Image sensor, electronic device and system

Abstract

This application provides an image sensor, electronic device, and system. The image sensor includes a pixel array and a dynamic detection module. The pixel array includes multiple pixels, each pixel including at least two adjacent first sub-pixels and second sub-pixels with different exposure times within the same frame. The dynamic detection module includes a light intensity contrast circuit, a threshold circuit, and a comparison circuit. The light intensity contrast circuit adjusts the first output voltage of the first sub-pixel to a target voltage; generates a first target level signal based on the magnitude relationship between the target voltage and a preset voltage; outputs the first target level signal to the threshold circuit and outputs the target voltage to the comparison circuit. After receiving the first target level signal, the threshold circuit adjusts the second output voltage of the second sub-pixel to the threshold voltage and outputs the threshold voltage to the comparison circuit. The comparison circuit compares the target voltage and the threshold voltage and outputs a second target level signal. This application can improve the robustness of the judgment when light intensity changes.

Description

Technical Field

[0001] This application relates to the field of image processing technology, and in particular to an image sensor, electronic device and system. Background Technology

[0002] Image sensors typically output the captured scene frame by frame. Currently, "Dynamic Vision" technology for image sensors—where the sensor only responds to moving objects and not to stationary ones—has found applications in some scenarios. The basic method for achieving dynamic vision is to detect changes in the incident light intensity captured by each pixel in the image sensor between two adjacent frames and compare this to a threshold. Alternatively, it compares the difference between the voltage output by each pixel in the same frame at the current moment and the voltage at a next moment with the threshold to determine the light intensity change. If the change exceeds the threshold, the incident light intensity is considered to have changed; if the change does not exceed the threshold, the incident light intensity is considered to have remained unchanged. The threshold is typically a percentage representing the relative change in incident light intensity at the current moment. For example, if the current incident light intensity is 500 lux and the threshold is 20%, then the comparison thresholds are 600 lux and 400 lux, where 600 lux is used to determine if the incident light intensity has increased, and 400 lux is used to determine if the incident light intensity has decreased.

[0003] Currently, when setting the judgment threshold, the influence of system noise (such as flicker noise of incident light, circuit noise, etc.) also needs to be considered. For example, when the incident light intensity is low, the noise-to-signal ratio is large, so the judgment threshold is usually set to a large value; when the incident light intensity is high, the noise-to-signal ratio is low, so the judgment threshold is usually set to a small value. Therefore, under normal circumstances, different pixels correspond to different incident light intensities, and different judgment thresholds are used. However, in current technologies, the judgment threshold for all pixels is the same, that is, different pixels in the same pixel array use the same judgment threshold regardless of the intensity of the incident light, which can lead to decreased judgment robustness or even misjudgment.

[0004] Therefore, improving the robustness of judgment when light intensity changes is an urgent technical problem to be solved. Summary of the Invention

[0005] This application provides an image sensor, electronic device, and system to improve the robustness of light intensity change detection.

[0006] In a first aspect, embodiments of this application provide an image sensor, including: a pixel array and a dynamic detection module; wherein the pixel array includes a plurality of pixels, each pixel including at least an adjacent first sub-pixel and a second sub-pixel, the first sub-pixel and the second sub-pixel having different exposure durations in the same frame; the dynamic detection module includes a light intensity contrast circuit, a threshold circuit, and a comparison circuit; the light intensity contrast circuit is connected to the first sub-pixel and is used to: receive a first output voltage of the first sub-pixel, adjust the first output voltage to a target voltage; and generate a first target level signal based on the magnitude relationship between the target voltage and a preset voltage, wherein the preset voltage is based on the light intensity. The voltage is set; the first target level signal is output to the control terminal of the threshold circuit through the first output terminal; and the target voltage is output to the first input terminal of the comparison circuit through the second output terminal; the threshold circuit is connected to the second sub-pixel and is used to: receive the second output voltage of the second sub-pixel, and after receiving the first target level signal through the control terminal, adjust the second output voltage to the threshold voltage, wherein each pixel corresponds to its own threshold voltage; output the threshold voltage to the second input terminal of the comparison circuit; the comparison circuit is used to: compare the target voltage and the threshold voltage, and output the second target level signal based on the comparison result.

[0007] In existing technologies, all pixels in an image sensor have the same judgment threshold. To address this, this application provides an image sensor that improves judgment robustness. The image sensor includes a pixel array and a dynamic detection module. The pixel array includes multiple pixels, each pixel including at least a first sub-pixel and a second sub-pixel with different exposure durations. Since the first and second sub-pixels are adjacent in the pixel array, it can be approximated that they receive the same incident light intensity at any given time. Because the output of a pixel after exposure is proportional to the product of the exposure duration and the incident light intensity, the dynamic detection module, after acquiring the output voltages of the first and second sub-pixels at different exposure durations, can adjust the outputs of different exposure durations to the same exposure duration and then compare them, thereby achieving light intensity change detection at different times within the same frame. Furthermore, compared to comparing light intensity changes between two frames in the digital domain, it can also achieve rapid light intensity change detection in the analog domain. Furthermore, when detecting changes in light intensity, this dynamic detection module can independently set the judgment threshold for each pixel based on the magnitude of the incident light intensity received by each sub-pixel within that pixel. That is, each pixel corresponds to its own threshold voltage; for example, a higher judgment threshold is set for pixels with low incident light intensity, and a lower judgment threshold is set for pixels with high incident light intensity. This method of setting separate judgment thresholds for different pixels in the pixel array within the same environment, with each pixel operating independently, improves the robustness of the judgment and adapts to the impact of noise on dynamic recognition.

[0008] In one possible implementation, the light intensity comparison circuit includes: a comparison circuit, the output terminal of which is the first output terminal of the light intensity comparison circuit; the comparison circuit is used to: generate the first target level signal based on the magnitude relationship between the target voltage and the preset voltage; and output the first target level signal to the control terminal of the threshold circuit.

[0009] In this embodiment, the light intensity comparison circuit in the dynamic detection module includes a comparison circuit that can be used to compare the magnitude of the incident light intensity of the first sub-pixel with the preset illumination intensity during its exposure time, and output different first target level signals according to the comparison result. If the incident light intensity during the exposure time is greater than the preset illumination intensity, a first target level signal is generated to indicate that the incident light intensity is strong; if the incident light intensity during the exposure time is less than the preset illumination intensity, a first target level signal is generated to indicate that the incident light intensity is weak.

[0010] In one possible implementation, the first target level signal includes a first level signal and a second level signal; the control terminal of the threshold circuit includes a first control terminal and a second control terminal; the comparison circuit includes a first comparator and a NOT gate; the first comparator is used to: receive the target voltage; compare the magnitude relationship between the target voltage and the preset voltage to generate the first level signal; and output the first level signal to the first control terminal through the output terminal of the first comparator; the NOT gate is used to: receive the first level signal and output the second level signal to the second control terminal through the output terminal of the NOT gate.

[0011] In this embodiment, the comparison circuit can compare the incident light intensity with a preset illumination intensity using a comparator and a NOT gate. For example, the comparator compares the incident light intensity with the preset illumination intensity and outputs a first-level signal, which is then inverted by the NOT gate to output a second-level signal. The first and second-level signals can work together to control the threshold circuit to generate threshold voltages of different magnitudes, i.e., to set a judgment threshold for each pixel, thereby improving the robustness of the judgment and adapting to the impact of noise on dynamic recognition.

[0012] In one possible implementation, the light intensity contrast circuit further includes: an adjustment circuit; the output terminal of the adjustment circuit is connected to the input terminal of the contrast circuit and serves as the second output terminal of the light intensity contrast circuit; the adjustment circuit is connected to the first sub-pixel and is used to: receive the first output voltage; adjust the first output voltage to the target voltage according to the ratio between the exposure time corresponding to the first sub-pixel and the exposure time corresponding to the second sub-pixel; and output the target voltage to the first input terminal of the comparison circuit.

[0013] In this embodiment, the adjustment circuit can amplify or reduce the output of sub-pixels with different exposure times to an equivalent sub-pixel output with the same exposure time. For example, according to the ratio between the exposure time corresponding to the first sub-pixel and the exposure time corresponding to the second sub-pixel, the first output voltage is adjusted to a target voltage, which is equivalent to the output of the first sub-pixel after exposure according to the exposure time corresponding to the second sub-pixel. This adjustment circuit can effectively adjust the first sub-pixel to the same exposure time as the second sub-pixel, reducing the error caused by the difference in exposure time.

[0014] In one possible implementation, the threshold voltage includes a first threshold voltage and a second threshold voltage; the threshold circuit includes a first threshold sub-circuit and a second threshold sub-circuit, both of which include a first control terminal and a second control terminal; the first threshold sub-circuit is connected to the second sub-pixel and is used to: receive the second output voltage, and after receiving the first level signal through the first control terminal and the second level signal through the second control terminal, adjust the second output voltage upward to the first threshold voltage; the second threshold sub-circuit is connected to the second sub-pixel and is used to: receive the second output voltage, and after receiving the first level signal through the first control terminal and the second level signal through the second control terminal, adjust the second output voltage downward to the second threshold voltage; wherein the first threshold voltage is greater than the second threshold voltage.

[0015] In this embodiment, the threshold circuit includes a first threshold sub-circuit and a second threshold sub-circuit. The first threshold sub-circuit generates a first threshold voltage, which can be used to determine whether the incident light intensity has increased. The second threshold sub-circuit generates a second threshold voltage, which can be used to determine whether the incident light intensity has decreased. Accordingly, the first threshold voltage is greater than the second threshold voltage. Furthermore, the threshold voltage varies depending on the first target level signal. For example, when the first target level signal indicates that the incident light intensity is greater than a preset illumination intensity, the first and second threshold voltages are smaller (i.e., low judgment thresholds); when the first target level signal indicates that the incident light intensity is less than a preset illumination intensity, the first and second threshold voltages are larger (i.e., high judgment thresholds). Generating different threshold voltages for different incident light intensities enhances the robustness of the dynamic detection module's judgment.

[0016] In one possible implementation, the first threshold sub-circuit includes a first capacitor, an operational amplifier, a first switch, a second switch, a second capacitor, a third switch, and a third capacitor; the ratio of the first capacitor to the second capacitor is different from the ratio of the first capacitor to the third capacitor; one end of the first capacitor is the input terminal of the first threshold sub-circuit and connected to the second sub-pixel, and the other end of the first capacitor is connected to the input terminal of the operational amplifier; the first switch is connected between the input terminal and the output terminal of the operational amplifier; the second switch and the second capacitor are connected in series between the input terminal and the output terminal of the operational amplifier; the third switch and the third capacitor are connected in series between the input terminal and the output terminal of the operational amplifier; the output terminal of the operational amplifier is the output terminal of the first threshold sub-circuit and connected to the second input terminal of the comparator circuit.

[0017] The first and second threshold sub-circuits have the same circuit structure, but their corresponding capacitor sizes are different, so that they can generate different threshold voltages respectively. In this embodiment, a simple first threshold sub-circuit is provided. The second output voltage can be adjusted to the first threshold voltage using an operational amplifier. Furthermore, because the ratio between the second and first capacitors is different from the ratio between the third and first capacitors, the first threshold sub-circuit can select different capacitors to conduct based on the first and second level signals, generating different first threshold voltages, thus ensuring that each pixel corresponds to its own first threshold voltage.

[0018] In one possible implementation, the control terminal of the first switch is used to receive a control signal, which controls the first switch to turn on after the second sub-pixel begins exposure and turn off before the second sub-pixel completes exposure; the control terminal of the second switch is the first control terminal used to receive the first level signal, and the control terminal of the third switch is the second control terminal used to receive the second level signal.

[0019] In this embodiment, the control signal can work in conjunction with the first target level signal to control the first threshold sub-circuit to generate a first threshold voltage, so that the dynamic detection module can determine the change in incident light intensity corresponding to the pixel.

[0020] In one possible implementation, the second target level signal includes a third level signal and a fourth level signal; the comparison circuit is specifically used to: compare the target voltage with the first threshold voltage and output the third level signal; compare the target voltage with the second threshold voltage and output the fourth level signal.

[0021] In this embodiment of the application, the comparison circuit needs to compare threshold voltages of different sizes and determine whether the incident light intensity of the corresponding pixel has changed based on the comparison result. For example, by comparing the target voltage with the first threshold voltage, it can be determined whether the incident light intensity of the corresponding pixel has become brighter or unchanged. By comparing the target voltage with the second threshold voltage, it can be determined whether the incident light intensity of the corresponding pixel has become darker or unchanged.

[0022] In one possible implementation, the comparison circuit includes a second comparator and a third comparator; a first input terminal of the comparison circuit includes one input terminal of the second comparator and one input terminal of the third comparator; a second input terminal of the comparison circuit includes another input terminal of the second comparator and another input terminal of the third comparator; one input terminal of the second comparator is connected to the second output terminal to receive the target voltage, and the other input terminal of the second comparator is connected to the output terminal of the first threshold sub-circuit to receive the first threshold voltage, and the second comparator is used to output the third level signal; one input terminal of the third comparator is connected to the second output terminal to receive the target voltage; the other input terminal of the third comparator is connected to the output terminal of the second threshold sub-circuit to receive the second threshold voltage, and the third comparator is used to output the fourth level signal.

[0023] In this embodiment, the comparison circuit includes two comparators to compare the magnitude relationship between the target voltage and the first threshold voltage and the second threshold voltage, respectively.

[0024] In one possible implementation, when the third level signal indicates that the target voltage is greater than the first threshold voltage, the brightness of the incident light intensity of the corresponding pixel changes from dark to bright; when the fourth level signal indicates that the target voltage is less than the second threshold voltage, the brightness of the incident light intensity of the corresponding pixel changes from bright to dark; when the third level signal and the fourth level signal indicate that the target voltage is greater than the second threshold voltage and less than the first threshold voltage, the brightness of the incident light intensity of the corresponding pixel remains unchanged.

[0025] In the embodiments of this application, the third-level signal and the fourth-level signal output by the comparison circuit can cooperate with each other to jointly indicate the change in the incident light intensity of the corresponding pixel.

[0026] Secondly, embodiments of this application provide an electronic device, which includes a circuit board and an image sensor provided by the first aspect or any possible implementation thereof, wherein the circuit board is electrically connected to the image sensor.

[0027] Thirdly, embodiments of this application provide a dynamic recognition system, the dynamic recognition system including the image sensor provided by the first aspect or any possible implementation of the first aspect, the image sensor being used for dynamic recognition.

[0028] It should be understood that the electronic device provided in the second aspect of this application and the dynamic recognition system provided in the third aspect are consistent with the technical solutions of the first aspect of this application. Their specific contents and beneficial effects can be referred to the image sensor provided in the first aspect above, and will not be repeated here. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application or the background art will be described below.

[0030] Figure 1 This is a schematic diagram illustrating the relationship between incident light intensity and a judgment threshold provided in an embodiment of this application.

[0031] Figure 2 This is a schematic diagram of the dynamic visual result output by the frame difference method provided in an embodiment of this application.

[0032] Figure 3 This is a schematic diagram of the structure of a set of pixel arrays provided in an embodiment of this application.

[0033] Figure 4 This is a schematic diagram of a set of first sub-pixels and second sub-pixels provided in an embodiment of this application.

[0034] Figure 5 This is a circuit diagram of a set of pixel structures provided in an embodiment of this application.

[0035] Figure 6A This is a schematic diagram of control signals corresponding to a first sub-pixel and a second sub-pixel provided in an embodiment of this application.

[0036] Figure 6B This is a schematic diagram of incident light intensity changes under multiple frames of images provided in an embodiment of this application.

[0037] Figure 7 This is a schematic diagram of the structure of an image sensor provided in an embodiment of this application.

[0038] Figure 8A This is a schematic diagram of the structure of a dynamic detection module provided in an embodiment of this application.

[0039] Figure 8B This is a schematic diagram of a pixel array corresponding to a threshold provided in an embodiment of this application.

[0040] Figure 9 This is a schematic diagram of another dynamic detection module provided in an embodiment of this application.

[0041] Figure 10 This is a circuit diagram of a light intensity comparison circuit provided in an embodiment of this application.

[0042] Figure 11A This is a schematic diagram of the structure of another dynamic detection module provided in the embodiments of this application.

[0043] Figure 11B This is a circuit diagram of a dynamic detection module provided in an embodiment of this application.

[0044] Figure 12 This is a control timing diagram of a first threshold sub-circuit provided in an embodiment of this application. Detailed Implementation

[0045] The embodiments of this application will now be described with reference to the accompanying drawings.

[0046] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0047] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0048] For ease of description, embodiments of this application may use spatial relation terms such as "below," "below," "lower than," "below," "above," "upper," etc., to describe the relationship between an element or feature shown in the accompanying drawings and other elements or features. It will be understood that these spatial relation terms are intended to include orientations of the device in use or operation other than those depicted in the drawings. For example, if the device in the drawings is flipped, the orientation of an element described as "below," "below," or "below" other elements or features will change to "above" said other elements or features. Thus, the exemplary terms "below" and "below" can encompass both up and down directions. The device may also have other orientations (rotated 90 degrees or in other orientations), and therefore the spatial relation descriptors used herein should be interpreted accordingly. Furthermore, it will be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or there may be one or more layers in between.

[0049] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0050] As used in this specification, the terms "component," "module," "system," etc., are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or a computer. As illustrated, applications running on computing devices and computing devices can both be components. One or more components may reside in a process and / or an execution thread, and components may be located on a single computer and / or distributed among two or more computers. Furthermore, these components can be executed from various computer-readable media on which various data structures are stored. Components can communicate, for example, via local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, and / or a network, such as the Internet interacting with other systems via signals).

[0051] First, in order to facilitate understanding of the embodiments of this application, the technical problems to be solved by the embodiments of this application are analyzed in detail below.

[0052] Typically, image sensors output a scene frame by frame. If most of the scene (such as the background) is static, with only some objects moving, adjacent frames from the image sensor will generate a lot of repetitive and redundant information (e.g., the static background). This increases redundant storage, computation, and power consumption. Moreover, in some applications, moving objects are more relevant information. For example, in home surveillance, moving objects such as intruders, elderly people who have fallen, or moving pets are more noteworthy than static objects like sofas and chairs in the background. Therefore, "Dynamic Vision" technology has been developed.

[0053] Dynamic vision, also known as motion detection, event detection, or brightness change detection, means that the image sensor only responds to moving objects whose incident light intensity changes, and does not respond to stationary objects. Therefore, when capturing key information, the image sensor can reduce the computational load and power consumption of a large amount of meaningless information, making it easier to discover key information. Current dynamic vision technologies are mainly divided into two types: one is dynamic vision detection based on a Dynamic Vision Sensor (DVS), and the other is dynamic vision detection using the frame difference method based on a Complementary Metal Oxide Semiconductor Image Sensor (CIS).

[0054] In dynamic monitoring, DVS first acquires the difference between the voltage of a pixel at the current moment and the voltage at a next moment. This difference is then fed into comparators and compared with two threshold voltages (ON / OFF, the magnitude of which is determined by a judgment threshold). The result of the dynamic vision assessment, or "event," is output. An event is defined as a change in the brightness of the incident light intensity, including three types: "from dark to bright," "from bright to dark," and "no change in brightness." For example, if the ON threshold (i.e., the judgment threshold) is set to +20%, meaning the difference is greater than the ON threshold voltage corresponding to +20%, then an ON event is triggered, indicating that the incident light intensity at the next moment is 20% stronger than the incident light intensity at the previous moment; if the OFF threshold (i.e., the judgment threshold) is set to -20%, meaning the difference is less than the OFF threshold voltage corresponding to -20%, then an OFF event is triggered, indicating that the incident light intensity at the next moment is 20% weaker than the incident light intensity at the previous moment; if the difference is within ±20%, meaning the difference is less than the ON threshold voltage and greater than the OFF threshold voltage, then a "brightness unchanged" event is triggered, indicating that the incident light intensity at the next moment is compared to the incident light intensity at the previous moment.

[0055] It should be noted that you should refer to the appendix. Figure 1 , Figure 1 This is a schematic diagram illustrating the relationship between incident light intensity and a judgment threshold provided in an embodiment of this application, as shown below. Figure 1 As shown, to reduce the impact of noise, the judgment threshold varies depending on the ambient incident light intensity. The judgment threshold is typically a percentage representing the relative change in incident light intensity at the current moment. For example, during the day when incident light intensity is high, the noise-to-signal ratio is small, so the judgment threshold is set to a low threshold, such as +10% for the ON threshold and -10% for the OFF threshold. At night when incident light intensity is low, the judgment threshold is set to a high threshold, such as +20% for the ON threshold and -20% for the OFF threshold. That is, when the incident light intensity is low, the noise-to-signal ratio is high, so a high threshold is set; when the incident light intensity is high, a low threshold is set. Therefore, generally, different incident light intensities result in different noise-to-signal ratios, and different judgment thresholds are used accordingly.

[0056] The basic method for achieving dynamic vision is to detect the change in incident light intensity captured by each pixel in an image sensor between previous and subsequent moments. Specifically, if a pixel captures a stationary object, the incident light intensity remains unchanged between the previous and subsequent moments. However, when a moving object passes by that pixel, the incident light intensity captured changes as the pixel captures the moving object instead of the stationary one. For example, the incident light intensity reflected from a black-clad burglar entering a house is typically less than the background light intensity, thus making the burglar a target for a dynamic vision sensor.

[0057] For dynamic visual detection using the frame difference method, please refer to the appendix. Figure 2 , Figure 2 This is a schematic diagram of the dynamic visual result output by the frame difference method provided in an embodiment of this application, such as... Figure 2 As shown in (1): CIS can output the images of frames 1-3 frame by frame. Compared with the first frame image, the second frame image has an additional "pentagon"; compared with the second frame image, the third frame image has an additional "square" and a "triangle". Therefore, the dynamic visual effect of this frame difference method should be as follows: Figure 2 As shown in (2). This scheme obtains the brightness change at adjacent moments by subtracting the gray values ​​of corresponding pixels in two adjacent frames, and uses the difference to determine moving objects, thus realizing dynamic vision function.

[0058] However, the two dynamic vision detection methods mentioned above have at least the following drawbacks.

[0059] First, during dynamic monitoring, the ON and OFF threshold voltages for all pixels in the pixel array are consistent and do not change due to differences in pixel position and corresponding incident light intensity. That is, the judgment threshold is consistent for each pixel. However, in practical applications, pixels in the same pixel array may have different incident light intensities due to their different positions. Furthermore, the above method compares the difference between the voltage output by each pixel at the current moment and the voltage at a later moment in the same frame with the judgment threshold to determine light intensity changes. Therefore, if all pixels are uniformly set to ON and OFF thresholds, the accuracy of intensity change judgment will be low when the incident light intensity is low, and the sensitivity will be low when the incident light intensity is high. This will lead to a decrease in the robustness of light intensity change judgment and may even result in misjudgment of dynamic objects due to noise.

[0060] Secondly, the frame difference method requires comparing the brightness changes between two adjacent frames when judging light intensity changes. Therefore, it needs to store the grayscale values ​​of all pixels in the previous frame, and then perform the difference operation on the corresponding pixels after the brightness value of the next frame is output. This significantly increases storage space and consequently increases chip area. Furthermore, since the frame difference method needs to compare the brightness changes between two adjacent frames, it also requires at least an analog-to-digital converter (ADC) to quantize the voltage value corresponding to the exposure, i.e., converting the analog signal into a digital signal (i.e., grayscale value) before comparison. The ADC conversion for each frame takes a relatively long time, resulting in a large time interval between adjacent frames, meaning a large time interval for the compared brightness information, making it impossible to detect rapidly changing light intensity.

[0061] Therefore, this application provides an image sensor that improves the robustness of judgment when rapidly detecting light intensity changes. Exemplarily, the image sensor includes a pixel array and a dynamic detection module. The dynamic detection module can set a corresponding threshold for each pixel in the pixel array based on the actual received incident light intensity. That is, different pixels can correspond to different judgment thresholds in the same environment, thereby improving the accuracy of judging light intensity changes in pixels with lower incident light intensity and increasing the sensitivity of judging light intensity changes in pixels with higher incident light intensity. This improves the robustness of the pixel array to dynamic visual judgment within a frame, adapting to the impact of noise on dynamic recognition. Furthermore, by comparing the output voltages of two adjacent pixels within the same frame, dynamic visual functionality is implemented in the analog domain, enabling rapid light intensity detection while reducing storage space and chip area. The specific structure and related description of this image sensor are provided in the following embodiments, which will not be described in this application.

[0062] Secondly, based on the technical problems mentioned above, and in order to facilitate understanding of the embodiments of this application, several pixel arrays on which the embodiments of this application are based will be described below.

[0063] The image sensor in this embodiment includes a pixel array and a dynamic detection module. The pixel array is used for photoelectric conversion during exposure, and the dynamic detection module is used for dynamic identification based on the electrical signals output by the pixel array. The pixel array includes multiple pixels, and each of these pixels includes multiple sub-pixels. Each pixel includes at least a first sub-pixel and a second sub-pixel, which are adjacent to each other and correspond to different exposure times. In other embodiments, the first and second sub-pixels have a filter film of the same color.

[0064] The adjacency of the first and second sub-pixels can be understood as two sub-pixels in adjacent rows or columns within the same column, or two sub-pixels in adjacent rows and columns. For an example, please refer to the appendix. Figure 3 , Figure 3 This is a schematic diagram of a pixel array structure provided in an embodiment of this application. For example... Figure 3 As shown in (1), the pixel array may include 4 pixels, each pixel including 4 sub-pixels, and all sub-pixels in each pixel correspond to a filter film of the same color. For example, the first pixel includes 4 red filter film sub-pixels arranged in a matrix, and this pixel includes at least a first sub-pixel and a second sub-pixel that are adjacent in position. Figure 3 As shown in (2) and (3), each sub-pixel in a pixel can correspond to a filter of a different color. In this case, the first sub-pixel and the second sub-pixel are two adjacent sub-pixels in the pixel that correspond to the same color filter. Figure 3 As shown in (4), in order to eliminate the influence of uneven light intensity, the first sub-pixel and the second sub-pixel can also be selected from two diagonally adjacent sub-pixels. Figure 3 As shown in (4), due to the different structures of the pixel arrays themselves, the first sub-pixel can be composed of at least two sub-pixels, and the second sub-pixel can also be composed of at least two sub-pixels. The multiple sub-pixels constituting the first sub-pixel can be exposed synchronously and output the voltage after photoelectric conversion together to form the output of the first sub-pixel; the multiple sub-pixels constituting the first sub-pixel can be exposed synchronously and output the voltage after photoelectric conversion together to form the output of the second sub-pixel.

[0065] Please refer to the attached document. Figure 4 and Figure 5 , Figure 4 This is a schematic diagram of a set of first sub-pixels and second sub-pixels provided in an embodiment of this application. Figure 5This is a circuit diagram illustrating a set of pixel structures provided in an embodiment of this application. Depending on the pixel structure, the structures of the first and second sub-pixels also differ. Taking a pixel comprising four sub-pixels with the same color filter as an example, when the sub-pixels in each pixel are as follows... Figure 5 The structure shown in (1), where each sub-pixel has a separate source follower (SF) and row gate (RS), is as follows: Figure 4 As shown, the first and second sub-pixels can be a single sub-pixel. For example: the first sub-pixel is sub-pixel P2, and the second sub-pixel is sub-pixel P1; the first sub-pixel is sub-pixel P0, and the second sub-pixel is sub-pixel P3. When each pixel is as follows... Figure 5 The structure shown in (2) refers to the situation where all sub-pixels within the same pixel share the same source follower (SF) and row gate (RS). Figure 4 As shown, the first sub-pixel and the second sub-pixel can each include multiple sub-pixels. For example, the output of the first sub-pixel can be considered as the combined output of sub-pixels P0 and P3, and the output of the second sub-pixel can be considered as the combined output of sub-pixels P1 and P2. In other embodiments, the output of the first sub-pixel can also be considered as the combined output of sub-pixels P0 and P1, and the output of the second sub-pixel can be considered as the combined output of sub-pixels P2 and P3; or, the output of the first sub-pixel can also be considered as the combined output of sub-pixels P0 and P2, and the output of the second sub-pixel can be considered as the combined output of sub-pixels P1 and P3. This application does not specifically limit the scope of these embodiments.

[0066] Based on the above Figure 5 Taking the structure of sub-pixel P0 shown in (1) as an example, the working principle of a sub-pixel is illustrated. Each sub-pixel can include one photodiode P operating under reverse bias and four transistors. The photodiode converts incident photons into electrons (called "photogenerated electrons"), which are then temporarily stored inside the photodiode. The four transistors include a reset gate (RST), a transmission gate (TG), a source follower (SF), and a row selector (RS). For example, as described above... Figure 5As shown in Figure (1), the sub-pixel P0 includes RST0, TG0, SF0, and RS0. The source of RST0, the gate of SF0, and the drain of TG0 are connected to a floating diffusion (FD) potential. When TG0 is turned on, photogenerated electrons generated and temporarily stored in the photodiode are introduced into FD and stored, changing the voltage VFD at point FD. The change in VFD is proportional to the product of the incident light intensity and the exposure time, thus converting the incident light signal into a voltage signal. When the sub-pixel is read, RS0 is turned on, and VFD is output to the Vertical Signal Line (VSL) through RS0, causing a change in the voltage on VSL, which is processed by the line circuit. Thus, the sub-pixel completes photoelectric conversion and voltage output. It should be noted that before the sub-pixel's exposure ends, a reset voltage (V) can be obtained through VSL. RST After the sub-pixel finishes exposure, the signal voltage (V) is obtained through VSL. SIG Reset voltage (V) RST ) and signal voltage (V SIG The difference is proportional to the product of the incident light intensity and the exposure time.

[0067] In some embodiments, the exposure duration corresponding to the first sub-pixel within the same frame is different from the exposure duration corresponding to the second sub-pixel. Please refer to the appendix. Figure 6A , Figure 6A This is a schematic diagram of control signals corresponding to a first sub-pixel and a second sub-pixel provided in an embodiment of this application, such as... Figure 6A As shown in (1) and (2), the time interval between the two conductions of the TG transistor of the first sub-pixel is the first exposure duration corresponding to the first sub-pixel, and the time interval between the two conductions of the TG transistor of the second sub-pixel is the second exposure duration corresponding to the second sub-pixel, as follows. Figure 6A As shown in (1), the first exposure duration is longer than the second exposure duration, as follows: Figure 6A As shown in (2), the first exposure duration is shorter than the second exposure duration. It is understood that, to ensure that the first sub-pixel and the second sub-pixel have different exposure durations within the same frame, the exposure start times of the first sub-pixel and the second sub-pixel can be set to be different, while the exposure end times of the first sub-pixel and the second sub-pixel can be the same. In other embodiments, the exposure end times of the first sub-pixel and the second sub-pixel can be different.

[0068] Please refer to the attached document. Figure 6B , Figure 6B This is a schematic diagram of incident light intensity changes under multiple frames of images provided in an embodiment of this application, such as... Figure 6BAs shown, because the first and second sub-pixels have different exposure durations within the same frame, the dynamic visual output of each frame is a change in light intensity. For example, the incident light intensity in the nth frame will change from low to high. Compared to the above... Figure 2 The corresponding frame difference method produces dynamic visual effects with constant output light intensity. Different exposure times for different pixels can capture rapidly changing light intensity, resulting in better dynamic visual detection.

[0069] It is understandable that if the sub-pixels included in the pixels of the pixel array are as described above... Figure 5 In the structure shown in (2), the control signals of the TG transistors corresponding to all sub-pixels in the first sub-pixel (e.g., sub-pixels P0 and P3) are consistent, that is, the start time and end time of exposure of all sub-pixels in the first sub-pixel are the same; the control signals of the TG transistors corresponding to all sub-pixels in the second sub-pixel (e.g., sub-pixels P1 and P2) are consistent, that is, the start time and end time of exposure of all sub-pixels in the second sub-pixel are the same; and the control signals of the TG transistors corresponding to the first sub-pixel (e.g., sub-pixels P0 and P3) and the second sub-pixel (e.g., sub-pixels P1 and P2) are different.

[0070] It is also understood that the pixel array and related pixel structure shown in the above embodiments are only a few exemplary implementations in the embodiments of this application, and the pixel array and related pixel structure in the embodiments of this application include, but are not limited to, the above structures.

[0071] Based on the above-mentioned pixel arrays, one of the image sensors on which the embodiments of this application are based will be described below.

[0072] For example, please refer to the appendix for details on a single pixel in a pixel array. Figure 7 , Figure 7 This is a schematic diagram of the structure of an image sensor provided in an embodiment of this application.

[0073] like Figure 7 As shown, the image sensor includes a pixel array and a dynamic detection module, and may also include Correlated Double Sampling (CDS), a Programmable Gain Amplifier (PGA), and an Analog-to-Digital Converter (ADC).

[0074] The pixel array includes multiple pixels, such as Figure 7As shown, each sub-pixel within a pixel is connected to the corresponding CDS, PGA, and ADC via a vertical signal column line (VSL). The CDS is used to acquire the output of the corresponding sub-pixel, that is, to acquire the reset voltage (V) of the sub-pixel. RST ) and signal voltage (V SIG Then, the reset voltage (V) RST ) and signal voltage (V SIG Do the difference, i.e., V RST -V SIG The process eliminates most of the noise, ensuring the difference is proportional to the product of the incident light intensity and the exposure time. This difference is then input to the PGA, which linearly amplifies it to meet the input swing requirements of the ADC. The ADC quantizes the received amplified voltage value and outputs the corresponding pixel's grayscale value, converting the analog signal into a digital signal (grayscale value) for subsequent image generation.

[0075] The dynamic detection module can connect to the first and second sub-pixels of a pixel, respectively, to receive the output of the sub-pixels and achieve dynamic detection. In some embodiments, the dynamic detection module can also be connected to the output of the CDS corresponding to the first and second sub-pixels, directly receiving the CDS output. Compared to comparing light intensity changes between two frames in the digital domain, the dynamic detection module achieves rapid light intensity detection in the analog domain.

[0076] For details, please refer to the appendix. Figure 8A , Figure 8A This is a schematic diagram of the structure of a dynamic detection module provided in an embodiment of this application, as shown below. Figure 8A As shown, the dynamic detection module may include a light intensity comparison circuit, a threshold circuit, and a comparison circuit.

[0077] The light intensity comparison circuit is connected to the first sub-pixel and is used to: receive the first output voltage of the first sub-pixel and adjust the first output voltage to a target voltage; generate a first target level signal based on the magnitude relationship between the target voltage and a preset voltage, wherein the preset voltage is a voltage set based on the light intensity; output the first target level signal to the control terminal of the threshold circuit through the first output terminal; and output the target voltage to the first input terminal of the comparison circuit through the second output terminal.

[0078] First, it should be noted that, as mentioned above Figure 7As shown, since the first and second sub-pixels are spatially adjacent within the pixel, it can be approximated that they receive the same incident light intensity at any given time. Furthermore, since the output of a sub-pixel after exposure is proportional to the product of the exposure duration and the incident light intensity, the dynamic detection module, after acquiring the output voltages of the first and second sub-pixels at different exposure durations, adjusts the output of one sub-pixel to a duration comparable to that of the other sub-pixel, and then compares it with the output of the other sub-pixel, thereby achieving the detection of light intensity changes at different times within the same frame.

[0079] The light intensity contrast circuit needs to adjust the output of the first sub-pixel to be equivalent to the output of the second sub-pixel before comparison. That is, adjusting the first output voltage to the target voltage avoids the impact of varying light intensity caused by different exposure times on dynamic recognition. For example, if the exposure time of the first sub-pixel is 0.5T and the exposure time of the second sub-pixel is T, then the output of the first sub-pixel is multiplied by 2 so that the adjusted output is equivalent to the output of the first sub-pixel after exposure for time T. As another example, if the exposure time of the first sub-pixel is 2T and the exposure time of the second sub-pixel is T, then the output of the first sub-pixel is divided by 2 so that the adjusted output is equivalent to the output of the first sub-pixel after exposure for time T.

[0080] Furthermore, when detecting changes in light intensity, the dynamic detection module can generate different level signals based on the magnitude of the incident light intensity received by each sub-pixel. This allows the threshold circuit to generate a corresponding judgment threshold for that pixel. Specifically, the light intensity comparison circuit generates a first target level signal based on the relationship between the target voltage and a preset voltage, where the preset voltage is a voltage set based on the light intensity. This first target level signal is output to the control terminal of the threshold circuit via the first output terminal. For example, if the target voltage is greater than the preset voltage, it indicates that the incident light intensity of the first sub-pixel is greater than the preset light intensity during the exposure time, and a first target level signal is generated to indicate that the incident light intensity of the first sub-pixel is strong. If the target voltage is less than the preset voltage, it indicates that the incident light intensity of the first sub-pixel is less than the preset light intensity during the exposure time, and a first target level signal is generated to indicate that the incident light intensity of the first sub-pixel is weak. This first target level signal can be output to the control terminal of the threshold circuit via the first output terminal to control the threshold circuit to generate threshold voltages of different magnitudes. For example: for pixels that detect strong incident light intensity, a lower judgment threshold is set, i.e., a low threshold voltage; for pixels that detect weak incident light intensity, a higher judgment threshold is set, i.e., a high threshold voltage.

[0081] It is understood that the aforementioned preset voltage is a voltage preset based on the light intensity. For example, if 500 lux is set as the preset light intensity, then the voltage corresponding to 500 lux is the preset voltage. When the target voltage is greater than the preset voltage, it indicates that the incident light intensity of the first sub-pixel is greater than 500 lux, which is a strong incident light intensity; when the target voltage is less than the preset voltage, it indicates that the incident light intensity of the first sub-pixel is less than 500 lux, which is a weak incident light intensity. This application does not illustrate any related modules or circuits for the preset voltage. These modules or circuits can be integrated within the dynamic detection module or set separately from the dynamic detection module; this embodiment does not impose specific limitations on this.

[0082] In other embodiments, multiple preset voltages can be set, each corresponding to a different light intensity. For example, two preset voltages can be set, one corresponding to a light intensity of 300 lux and the other to a light intensity of 600 lux. When the target voltage is less than the preset voltage corresponding to 300 lux, it indicates that the incident light intensity of the first sub-pixel is less than 300 lux, which is a weak incident light intensity; when the target voltage is greater than the preset voltage corresponding to 600 lux, it indicates that the incident light intensity of the first sub-pixel is greater than 600 lux, which is a strong incident light intensity; when the target voltage is greater than the preset voltage corresponding to 300 lux and less than the preset voltage corresponding to 600 lux, it indicates that the incident light intensity of the first sub-pixel is greater than 300 lux and less than 600 lux, which is a medium incident light intensity. Accordingly, the threshold circuit outputs different threshold voltages according to different incident light intensities. It is understood that the embodiments of this application do not specifically limit the number of preset voltages.

[0083] As mentioned above Figure 8A As shown, the threshold circuit is connected to the second sub-pixel and also to the light intensity comparison circuit, and is used to: receive the second output voltage of the second sub-pixel, and after receiving the first target level signal through the control terminal, adjust the second output voltage to the threshold voltage, wherein each pixel corresponds to its own threshold voltage; and output the threshold voltage to the second input terminal of the comparison circuit.

[0084] The threshold circuit can generate a threshold voltage corresponding to the pixel based on the second output voltage, controlled by the first target level signal. For example, when the second output voltage is constant, the threshold voltage generated when the first target level signal indicates that the incident light intensity of the first sub-pixel is weak is greater than the threshold voltage generated when the first target level signal indicates that the incident light intensity of the first sub-pixel is strong. The magnitude of this threshold value refers to the increase or decrease based on the first output voltage. For example, setting a lower threshold value (low threshold voltage) means increasing or decreasing the second output voltage by 10%; a higher threshold value (high threshold voltage) means increasing or decreasing the second output voltage by 20%. This method of setting corresponding threshold values ​​for different pixels in the pixel array within the same environment, making each pixel independent, improves the robustness of dynamic visual judgment.

[0085] Understandably, please refer to the appendix. Figure 8B , Figure 8B This is a schematic diagram illustrating a pixel array corresponding to a threshold determination method provided in an embodiment of this application. For example... Figure 8B As shown in (1), the incident light intensity of each pixel in the pixel array is different, such as Figure 8B As shown in (2), in the prior art, each pixel of the pixel array has a uniform judgment threshold, that is, all pixels uniformly correspond to a high judgment threshold, or all pixels uniformly correspond to a low judgment threshold. Figure 8B As shown in Figure (3), based on the above figure... Figure 8B As shown in Figure (1), for pixels with low incident light intensity, a higher judgment threshold can be set; for pixels with high incident light intensity, a lower judgment threshold can be set. This method, which sets corresponding judgment thresholds for different pixels in the pixel array under the same environment, ensures that each pixel is independent of the others, thereby improving the accuracy of judgment when the incident light intensity is low and the sensitivity of judgment when the incident light intensity is high, thus improving the robustness of judgment and adapting to the impact of noise on dynamic recognition.

[0086] As mentioned above Figure 8AAs shown, the comparison circuit is connected to the threshold circuit and the light intensity comparison circuit, respectively, and is used to: compare the target voltage and the threshold voltage, and output a second target level signal based on the comparison result. It can be understood that the comparison circuit compares the target voltage and the threshold voltage, obtains the comparison result, and outputs a second target level signal indicating the comparison result. Since the threshold voltage is obtained by increasing or decreasing the second output voltage, comparing the target voltage and the threshold voltage allows it to determine whether the light intensity change corresponding to the pixel exceeds the judgment threshold, thereby achieving dynamic visual detection. This method, by comparing the output voltages of two adjacent pixels within the same frame, achieves dynamic visual functionality in the analog domain, enabling the detection of rapidly changing light intensity while reducing storage space and chip area.

[0087] In addition, in some embodiments, the light intensity comparison circuit includes: a comparison circuit, the output terminal of which is the first output terminal of the light intensity comparison circuit; the comparison circuit is used to: generate the first target level signal based on the magnitude relationship between the target voltage and the preset voltage; and output the first target level signal to the control terminal of the threshold circuit.

[0088] Please refer to the attached document. Figure 9 , Figure 9 This is a schematic diagram of another dynamic detection module provided in an embodiment of this application. For example... Figure 9 As shown, the light intensity comparison circuit in the dynamic detection module includes a comparison circuit. The output terminal of the comparison circuit is the first output terminal of the light intensity comparison circuit mentioned above. The comparison circuit can be used to compare the magnitude of the incident light intensity of the first sub-pixel with the preset light intensity during its exposure time, that is, to compare the magnitude of the target voltage and the preset voltage, and output different first target level signals to the control terminal of the threshold circuit according to the comparison result.

[0089] In some embodiments, the first target level signal includes a first level signal and a second level signal; the control terminal of the threshold circuit includes a first control terminal and a second control terminal; the comparison circuit includes a first comparator and a NOT gate; the first comparator is used to: receive the target voltage; compare the magnitude relationship between the target voltage and the preset voltage to generate the first level signal; and output the first level signal to the first control terminal through the output terminal of the first comparator; the NOT gate is used to: receive the first level signal and output the second level signal to the second control terminal through the output terminal of the NOT gate.

[0090] Taking a preset voltage as an example, please refer to the appendix. Figure 10 , Figure 10 This is a circuit diagram of a light intensity comparison circuit provided in an embodiment of this application, as shown below. Figure 10As shown, the light intensity comparison circuit in this dynamic detection module includes a comparison circuit comprising a first comparator CMP1 and a NOT gate. The first comparator CMP1 has two input terminals, one of which receives the target voltage V. A The other input terminal receives a preset voltage V. B The preset voltage V B It is a voltage preset based on the light intensity.

[0091] The first comparator CMP1 can compare the target voltage V. A With preset voltage V B The magnitude relationship between them determines the output of a first-level signal V1 to the first control terminal, which is then inverted by a NOT gate and output to the second control terminal as a second-level signal V2. Wherein, according to... Figure 10 The circuit structure shown, at the target voltage V A Greater than the preset voltage V B At this time, a high-level signal V1 can be output to the NOT gate. This high-level signal is converted into a low-level signal V2 after passing through the NOT gate, indicating that the incident light intensity corresponding to the pixel is a strong incident light intensity. If the target voltage V A Less than the preset voltage V B At this time, a low-level signal can be output to the NOT gate. This low-level signal is converted into a high-level signal after passing through the NOT gate, indicating that the incident light intensity corresponding to the pixel is a weak incident light intensity. The aforementioned first-level signal V1 and second-level signal V2 can work together to control the threshold circuit to generate threshold voltages of different magnitudes, improving the robustness of the judgment and adapting to the impact of noise on dynamic recognition.

[0092] In some embodiments, the light intensity comparison circuit further includes: an adjustment circuit; the output terminal of the adjustment circuit is connected to the input terminal of the comparison circuit and is the second output terminal of the light intensity comparison circuit; the adjustment circuit is connected to the first sub-pixel and is used to: receive the first output voltage; adjust the first output voltage to the target voltage according to the ratio between the exposure time corresponding to the first sub-pixel and the exposure time corresponding to the second sub-pixel; and output the target voltage to the first input terminal of the comparison circuit.

[0093] The adjustment circuit connects the aforementioned contrast circuit, the first sub-pixel, and the comparison circuit. The input of the adjustment circuit is connected to the output of the first sub-pixel, the output of the adjustment circuit is connected to the input of the contrast circuit, and the second output of the light intensity contrast circuit is connected to the comparison circuit. The adjustment circuit can amplify or reduce the output of sub-pixels with different exposure times to an equivalent sub-pixel output with the same exposure time. For example, it receives the aforementioned first output voltage and adjusts it to a target voltage according to the ratio between the exposure time corresponding to the first sub-pixel and the exposure time corresponding to the second sub-pixel. This target voltage is equivalent to the output of the first sub-pixel after exposure according to the exposure time corresponding to the second sub-pixel. For example, if the exposure time corresponding to the first sub-pixel is 0.5T and the exposure time corresponding to the second sub-pixel is T, then the ratio between the exposure time corresponding to the first sub-pixel and the exposure time corresponding to the second sub-pixel is 2. Accordingly, the adjustment circuit can adjust the first output voltage V of the first sub-pixel. P1 The exposure time of the first sub-pixel is doubled to effectively adjust it to the same duration as that of the second sub-pixel, thus reducing errors caused by differences in exposure time. This is achieved by... Figure 5 As can be seen from the relevant description in (1), the first output voltage V P1 Including the reset voltage (V) of the first sub-pixel RST1 ) and signal voltage (V SIG1 Its reset voltage (V) RST1 ) and signal voltage (V SIG1 The difference (i.e., V) RST1 -V SIG1 It is proportional to the product of the incident light intensity of the first sub-pixel and the exposure time.

[0094] As mentioned above Figure 10 As shown, an exemplary circuit structure for an adjustment circuit is also provided. This adjustment circuit may include a fourth capacitor C7, an operational amplifier OP3, a fourth switching transistor T4, a fifth switching transistor T5, and a second capacitor C8. One end of the fourth capacitor C7 is connected to the first sub-pixel as the input terminal of the adjustment circuit, receiving a first output voltage V. P1 The other end of the fourth capacitor C7 is connected to one input terminal of the operational amplifier OP3; the fourth switch T4 is connected between one input terminal and the output terminal of the operational amplifier OP3; the fifth switch T5 and the second capacitor C8 are connected in series between one input terminal and the output terminal of the operational amplifier OP3; the output terminal of the operational amplifier OP3 is the output terminal of the adjustment circuit and is connected to the input terminal of the comparison circuit, wherein the other input terminal of the operational amplifier OP3 is connected to voltage V. REF For example, the voltage V REFThis is equal to 0.5VDD, but the embodiments in this application do not specifically limit this value. As can be seen from the operating principle of this regulating circuit, this V... A =V REF +C7 / C8×(V RST1 -V SIG1 Therefore, when the exposure time corresponding to the first sub-pixel is twice the exposure time corresponding to the second sub-pixel, the corresponding C7 / C8 = 0.5; when the exposure time corresponding to the first sub-pixel is 0.5 times the exposure time corresponding to the second sub-pixel, the corresponding C7 / C8 = 2. Furthermore, the specific operating principle of this adjustment circuit can be referred to in the following description of the operating principle of the first threshold sub-circuit, which will not be repeated here. It should be noted that the second capacitor C8 in this adjustment circuit can be an adjustable capacitor, that is, the capacitance value of the second capacitor C8 is variable.

[0095] In some embodiments, the threshold voltage includes a first threshold voltage and a second threshold voltage, wherein the first threshold voltage is greater than the second threshold voltage. It is understood that the first threshold voltage can be the ON threshold voltage corresponding to triggering an ON event, and the second threshold voltage can be the OFF threshold voltage corresponding to triggering an OFF event.

[0096] The aforementioned threshold circuit includes a first threshold sub-circuit and a second threshold sub-circuit. Both the first and second threshold sub-circuits include a first control terminal and a second control terminal. The first threshold sub-circuit is connected to the second sub-pixel and is used to: receive the second output voltage, and after receiving the first level signal through the first control terminal and the second level signal through the second control terminal, adjust the second output voltage upwards to the first threshold voltage. The second threshold sub-circuit is connected to the second sub-pixel and is used to: receive the second output voltage, and after receiving the first level signal through the first control terminal and the second level signal through the second control terminal, adjust the second output voltage downwards to the second threshold voltage.

[0097] Please refer to the attached document. Figure 11A and Figure 11B , Figure 11A This is a schematic diagram of the structure of another dynamic detection module provided in the embodiments of this application. Figure 11B This is a circuit diagram of a dynamic detection module provided in an embodiment of this application. Figure 11AAs shown, the threshold circuit includes a first threshold sub-circuit and a second threshold sub-circuit. The first threshold sub-circuit includes a first control terminal G1 and a second control terminal G2, used to receive a first level signal and a second level signal to generate a first threshold voltage. This first threshold voltage can be used to determine whether the incident light intensity has increased. The second threshold sub-circuit also includes a first control terminal G1 and a second control terminal G2, used to receive the first level signal and the second level signal to generate a second threshold voltage. The first threshold voltage can be used to determine whether the incident light intensity has increased, and the second threshold voltage can be used to determine whether the incident light intensity has decreased.

[0098] Furthermore, the threshold voltage varies depending on the first target level signal, i.e., when the first and second level signals are different. For example, when the first target level signal indicates that the incident light intensity is greater than the preset illumination intensity, i.e., according to the above... Figure 11B In the circuit structure shown, when the first level signal is a high-level signal and the second level signal is a low-level signal, the first threshold voltage and the second threshold voltage can be the threshold voltage corresponding to the low judgment threshold. For example, the low judgment threshold can be ±10%. When the first target level signal indicates that the incident light intensity is less than the preset illumination intensity, that is, according to the above... Figure 11B In the circuit structure shown, when the first level signal is a low level signal and the second level signal is a high level signal, the first threshold voltage and the second threshold voltage can be the threshold voltage corresponding to the high judgment threshold. For example, the high judgment threshold can be ±20%. This method of generating different threshold voltages according to different incident light intensities can enhance the robustness of the dynamic detection module's judgment.

[0099] In some embodiments, as described above Figure 11B As shown, the aforementioned first threshold sub-circuit includes a first capacitor C1, an operational amplifier OP1, a first switch T1, a second switch T2, a second capacitor C2, a third switch T3, and a third capacitor C3. One end of the first capacitor C1 is the input terminal of the aforementioned first threshold sub-circuit and is connected to the output of the aforementioned second sub-pixel to receive the second output voltage V. P2 The other end of the first capacitor C1 is connected to one input terminal of the operational amplifier OP1; the first switch T1 is connected between that input terminal and the output terminal of the operational amplifier OP1; the second switch T2 and the second capacitor C2 are connected in series between that input terminal and the output terminal of the operational amplifier OP1; the third switch T3 and the third capacitor C3 are connected in series between that input terminal and the output terminal of the operational amplifier OP1; the output terminal of the operational amplifier OP1 is the output terminal of the first threshold sub-circuit, which is connected to the second input terminal of the comparator circuit to output the first threshold voltage V to the comparator circuit. ON Additionally, another input terminal of the operational amplifier OP1 can be connected to the power supply voltage V. REF Among them, those mentioned above Figure 5 As can be seen from the relevant description in (1), the second output voltage V P2 Including the reset voltage (V) of the second sub-pixel RST2 ) and signal voltage (V SIG2 ), the reset voltage (V) of its second sub-pixel RST2 ) and signal voltage (V SIG2 The difference (i.e., V) RST2 -V SIG2 It is proportional to the product of the incident light intensity of the second sub-pixel and the exposure time.

[0100] The ratio of the first capacitor C1 to the second capacitor C2 is different from the ratio of the first capacitor C1 to the third capacitor C3. In some embodiments, the second capacitor C2 and the third capacitor C3 are adjustable capacitors, that is, the capacitance values ​​of the second capacitor C2 and the third capacitor C3 are variable. This embodiment does not specifically change this aspect.

[0101] From the above circuit structure, it can be seen that the first threshold sub-circuit can use an operational amplifier to convert the second output voltage V P2 Adjust to the first threshold voltage V ON Furthermore, since the ratio between the second capacitor C2 and the first capacitor C1 in the first threshold sub-circuit is different from the ratio between the third capacitor C3 and the first capacitor C1, the first threshold sub-circuit can select different capacitors to be turned on based on the first level signal V1 and the second level signal V2 to generate different magnitudes of the first threshold voltage, so that each pixel corresponds to its own first threshold voltage.

[0102] In some embodiments, the control terminal of the first switch T1 in the first threshold sub-circuit is used to receive a control signal AZ1. The control signal AZ1 is used to control the first switch T1 to turn on after the second sub-pixel begins exposure and to turn off before the second sub-pixel completes exposure. The control terminal of the second switch T2 is the first control terminal used to receive the first level signal V1, and the control terminal of the third switch T3 is the second control terminal used to receive the second level signal V2.

[0103] For example, if the first level signal V1 is high, controlling the second switch T2 to remain on; and the second level signal V2 is low, controlling the third switch T3 to remain off, please refer to the appendix. Figure 12 , Figure 12 This is a control timing diagram of a first threshold sub-circuit provided in an embodiment of this application, as shown below. Figure 12 As shown, the first switch T1 is turned on by the control signal AZ1, which short-circuits the input and output of the operational amplifier OP1. At this time, the output of the operational amplifier OP1 (i.e., the first threshold voltage V) is... ON V OUT1=V REF At this time, the input voltage of operational amplifier OP1 is the reset voltage V of the second sub-pixel. RST2 Then, control signal AZ1 turns off the first switch T1. After exposure, the output of the second sub-pixel is from V... RST2 Change to V SIG2 That is, the input voltage of op-amp OP1 is from V RST2 Change to V SIG2 According to the basic working principle of the circuit, the output of op-amp OP1 at this time (i.e., the first threshold voltage V) ON V OUT1 =V REF +C1 / C2×(V RST2 -V SIG2 ), where (V RST2 -V SIG2 This can be considered as the second output voltage V of the second sub-pixel. P2 The corresponding C1 / C2 can be considered as the judgment threshold corresponding to the first threshold sub-circuit.

[0104] It is understandable that when the first level signal V1 is low, controlling the second switch T2 to remain off; and the second level signal V2 is high, controlling the third switch T3 to remain on, the output V of the operational amplifier OP1 is... OUT1 =V REF +C1 / C3×(V RST2 -V SIG2 Therefore, when the ratio between the second capacitor C2 and the first capacitor C1 is different from the ratio between the third capacitor C3 and the first capacitor C1, the first level signal V1 and the second level signal V2 select different capacitors to conduct in order to control the first threshold sub-circuit to generate a first threshold voltage of different magnitudes.

[0105] For example, when C1 / C2 = 1.1 and C1 / C3 = 1.2, under conditions of high incident light intensity, the first level signal V1 and the second level signal V2 control the second switch T2 to remain on and the third switch T3 to remain off, causing the first threshold sub-circuit to generate an ON threshold set to the low judgment threshold + 10%, and the first threshold voltage V ON =V OUT1 =V REF +C1 / C2×(V RST2 -V SIG2 Correspondingly, when the incident light intensity is low, the first level signal V1 and the second level signal V2 control the second switch T2 to remain off, and the third switch T3 to remain on, so that the first threshold sub-circuit generates an ON threshold set to the high judgment threshold + 20%, and the first threshold voltage V ON =V OUT1 =VREF +C1 / C3×(V RST2 -V SIG2 This allows for the generation of first threshold voltages corresponding to different judgment thresholds based on light intensity, thus adapting to the influence of noise and improving the robustness of the judgment.

[0106] The first threshold sub-circuit and the second threshold sub-circuit have the same circuit structure, but their corresponding capacitor sizes are different, so that they can generate threshold voltages of different sizes respectively.

[0107] Correspondingly, as mentioned above Figure 11B As shown, the second threshold sub-circuit is identical to the first threshold sub-circuit, also including a first capacitor C4, an operational amplifier OP2, a first switch T1, a second switch T2, a second capacitor C5, a third switch T3, and a third capacitor C6. One end of the first capacitor C4 is the input terminal of the second threshold sub-circuit, connected to the second sub-pixel; the other end of the first capacitor C4 is connected to the input terminal of the operational amplifier OP2. The first switch T1 is connected between the input and output terminals of the operational amplifier OP2. The second switch T2 and the second capacitor C5 are connected in series between the input and output terminals of the operational amplifier OP2. The third switch T3 and the third capacitor C6 are connected in series between the input and output terminals of the operational amplifier OP2. The output terminal of the operational amplifier OP2 is the output terminal of the second threshold sub-circuit and is connected to the second input terminal of the comparator circuit.

[0108] The control terminal of the first switch T1 in the second threshold sub-circuit is used to receive the control signal AZ2. The control signal AZ2 is used to control the first switch T1 to turn on after the second sub-pixel begins exposure and to turn off before the second sub-pixel completes exposure. The control terminal of the second switch T2 is the first control terminal used to receive the first level signal V1. The control terminal of the third switch T3 is the second control terminal used to receive the second level signal V2.

[0109] It is understandable that the ratio of the first capacitor C4 to the second capacitor C5 is different from the ratio of the first capacitor C4 to the third capacitor C5. Furthermore, since the first threshold voltage is greater than the second threshold voltage, the ratios of the first capacitor C1 to the second capacitor C2 and the first capacitor C1 to the third capacitor C3 in the first threshold sub-circuit are both greater than 1, while the ratios of the first capacitor C4 to the second capacitor C5 and the first capacitor C4 to the third capacitor C5 in the second threshold sub-circuit are both less than 1.

[0110] For example, when C4 / C5 = 0.9 and C4 / C6 = 0.8, under conditions of high incident light intensity, the first level signal V1 and the second level signal V2 control the second switch T2 to remain on and the third switch T3 to remain off, causing the second threshold sub-circuit to generate an OFF threshold set to a low judgment threshold of -10%, and the second threshold voltage V OFF =V OUT2 =V REF +C4 / C5×(V RST2 -V SIG2 Correspondingly, when the incident light intensity is low, the first level signal V1 and the second level signal V2 control the second switch T2 to remain off, and the third switch T3 to remain on, so that the first threshold sub-circuit generates an OFF threshold set to the high judgment threshold -20%, and the second threshold voltage V... OFF =V OUT2 =V REF +C4 / C6×(V RST2 -V SIG2 This allows for the generation of second threshold voltages corresponding to different judgment thresholds based on light intensity, thus adapting to the influence of noise and improving the robustness of the judgment.

[0111] It is also understood that the first level signal V1 and the second level signal V2 cooperate with the first threshold sub-circuit and the second threshold sub-circuit to generate a threshold voltage corresponding to a low judgment threshold when the incident light intensity is strong, and generate a threshold voltage corresponding to a high judgment threshold when the incident light intensity is weak. Therefore, the embodiments of this application do not specifically limit the ratio relationship of each capacitor in the first threshold sub-circuit and the second threshold sub-circuit.

[0112] In some embodiments, the second target level signal includes a third level signal and a fourth level signal; the comparison circuit is specifically used to: compare the target voltage with the first threshold voltage and output a third level signal; compare the target voltage with the second threshold voltage and output a fourth level signal. The comparison circuit needs to compare threshold voltages of different magnitudes and, based on the comparison results corresponding to the different threshold voltages, determine whether the incident light intensity of the corresponding pixel has changed. For example, by comparing the target voltage with the first threshold voltage, it determines whether the incident light intensity of the corresponding pixel has become brighter or unchanged; by comparing the target voltage with the second threshold voltage, it determines whether the incident light intensity of the corresponding pixel has become darker or unchanged.

[0113] In some embodiments, the comparison circuit described above includes a second comparator and a third comparator. As described above... Figure 11BAs shown, the comparison circuit includes a second comparator CMP2 and a third comparator CMP3. One input terminal of the second comparator CMP2 and one input terminal of the third comparator CMP3 together form the first input terminal of the comparison circuit, which receives the target voltage V output from the second output terminal of the light intensity comparison circuit. A The other input terminal of the second comparator CMP2 and the other input terminal of the third comparator CMP3 together constitute the second input terminal of the comparator circuit. The other input terminal of the second comparator CMP2 is connected to the output terminal of the aforementioned first threshold sub-circuit to receive the first threshold voltage V. ON The other input terminal of the third comparator CMP3 is connected to the output terminal of the second threshold sub-circuit to receive the second threshold voltage V. OFF The second comparator CMP2 is used to output the third-level signal V3; the third comparator CMP3 is used to output the fourth-level signal V4. The two comparators in this comparison circuit can compare the target voltage V. A With the first threshold voltage V ON Second threshold voltage V OFF The magnitude relationship between them is used to quickly detect rapid changes in incident light intensity.

[0114] In some embodiments, when the third level signal indicates that the target voltage is greater than the first threshold voltage, the brightness of the incident light intensity of the corresponding pixel changes from dark to bright; when the fourth level signal indicates that the target voltage is less than the second threshold voltage, the brightness of the incident light intensity of the corresponding pixel changes from bright to dark; when the third level signal and the fourth level signal indicate that the target voltage is greater than the second threshold voltage and less than the first threshold voltage, the brightness of the incident light intensity of the corresponding pixel remains unchanged.

[0115] Based on the above Figure 11B Taking the circuit structure shown as an example, when the target voltage V A Voltage greater than the first threshold voltage V ON At that time, due to the first threshold voltage V ON Greater than the second threshold voltage V OFF Therefore, both the third-level signal V3 and the fourth-level signal V4 are high, meaning that the second comparator CMP2 outputs "1" and the third comparator CMP3 outputs "1". In other words, the comparator circuit outputting 11 indicates that the pixel has triggered an ON event, indicating that the brightness change of the incident light intensity is from dark to bright. When the target voltage V... A Less than the second threshold voltage V OFFAt this time, correspondingly, the third level signal V3 and the fourth level signal V4 are both at a low level, that is, the second comparator CMP2 outputs "0" and the third comparator CMP3 outputs "0". In other words, the comparator circuit outputting 00 indicates that the pixel has triggered an OFF event, indicating that the brightness change of the incident light intensity is from bright to dark. When the target voltage V... A Less than the first threshold voltage V ON And greater than the second threshold voltage V OFF Furthermore, due to the first threshold voltage V ON Greater than the second threshold voltage V OFF Therefore, both the third-level signal V3 and the fourth-level signal V4 are high, meaning that the second comparator CMP2 outputs "1" and the third comparator CMP3 outputs "1". In other words, the comparator circuit outputting 01 indicates that the pixel has triggered a "brightness unchanged" event, indicating that the brightness change of the incident light intensity is constant. The third-level and fourth-level signals output by the comparator circuit can work together to indicate the change in the incident light intensity of the corresponding pixel.

[0116] In summary, this application provides an image sensor that improves the robustness of judgment when performing rapid light intensity change detection. The image sensor includes a pixel array and a dynamic detection module. The pixel array includes multiple pixels, each pixel including at least a first sub-pixel and a second sub-pixel with different exposure durations within the same frame. Since the first and second sub-pixels are adjacent in the pixel array, it can be approximated that they receive the same incident light intensity at any given time. Because the output of a pixel after exposure is proportional to the product of the exposure duration and the incident light intensity, the dynamic detection module, after acquiring the output voltages of the first and second sub-pixels at different exposure durations, can adjust the outputs of different exposure durations to the same exposure duration and then compare them, thereby achieving light intensity change detection at different times within the same frame, thus realizing dynamic visual detection. Furthermore, compared to comparing light intensity changes between two consecutive frames in the digital domain, the image sensor of this application can achieve rapid light intensity detection within the same frame based on the analog domain. Compared to the time interval between comparing two adjacent frames, this significantly shortens the light intensity change detection time, achieving rapid light intensity detection. Furthermore, and most importantly, the dynamic detection module of this image sensor can independently set the judgment threshold for each pixel based on the magnitude of the incident light intensity received by that pixel when detecting changes in light intensity. That is, each pixel corresponds to its own threshold voltage. For example, a higher judgment threshold is set for pixels with low incident light intensity, and a lower judgment threshold is set for pixels with high incident light intensity. This approach, which sets separate judgment thresholds for different pixels in the pixel array within the same environment, increases the accuracy of judgment when the incident light intensity is low and improves the sensitivity when the incident light intensity is high, thereby enhancing the robustness of the judgment and adapting to the impact of noise on dynamic recognition.

[0117] This application also provides an electronic device, which includes a circuit board and the above-mentioned components. Figures 3-12 The illustrated embodiment involves an image sensor, and the circuit board is electrically connected to the image sensor. The electronic device can detect changes in light intensity through the image sensor to achieve dynamic visual detection.

[0118] This application embodiment also provides a dynamic recognition system, which includes an image sensor, and the image sensor can be one of the above-mentioned... Figures 3-12 The related embodiments shown involve image sensors.

[0119] It should be understood that the electronic device or dynamic identification system provided in the embodiments of this application is similar to the one described above. Figures 3-12 The related embodiments shown involve the same image sensor, and their specific details and beneficial effects can be found above. Figures 3-12The image sensors involved in the related embodiments shown will not be described in detail here.

[0120] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0121] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0122] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0123] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0124] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0125] If the integrated units described above are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which can be a personal computer, server, or network device, specifically a processor in the computer device) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium may include various media capable of storing program code, such as a USB flash drive, portable hard drive, magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM).

[0126] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. An image sensor, characterized in that, include: A pixel array and a dynamic detection module; wherein the pixel array includes multiple pixels, each pixel including at least an adjacent first sub-pixel and a second sub-pixel, the first sub-pixel and the second sub-pixel having different exposure durations in the same frame; The dynamic detection module includes a light intensity comparison circuit, a threshold circuit, and a comparison circuit; The light intensity comparison circuit is connected to the first sub-pixel and is used to: receive a first output voltage of the first sub-pixel and adjust the first output voltage to a target voltage; generate a first target level signal based on the magnitude relationship between the target voltage and a preset voltage, wherein the preset voltage is a voltage set based on the light intensity; output the first target level signal to the control terminal of the threshold circuit through a first output terminal; and output the target voltage to the first input terminal of the comparison circuit through a second output terminal. The threshold circuit is connected to the second sub-pixel and is used to: receive the second output voltage of the second sub-pixel, and after receiving the first target level signal through the control terminal, adjust the second output voltage to the threshold voltage, wherein each pixel corresponds to its own threshold voltage; and output the threshold voltage to the second input terminal of the comparison circuit. The comparison circuit is used to: compare the target voltage and the threshold voltage, and output a second target level signal based on the comparison result.

2. The image sensor according to claim 1, characterized in that, The light intensity comparison circuit includes: a comparison circuit, wherein the output terminal of the comparison circuit is the first output terminal of the light intensity comparison circuit; The comparison circuit is used to: generate a first target level signal based on the magnitude relationship between the target voltage and the preset voltage; The first target level signal is output to the control terminal of the threshold circuit.

3. The image sensor according to claim 2, characterized in that, The first target level signal includes a first level signal and a second level signal, and the control terminal of the threshold circuit includes a first control terminal and a second control terminal; The comparison circuit includes a first comparator and a NOT gate; The first comparator is configured to: receive the target voltage; compare the magnitude relationship between the target voltage and the preset voltage, and generate the first level signal; The first level signal is output to the first control terminal through the output terminal of the first comparator; The NOT gate is used to: receive the first level signal and output the second level signal to the second control terminal through the output terminal of the NOT gate.

4. The image sensor according to claim 3, characterized in that, The light intensity comparison circuit further includes: an adjustment circuit; the output terminal of the adjustment circuit is connected to the input terminal of the comparison circuit and is the second output terminal of the light intensity comparison circuit; The adjustment circuit is connected to the first sub-pixel and is used to: receive the first output voltage; adjust the first output voltage to the target voltage according to the ratio between the exposure time corresponding to the first sub-pixel and the exposure time corresponding to the second sub-pixel; and output the target voltage to the first input terminal of the comparison circuit.

5. The image sensor according to claim 3 or 4, characterized in that, The threshold voltage includes a first threshold voltage and a second threshold voltage; The threshold circuit includes a first threshold sub-circuit and a second threshold sub-circuit, and both the first threshold sub-circuit and the second threshold sub-circuit include a first control terminal and a second control terminal; The first threshold sub-circuit is connected to the second sub-pixel and is used to: receive the second output voltage, and after receiving the first level signal through the first control terminal and the second level signal through the second control terminal, adjust the second output voltage upward to the first threshold voltage; The second threshold sub-circuit is connected to the second sub-pixel and is used to: receive the second output voltage, and after receiving the first level signal through the first control terminal and the second level signal through the second control terminal, adjust the second output voltage down to the second threshold voltage; Wherein, the first threshold voltage is greater than the second threshold voltage.

6. The image sensor according to claim 5, characterized in that, The first threshold sub-circuit includes a first capacitor, an operational amplifier, a first switching transistor, a second switching transistor, a second capacitor, a third switching transistor, and a third capacitor; the ratio of the first capacitor to the second capacitor is different from the ratio of the first capacitor to the third capacitor; One end of the first capacitor is connected to the input terminal of the first threshold sub-circuit and to the second sub-pixel; the other end of the first capacitor is connected to the input terminal of the operational amplifier. The first switching transistor is connected between the input and output terminals of the operational amplifier; The second switch and the second capacitor are connected in series between the input and output terminals of the operational amplifier; The third switch and the third capacitor are connected in series between the input and output terminals of the operational amplifier. The output terminal of the operational amplifier is the output terminal of the first threshold sub-circuit connected to the second input terminal of the comparator circuit.

7. The image sensor according to claim 6, characterized in that, The control terminal of the first switch is used to receive a control signal, which is used to control the first switch to turn on after the second sub-pixel begins exposure and to turn off before the second sub-pixel completes exposure. The control terminal of the second switch is the first control terminal used to receive the first level signal, and the control terminal of the third switch is the second control terminal used to receive the second level signal.

8. The image sensor according to any one of claims 5-7, characterized in that, The second target level signal includes a third level signal and a fourth level signal; The comparison circuit is specifically used to: compare the target voltage with the first threshold voltage and output a third level signal; compare the target voltage with the second threshold voltage and output a fourth level signal.

9. The image sensor according to claim 8, characterized in that, The comparison circuit includes a second comparator and a third comparator; The first input terminal of the comparison circuit includes an input terminal of the second comparator and an input terminal of the third comparator; The second input terminal of the comparison circuit includes another input terminal of the second comparator and another input terminal of the third comparator; One input of the second comparator is connected to the second output to receive the target voltage, and the other input of the second comparator is connected to the output of the first threshold sub-circuit to receive the first threshold voltage. The second comparator is used to output the third level signal. One input of the third comparator is connected to the second output to receive the target voltage; the other input of the third comparator is connected to the output of the second threshold sub-circuit to receive the second threshold voltage, and the third comparator is used to output the fourth level signal.

10. The image sensor according to claim 8 or 9, characterized in that, When the third level signal indicates that the target voltage is greater than the first threshold voltage, the brightness of the incident light intensity of the corresponding pixel changes from dark to bright. When the target voltage is less than the second threshold voltage, the brightness of the incident light intensity of the corresponding pixel changes from bright to dark. When the third level signal and the fourth level signal indicate that the target voltage is greater than the second threshold voltage and less than the first threshold voltage, the brightness of the incident light intensity of the corresponding pixel remains unchanged.

11. An electronic device, characterized in that, The electronic device includes a circuit board and an image sensor as described in any one of claims 1-10, wherein the circuit board is electrically connected to the image sensor.

12. A dynamic identification system, characterized in that, The dynamic recognition system includes an image sensor as described in any one of claims 1-10, the image sensor being used for dynamic recognition.

Images