Fingerprint sensor apparatus, sensing method, and electronic device

Abstract

Provided in the embodiments of the present application are a fingerprint sensor apparatus, a method, and an electronic device. The fingerprint sensor apparatus comprises: an electrode layer, wherein there is a parasitic capacitance between the electrode layer and a metal layer or a metal trace or an equivalent metal structure of its adjacent structure, and the distance between the electrode layer and the adjacent structure decreases in the case of a pressing action, and returns in the case of removal of the pressing action; and a fingerprint sensor chip, which is electrically connected to the electrode layer, and is used for measuring a capacitance value of the parasitic capacitance, and outputting, on the basis of the capacitance value, a pressure value corresponding to the pressing action. By means of the embodiments of the present application, no additional pressure measurement hardware is required, enabling a reduction in the hardware cost of pressure measurement.

Description

Fingerprint sensor device, sensing method and electronic device

[0001] This application claims priority to Chinese Patent Application No. 202510070245X, filed on January 15, 2025, entitled "Fingerprint Sensor Device, Sensing Method and Electronic Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of sensing technology, specifically to a fingerprint sensor device, sensing method, and electronic device. Background Technology

[0003] Pressure detection for mobile phone displays is already in use in the industry; it detects the pressure applied by a finger pressing on the screen. However, the need for additional pressure detection hardware results in high costs, hindering widespread market adoption. Summary of the Invention

[0004] In view of the above problems, embodiments of this application provide a fingerprint sensor device, method, and electronic device to solve the above technical problems.

[0005] In a first aspect, embodiments of this application provide a fingerprint sensor device, comprising: an electrode layer, wherein the electrode layer and its adjacent structure have a parasitic capacitance in a metal layer or metal trace or equivalent metal structure, and the distance between the electrode layer and the adjacent structure decreases when a pressing action is performed and recovers when the pressing action is removed; and a fingerprint sensor chip electrically connected to the electrode layer, used to detect the capacitance value of the parasitic capacitance and output a pressure value corresponding to the pressing action based on the capacitance value.

[0006] In some possible implementations, the adjacent structure is a cover layer, the electrode layer is located between the cover layer and the fingerprint sensor chip, and the outer surface of the cover layer receives the pressing action.

[0007] In some possible implementations, the fingerprint sensor chip is an optical fingerprint sensor chip.

[0008] In some possible implementations, the adjacent structure is a support structure, the electrode layer is located between the support structure and the fingerprint sensor chip, the fingerprint sensor chip is located inside the cover layer, and the outer surface of the cover layer receives the pressing action.

[0009] In some possible implementations, the fingerprint sensor chip is an ultrasonic fingerprint sensor chip, and the electrode layer is the surface electrode layer of the ultrasonic transducer inside the ultrasonic fingerprint sensor.

[0010] In some possible implementations, the fingerprint sensor chip is specifically used to: determine the capacitance difference between the detected capacitance value and a reference capacitance value, and output a pressure value corresponding to the pressing action based on the capacitance difference.

[0011] In some possible implementations, the fingerprint sensor chip is also used to correct the pressure value based on the pressing position of the pressing action to obtain the actual pressure value.

[0012] In some possible implementations, the fingerprint sensor chip is specifically used to: determine the distance between the pressing position and the reference position; determine a correction coefficient corresponding to the distance; and correct the pressure value according to the correction coefficient to obtain the actual pressure value.

[0013] Secondly, embodiments of this application provide an electronic device, including: a cover layer, a support structure, and the aforementioned fingerprint sensor device, wherein the fingerprint sensor device is disposed between the cover layer and the support structure.

[0014] In some possible implementations, the electronic device further includes: a touch device for detecting the pressing position of the pressing action; and a processing unit configured to correct the pressure value based on the pressing position to obtain the actual pressure value.

[0015] In some possible implementations, the processing unit is configured to: determine the distance between the pressing position and the reference position; determine a correction coefficient corresponding to the distance; and correct the pressure value according to the correction coefficient to obtain the actual pressure value.

[0016] In some possible implementations, the processing unit is configured to query a preset distance-correction coefficient relationship curve to obtain the correction coefficient corresponding to the distance.

[0017] Thirdly, embodiments of this application provide a sensing method applied to an electronic device, the electronic device including a cover layer, a support structure, and a fingerprint sensor device. The fingerprint sensor device is located between the cover layer and the support structure and includes an electrode layer and a fingerprint sensor chip. Parasitic capacitance exists between the electrode layer and the metal layer or metal trace or equivalent metal structure of the cover layer or support structure, and the distance between the electrode layer and the cover layer or support structure decreases when a pressing action is applied to the cover layer and returns to its original value when the pressing action is removed. The sensing method includes: using the fingerprint sensor chip to detect the capacitance value of the parasitic capacitance when a pressing action is applied to the cover layer; and determining a pressure value corresponding to the pressing action based on the capacitance value.

[0018] In some possible implementations, the pressure value corresponding to the pressing action is determined based on the capacitance value, including:

[0019] Determine the capacitance difference between the detected capacitance value and the reference capacitance value; output the pressure value corresponding to the pressing action based on this capacitance difference.

[0020] In some possible implementations, the electronic device further includes a touch device, and the sensing method further includes: using the touch device to detect the pressing position of the pressing action; and correcting the pressure value based on the pressing position to obtain the actual pressure value.

[0021] In some possible implementations, the pressure value is corrected based on the pressing position to obtain the actual pressure value, including: determining the distance between the pressing position and the reference position; determining a correction coefficient corresponding to the distance; and correcting the pressure value based on the correction coefficient to obtain the actual pressure value.

[0022] In some possible implementations, determining the correction coefficient corresponding to the distance includes: querying a preset distance-correction coefficient relationship curve to obtain the correction coefficient corresponding to the distance.

[0023] The fingerprint sensor device, method, and electronic device provided in this application embodiment reduce the distance between the electrode layer and adjacent structure of the fingerprint sensor device when a pressure action is performed and restore it when the pressure action is removed. The parasitic capacitance existing in the metal layer, metal trace, or equivalent metal structure of the electrode layer and adjacent structure of the fingerprint sensor device changes when a pressure action is performed. By detecting the capacitance value of this parasitic capacitance, a pressure value corresponding to the pressure action is output based on the capacitance value. The embodiments of this application do not require additional pressure detection hardware, thus reducing the hardware cost of pressure detection.

[0024] These or other aspects of this application will become more apparent from the description of the following embodiments. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 shows a schematic diagram of the structure of the electronic device provided in an embodiment of this application.

[0027] Figure 2A shows a schematic diagram of an electronic device with an under-display fingerprint system provided in an embodiment of this application.

[0028] Figure 2B shows a schematic diagram of an electronic device with a side fingerprint system provided in an embodiment of this application.

[0029] Figure 3A shows a schematic diagram of a fingerprint sensor device provided in an embodiment of this application, wherein (a) is a schematic diagram of the connection structure and (b) is a schematic diagram of the distance change when static and when pressure is applied.

[0030] Figure 3B shows a schematic diagram of another fingerprint sensor device provided in the embodiments of this application, wherein (a) is a schematic diagram of the connection structure and (b) is a schematic diagram of the distance change when static and under applied pressure.

[0031] Figure 4 shows a schematic diagram of a pressure sensing area and a fingerprint sensor area provided in an embodiment of this application.

[0032] Figure 5 shows a system block diagram of an electronic device according to an embodiment of this application.

[0033] Figure 6 shows a schematic diagram of the relationship curve between distance and correction coefficient according to an embodiment of this application.

[0034] Figure 7 shows a flowchart of a sensing method according to an embodiment of this application.

[0035] Figure 8 shows a structural block diagram of a sensing device according to an embodiment of this application. Detailed Implementation

[0036] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0037] To enable those skilled in the art to better understand the solutions of this application, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0038] In the embodiments of this application, it should be noted that, in this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0039] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0040] In the description of the embodiments of this application, the words "example" or "for example" are used to indicate exemplification, illustration, or description. Any embodiment or design described as "example" or "for example" in the embodiments of this application is not to be construed as being more preferred or having more advantages than another embodiment or design. The use of the words "example" or "for example" is intended to present relative concepts in a clear manner.

[0041] Furthermore, in the embodiments of this application, "multiple" refers to two or more. Therefore, in the embodiments of this application, "multiple" can also be understood as "at least two". "At least one" can be understood as one or more, such as one, two, or more. For example, including at least one means including one, two, or more, and is not limited to which ones are included. For example, including at least one of A, B, and C, then it could include A, B, C, A and B, A and C, B and C, or A and B and C.

[0042] It should be noted that in the embodiments of this application, "and / or" describes the relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In addition, the character " / ", unless otherwise specified, generally indicates that the associated objects before and after it are in an "or" relationship.

[0043] It should be noted that in the embodiments of this application, "connection" can be understood as electrical connection. The connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0044] In a possible embodiment of this application, a fingerprint sensor device is used to detect pressure. Specifically, the distance between the electrode layer of the fingerprint sensor device and its adjacent structure decreases when pressure is applied and returns to its original value when the pressure is removed. Consequently, the parasitic capacitance existing between the electrode layer of the fingerprint sensor device and the metal layer, metal trace, or equivalent metal structure of the adjacent structure changes upon pressure. By detecting the capacitance value of this parasitic capacitance, a pressure value corresponding to the pressure application can be output based on the capacitance value. The pressure detection technology solution of this application embodiment does not require additional pressure detection hardware (e.g., a pressure sensor), thus reducing the hardware cost of pressure detection.

[0045] Figure 1 shows a schematic diagram of the structure of an electronic device according to an embodiment of this application. As shown in Figure 1, the electronic device 100 may include a cover layer 101, a support structure 102, and a fingerprint sensor device 103. The fingerprint sensor device 103 is disposed between the cover layer 101 and the support structure 102. A user's pressing action is applied to the cover layer 101. The pressing action may include a fingerprint input action or a non-fingerprint input action, that is, at least a portion of the cover layer 101 can be used for user interactions such as fingerprint input. The fingerprint sensor device 103 can detect and output a fingerprint image corresponding to the user's fingerprint. The fingerprint sensor device 103 may include, but is not limited to, an optical fingerprint sensor, an ultrasonic fingerprint sensor, a capacitive fingerprint sensor, etc.

[0046] In the embodiments of this application, the electronic device 100 can be a portable electronic device, such as a smartphone, tablet computer, laptop computer, personal digital assistant, etc. The electronic device 100 can also be a smart wearable device, such as a smartwatch, virtual reality headset, augmented reality headset, etc. The embodiments of this application do not limit the type of electronic device 100. For simplicity, this specification uses smartphones, tablet computers, laptop computers, personal digital assistants, and other electronic devices with displays as examples to describe the embodiments of this application.

[0047] In an electronic device with a display screen, the support structure 102 may include a mid-frame, which is generally located between the display screen and the rear shell of the electronic device. The mid-frame supports the display screen and carries various internal functional components of the electronic device, such as the motherboard, battery, camera, speaker, microphone, and various sensing units. In a specific embodiment, the support structure 102 also includes a frame surrounding the mid-frame. The frame may include multiple sides and carry power buttons, volume buttons, or other function buttons. The specific location of the fingerprint sensor device 103 in the electronic device 100 can be determined according to actual product design needs, and may be positioned between the display screen and the mid-frame, between the mid-frame and the rear shell, or on the frame.

[0048] In some possible implementations, as shown in FIG2A, the fingerprint sensor device 103 may be disposed in a partial or complete area below the display screen 104, thereby forming an under-display fingerprint system for users to input their fingerprints to realize the under-display fingerprint function of the electronic device 100. In this embodiment, the overlay layer 101 includes the display screen 104. The fingerprint sensor device 103 is located between the display screen 104 and the support structure 102. In a specific embodiment, the fingerprint sensor device 103 is located between the display screen 104 and the mid-frame, and may be fixedly connected to at least one of the display screen 104 and the mid-frame.

[0049] In some possible implementations, as shown in FIG2B, the fingerprint sensor device 103 is disposed on the side of the electronic device 100 to allow the user to input their fingerprint and realize the side fingerprint function of the electronic device 100. In this embodiment, the cover layer 101 may include a sensor cover plate 105. In a specific embodiment, the fingerprint sensor device 103 may be located between the frame and the sensor cover plate 105. In a specific embodiment, the fingerprint sensor device 103 may be a fingerprint recognition chip or a fingerprint module with a fingerprint recognition chip, which may be integrated above the power button or volume button on the side of the frame, embedded in a predetermined area on the side of the frame, or attached to the inner surface of the side of the frame.

[0050] In some possible implementations, the electrode layer 1031 of the fingerprint sensor device 103 is located between the cover layer 101 and the fingerprint sensor chip 1032, and the fingerprint sensor chip 1032 is disposed on the support structure 102. That is, the electronic device 100 may include a cover layer 101, an electrode layer 1031, a fingerprint sensor chip 1032, and a support structure 102 stacked together. As shown in FIG3A, FIG3A is a typical implementation of an optical fingerprint sensor. The electrode layer of the optical fingerprint sensor is used to transmit the electrical signal converted from the light signal detected by the optical sensor (including CMOS, CCD, and other light detection components) to other circuit parts. In some specific embodiments, referring to FIG2A, the electrode layer 1031 is located between the fingerprint sensor chip 1032 and the display screen 104, and the fingerprint sensor chip 1032 is located on the middle frame. In this embodiment, the cover layer 101 is specifically the display screen 104. In some specific embodiments, referring to FIG2B, the electrode layer 1031 is located between the sensor cover plate 105 and the fingerprint sensor chip 1032, and the fingerprint sensor chip 1032 is disposed on the bezel. In this embodiment, the cover layer 101 is specifically a sensor cover plate 105. In some specific embodiments, if the fingerprint sensor device 103 is disposed on the back of the electronic device to form a rear fingerprint system, the electrode layer 1031 is located between the back cover of the electronic device and the fingerprint sensor chip 1032.

[0051] Referring to Figure 3A, a parasitic capacitance exists between the metal layer, metal trace, or equivalent metal structure between the electrode layer 1031 and the display screen 104. The electrode layer 1031 can be considered as one plate of this parasitic capacitance Cp, and the metal layer, metal trace, or equivalent metal structure of the cover layer 101 can be considered as the other plate of this parasitic capacitance Cp. When a user presses on the cover layer 101, the cover layer 101 deforms or displaces, and the distance between the metal layer, metal trace, or equivalent metal structure of the cover layer 101 and the electrode layer 1031 decreases, causing the capacitance value of the parasitic capacitance Cp to increase. When the pressing action is removed, the deformation or displacement of the cover layer 101 returns to normal, and the distance between the metal layer, metal trace, or equivalent metal structure of the cover layer 101 and the electrode layer 1031 is restored. Specifically, as shown in Figure 3A, when no pressing action is applied to the display screen 104 (i.e., static), the distance between the display screen 104 and the electrode layer 1031 is L0; when a pressing action is applied to the display screen 104 (i.e., pressure is applied), the distance between the display screen 104 and the electrode layer 1031 is Lpressure, and this distance is related to the pressure magnitude. The fingerprint sensor chip 1032 can detect the capacitance value of the parasitic capacitance Cp and output the pressure value corresponding to the pressing action based on the capacitance value.

[0052] In some possible implementations, the electrode layer 1031 of the fingerprint sensor device 103 is located between the support structure 102 and the fingerprint sensor chip 1032, and the fingerprint sensor chip 1032 is disposed inside the cover layer 101. That is, the electronic device 100 may include a cover layer 101, an electrode layer 1031, a fingerprint sensor chip 1032, and a support structure 102 stacked together. As shown in FIG3B, FIG3B is a typical implementation of an ultrasonic fingerprint sensor. The ultrasonic fingerprint sensor includes an ultrasonic transducer, which is generally composed of a surface electrode layer, a PVDF (polyvinylidene fluoride) layer, a matrix electrode layer, and a substrate layer stacked sequentially. The surface electrode layer is located at the outermost layer of the ultrasonic transducer. When emitting ultrasonic waves, the surface electrode layer receives electrical signals and transmits them to the inner PVDF layer, causing the PVDF material to vibrate under the action of an electric field, thereby emitting ultrasonic waves. When receiving ultrasonic waves, the surface electrode layer can transmit the weak electrical signals generated by the ultrasonic vibration of the PVDF layer to the outside. The matrix electrode layer is located between the PVDF layer and the substrate layer and is mainly used for more precise control of the emission and reception of ultrasonic waves. The substrate layer provides physical support for the entire ultrasonic transducer. In this embodiment, the electrode layer 1031 is the surface electrode layer of the ultrasonic transducer of the ultrasonic fingerprint sensor. In some specific embodiments, referring to FIG2A, the electrode layer 1031 is located between the fingerprint sensor chip 1032 and the mid-frame, and the fingerprint sensor chip 1032 is located inside the display screen 104. In this embodiment, the support structure 102 is specifically the mid-frame, and the cover layer 101 is specifically the display screen 104. Further, the fingerprint sensor chip 1032 can be fixed to the display screen 104 by an adhesive layer. In some specific embodiments, referring to FIG2B, the electrode layer 1031 is located between the fingerprint sensor chip 1032 and the frame, and the fingerprint sensor chip 1032 is disposed inside the sensor cover plate 105. In this embodiment, the support structure 102 is specifically the frame, and the cover layer 101 is specifically the sensor cover plate 105.

[0053] Referring to Figure 3B, parasitic capacitance exists in the metal layer, metal traces, or equivalent metal structure (shown as the middle frame in Figure 3B) of the electrode layer 1031 and the support structure 102. The electrode layer 1031 can be considered as one plate of this parasitic capacitance Cp, and the metal layer, metal traces, or equivalent metal structure of the support structure 102 can be considered as the other plate of this parasitic capacitance Cp. When a user presses on the cover layer 101 (shown as the display screen 104 in Figure 3B), the cover layer 101 deforms or displaces. This deformation or displacement is transmitted to the electrode layer 1031, causing the distance between the electrode layer 1031 and the metal layer, metal traces, or equivalent metal structure of the support structure 102 to decrease, resulting in an increase in the capacitance value of the parasitic capacitance Cp. When the pressing action is removed, the deformation or displacement of the cover layer 101 recovers, and the distance between the electrode layer 1031 and the metal layer, metal traces, or equivalent metal structure of the support structure 102 returns to normal. Specifically, as shown in Figure 3B, when the pressing action is not applied to the display screen 104 (i.e., static), the distance between the electrode layer 1031 and the metal layer, metal trace, or equivalent metal structure of the mid-frame is L0; when the pressing action is applied to the display screen 104 (i.e., pressure is applied), the distance between the electrode layer 1031 and the metal layer, metal trace, or equivalent metal structure of the mid-frame is Lpressure, and this distance is related to the pressure magnitude. The fingerprint sensor chip 1032 can detect the capacitance value of the parasitic capacitance Cp and output the pressure value corresponding to the pressing action based on the capacitance value.

[0054] In some possible implementations, the fingerprint sensor chip 1032 is specifically used to: determine the capacitance difference between the detected capacitance value and a reference capacitance value, and output a pressure value corresponding to the pressing action based on the capacitance difference. The reference capacitance value is the capacitance of the parasitic capacitance Cp when no pressure is applied (i.e., static), and it can be measured before the electronic device 100 leaves the factory, or it can be measured during use of the electronic device 100. In a specific embodiment, an initial reference capacitance value can be measured and stored in the electronic device 100 before leaving the factory, and this reference capacitance value can be measured and updated during use of the electronic device, for example, whenever the electronic device 100 is powered on.

[0055] Please refer to Figures 3A and 3B. Under the premise of a fixed pressing pressure, when the finger presses at the center of the fingerprint sensor area, the deformation or displacement of the corresponding position of the electrode layer is the largest, and the change in the capacitance value of the parasitic capacitor is also the largest. When the pressing position deviates from the center of the fingerprint sensor area, the deformation or displacement of the corresponding position of the electrode layer decreases, and the change in the capacitance value of the parasitic capacitor becomes smaller. Specifically, as shown in Figure 4, for the same pressing pressure, when applied to the center point Po of the fingerprint sensor area, the change in the capacitance value of the parasitic capacitor is the largest. When applied to points Pa or Pb, the change in the capacitance value of the parasitic capacitor is smaller than the change in the capacitance value corresponding to Po. Furthermore, the distance between point Pa and the center point Po is smaller than the distance between point Pb and the center point Po, and the change in the capacitance value corresponding to point Pa is greater than the change in the capacitance value corresponding to point Pb. In some embodiments of this application, the electronic device 100 may include a touch device that can detect the pressing position. Furthermore, the electronic device 100 may correct the pressure value based on the pressing position.

[0056] Referring to Figure 5, the fingerprint sensor chip 1032 may include a fingerprint processing module 201, an interface module 202, and a capacitance detection module 203. The fingerprint processing module 201 is used to couple with the user's finger when the user presses the fingerprint sensor device 103 to input a fingerprint, thereby acquiring the user's fingerprint information. Based on the acquired fingerprint information, it generates corresponding fingerprint data and outputs the fingerprint data to the processor 106 through the interface module 202. The interface module 202 may specifically be a Serial Peripheral Interface (SPI). In some possible embodiments of this application, the capacitance detection module 203 is used to detect the capacitance value of the aforementioned parasitic capacitance Cp. The fingerprint processing module 201 is also used to generate a pressure value corresponding to the pressing action based on the capacitance value and output the pressure value to the processor 106 through the interface module 202.

[0057] In a specific embodiment, the fingerprint processing module 201 includes a sensing array, an output module, an interface module, and a driving module. The sensing array is used to couple with the user's finger when the user presses the fingerprint sensor to input a fingerprint, thereby acquiring the user's fingerprint information. Specifically, it includes multiple sensing electrodes arranged in an array. The area where the sensing array is located, or its effective fingerprint acquisition area, is the sensing area of ​​the fingerprint sensor device. The driving module and the output module are connected to the sensing array and the interface module 202, respectively. The driving module drives the sensing array to perform fingerprint scanning to acquire the user's fingerprint information. The output module generates corresponding fingerprint data based on the fingerprint information acquired by the sensing array and outputs the fingerprint data to the processor 106 through the interface module.

[0058] Furthermore, the output module may include an analog-to-digital converter (ADC) and a data processing unit. The ADC converts the analog electrical signals acquired by the sensing array into digital signals to obtain digital fingerprint information. The data processing unit processes the digital fingerprint information to generate corresponding fingerprint data. Specifically, the data processing unit may include a microcontroller, a digital signal processor, etc. The ADC also converts the analog electrical signals output by the capacitance detection module 203 into digital signals to obtain digital capacitance values. The data processing unit can output a pressure value corresponding to the pressing action based on the digital capacitance value and output this pressure value to the processor 106 via the interface module 202.

[0059] Please refer to Figure 5. The electronic device 100 may include a processor 106 and a touch device 107. The processor 106 may include a central processing unit (CPU), a microcontroller, etc. In a typical embodiment, the touch device 107 and the display screen 104 constitute a touch-sensitive display (also called a touch screen). The touch device 107 may specifically include a touch detection component and a touch screen controller. The touch detection component is disposed on the display screen 104 and is used to detect the user's touch position to obtain touch information and send the touch information to the touch screen controller. The touch screen controller is used to receive touch information from the touch detection component, convert it into touch point coordinates and send them to the processor 106, and can also receive and execute commands sent by the processor 106.

[0060] In some possible embodiments of this application, when performing pressure detection, the fingerprint sensor chip 1032 determines the pressure value corresponding to the pressing action (called the initial pressure value) based on the capacitance value, and obtains the pressing position detected by the touch device 107, and corrects the initial pressure value according to the pressing position to obtain the actual pressure value.

[0061] In some possible embodiments of this application, when performing pressure detection, the processor 106 can obtain a pressure value (called an initial pressure value) from the fingerprint sensor chip 1032, obtain the pressing position of the pressing action from the touch device 107, and correct the initial pressure value based on the pressing position to obtain the actual pressure value.

[0062] In a specific embodiment, the fingerprint sensor chip 1032 or processor 106 can determine the distance between the pressing position and the reference position, determine a correction coefficient corresponding to the distance, and correct the initial pressure value according to the correction coefficient to obtain the actual pressure value. Referring to Figure 4, the reference position can be the center point Po of the fingerprint sensor area. In a specific implementation, the position of the center point Po of the fingerprint sensor area can be pre-calibrated as the reference position and stored in the electronic device 100.

[0063] For fingerprint sensor areas that are small, if the pressing action occurs within the fingerprint sensor area, the initial pressure value can be used as the actual pressure value, omitting the pressure value correction process described above. If the pressing action occurs outside the fingerprint sensor area, the pressure value correction process described above should be performed. For fingerprint sensor areas that are large, the pressure value correction process can be omitted for certain areas within the fingerprint sensor area, while the pressure value correction process can be performed for other areas of the fingerprint sensor area and areas outside the fingerprint sensor area.

[0064] In some possible embodiments of this application, the fingerprint sensor chip 1032 or processor 106 can query a preset distance-correction coefficient relationship curve to obtain a correction coefficient corresponding to the aforementioned distance. Referring to Figures 4 and 6, for the circular pressure sensing area shown in Figure 4, specifically with the center point of the fingerprint sensor area as the center, the relationship curve between the correction coefficient and distance is shown in Figure 6. Specifically, the correction coefficient for the center point is 1, and the greater the distance from the center point, the larger the correction coefficient. Pressure values ​​at multiple locations on the electronic device 100 can be measured, and the distance-correction coefficient relationship curve can be obtained by fitting the pressure values ​​at multiple locations.

[0065] Considering the potential structural differences within the pressure-sensing area—for example, softer areas may exhibit different displacements or deformations under the same pressure compared to harder areas—this difference can lead to varying impacts on parasitic capacitance values ​​when pressed at different locations at the same distance from the center point. Consequently, the distance-to-correction-coefficient relationship curves differ across areas. Therefore, in some possible embodiments of this application, the pressure-sensing area can be divided into multiple sub-regions, and a distance-to-correction-coefficient relationship curve can be determined for each sub-region. The sub-regions can be defined according to actual product design requirements. When calibrating the initial pressure value to obtain the actual pressure value, the fingerprint sensor chip 1032 or processor 106 determines the distance between the pressing position and the reference position, identifies the sub-region corresponding to the pressing position, and queries the distance-to-correction-coefficient relationship curve for that sub-region to obtain the correction coefficient corresponding to the aforementioned distance.

[0066] This application also provides a sensing method, which can be implemented by the electronic device 100 of this application. The method utilizes a fingerprint sensor device to detect pressure. Specifically, the distance between the electrode layer of the fingerprint sensor device and the metal layer, metal trace, or equivalent metal structure of its adjacent structure decreases when pressure is applied and returns to its original value when the pressure is removed. Consequently, the parasitic capacitance existing between the electrode layer of the fingerprint sensor device and the metal layer, metal trace, or equivalent metal structure of the adjacent structure changes upon pressure. By detecting the capacitance value of this parasitic capacitance, a pressure value corresponding to the pressure application can be output based on the capacitance value.

[0067] Figure 7 shows a flowchart of a sensing method according to an embodiment of the present application. As shown in Figure 7, the sensing method includes steps S701 to S702.

[0068] Step S701: Use the fingerprint sensor chip to detect the capacitance value of the parasitic capacitance when the pressing action is applied to the cover layer.

[0069] In this embodiment of the application, in the electronic device 100, referring to FIG1, the parasitic capacitance may exist in the metal layer or metal trace of the cover layer 101 or the electrode layer of the fingerprint sensor device 103, or in the metal layer or metal trace of the support structure 102 or the electrode layer of the fingerprint sensor device 103.

[0070] Referring to Figure 2A, a fingerprint sensor device 103 is disposed under the display screen 104 to form an under-display fingerprint system. A pressing action is applied to the outer surface of the display screen 104 for fingerprint recognition or other user interactions. Referring to Figure 4, the pressing action can be applied within or outside the fingerprint sensor area; that is, the pressure sensing area can include the fingerprint sensor area and its periphery. In some implementations, referring to Figure 3A, a typical implementation of an optical fingerprint sensor, parasitic capacitance exists in the metal layer, metal trace, or equivalent metal structure of the display screen 104 and the electrode layer 1031 of the fingerprint sensor device 103. The metal layer, metal trace, or equivalent metal structure of the display screen 104 can be considered as one plate of the parasitic capacitance, and the electrode layer 1031 can be considered as the other plate of the parasitic capacitance. The distance between the metal layer, metal trace, or equivalent metal structure of the display screen 104 and the electrode layer 1031 decreases with the pressing force, and the capacitance value of the parasitic capacitance increases. In some implementations, referring to Figure 3B, which is a typical implementation of an ultrasonic fingerprint sensor, parasitic capacitance exists in the metal layer or metal trace or equivalent metal structure of the mid-frame and the electrode layer 1031 of the fingerprint sensor device 103. The electrode layer 1031 can be equivalent to one plate of the parasitic capacitance, and the metal layer or metal trace or equivalent metal structure of the mid-frame can be equivalent to the other plate of the parasitic capacitance. The distance between the metal layer or metal trace or equivalent metal structure of the mid-frame and the electrode layer 1031 decreases when the pressing force of the pressing action decreases, and the capacitance value of the parasitic capacitance increases.

[0071] Referring to Figure 2B, a fingerprint sensor device 103 is disposed on the side of the electronic device 100 to form a side fingerprint system. A pressing action can be applied to the sensor cover 105 of the side fingerprint device for fingerprint recognition or other user interactions. In a typical implementation of an optical fingerprint sensor, parasitic capacitance exists in the metal layer, metal trace, or equivalent metal structure of the sensor cover 105 and the electrode layer 1031 of the fingerprint sensor device 103. The metal layer, metal trace, or equivalent metal structure of the sensor cover 105 can be considered as one electrode of the parasitic capacitance, and the electrode layer 1031 can be considered as the other electrode of the parasitic capacitance. The distance between the metal layer, metal trace, or equivalent metal structure of the sensor cover 105 and the electrode layer 1031 decreases with the pressing force of the pressing action, and the capacitance value of the parasitic capacitance increases. In a typical implementation of an ultrasonic fingerprint sensor, parasitic capacitance exists in the metal layer or metal trace of the frame or an equivalent metal structure and the electrode layer 1031 of the fingerprint sensor device 103. The electrode layer 1031 can be considered as one plate of the parasitic capacitance, and the metal layer or metal trace of the frame or an equivalent metal structure can be considered as the other plate of the parasitic capacitance. The distance between the metal layer or metal trace of the frame or an equivalent metal structure and the electrode layer 1031 decreases when the pressing force of the pressing action decreases, and the capacitance value of the parasitic capacitance increases.

[0072] In a specific embodiment, the capacitance detection module 203 of the fingerprint sensor chip 1032 detects the capacitance value of the parasitic capacitance to obtain an analog capacitance value. The analog-to-digital converter converts the analog electrical signal output by the capacitance detection module 203 into a digital signal to obtain a digital capacitance value. In some cases, the fingerprint sensor device 103 detects whether a finger is pressing on its fingerprint sensing area. When a finger is detected pressing on the fingerprint sensing area, it collects fingerprint information and activates the pressure detection function. Specifically, referring to Figure 4, when a finger is pressed on the fingerprint sensor area, the fingerprint sensor chip 1032 detects the presence of a finger pressing on its fingerprint sensing area, collects fingerprint information, and detects the capacitance value of the parasitic capacitance. In some cases, the touch device 107 detects the contact between a finger and the display screen 104. When the touch device 107 detects the contact between a finger and the display screen 104, it notifies the fingerprint sensor chip 1032, and the fingerprint processing chip 1032 activates the pressure detection function. Specifically, referring to Figure 4, when the touch device 107 detects a finger pressing on the pressure sensing area, it notifies the fingerprint sensor chip 1032 to detect the capacitance value of the parasitic capacitance. In some implementations, the fingerprint sensor device 103 can periodically detect the capacitance value of the parasitic capacitance. In some implementations, the processor 106 controls the fingerprint sensor device 103 to enable pressure detection to detect the capacitance value of the parasitic capacitance.

[0073] Step S702: Determine the pressure value corresponding to the pressing action based on the capacitance value.

[0074] In a typical implementation, in the electronic device 100, the fingerprint sensor chip 1032 determines the pressure value corresponding to the pressing action based on the capacitance value. Specifically, the data processing unit of the fingerprint sensor chip 1032 determines the pressure value corresponding to the pressing action based on the capacitance value and sends it to the processor 106 through the interface module 202.

[0075] In a typical implementation, in the electronic device 100, the fingerprint sensor chip 1032 can send the capacitance value to the processor 106 via the interface module 202, and the processor 106 determines the pressure value corresponding to the pressing action based on the capacitance value. In a specific embodiment, the fingerprint sensor chip 1032 can periodically detect the capacitance value of the parasitic capacitance and send the capacitance value to the processor 106 via the interface module 202 when the capacitance value changes.

[0076] Referring to Figures 3A and 3B, the capacitance value of the parasitic capacitance is related to the distance between the two equivalent plates; the smaller the distance, the larger the capacitance value. For the same pressing position, the greater the applied pressure, the greater the change in distance. Therefore, the greater the applied pressure, the greater the change in the parasitic capacitance value. Assuming the parasitic capacitance value is a reference capacitance value when no pressure is applied, the greater the applied pressure, the greater the change in capacitance value compared to the reference capacitance value. Therefore, the pressure value can be determined by the change in capacitance value. In some possible implementations, the fingerprint sensor chip 1032 or processor 106 can determine the capacitance difference between the detected capacitance value and the reference capacitance value, and output the pressure value corresponding to the pressing action based on this capacitance difference.

[0077] Furthermore, the reference capacitance value can be measured and stored in the electronic device 100 before it leaves the factory, or it can be measured and stored in the electronic device 100 during use. In a specific embodiment, an initial reference capacitance value can be measured and stored in the electronic device 100 before it leaves the factory, and the reference capacitance value can be measured and updated during use of the electronic device 100, for example, the reference capacitance value can be measured and updated every time the electronic device 100 is powered on.

[0078] Referring to Figure 4, when the same pressing force is applied to the center point Po of the fingerprint sensor area, the change in parasitic capacitance is the largest. When applied to points Pa or Pb, the change in parasitic capacitance is smaller than the change in capacitance at point Po. Furthermore, the distance between point Pa and the center point Po is smaller than the distance between point Pb and the center point Po, and the change in capacitance at point Pa is greater than the change in capacitance at point Pb. In some embodiments of this application, the sensing method may further include steps S703 and S704.

[0079] Step S703: Use a touch device to detect the pressing position of the pressing action.

[0080] Step S704: Correct the pressure value according to the pressing position to obtain the actual pressure value.

[0081] In a typical implementation, in the electronic device 100, the fingerprint sensor chip 1032 determines the pressure value corresponding to the pressing action (referred to as the initial pressure value) based on the capacitance value, and obtains the pressing position detected by the touch device 107, and corrects the initial pressure value according to the pressing position to obtain the actual pressure value.

[0082] In a typical implementation, in electronic device 100, processor 106 can obtain a pressure value (referred to as initial pressure value) from fingerprint sensor chip 1032, obtain the pressing position of the pressing action from touch device 107, and correct the initial pressure value based on the pressing position to obtain the actual pressure value.

[0083] In a specific embodiment, the fingerprint sensor chip 1032 or processor 106 can determine the distance between the pressing position and the reference position, determine a correction coefficient corresponding to the distance, and correct the initial pressure value according to the correction coefficient to obtain the actual pressure value. Referring to Figure 4, the reference position can be the center point Po of the fingerprint sensor area. In a specific implementation, the position of the center point Po of the fingerprint sensor area can be pre-calibrated as the reference position and stored in the electronic device 100.

[0084] For fingerprint sensor areas that are small, if the pressing action occurs within the fingerprint sensor area, the initial pressure value can be used as the actual pressure value, omitting the pressure value correction process described above. If the pressing action occurs outside the fingerprint sensor area, for example, at the Pa and Pb pressing positions shown in Figure 4, step S704 is executed to perform pressure value correction. For fingerprint sensor areas that are large, the pressure value correction process can be omitted for certain areas within the fingerprint sensor area, while pressure value correction can be performed for other areas of the fingerprint sensor area and areas outside the fingerprint sensor area.

[0085] In some possible embodiments of this application, the fingerprint sensor chip 1032 or processor 106 can query a preset distance-correction coefficient relationship curve to obtain a correction coefficient corresponding to the aforementioned distance. Referring to Figures 4 and 6, for the circular pressure sensing area shown in Figure 4, specifically with the center point of the fingerprint sensor area as the center, the relationship curve between the correction coefficient and distance is shown in Figure 6. Specifically, the correction coefficient for the center point is 1, and the greater the distance from the center point, the larger the correction coefficient. Pressure values ​​at multiple locations on the electronic device 100 can be measured, and the distance-correction coefficient relationship curve can be obtained by fitting the pressure values ​​at multiple locations.

[0086] Considering the potential structural differences within the pressure-sensing area—for example, softer areas may exhibit different displacements or deformations under the same pressure compared to harder areas—this difference can lead to varying impacts on parasitic capacitance values ​​when pressed at different locations at the same distance from the center point. Consequently, this results in different distance-to-correction-coefficient curves for different areas. Therefore, in some possible embodiments of this application, the pressure-sensing area can be divided into multiple sub-regions, and a distance-to-correction-coefficient curve can be determined for each sub-region. The sub-regions can be defined according to actual product design requirements. When calibrating the initial pressure value to obtain the actual pressure value, the fingerprint sensor chip 1032 or processor 106 can determine the distance between the pressing position and the reference position, identify the sub-region corresponding to the pressing position, and query the distance-to-correction-coefficient curve for that sub-region to obtain the correction coefficient corresponding to the aforementioned distance.

[0087] This application also provides a sensing device, as shown in FIG8, which includes a fingerprint sensor 810 and a processing unit 820. The fingerprint sensor 810 is used to: collect fingerprint information of a user's fingerprint and generate fingerprint data, and detect the capacitance value of the parasitic capacitance of the electrode layer of the fingerprint sensor 810 and its adjacent structure. The processing unit 820 is used to execute the sensing method of the embodiments of this application. The sensing device may specifically be the electronic device 100 shown in FIG1, FIG2, FIG4, and FIG5. The fingerprint sensor 810 may specifically be a fingerprint sensor device 103, and the processing unit 820 may specifically be a processor 106 (such as a central processing unit CPU) shown in FIG5, used to execute the main steps of the methods of the above embodiments. In other alternative embodiments, the processing unit 820 may also be implemented using other processing units or control units with image processing capabilities (such as microcontrollers MCU).

[0088] This application also provides an electronic device 100, which may further include: a processor 106; and a memory storing a program, wherein the program includes instructions that, when executed by the processor 106, cause the processor 106 to perform the methods of the above embodiments, such as the sensing method shown in FIG7.

[0089] This application also provides a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to cause the processor 106 of the electronic device 100 to execute the sensing method of the above embodiments, such as the sensing method shown in FIG7.

[0090] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Although this application has disclosed preferred embodiments as above, it is not intended to limit this application. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this application. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A fingerprint sensor device, comprising: The electrode layer and its adjacent metal layer or metal trace or equivalent metal structure have parasitic capacitance, and the distance between the electrode layer and the adjacent structure decreases when a pressing action is performed and returns to its original value when the pressing action is removed. The fingerprint sensor chip is electrically connected to the electrode layer and is used to detect the capacitance value of the parasitic capacitance and output a pressure value corresponding to the pressing action based on the capacitance value.

2. The fingerprint sensor device as described in claim 1, wherein, The adjacent structure is a cover layer, the electrode layer is located between the cover layer and the fingerprint sensor chip, and the outer surface of the cover layer receives the pressing action.

3. The fingerprint sensor device as described in claim 2, wherein, The fingerprint sensor chip is an optical fingerprint sensor chip.

4. The fingerprint sensor device as described in claim 1, wherein, The adjacent structure is a support structure, the electrode layer is located between the support structure and the fingerprint sensor chip, the fingerprint sensor chip is located inside the cover layer, and the outer surface of the cover layer receives the pressing action.

5. The fingerprint sensor device as described in claim 4, characterized in that, The fingerprint sensor chip is an ultrasonic fingerprint sensor chip, and the electrode layer is the surface electrode layer of the ultrasonic transducer inside the ultrasonic fingerprint sensor.

6. The fingerprint sensor device as claimed in claim 1, wherein, The fingerprint sensor chip is specifically used to: determine the capacitance difference between the detected capacitance value and the reference capacitance value, and output a pressure value corresponding to the pressing action based on the capacitance difference.

7. The fingerprint sensor device according to any one of claims 1 to 6, wherein, The fingerprint sensor chip is also used to correct the pressure value according to the pressing position of the pressing action to obtain the actual pressure value.

8. The fingerprint sensor device as claimed in claim 7, wherein, The fingerprint sensor chip is specifically used for: determining the distance between the pressing position and the reference position; determining a correction coefficient corresponding to the distance; and correcting the pressure value according to the correction coefficient to obtain the actual pressure value.

9. An electronic device, comprising: The cover layer, the support structure, and the fingerprint sensor device as described in any one of claims 1 to 6, wherein the fingerprint sensor device is disposed between the cover layer and the support structure.

10. The electronic device of claim 9, wherein, The electronic device also includes: A touch device for detecting the pressing position of the pressing action; The processing unit is configured to correct the pressure value based on the pressing position to obtain the actual pressure value.

11. The electronic device of claim 10, wherein, The processing unit is configured to: determine the distance between the pressing position and the reference position; determine a correction coefficient corresponding to the distance; and correct the pressure value according to the correction coefficient to obtain the actual pressure value.

12. The electronic device of claim 11, wherein, The processing unit is configured to: query a preset distance-correction coefficient relationship curve to obtain the correction coefficient corresponding to the distance.

13. A sensing method applied to an electronic device, wherein, The electronic device includes a cover layer, a support structure, and a fingerprint sensor device. The fingerprint sensor device is located between the cover layer and the support structure and includes an electrode layer and a fingerprint sensor chip. The electrode layer and the metal layer, metal trace, or equivalent metal structure of the cover layer or the support structure have parasitic capacitance. The distance between the electrode layer and the cover layer or the support structure decreases when a pressing action is applied to the cover layer and returns to its original value when the pressing action is removed. The sensing method includes: The fingerprint sensor chip is used to detect the capacitance value of the parasitic capacitance when a pressing action is applied to the cover layer; The pressure value corresponding to the pressing action is determined based on the capacitance value.

14. The sensing method as described in claim 13, wherein, Determining the pressure value corresponding to the pressing action based on the capacitance value includes: Determine the capacitance difference between the measured capacitance value and the reference capacitance value; The pressure value corresponding to the pressing action is output based on the capacitance difference.

15. The sensing method as described in claim 13 or 14, wherein, The electronic device further includes a touch device, and the sensing method further includes: The touch device is used to detect the pressing position of the pressing action; The pressure value is adjusted according to the pressing position to obtain the actual pressure value.

16. The sensing method as described in claim 15, wherein, The step of correcting the pressure value based on the pressing position to obtain the actual pressure value includes: Determine the distance between the pressing position and the reference position; Determine the correction coefficient corresponding to the distance; The pressure value is corrected according to the correction factor to obtain the actual pressure value.

17. The sensing method of claim 16, wherein, Determining the correction coefficient corresponding to the distance includes: querying a preset distance-correction coefficient relationship curve to obtain the correction coefficient corresponding to the distance.

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