Fingerprint sensor device, sensing method and electronic equipment

Abstract

The embodiment of the invention provides a fingerprint sensor device and method and electronic equipment, the fingerprint sensor device part comprises an electrode layer, stray capacitance exists between the electrode layer and a metal layer or a metal wire or an equivalent metal structure of an adjacent structure of the electrode layer, and the distance between the electrode layer and the adjacent structure is reduced when a pressing action occurs. And when the pressing action is removed, resetting is carried out. And the fingerprint sensor chip is electrically connected with the electrode layer and is used for detecting the capacitance value of the parasitic capacitor and outputting a pressure value corresponding to the pressing action according to the capacitance value. According to the embodiment of the invention, additional pressure detection hardware is not needed, and the hardware cost of pressure detection can be reduced.

Description

Technical Field

[0001] The present application relates to the field of sensing technology, and in particular to a fingerprint sensor device, a sensing method and an electronic device. Background Art

[0002] Mobile phone display screen pressure detection has been applied in the industry. When a finger presses on the display screen, the finger pressure can be detected. However, due to the need to add pressure detection hardware, the solution cost is high and the market application has not been popularized. Summary of the invention

[0003] In view of the above problems, the embodiments of the present application provide a fingerprint sensor device, method and electronic device to solve the above technical problems.

[0004] In a first aspect, an embodiment of the present application provides a fingerprint sensor device, comprising: an electrode layer, wherein parasitic capacitance exists between the electrode layer and a metal layer or metal trace or equivalent metal structure of an adjacent structure, and the distance between the electrode layer and the adjacent structure decreases when a pressing action is applied, and recovers when the pressing action is removed; a fingerprint sensor chip, electrically connected to the electrode layer, for detecting the capacitance value of the parasitic capacitance, and outputting a pressure value corresponding to the pressing action according to the capacitance value.

[0005] In some possible implementations, the adjacent structure is a covering layer, the electrode layer is located between the covering layer and the fingerprint sensor chip, and the outer surface of the covering layer receives the pressing action.

[0006] In some possible implementations, the fingerprint sensor chip is an optical fingerprint sensor chip.

[0007] In some possible implementations, the adjacent structure is a supporting structure, the electrode layer is located between the supporting structure and the fingerprint sensor chip, the fingerprint sensor chip is located on the inner side of the covering layer, and the outer surface of the covering layer receives the pressing action.

[0008] In some possible implementations, the fingerprint sensor chip is an ultrasonic fingerprint sensor chip, and the electrode layer is a surface electrode layer of an ultrasonic transducer in the ultrasonic fingerprint sensor.

[0009] In some possible implementations, the fingerprint sensor chip is specifically used to: determine a capacitance difference between a detected capacitance value and a reference capacitance value, and output a pressure value corresponding to a pressing action according to the capacitance difference.

[0010] In some possible implementations, the fingerprint sensor chip is further used to correct the pressure value according to the pressing position of the pressing action to obtain an actual pressure value.

[0011] In some possible implementations, the fingerprint sensor chip is specifically used to: determine the distance between the pressed 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 an actual pressure value.

[0012] In a second aspect, an embodiment of the present application provides an electronic device, comprising: a covering layer, a supporting structure, and the above-mentioned fingerprint sensor device, wherein the fingerprint sensor device is arranged between the covering layer and the supporting structure.

[0013] In some possible implementations, the electronic device further includes: a touch device for detecting a pressing position of a pressing action; and a processing unit configured to correct the pressure value according to the pressing position to obtain an actual pressure value.

[0014] 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 an actual pressure value.

[0015] In some possible implementations, the processing unit is configured to: query a preset distance-correction coefficient relationship curve to obtain a correction coefficient corresponding to the distance.

[0016] In a third aspect, an embodiment of the present application provides a sensing method, which is applied to an electronic device, wherein the electronic device includes a covering layer, a supporting structure and a fingerprint sensor device, wherein the fingerprint sensor device is located between the covering layer and the supporting structure and includes an electrode layer and a fingerprint sensor chip, wherein parasitic capacitance exists between the electrode layer and the metal layer or metal wiring or equivalent metal structure of the covering layer or the supporting structure, and the distance between the electrode layer and the covering layer or the supporting structure decreases when a pressing action is applied to the covering layer, and recovers when the pressing action is removed, and 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 covering layer; and determining the pressure value corresponding to the pressing action according to the capacitance value.

[0017] In some possible implementations, determining a pressure value corresponding to a pressing action according to a capacitance value includes:

[0018] The capacitance difference between the detected capacitance value and the reference capacitance value is determined; and the pressure value corresponding to the pressing action is output according to the capacitance difference.

[0019] In some possible implementations, the electronic device further includes a touch control device, and the sensing method further includes: detecting a pressing position of a pressing action using the touch control device; and correcting the pressure value according to the pressing position to obtain an actual pressure value.

[0020] In some possible implementations, correcting the pressure value according to the pressed position to obtain the actual pressure value includes: determining the distance between the pressed 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.

[0021] 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.

[0022] In the fingerprint sensor device, method and electronic device provided by the embodiments of the present application, the distance between the electrode layer of the fingerprint sensor device and the adjacent structure decreases when a pressing action is encountered, and is restored when the pressing action is removed. The parasitic capacitance between the electrode layer of the fingerprint sensor device and the metal layer or metal wiring or equivalent metal structure of the adjacent structure changes when a pressing action is encountered. The capacitance value of the parasitic capacitance is detected, and the pressure value corresponding to the pressing action is output according to the capacitance value. The embodiments of the present application do not require additional pressure detection hardware, and can reduce the hardware cost of pressure detection.

[0023] These and other aspects of the present application will become more clearly understood in the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application is shown.

[0026] Figure 2A A schematic diagram of an electronic device with an under-screen fingerprint system provided by an embodiment of the present application is shown.

[0027] Figure 2B A schematic diagram of an electronic device with a side fingerprint system provided by an embodiment of the present application is shown.

[0028] Figure 3A A schematic diagram of a fingerprint sensor device provided in an embodiment of the present application is shown, wherein (a) is a schematic diagram of a connection structure, and (b) is a schematic diagram of distance changes in a static state and when pressure is applied.

[0029] Figure 3B A schematic diagram of another fingerprint sensor device provided in an embodiment of the present application is shown, wherein (a) is a schematic diagram of a connection structure, and (b) is a schematic diagram of distance changes in a static state and when pressure is applied.

[0030] Figure 4 A schematic diagram of a pressure sensing area and a fingerprint sensor area provided in an embodiment of the present application is shown.

[0031] Figure 5 A system block diagram of an electronic device according to an embodiment of the present application is shown.

[0032] Figure 6 A schematic diagram of a distance-correction coefficient relationship curve according to an embodiment of the present application is shown.

[0033] Figure 7 A flow chart of a sensing method according to an embodiment of the present application is shown.

[0034] Figure 8 A structural block diagram of a sensing device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0035] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0036] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0037] In the embodiments of the present application, it should be noted that, in this article, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0038] Moreover, the terms "comprises," "comprising," or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0039] In the description of the embodiments of the present application, words such as "example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "example" or "for example" in the embodiments of the present application is not to be interpreted as being more preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to present relative concepts in a clear manner.

[0040] In addition, the "plurality" in the embodiments of the present application refers to two or more than two. In view of this, in the embodiments of the present application, "plurality" can also be understood as "at least two". "At least one" can be understood as one or more, for example, one, two or more. For example, including at least one means including one, two or more, and there is no limit on which ones are included. For example, including at least one of A, B and C, then A, B, C, A and B, A and C, B and C, or A, B and C can be included.

[0041] It should be noted that, in the embodiments of the present application, "and / or" describes the association relationship of the associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

[0042] It should be noted that in the embodiments of the present application, "connection" can be understood as electrical connection, and 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 either a direct connection between A and B or an indirect connection between A and B through one or more other electrical components.

[0043] In a possible embodiment of the present 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 becomes smaller when a pressing action occurs, and is restored when the pressing action is removed. As a result, the parasitic capacitance between the electrode layer of the fingerprint sensor device and the metal layer or metal wiring or equivalent metal structure of the adjacent structure changes when a pressing action occurs. The capacitance value of the parasitic capacitance is detected, and the pressure value corresponding to the pressing action can be output based on the capacitance value. The pressure detection technical solution of the embodiment of the present application does not require additional pressure detection hardware (such as a pressure sensor), and can reduce the hardware cost of pressure detection.

[0044] Figure 1 A schematic diagram of the structure of an electronic device according to an embodiment of the present application is shown. Figure 1As shown, 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. The user's pressing action is applied to the cover layer 101, and the pressing action may include a fingerprint input action or a non-fingerprint input action, that is, at least a part of the area of ​​the cover layer 101 can be used for user interaction 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.

[0045] In the embodiments of the present application, the electronic device 100 may be a portable electronic device, and the portable electronic device may be a smart phone, a tablet computer, a laptop computer, a personal digital assistant, etc. The electronic device 100 may also be a smart wearable device, such as a smart watch, a virtual reality head mounted device, an augmented reality head mounted device, etc. The embodiments of the present application do not limit the type of the electronic device 100. For simplicity, in this specification, electronic devices with display screens such as smart phones, tablet computers, laptop computers, personal digital assistants, etc. are used as examples to illustrate the embodiments of the present application.

[0046] In an electronic device with a display screen, the support structure 102 may include a middle frame, which is generally located between the display screen and the back shell of the electronic device, and is used to support the display screen and to carry various functional components inside the electronic device, such as a motherboard, a battery, a camera, a speaker, a microphone, various sensor units, etc. In a specific embodiment, the support structure 102 also includes a frame located outside the middle frame, and the frame may include multiple sides and carry a power button, a volume button or other function buttons. The specific position of the fingerprint sensor device 103 in the electronic device 100 can be set between the display screen and the middle frame, between the middle frame and the back shell, or on the frame according to the actual product design needs.

[0047] In some possible implementations, such as Figure 2A As shown, the fingerprint sensor device 103 can be arranged in a partial area or the entire area below the display screen 104, so as to form an under-screen fingerprint system, so that the user can input the fingerprint to realize the under-screen fingerprint function of the electronic device 100. In this embodiment, the cover 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 middle frame, and can be fixedly connected to at least one of the display screen 104 and the middle frame.

[0048] In some possible implementations, such as Figure 2BAs shown, the fingerprint sensor device 103 is arranged on the side of the electronic device 100 for the user to input the fingerprint to 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 specifically 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.

[0049] 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 that are stacked. Figure 3A As shown, Figure 3A This is a typical implementation of an optical fingerprint sensor. The electrode layer of the optical fingerprint sensor is used to convert the optical signal detected by the optical sensor (including CMOS, CCD and other light detection components) into an electrical signal and transmit it to other circuit parts. In some specific embodiments, please combine Figure 2A As shown, 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, please combine Figure 2B As shown, the electrode layer 1031 is located between the sensor cover 105 and the fingerprint sensor chip 1032, and the fingerprint sensor chip 1032 is arranged on the frame. In this embodiment, the cover layer 101 is specifically the sensor cover 105. In some specific embodiments, if the fingerprint sensor device 103 is arranged on the back of the electronic device to form a back fingerprint system, the electrode layer 1031 is located between the back cover of the electronic device and the fingerprint sensor chip 1032.

[0050] Please continue to refer to Figure 3AAs shown, there is a parasitic capacitor between the metal layer or metal trace or equivalent metal structure between the electrode layer 1031 and the display screen 104. The electrode layer 1031 can be equivalent to one plate of the parasitic capacitor Cp, and the metal layer or metal trace or equivalent metal structure of the cover layer 101 can be equivalent to the other plate of the parasitic capacitor Cp. When the user's pressing action applies pressure to the cover layer 101, the cover layer 101 is deformed or displaced, and the distance between the metal layer or metal trace or equivalent metal structure of the cover layer 101 and the electrode layer 1031 becomes smaller, resulting in an increase in the capacitance value of the parasitic capacitor Cp. When the pressing action is removed, the deformation or displacement of the cover layer 101 is restored, and the distance between the metal layer or metal trace or equivalent metal structure of the cover layer 101 and the electrode layer 1031 is restored. Specifically, as Figure 3A As shown, when the pressing action is not applied to the display screen 104 (i.e. static), the distance between the display screen 104 and the electrode layer 1031 is L0; when the 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 the distance is related to the pressure. The fingerprint sensor chip 1032 can detect the capacitance value of the parasitic capacitor Cp and output the pressure value corresponding to the pressing action based on the capacitance value.

[0051] 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 that are stacked. Figure 3B As shown, Figure 3B It is a typical implementation of an ultrasonic fingerprint sensor. The ultrasonic fingerprint sensor includes an ultrasonic transducer. The ultrasonic transducer is generally composed of a surface electrode layer, a PVDF (polyvinylidene fluoride) layer, a matrix electrode layer and a substrate layer stacked in sequence. The surface electrode layer is located at the outermost layer of the ultrasonic transducer. When emitting ultrasonic waves, the surface electrode layer receives the electrical signal and transmits it to the internal PVDF layer, causing the PVDF material to vibrate under the action of the electric field, thereby emitting ultrasonic waves. When receiving ultrasonic waves, the surface electrode layer can transmit the weak electrical signal 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, please refer to Figure 2AAs shown, the electrode layer 1031 is located between the fingerprint sensor chip 1032 and the middle frame, and the fingerprint sensor chip 1032 is located inside the display screen 104. In this embodiment, the support structure 102 is specifically the middle 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 through an adhesive layer. In some specific embodiments, please combine Figure 2B As shown, the electrode layer 1031 is located between the fingerprint sensor chip 1032 and the frame, and the fingerprint sensor chip 1032 is arranged inside the sensor cover 105. In this embodiment, the support structure 102 is specifically a frame, and the covering layer 101 is specifically a sensor cover 105.

[0052] Please continue to refer to Figure 3B As shown, the metal layer or metal wiring or equivalent metal structure ( Figure 3B The electrode layer 1031 can be equivalent to one plate of the parasitic capacitor Cp, and the metal layer or metal trace or equivalent metal structure of the support structure 102 can be equivalent to the other plate of the parasitic capacitor Cp. The user's pressing action applies pressure to the cover layer 101 ( Figure 3B When the pressing action is removed, the deformation or displacement of the covering layer 101 is restored, and the distance between the electrode layer 1031 and the metal layer or metal wiring or equivalent metal structure of the supporting structure 102 is restored. Specifically, as Figure 3B As shown, 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 or metal wiring or equivalent metal structure of the middle 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 or metal wiring or equivalent metal structure of the middle frame is Lpressure, and the distance is related to the pressure. The fingerprint sensor chip 1032 can detect the capacitance value of the parasitic capacitor Cp and output the pressure value corresponding to the pressing action based on the capacitance value.

[0053] In some possible implementations, the fingerprint sensor chip 1032 is specifically used to: determine the capacitance difference between the detected capacitance value and the reference capacitance value, and output the pressure value corresponding to the pressing action according to the capacitance difference. Wherein, the reference capacitance value is the capacitance value of the parasitic capacitance Cp when no pressure is applied (ie, static), and it can be measured before the electronic device 100 leaves the factory, or it can also be measured during the use of the electronic device 100. In a specific embodiment, the initial reference capacitance value can be measured before leaving the factory and saved in the electronic device 100, and the reference capacitance value can be measured and updated during the use of the electronic device, for example, the reference capacitance value is measured and updated whenever the electronic device 100 is turned on.

[0054] Please continue to refer to Figure 3A and Figure 3B Under the premise of a fixed pressing force, 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 capacitance change 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 capacitance change of the parasitic capacitor becomes smaller. Specifically, Figure 4 As shown, when the pressing action of the same pressing force is applied to the center point Po of the fingerprint sensor area, the capacitance value change of the parasitic capacitor is the largest, and when applied to point Pa or point Pb, the capacitance value change of the parasitic capacitor is smaller than the capacitance value change 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 capacitance value change corresponding to point Pa is greater than the capacitance value change corresponding to point Pb. In some embodiments of the present application, the electronic device 100 may include a touch device, and the touch device may detect the pressing position. Furthermore, the electronic device 100 may correct the pressure value based on the pressing position.

[0055] See also 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 to collect the fingerprint information of the user's finger when the user presses the fingerprint sensor device 103 to input the fingerprint, generate corresponding fingerprint data based on the collected fingerprint information, and output the fingerprint data to the processor 106 through the interface module 202, and the interface module 202 may be specifically a serial peripheral interface (SPI). In some possible embodiments of the present application, the capacitance detection module 203 is used to detect the capacitance value of the aforementioned parasitic capacitance Cp, and 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.

[0056] In a specific embodiment, the fingerprint processing module 201 includes a sensing array, an output module, an interface module and a driving module, wherein the sensing array is used to couple with the user's finger to collect the fingerprint information of the user's finger when the user presses the fingerprint sensor to input the fingerprint, and specifically includes a plurality of sensing electrodes distributed in an array, and the area where the sensing array is located or its effective fingerprint collection 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; wherein the driving module is used to drive the sensing array to perform fingerprint scanning to collect the fingerprint information of the user's finger; the output module is used to generate corresponding fingerprint data based on the fingerprint information collected by the sensing array, and output the fingerprint data to the processor 106 through the interface module.

[0057] Furthermore, the output module may include an analog-to-digital converter and a data processing unit, wherein the analog-to-digital converter is used to convert the analog electrical signal collected by the sensing array into a digital signal to obtain fingerprint information in digital form. The data processing unit is used to process the fingerprint information in digital form to generate corresponding fingerprint data. The data processing unit may specifically include a microcontroller, a digital signal processor, etc. The analog-to-digital converter is also used to convert the analog electrical signal output by the capacitance detection module 203 into a digital signal to obtain a capacitance value in digital form. The data processing unit may output a pressure value corresponding to the pressing action based on the capacitance value in digital form, and output the pressure value to the processor 106 through the interface module 202.

[0058] Please continue reading Figure 5 , the electronic device 100 may include a processor 106 and a touch control device 107. The processor 106 may include a central processing unit (CPU), a microcontroller, etc. In a typical embodiment, the touch control device 107 and the display screen 104 constitute a touch-sensitive display (also called a touch screen). The touch control device 107 may specifically include a touch detection component and a touch screen controller. The touch detection component is arranged 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 the touch information from the touch detection component, and convert it into the touch point coordinates and send it to the processor 106, and can also receive commands sent by the processor 106 and execute them.

[0059] In some possible embodiments of the present application, when performing pressure detection, the fingerprint sensor chip 1032 determines the pressure value (called the initial pressure value) corresponding to the pressing action based on the capacitance value, 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.

[0060] In some possible embodiments of the present application, when performing pressure detection, the processor 106 can obtain a pressure value (referred to as an initial pressure value) from the fingerprint sensor chip 1032, obtain a pressing position of the pressing action from the touch device 107, and correct the initial pressure value based on the pressing position to obtain an actual pressure value.

[0061] In a specific embodiment, the fingerprint sensor chip 1032 or the processor 106 can determine the distance between the pressed 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. Figure 4 As shown, the reference position may 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 may be pre-calibrated as the reference position, and the reference position may be stored in the electronic device 100 .

[0062] In the case of a small fingerprint sensor area, if the pressing position of the pressing action is within the fingerprint sensor area, the initial pressure value can be used as the actual pressure value, and the above pressure value correction process is omitted; if the pressing position of the pressing action is outside the fingerprint sensor area, the above pressure value correction process is performed. In the case of a large fingerprint sensor area, the pressure value correction process may not be performed on part of the area inside the fingerprint sensor area, and the pressure value correction process may be performed on other areas of the fingerprint sensor area and areas outside the fingerprint sensor area.

[0063] In some possible embodiments of the present application, the fingerprint sensor chip 1032 or the processor 106 may query a preset distance-correction coefficient relationship curve to obtain a correction coefficient corresponding to the above distance. Figure 4 and Figure 6 ,for Figure 4 The circular pressure sensing area shown in FIG. 1 is specifically centered at the center point of the fingerprint sensor area. The relationship curve between the correction coefficient and the distance is shown in FIG. Figure 6 As shown, the correction coefficient of the specific center point is 1, and the greater the distance from the center point, the greater the correction coefficient. The pressure values ​​at multiple locations on the electronic device 100 can be measured, and the distance and correction coefficient relationship curve can be obtained by fitting based on the pressure values ​​at multiple locations.

[0064] Considering that there may be differences in the structure inside the pressure sensing area, for example, the displacement or deformation caused by the same pressing force is different in the softer area relative to the harder area. This difference may cause the pressing of different positions at the same distance from the center point to have different effects on the capacitance value of the parasitic capacitor, thereby making the distance and correction coefficient relationship curves of different areas different. To this end, in some possible embodiments of the present application, the pressure sensing area can be divided into multiple sub-areas, and the distance and correction coefficient relationship curve corresponding to each sub-area is determined separately. The sub-areas can be divided according to actual product design requirements. When correcting the initial pressure value to obtain the actual pressure value, the fingerprint sensor chip 1032 or the processor 106 determines the distance between the pressed position and the reference position, and determines the sub-area corresponding to the pressed position, and queries the distance and correction coefficient relationship curve corresponding to the sub-area to obtain the correction coefficient corresponding to the above distance.

[0065] The embodiment of the present application also provides a sensing method, which can be implemented by the electronic device 100 of the embodiment of the present application. The method uses a fingerprint sensor device to detect pressure. Specifically, the distance between the electrode layer of the fingerprint sensor device and the metal layer or metal wiring of the adjacent structure or the equivalent metal structure becomes smaller when a pressing action is encountered, and is restored when the pressing action is removed, and then the parasitic capacitance between the electrode layer of the fingerprint sensor device and the metal layer or metal wiring of the adjacent structure or the equivalent metal structure changes when a pressing action is encountered. By detecting the capacitance value of the parasitic capacitance, the pressure value corresponding to the pressing action can be output according to the capacitance value.

[0066] Figure 7 A flow chart of a sensing method according to an embodiment of the present application is shown. Figure 7 As shown, the sensing method includes step S701 to step S702.

[0067] Step S701 , using the fingerprint sensor chip to detect the capacitance value of the parasitic capacitance when a pressing action is applied to the cover layer.

[0068] In the embodiment of the present application, in the electronic device 100, reference Figure 1 As shown, parasitic capacitance may exist in the metal layer or metal trace or equivalent metal structure of the cover layer 101 and the electrode layer of the fingerprint sensor device 103 , or in the metal layer or metal trace or equivalent metal structure of the support structure 102 and the electrode layer of the fingerprint sensor device 103 .

[0069] refer to Figure 2A As shown, the fingerprint sensor device 103 is disposed under the display screen 104 to form an under-screen fingerprint system. A pressing action is applied to the outer surface of the display screen 104 to perform fingerprint recognition or other user interactions. Figure 4As shown, the pressing action can be applied inside or outside the fingerprint sensor area, that is, the pressure sensing area can include the fingerprint sensor area and its periphery. Figure 3A As shown in FIG. 1 , a typical implementation of an optical fingerprint sensor is shown. Parasitic capacitance exists in the metal layer or 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 or metal trace or equivalent metal structure of the display screen 104 can be equivalent to one plate of the parasitic capacitance, and the electrode layer 1031 can be equivalent to the other plate of the parasitic capacitance. When the pressing force of the metal layer or metal trace or equivalent metal structure of the display screen 104 decreases, the capacitance value of the parasitic capacitance increases. In some implementations, reference Figure 3B As shown, it is a typical implementation method of an ultrasonic fingerprint sensor, the parasitic capacitor exists in the metal layer or metal wiring or equivalent metal structure of the middle 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 capacitor, the metal layer or metal wiring or equivalent metal structure of the middle frame can be equivalent to the other plate of the parasitic capacitor, the distance between the metal layer or metal wiring or equivalent metal structure of the middle frame and the electrode layer 1031 decreases when the pressing force of the pressing action is encountered, and the capacitance value of the parasitic capacitor increases.

[0070] refer to Figure 2B As shown, the fingerprint sensor device 103 is arranged on the side of the electronic device 100 to form a side fingerprint system. The pressing action can be applied to the sensor cover 105 of the side fingerprint device to perform fingerprint recognition or other user interactions. In a typical implementation of the optical fingerprint sensor, the parasitic capacitor exists in the metal layer or 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 or metal trace or equivalent metal structure of the sensor cover 105 can be equivalent to one plate of the parasitic capacitor, and the electrode layer 1031 can be equivalent to the other plate of the parasitic capacitor. The distance between the metal layer or metal trace or equivalent metal structure of the sensor cover 105 and the electrode layer 1031 decreases when the pressing force of the pressing action is encountered, and the capacitance value of the parasitic capacitor increases. In a typical implementation of an ultrasonic fingerprint sensor, parasitic capacitance exists in the metal layer or metal trace or equivalent metal structure of the 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 frame can be equivalent to another plate of the parasitic capacitance. The distance between the metal layer or metal trace or equivalent metal structure of the frame and the electrode layer 1031 decreases when the pressing force is applied, and the capacitance value of the parasitic capacitance increases.

[0071] 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 the capacitance value in analog form, and the analog-to-digital converter converts the analog electrical signal output by the capacitance detection module 203 into a digital signal to obtain the capacitance value in digital form. In some cases, the fingerprint sensor device 103 detects whether there is a finger pressing on its fingerprint sensing area. When it is detected that the finger is pressing on the fingerprint sensing area, the fingerprint information is collected and the pressure detection function is turned on. For details, refer to Figure 4 As shown, when a finger is pressed in the fingerprint sensor area, the fingerprint sensor chip 1032 detects that a finger is pressed in its fingerprint sensing area, and can collect fingerprint information and detect the capacitance value of the parasitic capacitor. In some cases, the touch device 107 detects the contact between the finger and the display screen 104, and when the contact between the finger and the display screen 104 is detected, the fingerprint sensor chip 1032 is notified, and the fingerprint processing chip 1032 turns on the pressure detection function. For details, refer to Figure 4 As shown, when the touch control device 107 detects that a finger is pressed in the pressure sensing area, it notifies the fingerprint sensor chip 1032 to detect the capacitance value of the parasitic capacitor. In some implementations, the fingerprint sensor device 103 can periodically detect the capacitance value of the parasitic capacitor. In some implementations, the processor 106 controls the fingerprint sensor device 103 to turn on the pressure detection function to detect the capacitance value of the parasitic capacitor.

[0072] Step S702: determining a pressure value corresponding to the pressing action according to the capacitance value.

[0073] In a typical implementation, in the electronic device 100, the fingerprint sensor chip 1032 determines the pressure value corresponding to the pressing action according to the capacitance value. Specifically, the data processing unit of the fingerprint sensor chip 1032 determines the pressure value corresponding to the pressing action according to the capacitance value, and sends it to the processor 106 through the interface module 202.

[0074] In a typical implementation, in the electronic device 100, the fingerprint sensor chip 1032 can send the capacitance value to the processor 106 through the interface module 202, and the processor 106 determines the pressure value corresponding to the pressing action according to 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 through the interface module 202 when the capacitance value changes.

[0075] See also Figure 3A and 3B, the capacitance value of the parasitic capacitor is related to the distance between the two equivalent plates, and the smaller the distance, the greater the capacitance value. For the same pressing position, the greater the pressure applied, the greater the distance change. It can be seen that the greater the pressure applied, the greater the change in the capacitance value of the parasitic capacitor. Assuming that the capacitance value of the parasitic capacitor when no pressure is applied is the reference capacitance value, the greater the pressure applied, the greater the change in the capacitance value compared to the reference capacitance value, so the pressure value can be determined by the change in the capacitance value. In some possible implementations, the fingerprint sensor chip 1032 or the 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 the capacitance difference.

[0076] Further, the reference capacitance value may be measured and stored in the electronic device 100 before the electronic device 100 leaves the factory, or may be measured and stored in the electronic device 100 during use. In a specific embodiment, an initial reference capacitance value may be measured and stored in the electronic device 100 before leaving the factory, and the reference capacitance value may be measured and updated during use of the electronic device 100, for example, the reference capacitance value may be measured and updated each time the electronic device 100 is turned on.

[0077] Please refer to Figure 4 When the pressing action of the same pressing force is applied to the center point Po of the fingerprint sensor area, the capacitance value change of the parasitic capacitor is the largest. When applied to point Pa or point Pb, the capacitance value change of the parasitic capacitor is smaller than the capacitance value change corresponding to 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 capacitance value change corresponding to point Pa is greater than the capacitance value change corresponding to point Pb. In some embodiments of the present application, the sensing method may further include step S703 and step S704.

[0078] Step S703: Detect the pressed position of the pressing action by using the touch device.

[0079] Step S704: Correct the pressure value according to the pressed position to obtain an actual pressure value.

[0080] In a typical implementation, in the electronic device 100, the fingerprint sensor chip 1032 determines the pressure value (called the initial pressure value) corresponding to the pressing action based on the capacitance value, 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.

[0081] In a typical implementation, in the electronic device 100, the processor 106 can obtain a pressure value (referred to as an initial pressure value) from the fingerprint sensor chip 1032, obtain a pressing position of the pressing action from the touch device 107, and correct the initial pressure value based on the pressing position to obtain an actual pressure value.

[0082] In a specific embodiment, the fingerprint sensor chip 1032 or the processor 106 can determine the distance between the pressed 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. Figure 4 As shown, the reference position may 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 may be pre-calibrated as the reference position, and the reference position may be stored in the electronic device 100 .

[0083] In the case where the fingerprint sensor area is small, if the pressing position of the pressing action is within the fingerprint sensor area, the initial pressure value can be used as the actual pressure value, and the above pressure value correction process is omitted; if the pressing position of the pressing action is outside the fingerprint sensor area, for example Figure 4 At the two pressing positions Pa and Pb shown, step S704 is executed to perform pressure value correction. In the case where the fingerprint sensor area is large, the pressure value correction process may not be performed on part of the area inside the fingerprint sensor area, and the pressure value correction process may be performed on other areas of the fingerprint sensor area and areas outside the fingerprint sensor area.

[0084] In some possible embodiments of the present application, the fingerprint sensor chip 1032 or the processor 106 may query a preset distance-correction coefficient relationship curve to obtain a correction coefficient corresponding to the above distance. Figure 4 and Figure 6 ,for Figure 4 The circular pressure sensing area shown in FIG. 1 is specifically centered at the center point of the fingerprint sensor area. The relationship curve between the correction coefficient and the distance is shown in FIG. Figure 6 As shown, the correction coefficient of the specific center point is 1, and the greater the distance from the center point, the greater the correction coefficient. The pressure values ​​at multiple locations on the electronic device 100 can be measured, and the distance and correction coefficient relationship curve can be obtained by fitting based on the pressure values ​​at multiple locations.

[0085] Considering that there may be differences in the structure inside the pressure sensing area, for example, the displacement or deformation caused by the same pressing force is different in the softer area relative to the harder area. This difference may cause the pressing of different positions at the same distance from the center point to have different effects on the capacitance value of the parasitic capacitor, thereby making the distance and correction coefficient relationship curves of different areas different. To this end, in some possible embodiments of the present application, the pressure sensing area can be divided into multiple sub-areas, and the distance and correction coefficient relationship curve corresponding to each sub-area is determined separately. The sub-areas can be divided according to actual product design requirements. When correcting the initial pressure value to obtain the actual pressure value, the fingerprint sensor chip 1032 or the processor 106 can determine the distance between the pressed position and the reference position, and determine the sub-area corresponding to the pressed position, and query the distance and correction coefficient relationship curve corresponding to the sub-area to obtain the correction coefficient corresponding to the above distance.

[0086] The present application also provides a sensing device, such as Figure 8 As shown, the device 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 between 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 embodiment of the present application. The sensing device can be specifically Figure 1 Figure 2 Figure 4 , Figure 4 , Figure 5 The electronic device 100 shown in FIG. The fingerprint sensor 810 may be specifically a fingerprint sensor device 103, and the processing unit 820 may be specifically a Figure 5 The processor 106 (such as a central processing unit CPU) shown is used to execute the main steps of the methods of the above embodiments. In other alternative embodiments, the processing unit 820 can also be implemented by other processing units or control units (such as a microcontroller MCU) with image processing capabilities.

[0087] The present 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, and when the instructions are executed by the processor 106, the processor 106 executes the method of the above embodiment, for example Figure 7 The sensing method shown.

[0088] The present application also provides a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to enable the processor 106 of the electronic device 100 to execute the sensing method of the above embodiment, for example Figure 7 The sensing method shown.

[0089] The above are only preferred embodiments of the present application, and are not intended to limit the present application in any form. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technical personnel in the field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present application. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A fingerprint sensor device, characterized in that: include: An electrode layer, wherein parasitic capacitance exists between the electrode layer and a metal layer or metal trace or equivalent metal structure of an adjacent structure, and a distance between the electrode layer and the adjacent structure decreases when a pressing action is applied, and is restored 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 capacitor and output a pressure value corresponding to the pressing action according to the capacitance value.

2. The fingerprint sensor device according to claim 1, characterized in that The adjacent structure is a covering layer, the electrode layer is located between the covering layer and the fingerprint sensor chip, and the outer surface of the covering layer receives the pressing action.

3. The fingerprint sensor device according to claim 2, characterized in that The fingerprint sensor chip is an optical fingerprint sensor chip.

4. The fingerprint sensor device according to claim 1, wherein: The adjacent structure is a supporting structure, the electrode layer is located between the supporting structure and the fingerprint sensor chip, the fingerprint sensor chip is located on the inner side of the covering layer, and the outer surface of the covering layer receives the pressing action.

5. The fingerprint sensor device according to claim 4, characterized in that The fingerprint sensor chip is an ultrasonic fingerprint sensor chip, and the electrode layer is a surface electrode layer of an ultrasonic transducer in the ultrasonic fingerprint sensor.

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

7. The fingerprint sensor device according to any one of claims 1 to 6, characterized in that: 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 according to claim 7, characterized in that: 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 an actual pressure value.

9. An electronic device, characterized in that: include: A cover layer, a support structure, and a fingerprint sensor device as claimed in any one of claims 1 to 6, wherein the fingerprint sensor device is arranged between the cover layer and the support structure.

10. The electronic device according to claim 9, characterized in that: The electronic device further comprises: A touch device, used for detecting a pressing position of the pressing action; The processing unit is configured to correct the pressure value according to the pressing position to obtain an actual pressure value.

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

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

13. A sensing method, applied to an electronic device, characterized in that: The electronic device comprises a covering layer, a supporting structure and a fingerprint sensor device, wherein the fingerprint sensor device is located between the covering layer and the supporting structure and comprises an electrode layer and a fingerprint sensor chip, wherein parasitic capacitance exists between the electrode layer and a metal layer or metal trace or equivalent metal structure of the covering layer or the supporting structure, and a distance between the electrode layer and the covering layer or the supporting structure decreases when a pressing action is applied to the covering layer and is restored when the pressing action is removed, and the sensing method comprises: Using the fingerprint sensor chip to detect the capacitance value of the parasitic capacitance when a pressing action is applied to the cover layer; A pressure value corresponding to the pressing action is determined according to the capacitance value.

14. The sensing method according to claim 13, characterized in that: The determining, according to the capacitance value, a pressure value corresponding to the pressing action comprises: Determine a capacitance difference between the detected capacitance value and a reference capacitance value; A pressure value corresponding to the pressing action is output according to the capacitance difference.

15. The sensing method according to claim 13 or 14, characterized in that: The electronic device further includes a touch control device, and the sensing method further includes: Detecting a pressing position of the pressing action using the touch control device; The pressure value is corrected according to the pressed position to obtain an actual pressure value.

16. The sensing method according to claim 15, characterized in that: The step of correcting the pressure value according to the pressing position to obtain an actual pressure value includes: determining a distance between the pressed position and a reference position; determining a correction factor corresponding to the distance; The pressure value is corrected according to the correction coefficient to obtain an actual pressure value.

17. The sensing method according to claim 16, characterized in that: The 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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