Solid-state imaging device
By partitioning the CMOS sensor pixel array and setting independent signal processing timing and circuits in different regions, the problems of low frame rate and poor compatibility of the sensor are solved, and efficient signal processing and miniaturization design are achieved.
Patent Information
- Application Number
- JP2021554218
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2019-11-01
- Filing Date
- 2020-09-30
- Publication Date
- 2025-02-03
- Estimated Expiration
- 2040-09-30
AI Technical Summary
The pixel array of existing CMOS sensors has low frame rates due to the signal acquisition order, and the signal processing after partitioning is poorly compatible with other circuits, making it difficult to achieve miniaturization and diversification.
The pixel array is divided into multiple regions, each region having independent signal processing timing. By setting different signal lines and analog circuits on the first and second substrates, the signals of different regions are processed using the first and second analog circuits, and signal transmission and switching in the third direction are realized through the connection part, synchronous control is realized.
The frame rate of the sensor is improved, the signal transmission load is reduced, the rolling shutter distortion is suppressed, and efficient signal processing and miniaturization design is achieved.
Smart Images

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Abstract
Description
[Technical field]
[0001] The present disclosure relates to a solid-state imaging device. [Background technology]
[0002] A sensor equipped with a pixel array in which pixels such as conventional CMOS (Complementary Metal-Oxide Semiconductor) elements are formed in an array has a problem of low frame rate because signals are acquired in sequence from predetermined elements. In order to increase this frame rate, a configuration is conceivable in which the pixel array is divided into multiple regions, each of which is provided with a signal line, and an analog circuit and a logic circuit for receiving the signals. This type of configuration has low compatibility with other circuits and tends to be complicated, making it unsuitable for miniaturizing pixel size or increasing the number of pixels. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] JP 2012-054876 A Summary of the Invention [Problem to be solved by the invention]
[0004] In order to avoid this, it is conceivable to divide the pixel array into simple regions. In this simple division, a plurality of pixels in the pixel array that are adjacent but processed by different analog circuits, i.e., adjacent pixels straddling the boundary of the region, are propagated by signal lines with different signal processing timings. Due to the difference in signal processing timings, adjacent pixels straddling the boundary may receive light at significantly different timings compared to other adjacent pixels. As a result, this may cause rolling shutter distortion at the boundary of the region.
[0005] The present disclosure provides a solid-state imaging device that includes a plurality of regions in a pixel array and suppresses the occurrence of distortion. [Means for solving the problem]
[0006] According to one embodiment, a solid-state imaging device includes a first substrate having a pixel array in which a plurality of pixels, which output analog signals by photoelectric conversion, are arranged in a two-dimensional array as columns along a first direction and rows along a second direction intersecting the first direction; and a second substrate stacked on the first substrate, the second substrate having an analog circuit arranged to overlap with the pixel array in a third direction intersecting the first and second directions and processing analog signals output from the pixels, wherein the pixel array is divided by a pixel division section along the second direction into a first region and a second region, each region having consecutive pixels, and the analog circuit is connected to the pixels belonging to the first region and the pixels belonging to the second region, and is divided into a first analog circuit and a second analog circuit adjacent to each other in the third direction via a circuit division section arranged to overlap with the pixel division section.
[0007] The pixel array may include a first signal line arranged along the first direction for selecting one or more rows in the first direction from among rows having pixels continuous in the second direction, and an analog signal output from the pixel selected by the first signal line may be processed by an analog circuit. The first signal line allows the designation of pixels on a row-by-row basis.
[0008] The pixel array may include a second signal line arranged along the second direction for selecting one or more columns in the second direction from among columns having pixels consecutive in the first direction, and the analog signal output from the pixel selected by the first signal line may be transmitted via the second signal line and processed by the analog circuit, and the second signal line may be electrically disconnected in the pixel division section. The second signal line maintains a conducting state for each region of the pixel array and is not connected to different regions, thereby shortening the path.
[0009] The pixel division section and the circuit division section may be disposed near the center of the pixel array in the first direction.
[0010] In the pixel division section and the circuit division section, a connection section that connects the pixels and the analog circuit in the third direction may be provided. In this manner, the pixel array may be cut near the center, and the first substrate and the second substrate may be connected around the cut portion.
[0011] The connection section may include a first connection section connected to the second signal line and connecting the pixels belonging to the first region and the first analog circuit via the second signal line, and a second connection section connected to the second signal line and connecting the pixels belonging to the second region and the second analog circuit via the second signal line. The analog circuit of the second substrate may also be divided in the same manner as the pixel array.
[0012] The second substrate may include a first switch that switches the connection state between the first connection portion and the second connection portion. By providing the first switch on the second substrate, it is possible to keep the potentials of the floating diffusions in the first and second regions equal in the pixel array.
[0013] The first switch may switch the connection state between the first connection section and the second connection section based on the timing at which the analog signal is output to the analog circuit via the first connection section or the second connection section.
[0014] the first connection portion, the second connection portion, and the first switch are provided in a plurality of positions along the second direction; The multiple first switches may operate in synchronization.
[0015] The first connection portion and the second connection portion may be provided in a plurality of portions along the second direction, and may include a second switch that switches a mutual connection state of the plurality of first connection portions and a third switch that switches a mutual connection state of the plurality of second connection portions. The second switch can keep the potential in the row direction equal.
[0016] Based on the timing at which an analog signal is output to an analog circuit via the first connection portion or the second connection portion, the second switch may switch the mutual connection state of the first connection portions, and the third switch may switch the mutual connection state of the second connection portions.
[0017] The second switch and the third switch may operate synchronously.
[0018] A plurality of the second switches and a plurality of the third switches may be provided along the second direction, and the plurality of second switches and the plurality of the third switches may operate in synchronization with each other.
[0019] The semiconductor device may further include a first voltage source that applies a predetermined voltage to the first connection parts connected via the second switch, and a fourth switch that switches the connection state between the first voltage source and the first connection parts, and the second switch and the fourth switch may operate in synchronization. By controlling in this manner, it is possible to raise the potential of the floating diffusion to a predetermined potential.
[0020] The pixel may further include a second voltage source that applies a predetermined voltage to the second connection parts connected via the third switch, and a fifth switch that switches the connection state between the second voltage source and the second connection parts, and the third switch and the fifth switch may operate in synchronization. Furthermore, all the switches may operate in synchronization. The synchronization may be performed based on the timing of resetting the pixel or the timing of outputting an analog signal from the pixel.
[0021] The first connection portions and the second connection portions may be provided in numbers at least equal to the number of pixels present in the row.
[0022] The first connection portion and the second connection portion may be provided in a number equal to at least the number of pixels in the row multiplied by a predetermined number. In this manner, by providing the connection portions, it becomes possible to transmit output signals from pixels in the same row in parallel to the second substrate.
[0023] The connections may be formed by microbumps, micropads or via holes.
[0024] The first analog circuit and the second analog circuit may process analog signals of different pixels belonging to one or more rows along the second direction at the same timing.
[0025] The first analog circuit and the second analog circuit may change the number of analog signals that are processed at the same timing according to a predetermined condition.
[0026] The second board may include logic circuitry for converting analog signals to digital signals and processing the digital signals.
[0027] The logic circuit may be disposed on either side of the analog circuit in the first direction.
[0028] The logic circuit may include a first logic circuit that processes a digital signal output by the first analog circuit, and a second logic circuit that processes a digital signal output by the second analog circuit.
[0029] The image display device may include a plurality of pixel division sections and circuit division sections, a pixel array region divided into a plurality of regions, and analog circuits corresponding to each of the regions.
[0030] The second substrate may include a signal processing circuit that performs signal processing of a digital signal, an image processing circuit that performs image processing of the digital signal, which is image information, a memory unit that stores any of the digital signal, the data output by the signal processing circuit, and the data output by the image processing circuit, a selector that arbitrarily selects at least one of the data output by the signal processing circuit, the data output by the image processing circuit, and the data stored in the memory unit, and an interface that outputs the data selected by the selector or an arbitrary signal to the outside or accepts input of data or a signal from the outside. [Brief description of the drawings]
[0031] [Figure 1] FIG. 1 is a block diagram of a solid-state imaging device according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing an arrangement of a pixel array and an analog circuit according to an embodiment. [Diagram 3] FIG. 2 is a diagram showing a stacked state of a pixel array and an analog circuit according to an embodiment. [Figure 4] FIG. 4 is a diagram showing an example of wiring in a pixel array according to an embodiment. [Diagram 5] FIG. 1 is a diagram showing an outline of an analog circuit according to an embodiment. [Figure 6] FIG. 11 is a diagram showing potentials relative to switch control on a second substrate according to an embodiment. [Figure 7] FIG. 13 is a diagram showing potentials relative to switch control of a second substrate according to a comparative example. [Figure 8] FIG. 2 is a diagram showing a stacked state of a pixel array and an analog circuit according to an embodiment. [Figure 9] FIG. 4 is a diagram showing an example of wiring in a pixel array according to an embodiment. [Figure 10] FIG. 4 is a diagram showing an example of wiring in a pixel array according to an embodiment. [Figure 11] FIG. 2 is a diagram showing an example of wiring in an analog circuit according to an embodiment. [Figure 12] FIG. 2 is a diagram showing an example of wiring in an analog circuit according to an embodiment. [Figure 13] FIG. 2 is a diagram showing an example of wiring in an analog circuit according to an embodiment. [Figure 14] FIG. 2 is a diagram showing an example of wiring in an analog circuit according to an embodiment. [Figure 15] FIG. 2 is a diagram showing an example of wiring in an analog circuit according to an embodiment. [Figure 16] FIG. 4 is a diagram illustrating an example of a connection portion according to an embodiment. [Figure 17] FIG. 4 is a diagram illustrating an example of a connection portion according to an embodiment. [Figure 18] FIG. 4 is a diagram illustrating an example of a connection portion according to an embodiment. [Figure 19] FIG. 4 is a diagram showing an example of the layout of circuits on a second substrate according to an embodiment. [Figure 20]FIG. 2 is a diagram showing a stacked state of a solid-state imaging device according to an embodiment. [Figure 21] FIG. 2 is a diagram showing a stacked state of a solid-state imaging device according to an embodiment. [Figure 22] FIG. 2 is a diagram showing voltage application in an analog circuit according to an embodiment. [Diagram 23] FIG. 1 is a block diagram of an example of an Indirect-Time of Flight sensor to which the present technology is applied. [Figure 24] 1 is a circuit diagram showing an example of a configuration of a pixel 10230 according to an embodiment of the present technology. [Diagram 25] 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; [Figure 26] 4 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] Hereinafter, solid-state imaging devices according to some embodiments will be described with reference to the drawings.
[0033] (First embodiment) 1 is a block diagram showing functions of a solid-state imaging device 1 according to an embodiment. The solid-state imaging device 1 includes, for example, a first substrate 10 and a second substrate 20. The first substrate 10 includes an optical system 12 and a pixel array 14. The second substrate 20 includes an analog circuit 22, a logic circuit 24, and an input / output interface (hereinafter, input / output I / F) 26.
[0034] The optical system 12 is a system that corrects the optical path, aberrations, etc. so that the pixel array 14 can sense light. The optical system 12 includes, for example, a lens (including a virtual lens, etc.), and is installed so that the pixel array 14 appropriately receives light.
[0035] The pixel array 14 includes a plurality of pixels that perform photoelectric conversion on received light and output analog signals. The analog signals output by the respective pixels belonging to the pixel array 14 are transmitted to the second substrate 20 via the connection portion 30.
[0036] The analog circuit 22 is a circuit that processes analog signals output from each pixel of the pixel array 14. The analog circuit 22 may include, for example, an ADC (Analog to Digital Converter) that converts the analog signal into image data, which is a digital signal. The analog circuit 22 outputs the digital image data converted from the analog signal to the logic circuit 24.
[0037] The analog circuit 22 may further include, for example, a DAC (Digital to Analog Converter) that generates a digital signal used in analog-to-digital conversion, a comparator that compares the voltage output from the DAC with the voltage of the analog signal, a counter that counts the output from the comparator, and an amplifier that amplifies the output from the counter.
[0038] The logic circuit 24 includes a circuit for processing the various acquired digital signals, and performs appropriate signal processing on the digital signals output by the analog circuit 22. The logic circuit 24 is, for example, a digital circuit, and may include a signal processing circuit and an image processing circuit. The signal processing circuit may include, for example, a circuit for performing motion detection, a circuit for performing neural network processing, etc. The image processing circuit may include, for example, a circuit for performing various filtering processes, transformation processes, etc.
[0039] The input / output I / F 26 is an interface that outputs the data output by the logic circuit 24 to the outside and also accepts input of data, requests, etc. from the outside as necessary. The solid-state imaging device 1 may further include a selector that selects the data output by the logic circuit 24, and the input / output I / F 26 may output a signal selected by the selector to the outside.
[0040] The connection unit 30 connects the first substrate 10 and the second substrate 20. In this embodiment, in particular, a connection is made for outputting an analog signal output from a pixel belonging to the pixel array 14 arranged on the first substrate 10 to an analog circuit 22 arranged on the second substrate 20.
[0041] The above describes the configuration of the paths for the propagation of analog signals and digital signals according to this embodiment. For this reason, configurations necessary for other control are omitted. The first substrate 10 is appropriately provided with wiring, etc., for example, for accepting an output from which pixel of the pixel array 14. In addition, the second substrate 20 is appropriately provided with a control circuit, etc., for controlling each component of the solid-state imaging device 1. Furthermore, in addition to the above-mentioned connection section 30, the connection between the first substrate 10 and the second substrate 20 may be provided with a separate connection path for outputting a signal to wiring, for example, for selecting which pixel of the pixels belonging to the pixel array 14.
[0042] In this way, elements, wiring, and the like for achieving the functions and effects of the solid-state imaging device 1 are appropriately provided, although not shown.
[0043] FIG. 2 is a diagram showing an example of the arrangement of the pixel array 14 and the analog circuit 22 according to the present embodiment.
[0044] In the first substrate 10, the pixel array 14 includes a plurality of pixels 140 arranged in a two-dimensional array. The pixels 140 are arranged in an array along the first direction and the second direction. Each pixel 140 includes a light receiving element such as a photodiode (PD) that receives light through a lens as the optical system 12 and outputs an analog signal based on the intensity of the received light. In the description, pixels that are continuous in the second direction may be called a row, and pixels that are continuous in the first direction may be called a column. That is, an array is formed by providing a plurality of rows that are pixels that are continuous in the second direction in the first direction, in other words, an array is formed by providing a plurality of columns that are pixels that are continuous in the first direction in the second direction.
[0045] The pixel array 14 includes a first region 141 and a second region 142. The first region 141 and the second region 142 are divided by a pixel dividing section 143. The pixel dividing section 143 is provided, for example, near the center of the pixel array 14 in the first direction so as to cross the pixel array 14 along the second direction.
[0046] For example, in the case where n pixels 140 are provided along the first direction in the pixel array 14, the vicinity of the center is provided between the [n / 2]th pixel and the [n / 2]+1th pixel. [·] is a floor function. Note that this is not limited to this, and the pixel may not be exactly in the center, but may be significantly or insignificantly biased toward either the top or bottom side of the pixel array 14 in FIG. 2, but in this specification, the vicinity of the center is described in a broad sense.
[0047] In the second substrate 20, the analog circuit 22 is provided, for example, near the center of the area in which the pixel array 14 exists in a stacked state. The dashed line indicates the area in which the pixel array 14 is provided on the first substrate 10 in a stacked state. Second Board 20. The analog circuit 22 is thus provided so as to include the vicinity of the center of the range in which the pixel array 14 is provided.
[0048] The analog circuit 22 includes a first analog circuit 221 and a second analog circuit 222, and these circuits are disposed adjacent to each other via a circuit division section 223. For example, the circuit division section 223 is disposed so as to overlap with the pixel division section 143 in the third direction in a state in which the first substrate 10 and the second substrate 20 are stacked. The arrangement of the circuit division section 223 does not need to overlap with the pixel division section 143 strictly, and may have a deviation.
[0049] The first analog circuit 221 and the second analog circuit 222 each operate as an analog circuit. For example, the first analog circuit 221 and the second analog circuit 222 each operate as an ADC, convert an analog signal output from the pixel 140 into a digital signal, and output the digital signal.
[0050] The pixel array 14 and the analog circuit 22 are connected via a connection portion 30 that connects the first substrate 10 and the second substrate 20, for example, in the periphery of the pixel division portion 143 and the circuit division portion 223.
[0051] Here, the periphery refers to, for example, between two pixels 140 that are immediately adjacent in the first direction of the pixel division section 143 and the pixel division section 143. Note that this is not limited to this, and for example, instead of being between the pixels 140 and the pixel division section 143, the connection section 30 may be disposed so as to overlap directly below one or more pixels 140 near the center.
[0052] Fig. 3 is a diagram illustrating the positions of the pixel array 14 and the analog circuit 22 when the first substrate 10 and the second substrate 20 are stacked. As shown in Fig. 3, the pixel array 14 and the analog circuit 22 are stacked such that the pixel division section 143 and the circuit division section 223 overlap in the third direction near the center of the pixel array 14.
[0053] The connection unit 30 is disposed between the pixel array 14 and the analog circuit 22 along the third direction so as to connect the periphery of the pixel division unit 143 and the periphery of the circuit division unit 223. The first analog circuit 221 and the second analog circuit 222 receive analog signals from the pixels 140 connected by the connection unit 30 and perform appropriate processing. As described later, for example, digital circuits (logic circuits) are provided so as to sandwich the outside of the first analog circuit 221 and the second analog circuit 222 in the first direction.
[0054] Next, the connection between the pixel array 14 and the analog circuit 22 will be described in detail.
[0055] Fig. 4 is a diagram showing an example of wiring in the pixel array 14 according to the present embodiment. Analog signals output by the pixels 140 are transmitted to the analog circuit 22 via the wiring in Fig. 4. Note that in Fig. 4, the pixel division unit 143 is depicted with a wider gap between the pixels above and below than between the other pixels, but this is for the sake of explanation, and in reality, the gap may be the same as between the other pixels.
[0056] In the first substrate 10, the pixel array 14 includes a plurality of first signal lines 16 and a plurality of second signal lines 181 and 182. The second signal lines 181 and 182 associated with the same column are electrically disconnected in the periphery of the pixel division section 143. That is, in the first region 141 A second signal line 181 connected to the pixel 140 belonging to the second region 142 The second signal lines 182 connected to the pixels 140 belonging to are not directly and electrically connected to the first substrate 10.
[0057] Furthermore, in the periphery of the pixel division section 143, a plurality of first connection sections 301 and second connection sections 302 are provided as the connection section 30, and the pixels 140 are connected to the analog circuit 22 of the second substrate 20 via the second signal lines 181 and 182 and these connection sections. More specifically, the pixels 140 belonging to the first region 141 are connected to the analog circuit 22 via the second signal lines 181 and the first connection sections 301, and the pixels 140 belonging to the second region 142 are connected to the analog circuit 22 via the second signal lines 182 and the second connection sections 302.
[0058] The first signal line 16 is a wiring that selects which row of the pixel array 14 in which an analog signal output from the pixel 140 is to be processed. The first signal line 16 is connected to a row selection circuit at the end opposite to the end connected to the pixel 140, for example, and a signal from this row selection circuit is used to transmit the signal to the analog circuit. 22 Selects lines to be output to
[0059] The pixel 140 in a row unit selected by the first signal line 16 is transmitted to the first connection unit 301 or the second connection unit 302 via the corresponding second signal line 181, 182. Then, the first connection unit 301 or the second connection unit 302 outputs the analog signal output from the pixel 140 to the analog circuit 22, where processing of the analog signal is performed.
[0060] In the pixel array 14, the processing of the analog signals output from the pixels 140 is performed, for example, in order from the bottom row in FIG. 4. For example, processing is performed first on the pixels 140 belonging to the bottom row in FIG. 4. The analog signals output from the respective pixels 140 are subjected to signal processing in parallel in the analog circuit 22. Next, similar processing is performed on the row above, i.e., the second row from the bottom. This processing is performed, for example, by the row selection circuit selecting the rows in order from the bottom by a row-direction synchronization signal.
[0061] The same is true for the two rows that straddle the pixel division unit 143. When the processing of the row immediately below the pixel division unit 143 in FIG. 4 is completed, 143 The process for the line immediately above is executed. In this case, 1 The pixels 140 belonging to the region 141 transmit signals to the analog circuit 22 via the second signal line 181 and the first connection unit 301, whereas the pixels 140 belonging to the second region 142 transmit signals to the analog circuit 22 via the second signal line 182 and the second connection unit 302. Thereafter, scanning is sequentially performed from the lower side to the upper side of the second region 142 based on the row-direction synchronization signal.
[0062] The row selection is performed, for example, by applying a selection signal based on a synchronization signal to the first signal line 16 corresponding to the row selected by the row selection circuit. This selection signal controls the energization state of the signal output unit of the pixel 140 belonging to the selected row and the second signal lines 181 and 182, thereby outputting an analog signal to the analog circuit 22. The control of the energization state is performed, for example, by a MOSFET (Metal-Oxide-Semiconductor Field-Effect-Transistor) having a gate connected to the first signal line 16 and a drain and a source (or a source and a drain) connected to the pixel 140 and the second signal lines 181 and 182, respectively. This is not limited to this, and the energization state may be formed by a switch or the like driven by a signal via the first signal line 16 by other methods.
[0063] As described above, by dividing the area of the pixel array 14 provided on the first substrate 10 near the center and arranging the analog circuit 22 near the center so as to overlap on the stacked second substrate 20, it is possible to shorten the transmission path of the signal output from the pixel 140 in the second signal lines 181, 182. By shortening the transmission path, it is possible to reduce the load on the second signal lines 181, 182. As a result, it is possible to realize low power and high speed analog signal processing in the solid-state imaging device 1. By this high speed and by processing rows continuously across the entire pixel array 14, it is also possible to suppress rolling shutter distortion.
[0064] Second embodiment In addition to the above-described embodiment, by providing a switch on the second substrate 20, it is possible to further improve the accuracy of analog signal processing.
[0065] Fig. 5 is a diagram showing a schematic diagram of the connection around the circuit division part of the analog circuit 22 according to the present embodiment. Note that the aspect ratio of Fig. 5 is adjusted for the purpose of explanation, but the approximate stacking relationship and approximate size relationship with the pixel array 14 in Fig. 4 are as shown in Fig. 3.
[0066] As described above, the analog circuit 22 includes a first analog circuit 221 and a second analog circuit 222, with the circuit division section 220 sandwiched therebetween.
[0067] In the first analog circuit 221, for example, a wiring is arranged to connect the first connection section 301 from the first substrate 10. In the second analog circuit 222, for example, a wiring is arranged to connect the second connection section 302 from the first substrate 10. As shown in the figure, each connection section is 221 Then, for example, the second analog circuit 222 processes the analog signal that is connected and transmitted via a multiplexer (or an analog switch). The analog circuit 22 may include a comparison circuit and a counter circuit (not shown) before the multiplexer, and may output a digital signal converted based on the output from the DAC to the multiplexer or the like.
[0068] Between the first connection portion 301 and the second connection portion 302, the second substrate 20 is provided with a first switch 281.
[0069] The multiple first connection parts 301 are connected along the second direction, and a second switch 282 is provided between each of the first connection parts 301. The multiple second connection parts 302 are connected along the second direction, and a third switch 283 is provided between each of the second connection parts 302.
[0070] The first connection parts 301 are connected to a voltage source via a fourth switch 284 at one end of a wiring that connects them to each other via the second switch 282, for example. The second connection parts 302 are connected to a voltage source via a fifth switch 285 at one end of a wiring that connects them to each other via the third switch 283, for example. These voltage sources may be constant voltage sources. Furthermore, the voltages applied by these voltage sources may be the same voltage.
[0071] The first switches 281, which are present, switch the energization state between the corresponding first connection parts 301 and second connection parts 302 in synchronization with each other. That is, at a predetermined timing, the first connection part 301 is connected to the second connection part 302, which is connected to the second signal line 181 to which it is connected and the second signal line 182 belonging to the same column in the pixel array 14. Since this connection is performed synchronously, the second signal line 181 and the second signal line 182 belonging to the same column in the plurality of columns are connected on the second substrate 20 at the same timing. Therefore, at a predetermined timing, the potentials of the first connection part 301 and the second connection part 302 are controlled to be the same potential, and this potential is output to the first analog circuit 221 and the second analog circuit 222. This control makes it possible to align the potentials of the analog circuit 22 that processes the pixels in the same column.
[0072] The second switch 282 synchronously switches the energization state between the first connection units 301. The third switch 283 synchronously switches the energization state between the second connection units 302. Furthermore, the second switch 282 and the third switch 283 switch the energization state in synchronization. That is, the multiple first connection units 301 and the multiple second connection units 302 are connected to each other at a predetermined timing and controlled to the same potential. This control makes it possible to align the potential of the floating diffusion of the pixel 140.
[0073] Furthermore, the fourth switch 284 and the fifth switch 285 may be controlled in synchronization with the second switch 282 and the third switch 283. By controlling in this manner, it becomes possible to increase the potential of the floating diffusion of the pixel 140 to a predetermined potential at a predetermined timing.
[0074] Furthermore, the first switch 281, the second switch 282, the third switch 283, the fourth switch 284, and the fifth switch 285 may be switched in synchronization. For example, an analog signal is received from the pixel 140, and these switches are synchronously energized from the reset period in which processing of the analog signal is completed to the next transfer period. By processing in this manner, it is possible to raise the potential of the floating diffusion of the pixel 140 to a predetermined potential, and further to align the potentials of the first analog circuit 221 and the second analog circuit 222.
[0075] 6 shows an example of a timing chart of the potentials of the first analog circuit 221 and the second analog circuit 222 when controlled by the switches provided on the second substrate 20 described above. The top is a row synchronization signal output from the row selection circuit. Based on this row synchronization signal, analog signals of the pixels 140 belonging to one row are processed in parallel. The dotted line indicates a reset signal, and at this timing, for example, the charge in the circuit is reset. At the timing indicated by the dashed line, a row is crossed where processing is switched from the first analog circuit 221 to the second analog circuit 222.
[0076] The second chart from the top is an example of switch switching. The switches are turned on / off based on this synchronization signal. As described above, in synchronization with this synchronization signal, for example, the states of all the switches may be switched, or only the first switch 281, only the combination of the second switch 282 and the third switch 283, or only the combination of the second switch 282, the third switch 283, the fourth switch 284, and the fifth switch 285 may be switched.
[0077] In this embodiment, for example, the synchronization signal is issued at the timing of the end of row scanning. This is shown as an example, and is not limited to this. For example, the synchronization signal may be issued between the reset signal and the row synchronization signal. This timing may be described by a register or the like provided in the solid-state imaging device 1. Similarly, the synchronization signal, i.e., the period during which the switch is turned on, may also be set arbitrarily within a range in which signal processing is appropriately performed.
[0078] The third and fourth charts from the top are charts showing the transition of potential in a standby state. The fifth and sixth charts from the top are charts showing the transition of potential in a state in which an analog signal is received. These transitions of potential indicate, for example, changes in the signals of the first connection part 301 and the second connection part 302.
[0079] In the chart showing the state of the potential, a solid line indicates an actual potential that is connected, and a dotted line indicates that it is open and the state of the potential is unknown.
[0080] On the other hand, Fig. 7 shows a comparative example in which no switch control is performed, that is, all the switches are turned off. The operation of the switches will be explained using Figs. 6 and 7.
[0081] In the absence of the first switch 281, the first analog circuit 221 and the second analog circuit 222 continuously process the first region 141 and the second region 142. In this case, as shown by the arrow in FIG. 7, at the timing of processing the pixels 140 belonging to a row that straddles the pixel division unit 143, the second analog circuit 222 has been in a floating state for a long time, and therefore the potential is unknown. Since signal processing is performed from this unknown potential, there is a possibility that a discontinuous signal is generated. This discontinuity in the signal occurs not only in the standby state but also at the timing of signal processing.
[0082] On the other hand, when the first switch 281 is turned on in synchronization with the end of a row by a synchronization signal, it becomes possible to execute circuit switching at a timing when the potential difference between the first analog circuit 221 and the second analog circuit 222 is eliminated. This switching makes it possible to process the analog signal from the pixel 140 while maintaining the continuity of the signal potential, as shown by the arrow in Fig. 6. As a result, it becomes possible to suppress the introduction of noise due to discontinuity, excessive transient response, or a potential being measured as being lower than the actual potential.
[0083] By switching the second switch 282 and the third switch 283 in synchronization, it is possible to shorten the floating period in which the potential is in an unknown state as shown by the dotted line in Fig. 7. For example, in Fig. 7, at the timing of switching the regions, processing starts from a floating state in which the potential is unknown. As shown in Fig. 6, by dividing the floating period into small segments, it is possible to acquire a stable analog signal from the pixel 140.
[0084] Furthermore, it is possible to control the floating potential to a predetermined value by synchronizing the fourth switch 284 and the fifth switch 285. As a result, it is possible to obtain even more stable measurement results.
[0085] As described above, continuity is ensured by the first switch 281, and the potential of the floating diffusion can be stabilized by the second switch 282, the third switch 283, the fourth switch 284, and the fifth switch 285, making it possible to execute highly accurate processing even when the analog circuit 22 is divided.
[0086] As described above, only the first switch 281 may be switched, or only the second switch 282 to the fifth switch 285 may be switched. Furthermore, all of the first switch 281 to the fifth switch 285 may be switched in synchronization. As another example, the second switch 282 to the fifth switch 285 may be turned on, and the first switch 281 may be turned on at a later timing.
[0087] The control may be performed as follows.
[0088] For example, the third switch 283 connecting the second connection units 302 may be constantly connected when the analog signal of the pixel 140 belonging to the first region 141 is being processed. By maintaining the connection state in this manner, it is possible to maintain the floating state in each column equally until the pixel 140 to be processed transitions from the first region 141 to the second region 142.
[0089] Furthermore, the fifth switch 285 may be kept in a connected state. By keeping the third switch 283 and the fifth switch 285 in a connected state in this manner, it becomes possible to maintain the floating state in each column at a predetermined potential.
[0090] Similarly, when the analog signals of the pixels 140 belonging to the second region 142 are being processed, the second switch 282 may be constantly connected, or the second switch 282 and the fourth switch 284 may be constantly connected.
[0091] Third embodiment In the embodiment described above, the pixel array 14, the analog circuit 22, and the logic circuit 24 may be divided into more regions.
[0092] 8 is a diagram showing a stacked state of the pixel array 14 and the analog circuit 22 according to the present embodiment. The pixel array 14 is provided with three pixel division sections 143A, 143B, and 143C, and the corresponding second substrate 20 is provided with at least circuit division sections 223A and 223B, and further with a circuit division section 223C. Note that the circuit division section 223C is not an essential component.
[0093] The pixel array 14 is roughly divided into two regions by the pixel dividing section 143C. These regions are divided into a first region 141A and a second region 142A by the pixel dividing section 143A, and into a first region 141B and a second region 142B by the pixel dividing section 143B. In this way, the pixel array 14 is divided into, for example, four regions.
[0094] As in the above-described embodiment, one first signal line is arranged for pixels 140 that are consecutive in the second direction, i.e., pixels that belong to the same row. In contrast, the second signal lines connected to the pixels 140 that are consecutive in the first direction and belong to each of the regions 141A, 142A, 141B, and 142B are disconnected in each region as in the above-described embodiment, and are output to the analog circuit 22 via each connection portion. That is, in the example of FIG. 8, four second signal lines are provided in each column.
[0095] 9 is a diagram showing an outline of the pixel array 14 according to this embodiment. The pixel array 14 is divided into regions 141A, 142A, 141B, and 142B by pixel division units 143A, 143B, and 143C. In each divided region, a selection is made as to whether or not to output from the pixels 140 belonging to the same row. First signal line16 are provided for each row of pixels 140. As in Fig. 4, the spacing between pixels is wider at the locations across the pixel division section, but this is for the sake of explanation, and in reality, the spacing may be the same as the spacing between other pixels.
[0096] On the other hand, the second signal lines are provided so that outputs from the pixels 140 belonging to the same column are connected for each region, and are disconnected between different regions. For example, the second signal lines 181A arranged in the region 141A connect the pixels 140 belonging to the respective columns. On the other hand, the second signal lines are provided so as not to be electrically connected to the second signal lines 182A, 181B, and 182B in the other regions 142A, 141B, and 142B.
[0097] Each signal line is connected to the second substrate 20 by a connection portion. For example, each second signal line 181A in the first region 141A is connected to the analog circuit 22A via the first connection portion 301A. The same is true for the others, and the second signal line 182A in the second region 142A is connected to the analog circuit 22A via the second connection portion 302A. Also, in the upper side of the figure, as in the lower side, the second signal line 181B in the first region 141B is connected to the analog circuit 22B via the first connection portion 301B, and the second signal line 182B in the second region 142B is connected to the analog circuit 22B via the second connection portion 302B.
[0098] The pixel array 14 may be divided into a plurality of regions in this manner by a plurality of pixel division units 143. As shown in Fig. 9, second signal lines and connection units are provided independently in each region, and are connected to the analog circuit 22 of the second substrate 20, respectively.
[0099] Returning to Fig. 8, the second substrate 20 will be described. Analog circuits are provided in the regions where the connection sections 30 are provided in Fig. 9. For example, the second substrate 20 includes an analog circuit 22A and an analog circuit 22B.
[0100] As in the embodiment described above, each analog circuit 22 has circuit division sections 223A and 223B so as to overlap pixel division sections 143A and 143B in the third direction when stacked. The circuit division section 223A divides the analog circuit 22A into a first analog circuit 221A and a second analog circuit 222A, and the circuit division section 223B divides the analog circuit 22B into a first analog circuit 221B and a second analog circuit 222B. The configuration of each circuit is the same as that in FIG. 5, so details will be omitted.
[0101] The logic circuit may be provided, for example, below the first analog circuit 221A, between the second analog circuit 222A and the first analog circuit 221B, or above the second analog circuit 222B in the figure.
[0102] As described above, it is possible to increase the number of divisions of the pixel array 14. By increasing the number of divisions in this manner, it is possible to further reduce the load on the second signal line, thereby making it possible to achieve even higher speeds and lower power consumption.
[0103] (Fourth embodiment) In the above-described embodiments, one second signal line is provided for each column, but this is not limited thereto. For example, a plurality of second signal lines may be provided for the pixels 140 belonging to one column. Each of the plurality of second signal lines may be provided with a connection portion.
[0104] 10 is a diagram showing a pixel array, a second signal line, and a connection part according to the present embodiment. In this diagram, the pixels, the wiring, the connection part, and the like are all drawn on a plane, but this is not limited to this. For example, the pixels may be on the upper surface, the wiring may be provided below the pixels in the third direction, and the wiring and the connection part may be connected within the first substrate 10.
[0105] The pixel array 14 includes a plurality of pixels 140. A plurality of second signal lines 181, 182 are provided so that outputs of the pixels 140 belonging to the same column are connected to each other. Unlike the above-described embodiment, a plurality of second signal lines 181, 182 are provided between each column. For the sake of explanation, the first signal lines are not shown, but are provided in the same manner as in FIG. 4 and the like.
[0106] For example, twelve second signal lines 181, 182 may be provided between each pair of columns of pixels 140. In this case, analog signals output from twelve or fewer pixels 140 along the first direction may be output in parallel to the analog circuit 22 of the second substrate 20. That is, analog signal processing can be performed in parallel at the same timing for pixels 140 belonging to twelve or fewer rows.
[0107] A first signal line (not shown) specifies these 12 or less rows at the same time. In the figure, the points where the wiring connected from the pixel 140 and the second signal line are indicated by black dots are the points where they are electrically connected, and the points without black dots are the points where they are not electrically connected. For example, by providing switches at the points where the wiring from the pixel 140 and the second signal line intersect, and by the first signal line appropriately switching the states of these switches, it becomes possible to select the pixel 140 that processes the analog signal.
[0108] 11 is a diagram showing, as an example, wiring of an analog circuit having 12 pairs of second signal lines and 12 pairs of connection parts. The left diagram shows signal distribution at the timing of processing analog signals of pixels 140 belonging to a first region 141, and the right diagram shows signal distribution at the timing of processing analog signals of pixels 140 belonging to a second region 142.
[0109] In the left diagram, the first connection portion 301 is indicated by a solid line, and the second connection portion 302 is indicated by a dotted line. In this manner, 12 pairs of connection portions are provided in each row from the first substrate 10 to the second substrate 20. The left 6 pairs of connection portions transmit signals to be processed in the first analog circuit 221, and the right 6 pairs of connection portions transmit signals to be processed in the second analog circuit 222. Although not shown, a first switch 281, a second switch 282, and a third switch 283 may be provided between the respective connection portions. In addition, a fourth switch 284, a fifth switch 285, and a voltage source may be provided.
[0110] At the timing when the pixel 140 belonging to the first region 141 is the target of processing, as shown in the left diagram, the analog signal output from the first connection unit 301 is appropriately divided and output to the first analog circuit 221 and the second analog circuit 222. Then, the analog signal processing is performed in parallel in each analog circuit. In this way, it is possible to output signals from multiple pixels 140 to multiple analog circuits via short paths.
[0111] When the pixel 140 that performs signal processing transitions from belonging to the first region 141 to belonging to the second region 142, that is, when the selection of the first signal line by the row selection circuit exceeds the pixel division unit 143, the transition occurs as shown in the right diagram. When the transition occurs, the second connection unit 302 is distributed and connected to the first analog circuit 221 and the second analog circuit 222, and signals from the multiple pixels 140 can be appropriately processed in parallel in the same manner as described above.
[0112] As described above, according to this embodiment, it is possible to appropriately process analog signals output from pixels 140 across multiple rows in parallel. Even in the case of processing in this manner, by arranging the analog circuit 22 as in the above-described embodiment and appropriately arranging the signal lines, it is possible to reduce the load on the second signal line and thereby realize high-speed analog signal processing and low power consumption.
[0113] 12 to 15 show various processing methods for wiring that can process 12 signals per column in parallel, for example, as described above. Solid lines indicate wiring and connections that are used, and dotted lines indicate wiring and connections that are not used at that timing. In this way, instead of processing 12 rows of pixels 140 in one column in parallel, it is possible to switch between them based on settings such as the image to be acquired or low power mode.
[0114] 12 is a diagram showing an example in which, for example, eight rows of pixels 140 per column are processed in parallel. For example, in every six pairs of first connection parts 301 and second connection parts 302, wiring may be formed using the connection parts in the center. In this case, of the twelve second signal lines in FIG. 10, the two second signal lines at both ends and the center are not used. By coordinating the wiring of the first substrate 10 and the second substrate 20 in this way, it is possible to process eight rows of pixels 140 per column in parallel.
[0115] 13 is a diagram showing an example in which, for example, four rows of pixels 140 for one column are processed in parallel. In this way, four pixels may be processed in parallel using four connection parts and four wirings.
[0116] 14 is a diagram showing an example in which two rows of pixels 140 in one column are processed in parallel. In this way, two pixels may be processed in parallel using two connection parts and two wirings.
[0117] In the case of four pixels or two pixels, it is possible to achieve further reduction in power consumption by not using the second analog circuit 222. Fig. 15 is a diagram showing a case where two rows are processed for one column without using the second analog circuit 222. In this way, it is also possible to process signals in parallel using only the first analog circuit 221 without using the second analog circuit 222. In this case, for example, the control of the third switch 283 and the fifth switch 285 may also be omitted, or the first switch 281 may be omitted while providing time for sufficiently charging the floating potential.
[0118] In this way, it is possible to switch wiring appropriately depending on the situation. The situation may represent a predetermined condition. For example, when shooting high-speed video, it is acceptable to increase power consumption, so high-speed processing is performed using the configuration in FIG. 11. On the other hand, when shooting still images of stationary objects, wiring is performed so as to consume less power, as shown in FIG. 15.
[0119] In this embodiment, the case where there is one pixel division section and one circuit division section has been described, but this is not limited thereto. That is, even if there are multiple second signal lines between each pixel as in this embodiment, the pixel array 14 and the analog circuit 22 may be divided into more fine parts. Also, the number of wirings for one column does not have to be 12, and may be 11 or less, or 13 or more.
[0120] (Example of connection part implementation) The chip structure of the solid-state imaging device 1 in Fig. 1 will be described. As described above, the solid-state imaging device 1 is a laminate in which a first substrate 10 and a second substrate 20 are laminated. The first substrate 10 and the second substrate 20 are sometimes called dies. For example, in Fig. 2, the first substrate 10 and the second substrate 20 are rectangular, but the specific shapes and sizes are arbitrary. In addition, the first substrate 10 and the second substrate 20 may be the same size or different sizes.
[0121] 4 and the like is disposed on the first substrate 10. Furthermore, at least a part of the optical system 12 may be implemented on-chip on the first substrate 10.
[0122] The second substrate 20 is provided with at least an analog circuit 22, a logic circuit 24, and an input / output I / F 26, and may also be provided with other necessary circuits. For example, a clock generation circuit that outputs a clock signal that determines the timing of the row selection signal, synchronization signal, etc. described above may also be provided. Also, a control circuit that performs comprehensive or partial control of each circuit may be provided.
[0123] As a specific form of bonding the first substrate 10 and the second substrate 20, a so-called CoC (Chip on Chip) method may be adopted in which the first substrate 10 and the second substrate 20 are cut out from a wafer and diced, and then stacked and bonded together. Alternatively, a so-called CoW (Chip on Wafer) method may be adopted in which one of the first substrate 10 and the second substrate 20 (for example, the first substrate 10) is cut out from a wafer and diced, and then the diced first substrate 10 is bonded to the second substrate 20 before dicing. Alternatively, a so-called WoW (Wafer on Wafer) method may be adopted in which the first substrate 10 and the second substrate 20 are bonded together in the wafer state.
[0124] Various bonding methods may be used to bond the first substrate 10 and the second substrate 20. For example, plasma bonding or the like may be used.
[0125] In joining the first substrate 10 and the second substrate 20, the connection part electrically connecting the first substrate 10 and the second substrate 20 may be a joint as shown in the following figure. Note that the detailed circuit state is not shown, and only the connection part is shown. For this reason, the illustration of various circuit elements is omitted in the figure. Also, the second signal line 181 is described, but the same applies to the second signal lines 182, ..., etc.
[0126] 16 is a diagram showing an example of a connection part. In the following diagram, for example, the analog circuit 22 and the second signal line 181 are shown connected in the region where the second signal line 181 exists. The pixels 140 that receive the light collected by the optical system 12 are connected by the second signal line 181. The second signal line 181 is connected to the connection part 30 formed with, for example, microbumps, and connected to the analog circuit 22. For example, micropads are formed on both the pixel 140 side and the analog circuit 22 side, and these micropads are connected to each other by microbumps.
[0127] Fig. 17 is a diagram showing another example of the connection part. The connection part 30 may be connected by a micropad as shown in the figure, for example. The first substrate 10 and the second substrate 20 may be connected directly by the micropad without using the microbumps in Fig. 16.
[0128] 18 is a diagram showing another example of the connection unit 30. The connection unit 30 may be, for example, a via hole that is in contact with the second signal line 181 and the analog circuit 22, thereby connecting the pixel 140 and the analog circuit 22.
[0129] Furthermore, the first substrate 10 and the second substrate 20 are connected via the connection section 30 with respect to the pixels 140, but may further include connection lines for transmitting and receiving other signals as necessary.
[0130] (Example of mounting the second board) Next, a description will be given of an example of mounting the second substrate 20. Fig. 19 shows an example of mounting the second substrate 20. The region indicated by the dashed line on the second substrate 20 is the region on the first substrate 10 where the pixel array 14 exists.
[0131] For example, on the second substrate 20, the first analog circuit 221 and the second analog circuit 222 are arranged to sandwich the circuit division section 223 overlapping in the third direction of the pixel division section. A DAC 23 may be provided adjacent to these analog circuits. For example, a logic circuit 24 is provided to sandwich the analog circuit 22. The logic circuit 24 may include, for example, a first logic circuit adjacent to the first analog circuit 221 and a second logic circuit adjacent to the second analog circuit 222. In this case, the first logic circuit may process a signal output from the first analog circuit 221, and the second logic circuit may process a signal output from the second analog circuit 222.
[0132] Also, if necessary, a CPU (Central Processing Unit) serving as a control unit may be provided. A memory 25 is provided as a storage unit. The second substrate 20 is thus configured separately from the pixels 140, but is provided with circuits required for the solid-state imaging device 1. Although not shown, a selector, an input / output I / F 26, etc. are also provided.
[0133] 20 is a diagram showing an example of a solid-state imaging device 1 formed in two layers. The first substrate 10 includes an optical system and a pixel array 14 having pixels 140 in a two-dimensional array. The first substrate 10 further includes wiring, such as a first signal line and a second signal line, that is necessary for extracting pixel information.
[0134] The second substrate 20 includes various switches for switching the connection states of the connection parts for connection to the first substrate 10, an analog circuit 22, a logic circuit 24, a memory 25, and an input / output I / F 26. In addition, circuits necessary for controlling the solid-state imaging device 1 are also included.
[0135] Fig. 21 is a diagram showing an example of a solid-state imaging device 1 formed of three layers. The elements of the first substrate 10 and the second substrate 20 are almost the same as those in Fig. 19. However, the second substrate 20 does not include a memory, and the third substrate 40 includes a memory. In Fig. 20, the third substrate 40 is below the second substrate 20, but this is not limiting. That is, the third substrate 40 may be provided between the first substrate 10 and the second substrate 20.
[0136] When the solid-state imaging device 1 has three layers, the connections between the layers are similar to those in the above-described embodiment, and the layers are connected, for example, by the connection methods shown in FIGS.
[0137] 22 is a diagram showing an example of a power supply arrangement for the analog circuit 22 on the second substrate 20. In the figure, for ease of viewing, the power supply is drawn only for the portion corresponding to the first analog circuit 221, but the power supply is similarly arranged on the second analog circuit 222 side.
[0138] In the figure, for example, the diagonal hatched area slanting leftwards is wiring that applies the power supply voltage, and the diagonal hatched area slanting rightwards is wiring that is connected to the ground voltage. In this way, the first analog circuit 221 is provided with wiring for the power supply voltage and wiring for the ground voltage at equal intervals. This power supply is shown on the surface for ease of understanding, but it is not on the surface, but is embedded, for example, under each circuit in the second substrate 20.
[0139] By arranging the analog circuit 22 in the center, the power supply wiring on the chip of the second substrate 20 becomes longer. As a result, the power supply voltage observed at the end of the analog circuit 22 is suppressed by the amount of the resistance of the wiring and the current consumed. In such a case, if the power supply wiring is unevenly arranged, the shading characteristics in the second direction will further deteriorate. To avoid this, the power supply wiring is arranged evenly along the second direction, realizing equalization of the power supply in the horizontal direction. As a result, it is possible to reduce shading in the second direction.
[0140] Although all the embodiments have been described using the example of a CMOS sensor, the present invention is not limited to this. The present invention can also be applied to a CCD (Charge Coupled Device) or other types of light receiving device. For example, in the case of a CCD, the charges of the selected rows are propagated in sequence through vias, and the charges are processed by an analog circuit, thereby achieving the same action and effect.
[0141] The present disclosure can be utilized in indirect ToF sensors.
[0142] FIG. 23 shows a block diagram of an example of an Indirect-Time of Flight sensor to which this technology is applied.
[0143] [Example of Indirect-Time of Flight sensor configuration] 23 shows a block diagram of an example of an Indirect-Time of Flight sensor 10000 to which an embodiment of the present technology is applied. The Indirect-Time of Flight sensor 10000 includes a sensor chip 10001 and a circuit chip 10002 stacked on the sensor chip 10001.
[0144] The pixel area 10020 includes a plurality of pixels arranged in an array in a two-dimensional grid pattern on the sensor chip. The pixel area 10020 may be arranged in a matrix and may include a plurality of column signal lines. Each column signal line is connected to each pixel. Furthermore, a vertical drive circuit 10010, a column signal processing circuit 10040, a timing adjustment circuit 10050, and an output circuit 10060 are arranged on the circuit chip 10002.
[0145] The vertical drive circuit 10010 is configured to drive pixels and output pixel signals to a column signal processing circuit 10040. The column signal processing circuit 10040 performs analog-to-digital (AD) conversion processing on the pixel signals and outputs the AD converted pixel signals to an output circuit. The output circuit 10060 performs CDS (Correlated Double Sampling) processing and the like on the data from the column signal processing circuit 10040 and outputs the data to a downstream signal processing circuit 10120.
[0146] The timing control circuit 10050 is configured to control the drive timing of each of the vertical drive circuits 10010. The column signal processing section and the output circuit 10060 are synchronized with the vertical sync signal.
[0147] A pixel area 10020 has a plurality of pixels arranged in a two-dimensional grid pattern, and each pixel is configured to receive infrared light and perform photoelectric conversion to a pixel signal.
[0148] Furthermore, vertical signal lines VSL1 and VSL2 are wired in the vertical direction for each column of pixels 10230. If the total number of columns in the pixel region 10020 is M (M is an integer), then a total of 2×M vertical signal lines are wired. Each pixel has two taps. The vertical signal line VSL1 is connected to tap A of the pixel 10230, and the vertical signal line VSL2 is connected to tap B of the pixel 10230. Furthermore, the vertical signal line VSL1 transmits a pixel signal AINP1, and the vertical signal line VSL2 transmits a pixel signal AINP2.
[0149] The vertical drive circuit 210 sequentially selects and drives rows of the pixel blocks 221, and simultaneously outputs pixel signals AINP1 and AINP2 for each pixel block 221 in that row. In other words, the vertical drive circuit 210 simultaneously drives the 2kth row and the 2k+1th row of the pixels 230. The vertical drive circuit 210 is an example of a drive circuit as defined in the claims.
[0150] 24 is a circuit diagram showing a configuration example of a pixel 10230 according to the embodiment of the present technology. The pixel 10230 includes a photodiode 10231, two transfer transistors 10232 and 10237, two reset transistors 10233 and 10238, two taps (floating diffusion layers 10234 and 10239), two amplification transistors 10235 and 10239, and two selection transistors 10236 and 10241.
[0151] The photodiode 10231 photoelectrically converts received light to generate electric charges. The photodiode 10231 is disposed on the back side of the semiconductor substrate, with the surface on which the circuit is disposed being regarded as the front side. Such a solid-state imaging element is called a back-illuminated solid-state imaging element. Note that instead of the back-illuminated type, a front-illuminated type configuration in which the photodiode 10231 is disposed on the front side can also be used.
[0152] The transfer transistor 10232 sequentially transfers electric charges from the photodiode 10231 to the TAPA 10239 and the TAPB 10234 in accordance with a transfer signal TRG from the vertical drive circuit 10010. The TAPA 10239 and the TAPB 10234 accumulate the transferred electric charges and generate a voltage according to the amount of accumulated electric charges.
[0153] The overflow transistor 10242 is a transistor that sequentially discharges the charge of the photodiode 10231 to VDD, and has the function of resetting the photodiode.
[0154] The reset transistors 10233 and 10238 extract charges from the TAPA10239 and TAPB10234, respectively, in response to a reset signal RSTp from the vertical drive circuit 210, to initialize the charge amount. The amplifier transistors 10235 and 10240 amplify the voltages of the TAPA10239 and TAPB10234, respectively. The selection transistors 10236 and 10241 output the amplified voltage signals as pixel signals to the column signal processing unit 10040 via two vertical signal lines (for example, VSL1 and VSL2) in response to a selection signal SELp from the vertical drive circuit 210. VSL1 and VSL2 are connected to the inputs of one analog-digital converter in the column signal processing circuit 10040.
[0155] The circuit configuration of the pixel 230 is not limited to the configuration exemplified in FIG. 23, as long as it is capable of generating a pixel signal by photoelectric conversion. The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, a robot, etc.
[0156] FIG. 25 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving object control system to which the technology according to the present disclosure can be applied.
[0157] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 25, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also, as functional configurations of the integrated control unit 12050, a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (Interface) 12053 are illustrated.
[0158] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.
[0159] The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as head lamps, back lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves or signals of various switches transmitted from a portable device that replaces a key may be input to the body system control unit 12020. The body system control unit 12020 receives the input of these radio waves or signals and controls the door lock device, power window device, lamps, and the like of the vehicle.
[0160] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, an imaging unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the imaging unit 12031 to capture an image outside the vehicle and receives the captured image. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for a person, a car, an obstacle, a sign, or characters on a road surface, based on the received image.
[0161] The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according to the amount of light received. The imaging unit 12031 can output the electrical signal as an image, or as distance measurement information. The light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.
[0162] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing.
[0163] The microcomputer 12051 can calculate control target values for the driving force generating device, the steering mechanism, or the braking device based on the information inside and outside the vehicle acquired by the outside-of-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.
[0164] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on the driver's operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle acquired by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.
[0165] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12030 based on the information outside the vehicle acquired by the outside-vehicle information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicle information detection unit 12030, and perform cooperative control for the purpose of preventing glare, such as switching from high beams to low beams.
[0166] The audio / video output unit 12052 transmits at least one output signal of audio and video to an output device capable of visually or audibly notifying information to passengers in the vehicle or the outside of the vehicle. In the example of Fig. 25, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplified as the output device. The display unit 12062 may include at least one of an on-board display and a head-up display, for example.
[0167] FIG. 26 is a diagram showing an example of the installation position of the imaging unit 12031.
[0168] In FIG. 26, the imaging unit 12031 includes imaging units 12101, 12102, 12103, 12104, and 12105.
[0169] The imaging units 12101, 12102, 12103, 12104, and 12105 are provided at positions such as the front nose, side mirrors, rear bumper, back door, and the upper part of the windshield in the vehicle interior of the vehicle 12100. The imaging unit 12101 provided at the front nose and the imaging unit 12105 provided at the upper part of the windshield in the vehicle interior mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided at the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided at the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The imaging unit 12105 provided at the upper part of the windshield in the vehicle interior is mainly used to detect a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.
[0170] 26 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, an overhead image of the vehicle 12100 viewed from above is obtained by superimposing the image data captured by the imaging units 12101 to 12104.
[0171] At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera made up of a plurality of imaging elements, or may be an imaging element having pixels for detecting a phase difference.
[0172] For example, the microcomputer 12051 can extract, as a preceding vehicle, a three-dimensional object that is the closest three-dimensional object on the travel path of the vehicle 12100 and travels at a predetermined speed (for example, 0 km / h or more) in approximately the same direction as the vehicle 12100, by calculating the distance to each three-dimensional object in the imaging ranges 12111 to 12114 and the change over time of this distance (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104. Furthermore, the microcomputer 12051 can set a vehicle distance to be secured in advance in front of the preceding vehicle, and perform automatic brake control (including follow-up stop control) and automatic acceleration control (including follow-up start control). In this way, cooperative control can be performed for the purpose of automatic driving that travels autonomously without relying on the driver's operation.
[0173] For example, the microcomputer 12051 classifies and extracts three-dimensional object data on three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on distance information obtained from the imaging units 12101 to 12104, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Then, the microcomputer 12051 determines a collision risk indicating the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.
[0174] At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in the captured images of the imaging units 12101 to 12104. The recognition of such a pedestrian is performed, for example, by a procedure of extracting feature points in the captured images of the imaging units 12101 to 12104 as infrared cameras, and a procedure of performing pattern matching processing on a series of feature points that indicate the contour of an object to determine whether or not the object is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the captured images of the imaging units 12101 to 12104 and recognizes the pedestrian, the audio / image output unit 12052 controls the display unit 12062 to superimpose a rectangular contour line for emphasis on the recognized pedestrian. The audio / image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating a pedestrian at a desired position.
[0175] The above-described embodiment may be modified as follows.
[0176] (1) The solid-state imaging device a first substrate having a pixel array in which a plurality of pixels, which output analog signals by photoelectric conversion, are arranged in a two-dimensional array as columns along a first direction and rows along a second direction intersecting the first direction; a second substrate laminated on the first substrate, the second substrate having an analog circuit arranged to overlap the pixel array in a third direction intersecting the first direction and the second direction, the second substrate having an analog circuit that processes the analog signal output from the pixel; Equipped with the pixel array is divided into a first region and a second region, each of which includes consecutive pixels, by a pixel division unit along the second direction; The analog circuit is connected to the pixels belonging to the first region and the pixels belonging to the second region, and is divided into a first analog circuit and a second analog circuit that are adjacent in the third direction via a circuit division section that is arranged to overlap the pixel division section.
[0177] (2) In the pixel array, a first signal line arranged along the first direction, the first signal line selecting one or a plurality of rows in the first direction from among the rows including the pixels that are continuous in the second direction; Equipped with The analog signal output from the pixel selected by the first signal line is processed by the analog circuit. A solid-state imaging device according to (1).
[0178] (3) In the pixel array, a second signal line arranged in a plurality of rows along the second direction, the second signal line selecting one or a plurality of rows in the second direction from among the rows including the pixels that are continuous in the first direction; Equipped with The analog signal output by the pixel selected by the first signal line is transmitted via the second signal line and processed by the analog circuit; the second signal line is electrically disconnected in the pixel division portion; A solid-state imaging device according to (2).
[0179] (4) the pixel division unit and the circuit division unit are disposed near a center of the pixel array in the first direction. A solid-state imaging device according to (3).
[0180] (5) a connection portion that connects the pixel and the analog circuit in the third direction in the pixel division portion and the circuit division portion; The solid-state imaging device according to (3) above,
[0181] (6) The connection portion is a first connection portion connected to the second signal line and connecting the pixel belonging to the first region and the first analog circuit via the second signal line; a second connection portion connected to the second signal line and connecting the pixel belonging to the second region and the second analog circuit via the second signal line; The solid-state imaging device according to (5) above,
[0182] (7) a first switch that switches a connection state between the first connection portion and the second connection portion; The solid-state imaging device according to (6) above,
[0183] (8) based on a timing at which the analog signal is output to the analog circuit via the first connection unit or the second connection unit, The first switch switches a connection state between the first connection portion and the second connection portion. A solid-state imaging device according to (7).
[0184] (9) the first connection portion, the second connection portion, and the first switch are provided in a plurality of parts along the second direction, The first switches are operated synchronously. A solid-state imaging device according to (7) or (8).
[0185] (10) The first connection portion and the second connection portion are provided in a plurality of portions along the second direction, A second switch that switches a mutual connection state of the plurality of first connection parts; A third switch that switches a mutual connection state of the plurality of second connection parts; The solid-state imaging device according to any one of (6) to (9),
[0186] (11) based on a timing at which the analog signal is output to the analog circuit via the first connection unit or the second connection unit, The second switch switches a mutual connection state of the first connection parts, The third switch switches a mutual connection state of the second connection parts. A solid-state imaging device according to (10).
[0187] (12) The second switch and the third switch operate synchronously. A solid-state imaging device according to (10) or (11).
[0188] (13) the second switch and the third switch are each provided in a plurality of parts along a second direction, The plurality of second switches and the plurality of third switches operate synchronously. A solid-state imaging device according to (10) or (11).
[0189] (14) a first voltage source that applies a predetermined voltage to the first connection parts that are connected via the second switch; a fourth switch that switches a connection state between the first voltage source and the first connection parts; Equipped with The second switch and the fourth switch operate in synchronization. A solid-state imaging device according to any one of (10) to (13).
[0190] (15) A second voltage source that applies a predetermined voltage to the second connection parts that are connected via the third switch; a fifth switch that switches a connection state between the second voltage source and the second connection parts; Equipped with The third switch and the fifth switch operate in synchronization. A solid-state imaging device according to any one of (10) to (14).
[0191] (16) The first connection portion and the second connection portion are provided in at least the number of the pixels present in the row. A solid-state imaging device according to any one of (6) to (15).
[0192] (17) The first connection portion and the second connection portion are provided in a number equal to at least the number of the pixels present in the row multiplied by a predetermined number. A solid-state imaging device according to (16).
[0193] (18) The connection portion is formed by a microbump, a micropad, or a via hole. A solid-state imaging device according to any one of (5) to (17).
[0194] (19) the first analog circuit and the second analog circuit process the analog signals of different pixels belonging to one or more of the rows along the second direction at the same timing; A solid-state imaging device according to any one of (1) to (18).
[0195] (20) the first analog circuit and the second analog circuit change the number of the analog signals to be processed at the same timing under a predetermined condition; A solid-state imaging device according to (19).
[0196] (twenty one) The analog circuit converts the analog signal to a digital signal; A logic circuit for processing the digital signal; The solid-state imaging device according to (20) above,
[0197] (twenty two) the logic circuit is disposed on either side of the analog circuit in the first direction; A solid-state imaging device according to (21).
[0198] (twenty three) The logic circuit includes: a first logic circuit that processes the digital signal output from the first analog circuit; a second logic circuit that processes the digital signal output from the second analog circuit; Equipped with A solid-state imaging device according to (21) or (22).
[0199] (twenty four) A plurality of the pixel division units and the circuit division unit; an area of the pixel array divided into a plurality of areas and the analog circuits corresponding to each of the areas; Equipped with A solid-state imaging device according to (1).
[0200] (twenty five) The second substrate is A signal processing circuit that performs signal processing of the digital signal; an image processing circuit that performs image processing of the digital signal that is image information; a storage unit that stores any one of the digital signal, the data output by the signal processing circuit, and the data output by the image processing circuit; a selector that arbitrarily selects at least one of the data output by the signal processing circuit, the data output by the image processing circuit, and the data stored in the storage unit; an interface that outputs the data or any signal selected by the selector to an external device, or receives input of data or a signal from an external device; The solid-state imaging device according to any one of (1) to (24), comprising:
[0201] (26) All switches operate synchronously. A solid-state imaging device according to any one of (7) to (15).
[0202] (27) The synchronization is performed based on the timing of resetting the pixel or the timing of the analog signal output from the pixel. A solid-state imaging device according to (26).
[0203] The aspects of the present disclosure are not limited to the above-described embodiments, but include various conceivable modifications, and the effects of the present disclosure are not limited to the above-described contents. The components in each embodiment may be appropriately combined and applied. In other words, various additions, modifications, and partial deletions are possible within the scope of the conceptual idea and intent of the present disclosure derived from the contents defined in the claims and their equivalents. [Explanation of symbols]
[0204] 1: solid-state imaging device; 10: first substrate, 12:Optical system, 14: pixel array, 140:pixels, 141, 141A, 141B: 1st area, 142, 142A, 142B: 2nd area, 143, 143A, 143B, 143C: pixel division unit, 16: first signal line, 181, 182: second signal line, 20: second substrate, 22, 22A, 22B: analog circuit, 221, 221A, 221B: first analog circuit, 222, 222A, 222B: second analog circuit, 223, 223A, 223B, 223C: circuit division section, 23:DAC 24: Logic circuits, 25: Memory, 26: Input / Output I / F, 281: First switch, 282: Second switch, 283: 3rd switch, 284: 4th switch, 285: 5th switch, 30: Connection part, 301: first connection part, 302: Second connection part
Claims
1. a first substrate having a pixel array in which a plurality of pixels, which output analog signals by photoelectric conversion, are arranged in a two-dimensional array as columns along a first direction and rows along a second direction intersecting the first direction; a second substrate laminated on the first substrate, the second substrate having an analog circuit arranged to overlap the pixel array in a third direction intersecting the first direction and the second direction, the second substrate having an analog circuit that processes the analog signal output from the pixel; Equipped with the pixel array is divided into a first region and a second region, each of which includes consecutive pixels, by a pixel division unit along the second direction; the analog circuit is connected to the pixels belonging to the first region and the pixels belonging to the second region, and is divided into a first analog circuit and a second analog circuit that are adjacent to each other in the third direction via a circuit division section that is arranged to overlap with the pixel division section; Solid-state imaging device.
2. In the pixel array, a first signal line arranged along the first direction, the first signal line selecting one or more rows in the first direction from among the rows including the pixels that are continuous in the second direction; a second signal line arranged along the second direction, the second signal line selecting one or more of the columns in the second direction from among the columns including the pixels that are continuous in the first direction; Equipped with The analog signal output by the pixel selected by the first signal line is transmitted via the second signal line and processed by the analog circuit; the second signal line is electrically disconnected in the pixel division portion; 2. A solid-state imaging device according to claim 1.
3. the pixel division unit and the circuit division unit are disposed near a center of the pixel array in the first direction.
3. The solid-state imaging device according to claim 2.
4. a connection section that connects the pixel and the analog circuit in the third direction in the pixel division section and the circuit division section; 3. The solid-state imaging device according to claim 2, comprising:
5. The connection portion is a first connection portion connected to the second signal line and connecting the pixel belonging to the first region and the first analog circuit via the second signal line; a second connection portion connected to the second signal line and connecting the pixel belonging to the second region and the second analog circuit via the second signal line; The solid-state imaging device according to claim 4 .
6. a first switch that switches a connection state between the first connection portion and the second connection portion; The solid-state imaging device according to claim 5 .
7. based on a timing at which the analog signal is output to the analog circuit via the first connection unit or the second connection unit, The first switch switches a connection state between the first connection portion and the second connection portion.
7. A solid-state imaging device according to claim 6.
8. the first connection portion, the second connection portion, and the first switch are provided in a plurality of parts along the second direction, The first switches are operated synchronously.
7. A solid-state imaging device according to claim 6.
9. The first connection portion and the second connection portion are provided in a plurality of portions along the second direction, A second switch that switches a mutual connection state of the plurality of first connection parts; A third switch that switches a mutual connection state of the plurality of second connection parts; The solid-state imaging device according to claim 5 .
10. based on a timing at which the analog signal is output to the analog circuit via the first connection unit or the second connection unit, The second switch switches a mutual connection state of the first connection parts, The third switch switches a mutual connection state of the second connection parts.
10. The solid-state imaging device according to claim 9.
11. The second switch and the third switch operate synchronously.
10. The solid-state imaging device according to claim 9.
12. the second switch and the third switch are each provided in a plurality of parts along a second direction, The plurality of second switches and the plurality of third switches operate synchronously.
10. The solid-state imaging device according to claim 9.
13. a first voltage source that applies a predetermined voltage to the first connection parts that are connected via the second switch; a fourth switch that switches a connection state between the first voltage source and the first connection parts; Equipped with The second switch and the fourth switch operate in synchronization.
10. The solid-state imaging device according to claim 9.
14. A second voltage source that applies a predetermined voltage to the second connection parts that are connected via the third switch; a fifth switch that switches a connection state between the second voltage source and the second connection parts; Equipped with The third switch and the fifth switch operate in synchronization.
10. The solid-state imaging device according to claim 9.
15. the first analog circuit and the second analog circuit process the analog signals of different pixels belonging to one or more of the rows along the second direction at the same timing; 2. A solid-state imaging device according to claim 1.
16. the first analog circuit and the second analog circuit change the number of the analog signals to be processed at the same timing under a predetermined condition; 16. A solid-state imaging device according to claim 15.
17. The analog circuit converts the analog signal to a digital signal; A logic circuit for processing the digital signal; The solid-state imaging device according to claim 16, comprising:
18. the logic circuit is disposed on either side of the analog circuit in the first direction; 18. A solid-state imaging device according to claim 17.
19. A plurality of the pixel division units and the circuit division unit; an area of the pixel array divided into a plurality of areas and the analog circuits corresponding to each of the areas; Equipped with 2. A solid-state imaging device according to claim 1.
20. The second substrate is A signal processing circuit that performs signal processing of a digital signal; an image processing circuit that performs image processing of the digital signal that is image information; a storage unit that stores any one of the digital signal, the data output by the signal processing circuit, and the data output by the image processing circuit; a selector that arbitrarily selects at least one of the data output by the signal processing circuit, the data output by the image processing circuit, and the data stored in the storage unit; an interface that outputs the data or any signal selected by the selector to an external device, or receives input of data or a signal from an external device; The solid-state imaging device according to claim 1 .
Citation Information
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