Image sensor, operation method and electronic equipment

Abstract

The invention provides an image sensor, an operation method and an electronic device, the image sensor comprises a pixel array, and the pixel array comprises a plurality of pixel units arranged in an array; each pixel unit comprises a photoelectric conversion module and a reading module; wherein each photoelectric conversion module receives an optical signal and converts the optical signal into a voltage signal; each read-out module reads out the output signal of the corresponding photoelectric conversion module; the photoelectric conversion module comprises a photoelectric conversion area, a first storage area, a second storage area and a third storage area; the photoelectric conversion region converts an optical signal into a charge signal; the first storage area, the second storage area and the third storage area can store charge signals output by the photoelectric conversion area; the gains of the pixel units are adjusted to be the first gain, the second gain and the third gain, and then signals under different gains are read. The dynamic range of the image sensor is effectively expanded.

Description

Technical Field

[0001] The present invention relates to the field of image sensors, and in particular to an image sensor, an operating method, and an electronic device. Background Art

[0002] With the continuous improvement of process technology and pixel performance, the pixel full well capacity of traditional image sensors is getting higher and higher. In the signal readout stage, high gain is usually used to obtain dark light scenes of the image, and low gain is used to obtain bright light scenes of the image. Therefore, with the increase of full well capacity, the demand for low gain to obtain bright light scenes is getting higher and higher. This puts higher and higher demands on the realization of the capacitor of the low gain part in pixel design.

[0003] However, each pixel in the existing image sensor only relies on connecting switches and large capacitors at the floating diffusion points to achieve a larger full-well capacity. Therefore, each pixel in the existing image sensor actually still has only two gain modes, which still cannot meet the applicability requirements of different scenarios.

[0004] Based on this, the present invention provides a new image sensor and an operating method, and an electronic device to increase the gain mode of the image sensor in different working scenarios and effectively improve the dynamic range of the image sensor.

[0005] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because they are described in the background technology section of the present application. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide an image sensor and an operating method and an electronic device, so as to solve the problems of limited gain mode and limited dynamic range of the image sensor in the prior art.

[0007] To achieve the above-mentioned object and other related objects, the present invention provides an image sensor, wherein the image sensor comprises a pixel array, wherein the pixel array comprises a plurality of pixel units arranged in an array;

[0008] Each pixel unit includes a photoelectric conversion module and a readout module; wherein each photoelectric conversion module receives a light signal and converts it into a voltage signal; each readout module is connected to a corresponding photoelectric conversion module and receives a readout switch signal, and reads out an output signal of the corresponding photoelectric conversion module based on the readout switch signal;

[0009] The photoelectric conversion module includes a photoelectric conversion area, a first storage area, a second storage area and a third storage area;

[0010] The photoelectric conversion region is connected to a first control signal, and transfers a charge signal sensed and converted from the light signal based on the first control signal;

[0011] The first storage area is connected to the photoelectric conversion area to store the charge signal output by the photoelectric conversion area;

[0012] The second storage area is connected to the first storage area and receives a second control signal to store the charge signal overflowed from the photoelectric conversion area based on the first storage area;

[0013] The third storage area is connected to the first storage area or the second storage area and receives a third control signal to store the charge signal overflowed from the photoelectric conversion area based on the first storage area or the second storage area connected to the corresponding storage area;

[0014] The second control signal and the third control signal are controlled to adjust the gain of the pixel unit to be the first gain, the second gain and the third gain respectively, so as to read the data signal of the pixel unit under different gains.

[0015] Optionally, the photoelectric conversion area includes a photodiode and a transmission tube, the photodiode is connected to the first storage area via the transmission tube, and is used to convert the light signal into a charge signal, and the control end of the transmission tube is connected to the first control signal to transfer the charge signal to the first storage area.

[0016] Optionally, the first storage area is configured as a first floating diffusion node, the first floating diffusion node is connected to an output end of the photoelectric conversion area, and stores and senses a charge signal.

[0017] Optionally, the second storage area includes a first storage switch tube and a second floating diffusion node, wherein: the second floating diffusion node is connected to the first storage area via the first storage switch tube, and the control end of the first storage switch tube is connected to a second control signal, at least for transferring the charge signal overflowing from the photoelectric conversion area to the second floating diffusion node based on the first storage area.

[0018] Optionally, the third storage area includes a capacitor and a second storage switch tube, wherein: the first plate of the capacitor is connected to a preset voltage, and the second plate is connected to the first storage area or the second storage area via the second storage switch tube; the control end of the second storage switch tube is connected to the third control signal, at least for transferring the charge signal of the first storage area received by the second storage switch tube or the second storage area received by the second storage switch tube and overflowed from the photoelectric conversion area to the capacitor based on the third control signal.

[0019] Optionally, when the third storage area includes a capacitor, the first plate of the capacitor is connected to a variable voltage module for adjusting the preset voltage to a high level or a low level.

[0020] Optionally, the readout module includes an output tube and / or a selection tube; the control end of the output tube is connected to the photoelectric conversion module, the first end is connected to the working voltage, and the second end is connected to the first end of the selection tube, so as to amplify the output signal of the photoelectric conversion module; the control end of the selection tube is connected to the readout switch signal, and the second end serves as the output end of the readout module, and the selection tube is turned on based on the readout switch signal to output the output signal of the output tube.

[0021] Optionally, the photoelectric conversion module also includes a first reset switch, and the control end of the first reset switch is connected to a first reset signal; when the third storage area is connected to the first storage area, the first reset switch is set between the second storage area and the operating voltage; when the third storage area is connected to the second storage area, the first reset switch is set between the third storage area and the operating voltage or between the second storage area and the operating voltage; based on the first reset signal, at least the second storage area or the third storage area corresponding to the first reset switch is reset.

[0022] Optionally, the photoelectric conversion module also includes a second reset switch; when the third storage area is connected to the first storage area, the first end of the second reset switch is connected to the working voltage, the second end is set between the third storage area and the first storage area, and the control end of the second reset switch is connected to the second reset signal, and at least the third storage area is reset based on the second reset signal; when the third storage area is connected to the second storage area and the first reset switch is set between the second storage area and the working voltage, the first end of the second reset switch is connected to the working voltage, the second end is connected to the node between the second plate of the capacitor and the second storage switch tube, the control end of the second reset switch is connected to the second reset signal, and at least the third storage area is reset based on the second reset signal.

[0023] Optionally, the pixel unit includes at least two photodiodes that are shared, and the transmission tubes corresponding to each of the photodiodes relatively form an enclosed area, and adjacent transmission tubes share a first floating diffusion node in pairs, and the transmission tubes are arranged in the enclosed area and each of the first floating diffusion nodes is evenly distributed around the transmission tubes, the first storage switch and the second storage switch are connected in series and arranged on the side of the first floating diffusion node and are located in a first spatial area formed by adjacent photodiodes, and the first reset switch and the selection tube are distributed on both sides of the transmission tube and are located in a second spatial area formed by adjacent photodiodes.

[0024] Optionally, the image sensor comprises a signal generating module and the above-mentioned pixel array; the signal generating module comprises a readout switch signal generating unit;

[0025] The readout switch signal generating unit is used to generate a readout switch signal to select a pixel unit to be read out;

[0026] Each pixel unit in the pixel array is connected to a corresponding readout switch signal, and the corresponding pixel unit is selected based on the corresponding readout switch signal to read out the electrical signal after exposure conversion.

[0027] Optionally, the image sensor includes a first chip and a second chip stacked together, wherein:

[0028] At least the photoelectric conversion element corresponding to the photoelectric conversion area is arranged in the first chip, and at least the storage element corresponding to the third storage area is arranged in the second chip.

[0029] To achieve the above object and other related objects, the present invention provides an electronic device, which includes an image sensor as described in any one of the above solutions.

[0030] To achieve the above-mentioned purpose and other related purposes, the present invention provides an image sensor operation method, including: controlling the second control signal and the third control signal to adjust the gain of the pixel unit to be a first gain, a second gain and a third gain respectively, and then reading the data signal of the pixel unit under different gains, and the third gain corresponds to a third storage area, and the signal under the third gain is read out later than the signal under the first gain and the second gain.

[0031] Optionally, the operation method includes an exposure step, the exposure step including: controlling a first control signal, a second control signal and a third control signal so that the charge signal sensed and converted by the photoelectric conversion area to the light signal is transmitted to the first storage area, the second storage area and the third storage area or the converted charge signal is stored in the photoelectric conversion area;

[0032] Optionally, the operating method includes a readout step, and the readout step includes at least one of the following steps: controlling the readout switch signal to read the output signal of the first storage area; controlling the readout switch signal and the second control signal to read the output signals of the first storage area and the second storage area; controlling the readout switch signal, the second control signal and the third control signal to read the output signals of the first storage area, the second storage area and the third storage area.

[0033] Optionally, the operation method includes:

[0034] After the first control signal, the second control signal and the third control signal are controlled to be valid, the first control signal is invalidated, and the third control signal and the second control signal are kept valid to expose the photoelectric conversion area to obtain a charge signal;

[0035] Controlling the readout switch signal to be effective, and sequentially making the third control signal and the second control signal ineffective, so as to respectively read out a reset signal under a first gain and a reset signal under a second gain;

[0036] The first control signal is enabled, the charge signal after the exposure of the photoelectric conversion area is transmitted to the first storage area and read out to obtain an image signal under a second gain;

[0037] The second control signal is enabled and the first control signal is enabled, and the charge signal of the photoelectric conversion area after exposure is sequentially transmitted to the first storage area and the second storage area, and read out to obtain an image signal under a first gain;

[0038] The third control signal is enabled, the second control signal remains enabled, and the first control signal is enabled, and the charge signal of the photoelectric conversion area after exposure is sequentially transmitted to the first storage area, the second storage area, and the third storage area, and read out to obtain an image signal under a third gain;

[0039] The second control signal and the third control signal are enabled to simultaneously reset the first storage area, the second storage area and the third storage area and read out a reset signal at a third gain;

[0040] A real signal at the first gain is obtained based on the reset signal at the first gain and the image signal at the first gain; a real signal at the second gain is obtained based on the reset signal at the second gain and the image signal at the second gain; and a real signal at the third gain is obtained based on the reset signal at the third gain and the image signal at the third gain.

[0041] Optionally, when the photoelectric conversion module further includes a first reset switch, the third storage area is connected to the first storage area, and the first reset switch is arranged between the second storage area and the operating voltage, or when the photoelectric conversion module further includes a first reset switch, the third storage area is connected to the second storage area, and the first reset switch is arranged between the second storage area and the operating voltage, the pixel array operation method further includes setting a clearing step before reading out the first reset signal and the second reset signal:

[0042] The second control signal is controlled to be valid and the third control signal is controlled to be invalid, so as to reset the first storage area and the second storage area and clear the overflow signals of the first storage area and the second storage area.

[0043] Optionally, after controlling the first control signal, the second control signal, and the third control signal to be valid to reset the first storage area, the second storage area, and the third storage area, the pixel array operation method further includes:

[0044] Controlling the readout switch signal to be valid and making the first control signal and the third control signal invalid, so as to read out the overflow image signals of the first storage area and the second storage area;

[0045] Resetting the first storage area and the second storage area to read out overflow reset signals of the first storage area and the second storage area;

[0046] A true signal of the overflow signal is obtained based on the overflow image signal and the overflow reset signal.

[0047] Optionally, when the third storage area includes a capacitor and a second storage switch tube, and the first plate of the capacitor is connected to a preset voltage, and the second plate is connected to the first storage area or the second storage area via the second storage switch tube; the control end of the second storage switch tube is connected to the third control signal, and based on the third control signal, the charge signal of the first storage area received by the second storage switch tube or the charge signal of the second storage area received by the second storage switch tube is transferred to the capacitor, the pixel array operation method further includes:

[0048] When the charge signal of the first storage area received by the second storage switch tube or the charge signal of the second storage area received by the second storage switch tube is transferred to the capacitor based on the third control signal, the preset voltage is set to a high level; and / or, in the step of reading out the third storage area signal based on the switch tube corresponding to the third storage area being turned on, the preset voltage is set to a high level.

[0049] Optionally, when the third storage area includes a capacitor and a second storage switch tube, and the first electrode plate of the capacitor is connected to a preset voltage, and the second electrode plate is connected to the first storage area or the second storage area via the second storage switch tube; the control end of the second storage switch tube is connected to the third control signal, and based on the third control signal, the charge signal of the first storage area received by the second storage switch tube or the charge signal of the second storage area received by the second storage switch tube is transferred to the capacitor.

[0050] The operating method also includes: when transferring the charge signal of the first storage area received by the second storage switch tube or the charge signal of the second storage area received by the second storage switch tube to the capacitor based on the third control signal, setting the preset voltage to a high level and setting the preset voltage to a low level later than the second storage switch tube is turned off; and / or, in the step of reading out the third storage area signal based on the switch tube corresponding to the third storage area being turned on, setting the preset voltage to a high level and the high level corresponding to the effective period of the transmission tube and the reset tube.

[0051] Optionally, during the reset process before the exposure overflow stage until the first gain reset signal after the exposure overflow stage is read out and before the second gain reset signal is read out, the first storage switch of the second storage area is controlled to be effective, and during the reset process before the exposure overflow stage until the selection tube after the exposure overflow stage is turned on, the second storage switch of the third storage area is controlled to be effective, so as to realize the overflow of the exposure overflow stage signal and the readout of the corresponding signal in the readout stage.

[0052] As described above, the image sensor, operation method, and electronic device of the present invention have the following beneficial effects:

[0053] The image sensor and electronic device of the present invention control three gain switching modes, which can effectively improve the dynamic range of the image sensor. The pixel array reading method of the present invention can first read and quantize the signal corresponding to the switch tube connected to the photodiode, which can avoid the signal noise in the final read signal caused by operating the switch tube connected to the photodiode. The pixel array operation method of the present invention can effectively eliminate noise interference after the dynamic range of the image sensor is increased, so as to facilitate obtaining the real signal. The image sensor and electronic device of the present invention have simple structures, and the operation method of the image sensor of the present invention is simple and convenient, and can be well applied to the field of image sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 Shown is a schematic structural diagram of a first pixel unit of the present invention.

[0055] Figure 2 Display as Figure 1 Schematic diagram of the structure of a pixel unit with a second reset switch.

[0056] Figure 3 It is a schematic structural diagram of a second pixel unit of the present invention.

[0057] Figure 4 Display as Figure 3 Schematic diagram of the structure of a pixel unit with a second reset switch.

[0058] Figure 5It is a schematic structural diagram of the third pixel unit of the present invention.

[0059] Figure 6 Shown is a schematic diagram of a layout structure of a pixel unit of the present invention.

[0060] Figure 7 Shown is a timing diagram of the first operating method of the present invention.

[0061] Figure 8 Shown is a timing diagram of the second operation method of the present invention.

[0062] Component number description

[0063] 1 pixel unit

[0064] 11 Photoelectric conversion module

[0065] 111 Photoelectric conversion area

[0066] 112 Second storage area

[0067] 113a Third storage area

[0068] 113b Third storage area

[0069] 113c Third storage area

[0070] 12 Readout module DETAILED DESCRIPTION

[0071] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0072] See also Figures 1 to 8 It should be noted that the diagrams used in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the diagrams only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0073] Embodiment 1

[0074] like Figure 1 As shown, this embodiment provides an image sensor, which includes a pixel array. The pixel array includes a plurality of pixel units 1 arranged in an array. Each pixel unit 1 includes a photoelectric conversion module 11 and a readout module 12 .

[0075] like Figure 1 As shown, each photoelectric conversion module 11 receives an optical signal and converts it into a voltage signal.

[0076] Specifically, Figure 1 As shown, the photoelectric conversion module 11 includes a photoelectric conversion area 111, a first storage area, a second storage area 112 and a third storage area 113a.

[0077] As an example, the photoelectric conversion region 111 is connected to a first control signal, and based on the first control signal, transfers a charge signal sensed and converted by the optical signal.

[0078] In this embodiment, the photoelectric conversion area 111 includes a photodiode PD and a transmission tube TX; the photodiode PD is connected to the first storage area (in this embodiment, the first storage area is set as the first floating diffusion node FD1) via the transmission tube TX, and is used to convert the light signal into a charge signal. The photodiode PD senses light information to generate a charge signal, and the control end of the transmission tube TX is connected to the first control signal to transfer the charge signal to the first storage area. In this embodiment, the transmission tube and the photodiode are selected to be set in a one-to-one correspondence, and other embodiments may also be other ways. In addition, the number of photodiodes can be based on actual needs. A pixel unit may include at least two photodiodes, and at least two photodiodes share a pixel transistor in the pixel unit, such as an output tube, a reset tube, etc. The first control signal is controlled. When the first control signal is valid, the transmission tube TX is turned on; when the first control signal is invalid, the transmission tube TX is turned off. In addition, it should be noted that during the exposure process, although the first control signal is described as invalid, when the light intensity is strong, it can overflow through the transmission tube controlled by the first control signal. At this time, the above overflow can be achieved by controlling the transmission tube to be located in the subthreshold region through the first control signal. Similarly, the overflow process of the signal under strong light intensity is still applicable to the corresponding other control transistors, which can be understood by those skilled in the art.

[0079] As an example, the first storage area is connected to the photoelectric conversion area 111 to store the charge signal output by the photoelectric conversion area 111 .

[0080] In this embodiment, the first storage area is configured as a first floating diffusion node FD1 ; the first floating diffusion node FD1 is connected to the output end of the photoelectric conversion area 111 to store and sense charge signals.

[0081] As an example, the second storage area 112 is connected to the first storage area and receives a second control signal to store the charge signal output by the photoelectric conversion area based on the first storage area. The charge signal may be a charge signal overflowed from the photoelectric conversion area during exposure, or a signal that needs to be read out and is transferred to the second storage area during readout.

[0082] In this embodiment, the second storage area 112 includes a first storage switch tube DCG and a second floating diffusion node FD2; the second floating diffusion node FD2 is connected to the first storage area (the first floating diffusion node FD1 in this embodiment) via the first storage switch tube DCG; the control end of the first storage switch tube DCG is connected to a second control signal to transfer the charge signal overflowed from the first floating diffusion node FD1 to the second floating diffusion node FD2. The second control signal is controlled, and when the second control signal is valid, the first storage switch tube DCG is turned on; when the first control signal is invalid, the first storage switch tube DCG is turned off.

[0083] As an example, Figure 1 As shown, the third storage area 113a is connected to the first storage area (in this embodiment, the first floating diffusion node FD1), and receives a third control signal to store the charge signal output by the photoelectric conversion area into the third storage area 113a based on the first storage area connected to the corresponding storage area. The charge signal may be a charge signal overflowed from the photoelectric conversion area during the exposure process, or a signal that needs to be read out and is transferred to the third storage area during the readout process.

[0084] In this embodiment, during the exposure overflow stage, the third control signal is controlled to be valid and the second control signal is controlled to be valid, so that when the charge signal of the photoelectric conversion area overflows, it overflows to the second storage area and the third storage area at the same time, that is, the overflowed charge can be distributed among the storage nodes corresponding to the second storage area and the storage nodes corresponding to the third storage area. In one implementation, the charge signal overflowed from the photoelectric conversion area is distributed according to the ratio of the capacitance of the storage nodes in each storage area, and the capacitance of the storage nodes in each storage area can be set according to actual needs and process conditions.

[0085] In this embodiment, the third storage area 113a includes a capacitor OF_Cap and a second storage switch tube OF_CTL; the first plate of the capacitor OF_Cap is connected to a preset voltage Vc, and the second plate is connected to the first storage area (i.e., the first floating diffusion node FD1) via the second storage switch tube OF_CTL; the control end of the second storage switch tube OF_CTL is connected to the third control signal, and the charge signal of the first storage area received by the second storage switch tube OF_CTL is transferred to the capacitor OF_Cap based on the third control signal. When the third control signal is valid, the second storage switch tube OF_CTL is turned on; when the third control signal is invalid, the second storage switch tube OF_CTL is turned off.

[0086] In this embodiment, the photoelectric conversion module 11 is also connected to a variable voltage module, and a signal can be provided by a control circuit to adjust the preset voltage Vc to a high level or a low level. By adjusting the level state of the preset voltage Vc, the direction of the charge signal flowing into the capacitor OF_Cap is regulated. In addition, it should be noted that the high level here can be set according to actual needs, and can be any required value greater than 0 potential, and the low level here can be zero potential.

[0087] It should be noted that the capacitor OF_Cap can be set to any type of capacitor such as a MIM capacitor (Metal-Insulator-Metal, MIM) or a MOM capacitor (Metal-Oxide-Metal, MOM). In order to ensure that a sufficient charge signal can be stored, the capacitor OF_Cap is set to a MIM capacitor in this embodiment.

[0088] Specifically, in this embodiment, the photoelectric conversion module 11 further includes a first reset switch RST1, the control end of the first reset switch RST1 is connected to a first reset signal, and at least the second storage area 112 corresponding to the first reset switch is reset based on the first reset signal; in this embodiment, at least one of the first storage area, the second storage area 112 and the third storage area 113a can be reset based on the first reset signal; in this embodiment, the third storage area 113a is connected to the first storage area, and the first reset switch RST is arranged between the second storage area 112 and the working voltage VDD. When the second control signal and the third control signal are both invalid, the first reset switch RST is turned on and the working voltage VDD is provided to the second storage area 112 so that the second storage area 112 is reset. When the second control signal is valid and the third control signal is invalid, the working voltage is provided to the second storage area 112 and the first storage area connected to the second storage area 112 to reset them. When the second control signal and the third control signal are both valid, the working voltage is provided to the first storage area, the second storage area 112 and the third storage area 113a to reset them.

[0089] Specifically, in another example, Figure 2 As shown, the photoelectric conversion module 11 further includes a second reset switch RST2, the third storage area 113a is connected to the first storage area, the first end of the second reset switch RST2 is connected to the working voltage VDD, the second end is arranged between the third storage area 113a and the first storage area, the control end of the second reset switch RST2 is connected to the second reset signal, and at least the third storage area is reset based on the second reset signal. In this embodiment, the first storage area and the third storage area 113a can be reset based on the second reset signal. By turning on the second reset switch RST2, the working voltage VDD can be introduced into the node between the third storage area 113a and the first storage area, so that the first storage area is quickly reset, and the third storage area 113a is quickly reset when the third control signal is valid.

[0090] like Figure 1 As shown, each readout module 12 is connected to the corresponding photoelectric conversion module 11, and receives a readout switch signal, and reads out the output signal of the corresponding photoelectric conversion module 11 based on the readout switch signal. In this embodiment, the gain of the pixel unit is adjusted to be the first gain, the second gain and the third gain by controlling the second control signal and the third control signal, respectively, so as to read the image signal of the pixel unit under different gains; and the third gain corresponds to the third storage area, and the signal under the third gain is read later than the signal under the first gain and the second gain.

[0091] Specifically, the readout module 12 includes an output tube SF and / or a selection tube SEL. In the present embodiment, the readout module 12 includes an output tube SF and a selection tube SEL, the control end of the output tube SF is connected to the photoelectric conversion module 11, the first end is connected to the working voltage VDD, and the second end is connected to the first end of the selection tube SEL, so as to output the converted voltage signal of the photoelectric conversion module 11; the control end of the selection tube SEL is connected to the readout switch signal, and the second end is used as the output end of the readout module 12, and the selection tube SEL is turned on based on the readout switch signal to output the output signal of the output tube SF. In the present embodiment, the output tube SF is a source follower transistor.

[0092] As an example, the image sensor also includes: a signal generating module (not shown in the figure); the signal generating module includes a readout switch signal generating unit, and the readout switch signal generating unit is used to generate a readout switch signal to select the pixel unit that needs to be read out in the pixel array; each pixel unit in the pixel array is respectively connected to the corresponding readout switch signal, and the corresponding pixel unit is selected based on the corresponding readout switch signal to expose and read out the electrical signal after the exposure conversion.

[0093] As an example, the image sensor includes a first chip and a second chip that are stacked, wherein: at least the photoelectric conversion element corresponding to the photoelectric conversion area is arranged in the first chip, and at least the storage element corresponding to the third storage area is arranged in the second chip. In this example, the image sensor is set to a stacked stack structure, and the first chip and the second chip are two different wafers, which can be combined together by copper hybrid bonding (Cu-Cu HB). Of course, other methods can also be used to combine the two chips and connect electrical signals. In this example, at least the photoelectric conversion element corresponding to the photoelectric conversion area (such as a photodiode PD) is arranged on the first chip, and at least the storage element corresponding to the third storage area (such as a capacitor MIM) is arranged in the second chip, so that photoelectric conversion and storage of corresponding overflow signals can be effectively realized. Based on the above configuration, it is beneficial to effectively improve the dynamic range based on the circuit design and timing operation of the present invention. Of course, other chips can also be set to form a stacked structure to configure each device. In addition, it should be noted that other pixel circuits or circuits in the logic area can be allocated on each chip according to actual needs. For example, the pixel circuit corresponding to the above-mentioned pixel unit is set on the first chip, and the analog circuit corresponding to the above-mentioned switching signal generating module is set on the second chip. Alternatively, only the photodiode is set on the first chip, and other transistors are configured on the second chip or in an additionally configured chip.

[0094] Embodiment 2

[0095] like Figure 3As shown, this embodiment provides an image sensor. The pixel unit 2 in the pixel array of the image sensor of this embodiment is substantially the same as the pixel unit 1 of the first embodiment, except that the third storage area 113b in the pixel unit 2 of this embodiment is arranged at a different position.

[0096] Specifically, Figure 3 As shown, the third storage area 113b is connected to the second storage area 112, so that the charge signal output by the photoelectric conversion area is stored in the third storage area 113b based on the corresponding second storage area 112. It can be a charge signal overflowed from the photoelectric conversion area during exposure, or a signal that needs to be read out and is transferred to the second storage area during readout.

[0097] As an example, the third storage area 113b of the present embodiment includes a capacitor OF_Cap and a second storage switch tube OF_CTL. The first plate of the capacitor OF_Cap is connected to a preset voltage Vc, and the second plate is connected to the second storage area 112 via the second storage switch tube OF_CTL. In a further example, the second plate is connected to the second floating diffusion node FD2 via the second storage switch tube OF_CTL, and the first storage switch tube DCG is connected to the first storage area (i.e., the first floating diffusion node FD1); the control end of the second storage switch tube OF_CTL is connected to the third control signal, and the charge signal of the second storage area received by the second storage switch tube OF_CTL is transferred to the capacitor OF_Cap based on the third control signal. When the third control signal is valid, the second storage switch tube OF_CTL is turned on; when the third control signal is invalid, the second storage switch tube OF_CTL is turned off.

[0098] It should be noted that the preset voltage Vc of this embodiment can still be controlled by the variable voltage module, and the preset voltage can be adjusted to a high level or a low level by the variable voltage module to change the charge flow direction of the capacitor OF_Cap.

[0099] As an example, Figure 3 As shown, the photoelectric conversion module 11 of this embodiment further includes a first reset switch RST1, the control end of which is connected to a first reset signal, and based on the first reset signal, at least the second storage area 112 corresponding to the first reset switch RST1 is reset. In this embodiment, based on the first reset signal, at least one of the first storage area, the second storage area 112 and the third storage area 113b can be reset. Figure 3As shown, the third storage area 113b is connected to the second storage area 112, the first reset switch RST1 is set between the second storage area 112 and the working voltage VDD, the working voltage VDD is introduced into the second storage area 112 through the first reset switch RST1, and when the third control signal is valid, the working voltage VDD is provided to the third storage area 113b to reset it; when the second control signal is valid, the working voltage VDD is transferred to the first storage area to reset it. Therefore, the first storage area, the second storage area 112 and the third storage area 113b can be reset at the same time through the first reset switch RST1.

[0100] As another example, Figure 4 As shown, the photoelectric conversion module 11 of this embodiment further includes a second reset switch RST2; in this embodiment, the third storage area 113b is connected to the second storage area 112 and the first reset switch RST1 is set between the second storage area 112 and the working voltage VDD, the first end of the second reset switch RST2 is connected to the working voltage VDD, the second end is connected to the node between the second plate of the capacitor OF_Cap and the second storage switch tube OF_CTL, the control end of the second reset switch is connected to the second reset signal, and the capacitor OF_Cap is at least reset based on the second reset signal. By setting the second reset switch RST2, the working voltage VDD is directly introduced into the node between the capacitor OF_Cap and the second storage switch tube OF_CTL in the third storage area 113b, so as to realize the rapid reset of the capacitor OF_Cap and reduce the reset time.

[0101] Embodiment 3

[0102] like Figure 5 As shown, this embodiment provides an image sensor, wherein each pixel unit 3 is substantially the same as the pixel unit 2 of the second embodiment, except that: the position of the first reset switch RST1 of the pixel unit 3 of this embodiment is different.

[0103] Specifically, in this embodiment, the third storage area 113c is connected to the second storage area 112, and the first reset switch RST1 is arranged between the third storage area 113c and the working voltage VDD. In this embodiment, the first end of the first reset switch RST1 is connected to the working voltage VDD, and the second end is connected to the node between the second plate of the capacitor OF_Cap in the third storage area 113c and the second storage switch tube OF_CTL. The control end of the first reset switch RST1 is connected to the first reset signal, and based on the first reset signal, at least the third storage area 113 corresponding to the first reset switch RST1 can be reset; in this embodiment, based on the first reset signal, at least one of the first storage area, the second storage area 112 and the third storage area 113c can be reset.

[0104] It should be noted that, in this embodiment, the third storage area 113 c is directly connected to the working voltage VDD through the first reset switch RST1 , so the second reset switch RST2 may not be provided to shorten the reset time of the third storage area 113 c .

[0105] Embodiment 4

[0106] This embodiment provides an image sensor. Figure 6 As shown, a pixel unit in the pixel array includes at least two photodiodes PD that are shared. Figure 6 In the example shown in FIG. 1 , each pixel unit includes four 2×2 shared photodiodes PD; the transmission tubes TX corresponding to each photodiode PD relatively form an enclosed area, where the enclosed area refers to the area corresponding to the side of the transmission tube TX away from the photodiode PD, not a strict surrounding area; adjacent transmission tubes TX share a first floating diffusion node FD1 in pairs, Figure 6 In the example shown in FIG. 1 , two first floating diffusion nodes FD1 are shared by four transmission tubes TX in pairs; the transmission tubes SF are arranged in the enclosed area and the first floating diffusion nodes FD1 are evenly distributed around the transmission tubes. Figure 6 In the example, the two first floating diffusion nodes FD1 are symmetrically distributed on the left and right sides of the transmission tube SF; the first storage switch DCG and the second storage switch OF_CTL are connected in series and arranged on the side of a first floating diffusion node FD1 (such as the left first floating diffusion node) and are located in the first space area formed by the adjacent photodiode PD. Figure 6 In the example, the first space region is the space region formed by the photodiodes PD adjacent to each other; the first reset switch RST1 and the selection tube RS are distributed on both sides of the transmission tube SF and are located in the second space region formed by the adjacent photodiodes PD. Figure 6In the example, the second space area is the space area formed by the photodiodes PD adjacent to each other on the left and right; further, in this example, the first space area is the whole area, and the second space area is the dispersed area; in addition, in this example, the first space area and the second space area are vertically distributed. The above design is conducive to the connection of the pixel circuit in this embodiment, can optimize the wiring layout and reduce the interference between signals, and is conducive to the wiring connection of the second storage transistor and the first reset transistor.

[0107] Embodiment 5

[0108] The present embodiment provides an image sensor operation method, which is implemented based on the image sensor provided by the first to fourth embodiments, including: controlling the second control signal and the third control signal to adjust the gain of the pixel unit to be the first gain, the second gain and the third gain respectively, and then reading the image signal of the pixel unit under different gains; and the third gain corresponds to the third storage area, and the signal under the third gain is read out later than the signals under the first gain and the second gain.

[0109] As an example, during the reset process before the exposure overflow stage until the first gain reset signal after the exposure overflow stage is read out and before the second gain reset signal is read out, the first storage switch of the second storage area is controlled to be effective, and during the reset process before the exposure overflow stage until the selection tube after the exposure overflow stage is turned on, the second storage switch of the third storage area is controlled to be effective, so as to realize the overflow of the exposure overflow stage signal and the readout of the corresponding signal in the readout stage.

[0110] Specifically, the pixel array operation method includes an exposure step and a readout step. In this embodiment, for the convenience of description, the pixel array of the first embodiment (such as Figure 1 The pixel array operation method of this embodiment is still applicable to the second and third embodiments.

[0111] As a first example, the exposure overflow step includes: resetting the first storage area, the second storage area 112 and the third storage area 113a; the exposure overflow step includes: controlling the first control signal, the second control signal and the third control signal so that the charge signal sensed and converted by the photoelectric conversion area to the light signal is transmitted to the first storage area (first floating diffusion node FD1), the second storage area 112 and the third storage area 1113a; it should be noted that when the light signal intensity is weak, the photoelectric converted charge can also be stored in the photodiode without overflowing, which can be understood by those skilled in the art. Of course, the exposure step may also include controlling the first control signal so that the charge signal sensed and converted by the photoelectric conversion area 111 to the light signal is transmitted to the first storage area (the first floating diffusion node FD1 in this example); or, controlling the first control signal and the second control signal so that the charge signal sensed and converted by the photoelectric conversion area 111 to the light signal is transmitted to the first storage area (the first floating diffusion node FD1) and the second storage area 112, or controlling the first control signal and the third control signal so that the charge signal sensed and converted by the photoelectric conversion area 11 to the light signal is transmitted to the first storage area (the first floating diffusion node FD1) and the third storage area 113a.

[0112] As a first example, the readout step includes: controlling the readout switch signal to read the output signal of the first storage area; controlling the readout switch signal and the second control signal to read the output signals of the first storage area and the second storage area 112; controlling the readout switch signal, the second control signal and the third control signal to read the output signals of the first storage area, the second storage area 112 and the third storage area 113a.

[0113] In this embodiment, the signals at the first gain and the second gain are read out preferentially, and after the two signals are read out, the signal at the third gain is read out, wherein the first gain corresponds to the first floating diffusion node FD1 and the second floating diffusion node FD2 as the quantization area, the second gain corresponds to the first floating diffusion node FD1 as the quantization area, and the first gain corresponds to the first floating diffusion node FD1, the second floating diffusion node FD2 and even the connected capacitor CAP as the quantization area.

[0114] Combination Figure 1 The pixel unit 1 shown and Figure 7 The timing diagram shown further illustrates the image sensor operation method of the first example:

[0115] Exposure overflow step: In this example, after controlling the first control signal, the second control signal, and the third control signal, the first control signal is invalidated, so that the photoelectric conversion area 111 is exposed to obtain a charge signal that can overflow to the first storage area, the second storage area 112, and the third storage area 113; the first control signal is invalidated, and the transmission tube TX is turned off so that after the photodiode PD starts to be exposed, the overflowed charge signal will overflow to the first storage area, the second storage area 112, and the third storage area 113a because the second storage switch tube OF_CTL and the first storage switch tube DCG are kept turned on. Of course, it should also be noted that when the corresponding light intensity is weak, the charge signal converted by the photoelectric conversion module can also be directly stored in the photodiode.

[0116] In this example, in order to further ensure the charge flow direction when the capacitor OF_Cap stores the signal, the preset voltage Vc is set to a high level after the exposure starts, and the preset voltage Vc is set to a low level after the second storage switch tube OF_CTL is turned off, thereby ensuring the direction in which the overflow charge signal flows into the capacitor.

[0117] Reset step: Before exposure, the first storage area, the second storage area 112 and the third storage area 113 are reset at the same time. When the second storage switch tube OF_CTL is turned on, the transmission tube TX and the first storage switch tube DCG are turned on in sequence, so that the first storage area, the second storage area 112 and the third storage area 113a are reset at the same time. In this example, the first reset switch RST1 is set for reset, and other methods can also be used to reset the first storage area, the second storage area 112 and the third storage area 113a at the same time to reduce the influence of noise.

[0118] Reset signal readout step under the first gain and the second gain: In this example, a readout switch signal is provided, and the third control signal and the second control signal are invalidated in sequence. Before performing the readout, the second storage switch tube OF_CTL is turned off to make the third storage area 113a store independently. Then, the second storage switch tube OF_CTL and the first storage switch tube DCG are turned off respectively, so as to read out the reset signal L_RST under the first gain at time t11 and the reset signal H_RST under the second gain at time t12.

[0119] The steps of reading out the image signal under the first gain and the second gain: in this example, the first control signal is enabled and then disabled, so that the transmission tube TX is turned on so that the charge signal of the photoelectric conversion area 111 is transmitted to the first storage area and read out at time t13 to obtain the image signal H_SIG under the second gain; the second control signal is enabled, so that after the first storage switch tube DCG is turned on, the first control signal is enabled and then disabled, so that the transmission tube TX is turned on so that the charge signal of the photoelectric conversion area 111 after exposure is transmitted to the first storage area and the second storage area 112 in sequence and read out at time t14 to obtain the image signal L_SIG under the first gain.

[0120] The image signal readout step under the third gain: in this example, the third control signal is enabled, so that after the second storage switch tube OF_CTL is turned on, the first control signal is enabled and then the first control signal is disabled, so that the charge signal of the photoelectric conversion area 111 after exposure is sequentially transmitted to the first storage area, the second storage area 112 and the third storage area 113 and read out at time t15 to obtain the image signal OF_SIG under the third gain.

[0121] It should be noted that, in this example, in order to further ensure the charge flow direction when the capacitor OF_Cap stores signals, the preset voltage Vc can be set to a high level after the transmission tube is turned on, and the preset voltage Vc can be set to a low level before the transmission tube is turned off.

[0122] Reset signal reading step under the third gain: In this example, the second control signal and the third control signal are controlled and the first storage area, the second storage area 112 and the third storage area 113a are reset simultaneously to read out the reset signal OF_RST under the third gain at time t16.

[0123] In one implementation, the first reset signal RST1 is controlled to be valid to turn on the reset transistor to achieve the reset of the first storage area, the second storage area 112 and the third storage area 113a.

[0124] Furthermore, in this example, in order to further ensure the charge flow direction when the capacitor OF_Cap stores a signal, the preset voltage Vc may be set to a high level after the reset transistor is turned on, and may be set to a low level before the reset transistor is turned off.

[0125] Readout calculation steps: based on the reset signal L_RST at the first gain and the image signal L_SIG at the first gain, obtain the real signal at the first gain; based on the reset signal H_RST at the second gain and the image signal H_SIG at the second gain, obtain the real signal at the second gain; based on the reset signal OF_RST at the third gain and the image signal OF_SIG at the third gain, obtain the real signal at the third gain. The actual image of the final scene can be obtained based on the real signals at the three gains. This step can be implemented based on existing analog or digital circuits, and will not be repeated here.

[0126] Because the image sensor operation method of the first example has a large overflow of charge signals sensed and generated by the photodiode PD when processing a bright scene with high brightness, the voltage of the floating diffusion point FD is low when reading the charge signal, and the reset transistor and the like easily deviate from the normal working area, causing the position where there should be a bright spot to fail to be successfully read when reading the signal, resulting in a black spot. Therefore, this embodiment also controls the second example to avoid the aforementioned problem.

[0127] It should be noted that the image sensor operation method of the second example is only applicable to the image sensor controlled by the first embodiment and the image sensor controlled by the second embodiment. That is, in the first embodiment, the photoelectric conversion module 11 includes a first reset switch RST1, the third storage area 113a is connected to the first storage area, and the first reset switch RST1 is arranged between the second storage area 112 and the working voltage VDD; in the second embodiment, the photoelectric conversion module 11 includes a first reset switch RST1, the third storage area 113b is connected to the second storage area 112, and the first reset switch RST is arranged between the second storage area 112 and the working voltage VDD.

[0128] As a second example, the image sensor operation method in this example is basically the same as that in the first example, except that: the image sensor operation method in this example also includes setting a clearing step before reading out the first reset signal L_RST and the second reset signal H_RST: controlling the second control signal to be valid and the third control signal to be invalid, so as to reset the first storage area and the second storage area 112, and clear the overflow signals of the first storage area (first floating diffusion point FD1) and the second storage area 112.

[0129] Combination Figure 1 The pixel unit 1 shown and Figure 8 The timing diagram shown further illustrates the image sensor operation method of the second example:

[0130] In this example, after resetting the first storage area, the second storage area, and the third storage area (i.e., the reset step in the first example) and the exposure overflow step, the image sensor operation method further includes: controlling the readout switch signal to be valid and making the first control signal and the third control signal invalid, so as to read out the overflow image signal O_SIG of the first storage area and the second storage area 112 at time t21; resetting the first storage area and the second storage area 112 to read out the overflow reset signal O_RST of the first storage area and the second storage area at time t22. In one example, the reset is achieved by controlling the first reset signal RST1 to be valid and turning on the first reset transistor; in this example, the real signal of the overflow signal can be obtained based on the overflow image signal O_SIG and the overflow reset signal O_RST, and then the real signal of the overflow signal can be calculated with the above three gain signals to obtain the final image information. Of course, in other examples, only the operation of resetting the first storage area and the second storage area 112 can be performed to clear the overflow signal. In addition, in this embodiment, the overflow image signal O_SIG is read out by controlling the readout switch signal to turn on the selection transistor and then controlling the third control signal to be inactive to turn off the second storage transistor.

[0131] It should be noted that, as a second example, this example first reads out the overflow signal, and then performs a reset operation to clear the overflow signal, thereby eliminating the invalid overflow charge signal, so as to solve the image black spot problem caused by the reading error in the first example. In addition, the exposure overflow step, reset step, reset signal readout step under the first gain and the second gain, image signal readout step under the first gain and the second gain, reset signal readout step under the third gain, and image signal readout step under the third gain of this example are basically the same as those of the first example, see Figure 8 The moments t23-t28 will not be described here one by one.

[0132] This embodiment also provides an electronic device, which includes the image sensor as described above. The electronic device, for example, can be a vehicle-mounted device, which includes an image sensor. The specific structure of the image sensor refers to the above embodiment. Since this vehicle-mounted device adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here. Of course, the electronic device in this embodiment can also be monitoring equipment, machine vision, drones, mobile phones, cameras, etc.

[0133] In summary, the present invention provides an image sensor and an operation method, and an electronic device, wherein the pixel array includes a plurality of pixel units arranged in an array; each pixel unit includes a photoelectric conversion module and a readout module; wherein each photoelectric conversion module receives a light signal and converts it into a voltage signal; each readout module reads out the output signal of the corresponding photoelectric conversion module; the photoelectric conversion module includes a photoelectric conversion area, a first storage area, a second storage area, and a third storage area; the photoelectric conversion area converts the light signal into a charge signal; the first storage area, the second storage area, and the third storage area can store the charge signal output by the photoelectric conversion area; the gain of the pixel unit is adjusted to be the first gain, the second gain, and the third gain, respectively, so as to read the image signal under different gains. The present invention effectively improves the dynamic range of the image sensor. Therefore, the present invention effectively overcomes the various shortcomings in the prior art and has a high industrial utilization value.

[0134] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. An image sensor, characterized in that: The image sensor comprises a pixel array, and the pixel array comprises at least a plurality of pixel units arranged in an array; Each pixel unit includes a photoelectric conversion module and a readout module; wherein each photoelectric conversion module receives a light signal and converts it into a voltage signal; each readout module is connected to a corresponding photoelectric conversion module and receives a readout switch signal, and reads out an output signal of the corresponding photoelectric conversion module based on the readout switch signal; The photoelectric conversion module includes a photoelectric conversion area, a first storage area, a second storage area and a third storage area; The photoelectric conversion region is connected to a first control signal, and based on the first control signal, transfers a charge signal sensed and converted from the light signal; The first storage area is connected to the photoelectric conversion area to store the charge signal output by the photoelectric conversion area; The second storage area is connected to the first storage area and receives a second control signal to store the charge signal output by the photoelectric conversion area based on the first storage area; The third storage area is connected to the first storage area or the second storage area and receives a third control signal to store the charge signal output by the photoelectric conversion area based on the first storage area or the second storage area connected to the corresponding storage area; The second control signal and the third control signal are controlled to adjust the gain of the pixel unit to be the first gain, the second gain and the third gain respectively, so as to read the data signal of the pixel unit under different gains.

2. The image sensor according to claim 1, characterized in that: The photoelectric conversion region includes a photodiode and a transmission tube, wherein: The photodiode is connected to the first storage area via the transmission tube, and is used to convert the light signal into a charge signal. The control end of the transmission tube is connected to the first control signal, and transfers the charge signal to the first storage area. And / or, the first storage area is set as a first floating diffusion node, wherein: the first floating diffusion node is connected to the output end of the photoelectric conversion area to store and sense the charge signal; And / or, the readout module includes an output tube and / or a selection tube, wherein: The control end of the output tube is connected to the photoelectric conversion module, the first end is connected to the working voltage, and the second end is connected to the first end of the selection tube, so as to output the output signal of the photoelectric conversion module. The control end of the selection tube is connected to the readout switch signal, and the second end serves as the output end of the readout module. The selection tube is turned on based on the readout switch signal to output the output signal of the output tube.

3. The image sensor according to claim 1, characterized in that: The second storage area includes a first storage switch tube and a second floating diffusion node, wherein: The second floating diffusion node is connected to the first storage area via the first storage switch tube, The control end of the first storage switch tube is connected to a second control signal, and is at least used to transfer the charge signal overflowed from the photoelectric conversion area to the second floating diffusion node based on the first storage area; And / or, the third storage area includes a capacitor and a second storage switch tube, wherein: The first plate of the capacitor is connected to a preset voltage, and the second plate is connected to the first storage area or the second storage area via the second storage switch tube; The control end of the second storage switch tube is connected to the third control signal, and is at least used to transfer the charge signal of the first storage area received by the second storage switch tube or the second storage area received by the second storage switch tube and overflowed from the photoelectric conversion area to the capacitor based on the third control signal.

4. The image sensor according to claim 3, characterized in that: When the third storage area includes a capacitor, the first electrode plate of the capacitor is connected to a variable voltage module for adjusting the preset voltage to a high level or a low level.

5. The image sensor according to claim 1, wherein: The image sensor further comprises a signal generating module having a readout switch signal generating unit, wherein: The readout switch signal generating unit is used to generate a readout switch signal to select a pixel unit to be read out; Each pixel unit in the pixel array is respectively connected to a corresponding readout switch signal, and the corresponding pixel unit is selected based on the corresponding readout switch signal to read out the electrical signal after exposure conversion; And / or, the image sensor comprises a first chip and a second chip which are stacked, wherein: At least the photoelectric conversion element corresponding to the photoelectric conversion area is arranged in the first chip, and at least the storage element corresponding to the third storage area is arranged in the second chip.

6. The image sensor according to any one of claims 1 to 5, characterized in that: The pixel unit further includes a first reset switch, a control end of which is connected to a first reset signal; When the third storage area is connected to the first storage area, the first reset switch is arranged between the second storage area and the working voltage; When the third storage area is connected to the second storage area, the first reset switch is arranged between the third storage area and the working voltage or between the second storage area and the working voltage; At least the second storage area or the third storage area correspondingly connected to the first reset switch is reset based on the first reset signal.

7. The image sensor according to claim 6, characterized in that: The pixel unit further includes a second reset switch; When the third storage area is connected to the first storage area, the first end of the second reset switch is connected to the working voltage, the second end is arranged between the third storage area and the first storage area, the control end of the second reset switch is connected to the second reset signal, and at least the third storage area is reset based on the second reset signal; When the third storage area is connected to the second storage area and the first reset switch is set between the second storage area and the operating voltage, the first end of the second reset switch is connected to the operating voltage, the second end is connected to the node between the second plate of the capacitor and the second storage switch tube, and the control end of the second reset switch is connected to the second reset signal, and at least the third storage area is reset based on the second reset signal.

8. The image sensor according to claim 6, characterized in that: The pixel unit includes at least two photodiodes that are shared, and the transmission tubes corresponding to each of the photodiodes relatively form an enclosed area. Adjacent transmission tubes share a first floating diffusion node in pairs, and the transmission tubes are arranged in the enclosed area and the first floating diffusion nodes are evenly distributed around the transmission tubes. The first storage switch and the second storage switch are connected in series and arranged on the side of the first floating diffusion node and are located in a first space area formed by adjacent photodiodes. The first reset switch and the selection tube are distributed on both sides of the transmission tube and are located in a second space area formed by adjacent photodiodes.

9. An electronic device, characterized in that: Comprising the image sensor as claimed in any one of claims 1-8.

10. An image sensor operation method, implemented based on the image sensor according to any one of claims 1 to 8, characterized in that: The image sensor operating method comprises: The second control signal and the third control signal are controlled to adjust the gain of the pixel unit to be the first gain, the second gain and the third gain respectively, so as to read the data signal of the pixel unit under different gains, and the third gain corresponds to the third storage area, and the signal under the third gain is read out later than the signal under the first gain and the second gain.

11. The image sensor operating method according to claim 10, characterized in that: The operation method comprises an exposure step, wherein the exposure step comprises: Controlling the first control signal, the second control signal and the third control signal so that the charge signal sensed and converted by the photoelectric conversion area to the light signal is transmitted to the first storage area, the second storage area and the third storage area or the converted charge signal is stored in the photoelectric conversion area; And / or, the operation method comprises a readout step, wherein the readout step comprises at least one of the following steps: Controlling the readout switch signal to read the output signal of the first storage area; Controlling the readout switch signal and the second control signal to read output signals of the first storage area and the second storage area; The readout switch signal, the second control signal, and the third control signal are controlled to read output signals of the first storage area, the second storage area, and the third storage area.

12. The image sensor operating method according to claim 11, characterized in that: The operation method comprises: After the first control signal, the second control signal and the third control signal are controlled to be valid, the first control signal is invalidated, and the third control signal and the second control signal are kept valid to expose the photoelectric conversion area to obtain a charge signal; Controlling the readout switch signal to be effective, and sequentially making the third control signal and the second control signal ineffective, so as to respectively read out a reset signal under a first gain and a reset signal under a second gain; The first control signal is enabled, the charge signal after the exposure of the photoelectric conversion area is transmitted to the first storage area and read out to obtain an image signal under a second gain; The second control signal is enabled and the first control signal is enabled, the charge signal of the photoelectric conversion area after exposure is transmitted to the first storage area and the second storage area, and the image signal under the first gain is read out; The third control signal is enabled, the second control signal remains enabled, and the first control signal is enabled, and the charge signal of the photoelectric conversion area after exposure is sequentially transmitted to the first storage area, the second storage area, and the third storage area, and read out to obtain an image signal under a third gain; Keeping the second control signal and the third control signal valid, so as to simultaneously reset the first storage area, the second storage area and the third storage area and read out a reset signal under a third gain; A real signal at the first gain is obtained based on the reset signal at the first gain and the image signal at the first gain; a real signal at the second gain is obtained based on the reset signal at the second gain and the image signal at the second gain; and a real signal at the third gain is obtained based on the reset signal at the third gain and the image signal at the third gain.

13. The image sensor operating method according to claim 12, characterized in that: When the photoelectric conversion module further includes a first reset switch, the third storage area is connected to the first storage area, and the first reset switch is arranged between the second storage area and the operating voltage, or when the photoelectric conversion module further includes a first reset switch, the third storage area is connected to the second storage area, and the first reset switch is arranged between the second storage area and the operating voltage, the operation method further includes setting a clearing step before reading out the first reset signal and the second reset signal, wherein: Controlling the second control signal to be valid and the third control signal to be invalid, so as to reset the first storage area and the second storage area and clear overflow signals of the first storage area and the second storage area; Alternatively, after controlling the first control signal, the second control signal, and the third control signal to be valid to reset the first storage area, the second storage area, and the third storage area, the operating method further includes: Controlling the readout switch signal to be valid and making the first control signal and the third control signal invalid, so as to read out the overflow image signals of the first storage area and the second storage area; Resetting the first storage area and the second storage area to read out overflow reset signals of the first storage area and the second storage area; A true signal of the overflow signal is obtained based on the overflow image signal and the overflow reset signal.

14. The image sensor operating method according to claim 10, characterized in that: When the third storage area includes a capacitor and a second storage switch tube, and the first plate of the capacitor is connected to a preset voltage, and the second plate is connected to the first storage area or the second storage area via the second storage switch tube; the control end of the second storage switch tube is connected to the third control signal, and based on the third control signal, the charge signal of the first storage area received by the second storage switch tube or the charge signal of the second storage area received by the second storage switch tube is transferred to the capacitor, the image sensor operation method further includes: When the charge signal of the first storage area received by the second storage switch tube or the charge signal of the second storage area received by the second storage switch tube is transferred to the capacitor based on the third control signal, the preset voltage is set to a high level and the preset voltage is set to a low level later than the second storage switch tube is turned off; and / or, in the step of reading out the third storage area signal based on the conduction of the switch tube corresponding to the third storage area, the preset voltage is set to a high level and the high level corresponds to the effective period of the transmission tube and the reset tube.

15. The image sensor operating method according to any one of claims 10 to 14, characterized in that: During the reset process before the exposure overflow stage until the first gain reset signal after the exposure overflow stage is read out and before the second gain reset signal is read out, the first storage switch of the second storage area is controlled to be effective, and during the reset process before the exposure overflow stage until the selection tube after the exposure overflow stage is turned on, the second storage switch of the third storage area is controlled to be effective, so as to realize the overflow of the exposure overflow stage signal and the readout of the corresponding signal in the readout stage.

Images