Ultrasonic fingerprint identification module, display screen and electronic device

Abstract

The application discloses an ultrasonic fingerprint identification module, a display screen and electronic equipment, and belongs to the field of electronic equipment. The ultrasonic fingerprint identification module comprises a first electrode layer, a piezoelectric layer, a second electrode layer and a plurality of waveguide columns. The first electrode layer, the piezoelectric layer and the second electrode layer are sequentially stacked. One side of the piezoelectric layer is electrically connected with the first electrode layer, and the other side of the piezoelectric layer is electrically connected with the second electrode layer. The plurality of waveguide columns are arranged on the side of the first electrode layer away from the piezoelectric layer, and any two adjacent waveguide columns are spaced from each other. One end of each waveguide column is attached to the first electrode layer.

Description

Technical Field

[0001] This application belongs to the field of electronic equipment technology, specifically relating to an ultrasonic fingerprint recognition module, a display screen, and an electronic device. Background Technology

[0002] Because the accuracy of ultrasonic fingerprint recognition is almost unaffected by the light transmittance of the display screen, it is gradually being adopted by more and more electronic devices. In current technology, ultrasonic fingerprint recognition modules are generally connected and attached to the inside of the display screen using an adhesive layer. Since the piezoelectric layer, the second electrode layer, and the adhesive layer are all integral structures, the sound waves generated by the mechanical vibration of the piezoelectric layer diffuse outwards in the second electrode layer and adhesive layer as they propagate towards the outside of the display screen. This results in a relatively small portion of the sound waves propagating along the thickness direction of the display screen to the outer surface, leading to relatively low sound wave utilization, which is detrimental to improving recognition accuracy. Utility Model Content

[0003] The purpose of this application is to provide an ultrasonic fingerprint recognition module, a display screen, and an electronic device to solve the problem of low recognition accuracy of current ultrasonic fingerprint recognition modules.

[0004] In a first aspect, embodiments of this application provide an ultrasonic fingerprint recognition module, which includes a first electrode layer, a piezoelectric layer, a second electrode layer, and multiple waveguide pillars, wherein... The first electrode layer, the piezoelectric layer, and the second electrode layer are stacked sequentially. One side of the piezoelectric layer is electrically connected to the first electrode layer, and the other side of the piezoelectric layer is electrically connected to the second electrode layer. The waveguide pillars are all disposed on the side of the first electrode layer away from the piezoelectric layer, and any two adjacent waveguide pillars are spaced apart from each other, with one end of each waveguide pillar being attached to the first electrode layer.

[0005] Secondly, this application discloses a display screen, which includes a display module, an adhesive layer and the aforementioned ultrasonic fingerprint recognition module. The ultrasonic fingerprint recognition module is connected to the side of the display module away from its display side through the adhesive layer, and each of the waveguide pillars is sandwiched between the display module and the first electrode layer.

[0006] Thirdly, embodiments of this application disclose an electronic device, which includes a housing and the aforementioned display screen, wherein the display screen is mounted on the housing.

[0007] This application discloses an ultrasonic fingerprint recognition module, which can be installed on one side of a recognition medium, allowing users to perform fingerprint recognition operations from the side of the recognition medium away from the ultrasonic fingerprint recognition module. In the ultrasonic fingerprint recognition module, a first electrode layer, a piezoelectric layer, and a second electrode layer are stacked sequentially, and both the first and second electrode layers are electrically connected to the piezoelectric layer. When powered, the piezoelectric layer generates ultrasonic waves through mechanical vibration. Simultaneously, multiple waveguide pillars are provided on the side of the first electrode layer away from the piezoelectric layer, with one end of each waveguide pillar attached to the first electrode layer and the other end connected to the recognition medium. This allows sound waves to propagate as much as possible along the extension direction of each waveguide pillar within the waveguide pillar and to the textured surface of the recognition medium for reflection.

[0008] Furthermore, since any two adjacent waveguide pillars are spaced apart, the propagation of sound waves between adjacent waveguide pillars can be restricted, thereby improving the effective utilization rate of sound waves generated by the piezoelectric layer and allowing as many sound waves as possible to propagate into the recognition medium. Additionally, the guiding effect of the waveguide pillars on the sound waves makes the angle between the propagation direction of the sound waves propagating into the recognition medium and the stacking direction of the second electrode layer and the piezoelectric layer relatively smaller. This allows the sound waves, after being reflected from the textured surface on the other side of the recognition medium, to act on the piezoelectric layer as much as possible, increasing the amount of sound waves received and thus improving the efficiency and accuracy of fingerprint recognition. Attached Figure Description

[0009] Figure 1 This is a cross-sectional schematic diagram of a portion of the structure of the ultrasonic fingerprint recognition module disclosed in an embodiment of this application; Figure 2 This is a schematic diagram of a portion of the structure of the ultrasonic fingerprint recognition module disclosed in this application in another direction; Figure 3 This is a schematic diagram of the structure of a display screen disclosed in an embodiment of this application; Figure 4 This is a schematic diagram of the adhesive layer structure in the display screen disclosed in an embodiment of this application; Figure 5 This is a schematic diagram of another structure of the display screen disclosed in the embodiments of this application.

[0010] The attached diagram is described as follows: 100 - First electrode layer, 110 - Substrate, 120 - Electrode unit 200-piezoelectric layer 300-Second electrode layer 400-waveguide column, 500-Insulation Layer 600 - Adhesive layer, 610 - First adhesive layer, 620 - Acoustic wave conducting layer, 630 - Second adhesive layer 710 - Conductive adhesive, 720 - Flexible circuit board 900 - Display Module. Detailed Implementation

[0011] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0012] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0013] like Figures 1-5 As shown in the figure, this application discloses an ultrasonic fingerprint recognition module, which can be applied in electronic devices such as mobile phones and tablets, or in electronic devices such as time clocks. Typically, the ultrasonic fingerprint recognition module can be installed on one side of the recognition medium to use the recognition medium as a medium for interaction between the user and the ultrasonic fingerprint recognition module. The recognition module can be a plate-like structure formed of materials such as glass, or the recognition medium can be a display module. Figure 1 This is a cross-sectional schematic diagram of the ultrasonic fingerprint recognition module disclosed in the embodiments of this application. The ultrasonic fingerprint recognition module includes a first electrode layer 100, a piezoelectric layer 200, a second electrode layer 300, and a plurality of waveguide pillars 400.

[0014] In detail, the piezoelectric layer 200 is formed of a piezoelectric material. This material can generate mechanical vibrations when energized, emitting ultrasonic waves. Simultaneously, the sound waves acting on the piezoelectric material also cause it to generate corresponding electrical signals. Since fingerprints have valleys and ridges, and the reflection of ultrasonic waves differs at these locations, by acquiring the corresponding electrical signals generated by the sound waves reflected back from the fingerprint surface, the specific parameters of the sound wave reflection interface can be detected, thereby achieving fingerprint recognition.

[0015] In the ultrasonic fingerprint recognition module disclosed in this application, both the first electrode layer 100 and the second electrode layer 300 are electrically connected to the piezoelectric layer 200. During ultrasonic wave emission, one of the first electrode layer 100 and the second electrode layer 300 can act as a positive electrode, and the other as a negative electrode. When the first electrode layer 100, the piezoelectric layer 200, and the second electrode layer 300 are mutually conductive, the piezoelectric layer 200 vibrates mechanically, thereby emitting ultrasonic waves. During ultrasonic wave reception, the ultrasonic waves reflected from the fingerprint surface act on the piezoelectric layer 200, enabling the piezoelectric layer 200 to generate a corresponding electrical signal. This electrical signal can be received by the first electrode layer 100, and the specific parameters of the received electrical signal can be used for fingerprint recognition.

[0016] like Figure 1 As shown in the embodiment of this application, the first electrode layer 100, the piezoelectric layer 200, and the second electrode layer 300 are stacked sequentially. Both the first electrode layer 100 and the second electrode layer 300 include conductive materials such as metal, and both can be in sheet form, arranged on opposite sides of the piezoelectric layer 200. Both the first electrode layer 100 and the second electrode layer 300 are connected to a power source. Accordingly, during the assembly of the ultrasonic fingerprint recognition module, one side of the piezoelectric layer 200 is electrically connected to the first electrode layer 100, and the other side of the piezoelectric layer 200 is electrically connected to the second electrode layer 300. More specifically, the first electrode layer 100 and the second electrode layer 300 can be connected to a power source in the electronic device through conductive adhesive 710 and a flexible circuit board 720, so as to use the power source in the electronic device to power the ultrasonic fingerprint recognition module.

[0017] In one specific embodiment of this application, in order to improve the recognition accuracy of the ultrasonic fingerprint recognition module, such as Figure 1 As shown, the first electrode layer 100 may include a substrate 110 and a plurality of electrode units 120 embedded in the substrate 110. The substrate 110 is formed of an insulating material to ensure that the plurality of electrode units 120 are mutually insulated. All the plurality of electrode units 120 are electrically connected to the piezoelectric layer 200, and all the plurality of electrode units 120 can be connected to the power supply of the electronic device through the flexible circuit board 720. Furthermore, when the first electrode layer 100 includes a plurality of electrode units 120, the voltage applied to different electrode units 120 can be made different according to actual needs, thereby causing different mechanical vibration intensities in the regions of the piezoelectric layer 200 corresponding to different electrode units 120, and generating ultrasonic waves with different frequencies and other parameters. In this case, the fingerprint recognition accuracy can be further improved.

[0018] In the ultrasonic fingerprint recognition module disclosed in the embodiments of this application, the shape and size of the first electrode layer 100, the piezoelectric layer 200, and the second electrode layer 300 can be selected according to actual needs, and are not limited herein. For example, the first electrode layer 100, the piezoelectric layer 200, and the second electrode layer 300 can all be circular structures, or they can be rectangular structures, or even irregularly shaped structures.

[0019] In one specific embodiment of this application, the first electrode layer 100, the piezoelectric layer 200, and the second electrode layer 300 can have the same or similar shapes, and their dimensions can be the same or similar, so that the ultrasonic fingerprint recognition module occupies less overall installation space and reduces the assembly difficulty of the ultrasonic fingerprint recognition module. Furthermore, when the first electrode layer 100 includes a substrate 110 and multiple electrode units 120, the second electrode layer 300 can be a full-surface structure, stacked and covering one side surface of the piezoelectric layer 200, to reduce the overall processing difficulty of the ultrasonic fingerprint recognition module. For example, the second electrode layer 300 can be formed of metallic silver.

[0020] To improve the utilization rate of sound waves in the ultrasonic fingerprint recognition module, in the embodiments of this application, such as Figure 1 As shown, the ultrasonic fingerprint recognition module includes multiple waveguide pillars 400, all of which are disposed on the side of the first electrode layer 100 away from the piezoelectric layer 200. The waveguide pillars 400 are solid structures and can be formed using materials such as resin. Furthermore, after the first electrode layer 100 is processed, each waveguide pillar 400 is fixedly connected to the surface of the first electrode layer 100 away from the piezoelectric layer 200 by means of bonding or other methods.

[0021] To improve the propagation and guidance effect of the waveguide pillars 400 on sound waves, in a specific embodiment of this application, each waveguide pillar 400 is formed of a metal material, optionally aluminum or copper. Furthermore, when using this technical solution, after the first electrode layer 100 is processed, multiple waveguide pillars 400 can be formed on the surface of the first electrode layer 100 facing away from the piezoelectric layer 200 by electroplating or other methods. This allows each waveguide pillar 400 to be connected to the first electrode layer 100 during its formation, which also reduces the assembly difficulty of multiple waveguide pillars 400.

[0022] Meanwhile, in the ultrasonic fingerprint recognition module disclosed in the embodiments of this application, such as Figure 1 and Figure 2As shown, any two adjacent waveguide pillars 400 are spaced apart from each other, and one end of each waveguide pillar 400 is attached to the first electrode layer 100, and as... Figure 3 and Figure 5 As shown, in the application of ultrasonic fingerprint recognition modules, the ultrasonic fingerprint recognition module can be installed on one side of the recognition medium, and correspondingly, the other end of each waveguide post 400 can be directly or indirectly connected to the recognition medium.

[0023] As described above, the identification medium is a device used in electronic devices to mount ultrasonic fingerprint recognition modules. Based on this, a textured surface can be attached to or pressed onto the surface of the identification medium, allowing the ultrasonic waves emitted by the ultrasonic fingerprint recognition module to pass through the identification medium and be reflected on the textured surface. In one specific embodiment of this application, the electronic device may include a mobile phone, etc. In this case, the identification medium may include a display module.

[0024] As described above, the waveguide pillars 400 can be fixedly connected to the surface of the first electrode layer 100 facing away from the piezoelectric layer 200 by means of bonding, or multiple waveguide pillars 400 can be formed directly on the surface of the first electrode layer 100 by means of electroplating. In the above process, the multiple waveguide pillars 400 can be spaced apart from each other, and one end of each waveguide pillar 400 can be attached to the first electrode layer 100, ensuring a relatively reliable assembly relationship between each waveguide pillar 400 and the first electrode layer 100. Correspondingly, the waveguide pillars 400 and the identification medium can also be connected to each other by means of bonding, so that the end of the waveguide pillar 400 facing away from the first electrode layer 100 can indirectly form a connection relationship with the identification medium. Of course, in some embodiments of this application, when the first electrode layer 100 is directly fixedly connected to the identification medium, the waveguide pillars 400 and the identification medium can no longer be fixedly connected; instead, the surface of the waveguide pillar 400 and the identification medium can simply be attached to each other.

[0025] Furthermore, since the fingerprint ridge surface is typically attached to the central area of ​​the ultrasonic fingerprint recognition module during the fingerprint recognition process, the waveguide pillars 400 can be arranged almost evenly within the central area of ​​the ultrasonic fingerprint recognition module to improve the utilization rate of the waveguide pillars 400, thereby enhancing recognition efficiency and accuracy. Of course, in other embodiments of this application, waveguide pillars 400 can also be provided at different locations within the overall distribution area of ​​the ultrasonic fingerprint recognition module.

[0026] More specifically, the multiple waveguide pillars 400 can be arranged concentrically, that is, the multiple waveguide pillars 400 can form multiple ring structures, and the multiple ring structures are nested sequentially. Within the same ring structure, the spacing between any two adjacent waveguide pillars 400 can be equal. In other embodiments of this application, the spacing between adjacent waveguide pillars 400 within the same ring structure can also be unequal, and this is not limited herein.

[0027] As described above, each waveguide post 400 is positioned between the first electrode layer 100 and the identification medium, and any two adjacent waveguide posts 400 are spaced apart from each other. This allows air or other media to be sandwiched between adjacent waveguide posts 400, making it easier for sound waves to propagate along the extension direction of the waveguide post 400 within the waveguide post 400, and virtually preventing propagation between adjacent waveguide posts 400. In this configuration, the waveguide post 400 can serve as a transmission medium for sound waves, providing guidance. After the ultrasonic waves generated by the piezoelectric layer 200 propagate into the first electrode layer 100, the sound waves can propagate along multiple transmission paths formed by the waveguide posts 400 into the identification medium, thereby improving the utilization rate of the sound waves. Furthermore, the waveguide post 400 can also constrain the propagation direction of sound waves in the recognition medium, making the angle between the aforementioned propagation direction and the stacking direction of the piezoelectric layer 200 and the second electrode layer 300 relatively smaller. This allows the reflected sound waves generated after the sound waves in the recognition medium are reflected at the texture surface to act on the piezoelectric layer 200 as much as possible, further improving the effective utilization rate of the sound waves propagating in the recognition medium and enhancing fingerprint recognition efficiency and accuracy. The aforementioned stacking direction can be... Figure 1 Direction A in the middle.

[0028] This application discloses an ultrasonic fingerprint recognition module, which can be installed on one side of the recognition medium, allowing users to perform fingerprint recognition operations from the side of the recognition medium away from the ultrasonic fingerprint recognition module. In the ultrasonic fingerprint recognition module, a first electrode layer 100, a piezoelectric layer 200, and a second electrode layer 300 are stacked sequentially, and both the first electrode layer 100 and the second electrode layer 300 can be electrically connected to the piezoelectric layer 200. Thus, when powered, the piezoelectric layer 200 can generate ultrasonic waves through mechanical vibration. Simultaneously, a plurality of waveguide pillars 400 are provided on the side of the first electrode layer 100 away from the piezoelectric layer 200, with one end of each waveguide pillar 400 attached to the first electrode layer 100 and the other end connected to the recognition medium. This allows sound waves to propagate as much as possible along the extension direction of each waveguide pillar 400 within the waveguide pillar 400 and to the textured surface of the recognition medium for reflection.

[0029] Furthermore, since any two adjacent waveguide pillars 400 are spaced apart, the propagation of sound waves between adjacent waveguide pillars 400 can be restricted, thereby improving the effective utilization rate of the sound waves generated by the piezoelectric layer 200 and allowing as many sound waves as possible to propagate into the recognition medium. In addition, under the guiding effect of the waveguide pillars 400 on the sound waves, the angle between the propagation direction of the sound waves propagating into the recognition medium and the stacking direction of the second electrode layer 300 and the piezoelectric layer 200 can be made relatively smaller. This allows the sound waves to be reflected off the textured surface on the other side of the recognition medium and then act on the piezoelectric layer 200 as much as possible, thereby increasing the amount of sound waves received and improving the efficiency and accuracy of fingerprint recognition.

[0030] As described above, each waveguide post 400 is disposed between the first electrode layer 100 and the recognition medium, enabling the waveguide post 400 to guide the propagation direction of the sound waves propagating into the recognition medium. Optionally, at least one waveguide post 400 extends obliquely relative to the stacking direction of the piezoelectric layer 200 and the second electrode layer 300, or at least one waveguide post 400 can extend along the stacking direction of the piezoelectric layer 200 and the second electrode layer 300. To further increase the amount of sound waves acting on the piezoelectric layer 200 in the sound waves reflected from the surface of the recognition medium on the side opposite to the first electrode layer 100, in a specific embodiment of this application, such as... Figure 1 As shown, each waveguide post 400 can extend along the stacking direction of the piezoelectric layer 200 and the second electrode layer 300.

[0031] With the above technical solution, the propagation direction of the sound waves that travel through the waveguide post 400 to the recognition medium can be parallel to or substantially parallel to the stacking direction between the piezoelectric layer 200 and the second electrode layer 300. On the one hand, this can further increase the amount of effective sound waves that propagate to the texture surface and are reflected. On the other hand, it can also increase the amount of sound waves that are reflected back to the ultrasonic recognition module after being reflected from the texture surface and act on the piezoelectric layer 200. This can further improve the efficiency and accuracy of fingerprint recognition.

[0032] As described above, the first electrode layer 100 may include a substrate 110 and a plurality of electrode units 120 embedded in the substrate 110. During the application of voltage to the piezoelectric layer 200, each electrode unit 120 drives the entire piezoelectric layer 200 to vibrate. Therefore, the locations (or regions) with relatively strong mechanical vibration in the piezoelectric layer 200 are generally the locations (or regions) in the piezoelectric layer 200 corresponding to the electrode units 120. Furthermore, in this embodiment, any waveguide post 400 may be correspondingly disposed with at least one electrode unit 120. This allows the waveguide post 400 to provide acoustic wave guidance to the regions in the piezoelectric layer 200 that generate relatively strong mechanical vibration, thereby further improving the utilization rate of acoustic waves.

[0033] For example, one waveguide post 400 can correspond to one electrode unit 120. In this case, the coverage area of ​​the waveguide post 400 can be comparable to that of the electrode unit 120. Taking both the waveguide post 400 and the electrode unit 120 as cylindrical structures as an example, in this technical solution, the diameter of the waveguide post 400 can be comparable to the diameter of the electrode unit 120, and their centers can coincide or substantially coincide. Of course, the diameter of the waveguide post 400 can also be smaller than the diameter of the electrode unit 120, or the diameter of the waveguide post 400 can be slightly larger than the diameter of the electrode unit 120, but the same waveguide post 400 still corresponds to only one electrode unit 120.

[0034] Alternatively, one waveguide post 400 can correspond to multiple electrode units 120. In this case, taking the example that both the waveguide post 400 and the electrode unit 120 are cylindrical structures, the diameter of the waveguide post 400 is at least greater than the distance between two adjacent electrode units 120, thereby ensuring that one waveguide post 400 can correspond to at least two electrode units 120 respectively.

[0035] Alternatively, one electrode unit 120 can correspond to multiple waveguide pillars 400. In this case, the diameter of the waveguide pillars 400 is smaller than the diameter of the electrode unit 120.

[0036] In summary, in the above-mentioned various technical solutions, in a plane perpendicular to the stacking direction of the piezoelectric layer 200 and the second electrode layer 300, at least a portion of the projection of any waveguide post 400 coincides with the projection of at least one electrode unit 120. Of course, a portion of the projection of any waveguide post 400 may also coincide with the substrate 110 between the electrode units 120.

[0037] To further improve the waveguide efficiency of the waveguide pillar 400, in one specific embodiment of this application, in a plane perpendicular to the stacking direction of the piezoelectric layer 200 and the second electrode layer 300, the projection of the surface of any waveguide pillar 400 that is in contact with the first electrode layer 100 lies within the projection of an electrode unit 120. That is, in this embodiment, one waveguide pillar 400 corresponds to only one electrode unit 120. Of course, different waveguide pillars 400 can correspond to the same electrode unit 120, and the waveguide pillars 400 are generally distributed on the side of the electrode unit 120 away from the piezoelectric layer 200.

[0038] In other words, in this embodiment, along the aforementioned stacking direction, each waveguide post 400 is directly opposite the electrode unit 120. This prevents a portion of the waveguide post 400 from being wasted due to its alignment with the substrate 110 between the electrode units 120. In this embodiment, by aligning the entire waveguide post 400 with the region of relatively strong mechanical vibration in the piezoelectric layer 200 (i.e., the region of the piezoelectric layer 200 directly opposite the electrode unit 120), the amount of sound waves guided by the waveguide post 400 can be further increased, thereby improving the effective utilization rate of the sound waves.

[0039] As described above, the waveguide post 400 can extend along the aforementioned stacking direction. Based on this, in a specific embodiment of this application, the shape of the waveguide post 400 can be a cylinder or a right prism. Of course, the shape of the waveguide post 400 can also be the same as or similar to the shape of the electrode unit 120, so as to further improve the acoustic wave transmission of the waveguide post 400 to the region of the piezoelectric layer 200 directly opposite the electrode unit 120.

[0040] In the above embodiments, the first electrode layer 100 may include a plurality of electrode units 120. Specifically, the plurality of electrode units 120 may be randomly distributed in the substrate 110. Considering that the area in a user's fingerprint that is easily adhered to the recognition medium is usually the fingertip area, and it is usually an elliptical structure, in order to further improve the fingerprint recognition accuracy and recognition efficiency, in a specific embodiment of this application, the plurality of electrode units 120 may be arranged into a plurality of rings, and the plurality of ring structures may be nested in sequence, so that the distribution area of ​​the plurality of electrode units 120 is generally an elliptical structure. In this case, each electrode unit 120 may also be provided with at least one waveguide post 400, so that the distribution area of ​​the plurality of waveguide posts 400 is also generally elliptical.

[0041] In one specific embodiment of this application, such as Figure 2 As shown, the structure of the ultrasonic fingerprint recognition module disclosed in this application is illustrated in another direction, wherein multiple electrode units 120 are arranged in an array, and multiple waveguide pillars 400 are arranged in an array. By adopting the technical solution disclosed in this embodiment, the processing difficulty of the electrode units 120 and the waveguide pillars 400 can be reduced to a certain extent. Furthermore, in this embodiment, each electrode unit 120 can correspond to a waveguide pillar 400, and to reduce processing difficulty, each electrode unit 120 can be provided with only one waveguide pillar 400.

[0042] In detail, the array arrangement means that multiple electrode units 120 (or multiple waveguide columns 400) can be divided into multiple rows and multiple columns. Of course, the total number of rows and the total number of columns can be the same or different. Furthermore, the spacing between adjacent rows can be equal or unequal, and the spacing between adjacent rows can be equal or unequal to the spacing between adjacent columns. This article does not impose any restrictions on these aspects.

[0043] As described above, a second electrode layer 300 is provided on the side of the piezoelectric layer 200 opposite to the first electrode layer 100. To prevent damage to the second electrode layer 300 caused by other components scraping against it during the assembly of the electronic device, in this embodiment, such as... Figure 1 As shown, the ultrasonic fingerprint recognition module may further include an insulating layer 500, which is stacked on the side of the second electrode layer 300 facing away from the piezoelectric layer 200. In this case, the insulating layer 500 can provide protection for the second electrode layer 300, and at the same time, the insulating layer 500 can also insulate the second electrode layer 300 from other components in the electronic device, preventing other components from interfering with the normal operation of the ultrasonic fingerprint recognition module.

[0044] Specifically, the insulating layer 500 is formed of an insulating material. Furthermore, in this embodiment, the insulating layer 500 is formed of an acoustic wave reflective material with insulating properties, such as insulating ink. This enables the insulating layer 500 to also reflect acoustic waves, so that the acoustic waves generated by the mechanical vibration of the piezoelectric layer 200 that propagate away from the identification medium can be reflected at the insulating layer 500 and propagate back towards the identification medium. This can further improve the effective utilization rate of acoustic waves.

[0045] As mentioned above, the ultrasonic fingerprint recognition module is disposed on one side of the recognition medium. In order to ensure that the recognition accuracy of the ultrasonic fingerprint recognition module is relatively high, it is usually necessary to make the ultrasonic fingerprint recognition module fit in close contact with the surface of the recognition medium to minimize the loss of ultrasonic waves due to the air gap between them.

[0046] Therefore, in one specific embodiment of this application, such as Figure 3 As shown, it illustrates a structural schematic diagram of the display screen disclosed in this application, and it is also an application of an ultrasonic fingerprint recognition module. That is, the ultrasonic fingerprint recognition module can be connected to the display module 900 through the adhesive layer 600.

[0047] In detail, this application discloses a display screen, which includes a display module 900, an adhesive layer 600, and any of the aforementioned ultrasonic fingerprint recognition modules. The ultrasonic fingerprint recognition module is connected to the side of the display module 900 opposite to its display side via the adhesive layer 600, and each waveguide post 400 is sandwiched between the display module 900 and the first electrode layer 100. The display side of the display module 900 is the side facing which its light-emitting surface faces. In other words, in the display screen disclosed in this application, the ultrasonic fingerprint recognition module is located on the back of the display module 900 and does not obstruct the normal display function of the display module 900.

[0048] In one specific embodiment of this application, such as Figure 3 As shown, each waveguide post 400 is located on the side of the adhesive layer 600 away from the display module 900. That is, the adhesive layer 600 is entirely located between the ultrasonic fingerprint recognition module and the display module 900. In this case, each waveguide post 400 can be connected to the back of the display module 900 through the adhesive layer 600. Of course, the waveguide post 400 and the display module 900 are both in contact with the surface of the adhesive layer 600 to maximize the effective utilization of sound waves.

[0049] More specifically, adhesive layer 600 is double-sided adhesive. To further reduce sound wave loss when passing through adhesive layer 600, optionally, as... Figure 4 The diagram illustrates the structure of the adhesive layer 600 in this embodiment. The adhesive layer 600 includes a first adhesive layer 610, a sound wave conducting layer 620, and a second adhesive layer 630, which are sequentially stacked. The sound wave conducting layer 620 is formed of a metallic material. Since metallic materials have relatively low acoustic impedance, the sound wave loss in the adhesive layer 600 in this embodiment can be significantly reduced. Furthermore, the sound wave conducting layer 620 can typically be formed of copper.

[0050] To further reduce sound wave loss during propagation between the piezoelectric layer 200 and the display module 900, in another embodiment of this application, such as Figure 5 As shown, this illustrates another structural schematic diagram of the display screen disclosed in this application. Similarly, this is also an application form of the ultrasonic fingerprint recognition module. The adhesive layer 600 is located on the side of the first electrode layer 100 facing away from the piezoelectric layer 200. This places the adhesive layer 600 within the stacked space occupied by the waveguide post 400. In this case, the first electrode layer 100 can be bonded to the back of the display module 900 through the adhesive layer 600, thereby ensuring that the entire ultrasonic fingerprint recognition module can form a reliable fixed assembly relationship with the display module 900.

[0051] Accordingly, in the ultrasonic fingerprint recognition module disclosed in this application embodiment, each waveguide post 400 can be embedded in the adhesive layer 600, and at the same time, the end of each waveguide post 400 facing away from the first electrode layer 100 is attached to the back of the display module 900.

[0052] Specifically, in this embodiment, after multiple waveguide pillars 400 are formed on the surface of the first electrode layer 100 facing away from the piezoelectric layer 200, fluid adhesive can be applied by scraping to fill the gaps between the multiple waveguide pillars 400. Then, the adhesive can be used to bond the first electrode layer 100 to the display module 900. After the adhesive solidifies, the adhesive layer 600 in this embodiment is formed. Of course, in this embodiment, the coverage area of ​​the first electrode layer 100 may be larger than the coverage area of ​​the multiple waveguide pillars 400. In this case, the adhesive can also cover the area of ​​the first electrode layer 100 outside the multiple waveguide pillars 400 to improve the bonding reliability between the first electrode layer 100 and the display module 900.

[0053] Obviously, by adopting the above technical solution, since each waveguide post 400 is directly bonded to the display module 900, the loss of sound waves at the connection interface between the waveguide post 400 and the adhesive layer 600, as well as at the connection interface between the adhesive layer 600 and the display module 900, can be significantly reduced, thereby further improving the effective utilization rate of sound waves. Simultaneously, by adopting the above technical solution, the significant difference in acoustic impedance coefficients between the adhesive (i.e., the adhesive layer 600) and the waveguide post 400 allows the adhesive layer 600 to further prevent sound waves from propagating between different waveguide posts 400, thus making the sound wave guiding efficiency of each waveguide post 400 relatively higher. Furthermore, the adhesive layer 600 can also minimize the propagation of noise generated by other components in the electronic device into the waveguide post 400 and onto the piezoelectric layer 200, thereby preventing interference with the fingerprint recognition process.

[0054] Furthermore, when adopting the technical solution disclosed in this embodiment, the overall thickness of the display screen can be reduced to a certain extent, that is, the dimensions of each component in the display screen in the aforementioned stacking direction. Specifically, during the ultrasonic fingerprint recognition module's ultrasonic wave emission, the first electrode layer 100 also serves as a resonant cavity in the propagation of the sound wave to improve its propagation efficiency. For ultrasonic waves of the same frequency band, the resonant cavity dimensions that can improve their propagation efficiency are the same. Therefore, in this embodiment, the adhesive layer 600 and multiple waveguide pillars 400 are fixedly connected to the first electrode layer 100, and the first electrode layer 100 is connected to the display module 900 through the adhesive layer 600, allowing the adhesive layer 600 and the first electrode layer 100 to serve together as the ultrasonic resonant cavity. In this case, compared to the scheme where multiple waveguide pillars 400 are connected to the display module 900 through the adhesive layer 600, since the adhesive layer 600 and the waveguide pillars 400 share the same thickness space in this embodiment, the overall thickness of the display screen disclosed in this embodiment is relatively small, which is beneficial for the development of corresponding electronic devices towards thinner and lighter designs.

[0055] Based on the display screen disclosed in any of the above embodiments, this application also discloses an electronic device. Specifically, the electronic device can be a mobile phone or tablet computer, etc., and includes a housing and any of the above-described display screens. During the assembly of the electronic device, the display screen is mounted on the housing. More specifically, the display module of the display screen can form a mounting cavity with the housing, and the ultrasonic fingerprint recognition module in the display screen is located within the mounting cavity.

[0056] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0057] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. An ultrasonic fingerprint identification module, characterized in that, It includes a first electrode layer (100), a piezoelectric layer (200), a second electrode layer (300), and multiple waveguide pillars (400), wherein, The first electrode layer (100), the piezoelectric layer (200) and the second electrode layer (300) are stacked sequentially. One side of the piezoelectric layer (200) is electrically connected to the first electrode layer (100), and the other side of the piezoelectric layer (200) is electrically connected to the second electrode layer (300). Multiple waveguide pillars (400) are disposed on the side of the first electrode layer (100) away from the piezoelectric layer (200), and any two adjacent waveguide pillars (400) are spaced apart from each other, and one end of each waveguide pillar (400) is attached to the first electrode layer (100). 2.The ultrasonic fingerprint identification module of claim 1, wherein, The first electrode layer (100) includes a substrate (110) and a plurality of electrode units (120) embedded in the substrate (110), and each of the waveguide pillars (400) is correspondingly disposed with at least one of the electrode units (120). 3.The ultrasonic fingerprint identification module of claim 2, wherein, The plurality of electrode units (120) are arranged in an array, and the plurality of waveguide posts (400) are arranged in an array. 4.The ultrasonic fingerprint identification module of claim 1, wherein, At least one of the waveguide pillars (400) extends obliquely relative to the stacking direction of the piezoelectric layer (200) and the second electrode layer (300); or, at least one of the waveguide pillars (400) extends along the stacking direction. 5.The ultrasonic fingerprint identification module of claim 1, wherein, The ultrasonic fingerprint recognition module includes an insulating layer (500), which is stacked on the side of the second electrode layer (300) away from the piezoelectric layer (200). 6.The ultrasonic fingerprint identification module of claim 1, wherein, Each of the waveguide posts (400) is made of metal.

7. A display screen, characterized by The device includes a display module (900), an adhesive layer (600), and an ultrasonic fingerprint recognition module as described in any one of claims 1-6. The ultrasonic fingerprint recognition module is connected to the side of the display module (900) away from its display side through the adhesive layer (600), and each of the waveguide posts (400) is sandwiched between the display module (900) and the first electrode layer (100).

8. The display screen of claim 7, wherein, Each of the waveguide pillars (400) is located on the side of the adhesive layer (600) away from the display module (900), and each of the waveguide pillars (400) is bonded to the display module (900) through the adhesive layer (600). The adhesive layer (600) includes a first adhesive layer (610), a sound wave conducting layer (620) and a second adhesive layer (630) stacked in sequence. The sound wave conducting layer (620) is formed of metal material.

9. The display screen of claim 7, wherein, The adhesive layer (600) is located on the side of the first electrode layer (100) away from the piezoelectric layer (200). The first electrode layer (100) is bonded to the display module (900) through the adhesive layer (600). Each waveguide post (400) is embedded in the adhesive layer (600), and the end of each waveguide post (400) away from the first electrode layer (100) is attached to the display module (900).

10. An electronic device, comprising: The display screen according to any one of claims 7 to 9 is mounted to the housing.

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