Fingerprint identification module and electronic device

Abstract

The application provides a fingerprint identification module and an electronic device. The fingerprint identification module is arranged below a screen assembly of the electronic device and comprises an LED, an image sensor and a light shielding member. The light emitting surface of the LED faces the screen assembly and is configured to emit light signals. The light receiving surface of the image sensor faces the screen assembly and is configured to receive the light signals. The light signals received by the image sensor include fingerprint light signals returned from the finger after being emitted by the LED, so as to generate a fingerprint image. Part or all of the light shielding member is located between the LED and the image sensor and is configured to block part of the signal light emitted by the LED. The light signals emitted by the LED reach the image sensor after being reflected by the screen assembly, which interferes with the fingerprint information. The light shielding member is configured to block part of the light signals with large exit angles, so as to reduce the light signals reflected by the screen assembly, thereby reducing the interference with the fingerprint information and facilitating obtaining a high-definition fingerprint image.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fingerprint identification, and more particularly, to a fingerprint identification module and an electronic device. BACKGROUND

[0002] With the increase of screen proportion of mobile phones and the design of integrated back cover, people's demand for under-screen fingerprint identification is becoming stronger and stronger. Under-screen optical fingerprint identification is one of the under-screen fingerprint identification technologies. Its working principle is: when the finger is placed on the terminal screen, the terminal can emit light signals to the finger. The reflected light forms a fingerprint image on the sensor under the screen after the light signals are reflected by the fingerprint of the finger.

[0003] At present, it is known that a scheme is implemented by providing an external light source with strong penetration under the screen to achieve optical under-screen fingerprint identification. Specifically, after the external light source penetrates the screen to reach the finger, part of the light signals can return to the screen below and be received by the sensor. This part of the returned light signals can carry fingerprint information. After the sensor receives these light signals carrying fingerprint information, it can generate a fingerprint image for fingerprint identification. However, the external light source may generate a lot of reflected light when it is irradiated on the screen. These reflected lights do not reach the finger and do not carry fingerprint information. If they are received by the sensor, they will interfere with the light signals carrying fingerprint information received by the sensor, thereby affecting the clarity of the fingerprint image. SUMMARY

[0004] The present application provides a fingerprint identification module and an electronic device to reduce the interference of reflected light on fingerprint information and improve the clarity of the fingerprint image.

[0005] In a first aspect, a fingerprint identification module is provided. The fingerprint identification module is configured below a screen assembly of an electronic device and includes a light emitting diode (LED), an image sensor, and a light shielding member. The LED has a light emitting surface opposite to a lower surface of the screen assembly and is configured to emit light signals. The image sensor is located on one side of the LED and has a light receiving surface opposite to the lower surface of the screen assembly and is configured to receive the light signals. The light signals received by the image sensor include fingerprint light signals returned from the finger after being emitted by the LED, and the fingerprint light signals are used to generate a fingerprint image. Part or all of the light shielding member is located between the LED and the image sensor to block part of the light signals emitted by the LED.

[0006] The fingerprint light signals can be light signals carrying fingerprint information. In the embodiments of the present application, the fingerprint light signals include light signals scattered and refracted after being emitted by the LED to the inside of the finger and propagating through the inside of the finger, and light signals reflected by the surface of the finger after being emitted by the LED to the surface of the finger.

[0007] Correspondingly, part of the light signals emitted by the LED is reflected once or multiple times on the surface of the screen assembly to reach the image sensor, and this part of the light signals does not reach the finger and does not carry the fingerprint information, and thus interferes with the fingerprint light signals. In the embodiments of the present application, the light signals that do not carry the fingerprint information and reach the image sensor are referred to as stray light signals.

[0008] It should be understood that the fingerprint identification module provided by the embodiments of the present application can be applied to an LCD screen and can also be applied to an organic light-emitting diode (OLED) screen, and the application range of the fingerprint identification module is not limited in the present application.

[0009] Therefore, by arranging the light shielding member in the vicinity of the LED, the large-angle light emitted by the LED is blocked, so that the stray light reaching the image sensor through at least one reflection on the surface of the screen assembly is reduced, thereby reducing the interference of the stray light with the fingerprint light signals, that is, reducing the interference of the stray light with the fingerprint information, so as to facilitate improving the clarity of the fingerprint image.

[0010] In combination with the first aspect, in some implementations of the first aspect, on a plane passing through the light emitting center of the LED and the center of an active area (AA) of the image sensor, the light shielding member is configured to block the light signals emitted by the LED with an exit angle greater than θ, and θ is a predefined value.

[0011] That is, by arranging the light shielding member in the vicinity of the LED, the signal light emitted by the LED can be controlled within a certain angle range.

[0012] Since the shape of the light shielding member is not limited in the present application, the light shielding member can block the light signals emitted by the LED from one direction or from all directions. Therefore, the maximum exit angle of the light signals emitted by the LED after being blocked by the light shielding member can be different in different directions. In the embodiments of the present application, by designing the position and shape of the light shielding member, the maximum exit angle of the light signals can be minimized on the plane passing through the light emitting center of the LED and the center of the AA of the image sensor, for example, θ as described above.

[0013] In a possible design, θ is near half of the beam angle 2γ of the LED.

[0014] Since the radiation intensity of light is related to the exit angle, when the maximum exit angle θ is in the range greater than γ, more light signals, that is, more energy, can be included. However, in the case of a large maximum exit angle θ, the distance between the image sensor and the LED is far away (which can be seen from the calculation formula of the center distance L shown below), and the energy received by the image sensor is reduced. When the maximum exit angle θ is in the range less than or equal to γ, the energy loss received by the image sensor can be reduced, but the energy reaching the finger is reduced. Therefore, by designing the position and shape of the light shielding member, the maximum exit angle θ of the light signal in the plane passing through the light emitting center of the LED and the center of the AA of the image sensor can be designed to be γ or a value near γ, so as to balance the energy reaching the finger and the energy reaching the image sensor, thereby greatly improving the clarity of the fingerprint image.

[0015] In combination with the first aspect, in some implementations of the first aspect, the distance L between the light emitting center of the LED and the center of the AA of the image sensor satisfies: L≥h×tanθ+d×tanθ'+d×tanβ'+t×tanβ. Wherein, h represents the distance between the light emitting surface of the LED and the lower surface of the screen assembly, d represents the distance between the upper surface and the lower surface of the screen assembly, t represents the distance between the light sensing surface of the image sensor and the lower surface of the screen assembly, θ is a predefined value, θ represents the maximum exit angle of the light signal emitted by the LED after being shielded by the light shielding member in the plane passing through the light emitting center of the LED and the center of the AA of the image sensor, θ' represents the exit angle of the light signal with an incident angle of θ after refraction on the surface of the screen assembly, β is 1 / 2 of the field of view angle of the image sensor, and β' represents the incident angle corresponding to the exit angle β when the light signal is refracted on the surface of the screen assembly.

[0016] The distance L between the light emitting center of the LED and the center of the AA of the image sensor can be referred to as the center distance. The result calculated by h×tanθ+d×tanθ'+d×tanβ'+t×tanβ is the critical value L0 of the center distance L. When the center distance L is less than the critical value L0, more stray light can enter the image sensor, which interferes with the fingerprint light signal and is not conducive to obtaining a clear fingerprint image. When the center distance L is greater than the critical value L0, less fingerprint light signal enters the image sensor, the light signal entering the image sensor is reduced, the light intensity is weakened, and it is also not conducive to obtaining a clear fingerprint image.

[0017] Further, if the system tolerance is considered, the distance L between the light emitting center of the LED and the center of the AA of the image sensor satisfies: L≥h×tanθ+d×tanθ'+d×tanβ'+t×tanβ+Δ, and Δ represents the system tolerance.

[0018] The system tolerance can be an empirical value, or can be determined according to the size of the system (in the embodiments of the present application, the system can refer to the fingerprint identification module), the assembly position in the electronic device, and the cooperation relationship with the assembly part, etc. The specific value and determination method of the system tolerance Δ are not limited in the present application.

[0019] In combination with the first aspect, in some implementations of the first aspect, the light shielding member is a structural member with a light transmission hole, and the hole wall of the light transmission hole surrounds the light signal emitted by the LED from all directions to block a part of the light signal emitted by the LED.

[0020] The light shielding member can block the light signal from one direction, or can block the light signal from all directions. When the light shielding member blocks the light signal from all directions, the light shielding member can be designed as a structural member with a light transmission hole. The hole wall of the light transmission hole faces the LED and surrounds the light signal emitted by the LED from all directions. Therefore, only a part of the light signal with a small exit angle can exit from the light transmission hole, and a part of the light signal with a large exit angle is blocked by the light shielding member.

[0021] In combination with the first aspect, in some implementations of the first aspect, a surface of the light shielding member surrounding the light signal of the LED is coated with a light absorbing material, or the light shielding member is made of a light absorbing material.

[0022] When the light shielding member is used to block the light signal, the light shielding member can block the light signal by absorbing the light signal. Therefore, the surface of the light shielding member behind the light of the LED (i.e. the surface facing the LED) can be coated with a light absorbing material, or the light shielding member can be made of a light absorbing material to achieve the effect of absorbing the light signal.

[0023] In combination with the first aspect, in some implementations of the first aspect, the light shielding member is integrated on the middle frame of the electronic device; the middle frame is located between the screen assembly and the fingerprint identification module, and the middle frame has a light transmission hole in the area corresponding to the LED, and the hole wall of the light transmission hole surrounds the light signal emitted by the LED from all directions to block a part of the light signal emitted by the LED.

[0024] That is, the function of the light shielding member can be realized by the middle frame of the electronic device. Specifically, a light transmission hole can be arranged in the middle frame in the area corresponding to the LED, so that the hole wall of the light transmission hole can surround the light signal emitted by the LED from all directions to achieve the effect of blocking a part of the light signal emitted by the LED. The position of the light transmission hole of the middle frame can be designed with reference to the center distance L described above. The depth of the light transmission hole of the middle frame can be designed with reference to the predefined maximum exit angle θ and the aperture.

[0025] In some implementations of the first aspect, the fingerprint identification module is carried on a bracket and fixed under the screen assembly through the bracket. The bracket includes a main compartment for accommodating the image sensor and a secondary compartment for accommodating the LED. The light shielding member is integrated in the secondary compartment. The secondary compartment is a light transmission hole penetrating through the thickness direction of the bracket. The light transmission hole corresponds to the region of the LED. The hole wall of the light transmission hole surrounds the light signal emitted by the LED from all directions to block a part of the light signal emitted by the LED.

[0026] Specifically, the bracket can be used to carry the fingerprint identification module. In the assembly process, the bracket can be matched with the middle frame of the electronic device to fix the fingerprint identification module carried thereby under the screen assembly. The function of the light shielding hole can also be realized through the bracket. The secondary compartment of the bracket can be designed as a light transmission hole penetrating through the thickness direction of the bracket. The hole wall of the light transmission hole can surround the light signal emitted by the LED from all directions to achieve the effect of blocking a part of the light signal emitted by the LED. The secondary compartment of the bracket can be designed with reference to the center distance L described above. The wall thickness of the secondary compartment (or the hole depth of the light transmission hole) can be designed with reference to the predefined maximum exit angle θ and the aperture.

[0027] In the second aspect, an electronic device is provided. The electronic device includes a screen assembly and a fingerprint identification module. The fingerprint identification module includes an LED, an image sensor, and a light shielding member. The light emitting surface of the LED is opposite to the lower surface of the screen assembly and is used to emit a light signal. The image sensor is located on one side of the LED, and the light receiving surface of the image sensor is opposite to the lower surface of the screen assembly and is used to receive the light signal. The light signal received by the image sensor includes a fingerprint light signal returned from the finger after being emitted by the LED to the finger. The fingerprint light signal is used to generate a fingerprint image. Part or all of the light shielding member is located between the LED and the image sensor to block a part of the light signal emitted by the LED.

[0028] The fingerprint light signal can be a light signal carrying fingerprint information. In the embodiments of the present application, the fingerprint light signal includes a light signal scattered and refracted after being emitted by the LED to the inside of the finger and propagating through the inside of the finger, and a light signal reflected by the surface of the finger after being emitted by the LED to the surface of the finger.

[0029] Correspondingly, in the light signal emitted by the LED, a part of the light signal reaches the image sensor after being reflected one or more times on the surface of the screen assembly. This part of the light signal does not reach the finger and does not carry fingerprint information, and thus interferes with the fingerprint light signal. In the embodiments of the present application, the light signal reaching the image sensor without carrying fingerprint information is referred to as stray light signal.

[0030] The screen assembly can be an LCD screen or an OLED screen, and the application does not limit the screen assembly.

[0031] Therefore, the electronic device provided in the embodiments of the application achieves optical screen-under fingerprint identification by arranging the fingerprint identification module below the screen assembly. By arranging the light-blocking member in the vicinity of the LED, the wide-angle light emitted by the LED is blocked, so that the stray light reaching the image sensor after at least one reflection on the surface of the screen assembly is reduced, thereby reducing the interference of the stray light with the fingerprint light signal, that is, reducing the interference of the stray light with the fingerprint information, so that the clarity of the fingerprint image is improved.

[0032] In combination with the second aspect, in some implementations of the second aspect, on a plane passing through the light-emitting center of the LED and the center of the active display area AA of the image sensor, the light-blocking member is configured to block the light signal emitted by the LED and having an exit angle greater than θ, where θ is a predefined value.

[0033] That is, by arranging the light-blocking member in the vicinity of the LED, the signal light emitted by the LED can be controlled to be within a certain angle range.

[0034] Since the application does not limit the shape of the light-blocking member, the light-blocking member can block the light signal emitted by the LED from one direction or from all directions. Therefore, the maximum exit angle of the light signal emitted by the LED after being blocked by the light-blocking member can be different in different directions. In the embodiments of the application, the position and shape of the light-blocking member can be designed such that the maximum exit angle of the light signal is the smallest, for example, θ described above, on the plane passing through the light-emitting center of the LED and the center of the image sensor AA.

[0035] In a possible design, θ is near half of the beam angle 2γ of the LED.

[0036] Since the radiation intensity of light is related to the exit angle, when the maximum exit angle θ is in the range greater than γ, more light signals, that is, more energy, can be included. However, in the case where the maximum exit angle θ is large, the distance between the image sensor and the LED is far, and the energy received by the image sensor is reduced. When the maximum exit angle θ is in the range less than or equal to γ, the energy loss received by the image sensor can be reduced, but the energy reaching the finger is reduced. Therefore, by designing the position and shape of the light-blocking member, the maximum exit angle θ of the light signal can be designed to be γ or a value near γ on the plane passing through the light-emitting center of the LED and the center of the image sensor AA, so as to balance the energy reaching the finger and the energy reaching the image sensor, thereby greatly improving the clarity of the fingerprint image.

[0037] In some implementations of the second aspect, a distance L between the light emitting center of the LED and the center of the AA of the image sensor satisfies: L ≥ h × tanθ + d × tanθ' + d × tanβ' + t × tanβ, where h represents a distance between a light emitting surface of the LED and a lower surface of the screen assembly, d represents a distance between an upper surface and the lower surface of the screen assembly, t represents a distance between a light sensitive surface of the image sensor and the lower surface of the screen assembly, θ is a predefined value, θ represents a maximum exit angle of the light signal emitted by the LED and capable of reaching after being blocked by the light shielding member, θ' represents an exit angle of the light signal with an incident angle of θ after refraction on the surface of the screen assembly, β is 1 / 2 of a field of view angle of the image sensor, and β' represents an incident angle corresponding to the exit angle β when the light signal is refracted on the surface of the screen assembly.

[0038] The distance L between the light emitting center of the LED and the center of the AA of the image sensor can be referred to as a center distance. A result calculated by h × tanθ + d × tanθ' + d × tanβ' + t × tanβ is a critical value L0 of the center distance L. When the center distance L is less than the critical value L0, more stray light can enter the image sensor, which interferes with the fingerprint light signal and is not conducive to obtaining a clear fingerprint image. When the center distance L is greater than the critical value L0, less fingerprint light signal enters the image sensor, the light signal entering the image sensor is reduced, the light intensity is weakened, and it is also not conducive to obtaining a clear fingerprint image.

[0039] Further, if a system tolerance is considered, the distance L between the light emitting center of the LED and the center of the AA of the image sensor satisfies: L ≥ h × tanθ + d × tanθ' + d × tanβ' + t × tanβ + Δ, where Δ represents the system tolerance.

[0040] The system tolerance can be an empirical value, or can be determined according to the size of the system (in the embodiments of the present application, the system can be a fingerprint identification module), the assembly position in the electronic device, and the cooperation relationship with the assembly part, etc. The specific value and determination method of the system tolerance Δ are not limited in the present application.

[0041] In some implementations of the second aspect, the light shielding member is a structural member with a light passing hole, and a hole wall of the light passing hole surrounds the light signal emitted by the LED from all around to block a part of the light signal emitted by the LED.

[0042] The light shielding member can block the light signal from one direction or from all directions. When the light shielding member blocks the light signal from all directions, the light shielding member can be designed as a structure member with a light transmission hole. The hole wall of the light transmission hole faces the LED and surrounds the light signal emitted by the LED from all directions. Therefore, only a part of the light signal with a small exit angle can exit from the light transmission hole, and the part of the light signal with a large exit angle is blocked by the light shielding member.

[0043] With reference to the second aspect, in some implementations of the second aspect, the electronic device further includes a middle frame located between the screen assembly and the fingerprint identification module, the light shielding member is integrated on the middle frame, the middle frame has a light transmission hole in a region corresponding to the LED, and the hole wall of the light transmission hole surrounds the light signal emitted by the LED from all directions to block a part of the light signal emitted by the LED.

[0044] That is, the function of the light shielding member can be realized by the middle frame of the electronic device. Specifically, a light transmission hole can be arranged in the middle frame in a region corresponding to the LED, so that the hole wall of the light transmission hole can surround the light signal emitted by the LED from all directions to achieve the effect of blocking a part of the light signal emitted by the LED. The position of the light transmission hole of the middle frame can be designed with reference to the center distance L described above. The depth of the light transmission hole of the middle frame can be designed with reference to the predefined maximum exit angle θ and aperture.

[0045] With reference to the second aspect, in some implementations of the second aspect, the electronic device further includes a bracket, the fingerprint identification module is carried on the bracket, and the bracket fixes the fingerprint identification module below the screen assembly; the bracket includes a main compartment and a secondary compartment, the main compartment contains the sensor, the light shielding member is integrally designed with the secondary compartment, the secondary compartment contains the LED, the secondary compartment is a light transmission hole penetrating through the thickness direction of the bracket, the light transmission hole corresponds to the region of the LED, and the hole wall of the light transmission hole surrounds the light signal emitted by the LED from all directions to block a part of the light signal emitted by the LED.

[0046] Specifically, the bracket can be used to carry the fingerprint identification module. In the assembly process, the bracket can be matched with the middle frame of the electronic device to fix the fingerprint identification module carried thereby below the screen assembly. The function of the light shielding hole can also be realized by the bracket. The secondary compartment of the bracket can be designed as a light transmission hole penetrating through the thickness direction of the bracket, and the hole wall of the light transmission hole can surround the light signal emitted by the LED from all directions to achieve the effect of blocking a part of the light signal emitted by the LED. The secondary compartment of the bracket can be designed with reference to the center distance L described above. The wall thickness of the secondary compartment (or the depth of the light transmission hole) can be designed with reference to the predefined maximum exit angle θ and aperture.

[0047] With reference to the second aspect, in some implementations of the second aspect, the hole wall and the hole end face of the light hole are blackened for absorbing the received optical signals.

[0048] By blackening the hole wall and the hole end face of the light hole, the hole wall and the hole end face of the light hole have the function of absorbing optical signals, thereby achieving the effect of blocking the emission of large-angle optical signals.

[0049] With reference to the second aspect, in some implementations of the second aspect, the screen assembly includes a substrate at the bottom layer of the screen assembly, a lower surface of the substrate opposite to the fingerprint identification module, and an upper surface and a lower surface of the substrate blackened for absorbing the received optical signals.

[0050] Since a part of the light signals with small exit angles can pass through the light shielding member and be incident on the screen assembly, but are reflected multiple times between the upper and lower surfaces of the screen assembly and the interfaces of the layers of the screen assembly, and finally reach the image sensor. This part of reflected light does not reach the finger and does not carry fingerprint information, and thus interferes with the fingerprint information. This part of reflected light also belongs to part of the stray light described above.

[0051] The embodiments of the present application blacken the upper and lower surfaces of the substrate at the bottom of the screen assembly to absorb the optical signals reflected onto the surface of the substrate, thereby more greatly reducing the stray light and reducing the interference of the stray light with the fingerprint information, and thus further improving the clarity of the fingerprint image.

[0052] With reference to the first aspect or the second aspect, in some implementations, the fingerprint identification module includes a plurality of LEDs, a plurality of light shielding members corresponding to the plurality of LEDs, and an image sensor; the plurality of LEDs and the plurality of light shielding members corresponding thereto are uniformly distributed around the image sensor, and part or all of each light shielding member is located between the corresponding LED and the image sensor.

[0053] The present application does not limit the number of LEDs, the number of light shielding members, and the number of image sensors included in the fingerprint identification module. As an embodiment, the fingerprint identification module can include an image sensor, a plurality of LEDs, and light shielding members used in cooperation with the plurality of LEDs. The plurality of LEDs and the light shielding members can be uniformly distributed around the image sensor to make the optical signals reaching the image sensor have a relatively uniform light intensity. The center distance L of each LED and the image sensor can be designed with reference to the calculation formula of the center distance L described above.

[0054] It should be understood that uniformly distributing the plurality of LEDs and the plurality of light-shielding pieces around the image sensor is only one possible implementation, and should not constitute any limitation on the present application. The plurality of LEDs and the plurality of light-shielding pieces can also be unevenly distributed around the image sensor. In addition, the number of image sensors can also be multiple. The present application does not limit this.

[0055] In combination with the first aspect or the second aspect, in some implementations, the LED is an infrared LED.

[0056] Since the infrared LED has strong penetrating power, the optical signal can penetrate through the screen assembly to the finger, thereby realizing optical under-screen fingerprint recognition. However, it should be understood that using an infrared LED is only one possible implementation, and the present application does not exclude the possibility of using other light sources that can provide strong penetrating power to realize optical under-screen fingerprint recognition.

[0057] In combination with the first aspect or the second aspect, in some implementations, the fingerprint recognition module further includes at least one lens, the at least one lens is located between the screen assembly and the image sensor, and the imaging center of the at least one lens coincides with the AA center of the image sensor; the at least one lens is used to receive the optical signal, and the optical signal received by the at least one lens reaches the image sensor after being converged.

[0058] By adding at least one lens between the screen assembly and the image sensor, the optical signal reaching the lens reaches the image sensor after being converged by the lens. Therefore, the optical signal received by the image sensor is stronger, which is conducive to obtaining a clear fingerprint image.

[0059] In combination with the first aspect or the second aspect, in some implementations, the distance L' between the light-emitting center of the LED and the imaging center of the at least one lens satisfies: L' ≥ h x tan θ + d x tan θ' + d x tan α' + t' x tan α + CA / 2. Wherein, h represents the distance between the light-emitting surface of the LED and the lower surface of the screen assembly, d represents the distance between the upper surface and the lower surface of the screen assembly, t' represents the distance between the surface where the light-emitting hole of the at least one lens is located and the lower surface of the screen assembly, θ is a predefined value, θ represents the maximum exit angle that the optical signal emitted by the LED can reach after being shielded by the light-shielding piece in the plane passing through the light-emitting center of the LED and the AA center of the image sensor, θ' represents the exit angle of the optical signal with an incident angle of θ after being refracted on the surface of the screen assembly, CA represents the diameter of the light-emitting hole of the at least one lens, α is 1 / 2 of the field of view angle of the at least one lens, and α' represents the incident angle corresponding to the exit angle α when the optical signal is refracted on the surface of the screen assembly.

[0060] Based on the above-mentioned limitation of the center distance L, after adding the at least one lens, the calculation formula of the center distance L can be modified to adapt to the scenario after adding the lens. Here, L' is defined only to distinguish from the calculation formula of L, and L' represents the distance between the light emitting center of the LED and the imaging center of the lens. Since the imaging center of the lens coincides with the AA center of the image sensor, the distance between the light emitting center of the LED and the AA center of the image sensor can also be represented.

[0061] Further, if the system tolerance is considered, the distance L' between the light emitting center of the LED and the imaging center of the at least one lens satisfies: L' ≥ h x tan θ + d x tan θ' + d x tan α' + t' x tan α + CA / 2 + Δ, Δ represents the system tolerance.

[0062] The system tolerance can be an empirical value, or can be determined according to the size of the system (in the embodiments of the present application, the system can refer to a fingerprint identification module), the assembly position in the electronic device, and the cooperation relationship with the assembly part, etc. The specific value and determination method of the system tolerance Δ are not limited in the present application. BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 is a structural schematic diagram of an electronic device provided by an embodiment of the present application;

[0064] Figure 2 is a structural schematic diagram of a screen assembly for an electronic device;

[0065] Figure 3 is a schematic diagram of a fingerprint identification module acquiring fingerprint information;

[0066] Figure 4 is a schematic diagram of a light leakage phenomenon;

[0067] Figure 5 is a schematic diagram of a fingerprint identification module provided by an embodiment of the present application;

[0068] Figure 6 is another schematic diagram of a fingerprint identification module provided by an embodiment of the present application;

[0069] Figure 7 is a schematic diagram of a light shielding piece provided by an embodiment of the present application;

[0070] Figure 8 is a schematic diagram of the relative position relationship between a sensor and an LED provided by an embodiment of the present application;

[0071] Figure 9 is another schematic diagram of a fingerprint identification module provided by an embodiment of the present application;

[0072] Figure 10is a comparison chart of effects obtained by using and not using the light shielding piece in the fingerprint identification module provided by the embodiments of the present application;

[0073] Figure 11 is another schematic diagram of the fingerprint identification module provided by the embodiments of the present application;

[0074] Figure 12 is a schematic diagram of relative positions of the plurality of light source assemblies and the lens module in the fingerprint identification module provided by the embodiments of the present application;

[0075] Figure 13 is an assembly schematic diagram of the fingerprint identification module provided by the embodiments of the present application;

[0076] Figure 14 is another schematic diagram of the light shielding piece provided by the embodiments of the present application;

[0077] Figure 15 is another assembly schematic diagram of the fingerprint identification module provided by the embodiments of the present application;

[0078] Figure 16 is still another assembly schematic diagram of the fingerprint identification module provided by the embodiments of the present application;

[0079] Figure 17 is a schematic diagram of stray light reaching the lens module after multiple reflections provided by the embodiments of the present application;

[0080] Figure 18 is an arrangement schematic diagram of the plurality of LEDs, the plurality of light shielding pieces and the plurality of lens modules in the fingerprint identification module provided by the embodiments of the present application. DETAILED DESCRIPTION

[0081] The technical solutions in the present application will be described below with reference to the accompanying drawings.

[0082] In order to facilitate the understanding of the embodiments of the present application, the following points are first explained.

[0083] First, in order to facilitate understanding, the fingerprint identification module and the electronic device provided by the present application are described in detail below in combination with a plurality of drawings. However, these drawings are only examples for the purpose of understanding, and the relative distances between the components shown in the drawings, the shapes and sizes of the components are not necessarily the same as or scaled to the actual objects.

[0084] Secondly, in the embodiments of the present application, the designs of the sizes are based on the ideal state. The sizes designed in this way can be referred to as basic sizes. In contrast, the sizes after processing and assembly can be referred to as actual sizes. There is a certain size deviation between the basic sizes and the actual sizes. However, as long as the size deviations are within the tolerance range, they should fall within the protection scope of the present application. The tolerance is the allowable variation of the actual parameter value. The two limit values of the allowable variation of the actual size can be defined by the tolerance and the basic size, i.e. the limit size. In addition, the specific value of the tolerance can be predefined. The present application does not limit the specific value of the tolerance.

[0085] Thirdly, the fingerprint identification module provided by the present application is described in detail below in combination with multiple drawings. For the convenience of description, the relative positional relationship between the components is described by taking the face where the screen assembly is located as the reference face in the multiple drawings. The screen assembly includes multiple layers, but the upper and lower surfaces of the screen assembly are parallel or approximately parallel.

[0086] For the convenience of understanding and description, the face parallel to the screen assembly is denoted as the xoy plane in the following embodiments, and when the present application refers to the parallel to the screen assembly, it can mean parallel to the xoy plane; the direction perpendicular to the screen assembly is denoted as the z direction, and when the present application refers to the perpendicular to the screen assembly, it can mean the plane passing through the z direction, such as the yoz plane or the xoz plane.

[0087] In addition, the cross section in the direction perpendicular to the screen assembly is referred to in multiple places in the following embodiments. In the embodiments of the present application, the cross section in the direction perpendicular to the screen assembly refers to the cross section passing through the light emitting center of the LED and the imaging center of the lens in the lens module in the direction perpendicular to the screen assembly, such as the yoz plane shown in multiple drawings below.

[0088] It should be understood that these descriptions and definitions are only for the convenience of description and understanding, and should not constitute any limitation on the present application. The drawings of the present application are only for more clearly describing the fingerprint identification module, the relative positional relationship between the components in the fingerprint identification module, and the relative positional relationship between the fingerprint identification module and other components in the electronic device. Therefore, the placement direction of each component shown in the drawings is not limited to the placement direction of the fingerprint identification module in use and the electronic device provided with the fingerprint identification module.

[0089] Fourthly, in order to facilitate understanding, the light path diagrams of the light signal emitted by the LED to the finger, propagated inside the finger, returned to the screen assembly, and finally received by the sensor are shown in multiple drawings in the embodiments of the present application. These light path diagrams are only for the convenience of understanding and should not constitute any limitation on the present application. The present application does not limit the number of light signals entering the finger, the light path direction, etc.

[0090] Similarly, there are multiple figures showing the light path of the light signal reflected by the screen assembly to the sensor. These light path diagrams are only for ease of understanding and should not constitute any limitation on the present application. The present application does not limit the number of light signals reflected by the screen assembly, the light path, etc.

[0091] Fifth, in the embodiments of the present application, "at least one" can mean one or more. "Multiple" refers to two or more.

[0092] In addition, in order to facilitate the understanding of the embodiments of the present application, first, the terms involved in the present application are briefly explained.

[0093] 1、Beam angle: The angle formed by the two sides where the light intensity reaches 10% or 50% of the normal light intensity. Or, the angle between the light signals with 10% or 50% of the maximum light intensity. In the following, for the convenience of explanation, the beam angle is denoted as 2γ, and the light signal with an exit angle of γ can form a right circular cone with the light source center as the vertex. The angle formed by the right circular cone on any interface perpendicular to the cone base is the beam angle 2γ.

[0094] For example, if the beam angle is defined as the angle formed by the two sides where the light intensity reaches 50% of the normal light intensity, when the exit angle of the light is half of the beam angle γ, the intensity of the light signal emitted along the exit angle is 50% of the light intensity of the light center.

[0095] The infrared LED light emitting angle is generally large, and the beam angle is distributed between 30° and 140°. If the beam angle is defined as the angle formed by the two sides where the light intensity reaches 50% of the normal light intensity, then the beam angle of 30° can mean that when the exit angle of the light signal emitted by the infrared LED is 15°, the light intensity of the light signal is 50% of the light intensity of the light center of the infrared LED. The beam angle of 140° can mean that when the exit angle of the light signal emitted by the infrared LED is 70°, the light intensity of the light signal is 50% of the light intensity of the light center of the infrared LED.

[0096] 2、Field of view (FOV): Or called angle of view. The angle formed by the two edges of the maximum range of the measured target image that can pass through the lens of the optical instrument with the lens as the vertex. The field of view is a measure of the angle range of the photosensitive element receiving the image.

[0097] The embodiments of the present application are described in detail below.

[0098] Figure 1Fig. 1 is a structural schematic diagram of an electronic device 100 according to an embodiment of the present application. The electronic device 100 may, for example, be a mobile phone, a tablet computer, an e-book reader, a notebook computer, a vehicle-mounted device, a wearable device, or the like. Figure 1 The structure of the electronic device will be described below with the mobile phone as an example.

[0099] The electronic device 100 includes a housing 10 and a screen assembly 20. The housing 10 can be used to protect the electronic device. The housing 10 can specifically include a middle frame and a back cover. The middle frame can include a bezel exposed outside the electronic device 100 and an internal board enclosed by the bezel. The middle frame is generally made of metal material to ensure good mechanical strength. The screen assembly 20 is mounted above the internal board, and the back cover is mounted below the internal board. The bezel surrounds the periphery of the back cover and the screen assembly 20. In other words, the screen assembly 20 and the back cover are respectively mounted on both sides of the middle frame. When a user uses the electronic device 100, the screen assembly 20 is generally directed towards the user, and the back cover is away from the user.

[0100] The electronic device 100 further includes a control module 30. The control module 30 is housed inside the electronic device 100 and is covered by the middle frame, the back cover, and the screen assembly 20. The control module 30 can include at least one communication interface, a bus, at least one processor, and at least one memory. The at least one communication interface, the at least one processor, and the at least one memory can communicate with each other through the bus. The at least one communication interface is used to receive and send data. The screen assembly 20 can be connected to one or more communication interfaces, so that the control module 30 can start the driving unit in the driving circuit 205 to trigger the driving signal.

[0101] In the embodiments of the present application, the electronic device 100 further includes a fingerprint identification module 40. The fingerprint identification module 40 is housed inside the electronic device 100 and is located below the screen assembly 20 and is covered by the middle frame, the back cover, and the screen assembly 20. The fingerprint identification module 40 can be used to collect light signals and generate a fingerprint image based on the received light signals. In some possible designs, the fingerprint identification module 40 is integrated in the screen assembly 20 and is part of the screen assembly 20, or in other words, the screen assembly 20 can include the fingerprint identification module 40. In other possible designs, the fingerprint identification module 40 and the screen assembly 20 can be two independent modules, and the screen assembly 20 can not include the fingerprint identification module 40. The present application does not limit this. In the following embodiments, the fingerprint identification module 40 and the screen assembly 20 are defined as two independent modules for the convenience of understanding and description.

[0102] The fingerprint recognition module 40 can be connected with one or more communication interfaces to transmit the fingerprint image to a processor. At least one memory is used to store program codes. The program codes include codes for fingerprint recognition. At least one processor can be used to execute the above-mentioned application program codes. For example, the at least one processor can execute the codes for fingerprint recognition to realize fingerprint recognition.

[0103] Figure 2 FIG. 1 is a structural diagram of a screen assembly 20 for an electronic device according to an embodiment of the present application. Figure 2 To Figure 1 The structure of the screen assembly 20 of the electronic device 100 shown in FIG. 1 is further described. The screen assembly 20 can include, for example, a cover glass (CG) 201, an upper polarizer 202, a color film substrate 203, a liquid crystal (LC) layer 204, a driving circuit 205, a lower polarizer 206, a light-emitting diode (LED) 230 for providing a light source, an anti-reflection film 207, a light uniformization layer 208, a light guide layer 209, a reflective film 210, and a base 211. The above-mentioned layers are stacked. The above-mentioned components can be assembled by, for example, an optically clear adhesive (OCA) material. The reflective film 210 and the base 211 can block light from passing through the screen assembly 20 to irradiate the inside of the electronic device 100. The base 211 can include, for example, an iron frame or the like. Among them, the anti-reflection film 207, the light uniformization layer 208, the light guide layer 209, the reflective film 210, the base 211, and the LED 230 can constitute a backlight module for providing a uniform surface light source for the screen assembly 20.

[0104] The LED 230 provides a light signal as a light source. The light guide layer 209 uniformly disperses the light signal incident from the LED 230 to the entire plane. The light uniformization layer 208 makes the light signal more uniform. The anti-reflection film 207 improves the transmission intensity of the light signal emitted from the anti-reflection film 207.

[0105] The upper polarizer 202 and the lower polarizer 206 stacked on both sides of the liquid crystal layer 204 are used to change the polarization characteristics of the light signal. The driving circuit 205 disposed between the liquid crystal layer 204 and the lower polarizer 206 controls the liquid crystal in the liquid crystal layer 204 to be transparent or opaque, that is, controls whether the light incident from the anti-reflection film 207 passes through the liquid crystal layer 204 to reach an area outside the screen assembly 20 and is received by the human eye.

[0106] A plurality of driving units can be disposed on the driving circuit 205. For example, one driving unit can be one or more thin film transistors (TFTs). By controlling the driving circuit 205, the energization state of the driving unit can be controlled, thereby controlling the light transmission state of the liquid crystal in the liquid crystal layer 204. Specifically, when the driving circuit 205 controls the driving unit to be energized, the light signal from the LED 230 can reach the area outside the screen assembly 20 via the light guide layer 209, the light uniform layer 208, the anti-reflection film 207, the lower polarizing plate 206, the liquid crystal layer 204, the color filter substrate 203, the upper polarizing plate 202, and the cover plate 201.

[0107] It should be understood that the TFT listed above is only one possible form of the driving unit, and should not constitute any limitation on the present application.

[0108] Figure 3 Refers to a schematic diagram of the fingerprint identification module obtaining fingerprint information. As shown in Figure 3 , the fingerprint identification module 40 can be disposed below the screen assembly. The fingerprint identification module 40 can provide a light signal for obtaining fingerprint information, and receive a light signal returned by a finger to obtain fingerprint information of the finger. The screen assembly may, for example, be the screen assembly 20 shown in Figure 2 , or can be different from the screen assembly 20 shown in Figure 2 . The present application does not limit this.

[0109] As shown in Figure 3 , the fingerprint identification module 40 can include at least one LED 401 and at least one image sensor (hereinafter referred to as sensor) 402. Among them, the light emitting surface of the LED 401 is opposite to the lower surface of the screen assembly 20, and is used to emit a light signal. Optionally, the LED 401 is an infrared (IR) LED. Of course, the LED 401 can also be other light sources that can provide a light signal with strong penetration. The present application does not limit this. The sensor 402 is located on one side of the LED, and the light receiving surface of the sensor 402 is also opposite to the lower surface of the screen assembly 20, and is used to receive a light signal.

[0110] It should be noted that since the LED 401 can be used to provide a light signal with strong penetration, the light signal can penetrate the screen assembly 20 to reach the finger, and the reflection film 210 in the screen assembly 20 described above has no significant reflection effect on the light signal emitted by the LED 401. More accurately, the reflection film 210 is a transmission mode for the LED 401. In addition, since the substrate 211 at the bottom layer of the screen assembly 20 is opaque, it can block the propagation of the light signal in the direction above the screen assembly 20. If it is desired that the light signal penetrates the screen assembly 20 to reach the finger, an opening can be made at a position corresponding to the LED 501, so that the light signal can penetrate the screen assembly 20 and propagate upward. Similarly, if it is desired that the light signal returned from the finger penetrates the screen assembly 20 to reach the lens module 505, an opening can be made at a position corresponding to the lens module 505, so that the light signal can penetrate the screen assembly 20 and propagate downward.

[0111] Since the substrate 211 at the bottom layer of the screen assembly 20 is opened, the lower surface of the screen assembly 20 at the position corresponding to the LED 501 is not the lower surface of the substrate 211, but other layers exposed to the lower surface of the screen assembly 20 after the substrate 211 is removed, such as the reflection film 210 shown in FIG. 5B. Figure 2 Therefore, the lower surface of the screen assembly obtained after the substrate 211 of the screen assembly 20 is opened can be referred to as a backlight surface. Since it is at the bottom of the screen assembly 20, it can also be referred to as a backlight bottom. The backlight bottom is opposite to the upper surface of the LED 501 and the upper surface of the lens module 505. The backlight bottom is not necessarily entirely composed of the substrate of the screen assembly 200, but also partly composed of other layers above the substrate. Hereinafter, when referring to the lower surface of the screen assembly 20, it can be understood based on the above description. For the sake of brevity, the description will not be repeated hereinafter.

[0112] In addition, the specific introduction of the opening process will be described in detail hereinafter, and the detailed description of the opening process will be omitted here.

[0113] The specific process of acquiring the fingerprint information by the fingerprint identification module 40 provided in the embodiments of the present application will be described briefly below.

[0114] When a finger is placed on the screen assembly 20, light signals from the LED 401 are transmitted through the screen assembly 20 to the finger. A portion of the light signals can penetrate the skin surface of the finger and propagate inside the finger. The light signals inside the finger can propagate by means of scattering, refraction, etc. Among the light signals propagating inside the finger, a portion of the light signals can return to the screen assembly 20 via refraction and scattering of the skin surface and finally reach the sensor 402. Since the fingerprint of the finger can include ridges (or ridge lines) and valleys (or valley lines), the light signals reaching the sensor 402 can have bright and dark differences, from which the fingerprint of the finger can be extracted. For example, brighter light signals reaching the sensor 402 can correspond to the ridges of the finger, and darker light signals reaching the sensor 402 can correspond to the valleys of the finger. Therefore, the light signals read by the sensor 402 are the light signals returned from the finger, which can mainly include light signals that are emitted by the LED 401 to the inside of the finger, propagate inside the finger, and then are refracted and scattered. Of course, the light signals can also include a portion of light signals that are emitted by the LED 401 to the surface of the finger and then reflected back.

[0115] The area of the upper surface of the screen assembly 20 for receiving the light signals returned from the finger (which can include the above-mentioned refracted light, scattered light, and reflected light) can be referred to as an imaging area. That is, the light signals returned from the finger can enter the screen assembly 20 through the imaging area of the upper surface of the screen assembly 20 and then reach the sensor 402. The light signals reaching the sensor 402 can be used to obtain fingerprint information, which can be converted into an electrical signal to generate a fingerprint image. The fingerprint image is a form of representation of the fingerprint information. The fingerprint image can be sent to a processor, such as at least one processor in the control module 30 shown in the above-mentioned Figure 1

[0116] Hereinafter, for the convenience of description, the light signals emitted by the LED to the inside of the finger and scattered and refracted after propagating inside the finger, and the light signals emitted by the LED to the surface of the finger and reflected back by the surface of the finger, are collectively referred to as fingerprint light signals. Simply put, the fingerprint light signals are light signals carrying fingerprint information. The fingerprint light signals can be used to obtain fingerprint information and generate a fingerprint image. It can be understood that when the fingerprint light signals propagate downward through the screen assembly, they can also be reflected at the interface and lose a portion of the light signals. That is, the light signals returned from the surface of the finger do not necessarily all reach the sensor. However, this does not affect the collection of the fingerprint light signals by the sensor.

[0117] It should be understood that Figure 3 ​The imaging area shown in the figure is only for the convenience of understanding and should not constitute any limitation on the size of the area. In the process of collecting fingerprint information, the surface of the finger can be in contact with the imaging area to accurately obtain the fingerprint information of the finger.

[0118] In addition, for the convenience of understanding, Figure 3 The relative position relationship of the imaging area, the sensor 402 and the LED 401 is shown schematically, as well as the light signal (such as, Figure 3 The light signal a) in a) of the figure is the light path of the light signal emitted by the LED 401 to the screen assembly 20, returned to the screen assembly 20 after propagating in the finger, and then emitted to the sensor. As mentioned earlier, the light signal received by the sensor 402 is the light signal returned from the finger, which can specifically include: the light signal emitted by the LED 401 to the inside of the finger and then refracted and scattered out after propagating in the inside of the finger, and the light signal emitted by the LED 401 to the surface of the finger and then reflected back. Figure 3 The light signal a) shown in a) of the figure is an example of a fingerprint light signal. As shown in the figure, the light signal a) is refracted through the surface of the finger and enters the inside of the finger, and after scattering in the inside of the finger, part of the light signal returns to the screen assembly 20. A large part of the light signal entering the imaging area on the screen assembly 20 can reach the sensor to generate a fingerprint image.

[0119] It should be understood that, Figure 3 a) in the figure only schematically shows the light path of the light signal emitted by the LED to the inside of the finger and returned by the finger after propagating. The present application does not constitute any limitation on the actual propagation path of the light signal and the number of light signals incident to the inside of the finger. In addition, for the sake of brevity, Figure 3 The light path of the light signal a) emitted by the LED to the surface of the finger and reflected to the sensor is not shown in a) of the figure. However, this should not constitute any limitation on the present application.

[0120] Optionally, the fingerprint identification module 40 further comprises at least one lens 403, which can for example include 3 pieces of lens (3p Lens). The lens mentioned herein can for example be a convex lens. The at least one lens 403 can be arranged between the sensor 402 and the screen assembly 20. The imaging center of the at least one lens 403 coincides with the center of the active area (AA) on the light-sensitive surface of the sensor 402. The at least one lens 403 can be used to receive the fingerprint light signal, and the light signal converges through the at least one lens 403 to reach the sensor 402. Therefore, by arranging the at least one lens 403 between the sensor 402 and the screen assembly 20, the light signal can be converged to the sensor 402, thereby improving the clarity of the fingerprint image.

[0121] It should be understood that, Figure 3For the sake of understanding, a convex lens is shown schematically, but this should not constitute any limitation to the present application. The present application does not limit the number and type of lenses comprised by the at least one lens 403. In addition, for the sake of understanding, Figure 3 The field of view of the lens 403 and the area that the optical signal incident along the direction of the field of view can reach inside the screen assembly 20 are shown by the dashed line.

[0122] During the process of the optical signal emitted by the LED 401 and propagating outwards via the screen assembly 20, interface reflection can occur. For example, the optical signal can be reflected at the cover glass 201 of the screen assembly 20, and for another example, the optical signal can be reflected at the interface inside the screen assembly 20, such as the interface between the lower polarizer 206 and the anti-reflection film 207. The reflected light can enter the imaging area due to a large incident angle, or can enter the imaging area after multiple reflections with the interface, thereby interfering with the acquisition of the fingerprint information.

[0123] For example, Figure 3 The optical signal b shown in b) is reflected at the upper surface of the cover glass 201 of the screen assembly 20, and due to a large incident angle, the reflected optical signal enters the imaging area. The reflected optical signal has a large light intensity, and can form a strong light leakage on the sensor 402.

[0124] Figure 4 The light leakage phenomenon caused by the reflected optical signal entering the imaging area is shown. Figure 4 The schematic diagram of the test target above the screen assembly 20 after receiving the optical signal from the LED 401 is shown. Due to a part of the optical signal being reflected at the screen assembly 20 and failing to penetrate the screen assembly 20 to reach the test target, light leakage occurs. The reflected optical signal is shown by the dashed line. Figure 4 It can be seen that the light leakage causes the image on the test target to be partially overexposed, and the area used to identify the fingerprint information in the image is partially lost, thereby being not conducive to obtaining the information of each region of the finger fingerprint, and affecting the collection of the fingerprint information.

[0125] In the embodiments of the present application, for the sake of convenience, the optical signal reflected to the sensor via the surface of the screen assembly and the interface between the layers inside the screen assembly is referred to as stray light. The stray light interferes with the optical signal returned by the finger and reaching the sensor, affects the acquisition of the fingerprint information, and affects the definition of the fingerprint image, and thus can affect the effect of the fingerprint recognition. It should be understood that the reflection referred to herein is not limited to one time, and some optical signals can also reach the sensor after multiple reflections, such as shown in the following Figure 17 These optical signals are also part of the stray light.

[0126] Therefore, the fingerprint identification module is provided to reduce the interference of stray light, so as to reduce the influence on the fingerprint information and improve the definition of the fingerprint image.

[0127] The fingerprint identification module provided by the embodiments of the present application will be described in detail below with reference to the drawings. It should be understood that the fingerprint identification module provided by the present application is not limited to the LCD screen shown in the above Figure 2 , but can also be applied to the OLED screen. In other words, the screen assembly mentioned in the embodiments of the present application can be an LCD screen or an OLED screen. The application range of the fingerprint identification module is not limited in the present application.

[0128] Figure 5 is a schematic diagram of the fingerprint identification module provided by the embodiments of the present application. Figure 5 The fingerprint identification module 50 is specifically shown. The fingerprint identification module 50 can include at least one LED 501, at least one sensor 502 and at least one light shielding member. It should be understood that the figure is only an example, showing one LED 501, one sensor 502 and one light shielding member 504. However, this should not constitute any limitation on the present application. The number of LEDs, sensors and light shielding members is not limited in the present application.

[0129] Specifically, the light emitting surface of the LED 501 is opposite to the lower surface of the screen assembly 20, for emitting light signals to the direction of the screen assembly 20. The sensor 502 is located on one side of the LED 501. The light receiving surface of the sensor 502 is opposite to the lower surface of the screen assembly 20, which can be used to receive light signals. The light signals received by the sensor 502 can include the fingerprint light signals returned from the finger to which the LED 501 emits, for generating a fingerprint image. For the convenience of understanding, Figure 5 the field of view angle of the sensor 502 and the area where the light signals incident along the direction of the field of view angle into the screen assembly 20 can reach are shown by the dashed line in the figure.

[0130] The light shielding member 504 is arranged in the vicinity of the LED 501. Part or all of the light shielding member 504 is located between the LED 501 and the sensor 502, for blocking part of the light signals emitted by the LED 501. Figure 5 An example in which all of the light shielding member 504 is located between the LED 501 and the sensor 502 is shown. However, this should not constitute any limitation on the present application. For example, Figure 9 , Figures 11 to 17 both show the schematic diagram in which part of the light shielding member 504 is located between the LED 501 and the sensor 502.

[0131] Since the light shield 504 is arranged in the vicinity of the LED 501, the large-angle outgoing light emitted by the LED is blocked, so that the stray light reaching the sensor 502 after at least one reflection on the surface of the screen assembly 20 is reduced, thereby reducing the interference of the stray light on the fingerprint light signal, that is, reducing the interference of the stray light on the fingerprint information, so as to facilitate the improvement of the clarity of the fingerprint image.

[0132] Based on the above design, on the plane passing through the light-emitting center of the LED 501 and the AA center of the sensor 501, the outgoing angle of the light signal emitted by the LED 501 is less than or equal to the predefined angle θ described above. In other words, on the plane passing through the light-emitting center of the LED 501 and the AA center of the sensor 501, the light shield 504 can be used to block the light signal emitted by the LED 501 with an outgoing angle greater than θ. That is, after being blocked by the light shield 504, on the plane passing through the light-emitting center of the LED 501 and the AA center of the sensor 501, the maximum outgoing angle of the light signal emitted by the LED 501 is θ.

[0133] Among them, optionally, the predefined angle θ can be near half of the beam angle 2γ of the LED 501, that is, the predefined angle θ can be γ or a value near γ. This is because the radiation intensity of the LED lamp is related to the outgoing angle. Specifically, when the maximum outgoing angle θ is in the range greater than γ, more light signals can be included, that is, more energy can be included. However, in the case of a larger maximum outgoing angle θ, the distance between the image sensor and the LED will be farther (which can be seen from the calculation formula of the center distance L shown below), and the energy received by the image sensor will be reduced. When the maximum outgoing angle θ is in the range less than or equal to γ, the energy loss received by the image sensor can be reduced, but the energy reaching the finger will be reduced. Therefore, by designing the position and shape of the light shield, the maximum outgoing angle θ of the light signal on the plane passing through the light-emitting center of the LED and the AA center of the image sensor can be designed to be γ or a value near γ, so as to achieve a balance between the energy reaching the finger and the energy reaching the image sensor, thereby greatly improving the clarity of the fingerprint image.

[0134] It should be understood that the relationship between the radiation intensity of the light source and the outgoing angle and the related description of the beam angle have been described in detail above, and will not be repeated here for the sake of brevity.

[0135] In addition, the maximum outgoing angle of the LED mentioned below can refer to the maximum value of the outgoing angle that the light signal emitted by the LED can reach after being blocked by the light shield. For the sake of brevity, the same or similar cases will be omitted hereinafter.

[0136] It should be noted that, Figure 5The upper surface of the LED 501 is opposite to the lower surface of the screen assembly 20. That is, the upper surface of the LED 501 is a light emitting surface. The upper surface of the sensor 502 is opposite to the lower surface of the screen assembly 20. That is, the upper surface of the sensor 502 is a light receiving surface. In the following embodiments, when the upper surface of the LED is described, it can be considered as the light emitting surface of the LED; when the upper surface of the sensor is described, it can be considered as the light receiving surface of the sensor.

[0137] Optionally, the fingerprint identification module 50 further comprises at least one lens, which is located between the screen assembly 20 and the sensor 502, and the imaging center of the at least one lens is coincident with the AA center of the sensor 502. The at least one lens can be used to receive the light signal, and the light signal reaches the sensor 502 after converging through the at least one lens. In other words, the at least one lens can be used in cooperation with one sensor.

[0138] In one possible design, the sensor and the at least one lens can be defined as a lens module, that is, the lens module comprises the sensor; in another possible design, the at least one lens can be defined as a lens module, that is, the lens module and the sensor are defined separately. In this application, the sensor and the at least one lens are defined as a lens module. However, it should be understood that this is only a different definition, and does not constitute any limitation on the present application.

[0139] As described above, the at least one lens is used to converge the light rays so as to obtain a fingerprint image with high definition. In other words, even if the fingerprint identification module does not comprise the lens, the sensor can generate the fingerprint image based on the received light signal. Therefore, the fingerprint identification module can also not comprise the at least one lens described above, but only comprise the sensor. In the following, the multiple embodiments combined with the drawings are only illustrative, and multiple schematic diagrams of the fingerprint identification module are shown by taking the fingerprint identification module comprising the lens module as an example. If the fingerprint identification module does not comprise the at least one lens described above, the lens module can be replaced by the sensor in the following without special description.

[0140] In order to more clearly illustrate the fingerprint identification module provided by the embodiments of the present application, the fingerprint identification module will be further described below in combination with several examples in Figure 6

[0141] Figure 6 is another schematic diagram of the fingerprint identification module provided by the embodiments of the present application. Figure 6 ​Several examples of the fingerprint recognition module 50 are shown in detail. Specifically, the fingerprint recognition module 50 can include at least one LED 501, at least one lens module 505, and at least one light shield 504. Each lens module 505 can include one sensor 502 and at least one lens 503. The related descriptions of the at least one LED 501, the at least one lens module 505, and the at least one light shield 504 are referred to the above descriptions. Figure 5 For the convenience of understanding, Figure 6 The field of view of the lens 503 in the lens module 505 and the area where the optical signal incident into the screen assembly 20 along the direction of the field of view can reach are shown by the dashed line in FIG. 5.

[0142] The LED 501 can be used to provide a light source. The light emitting surface of the LED 501 is opposite to the lower surface of the screen assembly 20, so as to emit the optical signal towards the screen assembly 20. Optionally, the LED 501 is an infrared LED. The LED 501 can emit the optical signal which can penetrate the screen assembly 20 to reach the finger. The lens module 505 is located on one side of the LED 501. At least one lens 503 in the lens module 505 is used to receive the fingerprint optical signal which reaches the sensor 502 after converging through the at least one lens 503. Therefore, simply speaking, the sensor 502 can be used to receive the fingerprint optical signal. The light shield 504 can be placed close to the LED 501. One side of the light shield 504 faces the LED 501, and the other side faces the lens module 505. The side facing the LED 501 can be used to absorb part of the optical signal emitted by the LED 501. Specifically, the side of the light shield 504 facing the LED 501 is designed to absorb the optical signal with an exit angle greater than a predefined angle (i.e., θ described above). For the convenience of distinguishing and description, the side surface of the light shield 504 facing the LED 501 is referred to as a first surface, and the optical signal with an exit angle greater than the predefined angle θ is referred to as a large-angle exit light.

[0143] Optionally, the first surface of the light shield 504 is coated with a light-absorbing material. Alternatively, the light shield 504 is made of a light-absorbing material. The specific preparation process and material of the light shield 504 are not limited in the present application. As long as the surface of the light shield 504 facing the LED 501 has a light-absorbing effect.

[0144] In this embodiment, the fingerprint recognition module 50 includes one LED 501 and one lens module 505. The light-shielding member 504 can be designed to absorb light signals with an emission angle greater than a predefined angle and close to the lens module 505, thereby reducing the large-angle emitted light from the LED 501 and preventing a large amount of light signals from reaching the lens module 505 after reflection by the screen assembly 20, thus interfering with the fingerprint light signal. Therefore, the light-shielding member 504 can be designed to block the large-angle emitted light from the LED 501 in a certain direction (such as the direction close to the lens module 505), or in other words, it can be designed to block part of the large-angle emitted light from the LED 501; the light-shielding member 504 can also be designed to block the large-angle emitted light from the LED 501 in all directions, or in other words, it can be designed to block all the large-angle emitted light from the LED 501.

[0145] Figure 6 Examples of light-shielding element 504 are shown in a) to c). Figure 6 The light-shielding member 504 shown can be used to block the large-angle emitted light from the LED 501 in the direction close to the sensor 502. Therefore, the light-shielding member 504 can be flat, arc-shaped, etc. The following is in conjunction with... Figure 6 a) to c) in the diagram illustrate the relative positional relationship between LED 501 and light-shielding member 504, respectively.

[0146] To facilitate understanding and explanation, let's first discuss... Figure 6 The parameters involved in a) and b) are defined as follows: the distance between the lower surface of the light-shielding member 504 and the upper surface of the LED 501 is h1, the height of the light-shielding member 504 is h2, the distance between the light-emitting center of the LED 501 and the first surface of the light-shielding member 504 is w1, and the minimum distance between the side surface of the LED 501 near the lens module and the first surface of the light-shielding member 501 is w2.

[0147] exist Figure 6 In step a), the first surface of the light-shielding member 504 is perpendicular to the upper surface of the LED 501. The light-shielding member 504 is located in the area above the upper surface of the LED 501. A gap, h1, is left between the lower surface of the light-shielding member 504 and the upper surface of the LED 501, as described above. The design of this gap h1 is based on reliability considerations to prevent the light-shielding member 504 from colliding with the upper surface of the LED 501 and damaging the LED 501. Therefore, this gap h1 can be greater than or equal to the safe avoidance distance h0.

[0148] As mentioned above, the radiation intensity of the LED lamp is related to the exit angle. In the embodiments of the present application, the maximum exit angle θ of the light signal emitted by the LED 501 can be controlled to be around half of the beam angle γ of the LED, for example, 2γ = 30°, and the maximum exit angle θ is 15°.

[0149] It should be understood that the size of the predefined value θ can also be artificially defined. The θ = 15° listed here is only an example and should not constitute any limitation on the present application. By controlling the maximum exit angle of the light signal emitted by the LED 501, the light signal emitted by the LED 501 that reaches the lower surface of the screen assembly 20 can be controlled within a smaller range, and light signals with a large exit angle are avoided from being emitted to the screen assembly 20 and then reflected to the lens module 505.

[0150] Based on the above control of the maximum exit angle, the height h2 of the light shielding member 504 can be further designed. In Figure 6 In a), w1 / tanθ = h2 + h1. Thus, the height h2 of the light shielding member can be determined as h2 = w1 / tanθ - h1.

[0151] Figure 6 In b), the first surface of the light shielding member 504 is perpendicular to the upper surface of the LED 501. The light shielding member 504 is located on one side of the LED 501, and there is a spacing between the first surface of the light shielding member 504 and the side surface of the LED 501, and the minimum value of the spacing is the above-mentioned w2. Here, w2 is referred to as the minimum distance because the present application does not limit the shape of the LED 501, which can be a cylinder, a cube, a cuboid, or other irregular shapes. When the side surface of the LED 501 close to the sensor 502 is a plane, such as when the shape of the LED 501 is a cube, a cuboid, or the like, the distance between the side surface and the first surface is constant, i.e., w2; when the side surface of the LED 501 close to the sensor 502 is not a plane, such as when the shape of the LED 501 is a cylinder or the like, the distances between different points on the side surface of the LED 501 close to the sensor 502 and the first surface can be different. In this case, w2 can be defined as the minimum distance between the side surface of the LED 501 close to the sensor 502 and the first surface of the light shielding member 501.

[0152] The design of the minimum distance w2 can also be based on the consideration of reliability to avoid the light shielding member 504 colliding with the side surface of the LED 501 and damaging the LED 501. Therefore, the spacing w2 can also be greater than or equal to the safety distance h0.

[0153] Based on the above control of the maximum exit angle, the height h2 of the light shielding member 504 can be further designed. In Figure 6In b) of the above, w1 / tanθ=h2-h1. Thus, the height h2 of the light shielding member can be determined as w1 / tanθ+h1.

[0154] It should be understood that, Figure 6 The a) and b) shown are only two possible designs of the relative position relationship between the LED 501 and the light shielding member 504, and should not constitute any limitation to the present application.

[0155] For example, the first surface of the light shielding member 504 is not necessarily perpendicular to the upper surface of the LED 501. As shown in c) of the above, Figure 6 As shown in c) of the above, the light shielding member 504 can be trapezoidal in cross-sectional shape perpendicular to the direction of the screen assembly (e.g. in the yoz plane). That is, the first surface of the light shielding member 504 has an inclination angle smaller than 90° with the upper surface of the LED 501. When the first surface of the light shielding member 504 is not perpendicular to the upper surface of the LED 501, the safety clearance distance between the light shielding member 504 and the LED 501 still needs to be considered. Since Figure 6 As shown in c) of the above, the first surface of the light shielding member 504 can collide with the side of the LED 501 close to the lens module 505, so the minimum distance between the side and the first surface can be designed to be greater than or equal to the safety clearance distance.

[0156] Since the first surface of the light shielding member 504 has an inclination angle smaller than 90° with the upper surface of the LED 501, the distance between different positions on the first surface and the light emitting center of the LED 501 is different. The intersection line between the first surface of the light shielding member 504 and the upper surface can be projected on the upper surface of the LED 501 or the extension plane of the upper surface of the LED 501, and the distance between the light emitting center and the projection can be determined, e.g. denoted as w3. Then w3 / tanθ=h2-h1, thus h2=w3 / tanθ+h1 can be determined.

[0157] It should be understood that, Figure 6 As shown in c) of the above, the relative position relationship between the first surface of the light shielding member 504 and the LED 501 is only an example, and should not constitute any limitation to the present application. For example, the upper surface of the light shielding member 504 can also be located above the upper surface of the LED 501, then w3 / tanθ=h2+h1, thus h2=w3 / tanθ-h1 can be determined. In this case, h2 needs to be greater than or equal to the safety clearance distance h0.

[0158] It should be noted that from the relationship between w1 and h2 and the relationship between w3 and h2 shown in the above, the greater w1 or w3 is, the greater h1 is, and the volume of the light shielding member also increases. However, the volume of the light shielding member is restricted by the available space in the electronic device, so the relative position relationship between the light shielding member and the LED can be designed according to the available space.

[0159] It should also be understood that Figure 7 The a) to c) in FIG. 4 only show examples of the cross section of the light shield 504 in the direction perpendicular to the screen assembly 20. The present application does not limit the shape of the light shield 504.

[0160] Figure 7 The cross section and top view of the light shield 504 are shown.

[0161] Figure 7 The a) in FIG. 4 shows the cross section of the light shield 504 in the direction perpendicular to the screen assembly 20. Specifically, the cross section of the light shield 504 in the yoz plane is shown. As shown, the cross section of the light shield 504 in the yoz plane can be rectangular, square, or stepped, trapezoidal, etc. For brevity, they are not listed one by one here. But it can be understood that no matter what shape the cross section of the light shield 504 in the yoz plane is, the maximum emission angle of the LED 501 can be determined by the position of the intersection of the upper surface of the light shield 504 and the first surface.

[0162] Figure 8 The b) in FIG. 4 shows the top view of the light shield 504 obtained by looking down in the direction perpendicular to the screen assembly 20. As shown, when looking down in the direction perpendicular to the screen assembly 20, the light shield 504 can be square, rectangular, or circular arc, etc. For brevity, they are not listed one by one here.

[0163] Based on the above control of the maximum emission angle of the LED, the relative position relationship between the sensor 502 and the LED 501 can be further designed. As mentioned before, the sensor 502 does not want to receive reflected light from the screen assembly 20, so the sensor 502 can be placed as far away from the LED 501 as possible. But if the distance between the sensor 502 and the LED 501 is too far, the received fingerprint light signal strength is weak. Therefore, it is desirable to determine the distance between the sensor 502 and the LED 501 to balance the strength of the fingerprint light signal and the amount of stray light.

[0164] Figure 8 Further, the relative position relationship between the lens module 505 and the LED 501 is shown. For brevity, Figure 8 The lens module 505 is shown as a whole in FIG. 5, and the at least one lens 503 and the sensor 502 are not shown separately. Figure 8The relationship between the center distance L' of the lens module 505 and the LED 501 and various parameters is specifically shown. The center distance L' can specifically refer to the distance between the light emitting center of the LED 501 and the imaging lens center of the lens in the lens module 505. It should be understood that the definition of L is defined only for the convenience of understanding, and based on the same concept, those skilled in the art can make equivalent replacements or mathematical transformations on the definition of L'. These replacements or mathematical transformations should all fall within the protection scope of the present application.

[0165] For the convenience of distinguishing and explaining, it is assumed that the distance between the upper surface of the LED 501 and the lower surface of the screen assembly 20 is h. The light exit hole diameter (or also referred to as the clear aperture) of the imaging lens surface of the lens in the lens module 505 is CA. The FOV of the imaging lens of the lens in the lens module 505 is 2a. The distance between the surface of the light exit hole of the lens surface and the lower surface of the screen assembly 20 is t'. The distance between the upper surface and the lower surface of the screen assembly 20 is d. The maximum incidence angle of the light signal emitted by the LED 501 to the lower surface of the screen assembly 20 is related to the maximum emission angle of the LED 501, and in the present embodiment, the maximum emission angle of the LED 501 is θ, so the maximum incidence angle of the light signal emitted by the LED 501 to the lower surface of the screen assembly 20 is θ. Since the light signal is refracted after entering the screen assembly 20, the incidence angle of the light signal to the upper surface of the screen assembly 20 changes, for example, denoted as θ'. In addition, since the FOV of the imaging lens of the lens in the lens module 505 is 2a, the maximum incidence angle of the light signal emitted by the lower surface of the screen assembly 20 to the lens module 505 is a. Due to the refraction phenomenon of the light signal in different media, the incidence angle of the light signal incident to the lower surface from the upper surface of the screen assembly 20 is different from a, for example, denoted as a'. a' represents the incidence angle corresponding to the emission angle a when the light signal is refracted on the surface of the screen assembly. It should be noted that when the lens module 505 includes multiple lenses, the light exit hole of the imaging lens surface of the lens in the lens module 505 can be, for example, the light exit hole of the imaging lens surface of the lens closest to the screen assembly 20. If the screen assembly 20 is located above the lens module 505, the lens closest to the screen assembly 20 can refer to the uppermost lens among the multiple lenses included in the lens module 505. It should be understood that defining the light exit hole of the imaging lens surface of the lens closest to the screen assembly 20 as the light exit hole of the imaging lens surface of the lens in the lens module 505 is only one possible implementation manner, and should not constitute any limitation on the present application.

[0166] The critical point at which the lens module 505 can receive the light signal from the screen assembly 20 is: the light signal emitted by the LED 501 enters the screen assembly 20 at an incident angle θ and enters the lens module 505 at an incident angle α. That is, if the light signal emitted by the LED 501 enters the screen assembly 20 at an incident angle less than θ, or exits the screen assembly 20 at an exit angle less than α, the lens module 505 will not receive the light signal.

[0167] In other words, L'≥h×tanθ+d×tanθ'+d×tanα'+t'×tanα+CA / 2.

[0168] Once the parameters on the right side of the above formula are determined, the calculated value can be understood as the critical value of the center distance between the lens module 505 and the LED 501, for example, denoted as L0'.

[0169] Furthermore, considering system tolerances, the distance L between the light-emitting center of the LED and the center of the image sensor AA satisfies: L'≥h×tanθ+d×tanθ'+d×tanα'+t'×tanα+CA / 2+Δ, where Δ represents the system tolerance.

[0170] The system tolerance Δ can be an empirical value, or it can be determined based on the size of the system (in this embodiment, the system may refer to a fingerprint recognition module), its assembly position in the electronic device, and its fit with the components. This application does not limit the specific value and determination method of the system tolerance Δ.

[0171] As mentioned earlier, the lens module 505 expects to receive light signals reflected back from the finger, such as the light signals emitted by LED 501 into the finger, refracted and scattered after propagation within the finger, and the light signals emitted by LED 501 to the finger surface and reflected back. The lens module 505 does not want to receive light signals emitted from the upper and lower surfaces of the screen assembly 20 or from the cross-section within the screen assembly 20, as these are the stray light mentioned above, which interfere with the acquisition of fingerprint information.

[0172] To make it easier to understand, the following will be combined with Figure 8 a), b), and c) in the text explain in detail the different effects on fingerprint information when the center distance L' is equal to, less than, and greater than the critical value L0'. Figure 8 For ease of distinction and explanation, light signal 'a', which yields fingerprint information, is shown with a thin line, while light signal 'b', which does not yield fingerprint information, is shown with a thick line. It should be understood that light signals 'a' and 'b' are merely examples and should not constitute any limitation on the number, propagation path, or intensity of the light signals. Furthermore, for ease of understanding, Figure 8The dashed lines in the image show the field of view of the lens in the lens module 505 and the area that the light signal incident on the screen assembly 20 along the direction of this field of view can reach.

[0173] Furthermore, for ease of comparison, figures a), b), and c) use the same LED 501, light-shielding component 504, lens module 505, and screen assembly 20. Except for the lens module 505, which has been moved, the relative positions of the other components remain unchanged. For ease of comparison, the light-emitting center of LED 501 is used as the reference point in the figures, which is shown as a dashed line.

[0174] Figure 8 Figure a) shows the case where the center distance L' between the light-emitting center of LED 501 and the imaging center of lens module 505 is equal to the critical value L0'. As shown in the figure, when the light signal near the lens module 505 is blocked by the light shield 504, the light signal c shown in the figure is the light signal with the maximum emission angle that can be emitted from the light shield 504, and the emission angle of this light signal is θ. When the center distance L' is the critical value L0', the light signal c, after being reflected by the screen assembly 20, enters the lens module 505 exactly along the maximum incident angle α of the lens module 505.

[0175] If the center distance between the lens module 505 and the LED 501 is less than the critical value L0', the amount of stray light received by the lens module 505 will increase. Since when the center distance L' between the lens module 505 and the LED 501 is less than the critical value L0', for example, moving the lens module 505 closer to the LED 501... Figure 9 As shown by the dashed line in b), due to the leftward shift of the lens surface of the lens module 505, the corresponding image-taking area also shifts to the left. Reflected light that was originally outside the image-taking area enters the image-taking area, thus allowing reflected light that was originally not incident on the lens surface to enter the lens surface. Besides the light signal c shown in the figure, there may be more light signals with an exit angle less than θ that reach the lens module 505 after reflection from the screen assembly 20. This is equivalent to allowing some of the light signals emitted by the LED 501 and reflected back from the screen assembly 20 (i.e., the stray light mentioned above) to enter the lens module 505. When the center distance between the lens module 505 and the LED 501 is greater than or equal to the critical value L0', these light signals are outside the imaging lens and will not be received by the lens module 505. However, when the center distance between the lens module 505 and the LED 501 decreases, they enter the range of the imaging lens and are received by the lens module 505. Therefore, when the center distance L' between the lens module 505 and the LED 501 is less than the critical value L0', the amount of stray light received by the lens module 505 will increase.

[0176] If the distance between the lens module 505 and the LED 501 is greater than the critical value L0', the amount of stray light received by the lens module 505 can be reduced. This is because when the center distance L' between the lens module 505 and the LED 501 is greater than the critical value L0', for example, by moving the lens module 505 away from the LED 501, ... Figure 9 As shown by the dashed line in c), due to the rightward shift of the lens surface of the lens module 505, the corresponding image-capturing area also shifts to the right. This means that light signals with an exit angle of θ (light signal c in the figure) cannot enter the image-capturing area and are unlikely to be received by the lens module 505. Therefore, when the center distance L' between the lens module 505 and the LED 501 is greater than the critical value L0', the amount of stray light received by the lens module 505 can be reduced. However, in addition to the light signal c shown in the figure, there may be more light signals with exit angles smaller than θ that cannot enter the image-capturing area after returning from the finger, and are also unlikely to be received by the projection module 505. Therefore, the fingerprint light signal received by the lens module 505 will also be reduced, and the light intensity will be weakened. Therefore, when the distance between the lens module 505 and the LED 501 is too large, the fingerprint light signal collected by the sensor will be reduced, which may affect the clarity of the fingerprint image.

[0177] In summary, the center distance L' between the lens module 505 and the LED 501 can be designed to be greater than or equal to the critical value L0'.

[0178] A specific example is given below.

[0179] h=1mm, 2θ=30°, θ'=9.93°, CA=2.45mm, t'=0.8mm, d=1.956mm, 2α=123°, α'=35.86°, Δ=1mm.

[0180] Substituting into the above formula, we can obtain:

[0181] L'≥1×tan15°+1.956×tan9.93°+1.956×tan35.86°+0.8×tan61.5°+2.45 / 2+1;

[0182] Calculations show that L' ≥ 5.72 mm. That is, the critical value L0' of the center distance L' between the lens module 505 and the LED 501 is 5.72 mm. In other words, the minimum center distance L' between the lens module 505 and the LED 501 can be 5.72 mm.

[0183] It should be understood that the values ​​of the parameters listed above are for illustrative purposes only and should not constitute any limitation on this application. This application does not limit the specific values ​​of each parameter.

[0184] Based on the above design, the light shielding member 504 can reduce stray light reflected by the screen assembly 20 to the lens module 505 by absorbing a portion of the large-angle outgoing light. Thus, the interference with the fingerprint information can be reduced, and a high-definition fingerprint image can be obtained. In particular, the stray light with high light intensity can be reduced, light leakage can be avoided, and the exposure area can be reduced, which is beneficial to obtaining a fingerprint image with a large effective area. Therefore, the complete and clear fingerprint image can be obtained as a whole, and the fingerprint recognition efficiency can be improved.

[0185] It should be noted that the determination of the center distance L' shown above is made under the assumption that the fingerprint recognition module includes at least one lens. As described above, the fingerprint recognition module does not necessarily include the at least one lens, and in this case, the center distance L can be defined as the distance between the imaging center of the LED and the center of the sensor AA. Moreover, the center distance L satisfies: L≥h×tanθ+d×tanθ'+d×tanβ'+t×tanβ. Wherein, t represents the distance between the light receiving surface of the sensor and the lower surface of the screen assembly 20, and β is the FOV of the sensor, and β' represents the incident angle of the light signal emitted by the lower surface of the screen assembly to the sensor when the incident angle of the light signal on the lower surface of the screen assembly is β.

[0186] If the system tolerance is considered, the distance L between the light emitting center of the LED and the center of the sensor AA satisfies: L≥h×tanθ+d×tanθ'+d×tanβ'+t×tanβ+Δ, and Δ represents the system tolerance.

[0187] Of course, the at least one lens described above can also be replaced by other devices or combinations of devices. In this case, the definition of the center distance in the above can change accordingly, and the values and definitions of α, α', t, and CA in the calculation formula of the center distance L' can also change accordingly.

[0188] As described above, the light shielding member 504 can also be designed to block the large-angle outgoing light of the LED 501 in various directions. Figure 9 is another schematic view of the fingerprint recognition module provided by the embodiments of the present application. Figure 18 The light shielding member 504 shown in FIG. 5 can block the large-angle outgoing light from the LED 501 in various directions. For the sake of understanding, Figure 12 In FIG. 5, the field of view angle of the lens in the lens module 505 and the area where the light signal incident to the screen assembly 20 along the direction of the field of view angle can reach, and the maximum outgoing angle of the light signal emitted by the LED 501 and the area where the light signal incident to the screen assembly 20 along the direction of the maximum outgoing angle can reach are shown by the dashed lines.

[0189] Specifically, the light shielding member 504 can be a structural member with a light passing hole (or light emitting hole). The hole wall of the light passing hole surrounds the light signal emitted by the LED 501 from all directions to block a part of the emitted light emitted by the LED 501. For example, the light shielding member 504 can be in the shape of a cylinder, the inner surface of which can form a cylinder, an oblique cylinder, an elliptical cylinder, an inverted funnel, a cuboid, a cube, a planar hexagon, a trapezoidal body, or a stepped cylinder, a stepped oblique cylinder, a stepped elliptical cylinder, a stepped inverted funnel, a stepped cuboid, a stepped cube, a stepped parallelepiped, a stepped trapezoidal body, etc. For the sake of brevity, they will not be listed one by one here. It can be understood that the hole wall of the light passing hole of the light shielding member 504 described herein can be used to block the large-angle emitted light from various directions of the LED 501, which has the same function as the first surface described above, and can also be understood as the first surface described above.

[0190] Optionally, the hole of the light passing hole of the light shielding member 504 is circular, elliptical, square, or rectangular. Among them, the hole shape of the light passing hole can refer to the shape obtained by the intersection of the upper surface of the light shielding member 504 and the inner wall of the hole, or the projection shape obtained by the inner surface of the light shielding member 504 projecting onto the lower surface of the screen assembly 20.

[0191] Optionally, the cross-sectional shape of the light shielding member 504 in the direction perpendicular to the screen assembly 20 (i.e., in the yoz plane) is square, rectangular, trapezoidal, stepped square, stepped rectangular, or stepped trapezoidal.

[0192] The hole shape of the light passing hole of the light shielding member 504 described above and the cross-sectional shape in the direction perpendicular to the screen assembly 20 can be combined, so that the inner wall of the light passing hole of the light shielding member 504 can form various different shapes.

[0193] It should be noted that when the hole of the light passing hole of the light shielding member 504 is circular and the cross-sectional shape in the direction perpendicular to the screen assembly 20 is symmetric about the light-emitting center of the LED 501, the maximum emission angle of the light signal emitted by the LED 501 can be controlled to be the same in all directions, such as θ. This design is particularly suitable for the case of an array composed of multiple lens modules, multiple LEDs, and multiple light shielding members, as shown in FIG. 6; it can also be suitable for the case where multiple LEDs and multiple light shielding members are uniformly distributed in a lens module, as shown in c) of FIG. 7. Figure 12 Figure 9

[0194] ​​When the light-emitting aperture of the light-shielding member 504 is elliptical, square, or rectangular, the maximum emission angle of the light signal emitted by the LED 501 varies slightly in different directions. For example, for an elliptical shape, the maximum emission angle along the major axis is greater than that along the minor axis. For a square or rectangular shape, the maximum emission angle on the diagonal face is greater than the maximum emission angle between any two opposite faces. This design is particularly suitable for situations where two or more LEDs are distributed around a lens module, such as... Figure 9 As shown in a), b), and d), by using different maximum emission angles in different directions, more light signals can be incident on the screen component 20, which is beneficial for increasing light intensity, obtaining more fingerprint information, and thus obtaining a clearer and more accurate fingerprint image.

[0195] Therefore, based on the different maximum emission angles and the relative positional relationship between LED 501 and lens module 505, the shape of the light-transmitting hole of light-shielding component 504 can be reasonably designed.

[0196] When the inner surface of the light-shielding member 504 has a stepped cross-sectional shape in the direction perpendicular to the screen assembly 20, it facilitates the incidence of more light signals onto the screen assembly 20. For the same reason mentioned above, this facilitates the acquisition of more fingerprint light signals and results in a clearer and more accurate fingerprint image.

[0197] Figure 9 a) to d) show several different cross-sectional shapes of the light-transmitting hole wall of the light-shielding member 504 in a direction perpendicular to the screen assembly 20. Figure 9 The image shows several different cross-sectional shapes of the light-transmitting hole wall of the light-shielding member 504 on the yoz plane.

[0198] like Figure 9 As shown in a), the cross-section of the light-transmitting hole wall of the light-shielding member 504 in the direction perpendicular to the screen assembly 20 (such as the yoz plane) is rectangular, while the cross-section of the light-transmitting hole wall of the light-shielding member 504 in the direction parallel to the screen assembly 20 (such as the xoy plane) can be circular, elliptical, square, rectangular, etc. Therefore, Figure 9 The light-transmitting hole wall of the light-shielding member 504 shown in a) can be formed into a cylinder, elliptical cylinder, cube, cuboid, etc.

[0199] Figure 9 As shown in b), the cross-section of the light-transmitting hole wall of the light-shielding member 504 in the direction perpendicular to the screen assembly 20 (such as the yoz plane) is a parallelogram. The cross-section of the light-transmitting hole wall of the light-shielding member 504 in the direction parallel to the screen assembly 20 (such as the xoy plane) can be circular, elliptical, square, rectangular, etc. Therefore, Figure 9The light-transmitting hole wall of the light-shielding member 504 shown in b) can be formed into an oblique cylinder, an oblique elliptical cylinder, a cube, a parallelepiped, etc.

[0200] like Figure 9 As shown in c) of the diagram, the cross-section of the light-transmitting hole wall of the light-shielding member 504 in the direction perpendicular to the screen assembly 20 (e.g., the yoz plane) is stepped, while the cross-section of the light-transmitting hole wall of the light-shielding member 504 in the direction parallel to the screen assembly 20 (e.g., the xoy plane) can be circular, elliptical, square, rectangular, etc. Therefore, Figure 9 The light-transmitting hole wall of the light-blocking member 504 shown in c) can be formed into a stepped cylinder, a stepped elliptical cylinder, a stepped cube, a stepped cuboid, etc.

[0201] like Figure 9 As shown in d), the cross-section of the light-transmitting hole wall of the light-shielding member 504 in the direction perpendicular to the screen assembly 20 (such as the yoz plane) is stepped, and the cross-section of the light-transmitting hole wall of the light-shielding member 504 in the direction parallel to the screen assembly 20 (such as the xoy plane) can be circular or square, etc. Therefore, Figure 9 The light-transmitting hole wall of the light-shielding member 504 shown in d) can be formed into a trapezoidal shape, an inverted funnel shape, etc.

[0202] It should be understood that the above text, in combination with... Figure 6 Several different shapes may be formed for the wall of the light-transmitting hole of the light-shielding member 504, but this should not constitute any limitation on this application.

[0203] Figure 8 The relative positions of LED 501, lens module 505, and light shield 504 can be found in the above text. Figure 10 and Figure 4 For the sake of brevity, the description will not be repeated here.

[0204] Furthermore, the outer surface of the light-shielding member 504 can be formed into a cylinder, or a stepped cylinder, or a cuboid, cube, etc. This application does not limit this. Moreover, the shape of the wall of the light-transmitting hole of the light-shielding member 504 is independent of the shape of the outer surface. For example, the wall of the light-transmitting hole of the light-shielding member 504 can be formed into a cylinder, and the outer surface of the light-shielding member 504 can be formed into a cylinder, then the light-shielding member 504 can be a hollow cylinder. Another example is that the wall of the light-transmitting hole of the light-shielding member 504 can be formed into a cylinder. Yet another example is that the wall of the light-transmitting hole of the light-shielding member 504 is formed into an oblique cylinder, and the outer surface of the light-shielding member 504 can be formed into a cylinder. For simplicity, these are not listed here.

[0205] Figure 10 These are comparison images showing the effects of using and not using a light-shielding element in a fingerprint recognition module, as provided in the embodiments of this application. (Compared to the above...)Figure 10 resemblance, Figure 10 The diagram shows the test target located above the screen assembly 20 after receiving the light signal from LED 501. Figure 9 Figure a) shows a schematic diagram obtained without using a light shield in the fingerprint recognition module; Figure 9 b) shows the use of, for example, in a fingerprint recognition module Figure 7 The diagram shows the result after the light-shielding component is applied. A comparison reveals that without the light-shielding component, the light intensity distribution in the fingerprint recognition module is uneven, with light leakage occurring in multiple areas. However, with the light-shielding component applied, the light intensity distribution is more uniform, and the light leakage is largely eliminated.

[0206] On the other hand, in order to facilitate the normal use of the fingerprint recognition module 50, some improvements may be needed to the screen assembly 20.

[0207] For example, since the fingerprint recognition module 50 is located below the screen assembly 20, and the light signal emitted by the LED 401 needs to penetrate the screen assembly 20 to reach the finger, the substrate 211 of the screen assembly 20 may block the light signal from propagating upwards from the screen assembly 20. If it is desired that the light signal penetrates the screen assembly 20 to reach the finger, an opening needs to be made in the substrate 211 at the position corresponding to the LED 501, so that the light signal can propagate upwards from the screen assembly 20. Specifically, an opening can be made in the substrate 211 at the position corresponding to the light shield 504. The size of this opening can be determined based on the maximum emission angle of the LED 501 and the distance between the upper surface of the LED 501 and the upper surface of the substrate 211.

[0208] by Figures 5 to 9 Taking (a) as an example, assuming the maximum emission angle of the light signal emitted by LED 501 is θ, and the distance between the upper surface of LED 501 and the upper surface of substrate 211 is s1, the opening can be, for example, a circle with the light-emitting center of LED 501 as the center and s1×tanθ as the radius, or a square with the light-emitting center of LED 501 as the center and 2×s1×tanθ as the side length. The shape of this opening can be the same as the shape of the light-transmitting hole of the light-shielding member 504. For simplicity, they are not listed here one by one.

[0209] Similarly, the intensity of the fingerprint light signal reaching the screen assembly 20 after propagating in the finger is greatly weakened and cannot penetrate the base 211 of the screen assembly 20. If it is desired that the fingerprint light signal reaches the lens module 505, the base 211 needs to be opened to facilitate the fingerprint light signal to enter the fingerprint recognition module 50 to obtain the fingerprint information. Specifically, the base 211 can be opened at a position corresponding to the imaging area, so that the fingerprint light signal falling into the imaging area can penetrate the screen assembly 20 to reach the lens module 505. The size of the opening can be determined according to the distance between the upper surface of the lens module 505 and the upper surface of the base 211 and the FOV of the imaging lens in the lens module 505, for example. Assuming that the FOV of the imaging lens in the lens module 505 is 2a and the distance between the upper surface of the lens module 505 and the upper surface of the base 211 is s2, the opening can be a circle with the imaging center of the lens module 505 as the center and CA / 2 + s1 / tan a as the radius, for example. Wherein, the definitions of CA and a have been described in detail above, and will not be repeated here for brevity. Figure 11

[0210] Wherein, the opening processing can also be referred to as windowing, punching, holing, etc. That is, the part of the material on the base 211 that blocks the light signal is removed to ensure that the light signal is transmitted outward through the screen assembly 20 or to ensure that the light signal reaches the lens module through the screen assembly 20. Since the light signal can pass through the screen assembly 20 to the finger through the opening processing, the opening obtained through the opening processing can also be referred to as a light transmission hole.

[0211] It should be noted that the position on the base 211 corresponding to the light shielding member 504 specifically refers to the position on the base 211 corresponding to the light shielding member 504 when the fingerprint recognition module 50 and the screen assembly 20 are assembled in the electronic device. The position on the base 211 corresponding to the sensor 502 specifically refers to the position on the base 211 corresponding to the sensor 502 when the fingerprint recognition module 50 and the screen assembly 20 are assembled in the electronic device. Hereinafter, the same or similar cases will be omitted for brevity.

[0212] For the convenience of understanding the embodiments of the present application, the above describes the case that the fingerprint recognition module includes one LED, one lens module and one light shielding member. However, this should not constitute any limitation on the present application. The present application does not limit the number of LEDs, the number of sensors, the number of lens modules and the number of light shielding members. However, it can be understood that the light shielding member can be used in cooperation with the LED, so the number of light shielding members can correspond to the number of LEDs. The lens module and the sensor are used in cooperation, so the number of lens modules corresponds to the number of sensors. Figure 11

[0213] ​​Figure 11 is another schematic view of the fingerprint identification module provided by an embodiment of the present application. Figure 11 The fingerprint identification module 60 is specifically shown. The fingerprint identification module 60 includes a plurality of LEDs 601, a lens module 605, and a plurality of light shielding members 604. Figures 5 to 9 For brevity, the lens module 605 is shown as a whole, and at least one lens and a sensor are not shown separately. However, this should not constitute any limitation on the present application. For ease of understanding, Figures 5 to 9 In the lens module 605, the field of view of the lens and the area that the optical signal incident along the direction of the field of view can reach in the screen assembly 20 are shown by the dashed line, and the maximum exit angle of the light signal emitted by the LED 601 and the area that the optical signal incident along the direction of the maximum exit angle can reach in the screen assembly 20 are shown.

[0214] The LED 601 can correspond to the LED 501 shown in Figures 5 to 9 The lens module 605 can correspond to the lens module 505 shown in Figure 9 The related description of the LED 601 and the lens module 605 can be referred to the related description of the LED 501 and the lens module 505 in the foregoing. Figure 9 The light shielding member 604 can correspond to the light shielding member 504 shown in Figure 11 The related description of the light shielding member 604 can be referred to the related description of the light shielding member 504 in the foregoing. Figure 11 For brevity, the related description is not repeated here.

[0215] As shown in Figure 11 , the fingerprint identification module 60 includes two LEDs 601, two light shielding members 604, and a lens module 605. Each light shielding member 604 is used in cooperation with an LED 601 to form a light source assembly. The light source assembly can be arranged near the lens module 605 to provide an optical signal for obtaining fingerprint information. For example, the relative position relationship between the light source assembly and the lens module can be as described above: the distance L' between the center of the LED 601 and the center of the imaging lens of the lens module 605 is greater than or equal to the critical value L0' described above.

[0216] Since the two LEDs 601 and the two light shielding members 604 can form two light source assemblies, the two light source assemblies can be symmetrically distributed on both sides of the lens module 605, as Figure 12The light source assemblies can be distributed on both sides of the lens module 605, and the distance between each light source assembly and the lens module 605 can satisfy: the distance L' between the LED 601 and the center of the lens module 605 is greater than or equal to the critical value L0'. As described above, when the distance L' between the LED 601 and the center of the lens module 605 is L', the light emitting center of the LED 601 in the two light source assemblies can be distributed at any position on the circumference with the imaging lens center of the sensor 602 as the center and L' as the radius.

[0217] It should be understood that Figure 12 For the sake of convenience, the case where two light source assemblies are symmetrically placed on both sides of the lens module is shown. In fact, the number of light source assemblies is not limited in the present application. For example, the number of light source assemblies can be four, eight, twelve, etc. The plurality of light source assemblies can be uniformly or non-uniformly distributed on the circumference with the imaging lens center of the lens module as the center and L as the radius.

[0218] Figure 12 Several examples of the relative position relationship between the plurality of light source assemblies and the lens module are shown. Figure 12 The relative position relationship between the plurality of light source assemblies and the lens module is shown from the perspective of top view. Figure 11 The plurality of light source assemblies and a sensor are schematically shown. Figure 11 The light source assemblies shown in FIG. 6A can be, for example, the light source assemblies described above in connection with Figure 12 The light source assemblies described above, each of which is composed of a light shield 604 and an LED 601. The circular ring in the figure represents the light source assembly. The light shield is a hollow cylinder that blocks the LED below it, so the LED is not shown separately in the figure. The square in the figure represents the lens module. For example, it can be the lens module 605 described above in connection with Figure 12 It should be understood that the shapes shown in the figure should not constitute any limitation on the shape of the light shield and the lens module, etc. Specifically, Figure 12 a) in FIG. 6B shows an example where two light source assemblies are distributed on both sides of the lens module. Figure 12 b) in FIG. 6B shows an example where two light source assemblies are distributed on one side of the lens module. Figure 18 c) in FIG. 6B shows an example where four light source assemblies are uniformly distributed around the lens module. Figures 13 to 16 d) in FIG. 6B shows an example where four light source assemblies are distributed on both sides of the lens module in two groups. For the sake of brevity, examples are not shown one by one.

[0219] It should also be understood that the number of lens modules is not limited in the present application. The case where the fingerprint identification module includes a plurality of lens modules and a plurality of light source assemblies will be described in detail below, and the detailed description of this embodiment will be omitted here. Figures 13 to 16 The case where the fingerprint identification module includes a plurality of lens modules and a plurality of light source assemblies will be described in detail below, and the detailed description of this embodiment will be omitted here.

[0220] Of course, the center distance between the plurality of light source assemblies and the lens module can also be different, but should satisfy the condition that it is greater than or equal to the critical value L0'.

[0221] Figure 11 is a schematic diagram of an assembly of a fingerprint identification module provided by an embodiment of the present application. Figures 5 to 9 As shown in Figure 13 The fingerprint identification module 60 shown in the figure is taken as an example to show several possible implementation manners of the assembly of the fingerprint identification module in an electronic device. However, this should not constitute any limitation on the present application. Based on the same or similar method, Figure 13 The fingerprint identification module 50 shown in the figure can be assembled in an electronic device.

[0222] As an embodiment, the lens module in the fingerprint identification module can be independently fixed to the lower surface of the middle frame or the screen assembly. The LED and the light shield in the fingerprint identification module (i.e., the light source assembly described above) can also be independently fixed to the lower surface of the middle frame or the screen assembly.

[0223] Figure 9 An example in which the lens module in the fingerprint identification module is independently fixed to the middle frame, and the LED and the light shield are also independently fixed to the middle frame is shown in the figure.

[0224] Specifically, the lens module can be installed on the support 1 by, for example, a surface mounting technology (SMT) or other technology, and the support 1 can be fixed to the middle frame by a back adhesive or a screw. In order to ensure that the lens module receives the fingerprint light signal, the middle frame needs to be processed to have an opening. The opening position of the middle frame can correspond to the position of the lens module, that is, it corresponds to the base opening position of the screen assembly described above, or it corresponds to the image taking area. For the sake of distinction and description, the opening corresponding to the lens module is marked as opening 1. In addition, the number of openings 1 can be the same as the number of lens modules. Each opening 1 can correspond to one lens module. The size of the opening 1 can be related to the FOV of the imaging lens of the lens module, the light exit hole diameter CA, and the distance between the upper surface of the lens module and the lower surface of the middle frame. For example, assuming that the distance between the upper surface of the lens module and the upper surface of the middle frame is m2, then the opening 1 can be a circle with the center of the imaging lens of the lens module as the center and CA / 2+m2×tanα as the radius.

[0225] Figure 11The opening 1 shown can be a circular hole. The support 1 can be attached to the hole end face by, for example, back adhesive. That is, the upper surface of the support 1 is attached to the lower surface of the middle frame in the vicinity of the opening 1. It should be understood that the shape of the opening 1 listed here is only an example, and the opening 1 can also be, for example, a stepped hole, a square hole, etc., or even an irregularly shaped through hole, and the specific shape of the opening 1 is not limited in the present application. It should also be understood that the fixing method and position of the support 1 listed above are only examples and should not constitute any limitation on the present application.

[0226] The LED and the light shield in the fingerprint identification module (i.e., the light source assembly described above) can also be mounted on the support 2 by, for example, SMT technology, and the support 2 can be composed of a soft plate and a reinforcing plate. The support 2 can be used to carry the light source assembly. The support 2 can be fixed to the middle frame or the screen assembly by back adhesive or screws. Although not shown in the figure, the support 2 can be fixed to the middle frame or the screen assembly by back adhesive or screws in a direction perpendicular to the screen assembly (e.g., the z direction). The outer shape of the light shield can be, for example, as shown in Figure 13 or Figure 13 The present application does not limit this.

[0227] It should be noted that Figure 15 the inverted cone shown above the LED in Figure 16 is a schematic of the maximum exit angle of the LED formed inside the light shield. Figure 13 and Figure 14 Although not shown in the figure, Figure 14 the schematic and description of the maximum exit angle and FOV in

[0228] Figure 14 is another schematic diagram of the light shield provided by the embodiments of the present application. As shown in Figure 14 , the outer surface of the light shield extends outwardly with a flange. The flange can extend outwardly in part of the area of the outer surface of the light shield, as shown in Figure 13 , or can extend around the entire circumference of the outer edge of the light shield, and the present application does not limit this. The flange can be used to fix the light source assembly. For example, back adhesive can be applied to the upper surface of the flange to attach the light shield to the lower surface of the middle frame or the screen assembly. For another example, the flange and the middle frame can be connected by screws.

[0229] In order to avoid the LED and the light shielding piece, the middle frame needs to be opened. The opening position of the middle frame can correspond to the position of the light shielding piece. The opening size can be slightly larger than the outer surface of the light shielding piece. In order to distinguish and illustrate, the opening corresponding to the light shielding piece is marked as opening 2. And the number of opening 2 can be the same as the number of light shielding pieces. Each opening 2 can correspond to a light shielding piece.

[0230] Figure 14 The opening 2 shown is a stepped via hole. When the outer surface of the light shielding piece 604 extends a flange, the upper surface of the flange can be opposite to the stepped surface of the opening 2, and the light source assembly can be fixed by back adhesive bonding or screw connection.

[0231] It should be understood that the shape of the opening 2 listed here is only an example, and the opening 2 can also be a circular hole, a square hole, but this is only an example for easy understanding and should not constitute any limitation on the present application. It should also be understood that Figure 15 And Figure 15 The shape of the light shielding piece shown and the connection mode and position of the light shielding piece and the middle frame are only examples and should not constitute any limitation on the present application. Although not shown in the figure, the connection mode of the light shielding piece and the middle frame or the screen assembly is not limited to the above. For example, the outer surface of the light shielding piece can also not be provided with a flange. The light shielding piece can be a hollow cylinder, for example, and the opening 2 can be a circular through hole. The light shielding piece can be inserted into the circular through hole of the opening 2, and the inner surface of the opening 2 and the outer surface of the light shielding piece can be fixed by back adhesive.

[0232] Whether the opening 2 is a circular through hole or a stepped hole, the opening size of the opening 2 on the upper surface of the middle frame can be determined according to the maximum exit angle of the light signal emitted by the LED and the distance between the upper surface of the LED and the upper surface of the middle frame. And similar to the opening of the substrate 211 described above. The shape of the opening 2 can be the same as the shape of the light emitting hole of the light shielding piece 504. Assuming that the distance between the upper surface of the LED and the upper surface of the middle frame is m1, the opening 2 can be a circle with the light emitting center of the LED as the center and m1 / tanθ as the radius, or the opening 2 can be a square with the light emitting center of the LED as the center and 2×m1 / tanθ as the side length, etc. For the sake of brevity, they are not listed one by one here. The definition of θ has been described in detail above, and will not be repeated here for the sake of brevity.

[0233] It should also be understood that "fixing" as described herein can be achieved by existing methods such as back adhesive bonding or screw fixing. For the sake of brevity, the specific way of fixing will not be described in detail herein.

[0234] As another embodiment, the light shielding member is integrated on a middle frame of the electronic device. The middle frame is located between the screen assembly and the fingerprint identification module, and the middle frame has a light transmission hole in a region corresponding to the LED, a hole wall of the light transmission hole surrounding the light signal emitted by the LED from all around to block a part of the light signal emitted by the LED.

[0235] Specifically, the light shielding member in the fingerprint identification module can be integrated on the middle frame, or in other words, the light shielding member in the fingerprint identification module can be designed integrally with the middle frame. The function of the light shielding member in blocking the light signal can be realized by opening and blackening the middle frame. In addition, the lens module in the fingerprint identification module can be independently fixed on the middle frame or the screen assembly, and the LED can be independently fixed on the middle frame.

[0236] Figure 13 An example of integrating the light shielding member on the middle frame is shown. As shown in Figure 15 , the specific method of connecting the lens module on the middle frame through the support 1 can be the same as the method shown in the foregoing Figure 9 . In order to match the fingerprint identification module, the region of the middle frame corresponding to the sensor can be opened. The opening region and size can refer to the related description of the opening 1 in the foregoing. For brevity, details are not described here.

[0237] In Figure 11 , the region corresponding to the LED also needs to be opened. As described before, the region corresponding to the light shielding member can be referred to as opening 2. In the present embodiment, the opening 2 is also the light transmission hole on the middle frame for realizing the function of blocking a part of the light signal emitted by the LED. Therefore, the inner surface of the opening 2 is the hole wall of the light transmission hole of the light shielding member. By blackening the inner surface and the upper and lower end surfaces of the opening 2, the opening 2 can absorb the light signal incident to its surface, thereby realizing the function of the light shielding member in blocking the light signal. The inner surface of the opening 2 can form a circle, a square, a rectangle, etc., which are not limited in the present application. The shape formed by the inner surface of the opening 2 can refer to the shape formed by the hole wall of the light transmission hole of the light shielding member shown in Figure 15 or Figure 6 .

[0238] Figure 13The opening 2 is a stepped circular hole. The stepped surface of the stepped circular hole can be opposite to the upper surface of the LED. The inner surface (or hole wall) of the stepped circular hole can form two cylinders with different sizes. The inner surface forming the smaller cylinder can be used to block the large-angle light emitted from the LED to achieve the function of the light blocking member blocking the light signal. The inner surface forming the larger cylinder can surround the side surface of the LED. The LED can be mounted on the support 2 by techniques such as SMT. The upper surface of the support 2 can be fixed on the lower surface of the middle frame by back adhesive or threaded connection. The size of the opening 2 can be determined according to the height of the light blocking member and the maximum emission angle of the light signal emitted by the LED. For the size of the opening 2, please refer to the description above Figure 16 The relevant description about w1 or w3 is made. For example, when the light transmission hole of the light blocking member is circular, the size of the opening 2 can be, for example, a circle with w1 or w3 as the radius.

[0239] It should be understood that the relevant description of the opening 1 of the middle frame, the support 1 and the support 2 in the embodiment can refer to the description above Figure 16 made in the description, and for the sake of brevity, it will not be repeated here.

[0240] As a further embodiment, the fingerprint identification module is carried on a bracket and fixed under the screen assembly through the bracket. The bracket includes a main warehouse and a secondary warehouse, the main warehouse is used to accommodate the image sensor, and the secondary warehouse is used to accommodate the LED. The light blocking member is integrated in the secondary warehouse, the secondary warehouse is a light transmission hole penetrating the thickness direction of the bracket, the light transmission hole can be used to accommodate the LED, and the hole wall of the light transmission hole surrounds the LED from all around to block part of the light signal emitted by the LED.

[0241] Specifically, the fingerprint identification module can share the same bracket, and the bracket can simultaneously realize the functions of carrying and fixing the fingerprint identification module and the light blocking member blocking the light signal.

[0242] Figure 16 An example of the fingerprint identification module sharing the bracket is shown. As Figure 16As shown, based on the size and relative position relationship of the LED, the shade and the lens module, an integrated support can be obtained by machining. The support can be integrally formed, or can be obtained by machining. The present application does not limit this. The position corresponding to the lens module on the support is the main warehouse, which can be a through hole penetrating the thickness direction of the support, or a blind hole not penetrating the thickness direction of the support, and the main warehouse can be used to accommodate the lens module. The position corresponding to the LED and the shade on the support is the auxiliary warehouse, which can be a through hole penetrating the thickness direction of the support, used to accommodate the LED. The shade can be integrated in the auxiliary warehouse, and the inner surface (or hole wall) and the upper and lower end faces of the auxiliary warehouse can be blackened to absorb the light signal incident on its surface, and to block the light signal emitted by the LED from all around, thereby realizing the function of the shade. Since the light signal can pass through the auxiliary warehouse to the finger, the auxiliary warehouse of the support can be called a light transmission hole.

[0243] The middle frame can be designed in cooperation with the support. For example, the position corresponding to the main warehouse can be opened, which is the opening 1 described above. The position corresponding to the auxiliary warehouse can be opened, which is the opening 2 described above. Figure 16 The support shown in the middle is connected to the middle frame through the auxiliary warehouse. Specifically, the opening 2 of the middle frame can be a stepped hole, and the stepped surface of the stepped hole can be connected to the upper surface of the support by back glue bonding or screw connection, etc., to fix the support on the lower surface of the middle frame.

[0244] In addition, the LED and the lens module can be carried on the support, such as the support 1 and the support 2 described above, or the integrally designed support shown in the middle. Figure 17 The upper surface of the support is opposite to the lower surface of the support, and the support can be fixed on the lower surface of the support by back glue bonding or screw connection, etc.

[0245] It should be understood that Figure 17 The shape of the support shown in the middle is only an example and should not constitute any limitation on the present application. As long as the support is provided with a main warehouse for accommodating the lens module and an auxiliary warehouse for accommodating the LED, it should fall within the protection scope of the present application. In addition, the shade can be integrated in the auxiliary warehouse; the shade can be separately provided and accommodated in the auxiliary warehouse. The present application does not limit this. It should also be understood that the present application does not limit the fixing method and position of the support.

[0246] Based on the fingerprint recognition module provided in the above embodiments, by setting a light-shielding element at the edge of the LED to absorb large-angle emitted light, the light signal reflected from the surface and internal cross-section of the screen assembly and reaching the lens module can be reduced, thereby reducing interference with fingerprint information and facilitating the acquisition of higher-resolution fingerprint images. Furthermore, by providing various different assembly methods, multiple possible implementations of this fingerprint recognition module in electronic devices are offered.

[0247] However, it should be understood that the above is merely an example, illustrating several possible assembly diagrams for applying the fingerprint recognition module provided in the embodiments of this application to electronic devices. This should not constitute any limitation on the usage scenarios and assembly methods of the fingerprint recognition module. Any method that uses a light-shielding component to block large-angle emitted light to reduce interference from stray light on fingerprint information, thereby improving the clarity of the fingerprint image, should fall within the protection scope of this application.

[0248] On the other hand, light signals not blocked by the light-shielding component may be reflected after entering the screen assembly. Furthermore, some light signals may reach the sensor after multiple reflections. Although these light signals are weaker, they can still interfere with fingerprint information and affect the clarity of the fingerprint image. Therefore, this reflected light reaching the sensor after multiple reflections is also part of the stray light.

[0249] Figure 17 A schematic diagram is shown illustrating the process of reflections reaching the lens module. For ease of understanding, Figure 17 The dashed lines in the image show the field of view of the lens in the lens module 505 and the area that the light signal incident on the screen assembly along the direction of this field of view can reach.

[0250] For ease of comparison, Figure 17 a) shows a schematic diagram of the fingerprint light signal reaching the lens module. Figure 3 Figure b) shows a schematic diagram of the light reaching the lens module after multiple reflections. For Figure 17 The explanation of a) in the text can be found above. Figures 5 to 16 For the sake of brevity, the relevant description of a) in the text will not be repeated here. Figures 13 to 16 In (b), some light signals with smaller emission angles (such as light signal d shown in the figure) may not be blocked by the light-shielding component and still enter the screen assembly. However, after being reflected on the upper surface of the screen assembly, they reach the lower surface of the screen assembly. Specifically, the light signal can be reflected at the upper surface of the cover glass inside the screen assembly, reach the upper surface of the substrate inside the screen assembly, and then be reflected back. After multiple reflections on the upper and lower surfaces, the light signal may also enter the imaging area and eventually enter the lens module, causing interference with the fingerprint information.

[0251] In order to further reduce the influence of stray light on the fingerprint information, the upper and lower surfaces of the base of the screen assembly can be blackened to absorb the secondary reflected light signals and avoid the light signals from being reflected multiple times to the lens module.

[0252] It should be understood that the blackening of the base of the screen assembly can be used in combination with the fingerprint identification module shown in the above embodiments to further reduce the stray light. Figure 18

[0253] In addition, the gap between the upper surface of the light shielding member and the lower surface of the screen assembly (for example, the gap between the upper surface of the light shielding member and the lower surface of the screen assembly shown in the above embodiments) can be blocked by filling the light shielding foam to further reduce the stray light. Figure 18

[0254] Therefore, the embodiments of the present application absorb most of the stray light with high light intensity through the light shielding member in the fingerprint identification module, and absorb part of the stray light with low light intensity by blackening the base of the screen assembly, thereby greatly reducing the interference of the stray light on the fingerprint information, facilitating obtaining a high-definition fingerprint image, and thus facilitating improving the fingerprint identification efficiency.

[0255] The above embodiments provided by the present application are described in detail in combination with the multiple drawings. However, it should be understood that these embodiments and drawings are only examples for facilitating understanding of the present application and should not constitute any limitation on the present application. As long as the light shielding member is used to block the large-angle light signals of the LED to avoid the reflected light of the large-angle light signals from entering the lens module to interfere with the fingerprint signals, it should fall within the protection scope of the present application.

[0256] For example, the fingerprint identification module can include multiple lens modules. Each lens module can include at least one lens and one sensor. The multiple lens modules can be staggered with multiple LEDs and multiple light shielding members. For example, arranged in the form of “ABABA”. Figure 9 is a schematic diagram of the arrangement of the multiple LEDs, the multiple light shielding members, and the multiple lens modules in the fingerprint identification module provided by the embodiments of the present application. Figures 11 to 18 The multiple LEDs, the multiple light shielding members, and the multiple lens modules shown can form an array. In each row of the array, the light source assembly composed of the light shielding member and the LED and the lens module can be arranged in the form of “ABABA”. In each column of the array, the light source assembly composed of the light shielding member and the LED and the lens module can also be arranged in the form of “ABABA”. The hollow square block in the figure can represent a lens module, and the shaded square block can represent a light source assembly (i.e., a light shielding member and an LED).

[0257] ​​It can be understood that when the plurality of LEDs, the plurality of light shielding members and the plurality of lens modules are staggered, the light signals emitted by the LEDs in various directions can be reflected to the adjacent one or more lens modules. Therefore, in this case, the light shielding member can be designed to block the large-angle outgoing light in various directions, for example, the light shielding member shown in any one of the figures in ​ 、 ​ 、 ​ may be adopted.

[0258] Therefore, the light source is provided by the plurality of LEDs to improve the intensity of the light signal, and the fingerprint light signal is collected by the plurality of lens modules, so that the lens modules can collect the fingerprint light signal with sufficient light intensity in each area of the fingerprint of the finger, which is beneficial to obtain a complete and high-definition fingerprint image, thereby being beneficial to provide the fingerprint recognition efficiency.

[0259] It should be understood that ​ is only for ease of understanding and should not constitute any limitation on the present application. The shape of the lens module is not necessarily square, and the shapes of the light shielding member and the LED are not necessarily square. The number of rows and columns contained in the array is also not necessarily as shown in the figures.

[0260] It should be noted that when there are a plurality of lens modules, each lens module can generate fingerprint information based on the received fingerprint light signal, and generate a fingerprint image based on the fingerprint information. The fingerprint images generated by the plurality of lens modules can be combined into a complete fingerprint image. The specific method of combining the fingerprint images by the plurality of lens modules can refer to the prior art, and for the sake of brevity, the detailed description of the specific method is omitted here.

[0261] It should be understood that the present application details the structure of the fingerprint recognition module provided by the present application and the specific process of identifying the fingerprint by the fingerprint recognition module in combination with a plurality of embodiments and drawings. These embodiments and drawings are only to help those skilled in the art better understand the technical solutions of the present application, and are not a limitation on the technical solutions of the present application. Those skilled in the art will think of many improvements and other embodiments of the present application under the guidance of the foregoing description and the presentation in the related drawings. Therefore, the present application is not limited to the specific embodiments disclosed.

[0262] The present application also provides an electronic device, which can include a screen assembly and the fingerprint recognition module shown in any one of the plurality of embodiments described above. For example, the embodiments of the fingerprint recognition module described above in combination with ​ 、 ​ .

[0263] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A fingerprint identification module, characterized in that, The fingerprint identification module is arranged below a screen assembly of an electronic device, and includes: a light emitting diode (LED), a light emitting surface of the LED being opposite to a lower surface of the screen assembly, for emitting light signals; an image sensor, located at one side of the LED, and a light receiving surface of the image sensor being opposite to the lower surface of the screen assembly, for receiving light signals; the light signals received by the image sensor include fingerprint light signals returned from the LED to a finger, and the fingerprint light signals are used to generate a fingerprint image; a light shielding member, part or all of the light shielding member being located between the LED and the image sensor, for blocking a part of the light signals emitted by the LED; a distance L between a light emitting center of the LED and a center of an active area (AA) of the image sensor satisfies: L≥h×tanθ+d×tanθ'+d×tanβ'+t×tanβ; wherein h represents a distance between the light emitting surface of the LED and the lower surface of the screen assembly, d represents a distance between an upper surface of the screen assembly and the lower surface of the screen assembly, t represents a distance between the light receiving surface of the image sensor and the lower surface of the screen assembly, θ is a predefined value, θ represents a maximum exit angle of the light signals emitted by the LED and capable of reaching after being blocked by the light shielding member, θ' represents an exit angle of light signals with an incident angle of θ after refraction on the screen assembly surface, β is 1 / 2 of a field of view angle of the image sensor, and β' represents an incident angle corresponding to the exit angle β when the light signals are refracted on the screen assembly surface.

2. The fingerprint identification module of claim 1, wherein, On a plane passing through the light emitting center of the LED and the center of the AA of the image sensor, the light shielding member is used to block the light signals emitted by the LED with an exit angle greater than θ, and θ is a predefined value.

3. The fingerprint identification module according to claim 1 or 2, wherein, The distance L between the light emitting center of the LED and the center of the AA of the image sensor satisfies: L≥h×tanθ+d×tanθ'+d×tanβ'+t×tanβ+Δ; Δ represents a system tolerance.

4. The fingerprint identification module of claim 1 or 2, wherein, The light shielding member is a structural member with a light transmission hole, and a hole wall of the light transmission hole surrounds the light signals emitted by the LED from all around, for blocking a part of the light signals emitted by the LED.

5. The fingerprint identification module of claim 1 or 2, wherein, The light shielding member is integrated on a middle frame of the electronic device; the middle frame is located between the screen assembly and the fingerprint identification module, and the middle frame has a light transmission hole in a region corresponding to the LED, and a hole wall of the light transmission hole surrounds the light signals emitted by the LED from all around, for blocking a part of the light signals emitted by the LED.

6. The fingerprint identification module of claim 1 or 2, wherein, The fingerprint identification module is borne on a support and fixed under the screen assembly through the support; the support comprises a main compartment and a secondary compartment, the main compartment is used for accommodating the image sensor, and the secondary compartment is used for accommodating the LED; the light shielding piece is integrated in the secondary compartment, the secondary compartment is a light transmission hole penetrating through the thickness direction of the support, the light transmission hole corresponds to the region of the LED, and the hole wall of the light transmission hole surrounds the light signal emitted by the LED from all around to block a part of the light signal emitted by the LED.

7. The fingerprint identification module of claim 1 or 2, wherein the light source is a light emitting diode. The surface of the light shielding piece surrounding the light signal of the LED is coated with light-absorbing material, or the light shielding piece is made of light-absorbing material.

8. The fingerprint identification module of claim 1 or 2, wherein, The fingerprint identification module comprises a plurality of LEDs, a plurality of light shielding pieces corresponding to the plurality of LEDs and an image sensor; the plurality of LEDs and the plurality of light shielding pieces corresponding thereto are uniformly distributed around the image sensor, and part or all of each light shielding piece is located between the corresponding LED and the image sensor.

9. The fingerprint identification module of claim 1 or 2, wherein, The LED is an infrared LED. 10.The fingerprint identification module according to claim 1 or 2, characterized in that, The fingerprint identification module further comprises at least one lens, the at least one lens is located between the screen assembly and the image sensor, and the imaging center of the at least one lens coincides with the AA center of the image sensor; The at least one lens is used for receiving light signals, and the light signals received by the at least one lens reach the image sensor after being converged.

11. The fingerprint identification module of claim 10, wherein the light source is a light emitting diode (LED) or a laser diode. The distance L' between the light emitting center of the LED and the imaging center of the at least one lens satisfies: L' ≥ h × tanθ + d × tanθ' + d × tanα' + t' × tanα + CA / 2; Wherein, h represents the distance between the light emitting surface of the LED and the lower surface of the screen assembly, d represents the distance between the upper surface of the screen assembly and the lower surface of the screen assembly, t' represents the distance between the surface where the light exit hole of the at least one lens is located and the lower surface of the screen assembly, θ is a predefined value, θ represents the maximum exit angle of the light signal emitted by the LED and capable of reaching after being shielded by the light shielding piece on the plane passing through the light emitting center of the LED and the AA center of the image sensor, θ' represents the exit angle of the light signal with the incident angle θ after being refracted on the surface of the screen assembly, CA represents the diameter of the light exit hole of the at least one lens, α is 1 / 2 of the field of view angle of the at least one lens, and α' represents the incident angle corresponding to the exit angle α when the light signal is refracted on the surface of the screen assembly.

12. An electronic device, comprising: The fingerprint identification module comprises a plurality of LEDs, a plurality of light shielding pieces corresponding to the plurality of LEDs and an image sensor; the plurality of LEDs and the plurality of light shielding pieces corresponding thereto are uniformly distributed around the image sensor, and part or all of each light shielding piece is located between the corresponding LED and the image sensor. The LED is an infrared LED. The fingerprint identification module further comprises at least one lens, the at least one lens is located between the screen assembly and the image sensor, and the imaging center of the at least one lens coincides with the AA center of the image sensor; The at least one lens is used for receiving light signals, and the light signals received by the at least one lens reach the image sensor after being converged. The distance L' between the light emitting center of the LED and the imaging center of the at least one lens satisfies: L' ≥ h × tanθ + d × tanθ' + d × tanα' + t' × tanα + CA / 2; Wherein, h represents the distance between the light emitting surface of the LED and the lower surface of the screen assembly, d represents the distance between the upper surface of the screen assembly and the lower surface of the screen assembly, t' represents the distance between the surface where the light exit hole of the at least one lens is located and the lower surface of the screen assembly, θ is a predefined value, θ represents the maximum exit angle of the light signal emitted by the LED and capable of reaching after being shielded by the light shielding piece on the plane passing through the light emitting center of the LED and the AA center of the image sensor, θ' represents the exit angle of the light signal with the incident angle θ after being refracted on the surface of the screen assembly, CA represents the diameter of the light exit hole of the at least one lens, α is 1 / 2 of the field of view angle of the at least one lens, and α' represents the incident angle corresponding to the exit angle α when the light signal is refracted on the surface of the screen assembly. The fingerprint identification module comprises a plurality of LEDs, a plurality of light shielding pieces corresponding to the plurality of LEDs and an image sensor; the plurality of LEDs and the plurality of light shielding pieces corresponding thereto are uniformly distributed around the image sensor, and part or all of each light shielding piece is located between the corresponding LED and the image sensor. The LED is an infrared LED. A light shielding member, part or all of which is located between the LED and the image sensor, for blocking a part of the light signal emitted by the LED; A distance L between the light emitting center of the LED and the center of the AA of the image sensor satisfies: L≥h×tanθ+d×tanθ'+d×tanβ'+t×tanβ; wherein h represents a distance between the light emitting surface of the LED and the lower surface of the screen assembly, d represents a distance between the upper surface of the screen assembly and the lower surface of the screen assembly, t represents a distance between the light sensitive surface of the image sensor and the lower surface of the screen assembly, θ is a predefined value, θ represents a maximum exit angle of the light signal emitted by the LED and capable of reaching after being blocked by the light shielding member, θ' represents an exit angle of the light signal with an incident angle of θ after being refracted on the surface of the screen assembly, β is 1 / 2 of the field of view angle of the image sensor, and β' represents an incident angle corresponding to the exit angle β when the light signal is refracted on the surface of the screen assembly.

13. The electronic device of claim 12, wherein, On a plane passing through the light emitting center of the LED and the center of the effective display area AA of the image sensor, the light shielding member is used for blocking the light signal emitted by the LED with an exit angle greater than θ, and θ is a predefined value.

14. The electronic device of claim 12 or 13, wherein, The light shielding member is a structural member with a light transmission hole, and the hole wall of the light transmission hole surrounds the light signal emitted by the LED from all around to block a part of the light signal emitted by the LED.

15. The electronic device of claim 12 or 13, wherein, The electronic device further comprises a middle frame located between the screen assembly and the fingerprint identification module, and the light shielding member is integrated on the middle frame. The middle frame has a light transmission hole in a region corresponding to the LED, and the hole wall of the light transmission hole surrounds the light signal emitted by the LED from all around to block a part of the light signal emitted by the LED.

16. The electronic device of claim 12 or 13, wherein, The electronic device further comprises a bracket, and the fingerprint identification module is carried on the bracket. The bracket fixes the fingerprint identification module below the screen assembly. The bracket comprises a main compartment and a secondary compartment. The main compartment accommodates the sensor, and the secondary compartment accommodates the LED. The light shielding member is integrated on the secondary compartment. The secondary compartment is a light transmission hole penetrating through the thickness direction of the bracket. The light transmission hole corresponds to the region of the LED. The hole wall of the light transmission hole surrounds the light signal emitted by the LED from all around to block a part of the light signal emitted by the LED.

17. The electronic device of claim 16, wherein, The hole wall and the hole end surface of the light transmission hole are subjected to blackening treatment to absorb the received light signal.

18. The electronic device of any of claims 12, 13, 17, wherein, The screen assembly comprises a substrate located at the lowermost layer of the screen assembly. The lower surface of the substrate is opposite to the fingerprint identification module. The upper surface and the lower surface of the substrate are subjected to blackening treatment to absorb the received light signal.

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