CN115967864A

CN115967864A - Method, circuit, device and medium for collecting optical signal in image sensor

Info

Publication number: CN115967864A
Application number: CN202211711597.1A
Authority: CN
Inventors: 郭同辉
Original assignee: Pulse Vision Beijing Technology Co ltd
Current assignee: Pulse Vision Beijing Technology Co ltd
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2023-04-14
Anticipated expiration: 2042-12-29
Also published as: CN115967864B

Abstract

The embodiment of the disclosure discloses a method, a circuit, equipment and a medium for collecting optical signals in an image sensor, wherein the method comprises the following steps: determining the state of a control switch in a device group of an acquisition circuit for acquiring the current frame signal according to the evaluation result corresponding to the previous frame signal; in response to the control switch being in a closed state, collecting photoelectric charges generated by the current frame signal through a plurality of capacitors in a device group of the acquisition circuit; wherein the device group comprises a photodiode, at least one capacitor and the control switch; and outputting a target signal of the current frame signal based on the potential change generated by the plurality of capacitors for collecting the photoelectric charges. The embodiment of the disclosure increases the charge collection capability, is suitable for collecting stronger light image signals, and improves the photosensitive dynamic range of pixels; the problem of different light environment image signal acquisition is solved.

Description

Method, circuit, device and medium for collecting optical signal in image sensor

Technical Field

The present disclosure relates to image sensor technology, and more particularly, to a method, circuit, device, and medium for acquiring an optical signal in an image sensor.

Background

The image sensor has been widely used in the fields of digital cameras, mobile phones, medical treatment, automobiles, unmanned aerial vehicles, machine identification, and the like, and particularly, the rapid development of the technology for manufacturing Complementary Metal Oxide Semiconductor (CMOS) image sensors has made people have higher requirements for the quality of output images of the image sensors.

Disclosure of Invention

According to an aspect of the embodiments of the present disclosure, there are provided a method, a circuit, an apparatus, and a medium for acquiring an optical signal in an image sensor.

According to an aspect of the embodiments of the present disclosure, there is provided a method for acquiring an optical signal in an image sensor, including:

determining the state of a control switch in a device group of an acquisition circuit for acquiring the current frame signal according to the evaluation result corresponding to the previous frame signal;

in response to the control switch being in a closed state, collecting photoelectric charges generated by the current frame signal through a plurality of capacitors in a device group of the acquisition circuit; wherein the device group comprises a photodiode, at least one capacitor and the control switch;

and outputting a target signal of the current frame signal based on the potential change generated by the plurality of capacitors for collecting the photoelectric charges.

Optionally, the method further comprises:

processing the target signal through a quantization circuit and an evaluation circuit to determine an evaluation result of the current frame signal;

and determining the state of the control switch in the device group of the acquisition circuit when the next frame signal is acquired based on the evaluation result of the current frame signal.

Optionally, the determining, according to the evaluation result corresponding to the previous frame signal, the state of a control switch in a device group of an acquisition circuit for acquiring the current frame signal includes:

in response to the evaluation result that the quantization value is too low, determining that the control switch is switched off, and ending the quantization processing of the previous frame signal;

in response to the evaluation result that the quantization value is too high, determining that the control switch is closed, and ending the quantization processing of the previous frame signal;

and responding to the evaluation result that the quantized value is in a preset range, not changing the state of the control switch, and continuously processing the quantized value transmitted by the signal of the last frame.

Optionally, the device group further includes a reset transistor, and at least one capacitor in the device group includes: an auxiliary capacitor, and a common source region of the auxiliary transistor and the reset transistor;

the anode of the photodiode is grounded, and the cathode of the photodiode is connected with an auxiliary transistor configured as the control switch;

the source electrode of the auxiliary transistor is connected with the cathode electrode of the photodiode, and the drain electrode of the auxiliary transistor is connected with the source electrode of the reset transistor;

one end of the auxiliary capacitor is grounded, and the other end of the auxiliary capacitor is connected with the common active region;

the collecting the photoelectric charge generated by the current frame signal through a plurality of capacitors in a device group of the collecting circuit comprises:

converting a light signal into a photoelectric charge through the photodiode;

storing the photo-electric charge using the photodiode, the auxiliary transistor, the auxiliary capacitance, and the common active region.

Optionally, the acquisition circuit further includes a source follower transistor having a gate connected to the photodiode and the source of the auxiliary transistor, and a pixel selection transistor having a drain connected to the source of the source follower transistor and a source as an output terminal of the acquisition circuit; the drain electrode of the source following transistor is connected with a power supply;

the outputting a target signal of the current frame signal based on a potential change of the plurality of capacitors generated by collecting the photoelectric charges includes:

determining a change in potential of photodiodes in the device group based on the photoelectric charges collected by the device group;

obtaining a potential signal according to the detected potential change of the device group through the source follower transistor;

and outputting the target signal through the control of the pixel selection transistor according to an external control signal.

Optionally, the processing the target signal through a quantization circuit and an evaluation circuit to determine an evaluation result of the current frame signal includes:

quantizing the target signal through the quantization circuit to obtain a quantization value corresponding to the current frame signal;

and evaluating the quantized value through the evaluation circuit to determine whether the quantized value is in a preset range.

Optionally, the target signal comprises at least one of the following signals: pulse signals, potential signals, and values with limits.

According to another aspect of the embodiments of the present disclosure, there is provided an acquisition circuit of an optical signal in an image sensor, including: a device group including a control switch and an auxiliary circuit;

the device group is used for determining the state of the control switch in the device group for collecting the current frame signal according to the evaluation result corresponding to the previous frame signal; collecting photoelectric charges generated by the current frame signal through a plurality of capacitors in the device group in response to the control switch being in a closed state;

the auxiliary circuit is used for outputting a target signal of the current frame signal based on the potential change generated by collecting the photoelectric charges of the device group.

Optionally, the device group includes: a photodiode PD, an auxiliary transistor DCG configured as the control switch, a reset transistor RX, and an auxiliary capacitance Cap;

the anode of the photodiode PD is grounded, and the cathode of the photodiode PD is connected with the source electrode of the auxiliary transistor DCG;

the source electrode of the auxiliary transistor DCG is connected with the cathode electrode of the photodiode PD, and the drain electrode is connected with the source electrode of the reset transistor RX;

one end of the auxiliary capacitor Cap is grounded, and the other end of the auxiliary capacitor Cap is connected with the common active region PD2 of the auxiliary transistor DCG and the reset transistor RX;

the reset transistor RX and the auxiliary transistor DCG have a common source region PD2, and are connected to the auxiliary capacitor Cap through the common source region PD2, and a drain of the reset transistor RX is connected to a power supply source.

Optionally, the photodiode PD is configured to receive an optical signal to generate a photoelectric charge;

the reset transistor RX has a drain connected to a power supply and is configured to reset the photodiode PD and the auxiliary capacitor Cap according to an external control signal;

the device group collects the photoelectric charges based on the photodiode PD, the auxiliary transistor DCG, the auxiliary capacitance Cap, and the common source region PD2 when the control switch is in a closed state; the photo charge is collected based on the photodiode PD when the control switch is in an off state.

Optionally, the auxiliary circuit comprises: a source follower transistor SF having a gate connected to the photodiode PD and the source of the auxiliary transistor DCG, and a pixel selection transistor SX having a drain connected to the source of the source follower transistor SF and a source as an output terminal of the acquisition circuit; the drain of the source follower transistor SF is connected to a power supply.

Optionally, the device group generates a potential change according to the collection of the photoelectric charges;

the source following transistor SF detects and follows the potential change of the photodiode PD in the device group to obtain a potential signal;

the pixel selection transistor SX outputs the target signal according to control of an external control signal.

According to still another aspect of the embodiments of the present disclosure, there is provided an electronic device including: the image sensor comprises a processor, a memory which is in communication connection with the processor, and an acquisition circuit of an optical signal in the image sensor according to any one of the embodiments;

the memory stores computer-executable instructions;

the processor executes computer-executable instructions stored in the memory to control the acquisition circuit of the light signal in the image sensor to implement the method of any of the above embodiments.

Optionally, the electronic device comprises any one of: cameras, audio/video players, navigation devices, fixed location terminals, entertainment devices, smart phones, communication devices, mobile devices, vehicles or facilities, industrial devices, medical devices, security devices, flight devices, home appliance devices.

According to a further aspect of the embodiments of the present disclosure, there is provided a computer-readable storage medium, in which computer-executable instructions are stored, and when the instructions are executed, the instructions cause a computer to execute the method according to any one of the embodiments.

According to a further aspect of embodiments of the present disclosure, there is provided a computer program product comprising a computer program, wherein the computer program when executed by a processor implements the method of any of the embodiments described above.

Based on the method, the circuit, the equipment and the medium for acquiring the optical signals in the image sensor, provided by the embodiment of the disclosure, the state of the control switch is determined according to the evaluation result, and charge acquisition is performed according to one capacitor or a plurality of capacitors in the control switch controller group, so that when charge acquisition is performed through the plurality of capacitors, the charge acquisition capacity is increased, the method is suitable for acquisition of image signals with stronger light, and the photosensitive dynamic range of pixels is improved; the problem of different light environment image signal acquisition is solved.

The technical solution of the present disclosure is further described in detail by the accompanying drawings and examples.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

The present disclosure may be more clearly understood from the following detailed description, taken with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a circuit for collecting optical signals in an image sensor according to an embodiment of the disclosure;

FIG. 2 is a schematic diagram of a potential well of an acquisition circuit according to an embodiment of the present disclosure;

FIG. 3 is a response curve of the potential signal output by the acquisition circuit in an embodiment of the disclosure;

fig. 4 is a schematic flowchart of a method for acquiring an optical signal in an image sensor according to an exemplary embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of an acquisition circuit for an optical signal in an image sensor according to an exemplary embodiment of the present disclosure;

fig. 6 is a schematic structural diagram of an acquisition circuit for an optical signal in an image sensor according to another exemplary embodiment of the present disclosure;

fig. 7 is a schematic diagram illustrating a time sequence state change in an optical signal collection process according to an alternative example provided by an exemplary embodiment of the present disclosure;

FIG. 8a is a schematic diagram of a potential well of the acquisition circuit with the control switch turned off as provided by an exemplary embodiment of the present disclosure;

FIG. 8b is a potential well schematic of the acquisition circuit with the control switch closed as provided by an exemplary embodiment of the present disclosure;

FIG. 9 is a response curve of a potential signal output by an acquisition circuit under different light intensity environments according to an exemplary embodiment of the present disclosure;

fig. 10 illustrates a block diagram of an electronic device in accordance with an embodiment of the disclosure.

Detailed Description

Hereinafter, example embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. It should be understood that the described embodiments are only some of the embodiments of the present disclosure, and not all of the embodiments of the present disclosure, and it is to be understood that the present disclosure is not limited by the example embodiments described herein.

It should be noted that: the relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present disclosure unless specifically stated otherwise.

It will be understood by those of skill in the art that the terms "first," "second," and the like in the embodiments of the present disclosure are used merely to distinguish one element from another, and are not intended to imply any particular technical meaning, nor is the necessary logical order between them.

It is also understood that in embodiments of the present disclosure, "a plurality" may refer to two or more than two, and "at least one" may refer to one, two or more than two.

It is also to be understood that any reference to any component, data, or structure in the embodiments of the disclosure, may be generally understood as one or more, unless explicitly defined otherwise or stated otherwise.

In addition, the term "and/or" in the present disclosure is only one kind of association relationship describing an associated object, and means that three kinds of relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" in the present disclosure generally indicates that the former and latter associated objects are in an "or" relationship. The data referred to in this disclosure may include unstructured data, such as text, images, video, etc., as well as structured data.

It should also be understood that the description of the various embodiments of the present disclosure emphasizes the differences between the various embodiments, and the same or similar parts may be referred to each other, so that the descriptions thereof are omitted for brevity.

Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

CMOS image sensors can be classified into two categories according to the signal acquisition method: one is a method of setting an exposure time period for a pixel and measuring a voltage signal variation; the second method is to set a voltage variation to a pixel and measure an exposure time, and such an image sensor is called a pulse sequence image sensor. In an embodiment of the present application, a three-transistor structure is adopted for optical signal acquisition of the pulse sequence image sensor, and a schematic diagram of an acquisition circuit is shown in fig. 1. PD0 is a photodiode, RX0 is a reset transistor, SF0 is a source follower transistor, and SX0 is a pixel select transistor. As shown in fig. 1, vdd is a power supply terminal, vpix0 is a pixel signal output terminal, and an external signal processing circuit performs signal processing; GND is the device substrate potential 0V; where 100 marks the PD0 and RX0 device groups. The working principle of the pulse sequence type image sensor pixel is that the PD0 is reset by starting RX0, then RX0 is closed, the PD0 starts exposure and collects photoelectric charges, and the potential of the PD0 is reduced; and (3) starting the SX0 pixel to be selected, detecting the potential of the Vpix0 end by an external signal processing circuit, continuing exposure by the PD0 if the potential does not reach a preset value Vth, starting the RX0 to reset the PD0 if the potential reaches the preset value Vth, then closing the RX0, starting exposure by the PD0, and carrying out next frame work. A schematic diagram of a potential well of the pulse sequential image sensor pixel working device group 100 is shown in fig. 2. In fig. 2, 200 is a potential well diagram of the power supply Vdd, 201 is a potential well diagram of PD0, vpd0_ reset is a reset potential of PD0, PD0 is exposed, photoelectric charges are collected in 201, the potential drops from Vpd0_ reset to Vpd0, and Cpd0 is labeled as a capacitance of PD 0. Fig. 3 is a diagram illustrating the relationship between the output potential of the pixel signal output terminal Vpix0 and the time t in the quantization signal pulse operation of the pixel structure shown in fig. 1 and 2. Fig. 3 shows a curve 202 representing a response curve of the Vpix0 end potential with time t, where the Vpix0 end potential has a preset value of Vth01, in a pixel working state under a low light environment. And a curve 203 representing the pixel working state in a strong light environment, wherein the preset value is a response curve of the Vpix0 end potential of Vth02 along with time t, and Vth01 is greater than Vth02. As can be seen from fig. 3, the response curve of the pixel of the pulse train image sensor for detecting the strongest light is curve 203, i.e. the quantized value of each quantized signal pulse is 1. The maximum light detection capability of the pixel of the pulse sequence image sensor is proportional to Cpd0 shown in fig. 2. Therefore, the capacity of the pixels of the pulse sequence type image sensor for detecting the strongest light, namely the dynamic range of the photosensitive collection light signals of the pixels is restricted by the capacitance of PD0, so that stronger light, such as more image details under the sunlight at noon in summer, is difficult to detect.

Fig. 4 is a schematic flowchart of a method for acquiring an optical signal in an image sensor according to an exemplary embodiment of the present disclosure. The embodiment can be applied to an electronic device, as shown in fig. 4, and includes the following steps:

and step 410, determining the state of a control switch in a device group of the acquisition circuit for acquiring the current frame signal according to the evaluation result corresponding to the previous frame signal.

Optionally, the collecting circuit at least includes a device group, and the device group is configured to collect the optical signal, generate a photoelectric charge based on the optical signal, and store the photoelectric charge, so as to achieve the function of collecting the optical signal.

In step 420, in response to the control switch being in the closed state, photoelectric charges generated by the current frame signal are collected by a plurality of capacitors in the device group of the acquisition circuit.

The device group at least comprises a photodiode, at least one capacitor and a control switch.

Optionally, collecting photoelectric charges generated by the current frame signal through the photodiodes in the device group in response to the control switch being in the off state may also be included.

In some optional examples, the control switch in the device group controls one or more capacitors in the device group to collect photoelectric charges, so that the photoelectric charges are stored by the capacitors under the condition of strong light intensity, the capability of collecting the photoelectric charges is improved, stronger light can be detected, and more image details can be embodied under the condition of strong light intensity.

In step 430, a target signal of the current frame signal is output based on the potential variation generated by the collected photoelectric charges of the plurality of capacitors.

Optionally, the target signal may include at least one of: pulse signals, potential signals, values with limits, etc.

According to the method for acquiring the optical signal in the image sensor, provided by the embodiment of the disclosure, the state of the control switch is determined according to the evaluation result, and charge acquisition is performed according to one capacitor or a plurality of capacitors in the control switch controller group, so that when charge acquisition is performed through the plurality of capacitors, the charge acquisition capacity is increased, the method is suitable for acquisition of stronger optical image signals, and the photosensitive dynamic range of pixels is improved; the problem of different light environment image signal acquisition is solved.

In some optional embodiments, the method may further include:

and determining the state of a control switch in a device group of the acquisition circuit when the next frame signal is acquired based on the evaluation result of the current frame signal.

Alternatively, the processing the target signal by the quantization circuit and the evaluation circuit to determine the evaluation result of the current frame signal may include:

quantizing the target signal through a quantization circuit to obtain a quantization value corresponding to the current frame signal; the quantized value is evaluated by an evaluation circuit to determine whether the quantized value is within a preset range.

Optionally, in this embodiment, the quantization circuit performs quantization processing on the target signal, and optionally, the quantization process may be determined according to a preset threshold (a potential value set according to an actual scene), the potential value reaching the preset threshold is quantized to 1, the potential value not reaching the preset threshold is quantized to 0, that is, a potential sequence consisting of 1 and 0 may be obtained by quantization of the quantization circuit, and a frame signal is represented from one 1 to another 1, that is, when it is recognized that the quantization value is 1, the quantization processing of the current frame signal is ended; the number of 0 in the potential sequence corresponding to the current frame signal is evaluated by the evaluation circuit, and the number of 0 in the potential sequence represents the intensity of the light intensity, for example, the more the number of 0, the weaker the light intensity is, and the less the number of 0, the stronger the light intensity is; in this embodiment, when the light intensity is stronger, control switch is closed, when the light intensity is weaker, control switch disconnection to solve the photoelectric charge collection problem under the different light intensities.

In some optional embodiments, step 410 may comprise:

in response to the evaluation result that the quantization value is too low, determining that the control switch is switched off, and ending the quantization processing of the previous frame of signals;

in response to the evaluation result that the quantization value is too high, determining that the control switch is closed, and ending the quantization processing of the previous frame of signals;

and responding to the evaluation result that the quantized value is in the preset range, not changing the state of the control switch, and continuously processing the quantized value transmitted by the signal of the last frame.

Of course, this embodiment is equally applicable to determining the control switch state of the next frame signal based on the evaluation result of the current frame signal.

In this embodiment, the excessively low quantization value means that the number of 0 between two 1 s in the electric potential sequence obtained through quantization is large, for example, the preset range indicates that the number of 0 s is between a first threshold and a second threshold (specifically, values of the first threshold and the second threshold may be set according to an application scenario, and the first threshold is smaller than the second threshold), then, when the number of 0 s in the electric potential sequence is larger than the second threshold, it may be determined that the quantization value is excessively low, at this time, it indicates that the light intensity is weak, the control switch is turned off, and the photodiode in the device group is used to perform photoelectric charge collection on the current frame signal; when the number of 0 s in the electric potential sequence is smaller than a first threshold value, the quantization value is determined to be too high, at the moment, the light intensity is high, the control switch is closed, and photoelectric charge collection is carried out on the current frame signal through a plurality of capacitors in the device group; when the number of 0 in the potential sequence is in the preset range, the state of the current control switch is appropriate, the state of the control switch is unchanged, and the quantization processing of the signal of the previous frame is continued.

In some alternative embodiments, the state of the control switch in the previous frame signal is different, which may include the following two cases:

in the first case, the control switch (e.g., implemented by an auxiliary transistor) is in a closed state. If the quantization value is too low (which means that the target signal output by the output end of the acquisition circuit still does not reach the preset threshold value within the longest exposure time and the number of 0 in the quantization value is too much), ending the signal quantization of the current frame, disconnecting the control switch and starting the signal quantization work of the next frame; if the quantization value is too high, that is, the potential values of the two quantized values reaching the preset threshold (that is, the quantization value is 1) are relatively close to each other (for example, there is no interval between two 1 s or only one or two 0 s are spaced between two 1 s), the signal quantization of the current frame is finished, and the signal quantization of the next frame is started; the quantization value is in accordance with expectation, namely the quantization value is too low and the quantization value is too high, the quantization circuit continuously quantizes the signal of the frame, and the state of the control switch is kept unchanged.

In the second case, the control switch is in the off state. If the quantization value is too low, finishing the quantization of the signal of the frame and starting the quantization work of the signal of the next frame; if the quantization value is too high, closing the control switch and starting the next frame signal quantization work; the quantization value is in accordance with expectation, the quantization circuit continuously quantizes the frame signal, and the state of the control switch is kept unchanged.

In some optional embodiments, the device group further comprises a reset transistor, and at least one capacitor in the device group comprises: an auxiliary capacitor, and a common active region of the auxiliary transistor and the reset transistor;

the anode of the photodiode is grounded, and the cathode is connected with an auxiliary transistor configured as a control switch;

step 420 may include:

converting the optical signal into a photoelectric charge through a photodiode;

the photo-charges are stored using a photodiode, an auxiliary transistor, an auxiliary capacitor and a common active region.

Alternatively, the auxiliary capacitor may be a metal-metal capacitor, or may also be a MOS transistor capacitor.

In the embodiment, the auxiliary transistor is used as the control switch, and when the auxiliary transistor is in an off state (the control switch is turned off), the auxiliary transistor is suitable for collecting image optical signals with weak light intensity, and compared with the prior art, the photosensitive sensitivity of the pixel is kept unchanged; the auxiliary transistor is in an open state (the control switch is closed), the photodiode is communicated with the auxiliary capacitor, the photodiode converts a light signal into photoelectric charges, the photoelectric charges are collected due to the fact that the photoelectric signals are received, partial charges in the obtained photoelectric charges are shunted, and the auxiliary capacitor, the auxiliary transistor and the common active region are used for assisting in collection and storage, so that the capacity of a device group for collecting the photoelectric charges is improved when the auxiliary transistor is in the open state, the pixel photosensitive sensitivity is compressed, and the high-intensity image light signal collection device is suitable for collecting high-intensity image light signals.

Optionally, the acquisition circuit further comprises a source follower transistor with a gate connected to the photodiode and the source of the auxiliary transistor, and a pixel selection transistor with a drain connected to the source of the source follower transistor and a source as the output terminal of the acquisition circuit; the drain electrode of the source following transistor is connected with a power supply;

outputting a target signal of a current frame signal based on a potential change generated by collecting photoelectric charges of a plurality of capacitors, comprising:

determining the potential change of the photodiodes in the device group according to the photoelectric charges collected by the device group;

the target signal is output by the control of the pixel selection transistor according to an external control signal.

In the present embodiment, the potential of the device group is changed due to accumulation of photoelectric charges, the gate terminal of the source follower transistor is connected to the photodiode and follows the potential change of the photodiode to obtain a potential signal, the pixel selection transistor selects whether to output a target signal according to control of an external control signal, the external control signal may be an external clock circuit, the pixel selection transistor may be controlled to output the target signal based on a timing transmission signal of the external clock circuit, and the target signal may be any one or more of a pulse signal, a potential signal, a value with a limit, and the like.

Any of the image processing methods provided by the embodiments of the present disclosure may be performed by any suitable device having data processing capabilities, including but not limited to: terminal equipment, a server and the like. Alternatively, any image processing method provided by the embodiments of the present disclosure may be executed by a processor, for example, the processor may execute any image processing method mentioned by the embodiments of the present disclosure by calling a corresponding instruction stored in a memory. And will not be described in detail below.

Fig. 5 is a schematic structural diagram of an acquisition circuit for optical signals in an image sensor according to an exemplary embodiment of the present disclosure. As shown in fig. 5, the circuit provided in this embodiment includes: a device group 51 including control switches and an auxiliary circuit 52;

the device group 51 is used for determining the state of a control switch in the device group for collecting the current frame signal according to the evaluation result corresponding to the previous frame signal; and collecting photoelectric charges generated by the current frame signal through a plurality of capacitors in the device group in response to the control switch being in a closed state.

And an auxiliary circuit 52 for outputting a target signal of the current frame signal based on a potential change generated by collecting photoelectric charges of the device group.

According to the circuit for collecting the optical signals in the image sensor, provided by the embodiment of the disclosure, the state of the control switch is determined according to the evaluation result, and charge collection is performed according to one capacitor or a plurality of capacitors in the control switch controller group, so that when charge collection is performed through the plurality of capacitors, the charge collection capacity is increased, the circuit is suitable for collecting image signals with stronger light, and the photosensitive dynamic range of pixels is increased; the problem of different light environment image signal acquisition is solved.

Fig. 6 is a schematic structural diagram of an acquisition circuit for optical signals in an image sensor according to another exemplary embodiment of the present disclosure. As shown in fig. 6, in this embodiment, the device group 51 includes: a photodiode PD, an auxiliary transistor DCG configured to control a switch, a reset transistor RX, and an auxiliary capacitor Cap;

the anode of the photodiode PD is grounded, and the cathode is connected with the source electrode of the auxiliary transistor DCG;

the source electrode of the auxiliary transistor DCG is connected with the cathode electrode of the photodiode PD, and the drain electrode is connected with the source electrode of the reset transistor RX; alternatively, the source of the auxiliary transistor DCG is connected to the photodiode PD, the drain is connected to the source of the reset transistor RX, and the gate of the auxiliary transistor DCG is connected to the evaluation circuit to control the on/off of the auxiliary transistor DCG according to a control signal output by the evaluation result.

One end of the auxiliary capacitor Cap is grounded, and the other end of the auxiliary capacitor Cap is connected with the common active region PD2 of the auxiliary transistor DCG and the reset transistor RX; when the hardware is set, the drain terminal of the auxiliary transistor DCG and the source terminal of the reset transistor RX are connected to form a common source region PD2, and the reverse PN junction of the common source region PD2 can be regarded as a capacitor for storing photoelectric charges.

The reset transistor RX and the auxiliary transistor DCG have a common source region PD2, and are connected to the auxiliary capacitor Cap via the common source region PD2, and the other end (drain) of the reset transistor RX is connected to the power supply source.

The source of the reset transistor RX is connected to the drain of the auxiliary transistor DCG, and the gate thereof may be connected to an external clock control signal, so as to reset the photodiode PD and the auxiliary capacitor Cap according to the external clock control signal.

The auxiliary circuit 52 includes: a source follower transistor SF having a gate connected to the photodiode PD and the source of the auxiliary transistor DCG, and a pixel selection transistor SX having a drain connected to the source of the source follower transistor SF and a source as the output terminal Vpix of the acquisition circuit; the drain of the source follower transistor SF is connected to a power supply.

Optionally, a photodiode PD configured to receive a light signal to generate photoelectric charges;

a reset transistor RX having a drain connected to a power supply and configured to reset the photodiode PD and the auxiliary capacitor Cap according to an external control signal;

when the control switch is in a closed state, the device group 51 collects photoelectric charges based on the photodiode PD, the auxiliary transistor DCG, the auxiliary capacitor Cap, and the common active region PD 2; when the control switch is in an off state, photoelectric charges are collected based on the photodiode.

In the disclosed embodiment, when the control switch DCG is in a closed state, the photodiode PD receives a light signal, converts the light signal into photoelectric charges, and stores the photoelectric charges converted by the photodiode PD in a plurality of capacitors, that is, the photodiode PD, the auxiliary transistor DCG, the auxiliary capacitor Cap, and the common active region PD2, and forms a potential signal across the photodiode PD. In the present embodiment, the source follower transistor SF is connected to one end of the PD, and therefore, the source follower transistor SF can read out a potential signal from the photodiode PD at any signal readout timing, generate a continuous pulse signal, and output it. Compared with the existing discontinuous imaging with constant frame rate signal output and discontinuity, the embodiment of the application can read the potential signal at any time and generate a continuous pulse signal for realizing the continuity of the image signal.

Fig. 7 is a schematic diagram illustrating a time sequence state change in an optical signal collection process according to an alternative example provided by an exemplary embodiment of the disclosure. As shown in fig. 7, includes: the high level in the time sequence diagrams of the reset transistor RX, the auxiliary transistor DCG and the pixel selection transistor SX represents that the corresponding transistors are in an on state, and the high level pulse of the quantization signal pulse represents the operation of acquiring pixel signals. The timing sequence shown in fig. 7 will be described in detail below.

As shown in fig. 7, the quantization circuit quantizes the signal pulse operation and the pixel selection transistor SX timing pulse is kept consistent, the reset transistor RX is given a high level pulse operation, the photodiode PD is reset, and the potential of the output terminal Vpix rises; then, pixel selection transistor SX and the high-level pulse of the quantization signal pulse are used for carrying out pixel signal acquisition operation, the pulse of the first quantization signal is marked as the first pulse of the frame, and the signal quantization of the frame is represented; with the continuous collection of photoelectric charges by the photodiode PD, the potential signal of the output end Vpix is continuously reduced, when the potential signal is reduced to a preset threshold value Vth, the last signal is collected by the quantization signal pulse and is marked as a frame end pulse, and the signal quantization of the frame is finished by representation.

Fig. 8a is a schematic diagram of a potential well of the acquisition circuit when the control switch is turned off according to an exemplary embodiment of the disclosure. As shown in fig. 8a, the potential well 200 of the power supply Vdd, the common active region PD2 and the auxiliary capacitor Cap is 302, the capacitance thereof is Cap + Cpd2, the potential well 301 of the photodiode PD is Cpd, wherein the reset transistor RX and the auxiliary transistor DCG are in the off state (i.e., the control switch is turned off), and are suitable for the weak light image signal collection and quantization operation. Photosensitive charge is collected in the potential well 301 and the photodiode PD potential is lowered to Vpd. In the well structure shown in fig. 8a, the capacitance Cpd of the well 301 is consistent with Cpd0 of the prior art, and thus, the photosensitivity is consistent.

Fig. 8b is a potential well schematic of the acquisition circuit with the control switch closed as provided by an exemplary embodiment of the present disclosure. As shown in fig. 8b, the auxiliary transistor DCG is in an on state; a potential well 301 of the photodiode PD is communicated with the common active region PD2 and a potential well 302 of the auxiliary capacitor Cap; at the moment, the total capacitance is Ccap + Cpd2+ Cdcg + Cpd, and Cdcg is the channel capacitance of the auxiliary transistor DCG, so that the photoelectric charge collection capability of the collection circuit is greatly improved, and photoelectric charges are collected in the capacitances of PD, DCG, PD2 and Cap at the same time, and therefore, the collection circuit is suitable for collecting and quantizing optical image signals with strong light intensity.

Fig. 9 is a response curve of a potential signal output by an acquisition circuit under different light intensity environments according to an exemplary embodiment of the disclosure. As shown in fig. 9, and below, a schematic diagram of the quantization circuit quantizing the signal pulses is shown. The curve 600 is a response potential curve with a preset threshold value Vth01, and the pixel receives a weak light signal, which is consistent with the curve 202 shown in fig. 3 under the same light intensity in the prior art; the curve 601 in fig. 9 corresponding to the curve 203 in fig. 3 under the same light intensity (in this embodiment, the larger capacitor is used to store the photoelectric charges, so that the curve is spread wider and sparser, i.e., the denser curve is used to collect the light signal with stronger light intensity), and the preset threshold is Vth02. In conjunction with fig. 9, it can be seen that curve 602 (a curve denser than 601) is a curve of the pixel signal Vpix of the strongest light, so that the pixel of the present invention can detect the image signal of higher light intensity.

The sensitization dynamic range of this application pixel detection image signal obtains promoting, and relative prior art, the multiple EHDR that enlarges is shown as following formula (1):

EHDR = (Ccap + Cpd2+ Cdcg + Cpd)/Cpd formula (1)

Wherein the EHDR photosensitive dynamic range is raised by a multiple; ccap + Cpd2+ Cdcg + Cpd is the total capacitance for collecting photoelectric charges when the auxiliary transistor DCG is in an on state; cpd is the capacitance of the photoelectric charge.

Alternatively, the device group generates a potential change according to the collected photoelectric charges;

the source following transistor SF detects and follows the potential change of the device group to obtain a potential signal;

the pixel selection transistor SX outputs a target signal according to control of an external control signal.

Next, an electronic apparatus according to an embodiment of the present disclosure is described with reference to fig. 10. The electronic device may be either or both of the first device and the second device, or a stand-alone device separate from them, which stand-alone device may communicate with the first device and the second device to receive the acquired input signals therefrom.

As shown in fig. 10, the electronic device includes one or more processors and memory.

The processor may be a Central Processing Unit (CPU) or other form of processing unit having data processing capabilities and/or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

The memory may store one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and/or non-volatile memory. The volatile memory may include, for example, random Access Memory (RAM), cache memory (cache), and/or the like. The non-volatile memory may include, for example, read Only Memory (ROM), hard disk, flash memory, etc. One or more computer program products may be stored on the computer-readable storage medium and executed by a processor to implement the method for acquiring an optical signal in an image sensor of the various embodiments of the present disclosure described above and/or other desired functions.

In one example, the electronic device may further include: an input device and an output device, which are interconnected by a bus system and/or other form of connection mechanism (not shown).

The input means may also comprise, for example, a keyboard, a mouse, etc.

The output device may output various information including the determined distance information, direction information, and the like to the outside. The output devices may include, for example, a display, speakers, printer, and a communication network and its connected remote output devices, among others.

Of course, for simplicity, only some of the components of the electronic device relevant to the present disclosure are shown in fig. 10, omitting components such as buses, input/output interfaces, and the like. In addition, the electronic device may include any other suitable components, depending on the particular application.

In addition to the above-described methods and apparatuses, embodiments of the present disclosure may also be a computer program product comprising computer program instructions that, when executed by a processor, cause the processor to perform the steps in the method of acquiring an optical signal in an image sensor according to various embodiments of the present disclosure described in the above section of this specification.

The computer program product may write program code for carrying out operations for embodiments of the present disclosure in any combination of one or more programming languages, including an object oriented programming language such as Java, C + + or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device, or entirely on the remote computing device or server.

Furthermore, embodiments of the present disclosure may also be a computer-readable storage medium having stored thereon computer program instructions, which, when executed by a processor, cause the processor to perform the steps in the method for acquiring an optical signal in an image sensor according to various embodiments of the present disclosure described in the above section of this specification.

The computer readable storage medium may take any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may include, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a combination of any of the foregoing. More specific examples (a non-exhaustive list) of the readable storage medium include: an electrical connection having one or more wires, a portable disk, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

The foregoing describes the general principles of the present disclosure in conjunction with specific embodiments, however, it is noted that the advantages, effects, etc. mentioned in the present disclosure are merely examples and are not limiting, and they should not be considered essential to the various embodiments of the present disclosure. Furthermore, the foregoing disclosure of specific details is for the purpose of illustration and description and is not intended to be limiting, since the disclosure is not intended to be limited to the specific details so described.

In the present specification, the embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts in the embodiments are referred to each other. For the system embodiment, since it basically corresponds to the method embodiment, the description is relatively simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

The block diagrams of devices, apparatuses, systems referred to in this disclosure are only given as illustrative examples and are not intended to require or imply that the connections, arrangements, configurations, etc. must be made in the manner shown in the block diagrams. These devices, apparatuses, devices, systems may be connected, arranged, configured in any manner, as will be appreciated by one skilled in the art. Words such as "including," "comprising," "having," and the like are open-ended words that mean "including, but not limited to," and are used interchangeably herein. The words "or" and "as used herein mean, and are used interchangeably with, the word" and/or, "unless the context clearly dictates otherwise. The word "such as" is used herein to mean, and is used interchangeably with, the phrase "such as but not limited to".

The methods and apparatus of the present disclosure may be implemented in a number of ways. For example, the methods and apparatus of the present disclosure may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order for the steps of the method is for illustration only, and the steps of the method of the present disclosure are not limited to the order specifically described above unless specifically stated otherwise. Further, in some embodiments, the present disclosure may also be embodied as programs recorded in a recording medium, the programs including machine-readable instructions for implementing the methods according to the present disclosure. Thus, the present disclosure also covers a recording medium storing a program for executing the method according to the present disclosure.

It is also noted that in the devices, apparatuses, and methods of the present disclosure, each component or step can be decomposed and/or recombined. These decompositions and/or recombinations are to be considered equivalents of the present disclosure.

The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the disclosure. Thus, the present disclosure is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The foregoing description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit embodiments of the disclosure to the form disclosed herein. While a number of example aspects and embodiments have been discussed above, those of skill in the art will recognize certain variations, modifications, alterations, additions and sub-combinations thereof.

Claims

1. A method for collecting optical signals in an image sensor, comprising:

2. The method of claim 1, further comprising:

3. The method according to claim 1 or 2, wherein determining the state of the control switch in the device group of the acquisition circuit for acquiring the current frame signal according to the evaluation result corresponding to the previous frame signal comprises:

and responding to the evaluation result that the quantized value is in a preset range, not changing the state of the control switch, and continuing to process the quantized value transmitted by the previous frame of signal.

4. The method of any of claims 1-3, wherein the device group further comprises a reset transistor, and wherein at least one capacitor in the device group comprises: an auxiliary capacitor, and a common source region of the auxiliary transistor and the reset transistor;

converting a light signal into a photoelectric charge through the photodiode;

5. The method of claim 4, wherein the acquisition circuit further comprises a source follower transistor having a gate connected to the photodiode and to the source of the auxiliary transistor, and a pixel select transistor having a drain connected to the source of the source follower transistor and a source at the output of the acquisition circuit; the drain electrode of the source following transistor is connected with a power supply;

determining a change in potential of photodiodes in the device group based on the photo-electric charges collected by the device group;

6. The method according to any one of claims 2-5, wherein the processing the target signal by the quantization circuit and the evaluation circuit to determine the evaluation result of the current frame signal comprises:

7. The method according to any of claims 1-6, wherein the target signal comprises at least one of: pulse signals, potential signals, and values with limits.

8. An acquisition circuit for optical signals in an image sensor, comprising: a device group including a control switch and an auxiliary circuit;

9. The circuit of claim 8, wherein the set of devices comprises: a photodiode PD, an auxiliary transistor DCG configured as the control switch, a reset transistor RX, and an auxiliary capacitance Cap;

10. The circuit of claim 9, wherein the photodiode PD is configured to receive an optical signal to generate a photoelectric charge;

the device group collects the photoelectric charges based on the photodiode PD, the auxiliary transistor DCG, the auxiliary capacitance Cap, and the common source region PD2 when the control switch is in a closed state; the photoelectric charges are collected based on the photodiode PD when the control switch is in an off state.

11. The circuit of any of claims 8-10, wherein the auxiliary circuit comprises: a source follower transistor SF having a gate connected to the photodiode PD and the source of the auxiliary transistor DCG, and a pixel selection transistor SX having a drain connected to the source of the source follower transistor SF and a source as an output terminal of the acquisition circuit; the drain of the source follower transistor SF is connected to a power supply.

12. The circuit of claim 11, wherein the device group generates a potential change in accordance with the collection of the photoelectric charges;

13. The circuit of any of claims 8-12, wherein the target signal comprises at least one of: pulse signals, potential signals, and values with limits.

14. An electronic device, comprising: a processor, and a memory communicatively coupled to the processor, further comprising the light signal acquisition circuitry of the image sensor of any of claims 8-13;

the memory stores computer-executable instructions;

the processor executes computer-executable instructions stored in the memory to control the acquisition circuit of the light signal in the image sensor to implement the method of any one of claims 1-7.

15. The device of claim 14, wherein the electronic device comprises any one of: cameras, audio/video players, navigation devices, fixed location terminals, entertainment devices, smart phones, communication devices, mobile devices, vehicles or facilities, industrial devices, medical devices, security devices, flight devices, home appliance devices.

16. A computer-readable storage medium having computer-executable instructions stored therein that, when executed, cause a computer to perform the method of any of claims 1-7.

17. A computer program product comprising a computer program, wherein the computer program realizes the method of any of claims 1-7 when executed by a processor.