Patent Publication Number: US-2020302142-A1

Title: Fingerprint identification apparatus and electronic device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Application No. PCT/CN2019/079107, filed on Mar. 21, 2019, the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present application relate to the electronic field, and more particularly, to a fingerprint identification apparatus and an electronic device. 
     BACKGROUND 
     At present, an under-screen fingerprint identification solution is to attach an optical fingerprint identification module or an ultrasonic fingerprint identification module to the bottom of an organic light-emitting diode (OLED) screen, that is, either the optical fingerprint identification module or the ultrasonic fingerprint identification module is required to be closely adhered to a light-emitting layer of the bottom of a screen. 
     However, since the OLED screen is costly and fragile, the OLED screen is easily damaged when the fingerprint identification module is directly attached to the OLED screen. In addition, since the fingerprint identification module and the OLED screen are completely adhered, if the fingerprint identification module is damaged, the OLED screen is easily damaged when the fingerprint identification module is disassembled. Moreover, an attaching process of directly attaching the fingerprint identification module to the OLED screen is also relatively complicated. 
     Due to the above problems, costs and complexity of an electronic device are greatly increased, and maintainability is low. 
     SUMMARY 
     Provided are a fingerprint identification apparatus and an electronic device, which could reduce costs and complexity of the electronic device, and improve maintainability. Especially, in a scenario of a plurality of fingerprint sensor chips, the costs and complexity of the electronic device could be effectively reduced, and maintainability is greatly improved. In addition, a thickness of the fingerprint identification apparatus could be effectively reduced. 
     According to a first aspect, provided is a fingerprint identification apparatus applied to an electronic device having a display screen, where the fingerprint identification apparatus includes: 
     at least one fingerprint sensor chip; and 
     a support plate provided with a first opening window, where the at least one fingerprint sensor chip is fixedly disposed in the first opening window; 
     where the support plate is configured to be mounted to a middle frame of the electronic device such that the at least one fingerprint sensor chip is located under the display screen of the electronic device, the at least one fingerprint sensor chip is configured to receive a fingerprint detecting signal returned by reflection or scattering via a human finger above the display screen, and the fingerprint detecting signal is used to detect fingerprint information of the finger. 
     In an embodiment of the present application, after the at least one fingerprint sensor chip is fixedly mounted to a support plate, the at least one fingerprint sensor chip may be fixedly mounted under a display screen of an electronic device through the support plate, so that the at least one fingerprint sensor chip is prevented from being directly attached to the display screen of the electronic device, which could reduce mounting difficulty and complexity of the at least one fingerprint sensor chip, and improve maintainability. Especially, in a scenario that the at least one fingerprint sensor chip includes a plurality of chips, the plurality of chips may be fixedly mounted under a display screen at one time, which could reduce mounting complexity and improve mounting efficiency. In addition, the support plate is provided with a first opening window and the at least one fingerprint sensor chip is mounted in the first opening window, which could effectively reduce a thickness of a fingerprint identification apparatus. 
     According to a second aspect, provided is an electronic device, including: 
     a display screen; and the fingerprint identification apparatus according to the first aspect; where the fingerprint identification apparatus is disposed under the display screen to implement under-screen fingerprint detection. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic plan view of an electronic device to which the present application is applicable. 
         FIG. 2  is a schematic side cross-sectional view of the electronic device shown in  FIG. 1 . 
         FIGS. 3 to 7  are schematic structural diagrams of a fingerprint identification apparatus according to an embodiment of the present application. 
         FIG. 8  is a schematic structural diagram formed after a fingerprint identification apparatus is mounted to a middle frame of an electronic device according to an embodiment of the present application. 
         FIG. 9  is a schematic structural diagram formed by mounting the structure shown in  FIG. 8  to a display screen of an electronic device. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Technical solutions in embodiments of the present application will be described hereinafter with reference to the accompanying drawings. 
     The technical solutions of the embodiments of the present application may be applied to various electronic devices. 
     For example, portable or mobile computing devices such as smartphones, laptops, tablets and gaming devices, and other electronic devices such as electronic databases, automobiles and bank automated teller machines (ATM), which are not limited in the embodiments of the present application. 
     The technical solutions of the embodiments of the present application may be applied to a biometric identification technology. The biometric identification technology includes, but is not limited to, identification technologies, such as fingerprint identification, palm print identification, iris identification, human face identification and living body identification. For convenience of illustration, a fingerprint identification technology is described below as an example. 
     The technical solutions of the embodiments of the present application may be used for an under-screen fingerprint identification technology and an in-screen fingerprint identification technology. 
     The under-screen fingerprint identification technology refers to mounting a fingerprint identification module under a display screen, so as to realize a fingerprint identification operation in a display region of the display screen without setting a fingerprint capturing region in a region other than the display region on a front face of an electronic device. Specifically, the fingerprint identification module uses light returned from a top surface of a display component of the electronic device for fingerprint sensing and other sensing operations. This returned light carries information about an object (for example, a finger) that is in contact with the top surface of the display component, and the fingerprint identification module located under the display component implements under-screen fingerprint identification by capturing and detecting this returned light. The fingerprint identification module may be designed to achieve desired optical imaging by properly configuring an optical element for capturing and detecting returned light. 
     Correspondingly, the in-screen (In-display) fingerprint identification technology refers to mounting a fingerprint identification module or a part of a fingerprint identification module inside a display screen, so as to realize a fingerprint identification operation in a display region of the display screen without setting a fingerprint capturing region in a region other than the display region on a front face of an electronic device. 
       FIGS. 1 and 2  are schematic views showing an electronic device  100  applicable to an under-screen fingerprint identification technology.  FIG. 1  is a schematic front view of an electronic device  100 , and  FIG. 2  is a schematic partial cross-sectional structural view of the electronic device  100  shown in  FIG. 1 . 
     As shown in  FIG. 1  and  FIG. 2 , the electronic device  100  may include a display screen  120  and a fingerprint identification module  140 . 
     The display screen  120  may be a self-light-emitting display screen that adopts a self-light-emitting display unit as a display pixel. For example, the display screen  120  may be an organic light-emitting diode (OLED) display screen or a micro light-emitting diode (micro-LED) display screen. In other alternative embodiments, the display screen  120  may also be a liquid crystal display (LCD) screen or another passive light-emitting display screen, which is not limited in the embodiments of the present application. 
     In addition, the display screen  120  may specifically be a touch display screen, which may not only display an image, but also detect a touch or press operation of a user, thereby providing the user with a human-machine interaction interface. For example, in an embodiment, the electronic device  100  may include a touch sensor, and the touch sensor may specifically be a touch panel (TP), which may be disposed on a surface of the display screen  120 , or may be partially integrated or entirely integrated into an interior of the display screen  120  to form the touch display screen. 
     The fingerprint identification module  140  may be an optical fingerprint identification module, for example, an optical fingerprint sensor. 
     Specifically, the fingerprint identification module  140  may include a fingerprint sensor chip (hereinafter also referred to as an optical fingerprint sensor) having an optical sensing array. The optical sensing array includes a plurality of optical sensing units, and each of the optical sensing units may specifically include a photo detector or a photoelectric sensor. In other words, the fingerprint identification module  140  may include a photo detector array (or referred to as a photoelectric detector array, a photoelectric sensor array) including a plurality of photo detectors distributed in an array. 
     As shown in  FIG. 1 , the fingerprint identification module  140  may be disposed in a partial region under the display screen  120  such that a fingerprint capturing region (or detecting region)  130  of the fingerprint identification module  140  is at least partially located in a display region  102  of the display screen  120 . 
     Certainly, in other alternative embodiments, the fingerprint identification module  140  may also be disposed at another position, such as a side of the display screen  120  or a non-light-transmitting region of an edge of the electronic device  100 . In this case, an optical signal from at least part of the display region of the display screen  120  may be guided to the fingerprint identification module  140  by using an optical path design, so that the fingerprint capturing region  130  is actually located in the display region of the display screen  120 . 
     In some embodiments of the present application, the fingerprint identification module  140  may include only one fingerprint sensor chip, and in this case, the fingerprint capturing region  130  of the fingerprint identification module  140  has a smaller area and a fixed position, therefore, when performing fingerprint inputting, a user needs to press a finger at a specific position of the fingerprint capturing region  130 , otherwise the fingerprint identification module  140  may not be able to capture a fingerprint image, thereby resulting in poor user experience. 
     In other embodiments of the present application, the fingerprint identification module  140  may specifically include a plurality of fingerprint sensor chips; and the plurality of fingerprint sensor chips may be disposed under the display screen  120  side by side by means of splicing, and sensing regions of the plurality of fingerprint sensor chips collectively form the fingerprint capturing region  130  of the fingerprint identification module  140 . That is, the fingerprint capturing region  130  of the fingerprint identification module  140  may include a plurality of sub-regions, and each sub-region corresponds to a sensing region of one of the fingerprint sensor chips, so that the fingerprint capturing region  130  of the fingerprint identification module  140  may be extended to a main region of a lower half of the display screen, that is, it is extended to a region against which the finger is usually pressed, thereby achieving a blind pressing type of a fingerprint input operation. Alternatively, when the number of the fingerprint sensor chips is sufficient, the fingerprint detecting region  130  may also be extended to a half of the display region or even the entire display region, thereby achieving half-screen or full-screen fingerprint detection. 
     It should be understood that the specific form of the plurality of fingerprint sensor chips is not limited in the embodiment of the present application. 
     For example, the plurality of fingerprint sensor chips may be respectively fingerprint sensor die encapsulated individually, or may be a plurality of dies encapsulated in a same chip capsule. 
     For another example, the plurality of fingerprint sensor chips may also be fabricated and formed in different regions of a same die by a semiconductor process. 
     As shown in  FIG. 2 , a region where the optical sensing array of the fingerprint identification module  140  is located or a light sensing range of the optical sensing array of the fingerprint identification module  140  corresponds to the fingerprint capturing region  130  of the fingerprint identification module  140 . An area of the fingerprint capturing region  130  of the fingerprint identification module  140  may be equal to or not equal to an area of the region where the optical sensing array of the fingerprint identification module  140  is located or the optical sensing range of the optical sensing array of the fingerprint identification module  140 , which is not specifically limited in the embodiment of the present application. 
     For example, by an optical path design of light collimation, the area of the fingerprint capturing region  130  of the fingerprint identification module  140  may be designed to be substantially consistent with an area of the sensing array of the fingerprint identification module  140 . 
     For another example, by an optical path design of converging light or an optical path design of reflecting light, the area of the fingerprint capturing region  130  of the fingerprint identification module  140  may be larger than an area of the sensing array of the fingerprint identification module  140 . 
     An optical path design of the fingerprint identification module  140  is exemplarily described below. 
     In an example that the optical path design of the fingerprint identification module  140  adopts an optical collimator having an array of through holes with a high aspect ratio, the optical collimator may specifically be a collimator layer fabricated on a semiconductor silicon wafer, which has a plurality of collimating units or micro-holes, and a collimating unit may specifically be a small hole. Light in reflected light reflected back from a finger that is vertically incident to the collimating unit may pass through the collimating unit and be received by a fingerprint sensor chip under the collimating unit. However, light with an excessive large incident angle is attenuated through multiple reflection inside the collimating unit, therefore, each fingerprint sensor chip may basically only receive reflected light reflected back from a fingerprint pattern right above the fingerprint sensor chip, which could effectively improve image resolution and then improve a fingerprint identification effect. 
     Further, when the fingerprint identification module  140  includes a plurality of fingerprint sensor chips, one collimating unit may be configured for one optical sensing unit in an optical sensing array of each fingerprint sensor chip, and is disposed above a corresponding optical sensing unit by means of attachment. Certainly, the plurality of optical sensing units may also share one collimating unit, that is, the one collimating unit has a sufficiently large aperture to cover the plurality of optical sensing units. Since one collimating unit may correspond to the plurality of optical sensing units and a correspondence between a spatial period of the display screen  120  and a spatial period of the fingerprint sensor chips is broken, even if a spatial structure of a light-emitting display array of the display screen  120  and a spatial structure of the optical sensing array of the fingerprint sensor chip are similar, it could be effectively avoided that the fingerprint identification module  140  uses an optical signal passing through the display screen  120  to perform fingerprint imaging to generate Moire fringes, and the fingerprint identification effect of the fingerprint identification module  140  is effectively improved. 
     In an example that the optical path design of the fingerprint identification module  140  adopts an optical path design of an optical lens, the optical lens may include an optical lens layer having one or more lens units, for example, a lens group composed of one or more aspheric lenses, for converging reflected light reflected back from a finger to a sensing array of a fingerprint sensor chip under the optical lens layer, so that the sensing array may perform imaging based on the reflected light so as to obtain a fingerprint image of the finger. The optical lens layer may further be provided with a pinhole in an optical path of the lens unit, and the pinhole may cooperate with the optical lens layer to expand the field of view of the fingerprint identification module  140  to improve the fingerprint imaging effect of the fingerprint identification module  140 . 
     Further, when the fingerprint identification module  140  includes a plurality of fingerprint sensor chips, one optical lens may be configured for each of the fingerprint sensor chips for fingerprint imaging, or one optical lens may be configured for the plurality of fingerprint sensor chips to realize light convergence and fingerprint imaging. Even when one fingerprint sensor chip has dual sensing arrays (Dual-Array) or multiple sensing arrays (Multi-Array), two or more optical lenses may be configured for this fingerprint sensor chip to cooperate with the dual sensing arrays or the multiple sensing arrays for optical imaging, so as to reduce an imaging distance and enhance the imaging effect. 
     In an example that the optical path design of the fingerprint identification module  140  adopts an optical path design of a micro-lens layer, the micro-lens layer may have a micro-lens array formed by a plurality of micro-lenses, which may be provided above a sensing array of the fingerprint sensor chip by a semiconductor growth process or other processes, and each micro-lens may correspond to one of sensing units in the sensing array. Another optical film layer such as a medium layer or a passivation layer may be formed between the micro-lens layer and the sensing units, and more specifically, a light blocking layer having a micro-hole may also be provided between the micro-lens layer and the sensing units, where the micro-hole is formed between a corresponding micro-lens and a corresponding sensing unit, and the light blocking layer may block optical interference between adjacent micro-lenses and the sensing units such that light is converged to an interior of the micro-hole through the micro-lens and transmitted to a sensing unit corresponding to the micro-lens via the micro-hole for optical fingerprint imaging. 
     It should be understood that the several implementations of the foregoing optical path directing structure may be used alone or in combination, for example, a micro-lens layer may be further disposed under the collimator layer or the optical lens layer. Certainly, when the collimator layer or the optical lens layer is used in combination with the micro-lens layer, the specific laminated structure or optical path may require to be adjusted according to actual needs. 
     The fingerprint identification module  140  may be used for capturing fingerprint information (such as fingerprint image information) of a user. 
     In an example that the display screen  120  adopts an OLED display screen, the display screen  120  may adopt a display screen with a self-light-emitting display unit, for example, an organic light-emitting diode (OLED) display screen or a micro light-emitting diode (Micro-LED) display screen. The fingerprint identification module  140  may use a display unit (that is, an OLED light source) of the OLED display screen that is located in the fingerprint capturing region  130  as an excitation light source for optical fingerprint detection. 
     When a finger touches, is pressed against or approaches (collectively referred to as pressing for convenience of description) the fingerprint capturing region  130 , the display screen  120  emits a beam of light to a finger above the fingerprint capturing region  130 , and the beam of light is reflected by a surface of the finger to form reflected light or is scattered inside the finger to form scattered light. In related patent applications, the foregoing reflected light and scattered light are collectively referred to as reflected light for convenience of description. Since a ridge and a valley of a fingerprint have different light reflecting capabilities, reflected light from the ridge of the fingerprint and reflected light from the valley of the fingerprint have different light intensities. After passing through the display screen  120 , the reflected light is received by the fingerprint sensor chip in the fingerprint identification module  140  and converted into a corresponding electrical signal, that is, a fingerprint detecting signal; and fingerprint image data may be obtained based on the fingerprint detecting signal, and fingerprint matching verification may be further performed, thereby implementing an optical fingerprint identification function at the electronic device  100 . 
     Therefore, when a user needs to perform fingerprint unlocking or other fingerprint verification on the electronic device  100 , an input operation of fingerprint characteristics can be implemented merely by pressing a finger on the fingerprint capturing region  130  in the display screen  120 . Since capturing of the fingerprint characteristics can be implemented inside the display region  102  of the display screen  120 , a front face of the electronic device  100  in the above structure does not need to specially reserve space to set a fingerprint button (such as a Home button), so that it is possible that a full screen solution can be adopted. Therefore, the display region  102  of the display screen  120  could be substantially extended to the whole front face of the electronic device  100 . 
     Certainly, in other alternative solutions, the fingerprint identification module  140  may also provide an optical signal for fingerprint detection and identification by adopting an internal light source or an external light source. In this case, the fingerprint identification module  140  can not only apply to a self-light-emitting display screen such as an OLED display screen, but also apply to a non-self-light-emitting display screen such as a liquid crystal display screen or another passive light-emitting display screen. 
     In an example of a liquid crystal display screen having a backlight module and a liquid crystal panel, in order to support under-screen fingerprint detection of the liquid crystal display screen, an optical fingerprint system of the electronic device  100  may further include an excitation light source for optical fingerprint detection. The excitation light source may specifically be an infrared light source or a light source of non-visible light at a specific wavelength, which may be disposed under the backlight module of the liquid crystal display screen or disposed in an edge region under a protective cover of the electronic device  100 . The fingerprint identification module  140  may be disposed under the liquid crystal panel or the edge region of the protective cover, and by being directed over an optical path, light for fingerprint detection may reach the fingerprint identification module  140 . Alternatively, the fingerprint identification module  140  may also be disposed under the backlight module, and the backlight module allows the light for fingerprint detection to pass through the liquid crystal panel and the backlight module and reach the fingerprint identification module  140  by providing a hole on film layers such as a diffusion sheet, a brightening sheet, a reflection sheet or the like, or by performing other optical designs. When the fingerprint identification module  140  provides an optical signal for fingerprint detection by adopting an internal light source or an external light source, a detection principle may be the same. 
     As shown in  FIG. 1 , the electronic device  100  may further include a protective cover  110 . 
     The cover  110  may specifically be a transparent cover such as a glass cover or a sapphire cover which is located on the display screen  120  and covers a front face of the electronic device  100 , and a surface of the cover  110  may also be provided with a protective layer. Therefore, in an embodiment of the present application, the so-called finger being pressed against the display screen  120  may actually refer to the finger being pressed against the cover  110  on the display screen  120  or a surface of the protective layer covering the cover  110 . 
     As shown in  FIG. 2 , a circuit board  150  such as a flexible circuit board (FPC) may also be disposed under the fingerprint identification module  140 . 
     The fingerprint identification module  140  may be soldered to the circuit board  150  through a pad, and achieve electrical interconnection and signal transmission with other peripheral circuits or other elements of the electronic device  100  through the circuit board  150 . For example, the fingerprint identification module  140  may receive a control signal from a processing unit of the electronic device  100  through the circuit board  150 , and may also output the fingerprint detecting signal from the fingerprint identification module  140  to the processing unit, a control unit or the like of the electronic device  100  through the circuit board  150 . 
     In some embodiments, the fingerprint identification apparatus  140  may be directly fixed and attached to a lower surface of the display screen  120 . 
     However, since the display screen  120  is costly and fragile, the display screen  120  is easily damaged when the fingerprint identification module  140  is directly attached to the display screen  120 . 
     In addition, since the fingerprint identification module  140  and the display screen  120  are completely adhered, if the fingerprint identification module  140  is damaged, the display screen  120  is easily damaged when the fingerprint identification module  140  is disassembled. 
     Moreover, an attaching process of directly attaching the fingerprint identification module  140  to the display screen  120  is also relatively complicated. 
     Due to the above problems, costs and complexity of the electronic device  100  are greatly increased, and maintainability is low. 
     The present application provides a fingerprint identification apparatus, which could reduce the costs and the complexity of the electronic device  100  and improve the maintainability. 
     In the present application, the fingerprint identification apparatus includes at least one fingerprint sensor chip; and a support plate provided with a first opening window, where the at least one fingerprint sensor chip is fixedly disposed in the first opening window; where the support plate is configured to be mounted to a middle frame of the electronic device such that the at least one fingerprint sensor chip is located under the display screen of the electronic device, the at least one fingerprint sensor chip is configured to receive a fingerprint detecting signal returned by reflection or scattering via a human finger above the display screen, and the fingerprint detecting signal is used to detect fingerprint information of the finger. 
     The support plate may include a circuit board or a substrate provided with a wiring layer, therefore the at least one fingerprint sensor chip can be connected to the circuit board, or the at least one sensor chip can be connected to an external circuit board through the wiring layer of the substrate, thereby realizing a function of the at least one fingerprint sensor chip. 
     Hereinafter, a fingerprint identification apparatus  200  and an electronic device  300  according to an embodiment of the present application will be described in detail with reference to  FIGS. 3 to 9 . 
     It should be noted that, for convenience of description, in the embodiments of the present application, same reference numerals are used to represent same components, and detailed description of the same components is omitted in different embodiments for the sake of brevity. 
       FIGS. 3 and 4  are schematic structural diagrams of a fingerprint identification apparatus according to an embodiment of the present application. 
     As shown in  FIG. 3 , a fingerprint identification apparatus  200  includes a fingerprint sensor chip  201 , a stiffening plate  211 , and a circuit board  212 . The circuit board  212  is fixedly disposed under the stiffening plate  211 , and the stiffening plate  211  and the circuit board  212  form a supporting plate for supporting the fingerprint sensor chip  201 . The stiffening plate  211  is provided with a second opening window, and the circuit board  212  is provided with a third opening window. The second opening window of the stiffening plate  211  and the third opening window of the circuit board  212  form a first opening window of the support plate. The second opening window and the third opening window are not only configured to provide accommodation space for the fingerprint sensor chip  201 , but also configured to fix the fingerprint sensor chip  201 . 
     In addition, the fingerprint sensor chip  201  is electrically connected to the circuit board  212 , that is, the fingerprint sensor chip  201  may be connected to an external device or component through the circuit board  212 . 
     A lower surface of the stiffening plate  211  and an upper surface of the circuit board  212  are fixedly connected. For example, a first adhesive layer  213  may be provided between the lower surface of the stiffening plate  211  and the upper surface of the circuit board  212  and is configured to fixedly connect the stiffening plate  211  and the circuit board  212 . The first adhesive layer  213  may be any solid adhesive or liquid glue having adhesive properties. 
     The circuit board  212  is configured to be mounted under a display screen of an electronic device such as an upper surface of a middle frame of the electronic device, so that the fingerprint sensor chip  201  is located under the display screen. The fingerprint sensor chip  201  is configured to receive a fingerprint detecting signal returned by reflection or scattering via a human finger above the display screen, and the fingerprint detecting signal is used to detect fingerprint information of the finger. For example, the fingerprint sensor chip  201  may be disposed under a middle region of the display screen of the electronic device through the circuit board  212  so as to conform to a usage habit of a user and facilitate gripping by the user. 
     The fingerprint sensor chip  201  may include one or more optical fingerprint sensor chips. Each optical fingerprint sensor chip may include one or more optical fingerprint sensors or an array of optical fingerprint sensors. 
     When the fingerprint sensor chip  201  includes a plurality of optical fingerprint sensor chips, the plurality of optical fingerprint sensor chips may be arranged in the first opening window of the support plate side by side to be spliced into an optical fingerprint sensor chip component. 
     The stiffening plate  211  includes, but is not limited to, a metal stiffening plate, and a thickness of the stiffening plate  211  may range from 0.075 mm to 0.3 mm. For example, the metal stiffening plate may be a rigid stiffening plate, and a thickness of the stiffening plate  211  is 0.1 mm to control a thickness of the fingerprint identification apparatus  200 . 
     Surface roughness (Ra) of the stiffening plate  211  is greater than a certain threshold such as 0.25 μm, to improve the imaging effect. Specifically, when the surface roughness of the stiffening plate  211  is greater than a certain threshold, a surface of the stiffening plate  211  may scatter an optical signal, which could effectively reduce the optical signal that is emitted from the display screen and reflected inside the fingerprint identification apparatus  200 , thereby avoiding the influence of light reflection on imaging. In addition, when the surface roughness of the stiffening plate  211  is greater than a certain threshold, reliability of connections between the stiffening plate  211  and other components could be increased. For example, the reliability of the connections between the stiffening plate  211  and the circuit board  211  and the reliability of the connections between the stiffening plate  211  and the sensor chip  201  may be increased. 
     A color of the stiffening plate  211  may be dark such as black or dark brown, to improve a light absorption effect of the stiffening plate  211 , thereby further preventing interference of light reflected upward from the stiffening plate  211  to light received by the fingerprint sensor chip  201 . 
     Referring to  FIG. 3  again, a window size of the second opening window of the stiffening plate  211  may be larger than a window size of the third opening window of the circuit board  212  to expose a window position of the third opening window, the window position is provided with a pin of the circuit board, and the pin of the circuit board is connected to the fingerprint sensor chip  201  through a gold wire  214 . 
     The fingerprint sensor chip  201  is fixedly mounted in the second opening window and/or the first opening window through a first fixing adhesive  215 . The first fixing adhesive  215  includes, but is not limited to, a thermosetting adhesive. The first fixing adhesive  215  is not only configured to fix the fingerprint sensor chip  201 , but also configured to encapsulate the gold wire  214 . Optionally, an arc height of the gold wire  214  or an encapsulation height is smaller than the upper surface of the circuit board  212 . 
     In one implementation manner, an arc height or an encapsulation height of the gold wire  214  is less than a certain threshold, for example, the arc height or the encapsulation height of the gold wire is less than 70 μm. In another implementation manner, an upper surface of the fingerprint identification chip  201  is lower than an upper surface of the stiffening plate  211 , thereby providing mounting space for the gold wire  214  on the fingerprint sensor chip  201 . 
     Referring to  FIG. 3  again, a lower surface of the fingerprint sensor chip  201  may also be provided with a coating layer or a film layer  204  having a dielectric constant greater than a preset threshold for protecting the fingerprint sensor chip  201 . 
     Specifically, when the circuit board  212  is mounted to an upper surface of a middle frame of an electronic device, the fingerprint sensor chip  201  may be in direct contact with the upper surface of the middle frame, and further there is a risk of damaging the fingerprint sensor chip  201 ; the coating layer or the film layer  204  having the dielectric constant greater than the preset threshold is disposed on the lower surface of the fingerprint sensor chip  201 , the fingerprint sensor chip  201  can be effectively protected, and even a lower surface of the coating layer or the film layer  204  and a lower surface of the circuit board  212  may be on the same plane, and therefore, when the circuit board  212  is mounted to the upper surface of the middle frame, the coating layer or the film layer  204  may also be fixedly mounted to the upper surface of the middle frame. For example, as shown in  FIG. 3 , the circuit board  212  and the coating layer or the film layer  204  may be fixedly mounted on the upper surface of the middle frame by a solid adhesive or liquid glue. Optionally, the coating layer or the film layer  204  may be a coating layer or a film layer having a strength greater than a certain threshold. 
     Referring to  FIG. 3  again, an upper surface  202  of the fingerprint sensor chip  201  is a light incident surface of the fingerprint sensor chip  201 . An optical path stack layer  203  may be disposed above the upper surface  202 . The optical path stack layer  203  includes, but is not limited to, a microlens array including at least one microlens distributed in an array, and the microlens array is disposed above the fingerprint sensor chip  201 , and configured to collect a fingerprint detecting signal reflected or scattered via a finger. For example, the microlens array is used for a fingerprint detecting signal whose reflection angle or scattering angle is greater than a certain threshold. 
     In addition, the fingerprint identification apparatus  200  may further include a filter structure. 
     In one implementation manner, the filter structure may be a filter, which may be disposed above the upper surface  202  of the fingerprint sensor  201 . For example, the filter may be disposed between the upper surface  202  and the optical path stack layer  203 , or may be disposed inside or above the optical path stack layer, which is not specifically limited in the present application. 
     The filter may include one or more optical filters, the one or more optical filters may be configured, for example, as bandpass filters to allow transmission of the light emitted by OLED pixels while shielding other light components such as IR light in the sunlight. This optical filtering could be effective in reducing background light caused by the sunlight when the under-screen fingerprint identification apparatus  200  is used outdoors. The one or more optical filters may be implemented as, for example, optical filter coatings formed on one or more continuous interfaces or one or more discrete interfaces. It should be understood that the filter may be fabricated on a surface of any optical component or along an optical path to the fingerprint sensor chip  201  from reflected light formed by reflection of a finger. 
     In the embodiment of the present application, the filter is used to reduce undesired ambient light in fingerprint sensing to improve optical sensing of received light by the fingerprint sensor chip  201 . The filter may be specifically used to reject light at a specific wavelength, such as near infrared light and partial of red light. For example, a human finger absorbs most of energy of light at a below 580 nm, and if one or more optical filters or optical filtering layers are designed to reject light at a wavelength from 580 nm to infrared light, undesired contributions to the optical detection in fingerprint sensing from the environment light may be greatly reduced. 
     In addition, a light incident surface of the filter may be provided with an optical inorganic plating film or an organic blackening coating film such that reflectance of the light incident surface of the filter is lower than a first threshold, for example, 1%, thereby ensuring that the fingerprint sensor chip  201  can receive sufficient optical signals so as to improve a fingerprint identification effect. 
     In an example that the filter is fixed to an upper surface of the fingerprint sensor chip  201 , the filter and the fingerprint sensor chip  201  may be fixed by means of dispensing in a non-photosensitive region of the fingerprint sensor chip  201 , and there is a gap between the filter and a photosensitive region of the fingerprint sensor chip  201 ; or a lower surface of the filter is fixed on the upper surface of the fingerprint sensor chip  201  by glue having a refractive index lower than a preset refractive index. For example, the preset refractive index includes, but is not limited to,  1 . 3 . Alternatively, a periphery of the filter and the circuit board  212  are fixed by means of dispensing. 
     It should be noted that when the filter is attached to the upper surface of the fingerprint sensor chip  201  by filling of an optical adhesive, once the adhesive covering the upper surface of the fingerprint sensor chip  201  is uneven, a Newton ring phenomenon may occur, thereby affecting a fingerprint identification effect. 
     In another implementation manner, the filter structure may be a filter coating layer, which may be disposed on the upper surface  202  of the fingerprint sensor chip  201  or on an upper surface of the optical path stack layer  203 , which is not specifically limited in the present application. Compared with an implementation manner in which the filter structure is a filter, when the filter structure is a filter coating layer, the filter coating layer can be plated on the upper surface  202  of the fingerprint sensor chip  201  or the upper surface of the optical path stack layer  203  by a coating process, thus avoiding the use of a filter, such as a base material of blue glass or white glass, which may not only avoid the Newton ring phenomenon to improve the fingerprint identification effect, but also effectively reduce a thickness of the fingerprint identification apparatus  200 . 
     Referring to  FIG. 3  again, the fingerprint identification apparatus  200  may further include a foam layer  222 , which is fixedly disposed on the upper surface of the circuit board  212 . For example, the foam layer  222  may be fixedly disposed on the upper surface of the circuit board  212  through a second adhesive layer  223 . Optionally, the second adhesive layer  223  is a double-sided adhesive. It should be understood that in other alternative embodiments, the foam layer  222  and the second adhesive layer  223  may be combined into one layer. For example, in a process of manufacturing the foam layer  222 , an adhesive layer may be simultaneously formed on a lower surface of the foam layer  222 . 
     Further, when the foam layer  222  is fixed on the upper surface of the circuit board through the double-sided adhesive, the foam layer  222  may also be provided with a fourth opening window, and the fourth opening window is aligned with the first opening window. Therefore, an optical signal formed by light emitted by the display screen and reflected or scattered by the finger may be received by the fingerprint sensor chip  201  through the fourth opening window, thereby implementing under-screen fingerprint identification. Further, a window size of the fourth opening window may be smaller than or equal to the window size of the second opening window of the stiffening plate  211 . For example, the window size of the fourth opening window may be smaller than the size of the second opening window and greater than or equal to a size of the light incident surface of the fingerprint sensor chip  201  in the second opening window. Therefore, not only under-screen fingerprint identification can be ensured, but also an influence of under-screen fingerprint identification on normal display of the display screen can be avoided. 
     Referring to  FIG. 3  again, the fingerprint identification apparatus  200  may further include a first protective layer  221 . 
     The first protective layer  221  is detachably disposed on an upper surface of the foam layer  222 , and is configured to protect the foam layer  222  before the circuit board  212  is mounted to the middle frame. After the circuit board  212  is mounted to the middle frame, the first protective layer  221  may be removed first, and then the middle frame is mounted under the display screen so that the upper surface of the foam layer  222  is in direct contact with a lower surface of a light-emitting layer of the display screen. 
     The first protective layer  221  may be a heavy release film including, but not limited to, polyethylene glycol terephthalate (PET). As a heavy release PET release film is peelable and has better adhesion compared with a light release PET release film, the foam layer  222  will not fall off during processing and production after the foam layer  222  is attached to the heavy release PET release film, which is convenient for mass production. 
     Referring to  FIG. 3  again, the fingerprint identification apparatus  200  may further include a second protective layer  231 . 
     The second protective layer  231  is detachably disposed on the lower surface of the circuit board  212 , and the second protective layer is configured to carry and protect the circuit board  212  before the circuit board  212  is mounted to the middle frame. After the circuit board  212  is mounted to the middle frame, the second protective layer  231  may be removed first, and then the lower surface of the circuit board  212  may be directly and fixedly mounted to the upper surface of the middle frame. 
     The second protective layer  231  may be fixed to the lower surface of the circuit board  212  through a third adhesive layer  232  (such as a double-sided adhesive). Further, the second protective layer  231  may also be fixed to the lower surface of the coating layer or the film layer  204  through the third adhesive layer  232  to enhance stability, thereby preventing the second protective layer  231  from falling off during processing and production and facilitating mass production. Further, the second protective layer  231  is fixed to the lower surface of the circuit board  212  or the lower surface of the coating layer or the film layer  204  through the third adhesive layer  232  only at a middle position, so that the second protective layer  231  is easily peeled off when the circuit board  212  is mounted to the middle frame. 
       FIG. 4  is a schematic diagram of a detached component obtained by detaching the fingerprint identification sensor shown in  FIG. 3 . 
     As shown in  FIG. 4 , the stiffening plate  211  may also be provided with at least one through hole  2110  penetrating the stiffening plate in a surrounding region of the second opening window, and the at least one through hole  2110  is configured to expose a positioning identifier on the circuit board, and the positioning identifier is used to position a position of the fingerprint sensor chip  201  in the third opening window. For example, the positioning identifier is a specific pattern or a specific structure on the circuit board  212 . In a process of mounting the fingerprint sensor chip  201 , the position of the fingerprint sensor chip  201  may be determined through a position of the specific pattern or the specific structure, thereby improving mounting accuracy of the fingerprint sensor chip  201 . 
     Referring to  FIG. 4 , the fingerprint identification apparatus  200  may further include an image processor  240 . 
     The circuit board  212  is electrically connected to the image processor  240 . The image processor  240  may be specifically a micro processing unit (MCU) for receiving a fingerprint detecting signal (such as a fingerprint image) sent from the fingerprint sensor chip  201  through the circuit board  212  and simply processing the fingerprint detecting signal. 
     For example, the image processor  240  may include at least one capacitor, and the at least one capacitor is disposed on the image processor  240 , and is configured to optimize the fingerprint detecting signal captured by the fingerprint sensor chip  201 . For example, the at least one capacitor is configured to filter the fingerprint detecting signal captured by the fingerprint sensor chip  201 , where the fingerprint sensor chip  201  may correspond to one or more capacitors. 
     Referring to  FIG. 4  again, the fingerprint identification apparatus  200  may further include a connector  250  configured to connect to an external device or other components of the electronic device where the fingerprint identification apparatus  200  is located, so as to further implement communication with the external device or other components of the electronic device. For example, the connector  250  may be configured to connect a processor of the electronic device such that the processor of the electronic device receives a fingerprint detecting signal processed by the image processor  240  and performs fingerprint identification based on the processed fingerprint detecting signal. 
     It should be understood that  FIGS. 3 and 4  are only one examples of the present application and should not be understood as limitation to the embodiment of the present application. For example, in other alternative embodiments, the stiffening plate  211 , the first adhesive layer  213 , and the circuit board  212  may be replaced with other types of components. 
       FIG. 5  is another schematic diagram of a fingerprint identification apparatus according to an embodiment of the present application. 
     As shown in  FIG. 5 , the stiffening plate  211 , the first adhesive layer  213 , and the circuit board  212  shown in  FIG. 4  may be replaced with a substrate  216 . 
     In other words, the substrate  216  may be used as a support plate. The first opening window configured to accommodate and fix the fingerprint sensor chip  201  is disposed on the substrate  216 , such that after the substrate  216  is mounted to the middle frame of the electronic device, the fingerprint sensor  201  is located under the display screen of the electronic device, thereby implementing under-screen fingerprint identification. 
     The fingerprint sensor chip  201  may be fixed in the first opening window through a second fixing adhesive  219 . The second fixing adhesive  219  includes, but is not limited to, a plastic sealing adhesive. 
     A wiring layer may be provided inside the substrate  216 , and the fingerprint sensor chip  201  may be connected to the wiring layer through a gold wire  214 . Optionally, an arc height or an encapsulation height of the gold wire is less than a certain threshold, for example, the arc height or the encapsulation height of the gold wire may be less than 70 μm. 
     Referring to  FIG. 5 , the fingerprint identification apparatus  200  may further include a circuit board  218 . 
     The circuit board  218  may be fixedly connected to the substrate  216  through an electroconductive adhesive  217 . The electroconductive adhesive  217  may be an adhesive with certain conductivity after curing or drying. 
     The circuit board  218  may be a circuit board of any component, for example, a circuit board of the display screen or a circuit board of the fingerprint sensor chip  201 . For another example, the circuit board  218  may be a circuit board shared by the display screen and the fingerprint sensor chip  201  to simplify a structure of the electronic device. 
     Referring to  FIG. 5  again, the substrate  216  extends upward at a window position of the lower surface of the first opening window to form a first groove, the first groove is configured to expose a wiring layer of the substrate  216 , and the fingerprint sensor chip  201  may be electrically connected to the wiring layer of the substrate  216  through the first groove. For example, the exposed wiring layer in the first groove may be provided with a pad or a solder ball for electrical connection to the fingerprint sensor chip  201 . 
     Referring to  FIG. 5  again, since the first groove is a groove formed by the substrate  216  extending upward at the window position of the lower surface of the first opening window, a pin of the fingerprint sensor chip  201  is required to be disposed on the lower surface of the fingerprint sensor chip  201  so as to be electrically connected to the substrate  216 . 
     In some embodiments of the present application, the fingerprint sensor chip  201  may be provided with a through silicon via (TSV) and/or a rewiring layer (Redistribution Layer, RDL), and the TSV and/or RDL is configured to guide the pin of the fingerprint sensor chip  201  from an upper surface to a lower surface. The lower surface of the fingerprint sensor chip  201  may be provided with a wiring layer  205  through the TSV and/or RDL. The wiring layer  205  may be electrically connected to the wiring layer in the first groove of the substrate  216  through the gold wire  214 . 
     The fingerprint sensor chip  201  may be further provided with a protective layer  206  on a surface of the wiring layer for protecting and insulating the fingerprint sensor chip  201 . 
       FIG. 6  is a schematic diagram of a detached component obtained by detaching the fingerprint identification sensor shown in  FIG. 5 . 
     As shown in  FIG. 6 , the substrate  216  is provided at an edge position of an upper surface of the substrate  216  with a step  2161  formed by extending downward, and a pin  2162  of the substrate  216  is provided on the step  2161 . The pin  2162  of the substrate  216  may be electrically connected to a pin of a circuit board  218  through an electroconductive adhesive  217 , thereby implementing communication between the circuit board  218  and the substrate  216 . 
     It should be noted that since an upper surface of the substrate  216  is not shielded by other components before the fingerprint sensor chip  201  is mounted, a positioning identifier of the substrate  216  may be directly used to position a position of the fingerprint sensor chip  201  in the first opening window. 
       FIG. 7  is another schematic structural diagram of a fingerprint identification apparatus  200  according to an embodiment of the present application. 
     As shown in  FIG. 7 , the fingerprint identification apparatus may include a substrate  216 , and the fingerprint sensor chip  201  may be fixed in the first opening window through a third fixing adhesive  2110 . The third fixing adhesive  2110  includes, but is not limited to, a thermosetting adhesive and a plastic sealing adhesive. 
     The substrate  216  extends downward at a window position on an upper surface of the first opening window to form a second groove, the second groove is configured to expose a wiring layer of the substrate  216 , and the fingerprint sensor chip  201  is electrically connected to the wiring layer of the substrate  216 . Further, a lower surface of the fingerprint sensor chip  201  is provided with a coating layer or a film layer  204  having a dielectric constant larger than a preset threshold to protect the fingerprint sensor chip  201 . 
     It should also be understood that the forgoing drawings are only examples of the present application and should not be understood as limitation to the present application. 
     For example, in other alternative embodiments, the fingerprint sensor chip  201  may also be fixed to other components such as a back cover or a battery of an electronic device through the support plate, so that the fingerprint sensor chip  201  is disposed under the display screen of the electronic device. 
     For example, in the fingerprint identification apparatus  200  shown in  FIG. 3 , positions of the stiffening plate  211  and the circuit board  212  may be interchanged, that is, the stiffening plate  211  may be fixed under the circuit board through the first adhesive layer  213 . 
     An embodiment of the present application also provides an electronic device having a display screen, and the electronic device may include the fingerprint identification apparatus  200  described above, which may be located under the display screen for performing under-screen fingerprint identification. 
       FIGS. 8 and 9  are schematic diagrams of an electronic device  300  including the fingerprint identification apparatus  200  of  FIG. 3 . 
     As shown in  FIG. 8 , the electronic device  300  may include a middle frame  310 . The middle frame  310  is configured to support a display screen of the electronic device. An upper surface of the middle frame  310  extends downward to form a third groove, and the third groove is configured to accommodate the fingerprint identification apparatus  200 . Specifically, before the fingerprint identification apparatus  200  is mounted to the middle frame  310 , a second protective layer  231  of the fingerprint identification apparatus  200  is peeled off so that the circuit board  212  is fixed on an upper surface of the middle frame through the third adhesive layer  232  (such as a double-sided adhesive). 
     As shown in  FIG. 9 , the display screen may include a light-emitting layer  320  and a light shielding plate  330 . 
     The light shielding plate  330  is disposed under the light-emitting layer  320  and is provided with an opening window, the fingerprint identification apparatus  200  receives, through the opening window, an optical signal formed by light that is emitted by the light-emitting layer  320  and reflected by a human finger, and the optical signal is used for fingerprint identification. 
     There is a gap between the fingerprint sensor  201  in the fingerprint identification apparatus  200  and a lower surface of the light-emitting layer  320 . The gap may be an air gap that is not filled with any auxiliary material, which could ensure that the fingerprint sensor  201  is not in contact with the lower surface of the display screen when the display screen is pressed or the electronic device is dropped or collided, and stability and performance of fingerprint identification of the fingerprint sensor  201  are not affected. 
     The light-emitting layer  320  may be a light-emitting layer of the display screen, for example, the light-emitting layer  320  may be an OLED organic light-emitting panel made by using a low temperature poly-silicon (LTPS) technology, the display screen  210  is ultra-thin in thickness, light in weight and low in power consumption and may be used to provide clearer images. When there is a gap between the fingerprint sensor chip  201  and the light emitting layer  320 , the gap may be less than or equal to a preset threshold, which includes but is not limited to 600 μm. 
     The light shielding plate  330  may also be used as a screen print layer or an embossed layer, the screen print layer may be provided with patterns and texts, and the patterns and texts may be used as a logo such as a trademark pattern. The light shielding plate  330  may be a black sheet layer or a print layer for shielding light. 
     The display screen may further include a protective layer for protecting the display screen. Similar to the light shielding plate  330 , the protective layer is also provided with an opening window through which the fingerprint identification apparatus  200  receives an optical signal formed by light that is emitted by the light-emitting layer  320  and reflected by a human finger, and the optical signal is used for fingerprint identification. In other embodiments, the protective layer may also be referred to as a cushion layer or a back panel, or the light shielding plate  330  and the protective layer may be combined into one layer. 
     The protective layer may further include a heat dissipation layer. For example, the protective layer may include the heat dissipation layer that at least a portion thereof is made of a metal material. 
     It should be understood that the display screen may further include a wiring layer, which may include wiring for electrical connection of the fingerprint sensor chip  201  and/or the display screen. The display screen may further include a polarizer (POL). The polarizer may also be referred to as a polarizing plate, and is configured to generate polarized light. The polarized light is used for optical signal imaging. The display screen may further include cover glass for protecting the display screen. The cover glass and the polarizing plate may be attached by an optically clear adhesive (OCA). The OCA may be a double-sided adhesive tape without a substrate material, which is formed by making an optical acrylic adhesive into a material without a substrate and then bonding a release film on upper bottom and lower bottom layers respectively, that is, the OCA may be a layer of double-sided adhesive tape without a substrate material, which has an optical transparency property. 
     Taking a display screen being an OLED screen as an example, the display screen may be a flexible screen or a rigid screen, and the display screen may include a stack layer such as a screen print layer, a protective layer, or the like. The OLED screen will leak light downward after drilling holes to the respective layers. When a finger is placed on an illuminated OLED screen, the finger will reflect light emitted by the OLED screen, and the reflected light will penetrate the OLED screen until reaching a region under the OLED screen. A filter structure located under the OLED screen can be used to filter out an infrared signal component in leaked light. Since a fingerprint is a diffuse reflector, an optical signal formed by reflection or diffusion via a finger may exist in all directions. A micro lens array is disposed under the OLED screen and between the fingerprint sensor chips and can collect an optical signal leaked from the OLED screen. Therefore, the fingerprint sensor chip  201  performs imaging of a fingerprint image by receiving an optical signal, in which red light is filtered out. 
     It should be noted that the optical signal leaking from the OLED screen includes a fingerprint signal and an in-screen structure signal, and the in-screen structural signal may affect the imaging of the fingerprint image, for example, a Moiré fringe is generated when the imaging of the fingerprint image is performed. In this embodiment, by controlling a thickness of the foam layer  222  and a thickness of each part, a distance between the fingerprint sensor chip  201  and the OLED screen (for example, the lower surface of the light-emitting layer  320 ) may be within 600 μm such that the imaging of the screen structure is blurred, but imaging of a structure of the fingerprint is not affected. As the distance between the fingerprint sensor chip  201  and the OLED screen is smaller, the fingerprint identification performance is better; therefore, as long as reliability and process capability allow, the distance between the fingerprint sensor chip  201  and the OLED screen may be minimized as much as possible. 
     It should be understood that specific examples in embodiments of the present application are just for helping those skilled in the art better understand the embodiments of the present application, rather than for limiting the scope of the present application. 
     It should be understood that terms used in embodiments of the present application and the claims appended hereto are merely for the purpose of describing particular embodiments, and are not intended to limit the embodiments of the present application. For example, the use of a singular form of “a”, “the above” and “said” in the embodiment of the present application and the claims appended hereto are also intended to include a plural form, unless otherwise clearly indicated herein by context. 
     Those of ordinary skill in the art may be aware that, units of the examples described in the embodiments disclosed in this paper may be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate interchangeability between the hardware and the software, the foregoing illustration has generally described composition and steps of the examples according to functions. Whether these functions are performed by hardware or software depends on particular applications and designed constraint conditions of the technical solutions. Persons skilled in the art may use different methods to implement the described functions for each particular application, but it should not be considered that the implementation goes beyond the scope of the present application. 
     In the several embodiments provided in the present application, it should be understood that, the disclosed system and apparatus may be implemented in other manners. For example, the foregoing described apparatus embodiments are merely exemplary. For example, division of the units is merely logical function division and there may be other division manners in practical implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, apparatuses or units, and may also be electrical, mechanical, or connection in other forms. 
     The units described as separate components may or may not be physically separate, and components displayed as units may or may not be physical units, may be located in one position, or may be distributed on multiple network units. Part of or all of the units here may be selected according to a practical need to achieve the objectives of the solutions of the embodiments of the present application. 
     In addition, various functional units in the embodiments of the present application may be integrated into a processing unit, or each unit may exist alone physically, or two or more than two units may be integrated into one unit. The integrated unit may be implemented in a form of hardware, or may be implemented in a form of a software functional unit. 
     If the integrated unit is implemented in the form of the software functional unit and is sold or used as an independent product, it may be stored in a computer readable storage medium. Based on such understanding, the nature of the technical solutions of the present application, or the part contributing to the prior art, or all of or part of the technical solutions may be implemented in a form of software product. The computer software product is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, a server, or a network device, and the like) to execute all of or part of the steps of the method described in the embodiments of the present application. The storage medium includes: various media that may store program codes, such as a U-disk, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, a compact disk, and so on. 
     The foregoing descriptions are merely specific implementations of the present disclosure. The protection scope of the present application, however, is not limited thereto. Various equivalent modifications or replacements may be readily conceivable to any person skilled in the art within the technical scope disclosed in the present application, and such modifications or replacements shall fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.