The present invention relates to a photoelectric conversion device, a photoelectric conversion system, and a moving body.
Japanese Patent Laid-Open No. 2020-78020 describes a solid-state image capturing device that includes at least two column regions for A/D-converting pixel signals generated in pixels, a plurality of vertical signal lines for transferring the pixel signals to the column regions, and a free region where the plurality of vertical signal lines are not arranged. Two vertical signal lines adjacent to each other among the plurality of vertical signal lines are arranged so as to sandwich the free region, and the lengths of the two vertical signal lines are substantially the same. Further, each of the plurality of vertical signal lines includes a portion arranged so as to extend in an oblique direction from a Cu—Cu connection (an oblique direction with respect to the direction in which the Cu—Cu connection extends). In the invention described in Japanese Patent Laid-Open No. 2020-78020, it is a requirement that the lengths of two vertical signal lines arranged so as to sandwich the free region are substantially the same. Therefore, the design of a connection path between a vertical signal line arranged in a first substrate and a vertical signal line arranged in a second substrate is largely restricted.
The present invention provides a technique advantageous in reducing restrictions on the design of a connection path between a vertical signal line arranged in a first substrate and a vertical signal line arranged in a second substrate.
One of aspects of the present invention provides a photoelectric conversion device that includes a structure in which a first substrate and a second substrate are stacked, wherein the first substrate includes a plurality of pixels, a plurality of first vertical signal lines extending parallel to a first direction, and a plurality of first joints respectively electrically connected to the plurality of first vertical signal lines, and the second substrate includes a plurality of second joints respectively electrically connected to the plurality of first joints, a plurality of second vertical signal lines arranged so as to extend parallel to the first direction, a plurality of column circuits respectively electrically connected to the plurality of second vertical signal lines, a plurality of connecting lines respectively electrically connected to the plurality of second joints, and extending parallel to a second direction orthogonal to the first direction, and an interlayer connection configured to electrically connect each of the plurality of second vertical signal lines and the corresponding connecting line of the plurality of connecting lines.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note, the following embodiments are not intended to limit the scope of the claimed invention. Multiple features are described in the embodiments, but limitation is not made to an invention that requires all such features, and multiple such features may be combined as appropriate. Furthermore, in the attached drawings, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted.
The vertical signal line VSLO can include a first vertical signal line 30 arranged in a first substrate, and a second vertical signal line 130 arranged in a second substrate. The first vertical signal line 30 and the second vertical signal line 130 are electrically connected to each other. The photoelectric conversion device PEC can include a structure in which the first substrate and the second substrate are stacked. The photoelectric conversion device PEC may include a structure in which three or more substrates including the first substrate and the second substrate are stacked.
Each column circuit CC can include, for example, a current supply circuit 40 that supplies a current to the vertical signal line VSLO, among a plurality of the vertical signal lines VSLO (the first vertical signal lines 30 and the second vertical signal lines 130), corresponding to this column circuit CC. The column circuit CC may include a comparator 60 that compares the value of a signal supplied from the corresponding vertical signal line VSLO (the first vertical signal line 30 and the second vertical signal line 130) with the value of a ramp signal supplied from a ramp signal generation circuit 50. The ramp signal generation circuit 50 can be arranged in the second substrate. The column circuit CC may include a first memory 70 that holds a count value which is supplied from a counter 90 in accordance with the inversion of the output of the comparator 60. The counter 90 can be arranged in the second substrate. The counter 90 may be commonly provided for the plurality of the vertical signal lines VSLO, or may be individually provided for each of the plurality of the vertical signal lines VSLO. The comparator 60 and the first memory 70 can form an A/D convertor that generates a digital signal corresponding to the signal (analog signal) supplied from the vertical signal line VSLO (the first vertical signal line 30 and the second vertical signal line 130). The column circuit CC may include a second memory 80 that receives the signal (digital signal) held by the first memory 70. It can be understood that the comparator 60, the first memory 70, and the second memory 80 form as an example of a signal processing circuit that processes the signal supplied from the vertical signal line VSLO (the first vertical signal line 30 and the second vertical signal line 130). In place of such the arrangement example, another circuit (for example, an analog amplification circuit or a CDS circuit) may be provided as the signal processing circuit.
The photoelectric conversion device PEC may include a processing circuit 95 that processes signals supplied from a plurality of the second memories 80 or column circuits CC, and an output circuit 100 that outputs the signal generated by processing performed by the processing circuit 95. The processing circuit 95 may be configured to output an image signal generated using the plurality of pixels 10, or may be configured to output a signal obtained by processing the image signal generated using the plurality of pixels 10. The processing circuit 95 and the output circuit 100 can be arranged in the second substrate.
The pixel 10 is not limited to the arrangement described above, and various changes can be made. For example, the pixel 10 may have a function to change the capacitance value of the floating diffusion 420. In other words, the pixel 10 may have a function to change the sensitivity of the floating diffusion 420. The pixel 10 may be formed such that a plurality of the photoelectric conversion elements 400 share the floating diffusion 420. The pixel 10 may be a pixel that can assign such the plurality of the photoelectric conversion elements 400 to one microlens and detect the phase difference.
The second substrate 2 can include a plurality of second joints 112 respectively electrically connected to the plurality of first joints 111, and a plurality of the second vertical signal lines 130 arranged so as to extend parallel to the Y direction (first direction). In an example, the length of each of the plurality of the second vertical signal lines 130 in the direction parallel to the Y direction (first direction) is larger than the array pitch of the plurality of pixels 10 in the direction parallel to the Y direction (first direction). The second substrate 2 can also include the plurality of column circuits CC respectively electrically connected to the plurality of second vertical signal lines 130. The second substrate 2 can also include a plurality of connecting lines 120 respectively electrically connected to the plurality of second joints 112, and extending parallel to the X direction (second direction) orthogonal to the Y direction (first direction). The layer in which the plurality of second vertical signal lines 130 are arranged and the layer in which a plurality of connecting lines 120 are arranged are different layers. The second substrate 2 can also include interlayer connections 140 each of which electrically connects each of the plurality of second vertical signal lines 130 and the corresponding connecting line 120 of the plurality of connecting lines 120. The interlayer connection 140 can be a via plug (conductive member) that electrically connects the second vertical signal line 130 and the corresponding connecting line 120. In this manner, the second joint 112 and the corresponding second vertical signal line 130 can be electrically connected by the connecting line 120 extending parallel to the X direction (second direction) and the interlayer connection 140. This is advantageous in reducing restrictions on the design of the connection path between the vertical signal line 30 arranged in the first substrate 1 and the vertical signal line 130 arranged in the second substrate 2.
In the arrangement illustrated in
As illustrated in
As illustrated in
Each of the plurality of column circuits CC can include a multiplexer 250 that selects one second partial vertical signal line from the plurality of the second partial vertical signal lines 260a and 260b for the corresponding second vertical signal line 130 of the plurality of second vertical signal lines 130, and connects the selected second partial vertical signal line to the corresponding second vertical signal line 130. As has been described above, the second vertical signal line 130 is connected to the current supply circuit 40. The signal processing circuit that can be formed by the above-described comparator 60, first memory 70, and second memory 80, and the like can operate to process a signal output from the multiplexer 250 via the second vertical signal line 130.
By dividing the first vertical signal line 30 into the plurality of first partial vertical signal lines 30a and 30b, the parasitic capacitance in the signal readout path of the pixel 10 can be reduced, and the readout speed of reading out the signal of the pixel 10 can be increased. Although not shown in
Other modifications will be described below. In the example described above, one first vertical signal line is assigned to each pixel column, but an arrangement may be employed in which multiple first vertical signal lines are assigned to each pixel column so that signals of the pixels in multiple rows can be simultaneously read out. The comparator 60 may be formed to include a switch and a capacitance for an auto zero operation.
An example of a photoelectric conversion system using the photoelectric conversion device according to each embodiment described above will be described below.
The photoelectric conversion system 1200 shown in
The photoelectric conversion system 1200 includes a signal processor 1216 for processing an output signal output from the photoelectric conversion device 1215. The signal processor 1216 performs an operation of signal processing of performing various kinds of correction and compression for an input signal, as needed, thereby outputting the resultant signal. The photoelectric conversion system 1200 further includes a buffer memory unit 1206 for temporarily storing image data and an external interface unit (external I/F unit) 1209 for communicating with an external computer or the like. Furthermore, the photoelectric conversion system 1200 includes a recording medium 1211 such as a semiconductor memory for recording or reading out image capturing data, and a recording medium control interface unit (recording medium control I/F unit) 1210 for performing a recording or reading operation in or from the recording medium 1211. The recording medium 1211 may be incorporated in the photoelectric conversion system 1200 or may be detachable. In addition, communication with the recording medium 1211 from the recording medium control I/F unit 1210 or communication from the external I/F unit 1209 may be performed wirelessly.
Furthermore, the photoelectric conversion system 1200 includes a general control/arithmetic unit 1208 that performs various kinds of arithmetic operations and controls the entire digital still camera, and a timing generation unit 1217 that outputs various kinds of timing signals to the photoelectric conversion device 1215 and the signal processor 1216. Here, the timing signal and the like may be input from the outside, and the photoelectric conversion system 1200 need only include at least the photoelectric conversion device 1215 and the signal processor 1216 that processes an output signal output from the photoelectric conversion device 1215. As described in the fourth embodiment, the timing generation unit 1217 may be incorporated in the photoelectric conversion device. The general control/arithmetic unit 1208 and the timing generation unit 1217 may be configured to perform some or all of the control functions of the photoelectric conversion device 1215.
The photoelectric conversion device 1215 outputs an image signal to the signal processor 1216. The signal processor 1216 performs predetermined signal processing for the image signal output from the photoelectric conversion device 1215 and outputs image data. The signal processor 1216 also generates an image using the image signal. Furthermore, the signal processor 1216 may perform distance measurement calculation for the signal output from the photoelectric conversion device 1215. Note that the signal processor 1216 and the timing generation unit 1217 may be incorporated in the photoelectric conversion device. That is, each of the signal processor 1216 and the timing generation unit 1217 may be provided on a substrate on which pixels are arranged or may be provided on another substrate. An image capturing system capable of acquiring a higher-quality image can be implemented by forming an image capturing system using the photoelectric conversion device of each of the above-described embodiments.
A photoelectric conversion system and a moving body according to this embodiment will be described with reference to
The integrated circuit 1303 is an image capturing system application specific integrated circuit, and includes an image processor 1304 with a memory 1305, an optical distance measurement unit 1306, a distance measurement calculation unit 1307, an object recognition unit 1308, and an abnormality detection unit 1309. The image processor 1304 performs image processing such as development processing and defect correction for the output signal from each image preprocessor 1315. The memory 1305 temporarily stores a captured image, and stores the position of a defect in the captured image. The optical distance measurement unit 1306 performs focusing or distance measurement of an object. The distance measurement calculation unit 1307 calculates distance measurement information from a plurality of image data acquired by the plurality of photoelectric conversion devices 1302. The object recognition unit 1308 recognizes objects such as a vehicle, a road, a road sign, and a person. Upon detecting an abnormality of the photoelectric conversion device 1302, the abnormality detection unit 1309 notifies a main control unit 1313 of the abnormality.
The integrated circuit 1303 may be implemented by dedicated hardware, a software module, or a combination thereof. Alternatively, the integrated circuit 1303 may be implemented by an FPGA (Field Programmable Gate Array), an ASIC (Application Specific Integrated Circuit), or a combination thereof.
The main control unit 1313 comprehensively controls the operations of the photoelectric conversion system 1301, vehicle sensors 1310, a control unit 1320, and the like. A method in which the photoelectric conversion system 1301, the vehicle sensors 1310, and the control unit 1320 each individually include a communication interface and transmit/receive control signals via a communication network (for example, CAN standards) may be adopted without providing the main control unit 1313.
The integrated circuit 1303 has a function of transmitting a control signal or a setting value to each photoelectric conversion device 1302 by receiving the control signal from the main control unit 1313 or by its own control unit.
The photoelectric conversion system 1301 is connected to the vehicle sensors 1310 and can detect the traveling state of the self-vehicle such as the vehicle speed, the yaw rate, and the steering angle, the external environment of the self-vehicle, and the states of other vehicles and obstacles. The vehicle sensors 1310 also serve as a distance information acquisition unit that acquires distance information to a target object. Furthermore, the photoelectric conversion system 1301 is connected to a driving support control unit 1311 that performs various driving support operations such as automatic steering, adaptive cruise control, and anti-collision function. More specifically, with respect to a collision determination function, based on the detection results from the photoelectric conversion system 1301 and the vehicle sensors 1310, a collision with another vehicle or an obstacle is estimated or the presence/absence of a collision is determined. This performs control to avoid a collision when the collision is estimated or activates a safety apparatus at the time of a collision.
Furthermore, the photoelectric conversion system 1301 is also connected to an alarm device 1312 that generates an alarm to the driver based on the determination result of a collision determination unit. For example, if the determination result of the collision determination unit indicates that the possibility of a collision is high, the main control unit 1313 performs vehicle control to avoid a collision or reduce damage by braking, releasing the accelerator pedal, or suppressing the engine output. The alarm device 1312 sounds an alarm such as a sound, displays alarm information on the screen of a display unit such as a car navigation system or a meter panel, applies a vibration to the seat belt or a steering wheel, thereby giving an alarm to the user.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2021-185153, filed Nov. 12, 2021, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | Kind |
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2021-185153 | Nov 2021 | JP | national |