Signal sampling circuit, photoelectric sensing device, fingerprint acquisition system and sampling method

Abstract

The embodiment of the present application provides a signal sampling circuit, a photoelectric sensor device, a fingerprint collection system and a sampling method. The signal sampling circuit includes: a photoelectric conversion unit for converting an optical signal into a first electrical signal; a sampling unit including a first switch module and a first charge storage module; the sampling unit is used for, in the sampling stage, the first end and the third end of the first switch module are turned on, and the first electrical signal of the photoelectric conversion unit is transmitted to the first charge storage module for storage as a corresponding charge; in the signal reading stage, the second end and the third end of the first switch module are turned on, and the first charge storage module outputs the first electrical signal to the signal processing unit according to the stored charge. The embodiment of the present application can expose a large area at the same time, and then divide the signal of the acquisition area into different areas, so that the signal of a large area at the same time can be collected, so as to ensure the quality of signal collection and improve the display effect.

Description

Technical Field

[0001] The present application relates to the technical field of signal processing circuits. Specifically, the present application relates to a signal sampling circuit, a photoelectric sensor device, a fingerprint collection system and a sampling method. Background Art

[0002] Due to the limited number of channels of IC (Integrated Circuit), the signal sampling circuit can only collect signals from a small area at the same time, and cannot collect signals from a large area at the same time. The current sampling method is to first expose area A, collect area A, then expose area B, collect area B, and collect signals from area B in sequence.

[0003] However, the signals collected by the existing signal sampling method are not signals at the same time, and the signal in area A may be earlier than the signals in other areas, resulting in a problem of poor display effect. Summary of the invention

[0004] In view of the shortcomings of the existing methods, the present application proposes a signal sampling circuit, a photoelectric sensor device, a fingerprint collection system and a sampling method to solve the technical problem that the existing signal sampling circuit in the prior art cannot collect signals of a large area at the same time, resulting in poor display effect.

[0005] In a first aspect, an embodiment of the present application provides a signal sampling circuit, comprising:

[0006] A photoelectric conversion unit, used for converting the optical signal into a first electrical signal;

[0007] The sampling unit includes a first switch module and a first charge storage module; the first end of the first switch module is electrically connected to the photoelectric conversion unit, and the second end of the first switch module is configured to be electrically connected to the signal processing unit; the third end of the first switch module is electrically connected to the first end of the first charge storage module; the second end of the first charge storage module is electrically connected to the first voltage end;

[0008] The sampling unit is used to, during a sampling phase, connect the first and third ends of the first switch module and disconnect the second and third ends of the first switch module, so that the first electrical signal of the photoelectric conversion unit is transmitted to the first charge storage module and stored as a corresponding charge; during a signal reading phase, disconnect the first and third ends of the first switch module and connect the second and third ends of the first switch module, so that the first charge storage module outputs a first electrical signal to the signal processing unit according to the stored charge.

[0009] In a possible implementation, the first switch module includes a first switch device and a second switch device;

[0010] The first end of the first switch device serves as the first end of the first switch module, and the second end of the second switch device serves as the second end of the first switch module;

[0011] The second end of the first switch device and the first end of the second switch device together serve as the third end of the first switch module.

[0012] In a possible implementation, the photoelectric conversion unit includes a photoelectric conversion module, a reset module, and a second switch module;

[0013] The first end and the second end of the photoelectric conversion module are electrically connected to the second voltage end and the first node respectively;

[0014] The first end, the second end, and the control end of the reset module are electrically connected to the third voltage end, the first node, and the reset signal line respectively;

[0015] The first end, the second end and the control end of the second switch module are electrically connected to the fourth voltage end, the first end of the first switch module and the first node respectively.

[0016] In a possible implementation, the photoelectric conversion unit further includes: a third switch module;

[0017] The first end, the second end and the control end of the third switch module are electrically connected to the second end of the second switch module, the first end of the first switch module and the first control signal line respectively.

[0018] In one possible implementation, the photoelectric conversion module includes a photodiode and a second charge storage module;

[0019] The cathode and anode of the photodiode are electrically connected to the first node and the second voltage terminal respectively;

[0020] The first end and the second end of the second charge storage module are electrically connected to the first node and the second voltage end respectively.

[0021] In a possible implementation, the first switch device and the second switch device are both thin film transistors;

[0022] The control ends of the first switch device and the second switch device are electrically connected to the second control signal line and the third control signal line respectively.

[0023] In a second aspect, an embodiment of the present application provides a photoelectric sensor device, including: a signal sampling circuit as in the first aspect.

[0024] In a third aspect, an embodiment of the present application provides a fingerprint collection system, comprising: a signal processing unit and a photoelectric sensor device as in the second aspect;

[0025] The signal processing unit is electrically connected to the second end of the first switch module, and is used to read the first electrical signal to obtain image information.

[0026] In a fourth aspect, an embodiment of the present application provides a display device, including: a fingerprint collection system as in the third aspect.

[0027] In a fifth aspect, an embodiment of the present application provides a signal sampling method, which is applied to the signal sampling circuit of the first aspect, including:

[0028] In the sampling phase, the first terminal and the third terminal of the first switch module are controlled to be turned on, and the second terminal and the third terminal of the first switch module are turned off, so that the first electrical signal of the photoelectric conversion unit is transmitted to the first charge storage module and stored as a corresponding charge;

[0029] In the signal reading phase, the first and third ends of the first switch module are controlled to be disconnected, and the second and third ends of the first switch module are controlled to be connected, so that the first charge storage module outputs a first electrical signal to the signal processing unit according to the stored charge.

[0030] In a possible implementation, controlling the first end and the third end of the first switch module to be turned on, and the second end and the third end of the first switch module to be turned off, includes:

[0031] Control the first end and the second end of the first switch device of the first switch module to be turned on, and the first end and the second end of the second switch device of the first switch module to be turned off; the first end of the first switch device serves as the first end of the first switch module, and the second end of the second switch device serves as the second end of the first switch module; the second end of the first switch device and the first end of the second switch device serve together as the third end of the first switch module;

[0032] Controlling the first end and the third end of the first switch module to be disconnected, and the second end and the third end of the first switch module to be connected, comprises:

[0033] The first terminal and the second terminal of the first switch device are controlled to be disconnected, and the first terminal and the second terminal of the second switch device are controlled to be connected.

[0034] In a possible implementation, before the sampling stage, the following steps are also included:

[0035] In the reset stage, the control end of the reset module receives the first voltage signal, the first end and the second end of the reset module are turned on, and the third voltage of the third voltage end resets the control end of the second switch module and the photoelectric conversion module; the photoelectric conversion unit includes a photoelectric conversion module, a reset module and a second switch module; the first end and the second end of the photoelectric conversion module are electrically connected to the second voltage end and the first node, respectively; the first end, the second end and the control end of the reset module are electrically connected to the third voltage end, the first node and the reset signal line, respectively; the first end, the second end and the control end of the second switch module are electrically connected to the fourth voltage end, the first end of the first switch module and the first node, respectively;

[0036] In the exposure phase, the first terminal and the second terminal of the reset module are disconnected, and the photoelectric conversion unit converts the optical signal into a first electrical signal.

[0037] The beneficial technical effects brought about by the technical solution provided by the embodiment of the present application include:

[0038] In the sampling unit of the signal sampling circuit of the embodiment of the present application, in the sampling stage, the first end and the third end of the first switch module are turned on, the second end and the third end of the first switch module are turned off, and the first electrical signal of the photoelectric conversion unit is stored in the first charge storage module; in the signal reading stage, the first end and the third end of the first switch module are turned off, the second end and the third end of the first switch module are turned on, and the first charge storage module outputs the first electrical signal to the signal processing unit according to the stored charge. Therefore, the embodiment of the present application can control the first charge storage module to be electrically connected with the photoelectric conversion unit or the signal processing unit through the first switch module, and the first electrical signal is stored through the first charge storage module, thereby avoiding the problem that in the existing signal sampling circuit, when the partition signal is collected, the signal is not read after the switch device TFT is turned on, and it will be in a floating state, and the charge sharing problem of the parasitic capacitance on the data signal line is avoided. Therefore, the embodiment of the present application can expose a large area at the same time, and re-partition the signal of the acquisition area, so that the signal of the large area at the same time can be collected, the signal collection quality is guaranteed, and the display effect is improved.

[0039] Additional aspects and advantages of the present application will be partially given in the following description, which will become apparent from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0041] Figure 1 A schematic diagram of the structure of a signal sampling circuit provided in an embodiment of the present application;

[0042] Figure 2 A schematic diagram of the structure of a photoelectric conversion unit provided in an embodiment of the present application;

[0043] Figure 3 A schematic diagram of the structure of another signal sampling circuit provided in an embodiment of the present application;

[0044] Figure 4 A schematic diagram of the structure of another signal sampling circuit provided in an embodiment of the present application;

[0045] Figure 5 A schematic diagram of the structure of a fingerprint collection system provided in an embodiment of the present application;

[0046] Figure 6 A flow chart of a signal sampling method provided in an embodiment of the present application;

[0047] Figure 7 A flowchart of another signal sampling method provided in an embodiment of the present application.

[0048] Reference numerals:

[0049] 110- signal sampling circuit;

[0050] 111 - photoelectric conversion unit, 101 - photoelectric conversion module, 1011 - photodiode, 1012 - second charge storage module;

[0051] 1112 - reset module, 1113 - second switch module, 1114 - third switch module;

[0052] 112 - sampling unit, 1121 - first switch module, 1122 - first charge storage module;

[0053] 10- Fingerprint collection system;

[0054] 100-photoelectric sensor device;

[0055] 200- signal processing unit;

[0056] SW1-first switch device, SW2-second switch device;

[0057] M1-third switch device, M2-fourth switch device, M3-fifth switch device;

[0058] A-first node, C1-first capacitor, Cpd-second capacitor. DETAILED DESCRIPTION

[0059] The present application is described in detail below, and examples of embodiments of the present application are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar components or components with the same or similar functions. In addition, if the detailed description of the known technology is unnecessary for the features of the present application shown, it will be omitted. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be interpreted as limiting the present application.

[0060] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with those in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as here.

[0061] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be an intermediate element. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0062] The inventor of the present application has conducted research and found that the signals collected by the existing signal sampling method are not signals at the same time. Instead, area A is exposed first, area A is collected, area B is exposed, area B is collected, and the partitioned signal collection is realized in sequence. At present, without sacrificing exposure time or increasing the area of ​​the IC, the IC can read a larger display area. Currently, regardless of PPS (Passive Pixel Sensor CMOS) or APS (ActivePixel Sensor CMOS), TFT (Thin Film Transistor) will be turned on multiple times. After the switching device TFT is turned on, the signal is not read and will be in a floating state, which will cause the problem of charge sharing of the parasitic capacitance on the data signal line, thereby reducing the image quality.

[0063] Since the signal sampling circuit can only collect data from a small area at the same time, the signal in area A will appear earlier than the signal in other areas. In the dark state, the dead pixels in the display area corresponding to areas A and B will have the problem of "comet smear"; in the bright state, the image quality of the area collected later will be significantly reduced, with smear problems and poor display effects. At the same time, if the number of IC channels is increased to achieve simultaneous signal collection in a large area, the cost will increase dramatically.

[0064] The signal sampling circuit, photoelectric sensor device, fingerprint collection system and sampling method provided in this application are intended to solve the above technical problems in the prior art.

[0065] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments.

[0066] The present application embodiment provides a signal sampling circuit. Figure 1 As shown, the signal sampling circuit 110 includes: a photoelectric conversion unit 111 and a sampling unit 112 .

[0067] The photoelectric conversion unit 111 is used to convert an optical signal into a first electrical signal.

[0068] The sampling unit 112 includes a first switch module 1121 and a first charge storage module 1122; a first end of the first switch module 1121 is electrically connected to the photoelectric conversion unit 111. Figure 5 As shown, the second end of the first switch module 1121 is configured to be electrically connected to the signal processing unit 200 .

[0069] The third end of the first switch module 1121 is electrically connected to the first end of the first charge storage module 1122 ; the second end of the first charge storage module 1122 is electrically connected to the first voltage end.

[0070] The sampling unit 112 is used to, during the sampling phase, turn on the first and third ends of the first switch module 1121 and disconnect the second and third ends of the first switch module 1121, so that the first electrical signal of the photoelectric conversion unit 111 is transmitted to the charge corresponding to the storage layer of the first charge storage module 1122; during the signal reading phase, turn on the first and third ends of the first switch module 1121 and disconnect the second and third ends of the first switch module 1121, so that the first charge storage module 1122 outputs the first electrical signal to the signal processing unit 200 according to the stored charge.

[0071] Optionally, the first electrical signal of the photoelectric conversion unit 111 is stored in the first charge storage module 1122, that is, the first charge storage module 1122 stores charge; the first charge storage module 1122 outputs the first electrical signal according to the stored charge, that is, the first charge storage module 1122 releases charge.

[0072] In the embodiment of the present application, the first switch module 1121 can be used to control the first charge storage module 1122 to be electrically connected to the photoelectric conversion unit 111 or the signal processing unit 200, and the first charge storage module 1122 is used to store the first electrical signal, thereby avoiding the problem in the existing signal sampling circuit 110 that when collecting partitioned signals, the signal is not read after the switch device TFT is turned on, and is in a floating state, and the parasitic capacitance charge on the data signal line is redistributed. Therefore, the embodiment of the present application can expose a large area at the same time, and collect signals in the partitioned areas without sacrificing exposure time. Signals of a large area at the same time can be collected, thereby ensuring the signal collection quality and improving the display effect.

[0073] In some embodiments, in combination Figure 2 and Figure 4 As shown, the photoelectric conversion unit 111 includes a photoelectric conversion module 101 , a reset module 1112 and a second switch module 1113 .

[0074] The first end and the second end of the photoelectric conversion module 101 are electrically connected to the second voltage end and the first node A respectively.

[0075] The first terminal, the second terminal, and the control terminal of the reset module 1112 are electrically connected to the third voltage terminal, the first node A, and the reset signal line, respectively.

[0076] The first end, the second end and the control end of the second switch module 1113 are electrically connected to the fourth voltage end, the first end of the first switch module 1121 and the first node A, respectively.

[0077] Optionally, the photoelectric conversion module 101 is used to convert the optical signal into a first electrical signal during the exposure phase. The reset module 1112 is used to, during the reset phase, the control end of the reset module 1112 receives a first voltage signal, the first end and the second end of the reset module 1112 are turned on, and the third voltage of the third voltage end resets the control end of the second switch module 1113 and the photoelectric conversion module 101.

[0078] In some embodiments, see Figure 2 As shown, the photoelectric conversion unit 111 further includes: a third switch module 1114 .

[0079] The first end, the second end and the control end of the third switch module 1114 are electrically connected to the second end of the second switch module 1113 , the first end of the first switch module 1121 and the first control signal line, respectively.

[0080] Optionally, the third switch module 1114 is configured to receive a control signal of a first control signal line at a control end of the third switch module 1114 during a sampling phase, so that a first end and a second end of the third switch module 1114 are turned on.

[0081] Alternatively, as an example, see Figure 3 As shown, the photoelectric conversion unit 111 includes a photoelectric conversion module 101, a reset module 1112, a second switch module 1113 and a third switch module 1114; the sampling unit 112 includes a first switch module 1121 and a first charge storage module 1122. The specific electrical connection relationship is as follows Figure 1 and Figure 2 shown.

[0082] In some embodiments, see Figure 3 and Figure 4 As shown, the photoelectric conversion module 101 includes a photodiode 1011 and a second charge storage module 1012 .

[0083] The cathode and the anode of the photodiode 1011 are electrically connected to the first node A and the second voltage terminal, respectively.

[0084] The first terminal and the second terminal of the second charge storage module 1012 are electrically connected to the first node A and the second voltage terminal respectively.

[0085] Optionally, the photodiode 1011 is used to convert the optical signal into a first electrical signal, the second charge storage module 1012 is used to store charges, and the second voltage terminal is grounded.

[0086] In some embodiments, see Figure 4 As shown, the first switch module 1121 includes a first switch device SW1 and a second switch device SW2.

[0087] The first end of the first switch device SW1 serves as the first end of the first switch module 1121 , and the second end of the second switch device SW2 serves as the second end of the first switch module 1121 .

[0088] The second end of the first switch device SW1 and the first end of the second switch device SW2 together serve as the third end of the first switch module 1121 .

[0089] Optionally, when the first switch device SW1 is turned on and the second switch device SW2 is turned off, the first charge storage module 1122 stores the first electrical signal in the form of charge; when the first switch device SW1 is turned off and the second switch device SW2 is turned on, the first charge storage module 1122 outputs the stored charge in the form of a first electrical signal to the signal processing unit 200. The first electrical signal is used to represent image information, thereby realizing the process of sending image information.

[0090] In some embodiments, the first switching device SW1 and the second switching device SW2 are both thin film transistors.

[0091] The control terminals of the first switch device SW1 and the second switch device SW2 are electrically connected to the second control signal line and the third control signal line, respectively.

[0092] Alternatively, see Figure 4 As shown, as an example, the reset module 1112 includes a third switch device M1, the second switch module 1113 includes a fourth switch device M2, and the third switch module 1114 includes a fifth switch device M3. The photodiode 1011 includes a diode PIN, the second charge storage module 1012 includes a second capacitor Cpd, and the first charge storage module 1122 includes a first capacitor C1.

[0093] Optionally, the first voltage terminal and the second voltage terminal are both grounded, the third voltage terminal and the fourth voltage terminal both provide a VCC voltage, the first control signal line is Sel, and the first electrical signal is Vout.

[0094] Optionally, each switch device is a thin film transistor, and the control terminal of any switch device is the gate of the thin film transistor. If the first terminal of the thin film transistor is the source of the thin film transistor, the second terminal of the thin film transistor is the drain of the thin film transistor; if the first terminal of the thin film transistor is the drain of the thin film transistor, the second terminal of the thin film transistor is the source of the thin film transistor.

[0095] Based on the same inventive concept, an embodiment of the present application provides a photoelectric sensor device 100, including: a signal sampling circuit 110 as in any embodiment of the present application.

[0096] Optionally, the photoelectric sensing device 100 may be an active pixel sensor APS or a passive pixel sensor PPS, that is, the signal sampling circuit 110 of the embodiment of the present application may be applicable to both APS and PPS.

[0097] Optionally, the photoelectric sensing device 100 may be an APS with LTPS (Low Temperature Poly-silicon) / IGZO (indium gallium zinc oxide) material as TFT.

[0098] Based on the same inventive concept, the present application embodiment provides a fingerprint collection system 10, see Figure 5 As shown, the fingerprint collection system 10 includes: a photoelectric sensor device 100 and a signal processing unit 200 as in any embodiment of the present application.

[0099] The signal processing unit 200 is electrically connected to the second end of the first switch module 1121 for reading the first electrical signal to obtain image information.

[0100] Optionally, the photoelectric sensing device 100 includes the signal sampling circuit 110 of any embodiment of the present application.

[0101] Based on the same inventive concept, an embodiment of the present application provides a display device, including: a fingerprint collection system 10 as in any embodiment of the present application.

[0102] Optionally, the display device may be a liquid crystal display (LCD-Liquid Crystal Display).

[0103] The first charge storage module 1122 of the sampling unit 112 of the embodiment of the present application can store the first electrical signal, so that a large area can be exposed simultaneously, without sacrificing exposure time and without increasing the cost of IC, thereby doubling the reading area of ​​the display panel Panel.

[0104] The fingerprint collection system 10 and the display device provided in the embodiments of the present application have the same inventive concept and the same beneficial effects as the embodiments of the signal sampling circuits 110 described above. The contents not shown in detail in the fingerprint collection system 10 and the display device can be referred to the embodiments described above, and will not be repeated here.

[0105] Based on the same inventive concept, the embodiment of the present application provides a signal sampling method, which is applied to the signal sampling circuit 110 of any embodiment of the present application, see Figure 6 As shown, the signal sampling method includes: step S601 to step S602.

[0106] S601. In a sampling phase, the first and third ends of the first switch module 1121 are controlled to be turned on, and the second and third ends of the first switch module 1121 are turned off, so that the first electrical signal of the photoelectric conversion unit 111 is transmitted to the first charge storage module 1122 and stored as corresponding charges.

[0107] In some embodiments, in combination Figure 4 As shown, the first end of the first switch device SW1 serves as the first end of the first switch module 1121, and the second end of the second switch device SW2 serves as the second end of the first switch module 1121; the second end of the first switch device SW1 and the first end of the second switch device SW2 serve together as the third end of the first switch module 1121.

[0108] Optionally, controlling the first end and the third end of the first switch module 1121 to be turned on, and the second end and the third end of the first switch module 1121 to be turned off includes:

[0109] The first terminal and the second terminal of the first switch device SW1 of the first switch module 1121 are controlled to be turned on, and the first terminal and the second terminal of the second switch device SW2 of the first switch module 1121 are controlled to be turned off.

[0110] Controlling the first end and the third end of the first switch module 1121 to be disconnected, and the second end and the third end of the first switch module 1121 to be connected, comprises:

[0111] The first terminal and the second terminal of the first switch device SW1 are controlled to be disconnected, and the first terminal and the second terminal of the second switch device SW2 are controlled to be turned on.

[0112] S602, in the signal reading phase, controlling the first end and the third end of the first switch module 1121 to be disconnected, and the second end and the third end of the first switch module 1121 to be connected, so that the first charge storage module 1122 outputs a first electrical signal to the signal processing unit 200 according to the stored charge.

[0113] In some embodiments, before the sampling stage, the method further includes:

[0114] In the reset stage, the control end of the reset module 1112 receives the first voltage signal, the first end and the second end of the reset module 1112 are turned on, and the third voltage of the third voltage end resets the control end of the second switch module 1113 and the photoelectric conversion module 101; the photoelectric conversion unit 111 includes the photoelectric conversion module 101, the reset module 1112 and the second switch module 1113; the first end and the second end of the photoelectric conversion module 101 are electrically connected to the second voltage end and the first node A, respectively; the first end, the second end and the control end of the reset module 1112 are electrically connected to the third voltage end, the first node A, and the reset signal line, respectively; the first end, the second end and the control end of the second switch module 1113 are electrically connected to the fourth voltage end, the first end of the first switch module 1121, and the first node A, respectively;

[0115] In the exposure phase, the first terminal and the second terminal of the reset module 1112 are disconnected, and the photoelectric conversion unit 111 converts the optical signal into a first electrical signal.

[0116] Optionally, as an example, in combination Figure 4 and Figure 7 As shown, an embodiment of the present application provides a signal sampling method, including: step S701 to step S704.

[0117] S701 , in the reset stage, the control end of the reset module 1112 receives a first voltage signal, the first end and the second end of the reset module 1112 are turned on, and the third voltage of the third voltage end resets the control end of the second switch module 1113 and the photoelectric conversion module 101 .

[0118] Optionally, the control end of the third switching device M1 receives the first voltage signal, the first end and the second end of the third switching device M1 are turned on, the VCC voltage of the third voltage end is output to the first node A, the control end of the fourth switching device M2 and the second capacitor Cpd of the photoelectric conversion module 101 are reset, and the signal is initialized.

[0119] Optionally, in the reset phase, the fourth switch device M2 , the fifth switch device M3 , the first switch device SW1 , and the second switch device SW2 are all in a closed state.

[0120] S702 , in the exposure phase, the first end and the second end of the reset module 1112 are disconnected, and the photoelectric conversion unit 111 converts the optical signal into a first electrical signal.

[0121] Optionally, in the exposure phase, all switch devices in the signal sampling circuit 110 are turned off, that is, the first switch device SW1, the second switch device SW2, the third switch device M1, the fourth switch device M2 and the fifth switch device M3 are all in an off state.

[0122] Optionally, in the exposure phase, the second charge storage module 1012 accumulates charges, and the photodiode 1011 converts the optical signal into a first electrical signal.

[0123] S703 , in the sampling phase, the first and third ends of the first switch module 1121 are controlled to be turned on, and the second and third ends of the first switch module 1121 are turned off, so that the first electrical signal of the photoelectric conversion unit 111 is transmitted to the first charge storage module 1122 and stored as corresponding charges.

[0124] Optionally, in the sampling phase, the first and second ends of the first switch device SW1 are turned on, and the first and second ends of the second switch device SW2 are turned off, so that the first electrical signal of the photoelectric conversion unit 111 is transmitted to the first capacitor C1 and stored as corresponding charges.

[0125] Optionally, in the sampling phase, the control end of the first switch device SW1 receives a first voltage signal, and the first and second ends of the first switch device SW1 are turned on; the control end of the second switch device SW2 receives a second voltage signal, and the first and second ends of the second switch device SW2 are turned off.

[0126] Optionally, the first voltage signal is a high level signal, and the second voltage signal is a low level signal.

[0127] Optionally, the fourth switch device M2 is a source follower. In the sampling phase, the fourth switch device M2 is turned on, and the fifth switch device M3 is turned on under the control of the control signal of the first control signal line.

[0128] Optionally, when the control signal of the first control signal line is at a high level, the fifth switch device M3 is turned on.

[0129] S704, in the signal reading phase, control the first end and the third end of the first switch module 1121 to be disconnected, and the second end and the third end of the first switch module 1121 to be connected, so that the first charge storage module 1122 outputs a first electrical signal to the signal processing unit 200 according to the stored charge.

[0130] Optionally, in the signal reading stage, the first end and the second end of the first switching device SW1 are disconnected, and the first end and the second end of the second switching device SW2 are turned on, so that the first capacitor C1 outputs a first electrical signal to the signal processing unit 200 according to the stored charge, thereby facilitating the signal processing unit 200 to read the first electrical signal.

[0131] Optionally, in the sampling phase, the control end of the first switch device SW1 receives the second voltage signal, and the first and second ends of the first switch device SW1 are disconnected; the control end of the second switch device SW2 receives the first voltage signal, and the first and second ends of the second switch device SW2 are connected.

[0132] Optionally, in the sampling phase, the first switch device SW1 , the third switch device M1 , the fourth switch device M2 , and the fifth switch device M3 in the signal sampling circuit 110 are all in a closed state.

[0133] Optionally, the signal processing unit 200 reads the first electrical signal, including: converting the first electrical signal through an analog-to-digital converter ADC to obtain image information.

[0134] The signal sampling method provided in the embodiment of the present application has the same inventive concept and the same beneficial effects as the embodiments of the signal sampling circuit 110 described above. The contents not shown in detail in the signal sampling method can be referred to the embodiments described above and will not be repeated here.

[0135] Those skilled in the art will appreciate that the various operations, methods, steps, measures, and schemes in the processes discussed in this application may be alternated, altered, combined, or deleted. Further, other steps, measures, and schemes in the various operations, methods, and processes discussed in this application may also be alternated, altered, rearranged, decomposed, combined, or deleted. Further, the steps, measures, and schemes in the prior art that are similar to those disclosed in this application may also be alternated, altered, rearranged, decomposed, combined, or deleted.

[0136] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0137] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0138] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0139] The above description is only a partial implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A signal sampling circuit, characterized in that: include: A photoelectric conversion unit, used for converting the optical signal into a first electrical signal; A sampling unit, comprising a first switch module and a first charge storage module; The first end of the first switch module is electrically connected to the photoelectric conversion unit, and the second end of the first switch module is configured to be electrically connected to the signal processing unit; the third end of the first switch module is electrically connected to the first end of the first charge storage module; the second end of the first charge storage module is electrically connected to the first voltage end; The sampling unit is used for, in a sampling phase, the first end and the third end of the first switch module are turned on, and the second end and the third end of the first switch module are turned off, so that the first electrical signal of the photoelectric conversion unit is transmitted to the first charge storage module and stored as a corresponding charge; in a signal reading phase, the first end and the third end of the first switch module are turned off, and the second end and the third end of the first switch module are turned on, so that the first charge storage module outputs the first electrical signal to the signal processing unit according to the stored charge; The photoelectric conversion unit includes a photoelectric conversion module, a reset module and a second switch module; The first end and the second end of the photoelectric conversion module are electrically connected to the second voltage end and the first node respectively; The first end, the second end, and the control end of the reset module are electrically connected to the third voltage end, the first node, and the reset signal line respectively; The first end, the second end and the control end of the second switch module are electrically connected to the fourth voltage end, the first end of the first switch module and the first node respectively.

2. The signal sampling circuit according to claim 1, characterized in that: The first switch module includes a first switch device and a second switch device; The first end of the first switch device serves as the first end of the first switch module, and the second end of the second switch device serves as the second end of the first switch module; The second end of the first switch device and the first end of the second switch device together serve as the third end of the first switch module.

3. The signal sampling circuit according to claim 1, characterized in that: The photoelectric conversion unit further includes: a third switch module; The first end, the second end and the control end of the third switch module are electrically connected to the second end of the second switch module, the first end of the first switch module and the first control signal line respectively.

4. The signal sampling circuit according to claim 1, characterized in that: The photoelectric conversion module includes a photodiode and a second charge storage module; The cathode and anode of the photodiode are electrically connected to the first node and the second voltage terminal respectively; The first end and the second end of the second charge storage module are electrically connected to the first node and the second voltage end respectively.

5. The signal sampling circuit according to claim 2, characterized in that: The first switching device and the second switching device are both thin film transistors; The control ends of the first switch device and the second switch device are electrically connected to the second control signal line and the third control signal line respectively.

6. A photoelectric sensor device, characterized in that: include: The signal sampling circuit according to any one of claims 1 to 5.

7. A fingerprint collection system, characterized in that: include: A signal processing unit and a photoelectric sensing device as claimed in claim 6; The signal processing unit is electrically connected to the second end of the first switch module, and is used to read the first electrical signal to obtain image information.

8. A display device, characterized in that: include: The fingerprint collection system as claimed in claim 7.

9. A signal sampling method, applied to the signal sampling circuit according to any one of claims 1 to 5, characterized in that: include: In the sampling phase, the first terminal and the third terminal of the first switch module are controlled to be turned on, and the second terminal and the third terminal of the first switch module are turned off, so that the first electrical signal of the photoelectric conversion unit is transmitted to the first charge storage module and stored as a corresponding charge; In the signal reading stage, the first end and the third end of the first switch module are controlled to be disconnected, and the second end and the third end of the first switch module are controlled to be connected, so that the first charge storage module outputs the first electrical signal to the signal processing unit according to the stored charge.

10. The signal sampling method according to claim 9, characterized in that: The controlling the first end and the third end of the first switch module to be turned on, and the second end and the third end of the first switch module to be turned off, comprises: Controlling the first end and the second end of the first switch device of the first switch module to be turned on, and the first end and the second end of the second switch device of the first switch module to be turned off; the first end of the first switch device serves as the first end of the first switch module, and the second end of the second switch device serves as the second end of the first switch module; the second end of the first switch device and the first end of the second switch device serve together as the third end of the first switch module; The controlling the first end and the third end of the first switch module to be disconnected and the second end and the third end of the first switch module to be connected includes: The first end and the second end of the first switch device are controlled to be disconnected, and the first end and the second end of the second switch device are controlled to be connected.

11. The signal sampling method according to claim 9, characterized in that: Before the sampling stage, it also includes: In the reset stage, the control end of the reset module receives the first voltage signal, the first end and the second end of the reset module are turned on, and the third voltage of the third voltage end resets the control end of the second switch module and the photoelectric conversion module; the photoelectric conversion unit includes a photoelectric conversion module, a reset module and a second switch module; the first end and the second end of the photoelectric conversion module are electrically connected to the second voltage end and the first node, respectively; the first end, the second end and the control end of the reset module are electrically connected to the third voltage end, the first node and the reset signal line, respectively; the first end, the second end and the control end of the second switch module are electrically connected to the fourth voltage end, the first end of the first switch module and the first node, respectively; In the exposure phase, the first end and the second end of the reset module are disconnected, and the photoelectric conversion unit converts the optical signal into the first electrical signal.

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