Image sensor, control method thereof and computer readable storage medium

Abstract

The invention provides an image sensor, a control method of the image sensor and a readable storage medium, and the image sensor comprises a photoelectric conversion circuit which comprises a first photoelectric conversion sub-circuit; the signal output circuit comprises a floating diffusion node and an overflow circuit, one end of the overflow circuit is connected with the floating diffusion node, and the other end of the overflow circuit is grounded; and the controller is used for controlling the first photoelectric conversion sub-circuit and the overflow circuit to be conducted and enabling the first photoelectric conversion sub-circuit, the floating diffusion node and the overflow circuit to form an overflow path when the barrier heights of the first photoelectric conversion sub-circuit and the overflow circuit meet a preset condition. According to the embodiment of the invention, the charge accommodating range is expanded, and the detection range of the pixel structure in the image sensor on high-intensity light is expanded, so that the dynamic range is effectively expanded, and flicker suppression is realized.

Description

Technical Field

[0001] The present invention relates to the field of image processing technology, and in particular to an image sensor and a control method thereof and a computer-readable storage medium. Background Art

[0002] In the related technologies, the diversity of vehicle driving environments puts forward extremely high technical requirements for CIS (Camera Image Sensor), especially in terms of high dynamic range and LED (Light Emitting Diode) flicker suppression. The current technology still faces some challenges and is unable to improve the dynamic range and suppress LED flicker. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0004] To this end, an object of the present invention is to provide an image sensor that improves the charge accommodation range while increasing the detection range of high-intensity light by a pixel structure in the image sensor, thereby effectively improving the dynamic range and achieving flicker suppression.

[0005] Therefore, a second objective of the present invention is to provide a control method for an image sensor.

[0006] To this end, a third object of the present invention is to provide a non-transitory computer-readable storage medium.

[0007] In order to achieve the above-mentioned purpose, an embodiment of the first aspect of the present invention proposes an image sensor, comprising: a photoelectric conversion circuit, the photoelectric conversion circuit comprising a first photoelectric conversion sub-circuit; a signal output circuit, the signal output circuit comprising a floating diffusion node and an overflow circuit, one end of the overflow circuit is connected to the floating diffusion node, and the other end of the overflow circuit is grounded; the controller is used to: control the first photoelectric conversion sub-circuit and the overflow circuit to be turned on and when the barrier height of the first photoelectric conversion sub-circuit and the overflow circuit meets a preset condition, the first photoelectric conversion sub-circuit, the floating diffusion node and the overflow circuit form an overflow path.

[0008] According to the image sensor of the embodiment of the present invention, by controlling the first photoelectric conversion sub-circuit and the overflow circuit to be turned on and when the barrier height of the first photoelectric conversion sub-circuit and the barrier height of the overflow circuit meet preset conditions, the charge in the first photoelectric conversion sub-circuit can be transmitted to the overflow circuit to form an overflow path composed of the first photoelectric conversion sub-circuit, the floating diffusion node and the overflow circuit, and the excess charge after the first photoelectric conversion sub-circuit is fully loaded is transmitted through the overflow path to form an overflow path that can accommodate the excess charge. While improving the charge accommodation range, the detection range of the pixel structure in the image sensor to high-intensity light is improved, thereby effectively improving the dynamic range and achieving flicker suppression.

[0009] In addition, the image sensor according to the above embodiment of the present invention may also have the following additional technical features:

[0010] In some embodiments, the overflow circuit includes: a dual conversion gain control transistor, a source of which is connected to the floating diffusion node; an overflow capacitor, one end of which is connected to the drain of the dual conversion gain control transistor, and the other end of which is grounded.

[0011] In some embodiments, the first photoelectric conversion sub-circuit includes: a first photodiode, the anode of the first photodiode is grounded; a first transfer transistor, the source of the first transfer transistor is connected to the cathode of the first photodiode, and the drain of the first transfer transistor is connected to the floating diffusion node, for turning on or off the path between the first photodiode and the floating diffusion node.

[0012] In some embodiments, the barrier heights of the first photoelectric conversion sub-circuit and the overflow circuit meet a preset condition, including: the barrier height of the first transfer transistor is higher than the barrier height of the overflow circuit.

[0013] In some embodiments, the photoelectric conversion circuit further includes: at least one second photoelectric conversion sub-circuit.

[0014] In some embodiments, the second photoelectric conversion subcircuit includes: a second photodiode, the anode of the second photodiode is grounded; a second transfer transistor, the source of the second transfer transistor is connected to the cathode of the second photodiode, and the drain of the second transfer transistor is connected to the floating diffusion node.

[0015] In some embodiments, when controlling the first photoelectric conversion sub-circuit and the overflow circuit to be turned on, the controller is further used to: control the second transfer transistor to be turned off.

[0016] In some embodiments, after controlling the second transmission transistor to turn off, the controller is also used to: control the first transmission transistor and the dual conversion gain control transistor to turn off, so as to obtain a first reset signal of the photoelectric conversion circuit under high conversion gain after the first transmission transistor and the dual conversion gain control transistor are turned off.

[0017] In some embodiments, after obtaining the first reset signal of the photoelectric conversion circuit under high conversion gain, the controller is also used to: control the first transfer transistor to be turned on, so as to control the first transfer transistor to be turned off when the charge in the first photodiode is transferred to the floating diffusion node, so as to obtain the first valid signal of the photoelectric conversion circuit under high conversion gain.

[0018] In some embodiments, after obtaining the first valid signal of the photoelectric conversion circuit under high conversion gain, the controller is also used to: control the dual conversion gain control transistor and the first transfer transistor to be turned on, so as to obtain the first valid signal of the photoelectric conversion circuit under low conversion gain when the charge in the first photodiode is transferred to the floating diffusion node and the overflow capacitor.

[0019] In some embodiments, the signal output circuit further includes: a reset transistor, a drain of the reset transistor is connected to a power supply voltage, and a source of the reset transistor is connected to the floating diffusion node.

[0020] In some embodiments, after obtaining the first valid signal of the photoelectric conversion circuit under low conversion gain, the controller is also used to: control the reset transistor to be turned on, so as to control the reset transistor to be turned off after the floating diffusion node and the overflow capacitor are reset, so as to obtain the first reset signal of the photoelectric conversion circuit under low conversion gain.

[0021] In some embodiments, after obtaining a first reset signal of the photoelectric conversion circuit at a low conversion gain, the controller is further used to: control the dual conversion gain control transistor to turn off to obtain a second reset signal of the photoelectric conversion circuit at a high conversion gain.

[0022] In some embodiments, after controlling the dual conversion gain control transistor to turn off, the controller is also used to: control the second transfer transistor to turn on, so as to control the second transfer transistor to turn off when the charge of the second photodiode is transferred to the floating diffusion node, so as to obtain a second effective signal of the photoelectric conversion circuit under high conversion gain.

[0023] In some embodiments, after obtaining the second valid signal of the photoelectric conversion circuit at a high conversion gain, the controller is also used to: control the dual conversion gain control transistor to be turned on and the second transfer transistor to be turned on, so as to obtain the second valid signal of the photoelectric conversion circuit at a low conversion gain when the charge of the second photodiode is transferred to the floating diffusion node and the overflow capacitor.

[0024] In some embodiments, the signal output circuit also includes: an amplifying transistor, the drain of which is connected to the power supply voltage, and the gate of which is connected to the floating diffusion node; a row selecting transistor, the source of which is connected to the source of the amplifying transistor, and the drain of which is connected to the signal reading circuit.

[0025] In some embodiments, when controlling the first photoelectric conversion sub-circuit and the overflow circuit to be turned on, the controller is specifically used to: control the first photoelectric conversion sub-circuit and the overflow circuit to be turned on to a preset opening.

[0026] A second aspect of the present invention provides a control method for an image sensor, which is used for the image sensor described in the above embodiment of the present invention. The image sensor includes a photoelectric conversion circuit, a signal output circuit and a controller. The signal output circuit includes a floating diffusion node and an overflow circuit. The photoelectric conversion circuit includes a first photoelectric conversion sub-circuit. The control method includes: when the first photoelectric conversion sub-circuit and the overflow circuit are controlled to be turned on and the potential barrier height of the first photoelectric conversion sub-circuit and the overflow circuit meets a preset condition, the first photoelectric conversion sub-circuit, the floating diffusion node and the overflow circuit form an overflow path.

[0027] According to the control method of the image sensor of the embodiment of the present invention, by controlling the first photoelectric conversion sub-circuit and the overflow circuit to be turned on and when the barrier height of the first photoelectric conversion sub-circuit and the barrier height of the overflow circuit meet the preset conditions, the charge in the first photoelectric conversion sub-circuit can be transmitted to the overflow circuit to form an overflow path composed of the first photoelectric conversion sub-circuit, the floating diffusion node and the overflow circuit, and the excess charge after the first photoelectric conversion sub-circuit is fully loaded is transmitted through the overflow path to form an overflow path that can accommodate the excess charge. While improving the charge accommodation range, the detection range of the pixel structure in the image sensor to high-intensity light is improved, thereby effectively improving the dynamic range and flicker suppression.

[0028] A third aspect of the present invention provides a non-temporary computer-readable storage medium on which a control program for an image sensor is stored. When the control program for the image sensor is executed by a processor, the control method for the image sensor described in the above embodiment of the present invention is implemented.

[0029] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0031] Figure 1 is a schematic diagram of a pixel structure in an image sensor according to the related art;

[0032] Figure 2 is a schematic diagram of a data reading method in an image sensor according to the related art;

[0033] Figure 3 is a schematic diagram of a circuit in an image sensor according to the related art;

[0034] Figure 4 is a schematic diagram of a circuit in an image sensor according to an embodiment of the present invention;

[0035] Figure 5 is a circuit timing diagram of an image sensor according to an embodiment of the present invention;

[0036] Figure 6 FIG. 5 is a circuit timing diagram of an image sensor according to another embodiment of the present invention.

[0037] Reference numerals:

[0038] Image sensor 10;

[0039] Photoelectric conversion circuit 11; first photoelectric conversion sub-circuit 110;

[0040] Signal output circuit 12; first overflow circuit 121. DETAILED DESCRIPTION

[0041] Embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Embodiments of the present invention are described in detail below.

[0042] In related technologies, when a vehicle is driving, the ambient light changes greatly, and the dynamic range of the vehicle CIS needs to exceed 120dB, usually between 120dB-140dB. For example, when a vehicle drives from a dark basement to the outdoors facing the strong sunlight, or perceives pedestrians under the shade of trees under the headlights of oncoming vehicles at night, the CIS needs to be able to capture images clearly, so that the CIS has a high dynamic range to cope with such extreme light changes. In addition, since the flashing frequency of LED signs and traffic lights may not be synchronized with the sampling frequency of the CIS, flickering or distortion may occur in the image, which interferes with the machine vision system and affects driving safety.

[0043] In view of the above problems, current technologies have also proposed corresponding solutions, such as Figure 1 As shown in the figure, it is a schematic diagram of the pixel structure in the image sensor, where different colors represent different CFs (Color Filters). The scheme adopts a 4cell structure, that is, the pixel structure consists of four sub-pixels, three of which are used as LPDs (Large Photodetectors), and the other sub-pixel is used as an SPD (Small Photodetector) by combining a light absorption attenuation film and other methods to reduce the pixel light absorption sensitivity. In general, the optical absorption attenuation ratio of LPD to SPD is 1:10+.

[0044] like Figure 2 As shown in the figure, it is a schematic diagram of the data reading method in the image sensor. LPD performs two exposures within one exposure time of SPD, one long exposure and one short exposure, which are realized by splicing long and short exposures. Among them, the long exposure of 1stLPD (first LPD) is mainly used to obtain darker signals, and the long exposure of 2nd LPD (second LPD) is mainly used to obtain strong light signals; the long exposure of 3rd SPD (third SPD) and the short exposure of 4th LPD (fourth LPD) are mainly used to obtain medium light intensity signals, which mainly depends on the time ratio of long and short exposure of LPD and the optical sensitivity ratio of LPD / SPD. Taking the competitive company as an example, the sensitivity ratio of SPD to LPD is usually about 1:10+, and the time ratio of long and short exposure of LPD is about 1:50+.

[0045] Specifically, the circuit diagram of the image sensor is as follows: Figure 3As shown, the LPD performs long exposure to obtain darker signals; the SPD performs long exposure to obtain medium-intensity light signals; and the LPD performs short exposure to obtain ultra-strong light signals. The LPD / SPD sensitivity ratio (sensitivity ratio of long exposure / short exposure) is combined with the exp time ratio (experience time ratio) to form a high dynamic range performance, while also ensuring that the SNR (Signal to Noise Ratio) is not too low. In terms of timing design, the LPD performs two exposures within one exposure time of the SPD, so that the SPD does not have an overflow function during the exposure period. At the same time, the timing operation is complex, and the LFM (Linear Frequency Modulation) coverage range of the timing does not fully cover the entire dynamic range.

[0046] Based on the above, the embodiment of the present invention forms an overflow path by controlling the on or off state of the first photoelectric conversion subcircuit and the overflow circuit, thereby expanding the detection range of high-intensity light for short exposure and achieving the purpose of improving the dynamic range. In addition, only one exposure is required to achieve high dynamic range and LED flicker suppression, which is simpler to operate than the long and short exposure splicing of competitors, so that the SPD has an overflow function during exposure, and LED flicker suppression can also achieve full dynamic range coverage.

[0047] Reference below Figure 4-Figure 6 An image sensor according to an embodiment of the present invention is described.

[0048] Figure 4 is a circuit diagram of an image sensor according to an embodiment of the present invention. Figure 4 As shown, the image sensor 10 includes: a photoelectric conversion circuit 11, a signal output circuit 12 and a controller (not shown in the figure).

[0049] Among them, the photoelectric conversion circuit 11 includes a first photoelectric conversion sub-circuit 110; the signal output circuit 12 includes a floating diffusion node FD1 and an overflow circuit 121, one end of the overflow circuit 121 is connected to the floating diffusion node FD1, and the other end of the overflow circuit 121 is grounded; the controller is used to control the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 to be turned on, for example, to control the above circuits to be turned on to a preset opening, that is, not completely turned off, and when the barrier height of the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 meets the preset conditions, the first photoelectric conversion sub-circuit 110, the floating diffusion node FD1 and the overflow circuit 121 form an overflow path.

[0050] In an embodiment, the photoelectric conversion circuit 11 and the signal output circuit 12 are circuit components of a pixel structure, and the on or off state of the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 in the pixel structure are controlled based on the timing of the controller to form an overflow path composed of the first photoelectric conversion sub-circuit 110, the floating diffusion node FD1 and the overflow circuit 121, so that after the charge in the photoelectric conversion circuit 11 is fully loaded, the excess charge is accommodated through the overflow path, thereby improving the ability of the pixel circuit to accommodate charge, increasing the detection range of the pixel circuit for high-intensity light, and achieving the purpose of improving the dynamic range.

[0051] For example, at a first set timing, such as T0, the controller controls the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 to be turned on to a preset opening, that is, not completely turned off, and when it is determined that the barrier height of the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 meets the preset conditions, that is, the barrier height of the first photoelectric conversion sub-circuit 110 is higher than the barrier height of the overflow circuit 121, the excess charge flows to the overflow path according to the barrier height. It can be understood that a path can be formed by controlling the conduction or shutdown of the first photoelectric conversion sub-circuit 110 and the overflow circuit 121. However, on the basis of forming the path, the barrier height of the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 needs to meet the above-mentioned set conditions before the excess charge will transfer the charge to the overflow path, thereby achieving the purpose of improving the dynamic range.

[0052] Specifically, the photoelectric conversion circuit 11 is used to convert optical signals into electrical signals, and the floating diffusion node FD1 is used to store charges. When the photoelectric conversion circuit 11 is fully loaded and there is excess charge, the excess charge is transferred to the overflow path to increase the load capacity.

[0053] Thus, the above-mentioned image sensor 10 controls the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 to be turned on and when the barrier height of the first photoelectric conversion sub-circuit 110 and the barrier height of the overflow circuit 121 meet the preset conditions, the charge in the first photoelectric conversion sub-circuit 110 can be transmitted to the overflow circuit 121 to form an overflow path composed of the first photoelectric conversion sub-circuit 110, the floating diffusion node FD1 and the overflow circuit 121, and the excess charge after the first photoelectric conversion sub-circuit 110 is fully loaded is transmitted through the overflow path to form an overflow path that can accommodate the excess charge. While improving the charge accommodation range, the detection range of the 10-pixel structure in the image sensor to high-intensity light is improved, thereby effectively improving the dynamic range and flicker suppression.

[0054] In one embodiment of the present invention, Figure 4As shown, the overflow circuit 121 includes: a dual conversion gain control transistor DCG and an overflow capacitor FD2, the source of the dual conversion gain control transistor DCG is connected to the floating diffusion node FD1; one end of the overflow capacitor FD2 is connected to the drain of the dual conversion gain control transistor DCG, and the other end of the overflow capacitor FD2 is grounded.

[0055] In an embodiment, Figure 4 As shown, the source of the dual conversion gain control transistor DCG is connected to the floating diffusion node FD1, the drain of the dual conversion gain control transistor DCG is connected to one end of the overflow capacitor FD2, and the other end of the overflow capacitor FD2 is grounded. By controlling the on or off state of the dual conversion gain control transistor DCG, the overflow circuit 121 can be turned on or off.

[0056] Specifically, the on or off state of the dual conversion gain control transistor DCG can control the transfer of charges. For example, when the amount of charge in the first photoelectric conversion sub-circuit 110 exceeds the load capacity, by controlling the dual conversion gain control transistor DCG to be turned on, the excess charge is transferred to the overflow capacitor FD2. The overflow capacitor FD2 is larger, thereby improving the detection range of the image sensor 10 for high-intensity light.

[0057] In one embodiment of the present invention, Figure 4 As shown, the first photoelectric conversion sub-circuit 110 includes: a first photodiode PD4 and a first transfer transistor TX4, the anode of the first photodiode PD4 is grounded; the source of the first transfer transistor TX4 is connected to the cathode of the first photodiode PD4, and the drain of the first transfer transistor TX4 is connected to the floating diffusion node FD1, which is used to turn on or off the path between the first photodiode PD4 and the floating diffusion node FD1.

[0058] In an embodiment, the on or off state of the first transfer transistor TX4 is controlled. When the first photodiode PD4 is fully charged, the first transfer transistor TX4 is controlled to be turned on so that the charge can be transferred to the floating diffusion node FD1 and the overflow circuit 121 through the first transfer transistor TX4.

[0059] In one embodiment of the present invention, the photoelectric conversion circuit 11 further includes: at least one second photoelectric conversion sub-circuit.

[0060] In an embodiment, the photoelectric conversion circuit 11 further includes at least one second photoelectric conversion sub-circuit. For example, the photoelectric conversion circuit 11 includes two second photoelectric conversion sub-circuits or three photoelectric conversion sub-circuits.

[0061] In one embodiment of the present invention, Figure 4As shown, the second photoelectric conversion sub-circuit includes: a second photodiode and a second transfer transistor, the anode of the second photodiode is grounded; a second transfer transistor, the source of the second transfer transistor is connected to the cathode of the second photodiode, and the drain of the second transfer transistor is connected to the floating diffusion node FD1.

[0062] In an embodiment, when there are three second photoelectric conversion sub-circuits, the second photodiodes may be PD1, PD2, and PD3, respectively, and the second transfer transistors corresponding to the second photodiodes may be TX1, TX2, and TX3, respectively. When the first photodiode PD4 and the overflow circuit 121 are controlled to be turned on to a preset opening, the second transfer transistors TX1, TX2, and TX3 in the second photoelectric conversion sub-circuit are turned off.

[0063] Specifically, Figure 4 As shown, the anode of the second photodiode is grounded, that is, the anodes of the second photodiodes PD1, PD2, and PD3 are all grounded, and the second photodiode can convert the optical signal into an electrical signal, so that when the second transfer transistor is turned on, the charge in the second photodiode is transferred to the floating diffusion node FD1.

[0064] In one embodiment of the present invention, Figure 4 As shown, the barrier heights of the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 meet a preset condition, including: the barrier height of the first transmission transistor TX4 is higher than the barrier height of the overflow circuit 121 .

[0065] In an embodiment, Figure 4 As shown, in the process of forming the overflow path by the first photoelectric conversion sub-circuit 110, the floating diffusion node FD1 and the overflow circuit 121, the barrier height of the first photoelectric conversion sub-circuit 110 is higher than the barrier height of the overflow circuit 121, that is, the charge passes through the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 in sequence during the transmission process. In addition, the barrier height is also related to the voltage. The higher the barrier height, the smaller the corresponding voltage. On the contrary, the lower the barrier height, the larger the corresponding voltage. Therefore, the barrier height of the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 meets the set condition, which can also be understood as the voltage of the first photoelectric conversion sub-circuit 110 is less than the voltage of the overflow circuit 121, that is, Voff_TX4. <Voff_DCG。

[0066] By controlling the conduction states of the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 and making their potential barrier heights satisfy the above conditions, when the charge in the first photoelectric conversion sub-circuit 110 exceeds the load capacity and overflows, the charge will more easily flow to the direction with a lower potential barrier. Therefore, the charge will flow from the first photoelectric conversion sub-circuit 110, the floating diffusion node FD1 and the overflow circuit 121 in order of the potential barrier height, thereby preventing excessive charge accumulation in one of the places.

[0067] In one embodiment of the present invention, Figure 4 As shown, when controlling the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 to be turned on, the controller is also used to: control the second transfer transistor to be turned off.

[0068] In an embodiment, Figure 4 As shown, the controller controls the on or off state of the first photoelectric conversion sub-circuit and the overflow circuit 121. For example, when the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 are turned on to a preset opening, the second transfer transistors TX1, TX2, and TX3 are controlled to be turned off to form an overflow path of the first photodiode PD4, the floating diffusion node FD1, and the overflow capacitor FD2.

[0069] like Figure 5 As shown, corresponding to time T0, when the second transfer transistors TX1, TX2, and TX3 are turned off, the integration process of the first photodiode PD4 starts. At time T0, the first transfer transistor TX4 and the overflow circuit 121 are controlled to be turned on to a preset opening, that is, not fully turned on, so that the charge can overflow.

[0070] In one embodiment of the present invention, Figure 4 and Figure 5 As shown, after controlling the second transmission transistor TX4 to turn off, the controller is also used to: control the first transmission transistor TX4 and the dual conversion gain control transistor DCG to turn off, so as to obtain the first reset signal of the photoelectric conversion circuit 11 under high conversion gain after the first transmission transistor TX4 and the dual conversion gain control transistor DCG are turned off.

[0071] In an embodiment, in combination Figure 4 and Figure 5 As shown, at time T1, after controlling the second transmission transistor to turn off, the controller controls the first transmission transistor TX4 and the dual conversion gain control transistor DCG to turn off. At this moment, the photoelectric conversion circuit 11 completes its integration process.

[0072] Specifically, at moment T1, the controller controls the first transfer transistor TX4 and the dual conversion gain control transistor DCG to turn off, and the integration process of the photoelectric conversion circuit 11 ends. Since the overflow capacitor FD2 is a capacitor much larger than the floating diffusion node FD1, when the dual conversion gain control transistor DCG is turned off, most of the charges overflowing from the first photodiode PD4 during the integration period flow to the overflow capacitor FD2, and only a small amount of charge remains in the floating diffusion node FD1, thereby preventing the charge in the floating diffusion node FD1 from overflowing, and further, the first reset signal SPD HCG_SHR of the photoelectric conversion circuit 11 under high conversion gain can be read at moment T1, thereby improving the accuracy of signal reading.

[0073] In one embodiment of the present invention, Figure 4 and Figure 5 As shown, after obtaining the first reset signal of the photoelectric conversion circuit 11 under high conversion gain, the controller is also used to: control the first transfer transistor TX4 to be turned on, so as to control the first transfer transistor TX4 to be turned off when the charge in the first photodiode PD4 is transferred to the floating diffusion node FD1, so as to obtain the first valid signal of the photoelectric conversion circuit 11 under high conversion gain.

[0074] In an embodiment, in combination Figure 4 and Figure 5 As shown, at time T2, after obtaining the first reset signal SPD HCG_SHR of the photoelectric conversion circuit 11 under high conversion gain, the controller controls the first transfer transistor TX4 to be turned on, so that the charge accumulated in the first photodiode PD4 can be transferred to the floating diffusion node FD1 through the first transfer transistor TX4. After the charge transfer is completed, the controller controls the first transfer transistor TX4 to be turned off, so that the first valid signal SPD HCG_SHS of the photoelectric conversion circuit 11 under high conversion gain can be accurately read.

[0075] In one embodiment of the present invention, Figure 4 and Figure 5 As shown, after obtaining the first effective signal of the photoelectric conversion circuit 11 under high conversion gain, the controller is also used to: control the dual conversion gain control transistor DCG and the first transfer transistor TX4 to be turned on, so as to obtain the first effective signal of the photoelectric conversion circuit 11 under low conversion gain when the charge in the first photodiode PD4 is transferred to the floating diffusion node FD1 and the overflow capacitor FD2.

[0076] In an embodiment, in combination Figure 4 and Figure 5As shown, at time T3, after obtaining the first valid signal SPD HCG_SHS of the photoelectric conversion circuit 11 under high conversion gain, the controller controls the dual conversion gain control transistor DCG and the first transmission transistor TX4 to be turned on. When the first transmission transistor TX4 is turned on, the charge in the first photodiode PD4 begins to be transmitted. Since the dual conversion gain control transistor DCG is also in the on state, the charge in the first photodiode PD4 not only flows to the floating diffusion node FD1, but also flows to the overflow capacitor FD2. After the charge transfer is completed, the first valid signal SPD LCG_SHS of the photoelectric conversion circuit 11 under low conversion gain can be read, thereby improving the accuracy of signal acquisition.

[0077] In one embodiment of the present invention, Figure 4 As shown, the signal output circuit 12 further includes: a reset transistor RST, a drain of the reset transistor RST is connected to the power supply voltage, and a source of the reset transistor RST is connected to the floating diffusion node FD1.

[0078] In an embodiment, Figure 4 As shown, the source of the reset transistor RST is connected to the floating diffusion node FD1, and the drain of the reset transistor RST is connected to the power supply voltage. By controlling the reset transistor RST to be turned on, the charge in the overflow circuit 121 can be reset.

[0079] In one embodiment of the present invention, Figure 4 and Figure 5 As shown, after obtaining the first valid signal of the photoelectric conversion circuit 11 under low conversion gain, the controller is also used to: control the reset transistor RST to be turned on, so as to control the reset transistor RST to be turned off after the floating diffusion node FD1 and the overflow capacitor FD2 are reset, so as to obtain the first reset signal of the photoelectric conversion circuit 11 under low conversion gain.

[0080] In an embodiment, in combination Figure 4 and Figure 5 As shown, at time T4, after obtaining the first valid signal SPD LCG_SHS of the photoelectric conversion circuit 11 under low conversion gain, the controller controls the reset transistor RST to turn on, and the power supply voltage flows to the floating diffusion node FD1 and the overflow capacitor FD2 through the reset transistor RST, thereby resetting the floating diffusion node FD1 and the overflow capacitor FD2. After completing the reset of the floating diffusion node FD1 and the overflow capacitor FD2, the controller controls the reset transistor RST to turn off, thereby obtaining the first reset signal SPD LCG_SHR of the photoelectric conversion circuit 11 under low conversion gain, thereby improving the accuracy of signal reading.

[0081] In one embodiment of the present invention, Figure 4 and Figure 5As shown, after obtaining the first reset signal of the photoelectric conversion circuit 11 at a low conversion gain, the controller is also used to: control the dual conversion gain control transistor DCG to turn off to obtain the second reset signal of the photoelectric conversion circuit 11 at a high conversion gain.

[0082] In an embodiment, in combination Figure 4 and Figure 5 As shown, the process is still at time T4. After obtaining the first reset signal SPD LCG_SHR of the photoelectric conversion circuit 11 under low conversion gain, the controller controls the dual conversion gain control transistor DCG to turn off, and then obtains the second reset signal LPD HCG_SHR of the photoelectric conversion circuit 11 under high conversion gain.

[0083] In one embodiment of the present invention, Figure 4 and Figure 5 As shown, after controlling the dual conversion gain control transistor DCG to turn off, the controller is also used to: control the second transfer transistor to turn on, so as to control the second transfer transistor to turn off when the charge of the second photodiode is transferred to the floating diffusion node FD1, so as to obtain the second effective signal of the photoelectric conversion circuit 11 under high conversion gain.

[0084] In an embodiment, in combination Figure 4 and Figure 5 As shown, at time T5, after the controller controls the dual conversion gain control transistor DCG to turn off, it controls the second transfer transistors TX1, TX2, and TX3 to turn on, so that the charges in the second photodiodes PD1, PD2, and PD3 are transferred to the floating diffusion node FD1. At this time, the second transfer transistors TX1, TX2, and TX3 are controlled to be turned off, and the floating diffusion node FD1 accumulates the charges from the second photodiodes PD1, PD2, and PD3, thereby obtaining the second valid signal LPD HCG_SHS of the photoelectric conversion circuit 11 under high conversion gain.

[0085] In one embodiment of the present invention, Figure 4 and Figure 5 As shown, after obtaining the second effective signal of the photoelectric conversion circuit 11 under high conversion gain, the controller is also used to: control the dual conversion gain control transistor DCG and the second transfer transistor to be turned on, so as to obtain the second effective signal of the photoelectric conversion circuit 11 under low conversion gain when the charge of the second photodiode is transferred to the floating diffusion node FD1 and the overflow capacitor FD2.

[0086] In an embodiment, in combination Figure 4 and Figure 5As shown, at time T6, after obtaining the second valid signal LPD HCG_SHS of the photoelectric conversion circuit 11 under high conversion gain, the controller controls the dual conversion gain control transistor DCG and the second transfer transistors TX1, TX2, and TX3 to be turned on again, so that the remaining charges in the second photodiodes TX1, TX2, and TX3 are transferred to the floating diffusion node FD1 and the overflow capacitor FD2, that is, the charges in the second photodiodes PD1, PD2, and PD3 are transferred to the floating diffusion node FD1 and the overflow capacitor FD2, and after the remaining charge transfer is completed, the second valid signal LPD LCG_SHS of the photoelectric conversion circuit 11 under low conversion gain can be read, thereby improving the accuracy of signal acquisition.

[0087] In one embodiment of the present invention, Figure 4 As shown, the signal output circuit 12 also includes: an amplifier transistor SF and a row selection transistor RS, the drain of the amplifier transistor SF is connected to the power supply voltage, and the gate of the amplifier transistor SF is connected to the floating diffusion node FD1; the source of the row selection transistor RS is connected to the source of the amplifier transistor SF, and the drain of the row selection transistor RS is connected to the signal reading circuit.

[0088] In an embodiment, Figure 4 As shown, the drain of the amplifier transistor SF is connected to the power supply voltage, so that the drain of the amplifier transistor SF can obtain the power supply of the power supply voltage to power the amplifier transistor SF, the gate of the amplifier transistor SF is connected to the floating diffusion node FD1, the source of the amplifier transistor SF is connected to the source of the row selection transistor RS, so that the row selection transistor RS can receive the signal in the amplifier transistor SF, and the drain of the row selection transistor RS is connected to the signal reading circuit, so that the output signal of the amplifier transistor SF can be transmitted to the signal reading circuit through its drain, so as to convert the optical signal into an electrical signal and read it out.

[0089] In one embodiment of the present invention, when controlling the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 to be turned on, the controller is specifically used to control the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 to be turned on to a preset opening.

[0090] Specifically, the controller controls the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 to be turned on to a preset opening, that is, not completely turned off. When the charge of the photoelectric conversion circuit 11 exceeds the load range, the excess charge can be transmitted based on the formed overflow path, thereby improving the detection range of high-intensity light.

[0091] In addition, if Figure 6 As shown, the embodiment of this aspect can also be implemented by using a long and short splicing exposure method, and the working status at each moment is briefly explained below.

[0092] At time T0, the photoelectric conversion circuit 11 completes resetting and then starts a long exposure time to capture darker parts of the environment or situations where a long time of accumulation of light signals is required.

[0093] At time T1 , the reset transistor RST is turned off, and then the first reset signal LCG_SHR of the photoelectric conversion circuit 11 at a low conversion gain is obtained.

[0094] At time T2, after obtaining the first reset signal of the photoelectric conversion circuit 11 under low conversion gain, the dual conversion gain control transistor DCG is turned off, and the circuit switches to the high conversion gain state to obtain the first reset signal HCG_SHR of the photoelectric conversion circuit 11 under high conversion gain.

[0095] At time T3, after obtaining the first reset signal of the photoelectric conversion circuit 11 at high conversion gain, the second transmission transistor is turned off, that is, the second transmission transistors TX1, TX2, and TX3 are turned off, and then the first valid signal LPD HCG_SHS of the photoelectric conversion circuit 11 at high conversion gain is obtained.

[0096] At time T4, after acquiring the first valid signal of the photoelectric conversion circuit 11 at high conversion gain, the second transmission transistors TX1, TX2, and TX3 remain in the off state to acquire the second valid signal SPDHCG_SHS of the photoelectric conversion circuit 11 at high conversion gain.

[0097] At time T5 , after acquiring the second valid signal of the photoelectric conversion circuit 11 at the high conversion gain, the first transmission transistor TX4 is turned off, and then the third valid signal SPD HCG_SHS of the photoelectric conversion circuit 11 at the high conversion gain is acquired.

[0098] At time T6, the third valid signal of the photoelectric conversion circuit 11 under high conversion gain is obtained, and the first valid signal SPD LCG_SHS of the photoelectric conversion circuit 11 under low conversion gain is obtained. The reading order of LPD and SPD is not fixed here, and can be adjusted according to actual needs, that is, the reading order of the first photodiode PD4 and the second photodiodes TX1, TX2, TX3 is not limited. Then, the second transmission transistors TX1, TX2, TX3 are turned on, and the second transmission transistors TX1, TX2, TX3 are reset, and a spliced ​​short-time exposure is performed to prepare for the accumulation of short exposure signals.

[0099] At time T7, after obtaining the first valid signal of the photoelectric conversion circuit 11 at low conversion gain, the short exposure phase begins to obtain the second reset signal LCG_SHR of the photoelectric conversion circuit 11 at low conversion gain.

[0100] In summary, according to the image sensor 10 of the embodiment of the present invention, by controlling the first photoelectric conversion sub-circuit 110 and the overflow circuit 121 to be turned on and when the barrier height of the first photoelectric conversion sub-circuit 110 and the barrier height of the overflow circuit 121 meet the preset conditions, the charge in the first photoelectric conversion sub-circuit 110 can be transmitted to the overflow circuit 121 to form an overflow path composed of the first photoelectric conversion sub-circuit 110, the floating diffusion node FD1 and the overflow circuit 121, and the excess charge after the first photoelectric conversion sub-circuit 110 is fully loaded is transmitted through the overflow path to form an overflow path that can accommodate the excess charge. While improving the charge accommodation range, the detection range of the pixel structure in the image sensor 10 to high-intensity light is improved, and the traditional long and short exposure splicing method can also be adopted, thereby effectively improving the dynamic range and flicker suppression.

[0101] A second aspect of the present invention provides a control method for an image sensor, which is used for the image sensor described in any one of the above embodiments of the present invention. The image sensor includes a photoelectric conversion circuit, a signal output circuit and a controller. The signal output circuit includes a floating diffusion node and an overflow circuit. The photoelectric conversion circuit includes a first photoelectric conversion sub-circuit. The control method includes: when the first photoelectric conversion sub-circuit and the overflow circuit are controlled to be turned on and the barrier height of the first photoelectric conversion sub-circuit and the overflow circuit meets a preset condition, the first photoelectric conversion sub-circuit, the floating diffusion node and the overflow circuit form an overflow path.

[0102] Specifically, by controlling the off state of the first photoelectric conversion sub-circuit and the overflow circuit, these elements are turned on, and at the same time, the barrier heights of these elements are controlled so that the barrier heights of these elements meet the set conditions. When these conditions are met, the excess charge after full load in the first photoelectric conversion sub-circuit is transmitted through the overflow path to form an overflow path that can accommodate the excess charge. While increasing the charge accommodation range, the detection range of the pixel structure in the image sensor to high-intensity light is increased, thereby effectively improving the dynamic range and flicker suppression.

[0103] According to the control method of the image sensor of the embodiment of the present invention, by controlling the first photoelectric conversion sub-circuit and the overflow circuit to be turned on and when the barrier height of the first photoelectric conversion sub-circuit and the barrier height of the overflow circuit meet the preset conditions, the charge in the first photoelectric conversion sub-circuit can be transmitted to the overflow circuit to form an overflow path composed of the first photoelectric conversion sub-circuit, the floating diffusion node and the overflow circuit, and the excess charge after the first photoelectric conversion sub-circuit is fully loaded is transmitted through the overflow path to form an overflow path that can accommodate the excess charge. While improving the charge accommodation range, the detection range of the pixel structure in the image sensor to high-intensity light is improved, thereby effectively improving the dynamic range and flicker suppression.

[0104] In one embodiment of the present invention, the overflow circuit includes: a dual conversion gain control transistor, the source of the dual conversion gain control transistor is connected to the floating diffusion node; an overflow capacitor, one end of the overflow capacitor is connected to the drain of the dual conversion gain control transistor, and the other end of the overflow capacitor is grounded.

[0105] In one embodiment of the present invention, the first photoelectric conversion sub-circuit includes: a first photodiode, the anode of the first photodiode is grounded; a first transfer transistor, the source of the first transfer transistor is connected to the cathode of the first photodiode, and the drain of the first transfer transistor is connected to the floating diffusion node, which is used to turn on or off the path between the first photodiode and the floating diffusion node.

[0106] In one embodiment of the present invention, when the potential barrier heights of the first photoelectric conversion sub-circuit and the overflow circuit meet a preset condition, it includes: the potential barrier height of the first transfer transistor is higher than the potential barrier height of the overflow circuit.

[0107] In one embodiment of the present invention, the photoelectric conversion circuit further includes: at least one second photoelectric conversion sub-circuit.

[0108] In one embodiment of the present invention, the second photoelectric conversion subcircuit includes: a second photodiode, the anode of the second photodiode is grounded; a second transfer transistor, the source of the second transfer transistor is connected to the cathode of the second photodiode, and the drain of the second transfer transistor is connected to the floating diffusion node.

[0109] In one embodiment of the present invention, when controlling the first photoelectric conversion sub-circuit and the overflow circuit to be turned on, the controller is further used to: control the second transfer transistor to be turned off.

[0110] In one embodiment of the present invention, after controlling the second transfer transistor to turn off, it also includes: controlling the first transfer transistor and the dual conversion gain control transistor to turn off, so as to obtain a first reset signal of the photoelectric conversion circuit under high conversion gain after the first transfer transistor and the dual conversion gain control transistor are turned off.

[0111] In one embodiment of the present invention, after obtaining the first reset signal of the photoelectric conversion circuit at a high conversion gain, it also includes: controlling the first transfer transistor to be turned on so that when the charge in the first photodiode is transferred to the floating diffusion node, the first transfer transistor is controlled to be turned off so as to obtain the first valid signal of the photoelectric conversion circuit at a high conversion gain.

[0112] In one embodiment of the present invention, after obtaining the first effective signal of the photoelectric conversion circuit under high conversion gain, it also includes: controlling the dual conversion gain control transistor and the first transfer transistor to be turned on, so as to obtain the first effective signal of the photoelectric conversion circuit under low conversion gain when the charge in the first photodiode is transferred to the floating diffusion node and the overflow capacitor.

[0113] In one embodiment of the present invention, the signal output circuit further includes: a reset transistor, a drain of the reset transistor is connected to the power supply voltage, and a source of the reset transistor is connected to the floating diffusion node.

[0114] In one embodiment of the present invention, after obtaining the first valid signal of the photoelectric conversion circuit under low conversion gain, it also includes: controlling the reset transistor to be turned on, so as to control the reset transistor to be turned off after the floating diffusion node and the overflow capacitor are reset, so as to obtain the first reset signal of the photoelectric conversion circuit under low conversion gain.

[0115] In one embodiment of the present invention, after obtaining the first reset signal of the photoelectric conversion circuit at low conversion gain, it also includes: controlling the dual conversion gain control transistor to turn off to obtain the second reset signal of the photoelectric conversion circuit at high conversion gain.

[0116] In one embodiment of the present invention, after controlling the dual conversion gain control transistor to turn off, it also includes: controlling the second transfer transistor to turn on, so that when the charge of the second photodiode is transferred to the floating diffusion node, the second transfer transistor is controlled to turn off, so as to obtain a second effective signal of the photoelectric conversion circuit under high conversion gain.

[0117] In one embodiment of the present invention, after obtaining the second effective signal of the photoelectric conversion circuit at a high conversion gain, it also includes: controlling the dual conversion gain control transistor to be turned on and the second transfer transistor to be turned on, so as to obtain the second effective signal of the photoelectric conversion circuit at a low conversion gain when the charge of the second photodiode is transferred to the floating diffusion node and the overflow capacitor.

[0118] In one embodiment of the present invention, the signal output circuit also includes: an amplifying transistor, the drain of which is connected to the power supply voltage, and the gate of which is connected to the floating diffusion node; a row selecting transistor, the source of which is connected to the source of the amplifying transistor, and the drain of which is connected to the signal reading circuit.

[0119] In one embodiment of the present invention, controlling the first photoelectric conversion sub-circuit and the overflow circuit to be turned on includes: controlling the first photoelectric conversion sub-circuit and the overflow circuit to be turned on to a preset opening.

[0120] According to the control method of the image sensor of the embodiment of the present invention, by controlling the first photoelectric conversion sub-circuit and the overflow circuit to be turned on and when the barrier height of the first photoelectric conversion sub-circuit and the barrier height of the overflow circuit meet the preset conditions, the charge in the first photoelectric conversion sub-circuit can be transmitted to the overflow circuit to form an overflow path composed of the first photoelectric conversion sub-circuit, the floating diffusion node and the overflow circuit, and the excess charge after the first photoelectric conversion sub-circuit is fully loaded is transmitted through the overflow path to form an overflow path that can accommodate the excess charge. While improving the charge accommodation range, the detection range of the pixel structure in the image sensor to high-intensity light is improved, thereby effectively improving the dynamic range and flicker suppression.

[0121] A third aspect of the present invention provides a non-temporary computer-readable storage medium on which a control program for an image sensor is stored. When the control program for the image sensor is executed by a processor, the control method for the image sensor described in any one of the above embodiments of the present invention is implemented.

[0122] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0123] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An image sensor, characterized in that: include: A photoelectric conversion circuit, the photoelectric conversion circuit comprising a first photoelectric conversion sub-circuit; a signal output circuit, the signal output circuit comprising a floating diffusion node and an overflow circuit, one end of the overflow circuit is connected to the floating diffusion node, and the other end of the overflow circuit is grounded; The controller is used to control the first photoelectric conversion subcircuit and the overflow circuit to be turned on and when the potential barrier heights of the first photoelectric conversion subcircuit and the overflow circuit meet a preset condition, the first photoelectric conversion subcircuit, the floating diffusion node and the overflow circuit form an overflow path.

2. The image sensor according to claim 1, characterized in that The overflow circuit comprises: a dual conversion gain control transistor, the source of the dual conversion gain control transistor being connected to the floating diffusion node; An overflow capacitor, one end of which is connected to the drain of the dual conversion gain control transistor, and the other end of which is grounded.

3. The image sensor according to claim 1 or 2, characterized in that: The first photoelectric conversion subcircuit comprises: a first photodiode, wherein an anode of the first photodiode is grounded; A first transfer transistor, wherein the source of the first transfer transistor is connected to the cathode of the first photodiode, and the drain of the first transfer transistor is connected to the floating diffusion node, and is used to turn on or off the path between the first photodiode and the floating diffusion node.

4. The image sensor according to claim 3, characterized in that: The potential barrier heights of the first photoelectric conversion sub-circuit and the overflow circuit meet preset conditions, including: A barrier height of the first transfer transistor is higher than a barrier height of the overflow circuit.

5. The image sensor according to claim 3, characterized in that: The photoelectric conversion circuit further includes: at least one second photoelectric conversion sub-circuit.

6. The image sensor according to claim 5, characterized in that The second photoelectric conversion subcircuit comprises: a second photodiode, wherein an anode of the second photodiode is grounded; A second transfer transistor, a source of the second transfer transistor is connected to the cathode of the second photodiode, and a drain of the second transfer transistor is connected to the floating diffusion node.

7. The image sensor according to claim 6, characterized in that: When controlling the first photoelectric conversion sub-circuit and the overflow circuit to be turned on, the controller is further used to: control the second transfer transistor to be turned off.

8. The image sensor according to claim 7, characterized in that: After controlling the second transmission transistor to turn off, the controller is further configured to: The first transmission transistor and the dual conversion gain control transistor are controlled to be turned off, so as to obtain a first reset signal of the photoelectric conversion circuit under a high conversion gain after the first transmission transistor and the dual conversion gain control transistor are turned off.

9. The image sensor according to claim 8, characterized in that: After obtaining the first reset signal of the photoelectric conversion circuit under the high conversion gain, the controller is further used for: The first transfer transistor is controlled to be turned on, so that when the charge in the first photodiode is transferred to the floating diffusion node, the first transfer transistor is controlled to be turned off, so as to obtain a first effective signal of the photoelectric conversion circuit under a high conversion gain.

10. The image sensor according to claim 9, characterized in that: After acquiring the first valid signal of the photoelectric conversion circuit under high conversion gain, the controller is further used for: The dual conversion gain control transistor and the first transfer transistor are controlled to be turned on to obtain a first effective signal of the photoelectric conversion circuit at a low conversion gain when the charge in the first photodiode is transferred to the floating diffusion node and the overflow capacitor.

11. The image sensor according to claim 10, characterized in that: The signal output circuit also includes: A reset transistor, wherein a drain of the reset transistor is connected to a power supply voltage, and a source of the reset transistor is connected to the floating diffusion node.

12. The image sensor according to claim 11, characterized in that After acquiring the first valid signal of the photoelectric conversion circuit at the low conversion gain, the controller is further used for: The reset transistor is controlled to be turned on, and after the floating diffusion node and the overflow capacitor are reset, the reset transistor is controlled to be turned off, so as to obtain a first reset signal of the photoelectric conversion circuit under low conversion gain.

13. The image sensor according to claim 12, characterized in that: After obtaining a first reset signal of the photoelectric conversion circuit at a low conversion gain, the controller is further used to: The dual conversion gain control transistor is controlled to be turned off to obtain a second reset signal of the photoelectric conversion circuit under high conversion gain.

14. The image sensor according to claim 13, characterized in that: After controlling the dual conversion gain control transistor to turn off, the controller is further used for: The second transfer transistor is controlled to be turned on, so that when the charge of the second photodiode is transferred to the floating diffusion node, the second transfer transistor is controlled to be turned off, so as to obtain a second effective signal of the photoelectric conversion circuit under high conversion gain.

15. The image sensor according to claim 14, characterized in that: After acquiring the second valid signal of the photoelectric conversion circuit under the high conversion gain, the controller is further used for: The dual conversion gain control transistor and the second transfer transistor are controlled to be turned on to obtain a second effective signal of the photoelectric conversion circuit at a low conversion gain when the charge of the second photodiode is transferred to the floating diffusion node and the overflow capacitor.

16. The image sensor according to claim 1, characterized in that The signal output circuit also includes: an amplifying transistor, wherein a drain of the amplifying transistor is connected to a power supply voltage, and a gate of the amplifying transistor is connected to the floating diffusion node; A row selection transistor, wherein a source of the row selection transistor is connected to a source of the amplifying transistor, and a drain of the row selection transistor is connected to a signal reading circuit.

17. The image sensor according to claim 1, characterized in that When controlling the first photoelectric conversion sub-circuit and the overflow circuit to be turned on, the controller is specifically used to control the first photoelectric conversion sub-circuit and the overflow circuit to be turned on to a preset opening.

18. A method for controlling an image sensor, characterized in that: Used in an image sensor according to any one of claims 1 to 17, the image sensor comprising a photoelectric conversion circuit, a signal output circuit and a controller, the signal output circuit comprising a floating diffusion node and an overflow circuit, the photoelectric conversion circuit comprising a first photoelectric conversion sub-circuit, and the control method comprising: When the first photoelectric conversion subcircuit and the overflow circuit are controlled to be turned on and the potential barrier heights of the first photoelectric conversion subcircuit and the overflow circuit meet a preset condition, the first photoelectric conversion subcircuit, the floating diffusion node and the overflow circuit form an overflow path. 19 . A non-transitory computer-readable storage medium having a control program for an image sensor stored thereon, wherein the control program for the image sensor implements the control method for the image sensor according to claim 18 when executed by a processor.

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