Fingerprint detection module, electronic device, detection method, device and storage medium

Abstract

The present disclosure relates to a fingerprint detection module, equipment, method, device and storage medium. The module includes: at least one fingerprint recognition component and a collection component; the fingerprint recognition component includes: a reset unit, a photosensitive unit and a follower unit; the reset unit switches the output voltage of the photosensitive unit to an initial voltage according to a reset signal; the photosensitive unit, after the output voltage is the initial voltage, receives the reflected light of the fingerprint to be detected and accumulates charge, and outputs a first electrical signal according to the first level of a pulse control signal currently received; outputs a second electrical signal according to the first level of a next received pulse control signal; the difference between the second electrical signal and the first electrical signal indicates the accumulated charge between the photosensitive unit outputting the second electrical signal and the outputting the first electrical signal; the follower unit receives and forms a first voltage according to the first electrical signal, and receives and forms a second voltage according to the second electrical signal; the collection component receives the first voltage and the second voltage, and obtains the fingerprint to be detected according to the difference between the second voltage and the first voltage.

Description

Technical Field

[0001] The present disclosure relates to the field of fingerprint detection technology, and in particular to a fingerprint detection module, electronic equipment, detection method, device and storage medium. Background Art

[0002] In recent years, in-screen fingerprint detection based on touch screens has gradually become a trend. In-screen fingerprint detection is to set the fingerprint sensor in the display screen of the mobile terminal. Users can collect fingerprint information by touching the relevant area of ​​the display screen, and realize identity authentication fingerprint detection based on the fingerprint information.

[0003] However, when the related technology performs in-screen fingerprint detection, the accuracy of fingerprint detection is low and it is difficult to meet the user experience. Summary of the invention

[0004] In view of this, the present disclosure provides a fingerprint detection module, an electronic device, a detection method, a device and a storage medium.

[0005] According to a first aspect of an embodiment of the present disclosure, there is provided a fingerprint detection module, comprising: at least one fingerprint recognition component, and a collection component;

[0006] The fingerprint recognition component includes: a reset unit, a photosensitive unit and a following unit;

[0007] The reset unit is electrically connected to the output end of the photosensitive unit and is used to receive a reset signal and switch the voltage of the output end of the photosensitive unit from a current voltage to an initial voltage according to the reset signal;

[0008] The photosensitive unit is electrically connected to the following unit, and is used to receive a pulse control signal after the voltage at the output end of the photosensitive unit is switched to the initial voltage, and output a first electrical signal based on the first level of the pulse control signal; when the received pulse control signal is at a second level, receive the reflected light of the fingerprint to be detected and accumulate charges; and form a second electrical signal according to the accumulated charges and the first level of the next pulse control signal;

[0009] The following unit is electrically connected to the output end of the photosensitive unit, and is used to receive and output a first voltage according to the first electrical signal, and to receive and output a second voltage according to the second electrical signal;

[0010] The acquisition component is electrically connected to the fingerprint recognition component, and is used to receive the first voltage and the second voltage respectively, and obtain the fingerprint to be detected according to the difference between the second voltage and the first voltage.

[0011] According to a second aspect of an embodiment of the present disclosure, there is provided an electronic device, including:

[0012] A display module, comprising: a display array composed of a plurality of pixel units;

[0013] As in the fingerprint detection module provided by the first aspect of the embodiment of the present disclosure, the photosensitive unit of the fingerprint detection module is exposed through the gap between the pixel units;

[0014] The fingerprint detection module is used to obtain the fingerprint to be detected.

[0015] According to a third aspect of an embodiment of the present disclosure, a fingerprint detection method is provided. The method is used in an electronic device including the fingerprint detection module provided in the first aspect of the embodiment of the present disclosure, and the method includes:

[0016] Inputting a reset signal to the fingerprint detection module, wherein the reset signal is used to switch the output terminal voltage of the photosensitive unit from the current voltage to the initial voltage;

[0017] After the voltage at the output end of the photosensitive unit is switched to the initial voltage, a first level of a pulse control signal is input; wherein, after the voltage at the output end of the photosensitive unit is switched to the initial voltage, the photosensitive unit receives reflected light of the fingerprint to be detected and accumulates electric charge; the photosensitive unit outputs a first electrical signal according to the first level of the currently received pulse control signal, and the first electrical signal is used to form a first voltage;

[0018] inputting a second level of the pulse control signal;

[0019] After inputting the second level of the pulse control signal, inputting the first level of the next pulse control signal; wherein the photosensitive unit outputs a second electrical signal according to the first level of the next pulse control signal received, and the second electrical signal is used to form a second voltage; the difference between the second electrical signal and the first electrical signal indicates the charge accumulated by the photosensitive unit between the moment when the second electrical signal is output and the moment when the first electrical signal is output;

[0020] The fingerprint to be detected is obtained according to the difference between the second voltage and the first voltage.

[0021] According to a fourth aspect of an embodiment of the present disclosure, a detection device is provided, including:

[0022] processor;

[0023] a memory for storing processor-executable instructions;

[0024] Wherein, the processor is configured to: when executing the executable instructions, implement the steps in the method provided in the third aspect of the embodiment of the present disclosure.

[0025] According to the fifth aspect of an embodiment of the present disclosure, a non-temporary computer-readable storage medium is provided. When the instructions in the storage medium are executed by a processor of a mobile terminal, the mobile terminal is enabled to execute the steps in the method provided in the third aspect of an embodiment of the present disclosure.

[0026] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:

[0027] The disclosed embodiment provides a reset unit, which can switch the output voltage of the photosensitive unit from the current voltage to the initial voltage; the photosensitive unit can, after the output voltage is switched to the initial voltage, detect the reflected light of the fingerprint to be detected and accumulate charges, and output a first electrical signal based on the first level of the currently received pulse control signal, and output a second electrical signal based on the first level of the next received pulse control signal. The following unit directly outputs a first voltage to the acquisition component according to the received first electrical signal, and directly outputs a second voltage to the acquisition component according to the received second electrical signal, and the acquisition component obtains the fingerprint to be detected according to the difference between the second voltage and the first voltage to achieve fingerprint detection.

[0028] Compared with the active pixel sensor circuit that controls the output of the first voltage and the second voltage by setting a selection transistor, the photosensitive unit provided in the embodiment of the present disclosure receives the reflected light of the fingerprint to be detected and accumulates charge after the voltage at the output end of the photosensitive unit is switched to the initial voltage, outputs the first electrical signal based on the first level of the currently received pulse control signal, and outputs the second electrical signal based on the first level of the next received pulse control signal. There is no need to additionally set a selection transistor, and the first voltage and the second voltage can be formed according to the first electrical signal through the follower unit, and the first voltage and the second voltage can be formed according to the second electrical signal, and the acquisition component can be used to obtain the fingerprint to be detected according to the difference between the second voltage and the first voltage. While realizing fingerprint detection, the structure of the fingerprint recognition component is simplified, which is beneficial to reducing the cost of the fingerprint detection module.

[0029] In addition, by reducing the number of row selection transistors, the area in the fingerprint recognition module originally used to set the row selection transistors can be used to set the photosensitive surface of the photosensitive unit, which is beneficial to increase the area in which the photosensitive unit can receive the reflected light of the fingerprint to be detected, thereby increasing the range of the reflected light that the photosensitive unit can receive, thereby improving the signal-to-noise ratio of the fingerprint detection module and the accuracy of the acquired fingerprint to be detected.

[0030] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0032] Figure 1 This is a partial circuit diagram of an active pixel sensor.

[0033] Figure 2 The figure is a block diagram of a fingerprint detection module according to an exemplary embodiment.

[0034] Figure 3 is a schematic diagram of a fingerprint detection module according to an exemplary embodiment.

[0035] Figure 4 is a schematic diagram of another fingerprint detection module according to an exemplary embodiment.

[0036] Figure 5 is a schematic diagram of yet another fingerprint detection module according to an exemplary embodiment.

[0037] Figure 6 is a simplified model schematic diagram of a photosensitive unit according to an exemplary embodiment.

[0038] Figure 7 The figure is a timing diagram of a fingerprint detection module operation according to an exemplary embodiment.

[0039] Figure 8 is a schematic diagram of yet another fingerprint detection module according to an exemplary embodiment.

[0040] Fig. 9 is another fingerprint detection module operation timing diagram according to an exemplary embodiment.

[0041] Fig.10 It is a block diagram of an electronic device according to an exemplary embodiment.

[0042] Fig.11 It is a partial schematic diagram of an electronic device according to an exemplary embodiment.

[0043] Fig.12 It is a partial schematic diagram of another electronic device according to an exemplary embodiment.

[0044] Fig.13 The figure is a flow chart of a fingerprint detection method according to an exemplary embodiment.

[0045] Fig.14 The figure is a block diagram of a fingerprint detection device according to an exemplary embodiment. DETAILED DESCRIPTION

[0046] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0047] Figure 1 This is a partial circuit diagram of an active pixel sensor. Figure 1 As shown, the active pixel sensor includes a photosensitive device, a source follower transistor (M1), a reset transistor (M2), a selection transistor (M3) and a collection circuit.

[0048] The gate of the reset transistor is electrically connected to the reset signal line, the source of the reset transistor and the output end of the photosensitive device are both connected to node A, and the drain of the reset transistor is electrically connected to the reset voltage terminal. The reset signal line is used to provide a reset signal (RST). The reset voltage terminal is used to provide a reset voltage (V RST ).

[0049] The gate of the source follower transistor is electrically connected to node A, the drain of the source follower transistor is electrically connected to the power signal line, and the source of the source follower transistor is electrically connected to the drain of the selection transistor. The power signal line is used to provide a power signal (V DD ).

[0050] The gate of the selection transistor is electrically connected to the selection signal line, and the source of the selection transistor and the collection circuit are both electrically connected to the node C. The selection signal line is used to provide a selection signal (SEL).

[0051] Figure 1 When the active pixel sensor shown is working, it mainly includes three working phases in sequence: a reset phase, an integration phase and a readout phase.

[0052] In the reset phase, a reset signal is transmitted to the gate of the reset transistor through the reset signal line to turn on the reset transistor, and a reset voltage is transmitted from the drain of the reset transistor to the source of the reset transistor, so that the output voltage of the photosensitive device is the reset voltage, and the source follower transistor is turned on. In addition, a selection signal is transmitted to the selection transistor through the selection signal line to turn on the selection transistor, and the first signal is output to the acquisition circuit through the source of the selection transistor.

[0053] In the integration stage, the selection signal is stopped from being transmitted to the gate of the selection transistor to turn off the selection transistor; the reset signal is stopped from being transmitted to the reset transistor to turn off the reset transistor; the photosensitive device receives the reflected light of the fingerprint to be detected, and converts the reflected light into an electrical signal and outputs it to node A.

[0054] In the readout stage, the selection signal is transmitted to the gate of the selection transistor again to turn on the selection transistor; the control signal is input to node B to turn on the photosensitive device, and the photosensitive device transmits the electrical signal formed by the reflected light to the gate of the source follower transistor, so that the source follower transistor is turned on, and the selection transistor forms the electrical signal output by the source of the source follower transistor into a second signal, and outputs the second signal to the acquisition circuit through the source of the selection transistor. The acquisition circuit can form a fingerprint to be detected based on the first signal and the second signal obtained from node C.

[0055] Although passive pixel sensors can detect fingerprints using only one transistor and one photosensitive device, they have larger detection noise and lower accuracy than active pixel sensors. Therefore, active pixel sensors are usually used for fingerprint detection in related technologies.

[0056] However, since the active pixel sensor has three transistors, it occupies a large area and has poor light transmittance. Therefore, when the active pixel sensor is set in a display screen for fingerprint recognition, the effective photosensitivity area of ​​the photosensitive device is reduced, and the range of reflected light that the photosensitive device can receive is reduced, thereby reducing the intensity of the electrical signal formed by the photosensitive device based on the received reflected light, resulting in a decrease in the signal-to-noise ratio and a reduction in the accuracy of fingerprint detection.

[0057] Figure 2 is a schematic diagram of a fingerprint detection module 100 according to an exemplary embodiment. Figure 2 As shown, the fingerprint detection module 100 includes: at least one fingerprint recognition component 110, and a collection component 120;

[0058] The fingerprint recognition component 110 includes: a reset unit 111, a photosensitive unit 112 and a following unit 113;

[0059] The reset unit 111 is electrically connected to the output end of the photosensitive unit 112 and is used to receive a reset signal and switch the voltage of the output end of the photosensitive unit 112 from a current voltage to an initial voltage according to the reset signal;

[0060] The photosensitive unit 112 is electrically connected to the follower unit 113, and is used to receive the reflected light of the fingerprint to be detected and accumulate charge after the follower terminal voltage of the photosensitive unit 112 is switched to the initial voltage, and output a first electrical signal based on the first level of the currently received pulse control signal; output a second electrical signal according to the first level of the next received pulse control signal; wherein the difference between the second electrical signal and the first electrical signal indicates the charge accumulated by the photosensitive unit 112 between the moment of outputting the second electrical signal and the moment of outputting the first electrical signal;

[0061] The follower unit 113 is electrically connected to the output end of the photosensitive unit 112, and is used to receive and form a first voltage according to the first electrical signal, and to receive and form a second voltage according to the second electrical signal;

[0062] The acquisition component 120 is electrically connected to the fingerprint recognition component 110, and is used to receive the first voltage and the second voltage respectively, and obtain the fingerprint to be detected according to the difference between the second voltage and the first voltage.

[0063] The reset unit 111 may be electrically connected to a reset signal line for receiving a reset signal (RST).

[0064] It should be noted that the reset signal line can be electrically connected to a control module in an electronic device including the fingerprint detection module 100. The control module is used to provide a reset signal to the reset unit 111 through the reset signal line. The control module is also used to output the above-mentioned pulse control signal to the photosensitive unit 112. The control module includes but is not limited to: a central processing unit or an application processor, etc.

[0065] The reset signal may include a pulse signal having a third level and a fourth level, the third level being different from the fourth level. For example, the third level may be greater than the fourth level.

[0066] Taking the third level being greater than the fourth level as an example, when the reset signal received by the reset unit 111 is at the third level, the reset unit 111 is in the on state, and switches the output voltage of the photosensitive unit 112 from the current voltage to the initial voltage. That is, the reset unit 111 in the on state resets the output voltage of the photosensitive unit 112 to the initial voltage.

[0067] For example, one end of the reset unit 111 may be grounded. When the reset signal received by the reset unit 111 is at the third level, the reset unit 111 conducts the output end of the photosensitive unit 112 with the grounded end of the reset unit 111, so that the output end of the photosensitive unit 112 is grounded, so as to switch the output end voltage of the photosensitive unit 112 from the current voltage to the initial voltage. At this time, the initial voltage may be approximately 0.

[0068] Alternatively, one end of the reset unit 111 may be electrically connected to a power supply with a fixed voltage, and the fixed voltage of the power supply is equal to the initial voltage. When the reset signal received by the reset unit 111 is at the third level, the reset unit 111 conducts the connection between the output end of the photosensitive unit 112 and the power supply with a fixed voltage, so that the output end voltage of the photosensitive unit 112 is switched to the initial voltage.

[0069] When the reset signal received by the reset unit 111 switches from the third level to the fourth level, the reset unit 111 switches from the on state to the off state. The reset unit 111 in the off state does not reset the output terminal voltage of the photosensitive unit 112.

[0070] The photosensitive unit 112 may include a photosensitive element or a photosensitive array composed of multiple photosensitive elements. The photosensitive element may include a photosensitive diode or a photosensitive transistor.

[0071] The photosensitive unit 112 may include an input terminal, an output terminal and a photosensitive surface. The input terminal of the photosensitive unit 112 is used to receive a pulse control signal. The output terminal of the photosensitive unit 112 is used to output an electrical signal according to the pulse control signal. The photosensitive surface of the photosensitive unit 112 is used to receive the reflected light of the fingerprint to be detected and to form a cumulative charge according to the received reflected light. It can be understood that the charge amount of the accumulated charge formed by the photosensitive unit 112 is positively correlated with the light intensity of the received reflected light.

[0072] The reflected light intensities formed by the raised and recessed parts of the fingerprint are different, so the intensities of the reflected light detected by the photosensitive units 112 at different positions are also different.

[0073] It should be noted that the first electrical signal and the second electrical signal may both be voltage signals, or the first electrical signal and the second electrical signal may both be current signals. Furthermore, the signal value of the first electrical signal is different from the signal value of the second electrical signal.

[0074] Reference Figure 2 As shown, the follower unit 113 , the output end of the photosensitive unit 112 , and the reset unit 111 can all be electrically connected to the node Q. The first electrical signal and the second electrical signal generated by the photosensitive unit 112 are both transmitted to the follower unit 113 through the node Q.

[0075] For the same photosensitive unit 112, when the intensity of the reflected light of the fingerprint to be detected and the duration of receiving the reflected light are the same, the lower the photoelectric conversion efficiency of the photosensitive unit 112, the less the accumulated charge, and the smaller the difference between the second voltage and the first voltage.

[0076] When the values ​​of the first voltage and the second voltage are different, and the difference between the second voltage and the first voltage is less than or equal to the sensitivity threshold of the voltage collected by the collection component 120, the values ​​of the first voltage and the second voltage read by the collection component 120 will be the same, causing the collection component 120 to obtain an erroneous fingerprint to be detected, thereby reducing the accuracy of the acquired fingerprint to be detected.

[0077] It should be pointed out that the accumulated charge formed by the photosensitive unit 112 based on the received reflected light between two adjacent first level occurrence times makes the second voltage have a greater sensitivity than the collection component 120 relative to the first voltage, that is, the collection component 120 can distinguish the value of the second voltage from the value of the first voltage.

[0078] Compared with the active pixel sensor circuit that controls the output of the first voltage and the second voltage by setting a selection transistor, the photosensitive unit provided in the embodiment of the present disclosure receives the reflected light of the fingerprint to be detected and accumulates charge after the voltage at the output end of the photosensitive unit is switched to the initial voltage, outputs a first electrical signal based on the first level of the currently received pulse control signal, and outputs a second electrical signal based on the first level of the next received pulse control signal. There is no need to additionally set a selection transistor, and a first voltage can be formed according to the first electrical signal and a second voltage can be formed according to the second electrical signal through a follower unit, and the fingerprint to be detected can be obtained according to the difference between the second voltage and the first voltage by using an acquisition component. While realizing fingerprint detection, the structure of the fingerprint recognition component 110 is simplified, which is beneficial to reducing the cost of the fingerprint detection module 100.

[0079] In addition, by reducing the number of row selection transistors, the area originally used to set the row selection transistors in the fingerprint recognition module can be used to set the photosensitive surface of the photosensitive unit, which is beneficial to increase the area in which the photosensitive unit can receive the reflected light of the fingerprint to be detected, thereby increasing the range of the reflected light that the photosensitive unit can receive, thereby improving the signal-to-noise ratio and the accuracy of the acquired fingerprint to be detected.

[0080] In some embodiments, Figure 3 As shown, the reset unit 111 includes:

[0081] A reset transistor, the gate 1111 of the reset transistor is connected to the reset signal terminal, the source 1112 of the reset transistor is electrically connected to the acquisition component 120, and the drain 1113 of the reset transistor is electrically connected to the output terminal of the photosensitive unit 112; wherein the reset signal terminal is used to provide a reset signal.

[0082] When the voltage of the reset signal provided by the reset signal terminal to the gate 1111 of the reset transistor is greater than the first threshold voltage (V th ), the reset transistor is turned on, the reset unit 111 is in the on state, and the output voltage of the photosensitive unit 112 is switched from the current voltage to the initial voltage. Here, the first threshold voltage is the minimum voltage that needs to be input to the gate 1111 of the reset transistor when the reset transistor is turned on. For example, the first threshold voltage can be 0.7 volts or 0.8 volts, etc.

[0083] When the voltage of the reset signal provided by the reset signal terminal to the gate 1111 of the reset transistor is less than the first threshold voltage of the reset transistor, the reset transistor is turned off, and the reset unit 111 is in an off state.

[0084] In the disclosed embodiment, the function of the reset unit 111 is realized by a reset transistor, which is highly compatible with the prior art and does not increase the area of ​​the fingerprint detection module 100 or reduce the area of ​​the photosensitive unit 112 that can receive the reflected light of the fingerprint to be detected.

[0085] In some embodiments, Figure 4 As shown, the following unit 113 includes:

[0086] A follower transistor, the gate 1131 of the follower transistor is electrically connected to the output end of the photosensitive unit 112, the source 1132 of the follower transistor is electrically connected to the collection component 120, and the drain 1133 of the follower transistor is connected to the power supply.

[0087] When the photosensitive unit 112 outputs the first electrical signal or the second electrical signal, the first electrical signal or the second electrical signal is transmitted to the gate 1131 of the follower transistor. It should be noted that both the first electrical signal and the second electrical signal can make the gate 1131 voltage of the follower transistor greater than the second threshold voltage of the follower transistor. The second threshold voltage is the minimum voltage that needs to be input to the gate 1131 of the follower transistor when the follower transistor is turned on and the follower transistor operates in the saturation region. For example, the second threshold voltage may be 0.7 volts or 0.8 volts, etc.

[0088] That is to say, when the gate 1131 of the follower transistor receives the first electrical signal or the second electrical signal, the follower transistor is turned on, the follower unit 113 is in the on state, and the follower transistor can output a first voltage from the source 1132 according to the first electrical signal received by the gate 1131, and the follower transistor can also output a second voltage from the source 1132 according to the second electrical signal received by the gate 1131.

[0089] It should be noted that when the output voltage of the photosensitive unit 112 is the initial voltage, the initial voltage is less than the second threshold voltage of the follower transistor in the follower unit, that is, the initial voltage cannot turn on the follower transistor. Therefore, when the output voltage of the photosensitive unit 112 is the initial voltage, the follower transistor is turned off, and the follower unit 113 is in the off state.

[0090] The follower transistor may be a source follower transistor. Specifically, when the follower transistor is turned on, the output voltage of the source 1132 of the follower transistor may be linearly related to the input voltage of the gate 1131 of the follower transistor. When the input voltage of the gate 1131 of the follower transistor changes, the ratio of the change in the output voltage of the source 1132 of the follower transistor to the change in the input voltage of the gate 1131 of the follower transistor is a fixed value. For example, the fixed value may be 1.

[0091] It is understandable that compared to Figure 1The active pixel sensor shown requires three transistors, and the fingerprint recognition component 110 provided in the embodiment of the present disclosure includes two transistors, so there is no need to set a third transistor, which reduces the number of transistors in the fingerprint recognition component 110 and helps to reduce the area and cost occupied by the fingerprint detection module 100.

[0092] In addition, in the embodiment of the present disclosure, Figure 1 The photosensitive surface of the photosensitive unit 112 is set in the area used to set the third transistor. In this way, the photosensitive area of ​​the photosensitive unit 112 can be increased, and the amount of accumulated charge formed by the photosensitive unit 112 based on the received reflected light can be increased, thereby increasing the signal strength generated by the photosensitive unit 112 and improving the accuracy of the fingerprint to be detected obtained by the fingerprint detection module 100.

[0093] In some embodiments, Figure 5 As shown, the fingerprint detection module 100 further includes: a bias power supply 130;

[0094] The positive electrode of the bias power supply 130 is electrically connected to the acquisition component 120 , and the negative electrode of the bias power supply 130 is grounded.

[0095] The bias power supply 130 may have an on state and an off state. The bias power supply 130 may include a current source or a voltage source.

[0096] Taking the bias power supply 130 as a current source as an example, when the bias power supply 130 is in the on state, the bias power supply 130 can provide a bias current, and the bias current is used to increase the positive voltage of the bias power supply, so that the positive voltage of the bias power supply 130 gradually increases to be equal to the source output voltage of the follower transistor.

[0097] It should be pointed out that since the positive electrode of the bias power supply 130 is electrically connected to the connection point between the source 1132 of the follower transistor and the acquisition component 120, when the source 1132 of the follower transistor outputs the first voltage or the second voltage, the positive electrode voltage of the bias power supply 130 is equal to the output voltage of the source 1132 of the follower transistor.

[0098] When the bias power supply 130 is in the off state, the bias power supply 130 does not provide a bias current or the bias current provided is 0. At this time, the positive voltage of the bias power supply 130 is 0.

[0099] Taking the photosensitive unit 112 as a photosensitive diode as an example, Figure 6 yes Figure 5 A simplified model schematic diagram of the photosensitive unit 112 is shown in FIG. Figure 6 As shown, the photodiode can be regarded as a preset capacitor (C j ) and a preset current source (I PD) are connected in parallel, the node where the first plate of the preset capacitor and the negative electrode of the preset current source are connected in parallel is the input end of the photosensitive unit 112, and the node where the second plate of the preset capacitor and the positive electrode of the preset current source are connected in parallel is the output end of the photosensitive unit 112.

[0100] When the pulse control signal received by the photodiode is at the second level, the photodiode is turned off, and the photodiode receives the reflected light of the fingerprint to be detected and accumulates charges. The accumulated charges are distributed on the first plate and the second plate of the preset capacitor. The charges distributed on the second plate can cause the voltage at the node Q to rise.

[0101] It is understandable that the first plate and the second plate of the preset capacitor distribute the same amount of charge and have opposite charges. For example, the first plate may distribute negative charges and the second plate may distribute positive charges.

[0102] Figure 7 yes Figure 5 FIG. 1 is a working sequence diagram of the fingerprint detection module 100. Figure 5 and Figure 7 As shown, the photosensitive unit 112 is a photosensitive diode, V BIAS Used to indicate the level of the pulse control signal, V BIAS The unit of the voltage may be Volt, and the pulse control signal has a first level (V B2 ) and the second level (V B1 ), the first level is greater than the second level. RST is used to indicate the reset signal provided by the reset signal terminal, and the reset signal has a third level (V R2 ) and the fourth level (V R1 ), the third level is greater than the fourth level. V DD It is used to indicate the power signal provided by the power supply to the drain 1133 of the follower transistor. The bias power supply 130 is a current source. IB_EN is used to indicate the signal value of the power control signal for controlling the bias power supply 130. The power control signal has a first signal value (V I2 ) and the second signal value (V I1 ), the first signal value is greater than the second signal value. The fingerprint detection module 100 may include a reset phase and an integration phase.

[0103] Specifically, during the reset phase, at t 00The third level of the reset signal is input to the gate 1111 of the reset transistor at all times, the reset transistor is turned on under the action of the third level of the reset signal, and the power control signal has a second signal value, and the bias power supply 130 is in a closed state under the action of the power control signal with the second signal value. When the reset transistor is turned on, the output end of the photodiode (i.e., node Q) is electrically connected to the acquisition component 120 through the drain 1113 of the reset transistor and the source 1112 of the reset transistor, and the output end voltage of the photodiode is switched from the current voltage to the initial voltage. It should be noted that in the reset stage, the pulse control signal is the second level (V B1 ), followed by the transistor turning off. The acquisition component 120 can provide a fixed voltage (V RST ) as the initial voltage.

[0104] In t 01 At this moment, the reset signal switches from the third level to the fourth level. Under the action of the reset signal at the fourth level, the reset transistor is turned off, and the fingerprint detection module 100 enters the integration stage.

[0105] In the integration phase, the photodiode receives the reflected light of the fingerprint to be detected and accumulates the charge. After the output voltage of the photodiode is switched to the initial voltage, at t 02 The first level (V B2 ), the photodiode is turned on.

[0106] Since the internal resistance of the photodiode is very small, it can be considered that at t 02 At this moment, the gate voltage 1131 of the follower transistor may be equal to the first level. It should be noted that the difference between the first level and the second level (V LUP ) is greater than the second threshold voltage of the follower transistor. Thus, when the pulse control signal switches from the second level to the first level, the follower transistor can switch from the off state to the on state and the follower transistor operates in the saturation region.

[0107] In t 03 At the same time, the power control signal controlling the bias power supply 130 is switched from the second signal value to the first signal value, so as to switch the bias power supply 130 from the off state to the on state. When the bias power supply 130 is in the on state, the bias power supply 130 gradually builds up and increases the voltage at the node P. When the pulse control signal input to the photodiode is at the first level, after the bias power supply 130 enters the on state for a period of time, the positive electrode voltage of the bias power supply 130 is equal to the output voltage of the source 1132 of the follower transistor.

[0108] In t 04 At this moment, the photodiode 01 Time to t 04The accumulated charge at the time and the first level of the pulse control signal form a first electrical signal, and transmit the first electrical signal to the gate 1131 of the follower transistor. 04 The voltage at the node P is read out at time t as the first voltage. 04 The voltage at node P is read for the first time at time t 04 At this moment, the follower transistor operates in the saturation region.

[0109] In t 05 At this moment, the pulse control signal switches from the first level to the second level, so that the photodiode is turned off, and the voltage at the output end of the photodiode is less than the second threshold voltage of the follower transistor, so that the follower transistor is turned off.

[0110] In t 06 At the moment, the pulse control signal switches from the second level to the first level, and the photodiode is turned on again. It can be understood that compared with t 02 The first level of the pulse control signal input to the photodiode at time t 06 The first level of the pulse control signal input to the photodiode at the moment is the first level of the next pulse control signal. Under the first level of the next pulse control signal, the photodiode is turned on and the photodiode is turned on according to t 01 Time to t 07 The accumulated charge at the moment and the first level of the next pulse control signal form a second electrical signal, and transmit the second electrical signal to the gate 1131 of the follower transistor. 07 The voltage at the node P is read out at time t as the second voltage. 07 The voltage at node P is read a second time at time t 07 At this moment, the follower transistor operates in the saturation region.

[0111] It can be understood that the difference between the second voltage and the first voltage is used to indicate that the photosensitive diode is 04 Time to t 07 The charge accumulated at the moment, that is, the difference between the second voltage and the first voltage, is used to indicate the charge accumulated by the photodiode in the T1 period, where T1 is equal to t 07 With t 04 time difference.

[0112] After the acquisition component 120 reads the second voltage, it can be 08 At time t, the pulse control signal input to the photodiode is switched from the first level to the second level to turn off the photodiode. In addition, the bias power supply 130 may be turned off to save power. For example, at t 09The power control signal is switched from the first signal value to the second signal value at a certain moment to turn off the bias power supply 130 .

[0113] Due to the integration stage, the photodiode accumulates charges based on the received reflected light, and the preset capacitor in the simplified model of the photodiode is used. The accumulated charges increase the voltage at the node Q, causing the voltage at the node Q to change. Therefore, under the action of the accumulated charges and the first level of the pulse control signal, the follower transistor is turned on and can operate in the saturation region, and the follower transistor operating in the saturation region can be used as a follower device.

[0114] When the follower transistor is used as a follower device, when the gate voltage of the follower transistor changes, the source voltage of the follower transistor can change linearly with the gate voltage of the follower transistor. Since the output end (i.e., node Q) of the photodiode is connected to the gate of the follower transistor, and node P is connected to the source of the follower transistor, when the follower transistor is used as a follower device, the voltage output by the source 1132 of the follower transistor at node P will change linearly with the voltage at node Q, so the signal collected by the photodiode can be obtained by reading the voltage at node P, and then the fingerprint to be detected can be obtained.

[0115] Compared with the related art that requires three transistors and one photodiode to achieve fingerprint detection, the fingerprint recognition component 110 provided by the embodiment of the present disclosure only requires two transistors and one photodiode, thereby reducing the number of transistors in the fingerprint recognition component 110, simplifying the structure of the fingerprint recognition component 110, and helping to reduce the cost of the fingerprint detection module 100.

[0116] Moreover, it is helpful to increase the area where the photodiode can receive the reflected light of the fingerprint to be detected, thereby increasing the range of the reflected light that the photodiode can receive, thereby improving the signal-to-noise ratio of the fingerprint detection module 100 and the accuracy of the acquired fingerprint to be detected.

[0117] Reference Figure 7 As shown, from t 05 Time to t 06 During the time period t, the bias power supply 130 is in the on state. It can be understood that in some embodiments, from t 05 Time to t 06 At this moment, the bias power supply 130 may also be in a closed state to reduce the power consumption of the bias power supply 130 and save electric energy.

[0118] For example, from t 05 Time to t 06 At the moment, since the follower transistor is turned off, the source 1132 of the follower transistor does not output a signal to the acquisition component 120. Therefore, at the moment t 05 Time to t 06The power control signal is switched from the first signal value to the second signal value at all times to switch the bias power supply 130 from the on state to the off state, thereby reducing the power consumption of the fingerprint detection module 100. In this way, the effect of saving power can be further achieved.

[0119] In t 06 At this moment and before the acquisition component 120 reads the second voltage, the power control signal is switched from the second signal value back to the first signal value to switch the bias power supply 130 from the off state to the on state, so that the bias power supply 130 re-establishes the voltage at the node P, and the acquisition component 120 reads the voltage at the node P as the second voltage after the positive electrode voltage of the bias power supply 130 is equal to the output voltage of the source 1132 of the follower transistor.

[0120] In some embodiments, Figure 8 As shown, the fingerprint detection module 100 includes a plurality of fingerprint recognition components 110 ; wherein the output ends of the follower units 113 of the plurality of fingerprint recognition components 110 are connected in parallel to the positive electrode of the bias power supply 130 and the connection point of the acquisition component 120 .

[0121] Reference Figure 8 As shown, taking the fingerprint detection module 100 including two fingerprint recognition components, a first fingerprint recognition component 110a and a second fingerprint recognition component 110b, the reset unit 111 of each fingerprint recognition component includes a reset transistor, and the follower unit of each fingerprint recognition component includes a follower transistor as an example, the output end of the follower unit 113a of the first fingerprint recognition component 110a is the source 1132a of the follower transistor 113a, the output end of the follower unit 113b of the second fingerprint recognition component 110b is the source 1132b of the follower transistor 113b, the connection point between the positive electrode of the bias power supply 130 and the acquisition component 120 is the node P, and the output end of the follower unit 113b and the output end of the follower unit 113a are both electrically connected to the node P.

[0122] When the fingerprint detection module 100 includes multiple fingerprint recognition components 110, by connecting the output ends of the follower units 113 of the multiple fingerprint recognition components 110 in parallel to the positive electrode of the bias power supply 130 and the connection point of the acquisition component 120, the same bias power supply 130 can be used to establish the output terminal voltage of multiple follower units 112 through timing control. There is no need to set different bias power supplies at the output ends of different follower units, thereby realizing the reuse of the bias power supply 130, reducing the number of bias power supplies 130 required in the fingerprint recognition module, and helping to reduce the area and cost occupied by the fingerprint recognition module 100.

[0123] In practical applications, active pixel sensors may include multiple Figure 1 The sensor array consists of the sensor units shown in the dotted box.

[0124] Compared to Figure 1 Each sensor unit requires three transistors. When the fingerprint recognition module 100 provided in the embodiment of the present disclosure includes multiple fingerprint recognition components 110, each fingerprint recognition component 110 includes two transistors, and there is no need to set a third transistor, thereby reducing the number of transistors in each fingerprint recognition component 110, thereby significantly reducing the area and cost occupied by the fingerprint recognition module 100.

[0125] In addition, in the embodiment of the present disclosure, it is also possible to use Figure 1 is used to set the third transistor (for example Figure 1 The photosensitive surface of the photosensitive unit 112 is set in the area M3) in the middle. In this way, the photosensitive area of ​​the photosensitive unit 112 can be increased, the charge amount of the accumulated charge formed by the photosensitive unit 112 based on the received reflected light can be increased, and then the signal strength generated by the photosensitive unit 112 can be increased, thereby significantly improving the accuracy of the fingerprint to be detected obtained by the fingerprint detection module 100.

[0126] Taking the fingerprint detection module 100 including two fingerprint recognition components, a first fingerprint recognition component 110a and a second fingerprint recognition component 110b as an example, Fig. 9 yes Figure 8 The working timing diagram of the fingerprint detection module 100 is shown.

[0127] Combination Figure 8 and Fig. 9 As shown, the photosensitive unit 112a of the first fingerprint recognition component 110a and the photosensitive unit 112b of the second fingerprint recognition component 110b are both photosensitive diodes, V BIAS1 It is used to indicate the level of the first pulse control signal input to the photosensitive unit 112a, V BIAS2 It is used to indicate the level of the second pulse control signal input to the photosensitive unit 112b, V DD It is used to indicate the voltage provided by the power supply to the drain 1133a of the follower transistor of the first fingerprint recognition component 110a and to the drain 1133b of the follower transistor 113b of the second fingerprint recognition component 110b. The bias power supply 130 is a current source. IB_EN is used to indicate the power control signal for controlling the bias power supply 130.

[0128] The fingerprint detection module 100 may include a reset phase and an integration phase.

[0129] Specifically, during the reset phase, at t 00 At the same time, the third level of the reset signal is input to the gate 1111a of the reset transistor 111a of the first fingerprint recognition component 110a, and the reset transistor 111a is turned on under the action of the third level of the reset signal. 00At this moment, the power control signal is the second signal value, and the bias power supply 130 is in a closed state under the effect of the second signal value of the power control signal. When the reset transistor 111a is turned on, the output end of the photodiode 112a (i.e., the node Q1) is electrically connected to the acquisition component 120 through the drain 1113a of the reset transistor 111a and the source 1112a of the reset transistor 111a, and the output end voltage of the photodiode 112a is switched from the current voltage to the initial voltage.

[0130] Also, during the reset phase, at t 00 The third level of the reset signal is always input to the gate 1111b of the reset transistor 111b of the second fingerprint recognition component 110b, and the reset transistor 111b is turned on under the action of the third level of the reset signal, and the output end of the photodiode 112b (i.e., the node Q2) is electrically connected to the collection component 120 through the drain 1113b of the reset transistor 111b and the source 1112b of the reset transistor 111b, and the output end voltage of the photodiode 112b is switched from the current voltage to the initial voltage.

[0131] It should be noted that, in the reset phase, the first pulse control signal input to the photodiode 112a and the second pulse control signal input to the photodiode 112b are both at the second level (V B1 ), the photosensitive diode 112a and the photosensitive diode 112b are both turned off, so that the follower transistor 113a and the follower transistor 113b are turned off. The acquisition component 120 can provide a fixed voltage (V RST ) as the initial voltage. Also, the gate 1111a of the reset transistor 111a and the gate 1111b of the reset transistor 111b may be electrically connected to the same reset signal line and simultaneously receive a reset signal having the same level.

[0132] In t 01 At the moment, the reset signal switches from the third level to the fourth level. Under the effect of the reset signal at the fourth level, the reset transistor 111a and the reset transistor 111b are both turned off, and the fingerprint detection module 100 enters the integration stage.

[0133] In the integration phase, the photodiode 112a and the photodiode 112b receive the reflected light of the fingerprint to be detected and accumulate charge. After the output voltage of the photodiode 112a is switched to the initial voltage, at t 02 The first level of the first pulse control signal is input to the photodiode 112a at any time, and the photodiode 112a is turned on.

[0134] In t 03At this moment, the power control signal controlling the bias power supply 130 is switched from the second signal value to the first signal value, and the bias power supply 130 is switched from the off state to the on state, so as to gradually establish and increase the voltage at the node P. After the bias power supply 130 enters the on state for a period of time, the positive electrode voltage of the bias power supply 130 is equal to the source output voltage of the follower transistor 113 a.

[0135] In t 04 At this moment, the photodiode 112a is 01 Time to t 04 The accumulated charge at the time t and the first level of the first pulse control signal form a first electrical signal, and transmit the first electrical signal to the gate 1131a of the follower transistor 113a. 04 At time t, the voltage at node P is read as the first voltage. 04 At this moment, the follower transistor 113a operates in the saturation region.

[0136] It should be noted that when the first pulse control signal of the first level is input to the photodiode 112a, the second pulse control signal input to the photodiode 112b is of the second level, and the photodiode 112b is turned off.

[0137] After the acquisition component 120 reads the first voltage, at t 02 At time ', the first pulse control signal input to the photodiode 112a is switched from the first level to the second level, and the second pulse control signal input to the photodiode 112b is switched from the second level to the first level, and the photodiode 112b is turned on.

[0138] In t 04 At time t ', the photodiode 112b 01 Time to t 04 The accumulated charge at time t ′ and the first level of the second pulse control signal form a second first electrical signal, and transmit the second first electrical signal to the gate 1131b of the follower transistor 113b. 04 At time t ′, the voltage at node P is read as the second first voltage. 04 At the moment ', the follower transistor 113b operates in the saturation region.

[0139] It is understandable that when t 02 When the first pulse control signal input to the photodiode 112a is switched from the first level to the second level at moment ', the photodiode 112a is turned off, and the voltage at the output end of the photodiode 112a is less than the second threshold voltage of the follower transistor 113a, so that the follower transistor 113a is turned off.

[0140] It should be noted that the first first electrical signal and the second first electrical signal may have the same value, and the first first voltage and the second first voltage may have the same value. The first level of the first pulse control signal and the first level of the second pulse control signal may have the same value, and the second level of the first pulse control signal and the second level of the second pulse control signal may have the same value, but the first level of the first pulse control signal appears at a different time than the first level of the second pulse control signal.

[0141] In t 05 At this moment, the second pulse control signal input to the photodiode 112b switches from the first level to the second level, so that the photodiode 112b is turned off, and the voltage at the output end of the photodiode 112b is less than the second threshold voltage of the follower transistor 113b, so that the follower transistor 113b is turned off.

[0142] It should be noted that, in the integration phase, when the photodiode 112a changes from t 02 When the photodiode 112a is turned off at the moment t ′, it still receives the reflected light of the fingerprint to be detected and accumulates the charge. 02 From the moment ', the photodiode 112a is still receiving the reflected light of the fingerprint to be detected and accumulating charges.

[0143] Similarly, during the integration phase, when the photodiode 112b changes from t 05 When the photodiode 112b is turned off, it still receives the reflected light of the fingerprint to be detected and accumulates charge. 05 From that moment on, the photodiode 112b is still receiving the reflected light of the fingerprint to be detected and accumulating charges.

[0144] It is understandable that due to the difference between the valleys and ridges of the fingerprint, the light source irradiating the finger will generate different reflected light, so that the light intensity reaching different photosensitive diodes is different. Therefore, different photosensitive diodes in the fingerprint detection module 100 receive different reflected light intensities, and the amount of accumulated charge is also different, and then the value of the electrical signal generated according to the accumulated charge is different. That is, in the same duration of the integration stage, the amount of accumulated charge of the photosensitive diode 112a is different from the amount of accumulated charge of the photosensitive diode 112b.

[0145] In t 06 At this moment, the first pulse control signal input to the photodiode 112a is switched from the second level to the first level, that is, the first level of the next first pulse control signal is input to the photodiode 112a, and the photodiode 112a is turned on again under the first level of the next first pulse control signal.

[0146] It is understandable that compared to t02 The first level of the first pulse control signal input to the photodiode 112a at time t 06 The first level of the first pulse control signal input to the photodiode 112 a at any moment is the first level of the next first pulse control signal.

[0147] Under the first level of the next first pulse control signal, the photosensitive diode 112a is turned on, and the photosensitive diode 112a is turned on from t 01 Time to t 07 The accumulated charge at the time and the first level of the next first pulse control signal form the first second electrical signal, so that the follower transistor 113a is turned on. The acquisition component 120 can be at t 07 At time t, the voltage at node P is read as the first second voltage. 07 At this moment, the follower transistor 113a operates in the saturation region.

[0148] It should be pointed out that when the first level of the next first pulse control signal is input to the photodiode 112a, the second pulse control signal input to the photodiode 112b is the second level, the follower transistor 113b is turned off, and the follower transistor 113b will not affect the voltage at the node P, that is, the follower transistor 113b will not interfere with the value of the first second voltage output by the follower transistor 113a.

[0149] After the acquisition component 120 reads the first second voltage, at t 06 ′, the first level of the next second pulse control signal is input to the photodiode 112b, the photodiode 112b is turned on, and the photodiode 112b is turned on from t 01 Time to t 07 The accumulated charge at the time t′ and the first level of the next second pulse control signal form a second second electrical signal, which turns on the follower transistor 113b. 07 At time t ′, the voltage at node P is read as the second second voltage. 07 At the moment ', the follower transistor 113b operates in the saturation region.

[0150] It should be noted that when the first level of the next second pulse control signal is input to the photodiode 112b, the first pulse control signal input to the photodiode 112a is at the second level, the follower transistor 113a is turned off, and the follower transistor 113a will not affect the voltage at the node P, that is, the follower transistor 113a will not interfere with the value of the second second voltage output by the follower transistor 113b. After the acquisition component 120 reads the second second voltage, at t 08At this moment, the second pulse control signal input to the photodiode 112b is switched from the first level to the second level. Under the action of the second level of the second pulse control signal, the photodiode 112b is turned off.

[0151] For the first fingerprint recognition component 110a, the acquisition component 120 can determine the photosensitive diode 112a from t 04 Time to t 07 The amount of charge accumulated according to the reflected light of the fingerprint to be detected at the moment, that is, the difference between the first second voltage and the first first voltage is used to indicate the amount of charge accumulated by the photodiode 112a in the T1 period, T1 is equal to t 07 With t 04 time difference.

[0152] For the second fingerprint recognition component 110b, the acquisition component 120 can determine the photosensitive diode 112b from t 04 ' to t 07 The amount of charge accumulated according to the reflected light of the fingerprint to be detected at the moment ', that is, the difference between the second second voltage and the second first voltage is used to indicate the amount of charge accumulated by the photosensitive diode 112b in the T2 period, T2 is equal to t 07 ′ and t 04 '. T2 can be equal to T1.

[0153] It is understandable that when T1 is equal to T2, since the amount of charge accumulated by the photodiode 112a during the T1 period may be different from the amount of charge accumulated by the photodiode 112b during the T2 period, the value of the first second voltage may be different from the value of the second second voltage. In this way, the difference between the first voltage and the second voltage output by each fingerprint recognition component 110 may be different. The acquisition component 120 can obtain the fingerprint to be detected by obtaining the difference between the first voltage and the second voltage output by each fingerprint recognition component 110.

[0154] Since the first fingerprint recognition component 110a and the second fingerprint recognition component 110b are both electrically connected to the acquisition component 120 through the node P, when the source 1132a of the follower transistor 113a and the source 1132b of the follower transistor 113b output voltage at the same time, the acquisition circuit 120 cannot obtain the fingerprint information to be detected collected by the first fingerprint recognition component 110a and the second fingerprint recognition component 110b respectively according to the voltage read from the node P.

[0155] The present disclosure uses timing control to control the level of the pulse control signal input to the photodiode 112a to be different from the level of the pulse control signal input to the photodiode 112b when reading the first first voltage and the second first voltage, staggering the time for the follower transistor 113a to transmit the first first voltage to the node P and the time for the follower transistor 113b to transmit the second first voltage to the node P, so that the acquisition circuit 120 obtains the first first voltage output by the first fingerprint recognition component 110a and the second first voltage output by the second fingerprint recognition component 110b through the same node P.

[0156] In addition, the present disclosure controls the level of the pulse control signal input to the photodiode 112a to be different from the level of the pulse control signal input to the photodiode 112b when reading the first second voltage and the second voltage, thereby staggering the time for the follower transistor 113a to transmit the first second voltage to the node P and the time for the follower transistor 113b to transmit the second second voltage to the node P, so that the acquisition circuit 120 obtains the first second voltage output by the first fingerprint recognition component 110a and the second second voltage output by the second fingerprint recognition component 110b through the node P respectively.

[0157] Fig.10 is a schematic diagram of an electronic device 200 according to an exemplary embodiment. Fig.10 As shown, the electronic device 200 includes:

[0158] The display module includes: a display array composed of a plurality of pixel units 211;

[0159] As for the fingerprint detection module 100 provided in the embodiment of the present disclosure, the photosensitive unit 112 of the fingerprint detection module 100 is exposed through the gap between the pixel units 211; the fingerprint detection module 100 is used to obtain the fingerprint to be detected.

[0160] The display module may include an organic light emitting diode display module or a liquid crystal display module.

[0161] When the display module includes an organic light emitting diode display module, the pixel unit 211 includes an organic light emitting diode (OLED).

[0162] When the display module includes a liquid crystal display module, the pixel unit 211 includes: a liquid crystal pixel unit.

[0163] Since the fingerprint recognition component 110 is exposed through the gap between the pixel units, compared with the related art of setting an active pixel sensor in the display array for fingerprint detection, in the embodiment of the present disclosure, by setting the fingerprint detection module 100 in the electronic device 200, there is no need to additionally set a row selection transistor. When the gap between the pixel units remains unchanged, it is beneficial to increase the area used to set the photosensitive unit, thereby increasing the range of reflected light that the photosensitive unit can receive, increasing the strength of the electrical signal generated by the photosensitive unit according to the accumulated charge, and improving the signal-to-noise ratio and the accuracy of fingerprint detection.

[0164] In some embodiments, reference Fig.11 As shown, the photosensitive unit 112 and the pixel unit 211 are arranged in parallel on the same substrate; wherein the photosensitive unit 112 is located in a gap between at least two pixel units 211 .

[0165] When the pixel unit 211 includes an organic light emitting diode, the pixel unit 211 can emit light without a backlight.

[0166] When the display array is displaying, each pixel unit 211 has a light-emitting period and a display time slot. Exemplarily, the pixel unit 211 in the light-emitting period generates a light signal according to the driving signal, and the pixel unit 211 in the display time slot stops generating the light signal.

[0167] It is understandable that the display time slot is located between two adjacent light-emitting periods of the pixel unit 211. Due to the persistence of vision phenomenon, in the display time slot between two adjacent light-emitting periods, the visual effect of the light signal generated by the pixel unit 211 in the previous light-emitting period on the retina of the human eye will still remain in the human brain in the display time slot, that is, the user believes that the pixel unit 211 is still displaying in the display time slot.

[0168] Therefore, the photosensitive unit 112 can receive the reflected light of the fingerprint to be detected and accumulate charge within the display time slot of the pixel unit 211 to reduce the influence of the light emitted by the pixel unit 211 on the amount of charge accumulated by the photosensitive unit 112, thereby ensuring the accuracy of the acquired fingerprint to be detected.

[0169] In the present disclosure, by disposing the photosensitive unit 112 and the pixel unit 211 on the same substrate, there is no need to additionally dispose a substrate for supporting the photosensitive unit 112, which is beneficial to reducing the thickness of the electronic device and ensuring the lightness and thinness of the electronic device.

[0170] In some embodiments, reference Fig.12 As shown, the photosensitive unit 112 is located on the back side of the substrate where the pixel unit 211 is located, and is exposed through the gap between at least two of the pixel units 211 .

[0171] When active pixel sensors are used in liquid crystal displays (LCDs) for fingerprint detection, active pixel sensors can be embedded in pixel units on the control array substrate of the LCD (i.e., in-cell). Since the light transmittance of the reset transistor, source follower transistor, and row selection transistor of the active pixel sensor is very low or even non-transparent, the light emitted by the backlight source cannot pass through the reset transistor, source follower transistor, and row selection transistor to reach the liquid crystal array, so the active pixel sensor will reduce the aperture ratio of the liquid crystal display module, thereby reducing the display effect of the liquid crystal display.

[0172] The fingerprint detection component provided by the embodiment of the present disclosure does not need to be provided with a row selection transistor. Compared with the active pixel sensor, the aperture ratio of the liquid crystal display module provided with the present disclosure can be improved, thereby improving the display effect of the liquid crystal display module.

[0173] In addition, the embodiment of the present disclosure arranges the photosensitive unit 112 on the back side of the substrate where the pixel unit 211 is located, so that the photosensitive unit 112 and the pixel unit 211 can be respectively arranged on the opposite surfaces of the substrate. The method is simple and highly compatible with existing processes.

[0174] Fig.13 1 is a flow chart of a fingerprint detection method according to an exemplary embodiment, wherein the fingerprint detection method is used in an electronic device including the fingerprint detection module 100 provided in the embodiment of the present disclosure. Fig.13 As shown, the fingerprint detection method includes the following steps:

[0175] S100: inputting a reset signal to the fingerprint detection module; wherein the reset signal is used to switch the output voltage of the photosensitive unit from the current voltage to the initial voltage;

[0176] S110: After the voltage at the output end of the photosensitive unit is switched to the initial voltage, a first level of a pulse control signal is input; wherein, after the voltage at the output end of the photosensitive unit is switched to the initial voltage, the photosensitive unit receives the reflected light of the fingerprint to be detected and accumulates charge, and outputs a first electrical signal based on the first level of the currently received pulse control signal, and the first electrical signal is used to form a first voltage;

[0177] S120: inputting a second level of the pulse control signal;

[0178] S130: after inputting the second level of the pulse control signal, inputting the first level of the next pulse control signal; wherein the photosensitive unit outputs a second electrical signal according to the first level of the next pulse control signal received, and the second electrical signal is used to form a second voltage; the difference between the second electrical signal and the first electrical signal indicates the charge accumulated by the photosensitive unit between the moment of outputting the second electrical signal and the moment of outputting the first electrical signal;

[0179] S140: Acquire a fingerprint to be detected according to the difference between the second voltage and the first voltage.

[0180] Taking the photosensitive unit as a photodiode as an example, in S110, a first level of a pulse control signal can be input to the input end of the photodiode to turn on the photodiode and form a first electrical signal. Under the action of the first electrical signal, the follower unit outputs a first voltage.

[0181] In S120, after the pulse control signal input to the photodiode is switched from the first level to the second level, the photodiode is turned off, and the photodiode receives the reflected light of the fingerprint to be detected and accumulates charge.

[0182] It can be understood that, taking the first level of the pulse control signal in S110 as the first level appearing for the first time, the first level of the next pulse control signal in S130 can be regarded as the first level appearing for the second time of the pulse control signal.

[0183] Compared with the active pixel sensor circuit that controls the output of the first voltage and the second voltage by setting a selection transistor, the embodiment of the present disclosure, based on the provided fingerprint detection module, controls the timing of the first level and the second level in the reset signal and the pulse control signal, and can control the output of the first voltage and the second voltage without additionally setting a selection transistor. On the basis of ensuring the fingerprint detection function, the structure of the fingerprint recognition component is simplified, which is beneficial to reducing the cost of the fingerprint detection module.

[0184] In addition, by improving the circuit structure of the fingerprint detection module and controlling the timing, the row selection transistors are reduced, and the area originally used to set the row selection transistors can be used to set the photosensitive surface of the photosensitive unit, which is beneficial to increase the area that the photosensitive unit can receive the reflected light of the fingerprint to be detected, thereby increasing the range of the reflected light that the photosensitive unit can receive, thereby improving the signal-to-noise ratio and the accuracy of the acquired fingerprint to be detected.

[0185] In some embodiments, the reset unit of the fingerprint recognition component includes a reset transistor, and S100 may include:

[0186] A reset signal is input to the gate of the reset transistor to turn on the reset transistor; wherein the reset transistor switches the output voltage of the photosensitive unit from the current voltage to the initial voltage.

[0187] When the voltage of the reset signal is greater than the first threshold voltage of the reset transistor, the reset transistor is turned on, and the output voltage of the photosensitive unit is switched from the current voltage to the initial voltage. Here, the first threshold voltage is the minimum voltage that needs to be input to the gate of the reset transistor when the reset transistor is turned on. For example, the first threshold voltage can be 0.7 volts or 0.8 volts, etc.

[0188] When the voltage of the reset signal is less than the first threshold voltage of the reset transistor, the reset transistor is turned off.

[0189] In some embodiments, the first level of the pulse control signal is used to turn on the photosensitive unit and form a first electrical signal at the output end of the photosensitive unit; wherein the first electrical signal is transmitted to the gate of the follower transistor; the first electrical signal is used to turn on the follower transistor and output a first voltage at the source of the follower transistor.

[0190] Exemplarily, when the pulse control signal is at the second level, the follower transistor is turned off.

[0191] It should be noted that the difference between the first level and the second level of the pulse control signal is greater than the second threshold voltage of the follower transistor. When the pulse control signal switches from the second level to the first level, the follower transistor switches from the off state to the on state, and the follower transistor operates in the saturation region.

[0192] In some embodiments, when the fingerprint detection module includes multiple fingerprint recognition components, the fingerprint detection module includes multiple photosensitive units, and S110 includes: after the voltages at the output ends of the multiple photosensitive units are switched to the initial voltage, inputting the first level of the pulse control signal to the multiple photosensitive units in sequence; wherein, when the pulse control signal input to one photosensitive unit is the first level, the pulse control signal input to the remaining photosensitive units is the second level;

[0193] S120 includes: after sequentially inputting the first level of the pulse control signal to the plurality of photosensitive units, sequentially inputting the second level of the pulse control signal to the plurality of photosensitive units;

[0194] S130 includes: after inputting the second level of the pulse control signal to the multiple photosensitive units in sequence, inputting the first level of the next pulse control signal to the multiple photosensitive units in sequence; wherein, when the first level of the next pulse control signal is input to one photosensitive unit, the pulse control signal input to the remaining photosensitive units is the second level.

[0195] For example, when the fingerprint detection module includes a plurality of fingerprint recognition components arranged in parallel to form a row, the first level of the pulse control signal may be input to the photosensitive unit of each fingerprint recognition component in a sequence from left to right in S110. Alternatively, the first level of the pulse control signal may be input to the photosensitive unit of each fingerprint recognition component in a sequence from right to left in S110.

[0196] When the fingerprint detection module includes multiple fingerprint recognition components arranged in parallel to form a row, the first level of the pulse control signal can be input to the photosensitive unit of each fingerprint recognition component in a top-to-bottom order in S110. Alternatively, the first level of the pulse control signal can be input to the photosensitive unit of each fingerprint recognition component in a bottom-to-top order in S110.

[0197] When the fingerprint detection module includes multiple fingerprint recognition components arranged in parallel to form an array with multiple rows and columns, S110 can start from the first row and input the first level of the pulse control signal to the photosensitive unit of each fingerprint recognition component in the first row in a left-to-right order. After the first level of the pulse control signal is input to each photosensitive unit in the first row, the first level of the pulse control signal is input to each photosensitive unit in the second row in a left-to-right order. In this way, the first level of the pulse control signal is input to each photosensitive unit row by row until the pulse control signal is input to the photosensitive unit at the rightmost end of the last row.

[0198] It is understandable that in S130 , the first level of the next pulse control signal may be input to the plurality of photosensitive units in sequence according to the order of the first levels of the input pulse control signal in S110 .

[0199] In summary, in the embodiment of the present disclosure, the pulse control signals are input to the multiple photosensitive units in sequence, that is, the pulse control signals are input to the photosensitive units one by one in a certain order, without pausing or skipping one or more photosensitive units.

[0200] In the embodiment of the present disclosure, after the output terminal voltage of the multiple photosensitive units is switched to the initial voltage, the first level of the pulse control signal is sequentially input to the multiple photosensitive units; wherein, when the pulse control signal input to one photosensitive unit is the first level, the pulse control signal input to the remaining photosensitive units is the second level, thereby ensuring that when the fingerprint recognition component whose pulse control signal is the first level outputs the first voltage, the fingerprint recognition component whose pulse control signal is the second level will not affect the value of the first voltage, which is beneficial to ensuring the accuracy of the first voltage output by each fingerprint recognition component that is read.

[0201] Fig.14 1 is a block diagram of a device 800 for fingerprint detection according to an exemplary embodiment. The device 800 can perform the steps in the fingerprint detection method provided in the embodiment of the present disclosure. For example, the device 800 can be a mobile phone, a computer, a digital broadcast terminal, a messaging device, a game console, a tablet device, a medical device, a fitness device, a personal digital assistant, etc.

[0202] Reference Fig.14, the device 800 may include one or more of the following components: a processing component 802 , a memory 804 , a power component 806 , a multimedia component 808 , an audio component 810 , an input / output (I / O) interface 812 , a sensor component 814 , and a communication component 816 .

[0203] The processing component 802 generally controls the overall operation of the device 800, such as operations associated with display, phone calls, data communications, camera operations, and recording operations. The processing component 802 may include one or more processors 820 to execute instructions to complete all or part of the steps of the above-mentioned method. In addition, the processing component 802 may also include one or more modules to facilitate the interaction between the processing component 802 and other components. For example, the processing component 802 may include a multimedia module to facilitate the interaction between the multimedia component 808 and the processing component 802.

[0204] The memory 804 is configured to store various types of data to support operations on the device 800. Examples of such data include instructions for any application or method operating on the device 800, contact data, phone book data, messages, pictures, videos, etc. The memory 804 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk, or optical disk.

[0205] The power component 806 provides power to the various components of the device 800. The power component 806 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power to the device 800.

[0206] The multimedia component 808 includes a screen that provides an output interface between the device 800 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touch, slide, and gestures on the touch panel. The touch sensor may not only sense the boundaries of the touch or slide action, but also detect the duration and pressure associated with the touch or slide operation. In some embodiments, the multimedia component 808 includes a front camera and / or a rear camera. When the device 800 is in an operating mode, such as a shooting mode or a video mode, the front camera and / or the rear camera may receive external multimedia data. Each front camera and / or the rear camera may be a fixed optical lens system or have a focal length and optical zoom capability.

[0207] The audio component 810 is configured to output and / or input audio signals. For example, the audio component 810 includes a microphone (MIC), and when the device 800 is in an operating mode, such as a call mode, a recording mode, and a speech recognition mode, the microphone is configured to receive an external audio signal. The received audio signal can be further stored in the memory 804 or sent via the communication component 816. In some embodiments, the audio component 810 also includes a speaker for outputting audio signals.

[0208] I / O interface 812 provides an interface between processing component 802 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include, but are not limited to, a home button, a volume button, a start button, and a lock button.

[0209] The sensor assembly 814 includes one or more sensors for providing various aspects of status assessment for the device 800. For example, the sensor assembly 814 can detect the open / closed state of the device 800, the relative positioning of components, such as the display and keypad of the device 800, and the sensor assembly 814 can also detect the position change of the device 800 or a component of the device 800, the presence or absence of user contact with the device 800, the orientation or acceleration / deceleration of the device 800, and the temperature change of the device 800. The sensor assembly 814 may include a proximity sensor configured to detect the presence of nearby objects without any physical contact. The sensor assembly 814 may also include an optical sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 814 may also include an acceleration sensor, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

[0210] The communication component 816 is configured to facilitate wired or wireless communication between the device 800 and other devices. The device 800 can access a wireless network based on a communication standard, such as WiFi, 2G or 3G, or a combination thereof. In an exemplary embodiment, the communication component 816 receives a broadcast signal or broadcast-related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 816 also includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology or other technologies.

[0211] In an exemplary embodiment, the apparatus 800 may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors or other electronic components to perform the above method.

[0212] In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions is also provided, such as a memory 804 including instructions, and the instructions can be executed by the processor 820 of the device 800 to perform the above method. For example, the non-transitory computer-readable storage medium can be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0213] A non-transitory computer-readable storage medium, when instructions in the storage medium are executed by a processor of a mobile terminal, enables the mobile terminal to execute the steps in the fingerprint detection method provided in an embodiment of the present disclosure.

[0214] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the embodiments disclosed herein. The present disclosure is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and embodiments are to be considered as exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

[0215] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A fingerprint detection module, characterized in that: include: At least one fingerprint recognition component, and a collection component; The fingerprint recognition component includes: a reset unit, a photosensitive unit and a following unit; The reset unit is electrically connected to the output end of the photosensitive unit and is used to receive a reset signal and switch the voltage of the output end of the photosensitive unit from a current voltage to an initial voltage according to the reset signal; The photosensitive unit is electrically connected to the following unit, and is used to receive the reflected light of the fingerprint to be detected and accumulate charge after the voltage at the output end of the photosensitive unit is switched to the initial voltage, and output a first electrical signal based on the first level of the currently received pulse control signal; and output a second electrical signal according to the first level of the next received pulse control signal; wherein the difference between the second electrical signal and the first electrical signal indicates the charge accumulated by the photosensitive unit between the moment of outputting the second electrical signal and the moment of outputting the first electrical signal; The following unit is electrically connected to the output end of the photosensitive unit, and is used to receive and form a first voltage according to the first electrical signal, and to receive and form a second voltage according to the second electrical signal; The acquisition component is electrically connected to the fingerprint recognition component, and is used to receive the first voltage and the second voltage respectively, and obtain the fingerprint to be detected according to the difference between the second voltage and the first voltage.

2. The fingerprint detection module according to claim 1, characterized in that: The reset unit comprises: A reset transistor, wherein the gate of the reset transistor is connected to the reset signal terminal, the source of the reset transistor is electrically connected to the acquisition component, and the drain of the reset transistor is electrically connected to the output terminal of the photosensitive unit; wherein the reset signal terminal is used to provide the reset signal.

3. The fingerprint detection module according to claim 2, characterized in that: The following unit comprises: A follower transistor, wherein the gate of the follower transistor is electrically connected to the output end of the photosensitive unit, the source of the follower transistor is electrically connected to the collection component, and the drain of the follower transistor is connected to a power supply.

4. The fingerprint detection module according to any one of claims 1 to 3, characterized in that: The fingerprint detection module also includes: a bias power supply; The positive electrode of the bias power supply is electrically connected to the acquisition component, and the negative electrode of the bias power supply is grounded.

5. The fingerprint detection module according to claim 4, characterized in that: The fingerprint detection module includes a plurality of the fingerprint recognition components; wherein the output ends of the follower units of the plurality of the fingerprint recognition components are connected in parallel to the positive electrode of the bias power supply and the connection point of the acquisition component.

6. An electronic device, characterized in that: include: A display module, comprising: a display array composed of a plurality of pixel units; The fingerprint detection module according to any one of claims 1 to 5, wherein the photosensitive unit of the fingerprint detection module is exposed through the gap between the pixel units; The fingerprint detection module is used to obtain the fingerprint to be detected.

7. The electronic device according to claim 6, characterized in that: The photosensitive unit and the pixel unit are distributed in parallel on the same substrate; wherein the photosensitive unit is located in a gap between at least two of the pixel units.

8. The electronic device according to claim 6, characterized in that: The photosensitive unit is located on the back side of the substrate where the pixel unit is located, and is exposed through the gap between at least two of the pixel units.

9. A fingerprint detection method, characterized in that: The method is used in an electronic device comprising the fingerprint detection module according to any one of claims 1 to 5, and the method comprises: Inputting a reset signal to the fingerprint detection module, wherein the reset signal is used to switch the output terminal voltage of the photosensitive unit from the current voltage to the initial voltage; After the voltage at the output end of the photosensitive unit is switched to the initial voltage, a first level of a pulse control signal is input; wherein, after the voltage at the output end of the photosensitive unit is switched to the initial voltage, the photosensitive unit receives reflected light of the fingerprint to be detected and accumulates electric charge; the photosensitive unit outputs a first electrical signal according to the first level of the pulse control signal currently received, and the first electrical signal is used to form a first voltage; inputting a second level of the pulse control signal; After inputting the second level of the pulse control signal, inputting the first level of the next pulse control signal; wherein the photosensitive unit outputs a second electrical signal according to the first level of the next pulse control signal received, and the second electrical signal is used to form a second voltage; the difference between the second electrical signal and the first electrical signal indicates the charge accumulated by the photosensitive unit between the moment when the second electrical signal is output and the moment when the first electrical signal is output; The fingerprint to be detected is obtained according to the difference between the second voltage and the first voltage.

10. The method according to claim 9, characterized in that The reset unit of the fingerprint recognition component includes a reset transistor, and a reset signal is input to the fingerprint detection module, wherein the reset signal is used to switch the output voltage of the photosensitive unit from the current voltage to the initial voltage, including: The reset signal is input to the gate of the reset transistor to turn on the reset transistor; wherein the reset transistor switches the output voltage of the photosensitive unit from the current voltage to the initial voltage.

11. The method according to claim 9, characterized in that The first level of the pulse control signal is used to turn on the photosensitive unit and form a first electrical signal at the output end of the photosensitive unit; wherein the first electrical signal is transmitted to the gate of the follower transistor; the first electrical signal is used to turn on the follower transistor and output the first voltage at the source of the follower transistor.

12. The method according to claim 11, characterized in that When the pulse control signal is at the second level, the follower transistor is turned off.

13. The method according to claim 11, characterized in that The accumulated charge and the first level of the next pulse control signal are used to form a second electrical signal at the output end of the photosensitive unit; wherein the second electrical signal is transmitted to the gate of the follower transistor; The second electrical signal is used to turn on the follower transistor and form the second voltage at the source of the follower transistor.

14. The method according to claim 9, characterized in that When the fingerprint detection module includes a plurality of fingerprint recognition components, After the voltage at the output end of the photosensitive unit is switched to the initial voltage, the first level of the pulse control signal is input, including: After the voltages at the output ends of the plurality of photosensitive units are switched to the initial voltage, the first level of the pulse control signal is sequentially input to the plurality of photosensitive units; wherein, when the pulse control signal input to one photosensitive unit is at the first level, the pulse control signal input to the remaining photosensitive units is at the second level; The second level of the input pulse control signal comprises: After sequentially inputting the first level of the pulse control signal to the plurality of photosensitive units, sequentially inputting the second level of the pulse control signal to the plurality of photosensitive units; The inputting a first level of the next pulse control signal comprises: After the second level of the pulse control signal is input to the multiple photosensitive units in sequence, the first level of the next pulse control signal is input to the multiple photosensitive units in sequence; wherein, when the first level of the next pulse control signal is input to one photosensitive unit, the pulse control signal input to the remaining photosensitive units is the second level.

15. A detection device, characterized in that: include: processor; a memory for storing processor-executable instructions; Wherein, the processor is configured to: implement the steps in the method as claimed in any one of claims 9 to 14 when executing the executable instructions.

16. A non-transitory computer-readable storage medium, when the instructions in the storage medium are executed by a processor of a mobile terminal, the mobile terminal is enabled to perform the steps in the method according to any one of claims 9 to 14.

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