Method for reducing multi-column crosstalk of an image sensor

Abstract

The present invention provides a method for reducing multi-column crosstalk of an image sensor. The image sensor includes: multiple columns of column signal processing units, multiple columns of charge storage units corresponding to each of the column signal processing units, and multiple columns of leakage compensation units corresponding to each of the column signal processing units; the column signal processing unit is connected to at least one charge storage unit; the charge storage unit is adapted to provide the charge required for one flip of the column signal processing unit; the leakage compensation unit is connected to an external power supply and is used to supplement the leakage current generated when the column signal processing unit operates, so as to maintain the column signal processing unit in a normal operating state. The method provided by the present invention can reduce the crosstalk between multiple columns of column signal processing units.

Description

Technical Field

[0001] The present invention relates to the technical field of image sensors, and particularly to a method for reducing multi-column crosstalk of an image sensor. Background Art

[0002] With the continuous development of semiconductor technology, the design of high-pixel image sensors has become increasingly complex, and the circuit of an image sensor often includes hundreds or thousands of columns of column signal processing unit circuits. During the operation of the image sensor, when multiple column signal processing unit circuits need to work simultaneously, the instantaneous power consumption of the power supply voltage surges, resulting in a voltage drop. There is a certain risk of crosstalk between them, causing abnormal operation of other modules. Such a phenomenon will greatly reduce the signal stability and imaging quality, affecting the performance of the image sensor. Summary of the Invention

[0003] In order to solve the technical problem of multi-column crosstalk easily occurring in an image sensor in the prior art, the present invention provides a method for reducing multi-column crosstalk of an image sensor.

[0004] An embodiment of the present invention provides a method for reducing multi-column crosstalk of an image sensor, wherein the image sensor includes:

[0005] Multiple columns of column signal processing units, multiple columns of charge storage units corresponding to each of the column signal processing units, and multiple columns of leakage compensation units corresponding to each of the column signal processing units;

[0006] The column signal processing unit is connected to at least one charge storage unit; the charge storage unit is adapted to provide the charge required for one flip of the column signal processing unit.

[0007] The leakage compensation unit is connected to an external power supply and is used to supplement the leakage current generated when the column signal processing unit works, so as to maintain the column signal processing unit in a normal working state.

[0008] Preferably, when the column signal processing unit works, the charge storage unit provides part / all of the power supply required for one flip of the column signal processing unit, so as to reduce the interference of the column signal processing unit on the power supply system.

[0009] Preferably, the charge storage unit is adapted to: supplement charge before the column signal processing unit works and disconnect from the external power supply when the column signal processing unit works.

[0010] Preferably, the column signal processing unit works periodically.

[0011] Preferably, the column signal processing unit starts to work after receiving the falling edge of the column processing enable signal, and the charge consumption during operation is compensated by the charge storage unit; the leakage current consumption during the operation of the column signal processing unit is compensated by the leakage compensation unit.

[0012] Preferably, after the column signal processing unit receives the falling edge of the column processing enable signal and finishes normal operation, the column signal processing unit performs leakage compensation through the leakage compensation unit.

[0013] Preferably, the leakage compensation unit is arranged between the sampling power supply of the charge storage unit and the column signal processing unit.

[0014] Preferably, when the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit is large, the leakage compensation unit conducts, generating a supplementary current between the charge storage unit and the column signal processing unit to reduce the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit until the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit stabilizes at a small value; when the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit is small, the leakage compensation unit will turn off, isolating the charge storage unit and the column signal processing unit, and each maintaining its original state.

[0015] Preferably, the leakage compensation unit is an N-MOS transistor with the drain and source connected, a P-MOS transistor with the drain and source connected, a forward-connected diode, or a current source controlled by a timing circuit.

[0016] Preferably, two adjacent columns or two or more columns of the column signal processing units share a charge storage unit.

[0017] Preferably, the charge storage units are distributed in multiple columns of the column signal processing units.

[0018] Preferably, a leakage compensation unit is arranged between the charge storage unit and two adjacent columns or two or more columns of the column signal processing units.

[0019] Preferably, each column of the column signal processing units is respectively provided with a corresponding charge storage unit, and a leakage compensation unit is arranged between the column signal processing unit and the charge storage unit.

[0020] Preferably, the charge storage unit includes: a first charge storage unit connected to the high level end of the column signal processing or a second charge storage unit connected to the low level end of the column signal processing.

[0021] Preferably, the voltage provided by the first charge storage unit to the column signal processing unit is a first sampling voltage, and the voltage provided by the second charge storage unit to the column signal processing unit is a second sampling voltage, and the first sampling voltage is greater than the second sampling voltage.

[0022] Preferably, the column signal processing unit is adapted to sample separately from the first charge storage unit, sample separately from the second charge storage unit, or sample simultaneously from the first charge storage unit and the second charge storage unit.

[0023] Preferably, the value of the first sampling voltage or the second sampling voltage is determined according to the working requirements of the column signal processing unit.

[0024] Preferably, when multiple column signal processing units work simultaneously, the charge comes from the capacitors in their respective charge storage units to reduce crosstalk between them.

[0025] Compared with the prior art, the method for reducing multi-column crosstalk in the technical solution of the present invention has the following beneficial effects:

[0026] In the technical solution provided by the present invention, the charge used to provide the operation of the column signal processing unit is pre-stored in the charge storage unit. When multiple column signal processing units work simultaneously, the charge comes from their respective capacitor memories rather than directly from the reference voltage, which can reduce the crosstalk between multiple column signal processing units.

[0027] Furthermore, in the technical solution provided by the present invention, the leakage current generated when the column signal processing unit operates is compensated by the leakage compensation unit, so as to maintain the column signal processing unit in a normal operating state. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figures 1 to 5 It is a schematic diagram of an image sensor circuit in an embodiment provided by the technical solution of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Many specific details are set forth in the following description in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the spirit of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0030] Secondly, the present invention is described in detail using schematic diagrams. When detailing the embodiments of the present invention, for the sake of explanation, the schematic diagrams are only examples and should not limit the scope of protection of the present invention here.

[0031] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following provides a detailed description of a method for reducing multi-column crosstalk in an image sensor in conjunction with the accompanying drawings.

[0032] As Figure 1 shown, in one embodiment, the technical solution of the present invention provides a method for reducing multi-column crosstalk in an image sensor, and the image sensor includes: at least one column of column signal processing units and charge storage units;

[0033] The column signal processing unit is connected to at least one charge storage unit;

[0034] Different reference voltages are applied to both levels of the charge storage unit;

[0035] The charge storage unit is adapted to store sufficient charge before the column signal processing unit operates normally, so that when the column signal processing unit operates, driving energy can be obtained from the charge storage unit.

[0036] Specifically, the charge storage unit includes: a charge storage unit 1 connected to the high-level end A of the column signal processing unit or a charge storage unit 2 connected to the low-level end B of the column signal processing unit.

[0037] Specifically, the voltage provided by the charge storage unit 1 to the column signal processing unit is the first sampling voltage V A , and the voltage provided by the charge storage unit 2 to the column signal processing unit is the second sampling voltage V B , and the first sampling voltage V A is greater than the second sampling voltage V B .

[0038] Specifically, the first sampling voltage V A is equal to the voltage between the upper voltage V1 and the lower voltage V2 of the charge storage unit 1. The second sampling voltage V B is equal to the voltage value between the upper voltage V3 and the lower voltage V4 of the charge storage unit 2.

[0039] Specifically, the column signal processing unit is adapted to absorb charge from the charge storage unit 1 alone, absorb charge from the charge storage unit 2 alone, or absorb charge from both the charge storage unit 1 and the charge storage unit 2 simultaneously.

[0040] Specifically, the value of the first sampling voltage V A or the second sampling voltage V B is determined according to the working requirements of the column signal processing unit.

[0041] Specifically, when multiple column signal processing units are driven to work simultaneously, the charge comes from the charge storage units in their respective charge storage units, so as to reduce crosstalk between them.

[0042] In Figure 1 In the illustrated embodiment, the working process of the image sensor circuit capable of reducing crosstalk between multiple columns is as follows: It is divided into a charge storage unit charge replenishment stage and a column signal processing unit working stage:

[0043] Working state 1: Charge storage unit charge replenishment stage:

[0044] a. The input signal in of the column signal processing unit is not triggered;

[0045] b. The switches sw1 and sw2 are closed, and the charge storage unit 1 and the charge storage unit 2 are charged. After a certain time, the voltage between the A end and the B end is fully charged to the energy required for the normal operation of the column signal processing unit;

[0046] Working state 2: Column signal processing unit working stage:

[0047] c. The input signal in is triggered, and the column signal processing unit enters the working state;

[0048] d. The A end and the B end provide the required levels for the column signal processing unit.

[0049] However, it is measured in actual work that this method has a risk of abnormal operation due to the leakage current of column signal processing. As Figure 1 shown, specifically, there is a certain leakage current when the column signal processing unit is working, which causes the high-level end A end or the low-level end B end of the column signal processing unit to decrease and increase respectively, reducing the voltage difference between the two ends of the column signal processing unit. If this voltage difference is too low, the column signal processing unit will not be able to work normally.

[0050] Based on the above embodiments, the technical solution of the present invention also provides a method for reducing crosstalk between multiple columns of an image sensor, including an improved image sensor, where the image sensor includes: multiple columns of column signal processing units, multiple columns of charge storage units corresponding to each column signal processing unit, and multiple columns of leakage compensation units corresponding to each column signal processing unit;

[0051] The column signal processing unit is connected to at least one charge storage unit; the charge storage unit is adapted to provide the charge required for one flip of the column signal processing unit;

[0052] The leakage compensation unit is connected to an external power supply and is used to supplement the leakage current generated when the column signal processing unit is working, so as to maintain the column signal processing unit in a normal working state.

[0053] Specifically, when the column signal processing unit is working, the charge storage unit provides part / all of the power supply required for one flip of the column signal processing unit, so as to reduce the interference of the column signal processing unit to the power supply system.

[0054] Specifically, the charge storage unit is adapted to: replenish charge before the column signal processing unit works, and disconnect the connection with the external power supply when the column signal processing unit is working.

[0055] Specifically, the column signal processing unit works periodically.

[0056] Specifically, the column signal processing unit starts to work after receiving the flip edge of the column processing enable signal, and the charge consumption during the work is compensated by the charge storage unit; the leakage current consumption during the work of the column signal processing unit is compensated by the leakage compensation unit.

[0057] Specifically, after the column signal processing unit receives the flip edge of the column processing enable signal and works normally, the column signal processing unit performs leakage compensation through the leakage compensation unit.

[0058] Specifically, the leakage compensation unit is arranged between the sampling power supply of the charge storage unit and the column signal processing unit.

[0059] Specifically, when the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit is large, the leakage compensation unit will conduct, generating a supplementary current between the charge storage unit and the column signal processing unit, so as to reduce the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit until the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit stabilizes at a small value; when the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit is small, the leakage compensation unit will turn off, making the charge storage unit and the column signal processing unit in an isolated state and each maintaining its original state.

[0060] Specifically, the leakage compensation unit is an N-MOS transistor with the drain and source connected, a P-MOS transistor with the drain and source connected, a forward-connected diode or a current source controlled by a timing circuit.

[0061] Specifically, two adjacent columns or more than two columns of the column signal processing units share a charge storage unit.

[0062] Specifically, the charge storage units are distributed in multiple columns of the column signal processing units.

[0063] Specifically, a leakage compensation unit is provided between the charge storage unit and two or more adjacent column signal processing units.

[0064] Specifically, a corresponding charge storage unit is provided for each column of the column signal processing units, and a leakage compensation unit is provided between the column signal processing unit and the charge storage unit.

[0065] Specifically, the charge storage unit includes: a first charge storage unit connected to the high-level end of the column signal processing or a second charge storage unit connected to the low-level end of the column signal processing.

[0066] Specifically, the voltage provided by the first charge storage unit to the column signal processing unit is a first sampling voltage, the voltage provided by the second charge storage unit to the column signal processing unit is a second sampling voltage, and the first sampling voltage is greater than the second sampling voltage.

[0067] Specifically, the column signal processing unit is adapted to sample separately from the first charge storage unit, sample separately from the second charge storage unit, or sample simultaneously from the first charge storage unit and the second charge storage unit.

[0068] Specifically, the value of the first sampling voltage or the second sampling voltage is determined according to the working requirements of the column signal processing unit.

[0069] Specifically, when multiple column signal processing units work simultaneously, the charge comes from the capacitors in their respective charge storage units to reduce crosstalk between each other.

[0070] Reference Figure 2 , Figure 2 As shown in

[0071] a column signal processing unit;

[0072] And the A end of the column signal processing unit is connected to a charge storage unit 1; and both ends of the charge storage unit 1 are respectively controlled by a switch sw1 to conductively connect a voltage V1 and a voltage V2.

[0073] The B end of the column signal processing unit is connected to a charge storage unit 2; and both ends of the charge storage unit 2 are respectively controlled by a switch sw2 to conductively connect a voltage V3 and a voltage V4.

[0074] In this embodiment, the difference between the voltage V1 and the voltage V2 is set as a first sampling voltage Va, and the difference between the voltage V3 and the voltage V4 is set as a second sampling voltage Vb; the first sampling voltage Va is greater than the second sampling voltage Vb.

[0075] A leakage compensation unit 1 is provided between the A terminal of the column signal processing unit and the charge storage unit 1;

[0076] A leakage compensation unit 2 is provided between the B terminal of the column signal processing unit and the charge storage unit 2;

[0077] The charge storage unit is adapted to provide the charge required for one flip of the column signal processing unit; specifically, the charge storage unit is adapted to store sufficient charge in the charge storage unit before the column signal processing unit operates, so that when the column signal processing unit operates, the energy required for operation can be obtained from the charge storage unit.

[0078] The leakage compensation unit is connected to an external power supply and is used to supplement the charge consumed by the leakage current generated when the column signal processing unit operates, so as to maintain the column signal processing unit in a normal operating state.

[0079] The leakage compensation unit is an N-MOS transistor with the drain and source connected, a P-MOS transistor with the drain and source connected, a forward-connected diode or a current source controlled by a timing circuit.

[0080] Specifically, in this embodiment, the working process is as follows: It is divided into a charge replenishment stage of the charge storage unit and a working stage of the column signal processing unit:

[0081] Working state 1: Charge replenishment stage of the charge storage unit:

[0082] a. The input signal in of the column signal processing unit is not triggered;

[0083] b. The switches sw1 and sw2 are closed, and the charge storage unit 1 and the charge storage unit 2 replenish charge. After a certain period of time, the voltage between the A terminal and the B terminal is charged to the level required for the normal operation of the column signal processing unit;

[0084] Working state 2: Working stage of the column signal processing unit:

[0085] c. The input column processing enable signal in is triggered, and the column signal processing unit enters the working state;

[0086] d. The A terminal and the B terminal provide the required level for the column signal processing unit.

[0087] There is a leakage current in the column signal processing unit during the normal working stage. Without remedial measures, the voltage difference between the A end and the B end will be too small, resulting in the column signal processing unit being unable to work properly. In this embodiment, since there is a leakage compensation unit, the leakage compensation unit will supplement the leakage current of the column signal processing unit during the working stage of the column signal processing unit, maintain the voltage difference between the A end and the B end, and ensure the normal operation of the column signal processing unit.

[0088] Specifically, the column signal processing unit starts to work after receiving the falling edge of the column processing enable signal in. The charge consumption during operation is compensated by the charge storage unit; the leakage current consumption during the operation of the column signal processing unit is compensated by the leakage compensation unit. After the column signal processing unit receives the falling edge of the column processing enable signal and works normally, the column signal processing unit performs leakage compensation through the leakage compensation unit.

[0089] Specifically, when the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit is large, the leakage compensation unit will conduct, generating a supplementary current between the charge storage unit and the column signal processing unit, thereby reducing the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit until the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit stabilizes at a small value; when the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit is small, the leakage compensation unit will turn off, putting the charge storage unit and the column signal processing unit in an isolated state, and each maintaining its original state.

[0090] Specifically, the working state of the leakage compensation unit is: when the voltage difference between the voltage V1 and the A end where the column signal processing unit is connected to the leakage compensation unit 1 is large, the leakage compensation unit will conduct, generating a supplementary current between the voltage V1 and the A end, thereby reducing the voltage difference between the voltage V1 and the A end until the voltage difference between the voltage V1 and the A end stabilizes at a small value; when the voltage difference between the voltage V1 and the A end is small, the leakage compensation unit 1 will turn off, putting the voltage V1 and the A end in an isolated state, and each maintaining its original state.

[0091] When the voltage difference between the voltage V2 and the B end where the column signal processing unit is connected to the leakage compensation unit 2 is large, the leakage compensation unit will conduct, generating a supplementary current between the voltage V2 and the B end, thereby reducing the voltage difference between the voltage V2 and the B end until the voltage difference between the voltage V2 and the B end stabilizes at a small value; when the voltage difference between the voltage V2 and the B end is small, the leakage compensation unit 2 will turn off, putting the voltage V2 and the B end in an isolated state, and each maintaining its original state.

[0092] Reference Figure 3 , Figure 3Another implementation of the image sensor circuit for reducing multi-column crosstalk provided in this embodiment is shown. It includes n columns of column signal processing units. The upper A ends of the column signal processing units of all n columns are connected to the charge storage unit 1. The upper end of the charge storage unit 1 is connected to the first reference voltage V1 through switch 1, and the lower end of the charge storage unit 1 is connected to the second reference voltage V2 (i.e., the A end is connected to the first charge storage unit). The B end is similar.

[0093] Either the charge storage unit 1 or the charge storage unit 2 can be set arbitrarily. When only the charge storage unit 1 exists, the low-level B end of the column signal processing unit is grounded. When only the charge storage unit 2 exists, the high-level A end of the column signal processing unit is connected to the power supply voltage Vdd. Others are similar to Figure 2 the embodiment shown.

[0094] Reference Figure 4 , Figure 4 is Figure 3 one implementation method in the image sensor shown. It includes the column signal processing unit 1, column signal processing unit 2, column signal processing unit 3,..., column signal processing unit n, where n is a natural number. Compared with the Figure 3 embodiment, Figure 4 in the embodiment shown, the charge storage units all adopt capacitors C1 and C2 to implement.

[0095] In addition, the leakage compensation unit connected to the upper A end of the column signal processing unit is implemented by a P-MOS transistor, and the leakage compensation unit connected to the lower B end of the column signal processing unit is implemented by an N-MOS transistor. Here, V1 is connected to the power supply voltage and V4 is connected to the ground. The source of the P-MOS transistor is connected to V1, and the drain and gate are connected to the A end; the source of the N-MOS transistor is connected to V4, and the drain and gate are connected to the B end. During the sampling process: if the voltage at the A end becomes lower, the P-MOS transistor will turn on to charge the A end to maintain the voltage at the A end; if the voltage at the B end becomes higher, the N-MOS transistor will turn on to charge the B end to maintain the voltage at the B end.

[0096] Reference Figure 5 , Figure 5 Another implementation of the image sensor circuit for reducing multi-column crosstalk provided in this embodiment is shown. It includes n columns of column signal processing units, including: column signal processing unit 1, column signal processing unit 2, column signal processing unit 3,..., column signal processing unit n;

[0097] The first ends of each column of column signal processing units are respectively connected to a first charge storage unit in one-to-one correspondence, including: charge storage unit 1a, charge storage unit 2a, charge storage unit 3a,..., charge storage unit na;

[0098] The second ends of the column signal processing units in each column are respectively and correspondingly connected to second charge storage units, including: charge storage unit 1b, charge storage unit 2b, charge storage unit 3b, ……, charge storage unit nb;

[0099] A first leakage compensation unit is arranged between the first ends of the column signal processing units in each column and the first charge storage unit, including: leakage compensation unit 1a, leakage compensation unit 2a, leakage compensation unit 3a, ……, leakage compensation unit na;

[0100] A second leakage compensation unit is arranged between the second ends of the column signal processing units in each column and the second charge storage unit, including: leakage compensation unit 1b, leakage compensation unit 2b, leakage compensation unit 3b, ……, leakage compensation unit nb;

[0101] The charge storage unit is adapted to provide the charge required for one flip of the column signal processing unit; the leakage compensation unit is connected to an external power supply and is used to supplement the leakage current generated when the column signal processing unit works, so as to maintain the column signal processing unit in a normal working state.

[0102] When the column signal processing unit works, the charge storage unit provides part / all of the power supply required for one flip of the column signal processing unit, so as to reduce the interference of the column signal processing unit to the power supply system.

[0103] In the embodiments provided by the technical solution of the present invention, the leakage compensation unit will work in the sampling stage, supplement the leakage current of the column signal processing unit, maintain the voltage difference between the A end and the B point, and ensure the normal operation of the column signal processing unit. Further, in one implementation case, each column of column signal processing units has a separate leakage compensation unit, which can reduce the influence between columns.

[0104] Although the present invention has been disclosed above with preferred embodiments, it is not used to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention all belong to the protection scope of the technical solution of the present invention.

Claims

1. A method for reducing multi-column crosstalk of an image sensor, characterized in that, the image sensor includes: multiple columns of column signal processing units, multiple columns of charge storage units corresponding to each of the column signal processing units, and multiple columns of leakage compensation units corresponding to each of the column signal processing units; the column signal processing unit is connected to at least one charge storage unit; the charge storage unit is adapted to provide the charge required for one flip of the column signal processing unit, and the charge for providing the column signal processing unit to work is stored in the charge storage unit before the column signal processing unit works normally; the leakage compensation unit is connected to an external power supply and is used to supplement the leakage current generated when the column signal processing unit works, so as to maintain the column signal processing unit in a normal working state.

2. The method for reducing multi-column crosstalk of an image sensor according to claim 1, characterized in that, when the column signal processing unit works, the charge storage unit provides part / all of the power supply required for one flip of the column signal processing unit, so as to reduce the interference of the column signal processing unit to the power supply system.

3. The method for reducing multi-column crosstalk of an image sensor according to claim 1, characterized in that, the charge storage unit is adapted to: supplement charge before the column signal processing unit works, and disconnect the connection with the external power supply when the column signal processing unit works.

4. The method for reducing multi-column crosstalk of an image sensor according to claim 1, characterized in that, the column signal processing unit works periodically.

5. The method for reducing multi-column crosstalk of an image sensor according to claim 1 or 4, characterized in that, the column signal processing unit starts to work after receiving the flip edge of the column processing enable signal, and the charge consumption during work is compensated by the charge storage unit; the leakage current consumption during the working process of the column signal processing unit is compensated by the leakage compensation unit.

6. The method for reducing multi-column crosstalk of an image sensor according to claim 1, characterized in that, after the column signal processing unit receives the flip edge of the column processing enable signal and works normally, the column signal processing unit performs leakage compensation through the leakage compensation unit.

7. The method for reducing multi-column crosstalk of an image sensor according to claim 1, characterized in that, the leakage compensation unit is arranged between the sampling power supply of the charge storage unit and the column signal processing unit.

8. The method for reducing multi-column crosstalk of an image sensor according to claim 7, characterized in that, when the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit is large, the leakage compensation unit is turned on, and a supplementary current is generated between the charge storage unit and the column signal processing unit to reduce the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit until the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit is stabilized at a small value; When the voltage difference between the sampling voltage of the charge storage unit and the column signal processing unit is small, the leakage compensation unit is turned off, so that the charge storage unit and the column signal processing unit are in an isolated state and each maintains its original state.

9. The method for reducing multi-column crosstalk of an image sensor according to claim 1, wherein, the leakage compensation unit is an N-MOS transistor with its drain and source connected between the sampling power supply of the charge storage unit and the column signal processing unit, a P-MOS transistor with its drain and source connected, a forward-connected diode, or a current source controlled by a timing circuit.

10. The method for reducing multi-column crosstalk of an image sensor according to claim 1, wherein, two or more adjacent column signal processing units share a charge storage unit.

11. The method for reducing multi-column crosstalk of an image sensor according to claim 1 or 10, wherein, the charge storage units are distributed in multiple columns of the column signal processing units.

12. The method for reducing multi-column crosstalk of an image sensor according to claim 1 or 10, wherein, the leakage compensation unit is provided between the charge storage unit and two or more adjacent column signal processing units.

13. The method for reducing multi-column crosstalk of an image sensor according to claim 1, wherein, each column signal processing unit is respectively provided with a corresponding charge storage unit, and the leakage compensation unit is provided between the column signal processing unit and the charge storage unit.

14. The method for reducing multi-column crosstalk of an image sensor according to claim 1, wherein, the charge storage unit includes: a first charge storage unit connected to the high-level end of the column signal processing unit or a second charge storage unit connected to the low-level end of the column signal processing unit.

15. The method for reducing multi-column crosstalk of an image sensor according to claim 14, wherein, the voltage provided by the first charge storage unit to the column signal processing unit is a first sampling voltage, the voltage provided by the second charge storage unit to the column signal processing unit is a second sampling voltage, and the first sampling voltage is greater than the second sampling voltage.

16. The method for reducing multi-column crosstalk of an image sensor according to claim 15, wherein, the column signal processing unit is adapted to sample separately from the first charge storage unit, sample separately from the second charge storage unit, or sample simultaneously from the first charge storage unit and the second charge storage unit.

17. The method for reducing multi-column crosstalk of an image sensor according to claim 16, wherein, the value of the first sampling voltage or the second sampling voltage is determined according to the working requirements of the column signal processing unit.

18. The method for reducing multi-column crosstalk of an image sensor according to claim 1, wherein, when multiple column signal processing units work simultaneously, the charges come from the capacitors in their respective charge storage units to reduce crosstalk between them.

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