WO2020233570A1 - Fingerprint recognition device and electronic apparatus - Google Patents

Abstract

A fingerprint recognition device (02) and an electronic apparatus (01), relating to the field of fingerprint recognition. The fingerprint recognition device (02) comprises at least one fingerprint sensing element (20) and a graphene pressure-sensing layer (30). The fingerprint sensing element (20) is used to acquire a fingerprint of a user. The graphene pressure-sensing layer (30) is located on a side of the fingerprint sensing element (20) provided with a sensing surface, or located on a side of the fingerprint sensing element (20) facing away from the sensing surface of the fingerprint sensing element (20). The graphene pressure-sensing layer (30) deforms as a result of the touch pressure applied by the user. The invention can reduce the probability of ghost-touching when the electronic apparatus (01) is being used by a user.

Description

Fingerprint identification device and electronic equipment

This application claims the priority of a Chinese patent application filed with the State Intellectual Property Office of China with application number 201910431503.7, and the priority of a Chinese patent application with the title of "a fingerprint identification device, electronic equipment" on May 22, 2019. The entire content is incorporated into this application by reference.

Technical field

This application relates to the field of fingerprint identification, and in particular to a fingerprint identification device and electronic equipment.

Background technique

With the development of biometric technology, fingerprint recognition technology has the characteristics of good security, high reliability, simple and convenient use, etc., making fingerprint recognition technology widely used in various fields to protect personal information security, especially in the field of electronic equipment , Such as mobile phones, laptops, tablet computers, digital cameras, etc. However, in the process of using the above electronic device, when a finger accidentally touches the fingerprint recognition position in the electronic device, a false touch is prone to occur, causing the electronic device to be unlocked by mistake, thereby reducing the user experience.

Summary of the invention

The embodiments of the present application provide a fingerprint identification device and an electronic device, which can reduce the probability of a fingerprint false touch phenomenon when a user uses the electronic device.

In order to achieve the foregoing objectives, the following technical solutions are adopted in the embodiments of this application:

The first aspect of the embodiments of the present application provides a fingerprint identification device. The fingerprint identification device includes at least one fingerprint sensing element and a graphene pressure-sensitive layer. The fingerprint sensor is used to collect the user's fingerprint. The graphene pressure-sensitive layer is located on the side where the sensing surface of the fingerprint sensing element is located. Alternatively, the graphene pressure-sensitive layer may be located on the side of the fingerprint sensing element away from its sensing surface. The graphene pressure-sensitive layer is used to deform under the touch pressure applied by the user. When the user uses the electronic device with the above-mentioned fingerprint recognition device, when the finger touches the fingerprint recognition device, touch pressure is applied to the display module. The touch pressure can cause the display module to deform and drive the corresponding The connected graphene pressure-sensitive layer is deformed. When the graphene pressure-sensitive layer deforms, its impedance changes. In this case, the impedance value of the graphene pressure-sensitive layer after deformation can be compared with the impedance value before deformation, so as to obtain the touch pressure applied by the user. Or, in some other embodiments of the present application, the electrical signal provided by the graphene pressure-sensitive layer to the processor after the deformation is compared with the voltage before the deformation, so as to obtain the touch pressure applied by the user. Based on this, when the aforementioned touch pressure is obtained, it can be compared with a preset pressure threshold. When the aforementioned touch pressure is greater than the pressure threshold, it can indicate that the user is performing a real touch operation. In this case, each fingerprint sensing element can collect the user's fingerprint. The collected fingerprints can be matched with pre-entered fingerprints to realize fingerprint identification. Or, when the obtained touch pressure is less than the pressure threshold, it may indicate that the touch operation performed by the user is a wrong touch. In this case, each fingerprint sensor element will not collect the user's fingerprint to prevent false touch. In addition, the material constituting the graphene pressure-sensitive layer mainly includes graphene. The thickness of the single-layer graphene film in the graphene pressure-sensitive layer can be made very thin. Therefore, after the graphene pressure-sensitive layer is integrated with multiple fingerprint sensing elements, the size of the fingerprint identification device can be reduced. The fingerprint identification device's requirements for the spatial structure of the electronic equipment are reduced. In addition, after the graphene pressure-sensitive layer is deformed by force, its impedance can undergo a sensitive and recoverable linear change. Thus, the pressure sensing module with the graphene pressure sensing layer has higher sensitivity. When the touch pressure changes within 0˜500 g, there is still a linear relationship between the electrical signal sent by the graphene pressure-sensitive layer and the touch pressure applied by the user. Furthermore, the graphene pressure-sensitive layer has a very high strength, which can be more than 100 times the strength of steel, so as to reduce the probability that the graphene pressure-sensitive layer will break when users use electronic devices.

Optionally, the graphene pressure-sensitive layer includes a plurality of sensing sub-blocks arranged at intervals. Each sensing sub-block corresponds to at least one fingerprint sensing element. In this way, on the one hand, since the above-mentioned multiple sensing sub-blocks are not connected to each other, the probability of mutual interference of the touch pressure on each sensing sub-block is reduced, and each sensing sub-block is increased to sense the user's touch. The accuracy of the pressure. In another aspect, the actual touch area of the user can be obtained according to the number of sensing sub-blocks whose impedance values change each time the user touches. Then, the actual touch area is compared with a preset area threshold, and when the actual touch area is less than the area threshold, it can be determined that the user's touch operation is a wrong touch.

Optionally, the fingerprint identification device further includes a covering layer covering the sensing surface of the fingerprint sensing element. The graphene pressure-sensitive layer is located on the side surface of the cover layer away from the fingerprint sensing element. Alternatively, the graphene pressure-sensitive layer is located between the fingerprint sensing element and the cover layer. Thus, the integration of the fingerprint recognition module and the graphene pressure-sensitive layer can be realized.

Optionally, the fingerprint identification device further includes a substrate for carrying each fingerprint sensing element. The graphene pressure sensitive layer is located on the side surface of the substrate away from the fingerprint sensing element. Alternatively, the graphene pressure-sensitive layer is located between the substrate and the fingerprint sensing element. Thus, the integration of the fingerprint recognition module and the graphene pressure-sensitive layer can be realized.

The second aspect of the embodiments of the present application provides an electronic device. The electronic equipment includes a display module and any fingerprint identification device as described above. The display module includes a display surface and a back surface away from the display surface. The fingerprint identification device is located on the back of the display module, and the sensing surface of the fingerprint sensor element in the fingerprint identification device faces the back of the display module. This electronic device has the same technical effect as the fingerprint identification device provided in the foregoing embodiment, and will not be repeated here.

Optionally, the vertical projection of all fingerprint sensing elements in the fingerprint identification device on the display module is within the range of the vertical projection of the graphene pressure-sensitive layer on the display module. In this way, the graphene pressure-sensitive layer can cover each fingerprint sensing element, so that the graphene pressure-sensitive layer can cover any position in the fingerprint recognition device that can recognize fingerprints, thereby effectively reducing the pressure detection of the fingerprint recognition device The area of the blind zone improves the accuracy of the fingerprint recognition device in detecting touch pressure.

Optionally, the electronic device further includes a pressure-sensitive driving chip. The pressure-sensitive driving chip is electrically connected to the graphene pressure-sensitive layer, and is used to provide driving signals to each fingerprint sensing element. The above-mentioned fingerprint drive chip can be arranged on the motherboard. Or, in some other embodiments of the present application, the above-mentioned fingerprint driving chip and multiple fingerprint sensing elements may be located in the same package.

A third aspect of the embodiments of the present application provides a housing assembly. The housing assembly includes a middle frame and any fingerprint identification device as described above. Wherein, the middle frame includes a carrying board for carrying the circuit board and a frame arranged around the carrying board. Button holes are provided on the frame. The fingerprint identification device is located in the button hole and connected to the frame. The sensing surface of the fingerprint sensing element in the fingerprint identification device faces the outer surface of the frame, so that the user's fingerprint can be identified. The fingerprint sensing element and the graphene pressure sensing layer are electrically connected to the circuit board. The housing assembly has the same technical effect as the fingerprint identification device provided in the foregoing embodiment, and will not be repeated here.

The fourth aspect of the embodiments of the present application provides an electronic device. The electronic device includes a display module and the aforementioned housing assembly. The display module is located in the middle frame, the carrying board is away from the side surface of the circuit board, and the display module is connected with the middle frame. The electronic device has the same technical effect as the housing assembly provided in the foregoing embodiment, and will not be repeated here.

The fourth aspect of the embodiments of the present application provides an electronic device. The electronic equipment includes a fingerprint identification area, a display module and a fingerprint identification device. The display module includes a display surface and a back surface away from the display surface. The fingerprint identification device includes a graphene pressure-sensitive layer located in a fingerprint identification area and at least one fingerprint sensing element. The fingerprint sensing element is used to collect the user's fingerprint, and the sensing surface of the fingerprint sensing element faces the back of the display module. The graphene pressure-sensitive layer is connected to the back of the display module, and is used to deform under the touch pressure applied by the user. The above-mentioned electronic device has the same technical effect as the fingerprint identification device provided in the foregoing embodiment, and will not be repeated here.

Optionally, each fingerprint sensing element is connected to the back of the display module. The graphene pressure-sensitive layer is located on the periphery of the fingerprint sensor. Therefore, when the user performs fingerprint recognition through the fingerprint sensor element, the graphene pressure-sensitive layer located around the fingerprint sensor element can collect the user's touch pressure.

Optionally, the graphene pressure-sensitive layer is a closed frame structure. All fingerprint sensing elements are located in the hollow area of the frame structure. Therefore, when the user performs a touch operation, the graphene pressure-sensitive layer located around all the fingerprint sensing elements can be uniformly deformed at the pressing position, so that the obtained pressing force is more accurate.

Optionally, the electronic device further includes a middle frame. The middle frame includes a bearing board and a frame arranged around the bearing board. The back of the display module is connected with the frame, and there is a first gap between the back of the display module and the carrying plate. Each fingerprint sensing element is connected to a surface of the carrier plate facing the display module, and there is a second gap between the fingerprint sensing element and the graphene pressure sensitive layer. By arranging the fingerprint sensing element on the carrier board and having a second gap with the graphene pressure-sensitive layer, the distance between the user's finger and the fingerprint sensing element can be increased. Therefore, when the fingerprint sensor element is a photoelectric conversion element, the fingerprint sensor element is beneficial to distinguish the reflection of the ridge line of the finger and the reflection of the valley line.

Optionally, the vertical projection of all fingerprint sensing elements in the fingerprint identification device on the display module is within the range of the vertical projection of the graphene pressure-sensitive layer on the display module. In this way, the graphene pressure-sensitive layer can cover each fingerprint sensing element, so that the graphene pressure-sensitive layer can cover any position in the fingerprint recognition device that can recognize fingerprints, thereby effectively reducing the pressure detection of the fingerprint recognition device The area of the blind zone improves the accuracy of the fingerprint recognition device in detecting touch pressure.

Optionally, the graphene pressure-sensitive layer includes a plurality of sensing sub-blocks arranged at intervals. Each sensing sub-block corresponds to at least one fingerprint sensing element. The technical effect of the sensing sub-block is the same as that described above, and will not be repeated here.

Optionally, the electronic device further includes a pressure-sensitive driving chip. The pressure-sensitive driving chip is electrically connected to the graphene pressure-sensitive layer, and is used to provide driving signals to each fingerprint sensing element. The setting method of the pressure-sensitive driving chip is the same as that described above, and will not be repeated here.

Description of the drawings

FIG. 1a is a schematic structural diagram of an electronic device provided by some embodiments of this application;

FIG. 1b is a schematic structural diagram of some parts of the electronic device in FIG. 1a;

FIG. 2 is a schematic diagram of the structure of the display module in FIG. 1b;

FIG. 3 is a schematic structural diagram of a fingerprint identification module provided by some embodiments of the application;

4a is a schematic structural diagram of a pressure sensing module provided by some embodiments of the application;

4b is a schematic structural diagram of a pressure sensing module provided by some embodiments of the application;

FIG. 5 is a method of setting the fingerprint identification device in the electronic device according to some embodiments of the application;

FIG. 6a is an integration method of the fingerprint sensing element and the graphene pressure-sensitive layer provided by some embodiments of the application;

Fig. 6b is a schematic structural diagram of an electronic device having the fingerprint identification module shown in Fig. 6a;

Figure 6c is an enlarged view of the partial structure of Figure 6b;

FIG. 7 is another integration method of the fingerprint sensing element and the graphene pressure-sensitive layer in the fingerprint identification device provided by some embodiments of the application;

FIG. 8 is a schematic diagram of a circuit architecture for fingerprint recognition and pressure detection provided by some embodiments of the application;

FIG. 9 is a schematic structural diagram of a graphene pressure-sensitive layer provided by some embodiments of the application;

FIG. 10a is a schematic structural diagram of a housing assembly according to some embodiments of the application;

Figure 10b is a cross-sectional view taken along O1-O1 in Figure 10a;

Figure 10c is another cross-sectional view taken along O1-O1 in Figure 10a;

Figure 10d is another cross-sectional view taken along O1-O1 in Figure 10a;

Figure 10e is another cross-sectional view taken along O1-O1 in Figure 10a;

FIG. 11a is a schematic structural diagram of another electronic device provided by some embodiments of the application;

Figure 11b is another cross-sectional view taken along O2-O2 in Figure 11a;

Fig. 11c is a partial schematic diagram of a top view structure of the electronic device shown in Fig. 11b;

Fig. 11d is a partial schematic diagram of a top view structure of the electronic device shown in Fig. 11b;

FIG. 12 is a schematic structural diagram of another electronic device provided by some embodiments of the application.

Reference signs:

01-Electronic equipment; 02-Fingerprint identification device; 10-Display module; 11-Middle frame assembly; 12-Rear case; 101-Liquid crystal display; 102-BLU; 200-Fingerprint identification module; 20-Fingerprint sensor element; 21-fingerprint driver chip; 300-pressure sensing module; 30-graphene pressure-sensitive layer; 31-pressure-sensitive driver chip; 22-covering layer; 23-substrate; 100-processor; 301-sensing sub-block; 110 -Carrying board; 111- frame; 112- key hole; 04- fingerprint recognition area.

Detailed ways

The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

Hereinafter, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of these features. In the description of this application, unless otherwise specified, "plurality" means two or more.

In addition, in this application, the azimuthal terms such as "upper" and "lower" are defined relative to the schematic placement of the components in the drawings. It should be understood that these directional terms are relative concepts, and they are used for relative For the description and clarification, it can be changed correspondingly according to the changes in the orientation of the components in the drawings.

In this application, unless expressly stipulated and limited otherwise, the term "connected" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or a whole; it can be directly connected or Can be indirectly connected through an intermediary.

An embodiment of the present application provides an electronic device. The electronic device includes, for example, a mobile phone, a tablet computer, a personal digital assistant (PDA), a vehicle-mounted computer, and a smart wearable product. The embodiments of the present application do not impose special restrictions on the specific form of the above electronic equipment. For the convenience of description, the following is an example in which the electronic device 01 is a mobile phone as shown in FIG. 1a.

In this case, as shown in FIG. 1b, the above-mentioned electronic device 01 mainly includes a display module 10, a middle frame assembly 11, and a rear casing 12. The middle frame assembly 11 is located between the display module 10 and the rear shell 12.

The display module 10 is used for displaying images. The display module 10 has a display surface A for displaying images, and a back surface B away from the display panel. The back B of the display module 10 faces the middle frame 11 as shown in FIG. 1b.

In some embodiments of the present application, the display module 10 is a liquid crystal display module. In this case, the display module 10 includes a liquid crystal display (LCD) 101 as shown in FIG. 2 and a backlight module located on the back of the liquid crystal display 101 (away from the side surface of the LCD 101 for displaying images). Group (backlight unit, BLU) 102.

The BLU 102 may provide a light source to the liquid crystal display 101, so that each sub-pixel in the liquid crystal display 101 can emit light to realize image display.

Alternatively, in other embodiments of the present application, the display module 10 may be an organic light emitting diode (OLED) display screen. Since each sub-pixel in the OLED display screen is provided with an electroluminescence layer, the OLED display screen can realize self-luminescence after receiving the working voltage. In this case, the above-mentioned BLU does not need to be provided in the display module 10 with the OLED display screen.

As shown in Fig. 1b, the driving circuit in the display module 10 can pass through the middle frame 11 through a flexible printed circuit (FPC), and then connect with the main board on the middle frame 11, such as a printed circuit board (printed circuit board, PCB) electrical connection. Therefore, the display module 10 can be controlled by the chip on the PCB for image display.

In addition, when the above electronic device 01 has a fingerprint recognition function, the electronic device 01 also includes a fingerprint recognition device 02 for collecting and recognizing the user's fingerprint when the user touches and presses the electronic device 01 (as shown in Figure 1a) ).

The fingerprint identification device 02 includes at least one fingerprint sensing element 20 as shown in FIG. 3. The electronic device 01 also includes a fingerprint drive chip 21 electrically connected to each fingerprint sensing element 20. Among them, the fingerprint driving chip 21 and at least one fingerprint sensing element 20 may constitute the fingerprint identification module 200.

In some embodiments of the present application, the above-mentioned fingerprint drive chip 21 may be arranged on a PCB (hereinafter referred to as a motherboard) on the middle frame 11. Or, in some other embodiments of the present application, the aforementioned fingerprint drive chip 21 and the multiple fingerprint sensing elements 20 may be located in the same package. For the convenience of description, the following description is made by taking the fingerprint driving chip 21 on the motherboard of the electronic device 01 as an example. The user's fingerprint includes a plurality of raised ridges and sunken valleys. Based on this, each fingerprint drive chip 21 can provide a drive signal to each fingerprint sensor element 20, and under the drive of the drive signal, the fingerprint sensor element 20 can respond to a small portion of the user’s finger corresponding to the position of the fingerprint sensor element 20. Fingerprints of some areas are collected. Then, the collected signal is transmitted to the processor on the motherboard by means of electrical signals.

The processor can determine whether the user's fingerprint at the corresponding position of each fingerprint sensor element 20 is a ridge or valley line based on the above electrical signal, and can obtain the user's fingerprint by splicing the fingerprint information obtained by each fingerprint sensor element 20. So as to complete the collection or entry of user fingerprints. Next, the processor can also compare the fingerprints collected above with the fingerprints that have been entered to realize fingerprint identification.

In some embodiments of the present application, the aforementioned fingerprint sensing element 20 may be a photosensitive element capable of converting optical signals into electrical signals. In this case, the fingerprint identification device 02 also includes a light source. For example, a light source that emits infrared light.

In this way, when the user's finger touches the fingerprint identification device 02, the light source emits infrared light to the finger. After the infrared light is irradiated on the user’s finger, the angle of refraction of the ridge line and valley line of the finger and the intensity of the light reflected to the fingerprint sensor element 20 are different, so that the fingerprint sensor element 20 corresponding to the ridge line position and the fingerprint sensor element 20 corresponding to the valley line position are different. The magnitude of the electrical signal generated by the sensing element 20 after photoelectric conversion is also different.

In this case, each fingerprint sensing element 20 generates an electrical signal that matches the light signal reflected by the ridge or valley based on the intensity of the light reflected by the finger received. As a result, the aforementioned processor can determine the fingerprint information of the finger at the position where the fingerprint sensor 20 is located according to the electrical signal output by each fingerprint sensor 20.

Based on this, when the fingerprint sensor element 20 is a photosensitive element capable of converting light signals into electrical signals, the surface of the fingerprint sensor element 20 that receives light reflected by the finger is called the sensing surface of the fingerprint sensor element.

Or, in some other embodiments of the present application, the aforementioned fingerprint sensing element 20 may be an element capable of converting ultrasonic signals into electrical signals. In this case, the fingerprint identification device 02 also includes a signal generator for emitting ultrasonic waves. In this way, ultrasonic waves can be used to generate different echoes at the ridge and valley lines of the finger, so as to achieve the purpose of obtaining fingerprint information of the finger at the position where the fingerprint sensor 20 is located.

Based on this, when the fingerprint sensing element 20 is an element capable of converting ultrasonic signals into electrical signals, the side surface of the fingerprint sensing element 20 for receiving the ultrasonic echo reflected by the finger is called the sensing surface of the fingerprint sensing element.

Or, in some other embodiments of the present application, the fingerprint sensing element 20 may form an electric field with the electrolyte under the skin of the finger. The ridge line and valley line of the finger are respectively different from the electric field generated between the fingerprint sensor element 20, so as to achieve the purpose of obtaining fingerprint information of the finger at the position of the fingerprint sensor element 20.

Based on this, when the fingerprint sensor element 20 uses the method of forming an electric field with the electrolyte under the finger's skin to perform fingerprint recognition, the fingerprint sensor element 20 is in the electronic device 01, close to the side surface of the finger, which is called the sensing surface of the fingerprint sensor element .

It should be noted that the above is an example of the manner in which the fingerprint identification device 02 collects the user's fingerprint through the fingerprint sensor 20. The rest of the methods will not be repeated here. The present application does not limit the manner in which the fingerprint identification device 02 collects the user's fingerprint through the fingerprint sensing element 20, as long as the user's fingerprint can be collected to realize fingerprint identification.

In addition, in the process of the user's touch, the aforementioned fingerprint identification device 02 can obtain the user's touch pressure before collecting the user's fingerprint, so as to determine whether the current user's touch operation is based on the magnitude of the touch pressure. Real touch operation is wrong touch.

In order to obtain the touch pressure of the user's finger, the fingerprint identification device 02 provided in the embodiment of the present application further includes a graphene pressure-sensitive layer 30 as shown in FIG. 4a. The aforementioned electronic device 01 also includes a pressure-sensitive driving chip 31 electrically connected to the graphene pressure-sensitive layer 30. Wherein, the pressure-sensitive driving chip 31 and the graphene pressure-sensitive layer 30 can constitute a pressure sensing module 300.

In some embodiments of the present application, the pressure-sensitive driving chip 31 may be disposed on the main board on the middle frame 11. Or, in other embodiments of the present application, the pressure-sensitive driving chip 31 and the graphene pressure-sensitive layer 30 may also be located in the same package. For the convenience of description, the following descriptions are made by taking the pressure-sensitive driving chip 31 on the motherboard of the electronic device 01 as an example.

The graphene pressure-sensitive layer 30 is deformed under the touch pressure applied by the user, so that the graphene pressure-sensitive layer 30 is deformed. In addition, the pressure-sensitive driving chip 31 is used to provide a driving signal to the graphene pressure-sensitive layer 30 electrically connected thereto.

In some embodiments of the present application, the impedance change caused by the graphene pressure-sensitive layer 30 when deformed can be used to obtain the touch pressure of the user. At this time, the pressure sensing module 300 with the graphene pressure sensing layer 30 adopts an impedance type pressure sensing method.

For example, under the driving action of the driving signal provided by the pressure-sensitive driving chip 31, when the graphene pressure-sensitive layer 30 is deformed, the impedance of the graphene pressure-sensitive layer 30 will change. In this case, the processor electrically connected to the graphene pressure-sensitive layer 30 can obtain the touch pressure of the user according to the change in the impedance of the graphene pressure-sensitive layer 30.

For another example, under the driving action of the driving signal provided by the pressure-sensitive driving chip 31, when the graphene pressure-sensitive layer 30 is deformed, the impedance of the graphene pressure-sensitive layer 30 will change. The electrical signal output by the circuit, such as voltage or current, also changes. In this case, the processor electrically connected to the graphene pressure-sensitive layer 30 can obtain the touch pressure of the user according to the change of the electrical signal output by the circuit having the graphene pressure-sensitive layer 30.

Alternatively, in some other embodiments of the present application, the graphene pressure-sensitive layer 30 can be used as one electrode of the pressure-sensing capacitor, so that the graphene pressure-sensitive layer 30 can interact with the other electrode of the pressure-sensing capacitor when the graphene pressure-sensitive layer 30 is deformed. The change value of the capacitance generated between the two to obtain the touch pressure of the user. At this time, the pressure sensing module 300 with the graphene pressure sensing layer 30 adopts a capacitive pressure sensing method.

For example, under the driving action of the driving signal provided by the pressure-sensitive driving chip 31, when the graphene pressure-sensitive layer 30 is deformed, the capacitance value of the pressure-sensing capacitor will change. In this case, the processor can obtain the touch pressure of the user according to the change of the capacitance value of the pressure sensing capacitor.

In addition, the embodiment of the present application does not limit the pattern of the graphene pressure-sensitive layer 30, for example, it may be a block as shown in FIG. 4a. It can also be in the shape of a broken line as shown in Figure 4b. Those skilled in the art can set the pattern of the graphene pressure-sensitive layer 30 as needed.

For example, when the pressure sensing module 300 adopts the resistive pressure sensing method, before the user performs a touch operation, compared to the block-shaped graphene pressure-sensitive layer 30, the broken line graphene pressure-sensitive The line width of the layer 30 is thinner and the length is larger, so the initial impedance is larger.

Or, for another example, when the pressure sensing module 300 adopts the capacitive pressure sensing method, when the distance between the two electrodes in the pressure sensing capacitor remains unchanged, before the user performs a touch operation, the relative For the graphene pressure-sensitive layer 30 in the shape of a broken line, the block-shaped graphene pressure-sensitive layer 30 has a relatively large area between one electrode of the pressure-sensing capacitor and the other electrode of the pressure-sensing capacitor. The initial capacitance of the capacitor is relatively large.

It should be noted that the foregoing is only an example of the shape of the graphene pressure-sensitive layer 30, which is not limited in this application, as long as the sensitivity of the pressure-sensing module 300 with the graphene pressure-sensitive layer 30 can meet the design requirements. Just ask.

In addition, in some embodiments of the present application, the method for manufacturing the graphene pressure-sensitive layer 30 may be as follows: after the graphene piezoresistive paste and the metallic silver paste are mixed, the printing process is used to mix the composite material according to a preset pattern. The paste is printed on a flexible film substrate. After drying and curing, the graphene pressure-sensitive layer 30 is formed.

Alternatively, in some other embodiments of the present application, the method for manufacturing the graphene pressure-sensitive layer 30 may be to grow a single layer on a metal foil, such as copper foil, by chemical vapor deposition (CVD) or the like. Or multilayer graphene film. Then, the single-layer or multi-layer graphene film and the copper foil are peeled off by solution etching to form the graphene pressure-sensitive layer 30. Next, the peeled graphene pressure-sensitive layer 30 is transferred to the flexible film substrate.

Wherein, when the graphene film needs to be patterned, processes such as photolithography masking, plasma bombardment, etc. can be used to form the block or fold line graphene film.

It should be noted that, in the embodiments of the present application, the above-mentioned flexible film substrate may be polyimide film (PI), polyethylene terephthalate (PET), polymethyl methacrylate (polymethyl methacrylate, PMMA) and other membrane materials.

Hereinafter, through specific embodiments, the arrangement of the graphene pressure-sensitive layer 30 in the fingerprint identification device 02 and the arrangement of at least one fingerprint sensing element 20 in the electronic device 01 will be described in detail.

Example one

In this example, as shown in FIG. 5, the fingerprint identification device 02 is located on the back of the display module 10. For example, the fingerprint identification device 02 is pasted on the back of the display module 10 (the side surface facing the middle frame 11) through glue, such as optically clear adhesive (OCA). In order to enable the fingerprint sensor 20 to collect finger fingerprints, the sensor surface of the fingerprint sensor 20 faces the back of the display module 10. The description of the sensing surface of the fingerprint sensing element 20 is the same as that described above, and will not be repeated here.

In addition, in this example, all fingerprint sensing elements 20 in the fingerprint identification device 02 are integrated with the graphene pressure-sensitive layer 30. The integration method of the fingerprint sensor 20 and the graphene pressure-sensitive layer 30 will be described as an example below.

In some embodiments of the present application, the aforementioned graphene pressure-sensitive layer 30 may be located on the side where the sensing surfaces of the multiple fingerprint sensing elements 20 are located.

For example, as shown in FIG. 6a, the fingerprint identification module 200 further includes a covering layer 22 covering the sensing surface of each fingerprint sensing element 20, and a substrate 23 for carrying each fingerprint sensing element 20. Wherein, the above-mentioned cover layer 22 may be an encapsulation layer for encapsulating a plurality of fingerprint sensing elements 20. The substrate 23 may be a circuit board provided with a circuit structure. The circuit board can be a PCB or an FPC.

In this case, a plurality of fingerprint sensing elements 20 may be fabricated on the substrate 23, and the sensing surfaces of the plurality of fingerprint sensing elements 20 may be covered with the covering layer 22 to form the fingerprint identification module 200. Then, the above-mentioned graphene pressure-sensitive layer 30 is fabricated on the surface of the cover layer 22 of the fingerprint identification module 200 away from the fingerprint sensor element 20, so that the graphene pressure-sensitive layer 30 is located on the cover layer 22 away from the fingerprint sensor element 20 surface.

In this case, it can be seen from the above method of fabricating the graphene pressure-sensitive layer 30 that the graphene pressure-sensitive layer 30 can be fabricated on the surface of the covering layer 22 away from the fingerprint sensor 20 by printing. Alternatively, the graphene pressure-sensitive layer 30 formed by peeling off the single-layer or multi-layer graphene film grown on the copper foil is directly transferred to the surface of the covering layer 22 away from the fingerprint sensing element 20. In this way, the fingerprint identification module 200 can be integrated with the graphene pressure-sensitive layer 30. The manufacturing process of the graphene pressure-sensitive layer 30 is the same as described above, and will not be repeated here.

Alternatively, the flexible film substrate on which the graphene pressure-sensitive layer 30 is formed can also be attached to the surface of the cover layer 22 away from the fingerprint sensor 20. In this way, the fingerprint sensing element 20 and the graphene pressure-sensitive layer 30 can be integrated.

Based on this, when the fingerprint identification device 02 is arranged on the back of the display module 10, as shown in FIG. 6b, the side where the graphene pressure-sensitive layer 30 is located in the fingerprint identification device 02 can be connected to the display module 10 through a colloid. The back side is glued together.

In this case, when the fingerprint identification device 02 adopts an optical fingerprint identification method, in order to enable more light reflected by the finger to enter the fingerprint sensing element 20. The material constituting the above-mentioned covering layer 22 and the material of the flexible film substrate for supporting the graphene pressure-sensitive layer 30 can be selected from resin materials with higher light transmittance.

In addition, as shown in FIG. 6c, the vertical projection of all fingerprint sensing elements 20 in the fingerprint identification device 02 on the display module 10 is within the range of the vertical projection of the graphene pressure-sensitive layer 30 on the display module 10. In this way, the graphene pressure-sensitive layer 30 can cover all fingerprint sensing elements 20, so that the graphene pressure-sensitive layer 30 can cover any position in the touch fingerprint identification device 02 that can identify fingerprints, thereby effectively reducing fingerprint identification. The area of the pressure detection blind zone of the device 02 improves the accuracy of the fingerprint recognition device 02 to detect touch pressure.

Or, in the case where the graphene pressure-sensitive layer 30 may be located on the sensing surfaces of multiple fingerprint sensing elements 20, in other embodiments of the present application, as shown in FIG. 7, the graphene pressure-sensitive layer 30 may be located on the fingerprint sensor. Between the sensing element 20 and the covering layer 22. In this way, the fingerprint identification module 200 can be integrated with the graphene pressure-sensitive layer 30. The manufacturing process of the graphene pressure-sensitive layer 30 is the same as described above, and will not be repeated here.

Based on any of the above-mentioned integration methods of the fingerprint sensing element 20 and the graphene pressure-sensitive layer 30, when the user touches the fingerprint recognition device 02 while using the electronic device 01, the touch pressure will be applied to the display module 10 The touch pressure can cause the display module 10 to deform, thereby driving the graphene pressure-sensitive layer 30 connected to it to deform. When the pressure-sensitive driving chip 31 sends a driving signal to the graphene pressure-sensitive layer 30, when the graphene pressure-sensitive layer 30 is deformed, its impedance changes.

In this case, in some embodiments of the present application, the electronic device 01 having the fingerprint sensing element 20 further includes a processor 100 as shown in FIG. 8. The processor 100 can be arranged on a motherboard (PCB shown in FIG. 1b). Based on this, the processor 100 shown in FIG. 8 in the pressure sensing module 300 can compare the impedance value of the graphene pressure-sensitive layer 30 after deformation with the impedance value before deformation, thereby confirming the user according to the comparison result. The touch pressure applied. Or, in other embodiments of the present application, the processor 100 shown in FIG. 8 in the pressure sensing module 300 provides the electrical signal to the processor 100 according to the graphene pressure-sensitive layer 30 after the deformation, and the electrical signal before the deformation The voltage is compared to confirm the touch pressure applied by the user according to the comparison result.

Based on this, after the processor 100 obtains the aforementioned touch pressure, it can be compared with a preset pressure threshold, such as 1N. When the aforementioned touch pressure is greater than the pressure threshold, it can indicate that the user is performing a real touch operation.

In this case, the processor 100 may send the first instruction to the fingerprint driving chip 21. In response to the first instruction, the fingerprint drive chip 21 drives each fingerprint sensing element 20 electrically connected to the fingerprint drive chip 21 to collect the user's fingerprint. The collected fingerprints can be transmitted to the fingerprint identification module 200, and the collected fingerprints can be matched with the fingerprints entered in advance through the fingerprint identification module 200 to realize fingerprint identification.

Or, when the processor 100 obtains that the touch pressure is less than the pressure threshold, it may indicate that the touch operation performed by the user is a wrong touch.

In this case, the processor 100 may send a second instruction to the fingerprint driving chip 21. In response to the second instruction, the fingerprint driving chip 21 stops providing driving signals to the fingerprint sensing elements 20 electrically connected to the fingerprint driving chip 21. Therefore, the fingerprint identification device 02 will not collect the user's fingerprint when the user touches by mistake.

In addition, it can be seen from the above that the material constituting the graphene pressure-sensitive layer 30 mainly includes graphene. The thickness of the single-layer graphene film in the graphene pressure-sensitive layer 30 can be made very thin, for example, about 0.34 nm. Therefore, after the graphene pressure-sensitive layer 30 is integrated with a plurality of fingerprint sensing elements 20, the size of the fingerprint identification device 02 can be reduced. The requirement of the fingerprint identification device 02 on the space structure of the electronic device 01 is reduced.

In addition, after the graphene pressure-sensitive layer 30 is deformed by force, its impedance can undergo a sensitive and recoverable linear change. Thus, the pressure sensing module 300 with the graphene pressure-sensitive layer 30 has higher sensitivity. When the touch pressure changes within 0˜500 g, there is still a linear relationship between the electrical signal sent by the graphene pressure-sensitive layer 30 to the processor 100 and the touch pressure applied by the user.

Furthermore, the graphene pressure-sensitive layer 30 has a very high strength, which can be more than 100 times the strength of steel, so as to reduce the probability that the graphene pressure-sensitive layer 30 will break when a user uses an electronic device.

In addition, in order to further improve the accuracy of the graphene pressure-sensitive layer 30 in sensing the user's touch pressure, as shown in FIG. 9, the graphene pressure-sensitive layer 30 includes a plurality of sensing sub-blocks 301 arranged at intervals. Each sensing sub-block 301 corresponds to at least one fingerprint sensing element 20.

Multiple sensing sub-blocks 301 can be connected in parallel, and each sensing sub-block 301 is separately electrically connected to the fingerprint drive chip 21 and the processor 100 as shown in FIG. 8. In this way, on the one hand, since the plurality of sensing sub-blocks 301 are not connected to each other, the probability of mutual interference of the touch pressure on each sensing sub-block 301 is reduced, and the sensing of each sensing sub-block 301 is improved. The accuracy of the user's touch pressure.

In another aspect, the processor 100 in FIG. 8 can also obtain the actual touch area of the user according to the number of sensing sub-blocks 301 whose impedance values change each time the user touches. Then, the actual touch area is compared with a preset area threshold, and when the actual touch area is less than the area threshold, it can be determined that the user's touch operation is a wrong touch. At this time, the processor 100 can control the fingerprint driving chip 21 to stop providing driving signals to the fingerprint sensing elements 20 electrically connected to the fingerprint driving chip 21.

On the other hand, since the sensing sub-blocks 301 are connected in parallel, the data collected by them are independent of each other. Therefore, according to the position of the sensing sub-block 301 and the touch pressure it receives, the changing trend of the finger force during the user's touch can be obtained, so that the pressing direction, speed and pressing type of the finger can be obtained.

For example, taking the multiple sensing sub-blocks 301 in the graphene pressure-sensitive layer 30 arranged in a matrix as shown in FIG. 9 as an example, under the driving of the fingerprint driving chip 21 shown in FIG. When the deformation occurs sequentially from right to left, the processor 100 connected to each of the above-mentioned sensing sub-blocks 301 can determine the user's touch direction according to the sequence of changes in the impedance values of each of the above-mentioned sensing sub-blocks 301, thereby determining the user The touch method is swipe from left to right. In this way, the electronic device can perform an operation corresponding to the touch mode according to the determined touch mode. For example, the page turning action performed when reading an e-book.

Example two

In this example, as in Example 1, the graphene pressure-sensitive layer 30 in the fingerprint identification device 02 is integrated with the fingerprint identification module 200 mainly composed of multiple fingerprint sensing elements 20.

The difference from Example One is that in this example, the electronic device 01 includes a housing assembly 03 as shown in FIG. 10a. The housing assembly 03 includes a middle frame 11.

As shown in FIG. 10a, the middle frame 11 includes a carrying board 110 for carrying a circuit board, and a frame 111 arranged around the carrying board 110. The frame 111 is provided with a button hole 112. The key hole 112 is a through hole.

In addition, as shown in FIG. 10a, the housing assembly 03 also includes the aforementioned fingerprint identification device 02. The fingerprint identification device 02 can be used as a key set in the key hole 112 and connected to the frame 111. The sensing surface of the fingerprint sensing element 20 in the fingerprint identification device 02 faces the outer surface of the frame 111, so that the user's fingerprint can be identified.

The following describes how the fingerprint identification device 02 is arranged in the key hole 112 of the frame 111 in combination with the integration manner of the graphene pressure-sensitive layer 30 and the fingerprint identification module 200 in the fingerprint identification device 02.

In some embodiments of the present application, as in Example 1, the graphene pressure-sensitive layer 30 may be located on the sensing surface of the multiple fingerprint sensing elements 20.

For example, as shown in Figure 10b (a cross-sectional view taken along O1-O1 shown in Figure 10a), the fingerprint identification module 200 further includes a covering layer 22 covering the sensing surface of each fingerprint sensing element 20 and carrying each In the case of the substrate 23 of the fingerprint sensor 20, the graphene pressure-sensitive layer 30 can be fabricated on the surface of the cover layer 22 away from the fingerprint sensor 20.

Since the key hole 112 needs to expose the sensing surface of each fingerprint sensing element 20 in the fingerprint recognition module 200 to achieve fingerprint recognition, the sensing surface of the fingerprint sensing element 20 faces the covering layer 22. Therefore, the graphene pressure-sensitive layer 30 faces the outer side of the frame 111 relative to the fingerprint recognition module 200, thereby being closer to the user's finger.

The fingerprint identification module 200 and the key hole 112 can be bonded by an adhesive layer, or by arranging engagement components such as protrusions and grooves on the mating surface of the fingerprint identification module 200 and the key hole 112, the fingerprint identification device 02 The frames 111 are connected.

For another example, as shown in FIG. 10c (a cross-sectional view cut along O1-O1 shown in FIG. 10a), the graphene pressure-sensitive layer 30 is disposed between the fingerprint sensor 20 and the cover layer 22. At this time, the graphene pressure-sensitive layer 30 is integrated in the fingerprint identification module 200. As described above, in order to expose the sensing surface of each fingerprint sensing element 20 in the fingerprint recognition module 200 for fingerprint recognition, the graphene pressure-sensitive layer 30 faces the outside of the frame 111 relative to the fingerprint recognition module 200 and is closer to the user's finger.

Or, in some other embodiments of the present application, the graphene pressure-sensitive layer 30 is located on the side of the fingerprint sensing element 20 away from its sensing surface.

It can be seen from the above that the sensing surface of the fingerprint sensing element 20 faces the covering layer 22. In this situation. For example, as shown in FIG. 10d (a cross-sectional view taken along O1-O1 shown in FIG. 10a ), the graphene pressure-sensitive layer 30 is located on the surface of the substrate 23 away from the fingerprint sensor 20. As described above, in order to expose the sensing surface of each fingerprint sensing element 20 in the fingerprint recognition module 200 to achieve fingerprint recognition, the graphene pressure-sensitive layer 30 faces the inner side of the frame 111 relative to the fingerprint recognition module 200. Keep away from the user's fingers.

For another example, as shown in FIG. 10e (a cross-sectional view taken along O1-O1 shown in FIG. 10a ), the graphene pressure-sensitive layer 30 is located between the substrate 23 and the fingerprint sensor 20. As described above, in order to expose the sensing surface of each fingerprint sensing element 20 in the fingerprint recognition module 200 to achieve fingerprint recognition, the graphene pressure-sensitive layer 30 faces the inner side of the frame 111 relative to the fingerprint recognition module 200.

It should be noted that in the structures shown in FIG. 10c, FIG. 10d, and FIG. 10e, the manner in which the fingerprint identification device 02 is connected to the frame 111 is the same as that described above, and will not be repeated here. In addition, the manufacturing process of the graphene pressure-sensitive layer 30 is the same as that described in Example 1, and will not be repeated here.

In this example, similar to the example, in order to further improve the accuracy of the graphene pressure-sensitive layer 30 in sensing the user's touch pressure, the graphene pressure-sensitive layer 30 includes a plurality of sensing sub-blocks 301 arranged at intervals (as shown in FIG. 9) , I won’t repeat it here.

It can be seen from the above that the fingerprint identification device 02 can be used as a button to be arranged in the button hole 112 opened on the frame 111. In the case that the graphene pressure-sensitive layer 30 includes a plurality of sensing sub-blocks 301 arranged at intervals, the user can press differently The way of fingerprint identification device 02 enables different key operations.

For example, taking a plurality of sensing sub-blocks 301 in the graphene pressure-sensitive layer 30 arranged in a matrix as shown in FIG. 9 as an example, under the driving of the fingerprint driving chip 21 shown in FIG. When the sub-block 301 is deformed and the lower rows of sensing sub-blocks 301 are not deformed, the processor 100 connected to each of the above-mentioned sensing sub-blocks 301 can determine that the user presses according to the position of the sensing sub-block 301 whose impedance changes The position is at the top of the button. The upper end of the button can correspond to the volume increase function, so that the volume can be increased when the electronic device is playing audio.

Conversely, when the lower rows of sensing sub-blocks 301 are deformed, and the upper rows of sensing sub-blocks 301 are not deformed, the processor 100 connected to each of the above-mentioned sensing sub-blocks 301 can change the sensor according to the impedance value. The position of block 301 determines that the position pressed by the user is located at the lower end of the key. The lower end of the button can correspond to the volume reduction function, so that the volume can be reduced when the electronic device is playing audio.

Alternatively, the processor 100 may also determine that the user's touch operation is an upward sliding based on the impedance changes from bottom to top in the plurality of sensing sub-blocks 301 in turn. Conversely, when the plurality of sensing sub-blocks 301 sequentially move from top to bottom impedance When a change occurs, the processor 100 determines that the user's touch operation is sliding down. Thus, the electronic device 01 can perform operations that match different sliding directions.

Example three

In this example, the electronic device 01 has a fingerprint recognition area 04 as shown in FIG. 11a. When performing fingerprint recognition, the user can put his finger in the fingerprint recognition area 04.

In addition, the electronic device 01 also includes a fingerprint identification device 02 and a display module 10 as shown in FIG. 11b. The structure of the display module 10 is as described above, and will not be repeated here.

The fingerprint identification device 02 includes a graphene pressure sensitive layer 30 located in the fingerprint identification area 04 and at least one fingerprint sensing element 20. The fingerprint sensing element 20 is used to collect the user's fingerprint, and the sensing surface of the fingerprint sensing element 20 faces the back B of the display module 10 (as shown in FIG. 1b, the display module 10 faces the side surface of the middle frame 11).

As mentioned above, the above electronic device 01 also includes a pressure-sensitive driving chip 31 (shown in FIG. 8) electrically connected to the graphene pressure-sensitive layer 30. The function and setting method of the pressure-sensitive driving chip 31 are the same as described above, and will not be repeated here.

In addition, in this example, each fingerprint sensing element 20 is connected to the back of the display module 10, and as shown in FIG. 11c, the graphene pressure-sensitive layer 30 is disposed around all the fingerprint sensing elements 20.

For example, as shown in FIG. 11d, the graphene pressure-sensitive layer 30 is a closed frame structure. All the fingerprint sensing elements 20 are located in the hollow area of the frame structure, so that the graphene pressure-sensitive layer 30 is arranged around the fingerprint identification module 200 with the fingerprint sensing elements 20.

It should be noted that the manufacturing method of the graphene pressure-sensitive layer 30 is the same as that described above, and will not be repeated here. In addition, in the same way, in order to further improve the accuracy of the graphene pressure-sensitive layer 30 in sensing the user's touch pressure, the graphene pressure-sensitive layer 30 includes a plurality of sensing sub-blocks 301 arranged at intervals (as shown in FIG. 9). I won't repeat it here.

Example four

In this example, the same as example three, the electronic device 01 has a fingerprint recognition area 04. In addition, the electronic device 01 also includes a display module 10 and a fingerprint identification device 02. The fingerprint identification device 02 includes a graphene pressure sensitive layer 30 located in the fingerprint identification area 04 and at least one fingerprint sensing element 20. The fingerprint sensor 20 is used to collect a user's fingerprint, and the sensor surface of the fingerprint sensor 20 faces the back of the display module 10.

The difference from Example 3 is that the electronic device 01 also includes a middle frame 11 as shown in FIG. 12. The middle frame 11 includes a carrier board 110 for carrying a circuit board, and a frame 111 arranged around the carrier board 110.

In addition, the graphene pressure-sensitive layer 30 is connected to the back of the display module 10. The display module 10 is connected to the frame 111, and there is a first gap H1 between the back surface B of the display module 10 and the supporting board 110. Each fingerprint sensing element 20 is connected to a side surface of the supporting board 110 facing the display module 10, and the fingerprint sensing element 20 is located on the supporting board 110 with a second gap H2 between the fingerprint sensing element 20 and the graphene pressure-sensitive layer 30.

By disposing the fingerprint sensing element 20 on the carrier plate 110 and having a second gap H2 between the fingerprint sensing element 20 and the graphene pressure-sensitive layer 30, the distance between the user's finger and the fingerprint sensing element 20 can be increased. Therefore, when the fingerprint sensing element 20 is a photoelectric conversion element, the fingerprint sensing element 20 is advantageous for distinguishing the reflection of the ridge line of the finger and the reflection of the valley line.

The electronic device 01 also includes a pressure-sensitive driving chip 31 electrically connected to the graphene pressure-sensitive layer 30. In some embodiments of the present application, under the driving action of the driving signal provided by the pressure-sensitive driving chip 31, when the user performs fingerprint recognition, the graphene pressure-sensitive layer 30 deforms, and the resistance of the graphene pressure-sensitive layer 30 is reduced. Changes. In this way, the touch pressure of the user is obtained according to the amount of change in the impedance of the graphene pressure-sensitive layer 30.

Alternatively, the graphene pressure-sensitive layer 30 may form a pressure-sensing capacitor with the carrier plate 110. Driven by the driving signal provided by the pressure-sensitive driving chip 31, when the user performs fingerprint recognition, the graphene pressure-sensitive layer 30 is deformed and the capacitance value of the pressure-sensing capacitor changes. In this way, the touch pressure of the user is obtained according to the amount of change in the capacitance value of the sensing capacitor.

In addition, the vertical projection of all fingerprint sensing elements 20 in the fingerprint identification device 02 on the display module 10 is within the range of the vertical projection of the graphene pressure-sensitive layer 30 on the display module 10. In this way, the graphene pressure-sensitive layer 30 can cover all the fingerprint sensing elements 20, so that the graphene pressure-sensitive layer 30 can cover any position where the fingerprint identification device 02 can recognize fingerprints, thereby effectively reducing fingerprints The area of the pressure detection blind area of the identification device 02 improves the accuracy of the fingerprint identification device 02 in detecting touch pressure.

It should be noted that the manufacturing method of the graphene pressure-sensitive layer 30 is the same as that described above, and will not be repeated here. In addition, in the same way, in order to further improve the accuracy of the graphene pressure-sensitive layer 30 in sensing the user's touch pressure, the graphene pressure-sensitive layer 30 includes a plurality of sensing sub-blocks 301 arranged at intervals (as shown in FIG. 9). I won't repeat it here.

The above are only specific implementations of this application, but the protection scope of this application is not limited to this. Any change or replacement within the technical scope disclosed in this application shall be covered by the protection scope of this application . Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims (16)

1. A fingerprint identification device, characterized by comprising:

   At least one fingerprint sensing element, the fingerprint sensing element is used to collect a user's fingerprint;

   The graphene pressure-sensitive layer is located on the side where the sensing surface of the fingerprint sensing element is located, or on the side of the fingerprint sensing element away from its sensing surface; the graphene pressure-sensitive layer is used to Deformation occurs under the action of controlled pressure.
2. The fingerprint identification device of claim 1, wherein the graphene pressure-sensitive layer comprises a plurality of sensing sub-blocks arranged at intervals; each sensing sub-block corresponds to at least one fingerprint sensing element.
3. The fingerprint identification device according to claim 1 or 2, wherein the fingerprint identification device further comprises a covering layer covering the sensing surface of the fingerprint sensing element;

   The graphene pressure-sensitive layer is located on a side surface of the covering layer away from the fingerprint sensing element; or, the graphene pressure-sensitive layer is located between the fingerprint sensing element and the covering layer.
4. The fingerprint identification device of claim 1 or 2, wherein the fingerprint identification device further comprises a substrate for carrying each of the fingerprint sensing elements;

   The graphene pressure-sensitive layer is located on a side surface of the substrate away from the fingerprint sensing element; or, the graphene pressure-sensitive layer is located between the substrate and the fingerprint sensing element.
5. An electronic device, characterized by comprising a display module and the fingerprint identification device according to any one of claims 1-4;

   The display module includes a display surface and a back surface away from the display surface;

   The fingerprint identification device is located on the back of the display module, and the sensing surface of the fingerprint sensor element in the fingerprint identification device faces the back of the display module.
6. The electronic equipment of claim 5, wherein the vertical projection of all fingerprint sensing elements in the fingerprint identification device on the display module is located on the graphene pressure-sensitive layer on the display module Within the range of the vertical projection.
7. The electronic device of claim 5 or 6, wherein the electronic device further comprises a pressure-sensitive driving chip;

   The pressure-sensitive driving chip is electrically connected to the graphene pressure-sensitive layer, and is used to provide a driving signal to the graphene pressure-sensitive layer.
8. A housing assembly, characterized by comprising a middle frame and the fingerprint identification device according to any one of claims 1-4;

   The middle frame includes a carrying board for carrying the circuit board, and a frame arranged around the carrying board; the frame is provided with key holes;

   The fingerprint identification device is located in the key hole and is connected to the frame; the sensing surface of the fingerprint sensor element in the fingerprint identification device faces the outer surface of the frame;

   The fingerprint sensing element and the graphene pressure sensitive layer are electrically connected to the circuit board.
9. An electronic device, characterized by comprising a display module, and the housing assembly according to claim 8;

   The display module is located in the middle frame, the carrier board is away from a side surface of the circuit board, and the display module is connected to the middle frame.
10. An electronic device, characterized in that it comprises a fingerprint identification area, a display module and a fingerprint identification device;

    The display module includes a display surface and a back surface away from the display surface;

    The fingerprint identification device includes a graphene pressure-sensitive layer located in the fingerprint identification area and at least one fingerprint sensing element; the fingerprint sensing element is used to collect a user's fingerprint, and the sensing surface of the fingerprint sensing element faces the display The back of the module;

    The graphene pressure-sensitive layer is connected to the back of the display module, and is used to deform under the touch pressure applied by the user.
11. 10. The electronic device of claim 10, wherein each of the fingerprint sensing elements is connected to the back of the display module; and the graphene pressure-sensitive layer is located on the periphery of the fingerprint sensing elements.
12. The electronic device according to claim 11, wherein the graphene pressure-sensitive layer is a closed frame structure; all the fingerprint sensing elements are located in the hollow area of the frame structure.
13. 11. The electronic device according to claim 10, wherein the electronic device further comprises a middle frame; the middle frame comprises a carrier board and a frame arranged around the carrier board;

    The back of the display module is connected to the frame, and there is a first gap between the back of the display module and the carrier plate;

    Each of the fingerprint sensing elements is connected to a side surface of the carrier plate facing the display module, and there is a second gap between the fingerprint sensing elements and the graphene pressure-sensitive layer.
14. The electronic device of claim 13, wherein the vertical projection of all fingerprint sensing elements in the fingerprint identification device on the display module is located on the graphene pressure-sensitive layer on the display module Within the range of the vertical projection.
15. 11. The electronic device of claim 10, wherein the graphene pressure-sensitive layer comprises a plurality of sensing sub-blocks arranged at intervals; each sensing sub-block corresponds to at least one fingerprint sensing element.
16. 15. The electronic device according to any one of claims 10-15, wherein the electronic device further comprises a pressure-sensitive driving chip;

    The pressure-sensitive driving chip is electrically connected to the graphene pressure-sensitive layer, and is used to provide a driving signal to the graphene pressure-sensitive layer.

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