JP2017098513A - Imaging device, imaging apparatus, and focusing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce costs for an imaging device.SOLUTION: The imaging device comprises: a first imaging unit including first and second photoelectric conversion portions that respectively photoelectrically converts first and second color components of light by using photoelectrically converting films; and a second imaging unit that includes a third photoelectric conversion portion that receives and photoelectrically converts transmitted light through the first photoelectric conversion portion by using a photoelectrically converting film and a fourth photoelectric conversion unit that receives and photoelectrically converts transmitted light through the second photoelectric conversion portion by using a photoelectrically converting film.SELECTED DRAWING: Figure 4

Description

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

An imaging device including a first photoelectric conversion unit made of an organic photoelectric conversion film stacked on a semiconductor substrate and a second photoelectric conversion unit made of a photodiode formed on the semiconductor substrate is known (Patent Document 1). reference).
In the conventional imaging device, the space between the first photoelectric conversion unit and the second photoelectric conversion unit is increased due to the structural reason, and subject light is incident obliquely on the imaging surface.

JP 2009-130239 A

The imaging element uses a first imaging unit having first and second photoelectric conversion units that photoelectrically convert light of the first and second color components using a film that performs photoelectric conversion, and a film that performs photoelectric conversion. A third photoelectric conversion unit that receives and transmits photoelectrically transmitted light that has passed through the first photoelectric conversion unit, and receives transmitted light that has passed through the second photoelectric conversion unit using a photoelectric conversion film. And a second imaging unit having a fourth photoelectric conversion unit that performs photoelectric conversion.
An image pickup apparatus generates first image data by using the image pickup device according to any one of claims 1 to 9 and a photoelectric conversion signal output from the first image pickup unit. And a second image data generation unit that generates second image data by a photoelectric conversion signal output from the second imaging unit.
The imaging device includes a first imaging unit that receives incident light, and a second imaging unit that receives transmitted light that has passed through the first imaging unit, and the first imaging unit performs photoelectric conversion. A first pixel having first and second photoelectric conversion units arranged in a first direction, each of which photoelectrically converts the incident light using a film, and the second imaging unit performs photoelectric conversion A second pixel having third and fourth photoelectric conversion units arranged in a second direction different from the first direction, each of which photoelectrically converts the transmitted light using a film.
A focus adjustment device is a first phase-difference focus that performs focus detection of an imaging optical system based on the image sensor according to claim 11 and the first signal from the first and second photoelectric conversion units. A detection unit; a second phase difference type focus detection unit that performs focus detection of the imaging optical system based on second signals from the third and fourth photoelectric conversion units; and the first phase difference type focus. A focus adjustment unit that performs focus adjustment based on a focus detection result in the detection unit and a focus detection result in the second phase difference type focus detection unit.
An imaging apparatus detects a focus of an imaging optical system based on the imaging element according to claim 11 or 12, a first signal from the first photoelectric conversion unit, and a second signal from the second photoelectric conversion unit. The focus detection of the imaging optical system is performed based on the first phase difference type focus detection unit that performs the third phase, the third signal from the third photoelectric conversion unit, and the fourth signal from the fourth photoelectric conversion unit. Focus adjustment is performed based on the focus detection result in the second phase difference type focus detection unit, the focus detection result in the first phase difference type focus detection unit, and the focus detection result in the second phase difference type focus detection unit. A focus adjustment unit to perform, and an image signal generation unit that adds the first signal and the second signal and / or adds the third signal and the fourth signal to generate an image signal; .

It is a figure which illustrates the structure of the digital camera by 1st Embodiment. It is a figure which shows the outline | summary of the 1st and 2nd imaging part. (A) is a figure which shows arrangement | positioning of the pixel of 10 rows x 6 columns which are a part of 1st imaging part, (b) is a pixel of 10 rows x 6 columns which is a part of 2nd imaging part. It is a figure which shows arrangement | positioning. It is sectional drawing which shows the structure of 1 pixel of a 1st and 2nd imaging part. It is a figure which illustrates the signal read-out circuit structure of one pixel in the 1st and 2nd imaging part. It is the figure which showed typically each transistor formed in a semiconductor substrate. It is the figure which showed the readout circuit of the photoelectric conversion signal of the photoelectric conversion part of each pixel of the 1st and 2nd imaging part. It is sectional drawing which shows the structure of 1 pixel of the 1st and 2nd imaging part which concerns on 2nd Embodiment. It is a figure which illustrates the structure of the digital camera by 3rd Embodiment. (A) is a figure which shows arrangement | positioning of the pixel of 10 rows x 6 columns which are a part of 1st imaging part, (b) is a pixel of 10 rows x 6 columns which is a part of 2nd imaging part. It is a figure which shows arrangement | positioning. It is sectional drawing which shows the structure of 1 pixel of a 1st and 2nd imaging part. It is a figure which shows arrangement | positioning of the 1st and 2nd partial electrode when a pixel is seen from a to-be-photographed object side. It is a figure which illustrates the signal read-out circuit structure of one pixel in a 1st imaging part. It is the figure which simplified and showed the reading circuit of the photoelectric conversion signal of the 1st and 2nd photoelectric conversion part of each pixel of a 1st imaging part. It is the figure which simplified and showed the reading circuit of the photoelectric conversion signal of the 1st and 2nd photoelectric conversion part of each pixel of a 2nd imaging part. FIG. 10 is a block diagram illustrating in detail functions performed by the focus detection unit illustrated in FIG. 9. It is a flowchart showing the focus detection operation | movement in 3rd Embodiment. It is a block diagram which shows the modification of the signal read-out circuit regarding 3rd Embodiment.

--- First embodiment ---
FIG. 1 is a diagram illustrating a configuration of a digital camera 1 according to the first embodiment. The digital camera 1 includes a photographing optical system 10, an image sensor 11, an amplification circuit 23, an AD conversion circuit 24, a control unit 12, an operation unit 13, an image processing unit 14, a liquid crystal monitor 15, and a buffer memory 16. In addition, a memory card 17 is attached to the digital camera 1. The memory card 17 is composed of a non-volatile flash memory or the like and is detachable from the digital camera 1.

  The photographing optical system 10 includes a plurality of lenses and a diaphragm, and forms a subject image on the image pickup surface of the image pickup device 11. The plurality of lenses constituting the photographing optical system 10 include a focus lens that is driven in the optical axis direction for focus adjustment. The focus lens is driven in the optical axis direction by a lens driving unit (not shown).

The imaging device 11 includes first and second imaging units 21 and 22 stacked on each other. Each of the first and second imaging units 21 and 22 includes a plurality of pixels arranged two-dimensionally, receives a light beam from a subject via the photographing optical system 10, performs photoelectric conversion, and performs photoelectric conversion. Output the conversion signal. Each pixel of the first and second imaging units 21 and 22 outputs a photoelectric conversion signal, as will be described in detail later. These photoelectric conversion signals are used as signals for contrast-type focus detection as described later, or as signals for captured images. Note that the first and second imaging units 21 and 22 simultaneously start an imaging operation, that is, an exposure operation.
The amplification circuit 23 amplifies the photoelectric conversion signal with a predetermined amplification factor (gain) and outputs the amplified signal to the AD conversion circuit 24. The AD conversion circuit 24 AD converts the photoelectric conversion signal.
Note that at least one of the amplifier circuit 23 and the AD conversion circuit 24 may be provided inside the image sensor 11.

  The control unit 12 includes a microprocessor and its peripheral circuits, and performs various controls of the digital camera 1 by executing a control program stored in a ROM (not shown). Further, the control unit 12 functionally includes a focus detection unit 12a, an image composition unit 12b, and a focus detection area setting unit 12c. This functional unit is implemented in software by the control program. Note that this functional unit may be configured by an electronic circuit.

  The control unit 12 stores the photoelectric conversion signal AD converted by the AD conversion circuit 24 in the buffer memory 16. The focus detection unit 12 a is based on the photoelectric conversion signal of the first imaging unit 21 stored in the buffer memory 16 and / or based on the photoelectric conversion signal of the second imaging unit 22 stored in the buffer memory 16. A focus detection process using a known contrast detection method is performed.

  The image processing unit 14 is configured by an ASIC or the like. The image processing unit 14 performs various types of image processing such as interpolation processing, compression processing, and white balance processing on the photoelectric conversion signals of the first and second imaging units 21 and 22 to generate image data. The image synthesizing unit 12b synthesizes image data based on the photoelectric conversion signal of the first imaging unit 21 and image data based on the photoelectric conversion signal of the second imaging unit 22 to generate synthesized image data. These image data and composite image data are displayed on the liquid crystal monitor 15 or stored in the memory card 17.

The operation unit 13 includes various operation members such as a release operation member, a mode switching operation member, a focus detection area setting operation member, and a power supply operation member, and is operated by a photographer. The operation unit 13 outputs an operation signal corresponding to the operation of each operation member by the photographer to the control unit 12.
The focus detection area setting unit 12c sets a focus detection area of a predetermined area in the shooting screen in accordance with the operation of the operation member for setting the focus detection area. There are various methods for setting the focus detection area using the focus detection area setting unit 12c and the focus detection area setting operation member as described in detail below. For example, when the photographer operates the operation member for setting the focus detection area, the focus detection area setting unit 12c detects the focus of a predetermined area at an arbitrary position on the shooting screen according to the operation of the operation member for setting the focus detection area. Set the area. Alternatively, when focus detection areas are prepared in advance at a plurality of positions on the shooting screen and the photographer operates a focus detection area setting operation member to select one focus detection area from the plurality of focus detection areas, The detection area setting unit 12c sets a focus detection area according to the selection. Further, when the digital camera 1 includes a subject recognition unit that recognizes the face of the subject person from the captured image, when the subject recognition unit recognizes the face of the subject person, the focus detection area setting unit 12c includes the face portion. A focus detection area can also be set. In this case, the focus detection area setting operation member is an operation member for selecting a mode for automatically setting the focus detection area based on the recognition result of the face of the subject person by the subject recognition unit. The focus detection area set as the focus detection target area by the focus detection area setting unit 12c as described above is referred to as a set focus detection area.

(Description of first and second imaging units 21 and 22)
FIG. 2 is a diagram illustrating an overview of the first and second imaging units 21 and 22 according to the present embodiment. The imaging device includes first and second imaging units 21 and 21 stacked on each other. The 1st and 2nd imaging parts 21 and 21 have an organic photoelectric conversion film as a photoelectric conversion part. The first imaging unit 21 is stacked on the second imaging unit 22, and the first and second imaging units 21 and 22 are configured such that the optical axes of the imaging optical system 10 illustrated in FIG. It arrange | positions in the optical path of the imaging optical system 10 so that the center of each imaging surface of the imaging parts 21 and 22 may be passed. In FIG. 2, only the 4 × 3 pixels 210 and 220 are shown in FIG. 2 for the first and second imaging units 21 and 22, but in the present embodiment, Both pixels of m rows × n columns are arranged, and the pixels of the first imaging unit 21 and the pixels of the second imaging unit 22 have the same size.
As will be described later, since no wiring layer is provided between the first imaging unit 21 and the second imaging unit 22, the distance between the first imaging unit 21 and the second imaging unit 22. Can be made relatively small.

  Each pixel 210 of the first imaging unit 21 has an organic photoelectric conversion film that absorbs light of a predetermined color component, that is, light in a predetermined wavelength range and photoelectrically converts it, and transmits light in a wavelength range that has not been absorbed. Have. That is, the pixel 210 of the first imaging unit 21 includes a pixel that absorbs light of a magenta color component and performs photoelectric conversion, a pixel that absorbs light of a yellow color component and performs photoelectric conversion, and a cyan color component. A pixel that absorbs light and performs photoelectric conversion. For a pixel that absorbs light of a magenta color component, an organic material that performs photoelectric conversion by absorbing light of a magenta color component in an organic photoelectric conversion film is used. For a pixel that absorbs light of a yellow color component, an organic material that absorbs light of a yellow color component and performs photoelectric conversion in an organic photoelectric conversion film is used. For a pixel that absorbs light of a cyan color component, an organic material that performs photoelectric conversion by absorbing light of a cyan color component in an organic photoelectric conversion film is used. That is, a pixel that absorbs light of magenta color components and performs photoelectric conversion, a pixel that absorbs light of yellow color components and performs photoelectric conversion, and a pixel that absorbs light of cyan color components and performs photoelectric conversion The organic materials used for the organic photoelectric conversion film are different.

Each pixel 220 of the second imaging unit 22 has an organic photoelectric conversion film that absorbs light of a visible color component and performs photoelectric conversion. That is, each pixel 220 of the second imaging unit 22 absorbs light and performs photoelectric conversion over the entire wavelength range of visible light. In the second imaging unit 22, the organic material used for the organic photoelectric conversion film is the same for all the pixels 220.
The light of the color component that has not been absorbed (photoelectrically converted) by the first imaging unit 21 passes through the first imaging unit 21 and enters the second imaging unit 22, and is photoelectrically converted by the second imaging unit 22. Is done. Therefore, the color component photoelectrically converted by the first imaging unit 21 and the color component photoelectrically converted by the second imaging unit 22 are in a complementary color relationship. That is, among the pixels 210 of the first imaging unit 21, the light beam that has passed through the pixel that absorbs the magenta color component and performs photoelectric conversion forms a green color component that has a complementary color relationship with magenta. The light enters the pixel 220 of the unit 22.
Of the pixels 210 of the first imaging unit 21, the light beam that has passed through the pixel that absorbs and photoelectrically converts the yellow color component forms a blue color component that has a complementary color relationship with yellow, and the second imaging unit 22. Is incident on the second pixel 220.
Of the pixels 210 of the first imaging unit 21, the light beam that has passed through the pixels that absorb and photoelectrically convert the cyan color component forms a red color component that has a complementary color relationship with cyan, and the second imaging unit 22. Is incident on the second pixel 220.

As described above, the first imaging unit 21 can acquire a CMY image including three colors of Cy, Mg, and Ye, and the second imaging unit 22 includes three colors of R, G, and B. An RGB image can be acquired. By combining images based on the RGB image obtained by converting the CMY image acquired from the first imaging unit 21 by a known color system conversion process and the RGB image obtained by the second imaging unit 22, for example, high image quality A simple image can be generated.
It should be noted that the pixel 210 that absorbs the magenta color component and performs photoelectric conversion generally cannot absorb 100% of the magenta color component, and a part of the magenta color component passes through the pixel 210. Similarly, the pixel 210 that absorbs and photoelectrically converts the yellow color component generally cannot absorb 100% of the yellow color component, and a part of the yellow color component passes through the pixel 210. . In general, the pixel 210 that absorbs and photoelectrically converts the cyan color component cannot absorb 100% of the cyan color component, and part of the cyan color component passes through the pixel 210.

Thus, each pixel 210 of the first imaging unit 21 and the pixel 220 of the second imaging unit 22 to which the light beam transmitted through the pixel 210 is incident have a correspondence relationship. The pixels 210 and 220 of the first and second imaging units 21 and 22 having such a correspondence relationship are referred to as correspondence pixels.
The pixels 210 and 220 of the first and second imaging units 21 and 22 that are in a correspondence relationship absorb the color components that are complementary to each other and perform photoelectric conversion.

  FIG. 3 illustrates an arrangement of 10 rows × 6 columns of pixels 210 that are a part of the first imaging unit 21, an arrangement of pixels 220 of 10 rows × 6 columns that are a part of the second imaging unit 22, FIG. In FIG. 3A, “Mg” attached to the pixel 210 indicates a pixel that absorbs a magenta color component and performs photoelectric conversion. Similarly, “Ye” given to the pixel 210 indicates a pixel that absorbs a yellow color component and performs photoelectric conversion. “Cy” attached to the pixel 210 indicates a pixel that absorbs a cyan color component and performs photoelectric conversion. In the first imaging unit 21, “Mg” pixels 210 and “Ye” pixels 210 are alternately arranged in odd-numbered pixel columns, and “Cy” pixels 210 and “Mg” pixels 210 are arranged in even-numbered pixel columns. And are arranged alternately.

In FIG. 3B, “G” attached to the pixel 220 indicates a pixel that absorbs a green color component transmitted through the “Mg” pixel 210 and performs photoelectric conversion. Similarly, “B” attached to the pixel 220 indicates a pixel that absorbs and photoelectrically converts the blue color component transmitted through the “Ye” pixel 210. “R” attached to the pixel 220 indicates a pixel that absorbs a red color component transmitted through the “Cy” pixel 210 and performs photoelectric conversion. In the second imaging unit 22, “G” pixels 220 and “B” pixels 220 are alternately arranged in odd-numbered pixel columns, and “R” pixels 220 and “G” pixels 220 are arranged in even-numbered pixel columns. And are arranged alternately. That is, the second imaging unit 22 has a Bayer array of pixels.
3A and 3B, the “Mg” pixel 210 of the first imaging unit 21 and the “G” pixel 220 of the second imaging unit 22 are in a correspondence relationship, and the first imaging unit 21 The “Ye” pixel 210 of the second imaging unit 22 and the “B” pixel 220 of the second imaging unit 22 have a corresponding relationship, and the “Cy” pixel 210 of the first imaging unit 21 and the “R” of the second imaging unit 22 The pixel 220 has a correspondence relationship.

  As described above, each pixel 220 of the second imaging unit 22 includes an organic photoelectric conversion film that photoelectrically converts light in the entire visible light wavelength range. However, since each pixel 210 of the first imaging unit 21 configured by the organic photoelectric conversion film absorbs light of a predetermined color component and transmits light of the color component that has not been absorbed, the second imaging unit. The 22 corresponding pixels 220 play the same role as the color filter. Thereby, the complementary image (the Bayer array image in the example of FIG. 3) of the first imaging unit 21 is obtained from the second imaging unit 22. Therefore, a CMY image composed of three colors Cy, Mg, and Ye can be acquired from the first image capturing unit 21, and an RGB image composed of three colors R, G, and B can be acquired from the second image capturing unit 22. Can be acquired. As described above, since the first image pickup unit 21 replaces the color filter necessary for the conventional image pickup element, the incident light reflected by the color filter is effectively used by the first image pickup unit 21. can do. The CMY image acquired from the first imaging unit 21 is converted into an RGB image by a known color system conversion process by the image processing unit 14 shown in FIG.

  FIG. 4 is a cross-sectional view illustrating the configuration of the pixels 210 and 220 of the first and second imaging units 21 and 22. As shown in FIG. 4, the second imaging unit 22 is formed on the upper surface 50 a that is the surface on the incident light side of the semiconductor substrate 50 via the planarization layer 55. In the following description, with respect to the first and second imaging units 21 and 22, the incident light side is the upper side, and the semiconductor substrate 50 side is the lower side. The first imaging unit 21 is stacked on the surface of the second imaging unit 22, that is, the upper surface with an insulating layer 56 interposed therebetween. Thus, in the present embodiment, since no wiring layer is provided between the first imaging unit 21 and the second imaging unit 22, the first imaging unit 21 and the second imaging unit 22 are provided. Can be placed close to each other.

In the conventional imaging device, since it is necessary to provide a wiring layer between the first photoelectric conversion unit stacked on the semiconductor substrate and the semiconductor substrate, between the first photoelectric conversion unit and the second photoelectric conversion unit. The distance becomes larger. Therefore, at a position away from the center of the imaging surface, that is, at a position where the image height is high, subject light is incident on the imaging surface obliquely.
On the other hand, in the present embodiment, as described above, no wiring layer is provided between the first imaging unit 21 and the second imaging unit 22, and thus the first imaging unit 21 and the first imaging unit 21 The two imaging units 22 can be brought close to each other.
This reduces the possibility that subject light is incident on the second imaging unit obliquely. This reduction effect is particularly great in pixels at positions where the image height is high. That is, shading is reduced.
Furthermore, blurring of the image acquired from the first imaging unit 21 and the image acquired from the second imaging unit 22 can be suppressed.
Further, a microlens 233 is disposed above each pixel 210 of the first imaging unit 21, and each microlens 233, each pixel 210 of the first imaging unit 21, and each pixel of the second imaging unit 22. 220 is aligned in the optical axis direction of the microlens 233.

  Each pixel 210 of the first imaging unit 21 includes an organic photoelectric film 230, a transparent common electrode 231 formed on the upper surface of the organic photoelectric film 230, and a transparent partial electrode 232 formed on the lower surface of the organic photoelectric film 230. And have. The common electrode 231 is a common electrode for all the pixels 210. In each pixel 210, a signal generated in a region sandwiched between the common electrode 231 and the partial electrode 232 in the organic photoelectric film 230 is read out by the common electrode 231 and the partial electrode 232. In the present embodiment, a portion constituted by the common electrode 231, the partial electrode 232, and a region sandwiched between the common electrode 231 and the partial electrode 232 in the organic photoelectric film 230 is referred to as a photoelectric conversion unit 210 a.

  Each pixel 220 of the second imaging unit 22 includes an organic photoelectric film 250, a transparent common electrode 251 formed on the lower surface of the organic photoelectric film 250, and a transparent partial electrode 252 formed on the upper surface of the organic photoelectric film 250. And have. The common electrode 251 is a common electrode for all the pixels 220. In each pixel 220, a signal generated in a region sandwiched between the common electrode 251 and the partial electrode 252 in the organic photoelectric film 250 is read out by the common electrode 251 and the partial electrode 252. In the present embodiment, a part constituted by the common electrode 251, the partial electrode 252, and a region sandwiched between the common electrode 251 and the partial electrode 252 in the organic photoelectric film 250 is referred to as a photoelectric conversion unit 220 a.

  In the pixel 210 and the pixel 220 that are in correspondence with each other, the pitch of the partial electrodes 232 and the pitch of the partial electrodes 252 are equal in the direction perpendicular to the optical axis direction. As described above, since the first imaging unit 21 and the second imaging unit 22 can be arranged close to each other, when viewed from the subject side, the partial electrode 232 and the partial electrode 252 are arranged in the row and column directions. It became possible to overlap without shifting.

In the conventional imaging device, as described above, subject light is incident on the imaging surface obliquely at a position where the distance between the first photoelectric conversion unit and the second photoelectric conversion unit is large and the image height is high. In view of this, it is necessary to appropriately shift the position of the first photoelectric conversion unit and the position of the second photoelectric conversion unit.
On the other hand, in the present embodiment, the distance between the first imaging unit 21 and the second imaging unit 22 is small, and shading hardly occurs even at a position away from the center of the imaging surface. Therefore, it is not necessary to shift the position of the photoelectric conversion unit 220a relative to the position of the photoelectric conversion unit 210a for the corresponding pixels 210 and 220 of the first and second imaging units 21 and 22. Therefore, in designing and manufacturing the image sensor, it is not necessary to consider shifting the position of the first photoelectric conversion unit and the position of the second photoelectric conversion unit at a position where the image height is high. The cost can be reduced.
In the pixel 210 and the pixel 220 that are in a corresponding relationship, the center of the photoelectric conversion unit 210a and the center of the photoelectric conversion unit 220a when viewed from the subject side coincide with the optical axis 233a of the microlens 233.

  The signal readout circuit of the first imaging unit 22 and the signal readout circuit of the second imaging unit 22 are formed on the semiconductor substrate 50. The signal readout circuit will be described in detail later.

A voltage Vpc is applied to the common electrode 231 and the common electrode 251 through a wiring (not shown) as described later. The partial electrode 232 and the signal output end 311 formed on the semiconductor substrate 50 are connected by a wiring 235. Thereby, the partial electrode 232 is connected to the signal readout circuit of the first imaging unit 22 via the wiring 235 and the signal output terminal 311. Similarly, the partial electrode 252 and the signal output end 312 formed on the semiconductor substrate 50 are connected by a wiring 255. As a result, the partial electrode 252 is connected to the signal readout circuit of the second imaging unit 22 via the wiring 255 and the signal output terminal 312. The organic photoelectric film 250 and the common electrode 251 of the second imaging unit 22 are provided with through holes through which the wirings 235 and 255 pass. In this through hole, the organic photoelectric film 250 and the common electrode 251 and the wirings 235 and 255 are insulated.
In FIG. 4, the partial electrode 232 and the wiring 235 of each pixel 210 of the first imaging unit 21 are connected at the left end of the pixel 210, and the partial electrode 252 and the wiring of each pixel 220 of the second imaging unit 22 are connected. 255 is connected to the right end of the pixel 210.

  FIG. 5 is a diagram illustrating a part of the signal readout circuit configuration of one pixel 210 and 220 in the first and second imaging units 21 and 22. The signal readout circuit of each pixel 210 includes an output transistor 301, a reset transistor 302, and a selection transistor 303. A voltage Vpc is applied to the common electrode 231. The partial electrode 232 is connected to the gate of the output transistor 301.

  The output transistor 301 amplifies a voltage signal based on the charge from the partial electrode 232. The signal amplified by the output transistor 301 is read from the terminal Vout1 through the selection transistor 303. The reset transistor 302 discharges unnecessary charges in response to the reset signal φRST (that is, resets to the reference voltage Vref).

  The signal readout circuit of each pixel 220 is the same as the signal readout circuit of each pixel 210 described above. That is, the signal readout circuit of each pixel 220 includes an output transistor 304, a reset transistor 305, and a selection transistor 306. A voltage Vpc is applied to the common electrode 251. The partial electrode 252 is connected to the gate of the output transistor 304.

The output transistor 304 amplifies a voltage signal based on the charge from the partial electrode 252. The signal amplified by the output transistor 304 is read from the terminal Vout2 through the selection transistor 306. The reset transistor 305 discharges unnecessary charges in response to the reset signal φRST (that is, resets to the reference voltage Vref). The signal line of the selection signal φSEL is connected to the gates of the selection transistors 303 and 306 of the pixels 210 and 220 arranged in the same row. The signal line of the reset signal φRST is connected to the gates of the reset transistors 302 and 305 of the pixels 210 and 220 arranged in the same row.
In other words, in this embodiment, the selection signal φSEL from the same signal line is input to the selection transistor 303 and the selection transistor 306 in the pixel 210 and the pixel 220 that are in a corresponding relationship. In addition, the reset signal φRST from the same signal line is input to the reset transistor 302 and the reset transistor 305 in the pixel 210 and the pixel 220 that are in a corresponding relationship. Note that the selection signal φSEL from different signal lines may be input to the selection transistor 303 and the selection transistor 306 in the pixel 210 and the pixel 220 that are in a corresponding relationship. In addition, the reset signal φRST from different signal lines may be input to the reset transistor 302 and the reset transistor 305 in the pixel 210 and the pixel 220 that are in a corresponding relationship.

  FIG. 6 is a diagram schematically showing each transistor formed on the semiconductor substrate 50. In FIG. 6, the pixels 210 and 220 are shown as schematic sectional views, and the transistors 301 to 306 are shown as schematic plan views. In the present embodiment, each of the transistors 301 to 306 is an NMOS type transistor. As clearly shown in FIG. 6B, each of the transistors 301 to 306 has a hatched gate electrode G1 and n regions N1 and N2 on both sides of the gate electrode G1.

  FIG. 7 is a diagram illustrating a photoelectric conversion signal readout circuit of the photoelectric conversion units 210a and 220a of the pixels 210 and 220 of the first and second imaging units 21 and 22. In FIG. The readout circuit according to the first imaging unit 21 includes a row scanning circuit 151 and a horizontal output circuit 152 in addition to the output transistor 301, the reset transistor 302, and the selection transistor 303 described above.

  The row scanning circuit 151 outputs a timing signal for signal readout to the photoelectric conversion units 210a of the plurality of pixels 210 arranged in the row direction, that is, in the left-right direction in FIG. More specifically, the row scanning circuit 151 outputs a reset signal φRST (1) to the photoelectric conversion units 210a of the pixels 210 in the first row to reset the charge of the photoelectric conversion units 210a, and then performs predetermined exposure. After a time, the selection signal φSEL (1) for the photoelectric conversion units 210a of the plurality of pixels 210 in the first row is output.

  In response to the selection signal φSEL (1), the photoelectric conversion signals of the photoelectric conversion units 210a of the plurality of pixels 210 in the first row are simultaneously read out to the horizontal output circuit 152, respectively. The horizontal output circuit 152 sequentially outputs the photoelectric conversion signals of the read photoelectric conversion units 210a of the first row pixels from the output unit 152A.

Similarly, the row scanning circuit 151 outputs a reset signal φRST (2) to the photoelectric conversion units 210a of the pixels 210 in the second row to reset the charge of the photoelectric conversion units 210a, and then performs a predetermined exposure time. Later, the selection signal φSEL (2) is output. In response to the selection signal φSEL (2), the photoelectric conversion signals of the photoelectric conversion units 210a of the plurality of pixels 210 in the second row are simultaneously read out to the horizontal output circuit 152, respectively. The horizontal output circuit 152 sequentially outputs, from the output unit 152A, the photoelectric conversion signals of the photoelectric conversion units 210a of the second row pixels read out.
Similarly, the row scanning circuit 151 outputs a reset signal φRST (m) and a selection signal φSEL (m) to the photoelectric conversion units 210a of the pixels 210 in the (m) th row. In response to the selection signal φSEL (m), the photoelectric conversion signals of the photoelectric conversion units 210a of the plurality of pixels 210 in the (m) th row are simultaneously read out to the horizontal output circuit 152, respectively, from the output unit 152A of the horizontal output circuit 152 Output sequentially.

  The photoelectric conversion signal output from the first horizontal output circuit 152 is sent to the focus detection unit 12a and the image processing unit 14 via the buffer memory 16 shown in FIG. Based on the photoelectric conversion signal, a focus detection calculation of a contrast detection method is performed. Further, the image processing unit 14 generates image data based on the photoelectric conversion signal of each pixel 210.

Next, a readout circuit related to the second imaging unit 22 will be described. In the present embodiment, since the readout circuit related to the second imaging unit 22 has the same configuration as the readout circuit related to the first imaging unit 21, the part numbers of the members of the first imaging unit 21 in FIG. The readout circuit related to the second imaging unit 22 is shown by attaching the part number of the constituent element of the readout circuit related to the second imaging unit 22 in parentheses. That is, the readout circuit related to the second imaging unit 22 includes the row scanning circuit 151 and the horizontal output circuit 162 described above in addition to the output transistor 304, the reset transistor 305, and the selection transistor 306 described above. The row scanning circuit 151 outputs a signal readout timing signal to the photoelectric conversion units 220a of the plurality of pixels 220 arranged in the row direction. That is, the row scanning circuit 151 outputs a reset signal φRST (1) to the photoelectric conversion units 220a of the pixels 220 in the first row to reset the charge of the photoelectric conversion units 220a, and then after a predetermined exposure time The selection signal φSEL (1) is output.
Similarly, the row scanning circuit 151 outputs a reset signal φRST (2) to the photoelectric conversion unit 220a of the pixels 220 in the second row to reset the charge of the photoelectric conversion unit 220a, and then performs a predetermined exposure time. Thereafter, the selection signal φSEL (2) is output, and similarly, the reset signal φRST (m) and the selection signal φSEL (m) for the photoelectric conversion units 220a of the plurality of pixels 220 in the (m) th row are output.

  In response to the selection signal φSEL (m), the horizontal output circuit 162 simultaneously reads out the photoelectric conversion signals of the photoelectric conversion units 220a of the plurality of pixels 220 in the (m) th row. The horizontal output circuit 162 outputs the read photoelectric conversion signal of the photoelectric conversion unit 220a from the output unit 162A.

The photoelectric conversion signal output from the second horizontal output circuit 162 is sent to the focus detection unit 12a and the image processing unit 14 via the buffer memory 16 illustrated in FIG. 1, and the focus detection unit 12a includes each pixel 220. Based on the photoelectric conversion signal, a focus detection calculation of a contrast detection method is performed. Further, the image processing unit 14 generates image data based on the photoelectric conversion signal of each pixel 220. The focus detection unit 12a performs focus detection based on the photoelectric conversion signals of the pixels 210 and 220 in the region set by the focus detection area setting operation member.
Note that, as described above, the readout circuit related to the first imaging unit 21 and the readout circuit related to the second imaging unit 22 are both formed on the semiconductor substrate 50 shown in FIG.

  The image data of the image by the first imaging unit 21 after the conversion to the RGB image by the color system conversion process and the RGB image data by the second imaging unit 22 are synthesized by the image synthesis unit 12b of FIG. Composite image data is generated. For example, a high-quality image can be generated by image synthesis.

The first embodiment described above has the following operational effects.
(1) The imaging device 11 receives the first imaging unit 21 having the photoelectric conversion unit 210a that performs photoelectric conversion using the organic photoelectric film 230, and the transmitted light that has passed through the photoelectric conversion unit 210a, and causes the organic photoelectric film 250 to And a second imaging unit 22 having a photoelectric conversion unit 220a that performs photoelectric conversion using the second imaging unit 22. Thus, for example, a high-quality image can be generated by performing image synthesis based on the image from the first imaging unit 21 and the image from the second imaging unit 22.
In addition, since it is not necessary to provide a wiring layer or the like between the first imaging unit 21 and the second imaging unit 22, the distance between the first imaging unit 21 and the second imaging unit 22 can be reduced. . Accordingly, since shading is unlikely to occur even at a position away from the center of the imaging surface, that is, at a position where the image height is high, the photoelectric conversion of the corresponding pixels 210 and 220 of the first and second imaging units 21 and 22 is performed. It is not necessary to shift the position of the photoelectric conversion unit 220a relative to the position of the unit 210a. Therefore, in designing and manufacturing the image sensor, it is not necessary to consider shifting the position of the first photoelectric conversion unit and the position of the second photoelectric conversion unit at a position where the image height is high. The cost can be reduced.
Moreover, since the distance between the first imaging unit 21 and the second imaging unit 22 can be shortened, blurring of an image acquired from the first imaging unit 21 and an image acquired from the second imaging unit 22 is suppressed. it can.

(2) The photoelectric conversion unit 220a of the “G” pixel 220 receives the transmitted light that has passed through the photoelectric conversion unit 210a of the “Mg” pixel 210, and the photoelectric conversion unit 220a of the “B” pixel 220 receives the “Ye” pixel. The photoelectric conversion unit 210a of the “R” pixel 220 receives the transmitted light that has passed through the photoelectric conversion unit 210a of the “Cy” pixel 210, and receives the “Mg” pixel. The photoelectric conversion unit 210 a of 210 converts the incident light of the magenta color component photoelectrically, and the photoelectric conversion unit 210 a of the “Ye” pixel 210 photoelectrically converts the incident light of the yellow color component to the “Cy” pixel 210. The photoelectric conversion unit 210a photoelectrically converts incident light of the cyan color component, and the photoelectric conversion unit 220a of the “G” pixel 220 photoelectrically converts the transmitted light of the green color component that is complementary to the magenta color component. Converted," The photoelectric conversion unit 220a of the pixel 220 photoelectrically converts the transmitted light of the blue color component that is complementary to the yellow color component, and the photoelectric conversion unit 220a of the “R” pixel 220 converts the cyan color component and Is configured to photoelectrically convert the transmitted light of the red color component having a complementary color relationship. Thus, the first and second imaging units 21 and 22 can effectively photoelectrically convert incident light, respectively, and the first imaging unit 21 functions as a color filter for the second imaging unit 22. This eliminates the need for a dedicated color filter.

(3) The second imaging unit further includes a semiconductor substrate 50 provided with a readout circuit that reads out a photoelectric conversion signal from each photoelectric conversion unit 210a and a readout circuit that reads out a photoelectric conversion signal from each photoelectric conversion unit 220a. 22 is provided on one surface of the semiconductor substrate 50, and the first imaging unit 21 is provided on one surface of the circuit board 50 via the second imaging unit 22. As described above, since the first and second imaging units 21 and 22 stacked on each other have their readout circuits formed on the same semiconductor substrate 50, the configuration of the entire imaging device can be reduced in size. .

--- Second Embodiment ---
The second embodiment will be described with reference to FIG. 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 the second embodiment, the common electrode of each pixel of the first imaging unit and the common electrode of each pixel of the second imaging unit are mainly shared, that is, configured by the same electrode. This is different from the first embodiment.

  FIG. 8 is a cross-sectional view showing a configuration of one pixel 210A and 220A of the first and second imaging units 21 and 22 according to the second embodiment. In the second embodiment, a shared common electrode 236 is provided between the organic photoelectric film 230 of each pixel 210 </ b> A of the first imaging unit 21 and the organic photoelectric film 250 of each pixel 220 </ b> A of the second imaging unit 22. It has been. The shared common electrode 236 is a common electrode for all the pixels 210 </ b> A of the first imaging unit 21 and is also a common electrode for all the pixels 220 </ b> A of the second imaging unit 22. In other words, all the pixels 210 </ b> A of the first imaging unit 21 and all the pixels 220 </ b> A of the second imaging unit 22 share the common common electrode 236.

More specifically, each pixel 210 </ b> A of the first imaging unit 21 is formed on the organic photoelectric film 230, the transparent partial electrode 232 formed on the upper surface of the organic photoelectric film 230, and the lower surface of the organic photoelectric film 230. A transparent common common electrode 236. In the present embodiment, a portion constituted by the shared common electrode 236, the partial electrode 232, and a region sandwiched between the shared common electrode 236 and the partial electrode 232 in the organic photoelectric film 230 is referred to as a photoelectric conversion unit 210a.
Each pixel 220 </ b> A of the second imaging unit 22 includes the organic photoelectric film 250, the transparent partial electrode 252 formed on the lower surface of the organic photoelectric film 250, and the above-described transparent sharing formed on the upper surface of the organic photoelectric film 250. A common electrode 236. In the present embodiment, a portion constituted by the shared common electrode 236, the partial electrode 252, and a region sandwiched between the shared common electrode 236 and the partial electrode 252 in the organic photoelectric film 250 is referred to as a photoelectric conversion unit 220a.

In the second embodiment, the following operational effects are obtained in addition to the operational effects of the first embodiment.
(1) A common common electrode 236 is provided between the organic photoelectric film 230 of each pixel 210 </ b> A of the first imaging unit 21 and the organic photoelectric film 250 of each pixel 220 </ b> A of the second imaging unit 22. That is, the photoelectric conversion unit 210a of each pixel 210A has a common common electrode 236 on one surface of the organic photoelectric film 230, and the photoelectric conversion unit 220a of each pixel 220A has a common common electrode 236 on one surface of the organic photoelectric film 250. The common common electrode 236 of the photoelectric conversion unit 210a and the common common electrode 236 of the photoelectric conversion unit 220a are configured by a common electrode. Accordingly, the configuration of the first and second imaging units 21 and 22 can be simplified, and the distance between the photoelectric conversion unit 210a and the photoelectric conversion unit 220a, that is, the first imaging unit 21 and the second imaging unit 21a. The distance from the imaging unit 22 can be further reduced. Therefore, the operational effects in the first embodiment described above become more prominent.

--- Third embodiment ---
A third embodiment will be described with reference to FIGS. In the following description, the same components as those in the first or second 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 or second embodiment. In the third embodiment, the first and second implementations are mainly in that each pixel 210B, 220B has a first photoelectric conversion unit 1210a, 1220a and a second photoelectric conversion unit 1210b, 1220b, respectively. The form is different.

  FIG. 9 is a diagram illustrating the configuration of the digital camera 1 according to the third embodiment. The difference between the digital camera 1 according to the third embodiment and the configuration of the digital camera 1 according to the first embodiment shown in FIG. 1 is that the control unit 12 further has a signal addition unit 12d functionally. This is the structure of the first and second imaging units 21 and 22.

  As will be described in detail later, each pixel of the first and second imaging units 21 and 22 receives first and second photoelectric elements that respectively receive a pair of light beams that have passed through a pair of regions of the pupil of the photographing optical system 10. It has a conversion unit, and the first and second photoelectric conversion units of each pixel output first and second photoelectric conversion signals, respectively. These first and second photoelectric conversion signals are used as phase difference focus detection signals and also as image signals, as will be described later.

The focus detection unit 12 a is based on the first and second photoelectric conversion signals of the first imaging unit 21 stored in the buffer memory 16, and the first and second of the second imaging unit 22 stored in the buffer memory 16. Based on the second photoelectric conversion signal, the focus adjustment state of the photographing optical system 10 is detected.
The signal adding unit 12 d generates an image signal based on the first and second photoelectric conversion signals of the first and second imaging units 21 and 22 stored in the buffer memory 16. That is, the signal adding unit 12d adds the first and second photoelectric conversion signals of the pixels of the first imaging unit 21 to generate a first image signal, and also generates the pixels of the second imaging unit 22. The first and second photoelectric conversion signals are added to generate a second image signal.

10 illustrates an arrangement of 10 rows × 6 columns of pixels 210B, which is a part of the first imaging unit 21, and an arrangement of pixels 220B of 10 rows × 6 columns, which is a part of the second imaging unit 22. FIG. In FIG. 10A, each pixel 210B of the first imaging unit 21 includes first and second photoelectric conversion units 1210a and 1210b. The first and second photoelectric conversion units 1210a and 1210b are arranged in the column direction, that is, the vertical direction in FIG. The first and second photoelectric conversion units 1210a and 1210b will be described in detail later.
In FIG. 10B, each pixel 220B of the second imaging unit 22 includes first and second photoelectric conversion units 1220a and 1220b. These first and second photoelectric conversion units 1220a and 1220b are arranged in the row direction, that is, in the left-right direction in FIG. The first and second photoelectric conversion units 1220a and 1220b will be described in detail later.
As described above, the first and second photoelectric conversion units 1210a and 1210b of each pixel 210B of the first imaging unit 21 and the first and second photoelectric conversion units of each pixel 220B of the second imaging unit 22 are provided. 1220a and 1220b are arranged so as to be orthogonal to each other.

  Further, as will be described later, the first imaging unit 21 reads the first and second photoelectric conversion signals from the first and second photoelectric conversion units 1210a and 1210b of the pixel 210B in units of columns. That is, for example, the first imaging unit 21 simultaneously reads out the first and second photoelectric conversion signals of the ten pixels 210B located in the leftmost column in FIG. The first and second photoelectric conversion signals of the ten pixels 210B located in the first column are simultaneously read out, and the same applies to the first and second pixels of the ten pixels 210B in the next row located in the same manner. A photoelectric conversion signal is read out.

  On the other hand, the second imaging unit 22 reads the first and second photoelectric conversion signals from the first and second photoelectric conversion units 1220a and 1220b of the pixel 220B in units of rows. That is, for example, the second imaging unit 22 reads the first and second photoelectric conversion signals of the six pixels 220B located in the uppermost row in FIG. 10B at the same time, and then the lower row. The first and second photoelectric conversion signals of the six pixels 220B positioned at the same time are read out at the same time, and the first and second photoelectric conversion signals of the six pixels 220B in each row are read out in the same manner.

FIG. 11 is a cross-sectional view showing the configuration of one pixel 210B, 220B of the first and second imaging units 21, 22. As shown in FIG. FIG. 12 is a diagram showing the arrangement of the first and second partial electrodes 232a, 232b, 252a, and 252b when the pixels 210B and 220B are viewed from the subject side.
As shown in FIG. 11, each pixel 210 </ b> B of the first imaging unit 21 is formed on the organic photoelectric film 230, the transparent common electrode 231 formed on the upper surface of the organic photoelectric film 230, and the lower surface of the organic photoelectric film 230. Transparent first and second partial electrodes 232a and 232b. As shown in FIG. 12A, the first and second partial electrodes 232a and 232b are arranged in the vertical direction in the drawing, that is, in the column direction. In the present embodiment, a portion constituted by the common electrode 231, the first partial electrode 232 a, and a region sandwiched between the common electrode 231 and the first partial electrode 232 a in the organic photoelectric film 230 is a first portion. This is referred to as a photoelectric conversion unit 1210a. In the present embodiment, a portion constituted by the common electrode 231, the second partial electrode 232 b, and a region sandwiched between the common electrode 231 and the second partial electrode 232 b in the organic photoelectric film 230 is the second portion. This is referred to as a photoelectric conversion unit 1210b.

  As shown in FIG. 11, each pixel 220 </ b> B of the second imaging unit 22 is formed on the organic photoelectric film 250, the transparent common electrode 251 formed on the lower surface of the organic photoelectric film 250, and the upper surface of the organic photoelectric film 230. Transparent first and second partial electrodes 252a and 252b. As shown in FIG. 12B, the first and second partial electrodes 252a and 252b are arranged in the horizontal direction in the drawing, that is, in the row direction. In the present embodiment, a portion constituted by the common electrode 251, the first partial electrode 252 a, and a region sandwiched between the common electrode 251 and the first partial electrode 252 a in the organic photoelectric film 250 is a first portion. This is referred to as a photoelectric conversion unit 1220a. In the present embodiment, the portion constituted by the common electrode 251, the second partial electrode 252 b, and the region sandwiched between the common electrode 251 and the second partial electrode 252 b in the organic photoelectric film 250 is the second portion. This is referred to as a photoelectric conversion unit 1220b.

  The first partial electrode 232a and the signal output end 311a of the semiconductor substrate 50 are connected by a wiring 235a, and the second partial electrode 232b and the signal output end 311b of the semiconductor substrate 50 are connected by a wiring 235b. Thus, the first and second partial electrodes 232a and 232b are connected to the signal readout circuit of the first imaging unit 21, respectively. Similarly, the first partial electrode 252a and the signal output end 312a of the semiconductor substrate 50 are connected by a wiring 255a, and the second partial electrode 252b and the signal output end 312b of the semiconductor substrate 50 are connected by a wiring 255b. The Thus, the first and second partial electrodes 252a and 252b are connected to the signal readout circuit of the second imaging unit 22, respectively.

  In addition, a microlens 233 is disposed above each pixel 210B of the first imaging unit 21, and each microlens 233, each pixel 210B of the first imaging unit 21, and each pixel of the second imaging unit 22. 220B is aligned in the optical axis direction of the microlens 233.

  Since the microlens 233 and the first and second imaging units 21 and 22 are arranged as described above, the first and second photoelectric conversion units 1210a and 1210b of each pixel 210B of the first imaging unit 21 are arranged. Respectively receives a pair of light fluxes that have passed through the first and second pupil regions of the exit pupil of the photographing optical system 10, respectively, and the first and second photoelectric conversion units of each pixel 220B of the second imaging unit 22 1220a and 1220b respectively receive a pair of light beams that have passed through the third and fourth pupil regions of the exit pupil of the photographing optical system 10. Note that the arrangement direction of the first and second pupil regions and the arrangement direction of the third and fourth pupil regions are orthogonal to each other.

  FIG. 13 is a diagram illustrating a signal readout circuit configuration of one pixel 210 </ b> B in the first imaging unit 21. The signal readout circuit of each pixel 210B includes output transistors 301a and 301b, reset transistors 302a and 302b, and selection transistors 303a and 303b. A voltage Vpc is applied to the common electrode 231. The first partial electrode 232a is connected to the gate of the output transistor 301a, and the second partial electrode 232b is connected to the gate of the output transistor 301b.

The output transistor 301a amplifies the voltage signal based on the charge from the first partial electrode 232a, and the output transistor 301b amplifies the voltage signal based on the charge from the second partial electrode 232b. The signal amplified by the output transistor 301a is read from the terminal Vout1a via the selection transistor 303a, and the signal amplified by the output transistor 301b is read from the terminal Vout1b via the selection transistor 303b. The reset transistor 302a discharges unnecessary charges from the first photoelectric conversion unit 1210a in response to the reset signal φRST, and the reset transistor 302b discharges unnecessary charges from the second photoelectric conversion unit 1210b in response to the reset signal φRST.
The signal line of the selection signal φSEL is connected to the gates of the selection transistors 303a and 303b of the respective pixels 210 arranged in the same column. The signal line of the reset signal φRST is connected to the gates of the reset transistors 302a and 302b of each pixel 210B arranged in the same column.
That is, in this embodiment, the selection signal φSEL from the same signal line is input to the selection transistor 303a and the selection transistor 303b of the pixel 210B. The reset signal φRST from the same signal line is input to the reset transistor 302a and the reset transistor 302b of the pixel 210B. Note that the selection signal φSEL from different signal lines may be input to the selection transistor 303a and the selection transistor 303b of the pixel 210B. In addition, the reset signal φRST from different signal lines may be input to the reset transistor 302a and the reset transistor 302b of the pixel 210B.

  Since the signal readout circuit of each pixel 220B is the same as the signal readout circuit of each pixel 210B described above, description thereof is omitted.

  The focus detection unit 12a of the present embodiment shown in FIG. 9 is based on the first and second photoelectric conversion signals of the plurality of pixels 210B arranged in the column direction of the first imaging unit 21 as described later. A deviation amount, that is, a phase difference between a pair of images formed by the pair of light beams that have passed through the first and second pupil regions is detected, and a defocus amount is calculated based on the image deviation amount. In addition, the focus detection unit 12a is a pair that has passed through the third and fourth pupil regions based on the first and second photoelectric conversion signals of the plurality of pixels 220B arranged in the row direction of the second imaging unit 22. The amount of deviation of the pair of images formed by the luminous flux, that is, the phase difference is detected, and the defocus amount is calculated based on the amount of image deviation.

(Circuit configuration of the imaging unit 21)
FIG. 14 is a diagram schematically illustrating a photoelectric conversion signal readout circuit of the first and second photoelectric conversion units 1210a and 1210b of each pixel 210B of the first imaging unit 21. In FIG. 14, the first imaging unit 21 includes a column scanning circuit 153 and first and second horizontal output circuits 154 and 155. The column scanning circuit 153 outputs a timing signal R (n) for signal readout to the first and second photoelectric conversion units 1210a and 1210b of the plurality of pixels 210B arranged in the column direction, that is, the vertical direction in FIG. To do. Specifically, the column scanning circuit 153 includes a timing signal R (1) for the first and second photoelectric conversion units 1210a and 1210b of the plurality of pixels 210B in the first column, that is, a reset signal φRST (1), The selection signal φSEL (1) is output.

  In response to the selection signal φSEL (1), the first and second photoelectric conversion signals of the first and second photoelectric conversion units 1210a and 1210b of the plurality of pixels 210B in the first column are respectively the first and second photoelectric conversion signals. Simultaneously read out to the horizontal output circuits 154 and 155. In the third embodiment, the first photoelectric conversion signal of the first photoelectric conversion unit 1210a is read to the first horizontal output circuit 154, and the second photoelectric conversion signal of the second photoelectric conversion unit 1210b is read. Is read out by the second horizontal output circuit 155. The first horizontal output circuit 154 sequentially outputs the first photoelectric conversion signal of the first photoelectric conversion unit 1210a of the read first column pixel from the output unit 154A, and similarly, the second horizontal output circuit 155 sequentially outputs the read second photoelectric conversion signal of the second photoelectric conversion unit 1210b of the first column pixel from the output unit 155A.

Similarly, the column scanning circuit 153 selects the timing signal R (2) for the first and second photoelectric conversion units 1210a and 1210b of the plurality of pixels 210B in the second column, that is, the reset signal φRST (2) and the selection. The signal φSEL (2) is output. In accordance with the selection signal φSEL (2), the first and second photoelectric conversion signals of the first and second photoelectric conversion units 1210a and 1210b of the plurality of pixels 210B in the second column are respectively the first and second photoelectric conversion signals. Simultaneously read out to the horizontal output circuits 154 and 155. The first and second horizontal output circuits 154 and 155 sequentially output the first and second photoelectric conversion signals of the read first and second photoelectric conversion units 1210a and 1210b of the pixels in the second column, respectively. Output from 154A, 155A.
In the same manner, the column scanning circuit 153 performs the timing signal R (n) for the first and second photoelectric conversion units 1210a and 1210b of the plurality of pixels 210B in the (n) th column, that is, the reset signal φRST (n). And a selection signal φSEL (n). In response to the selection signal φSEL (n), the first and second photoelectric conversion signals of the first and second photoelectric conversion units 1210a and 1210b of the plurality of pixels 210B in the (n) th column are the first and second, respectively. Are simultaneously read out by the horizontal output circuits 154 and 155 and output sequentially from the output units 154A and 155A of the first and second horizontal output circuits 154 and 155.

  The first photoelectric conversion signal output from the first horizontal output circuit 154 and the second photoelectric conversion signal output from the second horizontal output circuit 155 are focused through the buffer memory 16 shown in FIG. The focus detection unit 12a is sent to the detection unit 12a and the signal addition unit 12d, and the focus detection unit 12a simultaneously reads the first and second photoelectric conversion signals of the first and second photoelectric conversion units 1210a and 1210b in the nth column. Based on the above, a phase difference focus detection calculation is performed. The signal adding unit 12d adds the photoelectric conversion signals of the first and second photoelectric conversion units 1210a and 1210b of each pixel 210B to generate an image signal.

  FIG. 15 is a diagram schematically illustrating a photoelectric conversion signal readout circuit of the first and second photoelectric conversion units 1220a and 1220b of each pixel of the second imaging unit 22. In FIG. 15, the second imaging unit 22 includes a row scanning circuit 163 and first and second horizontal output circuits 164 and 165. The signal readout circuits 163, 164, and 165 related to the photoelectric conversion signals of the first and second photoelectric conversion units 1220a and 1220b of the second imaging unit 22 are signal readout circuits 153 of the first imaging unit 22 shown in FIG. , 154, and 155, the differences will be described in the following description.

  The row scanning circuit 163 supplies a timing signal R (m) for signal readout to the first and second photoelectric conversion units 1220a and 1220b of the plurality of pixels 220B arranged in the row direction, in FIG. 15, in the left-right direction. Output. That is, the row scanning circuit 163 outputs a signal readout timing signal R (1) to the first and second photoelectric conversion units 1220a and 1220b of the plurality of pixels 220B in the first row, that is, a reset signal φRST ( 1) and a selection signal φSEL (1), and similarly, a timing signal R for signal readout to the first and second photoelectric conversion units 1220a and 1220b of the plurality of pixels 220B in the second row. (2) That is, the reset signal φRST (2) and the selection signal φSEL (2) are output, and similarly, the first and second photoelectric conversions of the plurality of pixels 220B in the (m) th row are sequentially performed. A timing signal R (m) for signal reading, that is, a reset signal φRST (m) and a selection signal φSEL (m) are output to the units 1220a and 1220b.

In response to the timing signal R (m), the first horizontal output circuit 164 simultaneously reads out the first photoelectric conversion signals of the first photoelectric conversion units 1220a of the plurality of pixels 220B in the (m) th row, and the like. In addition, the second horizontal output circuit 165 simultaneously reads out the second photoelectric conversion signals of the second photoelectric conversion units 1220b of the pixels 220B in the (m) th row.
The first horizontal output circuit 164 outputs the read first photoelectric conversion signal of the first photoelectric conversion unit 1220a from the output unit 164A, and the second horizontal output circuit 165 outputs the read second photoelectric conversion unit. The second photoelectric conversion signal 1220b is output from the output unit 165A.

  The first photoelectric conversion signal output from the first horizontal output circuit 164 and the second photoelectric conversion signal output from the second horizontal output circuit 165 are focused through the buffer memory 16 shown in FIG. The focus detection unit 12a is sent to the detection unit 12a and the signal addition unit 12d, and the focus detection unit 12a reads the first and second photoelectric conversion units 1220a and 1220b in the (m) th row that are simultaneously read out. Based on the converted signal, a phase difference focus detection calculation is performed. The signal adding unit 12d adds the first and second photoelectric conversion signals of the first and second photoelectric conversion units 1220a and 1220b of each pixel 220B to generate an image signal.

  Note that both the signal readout circuit example of the first imaging unit 21 shown in FIG. 14 and the signal readout circuit example of the second imaging unit 22 shown in FIG. 15 are formed on the semiconductor substrate 50 shown in FIG. Is formed.

FIG. 16 is a block diagram showing in detail the function performed by the focus detection unit 12a shown in FIG. The focus detection unit 12a includes first and second focus detection signal acquisition units 120 and 121, first and second contrast detection units 122 and 123, a determination unit 124, a selection unit 125, and a correlation calculation unit 126. And a defocus amount calculation unit 127.
The focus detection area setting unit 12c outputs position information regarding the set focus detection area set as the focus detection target area. The first focus detection signal acquisition unit 120 uses the first and second photoelectric conversion signals output from the first and second horizontal output circuits 154 and 155 of FIG. The first and second photoelectric conversion signals from the plurality of pixels 210B arranged in the column direction at the position corresponding to the set focus detection area set by the focus detection area setting unit 12c are acquired.

  Similarly, the second focus detection signal acquisition unit 121 outputs the first and second outputs from the first and second horizontal output circuits 164 and 165 shown in FIG. Among the photoelectric conversion signals, the first and second photoelectric conversion signals from the plurality of pixels 220B arranged in the row direction at the position corresponding to the set focus detection area set by the focus detection area setting unit 12c are acquired.

  In this way, the first focus detection signal acquisition unit 120 first and second read from the plurality of pixels 210B in the column direction array corresponding to the set focus detection area for the first imaging unit 21 at the same time. The photoelectric conversion signal is acquired. The first and second photoelectric conversion signals related to the first imaging unit 21 acquired by the first focus detection signal acquisition unit 120 are referred to as first focus detection signals. In addition, the second focus detection signal acquisition unit 121 first and second photoelectric conversions of the second imaging unit 22 that are simultaneously read from the plurality of pixels 220B in the row direction array corresponding to the set focus detection area. Get the signal. The first and second photoelectric conversion signals relating to the second imaging unit 22 acquired by the second focus detection signal acquisition unit 121 are referred to as second focus detection signals.

  The first and second focus detection signals are composed of first and second photoelectric conversion signals of pixels that perform photoelectric conversion by absorbing light of the same color component, respectively. Specifically, the first focus detection signal related to the first imaging unit 21 is the first and second photoelectric conversion signals of the Mg pixels 210B arranged in the column direction in FIG. 10A. Selected. Similarly, as the second focus detection signal related to the second imaging unit 22, the first and second photoelectric conversion signals of the G pixels 220B arranged in the row direction in FIG. 10B are selected. The Of course, the first focus detection signal is not limited to the first and second photoelectric conversion signals of the Mg pixel, but the first and second photoelectric conversion signals of the Cy pixel or Ye pixel can also be used. The second focus detection signal is not limited to the first and second photoelectric conversion signals of the G pixel, and the first and second photoelectric conversion signals of the R pixel or B pixel can also be used.

  The first contrast detection unit 122 calculates the first contrast amount of the subject image in the set focus detection area based on the first focus detection signal acquired by the first focus detection signal acquisition unit 120. The contrast amount is the first photoelectric conversion signal or the second photoelectric conversion signal (or the addition signal of the first and second photoelectric conversion signals) related to the adjacent pixel acquired by the first focus detection signal acquisition unit 120. The difference is integrated and calculated. The first contrast amount is a contrast amount of the subject image formed on the plurality of pixels 210B in the column direction arrangement of the first imaging unit 21 in the set focus detection area.

  Similar to the first contrast detection unit 122, the second contrast detection unit 123 and the first contrast detection unit 122 are based on the second focus detection signal acquired by the second focus detection signal acquisition unit 121. Similarly, the second contrast amount of the subject image in the set focus detection area is calculated. The second contrast amount is the contrast amount of the subject image formed on the plurality of pixels 220B in the row direction array of the second imaging unit 22 in the setting area.

  The determination unit 124 determines whether at least one of the first and second contrast amounts is greater than or equal to the first threshold value. The first threshold value is determined so that a focus detection signal having a contrast amount equal to or greater than the first threshold value can be effectively used for phase difference focus detection. Accordingly, when both the first and second contrast amounts are less than the first threshold value, the determination unit 124 has a very blurred subject image in the set focus detection area, that is, a very large defocus state. And the focus lens of the photographing lens 10 is driven to scan.

  The determination unit 124 determines whether or not the difference between the first contrast amount and the second contrast amount is greater than or equal to the second threshold when at least one of the first and second contrast amounts is greater than or equal to the first threshold. Determine whether. When the difference between the first and second contrast amounts is equal to or greater than the second threshold, the determination unit 124 determines that the focus detection signal having the larger contrast amount out of the first and second contrast amounts is the phase difference focus. Although it is suitable for detection, it is determined that the focus detection signal having the smaller contrast amount is not suitable for phase difference focus detection. If the difference between the first and second contrast amounts is less than the second threshold, the determination unit 124 determines that both the first and second focus detection signals are suitable for phase difference focus detection.

  The selection unit 125 selects one or both of the first and second focus detection signals of the first and second focus detection signal acquisition units 120 and 121 based on the output signal of the determination unit 124, and performs correlation. The data is sent to the calculation unit 126. More specifically, when the difference between the first and second contrast amounts is equal to or greater than the second threshold, the selection unit 125 determines that the first contrast amount is greater than the second contrast amount. The first focus detection signal of the first focus detection signal acquisition unit 120 is selected and output to the correlation calculation unit 126, and the second focus detection signal acquisition is performed when the second contrast amount is larger than the first contrast amount. The second focus detection signal of the unit 121 is selected and output to the correlation calculation unit 126. The selection unit 125 also detects the first and second focus detections of the first and second focus detection signal acquisition units 120 and 121 when the difference between the first and second contrast amounts is less than the second threshold. Both signals are selected and output to the correlation calculation unit 126.

  When the first focus detection signal is input from the selection unit 125, the correlation calculation unit 126 performs a correlation calculation based on the first focus detection signal to calculate the first image shift amount, and the selection unit 125. When the second focus detection signal is input from, a correlation calculation is performed based on the second focus detection signal to calculate a second image shift amount, and the first and second focus detections are performed from the selection unit 125. When a signal is input, a correlation calculation is performed based on the first focus detection signal to calculate a first image shift amount, and a correlation calculation is performed based on the second focus detection signal to generate a second image shift. Calculate the amount.

  The defocus amount calculation unit 127 calculates the defocus amount based on the correlation calculation result of the correlation calculation unit 126, that is, the image shift amount. Based on this defocus amount, focus adjustment of the photographing optical system is performed. As described above, when the selection unit 125 selects both the first and second focus detection signals, the defocus amount calculation unit 127 performs the first defocus based on the first focus detection signal. An average value of the amount and the second defocus amount based on the second focus detection signal is calculated and set as the final defocus amount. The focus of the photographing optical system is adjusted based on this final defocus amount.

  In this way, the readout circuit is configured so that the first and second photoelectric conversion signals are simultaneously read from the plurality of pixels 210B arranged in the column direction of the first imaging unit 21, and the first read simultaneously. The phase difference focus detection calculation is performed based on the second photoelectric conversion signal, that is, the first focus detection signal. Similarly, the readout circuit is configured such that the first and second photoelectric conversion signals are simultaneously read from the plurality of pixels 220B arranged in the row direction of the second imaging unit 22, and the first and second readouts are performed simultaneously. The phase difference focus detection calculation is performed based on the second photoelectric conversion signal, that is, the second focus detection signal. Thereby, if the phase difference focus detection calculation is performed by the first focus detection signal read simultaneously or by the second focus detection signal read simultaneously, the calculation accuracy of the defocus amount increases. The focus adjustment accuracy of the photographic optical system 10 is improved, and the quality of an image obtained by imaging can be improved.

FIG. 17 is a flowchart showing the focus detection operation in the third embodiment. The focus detection process illustrated in FIG. 17 is included in a control program executed by the control unit 12. When the photographer performs a predetermined focus detection operation, for example, a half-press operation of the release operation member, the control unit 12 starts the focus detection process shown in FIG.
In FIG. 16 and FIG. 17, in step S <b> 1, the first imaging unit 21 and the second imaging unit 22 capture the subject images formed by the imaging optical system 10, respectively. The first imaging unit 21 reads the first and second photoelectric conversion signals of the first and second photoelectric conversion units 1210a and 1210b of the plurality of pixels 210B arranged in the column direction at the same time. The second imaging unit 22 simultaneously reads the first and second photoelectric conversion signals of the first and second photoelectric conversion units 1220a and 1220b of the plurality of pixels 220B arranged in the row direction. The first and second photoelectric conversion signals from the first or second imaging units 21 and 22 are added by the signal addition unit 12d in FIG. 9 to become the first or second image signal, and the image processing in FIG. The image is processed by the unit 14 and displayed as a through image on the monitor 15 of FIG. Note that the through image may be displayed based on the first image signal from the first imaging unit 21 or may be displayed based on the second image signal of the second imaging unit 22.

  In step S2, the focus detection area setting unit 12c in FIG. 9 sets a set focus detection area in the shooting screen. In step S <b> 3, the first focus detection signal acquisition unit 120 includes a plurality of columns arranged in a column direction corresponding to the set focus detection area among the first and second photoelectric conversion signals output from the first imaging unit 21. The first and second photoelectric conversion signals of the first and second photoelectric conversion units 1210a and 1210b of the pixel 210B are acquired as the first focus detection signal. Similarly, the second focus detection signal acquisition unit 121 includes a plurality of pixels arranged in a row direction corresponding to the set focus detection area among the first and second photoelectric conversion signals output from the second imaging unit 22. The first and second photoelectric conversion signals of the first and second photoelectric conversion units 1220a and 1220b of 220B are acquired as second focus detection signals.

  In step S4, the first contrast detection unit 122 calculates the first contrast amount of the subject image in the set focus detection area based on the first focus detection signal acquired by the first focus detection signal acquisition unit 120. To do. As described above, the first contrast amount is the contrast amount in the column direction of the pixel 210B of the first imaging unit 21. Similarly, the second contrast detection unit 123 calculates the second contrast amount of the subject image in the set focus detection area based on the second focus detection signal acquired by the second focus detection signal acquisition unit 121. As described above, the second contrast amount is the contrast amount in the column direction of the pixel 220B of the second imaging unit 22.

  In step S5, the determination unit 124 determines whether at least one of the first and second contrast amounts is equal to or greater than the first threshold value. If the determination is negative, the process proceeds to step S6, and the determination is affirmative. Proceed to step S7. In step S6, it is determined that the subject image in the set focus detection area is very blurred, that is, is in a very large defocus state, and the focus lens of the photographing lens 10 is scan-driven. In step S7, the determination unit 124 determines whether or not the difference between the first contrast amount and the second contrast amount is greater than or equal to the second threshold value. If the determination is affirmative, the process proceeds to step S8, where a negative determination is made. If so, go to Step S9. In step S8, it is determined whether or not the first contrast amount is larger than the second contrast amount. If the determination is affirmative, the process proceeds to step S10. If the determination is negative, the process proceeds to step S11.

  In step S10, the first contrast amount is larger than the second contrast amount, that is, the contrast amount in the column direction of the first imaging unit 21 in the row direction of the second imaging unit 22 in the set focus detection area. Since it is larger than the contrast amount, the selection unit 124 selects the first focus detection signal of the first focus detection signal acquisition unit 120, and the correlation calculation unit 126 performs correlation calculation based on the first focus detection signal. A focus amount calculation unit 127 calculates a defocus amount based on the correlation calculation result. In step S11, the second contrast amount is larger than the first contrast amount, that is, in the set focus detection area, the contrast amount in the row direction of the second imaging unit 22 is in the column direction of the first imaging unit 21. Since it is larger than the contrast amount, the selection unit 124 selects the second focus detection signal of the second focus detection signal acquisition unit 121, the correlation calculation unit 126 performs the correlation calculation based on the second focus detection signal, A focus amount calculation unit 127 calculates a defocus amount based on the correlation calculation result.

  In step S9, the difference between the first and second contrast amounts is less than the second threshold value, that is, the first and second contrast amounts are substantially equal. The first and second focus detection signals of the two focus detection signal acquisition units 120 and 121 are selected, and the correlation calculation unit 126 performs a correlation calculation based on the first focus detection signal and the second focus detection signal. The defocus amount calculation unit 127 calculates the first defocus amount based on the correlation calculation result based on the first focus detection signal, and based on the correlation calculation result based on the second focus detection signal. A second defocus amount is calculated, and a final defocus amount is calculated from the first and second defocus amounts.

  In step S12, based on the defocus amounts calculated in steps S10, S11, and S9, the focus lens of the photographing optical system 10 is driven to perform focus adjustment. In step S13, it is determined whether or not the half-pressing operation of the release operation member is completed. If the determination is affirmative, the focus detection operation is terminated, and if the determination is negative, the process returns to step S1.

  As described above, in the third embodiment, the arrangement direction of the first and second photoelectric conversion units 1210a and 1210b of the pixel 210B of the first imaging unit 21 and the pixel 220B of the second imaging unit 22 are arranged. The arrangement direction of the first and second photoelectric conversion units 1220a and 1220b is different. Therefore, the contrast of the subject image formed on the plurality of pixels 210B arranged in the column direction of the first imaging unit 21 in the set focus detection area and the row direction of the second imaging unit 22 in the set focus detection area are arranged. Compared with the contrast of the subject image formed on the plurality of pixels 220B, high-precision focus detection can be performed based on the focus detection signal of the image sensor having the higher contrast.

In the third embodiment, either one or both of the first and second focus detection signals are selected according to the first and second contrast amounts, and the correlation is performed based on the selected focus detection signal. The calculation unit 126 performs a correlation calculation. Instead of this, the selection unit 125 always selects the first and second focus detection signals, and the correlation calculation unit 126 performs a correlation calculation on the first and second focus detection signals, and the first and second focus detection signals. One or both of the correlation calculation result by the first focus detection signal and the correlation calculation result by the second focus detection signal are selected based on the magnitude of the contrast amount, and the defocus amount is determined based on the selected correlation calculation result You may make it calculate.
Furthermore, the defocus amount calculation unit 127 calculates the defocus amount based on all the correlation calculation results calculated by the correlation calculation unit 126, and the first and second defocus amounts are calculated from the plurality of defocus amounts thus calculated. A desired defocus amount may be selected based on the magnitude of the contrast amount.

In an image sensor in which pixels having different division directions of the first and second photoelectric conversion units are provided on the imaging surface, two pixels having different division directions of the first and second photoelectric conversion units have the same amount of light. Even if each is incident, the output from the first and second photoelectric conversion units of each pixel may be different due to the difference in the dividing direction of the first and second photoelectric conversion units. Therefore, there is a possibility that the image quality of the image obtained by imaging is deteriorated.
In contrast, in the third embodiment, the photoelectric conversion signals of the first and second photoelectric conversion units 1210a and 1210b divided in the column direction of each pixel 210B of the first imaging unit 21 are added. Thus, an image signal is generated. Then, each pixel 220B of the second imaging unit 22 is configured to add the photoelectric conversion signals of the first and second photoelectric conversion units 1220a and 1220b divided in the row direction to generate an image signal. As a result, high-quality images can be obtained by the first and second imaging units 21 and 22.

<Modification of signal readout circuit>
FIG. 18 is a block diagram showing a modification of the signal readout circuit according to the third embodiment. In the above-described third embodiment, the AD conversion circuit 24 provided outside the image sensor 11 performs AD conversion on the first and second photoelectric conversion signals, and the signal of the control unit 12 provided outside the image sensor 11. The adder 12d adds the first and second photoelectric conversion signals.
On the other hand, in this modification, instead of the AD conversion circuit 24 provided outside the image pickup device 11 and the signal addition unit 12d of the control unit 12, the AD conversion unit provided inside the image pickup device 11 uses the first and first AD converters. The two photoelectric conversion signals are AD-converted, and the first and second photoelectric conversion signals are added by an adder provided inside the image sensor 11.
In the following description, the readout circuit of the second imaging unit is described. However, the readout circuit of the first imaging unit is the same, and thus the description of the readout circuit of the first imaging unit is omitted.

In FIG. 18, the image sensor 11 includes a row scanning circuit 163, an AD converter 166, a first and second photoelectric conversion signal horizontal output circuit 167, an adder 168, and an added signal horizontal output circuit. 169. In the following description, differences from the photoelectric conversion signal readout circuit of the second imaging unit 22 shown in FIG. 15 will be mainly described.
The AD conversion unit 166 includes n ADCs (analog-to-digital conversion circuits) 166a corresponding to the first photoelectric conversion units 1220a of the respective pixels 220B arranged in n columns in the row direction of the second imaging unit 22A. And n ADCs 166b corresponding to the second photoelectric conversion units 1220b of the respective pixels 220B.
The horizontal output circuits 167 for the first and second photoelectric conversion signals respectively correspond to the n memories 167a corresponding to the n ADCs 166a of the AD conversion unit 166 and the n ADCs 166b of the AD conversion unit 166, respectively. n memories 167b.
The adder 168 includes n digital adder circuits 168a corresponding to the respective pixels 220B arranged in n columns in the row direction.
The horizontal output circuit 169 for addition signals includes n memories 169a corresponding to the n digital addition circuits 168a of the addition unit 168, respectively.

In accordance with the timing signal R (1), the photoelectric conversion signals of the first and second photoelectric conversion units 1220a and 1220b of the n pixels 220B in the first row correspond to the ADCs 166a and 166b of the corresponding AD conversion unit 166, respectively. Are output simultaneously. The ADCs 166a and 166b convert the input photoelectric conversion signals of the first and second photoelectric conversion units 1220a and 1220b into digital signals, respectively, and corresponding horizontal output circuits for the first and second photoelectric conversion signals, respectively. The data is output to the memories 167a and 167b of 167. The memories 167a and 167b of the horizontal output circuit 167 for the first and second photoelectric conversion signals respectively store the digital signals output from the ADCs 166a and 166b. The horizontal output circuit 167 for the first and second photoelectric conversion signals sequentially outputs the first and second photoelectric conversion signals stored in the memories 167a and 167b from the output unit 167A.
In addition, the digital addition circuit 168a of the addition unit 168 adds the first and second photoelectric conversion signals AD-converted by the ADCs 166a and 166b for each pixel 220B. Each memory 169a of the horizontal output circuit 169 for the addition signal stores the digital addition signal output from the digital addition circuit 168a. The horizontal output circuit 169 for added signals sequentially outputs the digital added signal stored in each memory 169a from the output unit 169A.

Next, in accordance with the timing signal R (2), the first and second photoelectric conversion signals of the first and second photoelectric conversion units 1220a and 1220b of the plurality of pixels 220B in the second row are respectively converted into the AD conversion unit 166. Are converted into digital signals and sequentially output from the output unit 167A of the horizontal output circuit 167 for the first and second photoelectric conversion signals. The first and second photoelectric conversion signals AD-converted by the AD conversion unit 166 are added by the digital addition circuit 168a, and the addition signal is sequentially output from the output unit 169A of the horizontal output circuit 169 for the addition signal. .
Thereafter, the first and second photoelectric conversion signals of the first and second photoelectric conversion units 1220a and 1220b of the plurality of pixels 220B in the (m) -th row are sequentially AD according to the timing signal R (m). It is converted into a digital signal by the conversion unit 166 and sequentially output from the output unit 167A of the horizontal output circuit 167 for the first and second photoelectric conversion signals, and the addition signal is an output unit 169A of the horizontal output circuit 169 for the addition signal. Are output sequentially.
In this way, the AD converted first and second photoelectric conversion signals are output from the output unit 167A as focus detection signals, and in parallel therewith, the AD converted first and second photoelectric conversion signals are output. A signal addition signal is output as an image signal from the output unit 169A. Therefore, in this modification, a focus detection signal and an image signal are obtained during one frame period.

In the third embodiment described above, the following operational effects are obtained in addition to the operational effects of the first and second embodiments.
(1) Each pixel 210B of the first imaging unit 21 has first and second photoelectric conversion units 1210a and 1210b arranged in the column direction, and each pixel 220B of the second imaging unit 22 is a row. It has the 1st and 2nd photoelectric conversion parts 1220a and 1220b arranged in the direction. Thus, the arrangement direction of the first and second photoelectric conversion units 1210a and 1210b of each pixel 210B of the first imaging unit 21 and the first and second photoelectric conversions of each pixel 220B of the second imaging unit 22 are described. The arrangement direction of the parts 1220a and 1220b is different. Therefore, the contrast of the subject image formed on the plurality of pixels 210B arranged in the column direction of the first imaging unit 21 in the set focus detection area and the row direction of the second imaging unit 22 in the set focus detection area are arranged. Compared with the contrast of the subject image formed on the plurality of pixels 220B, high-precision focus detection can be performed based on the focus detection signal of the image sensor having the higher contrast.

(2) The readout circuit is configured such that the first and second photoelectric conversion signals are simultaneously read from the plurality of pixels 210B arranged in the column direction of the first imaging unit 21, and the first and second read simultaneously The phase difference focus detection calculation is performed based on the second photoelectric conversion signal, that is, the first focus detection signal. Similarly, the readout circuit is configured such that the first and second photoelectric conversion signals are simultaneously read from the plurality of pixels 220B arranged in the row direction of the second imaging unit 22, and the first and second readouts are performed simultaneously. The phase difference focus detection calculation is performed based on the second photoelectric conversion signal, that is, the second focus detection signal. Thereby, if the phase difference focus detection calculation is performed by the first focus detection signal read simultaneously or by the second focus detection signal read simultaneously, the calculation accuracy of the defocus amount increases. The focus adjustment accuracy of the photographic optical system 10 is improved, and the quality of an image obtained by imaging can be improved.

<Other variations>
(1) In the above description, for each of the pixels 210 and 220 at the center of the imaging surface of the first and second imaging units 21 and 22, the center of the photoelectric conversion unit 210a, the center of the photoelectric conversion unit 220a, and the microlens. The photoelectric conversion unit 210a, the photoelectric conversion unit 220a, and the microlens 233 are arranged so that the optical axis 233a of 233 coincides. However, for the pixels 210 and 220 located in the periphery of the imaging surface, the subject light that has passed through the imaging optical system 10 is incident on the imaging surface obliquely, so that the center of the microlens 233 is the center of the photoelectric conversion unit 210a. Also, it may be shifted with respect to the center of the photoelectric conversion unit 220a. Even in this case, since the interval between the photoelectric conversion unit 210a and the photoelectric conversion unit 220a is small, it is not necessary to shift the center of the photoelectric conversion unit 210a with respect to the center of the photoelectric conversion unit 220a.
(2) In the second imaging unit 22 described above, the material used for the organic photoelectric conversion film is the same for all the pixels 220. However, for the “G” pixel 220, a material that absorbs light of a green color component and performs photoelectric conversion may be used. Similarly, the “B” pixel 220 may use a material that photoelectrically converts light of a blue color component, and the “R” pixel 220 absorbs light of a red color component and performs photoelectric conversion. Materials may be used.

(3) In the above description, the shared common electrode 236 is shared by all the pixels 210A and 220A. However, the shared common electrode 236 is not necessarily shared by all the pixels 210A and 220A. For example, any one pixel 210A and one pixel 220A in the correspondence relationship with the one pixel 210A share the common common electrode, and the common common electrode serves as another pixel with the other pixel 210A. The common electrode shared by 220A may be a different electrode. The plurality of pixels 210A in a partial region of the first imaging unit 21 and the plurality of pixels 220A in correspondence with the plurality of pixels 210A may share one common common electrode.

(4) In the first and second embodiments described above, it is not essential to provide the microlens 233.
In addition, you may combine each embodiment and modification which were mentioned above, respectively. As an example, for example, the first and second imaging units 21 and 22 described in the third embodiment described above have the first common common electrode 236 described in the second embodiment. The second imaging units 21 and 22 may be configured.
(5) In the above description, the organic photoelectric films 230 and 250 using the organic material that absorbs light and performs photoelectric conversion are used in the photoelectric conversion units 210a and 220a. However, an inorganic material that absorbs light and performs photoelectric conversion is used. The photoelectric film used may be used.

  Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other embodiments 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, 10: Image pick-up optical system, 11: Image pick-up element, 12; Control part, 12d; Signal addition part, 14: Image processing part, 21: 1st image pick-up part, 22; Semiconductor substrate, 210, 220, 210A, 220A, 210B, 220B; pixel, 210a, 1210a; first photoelectric conversion unit, 210b, 1210b; second photoelectric conversion unit, 220a, 1220a; first photoelectric conversion unit 220b, 1220b; second photoelectric converters 151, 153; column scanning circuit 152; horizontal output circuit 154; first horizontal output circuit 155; second horizontal output circuit 163; row scanning circuit; 164; first horizontal output circuit, 165; second horizontal output circuit, 233; microlens, 230, 250; organic photoelectric film, 231,251; common electrode, 232,252; part First partial electrode, 232b, 252b; second partial electrode, 236; shared common electrode, 301, 301a, 301b, 304; output transistor, 302, 302a, 302b, 305; reset transistor, 303, 303a, 303b, 306; selection transistor

Claims (14)

A first imaging unit having first and second photoelectric conversion units that photoelectrically convert light of the first and second color components using a film that performs photoelectric conversion;
A third photoelectric conversion unit that receives and transmits photoelectrically transmitted light that has passed through the first photoelectric conversion unit using a film that performs photoelectric conversion, and a second photoelectric conversion unit that transmits through the film that performs photoelectric conversion And a second imaging unit having a fourth photoelectric conversion unit that receives the transmitted light and performs photoelectric conversion. The imaging device according to claim 1,
The film for photoelectric conversion is an imaging device which is an organic photoelectric conversion film. The image sensor according to claim 1 or 2,
The color component of the transmitted light that has passed through the first photoelectric conversion unit is in a complementary color relationship with the first color component,
An image sensor in which a color component of transmitted light that has passed through the second photoelectric conversion unit has a complementary color relationship with the second color component. The imaging device according to any one of claims 1 to 3,
A first readout circuit that reads out photoelectric conversion signals from the first and second photoelectric conversion units and a second readout circuit that reads out photoelectric conversion signals from the third and fourth photoelectric conversion units are provided. A semiconductor substrate,
The second imaging unit is provided on one surface of the semiconductor substrate,
The first imaging unit is an imaging device provided on the one surface of the semiconductor substrate via the second imaging unit. The imaging device according to any one of claims 1 to 4,
A transparent first common electrode is provided between the film for photoelectric conversion of the first photoelectric conversion unit and the film for photoelectric conversion of the third photoelectric conversion unit,
An imaging device in which a transparent second common electrode is provided between a film for photoelectric conversion of the second photoelectric conversion unit and a film for photoelectric conversion of the fourth photoelectric conversion unit. The imaging device according to claim 5,
The imaging device, wherein the first common electrode and the second common electrode are the same electrode. The imaging device according to any one of claims 1 to 6,
The first imaging unit further includes a fifth photoelectric conversion unit that photoelectrically converts light of a third color component different from the first and second color components using a film that performs photoelectric conversion,
The second imaging unit further includes a sixth photoelectric conversion unit that receives and transmits photoelectrically transmitted light that has passed through the fifth photoelectric conversion unit using a film that performs photoelectric conversion. The imaging device according to claim 4,
The first imaging unit further includes a fifth photoelectric conversion unit that photoelectrically converts light of a third color component different from the first and second color components using a film that performs photoelectric conversion,
The second imaging unit further includes a sixth photoelectric conversion unit that receives and photoelectrically transmits transmitted light that has passed through the fifth photoelectric conversion unit using a film that performs photoelectric conversion,
The first readout circuit further reads out a photoelectric conversion signal from the fifth photoelectric conversion unit,
The second reading circuit is an imaging device that further reads a photoelectric conversion signal from the sixth photoelectric conversion unit. The imaging device according to claim 7 or 8,
The color sensor of the transmitted light that has passed through the fifth photoelectric conversion unit is an image pickup device having a complementary color relationship with the third color component. The image sensor according to any one of claims 1 to 9,
A first image data generation unit that generates first image data by a photoelectric conversion signal output from the first imaging unit;
An imaging apparatus comprising: a second image data generation unit configured to generate second image data based on a photoelectric conversion signal output from the second imaging unit. A first imaging unit that receives incident light;
A second imaging unit that receives transmitted light that has passed through the first imaging unit,
The first imaging unit includes a first pixel having first and second photoelectric conversion units arranged in a first direction, each photoelectrically converting the incident light using a photoelectric conversion film,
The second imaging unit includes third and fourth photoelectric conversion units arranged in a second direction different from the first direction, each of which converts the transmitted light using a photoelectric conversion film. An imaging device having a second pixel. The imaging device according to claim 11,
The first and second photoelectric conversion units absorb and photoelectrically convert light of the first color component of the incident light,
The third and fourth photoelectric conversion units are image sensors that perform photoelectric conversion by absorbing the transmitted light of the second color component that is complementary to the first color component. The image sensor according to claim 11 or 12,
A first phase difference type focus detection unit that performs focus detection of the imaging optical system based on the first signals from the first and second photoelectric conversion units;
A second phase difference type focus detection unit that performs focus detection of the imaging optical system based on the second signals from the third and fourth photoelectric conversion units;
A focus adjustment apparatus comprising: a focus adjustment unit configured to perform focus adjustment based on a focus detection result in the first phase difference type focus detection unit and a focus detection result in the second phase difference type focus detection unit. The image sensor according to claim 11 or 12,
A first phase difference type focus detection unit that performs focus detection of the imaging optical system based on a first signal from the first photoelectric conversion unit and a second signal from the second photoelectric conversion unit;
A second phase difference type focus detection unit that performs focus detection of the imaging optical system based on a third signal from the third photoelectric conversion unit and a fourth signal from the fourth photoelectric conversion unit;
A focus adjustment unit that performs focus adjustment based on a focus detection result in the first phase difference type focus detection unit and a focus detection result in the second phase difference type focus detection unit;
An image pickup apparatus comprising: an image signal generation unit that generates an image signal by adding the first signal and the second signal and / or adding the third signal and the fourth signal.

Images