Light detection device, light detection system, and electronic device

Abstract

A light detection device according to one embodiment of the present disclosure comprises: a first photoelectric conversion element and a second photoelectric conversion element that each include a photoelectric conversion film for performing photoelectric conversion; and a readout circuit that includes a first floating diffusion which is electrically connected to the first photoelectric conversion element and a second floating diffusion which is electrically connected to the second photoelectric conversion element and that is capable of outputting a signal based on a charge accumulated in the first floating diffusion. The readout circuit includes a first transistor that is capable of electrically connecting the first floating diffusion to the second floating diffusion.

Description

Light detection device, light detection system, and electronic device

[0001] The present disclosure relates to a light detection device, a light detection system, and an electronic device.

[0002] An imaging device has been proposed that includes a phase difference pixel having two photoelectric conversion units, two charge holding units, and two MOS transistors as switching elements (Patent Document 1).

[0003] JP 2016-58559 A

[0004] It is desirable for a light detecting device to be able to accommodate miniaturization.

[0005] It is desirable to provide a photodetector that is advantageous for miniaturization.

[0006] A photodetector according to an embodiment of the present disclosure includes a first photoelectric conversion element and a second photoelectric conversion element, each having a photoelectric conversion film that photoelectrically converts light, a first floating diffusion electrically connected to the first photoelectric conversion element, and a second floating diffusion electrically connected to the second photoelectric conversion element, and a readout circuit capable of outputting a signal based on charge accumulated in the first floating diffusion. The readout circuit has a first transistor electrically connecting the first floating diffusion and the second floating diffusion. A photodetection system according to an embodiment of the present disclosure includes a photodetector and a computing device. The photodetector includes a first photoelectric conversion element and a second photoelectric conversion element, each having a photoelectric conversion film that photoelectrically converts light, the first floating diffusion electrically connected to the first photoelectric conversion element, and the second floating diffusion electrically connected to the second photoelectric conversion element, and the readout circuit is capable of outputting a signal based on charge accumulated in the first floating diffusion, and an AD conversion circuit capable of performing AD conversion. The readout circuit has a first transistor capable of electrically connecting the first floating diffusion and the second floating diffusion, and is capable of outputting a first signal based on the charge converted by the first photoelectric conversion element and a second signal based on the charge converted by the first photoelectric conversion element and the charge converted by the second photoelectric conversion element. The arithmetic unit is capable of generating a third signal based on the charge converted by the second photoelectric conversion element based on the first signal and the second signal converted into digital signals by the AD conversion circuit. An electronic device according to an embodiment of the present disclosure includes a first photoelectric conversion element and a second photoelectric conversion element, each having a photoelectric conversion film that photoelectrically converts light, a first floating diffusion electrically connected to the first photoelectric conversion element, and a second floating diffusion electrically connected to the second photoelectric conversion element, and is capable of outputting a signal based on the charge accumulated in the first floating diffusion. The readout circuit has a first transistor capable of electrically connecting the first floating diffusion and the second floating diffusion.

[0007] FIG. 1 is a block diagram illustrating an example of a schematic configuration of an imaging device that is an example of a photodetector according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating an example of a pixel unit of the imaging device according to an embodiment of the present disclosure. FIG. 3 is a diagram illustrating an example of a cross-sectional configuration of the imaging device according to an embodiment of the present disclosure. FIG. 4 is a diagram illustrating an example of a circuit configuration of a pixel of the imaging device according to an embodiment of the present disclosure. FIG. 5 is a diagram illustrating an example of a configuration of the imaging device according to an embodiment of the present disclosure. FIG. 6 is a diagram illustrating an example of an operation of the imaging device according to an embodiment of the present disclosure. FIG. 7 is a timing chart illustrating an example of an operation of the imaging device according to an embodiment of the present disclosure. FIG. 8 is a timing chart illustrating an example of an operation of the imaging device according to an embodiment of the present disclosure. FIG. 9 is a diagram illustrating another example of a cross-sectional configuration of the imaging device according to an embodiment of the present disclosure. FIG. 10 is a diagram illustrating another example of a circuit configuration of a pixel of the imaging device according to an embodiment of the present disclosure. FIG. 11 is a diagram illustrating an example of a configuration of the imaging device according to Variation 1 of the present disclosure. FIG. 12 is a diagram illustrating an example of a configuration of the imaging device according to Variation 1 of the present disclosure. FIG. 13 is a diagram illustrating an example of a planar configuration of the imaging device according to Variation 1 of the present disclosure. FIG. 14 is a diagram for describing an example configuration of a pixel of an imaging device according to Modification 2 of the present disclosure. FIG. 15 is a diagram for describing an example configuration of a pixel of an imaging device according to Modification 3 of the present disclosure. FIG. 16 is a diagram for describing an example configuration of a pixel of an imaging device according to Modification 3 of the present disclosure. FIG. 17 is a diagram for describing an example configuration of a pixel of an imaging device according to Modification 4 of the present disclosure. FIG. 18 is a diagram for describing an example configuration of a pixel of an imaging device according to Modification 4 of the present disclosure. FIG. 19 is a diagram for describing an example configuration of a pixel of an imaging device according to Modification 5 of the present disclosure. FIG. 20 is a diagram for describing an example configuration of a pixel of an imaging device according to Modification 5 of the present disclosure. FIG. 21 is a diagram for describing an example configuration of a pixel of an imaging device according to Modification 5 of the present disclosure. FIG. 22 is a diagram for describing an example configuration of a pixel of an imaging device according to Modification 5 of the present disclosure. FIG. 23 is a diagram for describing an example configuration of a pixel of an imaging device according to Modification 5 of the present disclosure. FIG. 24 is a diagram for describing an example configuration of a pixel of an imaging device according to Modification 5 of the present disclosure.FIG. 25 is a diagram for describing an example configuration of an imaging device according to Modification 6 of the present disclosure. FIG. 26 is a diagram for describing an example configuration of an imaging device according to Modification 6 of the present disclosure. FIG. 27 is a diagram for describing an example configuration of an imaging device according to Modification 6 of the present disclosure. FIG. 28 is a timing chart showing an example operation of an imaging device according to Modification 7 of the present disclosure. FIG. 29 is a diagram for describing an example configuration of an imaging device according to Modification 8 of the present disclosure. FIG. 30 is a diagram for describing an example configuration of an imaging device according to Modification 8 of the present disclosure. FIG. 31 is a diagram for describing an example configuration of an imaging device according to Modification 9 of the present disclosure. FIG. 32 is a timing chart showing an example operation of an imaging device according to Modification 9 of the present disclosure. FIG. 33A is a diagram for describing an example configuration of an imaging device according to Modification 10 of the present disclosure. FIG. 33B is a diagram for describing an example configuration of an imaging device according to Modification 10 of the present disclosure. FIG. 34 is a block diagram showing an example configuration of an electronic device. FIG. 35A is a schematic diagram illustrating an example overall configuration of a light detection system. FIG. 35B is a schematic diagram illustrating an example overall configuration of a light detection system. Fig. 36 is a block diagram showing an example of a schematic configuration of a vehicle control system. Fig. 37 is an explanatory diagram showing an example of installation positions of an outside-of-vehicle information detection unit and an imaging unit. Fig. 38 is a diagram showing an example of a schematic configuration of an endoscopic surgery system. Fig. 39 is a block diagram showing an example of the functional configuration of a camera head and a CCU.

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order: 1. Embodiment 2. Modification 3. Application Example 4. Application Example

[0009] 1. Embodiments Fig. 1 is a block diagram showing an example of a schematic configuration of an imaging device that is an example of a photodetector according to an embodiment of the present disclosure. Fig. 2 is a diagram showing an example of a pixel unit of an imaging device according to an embodiment. A photodetector is a device that can detect incident light. An imaging device 1 that is an example of a photodetector has a plurality of pixels PX each having a photoelectric conversion unit (photoelectric conversion element) and is configured to photoelectrically convert incident light to generate a signal. The imaging device 1 can, for example, receive light that has passed through an optical system (not shown) including an optical lens and generate a signal.

[0010] The imaging device 1 is configured, for example, using a semiconductor substrate (e.g., a silicon substrate) on which a plurality of pixels PX are provided. Each pixel PX of the imaging device 1 includes, for example, a photodiode (PD) as a photoelectric conversion unit and is configured to be capable of photoelectrically converting light. As shown in the example of FIG. 2 , the imaging device 1 has, as an imaging area, a region (pixel unit 100) in which a plurality of pixels PX are two-dimensionally arranged in a matrix. The pixel unit 100 can also be said to be a pixel array in which a plurality of pixels PX are arranged.

[0011] The imaging device 1 captures incident light (image light) from a subject to be measured via an optical system including an optical lens. The imaging device 1 captures an image of the subject formed by the optical lens. The imaging device 1 can generate pixel signals by photoelectrically converting the received light (e.g., visible light, infrared light, etc.). The imaging device 1, which is a photodetector, is a device that can receive incident light and generate a signal, and can also be called a light-receiving device.

[0012] The imaging device 1 (photodetector) may be configured as an image sensor, for example. The imaging device 1 may be, for example, a complementary metal oxide semiconductor (CMOS) image sensor. The imaging device 1 may have a structure (a stacked structure) formed by stacking multiple semiconductor layers. The imaging device 1 may be used in various electronic devices, such as digital still cameras, video cameras, and mobile phones.

[0013] 2, the incident direction of light from the subject is defined as the Z-axis direction, the left-right direction on the paper surface perpendicular to the Z-axis direction is defined as the X-axis direction, and the up-down direction on the paper surface perpendicular to the Z-axis and X-axis directions is defined as the Y-axis direction. In the following figures, directions may be indicated based on the direction of the arrow in FIG. 2.

[0014] 1 , the imaging device 1 includes a pixel unit 100 (pixel array), a vertical drive circuit 111, a signal processing circuit 112, a horizontal drive circuit 113, an output circuit 114, a control circuit 115, and an input / output terminal 116. The imaging device 1 is also provided with, for example, a plurality of control lines L1 and a plurality of signal lines L2.

[0015] The control line L1 is a signal line capable of transmitting a signal for controlling the pixel PX, and is connected to the vertical drive circuit 111 and the pixel PX of the pixel unit 100. In the example shown in Fig. 1, a plurality of control lines L1 are wired in the pixel unit 100 for each pixel row made up of a plurality of pixels PX arranged in the horizontal direction (row direction). The control line L1 is configured to transmit a control signal for reading out a signal from the pixel PX.

[0016] The plurality of control lines L1 for each pixel row of the imaging device 1 include, for example, wiring for transmitting signals for controlling selection transistors, wiring for transmitting signals for controlling reset transistors, etc. The control lines L1 can also be referred to as drive lines (pixel drive lines) for transmitting signals for driving the pixels PX.

[0017] The signal line L2 is a signal line capable of transmitting a signal from the pixel PX, and is connected to the pixel PX of the pixel unit 100 and the signal processing circuit 112. In the pixel unit 100, for example, one or more signal lines L2 are wired for each pixel column formed by a plurality of pixels PX arranged in the vertical direction (column direction).

[0018] The signal line L2 is a vertical signal line configured to transmit signals output from the pixels PX. In the imaging device 1, multiple signal lines L2 may be provided for one pixel column. The imaging device 1 may have multiple signal lines L2 for each pixel column.

[0019] The vertical drive circuit 111 is configured to be able to drive each pixel PX of the pixel unit 100. The vertical drive circuit 111 is configured with a plurality of circuits including, for example, a buffer, a shift register, an address decoder, etc. The vertical drive circuit 111 generates a signal for driving the pixel PX and outputs the signal to each pixel PX of the pixel unit 100 via a control line L1. The vertical drive circuit 111 is controlled by a control circuit 115, and controls the pixels PX of the pixel unit 100.

[0020] The vertical drive circuit 111 generates, for example, a signal for controlling the selection transistor of the pixel PX, a signal for controlling the reset transistor, etc., and supplies these signals to each pixel PX via a control line L1. The vertical drive circuit 111 can control the reading of pixel signals from each pixel PX. The vertical drive circuit 111 can also be considered a pixel control unit configured to be able to control each pixel PX.

[0021] The signal processing circuit 112 is configured to be able to perform signal processing of input pixel signals. The signal processing circuit 112 includes, for example, a load circuit, an AD (Analog-Digital) conversion circuit, a horizontal selection switch, etc. The load circuit is, for example, configured by a current source capable of supplying current to the amplification transistor of the pixel PX. The load circuit, together with the amplification transistor of the pixel PX, forms, for example, a source follower circuit.

[0022] The signal processing circuit 112 may include an amplifier circuit configured to amplify signals read from the pixels PX via the signal lines L2. A load circuit, an amplifier circuit, an AD conversion circuit, etc. may be provided for each of the multiple signal lines L2. A load circuit, an amplifier circuit, an AD conversion circuit, etc. may be provided for each pixel column of the pixel unit 100.

[0023] The signals output from each pixel PX selected and scanned by the vertical drive circuit 111 are input to the signal processing circuit 112 via a signal line L2. The signal processing circuit 112 can perform signal processing such as AD conversion of the pixel PX signal and CDS (Correlated Double Sampling).

[0024] The horizontal drive circuit 113 is composed of, for example, a buffer, a shift register, an address decoder, etc. The horizontal drive circuit 113 is configured to be able to drive the horizontal selection switches of the signal processing circuit 112. The horizontal drive circuit 113 drives each horizontal selection switch of the signal processing circuit 112 in sequence while scanning them. The signals of each pixel PX transmitted through each signal line L2 are subjected to signal processing by the signal processing circuit 112 and output to the horizontal signal line 121 in sequence by selective scanning by the horizontal drive circuit 113.

[0025] The output circuit 114 is configured to perform signal processing on an input signal and output the signal. The output circuit 114 performs signal processing on pixel signals sequentially input from the signal processing circuit 112 via the horizontal signal line 121, and outputs the processed pixel signals. The output circuit 114 can perform, for example, buffering, black level adjustment, column variation correction, various types of digital signal processing, and the like.

[0026] The control circuit 115 is configured to be able to control each part of the imaging device 1. The control circuit 115 receives externally provided clocks, data instructing the operation mode, etc., and can also output data such as internal information of the imaging device 1. The control circuit 115 has, for example, a timing generator configured to be able to generate various timing signals.

[0027] The control circuit 115 controls the driving of peripheral circuits such as the vertical drive circuit 111, the signal processing circuit 112, and the horizontal drive circuit 113 based on various timing signals (pulse signals, clock signals, etc.) generated by the timing generator. The input / output terminals 116 exchange signals with the outside.

[0028] The vertical drive circuit 111, the signal processing circuit 112, the horizontal drive circuit 113, the horizontal signal line 121, the output circuit 114, the control circuit 115, etc. may be provided on a single semiconductor substrate or may be provided separately on multiple semiconductor substrates. The imaging device 1 may have a structure (a stacked structure) formed by stacking multiple substrates.

[0029] Fig. 3 is a diagram illustrating an example of a cross-sectional configuration of an imaging device according to an embodiment. Fig. 4 is a diagram illustrating an example of a circuit configuration of a pixel of the imaging device according to the embodiment. As shown in Fig. 3, the imaging device 1 has, for example, a light receiving layer 20, a wiring layer 130, a semiconductor layer 110, and a wiring layer 120. The imaging device 1 has a configuration in which the light receiving layer 20, the wiring layer 130, the semiconductor layer 110, and the wiring layer 120 are stacked in the Z-axis direction.

[0030] Each pixel PX of the imaging device 1 has a plurality of photoelectric conversion units 11 (photoelectric conversion units 11a and 11b in FIG. 3). The photoelectric conversion units 11 (photoelectric conversion elements) are configured to receive light and generate signals. In each pixel PX of the imaging device 1, for example, a plurality of photoelectric conversion units 11 are arranged adjacent to each other.

[0031] 3 and 4, pixel PX has a photoelectric conversion unit 11a and a photoelectric conversion unit 11b. The photoelectric conversion unit 11b is provided next to the photoelectric conversion unit 11a. The photoelectric conversion units 11a and 11b each have a photoelectric conversion film 22 and are configured to be able to generate charges by photoelectric conversion. It can also be said that a pixel having the photoelectric conversion unit 11a and a pixel having the photoelectric conversion unit 11b are provided.

[0032] 4 and other circuit diagrams, for the sake of explanation, the photoelectric conversion unit 11 is represented by a diode symbol as a photodiode, and an example of reading out holes as carriers to a floating diffusion is schematically shown. However, the connection relationship of the diode (i.e., the connection relationship of the photoelectric conversion unit 11) is not limited to the illustrated example, and can be determined appropriately depending on the carriers (signal charges).

[0033] 3, the semiconductor layer 110 has opposing surfaces 11S1 and 11S2. The surface 11S2 of the semiconductor layer 110 is the surface opposite to the surface 11S1. The semiconductor layer 110 is made of a semiconductor substrate, for example, a Si (silicon) substrate.

[0034] The semiconductor layer 110 may be an SOI (Silicon On Insulator) substrate, a SiGe (Silicon Germanium) substrate, a SiC (Silicon Carbide) substrate, or may be formed using other semiconductor materials. The semiconductor layer 110 may be made of a III-V group compound semiconductor material, or the like.

[0035] The surface 11S1 of the semiconductor layer 110 is a light-receiving surface (light incident surface). The surface 11S2 of the semiconductor layer 110 is an element formation surface on which elements such as transistors are formed. Gate electrodes, gate insulating films (e.g., gate oxide films), etc. are provided on the surface 11S2 of the semiconductor layer 110. Note that the surface 11S2 is a surface on which various circuit elements such as transistors, capacitance elements, and resistance elements are provided, and can also be called a circuit surface.

[0036] 3, the light receiving layer 20 and the wiring layer 130 are provided on the surface 11S1 side of the semiconductor layer 110. The wiring layer 120 is provided on the surface 11S2 side of the semiconductor layer 110. The lens 91, the light receiving layer 20, etc. are provided on the side where light from the optical system is incident, and the wiring layer 120 is provided on the side opposite to the side where the light is incident.

[0037] The wiring layer 120 includes, for example, a conductor film and an insulating film, and has a plurality of wires and vias, etc. The wiring layer 120 is a multi-layer wiring layer, and includes, for example, two or more layers of wires, or three or more layers of wires. The wiring layer 120 has a configuration in which a plurality of wires are stacked with an insulating film interposed therebetween as an interlayer insulating film (interlayer insulating layer).

[0038] The wiring of the wiring layer 120 is formed using a metal material such as aluminum (Al), tungsten (W), or copper (Cu). The wiring of the wiring layer 120 may be formed using polysilicon (Poly-Si) or other conductive materials. The interlayer insulating film is formed using, for example, silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), or the like.

[0039] For example, a readout circuit 15 (see FIG. 4 ) configured to be able to output a signal based on photoelectrically converted charges is provided for each pixel PX in the semiconductor layer 110 and the wiring layer 120. As an example, the transistors RST, AMP, SEL, floating diffusion FDA, floating diffusion FDB, etc. of the readout circuit 15 are provided on the surface 11S2 side of the semiconductor layer 110.

[0040] The above-mentioned vertical driving circuit 111, signal processing circuit 112, horizontal driving circuit 113, horizontal signal line 121, output circuit 114, control circuit 115, etc. (see Figure 1) can be provided on a substrate separate from the semiconductor layer 110, or on the semiconductor layer 110 and the wiring layer 120.

[0041] The lens 91 is a lens that focuses light and is an optical component also called an on-chip lens. The lens 91 is made of, for example, silicon oxide, silicon nitride, silicon oxynitride, or the like. The lens 91 may also be made of other light-transmitting materials. The lens 91 is provided, for example, above the photoelectric conversion unit 11 a and the photoelectric conversion unit 11 b for each pixel PX.

[0042] Light from a subject to be measured is incident on the lens 91 (lens unit) via an optical system such as an imaging lens. The lens 91 guides the incident light toward the photoelectric conversion units 11a and 11b. In the imaging device 1, the photoelectric conversion units 11a and 11b each photoelectrically convert the light incident via the lens 91. Each of the photoelectric conversion units 11a and 11b can absorb the incident light and generate electric charges.

[0043] In the imaging device 1, for example, one lens 91 is provided for the photoelectric conversion unit 11 a and the photoelectric conversion unit 11 b. In the imaging device 1, the photoelectric conversion unit 11 a and the photoelectric conversion unit 11 b receive light that has passed through different regions of an optical system such as an imaging lens, and perform pupil division.

[0044] Phase difference data (phase difference information) can be obtained by using a signal based on the charges converted by the photoelectric conversion unit 11a and a signal based on the charges converted by the photoelectric conversion unit 11b. The phase difference data makes it possible to perform phase difference AF (autofocus). The pixels PX of the imaging device 1 are pixels that can be used for phase difference detection and can also be called phase difference pixels (or phase difference detection pixels).

[0045] 3, the photoelectric conversion unit 11a and the photoelectric conversion unit 11b of each pixel PX include a photoelectric conversion film 22 and an upper electrode 23. The photoelectric conversion unit 11a has a lower electrode 24a, and the photoelectric conversion unit 11b has a lower electrode 24b. The photoelectric conversion units 11a and 11b, each having the photoelectric conversion film 22, can also be referred to as a photoelectric conversion region.

[0046] The photoelectric conversion film 22 generates electric charges through photoelectric conversion. The photoelectric conversion film 22 photoelectrically converts incident light and can generate electric charges according to the amount of light received. The photoelectric conversion film 22 can also be called a photoelectric conversion layer. The photoelectric conversion film 22 (photoelectric conversion layer) is, for example, a photoelectric conversion film made of an organic material.

[0047] In the imaging device 1, for example, a photoelectric conversion film 22 made of an organic semiconductor material is provided in each pixel PX. Note that a photoelectric conversion film made of an inorganic material may also be disposed as the photoelectric conversion film 22. The material of the photoelectric conversion film 22 can be selected, for example, depending on the wavelength range of incident light to be measured.

[0048] The upper electrode 23 is, for example, an electrode common to the photoelectric conversion film 22 of multiple pixels PX, and is provided on one side of the photoelectric conversion film 22. In each pixel PX, a lower electrode 24a and a lower electrode 24b are provided for the photoelectric conversion film 22. The lower electrode 24a and the lower electrode 24b are provided for each pixel PX on the other side of the photoelectric conversion film 22. The lower electrodes 24a and 24b are electrodes used to read out the charges converted by the photoelectric conversion film 22.

[0049] 3 , the upper electrode 23 and the lower electrode 24a (or the lower electrode 24b) are arranged to sandwich the photoelectric conversion film 22. The lower electrode 24a and the lower electrode 24b are each provided to face the upper electrode 23, with a part of the photoelectric conversion film 22 sandwiched between them. The upper electrode 23 is an electrode above the photoelectric conversion film 22, and the lower electrodes 24a and 24b are electrodes below the photoelectric conversion film 22.

[0050] The upper electrode 23 is an electrode common to multiple pixels PX and can also be called a common electrode. The lower electrodes 24 a, 24 b can also be called readout electrodes. The upper electrode 23, the lower electrode 24 a, and the lower electrode 24 b are electrically connected to circuits provided in the semiconductor layer 110 and the wiring layer 120, for example, via different wirings, electrodes, etc.

[0051] 3, the lower electrode 24a and the lower electrode 24b are provided in the wiring layer 130. The wiring layer 130 is provided on the surface 11S1 of the semiconductor layer 110. The wiring layer 130 includes, for example, a conductor film and an insulating film, and has a plurality of wires and electrodes, etc. The wiring layer 130 may be a multi-layer wiring layer and may have a configuration in which a plurality of wires are stacked.

[0052] The wiring layer 130 has, for example, an insulating film such as an oxide film, a nitride film, or an oxynitride film as an interlayer insulating film. The insulating film of the wiring layer 130 may be made of, for example, silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), or the like, or may be made of other materials that transmit light to be measured.

[0053] The above-described upper electrode 23, lower electrode 24a, and lower electrode 24b are each, for example, a transparent electrode and may be made of ITO (indium tin oxide), IZO (indium zinc oxide), tin oxide (SnO), zinc oxide (ZnO), etc. The upper electrode 23, lower electrode 24a, and lower electrode 24b may be made of other metal oxides or may be made using other transparent conductive materials.

[0054] The upper electrode 23, the lower electrode 24a, and the lower electrode 24b may be formed using a tin oxide-based material such as antimony (Sb)-doped tin oxide (ATO) or fluorine (F)-doped tin oxide (FTO). The upper electrode 23, the lower electrode 24a, and the lower electrode 24b may be formed using a zinc oxide-based material.

[0055] The upper electrode 23, the lower electrode 24a, and the lower electrode 24b may be made of, for example, aluminum zinc oxide (AZO), gallium zinc oxide (GZO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), etc. The upper electrode 23, the lower electrode 24a, and the lower electrode 24b may be made of, for example, CuI, InSbO ４ , ZnMgO, CuInO ２ , MgIN ２ O ４ , CdO, ZnSnO ３ , TiO ２ , spinel oxide, YbFe ２ O ４ It may be formed using an oxide having a structure.

[0056] When transparency is not required, the upper electrode 23, the lower electrode 24a, or the lower electrode 24b may be made of, for example, an alkali metal (lithium (Li), sodium (Na), potassium (K), etc.), an alkaline earth metal (magnesium (Mg), calcium (Ca), etc.), etc. Furthermore, the upper electrode 23, the lower electrode 24a, or the lower electrode 24b may be formed using a metal material such as platinum (Pt), gold (Au), palladium (Pd), chromium (Cr), nickel (Ni), aluminum (Al), silver (Ag), tantalum (Ta), tungsten (W), copper (Cu), titanium (Ti), indium (In), tin (Sn), iron (Fe), cobalt (Co), or molybdenum (Mo).

[0057] The upper electrode 23, the lower electrode 24a, and the lower electrode 24b may be made of a conductive material such as impurity-containing polysilicon, a carbon-based material, an oxide semiconductor, a carbon nanotube, graphene, etc. Alternatively, the upper electrode 23, the lower electrode 24a, and the lower electrode 24b may be made of an organic material (e.g., a conductive polymer) such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid [PEDOT / PSS].

[0058] The photoelectric conversion film 22 may absorb, for example, 60% or more of light of a predetermined wavelength included at least in the visible light range to the near-infrared range, and perform charge separation. The photoelectric conversion film 22 absorbs, for example, light of some or all wavelengths in the visible light range of 400 nm or more and less than 1300 nm, and the near-infrared light range. The photoelectric conversion film 22 is configured, for example, by including two or more organic materials that function as p-type semiconductors or n-type semiconductors, and has a junction surface (p / n junction surface) between the p-type semiconductor and the n-type semiconductor.

[0059] Alternatively, the photoelectric conversion film 22 may have a laminated structure (p-type semiconductor layer / n-type semiconductor layer) of a layer made of a p-type semiconductor (p-type semiconductor layer) and a layer made of an n-type semiconductor (n-type semiconductor layer), a laminated structure (p-type semiconductor layer / bulk hetero layer) of a p-type semiconductor layer and a mixed layer (bulk hetero layer) of p-type semiconductors and n-type semiconductors, or a laminated structure (n-type semiconductor layer / bulk hetero layer) of an n-type semiconductor layer and a bulk hetero layer. The photoelectric conversion film 22 may also be formed only with a mixed layer (bulk hetero layer) of p-type semiconductors and n-type semiconductors.

[0060] For example, a p-type semiconductor is a hole transport material that functions relatively as an electron donor, and an n-type semiconductor is an electron transport material that functions relatively as an electron acceptor. For example, the photoelectric conversion film 22 provides a field where excitons (electron-hole pairs) generated upon light absorption separate into electrons and holes. Specifically, the electron-hole pairs separate into electrons and holes at the interface (p / n junction) between the electron donor and electron acceptor.

[0061] Examples of p-type semiconductors include naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, pyrene derivatives, perylene derivatives, tetracene derivatives, pentacene derivatives, quinacridone derivatives, thiophene derivatives, thienothiophene derivatives, benzothiophene derivatives, benzothienobenzothiophene (BTBT) derivatives, dinaphthothienothiophene (DNTT) derivatives, dianthracenothienothiophene (DATT) derivatives, benzobisbenzothiophene (BBBT) derivatives, thienothiophene derivatives, benzothienobenzothiophene (BTBT) derivatives, dibenzothienothiophene (DNTT) derivatives, dianthracenothienothiophene (DATT) derivatives, benzobisbenzothiophene (BBBT) derivatives, and thienothiophene derivatives. Examples of p-type semiconductors include thienoacene-based materials such as dibenzothienobisbenzothiophene (TBBT) derivatives, dibenzothienobisbenzothiophene (DBTBT) derivatives, dithienobenzodithiophene (DTBDT) derivatives, dibenzothienodithiophene (DBTDT) derivatives, benzodithiophene (BDT) derivatives, naphthodithiophene (NDT) derivatives, anthracenodithiophene (ADT) derivatives, tetracenodithiophene (TDT) derivatives, and pentacenodithiophene (PDT) derivatives. Examples of p-type semiconductors include triphenylamine derivatives, carbazole derivatives, picene derivatives, chrysene derivatives, fluoranthene derivatives, phthalocyanine derivatives, subphthalocyanine derivatives, subporphyrazine derivatives, metal complexes having heterocyclic compounds as ligands, polythiophene derivatives, polybenzothiadiazole derivatives, and polyfluorene derivatives.

[0062] As an n-type semiconductor, for example, fullerene C ６０ , fullerene C ７０ , fullerene C ７４Examples of the substituents contained in the fullerene derivatives include fullerenes and their derivatives, such as higher fullerenes and endohedral fullerenes. Examples of the substituents contained in the fullerene derivatives include halogen atoms, linear, branched, or cyclic alkyl groups or phenyl groups, groups having linear or condensed aromatic compounds, groups having halides, partial fluoroalkyl groups, perfluoroalkyl groups, silyl alkyl groups, silyl alkoxy groups, aryl silyl groups, aryl sulfanyl groups, alkyl sulfanyl groups, aryl sulfonyl groups, alkyl sulfonyl groups, aryl sulfide groups, alkyl sulfide groups, amino groups, alkyl amino groups, aryl amino groups, hydroxy groups, alkoxy groups, acyl amino groups, acyloxy groups, carbonyl groups, carboxy groups, carboxamido groups, carboalkoxy groups, acyl groups, sulfonyl groups, cyano groups, nitro groups, groups having chalcogenides, phosphine groups, phosphonic groups, and derivatives thereof. Specific examples of the fullerene derivatives include fullerene fluorides, PCBM fullerene compounds, and fullerene polymers. Other examples of n-type semiconductors include organic semiconductors that have higher HOMO levels and LUMO levels than p-type semiconductors, and inorganic metal oxides that are optically transparent.

[0063] As n-type organic semiconductor, for example, can be mentioned heterocyclic compound containing nitrogen atom, oxygen atom or sulfur atom.Specifically, for example, can be mentioned pyridine derivative, pyrazine derivative, pyrimidine derivative, triazine derivative, quinoline derivative, quinoxaline derivative, isoquinoline derivative, acridine derivative, phenazine derivative, phenanthroline derivative, tetrazole derivative, pyrazole derivative, imidazole derivative, thiazole derivative, oxazole derivative, imidazole derivative, benzimidazole derivative, benzotriazole derivative, benzoxazole derivative, carbazole derivative, benzofuran derivative, dibenzofuran derivative, subporphyrazine derivative, polyphenylenevinylene derivative, polybenzothiadiazole derivative, polyfluorene derivative, etc., organic molecule, organometallic complex, subphthalocyanine derivative, quinacridone derivative, cyanine derivative and merocyanine derivative that have in part of molecular skeleton thereof.

[0064] In addition to the p-type and n-type semiconductors, the photoelectric conversion film 22 may further include an organic material, a so-called dye material, that absorbs light in a predetermined wavelength range while transmitting light in other wavelength ranges. When the photoelectric conversion film 22 is formed using three types of organic materials, i.e., a p-type semiconductor, an n-type semiconductor, and a dye material, the p-type and n-type semiconductors may be materials that are optically transparent in the visible light range. This allows the photoelectric conversion film 22 to selectively convert light in the wavelength range absorbed by the dye material.

[0065] As shown in Fig. 3 , the imaging device 1 has a through electrode 40. The through electrode 40 is a connection electrode (connection portion) that connects circuits (elements) provided on different layers. As an example, the through electrode 40 is provided so as to penetrate the semiconductor layer 110. The through electrode 40 is a structure provided within the semiconductor layer 110 so as to penetrate the semiconductor layer 110.

[0066] In the imaging device 1, a plurality of through electrodes 40 (through electrodes 40a and 40b in FIG. 3 ) are provided for each pixel PX. The through electrodes 40 are formed, for example, from below the photoelectric conversion unit 11a or 11b to reach the surface 11S2 of the semiconductor layer 110. In the example shown in FIG. 3 , the through electrodes 40 extend in the Z-axis direction and are formed to reach the inside of the wiring layer 120.

[0067] In the imaging device 1, the photoelectric conversion unit 11a or the photoelectric conversion unit 11b is electrically connected to a circuit provided on the surface 11S2 side of the semiconductor layer 110 by the through electrode 40. The lower electrode 24a of the photoelectric conversion unit 11a is electrically connected to the readout circuit 15 via the through electrode 40a. The lower electrode 24b of the photoelectric conversion unit 11b is electrically connected to the readout circuit 15 via the through electrode 40b.

[0068] The charges photoelectrically converted by the photoelectric conversion unit 11a are transferred by the lower electrode 24a through the through electrode 40a to the floating diffusion FDA of the readout circuit 15. The charges photoelectrically converted by the photoelectric conversion unit 11b are transferred by the lower electrode 24b through the through electrode 40b to the floating diffusion FDB of the readout circuit 15.

[0069] The floating diffusions FDA and FDB store the transferred charges. Each of the floating diffusions FDA and FDB includes, for example, a semiconductor region provided in the semiconductor layer 110.

[0070] The through electrode 40 is made of, for example, tungsten (W), aluminum (Al), copper (Cu), silver (Ag), etc. The through electrode 40 may be formed using cobalt (Co), molybdenum (Mo), ruthenium (Ru), etc. The through electrode 40 may also be made of other metal materials.

[0071] 4, the pixel PX of the imaging device 1 includes the above-described photoelectric conversion units 11a and 11b, and a readout circuit 15. The readout circuit 15 includes, for example, floating diffusions FDA and FDB, a transistor AMP, a transistor SEL, a transistor RST, and a transistor BIN.

[0072] The readout circuit 15 is configured to be able to output a signal based on the charge photoelectrically converted by the photoelectric conversion unit 11 (photoelectric conversion units 11a and 11b). The readout circuit 15 is configured to be able to read out, for example, a signal based on the charge accumulated in the floating diffusion FDA, i.e., a signal based on the voltage of the floating diffusion FDA, to the signal line L2.

[0073] The transistors AMP, SEL, RST, and BIN are each a MOS transistor (MOSFET) having a gate, a source, and a drain terminal. In the example shown in Figure 4, the transistors AMP, SEL, RST, and BIN are each an NMOS transistor. Note that the transistor of the pixel PX may be a PMOS transistor.

[0074] The floating diffusion FDA and the floating diffusion FDB are each a storage unit configured to store transferred charges. For example, the floating diffusion FDA stores charges photoelectrically converted by the photoelectric conversion unit 11a. The floating diffusion FDB stores charges photoelectrically converted by the photoelectric conversion unit 11b.

[0075] The floating diffusion FDA accumulates the transferred charge and converts it into a voltage according to the capacitance of the floating diffusion FDA. The floating diffusion FDB accumulates the transferred charge and converts it into a voltage according to the capacitance of the floating diffusion FDB. The floating diffusions FDA and FDB can also be considered as holding units that can hold the transferred charge.

[0076] The transistor AMP is configured to generate and output a signal based on the charge accumulated in the floating diffusion FDA. As shown in Figure 4, the gate of the transistor AMP is electrically connected to the floating diffusion FDA, and the voltage converted by the floating diffusion FDA is input.

[0077] The drain of the transistor AMP is connected to a power supply line to which a power supply voltage (power supply voltage VDD in the example shown in FIG. 4) is supplied. The source of the transistor AMP is connected to a signal line L2 via a transistor SEL. The transistor AMP is an amplifying transistor that can generate a signal based on the voltage of the floating diffusion FDA and output it to the signal line L2.

[0078] The transistor SEL is configured to be able to control the output of a pixel signal. The transistor SEL is electrically connected in series to the transistor AMP, for example, as in the example shown in FIG. 4. The transistor SEL is controlled by a signal SSEL and is configured to be able to output a signal from the transistor AMP to a signal line L2. The transistor SEL is a selection transistor and can control the output timing of the pixel signal.

[0079] The transistor SEL is configured to be able to output a signal based on the charge converted by the photoelectric conversion unit 11. The transistor SEL can output a pixel signal of the pixel PX to a signal line L2. The transistor SEL may be electrically connected between the transistor AMP and a power supply line to which a power supply voltage VDD is applied. The transistor SEL may also be omitted as necessary.

[0080] The transistor RST is configured to be able to reset the voltage of the floating diffusion FDA. In the example shown in Figure 4, the transistor RST is electrically connected to a power supply line to which a power supply voltage VDD is applied and is configured to reset the charge. The transistor RST is controlled by a signal SRST to reset the charge accumulated in the floating diffusion FDA and to reset the voltage of the floating diffusion FDA.

[0081] 4, the transistor RST electrically connects the power supply line and the floating diffusion FDA and can discharge the charge accumulated in the floating diffusion FDA. The transistor RST can reset the charge accumulated in the floating diffusion FDB via the transistor BIN and reset the voltage of the floating diffusion FDB. The transistor RST is a reset transistor.

[0082] The transistor BIN is configured to be able to electrically connect the floating diffusion FDA and the floating diffusion FDB. The transistor BIN is controlled by a signal SBIN to electrically connect or disconnect the floating diffusion FDA and the floating diffusion FDB. The transistor BIN can also be called a binning element (or a binning transistor).

[0083] In the imaging device 1, for example, a transistor BIN is provided for every two photoelectric conversion units 11 (photoelectric conversion units 11a and 11b) adjacent in the row direction (or column direction). When the transistor BIN is in the off state, the floating diffusion FDA and the floating diffusion FDB are electrically disconnected, and the charge photoelectrically converted by the photoelectric conversion unit 11a is accumulated in the floating diffusion FDA.

[0084] When the transistor BIN is on, the floating diffusions FDA and FDB are electrically connected, and the charges converted by the photoelectric conversion unit 11a and the charges converted by the photoelectric conversion unit 11b are stored in the floating diffusions FDA and FDB.

[0085] When the transistor BIN is in the on state, the charges photoelectrically converted by the photoelectric conversion units 11 a and 11 b are accumulated and added in the floating diffusions FDA and FDB. When the transistor BIN is in the on state, the charges photoelectrically converted by the photoelectric conversion units 11 a and 11 b are added together, and a pixel signal based on the added charges can be read out.

[0086] The vertical drive circuit 111 (see Figure 1) of the imaging device 1 supplies control signals to the gates of transistors BIN, SEL, RST, etc. of each pixel PX via the control line L1 described above, turning the transistors on (conducting state) or off (non-conducting state).

[0087] The multiple control lines L1 for each pixel row of the imaging device 1 include, for example, a wiring for transmitting a signal SBIN that controls a transistor BIN, a wiring for transmitting a signal SSEL that controls a transistor SEL, and a wiring for transmitting a signal SRST that controls a transistor RST.

[0088] The transistors BIN, SEL, RST, etc. are on / off controlled by a vertical drive circuit 111. The vertical drive circuit 111 controls the readout circuit 15 of each pixel PX to output a pixel signal based on the charge generated by the photoelectric conversion unit 11 from each pixel PX to a signal line L2. The vertical drive circuit 111 can control the reading out of the pixel signal of each pixel PX to the signal line L2.

[0089] 5 is a diagram illustrating an example configuration of an imaging device according to an embodiment. The signal processing circuit 112 of the imaging device 1 includes, for example, an AD conversion circuit 50, a memory 65, and an arithmetic circuit 80. The AD conversion circuit 50 (AD conversion unit) is configured to be able to perform AD conversion and can output pixel signals converted into digital signals. The AD conversion circuit 50 is an ADC (Analog to Digital Converter).

[0090] The AD conversion circuit 50 is configured to convert an input analog signal into a digital signal. The AD conversion circuit 50 performs AD conversion processing on analog pixel signals input from each pixel PX via the signal line L2. For example, an AD conversion circuit 50 is provided for each of the multiple signal lines L2. An AD conversion circuit 50 can be provided for each pixel column of the pixel unit 100.

[0091] The AD conversion circuit 50 includes, for example, a comparison circuit 55 and a counter 60. The AD conversion circuit 50 is configured to convert an input pixel signal into a digital signal with a predetermined number of bits. The AD conversion circuit 50 is, for example, a single-slope ADC.

[0092] The comparison circuit 55 is configured, for example, by a comparator circuit and is configured to be able to compare the pixel signal with a reference signal (reference signal). The comparison circuit 55 (comparison unit) can compare the pixel signal, which is an analog signal to be converted, with the reference signal to be compared.

[0093] The comparator circuit 55 compares the signal output from the pixel PX with a reference signal whose voltage (potential) changes (for example, a ramp signal whose signal level changes over time), and outputs an output signal that is the comparison result. The output signal from the comparator circuit 55 is a signal that indicates the magnitude relationship between the signal output from the pixel PX and the reference signal.

[0094] The counter 60 of the AD conversion circuit 50 is configured to count in response to an input signal. The counter 60 (counter circuit) measures the time until the comparison result of the comparison circuit 55 is inverted, based on the input clock signal and the output signal from the comparison circuit 55, and can output a signal indicating the count value to the memory 65.

[0095] The memory 65 is a storage unit (storage circuit) and is configured by, for example, a latch (latch circuit). The memory 65 can store (hold) a digital signal indicating a count value corresponding to the period from when the comparison circuit 55 starts comparison until the comparison result is inverted (changed) as a pixel signal after AD conversion. The pixel signals sequentially output from each pixel PX are converted into digital signals by AD conversion in the AD conversion circuit 50.

[0096] The AD conversion circuit 50 performs AD conversion on the pixel signal from the pixel PX, for example, and outputs a pixel signal (pixel signal PA) that is a digital signal based on the charge converted by the photoelectric conversion unit 11 a of the pixel PX. The AD conversion circuit 50 can also output a pixel signal (pixel signal SigAB) that is a digital signal based on the charge converted by the photoelectric conversion unit 11 a and the charge converted by the photoelectric conversion unit 11 b.

[0097] The arithmetic circuit 80 is configured to acquire pixel signals from the pixels PX and perform arithmetic processing. The arithmetic circuit 80 is configured to, for example, include a logic circuit and a memory. The arithmetic circuit 80 is configured to generate a pixel signal (pixel signal PB) based on the charges converted by the photoelectric conversion unit 11 b, based on the pixel signals PA and SigAB from the AD conversion circuit 50.

[0098] The arithmetic circuit 80 may generate and output a pixel signal PB corresponding to the charge photoelectrically converted by the photoelectric conversion unit 11b, for example, by performing a subtraction process between the pixel signal SigAB and the pixel signal PA. The arithmetic circuit 80 may include a processor and a memory. Alternatively, for example, the arithmetic circuit 80 may be provided outside the imaging device 1.

[0099] Fig. 6 is a diagram for explaining an example of operation of the imaging device according to the embodiment. Fig. 7 is a timing chart showing an example of operation of the imaging device according to the embodiment. The timing chart shown in Fig. 7 shows control signals (signals SSEL, SRST, and SBIN) supplied to pixels PX of the imaging device 1, with the horizontal axis representing time.

[0100] 7, a transistor to which a high-level control signal is input is turned on, and a transistor to which a low-level control signal is input is turned off. Also, FIG. 7 schematically shows pixel signals that are read out from pixels PX and AD-converted.

[0101] At time t1, the signal SSEL goes high. When the signal SSEL goes high, the transistor SEL of the pixel PX shown in Fig. 4 goes on. In the pixel PX, the charge photoelectrically converted by the photoelectric conversion unit 11a is accumulated in the floating diffusion FDA.

[0102] During the period from time t1 to time t2, since the transistor SEL is in the on state, a signal corresponding to the voltage of the floating diffusion FDA, i.e., a signal based on the charge converted by the photoelectric conversion unit 11a, is output as a signal PDA to the signal line L2 by the transistor AMP.

[0103] The signal PDA is a signal corresponding to the charge transferred from the photoelectric conversion unit 11a when the floating diffusion FDA and the floating diffusion FDB are electrically disconnected. The signal PDA output to the signal line L2 is converted into a digital signal by AD conversion in the AD conversion circuit 50 of the signal processing circuit 112. The signal processing circuit 112 stores the converted digital signal PDA in the memory 65.

[0104] At time t2, the signal SBIN goes high, turning on the transistor BIN of the pixel PX and electrically connecting the floating diffusion FDB and the floating diffusion FDA to each other.

[0105] The charges photoelectrically converted by the photoelectric conversion unit 11a and the charges photoelectrically converted by the photoelectric conversion unit 11b are accumulated in the floating diffusion FDA and the floating diffusion FDB. In this case, the charges generated by the photoelectric conversion unit 11a and the photoelectric conversion unit 11b are added together in the floating diffusion FDA and the floating diffusion FDB.

[0106] During the period from time t2 to time t3, since the transistor SEL is in the on state, a signal corresponding to the voltage of the floating diffusion FDA, i.e., a signal based on the charges converted by the photoelectric conversion unit 11a and the charges converted by the photoelectric conversion unit 11b, is output as the signal PDAB to the signal line L2 by the transistor AMP.

[0107] The signal PDAB is a signal corresponding to the charges transferred from the photoelectric conversion units 11a and 11b when the floating diffusions FDA and FDB are electrically connected to each other. The signal PDAB output to the signal line L2 is converted into a digital signal by AD conversion in the AD conversion circuit 50.

[0108] At time t3, the signal SRST goes high. When the signal SRST goes high, the transistor RST of the pixel PX goes on. This causes the charges in the floating diffusions FDA and FDB to be discharged, and the voltages of the floating diffusions FDA and FDB are reset.

[0109] Furthermore, from time t3 to time t4, since the transistor SEL is in the on state, a signal according to the voltages of the floating diffusions FDA and FDB after resetting is output as a signal RSAB to the signal line L2 by the transistor AMP.

[0110] The signal RSAB can also be said to be a signal indicating the reset level (reference level) of the floating diffusions FDA and FDB when the floating diffusions FDA and FDB are electrically connected. The signal RSAB is input to the AD conversion circuit 50 via a signal line L2.

[0111] The AD conversion circuit 50 sets the above-mentioned signal PDAB as an initial value for down-counting, and performs AD conversion processing on the signal RSAB. The AD conversion circuit 50 generates a digital signal indicating the difference value (PDAB-RSAB) between the signals PDAB and RSAB, and outputs the digital signal to the arithmetic circuit 80 as the pixel signal SigAB.

[0112] The signal processing circuit 112 reads the signal PDA stored in the memory 65 and writes it back to the counter 60 of the AD conversion circuit 50. In the counter 60 of the AD conversion circuit 50, the signal PDA is set as the initial value for down-counting.

[0113] At time t4, the signal SBIN goes low, turning off the transistor BIN of the pixel PX and electrically disconnecting the floating diffusion FDB from the floating diffusion FDA.

[0114] At time t5, the signal SRST goes high, resetting the voltage of the floating diffusion FDA. Also, because the transistor SEL is on, a signal corresponding to the voltage of the floating diffusion FDA after resetting is output as the signal RSA to the signal line L2 by the transistor AMP.

[0115] The signal RSA can also be said to be a signal indicating the reset level (reference level) of the floating diffusion FDA when the floating diffusion FDA and the floating diffusion FDB are electrically disconnected. The signal RSA is input to the AD conversion circuit 50 via a signal line L2.

[0116] The AD conversion circuit 50 performs AD conversion processing on the signal RSA using the signal PDA as an initial value for down-counting. The AD conversion circuit 50 generates a digital signal indicating the difference value (PDA-RSA) between the signals PDA and RSA, and outputs the digital signal to the arithmetic circuit 80 as the pixel signal PA.

[0117] The arithmetic circuit 80 generates a pixel signal PB as a signal component corresponding to the amount of charge photoelectrically converted by the photoelectric conversion unit 11b, using the pixel signal SigAB and pixel signal PA output from the AD conversion circuit 50. In this way, the imaging device 1 can obtain the pixel signal PA corresponding to the charge converted by the photoelectric conversion unit 11a and the pixel signal PB corresponding to the charge converted by the photoelectric conversion unit 11b.

[0118] In pixel PX, when transistor BIN is turned on, the capacitance connected to the gate of transistor AMP increases, and the conversion gain when converting charge to voltage changes. When transistor BIN is turned on, the capacitance of the floating diffusion FDA, the capacitance of the floating diffusion FDB, etc. are added to the gate of transistor AMP.

[0119] The calculation circuit 80 calculates the capacitance C of the floating diffusion FDA when the transistor BIN is in the off state. Ａ and the capacitance C of the floating diffusions FDA and FDB when the transistor BIN is in the on state. ＡＢ The pixel signal PB is calculated using the ratio of

[0120] The arithmetic circuit 80 calculates the pixel signal PB based on, for example, the pixel signal SigAB (=PDAB-RSAB), the pixel signal PA, and the following equation (1): PB=(PDAB-RSAB)×C ＡＢ / C Ａ -PA... (1)

[0121] As shown in FIG. 6, the calculation circuit 80 calculates the coefficient C ＡＢ / C ＡThe pixel signal PB can be calculated by subtracting the value of the pixel signal PA (PDA-RSA) from the value of the pixel signal SigAB multiplied by . This allows the calculation process to be performed taking into account differences in conversion gain, making it possible to accurately determine the pixel signal PB.

[0122] The signal processing circuit 112 calculates the pixel signals PA and PB of each pixel PX using, for example, the calculation circuit 80. The signal processing circuit 112 outputs the pixel signals PA and PB to the output circuit 114 via a horizontal signal line 121. The output circuit 114 can output the pixel signals of each pixel PX to the outside of the imaging device 1.

[0123] Fig. 8 is a timing chart showing an example of operation of the imaging device according to the embodiment. The example of operation of the imaging device 1 will be further described with reference to the timing chart of Fig. 8. The example shown in Fig. 8 shows an example of a case where a pixel signal (pixel signal PAB) corresponding to the charge obtained by adding together the charge converted by the photoelectric conversion unit 11a and the charge photoelectrically converted by the photoelectric conversion unit 11b is calculated.

[0124] The signal SBIN is at a high level, and the transistor BIN is turned on. In this case, the charges converted by the photoelectric conversion unit 11a and the charges converted by the photoelectric conversion unit 11b are accumulated in the floating diffusions FDA and FDB. In the floating diffusions FDA and FDB, the charges photoelectrically converted by the photoelectric conversion unit 11a and the photoelectric conversion unit 11b are added together.

[0125] At time t11, signal SSEL goes high, turning on transistor SEL of pixel PX. During the period from time t11 to time t12, a signal corresponding to the voltage of floating diffusion FDA, i.e., a signal based on the charges converted by photoelectric conversion unit 11a and the charges converted by photoelectric conversion unit 11b, is output as signal PDAB to signal line L2 by transistor AMP. Signal PDAB output to signal line L2 is converted into a digital signal by AD conversion circuit 50.

[0126] At time t12, the signal SRST goes high. When the signal SRST goes high, the transistor RST of the pixel PX goes on. This causes the charges in the floating diffusions FDA and FDB to be discharged, and the voltages of the floating diffusions FDA and FDB to be reset.

[0127] Between time t12 and time t13, the transistor SEL is in the on state, and therefore a signal corresponding to the voltages of the floating diffusions FDA and FDB after reset is output as a signal RSAB to the signal line L2 by the transistor AMP. The signal RSAB is input to the AD conversion circuit 50 via the signal line L2.

[0128] The AD conversion circuit 50 sets the above-mentioned signal PDAB as an initial value for down-counting, and performs AD conversion processing on the signal RSAB. The AD conversion circuit 50 generates a digital signal indicating the difference value (PDAB-RSAB) between the signals PDAB and RSAB, and outputs the digital signal to the arithmetic circuit 80 as the pixel signal SigAB.

[0129] The arithmetic circuit 80 calculates the pixel signal PAB based on, for example, the pixel signal SigAB (=PDAB-RSAB) and the following equation (2): PAB=(PDAB-RSAB)×C ＡＢ / C Ａ ...(2)

[0130] The arithmetic circuit 80 calculates, for example, a coefficient C for the pixel signal SigAB (=PDAB-RSAB). ＡＢ / C Ａ The image pickup device 1 can obtain a pixel signal PAB corresponding to the charge obtained by adding together the charge converted by the photoelectric conversion unit 11 a and the charge converted by the photoelectric conversion unit 11 b.

[0131] As described above, the imaging device 1 according to this embodiment is provided with a transistor BIN that can electrically connect the floating diffusion FDA and the floating diffusion FDB. Compared to providing two MOS transistors as switch elements for each pixel, the number of elements and wiring can be reduced. The imaging device 1 can have a structure that is advantageous for miniaturizing pixels.

[0132] Furthermore, in this embodiment, compared to the case where multiple switch elements are provided, it is possible to prevent a large parasitic capacitance from being added to the floating diffusion, thereby suppressing deterioration of the conversion gain, and it is possible to suppress a decrease in the S / N ratio, thereby making it possible to obtain pixel signals with less noise.

[0133] Fig. 9 is a diagram illustrating another example of the cross-sectional configuration of the imaging device according to the embodiment. Fig. 10 is a diagram illustrating another example of the circuit configuration of a pixel of the imaging device according to the embodiment. Each pixel PX of the imaging device 1 may have a photoelectric conversion unit 11s, as in the examples shown in Figs. 9 and 10 .

[0134] In the semiconductor layer 110, a plurality of photoelectric conversion units 11s are provided along a surface 11S1 and a surface 11S2 of the semiconductor layer 110. For example, the photoelectric conversion unit 11s of each pixel PX is embedded in the semiconductor layer 110. The photoelectric conversion unit 11s is a photodiode (PD) that converts incident light into an electric charge.

[0135] 9, light from a subject to be measured is incident on the photoelectric conversion unit 11a, photoelectric conversion unit 11b, and photoelectric conversion unit 11s of pixel PX via a lens 91. For example, light that has passed through the photoelectric conversion unit 11a or the photoelectric conversion unit 11b is incident on the photoelectric conversion unit 11s of pixel PX. In the example shown in FIG. 9, the photoelectric conversion unit 11s can generate electric charges by photoelectrically converting light that passes through the lens 91 and the photoelectric conversion unit 11a (or the photoelectric conversion unit 11b).

[0136] The readout circuit 15 of the pixel PX is configured to be able to output a signal based on the charge photoelectrically converted by the photoelectric conversion unit 11s. The readout circuit 15 has a transistor TG, as in the example shown in Fig. 10. The transistor TG is a transfer transistor and is configured to be able to transfer the charge photoelectrically converted by the photoelectric conversion unit 11s.

[0137] The transistor TG is controlled by a signal STG to electrically connect or disconnect the photoelectric conversion unit 11s and the floating diffusion FDA. The transistor TG can transfer charges that are photoelectrically converted and stored in the photoelectric conversion unit 11s to the floating diffusion FDA.

[0138] The imaging device 1 can obtain pixel signals based on the charges converted by the photoelectric conversion unit 11 a, pixel signals based on the charges converted by the photoelectric conversion unit 11 b, and pixel signals based on the charges converted by the photoelectric conversion unit 11 s. Each of the photoelectric conversion units 11 a, 11 b, and 11 s may be configured to receive visible light and perform photoelectric conversion, or may be configured to receive infrared light (e.g., near-infrared light) and perform photoelectric conversion.

[0139] The photoelectric conversion units 11a, 11b, and 11s may be configured to generate charges by photoelectric conversion of visible light in different wavelength ranges. As an example, the photoelectric conversion units 11a and 11b may be configured to generate charges by photoelectric conversion of visible light in different wavelength ranges. The photoelectric conversion unit 11s may be configured to generate charges by photoelectric conversion of infrared light.

[0140] By using the pixel signals of each pixel PX, it is possible to generate a visible image (for example, an RGB image), an infrared image (IR image), etc. The wavelength ranges to which each of the photoelectric conversion units 11a, 11b, and 11s is sensitive can be set arbitrarily.

[0141] [Functions and Effects] The photodetector according to this embodiment includes a first photoelectric conversion element (photoelectric conversion unit 11 a) and a second photoelectric conversion element (photoelectric conversion unit 11 b), each having a photoelectric conversion film (photoelectric conversion film 22) that photoelectrically converts light, a first floating diffusion (floating diffusion FDA) electrically connected to the first photoelectric conversion element, and a second floating diffusion (floating diffusion FDB) electrically connected to the second photoelectric conversion element, and a readout circuit (readout circuit 15) that can output a signal based on the charge accumulated in the first floating diffusion. The readout circuit has a first transistor (transistor BIN) that can electrically connect the first floating diffusion and the second floating diffusion.

[0142] The photodetector (image capture device 1) according to this embodiment is provided with a transistor BIN that can electrically connect the floating diffusion FDA and the floating diffusion FDB. This allows the image capture device 1 to have a structure that is advantageous for miniaturization of pixels. This makes it possible to realize a photodetector that is advantageous for miniaturization.

[0143] Next, a modified example of the present disclosure will be described. In the following, the same components as those in the above embodiment will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0144] 2. Modifications (2-1. Modification 1) In the above-described embodiment, exemplary configurations of the imaging device 1 have been described, but the configuration of the imaging device 1 is not limited to the above-described examples. 11 and 12 are diagrams for explaining exemplary configurations of an imaging device according to Modification 1 of the present disclosure. For example, the transistor BIN may be provided on the surface 11S1 side of the semiconductor layer 110, or on the surface 11S2 side of the semiconductor layer 110.

[0145] As an example, the transistor BIN may be provided as a thin film transistor (TFT). As in the example shown in Fig. 11 , the transistor BIN may be formed as a thin film transistor (TFT) in the wiring layer 130. By arranging the transistor BIN on the surface 11S1 side of the semiconductor layer 110, it is possible to reduce the number of through electrodes 40, as in the example shown in Fig. 11 .

[0146] 12, the transistor BIN may be provided in the wiring layer 120. This allows further miniaturization by reducing the number of elements on the surface 11S2 of the semiconductor layer 110. As in the example shown in FIG. 11 or 12, the transistor BIN has a gate electrode 14, an insulating film 16 as a gate insulating film, and a semiconductor region 17 which is a region where a channel is formed (channel region). Furthermore, for example, the transistor BIN has a source electrode and a drain electrode.

[0147] 13 is a diagram illustrating an example of the planar configuration of an imaging device according to Modification 1. As shown in the example of FIG. 13, the through electrode 40 may be disposed away from the optical center of the lens 91 in the pixel PX. This makes it possible to suppress a decrease in sensitivity to incident light. Furthermore, the through electrode 40 may be disposed so as to be positioned at approximately equal distances from the optical centers of the lenses 91 in the surrounding pixels PX. In this case, optical symmetry can be ensured.

[0148] The semiconductor region 17 (channel region) of the transistor BIN may be formed so as to be located on the axis of the optical center of the lens 91. The semiconductor region 17 may also be provided so as to be located at approximately equal distances from each of the lower electrodes 24a and 24b. Furthermore, the semiconductor region 17 may be disposed so as to be located at the center of the pixel PX. By configuring the imaging device 1 in this manner, it is possible to reduce variations in sensitivity of the photoelectric conversion units 11a and 11b.

[0149] (2-2. Modification 2) FIG. 14 is a diagram for explaining an example of the configuration of a pixel of an imaging device according to Modification 2. As shown in FIG. 14, the pixel PX may have a capacitance C1. The capacitance C1 may be, for example, the coefficient (C ＡＢ / C Ａ ) is provided for the floating diffusion FDB as a capacitor for adjusting the capacitance.

[0150] The capacitance C1 is formed of, for example, a wiring capacitance, a diffusion capacitance, etc. The capacitance C1 may be an MIM capacitance, a MOS capacitance, etc., and may be formed as a capacitive element. In the imaging device 1, for example, the coefficient C ＡＢ / C Ａ The capacitor C1 is arranged so that the relationship between the capacitance and the capacitance of the pixel signal is 2. This simplifies the above-described calculation process of the pixel signal.

[0151] 15 is a diagram illustrating an example of the configuration of a pixel of an imaging device according to Modification 3. The pixel PX may have a transistor OFGB. The transistor OFGB is, for example, electrically connected to a floating diffusion FDB and configured to be able to discharge overflowing charges.

[0152] One of the source and drain of the transistor OFGB, for example, the source of the transistor OFGB, is electrically connected to the floating diffusion FDB, and the other of the source and drain of the transistor OFGB, for example, the drain of the transistor OFGB, is electrically connected to, for example, a potential line to which a predetermined potential (voltage) is supplied or a capacitive element.

[0153] The vertical drive circuit 111 controls the gate of the transistor OFGB to set the potential in the overflow path formed by the transistor OFGB. For example, the vertical drive circuit 111 controls the voltage supplied to the gate of the transistor OFGB to discharge overflowing charges. Furthermore, by setting the gate of the transistor OFGB to a high level, the transistor OFGB can have the same function as the transistor RST, i.e., the floating diffusion FDB can be reset.

[0154] 16, the pixel PX may include a transistor OFGA. The transistor OFGA is electrically connected to the floating diffusion FDA and is configured to be able to discharge overflowing charges. The vertical drive circuit 111 controls the voltage supplied to the gate of the transistor OFGA to discharge the overflowing charges.

[0155] (2-4. Modification 4) FIG. 17 is a diagram illustrating an example configuration of a pixel of an imaging device according to Modification 4. The readout circuit 15 may include a transistor FDG. As an example, the transistor FDG is configured to be able to electrically connect the floating diffusion FDA and the transistor RST. For example, the transistor FDG is controlled by a signal SFDG to electrically connect or disconnect the floating diffusion FDA and the transistor RST.

[0156] When the transistor FDG is turned on, the capacitance added to the floating diffusion FDA of the pixel PX increases, and the conversion gain when converting electric charge to voltage is switched. The transistor FDG is a switching transistor used to set the conversion gain. The transistor FDG can change the conversion gain by switching the capacitance connected to the gate of the transistor AMP.

[0157] The transistor FDG may be electrically connected in series to the transistor RST, or may be electrically connected in parallel to the transistor RST. As shown in the example of FIG. 17 , the pixel PX may have a capacitance C2 connected to the transistor FDG. The capacitance C2 may be, for example, a wiring capacitance, a diffusion capacitance, or the like. The capacitance C2 may be an MIM capacitance, a MOS capacitance, or the like, and may be configured as a capacitive element.

[0158] 18, the transistor FDG may be configured to electrically connect the floating diffusion FDA and the capacitor C2. For example, the transistor FDG is controlled by a signal SFDG to electrically connect or disconnect the floating diffusion FDA and the capacitor C2. By switching the connection state of the capacitor C2, the conversion gain can be changed.

[0159] (2-5. Modification 5) FIG. 19 is a diagram illustrating an example of the configuration of a pixel of an imaging device according to Modification 5. The pixel PX may have a photoelectric conversion unit 11c and a photoelectric conversion unit 11d provided in the semiconductor layer 110. The photoelectric conversion unit 11d is provided adjacent to the photoelectric conversion unit 11c. The readout circuit 15 of the pixel PX may have a transistor TGA and a transistor TGB.

[0160] The transistor TGA is configured to be able to transfer the charge photoelectrically converted by the photoelectric conversion unit 11c to the floating diffusion FDA. The transistor TGB is configured to be able to transfer the charge photoelectrically converted by the photoelectric conversion unit 11d to the floating diffusion FDA. The transistors TGA and TGB are each a transfer transistor.

[0161] For example, the photoelectric conversion unit 11c is provided in the semiconductor layer 110 so as to be located below the photoelectric conversion unit 11a. Furthermore, the photoelectric conversion unit 11d is provided in the semiconductor layer 110 so as to be located below the photoelectric conversion unit 11b. As schematically shown by the arrows in Figure 19, the photoelectric conversion unit 11c receives light that has passed through the photoelectric conversion unit 11a and generates charges by photoelectric conversion.

[0162] Furthermore, the photoelectric conversion unit 11d receives light that has passed through the photoelectric conversion unit 11b and generates charges through photoelectric conversion. In each pixel PX of the imaging device 1, the photoelectric conversion unit 11c and the photoelectric conversion unit 11d receive light that has passed through different regions of an optical system such as an imaging lens, and perform pupil division. Note that the arrangement direction of the photoelectric conversion units 11a and 11b may be different from the arrangement direction of the photoelectric conversion units 11c and 11d.

[0163] The photoelectric conversion units 11a and 11b may be arranged adjacent to each other in the horizontal direction (X-axis direction), as shown in Fig. 20. Alternatively, the photoelectric conversion units 11a and 11b may be arranged adjacent to each other in the vertical direction (Y-axis direction), as shown in Fig. 21.

[0164] The pixel PX may have two or more photoelectric conversion units 11, for example, four photoelectric conversion units 11 (photoelectric conversion units 11a to 11d in the examples shown in FIGS. 22 and 23). Furthermore, as shown in FIG. 23, the pixel PX may have a plurality of transistors BIN, for example, transistors BINB, BINC, and BIND.

[0165] The transistor BINC is configured to be able to electrically connect the floating diffusion FDA and the floating diffusion FDC, and is controlled by a signal SBINC to electrically connect or disconnect the floating diffusion FDA and the floating diffusion FDC.

[0166] The transistor BINB is configured to be able to electrically connect the floating diffusion FDA and the floating diffusion FDB. The transistor BINB is controlled by a signal SBINB to electrically connect or disconnect the floating diffusion FDA and the floating diffusion FDB.

[0167] The transistor BIND is configured to be able to electrically connect the floating diffusion FDA and the floating diffusion FDD. The transistor BIND is controlled by a signal SBIND to electrically connect or disconnect the floating diffusion FDA and the floating diffusion FDD.

[0168] In the imaging device 1, for example, one lens 91 is provided for each of the photoelectric conversion units 11a to 11d. In the imaging device 1, the photoelectric conversion units 11a to 11d receive light that has passed through different regions of an optical system such as an imaging lens, thereby enabling pupil division.

[0169] 24, a dummy transistor may be arranged in addition to the three transistors BIN (transistors BINB, BINC, and BIND) in the pixel PX. In the example shown in Fig. 24, by arranging one dummy transistor for each pixel PX, it is possible to ensure symmetry.

[0170] 25 to 27 are diagrams illustrating an example configuration of an imaging device according to Modification 6. A pixel PX of the imaging device 1 may have, for example, a photoelectric conversion unit 11s1 and a photoelectric conversion unit 11s2, as shown in Fig. 25. The photoelectric conversion unit 11s2 is formed in the semiconductor layer 110 so as to be stacked on the photoelectric conversion unit 11s1.

[0171] 25, the photoelectric conversion unit 11s2 is located closer to the light incident side than the photoelectric conversion unit 11s1. Each of the photoelectric conversion units 11s1 and 11s2 performs photoelectric conversion to generate charges according to the amount of received light. The photoelectric conversion units 11s1 and 11s2 of each pixel PX can also be referred to as a photoelectric conversion region.

[0172] The photoelectric conversion units 11s1 and 11s2 may be configured to perform photoelectric conversion on light in different wavelength ranges. The photoelectric conversion units 11s1 and 11s2 selectively receive and photoelectrically convert light in specific wavelength ranges depending on, for example, the positions at which the photoelectric conversion units 11s1 and 11s2 are provided in the semiconductor layer 110, the constituent materials, and the like.

[0173] The photoelectric conversion units 11s1 and 11s2 are located at different distances (depths) from the surface 11S1 of the semiconductor layer 110, and generate charges by absorbing light of different color wavelengths depending on the incident depth (penetration depth) of the light. In the example shown in Fig. 25, the photoelectric conversion unit 11s1 is located below the photoelectric conversion unit 11s2, and can generate charges by photoelectrically converting light that passes through the photoelectric conversion unit 11s2.

[0174] As an example, the photoelectric conversion units 11a and 11b of pixel PX receive and photoelectrically convert light mainly in the green (G) wavelength range from light from the subject to be measured. The photoelectric conversion unit 11s2 receives and photoelectrically converts light mainly in the blue (B) wavelength range. Furthermore, the photoelectric conversion unit 11s1 receives and photoelectrically converts light mainly in the red (R) wavelength range. Each pixel PX of the imaging device 1 can generate a pixel signal of an R component, a pixel signal of a G component, and a pixel signal of a B component. The imaging device 1 is capable of obtaining RGB pixel signals.

[0175] Furthermore, the imaging device 1 may have a light receiving layer 30 having a photoelectric conversion unit 11c, as shown in Fig. 26, for example. The light receiving layer 30 having the photoelectric conversion unit 11c is provided so as to be stacked on the light receiving layer 20 having the photoelectric conversion units 11a and 11b. As in the example shown in Fig. 26, the photoelectric conversion unit 11c of each pixel PX includes a photoelectric conversion film 32, an upper electrode 33, and a lower electrode 34, and is configured to be able to generate charges by photoelectric conversion. The photoelectric conversion unit 11c may be configured to photoelectrically convert light in a wavelength range different from that of the photoelectric conversion units 11a and 11b.

[0176] As an example, the photoelectric conversion unit 11c of pixel PX receives and photoelectrically converts light mainly in the blue (B) wavelength range from light from the subject to be measured. The photoelectric conversion units 11a and 11b receive and photoelectrically convert light mainly in the green (G) wavelength range. Furthermore, the photoelectric conversion unit 11s receives and photoelectrically converts light mainly in the red (R) wavelength range.

[0177] 27 , the imaging device 1 may include a filter 92. The filter 92 is configured to selectively transmit light in a specific wavelength range from among the incident light. The filter 92 may be, for example, an RGB color filter or an IR pass filter that transmits infrared light.

[0178] The filter 92 is provided above the photoelectric conversion unit 11s, for example, for each pixel PX or for each set of pixels PX. In the example shown in Fig. 27, the filter 92 is provided in the wiring layer 130 and located above the photoelectric conversion unit 11s. The photoelectric conversion unit 11s receives light that has passed through the lens 91, the photoelectric conversion unit 11a (or the photoelectric conversion unit 11b), and the filter 92, and performs photoelectric conversion on the received light.

[0179] As an example, when the photoelectric conversion units 11a and 11b receive and photoelectrically convert light in the green (G) wavelength range, a pixel PX having a filter 92 that transmits red (R) light and a pixel PX having a filter 92 that transmits blue (B) light may be provided. Note that the arrangement of the filters 92 is not limited to the example described above and can be set arbitrarily.

[0180] (2-7. Modification 7) Fig. 28 is a timing chart showing an example of the operation of an imaging device according to Modification 7. An example of the operation of the imaging device 1 will be described with reference to Fig. 28, as well as Fig. 4 and Fig. 5. Fig. 28 shows an example in which, in each pixel PX, an operation of resetting the floating diffusion (shutter operation) and an operation of reading out a signal corresponding to the photoelectrically converted charge (read operation) are performed alternately.

[0181] After the floating diffusion is reset by the shutter operation, a pixel signal corresponding to the charge accumulated through photoelectric conversion is read out by the read operation. For example, in the example shown in Fig. 28, the period Ta from time t3 to time t7 is a period during which charge corresponding to incident light is generated and accumulated, and is the signal accumulation period (i.e., the charge accumulation period).

[0182] At time t1, the signal SSEL goes high, and the signal SRST goes high, causing the transistor AMP to output a signal RDA corresponding to the voltage of the floating diffusion FDA when the transistor RST (reset transistor) is on to the signal line L2.

[0183] At time t2, the signal SBIN goes high. Also, since the transistor SEL is on, a signal corresponding to the voltages of the floating diffusions FDA and FDB when the transistor RST is on is output as the signal RDAB to the signal line L2.

[0184] At time t3, signal SRST goes low. Therefore, a signal corresponding to the voltage of the floating diffusions FDA and FDB after reset is output as signal RSAB to signal line L2 by transistor AMP. Also, at time t4, signal SBIN goes low. Therefore, a signal corresponding to the voltage of the floating diffusion FDA after reset is output as signal RSA to signal line L2.

[0185] The signal processing circuit 112 performs signal processing such as AD conversion and correlated double sampling on the signals RDA, RDAB, RSAB, and RSA. For example, the signal processing circuit 112 performs CDS processing to subtract the signal RDA from the signal RSA, and stores the CDS result (RSA-RDA) in the memory 65. The signal processing circuit 112 also performs CDS processing to subtract the signal RDAB from the signal RSAB, and stores the CDS result (RSAB-RDAB) in the memory 65.

[0186] At time t5, signal SSEL goes high. Signal SBIN is low, and transistor BIN is off. In this case, a signal based on the charges converted by photoelectric conversion unit 11a is output as signal PDA to signal line L2 by transistor AMP.

[0187] At time t6, the signal SBIN goes high. Also, because the transistor SEL is on, a signal based on the charges converted by the photoelectric conversion units 11a and 11b is output as the signal PDAB to the signal line L2 by the transistor AMP.

[0188] At time t7, signal SRST goes high. Therefore, a signal corresponding to the voltage of floating diffusions FDA and FDB when transistor RST is on is output as signal RDAB to signal line L2. Also, at time t8, signal SBIN goes low. Therefore, a signal corresponding to the voltage of floating diffusion FDA when transistor RST is on is output as signal RDA to signal line L2.

[0189] The signal processing circuit 112 performs signal processing such as AD conversion and correlated double sampling on the signals PDA, PDAB, RDAB, and RDA. For example, the signal processing circuit 112 performs CDS processing to subtract the signal RDA from the signal PDA, and stores the CDS result (PDA-RDA) in the memory 65. The signal processing circuit 112 also performs CDS processing to subtract the signal RDAB from the signal PDAB, and stores the CDS result (PDAB-RDAB) in the memory 65.

[0190] The signal processing circuit 112 calculates pixel signals PA and PAB based on the CDS results stored in the memory 65 and the following equations (3) and (4): PA=(PDA-RDA)-(RSA-RDA)=PDA-RSA (3) PAB=(PDAB-RDAB)-(RSAB-RDAB)=PDAB-RSAB (4)

[0191] Furthermore, the signal processing circuit 112 calculates a pixel signal PB based on the pixel signal PAB and the following equation (5): PB=(PDAB-RSAB)×C ＡＢ / C Ａ −PA (5) By reading out the signal and performing the calculation as described above, the difference between the signal component and the reset component can be obtained, and the kTC noise can be canceled.

[0192] 29 and 30 are diagrams for explaining a configuration example of an imaging device according to Modification 8. As shown in Fig. 29, the imaging device 1 may have an amplifier circuit 19. The amplifier circuit 19 is configured to be able to output a voltage based on a signal output from the readout circuit 15 and a reference voltage, for example.

[0193] 29 , a signal based on the voltage of the floating diffusion FDA is input from the readout circuit 15 to one input of the amplifier circuit 19. A reference voltage Vref is input from an external circuit to the other input of the amplifier circuit 19. The amplifier circuit 19 can generate and output a voltage Vout that is a signal voltage corresponding to the voltage of the output signal of the readout circuit 15 and the reference voltage Vref.

[0194] The transistor RST of the pixel PX is configured to be able to reset the floating diffusion FDA based on the voltage Vout output from the amplifier circuit 19. In this modification, the reset operation can be performed by feeding back the voltage Vout corresponding to the output voltage of the readout circuit 15, making it possible to suppress kTC noise.

[0195] 30, the periods Tb1 and Tb2 during which the signal SRST is at a high level may be set to be relatively long, taking into account the settling time of the feedback described above, thereby making it possible to effectively suppress kTC noise.

[0196] (2-9. Modification 9) Fig. 31 is a diagram illustrating an example configuration of an imaging device according to Modification 9. The pixel PX may have a plurality of output control circuits 18 (output control circuits 18a and 18b in Fig. 31). The output control circuit 18 includes, for example, capacitance elements C3 and C4, transistor RES, transistor SIG, transistor RSTB, transistor AMPB, and transistor SELB.

[0197] 31, the output control circuits 18a and 18b are controlled by different signals. For example, the output control circuit 18a is configured to output pixel signals to the signal processing circuit 112 via a signal line L2a. The output control circuit 18b is configured to output pixel signals to the signal processing circuit 112 via a signal line L2b.

[0198] 32 is a timing chart showing an example of the operation of the imaging device according to Modification 9. At time t1, signal SRST goes high. Also, signal SRSTB2 goes high, and signal SRES2 goes high. This causes transistor RSTB of output control circuit 18b to turn on, and transistor RES to turn on. Signal SBIN is high, and transistor BIN is on.

[0199] At time t2, signal SRES2 transitions from high to low. As a result, a reset component corresponding to the voltage of floating diffusions FDA and FDB when transistor RST is on is held as signal RSAB in capacitive element C3 of output control circuit 18b. In output control circuit 18b, the value of signal RSAB is determined at the timing when signal SRES2 transitions from high to low, and signal RSAB is held in capacitive element C3.

[0200] At time t3, the signal SRSTB1 goes high, and the signal SRES1 goes high. This causes the transistor RSTB of the output control circuit 18a to turn on, and the transistor RES to turn on. The signal SBIN is low, and the transistor BIN is off.

[0201] At time t4, the signal SRES1 transitions from high to low. As a result, a reset component corresponding to the voltage of the floating diffusion FDA when the transistor RST is on is held as the signal RSA in the capacitive element C3 of the output control circuit 18a. In the output control circuit 18a, the value of the signal RSA is determined at the timing when the signal SRES1 transitions from high to low, and the signal RSA is held in the capacitive element C3.

[0202] After photoelectric conversion is performed during the signal accumulation period (charge accumulation period), at time t5, the signal SRSTB1 goes high and the signal SSIG1 goes high. This causes the transistor RSTB of the output control circuit 18a to turn on, and the transistor SIG to turn on. Note that the signal SBIN is low and the transistor BIN is off.

[0203] At time t6, the signal SSIG1 transitions from high to low. As a result, a signal based on the charges converted by the photoelectric conversion unit 11a is held as the signal PDA in the capacitive element C4 of the output control circuit 18a. In the output control circuit 18a, the value of the signal PDA is determined at the timing when the signal SSIG1 transitions from high to low, and the signal PDA is held in the capacitive element C4.

[0204] At time t7, the signal SRSTB2 goes high, and the signal SSIG2 goes high. This causes the transistor RSTB of the output control circuit 18b to turn on, and the transistor SIG to turn on. Also, the signal SBIN is high, and the transistor BIN is on.

[0205] At time t8, signal SSIG2 transitions from high to low. As a result, a signal based on the charges converted by photoelectric conversion unit 11a and the charges converted by photoelectric conversion unit 11b is held as signal PDAB in capacitive element C4 of output control circuit 18b. In output control circuit 18b, the value of signal PDAB is determined at the timing when signal SSIG2 transitions from high to low, and signal PDAB is held in capacitive element C4.

[0206] At time t9, signal RSTB1 goes high, resetting the voltage at node N1 of output control circuit 18a shown in Fig. 31. Signal RSTB2 goes high, resetting the voltage at node N1 of output control circuit 18b.

[0207] Between time t10 and time t11, the signal SRES1 is at a high level. Also, because the signal SSELB1 is at a high level, a signal based on the voltage held in the capacitive element C3 of the output control circuit 18a, i.e., the signal RSA, is read out to the signal line L2a by the transistor AMPB of the output control circuit 18a.

[0208] Furthermore, from time t10 to time t11, the signal SRES2 is at a high level, so that a signal based on the voltage held in the capacitive element C3 of the output control circuit 18b, i.e., the signal RSAB, is read out to the signal line L2b by the transistor AMPB of the output control circuit 18b. At time t12, the signals RSTB1 and RSTB2 both become high level, and the node N1 is reset.

[0209] Between time t13 and time t14, the signal SSIG1 goes high, causing the signal PDA based on the voltage held in the capacitive element C4 of the output control circuit 18a to be read out to the signal line L2a by the transistor AMPB of the output control circuit 18a.

[0210] Also, from time t13 to time t14, signal SSIG2 goes high, and therefore a signal based on the voltage held in capacitive element C4 of output control circuit 18b, i.e., signal PDAB, is read out to signal line L2b by transistor AMPB of output control circuit 18b.

[0211] The signal processing circuit 112 performs signal processing such as AD conversion and subtraction processing on the signals RSA, RSAB, PDA, and PDAB. For example, the signal processing circuit 112 performs CDS processing to subtract the signal RSA from the signal PDA, thereby obtaining a pixel signal PA indicating (PDA-RSA).

[0212] Furthermore, the signal processing circuit 112 can obtain a pixel signal PB based on the pixel signal PA and the following equation (6): PB=(PDAB-RSAB)×C ＡＢ / C Ａ −PA (6) As described above, by subtracting the reset component from the signal component, it is possible to obtain a pixel signal with reduced kTC noise.

[0213] (2-10. Modification 10) Figures 33A and 33B are diagrams for explaining a configuration example of an imaging device according to Modification 10. The above-described arithmetic circuit 80 may be mounted on the imaging device 1 as in the example shown in Figure 33A, or may be provided outside the imaging device 1 as in the example shown in Figure 33B. For example, it may be configured as a light detection system 300 including a arithmetic device (arithmetic circuit 80) and a light detection device (imaging device 1).

[0214] 3. Application Examples (Application Example 1) The above-described light detection device (imaging device 1) can be applied to various electronic devices, such as imaging systems such as digital still cameras and digital video cameras, mobile phones with imaging functions, and other devices with imaging functions.

[0215] FIG. 34 is a block diagram showing an example of the configuration of an electronic device.

[0216] As shown in Figure 34, electronic device 1001 is equipped with an optical system 1002, a photodetector 1003, and a DSP (Digital Signal Processor) 1004, and is configured by connecting DSP 1004, a display device 1005, an operation system 1006, a memory 1008, a recording device 1009, and a power supply system 1010 via a bus 1007, and is capable of capturing still images and moving images.

[0217] The optical system 1002 is configured to have one or more lenses, and guides image light (incident light) from a subject to the photodetector 1003 , forming an image on the light receiving surface (sensor portion) of the photodetector 1003 .

[0218] The above-described photodetector (imaging device 1) can be applied as the photodetector 1003. Electrons are accumulated in the photodetector 1003 for a certain period of time in accordance with an image formed on the light-receiving surface via the optical system 1002. A signal corresponding to the electrons accumulated in the photodetector 1003 is then supplied to the DSP 1004.

[0219] The DSP 1004 performs various signal processing on the signal from the photodetector 1003 to acquire an image, and temporarily stores the image data in a memory 1008. The image data stored in the memory 1008 is recorded in a recording device 1009 or supplied to a display device 1005 to display the image. In addition, an operation system 1006 accepts various operations by a user and supplies operation signals to each block of the electronic device 1001. A power supply system 1010 supplies the power necessary to drive each block of the electronic device 1001.

[0220] Application Example 2 Fig. 35A is a schematic diagram showing an example of the overall configuration of a light detection system 2000 including a light detection device (imaging device 1). Fig. 35B is a schematic diagram showing an example of the circuit configuration of the light detection system 2000. The light detection system 2000 includes a light emitting device 2001 as a light source unit that emits light Lb, and a light detecting device 2002 as a light receiving unit that has a photoelectric conversion element.

[0221] The above-described light detection device (imaging device 1) can be used as the light detection device 2002. The light detection system 2000 may further include a system control unit 2003, a light source driving unit 2004, a sensor control unit 2005, a light source side optical system 2006, and a camera side optical system 2007.

[0222] The light detection device 2002 can detect light La and light Lb. Light La is external ambient light reflected by the subject 2100 (measurement target) (see FIG. 35A ). Light Lb is light emitted by the light emitting device 2001 that is reflected by the subject 2100. Light La is, for example, visible light, and light Lb is, for example, infrared light.

[0223] Light La can be detected by a photoelectric conversion unit in the photodetector 2002, and light Lb can be detected by a photoelectric conversion unit in the photodetector 2002. Image information of the subject 2100 can be obtained from light La, and distance information between the subject 2100 and the photodetector system 2000 can be obtained from light Lb.

[0224] The light detection system 2000 can be mounted on, for example, an electronic device such as a smartphone or a mobile object such as a car. The light emitting device 2001 can be configured using, for example, a semiconductor laser, a surface emitting semiconductor laser, or a vertical cavity surface emitting laser (VCSEL).

[0225] The method of detecting light Lb emitted from the light emitting device 2001 by the photodetector 2002 can be, for example, an iTOF system, but is not limited to this. In the iTOF system, the photoelectric conversion unit can measure the distance to the subject 2100 by, for example, time-of-flight (TOF).

[0226] For example, a structured light method or a stereo vision method can be adopted as a method for detecting light Lb emitted from light emitting device 2001 by light detection device 2002. For example, in the structured light method, light of a predetermined pattern is projected onto subject 2100, and the degree of distortion of the pattern is analyzed to measure the distance between light detection system 2000 and subject 2100.

[0227] In addition, in the stereo vision method, for example, two or more cameras are used to acquire two or more images of the subject 2100 viewed from two or more different viewpoints, thereby making it possible to measure the distance between the light detection system 2000 and the subject. Note that the light emitting device 2001 and the light detection device 2002 can be synchronously controlled by a system control unit 2003.

[0228] 4. Application Examples (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.

[0229] FIG. 36 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.

[0230] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 36, 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.

[0231] 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.

[0232] 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.

[0233] 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.

[0234] 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.

[0235] 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.

[0236] 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 distance between vehicles, maintaining vehicle speed, vehicle collision warning, vehicle lane departure warning, etc.

[0237] 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.

[0238] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 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.

[0239] 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. 36, 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.

[0240] FIG. 37 is a diagram showing an example of the installation position of the imaging unit 12031.

[0241] In FIG. 37, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0242] 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.

[0243] 37 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.

[0244] 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.

[0245] 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 allows the vehicle to travel autonomously without relying on driver operation.

[0246] 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.

[0247] 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.

[0248] An example of a mobile object control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to, for example, the image capturing unit 12031 of the above-described configuration. Specifically, for example, the image capturing device 1 or the like can be applied to the image capturing unit 12031. By applying the technology according to the present disclosure to the image capturing unit 12031, it becomes possible to obtain high-resolution captured images. It becomes possible to perform high-precision control using captured images in the mobile object control system.

[0249] (Application Example to Endoscopic Surgery System) 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 applied to an endoscopic surgery system.

[0250] FIG. 38 is a diagram showing an example of a schematic configuration of an endoscopic surgery system to which the technology according to the present disclosure (the present technology) can be applied.

[0251] 38 shows an operator (doctor) 11131 performing surgery on a patient 11132 on a patient bed 11133 using an endoscopic surgery system 11000. As shown in the figure, the endoscopic surgery system 11000 is composed of an endoscope 11100, other surgical tools 11110 such as an insufflation tube 11111 and an energy treatment tool 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0252] The endoscope 11100 is composed of a lens barrel 11101, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 11132, and a camera head 11102 connected to the base end of the lens barrel 11101. In the example shown, the endoscope 11100 is configured as a so-called rigid scope having a rigid lens barrel 11101, but the endoscope 11100 may also be configured as a so-called flexible scope having a flexible lens barrel.

[0253] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 11101. A light source device 11203 is connected to the endoscope 11100, and light generated by the light source device 11203 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 11101, and is irradiated via the objective lens toward an object to be observed inside the body cavity of the patient 11132. The endoscope 11100 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0254] An optical system and an image sensor are provided inside the camera head 11102, and light reflected from the object of observation (observation light) is collected by the optical system onto the image sensor. The observation light is photoelectrically converted by the image sensor to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. The image signal is sent to a camera control unit (CCU) 11201 as RAW data.

[0255] The CCU 11201 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and comprehensively controls the operations of the endoscope 11100 and the display device 11202. Furthermore, the CCU 11201 receives an image signal from the camera head 11102 and performs various types of image processing on the image signal, such as development processing (demosaic processing), to display an image based on the image signal.

[0256] Under the control of the CCU 11201, the display device 11202 displays an image based on an image signal that has been subjected to image processing by the CCU 11201.

[0257] The light source device 11203 is composed of a light source such as an LED (Light Emitting Diode), and supplies the endoscope 11100 with irradiation light when photographing the surgical site, etc.

[0258] The input device 11204 is an input interface for the endoscopic surgery system 11000. A user can input various information and instructions to the endoscopic surgery system 11000 via the input device 11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiation light, magnification, focal length, etc.) of the endoscope 11100.

[0259] The treatment tool control device 11205 controls the driving of the energy treatment tool 11112 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 11206 inflates the body cavity of the patient 11132 through the insufflation tube 11111 in order to ensure a clear field of view for the endoscope 11100 and a working space for the surgeon. The recorder 11207 is a device capable of recording various types of information related to the surgery. The printer 11208 is a device capable of printing various types of information related to the surgery in various formats such as text, images, or graphs.

[0260] The light source device 11203, which supplies illumination light to the endoscope 11100 when photographing the surgical site, can be configured from a white light source, such as an LED, a laser light source, or a combination of these. When the white light source is configured from a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, allowing the light source device 11203 to adjust the white balance of the captured image. In this case, it is also possible to time-share images corresponding to each RGB by irradiating the object of observation with laser light from each RGB laser light source and controlling the drive of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, color images can be obtained without providing a color filter to the image sensor.

[0261] Furthermore, the light source device 11203 may be controlled to change the intensity of light it outputs at predetermined time intervals. By controlling the driving of the image sensor of the camera head 11102 in synchronization with the timing of the change in light intensity to acquire images in a time-division manner and combining the images, it is possible to generate an image with a high dynamic range that is free from so-called blocked-up shadows and blown-out highlights.

[0262] The light source device 11203 may also be configured to supply light in a predetermined wavelength band corresponding to special light observation. Special light observation, for example, utilizes the wavelength dependence of light absorption in body tissues to irradiate light in a narrower band than the light irradiated during normal observation (i.e., white light) to capture high-contrast images of specific tissues, such as blood vessels on the surface of mucous membranes, in what is known as narrow band imaging. Alternatively, special light observation may involve fluorescence observation, in which images are obtained using fluorescence generated by irradiating excitation light. Fluorescence observation may involve irradiating excitation light onto body tissues and observing the fluorescence from the tissues (autofluorescence observation), or may involve locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the tissues with excitation light corresponding to the fluorescent wavelength of the reagent to obtain a fluorescent image. The light source device 11203 may be configured to supply narrow band light and / or excitation light corresponding to such special light observation.

[0263] FIG. 39 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0264] The camera head 11102 has a lens unit 11401, an imaging unit 11402, a drive unit 11403, a communication unit 11404, and a camera head control unit 11405. The CCU 11201 has a communication unit 11411, an image processing unit 11412, and a control unit 11413. The camera head 11102 and the CCU 11201 are connected to each other via a transmission cable 11400 so that they can communicate with each other.

[0265] The lens unit 11401 is an optical system provided at the connection portion with the lens barrel 11101. Observation light taken in from the tip of the lens barrel 11101 is guided to the camera head 11102 and enters the lens unit 11401. The lens unit 11401 is composed of a combination of multiple lenses including a zoom lens and a focus lens.

[0266] The imaging unit 11402 is composed of an imaging element. The imaging element constituting the imaging unit 11402 may be a single (so-called single-chip type) or multiple (so-called multi-chip type). When the imaging unit 11402 is composed of a multi-chip type, for example, each imaging element may generate an image signal corresponding to each of RGB, and a color image may be obtained by combining these signals. Alternatively, the imaging unit 11402 may be configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to 3D (dimensional) display. The 3D display allows the surgeon 11131 to more accurately grasp the depth of the biological tissue at the surgical site. Note that when the imaging unit 11402 is composed of a multi-chip type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0267] Furthermore, the imaging unit 11402 does not necessarily have to be provided in the camera head 11102. For example, the imaging unit 11402 may be provided inside the lens barrel 11101, immediately after the objective lens.

[0268] The driving unit 11403 is configured by an actuator, and moves the zoom lens and focus lens of the lens unit 11401 by a predetermined distance along the optical axis under the control of the camera head control unit 11405. This allows the magnification and focus of the image captured by the imaging unit 11402 to be adjusted appropriately.

[0269] The communication unit 11404 is configured by a communication device for transmitting and receiving various types of information to and from the CCU 11201. The communication unit 11404 transmits the image signal obtained from the imaging unit 11402 to the CCU 11201 via the transmission cable 11400 as RAW data.

[0270] Furthermore, the communication unit 11404 receives a control signal for controlling the driving of the camera head 11102 from the CCU 11201 and supplies the control signal to the camera head control unit 11405. The control signal includes information on the imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of imaging, and / or information specifying the magnification and focus of the captured image.

[0271] The image capturing conditions such as the frame rate, exposure value, magnification, and focus may be appropriately specified by the user, or may be automatically set by the control unit 11413 of the CCU 11201 based on the acquired image signal. In the latter case, the endoscope 11100 is equipped with a so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0272] The camera head control unit 11405 controls the driving of the camera head 11102 based on a control signal received from the CCU 11201 via the communication unit 11404 .

[0273] The communication unit 11411 is configured by a communication device for transmitting and receiving various information to and from the camera head 11102. The communication unit 11411 receives an image signal transmitted from the camera head 11102 via the transmission cable 11400.

[0274] Furthermore, the communication unit 11411 transmits to the camera head 11102 a control signal for controlling the driving of the camera head 11102. The image signal and the control signal can be transmitted by electrical communication, optical communication, or the like.

[0275] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data transmitted from the camera head 11102 .

[0276] The control unit 11413 performs various controls related to the imaging of the surgical site, etc. by the endoscope 11100 and the display of the captured image obtained by imaging the surgical site, etc. For example, the control unit 11413 generates a control signal for controlling the driving of the camera head 11102.

[0277] Furthermore, the control unit 11413 displays the captured image showing the surgical site, etc., on the display device 11202 based on the image signal subjected to image processing by the image processing unit 11412. At this time, the control unit 11413 may recognize various objects in the captured image using various image recognition technologies. For example, the control unit 11413 can recognize surgical tools such as forceps, specific biological parts, bleeding, mist generated when using the energy treatment tool 11112, etc., by detecting the shape and color of the edges of objects included in the captured image. When displaying the captured image on the display device 11202, the control unit 11413 may use the recognition results to superimpose various surgical support information on the image of the surgical site. By superimposing the surgical support information and presenting it to the surgeon 11131, the burden on the surgeon 11131 can be reduced and the surgeon 11131 can proceed with the surgery reliably.

[0278] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for electrical signal communication, an optical fiber for optical communication, or a composite cable of these.

[0279] In the illustrated example, communication is performed wired using a transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0280] The above describes an example of an endoscopic surgery system to which the technology according to the present disclosure can be applied. Of the above-described configurations, the technology according to the present disclosure can be suitably applied to, for example, the imaging unit 11402 provided in the camera head 11102 of the endoscope 11100. By applying the technology according to the present disclosure to the imaging unit 11402, it is possible to provide a high-definition endoscope 11100.

[0281] Although the present disclosure has been described above by way of embodiments, modifications, application examples, and applied examples, the present technology is not limited to the above-described embodiments, etc., and various modifications are possible. For example, although the modifications described above have been described as modifications of the above-described embodiments, the configurations of the modifications can be combined as appropriate.

[0282] In the above embodiments, an imaging device has been described as an example. However, the photodetector of the present disclosure may be, for example, a device that receives incident light and converts the light into an electric charge. The output signal may be a signal of image information or a signal of ranging information. The photodetector (imaging device) may be applied to an image sensor, a ranging sensor, etc. Note that the present disclosure is not limited to a back-illuminated image sensor, but may also be applied to a front-illuminated image sensor.

[0283] The photodetector according to the present disclosure may also be applied as a distance measuring sensor capable of measuring distances using a time-of-flight (TOF) method. The photodetector (image capture device) may also be applied as a sensor capable of detecting events, such as an event-driven sensor (also known as an event vision sensor (EVS), an event-driven sensor (EDS), or a dynamic vision sensor (DVS)).

[0284] According to one embodiment of the present disclosure, a photodetector includes a first photoelectric conversion element and a second photoelectric conversion element, each having a photoelectric conversion film that photoelectrically converts light, a first floating diffusion electrically connected to the first photoelectric conversion element, and a second floating diffusion electrically connected to the second photoelectric conversion element, and a readout circuit capable of outputting a signal based on charge accumulated in the first floating diffusion. The readout circuit has a first transistor electrically connecting the first floating diffusion and the second floating diffusion. This makes it possible to realize a photodetector that is advantageous for miniaturization.

[0285] Note that the effects described in this specification are merely examples and are not limited thereto, and other effects may be present. The present disclosure may also have the following configurations. (1) A photodetector including: a first photoelectric conversion element and a second photoelectric conversion element, each having a photoelectric conversion film that photoelectrically converts light; a first floating diffusion electrically connected to the first photoelectric conversion element; and a second floating diffusion electrically connected to the second photoelectric conversion element, and a readout circuit capable of outputting a signal based on charge accumulated in the first floating diffusion, wherein the readout circuit has a first transistor electrically connecting the first floating diffusion and the second floating diffusion. (2) The photodetector according to (1), including a pixel including at least one of the first photoelectric conversion element and the second photoelectric conversion element, wherein the pixel is a pixel usable for phase difference detection. (3) The photodetector according to (1) or (2), wherein the photoelectric conversion film is made of an organic material. (4) The photodetector according to any one of (1) to (3), wherein the readout circuit is capable of outputting a first signal based on the charges converted by the first photoelectric conversion element and a second signal based on the charges converted by the first photoelectric conversion element and the charges converted by the second photoelectric conversion element. (5) The photodetector according to (4), further comprising an arithmetic circuit capable of generating a third signal based on the charges converted by the second photoelectric conversion element, based on the first signal and the second signal. (6) The photodetector according to (4) or (5), further comprising an AD conversion circuit capable of performing AD conversion, wherein the arithmetic circuit is capable of generating the third signal based on the first signal and the second signal converted into digital signals by the AD conversion circuit. (7) The photodetector according to any one of (1) to (6), further comprising a semiconductor layer having at least a part of the readout circuit, and disposed so as to be stacked with a layer having the first photoelectric conversion element and the second photoelectric conversion element. (8) The photodetector according to (7), further comprising a through electrode provided to penetrate the semiconductor layer and capable of transferring the electric charges converted by the first photoelectric conversion element.(9) The photodetector according to (7) or (8), wherein the semiconductor layer has a first surface onto which light transmitted through the first photoelectric conversion element or the second photoelectric conversion element is incident and a second surface opposite to the first surface, and the first transistor is provided on the second surface side of the semiconductor layer. (10) The photodetector according to any one of (7) to (9), wherein the semiconductor layer has a first surface onto which light transmitted through the first photoelectric conversion element or the second photoelectric conversion element is incident and a second surface opposite to the first surface, and the first transistor is a thin film transistor and is provided on the first surface side of the semiconductor layer. (11) The photodetector according to any one of (7) to (10), further comprising a wiring layer provided between the semiconductor layer and a layer having the first photoelectric conversion element and the second photoelectric conversion element, and the first transistor is a thin film transistor and is provided in the wiring layer. (12) The photodetector according to any one of (7) to (11), further comprising a third photoelectric conversion element provided in the semiconductor layer, and the readout circuit having a second transistor capable of transferring charge converted by the third photoelectric conversion element to the first floating diffusion. (13) The photodetector according to (12), further comprising a fourth photoelectric conversion element provided in the semiconductor layer adjacent to the third photoelectric conversion element, and the readout circuit having a third transistor capable of transferring charge converted by the fourth photoelectric conversion element to the first floating diffusion. (14) The photodetector according to (13), further comprising a fourth photoelectric conversion element provided in the semiconductor layer adjacent to the third photoelectric conversion element, and the readout circuit having a third transistor capable of transferring charge converted by the fourth photoelectric conversion element to the first floating diffusion. (15) The photodetector according to any one of (1) to (14), further comprising a third transistor electrically connected to the second floating diffusion and capable of discharging overflowing charges.(16) The photodetector according to any one of (1) to (16), further comprising an amplifier circuit capable of outputting a first voltage based on a signal output from the readout circuit and a reference voltage, wherein the readout circuit has a fourth transistor capable of resetting the voltage of the first floating diffusion based on the first voltage output from the amplifier circuit. (17) The photodetector according to any one of (1) to (16), wherein the readout circuit has a plurality of capacitive elements capable of holding a voltage signal based on charge accumulated in the first floating diffusion. (18) The photodetector according to any one of (1) to (17), wherein the readout circuit has a fourth transistor electrically connected between the first floating diffusion and a first potential line, and wherein the readout circuit is capable of outputting a signal based on the voltage of the first floating diffusion when the fourth transistor is in an on state before and after a charge accumulation period. (19) A photodetection system comprising: a photodetector; and an arithmetic unit; wherein the photodetector includes a first photoelectric conversion element and a second photoelectric conversion element, each having a photoelectric conversion film that photoelectrically converts light; a first floating diffusion electrically connected to the first photoelectric conversion element; and a second floating diffusion electrically connected to the second photoelectric conversion element, a readout circuit capable of outputting a signal based on charges accumulated in the first floating diffusion; and an AD conversion circuit capable of performing AD conversion; wherein the readout circuit has a first transistor electrically connecting the first floating diffusion and the second floating diffusion, and is capable of outputting a first signal based on charges converted by the first photoelectric conversion element and a second signal based on charges converted by the first photoelectric conversion element and charges converted by the second photoelectric conversion element; and wherein the arithmetic unit is capable of generating a third signal based on charges converted by the second photoelectric conversion element, based on the first signal and the second signal converted into digital signals by the AD conversion circuit.(20) An electronic device comprising: a first photoelectric conversion element and a second photoelectric conversion element, each having a photoelectric conversion film that photoelectrically converts light; a first floating diffusion electrically connected to the first photoelectric conversion element; and a readout circuit capable of outputting a signal based on charge accumulated in the first floating diffusion, the readout circuit having a first transistor capable of electrically connecting the first floating diffusion and the second floating diffusion.

[0286] This application claims priority based on Japanese Patent Application No. 2024-093348, filed on June 7, 2024, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0287] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur depending on design requirements and other factors, and are intended to be within the scope of the appended claims and their equivalents.

Claims

1. A photodetector comprising: a first photoelectric conversion element and a second photoelectric conversion element, each having a photoelectric conversion film that photoelectrically converts light; a first floating diffusion electrically connected to the first photoelectric conversion element; and a readout circuit capable of outputting a signal based on the charge accumulated in the first floating diffusion, wherein the readout circuit has a first transistor electrically connecting the first floating diffusion and the second floating diffusion.

2. The photodetection device according to claim 1, comprising a pixel including at least one of the first photoelectric conversion element and the second photoelectric conversion element, the pixel being a pixel that can be used for phase difference detection.

3. The photodetector according to claim 1, wherein the photoelectric conversion film is made of an organic material.

4. The photodetector according to claim 1, wherein the readout circuit is capable of outputting a first signal based on the charge converted by the first photoelectric conversion element, and a second signal based on the charge converted by the first photoelectric conversion element and the charge converted by the second photoelectric conversion element.

5. The photodetector according to claim 4, further comprising an arithmetic circuit capable of generating a third signal based on the charge converted by the second photoelectric conversion element, based on the first signal and the second signal.

6. The photodetector according to claim 5, further comprising an AD conversion circuit capable of performing AD conversion, wherein the arithmetic circuit is capable of generating the third signal based on the first signal and the second signal converted into digital signals by the AD conversion circuit.

7. The photodetector according to claim 1, further comprising a semiconductor layer having at least a part of the readout circuit and provided so as to be stacked with a layer having the first photoelectric conversion element and the second photoelectric conversion element.

8. The photodetector according to claim 7, further comprising a through electrode provided to penetrate the semiconductor layer and capable of transferring the electric charges converted by the first photoelectric conversion element.

9. The photodetector according to claim 7, wherein the semiconductor layer has a first surface onto which light transmitted through the first photoelectric conversion element or the second photoelectric conversion element is incident, and a second surface opposite to the first surface, and the first transistor is provided on the second surface side of the semiconductor layer.

10. The photodetector device according to claim 7, wherein the semiconductor layer has a first surface onto which light transmitted through the first photoelectric conversion element or the second photoelectric conversion element is incident, and a second surface opposite to the first surface, and the first transistor is a thin film transistor and is provided on the first surface side of the semiconductor layer.

11. The photodetector device according to claim 7, further comprising a wiring layer provided between the semiconductor layer and a layer having the first photoelectric conversion element and the second photoelectric conversion element, wherein the first transistor is a thin film transistor and is provided in the wiring layer.

12. The photodetector according to claim 7, further comprising a third photoelectric conversion element provided in the semiconductor layer, wherein the readout circuit has a second transistor capable of transferring charges converted by the third photoelectric conversion element to the first floating diffusion.

13. The photodetector according to claim 12, further comprising a fourth photoelectric conversion element disposed adjacent to the third photoelectric conversion element in the semiconductor layer, and the readout circuit has a third transistor capable of transferring the charge converted by the fourth photoelectric conversion element to the first floating diffusion.

14. The photodetector according to claim 13, wherein the third photoelectric conversion element receives light that has passed through at least one of the first photoelectric conversion element and the second photoelectric conversion element, and the fourth photoelectric conversion element receives light that has passed through at least one of the second photoelectric conversion element and the first photoelectric conversion element.

15. The photodetector device according to claim 1, further comprising a third transistor electrically connected to the second floating diffusion and capable of discharging overflowing charges.

16. The photodetector according to claim 1, further comprising an amplifier circuit capable of outputting a first voltage based on the signal output from the readout circuit and a reference voltage, wherein the readout circuit has a fourth transistor capable of resetting the voltage of the first floating diffusion based on the first voltage output from the amplifier circuit.

17. The photodetector according to claim 1, wherein the readout circuit has a plurality of capacitance elements capable of holding a voltage signal based on the charge accumulated in the first floating diffusion.

18. The photodetector device according to claim 1, wherein the readout circuit has a fourth transistor electrically connected between the first floating diffusion and a first potential line, and the readout circuit is capable of outputting a signal based on the voltage of the first floating diffusion when the fourth transistor is in an on state before and after a charge accumulation period.

19. A photodetection system comprising: a photodetector; and an arithmetic unit; wherein the photodetector includes a first photoelectric conversion element and a second photoelectric conversion element, each having a photoelectric conversion film that photoelectrically converts light; a first floating diffusion electrically connected to the first photoelectric conversion element; and a second floating diffusion electrically connected to the second photoelectric conversion element, a readout circuit capable of outputting a signal based on charge accumulated in the first floating diffusion; and an AD conversion circuit capable of performing AD conversion, wherein the readout circuit has a first transistor electrically connecting the first floating diffusion and the second floating diffusion, and is capable of outputting a first signal based on charge converted by the first photoelectric conversion element and a second signal based on charge converted by the first photoelectric conversion element and charge converted by the second photoelectric conversion element; and wherein the arithmetic unit is capable of generating a third signal based on charge converted by the second photoelectric conversion element, based on the first signal and the second signal converted into digital signals by the AD conversion circuit.

20. An electronic device comprising: a first photoelectric conversion element and a second photoelectric conversion element, each having a photoelectric conversion film that photoelectrically converts light; a first floating diffusion electrically connected to the first photoelectric conversion element; and a readout circuit capable of outputting a signal based on charges accumulated in the first floating diffusion, the readout circuit having a first transistor electrically connecting the first floating diffusion and the second floating diffusion.

Images