Image sensor, signal processing method and electronic equipment

Abstract

The embodiment of the invention provides an image sensor, a signal processing method and electronic equipment, which are used for reducing the power consumption of the image sensor while enlarging the dynamic range of the image sensor. The image sensor comprises a first pixel array, a second pixel array, a plurality of first controllable current sources, a plurality of second controllable current sources and a comparator. Each first controllable current source in the plurality of first controllable current sources comprises a first current source, a first switch and a resistor which are sequentially connected between a power supply end and a grounding end, one end of the first switch and one end of the resistor are connected to a first node, and the first node is connected with a first input end of the comparator; each second controllable current source in the plurality of second controllable current sources comprises a second current source and a second switch, one end of the second current source is connected with the power supply end, the other end of the second current source is connected with one end of the second switch, and the other end of the second switch is connected to the second node; the second node is connected between the first node and one end of the first switch.

Description

Technical Field

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

[0002] An image sensor (IS) comprises a pixel array, a driver, an analog-to-digital converter (ADC), and processing circuitry. Each pixel in the pixel array converts a received light signal into a voltage signal; the driver selects and reads out the voltage signals from the pixel array; the ADC converts the voltage signals into digital signals; and the processing circuitry outputs an image signal based on the digital signals. In long-exposure scenarios, the IS experiences increased dark current in the pixel array. This charge accumulation is converted into a voltage signal V1, typically ranging from 0 to 17.6 mV. The ADC can receive voltage signals within a preset range of 0 to V2; in some examples, V2 can be 62.5 mV. The voltage signal V1 occupies a certain preset range, meaning the dark current occupies a certain preset range. This reduces the proportion of the effective voltage signal within the preset range, thus reducing the IS's dynamic range and degrading image quality. The effective voltage signal refers to the voltage signal converted from the light signal received by the IS.

[0003] Currently, the dynamic range of the IS (Interceptor) is increased by increasing the range of the reference voltage in the ADC, thereby increasing the proportion of the preset range occupied by the effective signal. However, increasing the range of the reference voltage in the ADC leads to an increase in the power consumption of the IS. Summary of the Invention

[0004] This application provides an image sensor, a signal processing method, and an electronic device for increasing the dynamic range of the image sensor while reducing its power consumption.

[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, an image sensor is provided, comprising a first pixel array, a second pixel array, a plurality of first controllable current sources, a plurality of second controllable current sources, and a comparator. Each of the plurality of first controllable current sources includes a first current source, a first switch, and a resistor sequentially connected between a power supply terminal and a ground terminal. One end of the first switch and one end of the resistor are connected to a first node, and the first node is connected to a first input terminal of the comparator. Each of the plurality of second controllable current sources includes a second current source and a second switch. One end of the second current source is connected to the power supply terminal, and the other end of the second current source is connected to one end of the second switch. The other end of the second switch is connected to a second node, and the second node is connected between the first node and one end of the first switch. The output terminals of both the first and second pixel arrays are connected to the second input terminal of the comparator, and the first pixel array is masked.

[0007] In the above technical solution, the first pixel array is blacked out, and it cannot receive light signals during the exposure period. When no light signals are received, the current in the first pixel array is a dark current, and the first pixel array is used to output a first voltage signal converted from dark current. The second pixel array receives light signals during the exposure period and outputs a second voltage signal during the third period, and outputs a third voltage signal after photoelectric conversion during the fourth period. The third voltage signal includes an effective voltage signal obtained from the light signal conversion and a third voltage sub-signal obtained from the dark current conversion in the second pixel array. Multiple first controllable current sources output a first preset reference voltage during the first period and a second preset reference voltage during the second period, according to a setting. The comparator first compares the first voltage signal and the second preset reference voltage to obtain a first level signal, that is, the comparator first quantizes the first voltage signal in the first pixel array to obtain the first level signal. The first level signal can be used to control the multiple second controllable current sources to be turned on during the third period and output a compensation voltage corresponding to the dark current; and to control the multiple second controllable current sources to be turned off during the fourth period. Multiple first controllable current sources output a target reference voltage in the third time period based on the sum of the compensation voltage and the first preset reference voltage. That is, the target reference voltage is obtained by increasing the compensation voltage on top of the first preset reference voltage. In the fourth time period, a second preset reference voltage is output. A comparator compares the target reference voltage and the second voltage signal in the third time period. Based on the comparator's circuit characteristics, the comparator increases the second voltage signal so that the increased second voltage signal equals the initial voltage value of the target reference voltage, and the magnitude of the increase in the second voltage signal equals the compensation voltage. In the fourth time period, the comparator compares the second preset reference voltage and the third voltage signal. The increased magnitude of the second voltage signal in the third time period (compensation voltage) offsets the voltage drop of the third voltage sub-signal obtained from dark current conversion in the third voltage signal. This compensates for the influence of the third voltage sub-signal obtained from dark current conversion in the second pixel array on the quantization range, increasing the quantization range of the effective voltage signal converted from light signals in the second pixel array, thus increasing the dynamic range of the image sensor. Furthermore, the range of the preset reference voltage is not increased during this process, reducing the power consumption of the image sensor.

[0008] In any possible implementation of the first aspect, the image sensor further includes a control circuit. The control circuit is used to control a plurality of first controllable current sources and a plurality of second controllable current sources, respectively. In the above possible implementations, based on the control circuit controlling the plurality of first controllable current sources and the plurality of second controllable current sources, the plurality of second controllable current sources output compensation voltages at different time periods, and the plurality of first controllable current sources output target reference voltages according to the compensation voltages and preset reference voltages. When the comparator quantizes the voltage signal in the second pixel array according to the target reference voltage, the influence of dark current in the second pixel array on the quantization range is compensated, thereby increasing the dynamic range of the image sensor.

[0009] In any possible implementation of the first aspect, the image sensor further includes: a digital signal processing circuit; the input terminal of the digital signal processing circuit is connected to the output terminal of the comparator, and the output terminal of the digital signal processing circuit is connected to the input terminal of the control circuit. In the above possible implementations, the digital signal processing circuit outputs different code values ​​according to different digital signals (different indication levels) output by the comparator, enabling the control circuit and downstream devices to recognize the code value, thus ensuring the normal operation of the image sensor.

[0010] In any possible implementation of the first aspect, a first pixel array is configured to convert the current within the first pixel array into a first voltage signal and output it when no optical signal is received. A plurality of first controllable current sources are configured to output a first preset reference voltage in a first time period and a second preset reference voltage in a second time period; the second time period follows the first time period. A comparator is configured to compare the first voltage signal and the second preset reference voltage and output a first level signal. A digital signal processing circuit is configured to output a compensation code value and a control signal based on the first level signal. The first time period is a reset phase for the first pixel array, and the second time period is the phase in which the first pixel array converts the current into the first voltage signal.

[0011] In the above possible implementations, the first pixel array is blacked out, and it receives no light signal during the exposure period. When no light signal is received, the current in the first pixel array is a dark current, and the first pixel array is used to output a first voltage signal for dark current conversion. The digital signal processing circuit outputs a compensation code value and a control signal corresponding to the dark current based on the first level signal. The compensation code value and control signal can be used to control multiple second controllable current sources to be turned on in the third period and output a compensation voltage corresponding to the dark current; and to control multiple second controllable current sources to be turned off in the fourth period. This causes multiple first controllable current sources to output a target reference voltage in the third period and a second preset reference voltage in the fourth period. The comparator compares the target reference voltage and the second voltage signal in the third period. Based on the circuit characteristics of the comparator, the comparator will increase the second voltage signal so that the increased second voltage signal is equal to the initial voltage value of the target reference voltage, and the magnitude of the increase in the second voltage signal is equal to the compensation voltage. The comparator compares the second preset reference voltage and the third voltage signal in the fourth time period. It uses the increased amplitude of the second voltage signal in the third time period (compensation voltage) to offset the voltage drop of the third voltage sub-signal obtained by dark current conversion in the third voltage signal. This compensates for the influence of the third voltage sub-signal obtained by dark current conversion in the second pixel array on the quantization range, and increases the quantization range of the effective voltage signal converted by light signal in the second pixel array, that is, increases the dynamic range of the image sensor.

[0012] In any possible implementation of the first aspect, a control circuit is configured to control a plurality of second controllable current sources to conduct in a third time period and output a compensation voltage based on a compensation code value and a control signal; and to control the plurality of second controllable current sources to turn off in a fourth time period; the third time period follows the second time period, and the fourth time period follows the third time period. A plurality of first controllable current sources are configured to output a target reference voltage in the third time period based on a first preset reference voltage and a compensation voltage; and are also configured to output a second preset reference voltage in the fourth time period. A second pixel array is configured to receive an optical signal and output a second voltage signal in the third time period, and output a photoelectric converted third voltage signal in the fourth time period. A comparator is further configured to compare the target reference voltage and the second voltage signal in the third time period and output a second level signal, and to compare the second preset reference voltage and the third voltage signal in the fourth time period and output a third level signal; a digital signal processing circuit is further configured to output an image signal based on the second level signal and the third level signal.

[0013] In the above possible implementations, the control circuit controls multiple second controllable current sources to conduct in the third time period according to the compensation code value and the control signal, and outputs the compensation voltage corresponding to the dark current; and controls multiple second controllable current sources to turn off in the fourth time period. This causes multiple first controllable current sources to output the target reference voltage in the third time period and output the second preset reference voltage in the fourth time period. The comparator compares the target reference voltage and the second voltage signal in the third time period. Based on the circuit characteristics of the comparator, the comparator will increase the second voltage signal so that the increased second voltage signal is equal to the initial voltage value of the target reference voltage, and the increase in the second voltage signal is equal to the compensation voltage. In the fourth time period, the comparator compares the second preset reference voltage and the third voltage signal. It uses the increase in the amplitude of the second voltage signal in the third time period (compensation voltage) to offset the voltage drop of the third voltage sub-signal obtained from the dark current conversion in the third voltage signal, compensating for the influence of the third voltage sub-signal obtained from the dark current conversion in the second pixel array on the quantization range, increasing the quantization range of the effective voltage signal converted by the light signal in the second pixel array, that is, increasing the dynamic range of the image sensor.

[0014] Secondly, a signal processing method is provided, applied in an image sensor. The image sensor includes a first pixel array, a second pixel array, multiple first controllable current sources, multiple second controllable current sources, and a comparator. The method includes: within an image frame: when the first pixel array does not receive an optical signal, it converts the current within the first pixel array into a first voltage signal and outputs it. The multiple first controllable current sources output a first preset reference voltage in a first time period and a second preset reference voltage in a second time period; the second time period follows the first time period. The comparator compares the first voltage signal and the second preset reference voltage and outputs a first level signal. The multiple second controllable current sources output a compensation voltage in a third time period; the compensation voltage is determined based on the first level signal; the third time period follows the second time period. The multiple first controllable current sources output a first target reference voltage in the third time period based on a compensation code value and the first preset reference voltage; and output a second preset reference voltage in a fourth time period; the fourth time period follows the third time period. The second pixel array receives an optical signal and outputs a second voltage signal in the third time period and a photoelectric converted third voltage signal in the fourth time period. The comparator compares the first target reference voltage and the second voltage signal in the third time period and outputs the second level signal; and compares the second preset reference voltage and the third voltage signal in the fourth time period and outputs the third level signal. The second level signal and the third level signal are used to determine the image signal corresponding to an image frame.

[0015] In any possible implementation of the second aspect, the image sensor further includes: a digital signal processing circuit; the method further includes: the digital signal processing circuit outputting a compensation code value and a control signal according to a first level signal.

[0016] In any possible implementation of the second aspect, the image sensor further includes: a control circuit; the plurality of second controllable current sources outputting a compensation voltage in a third time period, comprising: the control circuit controlling the plurality of second controllable current sources to conduct in the third time period according to a compensation code value and a control signal, and outputting a compensation voltage. The method further includes: the control circuit controlling the plurality of second controllable current sources to turn off in a fourth time period according to a compensation code value and a control signal.

[0017] In any possible implementation of the second aspect, the method further includes: a digital signal processing circuit outputting a first code value according to a second level signal; and outputting a second code value according to a third level signal; and determining an image signal according to the first code value and the second code value.

[0018] In any possible implementation of the second aspect, the method further includes: within another image frame following an image frame: a plurality of first controllable current sources output a third preset reference voltage in a first time period and output a fourth preset reference voltage in a second time period; the second time period follows the first time period; in a third time period, a second target reference voltage is output based on the third preset reference voltage and a compensation voltage determined in an image frame, and a fourth preset reference voltage is output in a fourth time period; the third time period follows the second time period, and the fourth time period follows the third time period. A second pixel array outputs a fourth voltage signal in the third time period and a fifth voltage signal after photoelectric conversion in the fourth time period; a comparator compares the second target reference voltage and the fourth voltage signal in the third time period and outputs a fourth level signal, and compares the fourth preset reference voltage and the fifth voltage signal in the fourth time period and outputs a fifth level signal, the fourth level signal and the fifth level signal being used to determine the image signal corresponding to the other image frame.

[0019] Thirdly, an electronic device is provided, comprising an image sensor and a processor, wherein the image sensor is used to output an image signal, and the processor is used to process the image signal, and the image sensor is provided as in the first aspect or any possible implementation thereof.

[0020] Understandably, the beneficial effects achieved by any of the signal processing methods and electronic devices provided above can be compared with the beneficial effects of the image sensor provided above, and will not be repeated here. Attached Figure Description

[0021] Figure 1 A schematic diagram illustrating the effect of dark current on the quantization range of an ADC, provided as an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application;

[0023] Figure 3 This is a schematic diagram of the structure of an image sensor provided in an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of the structure of a second pixel array 220 provided in an embodiment of this application;

[0025] Figure 5 This is a schematic diagram of another image sensor structure provided in an embodiment of this application;

[0026] Figure 6 This is a schematic diagram of the structure of another image sensor provided in an embodiment of this application;

[0027] Figure 7 A schematic diagram illustrating the quantization range of an image sensor provided in an embodiment of this application;

[0028] Figure 8 This is a flowchart of a signal processing method provided in an embodiment of this application. Detailed Implementation

[0029] The following sections will discuss the fabrication and use of various embodiments in detail. However, it should be understood that many applicable inventive concepts provided in this application can be implemented in a variety of specific environments. The specific embodiments discussed are merely illustrative of specific ways of implementing and using this application and technology, and do not limit the scope of this application.

[0030] Unless otherwise defined, all technical terms used herein have the same meaning as commonly known to one of ordinary skill in the art.

[0031] Each circuit or other component may be described or referred to as "for" performing one or more tasks. In this context, "for" is used to imply a structure by indicating that the circuit / component includes a structure (e.g., a circuit system) that performs one or more tasks during operation. Therefore, even when the specified circuit / component is currently inoperable (e.g., not turned on), it can still be referred to as "for performing that task." Circuits / components used with the term "for" include hardware, such as circuits that perform operations.

[0032] The technical solutions in the embodiments of this application will be described below with reference to the accompanying drawings. In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, a and b, a and c, b and c, a, b, and c; where a, b, and c can be single or multiple.

[0033] The embodiments of this application use terms such as "first" and "second" to distinguish objects with similar names, functions, or effects. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or order of execution. The term "coupling" is used to indicate an electrical connection, including direct connection via wires or terminals or indirect connection via other devices. Therefore, "coupling" should be considered as a broad type of electronic communication connection.

[0034] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0035] Before introducing the embodiments of this application, we will first explain the relevant knowledge of image sensors.

[0036] An image sensor (IS) comprises a pixel array, a driver, an analog-to-digital converter (ADC), and processing circuitry. Each pixel in the pixel array converts a received light signal into a voltage signal. For example, each pixel may include a photodiode and a readout circuit. The photodiode converts the received light signal into a voltage signal, and the readout circuit reads the voltage signal. The driver selects and reads the voltage signal from the pixel array. For example, the driver selects the readout circuit for each pixel and reads the voltage signal from the photodiode. The ADC converts the voltage signal into a digital signal. For example, the ADC may include a ramp generator and a comparator. The ramp generator outputs a preset reference voltage, and the comparator compares the preset reference voltage with the voltage signal and outputs a digital signal. The processing circuitry outputs an image signal based on the digital signal. The processing circuitry can also be called a digital signal processing circuit.

[0037] In addition, the IS (Instrument Array) process includes a reset phase and a photoelectric conversion phase. The reset phase is a preparation phase before the pixel array performs photoelectric conversion. During the reset phase, the capacitor of each pixel in the pixel array is charged to a certain voltage to prepare for the subsequent photoelectric conversion. The photoelectric conversion phase is the stage that converts the light signal into a voltage signal.

[0038] In long-exposure scenes, IS (Insulation Separation) increases the dark current in the pixel array. Specifically, during long exposures, IS increases the dark current in the photodiodes of the pixel array. This charge accumulation is converted into a voltage signal V1, typically ranging from 0 to 17.6 mV. When the ADC (Analog Converter) quantizes the voltage signal (converts it into a digital signal), the preset range allowed is 0 to V2. In some examples, V2 can be 62.5 mV. The proportion of the dark current-converted voltage signal V1 within this preset range is approximately... This means that the dark current occupies 27% of the preset range, resulting in the ADC quantizable effective voltage signal occupying only 73% of the preset range. Reducing the proportion of the preset range occupied by the effective voltage signal reduces the dynamic range of the image sensor (IS), thereby lowering image quality. The effective voltage signal refers to the voltage signal converted from the optical signal received by the IS, specifically the voltage signal converted from the optical signal received by the photodiode in the IS.

[0039] For example, Figure 1 This diagram illustrates the influence of dark current on the quantization range of an ADC, as provided in an embodiment of this application. Curve S001 represents a preset reference voltage (including a preset reference voltage Vra during the pixel array reset phase and a preset reference voltage Vrb during the photoelectric conversion phase); curve S002 represents the voltage signal converted from dark current output by the pixel array. During the reset phase: the photodiodes in the pixel array are not selected by the driver, and the pixel array does not output a voltage signal converted from dark current. The corresponding curve S002 remains equal to the initial value of the preset reference voltage Vra during the reset phase, indicating that no voltage signal converted from dark current is output during this phase. In practical applications, the pixel array outputs a voltage signal Va during this phase. The voltage signal Va is the voltage signal generated by noise in the pixel array; the ADC quantizes the voltage signal Va according to the reference voltage Vra, thereby determining the noise signal in the pixel array. During the photoelectric conversion phase: the photodiodes in the pixel array are selected by the driver, and the pixel array outputs a voltage signal V1 obtained from dark current conversion. The corresponding curve S002 generates a voltage drop in the voltage signal V1 during the photoelectric conversion phase, i.e., generates a voltage drop corresponding to the dark current. The ADC quantizes the voltage signal V1 according to the reference voltage Vrb. Figure 1 The voltage signal Va is not shown in the diagram.

[0040] Depend on Figure 1 It can be seen that, ideally, when there is no dark current in the pixel array, the range of the effective voltage signal that the ADC can quantize is equal to the preset range VFS0 of the ADC. When there is dark current in the pixel array, the voltage signal V1 obtained by dark current conversion occupies the preset range of the ADC as VFS1, and the range of the effective voltage signal that the ADC can quantize is VFS2, which reduces the quantization range of the effective voltage signal and reduces the dynamic range of IS.

[0041] Currently, the dynamic range of the IS (Interceptor) is increased by increasing the range of the reference voltage in the ADC, thereby increasing the proportion of the preset range occupied by the effective signal. However, increasing the range of the reference voltage in the ADC leads to an increase in the power consumption of the IS.

[0042] Based on this, this application provides an image sensor, which includes a first pixel array, a second pixel array, a plurality of first controllable current sources, a plurality of second controllable current sources, and a comparator. The first pixel array is blacked out, and during the exposure period, it does not receive any light signal. When no light signal is received, the current in the first pixel array is a dark current, and the first pixel array is used to output a first voltage signal converted from the dark current. The second pixel array receives the light signal during the exposure period and outputs a second voltage signal during a third period, and outputs a third voltage signal after photoelectric conversion during a fourth period; wherein, the third voltage signal includes an effective voltage signal obtained from the light signal conversion and a third voltage sub-signal obtained from the dark current conversion in the second pixel array. The plurality of first controllable current sources output a first preset reference voltage during the first period and a second preset reference voltage during the second period, according to a setting. The comparator first compares the first voltage signal and the second preset reference voltage to obtain a first level signal, that is, the comparator first quantizes the first voltage signal in the first pixel array to obtain the first level signal; the first level signal can be used to control the plurality of second controllable current sources to be turned on during the third period and output a compensation voltage corresponding to the dark current; and to control the plurality of second controllable current sources to be turned off during the fourth period. Multiple first controllable current sources output a target reference voltage in the third time period based on the sum of the compensation voltage and the first preset reference voltage. That is, the target reference voltage is obtained by increasing the compensation voltage on top of the first preset reference voltage. In the fourth time period, a second preset reference voltage is output. A comparator compares the target reference voltage and the second voltage signal in the third time period. Based on the comparator's circuit characteristics, the comparator increases the second voltage signal so that the increased second voltage signal equals the initial voltage value of the target reference voltage, and the magnitude of the increase in the second voltage signal equals the compensation voltage. In the fourth time period, the comparator compares the second preset reference voltage and the third voltage signal. The increased magnitude of the second voltage signal in the third time period (compensation voltage) offsets the voltage drop of the third voltage sub-signal obtained from dark current conversion in the third voltage signal. This compensates for the influence of the third voltage sub-signal obtained from dark current conversion in the second pixel array on the quantization range, increasing the quantization range of the effective voltage signal converted from light signals in the second pixel array, thus increasing the dynamic range of the image sensor. Furthermore, the range of the preset reference voltage is not increased during this process, reducing the power consumption of the image sensor.

[0043] The technical solution of this application can be applied to various electronic devices with display devices. Optionally, the electronic device may include, but is not limited to: mobile phone, tablet computer, camera, wearable device, in-vehicle device, virtual reality (VR) device, augmented reality (AR) device, wireless terminal in industrial control, smart home device, smart robot, workshop equipment, wireless terminal in self-driving, wireless terminal in remote medical surgery, wireless terminal in smart grid, wireless terminal in transportation safety, wireless terminal in smart city, or wireless terminal in smart home, and flying device, etc. For example, wearable devices include smartwatches; in-vehicle devices include devices on vehicles such as cars, airplanes, ships, trains, and high-speed trains; smart home devices include televisions; and flying device includes smart robots, drones, and airplanes.

[0044] The following example uses a mobile phone as an example to illustrate the structure of this electronic device. Figure 2 As shown, the electronic device may include components such as a radio frequency (RF) circuit 110, a memory 120, an input unit 130, a display device 140, a sensor 150, an audio circuit 160, a processor 170, and a power supply 180. Optionally, the display device 140 may be one of the display devices described above.

[0045] RF circuit 110 can be used to send and receive information, or to receive or send signals during a call. Specifically, it receives downlink information from the base station and processes it in processor 170; additionally, it sends uplink data to the base station. Typically, RF circuit 110 includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a low-noise amplifier (LNA), a duplexer, etc. Furthermore, RF circuit 110 can also communicate wirelessly with networks and other devices.

[0046] The memory 120 can be used to store data, software programs, and modules; it includes a program storage area and a data storage area. The program storage area can store the operating system and applications required for at least one function, such as sound playback and image playback functions. The data storage area can store data created based on the use of the electronic device, such as audio data, image data, and a phone book. Furthermore, the electronic device may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device. In embodiments of this application, the memory may include multiple memories, including a first memory and a second memory.

[0047] Input unit 130 can be used to receive input numerical or character information, and to generate key signal inputs related to user settings and function control of the electronic device. Input unit 130 may include touch screen 131 and other input devices 132. Touch screen 131 can collect touch operations on or near the user and drive corresponding connected devices according to a pre-set program. For example, touch operations may include operations performed by the user using a finger, stylus, or any suitable object or accessory on or near the touch screen. Optionally, other input devices 132 may include, but are not limited to, one or more of a physical keyboard, function keys, mouse, joystick, etc., such as volume control buttons, power switch buttons, etc.

[0048] Display device 140 can be used to display information input by the user or information provided to the user, as well as various menus of the electronic device. In one example, display device 140 may include a display screen 141. The display screen 141 may be configured as an LCD, an organic light-emitting diode (OLED), or an AMOLED. Furthermore, touch screen 131 may cover the display screen 141. When touch screen 131 detects a touch operation on or near it, it transmits the information to processor 170 to determine the type of touch event. Subsequently, processor 170 provides corresponding visual output on display screen 141 according to the type of touch event. Although in the figures, touch screen 131 and display screen 141 are shown as two separate components to implement the input and output functions of the electronic device, in some embodiments, touch screen 131 and display screen 141 may be integrated to implement the input and output functions of the electronic device.

[0049] Sensor 150 may include one or more sensors for providing status assessments of various aspects of the electronic device. Sensor 150 may include an image sensor 151, which can be used in imaging applications, i.e., as part of a camera or video camera. Furthermore, sensor 150 may also include an accelerometer, gyroscope, magnetometer, pressure sensor, or temperature sensor. Sensor 150 can detect acceleration / deceleration, orientation, on / off state, relative positioning of components, or temperature changes of the electronic device.

[0050] Audio circuitry 160, a speaker, and a microphone provide an audio interface between the user and the electronic device. Audio circuitry 160 converts received audio data into electrical signals and transmits them to the speaker, where the speaker converts them into sound signals for output. On the other hand, the microphone converts collected sound signals into electrical signals, which are then received by audio circuitry 160, converted into audio data, and output to RF circuitry 110 for transmission to, for example, another mobile phone, or to memory 120 for further processing.

[0051] The processor 170 is the control center of the electronic device, connecting various parts of the device through various interfaces and lines. It performs various functions and processes data by running or executing software programs and / or modules stored in the memory 120, and by calling data stored in the memory 120, thereby providing overall control of the electronic device. Optionally, the processor 170 may include one or more processing units, which may include, but are not limited to: a central processing unit (CPU), a network processing unit (NPU), a graphics processing unit (GPU), an image signal processor (ISP), a tensor processing unit (TPU), a data processing unit (DPU), a digital signal processor (DSP), a microcontroller circuit, or a microprocessor. Furthermore, the processor 170 may also include other hardware circuits or accelerators, such as application-specific integrated circuits (ASICs), complex programmable logic devices (CPLDs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. Optionally, the processor 170 may also be a combination of functions that implement computing, such as a combination of one or more microprocessors, a combination of a digital signal processor and a microprocessor, etc.

[0052] The electronic device may also include a power supply 180 (e.g., a battery) to power various components. The power supply 180 can be logically connected to the processor 170 via a power management system, thereby enabling functions such as charging, discharging, and power consumption management through the power management system. Optionally, the power management system can simultaneously support fast charging and non-fast charging technologies. In practical applications, the power management system can charge the battery in the power supply 180 using either fast charging or non-fast charging technologies.

[0053] The electronic device may also include a wireless fidelity (WiFi) module, a Bluetooth module, etc., which will not be described in detail in the embodiments of this application. Those skilled in the art will understand that... Figure 2The illustrated electronic device structure does not constitute a limitation on the electronic device and may include more or fewer components than illustrated, or combine certain components, or have different component arrangements.

[0054] Before introducing the image sensor provided in the embodiments of this application, the scenario of the embodiments of this application will be described first.

[0055] When taking photos in low-light conditions, such as indoors, at dusk, or at night, image sensors require long exposures to ensure image quality. Long exposures increase the dark current in the photodiode. When quantizing the voltage signal in the photodiode (including the effective voltage signal converted from the light signal and the voltage signal converted from the charge accumulated by the dark current), the voltage signal converted from the charge accumulated by the dark current occupies a certain quantization range. When the quantization range of the image sensor (i.e., the preset range of the comparator in the image sensor) is fixed, this reduces the quantization range of the effective voltage signal converted from the light signal, thus reducing the dynamic range of the image sensor and degrading image quality.

[0056] The following is combined Figure 3 The specific structure of the image sensor is described below. This image sensor can be described as described above. Figure 2 The image sensor 151 shown is included. The image sensor may include a complementary metal-oxide-semiconductor image sensor (CMOSIS).

[0057] Figure 3 This is a schematic diagram of an image sensor provided in an embodiment of this application. The image sensor includes a first pixel array 210, a second pixel array 220, a plurality of first controllable current sources 230, a plurality of second controllable current sources 240, and a comparator 250. Each of the plurality of first controllable current sources 230 includes a first current source A1, a first switch K1, and a resistor R connected sequentially between a power supply terminal VDD and a ground terminal GND. One end of the first switch K1 and one end of the resistor R are connected to a first node P1, and the first node P1 is connected to the first input terminal of the comparator 250. Each of the plurality of second controllable current sources 240 includes a second current source A2 and a second switch K2. One end of the second current source A2 is connected to the power supply terminal VDD, and the other end of the second current source A2 is connected to one end of the second switch K2. The other end of the second switch K2 is connected to a second node P2, and the second node P2 is connected between the first node P1 and one end of the first switch K1. The output terminals of the first pixel array 210 and the second pixel array 220 are both connected to the second input terminal of the comparator 250, and the first pixel array 210 is blacked out. Figure 3 The diagram only illustrates a portion of the image sensor's structure and does not constitute a limitation on the image sensor's structure.

[0058] In this embodiment, connection refers to electrical connection, which can be a direct electrical connection or an indirect electrical connection through an intermediate medium. The resistor R can also be a resistor implemented by a transistor. For example, the resistor R can be implemented by a transistor operating in the linear region, and this transistor can include a metal-oxide-semiconductor field-effect transistor (MOSFET).

[0059] Among them, there can be M first controllable current sources 230. The specific value of M is determined according to the preset range of comparator 250 and the size of the first current source A1. The preset range of comparator 250 refers to the maximum range of voltage signals that comparator 250 can receive. The preset range of comparator 250 is determined by the performance of comparator 250. The size of the first current source A1 is related to the accuracy of comparator 250.

[0060] In one possible implementation, the plurality of first controllable current sources 230 can be current-mode digital-to-analog converters (DACs). The plurality of first controllable current sources 230 can also be referred to as ramp generators.

[0061] Furthermore, there can be N second controllable current sources 240, where the specific value of N is determined based on the range of the compensation voltage corresponding to the dark current in the actual application and the magnitude of the second current source A2. The range of the compensation voltage corresponding to the dark current is related to the light intensity or exposure time of the shooting scene, and can be determined based on the experience of relevant personnel and actual needs. The magnitude of the second current source A2 is related to the accuracy of the comparator 250. Multiple second controllable current sources 240 can also be referred to as a compensation circuit.

[0062] Secondly, the first pixel array 210 is blacked out, meaning that the first pixel array 210 is a pixel array in the image sensor that does not receive light signals during the exposure period. Specifically, each pixel in the first pixel array 210 does not receive light signals during the exposure period. For each pixel in the first pixel array 210, not receiving light signals during the exposure period means that the photodiode in that pixel does not receive light signals during the exposure period. This exposure period is the exposure time required to take a picture in a low-light scene. This exposure time can be set according to actual needs or the experience of relevant personnel; this application does not impose specific limitations on it.

[0063] In a first possible embodiment, the first pixel array 210 can be used to convert the current within the first pixel array 210 into a first voltage signal V1 when no light signal is received. When no light signal is received, the current within the first pixel array 210 is the sum of the currents in the photodiodes of each pixel in the first pixel array 210, which can be referred to as dark current. For each pixel in the first pixel array 210, the photodiode within each pixel can be used to convert the current in that photodiode into a first sub-voltage signal, and the first pixel array 210 correspondingly obtains the first voltage signal V1. Optionally, the image sensor may further include a driver, which can be used to select the readout circuit in each pixel of the first pixel array 210, causing the first pixel array 210 to output the first voltage signal V1.

[0064] Furthermore, the second pixel array 220 is a pixel array in the image sensor that can receive light signals during the exposure period; that is, each pixel in the second pixel array 220 can be used to receive light signals during the exposure period. For each pixel in the second pixel array 220, receiving light signals during the exposure period means that the photodiode in that pixel array can be used to receive light signals during the exposure period.

[0065] In one possible embodiment, the second pixel array 220 can be used to receive optical signals and output a second voltage signal V2 in a third time period T3, and output a third voltage signal V3 after photoelectric conversion in a fourth time period T4. The fourth time period T4 follows the third time period T3.

[0066] The third time period T3 is the reset phase of the second pixel array 220, and the fourth time period T4 is the photoelectric conversion phase of the second pixel array 220. The second voltage signal V2 is the voltage signal generated by non-ideal factors (such as noise) in the second pixel array 220.

[0067] For example, the photodiode of each pixel in the second pixel array 220 converts the received light signal into a third sub-voltage signal, and the second pixel array 220 correspondingly obtains a third voltage signal V3. The driver can be used to select the readout circuit in each pixel of the second pixel array 220, so that the second pixel array 220 outputs the second voltage signal V2 in the third time period T3 and outputs the photoelectric converted third voltage signal V3 in the fourth time period T4.

[0068] The following will Figure 3The specific structures of the first pixel array 210 and the second pixel array 220 will be described below. Since the structures of the first pixel array 210 and the second pixel array 220 are similar, the second pixel array 220 will be used as an example in the following description. The second pixel array 220 includes A×B pixels. Since the structure of each pixel in the A×B pixels is the same, one pixel in the second pixel array 220 will be used as an example in the following description.

[0069] For example, Figure 4 This is a schematic diagram of the structure of the second pixel array 220 provided in an embodiment of this application. The second pixel array 220 includes a photodiode D, a readout circuit 221, and a third current source A3. The readout circuit 221 includes a first transistor M1, a second transistor M2, a third transistor M3, and a fourth transistor M4. One terminal (e.g., the drain) of the first transistor M1 and the drain of the second transistor M2 are both connected to the power supply terminal VDD. The other terminal (e.g., the source) of the first transistor M1, the gate of the second transistor M2, and the drain of the third transistor M3 are connected to a third node P3. The source of the third transistor M3 is connected to one end of the photodiode D. The source of the second transistor M2 and the drain of the fourth transistor M4 are connected. The source of the fourth transistor M4 and one end of the third current source A3 are connected to the fourth node P4. The fourth node P4 is connected to the output terminal of the second pixel array 220. The other end of the third current source A3 is connected to the ground terminal GND.

[0070] The gates of the first transistor M1, the third transistor M3, and the fourth transistor M4 can be used to receive the first control signal S1, the second control signal S2, and the third control signal S3, respectively. The first control signal S1, the second control signal S2, and the third control signal S3 can be sent by a driver in the image sensor.

[0071] The following is based on Figure 4 Taking the second pixel array 220 shown as an example, the working process of the second pixel array 220 will be explained.

[0072] Phase 1: Reset Phase (i.e., the third time period T3).

[0073] Photodiode D has not yet received a light signal; the first control signal S1 and the third control signal S3 are used to control the first transistor M1, the second transistor M2, and the fourth transistor M4 to turn on, respectively, while the second control signal S2 controls the third transistor M3 to turn off. Since photodiode D is not selected, it does not output a voltage signal corresponding to the dark current. The second pixel array 220 outputs a second voltage signal V2, which is a voltage signal generated by noise in the second pixel array 220.

[0074] The second stage: the photoelectric conversion stage (i.e., the fourth time period T4).

[0075] The photodiode receives and converts optical signals. The second control signal S2 and the third control signal S3 control the conduction of the second transistor M2, the third transistor M3, and the fourth transistor M4, respectively, while the first control signal S1 controls the first transistor M1 to turn off. With the photodiode D selected, the second pixel array 220 outputs a third voltage signal V3. The third voltage signal V3 includes a third voltage sub-signal V31 obtained from the conversion of the optical signal received by the second pixel array 220 and a third voltage sub-signal V32 obtained from the conversion of the dark current within the second pixel array 220. This voltage signal V31 can also be referred to as the effective voltage signal.

[0076] The working process of the first pixel array 210 will be explained below.

[0077] In the first stage: the reset stage (i.e., the first time period T1).

[0078] The working process of the first pixel array 210 in the first stage is similar to that of the second pixel array 220 in the first stage, and will not be described again here.

[0079] In the second stage: the stage of converting the current into the first voltage signal (i.e., the second time period T2).

[0080] Since the first pixel array 210 does not receive a light signal in this stage, the first pixel array 210 converts the current in the first pixel array 210 into a first voltage signal V1 and outputs it in the second stage.

[0081] In one possible embodiment, such as Figure 5 As shown, the image sensor also includes a control circuit 260. The control circuit 260 can be used to control a plurality of first controllable current sources 230. For example, the control circuit 260 can control the plurality of first controllable current sources 230 to output a first preset reference voltage Vr1 in a first time period T1, and to output a second preset reference voltage Vr2 in a second time period T2. The second time period T2 is after the first time period T1.

[0082] The third time period, T3, follows the second time period, T2.

[0083] The first time period T1 is the reset phase of the first pixel array 210, and the second time period T2 is the phase in which the first pixel array 210 converts the current in the first pixel array 210 into the first voltage signal V1.

[0084] For example, the control circuit 260 controls multiple first switches K1 among the multiple first controllable current sources 230, causing the multiple first switches K1 to close simultaneously at the beginning of the first time period T1, and controlling the corresponding first switch K1 to open at each fixed time after the beginning of the first time period T1. For example, if the beginning of the first time period T1 is t1, the control circuit 260 controls the multiple first switches K1 to close simultaneously at time t1; at time t2 after t1, it controls the first switch K11 among the multiple first switches K1 to open, and the difference between time t2 and time t1 is t0; at time t3 after t2, it controls the first switch K12 among the multiple first switches K1 to open, and the difference between time t3 and time t1 is 2t0; and so on, at time ta, it controls the first switch K1a among the multiple first switches K1 to open, and the difference between time ta and time t1 is at0, where at0 is less than the first time period T1. This causes the multiple first controllable current sources 230 to output a first preset reference voltage Vr1 in the first time period T1, and this first preset reference voltage Vr1 is a ramp voltage.

[0085] Similarly, the control circuit 260 controls multiple first switches K1 among the multiple first controllable current sources 230 to close simultaneously at the beginning of the second time period T2, and controls the corresponding first switch K1 to open at each fixed time after the beginning of the second time period T2. For example, if the beginning of the first time period T1 is t1, the control circuit 260 controls multiple first switches K1 to close simultaneously at time t1; at time t2 after t1, it controls the first switch K11 among the multiple first switches K1 to open, and the difference between time t2 and time t1 is t0; at time t3 after t2, it controls the first switch K12 among the multiple first switches K1 to open, and the difference between time t3 and time t1 is 2t0; and so on, at time ta, it controls the first switch K1a among the multiple first switches K1 to open, and the difference between time tm and time t1 is mt0, where mt0 is equal to the first time period T1. This causes the multiple first controllable current sources 230 to output a second preset reference voltage Vr2 in the second time period T2, where the first preset reference voltage Vr2 is a ramp voltage. In practical applications, the control circuit 260 can control one or more of the first switches K1 to open at each fixed time after the start of the first time period T1 or at each fixed time after the start of the second time period T2. In this embodiment, the control circuit 260 controlling one of the multiple first switches K1 to open is used as an example.

[0086] In practical applications, if the influence of multiple second controllable current sources 240 on multiple first controllable current sources 230 is not considered, when the comparator 250 quantizes the voltage signals in different pixel arrays, since the working process of each pixel array includes a first stage and a second stage, the control circuit 260 controls the multiple first controllable current sources 230 to output a first preset reference voltage Vr1 in the first stage of each pixel array, and controls the multiple first controllable current sources 230 to output a second preset reference voltage Vr2 in the second stage of each pixel array.

[0087] In one possible embodiment, comparator 250 can be used to convert analog signals into digital signals, for example, comparing a first voltage signal V1 and a second preset reference voltage Vr2, and outputting a first level signal. For example, when the first voltage signal V1 and the second preset reference voltage Vr2 are not equal, comparator 250 outputs a first level signal 0; when the first voltage signal V1 and the second preset reference voltage Vr2 are equal, comparator 250 outputs a first level signal 1.

[0088] For example, please continue reading Figure 5 The image sensor also includes a digital signal processing circuit 270. The input of the digital signal processing circuit 270 is connected to the output of the comparator 250, and the output of the digital signal processing circuit 270 is connected to the input of the control circuit 260. The digital signal processing circuit 270 can be used to output a compensation code value based on a first level signal. For example, when the first level signal is 0, the counter in the digital signal processing circuit 270 counts and accumulates; when the first level signal is 1, the counter in the digital signal processing circuit 270 counts and outputs a compensation code value. The digital signal processing circuit 270 is also used to output a fourth control signal S4.

[0089] In one possible embodiment, the control circuit 260 is further configured to control a plurality of second controllable current sources 240 to be turned on in a third time period T3 to output a compensation voltage based on the compensation code value and the fourth control signal S4; and to control the plurality of second controllable current sources 240 to be turned off in a fourth time period T4.

[0090] The fourth control signal S4 has different level states at different time periods. For example, the fourth control signal S4 is high at the third time period T3 and low at the fourth time period T4. When the fourth control signal S4 is high, the control circuit 260 can use it to control one or more of the second switches K2 of the multiple second controllable current sources 240 to close. When the fourth control signal S4 is low, the control circuit 260 can use it to control one or more of the second switches K2 of the multiple second controllable current sources 240 to open. The fourth control signal S4 can also be called the enable signal EN.

[0091] The multiple first controllable current sources 230 and multiple second controllable current sources 240 can be controlled by the same control circuit 260, or they can be controlled by different control circuits. For example, the control circuit 260 includes a first control circuit and a second control circuit. The first control circuit can be used to control the multiple first controllable current sources 230, and the second control circuit can be used to control the multiple second controllable current sources 240. This application does not make specific limitations in this regard. The following embodiments illustrate the example of multiple first controllable current sources 230 and multiple second controllable current sources 240 being controlled by the same control circuit 260.

[0092] For example, the control circuit 260 is further configured to determine, based on the compensation code value, the number of second switches K2 among the multiple second switches K2 of the multiple second controllable current sources 240 that need to be closed, and control the second switches K2 that need to be closed to close in the third time period T3 according to the fourth control signal S4, thereby controlling the multiple second controllable current sources 240 to conduct in the third time period T3, so that the multiple second controllable current sources 240 output compensation voltage. The control circuit 260 is further configured to control the second switches K2 closed in the third time period T3 to open in the fourth time period T4 according to the fourth control signal S4, so that the multiple second controllable current sources 240 are turned off in the fourth time period T4.

[0093] Furthermore, during the third time period T3, multiple second controllable current sources 240 are turned on and output compensation voltages; multiple first controllable current sources 230 output target reference voltage Vo during the third time period T3 based on the compensation voltage and the first preset reference voltage Vr1. For example, multiple first controllable current sources 230 output target reference voltage Vo during the third time period T3 based on the sum of the compensation voltage and the first preset reference voltage Vr1, that is, multiple first controllable current sources 230 increase the first preset reference voltage Vr1 based on the compensation voltage, that is, multiple first controllable current sources 230 raise the first preset reference voltage Vr1 based on the compensation voltage, so that the magnitude of the increase (raise) of the first preset reference voltage Vr1 is equal to the compensation voltage, so as to obtain the target reference voltage Vo. During the fourth time period T4, multiple second controllable current sources 240 are turned off; multiple first controllable current sources 230 are also used to output a second preset reference voltage Vr2 during the fourth time period T4.

[0094] In practical applications, after quantizing the first voltage signal V1 in the first pixel array 210, the image sensor quantizes the second voltage signal V2 and the third voltage signal V3 in the second pixel array 220 to determine the image signal. The following is an example... Figure 4 Taking the second pixel array 220 shown as an example, combined with Figure 5 The specific process of quantizing the second voltage signal V2 and the third voltage signal V3 of the image sensor is explained.

[0095] In one possible embodiment, during the third time period T3, the driver controls the first transistor M1, the second transistor M2, and the fourth transistor M4 to turn on according to the first control signal S1 and the third control signal S3, respectively, and controls the third transistor M3 to turn off according to the second control signal S2. At this time, the photodiode D is not selected, and the second pixel array 220 outputs the second voltage signal V2. The comparator 250 is also used to compare the target reference voltage Vo and the second voltage signal V2 during the third time period T3, and outputs a second level signal. For example, when the target reference voltage Vo and the second voltage signal V2 are not equal, the comparator 250 outputs the second level signal 0; when the target reference voltage Vo and the second voltage signal V2 are equal, the comparator 250 outputs the second level signal 1. The digital signal processing circuit 270 determines the first code value based on the second level signal. For example, when the second level signal is 0, the counter in the digital signal processing circuit 270 counts and accumulates; when the second level signal is 1, the counter in the digital signal processing circuit 270 performs this count and stops counting, thereby determining the first code value.

[0096] In one possible embodiment, during the fourth time period T4, the driver controls the second transistor M2, the third transistor M3, and the fourth transistor M4 to turn on according to the second control signal S2 and the third control signal S3, respectively, while the first control signal S1 controls the first transistor M1 to turn off. At this time, the photodiode D is selected, and the second pixel array 220 outputs a photoelectric converted third voltage signal V3. The third voltage signal includes a third voltage sub-signal V31 obtained from the conversion of the light signal and a third voltage sub-signal V32 obtained from the conversion of the dark current in the second pixel array. The comparator 250 compares the second preset reference voltage Vr2 and the third voltage signal V3 to determine and output a third level signal. For example, when the second preset reference voltage Vr2 and the third voltage signal V3 are not equal, the third level signal 0 is determined and output. When the second preset reference voltage Vr2 and the third voltage signal V3 are equal, the third level signal 1 is determined and output. The digital signal processing circuit 270 determines the second code value based on the third level signal. For example, when the third level signal is 0, the counter in the digital signal processing circuit 270 counts and accumulates; when the third level signal is 1, the counter in the digital signal processing circuit 270 performs this count and stops counting, thereby determining the second code value.

[0097] The digital signal processing circuit 270 outputs an image signal based on the first code value and the second code value. For example, the digital signal processing circuit 270 determines and outputs an image signal based on the difference between the second code value and the first code value.

[0098] In one possible embodiment, Figure 5 The multiple first controllable current sources 230, multiple second controllable current sources 240, and comparator 250 shown are integrated together, and the structure of the image sensor is as follows: Figure 6 As shown, the image sensor may include an analog-to-digital conversion circuit 10, which may include a plurality of first controllable current sources 230, a plurality of second controllable current sources 240, and a comparator 250.

[0099] To facilitate understanding, the following will be combined with... Figure 7 The quantization range of the image sensor is explained.

[0100] For example, Figure 7 This is a schematic diagram of the quantization range of an image sensor provided in an embodiment of this application. Curve S01 is the waveform of the fourth control signal S4 (enable signal EN); curve S02 represents the waveform of the preset reference voltage (including the first preset reference voltage Vr1 and the second preset reference voltage Vr2) in comparator 250; curve S03 represents the waveform of the reference voltage (including the target reference voltage Vo and the second preset reference voltage Vr2) in comparator 250; curve S04 represents the waveform of the third voltage sub-signal V32 of the dark current conversion in the second pixel array 220 in comparator 250 when the first preset reference voltage Vr1 is not compensated; curve S05 represents the waveform of the third voltage sub-signal V32 of the dark current conversion in the second pixel array 220 in comparator 250 after the first preset reference voltage Vr1 is compensated.

[0101] like Figure 7 As shown, assuming that multiple second controllable current sources 240 are not turned on during the third time period T3, multiple first controllable current sources 230 output a first preset reference voltage Vr1 during the third time period T3 and a second preset reference voltage Vr2 during the fourth time period T4. The first preset reference voltage Vr1 and the second preset reference voltage Vr2 in the comparator 250 are shown as curve S02. During the T3 time period (i.e., the reset phase of the second pixel array 220), the photodiode D in the second pixel array 220 is not selected by the driver, and the second pixel array 220 does not output the third voltage sub-signal V32 for dark current conversion. The corresponding curve S04 remains equal to the initial value of the first preset reference voltage Vra during the third time period T3, indicating that the second pixel array 220 does not output the third voltage sub-signal V32 during this phase. During the fourth time period T4 (i.e., the photoelectric conversion stage of the second pixel array 220), the photodiode D in the second pixel array 220 is selected by the driver, and the second pixel array 220 outputs the third voltage sub-signal V32 of dark current conversion. The corresponding curve S04 generates a voltage drop of the third voltage sub-signal V32 in the fourth time period T4, which is the voltage drop corresponding to the dark current. The third voltage sub-signal V32 corresponding to the dark current occupies a quantization range of F1, and the third voltage sub-signal V31 obtained from the light signal conversion in the second pixel array 220 occupies a quantization range of F2. The input range of the voltage signal allowed by the comparator 250 is F0, that is, the preset range of the comparator 250 is F0.

[0102] When the fourth control signal S4 is high during the third time period T3, it controls the multiple second controllable current sources 240 to turn on. When the fourth control signal S4 is low during the fourth time period T4, it controls the multiple second controllable current sources 240 to turn off. The multiple first controllable current sources 230 output a target reference voltage Vo based on the sum of the compensation voltage and the first preset reference voltage Vr1 during the third time period T3, and output a second preset reference voltage Vr2 during the fourth time period T4. The target reference voltage Vo and the second preset reference voltage Vr2 in the comparator 250 are shown in curve S03. Compared to curve S02, the target reference voltage Vo in curve S03 is obtained by increasing the compensation voltage based on the first preset reference voltage Vr1. During time period T3 (i.e., the reset phase of the second pixel array 220), the photodiode D in the second pixel array 220 is not selected by the driver, and the second pixel array 220 does not output the third voltage sub-signal V32 for dark current conversion. Since the target reference voltage Vo is obtained by increasing the compensation voltage on the basis of the first preset reference voltage Vr1, based on the circuit characteristics of the comparator 250, that is, the values ​​of the first input terminal and the second input terminal of the comparator 250 are equal at the beginning of the comparison, the comparator 250 will increase the third voltage sub-signal V32 for dark current conversion output by the second pixel array 220. The increase is equal to the compensation voltage, so that the curve S05 always remains equal to the initial value of the target reference voltage Vo in the third time period T3, indicating that the second pixel array 220 does not output the third voltage sub-signal V32 in this phase. During time period T4 (i.e., the photoelectric conversion stage of the second pixel array 220), the photodiode D in the second pixel array 220 is selected by the driver, and the second pixel array 220 outputs the third voltage sub-signal V32, which is a dark current conversion signal. The corresponding curve S05 generates a voltage drop of the third voltage sub-signal V32 in the fourth time period T4, which is the voltage drop corresponding to the dark current. The increase in amplitude of comparator 250 in the third time period T3 is equal to that of the third voltage sub-signal V32. That is, the increased amplitude in the third time period compensates for the voltage drop generated by the third voltage sub-signal V32 in the fourth time period T4. This compensates for the influence of the third voltage sub-signal V32 obtained from the dark current conversion in the third voltage signal V3 on the quantization range, so that the quantization range occupied by the third voltage sub-signal V31 obtained from the light signal conversion in the second pixel array 220 is F0, thereby increasing the quantization range of the third voltage sub-signal V31 and thus increasing the quantization range of the image sensor.

[0103] This application provides an image sensor, which includes a first pixel array 210, a second pixel array 220, a plurality of first controllable current sources 230, and a comparator 250. When the first pixel array 210 does not receive a light signal during the exposure period, it converts the current in the first pixel array 210 into a first voltage signal V1 and outputs it. When no light signal is received, the current in the first pixel array 210 is a dark current, meaning the first pixel array 210 converts the dark current into the first voltage signal V1 and outputs it. The second pixel array 220 receives a light signal during the exposure period and outputs a second voltage signal V2 in a third time period T3, and outputs a third voltage signal V3 after photoelectric conversion in a fourth time period T4. The third voltage signal V3 includes an effective voltage signal V31 obtained from the light signal conversion and a third voltage sub-signal V32 obtained from the dark current in the second pixel array. The comparator 250 compares the first voltage signal V1 with a second preset reference voltage Vr2 and outputs a first level signal. The digital signal processing circuit 270 outputs a compensation code value and a fourth control signal S4 based on the first level signal. The comparator 250 and digital signal processing circuit 270 first quantize the first voltage signal V1 in the first pixel array 210 according to the second preset reference voltage Vr2, and output the compensation code value corresponding to the dark current and the fourth control signal S4. The control circuit 260 controls multiple second controllable current sources 240 to be turned on in the third time period T3 according to the compensation code value and the fourth control signal S4, and outputs the compensation voltage; and controls multiple second controllable current sources 240 to be turned off in the fourth time period T4. Multiple first controllable current sources 230 output the target reference voltage Vo according to the sum of the compensation code value and the first preset reference voltage Vr1 in the third time period T3, and output the second preset reference voltage Vr2 in the fourth time period T4; that is, multiple first controllable current sources 230 compensate the first preset reference voltage Vr1 according to the compensation voltage corresponding to the dark current, and the increase in the first preset reference voltage Vr1 is equal to the compensation voltage, which is the first voltage signal V1 of the dark current conversion. Comparator 250 compares the target reference voltage Vo and the second voltage signal V2 and outputs a second level signal; that is, comparator 250 quantizes the second voltage signal V2 according to the target reference voltage Vo. Based on the circuit characteristics of comparator 250, comparator 250 will increase the second voltage signal V2 so that the increased second voltage signal V2 is equal to the initial voltage value of the target reference voltage Vo, and the increase in the second voltage signal V2 is equal to the compensation voltage.In the fourth time period T4, comparator 250 compares the second preset reference voltage Vr2 and the third voltage signal V3 and outputs a third level signal. That is, comparator 250 quantizes the third voltage signal V3 according to the second preset reference voltage Vr2, and uses the increased amplitude (compensation voltage) of the second voltage signal V2 in the third time period T3 to compensate for the voltage drop of the third voltage sub-signal V32 obtained by dark current conversion in the third voltage signal V3. This compensates for the influence of the third voltage sub-signal V32 obtained by dark current conversion in the third voltage signal V3 on the quantization range, and increases the quantization range of the effective voltage signal V31 of optical signal conversion in the third voltage signal V3, that is, increases the dynamic range of the image sensor. Moreover, the range of the preset reference voltage is not increased in this process, thus reducing the power consumption of the image sensor.

[0104] This application also provides a signal processing method, which is applied to an image sensor, and the image sensor can be as described above. Figure 3 , Figure 5 or Figure 6 The image sensor shown, such as Figure 8 As shown, within an image frame, the method includes the following steps:

[0105] S801. When the first pixel array 210 does not receive an optical signal, the current in the first pixel array 210 is converted into a first voltage signal V1 and output.

[0106] Secondly, the first pixel array 210 is blacked out, meaning that the first pixel array 210 is a pixel array in the image sensor that does not receive light signals during the exposure period. Specifically, each pixel in the first pixel array 210 does not receive light signals during the exposure period. For each pixel in the first pixel array 210, not receiving light signals during the exposure period means that the photodiode in that pixel does not receive light signals during the exposure period. This exposure period is the exposure time required to take a picture in a low-light scene. This exposure time can be set according to actual needs or the experience of relevant personnel; this application does not impose specific limitations on it.

[0107] In a first possible embodiment, the first pixel array 210 can be used to convert the current within the first pixel array 210 into a first voltage signal V1 when no light signal is received. When no light signal is received, the current within the first pixel array 210 is the sum of the currents in the photodiodes of each pixel in the first pixel array 210, which can be referred to as dark current. For each pixel in the first pixel array 210, the photodiode within each pixel can be used to convert the current in that photodiode into a first sub-voltage signal, and the first pixel array 210 correspondingly obtains the first voltage signal V1. Optionally, the image sensor may further include a driver, which can be used to select the readout circuit in each pixel of the first pixel array 210, causing the first pixel array 210 to output the first voltage signal V1.

[0108] S802, multiple first controllable current sources 230 output a first preset reference voltage Vr1 in the first time period T1, and output a second preset reference voltage Vr2 in the second time period T2. The second time period T2 is after the first time period T1.

[0109] The first time period T1 is the reset phase of the first pixel array 210, and the second time period T2 is the phase in which the first pixel array 210 converts the current in the first pixel array 210 into the first voltage signal V1.

[0110] In this embodiment, there can be M first controllable current sources 230. The specific value of M is determined based on the preset range of the comparator 250 and the size of the first current source A1. The preset range of the comparator 250 refers to the maximum range of voltage signals that the comparator 250 can receive, and this preset range is determined by the performance of the comparator 250. The size of the first current source A1 is related to the accuracy of the comparator 250. In one possible implementation, the multiple first controllable current sources 230 can be current-mode digital-to-analog converters (DACs).

[0111] In one possible embodiment, the image sensor may include a control circuit 260, and step S802 includes: the control circuit 260 controlling a plurality of first controllable current sources 230 to output a first preset reference voltage Vr1 in a first time period T1, and to output a second preset reference voltage Vr2 in a second time period T2.

[0112] For example, the control circuit 260 controls multiple first switches K1 among the multiple first controllable current sources 230, such that the multiple first switches K1 are simultaneously closed at the beginning of the first time period T1, and at each fixed time after the beginning of the first time period T1, the corresponding first switch K1 is controlled to open. This causes the multiple first controllable current sources 230 to output a first preset reference voltage Vr1 in the first time period T1, where the first preset reference voltage Vr1 is a ramp voltage.

[0113] Similarly, the control circuit 260 controls multiple first switches K1 among the multiple first controllable current sources 230 to close simultaneously at the beginning of the second time period T2, and controls the corresponding first switch K1 to open at each fixed time after the beginning of the second time period T2. This causes the multiple first controllable current sources 230 to output a second preset reference voltage Vr2 in the second time period T2, where the first preset reference voltage Vr2 is a ramp voltage.

[0114] In practical applications, if the influence of multiple second controllable current sources 240 on multiple first controllable current sources 230 is not considered, when the comparator 250 quantizes the voltage signals in different pixel arrays, since the working process of each pixel array includes a first stage and a second stage, the control circuit 260 controls the multiple first controllable current sources 230 to output a first preset reference voltage Vr1 in the first stage of each pixel array, and controls the multiple first controllable current sources 230 to output a second preset reference voltage Vr2 in the second stage of each pixel array.

[0115] S803 and comparator 250 compare the first voltage signal V1 and the second preset reference voltage Vr2, and output the first level signal.

[0116] For example, when the second preset reference voltage Vr2 of the first voltage signal V1 is not equal, the comparator 250 outputs a first level signal 0; when the second preset reference voltage Vr2 of the first voltage signal V1 is equal, the comparator 250 outputs a first level signal 1.

[0117] Furthermore, the image sensor also includes a digital signal processing circuit 270. The method provided in this embodiment further includes: the digital signal processing circuit 270 outputs a compensation code value based on a first level signal. For example, when the first level signal is 0, the counter in the digital signal processing circuit 270 counts and accumulates; when the first level signal is 1, the counter in the digital signal processing circuit 270 performs this count and stops, thereby determining the compensation code value, and the digital signal processing circuit 270 outputs the compensation code value.

[0118] Furthermore, the method provided in this application embodiment also includes a digital signal processing circuit 270 outputting a fourth control signal S4. The fourth control signal S4 can also be referred to as an enable signal EN.

[0119] S804 and multiple second controllable current sources 240 are turned on and output compensation voltage in the third time period T3. The compensation voltage is determined based on the first level signal; the third time period T3 is after the second time period T2.

[0120] Furthermore, multiple second controllable current sources 240 are turned off in the fourth time period T4.

[0121] The third time period T3 is the reset stage of the second pixel array 220, and the fourth time period T4 is the photoelectric conversion stage of the second pixel array 220.

[0122] Furthermore, there can be N second controllable current sources 240, where the specific value of N is determined based on the range of the compensation voltage corresponding to the dark current in the actual application and the magnitude of the second current source A2. The range of the compensation voltage corresponding to the dark current is related to the light intensity or exposure time of the shooting scene, and can be determined based on the experience of relevant personnel and actual needs. The magnitude of the second current source A2 is related to the accuracy of the comparator 250.

[0123] In one possible embodiment, step S804 includes: the control circuit 260 controlling a plurality of second controllable current sources 240 to conduct and output a compensation voltage during a third time period T3, based on the compensation code value and a fourth control signal S4. The control circuit 260 then controls the plurality of second controllable current sources 240 to turn off during a fourth time period T4.

[0124] The fourth control signal S4 has different level states at different time periods. For example, the fourth control signal S4 is high at the third time period T3 and low at the fourth time period T4. When the fourth control signal S4 is high, the control circuit 260 can use it to control one or more of the second switches K2 of the multiple second controllable current sources 240 to close. When the fourth control signal S4 is low, the control circuit 260 can use it to control one or more of the second switches K2 of the multiple second controllable current sources 240 to open. The fourth control signal S4 can also be called the enable signal EN.

[0125] The multiple first controllable current sources 230 and multiple second controllable current sources 240 can be controlled by the same control circuit 260, or they can be controlled by different control circuits. For example, the control circuit 260 includes a first control circuit and a second control circuit. The first control circuit can be used to control the multiple first controllable current sources 230, and the second control circuit can be used to control the multiple second controllable current sources 240. This application does not make specific limitations in this regard. The following embodiments illustrate the example of multiple first controllable current sources 230 and multiple second controllable current sources 240 being controlled by the same control circuit 260.

[0126] For example, the control circuit 260 determines the number of second switches K2 that need to be closed among the multiple second switches K2 of the multiple second controllable current sources 240 according to the compensation code value, and controls the second switches K2 that need to be closed to close in the third time period T3 according to the fourth control signal S4, thereby controlling the multiple second controllable current sources 240 to conduct in the third time period T3, so that the multiple second controllable current sources 240 output compensation voltage. The control circuit 260 controls the second switches K2 that were closed in the third time period T3 to open in the fourth time period T4 according to the fourth control signal S4, so that the multiple second controllable current sources 240 are turned off in the fourth time period T4.

[0127] S805, multiple first controllable current sources 230 output the first target reference voltage Vo1 according to the compensation code value and the first preset reference voltage Vr1 in the third time period T3, and output the second preset reference voltage Vr2 in the fourth time period T4; the fourth time period T4 is after the third time period T3.

[0128] Furthermore, during the third time period T3, multiple second controllable current sources 240 are turned on and output compensation voltages; multiple first controllable current sources 230 output target reference voltage Vo during the third time period T3 based on the compensation voltage and the first preset reference voltage Vr1. For example, multiple first controllable current sources 230 output target reference voltage Vo during the third time period T3 based on the sum of the compensation voltage and the first preset reference voltage Vr1, that is, multiple first controllable current sources 230 increase the first preset reference voltage Vr1 based on the compensation voltage, that is, multiple first controllable current sources 230 raise the first preset reference voltage Vr1 based on the compensation voltage, so that the magnitude of the increase (raise) of the first preset reference voltage Vr1 is equal to the compensation voltage, so as to obtain the target reference voltage Vo. During the fourth time period T4, multiple second controllable current sources 240 are turned off; multiple first controllable current sources 230 are also used to output a second preset reference voltage Vr2 during the fourth time period T4.

[0129] S806, the second pixel array 220 receives the optical signal and outputs the second voltage signal V2 in the third time period T3, and outputs the third voltage signal V3 after photoelectric conversion in the fourth time period T4.

[0130] Secondly, the second pixel array 220 is a pixel array in the image sensor that can receive light signals during the exposure period; that is, each pixel in the second pixel array 220 can be used to receive light signals during the exposure period. For each pixel in the second pixel array 220, receiving light signals during the exposure period means that the photodiode in the pixel array can be used to receive light signals during the exposure period. The photodiode of each pixel converts the received light signal into a third sub-voltage signal, and multiple pixels correspond to a third voltage signal V3. The driver can be used to select the readout circuit in each pixel of the second pixel array 220 to read out the third voltage signal V3, thus causing the second pixel array 220 to output the third voltage signal V3.

[0131] In one possible embodiment, during the third time period T3, the driver controls the first transistor M1, the second transistor M2, and the fourth transistor M4 to turn on according to the first control signal S1 and the third control signal S3, respectively, and controls the third transistor M3 to turn off according to the second control signal S2. At this time, photodiode D is not selected, and the second pixel array 220 outputs a second voltage signal V2. During the fourth time period T4, the driver controls the second transistor M2, the third transistor M3, and the fourth transistor M4 to turn on according to the second control signal S2 and the third control signal S3, respectively, and controls the first transistor M1 to turn off according to the first control signal S1. At this time, photodiode D is selected, and the second pixel array 220 outputs a third voltage signal V3 after photoelectric conversion. The third voltage signal includes a third voltage sub-signal V31 obtained from the conversion of the light signal and a third voltage sub-signal V32 obtained from the conversion of the dark current in the second pixel array.

[0132] S807 and comparator 250 compare the first target reference voltage Vo1 and the second voltage signal V2 in the third time period T3 and output a second level signal. In the fourth time period T4, they compare the second preset reference voltage Vr2 and the third voltage signal V3 and output a third level signal. The second level signal and the third level signal are used to determine the image signal corresponding to an image frame.

[0133] For example, when the target reference voltage Vo and the second voltage signal V2 are not equal, the comparator 250 outputs a second level signal 0; when the target reference voltage Vo and the second voltage signal V2 are equal, the comparator 250 outputs a second level signal 1. When the second preset reference voltage Vr2 and the third voltage signal V3 are not equal, a third level signal 0 is determined and output. When the second preset reference voltage Vr2 and the third voltage signal V3 are equal, a third level signal 1 is determined and output.

[0134] Furthermore, the digital signal processing circuit 270 determines the first code value based on the second level signal. For example, when the second level signal is 0, the counter in the digital signal processing circuit 270 counts and accumulates; when the second level signal is 1, the counter in the digital signal processing circuit 270 performs this count and stops counting, thereby determining the first code value.

[0135] Furthermore, the digital signal processing circuit 270 determines the second code value based on the third level signal. For example, when the third level signal is 0, the counter in the digital signal processing circuit 270 counts and accumulates; when the third level signal is 1, the counter in the digital signal processing circuit 270 performs this count and stops counting, thereby determining the second code value.

[0136] The digital signal processing circuit 270 outputs an image signal based on the first code value and the second code value. For example, the digital signal processing circuit 270 determines and outputs an image signal corresponding to an image frame based on the difference between the second code value and the first code value.

[0137] Optionally, for an image frame following an image frame, the image sensor can redetermine the compensation voltage corresponding to the other image frame, or directly use the compensation voltage corresponding to the image frame preceding the other image frame.

[0138] In a first possible embodiment, the image sensor can redetermine the compensation voltage corresponding to another image frame to determine the image signal corresponding to that other image frame. The specific process of determining the compensation voltage and the image signal corresponding to the other image frame is similar to the specific process of determining the compensation voltage and the image signal corresponding to one image frame described above. (See details below.) Figure 8 This will not be elaborated further here. In this embodiment, the compensation voltage corresponding to each image frame needs to be determined, which improves the compensation accuracy and the quality of the image signal.

[0139] In a second possible embodiment, the image sensor directly uses the compensation voltage corresponding to the image frame preceding another image frame.

[0140] For example, multiple first controllable current sources 230 output a third preset reference voltage Vr3 in a first time period T1 and a fourth preset reference voltage Vr4 in a second time period T2. In a third time period T3, a second target reference voltage Vo2 is output based on the third preset reference voltage Vr3 and a compensation voltage determined in an image frame, and the fourth preset reference voltage Vr4 is output in a fourth time period T4. The second pixel array 220 outputs a fourth voltage signal V4 in the third time period T3 and a fifth voltage signal V5 after photoelectric conversion in the fourth time period T4. The comparator 250 compares the second target reference voltage Vo2 and the fourth voltage signal V4 in the third time period T3 and outputs a fourth level signal. In the fourth time period T4, it compares the fourth preset reference voltage Vr4 and the fifth voltage signal V5 and outputs a fifth level signal; the fourth level signal and the fifth level signal are used to determine the image signal corresponding to another image frame.

[0141] For example, when the third preset reference voltage Vr3 is equal to the second preset reference voltage Vr1, the second target reference voltage Vo2 is equal to the first target reference voltage Vo1. At this time, the fourth preset reference voltage Vr4 is equal to the second preset reference voltage Vr2.

[0142] The digital signal processing circuit 270 determines the third code value based on the fourth level signal and the fourth code value based on the fifth level signal; and determines and outputs the image signal corresponding to another image frame based on the difference between the fourth code value and the third code value.

[0143] In this embodiment, the compensation code value corresponding to the image frame before another image frame is used, eliminating the need to re-determine the compensation code value, reducing the power consumption of the image sensor, and improving the efficiency of determining the image signal.

[0144] All relevant content involved in the above-described embodiments of the display device can be referenced in the embodiments of the display refresh method, and will not be repeated here.

[0145] This application provides a signal processing method. When the first pixel array 210 does not receive a light signal during the exposure period, it converts the current in the first pixel array 210 into a first voltage signal V1 and outputs it. When no light signal is received, the current in the first pixel array 210 is a dark current, meaning the first pixel array 210 converts the dark current into the first voltage signal V1 and outputs it. The second pixel array 220 receives a light signal during the exposure period and outputs a second voltage signal V2 in the third period T3, and outputs a third voltage signal V3 after photoelectric conversion in the fourth period T4. The third voltage signal V3 includes an effective voltage signal V31 obtained from the light signal conversion and a third voltage sub-signal V32 obtained from the dark current conversion in the second pixel array. A comparator 250 compares the first voltage signal V1 with a second preset reference voltage Vr2 and outputs a first level signal. A digital signal processing circuit 270 outputs a compensation code value and a fourth control signal S4 based on the first level signal. The comparator 250 and digital signal processing circuit 270 first quantize the first voltage signal V1 in the first pixel array 210 according to the second preset reference voltage Vr2, and output the compensation code value corresponding to the dark current and the fourth control signal S4. The control circuit 260 controls multiple second controllable current sources 240 to be turned on in the third time period T3 according to the compensation code value and the fourth control signal S4, and outputs the compensation voltage; and controls multiple second controllable current sources 240 to be turned off in the fourth time period T4. Multiple first controllable current sources 230 output the target reference voltage Vo according to the sum of the compensation code value and the first preset reference voltage Vr1 in the third time period T3, and output the second preset reference voltage Vr2 in the fourth time period T4; that is, multiple first controllable current sources 230 compensate the first preset reference voltage Vr1 according to the compensation voltage corresponding to the dark current, and the increase in the first preset reference voltage Vr1 is equal to the compensation voltage, which is the first voltage signal V1 of the dark current conversion. Comparator 250 compares the target reference voltage Vo and the second voltage signal V2 and outputs a second level signal; that is, comparator 250 compares the target reference voltage Vo and quantizes the second voltage signal V2. Based on the circuit characteristics of comparator 250, comparator 250 will increase the second voltage signal V2 so that the increased second voltage signal V2 is equal to the initial voltage value of the target reference voltage Vo, and the increase in the second voltage signal V2 is equal to the compensation voltage.In the fourth time period T4, comparator 250 compares the second preset reference voltage Vr2 and the third voltage signal V3 and outputs a third level signal. That is, comparator 250 quantizes the third voltage signal V3 according to the second preset reference voltage Vr2, and uses the increased amplitude of the second voltage signal V2 in the third time period T3 (the first voltage signal V1 corresponding to the dark current) to compensate for the voltage drop of the third voltage sub-signal V32 obtained by dark current conversion in the third voltage signal V3. This compensates for the influence of the third voltage sub-signal V32 obtained by dark current conversion in the third voltage signal V3 on the quantization range, and increases the quantization range of the effective voltage signal V31 of light signal conversion in the third voltage signal V3, that is, increases the dynamic range of the image sensor. Moreover, the range of the preset reference voltage is not increased in this process, thus reducing the power consumption of the image sensor.

[0146] Based on this, embodiments of this application also provide an electronic device, which includes a processor and an image sensor. The image sensor can be used to output an image signal, and the processor can be used to process the image signal. The image sensor can be the aforementioned... Figure 3 , Figure 5 or Figure 6 The image sensor shown is illustrated. It is understood that all relevant content from the above embodiments can be referenced in the embodiments of this electronic device, and will not be repeated here.

[0147] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can also be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules or units is merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another apparatus, or some features may be ignored or not executed.

[0148] The units described as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units; that is, it can be located in one place or distributed in multiple different locations. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0149] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. This readable storage medium may include various media capable of storing program code, such as a USB flash drive, external hard drive, read-only memory, random access memory, magnetic disk, or optical disk. Based on this understanding, the technical solution of the embodiments of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product.

[0150] Finally, it should be noted that the above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An image sensor, characterized in that, The image sensor includes a first pixel array, a second pixel array, multiple first controllable current sources, multiple second controllable current sources, and a comparator; Each of the plurality of first controllable current sources includes a first current source, a first switch, and a resistor connected sequentially between a power supply terminal and a ground terminal. One end of the first switch and one end of the resistor are connected to a first node, and the first node is connected to the first input terminal of the comparator. Each of the plurality of second controllable current sources includes a second current source and a second switch. One end of the second current source is connected to the power supply terminal, and the other end of the second current source is connected to one end of the second switch. The other end of the second switch is connected to a second node, and the second node is connected between the first node and one end of the first switch. The output terminals of the first pixel array and the second pixel array are both connected to the second input terminal of the comparator, and the first pixel array is blacked out.

2. The image sensor according to claim 1, characterized in that, The image sensor also includes: a control circuit; The control circuit is used to control the plurality of first controllable current sources and the plurality of second controllable current sources, respectively.

3. The image sensor according to claim 2, characterized in that, The image sensor also includes: a digital signal processing circuit; The input terminal of the digital signal processing circuit is connected to the output terminal of the comparator, and the output terminal of the digital signal processing circuit is connected to the input terminal of the control circuit.

4. The image sensor according to claim 3, characterized in that, The first pixel array is used to convert the current in the first pixel array into a first voltage signal and output it when no light signal is received; The plurality of first controllable current sources are used to output a first preset reference voltage in a first time period and to output a second preset reference voltage in a second time period; the second time period is after the first time period. The comparator is used to compare the first voltage signal and the second preset reference voltage, and output a first level signal; The digital signal processing circuit is used to output a compensation code value and a control signal based on the first level signal.

5. The image sensor according to claim 4, characterized in that, The control circuit is configured to control the plurality of second controllable current sources to be turned on in a third time period and output a compensation voltage according to the compensation code value and the control signal; and to control the plurality of second controllable current sources to be turned off in a fourth time period. The third time period is after the second time period, and the fourth time period is after the third time period; The plurality of first controllable current sources are used to output a target reference voltage in the third time period according to the first preset reference voltage and the compensation voltage; It is also used to output the second preset reference voltage during the fourth time period; The second pixel array is used to receive light signals, output a second voltage signal in the third time period, and output a third voltage signal after photoelectric conversion in the fourth time period; The comparator is also configured to compare the target reference voltage and the second voltage signal during the third time period and output a second level signal, and to compare the second preset reference voltage and the third voltage signal during the fourth time period and output a third level signal. The digital signal processing circuit is also used to output an image signal based on the second level signal and the third level signal.

6. A signal processing method, characterized in that, Applied in an image sensor, the image sensor including a first pixel array, a second pixel array, a plurality of first controllable current sources, a plurality of second controllable current sources, and a comparator, the method includes: Within an image frame: When the first pixel array does not receive an optical signal, it converts the current in the first pixel array into a first voltage signal and outputs it. The plurality of first controllable current sources output a first preset reference voltage in a first time period and output a second preset reference voltage in a second time period; the second time period is after the first time period. The comparator compares the first voltage signal with the second preset reference voltage and outputs a first level signal; The plurality of second controllable current sources output a compensation voltage in a third time period; the compensation voltage is determined based on the first level signal; the third time period is after the second time period; The plurality of first controllable current sources output a first target reference voltage in a third time period according to the compensation code value and the first preset reference voltage; and output the second preset reference voltage in a fourth time period; the fourth time period is after the third time period. The second pixel array receives the light signal and outputs the second voltage signal in the third time period, and outputs the third voltage signal after photoelectric conversion in the fourth time period; The comparator compares the first target reference voltage and the second voltage signal in the third time period and outputs a second level signal; and compares the second preset reference voltage and the third voltage signal in the fourth time period and outputs a third level signal. The second level signal and the third level signal are used to determine the image signal corresponding to the image frame.

7. The method according to claim 6, characterized in that, The image sensor further includes: a digital signal processing circuit; the method further includes: The digital signal processing circuit outputs a compensation code value and a control signal based on the first level signal.

8. The method according to claim 7, characterized in that, The image sensor further includes: a control circuit; the plurality of second controllable current sources output compensation voltage in the third time period, including: The control circuit controls the plurality of second controllable current sources to conduct during the third time period according to the compensation code value and the control signal, and outputs the compensation voltage. The method further includes: The control circuit controls the plurality of second controllable current sources to turn off during the fourth time period according to the compensation code value and the control signal.

9. The method according to claim 7 or 8, characterized in that, The method further includes: The digital signal processing circuit outputs a first code value based on the second level signal; and outputs a second code value based on the third level signal; and determines the image signal based on the first code value and the second code value.

10. The method according to any one of claims 6-9, characterized in that, The method further includes: Within another image frame following the first image frame: The plurality of first controllable current sources output a third preset reference voltage in a first time period and a fourth preset reference voltage in a second time period; the second time period is after the first time period; in a third time period, a second target reference voltage is output based on the third preset reference voltage and the compensation voltage determined in the image frame, and the fourth preset reference voltage is output in a fourth time period; the third time period is after the second time period, and the fourth time period is after the third time period. The second pixel array outputs a fourth voltage signal during the third time period and a fifth voltage signal after photoelectric conversion during the fourth time period; The comparator compares the second target reference voltage and the fourth voltage signal in the third time period and outputs a fourth level signal. In the fourth time period, it compares the fourth preset reference voltage and the fifth voltage signal and outputs a fifth level signal. The fourth level signal and the fifth level signal are used to determine the image signal corresponding to the other image frame.

11. An electronic device, characterized in that, The electronic device includes an image sensor and a processor, wherein the image sensor is the image sensor as described in any one of claims 1-5.

Images