Imaging element and distance measuring device

Abstract

An imaging element includes a photoelectric conversion section configured to perform photoelectric conversion, a plurality of charge storage sections configured to store charges obtained by the photoelectric conversion section, and a plurality of transfer sections configured to transfer the charges from the photoelectric conversion section to each of the plurality of charge storage sections. Each of the charge storage sections is provided between a first gate of a transistor included in a corresponding one of the transfer sections and a second gate provided at a position parallel to the first gate.

Description

Technical Field

[0001] This technology relates to imaging elements and ranging devices, and for example, to imaging elements and ranging devices suitable for use in ranging devices.

[0002] <Cross-reference to related applications>

[0003] This application claims the benefit of Japanese patent application JP2019-151755, filed on August 22, 2019, the entire contents of which are incorporated herein by reference. Background Technology

[0004] In recent years, advanced semiconductor technology has enabled the miniaturization of distance measuring modules for measuring distances to objects. Therefore, for example, it has become possible to install distance measuring modules in mobile terminals, such as smartphones, which correspond to small information processing devices with communication capabilities.

[0005] Typically, ranging methods used in ranging modules fall into two categories: Time-of-Flight (TOF) methods and structured light methods. In the TOF method, light is shone onto an object, and the light reflected from the object's surface is detected. The time of flight of the light is measured, and the distance to the object is calculated based on the measurement. In the structured light method, patterned light is shone onto the object, and the deformation of the pattern on the object's surface is imaged. The distance to the object is calculated based on the resulting image.

[0006] Semiconductor detection elements that measure the distance to a target object using the Time-of-Flight (ToF) method are known. In a ToF-based semiconductor detection element, light is emitted from a light source and reflected by the target object; the reflected light is then photoelectrically converted by a photodiode. The signal charge generated by the photoelectric conversion is distributed to two FDs (Floating Diffusion) via an alternately driven pair of gate electrodes (see, for example, Patent Document 1).

[0007] [List of cited references]

[0008] [Patent Literature]

[0009] [Patent Document 1]

[0010] Japanese Patent Publication No. 2009-8537 Summary of the Invention

[0011] [Technical Issues]

[0012] When semiconductor sensing elements are configured such that the signal charge generated by photoelectric conversion is distributed to two FDs through an alternately driven pair of gate electrodes, it may be necessary to read the signal quantities of the two FDs separately, and it may be necessary to accurately read the difference between the signal quantities. If the two FDs have different capacitances, it may be impossible to accurately read the difference between the signal quantities of the two FDs.

[0013] Therefore, semiconductor sensing elements are expected to have a structure in which two FDs have equal capacitance.

[0014] Given this situation, it is desirable to provide a structure in which multiple FDs have equal capacitance.

[0015] [Technical solution to the problem]

[0016] A first imaging element according to an embodiment of the present technology includes: a photoelectric conversion unit configured to perform photoelectric conversion; a plurality of charge storage units configured to store charge obtained by the photoelectric conversion unit; and a plurality of transmission units configured to transfer the charge from the photoelectric conversion unit to each of the plurality of charge storage units. Each of the charge storage units is disposed between a first gate of a transistor included in a corresponding transmission unit and a second gate disposed at a position parallel to the first gate.

[0017] A second imaging element according to an embodiment of the present technology includes: a photoelectric conversion unit configured to perform photoelectric conversion; a plurality of charge storage units configured to store charge obtained by the photoelectric conversion unit; a plurality of transmission units configured to transmit the charge from the photoelectric conversion unit to each of the plurality of charge storage units; and a trench disposed parallel to the gate of a transistor included in a corresponding transmission unit. Each of the charge storage units is disposed between the gate and the trench.

[0018] A ranging device according to an embodiment of the present technology includes: a light-emitting unit configured to emit illumination light; a light-receiving unit configured to receive reflected light generated due to reflection of the illumination light on a target object; and a calculation unit configured to calculate the distance to the target object based on a time interval from the emission of the illumination light to the reception of the reflected light. An imaging element arranged in the light-receiving unit includes: a photoelectric conversion unit configured to perform photoelectric conversion; a plurality of charge storage units configured to store charges obtained by the photoelectric conversion unit; and a plurality of transmission units configured to transfer the charges from the photoelectric conversion unit to each of the plurality of charge storage units. Each of the charge storage units is disposed between a first gate of a transistor included in a corresponding transmission unit and a second gate disposed at a position parallel to the first gate.

[0019] A first imaging element according to an embodiment of the present technology includes: a photoelectric conversion unit configured to perform photoelectric conversion; a plurality of charge storage units configured to store charge obtained by the photoelectric conversion unit; and a plurality of transmission units configured to transfer the charge from the photoelectric conversion unit to each of the plurality of charge storage units. Each of the charge storage units is disposed between a first gate of a transistor included in a corresponding transmission unit and a second gate disposed at a position parallel to the first gate.

[0020] A second imaging element according to an embodiment of the present technology includes: a photoelectric conversion unit configured to perform photoelectric conversion; a plurality of charge storage units configured to store charge obtained by the photoelectric conversion unit; a plurality of transmission units configured to transmit the charge from the photoelectric conversion unit to each of the plurality of charge storage units; and a trench disposed parallel to the gate of a transistor included in a corresponding transmission unit. Each of the charge storage units is disposed between the gate and the trench.

[0021] A ranging device according to an embodiment of the present technology includes: a light-emitting unit configured to emit illumination light; a light-receiving unit configured to receive reflected light generated due to reflection of the illumination light on a target object; and a calculation unit configured to calculate the distance to the target object based on a time interval from the emission of the illumination light to the reception of the reflected light. An imaging element arranged in the light-receiving unit includes: a photoelectric conversion unit configured to perform photoelectric conversion; a plurality of charge storage units configured to store charges obtained by the photoelectric conversion unit; and a plurality of transmission units configured to transfer the charges from the photoelectric conversion unit to each of the plurality of charge storage units. Each of the charge storage units is disposed between a first gate of a transistor included in a corresponding transmission unit and a second gate disposed at a position parallel to the first gate. Attached Figure Description

[0022] [ Figure 1 ] Figure 1 This is a diagram illustrating the construction of an embodiment of a ranging device applying the present technology.

[0023] [ Figure 2 ] Figure 2 This is a diagram showing an example of the structure of a light receiver.

[0024] [ Figure 3 ] Figure 3 This is a diagram showing an example of pixel construction.

[0025] [ Figure 4 ] Figure 4 This is a diagram showing the charge distribution in a pixel.

[0026] [ Figure 5 ] Figure 5 It is a diagram showing past light emission.

[0027] [ Figure 6 ] Figure 6 This is a diagram illustrating another readout method.

[0028] [ Figure 7 ] Figure 7 This is a diagram illustrating the generation of the capacitance difference between FD.

[0029] [ Figure 8 ] Figure 8 This is a plan view showing the construction of pixels according to the first embodiment.

[0030] [ Figure 9 ] Figure 9 This is a diagram showing the case where there is no difference in capacitance between FD.

[0031] [ Figure 10 ] Figure 10 This is a plan view showing another construction of the pixels according to the first embodiment.

[0032] [ Figure 11 ] Figure 11 This is a plan view showing the construction of pixels according to the second embodiment.

[0033] [ Figure 12 ] Figure 12 This is a plan view showing another construction of pixels according to the second embodiment.

[0034] [ Figure 13 ] Figure 13 This is a plan view showing the construction of pixels according to the third embodiment.

[0035] [ Figure 14 ] Figure 14 This is a circuit diagram showing the construction of a pixel according to the third embodiment.

[0036] [ Figure 15 ] Figure 15 This is a plan view showing another construction of pixels according to the third embodiment.

[0037] [ Figure 16 ] Figure 16 This is a diagram showing an example of the construction of pixels arranged in a vertical direction.

[0038] [ Figure 17 ] Figure 17 This is a plan view showing the construction of pixels according to the fourth embodiment.

[0039] [ Figure 18 ] Figure 18This is a diagram showing an example of a transistor arranged in a line symmetric manner.

[0040] [ Figure 19 ] Figure 19 This is a diagram showing an example of a point-symmetrically arranged transistor.

[0041] [ Figure 20 ] Figure 20 This is a plan view showing the construction of pixels according to the fifth embodiment.

[0042] [ Figure 21 ] Figure 21 This is a plan view showing another construction of the pixels according to the fifth embodiment.

[0043] [ Figure 22 ] Figure 22 This is a plan view showing the construction of pixels according to the sixth embodiment.

[0044] [ Figure 23 ] Figure 23 This is a cross-sectional view showing the construction of pixels according to the sixth embodiment.

[0045] [ Figure 24 ] Figure 24 This is a diagram showing a vertical transistor.

[0046] [ Figure 25 ] Figure 25 This is a diagram illustrating the generation of the capacitance difference between FD.

[0047] [ Figure 26 ] Figure 26 This is a plan view showing the construction of pixels according to the seventh embodiment.

[0048] [ Figure 27 ] Figure 27 This is a cross-sectional view showing the construction of pixels according to the seventh embodiment.

[0049] [ Figure 28 ] Figure 28 This is a diagram illustrating an example of a schematic construction of an endoscopic surgical system.

[0050] [ Figure 29 ] Figure 29 This is a block diagram illustrating an example of the functional structure of a camera head and camera control unit (CCU).

[0051] [ Figure 30 ] Figure 30 This is a block diagram illustrating an example of a schematic construction of a vehicle control system.

[0052] [ Figure 31 ] Figure 31This diagram illustrates the installation locations of the vehicle exterior information detection unit and the imaging unit. Detailed Implementation

[0053] The following will describe embodiments of this technology (hereinafter referred to as embodiments).

[0054] The technology according to embodiments of this disclosure can be applied to light receiving elements and imaging devices including such light receiving elements in ranging systems that use, for example, indirect TOF methods for ranging.

[0055] For example, a ranging system can be applied to in-vehicle systems, such as those installed in vehicles, for measuring distances to target objects outside the vehicle, and to gesture recognition systems for measuring distances to target objects such as a user's hand to recognize the user's gestures based on the measurement results. In this case, the gesture recognition results can be used, for example, for the operation of a car navigation system.

[0056] <Example of a distance measuring device construction>

[0057] Figure 1 An example of the construction of a ranging device applying this technology is shown.

[0058] The ranging device 10 includes a lens 11, a light receiving unit 12, a signal processing unit 13, a light emitting unit 14, and a light emitting control unit 15. The signal processing unit 13 includes a pattern switching unit 21 and a distance image generation unit 22. Figure 1 The ranging device 10 in the middle shines light onto the object and receives the light (reflected light) generated by the object's reflection of the radiated light (irradiated light) to measure the distance to the object.

[0059] The light-emitting system of the ranging device 10 includes a light-emitting unit 14 and a light-emitting control unit 15. In the light-emitting system, the light-emitting control unit 15 causes the light-emitting unit 14 to emit infrared light (IR) under the control of the signal processing unit 13. An IR bandpass filter can be provided between the lens 11 and the light receiving unit 12, and the light-emitting unit 14 can emit infrared light corresponding to the transmission wavelength band of the IR bandpass filter.

[0060] The light-emitting part 14 can be arranged inside or outside the housing of the ranging device 10. The light-emitting control part 15 causes the light-emitting part 14 to emit light of a predetermined pattern. The pattern is set by the pattern switching part 21 and is configured to switch at a predetermined time sequence.

[0061] A pattern switching unit 21 can be provided, and this pattern switching unit 21 can be configured to, for example, switch the light emission pattern while preventing the light emission pattern from overlapping with the pattern of another ranging device 10. Alternatively, the pattern switching unit 21 described above can be omitted.

[0062] The signal processing unit 13 acts as a calculation unit to calculate, for example, the distance from the ranging device 10 to the object based on the image signal provided from the light receiving unit 12. When the calculated distance is output as an image, for each pixel, the distance image generation unit 22 of the signal processing unit 13 generates and outputs a distance image representing the distance to the object.

[0063] <Construction of Imaging Elements>

[0064] Figure 2 This is a block diagram showing an example of the structure of the light receiver 12. The light receiver 12 can include a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

[0065] The light receiving unit 12 includes a pixel array unit 41, a vertical driving unit 42, a column processing unit 43, a horizontal driving unit 44, and a system control unit 45. The pixel array unit 41, the vertical driving unit 42, the column processing unit 43, the horizontal driving unit 44, and the system control unit 45 are disposed on a semiconductor substrate (chip) not shown.

[0066] Pixel array section 41 includes unit pixels (e.g., Figure 3 In the image (50), each pixel is arranged in a two-dimensional matrix and includes a photoelectric conversion element that generates a photocharge corresponding to the amount of incident light and stores the photocharge internally. Note that the photocharge corresponding to the amount of incident light may be simply referred to as "charge" in the following text, and each pixel may be simply referred to as "pixel" in the following text.

[0067] The pixel array section 41 also includes a matrix-like pixel array. Figure 2 Along the horizontal direction (the arrangement direction of pixels in a pixel row), for each row, pixel driving lines 46 and Figure 2 Vertical signal lines 47 are positioned along the vertical direction (the arrangement direction of pixels in a pixel column) for each column. For each row, one end of each pixel driving line 46 is connected to a corresponding output terminal of the vertical driving unit 42.

[0068] The vertical driving unit 42 is a pixel driving unit that includes a shift register or address decoder, and drives all pixels of the pixel array unit 41 simultaneously or in rows. The pixel signal output from each unit pixel in the pixel row selected and scanned by the vertical driving unit 42 is provided to the column processing unit 43 via a corresponding vertical signal line 47. The column processing unit 43 performs predetermined signal processing on the pixel signal output from the corresponding unit pixel in the selected row via the vertical signal line 47 for each pixel column of the pixel array unit 41, and temporarily holds the pixel signal generated by the signal processing.

[0069] Specifically, as signal processing, the column processing unit 43 performs at least noise reduction processing, such as CDS (Correlated Double Sampling) processing. The CDS processing performed by the column processing unit 43 eliminates pixel-specific reset noise and fixed-pattern noise, such as threshold variations in the amplification transistor. Note that in addition to noise reduction processing, the column processing unit 43 can also be equipped with, for example, an AD (Analog-Digital) conversion function to output signal levels using digital signals.

[0070] The horizontal drive unit 44 includes a shift register or address decoder, etc., and sequentially selects the unit circuits in the column processing unit 43 corresponding to the pixel column. Through the selection and scanning of the horizontal drive unit 44, the pixel signals generated by the signal processing of the column processing unit 43 are sequentially output to the signal processing unit 13.

[0071] The system control unit 45 includes, for example, a timing generator for generating various timing signals, and the system control unit 45 drives and controls the vertical drive unit 42, the column processing unit 43, and the horizontal drive unit 44 based on the various timing signals generated by the timing generator.

[0072] In the pixel array section 41, pixel driving lines 46 are arranged for each pixel row along the row direction relative to the matrix-like pixel array, and two vertical signal lines 47 are arranged for each pixel column along the column direction. For example, each pixel driving line 46 transmits a driving signal for performing the driving of the read-out signal from the pixel. Note that... Figure 1 The pixel driving line 46 is illustrated as a single line, but it is not limited to a single line. For each row, one end of the pixel driving line 46 is connected to a corresponding output terminal of the vertical driving section 42.

[0073] <Structure of a unit pixel>

[0074] The specific structure of each unit pixel 50 arranged in a matrix in the pixel array section 41 will now be described.

[0075] Pixel 50 includes a photodiode 61 (hereinafter referred to as PD 61) serving as a photoelectric conversion element, and pixel 50 is configured such that the charge generated by PD 61 is distributed to taps 51-1 and 51-2. The portion of the charge generated by PD 61 that is subsequently distributed to tap 51-1 is then read out from vertical signal line 47-1 and output as a detection signal SIG1. Additionally, the portion of the charge distributed to tap 51-2 is read out from vertical signal line 47-2 and output as a detection signal SIG2.

[0076] Tap 51-1 includes a transfer transistor 62-1, an FD (Floating Diffusion) 63-1, a reset transistor 64, an amplifying transistor 65-1, and a select transistor 66-1. Similarly, tap 51-2 includes a transfer transistor 62-2, an FD 63-2, a reset transistor 64, an amplifying transistor 65-2, and a select transistor 66-2.

[0077] Note that, as Figure 3 As shown, the reset transistor 64 can be shared by FD 63-1 and FD 63-2, or it can be set in FD 63-1 and FD 63-2 respectively.

[0078] With reset transistor 64 located in FD 63-1 and FD 63-2 respectively, the reset timing of FD 63-1 and FD 63-2 can be controlled separately, thereby achieving detailed control. With reset transistor 64 shared by FD 63-1 and FD 63-2, FD 63-1 and FD 63-2 can use the same reset timing, thus simplifying control and circuit construction.

[0079] In the following description, for example, reset transistor 64 is provided in FD 63-1 and FD 63-2 respectively. The configuration of reset transistor 64 shared by FD 63-1 and FD 63-2 will also be described as appropriate.

[0080] refer to Figure 4 This will explain the charge distribution in pixel 50. Here, distribution refers to reading out the charge stored in pixel 50 (PD 61) at different times, which means performing a readout for each tap.

[0081] like Figure 4 As shown, illumination light modulated from the light-emitting unit 14 is repeatedly turned on and off for illumination time T (one cycle = Tp), and reflected light is received at PD 61 after a delay time Td corresponding to the distance to the object. Transmission control signal TRT1 controls the on and off of transmission transistor 62-1, and transmission control signal TRT2 controls the on and off of transmission transistor 62-2. As... Figure 4 As shown, the transmission control signal TRT1 has the same phase as the illumination light, while the transmission control signal TRT2 has a phase generated by the phase reversal of the transmission control signal TRT1.

[0082] Therefore, when the transmission transistor 62-1 is turned on according to the transmission control signal TRT1, the charge generated by PD 61 through receiving reflected light is transferred to FD 63-1. Similarly, when the transmission transistor 62-2 is turned on according to the transmission control signal TRT2, the charge is transferred to FD 63-2. Thus, during a predetermined period of irradiation by irradiation light with a periodic irradiation time T, the charge transferred via transmission transistor 62-1 is sequentially stored in FD 63-1, and the charge transferred via transmission transistor 62-2 is sequentially stored in FD 63-2. Therefore, FD 63 acts as a charge storage unit for storing the charge generated by PD 61.

[0083] Then, after the charge storage period ends, when the selection transistor 66-1 is turned on according to the selection signal SELm1, the charge stored in FD 63-1 is read out via the vertical signal line 47-1, and a detection signal SIG1 corresponding to the charge amount is output from the light receiving unit 12. Similarly, when the selection transistor 66-2 is turned on according to the selection signal SELm2, the charge stored in FD 63-2 is read out via the vertical signal line 47-2, and a detection signal SIG2 corresponding to the charge amount is output from the light receiving unit 12.

[0084] When the reset transistor 64 is turned on according to the reset signal RST, the charge stored in FD 63-1 and the charge stored in FD 63-2 are discharged.

[0085] In this way, based on the delay time Td, pixel 50 can distribute the charge generated by PD 61 based on the received reflected light to taps 51-1 and 51-2, thereby outputting detection signals SIG1 and SIG2. The delay time Td corresponds to the time taken for the light emitted by the light-emitting unit 14 to travel to the object, and then, after being reflected by the object, to travel to the light-receiving unit 12, that is, it corresponds to the distance to the object. Therefore, the ranging device 10 can determine the distance (depth) to the object based on the detection signals SIG1 and SIG2 according to the delay time Td.

[0086] <Distance Measurement Method Based on Indirect Time-of-Flight Method>

[0087] refer to Figure 5 This section will explain distance calculation based on an indirect Time-of-Flight (TOF) method using a 2-tap approach. The 2-tap method uses two taps 51 to read the charge stored in a single PD 61. (Reference) Figure 5 This will explain the distance measurement method. (Refer to...) Figure 5 The description will provide an example of the 2-tap-4-phase method, which corresponds to the detection method using two taps and four phases.

[0088] One frame period for generating the distance image is divided into two signal detection periods, including frame A and frame B. One frame period for generating the distance image is set to, for example, approximately 1 / 30 of a second. Therefore, the A-frame period and the B-frame period are each set to approximately 1 / 60 of a second.

[0089] Light-emitting part 14 ( Figure 1 The output is modulated to repeatedly turn the illumination on and off for an illumination time T (one cycle = Tp). The illumination time Tp can be set to, for example, approximately 10 ns. The light receiving unit 12 receives the reflected light after a delay time Td corresponding to the distance to the object.

[0090] In the four-phase method, the light receiving unit 12 uses one of taps 51-1 and 51-2 to receive light at four times corresponding to the phase of the irradiated light (phase 0), the phase offset by 90° from the phase of the irradiated light (phase 90), the phase offset by 180° from the phase of the irradiated light (phase 180), and the phase offset by 270° from the phase of the irradiated light (phase 270). Note that the light reception used here includes a process that begins with the generation of charge by PD 61 and ends with the transfer of charge to FD 63 by turning on the transmission transistor 62.

[0091] exist Figure 5 In frame A, the transmission control signal TRT1 is turned on at a time when it is in the same phase as the illumination light (phase 0), and light reception begins via tap 51-1. Additionally, in frame A, the transmission control signal TRT2 is turned on at a time when it is 180° off from the phase of the illumination light (phase 180), and light reception begins via tap 51-2.

[0092] Additionally, in the B-frame, the transmission control signal TRT1 is turned on at a time when the phase of the illumination light is offset by 90° (phase 90), and light reception begins via tap 51-1. Furthermore, in the B-frame, the transmission control signal TRT2 is turned on at a time when the phase of the illumination light is offset by 270° (phase 270), and light reception begins via tap 51-2.

[0093] In this configuration, taps 51-1 and 51-2 receive light at times corresponding to phases that are 180° reversed. Assuming that during frame A, the illumination time is Tp, charge Q1 is stored in FD 63-1 of tap 51-1 at phase 0, and during frame A, charge Q1' corresponding to the cumulative illumination time Tp within frame A is stored in FD 63-1. Then, during the readout period, charge Q1' stored in FD 63-1 is read out as a signal corresponding to detection signal SIG1. Assuming the signal value of detection signal SIG1 corresponding to charge Q1' is signal value I1.

[0094] Assume that during frame A, the illumination time is Tp, and charge Q2 is stored in FD63-2 of tap 51-2 at phase 180. During frame A, charge Q2' corresponding to the cumulative illumination time Tp within frame A is stored in FD63-2. Then, during the readout period, charge Q2' stored in FD63-2 is read out as a signal corresponding to detection signal SIG2. Assume the signal value of detection signal SIG2 corresponding to charge Q2' is signal value I2.

[0095] Assume that during the B-frame period, the illumination time is Tp, and charge Q3 is stored in FD63-1 of tap 51-1 at phase 90. During the B-frame period, charge Q3' corresponding to the cumulative illumination time Tp within the B-frame period is stored in FD63-1. Then, during the readout period, charge Q3' stored in FD63-1 is read out from FD63-1 as a signal corresponding to detection signal SIG1. Assume that the signal value of detection signal SIG1 corresponding to charge Q3' is signal value I3.

[0096] Assume that during the B-frame period, the illumination time is Tp, and charge Q4 is stored in FD63-2 of tap 51-2 at phase 270. During the B-frame period, charge Q4' corresponding to the cumulative illumination time Tp within the B-frame period is stored in FD63-2. Then, during the readout period, charge Q4' stored in FD63-2 is read out from FD63-2 as a signal corresponding to detection signal SIG2. Assume that the signal value of detection signal SIG2 corresponding to charge Q4' is signal value I4.

[0097] Based on the distribution ratio among signal values ​​I1, I2, I3, and I4, the phase shift θ corresponding to the delay time Td can be detected. Specifically, the delay time Td is determined based on the phase shift θ, and thus the distance to the target object is determined based on the delay time Td.

[0098] The phase shift θ is determined by equation (1), and the distance D to the target object is calculated by equation (2). In equation (2), C represents the speed of light, and Tp represents the pulse width.

[0099] [Mathematical Expression 1]

[0100]

[0101] [Mathematical Expression 2]

[0102]

[0103] In this way, the distance to a predetermined target object can be calculated. This ranging method can measure distance while minimizing the influence of ambient light. The above and below explanations are based on the assumption that only the reflected light from the emitted pulsed light is received. However, in addition to the emitted pulsed light, various types of ambient light are also received simultaneously. Therefore, the charge stored in PD 61 comes from both the emitted pulsed light and the ambient light.

[0104] However, ambient light can be considered stable relative to the pulse period. When ambient light is stable, it is superimposed on the emitted pulse light as an offset equal to the signal values ​​I1, I2, I3, and I4. Therefore, in the calculation of equation (1), the component from the ambient light (the offset component) is canceled out, thus having no effect on the ranging result.

[0105] This example illustrates a Time-of-Flight (TOF) sensor based on the 2-tap-4-phase method. However, this embodiment can also be applied to TOF sensors based on another method. For example, ... Figure 6 As shown, this embodiment is also applicable to TOF sensors based on the 4-tap-4-phase method.

[0106] For example Figure 5 similar, Figure 6 This is a diagram illustrating a ranging method based on a 4-tap-4-phase method.

[0107] The TOF sensor based on the 4-tap-4-phase method is a sensor that includes four readout sections, each corresponding to one of the aforementioned taps 51. Figure 6 In the example shown, the readout section corresponds to four taps, which include a tap controlled by transmission control signal TRT1 (called tap TRT1), a tap controlled by transmission control signal TRT2 (called tap TRT2), a tap controlled by transmission control signal TRT3 (called tap TRT3), and a tap controlled by transmission control signal TRT4 (called tap TRT4).

[0108] In one frame corresponding to the distance image generation unit, readout is performed using tap TRT1 at the same phase (phase 0) as the phase of the irradiation light, and using tap TRT2 at a phase (phase 180) shifted by 180° from the phase of the irradiation light.

[0109] Further, readout is performed using tap TRT3 at a phase (phase 90) shifted by 90° from the phase of the irradiation light, and using tap TRT4 at a phase (phase 270) shifted by 270° from the phase of the irradiation light.

[0110] In this manner, a TOF sensor based on the 4-tap 4-phase method can perform processing equivalent to the processing of the 2-tap 4-phase method using one frame instead of two frames such as an A frame and a B frame.

[0111] The present technology described below can be applied to TOF sensors based on the 2-tap 4-phase method and TOF sensors based on the 4-tap 4-phase method. In the following description, applications of the TOF sensor based on the 2-tap 4-phase method will be mainly described by way of example, and applications of the TOF sensor based on the 4-tap 4-phase method will also be described as appropriate.

[0112] <Generation of Capacitance Difference Between FDs>

[0113] As described above, in a case where the distance is calculated by distributing the signal charge photoelectrically converted by the PD 61 to the FD 63-1 and the FD 63-2 and determining the difference in signal amount between the signals respectively read out from the FD 63-1 and the FD 63-2, accurate readout of the signal amount may be required. In a case where the FD 63-1 and the FD 63-2 have different capacitances, the signal amounts read out from the two respective FDs 63 may be inaccurate, which may lead to a decrease in accuracy of the calculated difference, and thus a decrease in accuracy of the calculated distance.

[0114] The cause of the capacitance difference between the FD 63-1 and the FD 63-2 is, for example, variation caused by the manufacturing process. Referring Figure 7 to, generation of the capacitance difference between the FD 63-1 and the FD 63-2 caused by the manufacturing process will be described.

[0115] As shown in Figure 7 A, consider the fabrication of a pixel including a PD 101 disposed at the center, a transfer transistor gate (hereinafter referred to as TG) 102-1 disposed above the PD 101, and a TG 102-2 disposed below the PD 101. Further, consider the fabrication of a pixel including an FD 103-1 disposed above the TG 102-1 and an FD 103-2 disposed below the TG 102-2.

[0116] As shown in Figure 7 As shown in Figure B, after PD 101 is formed, TG 102-1 and TG 102-2 are formed above and below PD 101, respectively. Figure 7 As shown in C, in Figure 7 A mask 121 is formed on the pixel shown in B. The mask 121 is a mask in which the FD 103 region is opened to form the FD 103 region. In the mask 121 used, the region of PD 101 is covered, and an opening region slightly larger than the FD 103 region to be formed is formed.

[0117] After the mask 121 is formed, for example, ion implantation is performed to implant ions into the opening portion and form FD 103. At this time, even if the opening of the mask 121 is located on TG 102, no ions are implanted into TG 102, so a slightly larger opening can be formed.

[0118] like Figure 7 As shown in B (above), in Figure 7 Point C and the adjacent Figure 7 At point D, mask 121 is placed in the appropriate position without displacement, and ions are implanted to form FD 103-1 and FD 103-2. Placing mask 121 in the appropriate position without displacement means placing mask 121 at a location where the formed FD 103-1 and FD 103-2 have the same area. This location is designated as location A. Assume that location A is the center location of PD 101.

[0119] Furthermore, assuming that the center position of mask 121 is position B, the assumption that mask 121 is placed in the appropriate position without displacement means that position A and position B coincide with each other.

[0120] like Figure 7 As shown in Figure B (below), when mask 121 is placed at a position shifted from position A and ions are implanted, in Figure 7 At point E and side by side Figure 7 At point F, the formed FD 103-1' and FD 103-2' are different in size from each other. Figure 7 E in the diagram shows that mask 121 is positioned downwards from position A. This displacement corresponds to the difference between position A and position B. If this difference exceeds the allowable range, the resulting FD 103-1' and FD 103-2' will be dimensionally different from each other.

[0121] Because mask 121 is shifted downwards, the area of ​​FD 103-1' is smaller than the area of ​​FD 103-2'. This shift of mask 121 may result in different areas of FD 103-1' and FD 103-2', leading to structures where FD 103-1' and FD 103-2' have different conversion efficiencies. Note that the above description uses the case where mask 121 is shifted vertically as an example; however, if mask 121 is shifted horizontally or obliquely, area differences may also occur between FD 103-1' and FD 103-2', resulting in structures where FD 103-1' and FD 103-2' have different conversion efficiencies.

[0122] Therefore, the following construction will be described: in which, even if the mask may be displaced during manufacturing, the multiple FD regions still have equal areas and therefore the same conversion efficiency.

[0123] <First Embodiment>

[0124] Figure 8 This is a plan view showing the construction of pixel 50a according to the first embodiment. Figure 8 In the following explanation, the horizontal direction in the figure is assumed to be the X-axis direction, and the vertical direction is assumed to be the Y-axis direction. Additionally, Figure 8 The X direction in the middle corresponds to Figure 2 The horizontal direction in the middle. Figure 8 The Y direction in the middle corresponds to Figure 2 The column direction (vertical direction) in the text.

[0125] like Figure 8 As shown, PD 61 is located in the central region of rectangular pixel 50a. TG 62-1 and TG 62-2 are located above PD 61 (on the upper side of PD 61). TG 62-1 is the gate portion of transmission transistor 62-1, and TG 62-2 is the gate portion of transmission transistor 62-2.

[0126] TG 62-1 and TG 62-2 are positioned near one of the four sides of PD 61. Figure 8 In the example shown, TG 62-1 and TG 62-2 are arranged side by side on the upper side of PD 61 along the X-axis.

[0127] An FD 63-1 is positioned above TG 62-1, and an FD 63-2 is positioned above TG 62-2. A gate for a reset transistor 64 (hereinafter referred to as RST 64) is positioned above FD 63-1 and FD 63-2.

[0128] In a vertical (Y-axis direction) strip shape, an amplifying transistor 65-1 (the gate of amplifying transistor 65-1) is arranged on the left side of FD 63-1 to amplify the signal from FD 63-1. Below the amplifying transistor 65-1, a selection transistor 66-1 (the gate of selection transistor 66-1) is arranged.

[0129] In a vertical (Y-axis direction) strip shape, an amplifying transistor 65-2 (the gate of amplifying transistor 65-2) is arranged on the right side of FD 63-2 to amplify the signal from FD 63-2. Below the amplifying transistor 65-2, a selection transistor 66-2 (the gate of selection transistor 66-2) is arranged.

[0130] A well contact 72-1 is located below the select transistor 66-1, and a well contact 72-2 is located below the select transistor 66-2. A discharge transistor (OFG) 71 is located below PD 61. The discharge transistor 71 is an anti-halo overflow gate.

[0131] Figure 8 The arrangements shown in the following description are examples and not intended to be limiting. Additionally, Figure 8 The example shown in the following description illustrates a construction with discharge transistor 71, but discharge transistor 71 can also be omitted from this construction.

[0132] exist Figure 8 In the example shown, TG 62-1, FD 63-1, amplifying transistor 65-1 and selecting transistor 66-1 are arranged in a linear symmetrical relationship with TG 62-2, FD 63-2, amplifying transistor 65-2 and selecting transistor 66-2 with respect to the center line (not shown) between TG 62-1 and TG 62-2.

[0133] Despite Figure 8 The wiring is not shown, but FD 63-1 and amplifying transistor 65-1 are connected together, and the signal from FD 63-1 is supplied to amplifying transistor 65-1. Additionally, FD 63-2 and amplifying transistor 65-2 are connected together, and the signal from FD 63-2 is supplied to amplifying transistor 65-2.

[0134] As described above, the linearly symmetrical construction allows the wiring length between FD 63-1 and amplifying transistor 65-1 to be substantially the same as the wiring length between FD 63-2 and amplifying transistor 65-2. Furthermore, for other wiring, the transversely oriented wiring can achieve the same length.

[0135] exist Figure 8In pixel 50a shown, FD 63-1 is positioned between TG 62-1 and RST 64, and FD 63-2 is positioned between TG 62-2 and RST 64. The distance between TG 62-1 and RST 64 is the same as the distance between TG 62-2 and RST 64.

[0136] When the width of FD 63-1 is the same as the width of FD 63-2, the size (area) of the region of FD 63-1 is the same as the size (area) of the region of FD 63-2. During manufacturing, a mask is used to set the widths of FD 63-1 and FD 63-2 to be the same, so that the region of FD 63-1 is identical in size (area) to the region of FD 63-2. This will refer to... Figure 9 Please provide an explanation.

[0137] Figure 9 A to E in the diagram show Figure 8 The pixel 50a shown includes TG 62-1, TG 62-2, and RST 64. Before forming FD 63, ... Figure 9 The positional relationships shown form TG 62-1, TG 62-2 and RST 64. Figure 9 A in the diagram shows the opening 131 for forming the mask of FD 63.

[0138] like Figure 9 As shown in A, the mask is a mask in which the region of FD 63 is opened to form the region of FD 63. Openings 131-1 and 131-2 in the mask are regions that are slightly larger than FD 63-1 and FD 63-2, respectively.

[0139] After forming a mask with openings 131-1 and 131-2, ion implantation is performed, for example, to implant ions into the opening portions, thereby forming FD 63-1 and FD 63-2, respectively. At this time, even if the opening 131 of the mask is located on TG 62 or RST 64, no ions are implanted into TG 62 or RST 64, so a slightly larger opening can be formed.

[0140] Assumption Figure 9 The state represented by A in the diagram is the optimal state. For example... Figure 9 As shown in A, the optimal state is assumed to be the state in which the overlapping portion between opening 131-1 and TG 62-1 is located in the center of TG 62-1 and the overlapping portion between opening 131-2 and TG 62-2 is located in the center of TG 62-2.

[0141] When in Figure 9 When FD 63 is formed in the state shown in A, as follows: Figure 9As shown in C, FD 63-1 is the upper center portion of TG 62-1 and is formed between TG 62-1 and RST 64. Similarly, FD 63-2 is the upper center portion of TG 62-2 and is formed between TG 62-2 and RST 64. Furthermore, the formed FD 63-1 and FD 63-2 have the same dimensions.

[0142] like Figure 9 As shown in Figure A, assume that both openings 131-1 and 131-2 have a width L1, and assume that the distance between the lower side of RST64 and the upper side of TG 62-1 (TG 62-2) in the figure is a height L2. In this case, as... Figure 9 As shown in Figure C, the area of ​​the formed FD 63-1 is (width L1 × height L2), and the area of ​​FD 63-2 is (width L1 × height L2). Therefore, the formed FD 63-1 and FD 63-2 have the same dimensions.

[0143] Figure 9 B in the diagram indicates that the mask has been moved upwards. Even with the mask moved upwards, the positional relationship between TG 62 and RST 64 remains unchanged, and the distance between TG 62 and RST 64 remains equal to the height L2. Furthermore, the width of the opening 131 is the width L1. Therefore, as... Figure 9 As shown in B, even when the mask is shifted upwards, such as Figure 9 As shown in C, FD 63-1 and FD 63-2 with areas of (width L1 × height L2) were also formed.

[0144] Specifically, even when the mask is shifted upwards relative to the optimal state, the area dimensions of the resulting FD 63-1 and FD 63-2 are the same. Even when the mask is shifted downwards, the area dimensions of the resulting FD 63-1 and FD 63-2 are the same.

[0145] Figure 9 The "D" in the figure indicates that the mask has shifted to the left. Even with the mask shifted to the left, the positional relationship between TG 62 and RST 64 remains unchanged, and the distance between TG 62 and RST 64 remains equal to the height L2. Furthermore, the width of the opening 131 is the width L1. Therefore, as... Figure 9 As shown in D, even when the mask is shifted to the left, such as Figure 9 As shown in E, FD 63-1 and FD 63-2 with areas of (width L1 × height L2) were also formed.

[0146] Specifically, even when the mask is shifted to the left relative to the optimal state, the area dimensions of the resulting FD 63-1 and FD 63-2 are the same. Even when the mask is shifted to the right, the area dimensions of the resulting FD 63-1 and FD 63-2 are the same.

[0147] In this way, even if the mask is shifted up, down, left, or right, the area dimensions of the resulting FD 63-1 and FD 63-2 are the same.

[0148] For reference Figure 7 As stated, if the shift mask results in area differences among the multiple FDs 63 formed, then the conversion efficiencies of the FDs 63 will differ from each other in the resulting structure. However, as referenced... Figure 9 Even with mask displacement, this technology can prevent potential area differences between the multiple FDs 63 formed, thereby preventing the formation of structures in which the conversion efficiencies of the FDs 63 may differ from each other.

[0149] For reference Figure 8 and Figure 9 As described, even if the mask shifts from its predetermined position during manufacturing, potential area differences between the formed multiple FDs 63 can be prevented. One condition for this structure is that TG 62 and RST 64 are formed parallel to each other, wherein the distance between TG 62 and RST 64 is ( Figure 9 The distance (represented as height L2) remains unchanged.

[0150] In other words, the gate of the transistor different from TG 62 is formed parallel to TG 62, and FD 63 is formed between TG 62 and the gate. Therefore, multiple FD 63 can be formed in a manner where there is no area difference between the multiple FD 63 formed.

[0151] Furthermore, in other words, when FD 63 is formed by ion implantation or the like, a region without ion implantation is formed at a position parallel to TG 62, and FD 63 is formed between TG 62 and the region paired with TG 62. Therefore, multiple FD 63s can be formed in a manner where there is no area difference between the multiple FD 63s formed.

[0152] Figure 10 It shows Figure 8 A plan view of another construction example of pixel 50a is shown. In contrast, Figure 10 The pixel 50a' shown is Figure 8The difference in pixel 50a shown is that RST 64 of pixel 50a' includes RST 64-1 and RST 64-2, and the other parts of pixel 50a' are similar to the corresponding parts of pixel 50a. Similar parts are indicated by the same reference numerals, and descriptions of these parts are omitted.

[0153] Figure 10 The pixel 50a' shown includes RST 64-1 paired with TG 62-1 and RST 64-2 paired with TG 62-2. In other words, pixel 50a' includes a separate RST 64, which includes RST 64-1 for resetting FD 63-1 and RST 64-2 for resetting FD 63-2.

[0154] RST 64-1 and RST 64-2 can be connected together via wiring and used as a single RST 64. This construction is similar to... Figure 8 The structure of pixel 50a shown is the same.

[0155] like Figure 10 As shown in pixel 50a', the gates mounted parallel to TG 62 can be configured for each of the multiple FDs 63, or as... Figure 8 As shown in pixel 50a, a gate shared by multiple FDs 63 can be set. When setting a gate for each of the multiple FDs 63, the TG 62 and the gate are set such that the distance between each TG 62 and the corresponding gate is the same.

[0156] <Second Embodiment>

[0157] Figure 11 This is a plan view showing the construction of pixel 50b according to the second embodiment. Figure 11 The pixel 50b shown includes a virtual gate 231. Figure 11 The pixel 50b shown is in relation to Figure 8 A virtual gate 231 is provided in the region corresponding to the area where the RST 64 of pixel 50a is located.

[0158] As in pixel 50b, the gate paired with TG 62 may not be the gate of the reset transistor, and Figure 11 The gate paired with TG 62 is shown as dummy gate 231. Dummy gate 231 is a gate that is not assigned any function, but it is configured to prevent possible area differences between the multiple FDs 63 due to mask shifting during manufacturing.

[0159] In pixel 50b, RST 64-1 is set to the left of FD 63-1 in the image, and RST 64-2 is set to the right of FD 63-2 in the image. The position of RST 64 can be changed appropriately.

[0160] The virtual gate 231 may include multiple virtual gates 231, such as virtual gate 231-1 and virtual gate 231-2, in other words, as Figure 12 As shown, the same number of virtual gates 231 as FD 63 can be set.

[0161] Figure 11 and Figure 12 The pixels 50b and 50b' shown are also configured such that TG 62 and the virtual gate 231 are arranged parallel to each other, and the distance between TG 62 and the virtual gate 231 remains constant. Therefore, the plurality of FDs 63 disposed between TG 62 and the virtual gate 231 have the same area.

[0162] <Third Embodiment>

[0163] Figure 13 This is a plan view showing the construction of pixel 50c according to the third embodiment. Figure 13 Pixel 50c shown includes a transistor for switching conversion efficiency. In Figure 13 In the diagram, the gate of transistor 251, used for switching conversion efficiency, is designated as FDG 251. Here, refer to... Figure 14 The circuit diagram shown illustrates pixel 50c, which is equipped with transistor 251 for switching conversion efficiency.

[0164] Figure 14 The circuit configuration of a general pixel 50c including a transistor 251 for switching conversion efficiency is shown (the circuit configuration associated with one of the FD 63 in pixel 50c) to illustrate a pixel 50c provided with a transistor 251 for switching conversion efficiency.

[0165] Figure 14 The pixel 50c shown is a pixel that includes PD 61, transmission transistor 62, FD 63, reset transistor 64, amplification transistor 65 and selection transistor 66, as well as transistor 251 for switching conversion efficiency and additional capacitor 252.

[0166] PD 61 is a photoelectric conversion element. PD 61 receives light from the subject, generates a charge corresponding to the amount of light received through photoelectric conversion, and stores the charge. A transfer transistor 62 is disposed between PD 61 and FD 63, and the transfer transistor 62 transfers the charge stored in PD 61 to FD 63 according to the drive signal TRG applied to the gate electrode of the transfer transistor 62.

[0167] FD 63 is a floating diffusion region (FD) that converts the charge transferred from PD 61 via transfer transistor 62 into an electrical signal (e.g., a voltage signal) and then outputs a voltage signal. FD 63 is connected to reset transistor 64 and to vertical signal line 47 via amplification transistor 65 and selection transistor 66.

[0168] Furthermore, FD 63 is also connected to an additional capacitor section 252 via a transistor 251 for switching conversion efficiency. The additional capacitor section 252 is a floating diffusion region (FD) that converts charge into an electrical signal (e.g., a voltage signal). Note that the additional capacitor section 252 is a floating diffusion region (FD), but since the additional capacitor section 252 performs capacitor operation, it is represented using the circuit symbol of a capacitor.

[0169] The transistor 251 for switching conversion efficiency is turned on and off according to the drive signal FDG, switching between a connection state in which FD 63 and the additional capacitor 252 are electrically connected together and a connection state in which FD 63 and the additional capacitor 252 are not electrically connected. Specifically, the drive signal FDG is provided to the gate electrode included in the transistor 251 for switching conversion efficiency, and by turning on the drive signal FDG, the potential directly below the transistor 251 for switching conversion efficiency is increased, thereby electrically connecting FD 63 and the additional capacitor 252 together.

[0170] In contrast, by disconnecting the drive signal FDG, the potential directly below the transistor 251 used for switching conversion efficiency is reduced, thereby disconnecting the electrical connection between FD 63 and the additional capacitor section 252. Therefore, by turning the drive signal FDG on and off, a capacitor can be added to FD 63 and the sensitivity of the pixel can be changed. Specifically, assuming ΔQ represents the change in stored charge, ΔV represents the corresponding voltage change, and C represents the capacitance value, the relationship ΔV = ΔQ / C holds.

[0171] Now, assume the capacitance value of FD 63 is CFD, and the capacitance value of the additional capacitor section 252 is CFD2. Then, when the drive signal FDG is turned on, the capacitance value C of the pixel area where the signal level is read is CFD+CFD2. Conversely, by turning off the drive signal FDG, the capacitance value C is changed to CFD, thereby increasing the voltage sensitivity (voltage change: FD conversion efficiency) to the charge change.

[0172] In this way, the sensitivity of pixel 50c is appropriately changed by turning the drive signal FDG on and off. For example, by turning on the drive signal FDG, the additional capacitor 252 is electrically connected to FD 63, so that a portion of the charge transferred from PD 61 to FD 63 is stored not only in FD 63 but also in the additional capacitor 252.

[0173] The reset transistor 64 is a component that properly initializes (resets) each region from FD 63 to the additional capacitor section 252, and the reset transistor 64 includes a drain connected to a power supply having a power supply voltage VDD and a source connected to FD 63. A drive signal RST is applied as a reset signal to the gate electrode of the reset transistor 64. Furthermore, setting the drive signal RST to the active state causes the reset transistor 64 to enter an electrically connected state, thereby resetting the potential of FD 63, etc., to the level of the power supply voltage VDD. In other words, FD 63, etc., is initialized.

[0174] The amplifying transistor 65 includes a gate electrode connected to FD 63 and a drain electrode connected to a power supply having a power supply voltage VDD. The amplifying transistor 65 also serves as the input of a source follower circuit that reads out the charge obtained through photoelectric conversion in PD 61. Specifically, the amplifying transistor 65 includes a source connected to the vertical signal line 47 via a select transistor 66, thereby forming a source follower circuit together with a constant current source connected to one end of the vertical signal line 47.

[0175] The selection transistor 66 is connected between the source of the amplifying transistor 65 and the vertical signal line 47, and the drive signal SEL is provided as a selection signal to the gate electrode of the selection transistor 66. By setting the drive signal SEL to the active state, the selection transistor 66 enters the electrically connected state, thereby causing the pixel equipped with the selection transistor 66 to enter the selection state. In the pixel that has entered the selection state, the signal output from the amplifying transistor 65 is read out to the column processing unit 43 via the vertical signal line 47.

[0176] Return to reference for instructions Figure 13 Description of pixel 50c shown. Figure 13 The pixel 50c shown includes the gate of a transistor 251 for switching conversion efficiency (hereinafter referred to as FDG 251), and also includes an additional capacitor 252 (hereinafter referred to as FDex 252).

[0177] Figure 13 The pixel 50c shown includes an FDG 251 shared by TG 62-1 and TG 62-2. However, with Figure 15Similar to the pixel 50c' shown, pixel 50c may include FDG 251-1 paired with TG 62-1 and FDG 251-2 paired with TG 62-2.

[0178] The following explanation is for reference only. Figure 15 Pixel 50c' is shown. In this figure, FD 63-1 is positioned between TG 62-1 and FDG251-1, and FDex 252-1, connected to FD 63-1, is positioned above FDG 251-1. Similarly, in this figure, FD 63-2 is positioned between TG 62-2 and FDG 251-2, and FDex 252-2, connected to FD 63-2, is positioned above FDG 251-2.

[0179] Figure 13 and Figure 15 The pixels 50c and 50c' shown are also configured such that TG 62 and FDG 251 are parallel to each other, and the distance between TG 62 and FDG 251 remains constant. Therefore, the plurality of FD 63 disposed between TG 62 and FDG 251 have the same area.

[0180] Furthermore, FDG 251 is connected to FD 63 and is provided with FDex 252 as part of the floating diffusion region. There are as many FDex 252s as FD 63. The area difference between the multiple FDex 252s results in a capacitance difference between FD 63s. Therefore, the multiple FDex 252s can preferably have the same area, and pixel 50c (pixel 50c') has such a configuration.

[0181] exist Figure 15 In the pixel 50c' shown, RST 64-1 and RST 64-2 are provided on the lower side of pixel 50c'. On the other hand, FDex 252-1 and FDex 252-2 are provided on the upper side of pixel 50c'. Multiple pixels 50c' are arranged two-dimensionally in the pixel array section 41. Figure 2 ). Figure 16 The image shows three pixels arranged vertically. Figure 16 A portion of pixels 50c'-1, 50c'-2, and 50c'-3 (arranged vertically) are shown.

[0182] The RST 64-1-1 of pixel 50c'-1 is positioned adjacent to the FDex 252-1-2 of pixel 50c'-2. Furthermore, the RST 64-1-1 of pixel 50c'-1 and the FDex 252-1-2 of pixel 50c'-2 are arranged parallel to each other (the distance between RST 64-1-1 and FDex 252-1-2 is constant). Specifically, FDex 252-1-2 is located between the two gates of the RST 64-1-1 of pixel 50c'-1 and the FDG 251-1-2 of pixel 50c'-2.

[0183] Similarly, the RST 64-2-1 of pixel 50c'-1 is positioned adjacent to the FDex 252-2-2 of pixel 50c'-2. Furthermore, the RST 64-2-1 of pixel 50c'-1 and the FDG 251-2-2 of pixel 50c'-2 are arranged parallel to each other (the distance between RST 64-2-1 and FDG 251-2-2 is constant). Specifically, FDex 252-2-2 is located between the two gates of the RST 64-2-1 of pixel 50c'-1 and the FDG 251-2-2 of pixel 50c'-2.

[0184] Therefore, FDex 252-1-2 and FDex 252-2-2 have the same height and width, and the same area. In other words, in this case, FDex 252-1-2 and FDex 252-2-2 set in pixel 50c'-2 have the same size.

[0185] Similarly, FDex 252-1-3 of pixel 50c'-3 is located between RST 64-1-2 of pixel 50c'-2 and FDG 251-1-3 of pixel 50c'-3. FDex 252-2-3 of pixel 50c'-3 is located between RST 64-2-2 of pixel 50c'-2 and FDG 251-2-3 of pixel 50c'-3. Therefore, FDex 252-1-3 and FDex 252-2-3 in pixel 50c'-3 are of the same size.

[0186] In this way, the gates provided in adjacent pixels and the gates provided in this pixel are arranged parallel to each other, and FDex 252 is provided between the gates. Then, similar to FD 63, it is possible to provide FDex 252 with no area difference.

[0187] <Fourth Embodiment>

[0188] Figure 17 This is a plan view showing the construction of pixel 50d according to the fourth embodiment. Figure 17The pixel 50d shown has been modified according to Figure 10 The structure obtained by pixel 50a' in the first embodiment shown.

[0189] Figure 10 Pixel 50a' shown represents an example where taps including TG 62-1, FD63-1, and RST 64-1 are arranged in the horizontal direction, and taps including TG 62-2, FD 63-2, and RST 64-2 are also arranged; in other words, the taps are arranged on one side of PD 61. Figure 17 As shown, taps including TG 62-1, FD 63-1 and RST 64-1 and taps including TG 62-2, FD 63-2 and RST 64-2 can be arranged in the vertical direction. In other words, taps can be arranged on both sides of PD 61.

[0190] Figure 17 The pixel 50d shown includes TG 62-1, FD 63-1 and RST 64-1 located above PD 61 in the figure, and TG 62-2, FD 63-2 and RST 64-2 located below PD 61 in the figure.

[0191] Also in Figure 17 In the pixel 50d shown, even if the mask is shifted in the vertical or horizontal direction during manufacturing, FD 63-1 and FD 63-2 can be formed without any area difference.

[0192] Note that in the reference Figure 17 In the example described, TG 62 and RST 64 are paired with FD 63 disposed between TG 62 and RST 64, but this configuration can also be combined with pixel 50b according to the second embodiment to include a virtual gate 231 disposed in the pixel instead of RST 64. Alternatively, this configuration can be combined with pixel 50c according to the third embodiment to include FDG 251 disposed in the pixel instead of RST 64.

[0193] Wiring

[0194] In pixel 50a according to the first embodiment, pixel 50b according to the second embodiment, and pixel 50c according to the third embodiment, such as Figure 18 As shown, transistors such as amplifying transistor 65 and selecting transistor 66 are arranged in a linearly symmetrical manner.

[0195] Figure 18 Pixel 50c' according to the third embodiment is shown. Figure 18In pixel 50c' shown, TG 62-1, FD63-1, FDG 251-1, FDex 252-1, amplifying transistor 65-1, selecting transistor 66-1, well contact 72-1, and RST 64-1 are arranged in a linearly symmetrical relationship with TG 62-2, FD 63-2, FDG 251-2, FDex 252-2, amplifying transistor 65-2, selecting transistor 66-2, well contact 72-2, and RST 64-2 relative to the line L represented by the dashed line.

[0196] The symmetrical arrangement of the lines described above allows the wiring connecting the transistors to have the same length on both sides (the length is the same on both sides within tap 51). For example, the length of the wiring connecting FD 63-1 and amplifying transistor 65-1 can be the same as the length of the wiring connecting FD 63-2 and amplifying transistor 65-2. Wiring of the same length allows each FD 63 to have the same conversion efficiency. Therefore, this makes the device robust to variations during manufacturing.

[0197] In the case where TG 62 and FD 63 are arranged in the vertical direction as in pixel 50d according to the fourth embodiment, as... Figure 19 As shown, the amplifying transistors 65 and the like are arranged in a point-symmetrical manner. Figure 19 Pixel 50d according to the fourth embodiment is shown.

[0198] TG 62-1, FD 63-1, FDG 251-1, FDex 252-1, amplifying transistor 65-1, selecting transistor 66-1, well contact 72-1, and RST 64-1 are surrounded by TG 62-2, FD 63-2, FDG 251-2, FDex 252-2, amplifying transistor 65-2, selecting transistor 66-2, well contact 72-2, and RST 64-2. Figure 19 Point P1 on PD 61 of pixel 50d is arranged in a point-symmetric relationship.

[0199] The point-symmetric arrangement described above allows the wiring connecting the transistors to have the same length within tap 51. For example, the length of the wiring connecting FD 63-1 and amplifying transistor 65-1 can be the same as the length of the wiring connecting FD 63-2 and amplifying transistor 65-2. Wiring of the same length allows each FD 63 to have the same conversion efficiency. Therefore, this makes the device robust to variations during manufacturing.

[0200] Note that the advantage of linear or point-symmetric arrangement of transistors, etc., is that, for example, as described above, variation is eliminated, but the application scope of this technology is not limited to linear or point-symmetric arrangement of transistors, etc.

[0201] Furthermore, the arrangement of transistors, etc., shown above and below are examples, not descriptions indicating limitations. Also, OFG 71 can be omitted in pixel 50.

[0202] <Fifth Embodiment>

[0203] In the first to fourth embodiments, a two-tap configuration has been described as an example. This technology is also applicable to the reference... Figure 6 The pixel 50 has a 4-tap structure. Figure 20 and Figure 21 An example of the construction of pixel 50 with a 4-tap configuration is shown. Note that... Figure 20 and Figure 21 Transistors such as amplifying transistor 65 or selecting transistor 66 are not shown, but transistors are provided in each tap (each FD 63).

[0204] Figure 20 Pixel 50e shown comprises four groups, each group including TG62, FD63, and RST64 located above and below PD 61 in the figure. The upper side of PD 61 includes TG 62-1, FD 63-1, and RST 64-1, all contained in a single tap. Additionally, the upper side of PD 61 also includes TG 62-2, FD 63-2, and RST 64-2, all contained in a single tap.

[0205] Additionally, the underside of PD 61 includes TG 62-3, FD 63-3, and RST 64-3, all housed in a single tap. Furthermore, the underside of PD 61 also includes TG 62-4, FD 63-4, and RST 64-4, all housed in a single tap.

[0206] FDs 63-1 to 63-4 are respectively positioned between TG 62 and RST 64, with TG 62 and RST 64 positioned parallel to FD. Therefore, as in the first to fourth embodiments, FDs 63-1 to FD 63-4 have the same area.

[0207] like Figure 21 As shown, taps can be set on the four sides of PD 61. Figure 21 The pixel 50e' shown includes a combination of TG 62, FD 63 and RST 64 respectively located above, below, left and right of PD 61 in the figure.

[0208] The upper side of PD 61 is provided with TG 62-1, FD 63-1 and RST 64-1 included in a single tap. In addition, the right side of PD 61 is provided with TG 62-2, FD 63-2 and RST 64-2 included in a single tap.

[0209] In addition, PD 61 has TG 62-3, FD 63-3 and RST 64-3 included in a single tap on its lower side. Furthermore, PD 61 has TG 62-4, FD 63-4 and RST 64-4 included in a single tap on its left side.

[0210] FDs 63-1 to 63-4 are respectively positioned between TG 62 and RST 64, with TG 62 and RST 64 positioned parallel to FD. Therefore, as in the first to fourth embodiments, FDs 63-1 to 63-4 according to the fifth embodiment also have the same area.

[0211] Note that in the reference Figure 20 and Figure 21 In the example described, RST 64 is paired with TG 62, and FD 63 is disposed between RST 64 and TG 62. However, this configuration can be combined with pixel 50b according to the second embodiment to include a virtual gate 231 disposed in the pixel instead of RST 64. Furthermore, this configuration can also be combined with pixel 50c according to the third embodiment to include an FDG 251 disposed in the pixel instead of RST 64.

[0212] <Sixth Embodiment>

[0213] In the first to fifth embodiments, for example, TG 62 and a gate different from TG 62 are parallel to each other, and FD63 is formed between TG 62 and the gate. Instead of another gate paired with TG 62, an element isolation portion can be used.

[0214] Figure 22 This is a plan view showing an example of the construction of pixel 50f according to the sixth embodiment. Figure 23 It shows Figure 22 The cross-sectional view of pixel 50f shown is a cross-sectional view constructed along line segment A-A' in the planar view.

[0215] A component isolation section 301 is provided in the space of pixel 50f. The component isolation section 301 includes an insulator composed of an oxide film such as SiO2.

[0216] like Figure 23As shown, PD 61 is disposed in P-well 302 made of Si substrate. More specifically, PD 61 includes an N-type impurity layer (charge storage layer) and a P-type impurity layer 303 disposed above the N-type impurity layer, including a depletion prevention layer (pinning layer) and having a high concentration.

[0217] An FD 63-1 is disposed to the left of the P-type impurity layer 303 in the figure, and the charge generated in PD 61 is stored in this FD 63-1. Figure 23 In the figure, the transfer gate (TG) 62-1 is arranged across the P-type impurity layer 303 and FD 63-1 in the lateral direction. When TG 62-1 is controllably turned on, TG 62-1 transfers the charge stored in PD 61 to FD 63-1, which contains a high concentration of N-type impurity layer, via the P-type impurity layer 303.

[0218] On the other hand, component isolation portions 301 (sometimes also referred to as STI (Shallow Trench Isolation)) are provided on the left and right portions of the P-well 302 in the figure. Component isolation portions 301 are formed by forming shallow trenches and backfilling the trenches with an insulator made of an oxide film such as SiO2. Component isolation portions 301 can also be constructed using a diffusion layer having a conductivity type opposite to that of the source and drain of the transistor. For example, when constructing the source and drain of the transmission transistor 62 using an N-type diffusion layer, a P-type diffusion layer can be used to construct the component isolation portion 301.

[0219] like Figure 24 As shown, a TG 62-1 can be formed using a vertical transistor. In Figure 24 The TG 62-1 shown has a vertical transistor trench formed therein, and a transfer gate is formed therein to read out charge from PD 61. The TG 62-1, thus configured as a vertical transistor, allows for efficient charge readout even from deep portions of PD 61.

[0220] Notice, Figure 23 and Figure 24 The cross-sectional structure shown is also applicable to pixels according to the first to fifth embodiments described above. Furthermore, the vertical transistor can also be used as a transistor other than TG 62 (transmission transistor 62).

[0221] exist Figures 22 to 24In the structure of pixel 50f shown, FD 63-1 is disposed between TG 62-1 and element isolation portion 301, and FD 63-2 is disposed between TG 62-2 and element isolation portion 301. Element isolation portion 301 replaces, for example, RST 64 in pixel 50a according to the first embodiment. Specifically, element isolation portion 301 is configured such that the distance between TG 62-1 and element isolation portion 301 is the same as the distance between TG 62-2 and element isolation portion 301, so TG 62-1 and TG 62-2 have the same area.

[0222] Therefore, multiple FD 63s with no area difference can be formed in pixel 50f.

[0223] Notice, Figure 25 The pixel 50f' shown can contain area differences between multiple FD 63. Figure 25 The pixel 50f' shown illustrates the case where TG 62-1 and FD 63-1 are positioned above PD 61 in the figure, and TG 62-2 and FD 63-2 are positioned below PD 61 in the figure.

[0224] like Figure 25 As shown in Figure A, without any displacement between the mask used to form the element isolation section 301 and the mask used to form the gate, the formed FD 63-1 and FD 63-2 can have the same area. However, as... Figure 25 As shown in B, when displacement occurs between the mask used to form the element isolation section 301 and the mask used to form the gate, specifically, when the mask is shifted in different directions, the formed FD 63-1' and FD 63-2' may have different areas.

[0225] Figure 25 The state indicated by B in the figure represents, for example, the mask used to form the component isolation portion 301 being shifted upwards in the figure, resulting in the formed FD 63-1' being larger than the formed FD 63-2'. In the case where the component isolation portion 301 and TG 62 are formed parallel to each other, FD 63 is formed between the component isolation portion 301 and TG 62, as shown... Figure 25 As shown, in a structure where TG62 and FD 63 are formed on two different sides of PD 61, area differences may occur among the multiple FD 63 formed. Therefore, as Figure 22 As shown, the configuration in which TG 62 and FD 63 are formed on the same side of PD 61 is more preferred.

[0226] Note that, as Figure 25The pixel 50f' constructed as shown is susceptible to mask displacement in the vertical direction as described above, but not susceptible to mask displacement in the lateral direction. Specifically, as in the case of pixel 50f', when multiple FDs 63 are formed along the vertical direction of PD 61, multiple FDs 63 with no area difference can be formed even if the mask is shifted in the lateral direction (which is different from the vertical direction) during manufacturing.

[0227] Therefore, if, for example, the manufacturing process can limit possible displacement to the lateral direction, it is also possible to form multiple FD 63s with no area difference. Figure 25 The pixel 50f' shown is an example, and this technology can be applied to pixel 50f'.

[0228] Although the sixth embodiment was described using a 2-tap case as an example, the sixth embodiment is also applicable to a 4-tap case.

[0229] <Seventh Embodiment>

[0230] Figure 26 This is a plan view showing a construction example of pixel 50g according to the seventh embodiment. Figure 27 It shows Figure 26 The cross-sectional view of pixel 50g shown is taken along line segment B-B' in the planar view.

[0231] A pixel separation section 321 is provided in the pixel 50g. The pixel separation section 321 is provided in such a way that it surrounds a pixel 50g. The pixel separation section 302 is formed by a trench, which is formed, for example, by a sidewall film made of SiO2 formed on the inner wall of the trench, and the trench is filled with a filler made of polycrystalline silicon.

[0232] The trench can be set to run through pixel 50g or extend through half of pixel 50g. Figure 27 The pixel 50g shown represents the case where pixel 50g is penetrated.

[0233] Note that SiO2 or SiN can be used as the sidewall film of the pixel separation section 302. Furthermore, polycrystalline silicon or doped polycrystalline silicon can be used as a filler. Additionally, the trenches in the pixel separation section 302 can be filled with a light-shielding material (e.g., a metal such as tungsten or copper).

[0234] In this way, when the pixel separation unit 321 is provided, FD 63-1 is provided between TG 62-1 and the pixel separation unit 321, and FD 63-2 is provided between TG 62-2 and the pixel separation unit 321.

[0235] The pixel separation section 321 replaces, for example, the element isolation section 301 in pixel 50f according to the sixth embodiment. Specifically, the pixel separation section 321 is configured such that the distance between TG 62-1 and the pixel separation section 321 is the same as the distance between TG 62-2 and the pixel separation section 321, so that TG 62-1 and TG 62-2 with the same area can be formed.

[0236] The element isolation section 301 and the pixel separation section 321 are similar in that they both have grooves formed and filled with a predetermined material. By forming the grooves, these sections can be separated. If such a separation section is provided at the position where it is paired with the TG 62, the dimensions of the multiple FDs 63 can be made equal to each other as described above.

[0237] Therefore, multiple FD 63s with no area difference can be formed in a pixel 50g.

[0238] Note that in pixel 50g, where TG 62 and FD 63 are formed on two different sides of PD 61, as in pixel 50f' ( Figure 25 The area may differ between the multiple FD 63s set up, therefore, as Figure 26 As shown, a configuration in which TG62 and FD63 are formed on the same side of PD61 is preferred.

[0239] Although the seventh embodiment was described using a 2-tap case as an example, the seventh embodiment is also applicable to a 4-tap case.

[0240] In this way, according to this technology, in a pixel having multiple FDs, it is possible to make the areas of the multiple FDs the same, thereby achieving the same conversion efficiency.

[0241] According to the first to seventh embodiments, the pixel 50 can be used as a pixel array portion 41 ( Figure 2 Pixels in ) . Furthermore, as a ranging device 10 ( Figure 1 The distance measuring device can use a pixel array section 41.

[0242] Applications of Endoscopic Surgical Systems

[0243] The technology disclosed herein (the technology) can be applied to various products. For example, the technology disclosed herein can be applied to endoscopic surgical systems.

[0244] Figure 28 This is a diagram illustrating an example of a schematic construction of an endoscopic surgical system to which the technology (the technology) according to embodiments of this disclosure can be applied.

[0245] exist Figure 28The image shows a surgeon (physician) 11131 using an endoscopic surgery system 11000 to perform surgery on a patient 11132 on a bed 11133. As shown, the endoscopic surgery system 11000 includes an endoscope 11100, other surgical tools 11110 such as a pneumoperitoneum tube 11111 and an energy device 11112, a support arm assembly 11120 supporting the endoscope 11100, and a trolley 11200 on which various devices for endoscopic surgery are mounted.

[0246] Endoscope 11100 includes a lens barrel 11101 and a camera head 11102, the portion of the lens barrel extending a predetermined length from its distal end inserted into the body cavity of patient 11132, the camera head being connected to the proximal end of the lens barrel 11101. In the illustrated example, an endoscope 11100 is shown configured as a rigid endoscope with a rigid lens barrel 11101. However, endoscope 11100 can also be configured as a flexible endoscope with a flexible lens barrel 11101.

[0247] The lens barrel 11101 has an opening at its distal end for mounting an objective lens. A light source device 11203 is connected to the endoscope 11100 to introduce light generated by the light source device 11203 through a light guide extending into the lens barrel 11101 to the distal end of the lens barrel 11101, and then through the objective lens onto the object being observed within the body cavity of the patient 11132. It should be noted that the endoscope 11100 can be a forward-looking endoscope, an oblique endoscope, or a lateral endoscope.

[0248] An optical system and imaging element are housed inside the camera head 11102 to focus reflected light (observation light) from the object being observed onto the imaging element via the optical system. The imaging element converts the observation light into an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. The image signal is then transmitted as raw (RAW) data to the CCU 11201.

[0249] The CCU 11201 includes a central processing unit (CPU), a graphics processing unit (GPU), etc., and centrally controls the operation of the endoscope 11100 and the display device 11202. Further, for example, the CCU 11201 receives image signals from the camera head 11102 and performs various image processing operations on the image signals, such as developing (de-mosaicing), to display an image based on the image signals.

[0250] The display device 11202 displays an image based on an image signal that has been image-processed by the CCU 11201 under the control of the CCU 11201.

[0251] For example, the light source device 11203 includes a light source such as a light-emitting diode (LED) and provides illumination light for imaging the surgical area to the endoscope 11100.

[0252] Input device 11204 is the input interface of endoscopic surgery system 11000. Users can input various information or commands into endoscopic surgery system 11000 through input device 11204. For example, users may input commands to change the imaging conditions of endoscope 11100 (type of illumination light, magnification, focal length, etc.).

[0253] The treatment tool control device 11205 controls the drive of the energy device 11112 to burn or cut tissue, close blood vessels, etc. The pneumoperitoneum device 11206 supplies gas into the patient's body cavity 11132 through the pneumoperitoneum tube 11111 to inflate the cavity, ensuring the endoscope 11100's field of vision and the surgeon's working space. The recorder 11207 is a device capable of recording various information related to the surgery. The printer 11208 is a device capable of printing various information related to the surgery in various formats such as text, images, or graphics.

[0254] It should be noted that the light source device 11203, which provides illumination light to the endoscope 11100 when imaging the surgical area, can be composed of a white light source, such as an LED, a laser light source, or a combination thereof. In the case where the white light source is composed of a combination of red, green, and blue (RGB) laser light sources, the white balance of the captured image can be adjusted by the light source device 11203 because the output intensity and timing of each color (each wavelength) can be controlled with high precision. Furthermore, in this case, if the laser beams from each RGB laser light source illuminate the object of observation in a time-division manner, the driving of the imaging element of the camera head 11102 is controlled synchronously with the illumination timing. Images corresponding to the R, G, and B colors can then be captured in a time-division manner. According to this method, color images can be obtained even without configuring a color filter for the imaging element.

[0255] Furthermore, the drive of the light source device 11203 can be controlled to change the intensity of the light to be output at predetermined intervals. By controlling the drive of the imaging element of the camera head 11102 in time-division multiplexing in sync with the change in light intensity, images can be acquired and synthesized in a time-division multiplexing manner, creating images with high dynamic range that do not have underexposed shadows or overexposed highlights.

[0256] Furthermore, the light source device 11203 can be configured to provide light corresponding to a predetermined wavelength band for special light observation. For example, in special light observation, by utilizing the wavelength dependence of light absorption by body tissues, a narrow band of light is irradiated compared to the irradiation light used in ordinary observation (i.e., white light), thereby performing narrow-band observation (narrow-band imaging) of predetermined tissues such as blood vessels in the mucosal surface with high contrast. Alternatively, in special light observation, fluorescence observation for obtaining an image from fluorescence generated by irradiating excitation light can be performed. In fluorescence observation, fluorescence observation of body tissues can be performed by irradiating the body tissue with excitation light (autofluorescence observation), or a fluorescence image can be obtained by locally injecting a reagent such as indocyanine green (ICG) into the body tissue and irradiating the body tissue with excitation light corresponding to the fluorescence wavelength of the reagent. The light source device 11203 can be configured to provide such narrow-band light and / or excitation light suitable for special light observation as described above.

[0257] Figure 29 It is shown Figure 28 A block diagram illustrating an example of the functional configuration of the camera head 11102 and CCU 11201 shown.

[0258] Camera head 11102 includes lens unit 11401, image capture unit 11402, drive unit 11403, communication unit 11404, and camera head control unit 11405. CCU 11201 includes communication unit 11411, image processing unit 11412, and control unit 11413. Camera head 11102 and CCU 11201 are connected via transmission cable 11400 for mutual communication.

[0259] Lens unit 11401 is an optical system disposed at the connection position with lens barrel 11101. Observation light entering from the distal end of lens barrel 11101 is guided to camera head 11102 and introduced into lens unit 11401. Lens unit 11401 is composed of a combination of multiple lenses, including zoom lenses and focusing lenses.

[0260] The imaging unit 11402 can contain one (single-plate type) or multiple (multi-plate type). For example, when the imaging unit 11402 is configured as a multi-plate type, image signals corresponding to each R, G, and B are generated by the imaging elements, and the image signals can be synthesized to obtain a color image. The imaging unit 11402 can also be configured to have a pair of imaging elements for acquiring right-eye and left-eye image signals corresponding to three-dimensional (3D) display. If 3D display is performed, the surgeon 11131 can then more accurately grasp the depth of the living tissue in the surgical area. It should be noted that when the imaging unit 11402 is configured in a stereoscopic manner, multiple lens unit 11401 systems are provided corresponding to each imaging element.

[0261] Furthermore, the camera unit 11402 may not necessarily be located on the camera head 11102. For example, the camera unit 11402 may be located directly behind the objective lens inside the lens barrel 11101.

[0262] The drive unit 11403 is composed of an actuator, and under the control of the camera head control unit 11405, it moves the zoom lens and focusing lens of the lens unit 11401 a predetermined distance along the optical axis. Therefore, the magnification and focus of the image captured by the imaging unit 11402 can be appropriately adjusted.

[0263] The communication unit 11404 comprises a communication device for sending and receiving various information to and from the CCU 11201. The communication unit 11404 transmits the image signal acquired from the camera unit 11402 as RAW data to the CCU 11201 via the transmission cable 11400.

[0264] Additionally, the communication unit 11404 receives control signals from the CCU 11201 for controlling the drive of the camera head 11102 and provides the control signals to the camera head control unit 11405. For example, the control signals include information related to shooting conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value when capturing the image, and / or information specifying the magnification and focus of the captured image.

[0265] It should be noted that imaging conditions such as frame rate, exposure value, magnification, or focus can be specified by the user or automatically set by the control unit 11413 of CCU 11201 based on the acquired image signal. In the latter case, automatic exposure (AE), automatic focus (AF), and automatic white balance (AWB) functions are set in the endoscope 11100.

[0266] The camera head control unit 11405 controls the driving of the camera head 11102 based on the control signals received from the CCU 11201 via the communication unit 11404.

[0267] The communication unit 11411 comprises a communication device for sending and receiving various information to and from the camera head 11102. The communication unit 11411 receives image signals transmitted to it from the camera head 11102 via the transmission cable 11400.

[0268] Furthermore, the communication unit 11411 transmits control signals for controlling the driving of the camera head 11102 to the camera head 11102. Image signals and control signals can be transmitted via electrical communication, optical communication, etc.

[0269] The image processing unit 11412 performs various image processing operations on the image signal in RAW data form transmitted from the camera head 11102.

[0270] The control unit 11413 performs various controls related to capturing images of the surgical area, etc., through the endoscope 11100 and displaying the captured images obtained by capturing images of the surgical area, etc. For example, the control unit 11413 creates control signals for controlling the drive of the camera head 11102.

[0271] Furthermore, the control unit 11413 controls the display device 11202 to display the captured image, which has been imaged of the surgical area, based on the image signal that has already been processed by the image processing unit 11412. At this time, the control unit 11413 can use various image recognition technologies to identify various objects in the captured image. For example, the control unit 11413 can identify surgical tools such as surgical forceps, specific living areas, bleeding, fog when using the energy device 11112, etc., by detecting the shape and color of the edges of objects contained in the captured image. When the control unit 11413 controls the display device 11202 to display the captured image, it can use the recognition results to display various surgical support information in an overlay manner with the image of the surgical area. When the surgical support information is displayed and presented to the surgeon 11131 in an overlay manner, the burden on the surgeon 11131 can be reduced, and the surgeon 11131 can perform the surgery reliably.

[0272] The transmission cable 11400 that connects the camera head 11102 and CCU 11201 is an electrical signal cable for electrical signal communication, an optical fiber for optical communication, or a composite cable for both electrical and optical communication.

[0273] Here, although wired communication is used via transmission cable 11400 in the example shown, communication between camera head 11102 and CCU 11201 can be carried out wirelessly.

[0274] <Application of Moving Bodies>

[0275] The technology disclosed herein (the Technology) is applicable to a wide variety of products. For example, the Technology can be implemented as a device installed on any type of mobile body such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility devices, airplanes, drones, ships, robots, etc.

[0276] Figure 30 This is a block diagram illustrating an example of a schematic construction of a vehicle control system, which is an example of a mobile body control system to which the technology according to embodiments of the present disclosure can be applied.

[0277] The vehicle control system 12000 includes multiple electronic control units interconnected via a communication network 12001. Figure 30 In the example shown, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and a comprehensive control unit 12050. Furthermore, a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network interface (I / F) 12053 are shown as functional components of the comprehensive control unit 12050.

[0278] The drive system control unit 12010 controls the operation of devices related to the vehicle's drive system according to various programs. For example, the drive system control unit 12010 is used as a control device for the following devices: a drive force generating device, such as an internal combustion engine or a drive motor, for generating the driving force of the vehicle; a drive force transmission mechanism for transmitting the driving force to the wheels; a steering mechanism for adjusting the steering angle of the vehicle; and a braking device for generating the braking force of the vehicle.

[0279] The body system control unit 12020 controls the operation of various devices installed on the vehicle body according to various programs. For example, the body system control unit 12020 is used as a control device for keyless entry systems, smart key systems, power windows, or various lights such as headlights, taillights, brake lights, turn signals, or fog lights. In this case, radio waves or signals from various switches transmitted from a portable device that serves as a substitute for a key can be input to the body system control unit 12020. The body system control unit 12020 receives these input radio waves or signals and controls the vehicle's door locking devices, power windows, lights, etc.

[0280] The exterior information detection unit 12030 detects information about the exterior of the vehicle having the vehicle control system 12000. For example, the exterior information detection unit 12030 is connected to the imaging unit 12031. The exterior information detection unit 12030 causes the imaging unit 12031 to image the exterior of the vehicle and receives the captured images. Based on the received images, the exterior information detection unit 12030 can perform detection processing for objects such as people, vehicles, obstacles, markings, or symbols on the road surface, or detection processing for the distance to these objects.

[0281] Imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal corresponding to the amount of light received. Imaging unit 12031 can output an electrical signal as an image, or it can output an electrical signal as information about the measured distance. Furthermore, the light received by imaging unit 12031 can be visible light, or it can be invisible light such as infrared light.

[0282] The in-vehicle information detection unit 12040 detects information about the interior of the vehicle. For example, the in-vehicle information detection unit 12040 is connected to a driver state detection unit 12041 that detects the driver's state. The driver state detection unit 12041 includes, for example, a camera that images the driver. Based on the detection information input from the driver state detection unit 12041, the in-vehicle information detection unit 12040 can calculate the driver's fatigue level or concentration level, or determine whether the driver is dozing off.

[0283] The microcomputer 12051 can calculate target control values ​​for the drive force generating device, steering mechanism, or braking device based on information about the vehicle's interior or exterior (obtained by the exterior information detection unit 12030 or the interior information detection unit 12040), and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform coordinated control aimed at realizing the functions of an advanced driver assistance system (ADAS), including: collision avoidance or impact mitigation, following distance based on the vehicle's distance, vehicle speed maintenance, collision warning, or lane departure warning, etc.

[0284] Furthermore, the microcomputer 12051 can perform cooperative control designed for autonomous driving, enabling the vehicle to drive autonomously by controlling the drive force generating device, steering mechanism, or braking device, etc., based on information about the inside or outside of the vehicle (which is obtained by the external information detection unit 12030 or the internal information detection unit 12040), without relying on the driver's operation.

[0285] Furthermore, the microcomputer 12051 can output control commands to the body system control unit 12020 based on information about the vehicle's exterior (obtained by the exterior information detection unit 12030). For example, the microcomputer 12051 can perform coordinated control aimed at preventing glare by controlling the headlights to switch from high beams to low beams, based on the position of the vehicle ahead or oncoming vehicle detected by the exterior information detection unit 12030.

[0286] The audio-visual output unit 12052 transmits at least one output signal of audio and image to an output device capable of visually or audibly notifying the vehicle's passengers or the outside of the vehicle. Figure 30 In the example, audio speaker 12061, display unit 12062, and instrument panel 12063 are shown as output devices. For example, display unit 12062 may include at least one of an in-vehicle display and a head-up display.

[0287] Figure 31 This is a diagram showing an example of the mounting position of the imaging unit 12031.

[0288] exist Figure 31 In the imaging unit 12031, there are imaging units 12101, 12102, 12103, 12104 and 12105.

[0289] Imaging units 12101, 12102, 12103, 12104, and 12105 are, for example, located on the front nose, side mirrors, rear bumper, and rear door of vehicle 12100, and on the upper part of the interior windshield. Imaging unit 12101 on the front nose and imaging unit 12105 on the upper part of the interior windshield primarily acquire images of the front of vehicle 12100. Imaging units 12102 and 12103 on the side mirrors primarily acquire images of the sides of vehicle 12100. Imaging unit 12104 on the rear bumper or rear door primarily acquires images of the rear of vehicle 12100. Imaging unit 12105 on the upper part of the interior windshield is primarily used to detect vehicles, pedestrians, obstacles, signals, traffic signs, or lanes ahead.

[0290] Incidentally, Figure 31An example of the imaging range of imaging units 12101 to 12104 is shown. Imaging range 12111 represents the imaging range of imaging unit 12101 installed on the front nose. Imaging ranges 12112 and 12113 represent the imaging ranges of imaging units 12102 and 12103 installed on the side mirrors, respectively. Imaging range 12114 represents the imaging range of imaging unit 12104 installed on the rear bumper or rear door. For example, by superimposing the image data captured by imaging units 12101 to 12104, a top-down image of the vehicle 12100 as viewed from above is obtained.

[0291] At least one of the imaging units 12101 to 12104 may have the function of obtaining distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera composed of multiple imaging elements, or may be an imaging element having pixels for phase difference detection.

[0292] For example, the microcomputer 12051 can determine the distance to each three-dimensional object within the imaging range 12111 to 12114 and the time change of that distance (relative speed to the vehicle 12100) based on distance information obtained from the imaging units 12101 to 12104. This allows it to extract the nearest three-dimensional object as the vehicle ahead, specifically, the three-dimensional object that exists on the vehicle 12100's travel path and travels at a predetermined speed (e.g., equal to or greater than 0 km / h) in substantially the same direction as the vehicle 12100. Furthermore, the microcomputer 12051 can pre-set a vehicle-to-vehicle distance to be maintained in front of the vehicle ahead and execute automatic braking control (including stop-and-go control) or automatic acceleration control (including start-and-go control), etc. Therefore, cooperative control designed for autonomous driving can be implemented, enabling the vehicle to drive autonomously without relying on driver operation.

[0293] For example, microcomputer 12051 can classify three-dimensional object data about three-dimensional objects into three-dimensional object data of two-wheeled vehicles, standard-sized vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from imaging units 12101 to 12104, extract the classified three-dimensional object data, and use the extracted three-dimensional object data to automatically avoid obstacles. For example, microcomputer 12051 identifies obstacles around vehicle 12100 as obstacles that the driver of vehicle 12100 can visually recognize and obstacles that the driver of vehicle 12100 cannot visually recognize. Then, microcomputer 12051 determines the collision risk, which represents the risk of collision with each obstacle. If the collision risk is equal to or higher than a set value and therefore there is a possibility of collision, microcomputer 12051 outputs a warning to the driver via audio speaker 12061 or display unit 12062, and performs forced deceleration or evasive steering through drive system control unit 12010. Microcomputer 12051 can thus assist in driving to avoid collision.

[0294] At least one of the imaging units 12101 to 12104 can be an infrared camera that detects infrared light. For example, the microcomputer 12051 can identify a pedestrian by determining whether a pedestrian exists in the images captured by the imaging units 12101 to 12104. This pedestrian identification is performed, for example, by a program that extracts feature points from the images captured by the imaging units 12101 to 12104 (which are infrared cameras) and a program that determines whether a person is a pedestrian by performing pattern matching processing on a series of feature points representing the outline of an object. When the microcomputer 12051 determines that a pedestrian exists in the images captured by the imaging units 12101 to 12104 and thus identifies the pedestrian, the sound image output unit 12052 controls the display unit 12062 so that a square outline for emphasis is displayed superimposed on the identified pedestrian. The sound image output unit 12052 can also control the display unit 12062 so that an icon or the like representing a pedestrian is displayed at a desired location.

[0295] In the specification, the system refers to the entire device that includes multiple devices.

[0296] Note that the effects described in the instruction manual are illustrative, not limiting, and may produce other effects.

[0297] Note that the embodiments of this technology are not limited to the above embodiments, and various changes can be made to the embodiments without departing from the spirit of this technology.

[0298] Note that this technology can also have the following configurations.

[0299] (1) An imaging element comprising:

[0300] A photoelectric conversion unit, which is configured to perform photoelectric conversion;

[0301] Multiple charge storage units configured to store the charge obtained by the photoelectric conversion unit; and

[0302] Multiple transmission units are configured to transfer the charge from the photoelectric conversion unit to each of the multiple charge storage units, wherein...

[0303] Each of the charge storage units is disposed between a first gate of a transistor included in a corresponding transport unit and a second gate disposed at a position parallel to the first gate.

[0304] (2) The imaging element according to (1) above, wherein,

[0305] The second gate includes the gate of a reset transistor configured to reset the charge storage section.

[0306] (3) The imaging element according to (1) above, wherein,

[0307] The second gate includes a dummy gate.

[0308] (4) The imaging element according to (1) above further includes:

[0309] An additional capacitor section, configured to add capacitance to the charge storage section; and

[0310] An additional transistor is configured to add the additional capacitor portion to the charge storage portion, wherein...

[0311] The charge storage section is disposed between the first gate and the second gate included in the additional transistor.

[0312] (5) The imaging element according to (4) above, wherein,

[0313] The additional capacitor is disposed between the second gate and the third gate disposed in the adjacent pixel.

[0314] (6) An imaging element comprising:

[0315] A photoelectric conversion unit, which is configured to perform photoelectric conversion;

[0316] Multiple charge storage units are configured to store the charge obtained by the photoelectric conversion unit;

[0317] Multiple transmission units, configured to transfer the charge from the photoelectric conversion unit to each of the multiple charge storage units; and

[0318] A trench, which is configured to be parallel to the gate of a transistor included in a corresponding transmission section, wherein,

[0319] Each of the charge storage units is disposed between the gate and the trench.

[0320] (7) The imaging element according to (6) above, wherein,

[0321] The grooves are arranged to surround the pixels.

[0322] (8) The imaging element according to any one of (1) to (7) above, wherein,

[0323] Two or four charge storage units are provided in the pixel.

[0324] (9) The imaging element according to any one of (1) to (8), wherein,

[0325] The plurality of charge storage units and the plurality of transmission units are arranged in a linear or point-symmetric relationship.

[0326] (10) A ranging device comprising:

[0327] The light-emitting part is configured to emit illumination light;

[0328] A light receiving unit, configured to receive reflected light generated by the reflection of the irradiated light on a target object; and

[0329] The calculation unit is configured to calculate the distance to the target object based on the time interval from the emission of the irradiated light to the reception of the reflected light, wherein...

[0330] The imaging element arranged in the light receiving section includes:

[0331] A photoelectric conversion unit, which is configured to perform photoelectric conversion;

[0332] Multiple charge storage units configured to store the charge obtained by the photoelectric conversion unit; and

[0333] Multiple transmission units are configured to transfer the charge from the photoelectric conversion unit to each of the multiple charge storage units, and,

[0334] Each of the charge storage units is disposed between a first gate of a transistor included in a corresponding transport unit and a second gate disposed at a position parallel to the first gate.

[0335] [List of reference numerals]

[0336] 10 Distance measuring device

[0337] 11 Lenses

[0338] 12 Optical Receiver

[0339] 13 Signal Processing Department

[0340] 14 Light-emitting part

[0341] 15. Lighting Control Unit

[0342] 21 Pattern switching section

[0343] 22 Distance Image Generation Unit

[0344] 41-pixel array

[0345] 42 Vertical drive unit

[0346] 43 processing units

[0347] 44 Horizontal drive unit

[0348] 45 System Control Department

[0349] 46-pixel drive line

[0350] 47 Vertical signal line

[0351] 50 pixels

[0352] 51 taps

[0353] 61 Photodiode

[0354] 62 Transmission Transistors

[0355] 63 FD, 64 Reset Transistor

[0356] 65 Amplifying Transistor

[0357] 66 Select Transistors

[0358] 71 Discharge Transistor

[0359] 72 well contacts, 121 masks

[0360] 131 opening, 231 virtual gate

[0361] 251 transistors for switching conversion efficiency

[0362] 252 Additional capacitors

[0363] 301 Component Isolation Section

[0364] 302-pixel separation section

[0365] 303 P-type impurity layer

[0366] 321 pixel separation section

Claims

1. An imaging element comprising: A photoelectric conversion unit, which is configured to perform photoelectric conversion; Multiple charge storage units are configured to store the charge obtained by the photoelectric conversion unit; A plurality of transmission units are configured to transfer the charge from the photoelectric conversion unit to each of the plurality of charge storage units; and A trench, which is configured to be parallel to the gate of a transistor included in a corresponding transmission section, wherein, Each of the charge storage units is disposed between the gate and the trench. The length of each charge storage unit in the direction perpendicular to the gate is equal to the distance between the gate and the trench, and The groove is a component isolation section.

2. The imaging element according to claim 1, wherein, The grooves are arranged to surround the pixels.

3. The imaging element according to claim 1 or 2, wherein, Two or four charge storage units are provided in the pixel.

4. The imaging element according to claim 1 or 2, wherein, The plurality of charge storage units are arranged in a linear or point-symmetric relationship, and the plurality of transmission units are arranged in a linear or point-symmetric relationship.

5. A ranging device, comprising: The light-emitting part is configured to emit illumination light; A light receiving unit is configured to receive reflected light generated by the reflection of the irradiated light on the target object; and The calculation unit is configured to calculate the distance to the target object based on the time interval from the emission of the irradiated light to the reception of the reflected light, wherein... The imaging element arranged in the light receiving section is the imaging element according to any one of claims 1-4.

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