and (2n+3) in FIG. 11. When the (2n+1) 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) row are transferred to the column signal line (22(1) )a, 22(1)b to 22(2M)a, 22(2M)b). Focus detection pixels arranged in odd-numbered columns for one line of (2n+1) rows output to column signal lines (22(1)a, 22(1)b to 22(2M)a, 22(2M)b) The analog signals of the pair of photoelectric converters 13 and 14 of 311 and the analog signals of the photoelectric converters 11 of the imaging signals 310 arranged in even-numbered columns are transmitted to the column signal lines 22(1)a, 22() according to the control signal TA1. 1) b to 22(2M)a, ADC of 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 converters 13 and 14 of the focus detection pixel 311 arranged in the odd-numbered columns for one line of (2n+1) rows and the even-numbered columns are input from the column AD converter 42 to the second column switch device 43. The digital signal of the photoelectric conversion unit 11 of the image pickup signal 310 arranged in 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-numbered 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 odd-numbered columns are transmitted to the M digital adder circuits (26(1, 2) to 26 (2M-1, 2M)) are added and output.

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

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

The data is stored in 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 (2n+1) rows and odd-numbered columns are transmitted in response to the scanning signal TS2 until the next horizontal synchronization signal HS is generated. The second horizontal output circuit 45 serially outputs the signals to the outside during the period .

Similarly, 2M digital signals corresponding to the output signals of the (2n+1) rows of imaging pixels stored in the memory ((28(1) to 28(2M)) of the first line memory 48 (focal points arranged in odd-numbered columns) The summed 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 imaging signal 310 arranged in an even numbered column are converted into the next horizontal synchronization signal HS according to the scanning signal TS1. The signals are serially output from the first horizontal output circuit 49 to the outside during the period until this occurs.

When the control signal R(2n+2) is emitted in synchronization with the next horizontal synchronization signal HS and the (2n+2) row of the pixel array section 40 is selected, one line of focus detection pixels 311 in the (2n+2) row and the imaging Analog signals from the pixels 310 are output to column signal lines (22(1)a, 22(1)b to 22(2M)a, 22(2M)b). Focus detection pixels arranged in even-numbered columns for one line of (2n+2) rows output to column signal lines (22(1)a, 22(1)b to 22(2M)a, 22(2M)b) The analog signals of the pair of photoelectric converters 13 and 14 of 311 and the analog signals of the photoelectric converters 11 of the image pickup signals 310 arranged in odd-numbered columns are transmitted to the column signal lines 22(1)a, 22() according to the control signal TA1. 1) b to 22(2M)a, ADC of 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 converters 13 and 14 of the focus detection pixels 311 arranged in the even columns for one line of (2n+2) rows and the odd columns are input from the column AD converter 42 to the second column switch device 43. The digital signal of the photoelectric conversion unit 11 of the image pickup signal 310 arranged in 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 converters 13 and 14 of the focus detection pixels 311 arranged in even-numbered 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 even-numbered columns are transmitted to the M digital adder circuits (26(1, 2) to 26 (2M-1, 2M)) are added and output.

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

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

The data is stored in 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 (2n+2) rows and even columns are transmitted in accordance with the scanning signal TS2 until the next horizontal synchronization signal HS is generated. The second horizontal output circuit 45 serially outputs the signals to the outside during the period . Based on the digital signal output from the second horizontal output circuit 45, the focus detection CPUa 222 of the body drive control device 214 detects the focus state of the interchangeable lens 202 (optical system), as shown in FIG. Adjust focus state.

2M digital signals corresponding to the output signals of the (2n+2) rows of imaging pixels stored in the memory ((28(1) to 28(2M)) of the first line memory 48 (focal points arranged in even columns) The summed 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 imaging pixel 310 arranged in the odd-numbered column are converted into the next horizontal synchronization signal HS according to the scanning signal TS1. 2M digital signals outputted from the first horizontal output circuit 49 (photoelectric conversion of a pair of focus detection pixels 311 in even-numbered columns) are sequentially output serially to the outside from the first horizontal output circuit 49 until the Based on the addition digital signals of the units 13 and 14 and the digital signal of the photoelectric conversion unit 11 of the odd-numbered imaging pixels 310, the image processing CPUb 223 of the body drive control device 214 converts the image data as shown in FIG. However, in this embodiment, in step S210 in FIG. and the digital signal of the photoelectric conversion unit 11 of the odd-numbered imaging pixels 310) are read out, image processing for display is performed on the read data, and then the data is displayed on the electronic viewfinder. In addition, in step S230 of FIG. and the digital signal of the photoelectric conversion unit 11 of the imaging pixel 310 in the odd-numbered column) is read out, and the read data is subjected to well-known image processing (demosaic processing, noise processing, gradation processing, white balance processing). etc.) are applied to generate image data.

When the control signal R(2n+3) is emitted in synchronization with the next horizontal synchronization signal HS and the (2n+3) row of the pixel array section 40 is selected, one line of focus detection pixels 311 in the (2n+3) row and the imaging Processing is repeated for the pixel 310 in the same manner as in the case of the control signal R(2n+1).

As described above, in the third embodiment, the pixel array section 40 imaging pixel 310 and the focus detection pixel 311 are mixed, the focus detection pixel 311 is arranged at the position of the green filter of the Bayer array, and the focus detection pixel 311 is arranged at the position of the red filter and the blue filter. In addition to arranging the imaging pixels 310, the selection process 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 numbered row or an even numbered row of the pixel array section 40. Therefore, compared to the configuration of the image sensor shown in FIG. 10, the number of digital circuits constituting the column digital adder 46, which is larger in circuit scale than the switch circuit, can be reduced (reduced from 2M to M). The number of memories constituting the second line memory 44, which has a larger circuit scale than a switch circuit, can be reduced (from 4M to 2M), and the configuration of the image sensor can be simplified. 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) compared to the configuration of the image sensor shown in FIG. This is the same as the number of data output during the scanning period, and the data transfer rate can be lowered. In addition, the data for focus detection read out from the second horizontal output circuit 45 is unified with the data of the focus detection pixel equipped with a green filter, which is convenient for focus detection (in nature, there are many objects with green contrast, (Generally, if the photographic lens has chromatic aberration, the focal position for green is the focal position).

In the third embodiment described above, the number of focus detection data in one row corresponds to the horizontal scanning of the second column scanning circuit 51 and the number of image data in accordance with the horizontal scanning of the first column scanning circuit 52. Since the numbers match, 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 also possible to further simplify the configuration of the image sensor.

In the third embodiment described above, 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 data of the pair of photoelectric conversion units of the focus detection pixels are read out for each frame. It is a heavy load to read the data, and a large amount of memory capacity is required to store the data, so frame thinning (reading once every few frames) / line thinning (reading one line every few lines) / Partial row reading (reading only some rows)/column thinning (reading one column every few columns)/partial column reading (reading only some columns) may be used.

FIG. 30 is a timing chart corresponding to FIG. 29 when performing row partial readout (reading out data from a pair of photoelectric conversion units of focus detection pixels 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. 29. On the other hand, when a line other than (2n+2) rows is selected (operation according to control signal R(2n+1) and control signal R(2n+3) in FIG. 30), control signal TM2 is not generated and the second line memory 44 is The memories (25 (1, 2) a, 25 (1, 2) b to 25 (2M-1, 2M) a, 25 (2M-1, 2M) b) contain a pair of photoelectric conversion units of focus detection pixels. No data is stored. Furthermore, since the scanning signal TS2 is not generated, the second horizontal output circuit 45 is not serially output to the outside during the period until the next horizontal synchronizing signal HS is generated.

The row for partial readout and the column for partial readout can be changed by sending information from the body drive control device 214 to the image sensor 212, depending on the position of the selected focus detection area.

In the third embodiment described above, each switch constituting the first column switch device 47 determines whether the row scanning circuit 41 selects an odd row or an even row of the pixel array section 40, as shown in FIG. In accordance with the output signal of the imaging pixel, two signals corresponding to the output signal of the imaging pixel are selected, and the selected two signals are distributed so as to match the pixels in the selected row and are stored in the memory of the first line memory 48. ((28(1) to 28(2M)), the selected two signals are fixedly stored in the first line memory 48 without being distributed to match the pixel arrangement order in the selected row. (28(1) to 28(2M)), and the first column scanning circuit 52 supplies the data to the memory ((28(1) to 28(2M)) of the first line memory 48. The row scanning circuit 41 sends the scanning signal TS1 to match the pixel arrangement order in the selected row depending on whether an odd numbered row or an even numbered row of the pixel array section 40 is selected. It may be modified to scan the memory ((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. will be explained only. 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.In contrast, in Figure 31, the number of column signal lines is reduced to 1 in the even columns, and the number of column signal lines in the odd columns is reduced to 1. By sharing the column signal lines, the number of column signal lines is reduced to 3M in total. In the fourth embodiment, by reducing the number of column signal lines, it is possible to alleviate the overcrowding of the wiring layout in the pixel array section 40 and increase the area of the photoelectric conversion section. Accurate focus detection becomes possible.

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

In FIG. 31, one end of each of the row control lines 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 receives a control signal R( 1) to R(2N) are output.

The photoelectric conversion unit of the imaging pixel 310 and the pair of photoelectric conversion units 13 and 14 of the focus detection pixel 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 performed at the same time. In the pixel array section 40, two column signal lines 22(2m+1)a and 22(2m+1)b are arranged in odd-numbered columns, and one column signal line 22(2m+2)a is arranged in even-numbered columns. The photoelectric conversion unit 11 of the imaging pixel 310 provided in the odd numbered column and the photoelectric conversion unit 14 of the focus detection pixel 311 provided in the odd numbered column are connected to one column signal line 22 of the two column signal lines provided in the odd numbered column. (2m+1)a, and the photoelectric conversion unit 13 of the focus detection pixel 311 provided in an odd numbered column is connected to the other column signal line 22(2m+1)b provided in an odd numbered column. Further, the photoelectric conversion units 11 of the imaging pixels 310 provided in the even-numbered columns and the photoelectric conversion units 14 of the focus detection pixels 311 provided in the even-numbered columns are connected to the column signal line 22 (2m+2)a provided in the even-numbered columns, The photoelectric conversion units 13 of the focus detection pixels 311 provided in even-numbered columns are connected to the column signal lines 22(2m+1)b provided in odd-numbered columns.

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

The column AD converter 42 has 3M column signal lines 22(1)a, 22(1)b to 22(2M)a provided corresponding to the pixel columns of the pixel array section 40. ADCs (Analog-to-Digital Conversion Circuits) 23(1)a, 23(1)b to 23(2M)a are provided, and the analog signals output from each pixel of the pixel array section 40 for each column are According to 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 has an ADC (23 (1) a , 23(1)b to 23(2M)a) are selected and outputted according to the control signal TW2 given from the timing control circuit 50.

32A and 32B are diagrams illustrating the selection operation of the switches 24 (2m+1, 2m+2) provided in two adjacent 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 the odd numbered columns (2m+1) and one ADC corresponding to the even numbered 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. 32(a) shows the selection operation of the switch 24 (2m+1, 2m+2) when the odd-numbered row of the pixel array section 40 is selected by the row scanning circuit 41. Three digital signals S(2m+1)a, S(2m+1)b, and S(2m+2)a corresponding to the imaging pixels 310 arranged in even-numbered columns and the focus detection pixels 311 in odd-numbered rows and odd-numbered columns are input. be done.

The switch 24 (2m+1, 2m+2) outputs a pair of digital addition signals (Q(2m+1, 2m+2)a, 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. 32(b) shows the selection operation of the switches 24 (2m+1, 2m+2) when the even-numbered rows of the pixel array section 40 are selected by the row scanning circuit 41. Three digital signals S(2m+1)a, S(2m+1)b, and S(2m+2)a corresponding to the imaging pixels 310 arranged in odd-numbered columns and the focus detection pixels 311 in even-numbered columns of even-numbered rows are input. be done.

The switch 24 (2m+1, 2m+2) outputs 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 numbered 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 and S(2m+1)b corresponding to the pair of photoelectric conversion units of the focus detection pixel 311 are selected and output. 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 in FIG. 25 (the filter arrangement corresponds to FIG. 4), in which the focus detection images 311 arranged in even-numbered rows in FIG. The focus detection pixel 312 is replaced with a focus detection pixel 312 having a pair of photoelectric conversion units 16 and 17.

That is, in odd-numbered rows, focus detection pixels 311 are arranged in odd-numbered columns and imaging pixels 310 are arranged in even-numbered columns, and in even-numbered rows, imaging pixels 310 are arranged in odd-numbered columns and focus detection pixels 312 are arranged in even-numbered columns. In terms of the Bayer array color filters, the focus detection pixel 311 and the focus detection pixel 312 are equipped with a green filter, and the imaging pixel 310 is equipped 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. Description of parts that are the same as the configuration of FIG. 26 will be omitted, and only characteristic parts will be described. The difference between the pixel array section 40 and FIG. 26 is that a focus detection pixel 312 including a pair of photoelectric conversion sections 16 and 17 separated in the vertical direction is arranged in an even numbered row and an even numbered column.

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

When using the image sensor 212 having the above configuration, the data of the pair of photoelectric converters 13 and 14 of the focus detection pixel 311 equipped with green filters arranged in odd rows and even columns is converted into photoelectric converters in the horizontal direction. Using a pair of data grouped for each conversion unit, phase difference detection is possible for subject images with contrast changes in the horizontal direction, and a focal point equipped with green filters arranged in even-numbered rows and columns Using a pair of data obtained by vertically grouping the data of the pair of photoelectric conversion units 16 and 17 of the detection pixel 312 for each photoelectric conversion unit, phase difference detection is possible for a subject image with a 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 image 311 arranged in the even-numbered row in FIG. 312.

That is, in odd-numbered rows, focus detection pixels 311 are arranged in odd-numbered columns and imaging pixels 310 are arranged in even-numbered columns, and in even-numbered rows, imaging pixels 310 are arranged in odd-numbered columns and focus detection pixels 312 are arranged in even-numbered columns. In terms of the Bayer array color filters, the focus detection pixel 311 and the focus detection pixel 312 are equipped with a green filter, and the imaging pixel 310 is equipped 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. Description of parts that are the same as the configuration of FIG. 31 will be omitted, and only characteristic parts will be described. The difference between the pixel array section 40 and FIG. 31 is that a focus detection pixel 312 including a pair of photoelectric conversion sections 16 and 17 separated in the vertical direction is arranged in an even numbered row and an even numbered column.

A pair of photoelectric conversion units 16 and 17 of each focus detection pixel 312 arranged in even-numbered rows and even-numbered columns are connected to the row scanning circuit 41 by the same row control line 21, and the control signal R (L) (L is Charge accumulation control and signal readout 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 numbered column, The output signal (analog signal) of the photoelectric conversion section 16 is output to the column signal line 22 (2m+2)a. In addition, the other photoelectric converter 17 of the pair of photoelectric converters 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-numbered columns. The output signal (analog signal) of the photoelectric conversion unit 17 is output to the column signal line 22(2m+1)b.

When using the image sensor 212 having the above configuration, the data of the pair of photoelectric converters 13 and 14 of the focus detection pixel 311 equipped with green filters arranged in odd rows and even columns is converted into photoelectric converters in the horizontal direction. Using a pair of data grouped for each conversion unit, phase difference detection is possible for subject images with contrast changes in the horizontal direction, and a focal point equipped with green filters arranged in even-numbered rows and columns Using a pair of data obtained by vertically grouping the data of the pair of photoelectric conversion units 16 and 17 of the detection pixel 312 for each photoelectric conversion unit, phase difference detection is possible for a subject image with a contrast change in the vertical direction. Become.

<Seventh embodiment>
In the first to sixth embodiments, the pixels (focus detection pixels, imaging pixels) are arranged in a square grid in the pixel array section 40, but pixel arrangements other than the square grid are also possible. It is possible to apply the invention.

FIG. 36 shows a pixel arrangement called a so-called honeycomb arrangement, which is a pixel arrangement obtained by rotating a square lattice arrangement by 45 degrees. Further, FIG. 37 shows a filter array corresponding to the pixel layout of FIG. 36. The filter array shown in FIG. 37 is a Bayer array tilted by 45 degrees. In the honeycomb array shown in FIGS. 36 and 37, 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 arranged.

The matrix in such a honeycomb array is defined as follows. In other words, the horizontal pixel array in which the green filter is arranged is an odd numbered row, the horizontal pixel arrangement in which a red or blue filter is arranged is an even numbered row, and the vertical pixel arrangement in which the green filter is arranged is an odd numbered row. The vertical pixel array in which the red filter or blue filter is arranged is an even numbered column.

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

In the pixel array section 40, focus detection pixels 411 are two-dimensionally arranged in 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 first column, and a green filter is arranged at this pixel. For this pixel arrangement of 2N rows and 2M columns, row control lines 21 (21(1) to 21(2N)) are wired for each row, and two column signal lines (22(1)a, 22(2N)) are wired in odd columns. (1)b to 22(2M-1)a, 22(2M-1)b) are wired. 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 receives control signals R(1) to 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 readout control are performed simultaneously according to the control signal R (L). It is done. Also, one photoelectric conversion unit 33 of the pair of photoelectric conversion units 33 and 34 of the focus detection pixel 411 arranged in an odd numbered column (2m+1 column) of an odd numbered row is connected to two column signals provided in an odd numbered column (2m+1 column). It is connected to one of the column signal lines 22(2m+1)b, and the output signal (analog signal) of the photoelectric conversion section 33 is output to the column signal line 22(2m+1)b. The other photoelectric converter 34 of the pair of photoelectric converters 33 and 34 of each focus detection pixel 411 is connected to the other column signal line 22 (2m+1)a of the two column signal lines provided in the odd numbered columns (2m+1 column). The output signal (analog signal) of the photoelectric conversion section 34 is output to the column signal line 22 (2m+1)a.

Also, one photoelectric conversion unit 33 of the pair of photoelectric conversion units 33 and 34 of the focus detection pixel 411 arranged in an even numbered column (2m+2 columns) of an even numbered row is connected to the two column signals provided in an odd numbered column (2m+1 column). It is connected to one of the column signal lines 22(2m+1)b, and the output signal (analog signal) of the photoelectric conversion section 33 is output to the column signal line 22(2m+1)b. The other photoelectric converter 34 of the pair of photoelectric converters 33 and 34 of each focus detection pixel 411 is connected to the other column signal line 22 (2m+1)a of the two column signal lines provided in the odd numbered columns (2m+1 column). The output signal (analog signal) of the photoelectric conversion section 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 pixel columns of the pixel array section 40. ADC (analog-digital conversion circuit) 23(1)a, 23(1)b to 23(2M-1)a, 23(2M-1)b provided for each pixel array section 40. A pair of analog signals output for each column from each focus detection pixel 411 is converted into an H-bit digital signal and output according to a control signal TA1 given 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) constituting the column AD converter 42. memory (25(1)a, 25(1)b to 25(2M-1)a, 25(2M-1)b), The digital signal output every (2M-1)a, 23(2M-1)b) is stored as an H-bit digital signal in accordance with 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 one pair of focus detection pixels for one row. The output signals of the photoelectric conversion sections 33 and 34 will be stored as digital signals.

The column digital addition device 46 includes 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. ), 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 outputted as an H-bit added digital signal.

The first line memory 48 is a memory (28(1) to 28(2M-1)) provided for each digital addition circuit (26(1) to 26(2M-1)) constituting the column digital addition device 46. ), and converts the addition digital signal outputted every digital addition circuit (26(1) to 26(2M-1)) into an H-bit digital signal in accordance with the control signal TM1 given from the timing control circuit 50. be memorized as . Here, each memory (28(1) to 28(2M-1)) of the first line memory 48 stores an addition signal ( (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 given from the second column scanning circuit 51, and the memories (25(1)a, 25(1)b to 25(2M-1)a, 25(2M- The H-bit digital signals stored in each of 1) and b) are sequentially read out to the second horizontal output circuit 45, and are passed through the second horizontal output circuit 45 to a pair of photoelectric conversion units 33 for focus detection, It is serially output to the outside as a 34 output signal (digital signal).

The first line memory 48 operates according to the scanning signal TS1 given from the first column scanning circuit 52, and is an H-bit added digital signal stored in each of the memories (28(1) to 28(2M-1)). are sequentially 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.

<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 in FIG. 36 (the filter arrangement corresponds to FIG. 37), in which the focus detection images 411 arranged in even-numbered rows in FIG. The focus detection pixel 412 is replaced with a focus detection pixel 412 having a pair of photoelectric conversion sections 36 and 37.

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

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

A pair of photoelectric conversion units 36 and 37 of each focus detection pixel 412 arranged in an even numbered row and an even numbered column (2m+2 columns) 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), charge accumulation control and signal readout control are performed simultaneously. Further, one photoelectric conversion unit 36 of the pair of photoelectric conversion units 36 and 37 of each focus detection pixel 412 is connected to one column signal line 22 (2m+1) a of two column signal lines provided in an odd numbered column (2m+1 column). The output signal (analog signal) of the photoelectric conversion section 36 is output to the column signal line 22 (2m+1)a. The other photoelectric converter 37 of the pair of photoelectric converters 36 and 37 of each focus detection pixel 412 is connected to the other column signal line 22 (2m+1) b of the two column signal lines provided in the odd numbered columns (2m+1 column). The output signal (analog signal) of the photoelectric conversion section 37 is output to the column signal line 22(2m+1)b.

When using the image sensor 212 having the above configuration, the data of the pair of photoelectric conversion units 33 and 34 of the focus detection pixel 411 equipped with green filters arranged in odd rows and odd columns is converted into photoelectric converters in the horizontal direction. Using a pair of data grouped for each conversion unit, phase difference detection is possible for subject images with contrast changes in the horizontal direction, and red and blue filters arranged in even rows and columns can be detected. The data of the pair of photoelectric conversion units 36 and 37 of the focus detection pixel 412 provided in the focus detection pixel 412 is vertically grouped for each photoelectric conversion unit, and a pair of data of the same color is used to align the subject image with contrast changes in the vertical direction. Phase difference detection becomes possible.

<Other embodiments>
In the present invention, the number of photoelectric conversion sections in a focus detection pixel is not limited to two, and the present invention can also be applied to a configuration in which a focus detection pixel includes two or more photoelectric conversion sections. For example, the focus detection pixel 311 shown in FIG. 6 includes two photoelectric conversion sections 13 and 14, which are obtained by dividing a square into two equal parts in the horizontal direction, and the two photoelectric conversion sections 13 and 14 are further divided into two equal parts in the vertical direction. The present invention can also 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 that are individually AD-converted. The configuration shown in FIG. 10 can be achieved by providing a column AD converter comprising a column AD converter and a column digital adder including a digital adder circuit that digitally adds digital signals of four photoelectric converters output from the column AD converter. A similar effect can be obtained.

Also, instead of providing four column signal lines corresponding to the four photoelectric conversion units, two of the four photoelectric conversion units and the other two photoelectric conversion units are connected to two virtual adjacent rows. It is also possible to reduce the number of column signal lines to two by structuring the image sensor as a photoelectric conversion section of a focus detection pixel. For example, if four photoelectric conversion units are arranged in two rows of two in each focus detection pixel 311, the two photoelectric conversion units in the upper row and the two photoelectric conversion units in the lower row are arranged in two virtual adjacent rows. The number of column signal lines is reduced to two by regarding this as the photoelectric conversion section of the focus detection pixel.

In the image sensor of the embodiment described above, 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 it is possible to increase the readout speed. For this purpose, it is also possible to divide the image array section into a plurality of regions, and to provide each region with one data output channel for focus detection and one data output channel for image data.

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

Furthermore, the present invention is applicable not only to an image sensor of the type in which a wiring layer exists between a microlens and a photoelectric conversion section as shown in FIG. The present invention can also be applied to a back-illuminated image sensor in which a wiring layer is arranged on the side opposite to the direction of the microlens. An image sensor that requires column signal lines 22, such as the image sensor according to the present invention, is provided with more wiring layers than a conventional image sensor. In a back-illuminated image sensor, wiring layers can be arranged without being restricted by the layout of the photoelectric conversion section, so flexibility with respect to an increase in the number of column signal lines is improved.

In the image sensor 212 in the embodiment described above, an example has been shown in which the image pixels are provided with color filters in a Bayer array, but the configuration and arrangement of the color filters are not limited to this, and complementary color filters (green: G, yellow) are used. :Ye, magenta: Mg, cyan: Cy) and arrays other than Bayer arrays. It is also applicable to monochrome image sensors.

The image sensor 212 in the embodiment described above includes the pixel array section 40 and other parts. The pixel array section 40 and the other parts were provided on separate substrates, and these separate substrates were stacked on each other.However, the pixel array section 40 and other parts were provided on the same substrate Good too.

Note that the imaging device is not limited to the above-described digital still camera configured to have an interchangeable lens attached to a camera body. For example, the present invention can be applied to a lens-integrated digital still camera or video camera. Furthermore, it can be applied to small camera modules built into mobile phones, surveillance cameras, visual recognition devices for robots, and vehicle-mounted cameras.

10 microlens, 11, 13, 14, 16, 17, 33, 34, 36, 37 photoelectric conversion section, 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 addition 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 conversion device, 43 second column switch device, 44 second line memory, 45 second horizontal output circuit, 46 column digital addition circuit, 47 first column switch device, 48 first line memory, 49 first horizontal output circuit, 50 timing control circuit, 51 second row scanning circuit, 52 first row scanning circuit, 71 photographing light flux, 73, 74 focus detection light flux, 90 exit pupil, 91 optical axis, 93, 94 distance measuring pupil, 95 area, 100 photographing screen; 101 focus detection area, 201 digital still camera, 202 interchangeable lens, 203 camera body, 204 mount, 206 lens drive control device, 208 zooming lens, 209 lens, 210 focusing lens, 211 aperture, 212 image sensor, 213 electricity contact, 214 body drive control device, 215 liquid crystal display element drive circuit, 216 liquid crystal display element, 217 eyepiece, 219 memory card, 220 image sensor control unit, 221 buffer memory, 222 CPUa, 223 CPUb, 310 image sensor, 311, 312, 411, 412 Focus detection pixels

Claims (11)

A first photoelectric conversion unit and a second photoelectric conversion unit that photoelectrically convert light transmitted through the first microlens to generate charges;
a first signal line that outputs a signal based on the charge generated by the first photoelectric conversion unit;
a second signal line that outputs a signal based on the charge generated by the second photoelectric conversion section;
a first A/D conversion section that is electrically connected to the first signal line and converts an analog signal based on the charge generated by the first photoelectric conversion section into a first digital signal; a second A/D conversion unit that is electrically connected to the second signal line and converts an analog signal based on the charge generated by the second photoelectric conversion unit into a second digital signal;
a first addition unit that adds the first digital signal and the second digital signal;
An imaging device comprising: The image sensor according to claim 1,
a third photoelectric conversion unit and a fourth photoelectric conversion unit that photoelectrically convert the light transmitted through the second microlens to generate charges;
a third signal line that outputs a signal based on the charge converted by the third photoelectric conversion section;
a fourth signal line that outputs a signal based on the charge converted by the fourth photoelectric conversion section;
An imaging device comprising: The image sensor according to claim 2,
a third A/D converter to which the third signal line is connected and which converts an analog signal based on the charge generated by the third photoelectric converter into a third digital signal; and a third A/D converter to which the third signal line is connected; a fourth A/D conversion unit to which a line is connected and converts an analog signal based on the charge generated by the fourth photoelectric conversion unit into a fourth digital signal,
a second addition unit that adds the third digital signal and the fourth digital signal;
An image sensor comprising: The image sensor according to claim 1,
comprising a third photoelectric conversion unit and a fourth photoelectric conversion unit that photoelectrically convert the light transmitted through the second microlens to generate charges;
The first signal line outputs a signal based on the charge converted by the third photoelectric conversion unit,
The second signal line outputs a signal based on the charge converted by the fourth photoelectric conversion unit,
The first A/D converter converts an analog signal based on the charge generated by the third photoelectric converter into a third digital signal,
The second A/D converter converts an analog signal based on the charge generated by the fourth photoelectric converter into a fourth digital signal,
The addition unit is an image sensor that adds the third digital signal and the fourth digital signal. The image sensor according to any one of claims 2 to 4,
The first photoelectric conversion section and the second photoelectric conversion section are provided side by side in a first direction,
The third photoelectric conversion section and the fourth photoelectric conversion section are image pickup elements arranged in parallel in a second direction intersecting the first direction. The image sensor according to any one of claims 1 to 5,
An imaging device including a first output line that outputs at least one of a signal based on the charge generated by the first photoelectric conversion unit and a signal based on the charge generated by the second photoelectric conversion unit. The image sensor according to claim 6,
The first output line is an image sensor that outputs at least one of the first digital signal and the second digital signal. The image sensor according to any one of claims 1 to 7,
An image sensor including a second output line that outputs a signal added by the adding section. The image sensor according to any one of claims 1 to 8,
An image sensor in which a substrate having the first photoelectric conversion section and the second photoelectric conversion section and a substrate having the first adding section are stacked. An image sensor according to any one of claims 1 to 9,
a generation unit that generates image data based on the signals added by the addition unit;
An imaging device comprising: The imaging device according to claim 10,
An imaging device including a detection section that performs focus detection of an optical system based on the first digital signal and the second digital signal.

Images