JP2017103712A - Imaging element, focus detection device, and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a decrease in the area of a light receiving portion of a plurality of photoelectric conversion units and to prevent degradation of imaging characteristics.SOLUTION: An imaging element comprises: four photoelectric conversion units arranged two by two in a first direction and in a second direction crossing the first direction; and first and second charge holding units for transferring charges of the photoelectric conversion portion. The four photoelectric conversion units comprise: a first photoelectric conversion unit and a second photoelectric conversion unit sequentially arranged in a first direction; a first photoelectric conversion unit and a third photoelectric conversion unit sequentially arranged in a second direction; and a second photoelectric conversion unit and a fourth photoelectric conversion unit arranged in order in a second direction. The charges generated by the first photoelectric conversion unit and the fourth photoelectric conversion unit are transferred to the first charge holding unit. The charges generated by the second photoelectric conversion unit and the third photoelectric conversion unit are transferred to the second charge holding unit.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an imaging device, a focus detection device, and an imaging device.

  There is known an imaging device in which a plurality of pixels provided with a plurality of pairs of photoelectric conversion units are arranged and focus detection can be performed by a phase difference method using an output from the pixels (for example, Patent Document 1). Such an image sensor has a problem that the light receiving area of the photoelectric conversion unit is reduced.

JP 2012-215785 A

According to the first aspect of the present invention, the imaging device includes four photoelectric conversion units arranged in two in a second direction intersecting the first direction and the first direction, and the photoelectric conversion unit. First and second charge holding units to which the charges are transferred, and the four photoelectric conversion units are arranged in the first direction in order, the first photoelectric conversion unit and the second photoelectric conversion unit The first photoelectric conversion unit and the third photoelectric conversion unit arranged in order in the second direction, the second photoelectric conversion unit and the fourth photoelectric conversion unit arranged in order in the second direction, The charges generated by the first photoelectric conversion unit and the fourth photoelectric conversion unit are transferred to the first charge holding unit, and the charges generated by the second photoelectric conversion unit and the third photoelectric conversion unit are Transferred to the second charge holding portion.
According to the second aspect of the present invention, the image sensor includes four photoelectric conversion units arranged in two in a second direction intersecting the first direction and the first direction, and the photoelectric conversion unit. First and second signal lines from which a signal based on the electric charge is output, and the four photoelectric conversion units are arranged in order in the first direction, a first photoelectric conversion unit and a second photoelectric conversion unit, The first photoelectric conversion unit and the third photoelectric conversion unit arranged in order in the second direction, the second photoelectric conversion unit and the fourth photoelectric conversion unit arranged in order in the second direction, The signal generated by the charges generated by the first photoelectric conversion unit and the fourth photoelectric conversion unit is output to the first signal line, and the charge generated by the second photoelectric conversion unit and the third photoelectric conversion unit. The signal is output to the second signal line.
According to the third aspect of the present invention, the focus detection apparatus includes the imaging element according to the first or second aspect, a control unit that controls transfer of charges from the four photoelectric conversion units, and the four A focus that performs phase difference focus detection based on signals generated by the photoelectric conversion units sequentially arranged in the first direction or the photoelectric conversion units sequentially arranged in the second direction among the photoelectric conversion units. A detection unit.
According to the fourth aspect of the present invention, the imaging apparatus includes the focus detection device according to the third aspect, the charges of the first and second photoelectric conversion units, and the charge of the third and fourth photoelectric conversion units. And an image generation unit for generating image data.

The figure which shows the structural example of the digital camera by embodiment of this invention The figure which shows the schematic structure of an image sensor The figure which shows typically the 1st area | region and 2nd area | region on an image pick-up element. The figure which shows typically the circuit structure of the image pick-up element in 1st Embodiment. The figure which shows the drive timing for reading an output signal from the pixel in 1st Embodiment. The figure which shows typically the circuit structure of the image pick-up element in 1st Embodiment. The figure which shows the drive timing for reading an output signal from the pixel in 1st Embodiment. The figure which shows schematic structure of the image pick-up element in a comparative example The figure which shows typically the circuit structure of the image pick-up element in a comparative example The figure which shows schematic structure of the image pick-up element in a comparative example The figure which shows typically the circuit structure of the image pick-up element in a comparative example The figure which shows typically the circuit structure of the image pick-up element in 2nd Embodiment. The figure which shows the drive timing for reading an output signal from the pixel in 2nd Embodiment. The figure which shows the drive timing for reading an output signal from the pixel in 2nd Embodiment.

-First embodiment-
Hereinafter, an embodiment will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of a lens-interchangeable digital camera 1 including an image sensor according to the present embodiment. The digital camera 1 shown in FIG. 1 includes an interchangeable lens 110 and a camera body 100, and the interchangeable lens 110 is attached to the camera body 100 via a lens mounting portion 105.

  The interchangeable lens 110 includes a lens control device 111, a zoom lens 112, a focus lens 113, an anti-vibration lens 114, a diaphragm 115, a lens operation unit 116, and the like. The lens control device 111 includes a CPU and peripheral components such as a memory, and controls the drive of the focus lens 113 and the diaphragm 115, detects the positions of the zoom lens 112 and the focus lens 113, transmits lens information to the camera body 100, and the camera body. The camera information from 100 is received.

  The camera body 100 includes an image sensor 101, a body control device 102, a body operation unit 103, a display unit 104, and the like. The image sensor 101 is disposed on the planned imaging plane (planned focal plane) of the interchangeable lens 110 and photoelectrically converts the subject image formed by the interchangeable lens 110. The body operation unit 103 includes a shutter button, a focus detection area setting member, and the like. The display unit 104 is a liquid crystal monitor (back monitor) mounted on the back surface of the camera body 100.

  The body control device 102 includes a CPU and peripheral components such as a memory. The body control device 102 is an arithmetic device that controls each component of the digital camera 1 and executes various data processing based on a control program. The body control apparatus 102 has a drive control unit 102a, a focus detection unit 102b, and an image processing unit 102c as functions. The drive control unit 102 a controls the drive control of the image sensor 101 to read out the image signal and the focus detection signal from the image sensor 101. The focus detection unit 102 b performs focus detection calculation based on the focus detection signal from the image sensor 101 and the focus adjustment of the interchangeable lens 110. The image processing unit 102c performs processing and recording of an image signal from the image sensor 101. The body control device 102 communicates with the lens control device 111 via an electrical contact 106 provided in the lens attachment unit 105, and receives lens information and transmits camera information (defocus amount, aperture value, etc.).

  A subject image is formed on the light receiving surface of the image sensor 101 by the light beam that has passed through the interchangeable lens 110. This subject image is photoelectrically converted by the image sensor 101, and an image signal and a focus detection signal are sent to the body control device 102.

  The focus detection unit 102b of the body control device 102 performs a focus detection calculation by a known image plane phase difference method based on a focus detection signal from the image sensor 101, thereby adjusting the focus adjustment state (defocus amount) of the interchangeable lens 110. Is detected. The body control device 102 sends this defocus amount to the lens control device 111. The lens control device 111 calculates a drive amount of the focus lens 113 based on the received defocus amount, and moves the focus lens 113 to a focus position by driving the focus lens 113 with a motor or the like (not shown) based on this drive amount. In other words, the imaging device 101, the drive control unit 102a, and the focus detection unit 102b constitute the focus detection device 2 in the present embodiment.

  Further, the image processing unit 102c of the body control device 102 processes the image signal from the image sensor 101 to generate captured image data, and stores it in a memory card (not shown). The image processing unit 102 c causes the display unit 104 to display a through image (live view image) based on a through image (live view image) signal from the image sensor 101.

(Configuration of image sensor)
FIG. 2 is a diagram illustrating a schematic configuration of the image sensor 101. Note that in FIG. 2, transistors and the like used for reading are omitted for easy understanding of the connection between the pixel 200 and the vertical signal line 300. In the image sensor 101, a plurality of pixels 200 are provided two-dimensionally in the horizontal direction (row direction) and the vertical direction (column direction). Hereinafter, the plurality of pixels 200 arranged in the horizontal direction are also referred to as pixel rows, and the plurality of pixels 200 arranged in the vertical direction are also referred to as pixel columns.

  Each pixel 200 includes four photoelectric conversion units (photodiodes) PD_1, PD_2, PD_3, and PD_4 provided under one microlens (not shown). Each photoelectric conversion unit PD_1, PD_2, PD_3, and PD_4 respectively receives four light beams that have passed through different regions of the exit pupil of the interchangeable lens 110. In the following description, the photoelectric conversion units PD_1 to PD_4 are collectively referred to as photoelectric conversion units PD. The photoelectric conversion unit PD is a charge storage type photoelectric conversion unit. In the case of a 4PD configuration having four photoelectric conversion units PD per pixel, two photoelectric conversion units PD are arranged in the horizontal direction (referred to as horizontal division), and two photoelectric conversion units PD are arranged in the vertical direction (vertical division and Call). In the example illustrated in FIG. 2, the photoelectric conversion units PD_1 and PD_3 are arranged in the horizontal direction, and the photoelectric conversion units PD_2 and PD_4 are arranged in the horizontal direction. The photoelectric conversion units PD_1 and PD_4 are arranged in the vertical direction, and the photoelectric conversion units PD_2 and PD_3 are arranged in the vertical direction. That is, the four photoelectric conversion units PD are arranged in 2 rows and 2 columns.

  Further, color filters (R: red filter, G: green filter, B: blue filter) are arranged at each pixel position according to the rules of the Bayer arrangement. That is, as the pixel 200, an R pixel having a red component spectral sensitivity (that is, a red filter is disposed), a G pixel having a green component spectral sensitivity (that is, a green filter is disposed), and a blue component. And a B pixel (that is, a blue filter is disposed). The pixel 200 serves as both a photographing pixel and a focus detection pixel, and the pixel 200 is disposed on the entire surface of the image sensor 101. Therefore, focus detection can be performed at an arbitrary position on the shooting screen. Further, at the time of photographing, it is possible to generate photographed image data by adding output signals from the photoelectric conversion units PD_1, PD_2, PD_3, and PD_4 of each pixel 200.

The image sensor 101 includes a vertical signal line 300 for reading an output signal from the photoelectric conversion unit PD. In the image sensor 101, two vertical signal lines 300 (300 _{1 to} 300 _2n ) are provided for each pixel column. For example, the first column of pixels 200, and the vertical signal lines 300 ₁ and the vertical signal line 300 ₂ is provided. The vertical signal lines 300 _1, and the left of the photoelectric conversion unit PD_4 and right of the photoelectric conversion unit PD_3 of the pixels of the first column 200 is connected. The vertical signal lines 300 _2, and the left of the photoelectric conversion unit PD_1 and right of the photoelectric conversion unit PD_2 of the pixels of the first column 200 is connected. That is, the vertical signal lines 300 _1, the diagonal direction is arranged photoelectric conversion unit PD_3 and the PD_4 are connected, the photoelectric conversion unit disposed in a different diagonal direction from above into the vertical signal line 300 ₂ PD_1 And PD_2 are connected.

The two photoelectric conversion units PD arranged in the row direction in one pixel 200 are read out to different vertical signal lines 300, respectively. For example, in the pixel 200 of one row, left photoelectric conversion unit PD_1 is read out to the vertical signal line 300 _2, the right of the photoelectric conversion unit PD_3 is read out to the vertical signal lines 300 _1. The photoelectric conversion unit PD_4 the left is read out to the vertical signal line 300 _1, the right of the photoelectric conversion unit PD_2 is read to the vertical signal line 300 _2. In the above configuration, although n columns of pixels 200 are arranged, 2n vertical signal lines 300 are required, but the influence on the entire area is small.

The drive control unit 102a controls the pixel 200 having the above-described configuration to read out an output signal from the photoelectric conversion unit PD arranged in the vertical direction at the same timing (first control) and the photoelectric arranged in the horizontal direction. Control (second control) for reading out an output signal from the conversion unit PD at the same timing is performed.
FIG. 3 shows a region (first region) R1 in which a plurality of pixels 200 are arranged as a pixel group controlled by the first control on the image sensor 101, and a plurality of pixels 200 as a pixel group controlled by the second control. A region (second region) R2 in which is arranged is schematically shown. The first region R1 and the second region R2 include a plurality of pixel rows in the vertical direction, and the first region R1 and the second region R2 are alternately provided along the vertical direction. In addition, arrangement | positioning with 1st area | region R1 and 2nd area | region R2 shown in FIG. 3 is an example, and is not limited to this arrangement example. Hereinafter, description will be made separately on the pixels 200 arranged in the first region R1 and the pixels 200 arranged in the second region R2. In the following description, terms such as the same timing and simultaneity are used. However, the timing is not limited to the same timing in the strict sense and is not limited at the same time, and includes a time width that does not cause a decrease in accuracy of focus detection calculation.

-Pixels arranged in the first region R1-
FIG. 4 is a diagram showing details of FIG. 2, showing connections at the transistor level. FIG. 4 shows a circuit configuration of one pixel 200 included in the first region R1 among the plurality of pixels 200 shown in FIG. Each pixel 200 of the image sensor 101 has a reading unit 400 for reading an output signal from the photoelectric conversion unit PD. Each pixel 200, two read-out portions 400 ₁ and 400 ₂ are provided, it is provided in common to two photoelectric conversion unit PD arranged diagonally, respectively. For example, in a photoelectric conversion unit PD_3 and PD_4 are read unit 400 ₁ is commonly provided in the photoelectric conversion unit PD_1 and PD_2 is read unit 400 ₂ is commonly provided. That is, the reading unit 400 ₁ reads the output signal from the photoelectric conversion unit Pd_3, the output signal from the photoelectric conversion unit PD_4. Reading unit 400 ₂ reads the output signal from the photoelectric conversion unit PD_1, the output signal from the photoelectric conversion unit PD_2. The output signal read from each reading unit 400 is output via the corresponding vertical signal line 300. For example, the output signal read from the read unit 400 ₁ is output through the vertical signal lines 300 _1, output signals read from the read unit 400 ₂ is outputted through the vertical signal line 300 ₂ .

Each reading unit 400 includes a reset transistor RST (RST ₁ , RST ₂ ), an amplification transistor SF (SF ₁ , SF ₂ ), a selection transistor SEL (SEL ₁ , SEL ₂ ), a floating diffusion FD (FD ₁ , FD ₂ ), The transfer transistors TX1 (TX1 ₁ , TX1 ₂ ) and TX2 (TX2 ₁ , TX2 ₂ ) are included. The floating diffusion FD operates as a charge accumulation unit or a charge retention unit that accumulates (holds) signal charges obtained by photoelectric conversion in the photoelectric conversion unit PD. The amplification transistor SF operates as an amplification unit that amplifies a signal corresponding to the potential of the floating diffusion FD. Each of the transfer transistors TX1 and TX2 operates as a transfer unit that transfers charges from the photoelectric conversion unit to the floating diffusion FD. The reset transistor RST operates as a reset unit that resets the potential of the floating diffusion FD and the charge of the photoelectric conversion unit. The selection transistor SEL operates as a selection unit for selecting the pixel 200. These parts are connected as shown in FIG. In FIG. 4, VDD is a power supply voltage.

The photoelectric conversion units PD arranged in the row direction of the respective pixels 200 are connected to transfer transistors TX1 and TX2 of different reading units 400, respectively. For example, in the pixel 200, the photoelectric conversion unit PD_1 on the left is connected to the transfer transistor TX1 ₂ read unit 400 _2, the right side of the photoelectric conversion unit PD_2 is connected to the transfer transistor TX2 ₂ read unit 400 _2. Right of the photoelectric conversion unit PD_3 is connected to the transfer transistor TX1 ₁ read unit 400 _1, the photoelectric conversion unit PD_4 the left is connected to the transfer transistor TX2 ₁ read unit 400 _1.

The photoelectric conversion unit PD_1 pixels 200, connected transfer transistor _TX1 2, TX2 ₁ gate to PD_4 is connected to the control line 210 to control pulse Vtx_1 by the local control line 211 is supplied. On the other hand, the gates of the transfer transistors TX1 ₁ and TX2 ₂ connected to the photoelectric conversion units PD_3 and PD_2 of the pixel 200 are connected to the control line 220 to which the control pulse Vtx_2 is supplied by the local control line 221. That is, for the photoelectric conversion unit PD on the left side of the pixel 200, the transfer transistors TX1 and TX2 are controlled by the control pulse Vtx_1, and for the right photoelectric conversion unit PD, the transfer transistors TX1 and TX2 are controlled by the control pulse Vtx_2. Is called.

(Reading output signal)
Control when reading an output signal from the pixel 200 of the image sensor 101 of the present embodiment will be described with reference to a timing chart shown in FIG. In FIG. 5, Vsel represents a control pulse of the selection transistor SEL. Vrst represents a control pulse of the reset transistor RST. Vtx_1 shows transfer transistor _TX1 2, TX2 ₁ control pulse corresponding to the left side of the photoelectric conversion unit PD_1, PD_4 pixel 200. Vtx_2 indicates a control pulse of the transfer transistors TX1 ₁ and TX2 ₂ corresponding to the photoelectric conversion units PD_3 and PD_2 on the right side of the pixel 200. These points are the same in FIGS. 7, 13, and 14 described later.

  As shown in FIG. 5, the drive control unit 102 a controls the drive timing for reading the output signal from the pixel 200 by outputting various control pulses to the reading unit 400. The drive control unit 102a selects a pixel row from which an output signal is read. The drive control unit 102a switches Vsel from Low level to High level, and turns on the selection transistor SEL. Thereby, the floating diffusion FD to the vertical signal line 300 are connected. FIG. 5 shows an example in which selection is performed line by line.

The drive control unit 102a switches Vrst from Low level to High level, turns on the reset transistor RST, and resets the potential of the floating diffusion FD. This is the first reset of the floating diffusion FD. Thereafter, the drive control unit 102a switches Vrst to the Low level and turns off the reset transistor RST. After the reset transistor RST is turned off, the potential level of the floating diffusion FD is stabilized for a predetermined stabilization time. This settled level is a dark level by the first reset, and becomes a dark signal corresponding to the photoelectric conversion units PD_1 and PD_4 on the left side of the pixel 200. Here, the dark signal “Dark — 4 ₁ , 1 ₂ , 4 ₃ , 1 for the left photoelectric conversion units PD — ₁ and PD — 4 in each column of pixels 200 by the first reset is provided to each vertical signal line 300 _{1 to} 300 _{2 n. 4} , 4 ₅ , 1 ₆ ,..., 4 _(2n-1) , 1 _2n ”are output simultaneously.

After settling of the dark level, the drive control unit 102a turns on the transfer transistor _TX1 2, TX2 ₁ connected to the photoelectric conversion unit PD_1 and PD_4 the left pixel 200 switches the Vtx_1 to High level. In the High level period of the Vtx_1, the signal charges accumulated in the photoelectric conversion unit PD_1 pixels 200 are transferred to the floating diffusion FD _2, the signal charge accumulated in the photoelectric conversion unit PD_4 is transferred to the floating diffusion FD _1. The drive control unit 102a switches Vtx_1 to the Low level and turns off the transfer transistors TX1 ₂ and TX2 ₁ connected to the photoelectric conversion units PD_1 and PD_4 of the pixel 200.

After the transfer transistors TX1 ₂ and TX2 ₁ are turned off, the potential levels of the floating diffusions FD ₁ and FD ₂ are stabilized for a predetermined stabilization time. This static potential level is a signal level obtained by reading at Vtx_1, and becomes a signal signal corresponding to each of the photoelectric conversion units PD_1 and PD_4 of the pixel 200. Here, signal signals “Sig — 4 ₁ , 1 ₂ , 4 ₃ , and left signal signals for the photoelectric conversion units PD — ₁ and PD — 4 in the pixels 200 of each column by charge transfer at Vtx — ₁ are connected to the vertical signal lines 300 _{1 to} 300 _{2 n} . 1 ₄ , 4 ₅ , 1 ₆ ,..., 4 _(2n−1) , 1 _2n ”are output simultaneously.

The difference between the dark signal and the signal signal output from each vertical signal line 300 in this way becomes the read signal amount of each photoelectric conversion unit PD_1 and PD_4 in the pixel 200, that is, an output signal. Therefore, in the plurality of pixels 200 arranged in the same pixel row, the output signals of the photoelectric conversion units PD_1 and PD_4 arranged in the vertical direction have temporal synchronism.
Note that the correlated double sampling (CDS) operation for obtaining the difference between the dark signal and the signal signal may be performed by a subsequent circuit in the sensor chip of the image sensor 101 or by a subsequent circuit outside the sensor chip. Also good.

After the signal level is settled, the drive control unit 102a switches Vrst from Low level to High level, turns on the reset transistor RST, and resets the potential of the floating diffusion FD. This is the second reset of the floating diffusion FD. Thereafter, the drive control unit 102a switches Vrst to the Low level and turns off the reset transistor RST. After the reset transistor RST is turned off, the potential level of the floating diffusion FD is stabilized for a predetermined stabilization time. This settled level is a dark level by the second reset, and becomes a dark signal corresponding to the photoelectric conversion units PD_2 and PD_3 on the right side of the pixel 200. Here, the dark signals “Dark — 3 ₁ , 2 ₂ , 3 ₃ , 2 for the right photoelectric conversion units PD — ₂ and PD — 3 in the pixels 200 of each column by the second reset are provided to the vertical signal lines 300 _{1 to} 300 _{2 n. 4} , 3 ₅ , 2 ₆ ,..., 3 _(2n−1) , 2 _2n ”are output simultaneously.

After the dark level is settled, the drive control unit 102a switches Vtx_2 to the high level and turns on the transfer transistors TX1 ₁ and TX2 ₂ connected to the photoelectric conversion units PD_3 and PD_2 on the right side of the pixel 200. In the High level period of the Vtx_2, the signal charges accumulated in the photoelectric conversion unit PD_3 pixels 200 are transferred to the floating diffusion FD _1, signal charges accumulated in the photoelectric conversion unit PD_2 are transferred to the floating diffusion FD _2. The drive control unit 102a switches Vtx_2 to the Low level and turns off the transfer transistors TX1 ₁ and TX2 ₂ connected to the photoelectric conversion units PD_3 and PD_2 of the pixel 200.

After the transfer transistors TX1 ₁ and TX2 ₂ are turned off, the potential level of the floating diffusion FD is stabilized for a predetermined stabilization time. This static potential level is a signal level obtained by reading Vtx_2, and is a signal signal corresponding to the photoelectric conversion units PD_3 and PD_2 of the pixel 200. The vertical signal lines 300 _{1 to} 300 _2n have signal signals “Sig — 3 ₁ , 2 ₂ , 3 ₃ , 2 ₄ , right-side photoelectric conversion units PD_3 and PD_2 in the pixels 200 of each column by charge transfer at Vtx_2. 3 ₅ , 2 ₆ ,..., 3 _(2n−1) , 2 _2n ”are output.

The difference between the dark signal and the signal signal output from each vertical signal line 300 in this way becomes the read signal amount of each photoelectric conversion unit PD_2 and PD_3 in the pixel 200, that is, an output signal. Therefore, in the plurality of pixels 200 arranged in the same pixel row, output signals of the photoelectric conversion units PD_2 and PD_3 arranged in the vertical direction have temporal synchronism.
Note that the correlated double sampling (CDS) operation for obtaining the difference between the dark signal and the signal signal may be performed by a subsequent circuit in the sensor chip of the image sensor 101 or by a subsequent circuit outside the sensor chip. Also good.

As described above, in the pixel 200, the drive control unit 102a causes the photoelectric conversion units PD_1 and PD_4 arranged in the vertical direction to output output signals at the same timing. The drive control unit 102a outputs an output signal from the photoelectric conversion units PD_2 and PD_3 arranged in the vertical direction at the same timing. That is, the drive control unit 102a permits charge transfer from the photoelectric conversion units PD_1 and PD_4 to the transfer transistors TX1 ₂ and TX2 ₁ at the same timing, and the same for the transfer transistors TX1 ₁ and TX2 ₂ . At this timing, charge transfer from the photoelectric conversion units PD_3 and PD_2 is permitted. Therefore, the drive control unit 102a, alternatively allowed for respectively connected to the transfer transistor TX1 ₂ and TX2 ₂ and a charge transfer of the photoelectric conversion unit PD_1 and PD_2 arranged in a diagonal direction of the pixel 200 To do. The drive control unit 102a selectively permits charge transfer to the transfer transistors TX1 ₁ and TX2 ₁ connected to the photoelectric conversion units PD_3 and PD_4 arranged in the diagonal direction of the pixel 200, respectively.
Thereby, charge transfer can be performed without providing floating diffusion for each of the photoelectric conversion units PD_1 to PD_4. Therefore, the number of components can be reduced and the area of the light receiving surface of the photoelectric conversion units PD_1 to PD_4 can be increased. it can.

  In the above description, the drive control unit 102a causes the photoelectric conversion units PD_1 and PD_4 to output output signals for the pixels 200 in the first region R1, and then outputs the output signals from the photoelectric conversion units PD_2 and PD_3. Although the drive timing is controlled, the present invention is not limited to this example. The drive control unit 102a controls the drive timing to output the output signals from the photoelectric conversion units PD_1 and PD_4 after outputting the output signals from the photoelectric conversion units PD_2 and PD_3 for the pixel 200 in the first region R1. Also good.

The drive control unit 102a performs the above-described control for each pixel row included in the first region R1 of the image sensor 101, and reads the output signal.
(Focus detection)
When performing focus adjustment in response to a half-pressing operation of the shutter button by the user, the focus detection unit 102b uses the output signal read out as described above as a focus detection signal, and uses a known image plane phase difference. Performs focus detection calculation by the method. In this case, the focus detection unit 102b generates a signal sequence using a plurality of output signals having temporal synchronization. For example, the focus detection unit 102b generates the first signal sequence {an} using the output signal from the photoelectric conversion unit PD_1 in each row, and uses the output signal from the photoelectric conversion unit PD_4 in each row to generate the second signal sequence { bn} is generated. The focus detection unit 102b detects a focus adjustment state of the interchangeable lens 110, that is, a defocus amount, by detecting a relative image shift amount between the generated first signal sequence {an} and the second signal sequence {bn}. To do.

  The focus detection unit 102b generates the first signal sequence {cn} using the output signal from the photoelectric conversion unit PD_3 in each row, and uses the output signal from the photoelectric conversion unit PD_2 in each row to generate the second signal sequence {dn}. May be generated. In particular, in the peripheral portion of the image sensor 101, the light flux from the subject is more susceptible to vignetting or the like than the central portion of the image sensor 101. The focus detection unit 102b outputs signals from the pair of photoelectric conversion units PD_1 and PD_4 or the photoelectric conversion units PD_2 and PD_3 that are less affected by vignetting among the output signals from the pixels 200 arranged in the periphery of the image sensor 101. May be selected and used as a focus detection signal. For the pixel 200 arranged at the center of the image sensor 101, the focus detection unit 102b uses an output signal from one of the photoelectric conversion units PD_1 and PD_4 or the photoelectric conversion units PD_2 and PD_3 as a focus detection signal. Can be used.

  As described above, a color filter is arranged at each pixel position of the image sensor 101 according to the Bayer array rule. Therefore, when the focus detection unit 102b generates the pair of signal sequences {an}, {bn} or the pair of signal sequences {cn}, {dn}, the output from the pixel 200 in which the same color filter is arranged. Use the signal. For example, when the focus detection calculation is performed using the output signal from the pixel 200 arranged in the first column as shown in FIG. 2, the focus detection unit 102b includes a G color filter as an example. The output signals from the pixels 200 in the first row, the third row,... Are used.

-Pixels arranged in the second region R2-
FIG. 6 is a circuit diagram showing connections at the transistor level of the respective pixels 200 arranged in the second region R2, and is a diagram showing FIG. 2 in detail. 6 also illustrates the circuit configuration of one pixel 200 included in the second region R2 among the plurality of pixels 200 illustrated in FIG.
The gates of the transfer transistors TX1 ₂ and TX1 ₁ connected to the photoelectric conversion units PD_1 and PD_3 of the pixel 200 are connected to a control line 210 to which a control pulse Vtx_1 is supplied by local control lines 251 and 252, respectively. The gates of the transfer transistors TX2 ₁ and TX2 ₂ connected to the photoelectric conversion units PD_4 and PD_2 of the pixel 200 are connected to a control line 220 to which a control pulse Vtx_2 is supplied by local control lines 253 and 254, respectively. That is, the transfer transistors TX1 and TX2 are controlled by the control pulse Vtx_1 for the upper photoelectric conversion unit PD of the pixel 200, and the transfer transistors TX1 and TX2 are controlled by the control pulse Vtx_2 for the lower photoelectric conversion unit PD. Done. The other configuration, that is, the signal circuit for reading out the electric charge accumulated in the photoelectric conversion unit PD to the vertical signal line 300 is the same as the pixel 200 arranged in the first region R1.

(Reading output signal)
With reference to the timing chart shown in FIG. 7, control when an output signal is read from the pixels 200 arranged in the second region R2 will be described. In the following description, the difference from the drive timing at the time of reading the output signal from the pixel 200 arranged in the first region R1 is mainly performed.
In FIG. 7, Vtx_1 represents a control pulse of the transfer transistors TX1 ₂ and TX1 ₁ corresponding to the photoelectric conversion units PD_1 and PD_3 on the upper side of the pixel 200. Vtx_2 indicates a control pulse of the transfer transistors TX2 ₁ and TX2 ₂ corresponding to the photoelectric conversion units PD_4 and PD_2 on the lower side of the pixel 200.

As shown in FIG. 7, the drive control unit 102a selects a pixel row from which an output signal is read by turning on the selection transistor SEL in the same manner as the pixel 200 in the first region R1. FIG. 7 also shows an example in which selection is performed line by line. The drive control unit 102a resets the potential of the first floating diffusion FD as in the case of the pixel 200 in the first region R1. When a predetermined settling time elapses, the dark signals “Dark — 3 ₁ , 1 for the upper photoelectric conversion units PD — ₁ and PD — ₃ in the pixels 200 of each column are reset to the vertical signal lines 300 _{1 to} 300 _{2 n} by the first reset. ₂ , 3 ₃ , 1 ₄ , 3 ₅ , 1 ₆ ,..., 3 _(2n−1) , 1 _2n ”are output simultaneously.

The drive control unit 102a switches Vtx_1 to the high level and turns on the transfer transistors TX1 ₂ and TX1 ₁ . In the High level period of the Vtx_1, the signal charges accumulated in the photoelectric conversion unit PD_1 pixels 200 are transferred to the floating diffusion FD _2, the signal charge accumulated in the photoelectric conversion unit PD_3 is transferred to the floating diffusion FD _1. The drive control unit 102a switches Vtx_1 to the low level and turns off the transfer transistors TX1 ₂ and TX1 ₁ . Thereafter, the potential levels of the floating diffusions FD ₁ and FD ₂ are stabilized at a predetermined stabilization time, and become signal levels by reading at Vtx_1. In each of the vertical signal lines 300 _{1 to} 300 _{2 n} , signal signals “Sig — 3 ₁ , 1 ₂ , 3, which correspond to the signal levels for the upper photoelectric conversion units PD — ₁ and PD — 3 in the pixels 200 of each column by charge transfer at Vtx — ₁ . ₃ , 1 ₄ , 3 ₅ , 1 ₆ ,..., 3 _(2n−1) , 1 _2n ”are output simultaneously.

The difference between the dark signal and the signal signal output from each vertical signal line 300 as described above becomes the output signal of each photoelectric conversion unit PD_1 and PD_3 in the pixel 200. Therefore, in the plurality of pixels 200 arranged in the same pixel row, the output signals of the photoelectric conversion units PD_1 and PD_3 arranged in the horizontal direction have temporal synchronism.
Note that the correlated double sampling (CDS) operation for obtaining the difference between the dark signal and the signal signal may be performed by a subsequent circuit in the sensor chip of the image sensor 101 or by a subsequent circuit outside the sensor chip. Also good.

After the signal level is settled, the drive control unit 102a resets the potential of the second floating diffusion FD in the same manner as the pixel 200 in the first region R1. When a predetermined settling time elapses, the dark signals “Dark — 4 ₁ , dark signals for the lower photoelectric conversion units PD — 2 and PD — 4 in the pixels 200 of each column are reset to the vertical signal lines 300 _{1 to} 300 _{2 n} . 2 ₂ , 4 ₃ , 2 ₄ , 4 ₅ , 2 ₆ ,..., 4 _(2n−1) , 2 _2n ”are output simultaneously.

After the dark level is settled, the drive control unit 102a switches Vtx_2 to the high level and turns on the transfer transistors TX2 ₁ and TX2 ₂ . In the High level period of the Vtx_2, the signal charges accumulated in the photoelectric conversion unit PD_4 pixels 200 are transferred to the floating diffusion FD _1, signal charges accumulated in the photoelectric conversion unit PD_2 are transferred to the floating diffusion FD _2. The drive control unit 102a switches Vtx_2 to the Low level and turns off the transfer transistors TX2 ₁ and TX2 ₂ . Thereafter, the potential level of the floating diffusion FD is stabilized at a predetermined stabilization time, and becomes a signal level by reading Vtx_2. In each of the vertical signal lines 300 _{1 to} 300 _2n , signal signals “Sig — 4 ₁ , 2 ₂ , 4 ₃ , 2 ₄ for the lower photoelectric conversion units PD — ₂ and PD — 4 in the pixels 200 of each column by charge transfer at Vtx — ₂ are provided. , 4 ₅ , 2 ₆ ,..., 4 _(2n−1) , 2 _2n ”are output.

The difference between the dark signal and the signal signal output from each vertical signal line 300 becomes the output signal of each photoelectric conversion unit PD_2 and PD_4 in the pixel 200. Therefore, in the plurality of pixels 200 arranged in the same pixel row, the output signals of the photoelectric conversion units PD_2 and PD_4 arranged in the horizontal direction have temporal synchronism.
Note that the correlated double sampling (CDS) operation for obtaining the difference between the dark signal and the signal signal may be performed by a subsequent circuit in the sensor chip of the image sensor 101 or by a subsequent circuit outside the sensor chip. Also good.

  Note that the drive control unit 102a outputs drive signals for the pixels 200 in the second region R2 so that output signals are output from the photoelectric conversion units PD_2 and PD_4 after output signals are output from the photoelectric conversion units PD_1 and PD_3. Although controlled, it is not limited to this example. The drive control unit 102a controls the drive timing to output the output signals from the photoelectric conversion units PD_1 and PD_3 after outputting the output signals from the photoelectric conversion units PD_2 and PD_4 for the pixels 200 in the second region R2. Also good.

(Focus detection)
The focus detection unit 102b uses the output signal read out as described above as a focus detection signal, and performs focus detection calculation by a known image plane phase difference method. In this case, the focus detection unit 102b generates a signal sequence using a plurality of output signals having temporal synchronization. For example, the focus detection unit 102b generates the first signal sequence {an} using the output signal from the photoelectric conversion unit PD_1 in each column, and uses the output signal from the photoelectric conversion unit PD_3 in each column to generate the second signal. A sequence {bn} is generated. The focus detection unit 102b detects a focus adjustment state of the interchangeable lens 110, that is, a defocus amount, by detecting a relative image shift amount between the generated first signal sequence {an} and the second signal sequence {bn}. To do. Note that the focus detection unit 102b generates a first signal sequence {cn} using the output signal from the photoelectric conversion unit PD_4 in each column, and generates a second signal using the output signal from the photoelectric conversion unit PD_2 in each column. A sequence {dn} may be generated.

  The focus detection unit 102b outputs signals from the pair of photoelectric conversion units PD_1 and PD_3 or the photoelectric conversion units PD_2 and PD_4 that are less affected by vignetting among the output signals from the pixels 200 arranged in the periphery of the image sensor 101. An output signal may be selected and used as a focus detection signal. In addition, when the focus detection unit 102b generates the pair of signal sequences {an}, {bn} or the pair of signal sequences {cn}, {dn}, the output from the pixel 200 in which the same color filter is arranged. Is used. For example, when the focus detection calculation is performed using the output signal from the pixel 200 arranged in the first row as shown in FIG. 2, the focus detection unit 102b includes a G color filter as an example. The output signals from the pixels 200 in the first column, the third column,... Are used.

  As described above, for the output signals from the plurality of pixels 200 provided in the first region R1, the focus detection unit 102b generates a pair of signal sequences along the vertical direction, and the image shift between the signal sequences. The defocus amount is calculated by detecting the amount. For the output signals from the plurality of pixels 200 provided in the second region R2, the focus detection unit 102b generates a pair of signal sequences along the horizontal direction and detects an image shift amount between the signal sequences. To calculate the defocus amount. Therefore, in the image sensor 101 including the pixels 200 having the same circuit configuration, the detection of the vertical image shift and the horizontal image shift of the subject image are performed using the output signal of the same frame. be able to.

-Image generation for shooting-
When performing a shooting operation in response to the user's full-press operation of the shutter button, the image processing unit 102c uses the output signal read out as described above as an image signal. In this case, the image processing unit 102c adds the output signals output from the photoelectric conversion units PD_1, PD_2, PD_3, and PD_4 for each pixel 200 to generate an image signal. The image processing unit 102c performs various types of image processing on the image signal to generate image data for shooting.

(Comparative example)
8 and 9 show the configuration of the pixel 500 in the comparative example, and FIGS. 10 and 11 show the configuration of the pixel 501 in the comparative example. 8 and 10 are diagrams for explaining a schematic configuration of the pixels 500 and 501 in the comparative example. Note that in FIGS. 8 and 10, transistors used for reading are omitted in order to easily understand the connection between the pixels 500 and 501 and the vertical signal lines 600 (600 ₁ and 600 ₂ ). 8 and 10 show some of the pixels 500 and 501 in the first column among the plurality of pixel columns. FIGS. 9 and 11 are diagrams showing details of FIGS. 8 and 10, respectively, and show connections at the transistor level. In each of the pixels 500 and 501, four photoelectric conversion units PD ′ (PD′_1, PD′_2, PD′_3, and PD′_4) are arranged in two rows and two columns.

In the pixel 500, the photoelectric conversion unit PD'_1 arranged vertically, the output signal from the PD'_4 is read out to the vertical signal lines 600 ₁ pixel 500, the photoelectric conversion unit PD'_2 arranged vertically, the output signal from the PD'_3 is read to the vertical signal line 600 _2. That is, output from the photoelectric conversion units PD′_1 and PD′_4 through the reset transistor RST ′ ₁ , the amplification transistor SF ′ ₁ , the selection transistor SEL ′ ₁ , and the floating diffusion FD ′ ₁ that are provided in common to both. The signal is read out. Output signals are output from the photoelectric conversion units PD′_2 and PD′_3 through the reset transistor RST ′ ₂ , the amplification transistor SF ′ ₂ , the selection transistor SEL ′ ₂ , and the floating diffusion FD ′ ₂ provided in common to both the photoelectric conversion units PD′_2 and PD′_3. Read out. Therefore, in the pixel 500, the output signals from the photoelectric conversion units PD′_1 and PD′_3 have temporal simultaneity, and the output signals from the photoelectric conversion units PD′_2 and PD′_4 have temporal simultaneity. Have

In the pixel 501, the photoelectric conversion unit PD'_1 arranged horizontally, the output signal from the PD'_3 is read out to the vertical signal lines 600 ₁ pixel 501, the photoelectric conversion unit PD'_2 arranged horizontally, the output signal from the PD'_4 is read to the vertical signal line 600 _2. That is, output from the photoelectric conversion units PD′_1 and PD′_3 through the reset transistor RST ′ ₁ , the amplification transistor SF ′ ₁ , the selection transistor SEL ′ ₁ , and the floating diffusion FD ′ ₁ provided in common to both the photoelectric conversion units PD′_1 and PD′_3. The signal is read out. Output signals are output from the photoelectric conversion units PD′_2 and PD′_4 via the reset transistor RST ′ ₂ , the amplification transistor SF ′ ₂ , the selection transistor SEL ′ ₂ , and the floating diffusion FD ′ ₂ provided in common to both the photoelectric conversion units PD′_2 and PD′_4. Read out. Therefore, in the pixel 501, output signals from the photoelectric conversion units PD′_1 and PD′_4 have temporal synchronism, and output signals from the photoelectric conversion units PD′_2 and PD′_3 have temporal synchronicity. Have

  As described above, the pixel 500 obtains an output signal having temporal synchronism in the horizontal direction, and the pixel 501 obtains an output signal having temporal synchrony in the vertical direction. However, the circuit configurations of the pixel 500 and the pixel 501 are different from each other.

According to the first embodiment described above, the following operational effects are obtained.
(1) The pixel 200 includes two photoelectric conversion units PD arranged in the row direction and the column direction, and two floating diffusions FD. In the four photoelectric conversion units PD, photoelectric conversion units PD_1 and PD_3 are sequentially arranged in the row direction, photoelectric conversion units PD_1 and PD_4 are sequentially arranged in the column direction, and photoelectric conversion units PD_3 and PD_2 are sequentially arranged in the column direction. The Charge generated by the photoelectric conversion unit PD_1 and the photoelectric conversion unit PD_2 is transferred to the floating diffusion FD _2, charge generated by the photoelectric conversion unit PD_3 and the photoelectric conversion unit PD_4 is floating diffusion FD ₁ transfer. Therefore, the number of transistors required for one pixel can be reduced from 16 to 10 as compared with the conventional technique in which a floating diffusion is provided for each of the four photoelectric conversion units. For this reason, the area of each light-receiving surface of the photoelectric conversion part PD of this Embodiment can be enlarged compared with the area of the light-receiving surface of the photoelectric conversion part of said prior art. That is, in this embodiment, it is possible to suppress the adverse effect on the imaging characteristics due to the decrease in the number of saturated electrons accompanying the decrease in the area of the light receiving surface and the saturation output decrease associated therewith. Thereby, for example, when the output from the pixel 200 is used for focus detection, it is possible to prevent a decrease in focus detection accuracy.

(2) The pixel 200 includes two photoelectric conversion units PD arranged in the row direction and the column direction, and a vertical signal line 300 from which a signal based on the charge of the photoelectric conversion unit PD is output. In the four photoelectric conversion units PD, photoelectric conversion units PD_1 and PD_3 are sequentially arranged in the row direction, photoelectric conversion units PD_1 and PD_4 are sequentially arranged in the column direction, and photoelectric conversion units PD_3 and PD_2 are sequentially arranged in the column direction. The Signal by generated electric charges in the photoelectric conversion unit PD_1 and the photoelectric conversion unit PD_2 is output to the vertical signal line 300 _2, signals by the generated electric charges in the photoelectric conversion unit PD_3 and the photoelectric conversion unit PD_4 is output to the vertical signal lines 300 ₁ Is done. Therefore, since the number of components required for one pixel can be reduced, the area of each light receiving surface of the photoelectric conversion unit PD is made larger than the area of the light receiving surface of the above-described conventional photoelectric conversion unit. be able to. That is, similarly to the above effect (1), it is possible to suppress the adverse effect on the imaging characteristics due to the decrease in the number of saturated electrons accompanying the decrease in the area of the light receiving surface and the accompanying decrease in the saturated output.

(3) The transfer of charge from the photoelectric conversion unit PD_1 and the transfer of charge from the photoelectric conversion unit PD_2 are alternatively performed, and the transfer of charge from the photoelectric conversion unit PD_3 and the charge from the photoelectric conversion unit PD_4 are performed. Is transferred alternatively. Furthermore, it becomes possible to output an output signal having temporal synchronism in the horizontal direction or an output signal having temporal synchronism in the vertical direction from the pixels 200 having the same circuit configuration. Therefore, unlike the case of using the pixels 500 and 501 as in the comparative example, a circuit configuration between an output signal having temporal synchronism in the horizontal direction and an output signal having temporal synchronism in the vertical direction. It is possible to prevent an output signal corresponding to a different capacitance due to the difference.

(4) for the pixel 200 in the first region R1, via the control line 210 to control pulse Vtx_1 is supplied, the transfer of charges in the photoelectric conversion unit PD_1 by the transfer transistor TX1 _2, photoelectric by the transfer transistor TX2 ₁ The charge transfer of the conversion unit PD_4 is performed at the same time. Via control line 220 to control pulse Vtx_2 is supplied, the transfer of charges in the photoelectric conversion unit PD_3 by the transfer transistor TX1 _1, the transfer of charges in the photoelectric conversion unit PD_2 by the transfer transistor TX2 ₂ are performed simultaneously.
For pixel 200 of the second region R2, via a control line 210 to control pulse Vtx_1 is supplied, the transfer of charges in the photoelectric conversion unit PD_1 by the transfer transistor TX1 _2, the photoelectric conversion unit by the transfer transistor TX1 ₁ Pd_3 The charge transfer is simultaneously performed. Via control line 220 to control pulse Vtx_2 is supplied, the transfer of charges in the photoelectric conversion unit PD_4 by the transfer transistor TX2 _1, the transfer of charges in the photoelectric conversion unit PD_2 by the transfer transistor TX2 ₂ are performed simultaneously. Therefore, unlike the comparative example, from the pixel 200 having the same circuit configuration for reading a signal, the photoelectric conversion unit PD arranged in the vertical direction or the photoelectric conversion unit PD arranged in the horizontal direction at the same timing. The output signal can be read out.

(5) The control lines 210 and 220 are provided in common for the pixel column composed of the plurality of pixels 200, and the control line 210 is connected to the transfer transistors TX1 ₂ and TX2 ₁ for the pixels 200 in the first region R1. The control line 220 is connected to the transfer transistors TX1 ₁ and TX2 ₂ . For the pixel 200 in the second region R2, the control line 210 is connected to the transfer transistors TX1 ₂ and TX1 ₁ , and the control line 220 is connected to the transfer transistors TX2 ₁ and TX2 ₂ . Therefore, the pixel 200 is included in either the first region R1 or the second region R2 by making the transfer transistors TX1, TX2 connected to the local control lines 211, 221 and 251 to 254 from the control lines 210, 220 different. Can be made. That is, the degree of freedom of arrangement of the first region R1 and the second region R2 can be improved.

-Second Embodiment-
A second embodiment of the present invention will be described with reference to the drawings. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and different points will be mainly described. Points that are not particularly described are the same as those in the first embodiment. In this embodiment, the connection of the local control line connecting the control line and the transfer transistor of the pixel is different from that of the first embodiment.

FIG. 12 is a circuit diagram showing connection at the transistor level of each pixel 200 of the image sensor 101 in the second embodiment, and is a diagram showing FIG. 2 in detail.
The gate of the transfer transistor TX1 ₂ connected to the photoelectric conversion unit PD_1 pixel 200 is connected to the control line 210 to control pulse Vtx_1 by the local control line 261 is supplied. The gate of the transfer transistor TX1 ₁ connected to the photoelectric conversion unit PD_3 is connected to the control line 220 to control pulse Vtx_2 by the local control line 262 is supplied. Transfer transistors TX2 ₁ gate connected to the photoelectric conversion unit PD_4 is connected to the control line 230 to control pulse Vtx_3 by the local control line 263 is supplied. The gate of the transfer transistor TX2 ₂ connected to the photoelectric conversion unit PD_2 is connected to the control line 240 to control pulse Vtx_4 by the local control line 264 is supplied. That is, for each of the four photoelectric conversion units PD of the pixel 200, the transfer transistors TX1 and TX2 are controlled by the control pulses Vtx_1, Vtx_2, Vtx_3, and Vtx_4, respectively. Other configurations are the same as those of the pixel 200 according to the first embodiment.

(Reading output signal)
With reference to the timing charts shown in FIGS. 13 and 14, control when an output signal is read from the pixel 200 of the image sensor 101 of the present embodiment will be described. FIG. 13 shows a case where an output signal having temporal simultaneity in the vertical direction is read from the photoelectric conversion unit PD (first control), and FIG. 14 shows temporal simultaneity in the horizontal direction from the photoelectric conversion unit PD. The case where the output signal which has is read (2nd control) is shown. In Figure 13, 14, Vtx_1 shows a control pulse of the transfer transistor TX1 ₂ corresponding to the photoelectric conversion unit PD_1 of pixels 200. Vtx_2 shows a control pulse of the transfer transistor TX1 ₁ corresponding to the photoelectric conversion unit Pd_3. Vtx_3 shows a control pulse of the transfer transistor TX2 ₁ corresponding to the photoelectric conversion unit PD_4. Vtx_4 shows a control pulse of the transfer transistor TX2 ₂ corresponding to the photoelectric conversion unit PD_2.

First, the first control for reading out an output signal having temporal synchronism in the vertical direction from the photoelectric conversion unit PD will be described. In the following description, the difference from the drive timing at the time of reading the output signal from the pixel 200 arranged in the first region R1 in the first embodiment is mainly performed.
As shown in FIG. 13, the drive control unit 102a resets the potential of the first floating diffusion FD in the same manner as in the first embodiment. When a predetermined settling time elapses, the dark signals “Dark — 4 ₁ , 1 for the left photoelectric conversion units PD — ₁ and PD — ₄ in the pixels 200 of each column are reset to the vertical signal lines 300 _{1 to} 300 _{2 n} by the first reset. ₂ , 4 ₃ , 1 ₄ , 4 ₅ , 1 ₆ ,..., 4 _(2n−1) , 1 _2n ”are output simultaneously.

The drive control unit 102a switches Vtx_1 and Vtx_3 to High level at the same timing, and turns on the transfer transistors TX1 ₂ and TX2 ₁ connected to the photoelectric conversion units PD_1 and PD_4 on the left side of the pixel 200. In the High level period of the Vtx_1, the signal charges accumulated in the photoelectric conversion unit PD_1 pixels 200 are transferred to the floating diffusion FD _2, the High level period of Vtx_3, the signal charge accumulated in the photoelectric conversion unit PD_4 floating diffusion FD ₁ is transferred. The drive control unit 102a switches Vtx_1 and Vtx_3 to the Low level at the same timing, and turns off the transfer transistors TX1 ₂ and TX2 ₁ . Thereafter, the potential level of the floating diffusion FD is stabilized at a predetermined stabilization time, and becomes a signal level by reading Vtx_1 and Vtx_3. The vertical signal lines 300 _{1 to} 300 _2n include signal signals “Sig — 4 ₁ , 1 ₂ , 4 ₃ , 1 ₄ , 4 ₅ , 1 ₆ , left-side photoelectric conversion units PD_1 and PD_4 in the pixels 200 of each column. ..., 4 _(2n-1) , _12n "are output.

  The difference between the dark signal and the signal signal output from each vertical signal line 300 becomes the output signal of each photoelectric conversion unit PD_1, PD_4 in the pixel 200. Therefore, in the plurality of pixels 200 arranged in the same pixel row, the output signals of the photoelectric conversion units PD_1 and PD_4 arranged in the vertical direction have temporal synchronism.

After the signal level is settled, the drive control unit 102a resets the potential of the second floating diffusion FD in the same manner as in the first embodiment. When a predetermined settling time elapses, the dark signals “Dark — 3 ₁ , 2 for the right photoelectric conversion units PD — 2 and PD — 3 in the pixels 200 of each column are reset to the vertical signal lines 300 _{1 to} 300 _{2 n} by the second reset. ₂ , 3 ₃ , 2 ₄ , 3 ₅ , 2 ₆ ,..., 3 _(2n−1) , 2 _2n ”are output simultaneously.

After the dark level is settled, the drive control unit 102a switches Vtx_2 and Vtx_4 to the high level at the same timing to turn on the transfer transistors TX1 ₁ and TX2 ₂ . In the High level period of the Vtx_2, the signal charges accumulated in the photoelectric conversion unit PD_3 pixels 200 are transferred to the floating diffusion FD _1, the High level period of Vtx_4, the signal charge accumulated in the photoelectric conversion unit PD_2 floating diffusion FD ₂ is transferred. The drive control unit 102a switches Vtx_2 and Vtx_4 to the low level at the same timing to turn off the transfer transistors TX1 ₁ and TX2 ₂ . Thereafter, the potential level of the floating diffusion FD is stabilized at a predetermined stabilization time, and becomes a signal level by reading Vtx_2 and Vtx_4. The vertical signal lines 300 _{1 to} 300 _2n include signal signals “Sig — 3 ₁ , 2 ₂ , 3 ₃ , 2 ₄ , 3 ₅ , 2 ₆ , for the photoelectric conversion units PD_2 and PD_3 on the right side in the pixels 200 of each column. ... 3 _(2n-1) , 2 _2n "is output.

  Thus, the difference between the dark signal and the signal signal output from each vertical signal line 300 becomes the output signal of each photoelectric conversion unit PD_2 and PD_3 in the pixel 200. Therefore, in the plurality of pixels 200 arranged in the same pixel row, output signals of the photoelectric conversion units PD_2 and PD_3 arranged in the vertical direction have temporal synchronism.

Next, the second control for reading an output signal having temporal synchronism in the horizontal direction from the photoelectric conversion unit PD will be described. In the following description, the difference from the drive timing at the time of reading the output signal from the pixel 200 arranged in the second region R2 in the first embodiment is mainly performed.
As shown in FIG. 14, the drive control unit 102a resets the potential of the first floating diffusion FD in the same manner as in the first embodiment. When a predetermined settling time elapses, the dark signals “Dark — 3 ₁ , 1 for the upper photoelectric conversion units PD — ₁ and PD — ₃ in the pixels 200 of each column are reset to the vertical signal lines 300 _{1 to} 300 _{2 n} by the first reset. ₂ , 3 ₃ , 1 ₄ , 3 ₅ , 1 ₆ ,..., 3 _(2n−1) , 1 _2n ”are output simultaneously.

The drive control unit 102a switches Vtx_1 and Vtx_2 to the high level at the same timing to turn on the transfer transistors TX1 ₂ and TX1 ₁ . In the High level period of the Vtx_1, the signal charges accumulated in the photoelectric conversion unit PD_1 pixels 200 are transferred to the floating diffusion FD _2, the High level period of Vtx_2, the signal charge accumulated in the photoelectric conversion unit PD_3 floating diffusion FD ₁ is transferred. The drive control unit 102a switches Vtx_1 and Vtx_2 to the Low level at the same timing to turn off the transfer transistors TX1 ₂ and TX1 ₁ . Thereafter, the potential level of the floating diffusion FD is stabilized at a predetermined stabilization time, and becomes a signal level by reading Vtx_1 and Vtx_2. The vertical signal lines 300 _{1 to} 300 _2n include signal signals “Sig — 3 ₁ , 1 ₂ , 3 ₃ , 1 ₄ , 3 ₅ , 1 ₆ , for the upper photoelectric conversion units PD_1 and PD_3 in the pixels 200 of each column. .., 3 _(2n-1) , _12n "are output.

  Thus, the difference between the dark signal and the signal signal output from each vertical signal line 300 becomes the output signal of each photoelectric conversion unit PD_1, PD_3 in the pixel 200. Therefore, in the plurality of pixels 200 arranged in the same pixel row, the output signals of the photoelectric conversion units PD_1 and PD_3 arranged in the horizontal direction have temporal synchronism.

After the signal level is settled, the drive control unit 102a resets the potential of the second floating diffusion FD in the same manner as in the first embodiment. When a predetermined settling time elapses, the dark signals “Dark — 4 ₁ , dark signals for the lower photoelectric conversion units PD — 2 and PD — 4 in the pixels 200 of each column are reset to the vertical signal lines 300 _{1 to} 300 _{2 n} . 2 ₂ , 4 ₃ , 2 ₄ , 4 ₅ , 2 ₆ ,..., 4 _(2n−1) , 2 _2n ”are output simultaneously.

After the dark level is settled, the drive control unit 102a switches Vtx_3 and Vtx_4 to the high level at the same timing to turn on the transfer transistors TX2 ₁ and TX2 ₂ . In the High level period of the Vtx_3, the signal charges accumulated in the photoelectric conversion unit PD_4 pixels 200 are transferred to the floating diffusion FD _1, the High level period of Vtx_4, the signal charge accumulated in the photoelectric conversion unit PD_2 floating diffusion FD ₂ is transferred. The drive control unit 102a switches Vtx_3 and Vtx_4 to the Low level at the same timing to turn off the transfer transistors TX2 ₁ and TX2 ₂ . Thereafter, the potential level of the floating diffusion FD is stabilized at a predetermined stabilization time, and becomes a signal level by reading Vtx_3 and Vtx_4. In each of the vertical signal lines 300 _{1 to} 300 _2n , signal signals “Sig — 4 ₁ , 2 ₂ , 4 ₃ , 2 ₄ , 4 ₅ , 2 ₆ for the lower photoelectric conversion units PD_2 and PD_4 in the pixels 200 of each column are provided. ,..., 4 _(2n−1) , 2 _2n ”are output.

  Thus, the difference between the dark signal and the signal signal output from each vertical signal line 300 becomes the output signal of each photoelectric conversion unit PD_2 and PD_4 in the pixel 200. Therefore, in the plurality of pixels 200 arranged in the same pixel row, the output signals of the photoelectric conversion units PD_2 and PD_4 arranged in the horizontal direction have temporal synchronism.

According to the second embodiment described above, in addition to the function and effect (1) obtained in the first embodiment, the following function and effect can be obtained.
The control lines 210, 220, 230, and 240 are provided in common for a pixel column that includes a plurality of pixels 200 arranged in the row direction. The transfer transistors TX1 ₁ , TX1 ₂ , TX2 ₁ , TX2 ₂ are connected to control lines 220, 210, 230, 240 via local control lines 262, 261, 263, 264, respectively. The drive controller 102a simultaneously turns on the transfer transistors TX1 ₂ and TX2 ₁ via the control lines 210 and 230, and simultaneously turns on the transfer transistors TX1 ₁ and TX2 ₂ via the control lines 220 and 240. 1 control is performed. The drive controller 102a simultaneously turns on the transfer transistors TX1 ₂ and TX1 ₁ via the control lines 210 and 220, and simultaneously turns on the transfer transistors TX2 ₁ and TX2 ₂ via the control lines 230 and 240. 2 Control is performed. An output signal having temporal synchronism in the horizontal direction can be output to the pixels 200 having the same circuit configuration including the connection of the local control lines 261 to 264 only by changing the control pulse in the vertical direction. It is also possible to output an output signal having simultaneity.

The following modifications are also within the scope of the present invention, and one or a plurality of modifications can be combined with the above-described embodiment.
(1) The present invention is not limited to one in which four photoelectric conversion units PD are arranged in one pixel 200. For example, a photoelectric conversion unit PD of 2 rows and 2 columns is set as one set, two sets of photoelectric conversion units PD are arranged in the vertical direction, and a photoelectric conversion unit PD of 4 rows and 2 columns is provided in one pixel 200, or 2 A pair of photoelectric conversion units PD may be arranged in the horizontal direction, and the two rows by four columns of photoelectric conversion units PD may be provided in one pixel 200.

(2) The pixel 200 in which the plurality of photoelectric conversion units PD are arranged is not limited to the one provided in the entire area of the image sensor 101. The pixel 200 may be provided in a partial area of the image sensor 101, and a pixel provided with one photoelectric conversion unit may be provided in another area. In this case, for example, the pixel 200 can be provided at a position where the G color filter is provided. In addition, when the pixel 200 is provided in a partial region of the imaging element 101, the color filter may not be provided in the pixel 200. In this case, when the image data for photographing is generated, the image signal at the position of the pixel 200 may be generated by interpolating with the image signal from the pixels arranged around the pixel 200.

  As long as the characteristics of the present invention are not impaired, the present invention is not limited to the above-described embodiments, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

DESCRIPTION OF SYMBOLS 1 ... Digital camera, 2 ... Focus detection apparatus, 101 ... Image sensor,
102 ... Body control device, 102a ... Drive control unit, 102b ... Focus detection unit,
102c: Image processing unit, 200: Pixel, 300: Vertical signal line,
210, 220, 230, 240 ... control lines,
211, 221 251 252 253 254 261 262 263 264 local control lines,
FD: Floating diffusion, TX1, TX2: Transfer transistor,
PD: photoelectric conversion unit, RST: reset transistor

Claims (9)

Four photoelectric conversion units arranged in two in a second direction intersecting the first direction and the first direction;
First and second charge holding units to which charges of the photoelectric conversion unit are transferred,
The four photoelectric conversion units include a first photoelectric conversion unit and a second photoelectric conversion unit that are sequentially arranged in the first direction, and a first photoelectric conversion unit and a third that are sequentially arranged in the second direction. A photoelectric conversion unit, the second photoelectric conversion unit and the fourth photoelectric conversion unit arranged in order in the second direction,
The charges generated by the first photoelectric conversion unit and the fourth photoelectric conversion unit are transferred to the first charge holding unit, and the charges generated by the second photoelectric conversion unit and the third photoelectric conversion unit are An image sensor transferred to the second charge holding unit. Four photoelectric conversion units arranged in two in a second direction intersecting the first direction and the first direction;
A first signal line and a second signal line for outputting a signal based on charges of the photoelectric conversion unit;
The four photoelectric conversion units include a first photoelectric conversion unit and a second photoelectric conversion unit that are sequentially arranged in the first direction, and a first photoelectric conversion unit and a third that are sequentially arranged in the second direction. A photoelectric conversion unit, the second photoelectric conversion unit and the fourth photoelectric conversion unit arranged in order in the second direction,
The signal generated by the charges generated by the first photoelectric conversion unit and the fourth photoelectric conversion unit is output to the first signal line, and is generated by the second photoelectric conversion unit and the third photoelectric conversion unit. The image sensor in which the signal due to electric charge is output to the second signal line. The image sensor according to claim 1 or 2,
The charge transfer of the first photoelectric conversion unit and the charge transfer of the fourth photoelectric conversion unit are alternatively performed, the charge transfer of the second photoelectric conversion unit, and the third photoelectric conversion unit An image sensor in which the charge transfer is performed alternatively. The imaging device according to claim 3,
A plurality of pixels having the four photoelectric conversion units,
The plurality of pixels include first and second pixel groups disposed in first and second regions of the imaging surface, respectively.
For the first pixel group, the charge transfer of the first photoelectric conversion unit and the charge transfer of the third photoelectric conversion unit are performed simultaneously, and the charge transfer of the second photoelectric conversion unit The charge transfer of the fourth photoelectric conversion unit is performed simultaneously,
For the second pixel group, the transfer of the charge of the first photoelectric conversion unit and the transfer of the charge of the second photoelectric conversion unit are performed simultaneously, and the transfer of the charge of the third photoelectric conversion unit An image sensor in which charge transfer of the fourth photoelectric conversion unit is performed simultaneously. The imaging device according to claim 4,
First to fourth charge transfer units respectively transferring charges from the first to fourth photoelectric conversion units;
First and second control lines common to a plurality of pixels provided in the first direction for the first pixel group;
A third control line common to the plurality of pixels provided in the first direction with respect to the second pixel group, and a fourth control line;
The first control line is connected to the first and third charge transfer units of each of the plurality of pixels provided in the first direction,
The second control line is connected to the second and fourth charge transfer units of each of the plurality of pixels provided in the first direction,
The third control line is connected to the first and second charge transfer units of each of the plurality of pixels provided in the first direction;
The imaging device, wherein the fourth control line is connected to the third and fourth charge transfer units of each of the plurality of pixels provided in the first direction. The imaging device according to claim 4,
First to fourth charge transfer units respectively transferring charges from the first to fourth photoelectric conversion units;
The first and second pixel groups having first to fourth control lines common to a plurality of pixels provided in the first direction;
The first control line is connected to the first charge transfer unit of each of the plurality of pixels provided in the first direction,
The second control line is connected to the second charge transfer unit of each of the plurality of pixels provided in the first direction,
The third control line is connected to the third charge transfer unit of each of the plurality of pixels provided in the first direction,
The fourth control line is connected to the fourth charge transfer unit of each of the plurality of pixels provided in the first direction,
For the first pixel group, the first charge transfer unit and the third charge transfer unit are simultaneously controlled to be turned ON via the first control line. In addition, the second charge transfer unit and the fourth charge transfer unit are simultaneously controlled to be turned ON via the second control line,
For the second pixel group, the first charge transfer unit and the second charge transfer unit are simultaneously controlled to be turned ON via the first control line. In addition, the imaging element in which the third charge transfer unit and the fourth charge transfer unit are simultaneously ON-controlled via the third control line. The imaging device according to any one of claims 1 to 6,
The four photoelectric conversion units receive the four light beams that have passed through the four regions of the pupil of the optical system, and generate electric charges. The image sensor according to any one of claims 1 to 7,
A control unit for controlling transfer of charges from the four photoelectric conversion units;
Out of the four photoelectric conversion units, the phase difference focus is based on the signals generated by the photoelectric conversion units sequentially arranged in the first direction or the photoelectric conversion units sequentially arranged in the second direction. And a focus detection unit that performs detection. A focus detection apparatus according to claim 8;
An imaging device comprising: an image generation unit configured to generate image data based on charges of the first and second photoelectric conversion units and charges of the third and fourth photoelectric conversion units.

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