Imaging device

Abstract

The present technology relates to an image capture device that provides an improved image quality of a captured image. The image capture device is provided with: a photoelectric conversion unit for performing photoelectric conversion; a first capacitor and a second capacitor for holding a signal from the photoelectric conversion unit; and an initialization switch for initializing the second capacitor. One end of the first capacitor, one end of the second capacitor, and an amplifier for amplifying the signal from the photoelectric conversion unit are connected. The other end of the second capacitor and one end of the initialization switch are connected. The other end of the first capacitor and the other end of the initialization switch are connected to a voltage source. The present technology may be applied to an image capture device, for example.

Description

[Technical Field]

[0001] The present technology relates to an imaging device, and for example, to an imaging device that can further improve image quality. [Background technology]

[0002] BACKGROUND ART Camera-equipped mobile phones, digital still cameras, medical devices such as endoscopes, and the like that use imaging elements such as CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor) image sensors are known.

[0003] Patent Document 1 proposes that in a global shutter operation, a voltage is held in a capacitor within a pixel, and the voltage is continued to be held during a readout operation for each row. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-9294 Summary of the Invention [Problem to be solved by the invention]

[0005] After the global shutter operation, the pixels are read out row by row, and the first row to be read out has a short signal retention period, while the last row to be read out continues to retain its signal while the other rows are being read. If there is leakage current in the capacitance elements or switches within the pixels, the signal held in the capacitance may change before it is read out, which could result in degradation of image quality.

[0006] It is desirable to reduce the influence of leakage current and improve image quality.

[0007] The present technology has been made in view of such circumstances, and is intended to reduce the influence of leakage current and improve image quality. [Means for solving the problem]

[0008] According to one aspect of the present technology, there is provided an imaging device including: a photoelectric conversion unit that performs photoelectric conversion; a first capacitor and a second capacitor that hold a signal from the photoelectric conversion unit; and an initialization switch that initializes the second capacitor. a dummy switch having the same characteristics as the initialization switch between the first capacitor and a voltage source; one end of the first capacitance, one end of the second capacitance, and an amplifier that amplifies a signal from the photoelectric conversion unit are connected, the other end of the second capacitance and one end of the initialization switch are connected, and the other end of the first capacitance and the other end of the initialization switch are connected The same An imaging device connected to a voltage source.

[0009] According to one aspect of the present technology, there is provided an imaging device including: a photoelectric conversion unit that performs photoelectric conversion; a first capacitor and a second capacitor that hold a signal from the photoelectric conversion unit; and an initialization switch that initializes the second capacitor. A dummy switch having the same characteristics as the initialization switch is provided between the first capacitor and the voltage source. One end of the first capacitance, one end of the second capacitance, and an amplifier that amplifies a signal from the photoelectric conversion unit are connected, the other end of the second capacitance and one end of the initialization switch are connected, and the other end of the first capacitance and the other end of the initialization switch are connected. Identical It is connected to a voltage source.

[0010] The imaging device may be an independent device or an internal block constituting a single device. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a digital camera. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of an imaging unit. [Figure 3] FIG. 2 is a circuit diagram of an imaging unit according to a first embodiment. [Figure 4] FIG. 4 is a diagram for explaining the operation of the imaging unit. [Figure 5]FIG. 10 is a diagram for explaining the influence of a leakage current. [Figure 6] FIG. 10 is a diagram for explaining the arrangement of capacitive elements. [Figure 7] FIG. 10 is a circuit diagram of an imaging unit according to a second embodiment. [Figure 8] FIG. 10 is a diagram for explaining the influence of a leakage current. [Figure 9] FIG. 4 is a diagram for explaining the operation of the imaging unit. [Figure 10] FIG. 10 is a circuit diagram of an imaging unit according to a third embodiment. [Figure 11] FIG. 1 is a diagram illustrating an example of a schematic configuration of an endoscopic surgery system. [Figure 12] FIG. 2 is a block diagram showing an example of the functional configuration of a camera head and a CCU. [Figure 13] 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; [Figure 14] FIG. 2 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, modes for carrying out the present technology (hereinafter referred to as embodiments) will be described.

[0013] <Electronic device configuration> The present technology can be applied to electronic devices such as digital cameras, etc. Here, the description will continue with an example in which the present technology is applied to a digital camera.

[0014] 1 is a block diagram showing an example of the configuration of an embodiment of a digital camera to which the present technology is applied. Note that the digital camera is capable of capturing both still images and moving images.

[0015] In FIG. 1, the digital camera includes an optical system 1, an imaging unit 2, a memory 3, a signal processing unit 4, an output unit 5, and a control unit 6.

[0016] The optical system 1 has, for example, a zoom lens, a focus lens, an aperture, etc. (not shown), and causes external light to be incident on the imaging unit 2. The imaging unit 2 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, and functions as an imaging device that receives incident light from the optical system 1, performs photoelectric conversion, and outputs image data corresponding to the incident light from the optical system 1.

[0017] The memory 3 temporarily stores image data output by the imaging unit 2. The signal processing unit 4 performs signal processing using the image data stored in the memory 3, such as noise removal and white balance adjustment, and supplies the processed image data to the output unit 5. The output unit 5 outputs the image data from the signal processing unit 4.

[0018] The output unit 5 has a display (not shown) made up of, for example, a liquid crystal display or the like, and displays an image corresponding to the image data from the signal processing unit 4 as a so-called through image. The output unit 5 has a driver (not shown) that drives a recording medium such as a semiconductor memory, a magnetic disk, or an optical disk, and records the image data from the signal processing unit 4 on the recording medium.

[0019] The control unit 6 controls each block that constitutes the digital camera in accordance with user operations and the like.

[0020] In the digital camera configured as above, the imaging unit 2 receives incident light from the optical system 1 and outputs image data in accordance with the incident light.

[0021] The image data output by the imaging unit 2 is supplied to and stored in a memory 3. The image data stored in the memory 3 is subjected to signal processing by a signal processing unit 4, and the resulting image data is supplied to and output from an output unit 5.

[0022] <Configuration example of imaging unit> Fig. 2 is a block diagram showing an example of the configuration of the imaging unit 2 in Fig. 1. In Fig. 2, the imaging unit 2 includes a pixel array 10, a control unit 20, a pixel driving unit 21, a column-parallel AD conversion device 22, and an output unit 23.

[0023] The pixel array 10 includes M×N pixels 11 (M and N are integers equal to or greater than 1) that perform photoelectric conversion. 1,1 ,11 1,2 ,···,11 1,M ,11 2,1 ,11 2,2 ,···,11 2,N ,···,11 M、1 ,11 M、2 ,···,11 M、N The M×N pixels 11 function as an imaging unit (imaging element) that captures an image. 1,1 to 11 M、N are arranged in a matrix (lattice) of M rows and N columns on a two-dimensional plane.

[0024] N pixels 11 arranged in the row direction (horizontal direction) of the mth row (m=1, 2, . . . , M) (from the top) of the pixel array 10 m,1 to 11 m,n A pixel control line 41m extending in the row direction is connected to each of the pixel electrodes 41a and 41b.

[0025] Also, M pixels 11 arranged in the column direction (vertical direction) in the nth column (n=1, 2, . . . , N) (from the left) 1,n to 11 M、n A VSL (Vertical Signal Line) 42n extending in the column direction is connected to the pixel 11. 1,n to 11 M、n In addition, a current source 43n is connected.

[0026] The pixel 11m,n performs photoelectric conversion of light incident thereon (incident light). Furthermore, the pixel 11m,n outputs a voltage (electrical signal) corresponding to the charge obtained by the photoelectric conversion onto the VSL 42n in accordance with control from the pixel drive unit 21 via the pixel control line 41m.

[0027] The pixel 11m,n can perform photoelectric conversion of light of a predetermined color that is incident via a color filter (not shown) such as a Bayer array.

[0028] The control unit 20 controls the pixel driving unit 21, the column-parallel AD conversion device 22 (including the reference signal output unit 33, clock output unit 34, etc.), and other necessary blocks according to predetermined logic or the like.

[0029] The pixel driving section 21, under the control of the control section 20, controls (drives) via a pixel control line 41m, the pixels 11m,1 to 11m,N connected to that pixel control line 41m.

[0030] The column-parallel AD conversion device 22 connects the pixels 11m,1 to 11m,N arranged in each row with the VSLs 421 to 422. N Therefore, an electrical signal (voltage) (hereinafter also referred to as a VSL signal) output by the pixel 11m,n onto the VSL 42n is supplied to the column-parallel AD conversion device 22.

[0031] The column-parallel AD conversion device 22 converts VSLs 421 to 422 from the pixels 11m,1 to 11m,N arranged in one row. N The digital data obtained as a result of the AD conversion is supplied to the output unit 23 as pixel values ​​(pixel data) of the pixels 11m,1 to 11m,N.

[0032] Here, the column-parallel AD conversion device 22 performs AD conversion of the electrical signals of all N pixels 11m,1 to 11m,N arranged in a row in parallel, and can also perform AD conversion of the electrical signals of one or more pixels (less than N) out of the N pixels 11m,1 to 11m,N in parallel.

[0033] However, for simplicity of explanation, it is assumed below that the column-parallel AD conversion device 22 performs AD conversion of all VSL signals of N pixels 11m,1 to 11m,N arranged in one row in parallel.

[0034] The column-parallel AD conversion device 22 includes N ADCs (Analog to Digital Converters) 311 to 31m,N to perform AD conversion of all VSL signals of N pixels 11m,1 to 11m,N arranged in one row in parallel. N It has.

[0035] Furthermore, the column-parallel AD conversion device 22 includes a reference signal output unit 33 and a clock output unit .

[0036] The reference signal output unit 33 is configured by, for example, a DAC (Digital to Analog Converter), and outputs a reference signal having a period in which the level (voltage) changes from a predetermined initial value to a predetermined final value with a constant gradient like a ramp signal to the ADCs 311 to 313 via a reference signal line 33A. N The signal is supplied (output) to

[0037] The clock output unit 34 outputs a clock of a predetermined frequency to the ADCs 311 to 313 via a clock line 34A. N The signal is supplied (output) to

[0038] The ADC 31n is connected to the VSL 41n, and therefore the ADC 31n is supplied with a VSL signal (electrical signal) that the pixel 11m,n outputs onto the VSL 41n.

[0039] The ADC 31n performs AD conversion of the VSL signal output by the pixel 11m,n using the reference signal from the reference signal output unit 33 and the clock from the clock output unit 34, and further performs CDS (Correlated Double Sampling) to obtain digital data as a pixel value.

[0040] Here, ADC 31n compares the VSL signal of pixel 11m,n with the reference signal from reference signal output unit 33, and performs AD conversion of the VSL signal of pixel 11m,n by counting the time required for the level of the reference signal to change until the levels of the VSL signal of pixel 11m,n and the reference signal match (until the magnitude relationship between the VSL signal and the reference signal is reversed).

[0041] In the ADC 31n, the time required for the level of the reference signal to change until the levels of the VSL signal of the pixel 11m,n and the reference signal match is counted by counting the clocks from the clock output unit .

[0042] In addition, N ADCs 311 to 31 N The VSL signals of N pixels 11m,1 to 11m,N in each of the first to Mth rows of the pixel array 10 are supplied sequentially, for example, starting from the first row, and AD conversion and CDS of the VSL signals are performed on a row-by-row basis.

[0043] The output unit 23 selects a column n from which to read out pixel values, and reads out the result of AD conversion (and CDS) of pixel 11m,n obtained by the ADC 31n of that column n from that ADC 31n as a pixel value, and outputs it to the outside (in this embodiment, memory 3 (Figure 1)).

[0044] Although it has been described here that the ADC 31n performs CDS in addition to AD conversion, it is possible for the ADC 31n to perform only AD conversion, and for CDS to be performed by the output unit 23. In the following, a description of the CDS will be omitted as appropriate.

[0045] <Configuration example of imaging unit> 3 is a circuit diagram of the imaging unit 2, and is a circuit diagram showing an example configuration of the pixel 11m,n (hereinafter referred to as pixel 11) in Fig. 2 and a part of the column-parallel AD conversion device 22. The configuration of the imaging unit 2 shown in Fig. 3 will be described as the configuration of the imaging unit 2a in the first embodiment.

[0046] In Figure 3, a pixel 11 of a pixel array 10 includes a PD (photodiode) 61, a transfer transistor 62, an FD (floating diffusion) 63, a conversion efficiency switching switch 64, an FD reset transistor 65, an in-pixel amplification transistor 66, a constant current source 67, a sampling switch 68, a first capacitance 69, a second capacitance 70, an initialization switch 71, an output transistor 72, and a selection transistor 73.

[0047] The pixel 11 includes a memory unit 80 that temporarily stores a reset level and a signal level in order to realize a so-called global shutter, in which all pixels are reset at the same time and exposed at the same time. The memory unit 80 includes a sampling switch 68, a first capacitor 69, a second capacitor 70, an initialization switch 71, and an output transistor 72.

[0048] The PD 61 is a photoelectric conversion element made up of, for example, a PN junction photodiode, which receives light from a subject, generates an electric charge according to the amount of received light through photoelectric conversion, and accumulates the electric charge.

[0049] The transfer transistor 62 is provided between the PD 61 and the FD 63, and transfers the charge stored in the PD 61 to the FD 63 in response to a drive signal TX applied to the gate electrode of the transfer transistor 62.

[0050] In FIG. 3, the transfer transistor 62, the conversion efficiency changeover switch 64, the FD reset transistor 65, and the in-pixel amplification transistor 66 are configured by N-channel MOS transistors.

[0051] Drive signals TX, DCG, and RST are supplied to the gate electrodes of the transfer transistor 62 through the FD reset transistor 65. These drive signals are pulse signals that are active (on) when high level and inactive (off) when low level.

[0052] Therefore, for example, in the transfer transistor 62, when the drive signal TX supplied to the gate electrode of the transfer transistor 62 becomes active and the transfer transistor 62 is turned on, the charge accumulated in the PD 61 is transferred to the FD 63.

[0053] The FD 63 is a floating diffusion region (FD) that converts the charge transferred from the PD 61 via the transfer transistor 62 into an electric signal, for example, a voltage signal, and outputs it.

[0054] The FD 63 is connected to an FD reset transistor 65 and also to a memory unit 80 via an in-pixel amplification transistor 66. The FD 63 is also connected to a charge storage unit (not shown) which is a capacitance (capacitor) that stores electric charges via a conversion efficiency changeover switch 64.

[0055] The conversion efficiency changeover switch 64 is turned on and off in response to the drive signal DCG, thereby switching the connection state between the FD 63 and the charge storage unit between an electrically connected state and an electrically disconnected state.

[0056] That is, a drive signal DCG is supplied to the gate electrode that constitutes the conversion efficiency changeover switch 64, and when this drive signal DCG is turned on, the potential directly below the conversion efficiency changeover switch 64 becomes deeper, and the FD63 and the charge storage unit are electrically connected.

[0057] On the other hand, when the drive signal DCG is turned off, the potential directly below the conversion efficiency changeover switch 64 becomes shallow, and the FD 63 and the charge storage unit are electrically disconnected. Therefore, by turning the drive signal DCG on and off, capacitance is added to the FD 63, and the sensitivity of the pixel can be changed.

[0058] The FD reset transistor 65 is an element that appropriately initializes (resets) each region from the FD 63 to the charge storage section, and has a drain connected to the power supply of the power supply voltage Vdd and a source connected to the FD 63. A drive signal RST is applied to the gate electrode of the FD reset transistor 65 as a reset signal.

[0059] Furthermore, when the drive signal RST is set to an active state, the FD reset transistor 65 is set to a conductive state, and the potential of the FD 63 and the like is reset to the level of the power supply voltage Vdd. That is, the FD 63 and the like are initialized.

[0060] The in-pixel amplifying transistor 66 has a gate electrode connected to the FD 63 and a drain connected to a power supply of the power supply voltage Vdd, and serves as an input section of a source follower circuit that reads out charges obtained by photoelectric conversion in the PD 61. That is, the in-pixel amplifying transistor 66 configures a source follower circuit by connecting its source to a constant current source 67.

[0061] The wiring connecting the in-pixel amplifying transistor 66 and the constant current source 67 is also connected to a wiring connecting a sampling switch 68 in the memory unit 80. The sampling switch 68 can be configured as an NMOS. A drive signal SAM is supplied to the gate of the sampling switch 68. When the drive signal SAM is activated, a signal is supplied to the memory unit 80 via the in-pixel amplifying transistor 66.

[0062] One end of a first capacitor 69 and one end of a second capacitor 70 are connected to the drain side of the sampling switch 68. The part where the sampling switch 68, the first capacitor 69, and the second capacitor 70 are connected is referred to as an X node. The other end of the first capacitor 69 is connected to the power supply voltage Vdd. The other end of the second capacitor 70 is connected to the source of the initialization switch 71 and the gate of the output transistor 72. The part where the second capacitor 70, the initialization switch 71, and the output transistor 72 are connected is referred to as a Y node.

[0063] The drain of the initialization switch 71 is connected to the power supply voltage Vdd. The drain of the output transistor 72 is also connected to the power supply voltage Vdd. The source of the output transistor 72 is connected to the drain of the selection transistor 73. The source of the selection transistor 73 is connected to VSL42.

[0064] A drive signal SEL is supplied to the gate of the selection transistor 73. When the drive signal SEL is set to an active state, the selection transistor 73 becomes conductive, and the signal stored in the memory unit 80 is output to the VLS 42.

[0065] <Operation of the imaging unit> The operation of the imaging unit 2a shown in FIG. 3 will be described with reference to FIG.

[0066] During the shutter period, a global shutter operation is performed. The exposure period begins when the drive signals RST and TX are set to the active state (denoted as Hi) and the charge in the PD 61 is reset. After the exposure period ends, the bias potential applied to the gate of the constant current source 67 is increased, causing the in-pixel amplifier transistor 66 to operate as a source follower circuit.

[0067] When the drive signal RST is changed from an inactive state (described as Lo) to Hi, the FD reset transistor 65 is turned on and the potential of the FD 63 is reset. At this time, the drive signals CAL and SAM are also switched from Lo to Hi, and the sampling switch 68 and the initialization switch 71 are turned on. In this state, the X node holds the level of the reset potential of the FD 63, and the Y node is initialized to the power supply voltage Vdd.

[0068] When the drive signal CAL is switched from Hi to LO, the Y node holds the initialization voltage, and the X node holds the FD reset potential. This period is referred to as the reset setting period.

[0069] Since the drive signal SAM remains in the Hi state even after the reset setting period, the sampling switch 68 remains in the On state. In this state, the drive signal TX is switched from Lo to Hi, causing the signal charge from the PD 61 to be transferred to the FD 63. Because the sampling switch 68 is in the On state, the signal charge transferred to the FD 63 is supplied to the X node via the in-pixel amplification transistor 66. Therefore, a potential corresponding to (FD reset level + signal charge) is written to the X node. This period is referred to as the signal setting period.

[0070] During the signal setting period, the second capacitor 70 is in a floating state, so when the voltage at the X node changes, the voltage at the Y node also changes accordingly. Since the voltage at the X node changes from (FD reset potential) to (FD reset potential + potential according to signal charge), the voltage at the Y node changes from (initialization potential) to (initialization voltage + potential according to signal charge).

[0071] In this state, the drive signal SAM is switched from Hi to Lo, and the sampling switch 68 is turned off. By turning off the sampling switch 68, the potential in the memory unit 80 is maintained. The operations up to this point are performed simultaneously for all pixels 11 in the pixel array 10, thereby realizing a global shutter.

[0072] When a signal is held in the memory unit 80, reading of the signal held in the memory unit 80 begins during the readout period. When the row to be readout is selected by setting the drive signal SEL to Hi, the selection transistor 73 becomes conductive. When the selection transistor 73 becomes conductive, the voltage of the Y node is output to VSL42 via the output transistor 72.

[0073] At this point, the voltage of the Y node is a voltage (signal) according to (FD reset level+potential according to the signal charge). With the signal in this state as the signal level, the ADC 31 performs AD conversion.

[0074] When AD conversion of the signal level is performed, the drive signal CAL is set to Hi for a predetermined period of time, and the initialization switch 71 is turned on for a predetermined period of time, thereby setting the Y node to the initialization voltage. AD conversion is performed by the ADC 31 using the signal in this state as the reset level.

[0075] By calculating the difference between the signal level converted by the ADC 31 and the reset level, the amount of signal charge from which the initialization voltage has been cancelled can be obtained.

[0076] <The effect of leakage current> As described with reference to the timing chart of Fig. 4, the imaging unit 2a shown in Fig. 3 stores signals in the memory unit 80 by a global shutter operation, and then reads out row by row. Since reading out is performed row by row, the timing of reading out the first row and the last row is different.

[0077] If a leakage current occurs in the pixel 11, the effect of the leakage current may differ between the row that is read out first and the row that is read out last, and the effect of the leakage current may be greater in the row that is read out last. For example, the amount of signal held in the first capacitor 69 or the second capacitor 70 in the pixel 11 may deviate from the correct value due to the leakage current.

[0078] Here, let us consider the leakage current in the first capacitance 69 and the second capacitance 70. FIG.

[0079] The Y node is initialized with the power supply voltage Vdd, and the first capacitor 69 is connected to the power supply voltage Vdd. To be precise, the Y node is initialized with a voltage (Vdd-Vth) obtained by subtracting the voltage Vth applied to the initialization switch 71, but here the explanation will continue assuming that the voltage Vth is a small value and has no effect.

[0080] In this state, a leakage current flows from the Y node to the X node via the second capacitance 70, causing the potential at the Y node to drop. On the other hand, because the first capacitance 69 is connected to the power supply voltage Vdd, a leakage current flows to the X node via the first capacitance 69, causing the potential at the X node to rise. Therefore, the potential drop at the Y node is suppressed by the rise in the potential at the X node.

[0081] In this way, the influence of leakage current can be reduced by connecting one end of the first capacitor 69 to the power supply voltage Vdd and the other end to the X node, and by connecting one end of the second capacitor 70 to the power supply voltage Vdd and the other end to the X node, similar to the first capacitor 69. This makes it possible to prevent leakage current from making it impossible to maintain accurate values, thereby improving image quality.

[0082] <Regarding pressure resistance and efficient layout> By configuring the imaging unit 2a with a circuit such as that shown in Fig. 3, it is possible to obtain the effect of reducing the withstand voltage of the capacitors. This will be explained with reference to Fig. 6. Fig. 6 is a diagram showing an example of the cross-sectional configuration of a first capacitor 69 and a second capacitor 70.

[0083] When the first capacitor 69 and the second capacitor 70 are laid out using MOS capacitors, the configuration shown in Figure 6 is obtained. The MOS capacitor is formed by a capacitance made of an oxide film sandwiched between a diffusion layer and a gate electrode. In the example shown in Figure 6, the first capacitor 69 includes a diffusion layer 93 and an oxide film 101 formed in a well 91, and the second capacitor 70 includes a diffusion layer 95 and an oxide film 103 formed in the well 91.

[0084] A wiring 97 connected to the power supply voltage Vdd and an X node are connected to the diffusion layer 93. The X node and a Y node are connected to the diffusion layer 95. The Y node is connected to a wiring 99 connected to the power supply voltage Vdd via an initialization switch 71 (not shown in FIG. 6).

[0085] In the FD reset state, the X node has a value close to voltage Vdd. When the transfer transistor 62 is turned on, the potential of the X node becomes a potential that is lower than voltage Vdd by the amount of the signal charge. For the first capacitor 69 and the second capacitor 70, the voltage difference applied to the capacitive element is smaller when the opposing electrodes have a potential close to voltage Vdd. In FIG. 6, the opposing electrodes are electrodes 97 and 99, and both electrodes 97 and 99 are electrodes to which voltage Vdd is applied.

[0086] 6, the voltage Vdd is applied to both the electrodes 97 and 99, which are opposing electrodes, and therefore it is possible to reduce the voltage difference applied to the first capacitor 69 and the second capacitor 70. This makes it possible to reduce the withstand voltage required for each of the first capacitor 69 and the second capacitor 70.

[0087] If the potential of well 91 is fixed to the same voltage Vdd as the power supply voltage Vdd, and if electrode 97 connected to diffusion layer 93 is grounded, a large potential difference will occur between diffusion layer 93 and well 91, which may cause problems with the breakdown voltage of the PN junction or lead to unnecessary parasitic capacitance between the PN junctions.

[0088] To resolve this concern, for example, the diffusion layer 93 and the diffusion layer 95 are formed in separate wells 91. In other words, the well 91 containing the diffusion layer 93 (referred to as well 91-1) and the well 91 containing the diffusion layer 95 (referred to as well 91-2) are provided in a separated state. In this case, it is necessary to form two wells, well 91-1 and well 91-2, and arrange them with a predetermined distance between them, which may hinder the density of the layout and hinder the miniaturization of the imaging unit 2.

[0089] In this embodiment, as shown in FIG. 6, the power supply voltage Vdd is connected to the diffusion layer 93, and an electrode 99 to which the power supply voltage Vdd is connected is disposed near the diffusion layer 95. Therefore, even if the potential of the well 91 is fixed to the voltage Vdd, there are no locations where a large potential difference occurs, and it is possible to eliminate the problem of the withstand voltage of the PN junction and the concern that unnecessary parasitic capacitance will occur between the PN junctions.

[0090] According to the present technology, it is possible to cancel out the leakage currents of the first capacitor 69 and the second capacitor 70 and suppress fluctuations in the voltage level while the signal charge is being held. It is possible to ease the withstand voltage limitations of capacitive elements such as the first capacitor 69 and the second capacitor 70. It is possible to improve the layout efficiency of capacitive elements such as the first capacitor 69 and the second capacitor 70.

[0091] <Configuration and operation of the imaging unit in the second embodiment> Fig. 7 is a diagram showing an example of the configuration of the imaging unit 2b in the second embodiment. The imaging unit 2b shown in Fig. 7 differs from the imaging unit 2a in the first embodiment shown in Fig. 3 in that a dummy switch 201 is added, but other parts have the same configuration.

[0092] The dummy switch 201 is provided between the first capacitor 69 and the wiring that supplies the power supply voltage Vdd. The dummy switch 201 is a switch that has the same characteristics as the initialization switch 71.

[0093] With this configuration, it is possible to further reduce the influence of the leakage current, as will be described with reference to Fig. 8. Fig. 8 is a diagram for explaining the potential relationship between the first capacitance 69 and the second capacitance 70, similar to Fig. 5.

[0094] The Y node is initialized by the power supply voltage Vdd, but is reset at a voltage lower than the voltage Vdd (=voltage Vdd-voltage Vth) because voltage Vth is applied to the transistor of the initialization switch 71. When the initialization switch 71 transitions from the on state to the off state, there are effects such as charge injection and clock feedthrough, so the initialization potential of the Y node may become a value that deviates from the power supply voltage Vdd.

[0095] In the configuration described with reference to Figure 5, the first capacitance 69 is also connected to the power supply voltage Vdd, so the potential states of the first capacitance 69 and the second capacitance 70 are different, and the leakage currents also have different values, which may not be able to cancel each other out, resulting in a residual error.

[0096] In contrast to this, in the configuration described with reference to FIG. 8, the dummy switch 201 is provided, thereby making it possible to prevent the occurrence of residual errors.

[0097] 8, by providing the dummy switch 201, the potential of the first capacitor 69 is reduced by the voltage Vth of the dummy switch 201 (voltage Vdd-voltage Vth). Similarly, by providing the initialization switch 71, the potential of the second capacitor 70 is reduced by the voltage Vth of the initialization switch 71 (voltage Vdd-voltage Vth).

[0098] In this way, it is possible to more accurately align the potential states of the first capacitor 69 and the second capacitor 70. This makes it possible to prevent the occurrence of residual error in the cancellation of the leakage current.

[0099] The operation of the imaging unit 2b configured with the dummy switch 201 will be described with reference to Fig. 9. The timing chart shown in Fig. 9 is a timing chart in which the operation of the dummy switch 201 is added to the timing chart shown in Fig. 4. Since the operation other than the dummy switch 201 is the same as that of the imaging unit 2a in the first embodiment, a description thereof will be omitted.

[0100] A drive signal DUM is supplied to the gate of the dummy switch 201, and when the drive signal DUM is set to Hi, the dummy switch 201 becomes conductive. During both the shutter period and the readout period, the drive signal DUM is also set to Hi at the same time that the drive signal CAL is set to Hi. Therefore, when the initialization switch 71 is turned on, the dummy switch 201 is also turned on.

[0101] When the drive signal CAL is switched from Hi to Lo, the drive signal DUM is also switched from Hi to Lo. Therefore, when the initialization switch 71 is turned off, the dummy switch 201 is also turned off. In this way, the dummy switch 201 is controlled to be turned on and off at the same timing as the initialization switch 71.

[0102] In this way, one end of the first capacitor 69 is connected to the power supply voltage Vdd via the dummy switch 201 and the other end is connected to the X node, and the second capacitor 70, like the first capacitor 69, is also connected to the power supply voltage Vdd via the initialization switch 71 and the other end is connected to the X node, thereby reducing the effects of leak current. This makes it possible to prevent the inability to maintain accurate values ​​due to leak current, and improve image quality.

[0103] When the voltage of the Y node being held has barely changed from the initial voltage, the effects of leakage current can be minimized. In other words, when the amount of signal charge is small, the effects of leakage current can be minimized. An example of a small amount of signal charge is when capturing a dark scene.

[0104] When shooting a dark scene, it is necessary to reduce circuit noise to ensure a high S / N ratio, but according to this embodiment, when shooting such a dark scene, the effects of leakage current can be minimized and circuit noise can be reduced, making it possible to shoot with improved image quality even when shooting a dark scene.

[0105] <Configuration and operation of the imaging unit in the third embodiment> 10 is a diagram showing a configuration example of the imaging unit 2c in the fourth embodiment. In the imaging unit 2a in the first embodiment (FIG. 3) and the imaging unit 2b in the second embodiment (FIG. 7), the first capacitor 69 and the second capacitor 70 are connected to the power supply voltage Vdd that supplies the voltage Vdd that resets the FD 63.

[0106] The imaging unit 2c in the third embodiment differs from the imaging units 2a and 2b in the first and second embodiments in that the first capacitor 69 and the second capacitor 70 are connected to a power supply voltage Vr that supplies a potential Vr, but is otherwise similar.

[0107] The influence of the leak current can be reduced by aligning the potential states of the first capacitor 69 and the second capacitor 70. Therefore, as shown in Fig. 10, a configuration may be adopted in which the first capacitor 69 and the second capacitor 70 are connected to a voltage source that supplies a potential Vr.

[0108] The first capacitor 69 has one end connected to the X node and the other end connected to the potential Vr. The second capacitor 70 has one end connected to the X node and the other end connected to the potential Vr via the initialization switch 71.

[0109] The potential Vr is used as a reset potential. In the configuration of the imaging unit 2c shown in Fig. 10, the power supply voltage Vdd for resetting F63 and the power supply voltage Vr for resetting the second capacitor are provided as different voltage sources. In this way, a configuration having different voltage sources may be used.

[0110] In this way, it is also possible to configure the first capacitor 69 and the second capacitor 70 to be connected to independent power supply voltages Vr. It is also possible to apply the second embodiment to the third embodiment and provide a dummy switch 201 between the first capacitor 69 and the power supply voltage Vr.

[0111] The operation of the imaging unit 2c in the third embodiment is the same as that of the imaging unit 2a in the first embodiment. When the dummy switch 201 is provided in the third embodiment, the operation of the imaging unit 2c is the same as that of the imaging unit 2c in the second embodiment.

[0112] In the imaging section 2c of the third embodiment, too, the leakage currents of the first capacitor 69 and the second capacitor 70 can be offset to suppress fluctuations in voltage level while signal charges are being held. The withstand voltage restrictions of capacitive elements such as the first capacitor 69 and the second capacitor 70 can be relaxed. The layout efficiency of capacitive elements such as the first capacitor 69 and the second capacitor 70 can be improved.

[0113] <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.

[0114] FIG. 11 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.

[0115] 11 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 instruments 11110 such as an insufflation tube 11111 and an energy treatment instrument 11112, a support arm device 11120 that supports the endoscope 11100, and a cart 11200 on which various devices for endoscopic surgery are mounted.

[0116] 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.

[0117] 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 towards 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.

[0118] 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 onto the image sensor by the optical system. 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.

[0119] 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 image processing on the image signal, such as development processing (demosaic processing), to display an image based on the image signal.

[0120] 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.

[0121] The light source device 11203 is configured from a light source such as an LED (light emitting diode), and supplies irradiation light to the endoscope 11100 when photographing an operation site or the like.

[0122] 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 irradiating light, magnification, focal length, etc.) of the endoscope 11100.

[0123] 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.

[0124] The light source device 11203 that supplies illumination light to the endoscope 11100 when photographing the surgical site can be configured from a white light source configured from, for example, 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, making it possible to adjust the white balance of the captured image in the light source device 11203. In this case, it is also possible to capture images corresponding to each RGB in a time-division manner by irradiating the object of observation with laser light from each RGB laser light source in a time-division manner and controlling the drive of the image sensor of the camera head 11102 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter to the image sensor.

[0125] 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 of so-called blocked-up shadows and blown-out highlights.

[0126] 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 with a narrower band than the light irradiated during normal observation (i.e., white light), thereby capturing high-contrast images of specific tissues, such as blood vessels on the surface of mucous membranes, known as narrow-band imaging. Alternatively, special light observation may be performed using fluorescence observation, in which images are obtained using fluorescence generated by irradiating excitation light. Fluorescence observation can involve irradiating excitation light onto body tissues and observing the fluorescence from the tissues (autofluorescence observation), or locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the tissue 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.

[0127] FIG. 12 is a block diagram showing an example of the functional configuration of the camera head 11102 and the CCU 11201 shown in FIG.

[0128] 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 by a transmission cable 11400 so that they can communicate with each other.

[0129] The lens unit 11401 is an optical system provided at the connection point 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.

[0130] The imaging unit 11402 may include one imaging element (a so-called single-chip type) or multiple imaging elements (a so-called multi-chip type). When the imaging unit 11402 is configured as 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. 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 configured as a multi-chip type, multiple lens units 11401 may be provided corresponding to each imaging element.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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 so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0136] 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 .

[0137] 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.

[0138] 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.

[0139] The image processing unit 11412 performs various image processing operations on the image signal, which is RAW data sent from the camera head 11102 .

[0140] 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.

[0141] Furthermore, the control unit 11413 causes the display device 11202 to display a captured image showing the surgical site, etc., based on the image signal that has been image processed 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.

[0142] The transmission cable 11400 connecting the camera head 11102 and the CCU 11201 is an electrical signal cable for communication of electrical signals, an optical fiber for optical communication, or a composite cable of these.

[0143] In the illustrated example, communication is performed by wire using the transmission cable 11400, but communication between the camera head 11102 and the CCU 11201 may also be performed wirelessly.

[0144] <Application to a moving object> 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 moving 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.

[0145] FIG. 13 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.

[0146] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 13, 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.

[0147] 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, a braking device for generating a braking force of the vehicle, etc.

[0148] 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 may 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.

[0149] 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.

[0150] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according 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.

[0151] 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.

[0152] 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 drivetrain 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 avoiding or mitigating collisions between vehicles, following based on the distance between vehicles, maintaining vehicle speed, warning of vehicle collisions, or warning of vehicle lane departure.

[0153] 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.

[0154] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12030 based on the information about the outside of 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 for the purpose of preventing glare, such as switching from high beams to low beams.

[0155] 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. 13, 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.

[0156] FIG. 14 is a diagram showing an example of the installation position of the imaging unit 12031.

[0157] In FIG. 14, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.

[0158] 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 at the front nose and the imaging unit 12105 provided at 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 at the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided at the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided at the top of the windshield inside the vehicle cabin is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

[0159] 14 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, a bird's-eye view image of the vehicle 12100 viewed from above can be obtained.

[0160] At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera made up of multiple imaging elements, or may be an imaging element having pixels for phase difference detection.

[0161] For example, 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) based on the distance information obtained from the imaging units 12101 to 12104, 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 (for example, 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 automatic driving, which runs autonomously without relying on driver operation.

[0162] 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 the collision risk, which indicates the degree of 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 drivetrain control unit 12010.

[0163] 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 or not a pedestrian is present in the images captured by the image capturing units 12101 to 12104. The pedestrian recognition is performed, for example, by extracting feature points from the images captured by the image capturing units 12101 to 12104, which are infrared cameras, and then performing pattern matching on a series of feature points that indicate the outline of an object to determine whether or not 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.

[0164] In this specification, a system refers to an entire device that is made up of multiple devices.

[0165] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0166] It should be noted that the embodiments of the present technology are not limited to the above-described embodiments, and various modifications are possible within the scope of the present technology.

[0167] The present technology can also be configured as follows. (1) a photoelectric conversion unit that performs photoelectric conversion; a first capacitor and a second capacitor for holding a signal from the photoelectric conversion unit; an initialization switch for initializing the second capacitor; Equipped with one end of the first capacitance, one end of the second capacitance, and an amplifier that amplifies a signal from the photoelectric conversion unit are connected to each other; the other end of the second capacitor is connected to one end of the initialization switch; The other end of the first capacitor and the other end of the initialization switch are connected to a voltage source. Imaging device. (2) The voltage source is a voltage source that supplies a voltage to reset the floating diffusion. The imaging device according to (1) above. (3) The voltage source is a voltage source different from the voltage source that supplies the voltage that resets the floating diffusion. The imaging device according to (1) above. (4) a dummy switch having the same characteristics as the initialization switch is further provided between the first capacitor and the voltage source; The imaging device according to any one of (1) to (3). (5) The initialization switch and the dummy switch are turned on and off at approximately the same timing. The imaging device according to (4) above. (6) a switch that is turned on when a signal from the photoelectric conversion unit is held in the first capacitor and the second capacitor; The switch is connected to one end of the first capacitance and one end of the second capacitance. The imaging device according to any one of (1) to (5). (7) The first capacitor includes a first diffusion layer and a first oxide film formed in a well, and the second capacitor includes a second diffusion layer and a second oxide film formed in the well, and the first diffusion layer and the second diffusion layer are formed in the same well. The imaging device according to any one of (1) to (6). [Explanation of symbols]

[0168] 1 optical system, 2 imaging unit, 3 memory, 4 signal processing unit, 5 output unit, 6 control unit, 10 pixel array, 11 pixel, 20 control unit, 21 pixel drive unit, 22 column parallel AD conversion device, 23 output unit, 33 reference signal output unit, 34 clock output unit, 41 pixel control line, 43 current source, 62 transfer transistor, 64 conversion efficiency switch, 65 FD reset transistor, 66 in-pixel amplifier transistor, 67 constant current source, 68 sampling switch, 69 first capacitance, 70 second capacitance, 71 initialization switch, 72 output transistor, 73 selection transistor, 80 memory unit, 91 well, 93 diffusion layer, 95 diffusion layer, 97 electrode, 99 wiring, 101 oxide film, 103 Oxide film, 111 pixels, 201 dummy switches

Claims

1. a photoelectric conversion unit that performs photoelectric conversion; a first capacitor and a second capacitor for holding a signal from the photoelectric conversion unit; an initialization switch for initializing the second capacitor; a dummy switch having the same characteristics as the initialization switch between the first capacitor and a voltage source; Equipped with one end of the first capacitance, one end of the second capacitance, and an amplifier that amplifies a signal from the photoelectric conversion unit are connected to each other; the other end of the second capacitor is connected to one end of the initialization switch; The other end of the first capacitor and the other end of the initialization switch are connected to the same voltage source. Imaging device.

2. The voltage source is a voltage source that supplies a voltage to reset the floating diffusion. The imaging device according to claim 1 .

3. The voltage source is a voltage source different from the voltage source that supplies the voltage that resets the floating diffusion. The imaging device according to claim 1 .

4. The initialization switch and the dummy switch are turned on and off at approximately the same timing. The imaging device according to claim 1 .

5. a switch that is turned on when a signal from the photoelectric conversion unit is held in the first capacitor and the second capacitor; The switch is connected to one end of the first capacitance and one end of the second capacitance. The imaging device according to claim 1 .

6. The first capacitor includes a first diffusion layer and a first oxide film formed in a well, and the second capacitor includes a second diffusion layer and a second oxide film formed in the well, and the first diffusion layer and the second diffusion layer are formed in the same well. The imaging device according to claim 1 .

Images