Imaging device

Abstract

Provided is an imaging device comprising: a plurality of pixel units which each include a first and second photoelectric conversion unit that have differing light reception sensitivities and a node that is provided between the first photoelectric conversion unit and the second photoelectric conversion unit; and connection parts which each electrically connect the node of one pixel unit to the node of another pixel unit.

Description

Imaging device

[0001] The present disclosure relates to an imaging device.

[0002] There has been a demand for imaging devices to expand the illuminance range of a subject that can be photographed with gradation, i.e., the dynamic range. Accordingly, as disclosed in Patent Document 1 below, a technology has been proposed for expanding the dynamic range by intentionally creating a difference in light receiving sensitivity between a pair of photodiodes that detect light of the same color and that constitute one pixel unit, by changing the areas in a plan view of the pair of photodiodes.

[0003] JP 2023-11858 A

[0004] In recent years, there has been a strong demand for imaging devices with an increased number of pixels (maximum number of pixels) in order to obtain higher-resolution images. However, in imaging devices, increasing the number of pixels increases the amount of output data, which inevitably leads to slower readout speeds and processing speeds, higher power consumption, and an increased data rate.

[0005] Therefore, the present disclosure proposes an imaging device that achieves faster readout speeds and processing speeds, lower power consumption, and suppressed increases in data rate without reducing the number of pixels.

[0006] According to the present disclosure, an imaging device is provided that includes a plurality of pixel units, each including first and second photoelectric conversion units having different light receiving sensitivities and a node provided between the first photoelectric conversion unit and the second photoelectric conversion unit, and a connection unit that electrically connects the node of one of the pixel units to the node of another of the pixel units.

[0007] FIG. 1 is an explanatory diagram showing an example configuration of an imaging device 10 according to an embodiment of the present disclosure. FIG. 2 is an equivalent circuit diagram of a pixel unit 100a according to a comparative example. FIG. 3 is an explanatory diagram showing an example planar configuration of a main part of a pixel unit 100a according to a comparative example. FIG. 4 is an explanatory diagram showing an example cross-sectional configuration of a main part of a pixel unit 100a according to a comparative example. FIG. 5 is an explanatory diagram (part 1) showing an example planar configuration of a main part of a pixel unit 100 according to a first embodiment of the present disclosure. FIG. 6 is an explanatory diagram (part 2) showing an example planar configuration of a main part of a pixel unit 100 according to a first embodiment of the present disclosure. FIG. 7 is an explanatory diagram showing an example stacked configuration of an imaging device 10 according to a first embodiment of the present disclosure. FIG. 8 is an explanatory diagram showing an example planar configuration of a main part of a pixel unit 100 according to a second embodiment of the present disclosure. FIG. 9 is an explanatory diagram showing an example planar configuration of a main part of a pixel unit 100 according to a second embodiment of the present disclosure. FIG. 10 is an explanatory diagram (part 1) showing an example planar configuration of a main part of a pixel unit 100 according to a third embodiment of the present disclosure. FIG. 11 is an equivalent circuit diagram (part 1) of a main part of a pixel unit 100 according to a third embodiment of the present disclosure. FIG. 2 is an explanatory diagram (part 2) showing an example of a planar configuration of a main part of a pixel unit 100 according to a third embodiment of the present disclosure. FIG. 3 is an explanatory diagram (part 3) showing an example of a planar configuration of a main part of a pixel unit 100 according to a third embodiment of the present disclosure. FIG. 4 is an explanatory diagram (part 4) showing an example of a planar configuration of a main part of a pixel unit 100 according to a third embodiment of the present disclosure. FIG. 5 is an explanatory diagram (part 5) showing an example of a planar configuration of a main part of a pixel unit 100 according to a third embodiment of the present disclosure. FIG. 6 is an equivalent circuit diagram (part 5) of a main part of a pixel unit 100 according to a third embodiment of the present disclosure. FIG. 7 is an equivalent circuit diagram (part 7) of a main part of a pixel unit 100 according to a fourth embodiment of the present disclosure. FIG. 8 is an equivalent circuit diagram (part 8) of a main part of a pixel unit 100 according to a fourth embodiment of the present disclosure. Fig. 1 is an equivalent circuit diagram of a main part of a pixel unit 100 according to a fifth embodiment of the present disclosure. Fig. 2 is an equivalent circuit diagram of a main part of a pixel unit 100 according to a fifth embodiment of the present disclosure. Fig. 3 is an equivalent circuit diagram of a main part of a pixel unit 100 according to a sixth embodiment of the present disclosure. Fig. 4 is an equivalent circuit diagram of a main part of a pixel unit 100 according to the sixth embodiment of the present disclosure.It is an explanatory diagram showing an example of a schematic functional configuration of a camera. It is a block diagram showing an example of a schematic functional configuration of a smartphone. It is a block diagram showing an example of a schematic configuration of a vehicle control system. It is an explanatory diagram showing an example of an installation position of an outside-vehicle information detection unit and an imaging unit.

[0008] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted. Furthermore, in this specification and the drawings, multiple components having substantially the same or similar functional configurations may be distinguished by adding different letters after the same reference numeral. However, when there is no particular need to distinguish between multiple components having substantially the same or similar functional configurations, only the same reference numerals will be used.

[0009] Furthermore, the drawings referenced in the following description are intended to facilitate the description and understanding of the embodiments of the present disclosure. For clarity, the shapes, dimensions, ratios, etc. shown in the drawings may differ from the actual shapes. Furthermore, descriptions of specific shapes in the following description do not only refer to the geometrically specific shape, but also include shapes similar to the specific shape that have tolerances (errors and distortions) in the manufacture and use of imaging devices. For example, the term "approximately circular shape" in the following description does not necessarily refer to a perfect circle, but also to shapes similar to a perfect circle, such as an ellipse. Furthermore, the design of the devices shown in the drawings can be modified as appropriate, taking into account the following description and known technologies.

[0010] Furthermore, in the following description, "electrically connected" means connecting a plurality of elements directly or indirectly via another element.

[0011] In the following description, "sharing" means that different elements (e.g., photodiodes, pixel units, etc.) share one other element (e.g., on-chip lenses, floating diffusions, etc.).

[0012] 1. Schematic configuration of an imaging device 1.1 Imaging device 1.2 Pixel unit 2. Background leading to creation of embodiments of the present disclosure 3. First embodiment 4. Second embodiment 5. Third embodiment 6. Fourth embodiment 7. Fifth embodiment 8. Sixth embodiment 9. Summary 10. Application examples 10.1 Application example to a camera 10.2 Application example to a smartphone 10.3 Application example to a mobile object 11. Supplementary information

[0013] <<1. Schematic Configuration of Imaging Device>> <1.1 Imaging Device> First, a schematic configuration of an imaging device 10 according to an embodiment of the present disclosure will be described with reference to FIG. 1 . FIG. 1 is an explanatory diagram showing an example of the planar configuration of the imaging device 10 according to an embodiment of the present disclosure. As shown in FIG. 1 , the imaging device 10 according to an embodiment of the present disclosure includes a pixel array section 33 in which a plurality of pixel units 100 are arranged in a matrix on a semiconductor substrate 15 made of silicon, for example, and a peripheral circuit section provided to surround the pixel array section 33. Furthermore, the imaging device 10 includes a column signal processing circuit section 34, a vertical drive circuit section 35, a horizontal drive circuit section 36, an output circuit section 38, a control circuit section 40, and the like as the peripheral circuit section. Each block of the imaging device 10 will be described in detail below.

[0014] (Pixel Array Section 33) The pixel array section 33 has a plurality of pixel units 100 arranged two-dimensionally in a matrix along the row direction (X direction in FIG. 1) and column direction (Y direction in FIG. 1) on the semiconductor substrate 15. Each pixel unit 100 has a photodiode (photoelectric conversion section) (not shown) that performs photoelectric conversion on incident light and generates electric charges, and a plurality of pixel transistors (e.g., MOS (Metal-Oxide-Semiconductor) transistors) (not shown). The pixel transistors include MOS transistors such as, for example, a transfer transistor, a selection transistor, a reset transistor, and an amplification transistor. Details of the pixel units 100 will be described later.

[0015] (Column Signal Processing Circuit Unit 34) The column signal processing circuit unit 34 is arranged for each column of pixel units 100, and performs signal processing such as noise removal for each pixel column on pixel signals output from one row of pixel units 100. For example, the column signal processing circuit unit 34 performs signal processing such as CDS (Correlated Double Sampling) and AD (Analog-Digital) conversion in order to remove fixed pattern noise specific to each pixel.

[0016] (Vertical Drive Circuit Unit 35) The vertical drive circuit unit 35 is formed of, for example, a shift register, selects a pixel drive wiring 42, supplies a pulse for driving the pixel unit 100 to the selected pixel drive wiring 42, and drives the pixel units 100 row by row. That is, the vertical drive circuit unit 35 selects and scans each pixel unit 100 in the pixel array unit 33 row by row in the vertical direction (Y direction in FIG. 1 ), and supplies a pixel signal based on a signal charge generated in accordance with the amount of light received by the photodiode of each pixel unit 100 to a column signal processing circuit unit 34 (described later) through a vertical signal line 44.

[0017] (Horizontal drive circuit unit 36) The horizontal drive circuit unit 36 ​​is formed, for example, by a shift register, and sequentially outputs horizontal scanning pulses to select each of the above-mentioned column signal processing circuit units 34 in turn, and cause each column signal processing circuit unit 34 to output a pixel signal to the horizontal signal line 46.

[0018] (Output Circuit Unit 38) The output circuit unit 38 performs signal processing on pixel signals sequentially supplied from each of the column signal processing circuits 34 via the horizontal signal line 46 and outputs the processed signals. The output circuit unit 38 may function as a functional unit that performs buffering, or may perform processes such as black level adjustment, column variation correction, and various digital signal processing. Note that buffering refers to temporarily storing pixel signals to compensate for differences in processing speed and transfer speed when exchanging pixel signals. Furthermore, the input / output terminals 48 are terminals for exchanging signals with external devices.

[0019] (Control Circuit Unit 40) The control circuit unit 40 receives an input clock and data instructing the operation mode and the like, and outputs data such as internal information of the imaging device 10. That is, the control circuit unit 40 generates clock signals and control signals that serve as references for the operations of the vertical drive circuit unit 35, column signal processing circuit unit 34, horizontal drive circuit unit 36, etc., based on a vertical synchronization signal, a horizontal synchronization signal, and a master clock. The control circuit unit 40 then outputs the generated clock signals and control signals to the vertical drive circuit unit 35, column signal processing circuit unit 34, horizontal drive circuit unit 36, etc.

[0020] In the embodiment of the present disclosure, the imaging device 10 is not limited to the form shown in FIG. 1, but can be modified into various forms.

[0021] <1.2 Pixel Unit> Next, a detailed configuration of a pixel unit 100a according to a comparative example will be described with reference to Fig. 2. Fig. 2 is an equivalent circuit diagram of the pixel unit 100a according to the comparative example. Here, the comparative example refers to the pixel unit 100a that the inventors of the present disclosure had studied before creating the embodiments of the present disclosure.

[0022] As shown in Fig. 2, the pixel unit 100a has photodiodes (photoelectric conversion units) PD1 and PD2 as photoelectric conversion elements that convert light into electric charges. The pixel unit 100a also has, for example, transistors AMP, FCG, FDG, RST, SEL, TGL, and TGS as pixel transistors. The pixel unit 100a also has a capacitance element FC and a floating diffusion (charge storage unit) FD. In the example shown in Fig. 2, the transistors AMP, FCG, FDG, RST, SEL, TGL, and TGS are n-type MOS transistors.

[0023] 2 also shows control lines FCGL, FDGL, TGLL, TGSL, a reset signal line RSTL, a selection line SELL, and a signal line SGL. The control line TGLL extends in the horizontal direction (the X direction in FIG. 1), and a signal STGL is applied to the control line TGLL by the vertical drive circuit unit 35. The control line FDGL extends in the horizontal direction, and a signal SFDG is applied to the control line FDGL by the vertical drive circuit unit 35. The reset signal line RSTL extends in the horizontal direction, and a signal SRST is applied to the reset signal line RSTL by the vertical drive circuit unit 35. The control line FCGL extends in the horizontal direction, and a signal SFCG is applied to the control line FCGL by the vertical drive circuit unit 35. The control line TGSL extends in the horizontal direction, and a signal STGS is applied to the control line TGSL by the vertical drive circuit unit 35. The selection line SELL extends in the horizontal direction, and a signal SSEL is applied to the selection line SELL by the vertical drive circuit unit 35. The signal line SGL extends in the vertical direction (the Y direction in FIG. 1 ), and is electrically connected to the column signal processing circuit unit 34.

[0024] The photodiodes PD1 and PD2 are photoelectric conversion elements (photoelectric conversion units) that generate and store an amount of charge corresponding to the amount of light received. Specifically, the photodiodes PD1 and PD2 have a photoelectric conversion region containing impurities of a first conductivity type (e.g., n-type) disposed within a second conductivity type (e.g., p-type) impurity region formed on a semiconductor substrate 15 made of silicon. In the comparative example, for example, the light-receiving region of the photodiode PD1 that can receive light is wider than the light-receiving region of the photodiode PD2, thereby making the photodiode PD1 more sensitive to light than the photodiode PD2. In other words, the pixel unit 100a according to the comparative example includes a pair of photodiodes PD1 and PD2 that detect light of the same color, and a difference in light-receiving sensitivity is intentionally established between the pair of photodiodes PD1 and PD2. That is, the pixel unit 100a according to the comparative example has a subpixel structure.

[0025] 2, the anode of the photodiode PD1 is grounded, and the cathode of the photodiode PD1 is electrically connected to one of the source and drain of the transistor TGL. Also, the anode of the photodiode PD2 is grounded, and the cathode of the photodiode PD2 is electrically connected to one of the source and drain of the transistor TGS.

[0026] The gate of the transistor TGL is connected to a control line TGLL, one of the source and drain of the transistor TGL is electrically connected to the cathode of the photodiode PD1, and the other of the source and drain of the transistor TGL is electrically connected to the floating diffusion FD. The transistor TGL becomes conductive in response to a voltage applied to its gate, and can transfer the charge generated in the photodiode PD1 to the floating diffusion FD. In other words, the transistor TGL functions as a transfer transistor.

[0027] The floating diffusion FD accumulates electric charges from the photodiodes PD1 and PD2, and is configured using, for example, an impurity diffusion layer formed on the surface of the semiconductor substrate 15. In Fig. 2, the floating diffusion FD is indicated by a symbol for a capacitance element.

[0028] The floating diffusion FD is electrically connected to the gate of a transistor AMP, which is an amplifying transistor that converts electric charge into a voltage and outputs the voltage as a signal. One of the source and drain of the transistor AMP is electrically connected to one of the source and drain of a transistor SEL, which is a selection transistor that outputs the converted signal to a signal line SGL in accordance with a selection signal. The other of the source and drain of the transistor AMP is electrically connected to a power supply circuit (power supply potential VDD).

[0029] The other of the source and drain of the transistor SEL is electrically connected to the signal line SGL that transmits the converted voltage as a signal, and is further electrically connected to the column signal processing circuit unit 34. The gate of the transistor SEL is electrically connected to a selection line SELL that selects a row to output a signal, and is further electrically connected to the vertical drive circuit unit 35. That is, the charge accumulated in the floating diffusion FD is converted into a voltage (pixel signal) by the transistor AMP under the control of the transistor SEL, and is output to the signal line SGL.

[0030] 2, the floating diffusion FD is electrically connected, via a transistor FDG, to one of the drain and source of a transistor RST, which is a reset transistor for resetting the accumulated charge. The gate of the transistor RST is electrically connected to a reset signal line RSTL and is further electrically connected to the above-mentioned vertical drive circuit unit 35. The other of the drain and source of the transistor RST is electrically connected to a power supply circuit (power supply potential VDD). The transistor RST becomes conductive in response to a voltage applied to its gate, and can reset (discharge to the power supply circuit (power supply potential VDD)) the charge accumulated in the floating diffusion FD.

[0031] One of the source and drain of the transistor TGS is electrically connected to the cathode of the photodiode PD2, and the gate of the transistor TGS is connected to a control line TGSL. The transistor TGS becomes conductive in response to a voltage applied to its gate, and can transfer the charge generated in the photodiode PD2 to the floating diffusion FD, etc. In other words, the transistor TGS functions as a transfer transistor.

[0032] The other of the source and the drain of the transistor TGS is electrically connected to one end of the capacitance element FC and to one of the source and the drain of the transistor FCG.

[0033] One end of the capacitance element FC is electrically connected to the other of the source and drain of the transistor TGS and one of the source and drain of the transistor FCG, and one end of the capacitance element FC is electrically connected to the power supply circuit (power supply potential VDD).

[0034] The gate of the transistor FCG is connected to a control line FCGL, and one of the source and drain of the transistor FCG is electrically connected to one end of the capacitive element FC and the other of the source and drain of the transistor TGS. Furthermore, the other of the source and drain of the transistor FCG is electrically connected to one of the source and drain of the transistor RST and one of the source and drain of the transistor FDG.

[0035] The gate of the transistor FDG is connected to a control line FDGL, one of the source and drain of the transistor FDG is electrically connected to one of the source and drain of the transistor RST and the other of the source and drain of the transistor FCG, and the other of the source and drain of the transistor FDG is electrically connected to the floating diffusion FD.

[0036] When a signal SFDG is applied to the gate of the transistor FDG, the transistor FDG becomes conductive, and as a result, the floating diffusion FD and the transistor FDG form a combined capacitance. As the capacitance value increases in this way, the conversion efficiency when converting electric charge into a voltage signal can be reduced. In other words, the transistor FDG functions as a switching transistor that switches the transfer efficiency.

[0037] Furthermore, when a signal SFDG is applied to the gate of the transistor FDG and a signal SFCG is applied to the gate of the transistor FCG, the transistors FDG and FCG are turned on, and therefore the transistors FDG and FCG and the capacitance element FC form a composite capacitance that can store the charge generated in the photodiode PD2. In other words, the transistor FCG functions as a capacitance-connected transistor connected to the capacitance element FC.

[0038] In the comparative example, as explained above, the photodiode PD1 has a wider light-receiving area than the photodiode PD2. Therefore, when an object with a certain illuminance is photographed with a certain exposure time, the charge generated in the photodiode PD1 is greater than the charge generated in the photodiode PD2. In other words, since the photodiode PD1 generates a large amount of charge, it can be said that the photodiode PD1 is an imaging element that can photograph an object even with low illuminance.

[0039] Therefore, when the charges generated in the photodiode PD1 and the charges generated in the photodiode PD2 are transferred to the floating diffusion FD and then subjected to charge-to-voltage conversion, the voltage change before and after the charges generated in the photodiode PD1 are transferred to the floating diffusion FD is larger than the voltage change before and after the charges generated in the photodiode PD2 are transferred to the floating diffusion FD. Therefore, when comparing the photodiodes PD1 and PD2, it can be said that the photodiode PD1 has higher sensitivity than the photodiode PD2.

[0040] In contrast, the photodiode PD2 has a narrower light-receiving area than the photodiode PD1, and therefore generates a smaller amount of charge. Therefore, the charge generated by the photodiode PD2 is less likely to saturate the floating diffusion FD, even when the subject is highly illuminant. Furthermore, even when high-intensity light is incident on the photodiode PD2 and a charge exceeding the saturation charge capacity of the photodiode PD2 is generated, the photodiode PD2 can accumulate the charge exceeding the saturation charge capacity in the capacitance element FC, etc. Therefore, when converting the charge generated by the photodiode PD2 into a voltage, the charge-voltage conversion can be performed after adding both the charge accumulated in the photodiode PD2 and the charge accumulated in the capacitance element FC, etc. Therefore, the photodiode PD2 can capture images with more gradation over a wider range of illumination than the photodiode PD1. In other words, the photodiode PD2 can capture images with a wider dynamic range.

[0041] Therefore, the image pickup device 10 according to the comparative example can obtain two images: a highly sensitive image captured using the photodiode PD1, and an image with a wide dynamic range captured using the photodiode PD2. These two images are then combined into a single image through wide dynamic range image synthesis processing, which combines the two images into a single image, in, for example, an image signal processing circuit provided inside the image pickup device 10 or an image signal processing device connected externally.

[0042] The equivalent circuit of the pixel unit 100a according to the comparative example is not limited to the example shown in FIG. 2, and may include other elements, for example, and is not particularly limited.

[0043] Next, a detailed configuration of a pixel unit 100a according to a comparative example will be described with reference to FIGS. 3A and 3B. FIG. 3A is an explanatory diagram showing an example of a planar configuration of a main part of the pixel unit 100a according to the comparative example. In FIG. 3A, the on-chip lens 106 is not shown, and in FIG. 3, "R" indicates a photodiode PD that detects red light, "B" indicates a photodiode PD that detects blue light, and "G" indicates a photodiode PD that detects green light (note that the same is indicated in the figures referred to in the following description). FIG. 3B is an explanatory diagram showing an example of a cross-sectional configuration of a main part of the pixel unit 100a according to the comparative example, and corresponds to a cross-sectional view taken along line A-A' in FIG. 3A.

[0044] In the comparative example, the multiple photodiodes PD are arranged in the pixel array section 33 according to a predetermined rule. Specifically, in the comparative example, as shown in FIG. 3A , the photodiode PD1 has an octagonal shape in a plan view, and the photodiode PD2 has a rectangular shape in a plan view. The pair of photodiodes PD1 and PD2 arranged adjacent to each other constitute a pixel unit 100a and have color filters 104 of the same type (color) that transmit light having wavelengths in a predetermined wavelength band. Furthermore, each of the pair of photodiodes PD1 and PD2 has an on-chip lens 106 that is substantially circular in a plan view (see FIG. 3B ).

[0045] 3B , in the comparative example, each of the photodiodes PD1 and PD2 constituting one pixel unit 100a mainly includes, for example, an on-chip lens 106, a color filter 104, and a light-shielding portion 108. Furthermore, each of the photodiodes PD1 and PD2 further includes a photoelectric conversion region 102 provided in the semiconductor substrate 15.

[0046] 3B , each of the photodiodes PD1 and PD2 has one on-chip lens 106 that is provided above the light incident surface of the semiconductor substrate 15 and that focuses incident light onto the photoelectric conversion region 102. In the comparative example, the incident light focused by the on-chip lens 106 enters the photoelectric conversion region 102 via a color filter 104 that is provided below the on-chip lens 106. The color filter 104 can be, for example, a color filter that transmits light having a red wavelength component, a color filter that transmits light having a green wavelength component, or a color filter that transmits light having a blue wavelength component.

[0047] 3B , a light-shielding portion 108 is provided on the light incident surface of the semiconductor substrate 15 so as to surround the color filter 104. The light-shielding portion 108 is provided between the adjacent photodiodes PD1 and PD2, thereby blocking light between the adjacent photodiodes PD1 and PD2. Although not shown in FIG. 3B , an interlayer insulating film may be provided between the semiconductor substrate 15 and the color filter 104.

[0048] 3B , in the comparative example, a photoelectric conversion region 102 having impurities of a first conductivity type (e.g., n-type) is provided for each of the photodiodes PD1 and PD2 in a semiconductor substrate 15 having a second conductivity type (e.g., p-type). The photoelectric conversion region 102 can absorb light having red wavelength components, green wavelength components, blue wavelength components, etc., that is incident via the color filter 104 described above, and generate electric charges.

[0049] Furthermore, an element isolation wall (not shown) that surrounds and physically separates the photoelectric conversion regions 102 provided for each of the photodiodes PD1 and PD2 may be provided in the semiconductor substrate 15. The element isolation wall is made of, for example, a deep trench isolation (DTI). The DTI is formed by forming a trench that extends from the light incident surface side of the semiconductor substrate 15 along the thickness direction of the semiconductor substrate 15 to the middle of the semiconductor substrate 15 or through the entire semiconductor substrate 15, and then filling the trench with a material such as an oxide film or a metal film.

[0050] Furthermore, the charges generated in the photoelectric conversion region 102 are transferred to a floating diffusion FD provided in an impurity diffusion region having a first conductivity type (e.g., n-type) provided in the semiconductor substrate 15, for example, via a pixel transistor (not shown) provided on the opposite side of the light incident surface of the semiconductor substrate 15.

[0051] The configuration of the pixel unit 100a according to the comparative example is not limited to the example shown in Figures 3A and 3B, and may include other elements, for example, and is not particularly limited.

[0052] <<2. Background to the Creation of the Embodiments of the Present Disclosure>> Next, before describing the embodiments of the present disclosure, the background to the creation of the embodiments of the present disclosure by the inventors will be described.

[0053] As explained above, in the comparative example, in order to further expand the illuminance range of a subject that can be photographed with gradation, i.e., the dynamic range, the areas of the photodiodes PD1 and PD2 that detect light of the same color are changed in a planar view to intentionally provide a difference in light sensitivity between the photodiodes PD1 and PD2. In other words, the pixel unit 100a of the imaging device 10 according to the comparative example has a subpixel structure in which a difference in light sensitivity is intentionally provided between the pair of photodiodes PD1 and PD2 that detect light of the same color.

[0054] In recent years, there has been a strong demand for increasing the number of pixels (maximum number of pixels), that is, increasing the number of pixel units 100 a, in order to obtain higher-resolution images in the imaging device 10. However, since the imaging device 10 according to the comparative example has a subpixel structure, increasing the number of pixel units 100 a increases the amount of output data, which inevitably leads to slower readout speeds and processing speeds, higher power consumption, and an increase in data rate.

[0055] In view of these circumstances, the inventors have devised an embodiment of the present disclosure that achieves increased readout speed and processing speed, reduced power consumption, and suppressed increases in data rate without reducing the number of pixel units 100 (number of pixels). In the embodiment of the present disclosure, the floating diffusions FD of the pixel units 100 are connected via a connection unit (e.g., a transistor) so that the floating diffusion FD is shared among multiple pixel units 100. Furthermore, in the embodiment of the present disclosure, a mode is provided in which output signals from multiple pixel units 100 connected via the connection unit are added together within the imaging device 10. In this manner, the embodiment of the present disclosure can achieve increased readout speed and processing speed, reduced power consumption, and suppressed increases in data rate without reducing the number of pixel units 100 (number of pixels). Furthermore, the embodiment of the present disclosure can improve the S / N ratio of the signal ultimately output from the imaging device 10 by adding together output signals from multiple pixel units 100 connected via the connection unit.

[0056] Hereinafter, details of the embodiments of the present disclosure created by the inventors will be described one by one.

[0057] <<3. First Embodiment>> First, details of the first embodiment of the present disclosure will be described with reference to FIGS. 4 to 6. FIGS. 4 and 5 are explanatory diagrams showing an example of a planar configuration of a main part of a pixel unit 100 according to this embodiment. Note that the on-chip lens 106 is not shown in FIGS. 4 and 5, and in FIGS. 4 and 5, "R" indicates a photodiode PD that detects red light, "B" indicates a photodiode PD that detects blue light, and "G" indicates a photodiode PD that detects green light (note that similar indications are used in figures referred to in the following description). Furthermore, FIG. 6 is an explanatory diagram showing an example of a stacked configuration of an image pickup device 10 according to this embodiment. Note that in the following description, it is assumed that the embodiment of the present disclosure is applied to an image pickup device 10 having a subpixel structure.

[0058] In this embodiment, the multiple photodiodes PD are arranged according to a predetermined rule in the pixel array section 33. In detail, as shown in Fig. 4, pixel units 100 each including a pair of photodiodes PD1 and PD2 arranged adjacent to each other and detecting light of the same color are arranged in a matrix on the semiconductor substrate 15 along the row direction (X direction in the drawing) and the column direction (Y direction in the drawing).

[0059] Specifically, as shown in FIG. 4 , for example, the plurality of pixel units 100 includes a pair of photodiodes PD1 and PD2 that generate charge with light having a red wavelength component (e.g., wavelength 620 nm to 750 nm), a pair of photodiodes PD1 and PD2 that generate charge with light having a green wavelength component (e.g., wavelength 495 nm to 570 nm), and a pair of photodiodes PD1 and PD2 that generate charge with light having a blue wavelength component (e.g., wavelength 450 nm to 495 nm). Furthermore, these plurality of pixel units 100 are two-dimensionally arranged, for example, according to a Bayer array. Here, the Bayer array is an array pattern in which pixel units 100 including a pair of photodiodes PD1 and PD2 that detect green light are arranged in a checkerboard pattern, and pixel units 100 including a pair of photodiodes PD1 and PD2 that detect red light and pixel units 100 including a pair of photodiodes PD1 and PD2 that detect blue light are arranged alternately in each row in the remaining portion. In this embodiment, the arrangement of the plurality of pixel units 100 is not limited to the Bayer arrangement.

[0060] Furthermore, in this embodiment, the photodiode (first photoelectric conversion unit) PD1, which has higher light-receiving sensitivity than the photodiode (second photoelectric conversion unit) PD2, has a substantially octagonal shape in a plan view, and its light-receiving area is larger than the light-receiving area of ​​the photodiode PD2. That is, in this embodiment as well, the photodiode PD1 has a higher sensitivity than the photodiode PD2. Furthermore, the photodiode PD2 has a substantially rectangular shape in a plan view. A pair of photodiodes PD1 and PD2, which are arranged adjacent to each other and detect light of the same color, constitute one pixel unit 100. Note that, in this embodiment, the shape of the photodiode PD is not limited to the shape described above.

[0061] Furthermore, a pair of photodiodes PD1 and PD2 that detect the same color have color filters 104 of the same type (color) that transmit light having wavelengths in a predetermined wavelength band. Specifically, the color filters 104 can be, for example, a color filter that transmits light having a red wavelength component (e.g., wavelengths of 620 nm to 750 nm), a color filter that transmits light having a green wavelength component (e.g., wavelengths of 495 nm to 570 nm), or a color filter that transmits light having a blue wavelength component (e.g., wavelengths of 450 nm to 495 nm). Note that, in this embodiment, the color filters 104 are not limited to those having the above-mentioned colors, and color filters that transmit light having wavelength components of other colors may also be used. Furthermore, the color filters 104 can be formed, for example, from a material in which a pigment or dye is dispersed in a transparent binder such as silicone.

[0062] Furthermore, each of the pair of photodiodes PD1 and PD2 has a circular on-chip lens 106 (not shown). Note that the cross section of the photodiodes PD1 and PD2 in this embodiment is similar to the cross section of the comparative example shown in FIG. 3B , and therefore a description thereof will be omitted here.

[0063] In the example shown in FIG. 4 , the light-receiving area of ​​photodiode PD1 capable of receiving light is larger than the light-receiving area of ​​photodiode PD2, thereby making the light-receiving sensitivity of photodiode PD1 higher than that of photodiode PD2. However, this embodiment is not limited to creating a difference in the light-receiving sensitivity between the pair of photodiodes PD1 and PD2 that detect light of the same color by providing a difference in the area of ​​the light-receiving area. In this embodiment, for example, the refractive index or light transmittance of the color filters 104 of the pair of photodiodes PD1 and PD2 may be different. This results in a difference in the ease with which light is guided to the photoelectric conversion region 102, resulting in a difference in light-receiving sensitivity between the pair of photodiodes PD1 and PD2 that detect light of the same color.

[0064] The pixel unit 100 according to this embodiment also includes a node that electrically connects the pair of photodiodes PD1 and PD2, and the node is electrically connected to the floating diffusion FD via another element. Details of the node will be described later.

[0065] Furthermore, in this embodiment, as shown in FIG. 4 , a connection unit 250 is provided that electrically connects the node to the node of another pixel unit 100 that detects light of the same color. The connection unit 250 includes, for example, wiring, a transistor, etc., and can electrically connect the floating diffusions FD of the pixel units 100 that detect light of the same color. In other words, the connection unit 250 can connect between multiple pixel units 100 that have color filters 104 of the same color. In this way, the floating diffusion FD can be shared between multiple pixel units 100 that detect light of the same color.

[0066] For example, in the example shown in FIG. 4 , four pixel units 100 that detect light of the same color are not adjacent to each other on the semiconductor substrate 15, but are electrically connected by the connection portions 250. Note that in this embodiment, the number of pixel units 100 connected by the connection portions 250 is not particularly limited as long as it is two or more. Also, in the example shown in FIG. 4 , the number of pixel units 100 that detect light of the same color connected to one connection portion 250 is the same for red, green, and blue, that is, four, but this is not limited to this in this embodiment. For example, the connection portion 250 may connect a different number of pixel units 100 for each color depending on the specifications required for the imaging device 10, the light receiving sensitivity of each color of light, etc.

[0067] Furthermore, this embodiment is not limited to the example shown in FIG. 4 , and may have a configuration such as that shown in FIG. 5 . Specifically, as shown in FIG. 5 , the photodiode PD1, which has higher light-receiving sensitivity than the photodiode PD2, has a substantially L-shape in plan view, and its light-receiving area is larger than that of the photodiode PD2. Furthermore, the photodiode PD2 has a substantially rectangular shape in plan view. Furthermore, in the example of FIG. 5 , the pair of photodiodes PD1 and PD2 constituting one pixel unit 100 may share one substantially circular on-chip lens 106 (not shown). Note that the cross sections of the photodiodes PD1 and PD2 in this embodiment are similar to the cross-sectional view of the comparative example shown in FIG. 3B , and therefore will not be described here.

[0068] Also in the example of FIG. 5 , the pixel unit 100 includes a node electrically connecting the pair of photodiodes PD1 and PD2, and the node is electrically connected to the floating diffusion FD via another element. Furthermore, also in the example of FIG. 5 , a connection unit 250 is provided that electrically connects the node to the node of another pixel unit 100 that detects light of the same color. The connection unit 250 is formed, for example, from wiring, a transistor, or the like, and can electrically connect the floating diffusions FD of each pixel unit 100 that detects light of the same color. In other words, the connection unit 250 can connect multiple pixel units 100 that have color filters 104 of the same color. In this way, the floating diffusion FD can be shared among multiple pixel units 100 that detect light of the same color. More specifically, in the example shown in FIG. 5 , four pixel units 100 that detect light of the same color are electrically connected by the connection unit 250.

[0069] Furthermore, in this embodiment, the use of a stacked structure allows the imaging device 10 to be made compact. For example, in the example shown in FIG. 6 , a substrate 60 on which the above-described peripheral circuitry is provided, a substrate 50 on which the above-described pixel transistors are provided, and a semiconductor substrate 15 on which photodiodes PD1, PD2, etc. are provided are stacked. Furthermore, a connection portion 250 made of wiring or the like can be provided on the substrate 50. Note that in the example shown in FIG. 6 , the semiconductor substrate 15 is provided with photodiodes PD1 and PD2 having the configuration shown in FIG. 5 above. However, in this embodiment, the configuration of the photodiodes PD1 and PD2 provided on the semiconductor substrate 15 is not limited to the example shown in FIG. 5 and may be, for example, the configuration shown in FIG. 4 .

[0070] Furthermore, in this embodiment, all pixel transistors are not limited to being provided on the substrate 50, but it is sufficient that at least some of the pixel transistors are provided, and the remaining pixel transistors can be provided on the substrate 60, the semiconductor substrate 15, etc. Furthermore, as will be described later, if the connection section 250 includes a transistor, the transistor can be provided on the substrate 50, etc. Furthermore, in this embodiment, the imaging device 10 is not limited to having a stacked structure of three substrates, but may have a stacked structure of two or more substrates, or may be composed of a single substrate.

[0071] As described above, in this embodiment, by connecting multiple pixel units 100 that detect light of the same color via the connection section 250, the floating diffusion FD is shared among the multiple pixel units 100. In this manner, in this embodiment, pixel signals can be added between the multiple pixel units 100 while maintaining color gamut. Therefore, according to this embodiment, since pixel signals can be added, it is possible to achieve faster readout speeds and processing speeds, lower power consumption, and suppress increases in data rate without reducing the number of pixel units 100. Furthermore, according to this embodiment, pixel signals output from the multiple pixel units 100 connected via the connection section 250 are added, thereby improving the S / N ratio of the signal finally output from the imaging device 10.

[0072] It should be noted that the configurations of the pixel unit 100 and the imaging device 10 according to this embodiment are not limited to the examples shown in FIGS.

[0073] 7A and 7B, a second embodiment of the present disclosure will be described. Fig. 7A is an explanatory diagram showing an example of the planar configuration of a main part of a pixel unit 100 according to this embodiment, and Fig. 7B is an explanatory diagram showing an example of the planar configuration of a main part of the pixel unit 100 according to this embodiment.

[0074] In the first embodiment described above, among the plurality of pixel units 100 arranged according to the Bayer array, four pixel units 100 that detect light of the same color and that are not adjacent to each other on the semiconductor substrate 15 are electrically connected by the connection portion 250. However, in the present disclosure, the combination of the plurality of pixel units 100 connected by the connection portion 250 is not limited to this form. Therefore, in the present embodiment, variations of the plurality of pixel units 100 connected by the connection portion 250 will be described.

[0075] 7A , pixel units 100 including a pair of photodiodes PD1 and PD2 arranged adjacent to each other and detecting light of the same color are arranged two-dimensionally, for example, according to the Bayer array, as in the first embodiment. Furthermore, four pixel units 100 arranged adjacent to each other on the semiconductor substrate 15 and detecting light of different colors are electrically connected by a connection portion 250. In other words, the multiple pixel units 100 connected by the connection portion 250 have color filters 104 of different colors. Note that in this embodiment, the number of pixel units 100 connected by the connection portion 250 is not particularly limited as long as it is two or more.

[0076] As described above, in this embodiment, by connecting multiple pixel units 100 that detect light of different colors with the connection section 250, the floating diffusion FD is shared among these multiple pixel units 100. In this manner, in this embodiment, the configuration of the connection section 250 can be simplified and shortened, facilitating manufacturing and enabling pixel signals to be added between multiple pixel units 100 while suppressing increases in wiring resistance, etc. Therefore, according to this embodiment, pixel signals can be added, thereby achieving higher readout speeds and processing speeds, lower power consumption, and suppressed increases in data rate, without reducing the number of pixel units 100. Furthermore, according to this embodiment, pixel signals output from multiple pixel units 100 connected by the connection section 250 are added, thereby improving the S / N ratio of the signal finally output from the imaging device 10. Note that, since the multiple pixel units 100 that detect light of different colors are connected, this embodiment has a lower color reproducibility than the first embodiment. However, this embodiment can be effective in applications where sensitivity is more important than color reproducibility, such as image monitoring in dark places.

[0077] Next, an example shown in FIG. 7B will be described. In the example shown in FIG. 7B , four pixel units 100 arranged in two rows in the row direction (X direction in the figure) and two columns in the column direction (Y direction in the figure) have color filters 104 of the same color. These four pixel units 100 form one unit and are arranged in a Bayer array. A Bayer array in which four pixel units 100 form one unit is referred to as a quad-Bayer array. Furthermore, four pixel units 100 that are adjacent to each other on the semiconductor substrate 15 and detect light of the same color are electrically connected by a connection portion 250. In other words, the pixel units 100 connected by the connection portion 250 have color filters 104 of the same color. In this embodiment, the number of pixel units 100 connected by the connection portion 250 is not particularly limited as long as it is two or more.

[0078] As described above, in this embodiment, in a Quad Bayer arrangement, adjacent pixel units 100 that detect light of the same color are connected by the connection section 250, thereby sharing a floating diffusion FD between the pixel units 100. In this manner, in this embodiment, the shape of the connection section 250 can be simplified and shortened, facilitating manufacturing and enabling pixel signals to be added between the pixel units 100 while suppressing increases in wiring resistance, etc. Furthermore, according to this embodiment, pixel signals can be added while maintaining color gamut, thereby achieving faster readout speeds and processing speeds, lower power consumption, and suppressed increases in data rate, without reducing the number of pixel units 100. In addition, according to this embodiment, pixel signals output from the pixel units 100 connected by the connection section 250 are added, thereby improving the S / N ratio of the pixel signal ultimately output from the imaging device 10.

[0079] It should be noted that the configuration of the pixel unit 100 according to this embodiment is not limited to the examples shown in FIGS. 7A and 7B.

[0080] <<5. Third Embodiment>> Next, a third embodiment of the present disclosure will be described with reference to Figures 8A to 12B. Figures 8A, 9A, 10A, 11A, and 1A are explanatory diagrams showing an example of the planar configuration of a main part of a pixel unit 100 according to this embodiment. In these figures, only the connection parts 250 that connect multiple pixel units 100 that detect red light are shown, and the connection parts 250 that connect multiple pixel units 100 that detect light of other colors are not shown. Also, Figures 8B, 9B, 10B, 11B, and 12B are equivalent circuit diagrams of the main part of the pixel unit 100 according to this embodiment.

[0081] In the first and second embodiments described above, four pixel units 100 arranged in two rows in the row direction (X direction in the drawings) and two columns in the column direction (Y direction in the drawings) are electrically connected by the connection portion 250. However, in the present disclosure, the number and arrangement of the plurality of pixel units 100 connected by the connection portion 250 are not limited to this form. Therefore, in the present embodiment, variations in the number and arrangement of the plurality of pixel units 100 connected by the connection portion 250 will be described.

[0082] 8A , the pixel units 100 are arranged two-dimensionally, for example, according to the Bayer array, as in the first embodiment. Furthermore, in the example shown in FIG. 8A , two pixel units 100 that detect red light are spaced apart from each other and arranged in one row in the row direction (X direction in the figure) and two columns in the column direction (Y direction in the figure), and are connected by a connection portion 250. In this manner, in this embodiment, by connecting the two pixel units 100 that detect red light and are arranged in one row and two columns on the semiconductor substrate 15 by the connection portion 250, the floating diffusion FD can be shared between the two pixel units 100.

[0083] The configuration of the pixel units 100 connected by the connection portion 250 shown in FIG. 8A can be represented by an equivalent circuit as shown in FIG. 8B.

[0084] As described above, the pixel unit 100 of this embodiment has a subpixel structure. Specifically, similar to the comparative example, the pixel unit 100 includes photodiodes (photoelectric conversion units) PD1 and PD2. The pixel unit 100 also includes, for example, transistors AMP, FCG, FDG, RST, SEL, TGL, and TGS as pixel transistors. The pixel unit 100 also includes a capacitive element FC and a floating diffusion (charge storage unit) FD. In the example shown in FIG. 8B , the transistors AMP, FCG, FDG, RST, SEL, TGL, and TGS are n-type MOS transistors.

[0085] In this embodiment, as in the comparative example, the light receiving area capable of receiving light of the photodiode (first photoelectric conversion unit) PD1 is wider than the light receiving area capable of receiving light of the photodiode (second photoelectric conversion unit) PD2, and thus the light receiving sensitivity of the photodiode PD1 is higher than that of the photodiode PD2.

[0086] 8B, in this embodiment, as in the comparative example, the anode of photodiode PD1 is grounded and the cathode of photodiode PD1 is electrically connected to one of the source and drain of transistor TGL, and the anode of photodiode PD2 is grounded and the cathode of photodiode PD2 is electrically connected to one of the source and drain of transistor TGS.

[0087] In addition, the gate of the transistor (first transfer transistor) TGL is connected to a control line TGLL (not shown), one of the source and drain of the transistor TGL is electrically connected to the cathode of the photodiode PD1, and the other of the source and drain of the transistor TGL is electrically connected to the floating diffusion FD.

[0088] The floating diffusion FD accumulates the charges from the photodiodes PD1 and PD2, and in FIG. 8B, the floating diffusion FD is indicated by a symbol of a capacitive element.

[0089] The floating diffusion FD is electrically connected to the gate of a transistor (amplification transistor) AMP. One of the source and drain of the transistor AMP is electrically connected to one of the source and drain of a transistor (selection transistor) SEL. The other of the source and drain of the transistor AMP is electrically connected to a power supply circuit (power supply potential VDD).

[0090] The other of the source and drain of the transistor SEL is electrically connected to the signal line SGL and is further electrically connected to the column signal processing circuit unit 34. The gate of the transistor SEL is electrically connected to a selection line SELL (not shown) and is further electrically connected to the vertical drive circuit unit 35.

[0091] 8B , the floating diffusion FD is electrically connected to one of the drain and source of a transistor (reset transistor) RST via a transistor FDG. The gate of the transistor RST is electrically connected to a reset signal line RSTL (not shown) and is further electrically connected to the above-mentioned vertical drive circuit unit 35. The other of the drain and source of the transistor RST is electrically connected to a power supply circuit (power supply potential VDD).

[0092] The transistor (second transfer transistor) TGS has one of its source and drain electrically connected to the cathode of the photodiode PD2, and its gate connected to a control line TGSL (not shown). The other of its source and drain is electrically connected to one end of the capacitance element FC and to one of the source and drain of the transistor FCG.

[0093] One end of the capacitance element FC is electrically connected to the other of the source and drain of the transistor TGS and one of the source and drain of the transistor FCG, and one end of the capacitance element FC is electrically connected to the power supply circuit (power supply potential VDD).

[0094] The gate of the transistor (capacitor-coupled transistor) FCG is connected to a control line FCGL (not shown), and one of the source and drain of the transistor FCG is electrically connected to one end of the capacitive element FC and the other of the source and drain of the transistor TGS. Furthermore, the other of the source and drain of the transistor FCG is electrically connected to one of the source and drain of the transistor RST and one of the source and drain of the transistor FDG.

[0095] The gate of the transistor (switching transistor) FDG is connected to a control line FDGL, one of the source and drain of the transistor FDG is electrically connected to one of the source and drain of the transistor RST and the other of the source and drain of the transistor FCG, and the other of the source and drain of the transistor FDG is electrically connected to the floating diffusion FD.

[0096] 8B, in the pixel unit 100, the two photodiodes PD1 and PD2 are electrically connected by a node ND via at least one pixel transistor among the plurality of pixel transistors included in the pixel unit 100. For example, as shown in FIG. 8B, the node ND is located between the transistor RST and the transistor FDG.

[0097] Furthermore, in this embodiment, the connection section 250 electrically connects to the node ND of each pixel unit 100, thereby electrically connecting the pixel units 100 together. In this embodiment, the connection section 250 may include one or more connection transistors FDL. For example, in the example shown in FIG. 8B , the connection section 250 includes one connection transistor FDL, and the connection transistor FDL is an n-type MOS transistor. In the example shown in FIG. 8B , by controlling the connection transistor FDL, it is possible to read out pixel signals from each of the pixel units 100 connected by the connection section 250.

[0098] In this embodiment, the node electrically connected directly by the connection portion 250 is preferably a node that is not directly connected to the photodiode PD1 and is distant from the photodiode PD1, such as the node ND shown in FIG. 8B . As described above, the photodiode PD1 is an image sensor capable of capturing images of subjects in low illumination. If the connection transistor FDL of the connection portion 250 were directly connected to the photodiode PD1, noise from the connection transistor FDL would be carried over to the pixel signal from the photodiode PD1. This would result in a deterioration in the S / N ratio of the pixel signal when capturing images of subjects in low illumination, for which the photodiode PD1 is primarily used. Therefore, in this embodiment, the node electrically connected directly by the connection portion 250 is preferably a node that is not directly connected to the photodiode PD1 and is distant from the photodiode PD1. On the other hand, in this embodiment, the node electrically connected directly by the connection portion 250 is preferably located closer to the photodiode PD2 than to the photodiode PD1. In other words, in this embodiment, the length of the wiring between the photodiode PD1 and the node ND may be shorter than the length of the wiring between the photodiode PD1 and the node ND. For example, even if the connection transistor FDL of the connection unit 250 is electrically connected to the node and noise from the connection transistor FDL is carried over to the pixel signal from the photodiode PD2, the noise has less of an effect on the pixel signal when photographing a subject with high illumination, in which the photodiode PD2 is primarily used, compared to the above-mentioned case. Therefore, in this embodiment, the node electrically connected directly by the connection unit 250 may be located closer to the photodiode PD2 than to the photodiode PD1.

[0099] In this embodiment, it is preferable that the nodes that are electrically connected directly by the connection unit 250 have the form described above, but depending on the specifications required for the imaging device 10, they are not limited to the form described above.

[0100] 9A , for example, the pixel units 100 are two-dimensionally arranged according to the Bayer array. Furthermore, in the example shown in FIG. 9A , two pixel units 100 that detect red light are spaced apart from each other and arranged in two rows in the row direction (X direction in the figure) and one column in the column direction (Y direction in the figure), and are connected by a connection portion 250. In this manner, in this embodiment, by connecting the two pixel units 100 that detect red light and are arranged in two rows and one column on the semiconductor substrate 15 by the connection portion 250, the floating diffusion FD can be shared between the two pixel units 100.

[0101] The configuration of the pixel units 100 connected by the connection portion 250 shown in FIG. 9A can be represented by an equivalent circuit as shown in FIG. 9B. Note that the equivalent circuit of the pixel unit 100 is the same as the equivalent circuit shown in FIG. 8B, and therefore a description thereof will be omitted here. In the example shown in FIG. 9B, the connection portion 250 can include two connection transistors FDL provided for each pixel unit 100. In addition, in the example shown in FIG. 9B, by controlling each connection transistor FDL, it is possible to read out pixel signals from each of the multiple pixel units 100 connected by the connection portion 250.

[0102] 10A , for example, the pixel units 100 are two-dimensionally arranged according to the Bayer array. Furthermore, in the example shown in FIG. 10A , four pixel units 100 that detect red light are spaced apart from one another and arranged in two rows in the row direction (X direction in the figure) and two columns in the column direction (Y direction in the figure), and are connected by a connection portion 250. In this manner, in this embodiment, by connecting the four pixel units 100 that detect red light and are arranged in two rows and two columns on the semiconductor substrate 15 by the connection portion 250, the floating diffusion FD can be shared among the four pixel units 100.

[0103] 10A , the configuration of the pixel units 100 connected by the connection portion 250 can be represented by an equivalent circuit as shown in FIG. 10B . Note that the equivalent circuit of the pixel unit 100 is the same as the equivalent circuit shown in FIG. 8B , and therefore a description thereof will be omitted here. In the example shown in FIG. 10B , the connection portion 250 can include four connection transistors FDL provided for each pixel unit 100. In the example shown in FIG. 10B , by controlling each connection transistor FDL, it is possible to read out pixel signals from each of the pixel units 100 connected by the connection portion 250.

[0104] 11A , for example, the pixel units 100 are two-dimensionally arranged according to the Bayer array. Furthermore, in the example shown in FIG. 11A , nine pixel units 100 that detect red light are spaced apart from one another and arranged in three rows in the row direction (X direction in the figure) and three columns in the column direction (Y direction in the figure), and are connected by connecting portions 250. In this manner, in this embodiment, by connecting the nine pixel units 100 that detect red light and are arranged in three rows and three columns on the semiconductor substrate 15 by the connecting portions 250, the floating diffusion FD can be shared among the nine pixel units 100.

[0105] 11A can be represented by an equivalent circuit as shown in FIG. 11B. The equivalent circuit of the pixel unit 100 is the same as the equivalent circuit shown in FIG. 8B, and therefore a description thereof will be omitted. In the example shown in FIG. 11B, the connection section 250 can include nine connection transistors FDL, each of which is provided for each pixel unit 100. In the example shown in FIG. 11B, pixel signals from each of the pixel units 100 connected by the connection section 250 can be read out by controlling each connection transistor FDL.

[0106] 12A , the pixel units 100 are arranged two-dimensionally according to the Bayer array. Furthermore, in the example shown in FIG. 12A , the 16 pixel units 100 that detect red light are spaced apart from one another and arranged in four rows in the row direction (X direction in the figure) and four columns in the column direction (Y direction in the figure), and are connected by the connection portions 250. In this manner, in this embodiment, by connecting the 16 pixel units 100 that detect red light and are arranged in four rows and four columns on the semiconductor substrate 15 by the connection portions 250, the floating diffusion FD can be shared among the 16 pixel units 100.

[0107] 12A , the configuration of the pixel units 100 connected by the connection portion 250 can be represented by an equivalent circuit as shown in FIG. 12B . Note that the equivalent circuit of the pixel unit 100 is the same as the equivalent circuit shown in FIG. 8B , and therefore a description thereof will be omitted here. In the example shown in FIG. 12B , the connection portion 250 can include 16 connection transistors FDL, one for each pixel unit 100. In the example shown in FIG. 12B , by controlling each connection transistor FDL, it is possible to read out pixel signals from each of the pixel units 100 connected by the connection portion 250.

[0108] 8A to 12B , the configuration and circuit configuration of the pixel unit 100 according to the present embodiment are not limited to the examples shown in Fig. 8A to 12B . In the present embodiment, for example, a number of pixel units 100 other than those described above may be connected by the connection portion 250, or pixel units 100 arranged in an arrangement other than those described above may be connected by the connection portion 250.

[0109] 6. Fourth Embodiment Next, a fourth embodiment of the present disclosure will be described with reference to Figures 13A and 13B, which are equivalent circuit diagrams of a main part of a pixel unit 100 according to this embodiment.

[0110] In the third embodiment described above, the connection section 250 has the same number of connection transistors FDL as the pixel units 100, each of which is provided for each pixel unit 100. However, in the present disclosure, the number of connection transistors FDL included in the connection section 250 is not limited to this. Therefore, in the present embodiment, variations in the number of connection transistors FDL included in the connection section 250 will be described.

[0111] 13A , the connection section 250 electrically connects four pixel units 100 that detect light of the same color and are arranged in two rows in the row direction (X direction in the figure) and two columns in the column direction (Y direction in the figure). Specifically, the connection section 250 includes one connection transistor FDL, and the connection transistor FDL is provided only between the pixel units 100 located in different rows. Furthermore, in the example shown in FIG. 13A , pixel signals from the pixel units 100 connected by the connection section 250 can be read out by reading out the pixel signals from the pixel units 100 located in the same row at different timings.

[0112] 13B , the connection section 250 electrically connects nine pixel units 100 that detect light of the same color and are arranged in three rows in the row direction (X direction in the figure) and three columns in the column direction (Y direction in the figure). Specifically, the connection section 250 includes two connection transistors FDL, and the connection transistors FDL are provided only between pixel units 100 located in different rows. In the example shown in FIG. 13B , pixel signals from the pixel units 100 connected by the connection section 250 can be read out by reading out the pixel signals from the pixel units 100 located in the same row at different timings.

[0113] 13A and 13B , for example, the connection section 250 may electrically connect 16 pixel units 100 that detect light of the same color and are arranged in four rows and four columns. In this case, the connection section 250 may include three connection transistors FDL, and the connection transistors FDL may be provided only between the pixel units 100 located in different rows.

[0114] 7. Fifth Embodiment Next, a fifth embodiment of the present disclosure will be described with reference to FIGS. 14A and 14B. FIGS. 14A and 14B are equivalent circuit diagrams of a main part of a pixel unit 100 according to this embodiment. In this embodiment, variations in the number of connection transistors FDL included in a connection section 250 will also be described.

[0115] 14A , the connection section 250 electrically connects four pixel units 100 that detect light of the same color and are arranged in two rows in the row direction (X direction in the figure) and two columns in the column direction (Y direction in the figure). Specifically, the connection section 250 includes one connection transistor FDL, and the connection transistor FDL is provided only between the pixel units 100 located in different columns. Furthermore, in the example shown in FIG. 14A , pixel signals from the pixel units 100 connected by the connection section 250 can be read out by reading out the pixel signals from the pixel units 100 located in the same column at different timings.

[0116] 14B , the connection section 250 electrically connects nine pixel units 100 that detect light of the same color and are arranged in three rows in the row direction (X direction in the figure) and three columns in the column direction (Y direction in the figure). Specifically, the connection section 250 includes two connection transistors FDL, and the connection transistors FDL are provided only between the pixel units 100 located in different columns. Furthermore, in the example shown in FIG. 14B , pixel signals from the pixel units 100 connected by the connection section 250 can be read out by reading out the pixel signals from the pixel units 100 located in the same column at different timings.

[0117] 14A and 14B , for example, the connection section 250 may electrically connect 16 pixel units 100 that detect light of the same color and are arranged in four rows and four columns. In this case, the connection section 250 may include three connection transistors FDL, and the connection transistors FDL may be provided only between the pixel units 100 located in different columns. In addition, in the embodiments of the present disclosure, the number and positions of the connection transistors FDL are not limited to the numbers and positions described in the fourth and fifth embodiments, and various forms can be selected depending on the control of readout of the pixel units 100.

[0118] 8. Sixth Embodiment Next, a sixth embodiment of the present disclosure will be described with reference to Figures 15A and 15B, which are equivalent circuit diagrams of a main part of a pixel unit 100 according to this embodiment.

[0119] In the third to fifth embodiments described above, the connection unit 250 includes the connection transistor FDL. However, the present disclosure is not limited to a configuration in which the connection unit 250 includes the connection transistor FDL. Therefore, in this embodiment, a configuration in which the connection unit 250 does not include the connection transistor FDL will be described.

[0120] 15A , the connection section 250 electrically connects four pixel units 100 that detect light of the same color and are arranged in two rows in the row direction (X direction in the figure) and two columns in the column direction (Y direction in the figure). Specifically, in the configuration shown in FIG. 15A , the connection section 250 does not include a connection transistor FDL. In the example shown in FIG. 15A , pixel signals from the pixel units 100 connected by the connection section 250 can be read out by reading out signals at different timings between the pixel units 100 located in the same column and between the pixel units 100 in the same row.

[0121] 15B , the connection section 250 electrically connects nine pixel units 100 that detect light of the same color and are arranged in three rows (X direction in the figure) and three columns (Y direction in the figure). Specifically, in the configuration shown in FIG. 15B , the connection section 250 does not include a connection transistor FDL. In the example shown in FIG. 15B , pixel signals from the pixel units 100 connected by the connection section 250 can be read out by reading out signals at different timings between the pixel units 100 located in the same column and between the pixel units 100 in the same row.

[0122] 15A and 15B , for example, the connection section 250 may electrically connect 16 pixel units 100 that detect light of the same color and are arranged in four rows and four columns. In this case, the connection section 250 may not include the connection transistor FDL.

[0123] <<9. Summary>> As described above, in each embodiment of the present disclosure, the floating diffusion FD is shared among the plurality of pixel units 100 by connecting the plurality of pixel units 100 with the connection section 250. In this manner, in this embodiment, pixel signals can be added between the plurality of pixel units 100. Therefore, according to this embodiment, since pixel signals can be added, it is possible to achieve higher readout speeds and processing speeds, lower power consumption, and suppression of increases in data rate without reducing the number of pixel units 100. Furthermore, according to this embodiment, pixel signals output from the plurality of pixel units 100 connected by the connection section 250 are added, so the S / N ratio of the signal finally output from the imaging device 10 can be improved.

[0124] Furthermore, in the above-described embodiments of the present disclosure, a case has been described in which the present disclosure is applied to a back-illuminated CMOS (Complementary MOS) image sensor structure, but the embodiments of the present disclosure are not limited to this and may be applied to other structures.

[0125] In the above-described embodiment of the present disclosure, a photodiode PD in which the first conductivity type is n-type, the second conductivity type is p-type, and electrons are used as signal charges has been described, but the embodiment of the present disclosure is not limited to such an example. For example, the present embodiment can be applied to a photodiode PD in which the first conductivity type is p-type, the second conductivity type is n-type, and holes are used as signal charges.

[0126] In the above-described embodiment of the present disclosure, the semiconductor substrate 15 does not necessarily have to be a silicon substrate, but may be another substrate (for example, an SOI (Silicon On Insulator) substrate, a SiGe substrate, etc.) The semiconductor substrate 15 may also be one in which a semiconductor structure or the like is formed on such various substrates.

[0127] Furthermore, the imaging device 10 according to the embodiment of the present disclosure is not limited to an imaging device that detects the distribution of incident light amounts of visible light and captures an image. For example, the present embodiment can be applied to an imaging device that captures the distribution of incident amounts of infrared rays, X-rays, particles, etc. as an image, or an imaging device (physical quantity distribution detection device) such as a fingerprint detection sensor that detects the distribution of other physical quantities such as pressure or capacitance and captures an image.

[0128] Furthermore, in this embodiment, it is possible to manufacture the semiconductor device by using the method, apparatus, and conditions that are used in the manufacture of a general semiconductor device, i.e., in this embodiment, it is possible to use the existing semiconductor device manufacturing process.

[0129] Examples of the above-mentioned method include a PVD (Physical Vapor Deposition) method, a CVD (Chemical Vapor Deposition) method, and an ALD (Atomic Layer Deposition) method. Examples of PVD methods include vacuum deposition, EB (electron beam) deposition, various sputtering methods (magnetron sputtering, RF (radio frequency)-DC (direct current) combined bias sputtering, ECR (electron cyclotron resonance) sputtering, facing target sputtering, high frequency sputtering, etc.), ion plating, laser ablation, molecular beam epitaxy (MBE), and laser transfer. Examples of CVD methods include plasma CVD, thermal CVD, metal organic (MO) CVD, and photo CVD. Other methods include electroplating, electroless plating, spin coating, dipping, casting, microcontact printing, drop casting, various printing methods such as screen printing, inkjet printing, offset printing, gravure printing, and flexographic printing, stamping, spraying, and various coating methods such as air doctor coater, blade coater, rod coater, knife coater, squeeze coater, reverse roll coater, transfer roll coater, gravure coater, kiss coater, cast coater, spray coater, slit orifice coater, and calendar coater. Furthermore, patterning methods include chemical etching such as shadow mask, laser transfer, and photolithography, and physical etching using ultraviolet light or laser. Additionally, planarization techniques include CMP (Chemical Mechanical Polishing), laser planarization, and reflow.

[0130] <<10. Application Examples>> <10.1 Application Example to a Camera> The technology according to the present disclosure (the present technology) can be further applied to various products. For example, the technology according to the present disclosure may be applied to a camera or the like. Therefore, with reference to FIG. 16 , a configuration example of a camera 700 as an electronic device to which the present technology is applied will be described. FIG. 16 is an explanatory diagram showing an example of a schematic functional configuration of a camera 700 to which the technology according to the present disclosure (the present technology) can be applied.

[0131] As shown in FIG. 16 , the camera 700 includes an image capture device 702, an optical lens 710, a shutter mechanism 712, a drive circuit unit 714, and a signal processing circuit unit 716. The optical lens 710 focuses image light (incident light) from a subject on the imaging surface of the image capture device 702. This causes signal charge to accumulate in the pixel units 100 of the image capture device 702 for a certain period of time. The shutter mechanism 712 opens and closes to control the light irradiation period and light blocking period of the image capture device 702. The drive circuit unit 714 supplies drive signals to the image capture device 702 that control the signal transfer operation and the shutter operation of the shutter mechanism 712. In other words, the image capture device 702 transfers signals based on the drive signals (timing signals) supplied from the drive circuit unit 714. The signal processing circuit unit 716 performs various signal processing. For example, the signal processing circuit unit 716 outputs the processed video signal to a storage medium such as a memory (not shown), or to a display unit (not shown).

[0132] Specifically, for example, the technology of the present disclosure can be applied to the imaging device 702.

[0133] The above describes an example configuration of the camera 700. Each of the above components may be configured using general-purpose components, or may be configured using hardware specialized for the function of each component. Such a configuration may be modified as appropriate depending on the technical level at the time of implementation.

[0134] 10.2 Application Example to Smartphones For example, the technology according to the present disclosure may be applied to smartphones, etc. Therefore, a configuration example of a smartphone 900 as an electronic device to which the present technology is applied will be described with reference to Fig. 17. Fig. 17 is a block diagram showing an example of a schematic functional configuration of a smartphone 900 to which the technology according to the present disclosure (the present technology) can be applied.

[0135] 17 , the smartphone 900 includes a CPU (Central Processing Unit) 901, a ROM (Read Only Memory) 902, and a RAM (Random Access Memory) 903. The smartphone 900 also includes a storage device 904, a communication module 905, and a sensor module 907. The smartphone 900 also includes an imaging device 909, a display device 910, a speaker 911, a microphone 912, an input device 913, and a bus 914. The smartphone 900 may also include a processing circuit such as a DSP (Digital Signal Processor) instead of or in addition to the CPU 901.

[0136] The CPU 901 functions as an arithmetic processing unit and control device, and controls all or part of the operations within the smartphone 900 in accordance with various programs recorded in the ROM 902, RAM 903, storage device 904, etc. The ROM 902 stores programs and calculation parameters used by the CPU 901. The RAM 903 temporarily stores programs used in the execution of the CPU 901 and parameters that change as appropriate during the execution. The CPU 901, ROM 902, and RAM 903 are interconnected by a bus 914. The storage device 904 is a data storage device configured as an example of a storage unit of the smartphone 900. The storage device 904 is configured, for example, by a magnetic storage device such as an HDD (hard disk drive), a semiconductor storage device, an optical storage device, etc. This storage device 904 stores programs executed by the CPU 901, various data, and various data acquired from outside.

[0137] The communication module 905 is a communication interface configured with, for example, a communication device for connecting to the communication network 906. The communication module 905 may be, for example, a communication card for a wired or wireless local area network (LAN), Bluetooth (registered trademark), or wireless USB (WUSB). The communication module 905 may also be a router for optical communication, a router for asymmetric digital subscriber line (ADSL), or a modem for various communications. The communication module 905 transmits and receives signals between the Internet and other communication devices using a predetermined protocol such as TCP (Transmission Control Protocol) / IP (Internet Protocol). The communication network 906 connected to the communication module 905 is a wired or wireless network, such as the Internet, a home LAN, infrared communication, or satellite communication.

[0138] The sensor module 907 includes various sensors such as a motion sensor (e.g., an acceleration sensor, a gyro sensor, a geomagnetic sensor, etc.), a biometric information sensor (e.g., a pulse sensor, a blood pressure sensor, a fingerprint sensor, etc.), or a position sensor (e.g., a GNSS (Global Navigation Satellite System) receiver, etc.).

[0139] The imaging device 909 is provided on the surface of the smartphone 900 and can capture an image of an object located on the back or front side of the smartphone 900. Specifically, the imaging device 909 can include an imaging element (not shown) such as a CMOS image sensor to which the technology according to the present disclosure (the present technology) can be applied, and a signal processing circuit (not shown) that performs imaging signal processing on a signal photoelectrically converted by the imaging element. Furthermore, the imaging device 909 can further include an optical system mechanism (not shown) including an imaging lens, a zoom lens, a focus lens, and the like, and a drive system mechanism (not shown) that controls the operation of the optical system mechanism. The imaging element collects incident light from the object as an optical image, and the signal processing circuit photoelectrically converts the formed optical image on a pixel-by-pixel basis, reads out the signal from each pixel as an imaging signal, and performs image processing to obtain a captured image.

[0140] The display device 910 is provided on the surface of the smartphone 900 and can be, for example, a display device such as an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) display. The display device 910 can display an operation screen, an image captured by the imaging device 909 described above, and the like.

[0141] The speaker 911 can output, for example, telephone call audio and audio accompanying the video content displayed by the display device 910 described above to the user.

[0142] The microphone 912 can collect, for example, the user's voice during a call, voice including commands to activate functions of the smartphone 900, and voice from the surrounding environment of the smartphone 900.

[0143] The input device 913 is a device operated by a user, such as a button, a keyboard, a touch panel, or a mouse. The input device 913 includes an input control circuit that generates an input signal based on information input by the user and outputs the signal to the CPU 901. By operating the input device 913, the user can input various data to the smartphone 900 and instruct processing operations.

[0144] Specifically, for example, the technology of the present disclosure can be applied to the imaging device 909.

[0145] The above describes an example configuration of the smartphone 900. Each of the above components may be configured using general-purpose components, or may be configured using hardware specialized for the function of each component. Such a configuration may be changed as appropriate depending on the technical level at the time of implementation.

[0146] 10.3 Application Examples to Mobile Bodies The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of mobile body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, or a robot.

[0147] FIG. 18 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile object control system to which the technology according to the present disclosure can be applied.

[0148] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 18, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (Interface) 12053.

[0149] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0150] The body system control unit 12020 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0151] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture images outside the vehicle and receives the captured images. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, characters on the road surface, etc. based on the received images.

[0152] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The imaging unit 12031 can output the electrical signal as an image or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

[0153] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

[0154] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0155] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0156] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12030 based on the information outside the vehicle acquired by the outside information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching from high beams to low beams.

[0157] The audio / video output unit 12052 transmits at least one of audio and video output signals to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle of information. In the example of Fig. 18, the output devices are exemplified by an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0158] FIG. 19 is a diagram showing an example of the installation position of the imaging unit 12031.

[0159] In FIG. 19, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0160] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided on the front nose and the imaging unit 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided on the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided on the top of the windshield inside the vehicle cabin is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0161] 19 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, by overlaying the image data captured by the imaging units 12101 to 12104, an overhead image of the vehicle 12100 viewed from above can be obtained.

[0162] At least one of the image capturing units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the image capturing units 12101 to 12104 may be a stereo camera made up of multiple image capturing elements, or may be an image capturing element having pixels for phase difference detection.

[0163] For example, based on the distance information obtained from the imaging units 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the imaging ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which runs autonomously without relying on driver operation.

[0164] For example, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines a collision risk that indicates the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0165] At least one of the image capturing units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether a pedestrian is present in the images captured by the image capturing units 12101 to 12104. Such pedestrian recognition is performed, for example, by extracting feature points from the images captured by the image capturing units 12101 to 12104 as infrared cameras and performing pattern matching on a series of feature points that indicate the outline of an object to determine whether the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the images captured by the image capturing units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular outline on the recognized pedestrian for emphasis. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating the pedestrian at a desired position.

[0166] The above describes an example of a vehicle control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to, for example, the image capturing unit 12031 and the like among the above-described components.

[0167] <<11. Supplementary Information>> Although preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person skilled in the art of the present disclosure can conceive of various modified or altered examples within the scope of the technical idea described in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

[0168] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that will be apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0169] Note that the present technology can also have the following configurations. (1) An imaging device comprising: a plurality of pixel units, each including first and second photoelectric conversion units having different light receiving sensitivities and a node provided between the first photoelectric conversion unit and the second photoelectric conversion unit; and a connection unit that electrically connects the node of one of the pixel units to the node of another of the pixel units. (2) The imaging device described in (1) above, wherein the plurality of pixel units electrically connected via the connection unit share a charge accumulation unit that accumulates charge generated in the first and second photoelectric conversion units. (3) The imaging device described in (2) above, wherein the connection unit electrically connects the plurality of nodes of two or more of the pixel units. (4) The imaging device described in (3) above, wherein the plurality of pixel units are arranged in a matrix along row and column directions on a semiconductor substrate. (5) The imaging device according to (4), wherein the connection portion connects the plurality of pixel units arranged in 1 row x 2 columns, 2 rows x 1 column, 2 rows x 2 columns, 3 rows x 3 columns, or 4 rows x 4 columns. (6) The imaging device according to (4), wherein the connection portion includes one or more connection transistors. (7) The imaging device according to (6), wherein the connection transistor is provided for each of the plurality of pixel units electrically connected via the connection portion. (8) The imaging device according to (6), wherein the connection transistor is provided between the pixel units located in different rows. (9) The imaging device according to (6), wherein the connection transistor is provided between the pixel units located in different columns. (10) The imaging device according to (2) or (3), wherein the plurality of pixel units electrically connected via the connection portion have color filters of the same color. (11) The imaging device according to (10), wherein the plurality of pixel units electrically connected via the connection portion are provided adjacent to each other on a semiconductor substrate. (12) The imaging device according to (10), wherein the plurality of pixel units electrically connected via the connection portion are not provided adjacent to each other on a semiconductor substrate.(13) The imaging device according to (2) or (3), wherein the plurality of pixel units electrically connected via the connection portion have color filters of different colors. (14) The imaging device according to any one of (2) to (13), wherein the light receiving area of ​​the first photoelectric conversion portion is larger than the light receiving area of ​​the second photoelectric conversion portion. (15) The imaging device according to (14), wherein, in a plan view, the light receiving area of ​​the first photoelectric conversion portion has a substantially octagonal shape, and the light receiving area of ​​the second photoelectric conversion portion has a substantially rectangular shape. (16) The imaging device according to (14), wherein, in a plan view, the light receiving area of ​​the first photoelectric conversion portion has a substantially L-shape, and the light receiving area of ​​the second photoelectric conversion portion has a substantially rectangular shape. (17) The imaging device according to any one of (2) to (16), wherein each pixel unit further includes a plurality of pixel transistors that drive the first and second photoelectric conversion units, and the first and second photoelectric conversion units are electrically connected to the node via at least one of the pixel transistors. (18) The imaging device according to (17), wherein the node is provided at a position closer to the second photoelectric conversion unit than the first photoelectric conversion unit.(19) The imaging device according to (17) or (18), wherein each of the pixel units includes, as the plurality of pixel transistors, a first transfer transistor electrically connected to one terminal of the first photoelectric conversion unit and transferring the charge to the charge accumulation unit, a second transfer transistor electrically connected to one terminal of the second photoelectric conversion unit and transferring the charge to the charge accumulation unit, an amplifying transistor electrically connected to the charge accumulation unit and converting the charge from the charge accumulation unit into a pixel signal, a selecting transistor electrically connected to the amplifying transistor and selecting the pixel signal to be output, a switching transistor provided between the first transfer transistor and the second transfer transistor and switching the conversion efficiency of each of the pixel units, a reset transistor electrically connected to the charge accumulation unit via the switching transistor and resetting the charge accumulation unit, a capacitive element provided between the second transfer transistor and the reset transistor, and a capacitive-connecting transistor provided between the capacitive element and the switching transistor and controlling connection with the capacitive element, and the node is located between the reset transistor and the switching transistor. (20) The imaging device according to any one of (17) to (19), wherein the first and second photoelectric conversion units and at least some of the plurality of pixel transistors are provided in different stacked layers.

[0170] 10 Imaging device 15 Semiconductor substrate 33 Pixel array section 34 Column signal processing circuit section 35 Vertical drive circuit section 36 Horizontal drive circuit section 38 Output circuit section 40 Control circuit section 42 Pixel drive wiring 44 Vertical signal line 46 Horizontal signal line 48 Input / output terminal 50, 60 Substrate 100, 100a Pixel unit 102 Photoelectric conversion region 104 Color filter 106 On-chip lens 108 Light-shielding section 250 Connection section AMP, FCG, FDG, RST, SEL, TGL, TGS Transistor FC Capacitor element FCGL, FDGL, TGLL, TGSL Control line FD Floating diffusion FDL Connection transistor ND Node PD, PD1, PD2 Photodiode RSTL Reset signal line SELL Selection line SGL Signal line VDD Power supply potential

Claims

1. An imaging device comprising: a plurality of pixel units, each of which includes first and second photoelectric conversion units having different light receiving sensitivities and a node provided between the first photoelectric conversion unit and the second photoelectric conversion unit; and a connection unit that electrically connects the node of one of the pixel units to the node of another of the pixel units.

2. The imaging device according to claim 1, wherein the plurality of pixel units electrically connected via the connection section share a charge accumulation section that accumulates charges generated in the first and second photoelectric conversion sections.

3. The imaging device according to claim 2, wherein the connection portion electrically connects a plurality of the nodes of two or more of the pixel units.

4. The imaging device according to claim 3, wherein the plurality of pixel units are arranged in a matrix along row and column directions on a semiconductor substrate.

5. The imaging device according to claim 4, wherein the connection section connects the plurality of pixel units arranged in 1 row x 2 columns, 2 rows x 1 column, 2 rows x 2 columns, 3 rows x 3 columns, or 4 rows x 4 columns.

6. The imaging device according to claim 4, wherein the connection portion includes one or more connection transistors.

7. The imaging device according to claim 6, wherein the connection transistor is provided for each of the plurality of pixel units electrically connected via the connection portion.

8. The imaging device according to claim 6, wherein the connection transistors are provided between the pixel units located in different rows.

9. The imaging device according to claim 6, wherein the connection transistors are provided between the pixel units located in different columns.

10. The imaging device according to claim 2, wherein the plurality of pixel units electrically connected via the connection portion have color filters of the same color.

11. The imaging device according to claim 10, wherein the plurality of pixel units electrically connected via the connection portion are provided adjacent to each other on a semiconductor substrate.

12. The imaging device according to claim 10, wherein the plurality of pixel units electrically connected via the connection portion are not provided adjacent to each other on a semiconductor substrate.

13. The imaging device according to claim 2, wherein the pixel units electrically connected via the connection portion have color filters of different colors.

14. The imaging device according to claim 2, wherein the light receiving area of ​​the first photoelectric conversion unit is larger than the light receiving area of ​​the second photoelectric conversion unit.

15. An imaging device as described in claim 14, wherein, in a plan view, the light receiving area of ​​the first photoelectric conversion element has a substantially octagonal shape, and the light receiving area of ​​the second photoelectric conversion element has a substantially rectangular shape.

16. The imaging device according to claim 14, wherein, in a plan view, the light receiving area of ​​the first photoelectric conversion unit has a substantially L-shape, and the light receiving area of ​​the second photoelectric conversion unit has a substantially rectangular shape.

17. The imaging device of claim 2, wherein each pixel unit further includes a plurality of pixel transistors that drive the first and second photoelectric conversion units, and the first and second photoelectric conversion units are electrically connected to the node via at least one of the plurality of pixel transistors.

18. The imaging device according to claim 17, wherein the node is provided at a position closer to the second photoelectric conversion unit than to the first photoelectric conversion unit.

19. The imaging device of claim 17, wherein each of the pixel units includes, as the plurality of pixel transistors, a first transfer transistor electrically connected to one terminal of the first photoelectric conversion unit and transferring the charge to the charge accumulation unit; a second transfer transistor electrically connected to one terminal of the second photoelectric conversion unit and transferring the charge to the charge accumulation unit; an amplifying transistor electrically connected to the charge accumulation unit and converting the charge from the charge accumulation unit into a pixel signal; a selection transistor electrically connected to the amplifying transistor and selecting the pixel signal to be output; a switching transistor provided between the first transfer transistor and the second transfer transistor and switching the conversion efficiency of each of the pixel units; a reset transistor electrically connected to the charge accumulation unit via the switching transistor and resetting the charge accumulation unit; a capacitance element provided between the second transfer transistor and the reset transistor; and a capacitive connection transistor provided between the capacitance element and the switching transistor and controlling a connection with the capacitance element, and the node is located between the reset transistor and the switching transistor.

20. The imaging device according to claim 17, wherein the first and second photoelectric conversion units and at least some of the plurality of pixel transistors are provided in different stacked layers.

Images