Method for accelerating stabilization of far-end row driving signal and image sensor

Abstract

The invention discloses a method for accelerating stabilization of a far-end row driving signal and an image sensor, and the method comprises the steps: directly detecting the far-end level of the row driving signal, and comparing the far-end level with a preset first preset threshold value; and when the change of the row driving signal exceeds a first preset threshold value, an auxiliary driving circuit connected to the pull-up voltage or the pull-down voltage at the far end is fed back and controlled to be started, so that the row driving signal at the far end is accelerated and stabilized to a target level. According to the scheme, limitation of a pixel structure or a row selection signal can be avoided, the row driving signal at the far end can be rapidly stabilized to the target level, the stabilizing time of row driving can be shortened, the reading speed can be increased, the situation that voltage difference is formed between the far-end signal and the near-end signal and influences reading of the far-end signal can be avoided, and the reading efficiency is improved. Therefore, a fixed pattern on the image is prevented from being formed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of image sensors, in particular to a method for accelerating the stabilization of row drive signals at a remote end and an image sensor. BACKGROUND

[0002] An image sensor is a device that converts an optical image into an electric signal by using the photoelectric conversion function of a photoelectric device in a pixel array. The image information is recorded by processing and storing the electric signal through peripheral circuits.

[0003] In an image sensor, a row drive circuit is usually connected to one end of a pixel array. Adjacent one or several rows of pixel units share a row drive signal. However, the distance between different pixel units in the pixel array and the row drive circuit at the end is different, and the settling time of the drive signal is also different when the level changes. Generally, the closer the distance to the drive circuit, the faster the signal stabilizes, which is called a row drive near-end signal. The farther the distance to the drive circuit, the slower the signal stabilizes, which is called a row drive far-end signal.

[0004] As the resolution of image sensors improves, the pixel array becomes larger. On the one hand, the distance between the far-end pixel unit and the drive circuit becomes larger, and the metal resistance becomes larger. On the other hand, the number of pixel units connected to a drive line also increases, and the capacitive load becomes larger. Therefore, the resistance-capacitance delay (RC delay) of the row drive far-end signal becomes larger, and a longer settling time is required, which seriously affects the time of row operation and slows down the frame rate of image readout. In addition, if the far-end signal cannot be stabilized, there will be a voltage difference between the far-end signal and the near-end signal, which will affect the readout of the far-end signal and form a fixed pattern (FPN: fixed pattern noise) on the image.

[0005] To accelerate the stabilization of the far-end signal, some solutions propose sending a row selection signal to the far end and adding a drive at the far end. The near-end and far-end drive are used simultaneously to accelerate the stabilization of the far-end signal. However, these solutions have a common feature that the drive circuit at the far end needs the control of the row selection signal, and cannot be used for pixel units without a row selection signal, such as 3T pixel structure (which does not include a selection transistor). SUMMARY

[0006] Based on the above-described problems, the present application proposes a method for accelerating the stabilization of row drive signals at a remote end and an image sensor. It can quickly stabilize the row drive signal at the far end to the target level without being limited by the pixel structure or the row selection signal, avoid the formation of a voltage difference between the far-end signal and the near-end signal, affect the readout of the far-end signal, and thus avoid the formation of a fixed pattern on the image.

[0007] In a first aspect, the present application provides a method for accelerating the stability of a row drive signal at a remote end, characterized by comprising the following steps: Step S1, detecting a remote end level of the row drive signal; Step S2, comparing the detected remote end level with a first preset threshold, if the remote end level exceeds the first preset threshold, directly entering step S4 or entering step S3, if the remote end level does not exceed the first preset threshold, returning to step S1 for continuous execution; Step S3, judging whether the current time is within a valid driving time or an invalid driving time, if it is within the valid driving time, entering step S4, if it is within the invalid driving time, returning to step S1 for continuous execution again; Step S4, feedback control connecting to turn on a pull-up voltage auxiliary driving circuit or a pull-down voltage auxiliary driving circuit at the remote end, so as to accelerate the stability of the row drive signal at the remote end to a target level.

[0008] Preferably, one or both of the pull-up voltage auxiliary driving circuit and the pull-down voltage auxiliary driving circuit are connected to the remote end; when both are connected, the method further comprises the following steps: Step S01, detecting the remote end level; Step S02, judging whether an upcoming rising edge or a falling edge is based on the remote end level, if the upcoming rising edge, entering step S03, if the upcoming falling edge, entering step S04; Step S03, controlling the pull-down voltage auxiliary driving circuit to remain closed, and controlling the pull-up voltage auxiliary driving circuit to be in a feedback control state; Step S04, controlling the pull-up voltage auxiliary driving circuit to remain closed, and controlling the pull-down voltage auxiliary driving circuit to be in a feedback control state.

[0009] Preferably, the pull-up voltage auxiliary driving circuit or the pull-down voltage auxiliary driving circuit is closed by any of the following ways, after the pull-up voltage auxiliary driving circuit or the pull-down voltage auxiliary driving circuit is turned on, maintaining the opening for a preset period of time and then automatically closing; or, after the pull-up voltage auxiliary driving circuit or the pull-down voltage auxiliary driving circuit is turned on, continuing to detect the remote end level change in real time, and when the detected remote end level change exceeds a second preset threshold, feedback control is performed to close the corresponding pull-up voltage auxiliary driving circuit or pull-down voltage auxiliary driving circuit.

[0010] In a second aspect, the present application provides an image sensor driven by the method for accelerating the stability of a row drive signal at a remote end according to any of the preceding embodiments, the image sensor comprising: A pixel array comprising a plurality of pixel rows, each pixel row having a first end and a second end opposite to the first end as the far end; A row driving circuit is coupled to the first end to provide a row driving signal from the first end to the pixel row; A remote driving circuit is coupled to the second terminal. The remote driving circuit includes several sub-remote driving circuits, each including the pull-up voltage auxiliary driving circuit and / or the pull-down voltage auxiliary driving circuit.

[0011] Preferably, the sub-remote driving circuit further includes a control circuit that predicts whether the upcoming remote driving signal is a rising edge or a falling edge.

[0012] Preferably, the control circuit includes a mask signal generation circuit, which is controlled by a first pulse signal. When the first pulse signal is at a first level, the control circuit detects the far-end level and outputs a mask signal, wherein the level of the mask signal represents the level of the far-end level. Wherein, if the mask signal is low, it indicates that the upcoming remote row drive signal is a rising edge; if the mask signal is high, it indicates that the upcoming remote row drive signal is a falling edge; or, If the mask signal is high, the upcoming remote row drive signal is indicated by a rising edge; if the mask signal is low, the upcoming remote row drive signal is indicated by a falling edge.

[0013] Preferably, the control circuit controls the pull-up voltage auxiliary drive circuit or the pull-down voltage auxiliary drive circuit to be in a closed state or in a feedback control state through the first pulse signal and the mask signal.

[0014] Preferably, the sub-remote driving circuit further includes: A first feedback circuit, comprising a first sub-comparison circuit, is used to detect the remote end level and determine whether the remote end level rises above a first sub-preset value. If it exceeds the first sub-preset value, the first feedback circuit controls the pull-up voltage auxiliary drive circuit to turn on; or... The second feedback circuit includes a third sub-comparison circuit. The third sub-comparison circuit is used to detect the remote end level and determine whether the remote end level drops below a third sub-preset value. If it exceeds the third sub-preset value, the second feedback circuit controls the pull-down voltage auxiliary drive circuit to turn on.

[0015] Preferably, the first feedback circuit further includes a second sub-comparison circuit, which is used to detect the far-end level and determine whether the far-end level continues to rise beyond a second sub-preset value. If it exceeds the second sub-preset value, the first feedback circuit controls the pull-up voltage auxiliary drive circuit to turn off; or, The second feedback circuit further includes a fourth sub-comparison circuit, which is used to detect the far-end level and determine whether the far-end level continues to drop beyond a fourth sub-preset value. If it exceeds the fourth sub-preset value, the second feedback circuit controls the pull-down voltage auxiliary drive circuit to turn off.

[0016] Preferably, the first feedback circuit is modulated by a first adjustable pulse. After its feedback control activates the corresponding pull-up voltage auxiliary drive circuit, the closure of the pull-up voltage auxiliary drive circuit is controlled by the first adjustable pulse. After an adjustable activation time, the pull-up voltage auxiliary drive circuit automatically closes; or, The second feedback circuit is modulated by the second adjustable pulse. After the feedback control turns on the corresponding pull-down voltage auxiliary drive circuit, the turn-off of the pull-down voltage auxiliary drive circuit is controlled by the second adjustable pulse. After a period of adjustable-width turn-on time, the pull-down voltage auxiliary drive circuit automatically turns off. The first adjustable pulse control and the second adjustable pulse may be the same or different.

[0017] Preferably, the first adjustable pulse control and the second adjustable pulse are the same as or different from the first pulse signal.

[0018] Preferably, the current time is determined to be within the effective driving time by detecting the first pulse signal.

[0019] Compared with existing technologies, the technical solution of this invention has the following beneficial effects: On the one hand, the method and image sensor provided by this invention for accelerating the stabilization of the far-end line drive signal directly detects the far-end level of the line drive signal and compares it with a preset first threshold. When the change in the line drive signal exceeds the first preset threshold, feedback control is activated to turn on the pull-up voltage auxiliary drive circuit or pull-down voltage auxiliary drive circuit connected to the far end, thereby accelerating the stabilization of the far-end line drive signal to the target level, reducing the stabilization time of the line drive, and improving the reading speed. This solution is not limited by pixel structure or line selection signal, and can quickly stabilize the far-end line drive signal to the target level, avoiding voltage differences between the far-end signal and the near-end signal from affecting the reading of the far-end signal, thereby avoiding the formation of fixed patterns on the image.

[0020] On the other hand, the method and image sensor for accelerating the stabilization of the remote line drive signal provided by the present invention can be configured with only one of the pull-up voltage auxiliary drive circuit and the pull-down voltage auxiliary drive circuit at the remote end, or both. The control circuit is controlled to activate only one of the pull-up voltage auxiliary drive circuit and the pull-down voltage auxiliary drive circuit at a given time based on the rising edge and falling edge. This allows for precise matching regardless of whether the remote level is rising, falling, or rising for some time and falling for others. This enables the remote level to stabilize to the target level quickly under different conditions, reducing the stabilization time of the line drive and improving the reading speed.

[0021] In addition, by limiting the pull-up voltage auxiliary drive circuit or the pull-down voltage auxiliary drive circuit to be turned on only during the effective drive time, circuit failures caused by erroneous voltage pull-ups during the ineffective drive time can be avoided, and power consumption can be further saved. Attached Figure Description

[0022] The accompanying drawings, which form part of this specification, are used to further understand the invention. The drawings illustrate embodiments of the invention and, together with the specification, serve to explain the principles of the invention.

[0023] Figures la-d Example of an embodiment of a method for accelerating the stabilization of remote line drive signals.

[0024] Figure 2a An example of an image sensor corresponding to a method for accelerating the stabilization of the remote line drive signal.

[0025] Figure 2b This is an example of a remote drive circuit.

[0026] Figure 3a This is an example of a remote drive circuit.

[0027] Figure 3b This is yet another example of a remote drive circuit.

[0028] Figure 3c This is yet another example of a remote drive circuit.

[0029] Figure 3d This is the timing diagram for the control circuit.

[0030] Figures 4a-b Example of a comparator in a child remote drive circuit.

[0031] Figure 5a This is yet another example of a remote drive circuit.

[0032] Figure 5b This is another example of a child remote drive circuit.

[0033] Figure 5c This is yet another example of a remote drive circuit. Detailed Implementation

[0034] The following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0035] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the present invention.

[0036] In a first aspect, the present invention provides a method for accelerating the stabilization of remote line drive signals, such as... Figure la The image shows an example of this method, which includes the following steps: Step S1: Detect the far-end level of the line drive signal.

[0037] Step S2: Compare the detected remote level with a preset first threshold. If the remote level exceeds the first preset threshold, proceed directly to step S4 or step S3. If it does not exceed the first preset threshold, return to step S1 to continue execution.

[0038] Step S3: Determine whether the current time is within the valid driving time or the invalid driving time. If it is within the valid driving time, proceed to step S4; if it is within the invalid driving time, return to step S1 and continue execution. Step S4: Control the auxiliary driving circuit to turn on. Specifically, the auxiliary driving circuit may include one or both of a pull-up voltage auxiliary driving circuit or a pull-down voltage auxiliary driving circuit. By controlling the pull-up voltage auxiliary driving circuit or pull-down voltage auxiliary driving circuit connected to the remote end to turn on, the row driving signal at the remote end can be accelerated to stabilize to the target level, which can reduce the stabilization time of the row driving, improve the reading speed, and avoid the voltage difference between the remote end signal and the near end signal affecting the reading of the remote end signal, thereby avoiding the formation of fixed patterns on the image.

[0039] In addition, by limiting the pull-up voltage auxiliary drive circuit or the pull-down voltage auxiliary drive circuit to be turned on only during the effective drive time, circuit failures caused by erroneous voltage pull-ups during the ineffective drive time can be avoided, and power consumption can be further saved.

[0040] It is understandable that the first preset threshold is only a general term for a type of attribute value. It is understandable that the pull-up voltage auxiliary drive circuit is used to accelerate the pull-up of the second-end horizontal drive signal to stabilize it to the first target level when the horizontal drive signal at the first end starts to rise; the pull-down voltage auxiliary drive circuit is used to accelerate the pull-down of the second-end horizontal drive signal to stabilize it to the second target level when the horizontal drive signal at the first end starts to fall. Among them, judging whether the far-end level exceeds the first preset threshold includes two cases: (1) during the pull-up process, judging whether the far-end level rises above the first sub-preset value; (2) during the pull-down process, judging whether the far-end level falls below the third sub-preset value. It can be seen that the first preset threshold can be different in different scenarios.

[0041] Preferably, when the remote end is connected to both a pull-up voltage auxiliary drive circuit and a pull-down voltage auxiliary drive circuit, in order to avoid the pull-up voltage auxiliary drive circuit and the pull-down voltage auxiliary drive circuit being turned on simultaneously and causing incorrect voltage pull-up, such as... Figure lb As shown, the method provided by the present invention further includes the following steps before step S4: Step S01: Detect the remote end voltage level.

[0042] Step S02: Based on whether the upcoming remote level is a rising edge or a falling edge, if it is a rising edge, proceed to step S03; if it is a falling edge, proceed to step S04.

[0043] Step S03: Keep the pull-down voltage auxiliary drive circuit closed and keep the pull-up voltage auxiliary drive circuit in a feedback control state.

[0044] Step S04: Keep the pull-up voltage auxiliary drive circuit closed and keep the pull-down voltage auxiliary drive circuit in a feedback control state.

[0045] Preferably, either the pull-up voltage auxiliary drive circuit or the pull-down voltage auxiliary drive circuit can be turned off in either of the following ways: First, after the pull-up voltage auxiliary drive circuit or the pull-down voltage auxiliary drive circuit is turned on, it is maintained on for a preset time period and then automatically turned off; such as Figure lc It is illustrated that after step S4, the following steps are included: S5: The auxiliary drive circuit is kept on for a preset period of time, and then the auxiliary drive circuit is automatically turned off.

[0046] The auxiliary drive mentioned here can refer to a pull-up voltage auxiliary drive circuit or a pull-down voltage auxiliary drive circuit, and the same applies in the context. Secondly, after the pull-up voltage auxiliary drive circuit or the pull-down voltage auxiliary drive circuit is turned on, it continues to detect changes in the remote end level in real time, and when the detected change in the remote end level exceeds a second preset threshold, it feeds back to control the auxiliary drive circuit to turn off. For example... Figure IdAs shown, after step S4, the following steps are included: S5´: Continue probing the far-end level of the row drive signal; S6': Compare the remote end level with the preset second preset threshold and determine whether the remote end level exceeds the second preset threshold; if it exceeds the second preset threshold, proceed to step S7', otherwise proceed to the S5' loop.

[0047] S7´: Controls the auxiliary drive circuit to shut down.

[0048] Similar to the first preset threshold, determining whether the remote level exceeds the second preset threshold includes two cases: (1) during the pull-up process, determining whether the remote level continues to rise beyond the second sub-preset value; (2) during the pull-down process, determining whether the remote level continues to fall beyond the fourth sub-preset value. It can be seen that the second preset threshold can be different in different scenarios. It is understandable that the second preset threshold is only a general term for a type of attribute value.

[0049] Secondly, the present invention provides an image sensor driven by a method for stabilizing a remote line drive signal according to any of the foregoing embodiments, such as... Figure 2a The image sensor shown is an example of an image sensor using the method for stabilizing the line drive signal at the far end provided by the present invention. The image sensor includes: a pixel array 30, which includes a plurality of pixel rows (not shown), each pixel row having a first end (proximal end) and a second end opposite to the first end, the second end serving as the far end; a line drive circuit 10 disposed at the proximal end, which is coupled to the first end to provide a line drive signal from the first end to the pixel row; the line drive circuit 10 can generate various line drive signals for line driving, such as a reset control signal RST, a transfer transistor control signal Tx, a line selection signal SEL, a dual conversion gain control signal DCG, and other line drive signals besides those listed above, and the specific embodiments are not limited thereto. A far end drive circuit 20 disposed at the far end is coupled to the second end. For example, as shown... Figure 2b As shown, the remote driving circuit 20 includes several sub-remote driving circuits 201, ..., 2020. n Where n≥1 and is an integer, the sub-far end drive circuit includes one or both of a pull-up voltage auxiliary drive circuit and a pull-down voltage auxiliary drive circuit.

[0050] Preferably, a plurality of sub-far-end driving circuits can be formed in an array to correspond to the second end of a pixel row, or to the second end of a plurality of different row driving signal outputs for any pixel row. For example, each sub-far-end driving circuit can be configured one-to-one with each pixel row to meet the requirement of stable row driving signals for each row of pixels; alternatively, sub-far-end driving circuits can be configured only for a subset of pixel rows, such as those pixel rows where the instability of a certain type of row driving signal is very obvious; furthermore, depending on the actual situation, several pixel rows with the same row driving signal type can be configured to share a sub-far-end driving circuit at their respective second ends; alternatively, depending on the actual situation, the second ends corresponding to different row driving signal types can be configured to share a sub-far-end driving circuit. The foregoing examples are merely illustrative; specific embodiments are not limited by the number of pixel rows corresponding to the sub-far-end driving circuit, the position of the pixel rows, or the type of row driving signal, etc., and can all be configured as needed, all within the scope of this invention.

[0051] Preferred, such as Figures 3a-b As shown in Figures 5a and 5b, the sub-far-end drive circuit includes pull-up voltage auxiliary drive circuits 21 and 25. The pull-up voltage auxiliary drive circuit may include a first switching module M. 3a M 5a and connected to the first switch module M 3a M 5a One end has a first high-level potential VDD, the potential of which is adjustable, and the first switch module M 3a M 5a The other end is connected to the second end (far end) of several pixel rows, the first switch module M 3a M 5a Controlled by the feedback signal output from the first feedback circuits 23 and 27; the first switching module may be a PMOS transistor as shown in the attached diagram, or other types of switching modules, and the specific embodiments are not limited thereto. The pull-down voltage auxiliary drive circuits 22 and 26 include a second switching module M. 3b M 5b and connected to the second switch module M 3b M 5b One end of the first low-level potential VSS (where the level of the first low-level potential VSS is adjustable), the second switch module M 3b M 5b The other end is connected to the second end (far end) of several pixel rows, the second switch module M 3b M 5b It is controlled by the feedback signal output by the second feedback circuit 24, 28. The second switching module may be, for example, an NMOS transistor as shown in the attached figure, or other types of switching modules, and the specific embodiments are not limited thereto.

[0052] Preferably, the sub-remote drive circuits further include a first feedback circuit and / or a second feedback circuit. (See attached diagram) Figure 3a For example, the first feedback circuit 23 includes a first sub-comparison circuit, which may include, for example, a comparator Comp1 and an NOT gate 232. The first sub-comparison circuit is used to detect the far-end level V of the row drive signal. B And determine the remote level V B If the voltage rises above a first preset value, and if it does, the first feedback circuit 23 controls the pull-up voltage auxiliary drive circuit 21 to turn on. The first feedback circuit 23 also includes a second sub-comparison circuit, which may include, for example, a comparator Comp2. The second sub-comparison circuit is used to detect the remote level V. B And determine the remote level V B If the value continues to rise beyond the second sub-preset value, and if it does, the first feedback circuit 23 controls the pull-up voltage auxiliary drive circuit 21 to shut down. The first feedback circuit 23 also includes an NOT gate 232 and a NAND gate 231 connected to the output of the comparator Comp1. The first and second inputs of the NAND gate 231 are respectively connected to the comparison results of the first and second sub-preset thresholds to control the first switching module M. 3a Turning it on and off.

[0053] As attached Figure 3b For example, the second feedback circuit 24 includes a third sub-comparison circuit, which includes a comparator Comp3 and an NOT gate 242. The third sub-comparison circuit is used to detect the remote level V. B And determine the remote level V B If the voltage drop exceeds the third sub-preset value, the second feedback circuit 24 controls the pull-down voltage auxiliary drive circuit 22 to turn on. The second feedback circuit 24 also includes a fourth sub-comparison circuit, which may include, for example, Comp4. The fourth sub-comparison circuit is used to detect the remote level V. B And determine the remote level V B If the voltage continues to drop beyond the fourth sub-preset value, and if it does, the second feedback circuit 24 controls the pull-down voltage auxiliary drive circuit 22 to shut down. The second feedback circuit 24 also includes NOT gate 242, NAND gate 241, and NOT gate 243 connected to the output of comparator Comp3. The first and second inputs of NAND gate 241 are respectively connected to the comparison results of the first and second sub-preset thresholds. This result is processed by NOT gate 243 and then applied to the second switching module M. 3b The control terminal controls the pull-down voltage auxiliary drive circuit 22 to turn on and off.

[0054] As an optional comparator example in an embodiment of the present invention, the appendix... Figure 4aIn this context, the comparator may include a transistor M. 1p M 1n Transistor M can be made more flexible by setting a sufficient aspect ratio or other methods. 1p With a sufficiently large on-resistance, its output voltage EN depends only on M. 1n The operating state of the transistor, and transistor M 1p Alternatively, multiple MOSFETs can be connected in series. The remote drive signal V... B With M 1n The threshold voltage V of the tube thn The sum of the voltage VSS and the ground voltage is compared, and the level V of the remote drive signal is... B Greater than M 1n The threshold voltage V of the tube thn When M is the sum of the ground voltage VSS, 1n When the transistor is turned on, EN toggles from high to low.

[0055] Appendix Figure 4b In, M 2n By setting a sufficient width-to-length ratio or other methods, its on-resistance can be made large enough that the output voltage EN' depends only on M. 2p The working status of the pipe. M 2n Alternatively, multiple MOSFETs can be connected in series. The remote signal V... B Will with M 2p The threshold voltage V of the tube thp Compare the sum of the voltage and ground voltage VSS. When the level of the remote signal is greater than M... 2p When the threshold voltage and high voltage VDD of the transistor are combined, M 2p When the transistor is turned on, EN' toggles from high to low.

[0056] With attachment Figures 3a-b For example, in the embodiments shown below Figure 3a In the above, comparator Comp1 is used to compare the row drive signal V at the second terminal. B The comparator checks whether the rise in voltage level exceeds the first preset threshold. If yes, it outputs EN1 at a low level; otherwise, it outputs EN1 at a high level. The output of comparator Comp2 is connected to the second input of the first logic NAND gate 231, used to compare the voltage level V of the row drive signal at the second input. B If the rise exceeds the second preset threshold, output EN2 at a low level; otherwise, output EN2 at a high level.

[0057] Appendix Figure 3b In the above, comparator Comp3 is used to compare the level V of the row drive signal at the second terminal. B If the drop exceeds the third preset threshold, output EN1' low; otherwise, output EN1' high. Comparator Comp4 is used to compare the level V of the row drive signal at the second terminal.B If the drop exceeds the fourth preset threshold, output EN2' low level; otherwise, output EN2' high level.

[0058] The comparators involved in the embodiments of the present invention can be selected from the aforementioned example comparators according to actual needs to simplify the circuit. Optionally, the comparators used in the embodiments of the present invention can also be configured using Schmitt triggers or other types of comparators, which will not be elaborated further.

[0059] Preferably, after the pull-up voltage auxiliary drive circuit or the pull-down voltage auxiliary drive circuit is turned on, the first feedback circuit and the second feedback circuit can maintain the corresponding pull-up voltage auxiliary drive circuit or pull-down voltage auxiliary drive circuit on for a preset time period and then automatically turn it off. (Illustrative example, such as...) Figure 5a As shown, the first feedback circuit 27 includes a Schmitt trigger 273, an NOT gate 272, and a NAND gate 271 connected in series. The output of the NOT gate 272 is connected to the first input of the NAND gate 271. The second input of the NAND gate 271 is connected to a first adjustable pulse DEN1. By connecting the first adjustable pulse signal to the second input of the NAND gate 271, after the first feedback circuit 27 controls the activation of the pull-up voltage auxiliary drive circuit 25, the activation time of the pull-up voltage auxiliary drive circuit 25 can be controlled by the first adjustable pulse DEN1. The first feedback circuit 27 is controlled by the first adjustable pulse DEN1. After a period of adjustable activation time, the pull-up voltage auxiliary drive circuit 25 automatically deactivates. Optionally, the Schmitt trigger 273 and the NOT gate 272 can be omitted, and the remote level V can be connected to the first input of the NAND gate 271. B The sum of the threshold voltage of NAND gate 271 and the ground level VSS of NAND gate 271 can be used as the first preset threshold (first sub-preset threshold) to complete the comparison of the first preset threshold (first sub-preset threshold) (equivalent to a first sub-comparison circuit). The pulse width of the first adjustable pulse DEN1 can be adjusted using digital circuitry. The rising edge of the first adjustable pulse DEN1 is related to the near-end signal VSS. A Alignment with the rising edge of the near-end signal V A When it begins to rise, attached Figure 5a The circuit shown will start working. When the remote signal V B When the voltage level exceeds the first preset threshold (first sub-preset threshold), the first switch module M... 5a Conduction, acceleration signal V B Pull up until the falling edge of the first adjustable pulse DEN1 arrives, causing the first switching module M to... 5a When the circuit is cut off, the pull-up voltage auxiliary drive circuit 25 will automatically shut down.

[0060] like Figure 5bAs shown, the second feedback circuit 28 may include a Schmitt trigger 283, a NOT gate 282, and a NOR gate 281. The output of the Schmitt trigger 283 is connected to the input of the NOT gate 282. The output of the NOT gate 282 is connected to the first input of the NOR gate 281. The second input of the NOR gate 281 is connected to the second adjustable pulse DEN2. By connecting the second adjustable pulse DEN2 to the second input of the NOR gate 281, after the second feedback circuit controls the opening of the pull-down voltage auxiliary drive circuit 26, the opening time of the pull-down voltage auxiliary drive circuit 26 is controlled by the second adjustable pulse DEN2. After a period of adjustable opening time, the pull-down voltage auxiliary drive circuit 26 automatically closes. The Schmitt trigger 283 can be used to set the comparison of the first preset threshold (third sub-preset threshold). Alternatively, an inverter (NOT gate) can be used instead of the Schmitt trigger 283. In this case, the sum of the inverter's threshold voltage and ground voltage VSS can be used as the first preset threshold (third sub-preset threshold) to complete the comparison (equivalent to a third sub-comparison circuit). The second adjustable pulse DEN2 is a pulse signal connected to the second input of the NOR gate 281, and its pulse width can be adjusted using digital circuitry. The rising edge of the second adjustable pulse DEN2 coincides with the near-end signal V... A The falling edge is aligned. When the near-end signal V A This circuit starts working as the descent begins. When the remote signal V... B When the voltage level is lower than the first preset threshold (third sub-preset threshold), the second switch module M... 5b The circuit is turned on, and the acceleration signal is pulled down until the falling edge of the second adjustable pulse DEN2 arrives, M 5b When the circuit is closed, the pull-down voltage auxiliary drive circuit 26 automatically shuts down.

[0061] Preferably, the second adjustable pulse DEN2 is the same as the first adjustable pulse DEN1 to significantly reduce wiring and lower costs. When the second adjustable pulse DEN2 and the first adjustable pulse DEN1 are the same, if the pull-down voltage auxiliary drive circuit 26 operates alone, the second adjustable pulse DEN2 needs to be connected to the second input terminal of the NOR gate 281 through the NOT gate 284. Optionally, the second adjustable pulse DEN2 and the first adjustable pulse DEN1 can be different.

[0062] In image sensors, for certain signals, the falling edge of the previous line and the rising edge of the next line may occur simultaneously. If auxiliary drive circuits are used to accelerate both the falling and rising edges, this may cause the pull-up and pull-down auxiliary drive circuits to conduct simultaneously, leading to circuit failure. Therefore, this invention provides a preferred embodiment in which the sub-far-end drive circuit further includes a control circuit. The control circuit is used to predict whether the upcoming far-end row drive signal is a rising edge or a falling edge. Specifically, if the control circuit predicts that the upcoming edge is a rising edge, it controls the pull-down auxiliary drive circuit to remain off and controls the pull-up auxiliary drive circuit to be in a feedback control state; if the control circuit predicts that the upcoming edge is a falling edge, it controls the pull-up auxiliary drive circuit to remain off and controls the pull-down auxiliary drive circuit to be in a feedback control state. Accordingly, the aforementioned problem of simultaneous conduction can be solved, and the problem of the pull-up and pull-down auxiliary drive circuits working simultaneously due to other reasons can also be avoided.

[0063] Preferably, the control circuit includes a mask signal generation circuit, which is controlled by a first pulse signal. When the first pulse signal is at a first level, the control circuit detects the far-end level and outputs a mask signal, the level of which represents the level of the far-end level. Optionally, if the mask signal is low, it indicates that the far-end line drive signal is about to have a rising edge; if the mask signal is high, it indicates that the far-end line drive signal is about to have a falling edge; or, if the mask signal is high, it indicates that the far-end line drive signal is about to have a rising edge; if the mask signal is low, it indicates that the far-end line drive signal is about to have a falling edge.

[0064] Optionally, the first pulse signal may contain valid or invalid drive time information. By detecting and analyzing the first pulse signal, it can be determined whether the current time is within the valid drive time or the invalid drive time.

[0065] For example, such as Figure 3c As shown, an example is attached. Figures 3a-b When all circuits are connected to the remote end, a specific example of the control circuit includes a latch 610 and several logic gates (e.g., NOR gates 611, 616, NAND gates 612, 617, Schmitt trigger 613, NOT gate 615) and a first pulse signal DEN. The control circuit can control the remote level V of the row drive signal. B Detect and generate a new mask signal Ms, through, as... Figure 3cThe connection relationship of the logic gates shown (e.g., NOR gates 611, 616, NAND gates 612, 617, NOT gate 615; the logic gate cases are only examples, and specific embodiments are not limited thereto) can generate a logical relationship between the first pulse signal DEN and the mask signal Ms, thereby coordinating to control the pull-up voltage auxiliary drive circuit and the pull-down voltage auxiliary drive circuit to remain in the off state or to be in a feedback control state.

[0066] Controlled by the mask signal Ms and the first pulse signal DEN, only one of the pull-up voltage auxiliary drive circuit and the pull-down voltage auxiliary drive circuit will be on at any given time, while the other will be off. Furthermore, the pull-up voltage auxiliary drive circuit and the pull-down voltage auxiliary drive circuit can also be controlled by their corresponding feedback circuits to precisely match the pull-up requirements. (Appendix) Figure 3c The example illustrates that the mask signal Ms can be generated using a latch 610, but it can also be generated using a trigger or other probe. Furthermore, the control circuit provided in this embodiment also incorporates a Schmitt trigger 613, which can reduce the impact of glitches at the far-end level on the circuit.

[0067] With attachment Figure 3c For example, when the first pulse signal DEN is low, the far-end level V of the horizontal drive signal... B The signal will be detected in latch 610, which outputs a mask signal Ms. When the remote level is low, the mask signal Ms is low, at which point the pull-up voltage auxiliary drive circuit 21 is enabled and in a feedback control state, while the pull-down voltage auxiliary drive circuit is disabled. When the next pulse of the first pulse signal DEN arrives, the pull-up voltage auxiliary drive circuit 21 will receive feedback and accelerate the pull-up. When the remote level V... B When the signal is high, the mask signal Ms is high. At this time, the pull-up voltage auxiliary drive circuit 21 is disabled, and the pull-down voltage auxiliary drive circuit 22 is enabled, placing it in a feedback control state. Therefore, when the next pulse of the first pulse signal DEN arrives, the pull-down voltage auxiliary drive circuit 22 will receive feedback and turn on to accelerate the pull-down. For example... Figure 3d The diagram illustrates the timing sequence of the operation. It shows that when the first pulse signal DEN is low (i.e., both pull-up and pull-down enable are disabled), continuous time probing of the remote signal generates a mask signal Ms, which determines whether the next edge is a rising or falling edge. The first pulse signal DEN is divided into DEN signals using the mask signal Ms and corresponding logic gates. up and DEN dn They respectively control the enable of the pull-up voltage auxiliary drive circuit 21 and the enable of the pull-down voltage auxiliary drive circuit 22.

[0068] like Figure 5cAs shown, an example is attached. Figures 5a-b When all circuits are connected to the remote end, a specific example of the control circuit is as follows: Control circuit 60 includes a latch 610 and several logic gates (e.g., NOR gate 611, NAND gate 612, Schmitt trigger 613, NOT gate 615, NAND gate 271, NOR gate 281, etc.; the logic gate configuration is merely an example, and specific embodiments are not limited thereto). In this embodiment, the control circuit also includes a Schmitt trigger 613. The inclusion of the Schmitt trigger 613 can reduce the impact of glitches in the remote level on the circuit. It can be seen that the control circuit 60 of this embodiment and the attached... Figure 3c The examples differ slightly, but the principles are similar. Both achieve the control of the pull-up voltage auxiliary drive circuit and the pull-down voltage auxiliary drive circuit to remain in a closed state or a feedback control state by generating a logical relationship between the first pulse signal DEN and the mask signal Ms., which will not be elaborated further here.

[0069] Preferably, the first pulse signal DEN can share a single first adjustable pulse DEN1 and second adjustable pulse DEN2. Specifically, they can be categorized according to different row drive signal types, with similar signals sharing a single first pulse signal DEN to significantly reduce wiring. For example, one pulse signal can be used for multiple reset controls RST, while another pulse signal can be used for multiple transfer transistors Tx. Optionally, the first pulse signal DEN can also be used differently from the first adjustable pulse DEN1 and second adjustable pulse DEN2.

[0070] The image sensor provided by this invention also includes other common structures, such as a readout circuit 40 and other logic circuits 50 connected to the row drive circuit, etc. In other optional embodiments, the signals of the logic circuit 50 may also be selectively connected to the remote drive circuit 20, such as... Figure 2a As shown, for example, the pulse signal generation circuits of the first pulse signal DEN and the first adjustable pulse DEN1, the second adjustable pulse DEN2, etc., can be set within the module of the logic circuit 50 to reduce the size of the remote driving circuit. The specific details will not be elaborated further in this invention.

[0071] The present invention provides a method and image sensor for accelerating the stabilization of the far-end line drive signal. It directly detects the far-end level of the line drive signal and compares it with a preset first threshold. When the change in the line drive signal exceeds the first preset threshold and is within the effective driving time, feedback control activates the auxiliary drive circuit connected to the far-end pull-up or pull-down voltage, thereby accelerating the stabilization of the far-end line drive signal to the target level. This solution is not limited by pixel structure or line selection signal, and can quickly stabilize the far-end line drive signal to the target level, avoiding voltage differences between the far-end and near-end signals that could affect the far-end signal readout, thus preventing the formation of fixed patterns on the image.

[0072] The basic concepts have been described above. It is clear that the detailed disclosure above is merely illustrative and does not constitute a limitation of the present invention. Although not explicitly stated herein, various modifications, improvements, and corrections may be made to the present invention by those skilled in the art. Such modifications, improvements, and corrections are suggested in this invention and therefore remain within the spirit and scope of the exemplary embodiments of the present invention.

[0073] It should be understood that the embodiments described in this invention are merely illustrative of the principles of the invention. Other modifications may also fall within the scope of this invention. Therefore, alternative configurations of the embodiments of this invention are considered as examples and not limitations, and are regarded as consistent with the teachings of this invention. Accordingly, the embodiments of this invention are not limited to those explicitly described and illustrated herein.

Claims

1. A method for accelerating the stabilization of a remote line drive signal, characterized in that, Includes the following steps: Step S1: Detect the far-end level of the row drive signal; Step S2: Compare the detected remote level with a preset first preset threshold. If the remote level exceeds the first preset threshold, proceed directly to step S4 or step S3. If it does not exceed the first preset threshold, return to step S1 to continue execution. Step S3: Determine whether the current time is within the valid driving time or the invalid driving time. If it is within the valid driving time, proceed to step S4. If it is within the invalid driving time, return to step S1 to continue execution. Step S4: The feedback control connected to the remote end pull-up voltage auxiliary drive circuit or pull-down voltage auxiliary drive circuit is turned on, so that the row drive signal at the remote end is accelerated and stabilized to the target level.

2. The method according to claim 1, characterized in that, The remote end is connected to one or both of a pull-up voltage auxiliary drive circuit and a pull-down voltage auxiliary drive circuit; wherein when both are connected, the method further includes the following steps: Step S01: Detect the remote end voltage level; Step S02: Based on whether the upcoming remote level is a rising edge or a falling edge, if it is a rising edge, proceed to step S03; if it is a falling edge, proceed to step S04. Step S03: Control the pull-down voltage auxiliary drive circuit to remain closed, and control the pull-up voltage auxiliary drive circuit to be in a feedback control state; Step S04: Control the pull-up voltage auxiliary drive circuit to remain closed, and control the pull-down voltage auxiliary drive circuit to be in a feedback control state.

3. The method according to claim 1 or 2, characterized in that, The pull-up voltage auxiliary drive circuit or the pull-down voltage auxiliary drive circuit is turned off in any of the following ways. After the pull-up voltage auxiliary drive circuit or the pull-down voltage auxiliary drive circuit is turned on, it will be turned on for a preset period of time and then automatically turned off. or, After the pull-up voltage auxiliary drive circuit or the pull-down voltage auxiliary drive circuit is turned on, the change in the remote level continues to be detected in real time, and when the change in the remote level is detected to exceed the second preset threshold, the corresponding pull-up voltage auxiliary drive circuit or pull-down voltage auxiliary drive circuit is turned off.

4. An image sensor, driven by the method for accelerating the stabilization of the remote line drive signal according to any one of claims 1 to 3, wherein the image sensor comprises: A pixel array comprising a plurality of pixel rows, each pixel row having a first end and a second end opposite to the first end as the far end; A row driving circuit is coupled to the first end to provide a row driving signal from the first end to the pixel row; A remote driving circuit is coupled to the second terminal. The remote driving circuit includes several sub-remote driving circuits, each including the pull-up voltage auxiliary driving circuit and / or the pull-down voltage auxiliary driving circuit.

5. An image sensor according to claim 4, characterized in that, The sub-remote driving circuit further includes a control circuit, which predicts whether the upcoming remote driving signal is a rising edge or a falling edge.

6. An image sensor according to claim 5, characterized in that, The control circuit includes a mask signal generation circuit, which is controlled by a first pulse signal. When the first pulse signal is at a first level, the circuit detects the remote level and outputs a mask signal. The level of the mask signal represents the level of the remote line drive signal. Wherein, if the mask signal is low, it indicates that the upcoming remote row drive signal is a rising edge; if the mask signal is high, it indicates that the upcoming remote row drive signal is a falling edge; or, If the mask signal is high, the upcoming remote row drive signal is indicated by a rising edge; if the mask signal is low, the upcoming remote row drive signal is indicated by a falling edge.

7. An image sensor according to claim 6, characterized in that, The control circuit controls the pull-up voltage auxiliary drive circuit or the pull-down voltage auxiliary drive circuit to be either kept off or in a feedback control state through the first pulse signal and the mask signal.

8. An image sensor according to claim 4, characterized in that, The sub-remote drive circuit also includes: A first feedback circuit, comprising a first sub-comparison circuit, is used to detect the remote end level and determine whether the remote end level rises above a first sub-preset value. If it exceeds the first sub-preset value, the first feedback circuit controls the pull-up voltage auxiliary drive circuit to turn on; or... The second feedback circuit includes a third sub-comparison circuit. The third sub-comparison circuit is used to detect the remote end level and determine whether the remote end level drops below a third sub-preset value. If it exceeds the third sub-preset value, the second feedback circuit controls the pull-down voltage auxiliary drive circuit to turn on.

9. An image sensor according to claim 8, characterized in that, The first feedback circuit further includes a second sub-comparison circuit, which is used to detect the far-end level and determine whether the far-end level continues to rise beyond a second sub-preset value. If it exceeds the second sub-preset value, the first feedback circuit controls the pull-up voltage auxiliary drive circuit to turn off; or, The second feedback circuit further includes a fourth sub-comparison circuit, which is used to detect the far-end level and determine whether the far-end level continues to drop beyond a fourth sub-preset value. If it exceeds the fourth sub-preset value, the second feedback circuit controls the pull-down voltage auxiliary drive circuit to turn off.

10. An image sensor according to claim 8, characterized in that, The first feedback circuit is modulated by a first adjustable pulse. After its feedback control activates the corresponding pull-up voltage auxiliary drive circuit, the closure of the pull-up voltage auxiliary drive circuit is controlled by the first adjustable pulse. After an adjustable activation time, the pull-up voltage auxiliary drive circuit automatically closes; or, The second feedback circuit is modulated by the second adjustable pulse. After the feedback control turns on the corresponding pull-down voltage auxiliary drive circuit, the turn-off of the pull-down voltage auxiliary drive circuit is controlled by the second adjustable pulse. After a period of adjustable-width turn-on time, the pull-down voltage auxiliary drive circuit automatically turns off. The first adjustable pulse control and the second adjustable pulse may be the same or different.

11. An image sensor according to claim 10, characterized in that, The first adjustable pulse control and the second adjustable pulse may be the same as or different from the first pulse signal.

12. An image sensor according to claim 11, characterized in that, The first pulse signal is detected to determine whether the current time is within the effective driving time.

Images