TDI-CMOS image sensor and control method thereof

Abstract

The invention discloses a TDI-CMOS image sensor and a control method thereof. The TDI-CMOS image sensor comprises a first image acquisition unit and a second image acquisition unit which are located on the same substrate, wherein the sensitivity of the first image acquisition unit is higher than that of the second image acquisition unit; the first image acquisition unit and the second image acquisition unit are used for performing image acquisition on the same scene at the same time; and the first image acquisition unit and the second image acquisition unit are used for fusing images acquired in the same scene and then taking the fused images as a final result image. By adopting the scheme, the dynamic range of the TDI-CMOS image sensor can be expanded.

Description

Technical Field

[0001] The present invention relates to the technical field of image sensors, and in particular to a TDI-CMOS image sensor and a control method thereof. Background Art

[0002] Image sensors are traditionally designed and manufactured using the Charge Coupled Device (CCD) process. In the 1980s and 1990s, the CCD process achieved great development due to its application in consumer cameras. However, after 2005, the application of CCD in the consumer field was quickly replaced by the Complementary Metal Oxide Semiconductor (CMOS) process. The original CCD production lines were closed one after another, and there are only a few CCD production lines left in the world. The design and manufacture of Time Delay Integration (TDI) image sensors still partially use CCD processes. The reason is that the working principle of TDI image sensors depends on the operation mode of CCD.

[0003] Considering the withdrawal of CCD process lines, some companies have been researching how to embed devices with CCD-like functions in CMOS process since 2012, which are called embedded CCD (eCCD) to make TDI image sensors. This image sensor is based on CMOS process, so it is called TDI-CMOS image sensor, and the core is eCCD. In comparison, the image sensor based on CCD process is called TDI-CCD image sensor.

[0004] However, the dynamic range of existing TDI-CMOS image sensors needs to be improved. Summary of the invention

[0005] The problem to be solved by the present invention is to improve the dynamic range of a TDI-CMOS image sensor.

[0006] To solve the above problems, an embodiment of the present invention provides a TDI-CMOS image sensor, the TDI-CMOS image sensor comprising: a first image acquisition unit and a second image acquisition unit located on the same substrate;

[0007] Among them, the sensitivity of the first image acquisition unit is higher than the sensitivity of the second image acquisition unit; the first image acquisition unit and the second image acquisition unit are used to acquire images of the same scene at the same time; the images acquired by the first image acquisition unit and the second image acquisition unit for the same scene are fused as the final result image.

[0008] In a possible embodiment, the first image acquisition unit includes: a first pixel array, a first capacitor module and a first pixel readout circuit; each column of pixel units in the first pixel array is connected to a first pixel readout circuit via a first capacitor module.

[0009] In a possible embodiment, the first pixel array includes: a plurality of first eCCD pixel units distributed in an array; the first eCCD pixel unit is a 2-phase CCD structure, a 3-phase CCD structure, or a 4-phase CCD structure.

[0010] In a possible embodiment, the first image acquisition unit includes: a first floating diffusion node; and the first capacitor module is connected to the first pixel array through the first floating diffusion node.

[0011] In a possible embodiment, the second image acquisition unit includes: a second pixel array, a second capacitor module and a second pixel readout circuit; each column of pixel units in the second pixel array is connected to a second pixel readout circuit through a second capacitor module; and the capacitance value of the first capacitor module is smaller than the capacitance value of the second capacitor module.

[0012] In a possible embodiment, the second pixel array includes: a plurality of second eCCD pixel units distributed in an array; the second eCCD pixel unit is a 2-phase CCD structure, a 3-phase CCD structure, or a 4-phase CCD structure.

[0013] In a possible embodiment, a ratio between the number of polysilicon electrodes in the first eCCD pixel unit and the number of polysilicon electrodes in the second eCCD pixel unit matches a brightness requirement of the final result image.

[0014] In a possible embodiment, the second image acquisition unit includes: a second floating diffusion node; and the second capacitor module is connected to the second pixel array through the second floating diffusion node.

[0015] In a possible embodiment, a ratio of the first capacitor module to the second capacitor module matches a dynamic range requirement of the TDI-CMOS image sensor.

[0016] An embodiment of the present invention further provides a control method for any of the above-mentioned TDI-CMOS image sensors, the method comprising:

[0017] Controlling the first image acquisition unit and the second image acquisition unit to simultaneously acquire images of the same scene;

[0018] The images simultaneously acquired by the first image acquisition unit and the second image acquisition unit are fused to obtain a final result image.

[0019] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0020] By applying the solution of the present invention, by arranging a first image acquisition unit and a second image acquisition unit on the same substrate, the first image acquisition unit and the second image acquisition unit can simultaneously acquire images of the same scene. Since the sensitivity of the first image acquisition unit is higher than that of the second image acquisition unit, the first image acquisition unit can capture more details in dark places relative to the second image acquisition unit, and the second image acquisition unit can capture more details in bright places relative to the first image acquisition unit. Therefore, the image acquired by fusing the images acquired by the first image acquisition unit and the second image acquisition unit can be an image with clear light and dark distinctions, thereby improving the dynamic range of the TDI-CMOS image sensor, thereby improving the quality of the output image. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a top view of a conventional TDI-CMOS image sensor;

[0022] Figure 2 It is a schematic diagram of the cross-sectional structure of an eCCD pixel unit;

[0023] Figure 3 yes Figure 1 A schematic diagram of the timing of the driving voltage signal applied to each electrode of the eCCD pixel unit;

[0024] Figure 4 It is a schematic diagram of charge transfer in two adjacent eCCD pixel units in the same column of a TDI-CMOS image sensor;

[0025] Figure 5 is a top view of a TDI-CMOS image sensor in an embodiment of the present invention;

[0026] Figure 6 is a structural schematic diagram of a first image acquisition unit in an embodiment of the present invention;

[0027] Figure 7 is a schematic diagram of a partial cross-sectional structure of a first image acquisition unit in an embodiment of the present invention;

[0028] Figure 8 is a structural schematic diagram of a second image acquisition unit in an embodiment of the present invention;

[0029] Fig. 9is a schematic diagram of a partial cross-sectional structure of a second image acquisition unit in an embodiment of the present invention;

[0030] Fig.10 The figure is a flow chart of a TDI-CMOS image sensor control method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] Figure 1 This is a top view of a conventional TDI-CMOS image sensor. Figure 1 In a conventional TDI-CMOS image sensor, only one pixel array 11 is arranged on a substrate 10, which is also called a single-segment TDI-CMOS image sensor. The pixel array 11 is composed of a plurality of eCCD pixel units distributed in an array. In a TDI-CMOS image sensor, after the image signal is converted into electrons by the photoelectric effect, it is conducted step by step through the electrodes of each eCCD pixel unit, and then at the end of the same eCCD pixel unit, it is conducted to the floating diffusion (FD) node through the transmission tube TX. Finally, the signal on the FD node reaches the readout circuit after passing through the capacitor, and is quantized and read out by the readout circuit.

[0032] Figure 2 The cross-sectional structure diagram of an eCCD pixel unit is shown in FIG. Figure 1 As shown, each eCCD pixel unit may include four polysilicon electrodes, namely, a first electrode PH1, a second electrode PH2, a third electrode PH3 and a fourth electrode PH4. These four electrodes do not overlap each other. Below the polysilicon electrode is a gate oxide layer 21, below the gate oxide layer 21 is a silicon substrate 22, and N-type ions are injected into the silicon substrate 22 to form a channel. Each polysilicon electrode corresponds to a different channel region.

[0033] Figure 3 for Figure 1 A schematic diagram of the timing of the driving voltage signals applied to each electrode of the eCCD pixel unit. By applying different driving voltages to different electrodes, the charge in the channel can be transferred in a certain direction.

[0034] Figure 4 The schematic diagram of charge transfer in two adjacent eCCD pixel units in the same column of the TDI-CMOS image sensor is shown in FIG. The two adjacent eCCD pixel units are divided into the n-1th eCCD pixel unit and the nth eCCD pixel unit in the column. The n-1th eCCD pixel unit has a first electrode PH1_n-1, a second electrode PH2_n-1, a third electrode PH3_n-1 and a fourth electrode PH4_n-1. The nth eCCD pixel unit has a first electrode PH1_, a second electrode PH2_n, a third electrode PH3_n and a fourth electrode PH4_n. The eCCD pixel units in the same column share the same gate oxide layer and silicon substrate.

[0035] Reference Figure 3 and Figure 4 When the charge is transferred between the polysilicon electrode and the transmission tube TX, the phase of each polysilicon electrode and the transmission tube TX operation signal needs to be phase-matched so that the charge can be transmitted in the designed direction.

[0036] For example, at time T1, the charge converted by the photoelectric effect of the image signal is located in the channel region below the first electrode PH1_n-1 and the second electrode PH2_n-1 of the n-1th eCCD pixel unit. The charge converted by the photoelectric effect of the image signal is located in the channel region below the first electrode PH1_n and the second electrode PH2_n of the nth eCCD pixel unit.

[0037] At time T2, the charges in the channel region below the first electrode PH1_n-1 and the second electrode PH2_n-1 are transferred to the channel region below the first electrode PH1_n-1, the second electrode PH2_n-1 and the third electrode PH3_n-1. The charges in the channel region below the first electrode PH1_n and the second electrode PH2_n are transferred to the channel region below the first electrode PH1_n, the second electrode PH2_n and the third electrode PH3_n.

[0038] At time T3, the charges in the channel region below the first electrode PH1_n-1, the second electrode PH2_n-1 and the third electrode PH3_n-1 are transferred to the channel region below the second electrode PH2_n-1 and the third electrode PH3_n-1. The charges in the channel region below the first electrode PH1_n, the second electrode PH2_n and the third electrode PH3_n are transferred to the channel region below the second electrode PH2_n and the third electrode PH3_n.

[0039] At time T4, the charges in the channel region below the second electrode PH2_n-1 and the third electrode PH3_n-1 are transferred to the channel region below the second electrode PH2_n-1, the third electrode PH3_n-1 and the fourth electrode PH4_n-1. The charges in the channel region below the second electrode PH2_n and the third electrode PH3_n are transferred to the channel region below the second electrode PH2_n, the third electrode PH3_n and the fourth electrode PH4_n.

[0040] At time T5, the charges in the channel region below the second electrode PH2_n-1, the third electrode PH3_n-1 and the fourth electrode PH4_n-1 are transferred to the channel region below the third electrode PH3_n-1 and the fourth electrode PH4_n-. The charges in the channel region below the second electrode PH2_n, the third electrode PH3_n and the fourth electrode PH4_n are transferred to the channel region below the third electrode PH3_n and the fourth electrode PH4_n.

[0041] …

[0042] Finally, the charges in the channel region can be read out through the transfer transistor TX.

[0043] Dynamic Range (DR) is one of the most important parameters of image sensors. It determines the distribution range of light intensity from the darkest shadow to the brightest highlight that the image sensor can receive, which determines the details, layers, and features of the captured image.

[0044] High Dynamic Range (HDR) is the ratio of the maximum measurable light intensity to the minimum measurable light intensity. It can also be defined as the ratio of the number of pixel noise electrons when the pixel well capacity is saturated to the number under no light conditions, expressed in decibels (dB). High dynamic range is usually achieved by increasing full well capacity, reducing readout noise, logarithmic response technology, large and small full well technology, and multiple exposure technology.

[0045] Compared with area array image sensors, the working principle of TDI-CMOS image sensors is more special. It needs to "push-scan" the object to be photographed, and cannot take multiple shots. As a result, the single-segment TDI-CMOS image sensor can only choose a high-sensitivity (small capacitance) mode or a low-sensitivity (large capacitance) mode. Therefore, it cannot take into account a small amount of charge (corresponding to low-light scenes) and a large amount of charge (corresponding to high-light scenes) well, and the dynamic range is poor.

[0046] To solve this problem, the present invention provides a TDI-CMOS image sensor. The TDI-CMOS image sensor includes a first image acquisition unit and a second image acquisition unit formed on the same substrate. Since the sensitivity of the first image acquisition unit is higher than that of the second image acquisition unit, when the first image acquisition unit and the second image acquisition unit are used to simultaneously acquire images of the same scene, the dynamic range can be significantly improved. The final result image can have better dark details and bright details, and the image quality is better.

[0047] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0048] Figure 5 FIG. 1 is a top view of a TDI-CMOS image sensor according to an embodiment of the present invention. Figure 5 , the TDI-CMOS image sensor in the embodiment of the present invention may include:

[0049] Substrate 51;

[0050] And a first image acquisition unit 52 and a second image acquisition unit 53 are located on the substrate 51 .

[0051] Among them, the sensitivity of the first image acquisition unit 52 is higher than the sensitivity of the second image acquisition unit 53; the first image acquisition unit 52 and the second image acquisition unit 53 are used to acquire images of the same scene at the same time; the first image acquisition unit 52 and the second image acquisition unit 53 fuse the images acquired from the same scene as the final result image.

[0052] Since the sensitivity of the first image acquisition unit 52 is higher than that of the second image acquisition unit 53, the first image acquisition unit 52 can use high sensitivity to capture images with more dark details, and the second image acquisition unit 53 can use low sensitivity to capture images with more bright details, thereby improving the dynamic range of the TDI-CMOS image sensor, so that the final result image is an image with clear light and dark distinctions and better image quality.

[0053] In a specific implementation, the substrate 51 may be a silicon substrate. Integrating the first image acquisition unit 52 and the second image acquisition unit 53 on the same substrate can effectively reduce the size of the TDI-CMOS image sensor, and can also ensure that the high-sensitivity and low-sensitivity image acquisition units can capture the same position, which is conducive to the integration of the two, compared with integrating the first image acquisition unit 52 and the second image acquisition unit 53 on different substrates.

[0054] Figure 6 FIG. 5 is a schematic diagram of the structure of the first image acquisition unit 52 in one embodiment of the present invention. Figure 6, the first image acquisition unit 52 may include: a first pixel array 521, a plurality of first capacitor modules CS and a plurality of first pixel readout circuits 523; each column of pixel units in the first pixel array 521 is connected to a first pixel readout circuit 523 via a first capacitor module CS. The first image acquisition unit 52 may also include a first transmission tube TX1, and the image signal acquired by the same column of pixel units is converted into a charge through the photoelectric effect, and is transmitted to the first floating diffusion node and the first capacitor module CS through the first transmission tube TX1, and then transmitted to the first pixel readout circuit 523 by the first capacitor module CS, and the first pixel readout circuit 523 reads the pixel units of the column.

[0055] Specifically, the first pixel array 521 may be composed of a plurality of first eCCD pixel units eCCD1 distributed in an array. The signals collected by the first eCCD pixel units eCCD1 in each column are sequentially transmitted through the first transmission tube TX1 and the first capacitor module CS, and then transmitted to the first pixel readout circuit 523, and the first pixel readout circuit outputs the images collected by the eCCD pixel units eCCD1 in each column.

[0056] In a specific implementation, each of the first eCCD pixel units is a 2-phase CCD structure, a 3-phase CCD structure, or a 4-phase CCD structure. When the first eCCD pixel unit is a 2-phase CCD structure, the first eCCD pixel unit has two polysilicon electrodes. When the first eCCD pixel unit is a 3-phase CCD structure, the first eCCD pixel unit has three polysilicon electrodes. When the first eCCD pixel unit is a 4-phase CCD structure, the first eCCD pixel unit has four polysilicon electrodes.

[0057] In the first pixel array, the structures of the first eCCD pixel units may be the same, for example, they may all be 4-phase CCD structures. Regardless of the structure of the first eCCD pixel unit, each of the polysilicon electrodes has a one-to-one corresponding channel region in the substrate. The polysilicon electrodes are used to receive a corresponding driving voltage signal so that charges are transferred between the channel regions along a preset charge transfer direction.

[0058] Figure 7 FIG. 5 is a schematic diagram of a partial cross-sectional structure of a first image acquisition unit 52 in an embodiment of the present invention. Figure 7In one embodiment, the first eCCD pixel unit has four polysilicon electrodes, namely polysilicon electrode PH1 to polysilicon electrode PH4. The charge of the last first eCCD pixel unit in a column of the first pixel array is transmitted to the first floating diffusion node FD1 and the first capacitor module CS after passing through the first transmission tube TX1. The first capacitor module CS then transmits the stored charge to the connected first pixel readout circuit, which reads it out. A gate oxide layer 71 is provided below the first pixel array and the first transmission tube. The material of the gate oxide layer 71 is generally SiO 2 .

[0059] Figure 8 FIG. 5 is a schematic diagram of the structure of the second image acquisition unit 53 in one embodiment of the present invention. Figure 8 , the second image acquisition unit 53 may include: a second pixel array 531, a plurality of second capacitor modules CL and a plurality of second pixel readout circuits 533. Each column of pixel units in the second pixel array 531 is connected to a second pixel readout circuit 533 via a second capacitor module CL. The second image acquisition unit 53 may also include a second transmission tube TX2, and the charge obtained by converting the image signal acquired by each column of pixel units through the photoelectric effect is transmitted to the second floating diffusion node and the second capacitor module CL through the second transmission tube TX2, and then transmitted to the second pixel readout circuit 533 by the second capacitor module CL, and read out by the second pixel readout circuit.

[0060] Specifically, the second pixel array 531 may be composed of a plurality of second eCCD pixel units eCCD2 distributed in an array. The size of the second pixel array 531 may be the same as or different from that of the first pixel array. The structure of the second eCCD pixel unit eCCD2 may be the same as or different from that of the first eCCD pixel unit.

[0061] In a specific implementation, each of the second eCCD pixel units can be a 2-phase CCD structure, a 3-phase CCD structure, or a 4-phase CCD structure. When the second eCCD pixel unit is a 2-phase CCD structure, the second eCCD pixel unit has two polysilicon electrodes. When the second eCCD pixel unit is a 3-phase CCD structure, the second eCCD pixel unit has three polysilicon electrodes. When the second eCCD pixel unit is a 4-phase CCD structure, the second eCCD pixel unit has four polysilicon electrodes.

[0062] In the first pixel array, the structures of the second eCCD pixel units may be the same, for example, they may all be 4-phase CCD structures. Regardless of the structure of the second eCCD pixel units, each of the polysilicon electrodes has a one-to-one corresponding channel region in the substrate. The polysilicon electrodes are used to receive corresponding driving voltage signals so that charges are transferred between the channel regions along a preset charge transfer direction.

[0063] Fig. 9 FIG. 5 is a schematic diagram of a partial cross-sectional structure of the second image acquisition unit 53 in one embodiment of the present invention. Figure 7 In one embodiment, the second eCCD pixel unit may also have four polysilicon electrodes, namely polysilicon electrode PH1 to polysilicon electrode PH4. The charge of the last second eCCD pixel unit in a column of the second pixel array reaches the second floating diffusion node FD2 and the second capacitor module CL after passing through the second transmission tube TX2, and then is transmitted to the connected second pixel readout circuit, and is quantized and read out by the connected second pixel readout circuit. The second pixel array and the second transmission tube are also located in the gate oxide layer 71, and the gate oxide layer 71 is located above the substrate 50.

[0064] In a specific implementation, the first capacitor module affects the sensitivity of image acquisition by the first image acquisition unit. The smaller the value of the first capacitor module, the higher the sensitivity of image acquisition by the first image acquisition unit. Similarly, the second capacitor module affects the sensitivity of image acquisition by the second image acquisition unit. The smaller the value of the second capacitor module, the higher the sensitivity of image acquisition by the second image acquisition unit.

[0065] In an embodiment of the present invention, the capacitance value of the first capacitor module is smaller than the capacitance value of the second capacitor module, that is, the first capacitor module is a small capacitor and the second capacitor module is a large capacitor, thereby making the sensitivity of the first image acquisition unit higher than the sensitivity of the second image acquisition unit, thereby making it possible to integrate two image acquisition units with different sensitivities on the same substrate at the same time to improve the dynamic range.

[0066] In a specific implementation, the first capacitor module can be composed of a single capacitor, or a plurality of capacitors connected in series or in parallel. When the first capacitor module is composed of a plurality of capacitors connected in series, the total capacitance value decreases, and when the first capacitor module is composed of a plurality of capacitors connected in parallel, the total capacitance value increases.

[0067] In a specific implementation, the second capacitor module can be composed of a single capacitor, or a plurality of capacitors connected in series or in parallel. When the second capacitor module is composed of a plurality of capacitors connected in series, the total capacitance value decreases, and when the second capacitor module is composed of a plurality of capacitors connected in parallel, the total capacitance value increases.

[0068] In a specific implementation, the capacitance ratio of the first capacitor module to the second capacitor module can be allocated according to the dynamic range requirement. The smaller the capacitance value of the first capacitor module, the more dark details captured by the first image acquisition unit. The larger the capacitance value of the second capacitor module, the more bright details captured by the second image acquisition unit. For example, the capacitance ratio of the first capacitor module to the second capacitor module can be 1:2, 1:4, 1:8, 1:16, 1:32, 1:64, etc.

[0069] In one embodiment of the present invention, the ratio between the number of polysilicon electrodes in the first eCCD pixel unit and the number of polysilicon electrodes in the second eCCD pixel unit matches the brightness requirement of the final result image. In the same eCCD pixel unit, the more polysilicon electrodes there are, the greater the brightness of the image captured by the image acquisition unit, and after the image fusion, the brightness of the final result image is also greater.

[0070] In one embodiment of the present invention, the number of polysilicon electrodes in the first eCCD pixel unit is greater than the number of polysilicon electrodes in the second eCCD pixel unit. At this time, since the first capacitance of the first eCCD pixel unit is smaller, that is, the sensitivity is higher, therefore, compared with the second eCCD pixel unit, increasing the number of polysilicon electrodes in the first eCCD pixel unit can increase the full well capacity of the first eCCD pixel unit, thereby increasing the brightness of the image collected by the first image acquisition unit, thereby enabling the final result image to display more dark details and improve the quality of the final result image.

[0071] For example, the ratio between the number of polysilicon electrodes in the second eCCD pixel unit and the number of polysilicon electrodes in the first eCCD pixel unit can be set to 1:2, 1:4, 1:8, 1:16, 1:32, 1:64, etc.

[0072] In some embodiments, the ratio between the number of polysilicon electrodes in the second eCCD pixel unit and the number of polysilicon electrodes in the first eCCD pixel unit can also be set to 1:1. In this case, the brightness of the image captured by the first image acquisition unit is the same as the brightness of the image captured by the second image acquisition unit.

[0073] By using the TDI-CMOS image sensor in the embodiment of the present invention, two image acquisition units are integrated on the same substrate at the same time, so that image signals of two different spectral bands can be acquired, thereby improving the dynamic range. In addition, by changing the number of polysilicon electrodes in the eCCD pixel unit in the two image acquisition units, the brightness of the final result image can be changed, so that both the imaging effect in low light and the dynamic range in high light can be increased, and the details in dark and bright areas can be better distinguished.

[0074] In order to enable those skilled in the art to better understand and implement the present invention, the control method corresponding to the above-mentioned TDI-CMOS image sensor is described in detail below.

[0075] Reference Fig.10 The embodiment of the present invention further provides a control method of a TDI-CMOS image sensor, the method comprising:

[0076] Step 101, controlling the first image acquisition unit and the second image acquisition unit to simultaneously acquire images of the same scene;

[0077] Step 102: Fusing the images simultaneously acquired by the first image acquisition unit and the second image acquisition unit to obtain a final result image.

[0078] In a specific implementation, before controlling the first image acquisition unit and the second image acquisition unit to perform image acquisition, the number of polysilicon electrodes in the first eCCD pixel unit and the second eCCD pixel unit can be set according to actual brightness requirements, so that the final result image can fully display the captured dark details and bright details.

[0079] In a specific implementation, before controlling the first image acquisition unit and the second image acquisition unit to perform image acquisition, the capacitance values ​​of the first capacitor and the second capacitor can be set according to the dynamic range requirements, so that the final result image can capture more dark details and bright details.

[0080] In a specific implementation, the first image acquisition unit and the second image acquisition unit are integrated on the same substrate, so that the actual shooting scene can be more conveniently "push-scanned" for shooting. The first image acquisition unit and the second image acquisition unit simultaneously perform "push-scanned" shooting, so that the shooting images of the same scene can be obtained. The shooting images obtained by the two image acquisition units can be fused later to obtain the final result image.

[0081] The final result image can not only have more dark details and bright details, but also can fully display the details, and the image quality is better.

[0082] From the above content, it can be seen that the TDI-CMOS image sensor in the embodiment of the present invention adopts high and low sensitivity (large and small capacitors) technology and a design of two different levels (i.e., the number of polysilicon electrodes in the first eCCD pixel unit and the second eCCD pixel unit is different), which effectively improves the dynamic range, and can take into account the imaging effect under dark light and increase the dynamic range under high light.

[0083] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A TDI-CMOS image sensor, characterized in that: include: A first image acquisition unit and a second image acquisition unit located on the same substrate; Among them, the sensitivity of the first image acquisition unit is higher than the sensitivity of the second image acquisition unit; the first image acquisition unit and the second image acquisition unit are used to acquire images of the same scene at the same time; the images acquired by the first image acquisition unit and the second image acquisition unit for the same scene are fused as the final result image.

2. The TDI-CMOS image sensor according to claim 1, characterized in that: The first image acquisition unit includes: a first pixel array, a first capacitor module and a first pixel readout circuit; each column of pixel units in the first pixel array is connected to a first pixel readout circuit through a first capacitor module.

3. The TDI-CMOS image sensor according to claim 2, characterized in that: The first pixel array includes: a plurality of first eCCD pixel units distributed in an array; the first eCCD pixel unit is a 2-phase CCD structure, a 3-phase CCD structure or a 4-phase CCD structure.

4. The TDI-CMOS image sensor according to claim 2, characterized in that: The first image acquisition unit includes: a first floating diffusion node; and the first capacitor module is connected to the first pixel array through the first floating diffusion node.

5. The TDI-CMOS image sensor according to claim 2, characterized in that: The second image acquisition unit includes: a second pixel array, a second capacitor module and a second pixel readout circuit; each column of pixel units in the second pixel array is connected to a second pixel readout circuit through a second capacitor module; the capacitance value of the first capacitor module is less than the capacitance value of the second capacitor module.

6. The TDI-CMOS image sensor according to claim 5, characterized in that: The second pixel array includes: a plurality of second eCCD pixel units distributed in an array; the second eCCD pixel unit is a 2-phase CCD structure, a 3-phase CCD structure or a 4-phase CCD structure.

7. The TDI-CMOS image sensor according to claim 6, characterized in that: The ratio between the number of polysilicon electrodes in the first eCCD pixel unit and the number of polysilicon electrodes in the second eCCD pixel unit matches the brightness requirement of the final result image.

8. The TDI-CMOS image sensor according to claim 5, characterized in that: The second image acquisition unit includes: a second floating diffusion node; and the second capacitor module is connected to the second pixel array through the second floating diffusion node.

9. The TDI-CMOS image sensor according to claim 5, characterized in that: The ratio of the first capacitor module to the second capacitor module matches the dynamic range requirement of the TDI-CMOS image sensor.

10. A control method for the TDI-CMOS image sensor according to any one of claims 1 to 9, characterized in that: include: Controlling the first image acquisition unit and the second image acquisition unit to simultaneously acquire images of the same scene; The images simultaneously acquired by the first image acquisition unit and the second image acquisition unit are fused to obtain a final result image.

Images