A fingerprint identification device and a terminal device

Abstract

The application provides a fingerprint identification device and a terminal device, and the fingerprint identification device comprises a circuit board, a fingerprint chip, which is electrically connected with the circuit board and is stacked along the thickness direction of the circuit board, the fingerprint chip comprising an identification area, which is used for acquiring and identifying fingerprints, a plurality of light emitting units, which are all electrically connected with the circuit board, the plurality of light emitting units being connected in parallel, and the plurality of light emitting units being arranged at intervals around the identification area along a plane perpendicular to the thickness direction of the circuit board. Thus, the plurality of light emitting units form a uniform surrounding light source array outside the identification area, which is beneficial to the user to press the finger on the identification area when performing fingerprint identification, and improves the identification efficiency of the fingerprint identification device; each light emitting unit can emit light independently, which is beneficial to the user to customize the fingerprint identification device, and improves the user experience.

Description

Technical Field

[0001] This utility model belongs to the field of optical fingerprint technology, and in particular relates to a fingerprint recognition device and terminal equipment. Background Technology

[0002] With the continuous development of various terminal devices, users have increasingly higher requirements for device security and confidentiality. Therefore, fingerprint recognition technology is now widely used in various terminal devices, allowing users to quickly and effectively unlock or encrypt their devices by touching the fingerprint recognition device. However, the effective recognition area of ​​fingerprint recognition devices is relatively small, and users' fingers may easily press on the invalid functional area, leading to recognition failure. Utility Model Content

[0003] The purpose of this invention is to provide a fingerprint recognition device and terminal equipment to solve the problem of frequent fingerprint recognition failures.

[0004] To achieve the objectives of this utility model, the following technical solution is provided:

[0005] Firstly, this utility model provides a fingerprint recognition device, comprising: a circuit board; a fingerprint chip electrically connected to the circuit board and stacked sequentially with the circuit board along the thickness direction of the circuit board, the fingerprint chip including a recognition area for acquiring and recognizing fingerprints; and multiple light-emitting units, all electrically connected to the circuit board, the multiple light-emitting units being connected in parallel and arranged at intervals around the recognition area along a plane perpendicular to the thickness direction of the circuit board. Thus, on the one hand, the multiple light-emitting units form a uniformly surrounding light source array around the recognition area, which is beneficial for users to press their fingers on the recognition area when performing fingerprint recognition, improving the recognition efficiency of the fingerprint recognition device; furthermore, the surrounding light source can provide uniform and soft illumination from multiple angles, greatly reducing shadows and uneven brightness caused by single-point or unilateral light sources, which is beneficial for improving the recognition success rate under complex finger conditions, such as wet, dry, or slightly peeling fingers. On the other hand, compared to the solution of independently setting the light source outside the device, integrating and surrounding the light-emitting units in the vicinity of the recognition area effectively reduces the overall size of the fingerprint recognition device; each light-emitting unit can emit light independently, which is beneficial for users to personalize the fingerprint recognition device and improve the user experience.

[0006] In one possible implementation, the fingerprint chip includes a functional area along a plane perpendicular to the thickness direction of the circuit board, surrounding the recognition area. The functional area includes multiple receiving cavities, each accommodating at least one light-emitting unit. This offers several advantages: First, it improves the accuracy and stability of the light source layout. The position of the light-emitting unit relative to the recognition area along the thickness direction of the circuit board and its circumferential position in the plane perpendicular to the thickness direction of the circuit board are accurately positioned and stably fixed through the receiving cavities, avoiding light source misalignment caused by assembly tolerances such as adhesive bonding between components. Second, it simplifies the structural design of the fingerprint recognition device, eliminating the need for additional complex brackets or fixing mechanisms to secure the light-emitting unit, thus streamlining components and the assembly process. Third, it optimizes the optical path. With the light-emitting unit embedded within the fingerprint chip, compared to external or protruding mounting methods, the emitted light can be projected more directly and effectively, reducing ineffective scattering and increasing light utilization.

[0007] In one possible implementation, multiple light-emitting units are arranged in a matrix around the perimeter of the recognition area. This regular matrix arrangement provides illumination at more discrete points around the recognition area, significantly expanding the coverage of the illumination angle and producing a more uniform and omnidirectional illumination effect. This helps to clearly indicate the location of the recognition area to the user, improving the recognition efficiency of the fingerprint recognition device. Furthermore, the matrix layout offers good regularity, facilitating mass production, precision manufacturing, and automated assembly. The welding or bonding points of the light-emitting units and their driving circuits exhibit strong regularity, leading to more efficient production and quality control. High consistency in optical design, with more symmetrical paths from each light-emitting unit to the recognition area, combined with good structural design and optical materials, easily achieves a high degree of uniformity in brightness and color throughout the entire field of view.

[0008] In one possible implementation, the fingerprint recognition device includes a cover plate and an encapsulation layer. Along the thickness direction of the circuit board, the circuit board, the fingerprint chip, the encapsulation layer, and the cover plate are stacked sequentially. The encapsulation layer includes multiple through-holes, each corresponding to a specific receiving cavity. This achieves several advantages: firstly, the through-holes and receiving cavities are precisely aligned, forming a clear light path from the light-emitting unit through the encapsulation layer to the cover plate; secondly, it minimizes light loss and interference, as the light emitted from the light-emitting unit exits directly through the through-holes, avoiding absorption and scattering by the encapsulation layer material; and thirdly, it helps ensure light directionality, as the boundaries of the through-holes constrain the direction of light and prevent severe lateral diffusion, making the light illuminating the cover plate more concentrated and controllable. This allows users to more intuitively see the location of the recognition area, improving the effective recognition rate of the fingerprint recognition device.

[0009] In one possible implementation, the fingerprint recognition device includes a light-transmitting layer for transmitting at least one of visible light and infrared light. Along the thickness direction of the circuit board, the circuit board, the fingerprint chip, the encapsulation layer, the cover plate, and the light-transmitting layer are sequentially stacked. The light-transmitting layer can eliminate stray light and increase light transmittance, enhance the scratch resistance of the fingerprint recognition device surface, and protect the surface of the optical path, thereby significantly improving image quality and long-term user experience.

[0010] In one possible implementation, the light-transmitting layer includes a first light-transmitting layer and a second light-transmitting layer. The second light-transmitting layer surrounds the first light-transmitting layer along a plane perpendicular to the thickness direction of the circuit board. Along the thickness direction of the circuit board, the first light-transmitting layer is disposed opposite to the recognition area, and the second light-transmitting layer is disposed opposite to a plurality of the light-emitting units. Thus, the light sensed by the recognition area primarily passes through the first light-transmitting layer for recognition, while the light emitted by the light-emitting units passes through the second light-transmitting layer and is displayed on the cover plate, helping to reduce interference from the illumination light of the light-emitting units with fingerprint recognition in the recognition area.

[0011] In one possible implementation, the first light-transmitting layer includes an infrared-transmitting ink layer, and the second light-transmitting layer includes a visible-light-transmitting ink layer. By positioning the infrared-transmitting ink layer opposite to the recognition area, on the one hand, it helps to improve signal transmittance, especially by selecting materials with high transmittance to infrared fingerprint imaging signal light, ensuring minimal loss of key sensing signals; on the other hand, it effectively shields ambient light interference, as the infrared-transmitting ink also has high visible light blocking properties, preventing visible light from the environment, such as sunlight and LED lights, from entering the recognition area, greatly improving image contrast. By positioning the visible-light-transmitting ink layer opposite to multiple light-emitting units, on the one hand, it helps to improve the visible light brightness and clarity of the light-emitting units; on the other hand, it can provide diverse visual effects, for example, inks with different transparency or colors can be selected, such as making a pale white, light gray, or even light-colored semi-transparent area, to meet the design requirements of the terminal device.

[0012] In one possible implementation, the light-emitting unit includes a micro LED. This reduces power consumption of the terminal device and improves battery life. Furthermore, because the fingerprint recognition device has a small internal space and limited heat dissipation, the micro LED, with its lower heat generation, also prevents the temperature inside the fingerprint recognition device from becoming too high.

[0013] In one possible implementation, the length of the fingerprint recognition device along the thickness direction of the circuit board is less than or equal to 1.5 mm. This facilitates the integration of the fingerprint recognition device into ultra-thin terminal devices, such as mobile phones and smartwatches, without significantly increasing the thickness of the terminal device, thus helping the fingerprint recognition device meet under-screen installation requirements.

[0014] In one possible implementation, the area of ​​the fingerprint chip along the plane perpendicular to the thickness direction of the circuit board is less than or equal to 20mm*20mm. Therefore, the fingerprint chip can integrate a recognition area and a functional area, simultaneously possessing fingerprint recognition functionality and an effective range indication function. Furthermore, it allows for flexible placement of the fingerprint recognition device in various narrow locations within the terminal device.

[0015] In one possible implementation, the area of ​​the recognition area along a plane perpendicular to the thickness direction of the circuit board is less than or equal to 4mm x 5mm. Therefore, by surrounding the small recognition area with light-emitting units, it helps encourage the user to press the small area more naturally with a specific fingertip, thus improving the recognition rate and speed of the fingerprint recognition device.

[0016] Secondly, this utility model also provides a terminal device, including a fingerprint recognition device as described in any of the foregoing claims. Thus, users can encrypt or unlock the terminal device using the fingerprint recognition device. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the terminal device provided in the embodiments of this application;

[0019] Figure 2 This is an exploded view of the fingerprint recognition device provided in the first embodiment of this application;

[0020] Figure 3 yes Figure 2 A top view of the fingerprint recognition device in the image;

[0021] Figure 4 yes Figure 2 Side view of the fingerprint recognition device in the image;

[0022] Figure 5 yes Figure 4 Cross-sectional view at point AA;

[0023] Figure 6 This is a cross-sectional schematic diagram of the fingerprint recognition device provided in the second embodiment of this application;

[0024] Figure 7 This is a cross-sectional schematic diagram of the fingerprint recognition device provided in the third embodiment of this application;

[0025] Figure 8 This is an exploded view of the fingerprint recognition device provided in the fourth embodiment of this application;

[0026] Figure 9 This is an exploded view of the fingerprint recognition device provided in the fifth embodiment of this application;

[0027] Key reference numerals: Circuit board - 10; Cavity - 110; Fingerprint chip - 20; Recognition area - 210; Functional area - 220; Receiving cavity - 221; Light-emitting unit - 30; Cover plate - 40; Encapsulation layer - 50; Through hole - 510; Light-transmitting layer - 60; First light-transmitting layer - 610; Second light-transmitting layer - 620; Substrate - 70; Receiving groove - 710; Thickness direction of circuit board - X direction. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] It is understood that the terminology in the specification, claims, and accompanying drawings of this application is for describing specific embodiments only and is not intended to limit this application. The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Unless the context clearly states otherwise, the singular forms "a" and "described" are also intended to include the plural forms. The term "comprising," and any variations thereof, are intended to cover non-exclusive inclusion. Furthermore, this application can be implemented in many different forms and is not limited to the embodiments described herein. The purpose of providing the following specific embodiments is to facilitate a clearer and more thorough understanding of the disclosure of this application, wherein words indicating orientation such as up, down, left, and right refer only to the position of the illustrated structure in the corresponding drawings. In the description of this application, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," and "set on" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0030] The following description provides preferred embodiments for carrying out this application; however, this description is for the purpose of illustrating the general principles of this application and is not intended to limit the scope of this application. The scope of protection of this application shall be determined by the appended claims.

[0031] This application provides a terminal device 1000, which may include, but is not limited to, devices with fingerprint recognition devices 1 such as mobile phones, laptops, smart home appliances, and smart home devices. It is understood that, to enable those skilled in the art to better understand the terminal device 1000, this application uses a mobile phone as an example for detailed description. It should be noted that the use of a mobile phone as the terminal device 1000 is for illustrative purposes only, and this application does not impose specific limitations. For example, the product type of the terminal device 1000 can also be set according to actual needs.

[0032] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a terminal device 1000 provided in an embodiment of this application. Exemplarily, in this embodiment, the terminal device 1000 includes a fingerprint recognition device 1, a housing 2, a touch display 3, and a controller 4. The touch display 3 is mounted on the housing 2. The fingerprint recognition device 1 and the controller 4 are both housed in the space between the touch display 3 and the housing 2. The sensing surface of the fingerprint recognition device 1 faces the touch display 3, so that the fingerprint recognition device 1 can recognize fingerprints pressed on the touch display 3. Both the fingerprint recognition device 1 and the touch display 3 are electrically connected to the controller 4, which controls the display on the touch display 3 and the recognition by the fingerprint recognition device 1.

[0033] Users unlock terminal device 1000 by pressing their fingerprint onto fingerprint recognition device 1, which in turn triggers the touch display 3 via controller 4. In some scenarios, users can also encrypt terminal device 1000 by pressing their fingerprint onto fingerprint recognition device 1 via controller 4. However, the effective recognition area of ​​fingerprint recognition device 1 is typically small, and users may press their fingerprint into ineffective areas, resulting in multiple presses and reducing the effective recognition rate of fingerprint recognition device 1. The fingerprint recognition device 1 provided in this application embodiment has a function to indicate the effective recognition area, facilitating clear and quick unlocking or encryption of terminal device 1000 by the user.

[0034] Please see Figure 2 , Figure 2This is an exploded view of the fingerprint recognition device 1 provided in the first embodiment of this application. In this embodiment, the fingerprint recognition device 1 includes a circuit board 10, a fingerprint chip 20, and multiple light-emitting units 30. The fingerprint chip 20 and the multiple light-emitting units 30 are all electrically connected to the circuit board 10. For example, the fingerprint chip 20 is packaged on the circuit board 10 using a chip-on-board (COB) process, and the fingerprint chip 20 is electrically connected to the circuit board 10 by wire bonding (WB). The circuit board 10 can provide power and communication interfaces for the fingerprint chip 20, and provide power and control signals for the multiple light-emitting units 30. It can also realize electrical connection and communication with an external control system. The circuit board 10 can also be used to electrically connect the fingerprint recognition device 1 to the host in the terminal device 1000.

[0035] In one possible implementation, the circuit board 10 can be an ultra-thin printed circuit board (PCB) or a flexible printed circuit (FPC), wherein the FPC can be reinforced with a corresponding reinforcing plate. This facilitates wiring within the confined space of the terminal device 1000.

[0036] In one possible implementation, one end of the circuit board 10 may be provided with a pluggable connector, and the terminal device 1000 is provided with a corresponding socket, thereby facilitating the disassembly and assembly of the fingerprint recognition device 1.

[0037] In one possible implementation, the circuit board 10 is used to carry the fingerprint chip 20 and other functional chips. For example, the circuit board 10 also has a power chip for supplying power to the fingerprint chip 20. The fingerprint chip 20 is formed by BGA (Ball Grid Array) technology or LGA (Land Grid Array) technology.

[0038] In one possible implementation, the surface of the circuit board 10 may be coated with a black light-shielding layer, such as black ink, to absorb and block ambient light and stray light from entering the fingerprint chip 20.

[0039] Along the thickness direction of circuit board 10, i.e. Figure 2In the X direction shown, the fingerprint chip 20 and the circuit board 10 are tightly bonded and stacked. The fingerprint chip 20 includes a recognition area 210, which is used to detect user touch, collect fingerprint information when the user touches the chip, and perform feature extraction and feature comparison based on the fingerprint information to determine whether it matches pre-stored fingerprint information. The recognition area 210 integrates a high-density pixel sensor array, such as an optical sensor and an ultrasonic transducer. The area covered by the sensor used for fingerprint recognition is defined as the recognition area 210.

[0040] Multiple light-emitting units 30 are connected in parallel, meaning the circuit board 10 can control the independent light emission of each light-emitting unit 30. The multiple light-emitting units 30 are arranged along a plane perpendicular to the thickness direction of the circuit board 10. Figure 2 As shown, the YZ plane is arranged at intervals around the recognition area 210. When the user operates the fingerprint recognition device 1, multiple light-emitting units 30 can emit light under the action of a driving signal to indicate the range of the recognition area 210. Thus, on the one hand, the multiple light-emitting units 30 form a uniformly surrounding light source array around the recognition area 210, which is beneficial for the user to press their finger on the recognition area 210 when performing fingerprint recognition, improving the recognition efficiency of the fingerprint recognition device 1; and the surrounding light source can provide uniform and soft illumination from multiple angles, greatly reducing the shadows and uneven brightness caused by single-point or single-sided light sources, which is beneficial to improving the recognition success rate under complex finger conditions, such as wet, dry, or slightly peeling fingers. On the other hand, compared with the solution of setting the light source independently outside the device, integrating the light-emitting units 30 and surrounding them in the vicinity of the recognition area 210 effectively reduces the overall size of the fingerprint recognition device 1; each light-emitting unit 30 can emit light independently, which is beneficial for users to personalize the fingerprint recognition device 1 and improve the user experience.

[0041] Understandably, multiple light-emitting units 30 surround the recognition area 210, and the shape of the recognition area 210 is indicated by the multiple light-emitting units 30. Figure 2 The shape of the identification area 210 shown is square. In some possible implementations, the shape of the identification area 210 may also be circular, triangular or other irregular shape. This application does not make specific limitations.

[0042] Please see Figure 3 , Figure 3 yes Figure 2The image shows a top view of the fingerprint recognition device 1. As an example, the plurality of light-emitting units 30 include two colors of light sources, which are used to emit light alternately in sequence to form a flowing light signal to prompt the user to press their finger on the recognition area 210. Optionally, in the aforementioned at least two colors of light sources, light-emitting units 30 of the same color are arranged at intervals, and light-emitting units 30 of different colors are arranged adjacent to each other. It is understood that the adjacent or spaced relationship of the light-emitting units 30 is relative to the Y or Z direction shown in the figure.

[0043] In one possible implementation, the light-emitting unit 30 emits white or colored light, such as white, red, green, or yellow. In another possible implementation, the light-emitting unit 30 emits light either continuously or by flashing.

[0044] Please see Figure 2 , Figure 3 , Figure 4 and Figure 5 , Figure 4 yes Figure 2 Side view of fingerprint recognition device 1 in the middle. Figure 5 yes Figure 4 Cross-sectional view at point AA. The fingerprint chip 20 includes a functional area 220 along the YZ plane, which surrounds the recognition area 210. The functional area 220 can be used to accommodate other functional elements.

[0045] In one possible implementation, the recognition area 210 is typically located in the central region of the fingerprint chip 20 and is composed of a sensor array, such as optical pixel units, capacitive sensing motors, and ultrasonic transducers, for collecting user fingerprint information. In another possible implementation, the recognition area 210 has a fingerprint sensor with a window similar to an image acquisition window facing outwards from the fingerprint chip 20. Along the thickness direction of the fingerprint chip 20, the projection area of ​​the fingerprint acquisition window of the sensor can be the recognition area 210 described in this embodiment. In another possible implementation, a functional area 220 surrounds the recognition area 210. The functional area 220 may integrate pads for connecting to a circuit board; or it may have mechanical structures for forming a receiving cavity or heat dissipation channel, etc. In one possible implementation, there is no clear boundary between the recognition area 210 and the functional area 220, but the recognition area 210 and the functional area 220 on the fingerprint chip 20 can be clearly distinguished based on the sensor integrated within the fingerprint chip 20 and the light-emitting unit 30 provided in the peripheral functional area 220.

[0046] Functional area 220 includes multiple receiving cavities 221, which are used to accommodate at least one light-emitting unit 30. In the following embodiment, one receiving cavity 221 accommodating one light-emitting unit 30 is used as an example for illustration. It can be understood that one receiving cavity 221 can also accommodate two, three or four light-emitting units 30, etc., and this embodiment does not make a specific limitation.

[0047] Specifically, the receiving cavity 221 includes holes in the functional area 220, penetrating two opposite surfaces of the functional area 220 along the X direction, so that the light emitted by the light-emitting unit 30 can pass through. The light-emitting unit 30, by being embedded in and fixed within the receiving cavity 221, can form a tight connection with the fingerprint chip 20. This has several advantages: First, it improves the accuracy and stability of the light source layout. The position of the light-emitting unit 30 relative to the recognition area 210 along the X direction and its circumferential position in the YZ plane are accurately positioned and stably fixed by the receiving cavity 221, avoiding light source offset caused by assembly tolerances such as adhesive bonding between components. Second, it simplifies the structural design of the fingerprint recognition device 1, eliminating the need for additional complex brackets or fixing mechanisms to fix the light-emitting unit 30, thus simplifying components and the assembly process. Third, it optimizes the optical path. With the light-emitting unit 30 embedded within the fingerprint chip 20, compared to external or protruding mounting methods, the emitted light can be projected more directly and effectively, reducing ineffective scattering and increasing light utilization.

[0048] In one possible implementation, the receiving cavity 221 can also be a blind hole, with the opening facing the light-emitting unit 30 along the X direction. In another possible implementation, the plane where the light-emitting unit 30 is located is parallel to or coincides with the plane where the fingerprint chip 20 is located.

[0049] Please see Figure 6 and Figure 7 , Figure 6 This is a cross-sectional view of the fingerprint recognition device 1 provided in the second embodiment of this application. Figure 7 This is a cross-sectional view of the fingerprint recognition device 1 provided in the third embodiment of this application. It will be understood that the light-emitting unit 30 can be accommodated in various ways. For example... Figure 6 As shown, a separate substrate 70 is located between the fingerprint chip 20 and the circuit board 10 along the X direction. The substrate 70 includes a receiving groove 710, which is disposed opposite to the light-emitting unit 30 along the X direction, for accommodating and fixing multiple light-emitting units 30. Or as... Figure 7As shown, the light-emitting unit 30 is directly housed within the circuit board 10. Specifically, the circuit board 10 has a cavity 110 to accommodate the light-emitting unit 30. The above-described method of accommodating the light-emitting unit 30 is merely an example and is not specifically limited in this embodiment. Regardless of the method of accommodating the light-emitting unit 30, along the X direction, the functional area 220 and the position opposite to the multiple light-emitting units 30 need to have a accommodating cavity 221 structure for the light emitted by the light-emitting unit 30.

[0050] Please see Figure 2 In this embodiment, multiple light-emitting units 30 are arranged in a matrix around the perimeter of the recognition area 210. Specifically, the multiple light-emitting units 30 distributed around the perimeter of the recognition area 210 are not simply arranged in a ring or as discrete points, but rather in a regular grid pattern of rows and columns. For example, on each of the four sides (up, down, left, right) of the YZ plane containing the recognition area 210, one or more rows, one or more columns of light-emitting units can be arranged, forming a frame-like surrounding structure, with the light-emitting units exhibiting an orderly spacing in both the Y and Z directions. Figure 2 As shown, the recognition area 210 has two rows of light-emitting units 30 on both sides along the Y direction and three rows of light-emitting units on both sides along the Z direction. Therefore, on the one hand, the regular matrix arrangement of the light-emitting units 30 provides illumination to more discrete points around the recognition area 210, greatly expanding the coverage of the illumination angle and producing a more highly uniform and omnidirectional illumination effect. This is beneficial for comprehensively indicating the location of the recognition area 210 to the user, improving the recognition efficiency of the fingerprint recognition device 1. On the other hand, the matrix layout has good regularity, which is conducive to mass precision manufacturing and automated assembly. The welding points or bonding points of the light-emitting units 30 and their driving circuits have strong regularity, making production and quality inspection more efficient. The optical design has high consistency, and the path from each light-emitting unit 30 to the recognition area 210 is more symmetrical. Combined with good structural design and optical materials, it is easy to achieve a high degree of uniformity in brightness and color throughout the entire field of view.

[0051] In one possible implementation, the multiple light-emitting units 30 may also be arranged in a ring or irregular shape around the recognition area 210, and this embodiment does not impose a specific limitation. It can be understood that the multiple light-emitting units 30 are mainly used to indicate the range of the recognition area 210, and based on this, the light-emitting units 30 can have a variety of arrangements around the recognition area 210.

[0052] Please see Figure 8 , Figure 8This is an exploded view of the fingerprint recognition device 1 provided in the fourth embodiment of this application. In this embodiment, the fingerprint recognition device 1 includes a cover plate 40 and an encapsulation layer 50. Along the X direction, the circuit board 10, the fingerprint chip 20, the encapsulation layer 50, and the cover plate 40 are stacked sequentially. The cover plate 40 is a protective sheet covering the outermost layer of the entire fingerprint recognition device 1, which is directly or indirectly contacted by the user. The material of the cover plate 40 can be glass, sapphire, or a high-strength transparent plastic film. It can be bonded to the surface of the encapsulation layer 50 by an adhesive layer. Its main function is physical protection, resisting friction, impact, etc., protecting the internal precision structures such as the encapsulation layer 50 and the fingerprint chip 20 from damage and contamination, and providing a surface for finger contact. The shape of the cover plate 40 usually matches the shape of the fingerprint chip 20, for example, it is circular, square, or other shapes. In one possible embodiment, the cover plate 40 can be an indium tin oxide (ITO) transparent film, which has a conductive effect. It is understood that this embodiment does not specifically limit the material of the cover plate 40.

[0053] The encapsulation layer 50 is used to bond and fix at least one of the fingerprint chip 20, the light-emitting unit 30, and the cover plate 40, and can fill the gaps to reduce interface reflection loss when light propagates between the fingerprint chip 20 and the cover plate 40; it helps to form a physical barrier to isolate moisture and dust; and it also provides a certain degree of buffer protection. After curing, the encapsulation layer 50 is a solid layer with a certain thickness that allows light emitted by the light-emitting unit 30 to pass through. In one possible embodiment, the encapsulation layer 50 can be a die-attach film (DAF), for example, an epoxy resin-based material. The die-attach film can provide a strong bond between the fingerprint chip 20 and the cover plate 40, and form an ultra-thin, dense dielectric protective layer, increasing the mechanical strength of the fingerprint recognition device 1 and improving the durability of the fingerprint recognition device 1.

[0054] In one possible implementation, the body of the encapsulation layer 50 may also be formed of an opaque material, in black or other preset colors, which helps to avoid stray light interfering with the identification area 210. It is understood that this embodiment does not specifically limit the material of the cover plate 40.

[0055] The encapsulation layer 50 includes multiple through holes 510, each corresponding to a multiple receiving cavity 221. It is understood that the diameter of the through hole 510 can be greater than, equal to, or smaller than the diameter of the receiving cavity 221; this embodiment does not impose a specific limitation. The cross-sections of the through hole 510 and the receiving cavity 221 along the YZ plane can be triangular, quadrilateral, or circular, etc.; this embodiment does not impose a specific limitation. The cross-sections of the through hole 510 and the receiving cavity 221 along the YZ plane can be the same or different; this embodiment does not impose a specific limitation. In one possible implementation, both the through hole 510 and the receiving cavity 221 are circular holes with consistent diameters, which facilitates mass production of the encapsulation layer 50 and the fingerprint chip 20, and maximizes the light transmission efficiency of the light emitted by the light-emitting unit 30. Thus, on the one hand, the through hole 510 is precisely aligned with the receiving cavity 221, forming a clear light channel through which the light emitted from the light-emitting unit 30 passes through the encapsulation layer 50 and reaches the cover plate 40; on the other hand, it helps to minimize light loss and interference, as the light emitted from the light-emitting unit 30 is emitted directly from the through hole 510, avoiding absorption and scattering by the encapsulation layer 50 material; thirdly, it helps to ensure light directionality, as the boundary of the through hole 510 plays a role in constraining the direction of light and avoiding severe lateral diffusion, making the light illuminating the cover plate 40 more concentrated and controllable, which helps users to see the position of the recognition area 210 more intuitively and improves the effective recognition rate of the fingerprint recognition device 1.

[0056] Please see Figure 9 , Figure 9 This is an exploded view of the fingerprint recognition device 1 provided in the fifth embodiment of this application. In this embodiment, the fingerprint recognition device 1 includes a light-transmitting layer 60, which covers the cover plate 40 along the X direction. The light-transmitting layer 60 is used to transmit at least one of visible light and infrared light. For example, the light-transmitting layer 60 is used to transmit visible light or infrared light, or simultaneously. The area of ​​the light-transmitting layer 60 along the YZ plane can be greater than, equal to, or less than the area of ​​the cover plate 40 along the YZ plane; this embodiment does not impose a specific limitation. The light-transmitting layer 60 can be used to eliminate stray light and increase light transmittance, enhance the scratch resistance of the fingerprint recognition device 1 surface, and protect the surface of the optical path, thereby significantly improving imaging quality and long-term user experience.

[0057] Please see Figure 2 and Figure 9In this embodiment, the light-transmitting layer 60 includes a first light-transmitting layer 610 and a second light-transmitting layer 620. The second light-transmitting layer 620 surrounds the first light-transmitting layer 610 along the YZ plane. Along the X direction, the first light-transmitting layer 610 is disposed opposite to the recognition area 210, and the second light-transmitting layer 620 is disposed opposite to a plurality of light-emitting units 30. Along the X direction, the first light-transmitting layer 610 covers the recognition area 210, and the second light-transmitting layer 620 covers the plurality of light-emitting units 30. Thus, the light sensed by the recognition area 210 mainly passes through the first light-transmitting layer 610 and is recognized, while the light emitted by the light-emitting units 30 passes through the second light-transmitting layer 620 and is displayed on the cover plate 40, which helps to reduce the interference of the illumination light of the light-emitting units 30 with the fingerprint recognition of the recognition area 210.

[0058] Please see Figure 9 In this embodiment, the first light-transmitting layer 610 includes an infrared-transmitting ink layer, and the second light-transmitting layer 620 includes a visible-light-transmitting ink layer. The infrared-transmitting ink layer can absorb or block visible light while transmitting infrared light; the visible-light-transmitting ink layer can absorb or block infrared light while transmitting visible light. Along the X-direction, by aligning the infrared-transmitting ink layer with the recognition area 210, on the one hand, it helps improve signal transmittance, especially by selecting materials with high transmittance to infrared fingerprint imaging signal light, ensuring minimal loss of key sensing signals; on the other hand, it effectively shields against ambient light interference. The infrared-transmitting ink also has high visible light blocking properties, blocking visible light from the environment, such as sunlight and LED lights, from entering the recognition area 210, greatly improving image contrast. Along the X-direction, by aligning the visible-light-transmitting ink layer with multiple light-emitting units 30, on the one hand, it helps improve the visible light brightness and clarity of the light-emitting units 30; on the other hand, it provides diverse visual effects. For example, inks with different transparency or colors can be selected, such as creating a pale white, light gray, or even light-colored semi-transparent area, to meet the design requirements of the terminal device 1000.

[0059] Please see Figure 9 In this embodiment, the light-emitting unit 30 includes a micro LED. Micro LEDs have the advantages of low energy consumption and low heat generation. On the one hand, this can reduce the power consumption of the terminal device 1000 and improve battery life. On the other hand, since the internal space of the fingerprint recognition device 1 is small and the heat dissipation effect is limited, the micro LED with its small heat generation can also prevent the temperature inside the fingerprint recognition device 1 from becoming too high, which is beneficial to improving the recognition accuracy and stability of the fingerprint recognition device 1.

[0060] It is understood that the light-emitting unit 30 can also be a point light source, such as a light-emitting diode (LED) or an organic light-emitting diode (OLED). Optionally, the LED can be a front-emitting LED or a side-emitting LED. In specific implementations, a suitable LED can be selected as the light source based on factors such as the installation environment. Alternatively, in other possible implementations, the light-emitting unit 30 can also be a vertical cavity surface emitting laser (VCSEL) or other types of lasers, etc., and this embodiment does not impose specific limitations.

[0061] Please see Figure 2 and Figure 4 In this embodiment, the length of the fingerprint recognition device 1 along the X direction is less than or equal to 1.5 mm. For example, the length of the fingerprint recognition device 1 along the X direction is 0.6 mm, 0.9 mm, or 1.2 mm, etc., and this embodiment does not impose a specific limitation. This facilitates the integration of the fingerprint recognition device 1 into ultra-thin terminal devices 1000, such as mobile phones and smartwatches, without significantly increasing the thickness of the terminal device 1000, thus helping the fingerprint recognition device 1 meet the requirements for under-screen installation.

[0062] In this embodiment, the area of ​​the fingerprint chip 20 along the YZ plane is less than or equal to 20mm*20mm. It should be noted that the lengths of the fingerprint chip 20 along the Y and Z directions can be equal or unequal. For example, the area of ​​the fingerprint chip 20 along the YZ plane can be 10mm*10mm, 15mm*10mm, or 12mm*15mm, etc. This embodiment does not impose a specific limitation. Therefore, the fingerprint chip 20 includes a recognition area 210 and a functional area 220, simultaneously possessing fingerprint recognition functionality and an effective range reminder function. Furthermore, it allows the fingerprint recognition device 1 to be flexibly placed in various narrow locations within the terminal device 1000.

[0063] In this embodiment, the area of ​​the recognition area 210 along the YZ plane is less than or equal to 4mm*5mm. It should be noted that the lengths of the fingerprint chip 20 along the Y and Z directions can be equal or unequal. For example, the area of ​​the recognition area 210 along the YZ plane can be 4mm*5mm, 4mm*4mm, or 3mm*4mm, etc. This embodiment does not impose a specific limitation. Therefore, by having the light-emitting unit 30 surround the small recognition area 210, it helps to encourage the user to press the small area more naturally with a specific finger part, thus improving the recognition rate and speed of the fingerprint recognition device 1.

[0064] The above-disclosed embodiments are merely some preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that implementing all or part of the above embodiments and making equivalent changes in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A fingerprint recognition device, characterized in that, include: Circuit board; A fingerprint chip is electrically connected to the circuit board and is stacked sequentially with the circuit board along the thickness direction of the circuit board. The fingerprint chip includes a recognition area for acquiring and recognizing fingerprints. Multiple light-emitting units are electrically connected to the circuit board. The multiple light-emitting units are connected in parallel and are arranged at intervals around the identification area along a plane perpendicular to the thickness direction of the circuit board.

2. The fingerprint recognition device according to claim 1, characterized in that, The fingerprint chip includes a functional area along a plane perpendicular to the thickness direction of the circuit board, the functional area surrounding the recognition area, and the functional area including a plurality of receiving cavities, each of the receiving cavities being used to accommodate at least one of the light-emitting units.

3. The fingerprint recognition device according to claim 1, characterized in that, The plurality of light-emitting units are arranged in a matrix around the perimeter of the recognition area.

4. The fingerprint recognition device according to claim 2, characterized in that, The fingerprint recognition device includes a cover plate and an encapsulation layer. Along the thickness direction of the circuit board, the circuit board, the fingerprint chip, the encapsulation layer, and the cover plate are stacked in sequence. The encapsulation layer includes multiple through holes, and the multiple through holes are arranged one-to-one with the multiple receiving cavities.

5. The fingerprint recognition device according to claim 4, characterized in that, The fingerprint recognition device includes a light-transmitting layer for transmitting at least one of visible light and infrared light. Along the thickness direction of the circuit board, the circuit board, the fingerprint chip, the encapsulation layer, the cover plate, and the light-transmitting layer are stacked in sequence.

6. The fingerprint recognition device according to claim 5, characterized in that, The light-transmitting layer includes a first light-transmitting layer and a second light-transmitting layer. The second light-transmitting layer is used to surround the first light-transmitting layer along a plane perpendicular to the thickness direction of the circuit board. Along the thickness direction of the circuit board, the first light-transmitting layer is disposed opposite to the identification area, and the second light-transmitting layer is disposed opposite to the plurality of light-emitting units.

7. The fingerprint recognition device according to claim 6, characterized in that, The first light-transmitting layer includes an infrared-transmitting ink layer, and the second light-transmitting layer includes a visible-light-transmitting ink layer.

8. The fingerprint recognition device according to any one of claims 1-7, characterized in that, The light-emitting unit includes a micro LED.

9. The fingerprint recognition device according to claim 8, characterized in that, The length of the fingerprint recognition device along the thickness direction of the circuit board is less than or equal to 1.5 mm; and / or, The area of ​​the fingerprint chip along the plane perpendicular to the thickness direction of the circuit board is less than or equal to 20mm*20mm; and / or, The area of ​​the identification area along the plane perpendicular to the thickness direction of the circuit board is less than or equal to 4mm*5mm.

10. A terminal device, characterized in that, Includes the fingerprint recognition device as described in any one of claims 1-9.

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