WO2021036102A1

WO2021036102A1 - Fingerprint identification apparatus and electronic device

Info

Publication number: WO2021036102A1
Application number: PCT/CN2019/125386
Authority: WO
Inventors: 蒋鹏; 马明
Original assignee: 深圳市汇顶科技股份有限公司
Priority date: 2019-08-23
Filing date: 2019-12-13
Publication date: 2021-03-04
Also published as: CN211375615U; CN211375616U; CN211375617U; WO2021036100A1; WO2021036101A1

Abstract

Disclosed in embodiments of the present application are a fingerprint identification apparatus and an electronic device, capable of improving the performance of fingerprint identification apparatuses. The fingerprint identification apparatus is suitable for use under a display screen to achieve under-screen optical fingerprint identification. The fingerprint identification apparatus comprises multiple fingerprint identification units. Each fingerprint identification unit comprises: a microlens; at least two light barrier layers, each of which is provided with a light transmitting hole(s) to form three light guide channels in different directions; and three pixel units, respectively located at the bottoms of the three light guide channels. After fingerprint optical signals returned from a finger above the display screen are converged by the microlens, three target fingerprint optical signals in different directions are respectively transmitted to the three pixel units through the three light guide channels. Three pixel units in each of multiple groups in the fingerprint identification apparatus receive three fingerprint optical signals in different directions and convert same to form three fingerprint images, the three fingerprint images are moved and reconstructed into a reconstructed image, and the reconstructed image is used for fingerprint identification.

Description

Fingerprint identification device and electronic equipment

This application claims the priority of the following applications, all of which are incorporated into this application through the application:

A PCT application filed with the Chinese Patent Office on August 23, 2019, the application number is PCT/CN2019/102366, and the invention title is "fingerprint detection device, method and electronic equipment";

On October 18, 2019, a PCT application was filed with the Chinese Patent Office with the application number PCT/CN2019/111978 and the invention title "Fingerprint Detection Device and Electronic Equipment".

Technical field

This application relates to the field of fingerprint identification technology, and more specifically, to a fingerprint identification device and electronic equipment.

Background technique

With the rapid development of the terminal industry, people pay more and more attention to biometric technology, and more convenient under-screen biometric identification technology, such as the practical application of under-screen fingerprint identification technology, has become a popular demand. The fingerprint recognition technology under the screen is to set the fingerprint recognition device under the display screen, and realize fingerprint recognition by collecting fingerprint images. For example, the fingerprint identification device may converge the received light signals to the pixel array in the photoelectric sensor through a microlens array, and the photoelectric sensor generates a fingerprint image based on the light signal received by the pixel array, and then performs fingerprint recognition.

In some related technologies, the microlens array in the fingerprint identification device is located directly above the pixel array, and one microlens corresponds to a pixel unit, that is, each microlens in the microlens array focuses the received light to the same microlens In the corresponding pixel unit, a plurality of pixel units are arranged in an array. With this technical solution, the overall light input of the fingerprint identification device is small, the exposure time is long, the overall imaging quality is poor, and the identification performance of dry fingers is poor. At the same time, the thickness of the optical path in the fingerprint identification device is thick, which increases the processing difficulty and cost of the optical path, and is not conducive to the development of the thinner and lighter fingerprint identification device.

Therefore, how to comprehensively improve the performance of the fingerprint identification device is an urgent problem to be solved.

Summary of the invention

The embodiments of the present application provide a fingerprint identification device and electronic equipment, which can improve the performance of the fingerprint identification device.

In a first aspect, a fingerprint identification device is provided, which is suitable for under the display screen to realize under-screen optical fingerprint identification. The fingerprint identification device includes a plurality of fingerprint identification units distributed in a square array, and the plurality of fingerprint identification Each fingerprint recognition unit in the unit includes:

Micro lens

At least two light-blocking layers are arranged under the microlens, and each of the at least two light-blocking layers is provided with light-passing holes to form three light guide channels in different directions;

Three pixel units are arranged under the at least two light blocking layers, and the three pixel units are respectively located at the bottom of the three light guide channels;

Wherein, the fingerprint light signals returned from the finger above the display screen after being reflected or scattered are condensed by the microlens, and the three target fingerprint light signals in different directions are respectively transmitted to the three pixel units through the three light guide channels , The three target fingerprint light signals are used to detect the fingerprint information of the finger.

According to the solution of the present application, one microlens corresponds to three pixel units, and the three pixel units respectively receive the target fingerprint light signals in three directions condensed by the microlens and passed through the three light guide channels. The fingerprint light signal is received by the three pixel units respectively. Compared with the technical solution that one microlens corresponds to one pixel unit, the amount of light entering the fingerprint identification device can be increased, the exposure time can be reduced, and the field of view of the fingerprint identification device can be increased. In addition, the angle of the fingerprint light signal received by the pixel unit is determined by the relative positional relationship between the pixel unit and the microlens. If the pixel unit shifts farther from the center of the microlens, the greater the angle of the fingerprint light signal received by the pixel unit. Therefore, by flexibly setting the position of the pixel unit, the pixel unit can receive fingerprint light signals at a large angle, which greatly improves the recognition problem of dry fingers, and can reduce the thickness of the optical path in the fingerprint recognition unit, thereby reducing the fingerprint recognition device Thickness, reduce process cost. In addition, compared to the technical solution of one microlens corresponding to four pixel units, the area of the unit pixel unit in the pixel array is increased, which facilitates the layout and routing of the pixel units in the pixel array, and the number of pixel units in the pixel array is reduced. Therefore, the amount of data for fingerprint processing is reduced, and the processing speed of fingerprint recognition can be improved. In summary, while improving the identification problem of dry fingers, reducing the thickness of the fingerprint identification device, and reducing the process cost, the circuit design of the pixel array is facilitated, and the processing speed of fingerprint identification is improved.

In a possible implementation manner, the directions of at least two of the three light guide channels are inclined with respect to the display screen.

Using the solution of the implementation of this application, if the three pixel units respectively receive the fingerprint light signal in the vertical direction and the fingerprint light signal in the oblique direction, when the finger is in good contact with the display screen, the fingerprint light signal in the vertical direction is strong, and the corresponding The fingerprint image signal is of good quality and can quickly perform fingerprint recognition. At the same time, when the dry finger is in poor contact with the display screen, the fingerprint light signal in the oblique direction can improve the fingerprint recognition problem of the dry finger and can reduce the thickness of the fingerprint recognition device. If the three pixel units all receive the fingerprint light signals in the oblique direction, the fingerprint light signals in different oblique directions are used to further optimize the identification problem of dry fingers.

In a possible implementation manner, the included angle of the projection of the two light guide channels of the three light guide channels on the plane where the three pixel units are located is 90 degrees.

Using the solution of the implementation of this application, the fingerprint light signals received by two of the three pixel units are perpendicular to each other, which facilitates the collection of fingerprint light signals perpendicular to the ridge and valley lines of the fingerprint, and can improve the fingerprint received by the fingerprint identification unit. The quality of the optical signal, thereby improving the quality of the fingerprint image, and improving the fingerprint recognition performance of the fingerprint recognition device.

In a possible implementation manner, the included angles of the three light guide channels and the display screen are the same.

In a possible implementation manner, the three pixel units respectively include three photosensitive areas, and the three photosensitive areas are respectively located at the bottom of the three light guide channels.

In a possible implementation manner, at least one of the three photosensitive areas is arranged deviating from the center of the pixel unit where it is located.

In a possible implementation, at least one of the three photosensitive areas deviates in a direction away from the center of the microlens.

In a possible implementation manner, the three pixel units form a quadrangular pixel area, and two of the three photosensitive areas are located on one side of the pixel area at the same time.

In a possible implementation manner, the three pixel units include a first pixel unit, the first pixel unit includes a first photosensitive area, and both the first pixel unit and the first photosensitive area are quadrangular; wherein, the The length and width of the first pixel unit are respectively L and W, W≦L, and both W and L are positive numbers, and the length and width of the first photosensitive area are both greater than or equal to 0.1×W.

By adopting the solution of the implementation of the present application, the photosensitive area of the pixel unit is increased, and the full well capacity of the pixel unit and the dynamic range of the pixel unit can be increased, thereby improving the overall performance of the pixel unit and realizing high dynamic range imaging of the fingerprint identification device.

In a possible implementation manner, the three target fingerprint light signals respectively form three light spots on the three pixel units, and the three photosensitive areas are quadrilateral areas and are respectively circumscribed to the three light spots.

In a possible implementation, the height of the optical path between the microlens and the plane where the three pixel units are located is calculated according to a formula: h=x×cotθ;

Where h is the height of the optical path, x is the distance between the center of the first photosensitive area in the three photosensitive areas and the projection point of the center of the microlens on the plane where the three pixel units are located, and θ is the first photosensitive area. The angle between the first target fingerprint optical signal received by a photosensitive area and the vertical direction, the angle between the first target fingerprint optical signal and the vertical direction in the three target fingerprint optical signals is greater than the other two of the three target fingerprint optical signals The included angle between a target fingerprint light signal and a vertical direction, where the vertical direction is a direction perpendicular to the display screen.

In a possible implementation manner, two of the three pixel units are squares with side length a, and the other pixel unit is a rectangle with length 2a and width a, where a is a positive number.

In a possible implementation manner, the angles between the three light guide channels and the plane where the three pixel units are located are between 30° and 90°.

In a possible implementation manner, the bottom light-blocking layer of the at least two light-blocking layers is provided with three light-passing holes corresponding to the three pixel units, respectively.

In a possible implementation, the bottom light blocking layer is a metal wiring layer on the surface of the three pixel units.

In a possible implementation manner, the apertures of the light-passing holes in the three light guide channels are sequentially reduced from top to bottom.

In a possible implementation manner, the three light guide channels overlap the light passing holes in the top light blocking layer of the at least two light blocking layers.

In a possible implementation manner, the fingerprint identification unit further includes: a transparent medium layer;

Wherein, the lens medium layer is used to connect the micro lens, the at least two light blocking layers, and the three pixel units.

In a possible implementation, the fingerprint identification unit further includes: an optical filter layer;

Wherein, the optical filter layer is arranged in the optical path between the display screen and the plane where the three pixel units are located, and is used to filter the light signal of the non-target waveband so as to pass the light signal of the target waveband.

In a possible implementation, the optical filter layer is integrated on the surface of the three pixel units.

In a possible implementation manner, the optical filter layer is disposed between the bottom light-blocking layer of the at least two light-blocking layers and the plane where the three pixel units are located.

In a possible implementation, multiple groups of the three pixel units include multiple target pixel units, and the light guide channels corresponding to the multiple target pixel units are provided with a color filter layer, and the color filter layer is used to pass red Visible light, green visible light, or blue visible light.

Through the technical solution of this implementation mode, multiple target pixel units can be set to sense the color light signal, and the fingerprint area and non-finger press on the display screen can be determined according to the difference of the color light signals received by different target pixel units. During the process of fingerprint recognition, fingerprint recognition is directly performed on the light signal sensed by the pixel unit corresponding to the fingerprint area pressed by the finger, and the interference caused by the pixel unit corresponding to the non-finger pressing area on fingerprint recognition is avoided, thereby Improve the success rate of fingerprint recognition. In addition, since the absorption and reflection performance of the color light signal of the finger is different from the absorption and reflection performance of the color light signal of other materials, according to the intensity of the received color light signal, the anti-counterfeiting function of fingerprint recognition can be enhanced, or it can be judged. Real finger pressing or fake finger pressing.

In a possible implementation manner, multiple groups of areas where the three pixel units are located are composed of multiple unit pixel areas, and each unit pixel area of the multiple unit pixel areas is provided with one target pixel unit.

In a possible implementation manner, the multiple target pixel units are evenly distributed in multiple groups of the three pixel units.

In a possible implementation manner, the color filter layer is disposed in the light-passing hole of the light guide channel corresponding to the target pixel unit.

In a possible implementation manner, the fingerprint identification device includes multiple groups of the three pixel units;

Multiple groups of light signals received by a plurality of first pixel units of the three pixel units are used to form the first fingerprint image of the finger, and multiple groups of light signals received by multiple second pixel units of the three pixel units are used for To form a second fingerprint image of the finger, the light signals received by a plurality of third pixel units of the three pixel units are used to form a third fingerprint image of the finger. The first fingerprint image and the second fingerprint One or more of the image and the third fingerprint image are used for fingerprint recognition.

In a possible implementation manner, the average value of pixels of each X first pixel units in the plurality of first pixel units is used to form a pixel value in the first fingerprint image; and/or, the plurality of first pixel units The average value of the pixels of every X second pixel units in the two pixel units is used to form a pixel value in the second fingerprint image, and/or, the pixels of every X third pixel units in the plurality of third pixel units The average value is used to form a pixel value in the third fingerprint image, where X is a positive integer.

By adopting the solution of this embodiment, the number of pixels in the fingerprint image can be further reduced, and the speed of fingerprint recognition can be improved. In this embodiment, if several pixel units in X pixel units fail, the X pixel units can still be The output of the pixel value will not affect the formation of the fingerprint image and the effect of fingerprint recognition.

In a possible implementation manner, the plurality of first pixel units are not adjacent to each other, and/or the plurality of second pixel units are not adjacent to each other, and/or, the plurality of third pixel units are not adjacent to each other. The pixel units are not adjacent to each other.

In a possible implementation, the fingerprint identification device further includes a processing unit configured to move the first fingerprint image, the second fingerprint image, and the third fingerprint image to combine to form a reconstructed image, and According to the quality parameter of the reconstructed image, the moving distances of the first fingerprint image, the second fingerprint image and the third fingerprint image are adjusted to form a target reconstructed image, and the target reconstructed image is used for fingerprint identification.

In a possible implementation manner, the distance between the fingerprint identification device and the display screen is 0 to 1 mm.

In a second aspect, an electronic device is provided, including: a display screen; and

In the first aspect or in any one of the possible implementations of the first aspect, the fingerprint identification device is arranged under the display screen to realize the off-screen optical fingerprint identification.

The above-mentioned fingerprint identification device is provided in an electronic device, and the fingerprint identification performance of the fingerprint identification device is improved, thereby improving the fingerprint identification performance of the electronic device.

Description of the drawings

Fig. 1 is a schematic plan view of an electronic device to which the present application can be applied.

2 and 3 are a schematic cross-sectional view and a schematic top view of a fingerprint identification device according to an embodiment of the present application.

4 and 5 are a schematic cross-sectional view and a schematic top view of another fingerprint identification device according to an embodiment of the present application.

Fig. 6 is a schematic top view of a fingerprint identification device according to an embodiment of the present application.

Fig. 7 is a schematic three-dimensional structural diagram of a fingerprint identification unit according to an embodiment of the present application.

Fig. 8 is a schematic top view of the fingerprint identification unit in Fig. 7.

Fig. 9 is a schematic cross-sectional view of the fingerprint identification unit in Fig. 8 along the A-A' direction.

Fig. 10 is a schematic top view of the fingerprint recognition unit in Fig. 7.

Fig. 11 is a schematic cross-sectional view of the fingerprint recognition unit in Fig. 10 along the A-A' direction.

Fig. 12 is a schematic top view of another fingerprint identification unit according to an embodiment of the present application.

Fig. 13 is a schematic cross-sectional view of the fingerprint recognition unit in Fig. 12 along the A-A' direction.

Fig. 14 is a schematic top view of another fingerprint identification unit according to an embodiment of the present application.

Fig. 15 is a schematic top view of another fingerprint identification unit according to an embodiment of the present application.

Fig. 16 is a schematic top view of a fingerprint identification device according to an embodiment of the present application.

Fig. 17 is a schematic top view of another fingerprint identification unit according to an embodiment of the present application.

Fig. 18 is a schematic top view of another fingerprint identification unit according to an embodiment of the present application.

Fig. 19 is a schematic top view of another fingerprint identification unit according to an embodiment of the present application.

Fig. 20 is a schematic diagram of a pixel array in a fingerprint identification device according to an embodiment of the present application.

21a to 21d are schematic diagrams of four types of pixel arrays in a fingerprint identification device according to an embodiment of the present application.

Fig. 22 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

FIG. 23 to FIG. 28 are schematic diagrams of fingerprint images in the fingerprint identification process of an embodiment of the present application.

detailed description

The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

It should be understood that the embodiments of this application can be applied to optical fingerprint systems, including but not limited to optical fingerprint identification systems and products based on optical fingerprint imaging. The embodiments of this application only take optical fingerprint systems as an example for illustration, but should not be implemented in this application. The examples constitute any limitation, and the examples of this application are also applicable to other systems that use optical imaging technology.

As a common application scenario, the optical fingerprint system provided in the embodiments of this application can be applied to smart phones, tablet computers, and other mobile terminals with display screens or other electronic devices; more specifically, in the above electronic devices, fingerprint identification The device may specifically be an optical fingerprint device, which may be arranged in a partial area or an entire area under the display screen, thereby forming an under-display optical fingerprint system. Alternatively, the fingerprint identification device may be partially or fully integrated into the display screen of the electronic device, thereby forming an in-display optical fingerprint system.

1 is a schematic structural diagram of an electronic device to which the embodiment of the application can be applied. The electronic device 10 includes a display screen 120 and an optical fingerprint device 130, wherein the optical fingerprint device 130 is disposed in a partial area under the display screen 120. The optical fingerprint device 130 includes an optical fingerprint sensor, and the optical fingerprint sensor includes a sensing array 133 having a plurality of optical sensing units 131, and the area where the sensing array 133 is located or its sensing area is the fingerprint detection area 103 of the optical fingerprint device 130. As shown in FIG. 1, the fingerprint detection area 103 is located in the display area of the display screen 120. In an alternative embodiment, the optical fingerprint device 130 can also be arranged in other positions, such as the side of the display screen 120 or the non-transmissive area at the edge of the electronic device 10, and at least part of the display area of the display screen 120 is designed through the optical path. The optical signal is guided to the optical fingerprint device 130, so that the fingerprint detection area 103 is actually located in the display area of the display screen 120.

It should be understood that the area of the fingerprint detection area 103 may be different from the area of the sensing array of the optical fingerprint device 130. For example, through the optical path design of lens imaging, the reflective folding optical path design, or other optical path design such as light convergence or reflection, the optical fingerprint can be made The area of the fingerprint detection area 103 of the device 130 is larger than the area of the sensing array of the optical fingerprint device 130. In other alternative implementations, if for example, light collimation is used for light path guidance, the fingerprint detection area 103 of the optical fingerprint device 130 can also be designed to be substantially the same as the area of the sensing array of the optical fingerprint device 130.

Therefore, when the user needs to unlock the electronic device or perform other fingerprint verification, he only needs to press his finger on the fingerprint detection area 103 located on the display screen 120 to realize fingerprint input. Since fingerprint detection can be implemented in the screen, the electronic device 10 with the above structure does not need to reserve space on the front side to set the fingerprint button (such as the Home button), so that a full-screen solution can be adopted, that is, the display area of the display screen 120 can be basically Extend to the front of the entire electronic device 10.

As an optional implementation, as shown in FIG. 1, the optical fingerprint device 130 includes a light detecting portion 134 and an optical component 132. The light detecting portion 134 includes a sensing array and a reading circuit electrically connected to the sensing array. Other auxiliary circuits, which can be fabricated on a chip (Die) through a semiconductor process, such as an optical imaging chip or an optical fingerprint sensor. The sensing array is specifically a photodetector array, which includes a plurality of arrays distributed The photodetector can be used as the above-mentioned optical sensing unit; the optical component 132 can be arranged above the sensing array of the light detecting part 134, and it can specifically include a light guide layer or a light path guide structure and other optical elements. The light guide layer or light path guide structure is mainly used to guide the reflected light reflected from the surface of the finger to the sensing array for optical detection.

In terms of specific implementation, the optical assembly 132 and the light detecting part 134 may be packaged in the same optical fingerprint component. For example, the optical component 132 and the optical detection part 134 can be packaged in the same optical fingerprint chip, or the optical component 132 can be arranged outside the chip where the optical detection part 134 is located, for example, the optical component 132 can be attached to the Above the chip, or part of the components of the optical assembly 132 are integrated into the above-mentioned chip.

Among them, the light guide layer or light path guiding structure of the optical component 132 has multiple implementation schemes. For example, the light guide layer may specifically be a collimator layer made on a semiconductor silicon wafer, which has multiple collimators. Unit or micro-hole array, the collimating unit can be specifically a small hole, the reflected light reflected from the finger, the light that is perpendicularly incident on the collimating unit can pass through and be received by the optical sensor unit below it, and the incident angle Excessive light is attenuated by multiple reflections inside the collimating unit, so each optical sensor unit can basically only receive the reflected light reflected by the fingerprint pattern directly above it, so the sensor array can detect the finger Fingerprint image.

In another embodiment, the light guide layer or the light path guide structure may also be an optical lens (Lens) layer, which has one or more lens units, such as a lens group composed of one or more aspheric lenses, which is used for The reflected light reflected from the finger is condensed to the sensing array of the light detection part 134 below it, so that the sensing array can perform imaging based on the reflected light, thereby obtaining a fingerprint image of the finger. Optionally, the optical lens layer may further have a pinhole formed in the optical path of the lens unit, and the pinhole may cooperate with the optical lens layer to expand the field of view of the optical fingerprint device, so as to improve the fingerprint imaging effect of the optical fingerprint device 130.

In other embodiments, the light guide layer or the light path guide structure may also specifically adopt a micro-lens (Micro-Lens) layer. The micro-lens layer has a micro-lens array formed by a plurality of micro-lenses. The process is formed above the sensing array of the light detecting part 134, and each microlens may correspond to one of the sensing units of the sensing array, respectively. In addition, other optical film layers may be formed between the micro lens layer and the sensing unit, such as a dielectric layer or a passivation layer. More specifically, a light blocking layer with micro holes may also be formed between the micro lens layer and the sensing unit. The micro-hole is formed between the corresponding micro-lens and the sensing unit. The light blocking layer can block the optical interference between the adjacent micro-lens and the sensing unit, and make the light corresponding to the sensing unit converge into the micro-hole through the micro-lens And it is transmitted to the sensing unit through the micro-hole for optical fingerprint imaging. It should be understood that several implementation solutions of the above-mentioned light path guiding structure can be used alone or in combination. For example, a microlens layer can be further provided under the collimator layer or the optical lens layer. Of course, when the collimator layer or the optical lens layer is used in combination with the micro lens layer, the specific laminated structure or optical path may need to be adjusted according to actual needs.

As an optional embodiment, the display screen 120 may adopt a display screen with a self-luminous display unit, such as an organic light-emitting diode (OLED) display screen or a micro-LED (Micro-LED) display screen. Taking the OLED display screen as an example, the optical fingerprint device 130 may use the display unit (ie, OLED light source) of the OLED display screen 120 located in the fingerprint detection area 103 as the excitation light source for optical fingerprint detection. When the finger 140 is pressed on the fingerprint detection area 103, the display screen 120 emits a beam of light 111 to the target finger 140 above the fingerprint detection area 103. The light 111 is reflected on the surface of the finger 140 to form reflected light or scattered inside the finger 140. The scattered light is formed. In related patent applications, for ease of description, the above-mentioned reflected light and scattered light are collectively referred to as reflected light. Because the ridge and valley of the fingerprint have different light reflection capabilities, the reflected light 151 from the fingerprint ridge and the reflected light 152 from the fingerprint valley have different light intensities. After the reflected light passes through the optical component 132, It is received by the sensor array 134 in the optical fingerprint device 130 and converted into a corresponding electrical signal, that is, a fingerprint detection signal; based on the fingerprint detection signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed, so that the electronic device 10 Realize the optical fingerprint recognition function.

In other embodiments, the optical fingerprint device 130 may also use a built-in light source or an external light source to provide an optical signal for fingerprint detection. In this case, the optical fingerprint device 130 may be suitable for non-self-luminous display screens, such as liquid crystal display screens or other passively-luminous display screens. Taking a liquid crystal display with a backlight module and a liquid crystal panel as an example, in order to support the under-screen fingerprint detection of the liquid crystal display, the optical fingerprint system of the electronic device 10 may also include an excitation light source for optical fingerprint detection. It can be specifically an infrared light source or a light source of invisible light of a specific wavelength, which can be arranged under the backlight module of the liquid crystal display or arranged in the edge area under the protective cover of the electronic device 10, and the optical fingerprint device 130 can be arranged with a liquid crystal panel or Under the edge area of the protective cover and guided by the light path so that the fingerprint detection light can reach the optical fingerprint device 130; or, the optical fingerprint device 130 can also be arranged under the backlight module, and the backlight module passes through the diffusion sheet, the brightness enhancement sheet, The film layer such as the reflective sheet has holes or other optical designs to allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint device 130. When the optical fingerprint device 130 adopts a built-in light source or an external light source to provide an optical signal for fingerprint detection, the detection principle is the same as that described above.

It should be understood that, in specific implementation, the electronic device 10 further includes a transparent protective cover plate, which may be a glass cover plate or a sapphire cover plate, which is located above the display screen 120 and covers the front surface of the electronic device 10. Because, in the embodiment of the present application, the so-called finger pressing on the display screen 120 actually refers to pressing on the cover plate above the display screen 120 or covering the surface of the protective layer of the cover plate.

It should also be understood that the electronic device 10 may further include a circuit board 150 disposed under the optical fingerprint device 130. The optical fingerprint device 130 can be adhered to the circuit board 150 through adhesive, and is electrically connected to the circuit board 150 through soldering pads and metal wires. The optical fingerprint device 130 can realize electrical interconnection and signal transmission with other peripheral circuits or other components of the electronic device 10 through the circuit board 150. For example, the optical fingerprint device 130 can receive the control signal of the processing unit of the electronic device 10 through the circuit board 150, and can also output the fingerprint detection signal from the optical fingerprint device 130 to the processing unit or the control unit of the electronic device 10 through the circuit board 150 Wait.

On the other hand, in some embodiments, the optical fingerprint device 130 may include only one optical fingerprint sensor. At this time, the fingerprint detection area 103 of the optical fingerprint device 130 has a small area and a fixed position. Therefore, the user needs to perform fingerprint input Press the finger to a specific position of the fingerprint detection area 103, otherwise the optical fingerprint device 130 may not be able to collect fingerprint images, resulting in poor user experience. In other alternative embodiments, the optical fingerprint device 130 may specifically include a plurality of optical fingerprint sensors; the plurality of optical fingerprint sensors may be arranged side by side under the display screen 120 in a splicing manner, and the sensing areas of the plurality of optical fingerprint sensors are common The fingerprint detection area 103 of the optical fingerprint device 130 is constituted. In other words, the fingerprint detection area 103 of the optical fingerprint device 130 may include multiple sub-areas, and each sub-area corresponds to the sensing area of one of the optical fingerprint sensors, so that the fingerprint collection area 103 of the optical fingerprint device 130 can be extended to display The main area of the lower half of the screen is extended to the area where the finger is habitually pressed, so as to realize the blind fingerprint input operation. Alternatively, when the number of optical fingerprint sensors is sufficient, the fingerprint detection area 103 can also be extended to half of the display area or even the entire display area, thereby realizing half-screen or full-screen fingerprint detection.

It should also be understood that, in the embodiments of the present application, the sensing array in the optical fingerprint device may also be referred to as a pixel array, and the optical sensing unit or sensing unit in the sensing array may also be referred to as a pixel unit or a pixel.

It should be noted that the optical fingerprint device in the embodiments of the present application may also be referred to as an optical fingerprint identification module, a fingerprint identification device, a fingerprint identification module, a fingerprint module, a fingerprint acquisition device, etc., and the above terms can be replaced with each other.

Figures 2 and 3 show a schematic cross-sectional view and a schematic top view of a fingerprint identification device.

As shown in FIG. 2 and FIG. 3, the fingerprint identification device 200 includes a microlens array 210, at least one light blocking layer 220 and a pixel array 230. The microlens array 210 is located directly above the pixel array 230 and at least one layer of light blocking layer 220, and one microlens 211 corresponds to a pixel unit 231, that is, each microlens 211 in the microlens array 210 passes the received light at least The small holes 2201 of one layer of light blocking layer 220 are focused into the pixel unit 231 corresponding to the same micro lens 211. The optical signal received by each microlens 211 is mainly a fingerprint optical signal incident perpendicular to the microlens array 210 after being reflected or scattered by a finger above the display screen.

As shown in FIG. 3, the pixel units 231 in the pixel array 230 are arranged periodically, and the photosensitive area 2311 of each pixel unit 231 in the pixel array 230 is arranged at the center of the same pixel unit, so as to improve the sensitivity of the photosensitive area. Duty cycle.

In other words, the multiple microlenses 211 in the microlens array 210 correspond to the multiple pixel units 231 in the pixel array 230 one-to-one, and the photosensitive regions 2311 of the multiple pixel units 231 in the pixel array 230 are periodically arranged and uniformly distributed.

However, the photosensitive area of the pixel array 230 is affected by the size of the microlens array 210, and the thickness of the fingerprint identification device 200 is relatively large, which further increases the processing difficulty, cycle and cost of the optical path of the fingerprint identification device 200.

In addition, in normal life scenes, such as washing hands, waking up in the morning, plastering fingers, low temperature, etc., the fingers are usually dry and the cuticle is uneven. When it is pressed on the display screen, local areas of the fingers will have poor contact . When the dry finger is not in contact with the display screen, the fingerprint ridge and valley of the fingerprint image in the vertical direction formed by the fingerprint identification device 200 have poor contrast, and the image is blurred to the point where the fingerprint lines cannot be distinguished. Finger fingerprint recognition performance is poor.

4 and 5 show a schematic cross-sectional view and a schematic top view of another fingerprint identification device.

As shown in FIG. 4 and FIG. 5, the fingerprint identification device 200 includes: a microlens array 210, at least one light blocking layer 220 and a pixel array 230. The at least one light blocking layer is formed with a plurality of light guide channels corresponding to each microlens in the microlens array 210, and each of the plurality of light guide channels is provided with a pixel unit at the bottom of each light guide channel.

For example, as shown in 3a and FIG. 5, the light blocking layer under the first microlens 211 in the microlens array 210 is formed with 4 light guide channels, and the first microlens 211 corresponds to the 4 pixels located below it. Each pixel unit includes the first pixel unit 231 and the second pixel unit 232 shown in the figure.

Optionally, as shown in FIG. 4, of the at least one light blocking layer, the uppermost light blocking layer is a first light blocking layer 221, and a second light blocking layer 222 is provided under the first light blocking layer 221, and A third light blocking layer 223 is provided above the pixel array 230. Wherein, on the first light blocking layer 221, a first small hole 2211 corresponding to the first microlens 211 is formed, and on the second light blocking layer 222, a second small hole 2221 corresponding to the first microlens 211 and The third small hole 2222, and the second small hole 2221 and the third small hole 2222 are both located below the first small hole 2211. In addition, on the third light blocking layer 223, a first microlens 211 is formed. Four small holes 2231 and a fifth small hole 2232. In this structure, the first small hole 2211, the second small hole 2221, and the fourth small hole 2231 form a light guide channel corresponding to the first microlens, and the light signal in the first direction condensed by the first microlens passes through the light guide. The channel is received by the first photosensitive area 2311 in the first pixel unit 231. The first small hole 2211, the third small hole 2222, and the fifth small hole 2232 form another light guide channel corresponding to the first microlens. The optical signal in the second direction condensed by the first microlens passes through the light guide channel and is second The second photosensitive area 2321 in the pixel unit 232 unit is received.

4 is a schematic cross-sectional view of the fingerprint identification device 200. The figure only shows a case where one microlens corresponds to two light guide channels and two pixel units. It should be understood that in the embodiment of the present application, one microlens corresponds to 4 The situation of one light guide channel and 4 pixel units, and the other 2 light guide channels and 2 pixel units corresponding to one microlens can be seen in FIG. 4.

As shown in FIG. 5, in the fingerprint identification device 200, a plurality of microlenses in the microlens array 210 are arranged in a square array, and a plurality of pixel units in the pixel array 230 are also arranged in a square array under the microlens array, and one The microlens corresponds to 4 pixel units, and the centers of the 4 pixel units coincide with the centers of the corresponding microlenses in the vertical direction.

Through the solution of this embodiment, through the design of the light path, the 4 pixel units corresponding to a single microlens can receive light signals in 4 directions at the same time, thereby increasing the light input of the fingerprint identification device, reducing the exposure time, and increasing the field of view. At the same time, the imaging optical path of a single microlens and a multi-pixel unit can perform non-frontal light imaging (ie oblique light imaging) of the object beam of the fingerprint, which can improve the recognition effect of dry fingers, and can expand the optical system The object-side numerical aperture and shorten the thickness of the optical path design of the pixel array can ultimately effectively reduce the thickness of the fingerprint identification device.

However, in this embodiment, the pixel array includes 4 types of pixel units, and each type of pixel unit receives light signals in one direction. Therefore, when performing fingerprint recognition, the electrical signals generated by the 4 types of pixel units need to be processed to form a fingerprint image. The signal is used for fingerprint identification, the amount of data is large and the signal processing time is long. In addition, since one microlens corresponds to 4 pixel units, there are a large number of pixel units in the pixel array, which is not conducive to the layout and routing of the pixel units. Third, limited by the fixed arrangement of the pixel array, the inclination angle of the light signal received by the pixel unit is limited, the recognition performance of the dry finger is not optimal, and the overall optical path is still thick, which is not conducive to further lightness and thinness of the fingerprint recognition device化 development.

Based on the above problems, in the embodiments of the present application, a fingerprint identification device is provided, which can optimize the recognition performance of dry fingers while increasing the light input of the fingerprint identification device, reducing the exposure time, increasing the optical resolution and the optical field of view. , And reduce the thickness of the fingerprint identification device.

Hereinafter, the fingerprint identification device of the embodiment of the present application will be described in detail with reference to FIGS. 6-28.

It should be noted that, for ease of understanding, in the embodiments shown below, the same structures are given the same reference numerals, and for brevity, detailed descriptions of the same structures are omitted.

It should be understood that the number and arrangement of the pixel units, microlenses, and light-passing holes on the light-blocking layer in the embodiments of the present application shown below are only exemplary descriptions, and should not constitute any limitation to the present application. .

FIG. 6 is a schematic top view of a fingerprint identification device 300 provided by an embodiment of the present application. The fingerprint identification device 300 is suitable for under the display screen to realize under-screen optical fingerprint identification.

As shown in FIG. 6, the fingerprint identification device 300 may include a plurality of fingerprint identification units 301 distributed in an array. Wherein, the plurality of fingerprint identification units 301 includes a plurality of microlenses arranged in a square array. If the plurality of microlenses are circular microlenses, the centers of the plurality of microlenses are arranged in a square array. The centers of adjacent microlenses form a square.

Of course, the fingerprint identification device 300 may also include a plurality of fingerprint identification units 301 interlaced in structure. For example, the microlens in each fingerprint identification unit in the fingerprint identification device 300 can converge the received oblique light signal to the pixel unit below the microlens in the plurality of adjacent fingerprint identification units. In other words, each microlens condenses the received oblique light signal to the pixel unit under the multiple microlenses adjacent to the same microlens.

Optionally, FIG. 7 shows a schematic three-dimensional structural diagram of a fingerprint identification unit 301.

As shown in FIG. 7, each fingerprint identification unit 301 of the plurality of fingerprint identification units includes:

Micro lens 310;

At least two light-shielding layers are arranged under the above-mentioned microlens 310, and each light-shielding layer of the at least two light-shielding layers is provided with light-passing holes to form three light guide channels in different directions (first guide Light channel, second light guide channel and third light guide channel);

Three pixel units (the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333) are arranged under the at least two light blocking layers, and the three pixel units are distributed at the bottom of the three light guide channels ；

Among them, the fingerprint light signals returned after being reflected or scattered from the finger above the display screen are condensed by the above-mentioned microlens 310, and the three target fingerprint light signals in different directions (the first target fingerprint light signal, the second target fingerprint light signal and the The third target fingerprint light signal) is respectively transmitted to the above three pixel units through the above three light guide channels, and the three target fingerprint light signals are used to detect fingerprint information of the finger.

In this application, the microlens 310 may be various lenses with a convergence function, which are used to increase the field of view and increase the amount of light signals transmitted to the pixel unit. The material of the micro lens 310 may be an organic material, such as resin. Optionally, the surface of the micro lens 310 may be a spherical surface or an aspherical surface. The micro lens 310 may be a round lens or a square lens, etc., which is not limited in the embodiment of the present application.

Optionally, if the microlens 310 is a circular microlens, its diameter is not greater than the arrangement period of three pixel units. For example, if the maximum range covered by three pixel units in the horizontal and vertical directions is an A×B quadrilateral area, where A≤B, and A and B are positive integers, the diameter of the microlens 310 is less than or equal to A.

In this application, the pixel unit may be a photoelectric conversion unit. Optionally, the pixel unit may include a complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS) device, specifically including a photodiode (PD) and a CMOS switch tube, etc., where the photodiode is composed of a PN junction The composed semiconductor device has unidirectional conductivity characteristics, which can convert the received optical signal into the corresponding electrical signal, so as to realize the conversion from the light image to the point image. The CMOS switch tube is used to receive the control signal to control the work of the photodiode, and can Used to control the electrical signal of the output photodiode.

Optionally, as shown in FIG. 7, the three pixel units in the fingerprint identification unit 301 may be quadrilateral, and the three quadrilateral pixel units correspond to the microlens 310 and are arranged under the microlens 310.

It should be noted here that the three pixel units arranged under the microlens 310 can also be polygonal or other special-shaped patterns, so that the pixel array in the fingerprint identification device 300 has higher symmetry and higher sampling efficiency. Adjacent pixels are equidistant, better angular resolution, less aliasing effect.

Optionally, in a possible implementation manner, the fingerprint identification unit 301 includes two light-blocking layers, such as the first light-blocking layer 321 and the second light-blocking layer 322 in FIG. 7. The first light blocking layer 321 is formed at any position between the micro lens 310 and the plane where the three pixel units are located, which is not limited in the embodiment of the present application.

The second light blocking layer 322 is not shown in FIG. 7, and it may be formed on the surfaces of the first pixel unit 331 and the second pixel unit 332, and specifically may be metal on the surfaces of the first pixel unit 331 and the second pixel unit 332. Floor.

Of course, the second light blocking layer 322 can also be formed at any position between the microlens 310 and the plane where the three pixel units are located, for example, formed between the first light blocking layer 321 and the plane where the three pixel units are located. The application embodiment also does not specifically limit this.

Optionally, as shown in FIG. 7, a first light-passing hole 3211 is formed on the first light-blocking layer 321, and three light-passing holes are formed on the second light-blocking layer 322, which are respectively the second light-passing holes. A hole 3221, a third light-passing hole 3222, and a fourth light-passing hole 3223. The second light-passing hole 3221 and the first light-passing hole 3211 form a first light guide channel for passing the first target fingerprint light signal in the fingerprint light signal condensed by the microlens 310, which is located in the first light guide. The first pixel unit 331 at the bottom of the light guide channel is used for detecting fingerprint information. Similarly, the third light-passing hole 3222 and the first light-passing hole 3211 form a second light guide channel for passing the second target fingerprint light signal, which is located at the second pixel unit 332 at the bottom of the second light guide channel. After receiving, the first target fingerprint optical signal and the second target fingerprint optical signal are used to detect fingerprint information, and the fourth light-passing hole 3223 and the first light-passing hole 3211 form a third light guide channel for passing through the third target The fingerprint light signal is received by the third pixel unit 333 at the bottom of the third light guide channel. The first target fingerprint light signal, the second target fingerprint light signal, and the third target fingerprint light signal are used to detect fingerprint information.

In the embodiment of the present application, the first light-passing aperture 3211, the second light-passing aperture 3321, the third light-passing aperture 3222, and the fourth light-passing aperture 3223 can be located at any position under the microlens 310, aiming to Form any three light guide channels in different directions. In other words, the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333 corresponding to the microlens 310 can also be located at any position below the microlens 310, and are intended to receive three light guide channels passing through three different directions. Fingerprint light signals in different directions.

Optionally, by adjusting the relative positional relationship between the three pixel units and the microlens 310, and constructing a light guide channel between the pixel unit and the microlens 310 by opening small holes on the light blocking layer to pass through different directions Fingerprint light signals, so that the photosensitive areas in the three pixel units receive fingerprint light signals from different directions.

Optionally, it is also possible to adjust the area of the photosensitive regions in the three pixel units and/or the relative positional relationship of the photosensitive regions in the pixel units, so that the photosensitive regions in the three pixel units receive fingerprint light signals in different directions.

Through the solution of the embodiment of the present application, one microlens corresponds to three pixel units, and the three pixel units respectively receive fingerprint light signals in three directions condensed by the microlens and passed through the three light guide channels. The fingerprint light signal is received by the three pixel units respectively. Compared with the technical solution of one microlens corresponding to one pixel unit (such as the fingerprint identification device in Figure 2 and Figure 3), it can increase the amount of light entering the fingerprint identification device, reduce the exposure time, and increase the field of view of the fingerprint identification device . Moreover, in the embodiment of the present application, the angle of the fingerprint light signal received by the pixel unit (the angle between the fingerprint light signal and the direction perpendicular to the display screen) is determined by the relative positional relationship between the pixel unit and the microlens. The farther the center of the lens, the larger the angle of the fingerprint light signal received by the pixel unit. Therefore, by flexibly setting the position of the pixel unit, the pixel unit can receive fingerprint light signals at a large angle, which greatly improves the recognition problem of dry fingers, and can reduce the thickness of the optical path in the fingerprint recognition unit, thereby reducing the fingerprint recognition device Thickness, reduce process cost.

In addition, compared to the technical solution in which one microlens corresponds to four pixel units (for example, the fingerprint identification device in FIG. 4 and FIG. 5), in the embodiment of the present application, one microlens corresponds to three pixel units, so the unit pixel in the pixel array The increased area of the unit facilitates the layout and routing of the pixel units in the pixel array, and the number of pixel units in the pixel array is reduced, so the amount of data for fingerprint processing is reduced, and the processing speed of fingerprint recognition can be improved.

In summary, using the technical solutions of the embodiments of the present application can improve the identification problem of dry fingers, reduce the thickness of the fingerprint identification device, and reduce the process cost, while facilitating the circuit design of the pixel array and improving the processing speed of fingerprint identification.

Optionally, the target fingerprint light signals in the three directions received by the fingerprint recognition unit 301 are all light signals inclined with respect to the display screen, or one of the target fingerprint light signals in the three directions is perpendicular to the display screen. The oblique optical signal, and the other two target fingerprint optical signals are optical signals oblique to the display screen.

In other words, in the fingerprint identification device 301, the directions of the light guide channels in three different directions formed in at least two light-blocking layers are all inclined directions with respect to the display screen. Or, the direction of one light guide channel among the three light guide channels in different directions is a direction perpendicular to the display screen, and the direction of the other two light guide channels is a direction inclined with respect to the display screen.

Optionally, the angle of the target fingerprint light signal in the above three directions (the angle between the target fingerprint light signal and the direction perpendicular to the display screen) may be between 0° and 60°. In other words, the angle of the fingerprint light signal received by the microlens 310 may also be between 0° and 60°.

That is to say, the angle between the three light guide channels in different directions formed in at least two light-blocking layers and the direction perpendicular to the display screen can also be between 0° and 60°, or in other words, the angles formed in at least two light-blocking layers The angle between the three light guide channels in different directions and the display screen can be between 30° and 90°. If the display screen is arranged parallel to the plane where the above three pixel units are located, three of the at least two light blocking layers are formed. The angle between the light guide channels in different directions and the plane where the above three pixel units are located may be between 30° and 90°.

In some embodiments of the present application, the bottom light-blocking layer of the at least two light-blocking layers is provided with three light-passing holes corresponding to the three pixel units, respectively.

For example, as shown in Fig. 7, the fingerprint identification unit includes two light-blocking layers, the top light-blocking layer of the two-layer light-blocking layer is provided with a first light-passing hole 3211, and the bottom layer of the two-layer light-blocking layer blocks light A second light-passing hole 3221 corresponding to the first pixel unit 331 and a third light-passing hole 3222 corresponding to the second pixel unit 332 are provided on the layer.

Optionally, if the at least two light-blocking layers are more than two multi-layer light-blocking layers, the direction of the light guide channel in the multi-layer light-blocking layer may be the center of the uppermost light-passing hole in the light guide channel The direction of the connection with the center of the lowermost light-passing hole. Or the direction of the light guide channel is a direction close to the direction connecting the center, for example, the direction of the light guide channel is within ±5° of the direction connecting the center.

For example, in FIG. 7, the direction of the first light guide channel corresponding to the first pixel unit 331 is the connecting direction of the first light-passing hole 3211 and the second light-passing hole 3221 or a direction close to the connecting direction. , The direction of the second light guide channel corresponding to the second pixel unit 331 is the connecting direction of the first light-passing hole 3211 and the third light-passing hole 3222 or a direction close to the connecting direction, and the third pixel unit The direction of the third light guide channel corresponding to 333 is the connecting direction of the first light-passing hole 3211 and the fourth light-passing hole 3223 or a direction close to the connecting direction.

Optionally, the at least two light-blocking layers may also be three light-blocking layers. For example, another light-blocking layer is provided in the two light-blocking layers in the above-mentioned application embodiment, and the light-blocking layer is also provided The light passing holes corresponding to the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333 form three light guide channels corresponding to the three pixel units.

Optionally, if the at least two light-blocking layers are three and more than three light-blocking layers, the light-blocking layer between the bottom light-blocking layer and the top light-blocking layer is the middle light-blocking layer, and three light-guiding channels The connecting direction of the light-passing holes of the bottom light-blocking layer and the top light-shielding layer is the direction of the light guide channel, and the center of the light-passing holes in the middle light-shielding layer can be located at the connection line of the three light guide channels. on.

Optionally, the bottom light-blocking layer in the at least two light-blocking layers is a metal wiring layer on the surface of the three pixel units.

For example, the metal wiring layers of the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333 are arranged at the back focal plane position of the microlens 310, and the metal wiring layer is the bottom light-blocking layer of at least two light-blocking layers. , And above the photosensitive regions of the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333 are respectively formed a second light-passing hole 3221, a third light-passing hole 3222, and a fourth light-passing hole 3223.

In other words, the bottom light-shielding layer of at least two light-shielding layers is formed on the metal wiring layer of the fingerprint sensor chip, and a corresponding light-passing hole is formed above the photosensitive area of each pixel unit. In other words, the metal wiring layer of the fingerprint sensor chip can be reused for the optical path layer between the microlens and the pixel unit.

Optionally, the top light-blocking layer of the at least two light-blocking layers is provided with at least one light-passing hole corresponding to the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333. For example, the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333 may be provided with a light-passing hole in the top light blocking layer. For example, the first pixel unit 331 may also be provided in the top light blocking layer. , The second pixel unit 332 and the third pixel unit 333 are jointly provided with a light-passing hole, such as the above-mentioned first light-passing hole 3211, in other words, the first light guide channel and the second pixel unit corresponding to the first pixel unit 321 The second light guide channel corresponding to 322 and the third light guide channel corresponding to the third pixel unit 333 overlap the light passing holes in the top light blocking layer of the at least two light blocking layers.

Optionally, the apertures in the three light guide channels are sequentially reduced from top to bottom, for example, the second aperture 3221, the third aperture 3222, and the fourth aperture 3223. The apertures of are all smaller than the aperture of the first light-passing hole 3211.

In other words, the aperture of the light-passing hole in the upper light-shielding layer is set to be larger than the aperture of the light-passing hole in the lower light-shielding layer, thereby. It is possible to make at least two light blocking layers to guide more (a certain angle range) of light signals to the corresponding pixel units.

It should be understood that, in specific implementation, those skilled in the art can determine the direction of the light guide channel according to the requirements of the light path design, so as to determine the distribution of the light-passing holes in the at least two light blocking layers, and form a light guide channel that meets the requirements of the light path design. The target fingerprint light signal passing through a specific direction is received by the pixel unit.

In a specific implementation, the transmittance of each of the at least two light-shielding layers to light of a specific wavelength band (such as visible light or above 610nm) is less than a preset threshold (such as 20%) to avoid corresponding light by. The light-transmitting holes may be cylindrical through-holes, or through-holes of other shapes, such as polygonal through-holes. The aperture of the light-transmitting aperture may be greater than a predetermined value, for example, the aperture of the light-transmitting aperture is greater than 100 nm, so as to transmit the required light for imaging. The aperture of the light-passing hole should also be smaller than a predetermined value to ensure that the light-blocking layer can block unwanted light. For another example, the aperture of the light-passing hole may be smaller than the diameter of the microlens.

As an example, the light-transmitting small holes in the at least two light blocking layers may also include large-aperture openings that are equivalently synthesized by a plurality of small-aperture openings. For example, a plurality of small-aperture openings in the top light-blocking layer of the at least two light-blocking layers for transmitting light signals condensed by the same microlens can be combined into one large-aperture opening.

Optionally, each of the at least two light-blocking layers may be a metal layer, and correspondingly, the light-passing holes provided in the light-blocking layer may be through holes formed in the metal layer. The light-blocking layer in the at least two light-blocking layers may also be a black polymer light-absorbing material. For example, for an optical signal greater than a predetermined angle, the at least two light-blocking layers have a visible light waveband transmittance of less than 2%.

It should be understood that the parameter settings of the light-passing holes in the light-blocking layer should be as far as possible to maximize the transmission of the light signal required for imaging to the pixel unit, and the unneeded light is blocked as much as possible. For example, the parameters of the light-passing hole can be set to maximize the transmission of the optical signal obliquely incident at a specific angle (for example, 35 degrees) to the corresponding pixel unit, and to maximize the blocking of other optical signals.

In some embodiments of the present application, the aforementioned fingerprint identification unit 301 may further include a transparent medium layer.

Wherein, the lens medium layer is used to connect the aforementioned micro lens 310, at least two light blocking layers, and three pixel units (a first pixel unit 331, a second pixel unit 332, and a third pixel unit 333).

For example, the transparent medium layer can transmit optical signals in the target wavelength band (that is, optical signals in the wavelength band required for fingerprint detection). For example, the transparent dielectric layer can be oxide or nitride. Optionally, the transparent medium layer may include multiple layers to implement functions such as protection, transition, and buffering respectively. For example, a transition layer can be provided between the inorganic layer and the organic layer to achieve a tight connection; a protective layer can be provided on the easily oxidized layer to achieve protection.

In some embodiments of the present application, the aforementioned fingerprint identification unit 301 may further include an optical filter layer.

Wherein, the optical filter layer is arranged in the optical path between the microlens 310 and the plane where the three pixel units are located or above the microlens 310, and the optical filter layer is used to filter non-target optical signals in the wavelength band so as to pass through The optical signal of the target band.

For example, the transmittance of the optical filter layer to light in the target wavelength band may be greater than or equal to a preset threshold, and the cut-off rate of light in the non-target wavelength range may be greater than or equal to the preset threshold. For example, the preset threshold may be 80%. Optionally, the optical filter layer may be an independently formed optical filter layer. For example, the optical filter layer may be an optical filter layer formed by using blue crystal or blue glass as a carrier. Optionally, the optical filter layer may be a coating formed on the surface of any layer in the optical path between the microlens 310 and the plane where the three pixel units are located. For example, a coating film may be formed on the surface of the pixel unit, the surface of any one of the transparent medium layers, or the surface of the microlens to form an optical filter layer.

Optionally, when at least two light blocking layers are located above the pixel unit instead of the surface of the pixel unit, the optical filter layer is disposed between the bottom light blocking layer of the at least two light blocking layers and the plane where the three pixel units are located.

Optionally, when the bottom light blocking layer of the at least two light blocking layers is a metal wiring layer on the surface of the pixel unit, the optical filter layer is arranged between the bottom light blocking layer and the light blocking layer above it.

Optionally, the optical filter layer is grown on the surface of the sensor chip where the pixel unit is located and integrated in the sensor chip.

Optionally, a physical vapor deposition (Physical Vapor Deposition, PVD) process can be used to coat the pixel unit to form an optical filter layer, for example, through atomic layer deposition, sputtering coating, electron beam evaporation coating, ion beam coating, etc. A multilayer filter material film is prepared above the pixel unit.

Optionally, in the embodiment of the present application, the optical filter layer includes a multilayer oxide film, wherein the multilayer oxide film includes a silicon oxide film and a titanium oxide film, and the silicon oxide film and the titanium oxide film The optical filter layer is alternately grown in sequence; or the multilayer oxide film includes a silicon oxide film and a niobium oxide film, and the silicon oxide film and the niobium oxide film are alternately grown in sequence to form the optical filter layer.

Optionally, in the embodiment of the present application, the thickness of the optical filter layer is between 1 μm and 10 μm.

Optionally, the optical filter layer is used to pass optical signals in the wavelength range of 400 nm to 650 nm. In other words, the wavelength range of the above-mentioned target wavelength range includes 400 nm to 650 nm.

8 and 10 show two schematic top views of the fingerprint identification unit 301 in FIG. 7.

As shown in FIGS. 8 and 10, the area where the first pixel unit 331, the second pixel unit 332 and the third pixel unit 333 are located (for ease of description, the area where the three pixel units are located is referred to as the pixel area 330 for short) may be located Right below the microlens 310, the center of the pixel area 330 and the center of the microlens 310 coincide in the vertical direction. Among them, the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333 all receive the target fingerprint light signal in the oblique direction, that is, the first light guide channel corresponding to the first pixel unit 331 and the second pixel unit 332 corresponding The directions of the second light guide channel and the third light guide channel corresponding to the third pixel unit 333 are both inclined with respect to the display screen.

Wherein, the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333 all include a photosensitive area (Active Area, AA) for receiving the first target fingerprint light signal and the first target fingerprint light signal passing through the three light guide channels, respectively. The second target fingerprint optical signal and the third target fingerprint optical signal are converted into corresponding electrical signals. The photosensitive area can be the area where the photodiode in the pixel unit is located, that is, the area in the pixel unit that receives the light signal, and other areas in the pixel unit can be used to set other circuits in the pixel unit and for the wiring arrangement between pixels . Optionally, the light sensitivity of the photosensitive region to blue light, green light, red light or infrared light is greater than a first predetermined threshold, and the quantum efficiency is greater than a second predetermined threshold. For example, the first predetermined threshold may be 0.5v/lux-sec, and the second predetermined threshold may be 40%. In other words, the photosensitive area has high light sensitivity and high quantum efficiency for blue light (wavelength of 460±30nm), green light (wavelength of 540±30nm), red light or infrared light (wavelength ≥610nm), In order to detect the corresponding light.

The first photosensitive area 3311 of the first pixel unit 331 is located below the second light-passing hole 3221, that is, at the bottom of the first light guide channel, and is used to receive the first target fingerprint light signal; the second pixel unit 332 The photosensitive area 3321 is located below the third light-passing hole 3222, that is, at the bottom of the second light guide channel, for receiving the second target fingerprint light signal; the third photosensitive area 3331 of the third pixel unit 333 is located at the fourth light-passing Below the small hole 3223, that is, at the bottom of the third light guide channel, is used to receive the optical signal of the third target fingerprint.

Fig. 9 shows a schematic cross-sectional view of the fingerprint identification unit 301 in Fig. 8 along the A-A' direction.

As shown in FIG. 9, the second target fingerprint light signal 312 is received by the first light-sensitive area 3321 in the second pixel unit through the second light guide channel formed by the first light-passing hole 3211 and the third light-passing hole 3222. The third target fingerprint light signal 313 is received by the third photosensitive area 3331 in the third pixel unit through the third light guide channel formed by the first light-passing hole 3211 and the fourth light-passing hole 3223.

Optionally, in the embodiment of the present application, the distance from the center of the second photosensitive area 3321 to the center of the microlens 310 and the distance from the center of the third photosensitive area 3331 to the center of the microlens 310 are equal. Optionally, the distance from the center of the first photosensitive area 3311 to the center of the microlens 310 may be equal to or not the same as the distance from the center of the third photosensitive area 3331 to the center of the microlens 310.

Optionally, in this case, the second target fingerprint optical signal 312 received by the second photosensitive area 3321 and the third target fingerprint optical signal 313 received by the third photosensitive area 3331 have the same angle with the display screen, or in other words, the first The angle between the second light guide channel corresponding to the two photosensitive areas 3321 and the display screen is equal to the angle between the third light guide channel corresponding to the third photosensitive area 3331 and the display screen.

Fig. 11 shows a schematic cross-sectional view of the fingerprint recognition unit 301 in Fig. 10 along the A-A' direction.

As shown in FIG. 11, the distance from the center of the second photosensitive area 3321 to the center of the microlens 310 and the distance from the center of the third photosensitive area 3331 to the center of the microlens 310 are not equal. At this time, the second photosensitive area 3321 receives the first The angle between the second target fingerprint light signal 312 and the third target fingerprint light signal 313 received by the third photosensitive area 3331 and the display screen is different, or in other words, the second light guide channel corresponding to the second photosensitive area 3321 is sandwiched between the display screen The angle and the included angle between the third light guide channel corresponding to the third photosensitive area 3331 and the display screen are not equal.

8 to 11 above show the case where the fingerprint identification unit 301 includes two light blocking layers. Optionally, the fingerprint identification unit 301 may also include three light blocking layers.

FIG. 12 shows a schematic top view of a fingerprint identification unit 301, and FIG. 13 shows a schematic cross-sectional view of the fingerprint identification unit 301 in FIG. 12 along the direction A-A'.

As shown in FIGS. 12 and 13, the fingerprint identification unit 301 includes three light-blocking layers. Wherein, the top light blocking layer is provided with the first light passing hole 3211, and the bottom light blocking layer is provided with the second light passing hole 3221, the third light passing hole 3222, and the fourth light passing hole 3223. In addition, a fifth light-passing hole 3231, a sixth light-passing hole 3232, and a seventh light-passing hole 3233 are provided in the newly added light blocking layer of the intermediate layer. Among them, the first light-passing hole 3221, the fifth light-passing hole 3231, and the second light-passing hole 3221 form the first light guide channel corresponding to the first photosensitive area 3311 unit, and the centers of the three light-passing holes can be Located on the same line. In addition, the first light-passing aperture 3221, the sixth light-passing aperture 3232, and the third light-passing aperture 3222 form a second light guide channel corresponding to the second photosensitive area 3321, and the center of the three light-passing apertures can also be Are located on the same straight line, and the first light-passing hole 3221, the seventh light-passing hole 3233, and the fourth light-passing hole 3223 form a third light guide channel corresponding to the third photosensitive area 3331. The centers of the holes can also be on the same straight line.

Optionally, in the embodiment of the present application, the aperture of the first light-passing aperture 3221 is larger than the apertures of the fifth light-passing aperture 3231, the sixth light-passing aperture 3232, and the seventh light-passing aperture 3233, and The apertures of the light passing holes 3231, the sixth light passing holes 3232, and the seventh light passing holes 3233 are larger than the apertures of the second light passing holes 3221, the third light passing holes 3222, and the fourth light passing holes 3223.

It should be understood that in the present application, the fingerprint identification unit 301 may also include more light-blocking layers. In the following, two light-blocking layers are used as a schematic illustration. For the case of multiple light-blocking layers with more than two layers, please refer to Relevant instructions will not be repeated here.

Referring to FIG. 8, FIG. 10, and FIG. 12, in a possible implementation manner, the photosensitive area in the three pixel units only occupies a small part of the area in the pixel unit, so as to meet the requirements of receiving light signals.

In the embodiment of this application, the center of the first photosensitive area 3311 may be located at the bottom of the first light guide channel, the center of the second photosensitive area 3321 may be located at the bottom of the second light guide channel, and the center of the third photosensitive area 3331 It can be located at the bottom of the third light guide channel. In other words, the center of the first photosensitive area 3311 may be located on the line connecting the first light-passing hole 3211 and the second light-passing hole 3221, and the center of the second photosensitive area 3321 may be located between the first light-passing hole 3211 and the third light-passing hole 3211. On the line connecting the light-passing aperture 3222, the center of the third photosensitive area 3331 may be located on the line connecting the first light-passing aperture 3211 and the fourth light-passing aperture 3223.

Through the above arrangement, the first target fingerprint light signal forms a first light spot 3301 on the first pixel unit 331 through the first light guide channel, and the second target fingerprint light signal forms a first light spot 3301 on the second pixel unit 332 through the second light guide channel. With two light spots 3302, the third target fingerprint light signal forms a third light spot 3303 on the third pixel unit 333 through the third light guide channel.

In order to maximize the reception of the first target fingerprint optical signal, the second target fingerprint optical signal, and the third target fingerprint optical signal, optionally, the first photosensitive area 3311 on the first pixel unit 331 may completely cover the first light spot 3301. The second photosensitive area 3321 on the second pixel unit 332 can completely cover the second light spot 3302, and the third photosensitive area 3331 on the third pixel unit 333 can completely cover the third light spot 3303.

Optionally, among the three pixel units, the first pixel unit 331 is a quadrilateral area, and its length and width are respectively L and W, where W≤L, W and L are both positive numbers, and the first pixel unit 331 The length and width of the first photosensitive region 3311 are both greater than or equal to 0.1×W. Of course, the sizes of the other three pixel units and the photosensitive area in the three pixel units can also correspondingly satisfy the above conditions.

In a possible implementation, as shown in FIGS. 8, 10, and 12, the first photosensitive area 3311 is a quadrangular area and circumscribes the first spot 3301. Similarly, the second photosensitive area 3321 is The quadrilateral area is circumscribed to the second light spot 3302, and the third photosensitive area 3331 is a quadrilateral area and circumscribes the third light spot 3303.

In this case, the photosensitive area in the pixel unit is small, but the fingerprint light signal after passing through the light guide channel is fully received, which meets the fingerprint imaging requirements. At the same time, the area of other areas in the pixel unit is larger, which gives the pixel The wiring of the unit provides sufficient space, reduces the process requirements, and improves the efficiency of the process manufacturing, and other areas can be used to set other circuit structures, which can improve the signal processing capability of the pixel unit.

It should be understood that when the photosensitive area in the three pixel units only occupies a small part of the area in the pixel unit, the center of the photosensitive area may not be located at the bottom of the light guide channel, but a certain offset occurs. At this time, the photosensitive area can be enlarged. The area of the area is such that the photosensitive area can cover the entire area of the light spot of the fingerprint light signal on the pixel unit.

Optionally, in FIG. 8, FIG. 10, and FIG. 12, the first pixel unit 331 and the second pixel unit 332 are square pixels, the side length of the square pixel is a, a is a positive number, and the third pixel unit 333 is The rectangular pixel has a length of 2a and a width of a.

It should be understood that in this embodiment of the application, in addition to the pixel distribution shown in the above figure, the shape, size and relative position of the three pixel units can be set arbitrarily, and the shape and size of the three pixels can be the same or different. The embodiment does not make any limitation on this. For example, the first pixel unit and the third pixel unit of the three pixel units are square pixels, and the second pixel unit is rectangular pixels, or the three pixel units are all square pixels, and so on.

In FIGS. 8, 10 and 12, the first photosensitive area 3311, the second photosensitive area 3321 and the third photosensitive area 3331 are offset from the center of the three pixel units. Since the first pixel unit 331, the second pixel unit 332, and the second pixel unit 333 all receive light signals in an oblique direction, and the greater the tilt angle, the farther the photosensitive area in the pixel unit is from the center of the microlens. Therefore, the first photosensitive area 3311, the second photosensitive area 3321, and the third photosensitive area 3331 are not only offset from the center of the pixel unit, but also shifted away from the center of the microlens, which can increase the reception of the three photosensitive areas. The target fingerprint light signal angle, thereby reducing the thickness of the fingerprint identification unit.

It should be understood that in the embodiment of the present application, the three photosensitive areas may also be located at the center of the three pixel units respectively. In order to meet the angular requirement of the photosensitive area to receive light signals, the three pixel units may be directed away from the center of the microlens. Offset, increase the angle of the target fingerprint light signal received by the three photosensitive areas, and reduce the thickness of the fingerprint identification unit.

In the embodiment of the present application, the three pixel units can also be arranged at any position under the microlens, and the three photosensitive areas can be arranged at any position in the three pixel units, in order to receive target fingerprints passing through the three channels For optical signals, the embodiments of the present application do not make any restrictions on the positions of the three pixel units and the specific positions of the three photosensitive areas in the pixel units.

As shown in FIGS. 8, 10, and 12, the pixel area 330 composed of the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333 is a quadrangular pixel area. The first photosensitive area 3311 and the second photosensitive area 3311 The area 3321 may be located on the same side of the pixel area 330. In this case, the projection of the first target fingerprint light signal received by the first photosensitive area 3311 and the second target fingerprint light signal received by the second photosensitive area 3321 on the plane where the pixel area 330 is located is an included angle of 90°, or In other words, the projection of the first light guide channel on the plane of the pixel area 330 and the projection of the second light guide channel on the plane of the pixel area 330 form an angle of 90°.

Further, the third photosensitive area 3331 may be located on the same side of the pixel area 330 as the first photosensitive area 3311 and the second photosensitive area 3321 described above, or may be located on other sides of the pixel area 330, for example, as shown in FIG. 8, FIG. 10 and FIG. As shown in 12, the first photosensitive area 3311 and the second photosensitive area 3321 are located on the upper side of the pixel area 330, and the third photosensitive area 331 is located on the lower side of the pixel area 330. Optionally, the projection of the third target fingerprint light signal received by the third photosensitive area 3331 and the first target fingerprint light signal received by the first photosensitive area 3311 on the plane where the pixel area 330 is located is a first included angle. The projection of the third target fingerprint optical signal received by the third photosensitive area 3331 and the second target fingerprint optical signal received by the second photosensitive area 3311 on the plane where the pixel area 330 is located is a second included angle, and the first included angle and The second included angle may be equal. In other words, the first photosensitive area 3311 and the second photosensitive area 3321 are symmetrically distributed with respect to the third photosensitive area 3331.

FIG. 14 shows a schematic top view of another fingerprint identification unit 301. As shown in FIG. 14, the first photosensitive area 3311 and the second photosensitive area 3321 are located on the upper side of the pixel area 330 at the same time. The third photosensitive area 3321 and the second photosensitive area 3321 are located on the left side of the pixel area 330 at the same time. At this time, the first target fingerprint light signal received by the first photosensitive area 3311 and the third target fingerprint light signal received by the third photosensitive area 3331 form an angle of 180° on the plane where the pixel area 330 is located, and the second photosensitive area 3321 receives The angle between the first target fingerprint optical signal and the third target fingerprint optical signal received by the third photosensitive area 3331 is 90° on the plane where the pixel area 330 is located, or in other words, the projection of the first light guide channel on the plane where the pixel area 330 is located It forms an angle of 180° with the projection of the third light guide channel on the plane of the pixel area 330, and the projection of the second light guide channel on the plane of the pixel area 330 and the projection of the third light guide channel on the plane of the pixel area 330 are 90 degrees. °Included angle.

With the solution of the embodiment of the present application, the fingerprint light signals received by two pixel units in the three pixel units are perpendicular to each other, which facilitates the collection of fingerprint light signals perpendicular to the ridges and valleys of the fingerprint, and can improve the fingerprint recognition unit received The quality of the fingerprint light signal, thereby improving the quality of the fingerprint image, and improving the fingerprint recognition performance of the fingerprint recognition device.

The above-mentioned Figures 8, 10, 12 and 14 only illustrate the top view schematic diagrams of several fingerprint identification units 301. It should be understood that the projection of any two light guide channels in the plane where the pixel area 330 is located among the three light guide channels can be It is any angle between 0° and 180°, and the angle between the three light guide channels and the plane where the pixel area 330 is located can also be any angle between 0° and 90°, which is not limited in the embodiment of the present application. .

It should also be understood that, in the embodiment of the present application, the pixel unit and the photosensitive area in the pixel unit can be set to adjust the direction of the corresponding light guide channel to meet the light path requirement of the design.

In the above application embodiment, the photosensitive area in the three pixel units only occupies a small part of the area in the pixel unit. In another possible implementation manner, the photosensitive area in the three pixel units occupies most of the pixel unit. Area to improve the dynamic range of the pixel unit.

Optionally, FIG. 15 shows another schematic top view of the fingerprint identification unit 301.

As shown in FIG. 15, the photosensitive area of the three pixel units is relatively large, and in addition to covering the light spot on the pixel unit, it also covers other areas. In FIG. 15, the photosensitive area in the three pixel units occupies most of the area of the pixel unit. For example, the first photosensitive area 3311 in the first pixel unit 331 occupies more than 95% of the area of the first pixel unit 331, and/or the second photosensitive area 3321 in the second pixel unit 332 occupies the second pixel unit More than 95% of the area in 332, and/or the third photosensitive region 3331 in the third pixel unit 333 occupies more than 95% of the area in the third pixel unit 333.

In this embodiment, the photosensitive area of the pixel unit is increased, which can increase the full well capacity of the pixel unit and the dynamic range of the pixel unit (Dynamic Range), thereby improving the overall performance of the pixel unit and realizing high dynamic range imaging of the fingerprint recognition device (High Dynamic Range Imaging, HDR).

It should be understood that the above embodiments in FIGS. 8 to 15 only show a top view of part of the fingerprint recognition unit 301 when the center of the pixel area 330 and the center of the microlens overlap in the vertical direction, and the third pixel unit The middle photosensitive area can be respectively arranged in any area of the pixel unit, so as to realize the receiving of target fingerprint light signals from different angles.

FIG. 16 is a schematic top view of another fingerprint identification device 300 provided by an embodiment of the present application. The fingerprint identification device 300 is also composed of a plurality of fingerprint identification units 301. As shown in FIG. 16, the plurality of fingerprint identification units 301 are arranged in an array. Wherein, the pixel unit in each fingerprint recognition unit 301 only receives the fingerprint light signal condensed by the micro lens in the fingerprint recognition unit 301, and does not receive the fingerprint light signal condensed by the micro lens in the other fingerprint recognition unit 301.

In the fingerprint identification unit 301 of the embodiment of the present application, the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333 corresponding to the microlens 310 are spatially located obliquely below the microlens 310, and the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333 are located diagonally below the microlens 310. The center of the pixel area 330 where the one pixel unit 331, the second pixel unit 332, and the third pixel unit 333 are located does not coincide with the center of the microlens 310 in the vertical direction.

Specifically, in the embodiment of the present application, the three photosensitive areas in the three pixel units are all located obliquely below their corresponding light guide channels, so that the three photosensitive areas only receive light passing through their corresponding light guide channels. Signal, and will not receive light signals in other directions converged by other microlenses, causing interference with fingerprint recognition.

FIG. 17 shows a top view of a fingerprint identification unit 301 of the fingerprint identification device 300.

As shown in FIG. 17, the centers of the three photosensitive regions may be located at the bottom of the corresponding light guide channel respectively. The three photosensitive areas are quadrilateral areas and are circumscribed to the light spots formed by the target fingerprint light signal in the pixel unit.

Optionally, the centers of the three photosensitive areas may also be offset from the bottom of their corresponding light guide channels, but the three photosensitive areas also include the aforementioned light spots. For example, the photosensitive area in the three pixel units occupies more than 95% of the area of the pixel unit in which it is located.

As shown in FIG. 17, the pixel area 330 composed of the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333 is a quadrangular pixel area. The second photosensitive area 3321 and the third photosensitive area 3331 may be located in the pixel area. On the same side of 330, the projection of the second target fingerprint optical signal received by the second photosensitive area 3321 and the third target fingerprint optical signal received by the third photosensitive area 3331 on the plane where the pixel area 330 is located is an included angle of 180°, or In other words, the projection of the second light guide channel on the plane of the pixel area 330 and the projection of the third light guide channel on the plane of the pixel area 330 form an angle of 180°.

Further, the projection of the first light guide channel on the plane where the pixel area 330 is located and the projection of the third light guide channel on the plane where the pixel area 330 is located form an angle of 90°, and the projection of the first light guide channel on the plane where the pixel area 330 is located It also forms an angle of 90° with the projection of the second light guide channel on the plane where the pixel area 330 is located. At this time, the second light guide channel and the third light guide channel are symmetrically distributed relative to the first light guide channel, and the second photosensitive area and the third photosensitive area are symmetrically distributed relative to the first photosensitive area.

FIG. 18 shows a schematic top view of another fingerprint identification unit 301. As shown in FIG. 18, the first photosensitive area 3311 and the second photosensitive area 3321 are located on the upper side of the pixel area 330 at the same time. At this time, the angle between the first target fingerprint light signal received by the first photosensitive area 3311 and the second target fingerprint light signal received by the second photosensitive area 3321 may be an acute angle less than 90° on the plane where the pixel area 330 is located, or in other words, The projection of the first light guide channel on the plane where the pixel area 330 is located and the projection of the second light guide channel on the plane where the pixel area 330 is located have an acute angle less than 90°.

Further, the angle between the first target fingerprint light signal received by the first photosensitive area 3311 and the second target fingerprint light signal received by the third photosensitive area 3321 may be an obtuse angle greater than 90° on the plane where the pixel area 330 is located, or in other words, The projection of the first light guide channel on the plane where the pixel area 330 is located and the projection of the third light guide channel on the plane where the pixel area 330 is located have an obtuse angle greater than 90°.

It should be understood that the projections of any two of the three light guide channels on the plane where the pixel area 330 is located can present any included angle between 0° and 180°, and the three light guide channels and the plane where the pixel area 330 is located The included angle can also be any angle, which is not limited in the embodiment of the present application.

Optionally, based on the foregoing application embodiment, in a possible implementation manner, the distance from the center of the first photosensitive area 3311 in the first pixel unit 331 to the center of the microlens 310, and the second pixel unit 332 The distance from the center of the photosensitive region 3321 to the center of the microlens 310 and the distance from the center of the second photosensitive region 3331 in the third pixel unit 332 to the center of the microlens 310 are equal.

Optionally, in this case, the first target fingerprint optical signal received by the first photosensitive area 3311, the second target fingerprint optical signal received by the second photosensitive area 3321, and the third target fingerprint optical signal received by the third photosensitive area 3331 , The angle between the three target fingerprint light signals and the display screen is the same, in other words, the angle between the first light guide channel corresponding to the first photosensitive area 3311 and the display screen, and the second light guide channel corresponding to the second photosensitive area 3321 The included angle with the display screen and the included angle between the third light guide channel corresponding to the third photosensitive area 3331 and the display screen are equal.

Of course, the distance from the center of the first photosensitive area 3311 to the center of the microlens 310, the distance from the center of the second photosensitive area 3321 to the center of the microlens 310, and the distance from the center of the third photosensitive area 3331 to the center of the microlens 310 are any The two distances may not be equal, or the three distances are not equal. At this time, any two of the three angles between the first target fingerprint optical signal, the second target fingerprint optical signal, and the third target fingerprint optical signal and the display screen The included angles are not equal, or the three included angles are not equal, or in other words, any two of the three included angles between the first light guide channel, the second light guide channel, and the third light guide channel and the display screen are not the same. Equal, or none of the three included angles are equal.

The above FIGS. 17 and 18 only illustrate two cases where the pixel area 330 where the three pixel units in the fingerprint identification unit 301 are located is diagonally below the microlens 310. It should be understood that the pixel region 300 may also be located diagonally below the microlens 310 The embodiment of the present application does not make any limitation on any area of, and the photosensitive area of the three pixel units can be located in any area of the pixel unit where it is located, and the embodiment of the present application does not make any limitation on this.

It should be understood that whether the pixel area 330 where the three pixel units are located is obliquely below the microlens 310 or directly below the microlens 310, as the pixel unit and the photosensitive area move, the target fingerprint light signal received by the photosensitive area The direction and the direction of the light guide channel corresponding to the photosensitive area also change accordingly. In other words, the position of the pixel unit and the photosensitive area relative to the microlens can also be designed according to the direction required by the target fingerprint light signal in the optical path design.

Specifically, in a possible optical path design, the angle of the first target fingerprint optical signal is greater than the angle of the second target fingerprint optical signal and the third target fingerprint optical signal, where the angle of the optical signal refers to the angle between the optical signal and the vertical The angle between the direction of the display screen.

The height h of the optical path between the microlens 310 and the plane where the three pixel units are located is calculated according to the following formula:

h=x×cotθ;

Where x is the distance between the center of the first photosensitive area 3311 receiving the optical signal of the first target fingerprint and the projection point of the center of the microlens 310 on the plane where the three pixel units are located, and θ is the distance of the optical signal of the first target fingerprint angle.

The above application embodiment shows a situation where all three pixel units in the fingerprint identification unit 301 receive the oblique light signal. Optionally, one of the three pixel units can receive the target fingerprint light signal in the vertical direction, and the other two The pixel unit receives the target fingerprint light signal in the oblique direction. In other words, the direction of the light guide channel corresponding to one of the three pixel units is perpendicular to the display screen, and the direction of the light guide channel corresponding to the other two pixel units is relative to the direction of the light guide channel. The display is tilted.

Hereinafter, the first pixel unit 331 and the third pixel unit 333 receive the target fingerprint light signal in the oblique direction, and the second pixel unit 332 receives the target fingerprint light signal in the vertical direction for example.

FIG. 19 shows a top view of a fingerprint identification unit 301 of the fingerprint identification device 300.

As shown in FIG. 19, the second photosensitive area 3321 in the second pixel unit 332 is located directly below the center of the microlens 310, or in other words, the center of the second photosensitive area 3321 and the center of the microlens 310 overlap in the vertical direction. At this time, the second light guide channel corresponding to the second photosensitive area 3321 is also correspondingly perpendicular to the microlens 310 or perpendicular to the display screen. At this time, the center of the first light-passing hole 3211, the center of the third light-passing hole 3222, the center of the microlens 310, and the center of the second photosensitive area 3321 in the second light guide channel are all located at the same vertical to the display screen. On the straight line.

The first photosensitive area 3311 in the first pixel unit 331 and the third photosensitive area 3331 in the third pixel unit 333 are located obliquely below the center of the microlens 310, and receive light signals inclined to the display screen. The directions of the light channel and the third light guide channel are arranged obliquely to the display screen. Specifically, the first pixel unit 331, the third pixel unit 333 and the related technical features can refer to the technical features in the technical solution for receiving the oblique light signal by the three pixel units, which will not be repeated here.

The above FIG. 19 only exemplifies a situation where the first pixel unit 331 and the third pixel unit 333 in the fingerprint identification unit 301 are located diagonally below the microlens 310. It should be understood that the first pixel unit 331 and the third pixel unit 333 are also It can be located in any area obliquely below the microlens 310, which is not limited in the embodiment of the present application, and the photosensitive area in the three pixel units can be located in any area in the pixel unit where it is located. This is also the case in the embodiment of the present application. Do not make any restrictions.

In the embodiment of this application, the fingerprint light signal in the vertical direction and the fingerprint light signal in the oblique direction are respectively received through three pixel units. When the finger is in good contact with the display screen, the fingerprint light signal in the vertical direction is strong, and the corresponding fingerprint The image signal quality is good, and fingerprint recognition can be performed quickly. At the same time, when the dry finger is in poor contact with the display screen, the fingerprint light signal in the oblique direction can improve the fingerprint recognition problem of the dry finger and reduce the thickness of the fingerprint recognition device.

The fingerprint identification unit 301 in this application is described in detail above with reference to FIGS. 6-19.

Specifically, the fingerprint identification device 300 includes a plurality of fingerprint identification units 301, wherein each fingerprint identification unit of the plurality of fingerprint identification units 301 includes the above three pixel units. Therefore, the fingerprint identification device 300 includes a plurality of groups The above-mentioned three pixel units, and the multiple groups of the above-mentioned three pixel units form the pixel array 302 of the fingerprint identification device 300.

Optionally, as shown in FIG. 20, in a possible implementation manner, three pixel units in a fingerprint recognition unit 301 are quadrilateral pixel units and form a quadrilateral area, and the pixel array 302 of the fingerprint recognition device 300 appears as A pixel matrix in which a plurality of quadrilateral pixel unit arrays are arranged.

Optionally, a plurality of target pixel units 3021 are provided in the pixel array 302, and a color filter layer is provided in the light guide channel corresponding to the plurality of target pixel units 3021, and the color filter layer is used to pass color light of a specific wavelength. , Received by multiple target pixel units.

Optionally, the multiple target pixel units 3021 may all be the above-mentioned first pixel unit 331, or the above-mentioned second pixel unit 332, or the above-mentioned third pixel unit 333, and may also include the above-mentioned first pixel unit 331 and the above-mentioned second pixel unit 331. The pixel unit 332 and the third pixel unit are not limited in the embodiment of the present application.

Optionally, the color filter layer may be arranged at any light path position in the light guide channel corresponding to the target pixel unit, for example, arranged in the light-passing holes of at least two light-blocking layers, or may also be arranged at two-layer blocking layers. Between the optical layers, or can also be arranged on the surface of the target pixel unit.

In a possible implementation, if the target pixel unit corresponds to three light-blocking layers or more than three light-blocking layers, the color filter layer may be disposed in the middle light-blocking layer of the light guide channel.

Optionally, in the embodiment of the present application, multiple target pixel units 3021 in the pixel array 302 are used to sense one of a red light signal, a blue light signal, or a green light signal. For example, the multiple target pixel units 3021 only The red light signal is sensed and a corresponding electrical signal is formed, and light signals other than the red light signal are not sensed.

When the finger is pressed, the multiple target pixel units 3021 sense the red light signal, some of the multiple target pixel units can receive the red light signal passing through the finger, and the other part of the target pixel units cannot receive the red light signal passing through the finger.

Based on the difference of the red light signals sensed by the multiple target pixel units 3021, the fingerprint area 303 of the finger is determined.

In the embodiment of the present application, the red light signals sensed by the multiple target pixel units 3021 may be complete red light signals, for example, light signals with a wavelength between 590 nm and 750 nm, or may also be part of the red light signal. The optical signal in the wavelength band, for example, the red optical signal is a red optical signal in any wavelength range or wavelength between 590 nm and 750 nm.

Optionally, the green light signal and the blue light signal sensed by the multiple target pixel units 3021 may be a complete green waveband light signal or a blue waveband light signal, for example, a green light signal with a wavelength between 490nm and 570nm or a wavelength between 450nm and 570nm. The blue light signal between 475nm, or the light signal of the green waveband or part of the blue waveband, for example, the green light signal is the green light signal of any waveband range or any wavelength between 490nm～570nm, the blue light signal It is a green light signal of any wavelength range or any wavelength between 450nm～475nm.

Therefore, in the technical solution of the embodiment of the present application, a plurality of target pixel units 3021 can be provided to sense the color light signal, and the fingerprint pressed by the finger on the display screen can be determined according to the difference of the color light signal received by different target pixel units. Areas and non-finger-pressed areas, in the process of fingerprint recognition, the light signals sensed by the pixels corresponding to the fingerprint area pressed by the finger are directly subjected to fingerprint recognition processing, thereby avoiding the fingerprint recognition caused by the pixels corresponding to the non-finger pressing area Interference, thereby increasing the success rate of fingerprint recognition. In addition, since the absorption and reflection performance of the color light signal of the finger is different from the absorption and reflection performance of the color light signal of other materials, according to the intensity of the received color light signal, the anti-counterfeiting function of fingerprint recognition can be enhanced, or it can be judged. Real finger pressing or fake finger pressing.

The fingerprint identification device 300 includes multiple sets of the above three pixel units, and the multiple sets of the above three pixel units form the pixel array 302 of the fingerprint identification device 300.

Optionally, the multiple target pixel units 3021 are uniformly or non-uniformly distributed in the pixel array 302.

Optionally, the pixel array 302 is composed of a plurality of unit pixel regions 3023, and each unit pixel region 3023 of the plurality of unit pixel regions 3023 is provided with one target pixel unit 3021.

For example, as shown in FIG. 20, the unit pixel area 3023 may be a pixel area of 4 fingerprint identification units, that is, a pixel area of 12 pixel units. It should be understood that the unit pixel area may also be a pixel unit area of any size, which is not limited in the embodiment of the present application.

Optionally, in each unit pixel area, the relative positional relationship of the target pixel unit in the unit pixel area is the same. For example, as shown in FIG. 20, in each unit pixel area, the target pixel unit is located at the lower right corner of the unit pixel area. It should be understood that, in each unit pixel area, the relative positional relationship of the target pixel unit in the unit pixel area may also be different, and the target pixel unit is arbitrarily set in the unit pixel area, which is not limited in the embodiment of the present application.

21a to 21d show schematic diagrams of the pixel array 302 in four types of fingerprint identification devices 300. As shown in FIGS. 21a to 21d, the number "1" represents the aforementioned first pixel unit 331, the number "2" represents the aforementioned second pixel unit 332, and the number "3" represents the aforementioned third pixel unit 333.

As shown in FIG. 21a, the multiple first pixel units 331 are arranged in multiple columns in the pixel array 302, the multiple second pixel units 332 and the multiple third pixel units 333 are alternately arranged in one column, and the two columns of the first pixel units 331 In between is an alternating column of second pixel units 332 and third pixel units 333.

As shown in FIG. 21b, the multiple first pixel units 331 are arranged in multiple rows in the pixel array 302, the multiple second pixel units 332 and the multiple third pixel units 333 are alternately arranged in one row, and the two rows of first pixel units 331 In between is a column of alternating rows of the second pixel unit 332 and the third pixel unit 333.

As shown in FIGS. 21c and 21d, the plurality of first pixel units 331 are not adjacent to each other, the plurality of second pixel units 332 are not adjacent to each other, and the plurality of third pixel units 333 are not adjacent to each other. Next, the top, bottom, left, and right of a first pixel unit 331 are the second pixel unit 332 or the third pixel unit 333. Similarly, the top, bottom, left, and right of a second pixel unit 332 are the first pixel unit 331 or the third pixel unit 333. The top, bottom, left, and right sides of a third pixel unit 333 are the first pixel unit 331 or the second pixel unit 332.

It should be understood that the foregoing FIGS. 21a to 21d are only schematic diagrams of four pixel arrays 302, in which the relative positional relationship of the first pixel unit 331, the second pixel unit 332, and the third pixel unit 333 can be set arbitrarily, for example, The position of the first pixel unit 331 may also be the second pixel unit 332 or the third pixel unit 333, which is not limited in the embodiment of the present application.

In the pixel array 302, a plurality of first pixel units 331 receive fingerprint light signals in one direction, and the fingerprint light signals are used to form the first fingerprint image of the finger, and the first target fingerprint light received by one first pixel unit 331 The signal is used to form a pixel in the first fingerprint image. A plurality of second pixel units 332 receive the fingerprint light signal in another direction, and the fingerprint light signal is used to form a second fingerprint image of the finger, and the second target fingerprint light signal received by one second pixel unit 332 is used to form a second fingerprint image. A pixel in the fingerprint image. The plurality of third pixel units 333 receive the fingerprint light signal in the third direction, the fingerprint light signal is used to form the third fingerprint image of the finger, and the third target fingerprint light signal received by one third pixel unit 333 is used to form the third fingerprint light signal. A pixel in the three fingerprint image. The first fingerprint image, the second fingerprint image, and the third fingerprint image can be used for fingerprint identification alone, or any two or three of them can be reconstructed, and the reconstructed fingerprint image can be fingerprinted.

Optionally, in a possible implementation manner, the first target fingerprint light signal received by one first pixel unit 331 is used to form one pixel in the first fingerprint image. The second target fingerprint light signal received by a second pixel unit 332 is used to form a pixel in the second fingerprint image. The third target fingerprint light signal received by a third pixel unit 333 is used to form a pixel in the third fingerprint image.

Optionally, in another possible implementation manner, the first target fingerprint light signal received by the X first pixel units 331 in the plurality of first pixel units is used to form a pixel in the first fingerprint image. The second target fingerprint light signal received by the X second pixel units 332 in the plurality of first pixel units is used to form a pixel in the second fingerprint image. The third target fingerprint light signal received by the X third pixel units 333 in the plurality of first pixel units is used to form a pixel point in the third fingerprint image. Among them, X is a positive integer.

Of course, in addition to the foregoing embodiments, the first target fingerprint light signal received by each A first pixel unit 331 in the plurality of first pixel units may be used to form one pixel in the first fingerprint image. The second target fingerprint light signal received by every B second pixel units 332 in the plurality of second pixel units is used to form one pixel in the second fingerprint image. The third target fingerprint light signal received by every C third pixel units 333 in the plurality of third pixel units is used to form a pixel point in the third fingerprint image. Among them, A, B, and C are positive integers, and at least two of them are not equal to each other.

Specifically, in the embodiment of the present application, the fingerprint identification device 300 further includes a processing unit. Optionally, the processing unit may be a processor, and the processor may be a processor in the fingerprint identification device 300, such as a micro-control unit ( Microcontroller Unit, MCU) and so on. The processor may also be a processor in an electronic device where the fingerprint identification device 300 is located, such as a main control chip in a mobile phone, etc., which is not limited in the embodiment of the present application.

Specifically, the processing unit includes a first sub-processing unit, a second sub-processing unit, and a third sub-processing unit, wherein the first sub-processing unit is used to obtain the electrical signals of the X first pixel units 331 to form a finger A pixel value in the first fingerprint image, the second sub-processing unit is used to obtain the electrical signals of X second pixel units 332 to form a pixel value in the second fingerprint image of the finger, and the third sub-processing unit is used to obtain The electrical signals of the X third pixel units 333 form a pixel value in the third fingerprint image of the finger.

Optionally, the first sub-processing unit is configured to connect to the X first pixel units 331 in the pixel array 302 through metal wiring, and use the average value of the pixel values of the X first pixel units 331 as the first fingerprint image A pixel value in.

The second sub-processing unit is used to connect to the X second pixel units 332 in the pixel array 302 through metal traces, and use the average value of the pixel values of the X second pixel units 332 as a pixel in the second fingerprint image value.

The third sub-processing unit is used to connect to the X third pixel units 332 in the pixel array 302 through metal traces, and use the average value of the pixel values of the X second pixel units 332 as a pixel in the second fingerprint image value.

Optionally, the X first pixel units 331 may be adjacent X pixel units in the plurality of first pixel units 331 of the pixel array 302, for example, may be 4 first pixel units of 2×2, or There are 9 first pixel units of 3×3. Similarly, the X second pixel units 332 may be adjacent X pixel units among the plurality of second pixel units 332 of the pixel array 302, or the Xth pixel units. The three-pixel unit 333 may be X adjacent pixel units among the plurality of third pixel units 333 of the pixel array 302, and the embodiment of the present application does not specifically limit X. Fig. 22 is a schematic block diagram of an electronic device including a plurality of fingerprint recognition units.

As shown in FIG. 22, the electronic device 30 may include a display screen 120, a filter 400 located below the display 120, and a fingerprint identification device 300 composed of a plurality of fingerprint identification units 301 located below the filter 400 Each of the pixel units of the fingerprint identification unit 301, that is, the aforementioned pixel array 302, may be arranged on the upper surface of the substrate 500. The pixel array 302 and the substrate 500 may be referred to as a fingerprint sensor or an image sensor.

Optionally, in the embodiment of the present application, the filter 400 may also be grown on the surface of the pixel array 302 and integrated with the pixel array 302 in a fingerprint sensor or an image sensor.

Specifically, the substrate may be the circuit board 150 in FIG. 1, which specifically may be a printed circuit board (PCB), a flexible printed circuit (FPC) or a software combination board, etc. The embodiments of this application are This is not limited.

The fingerprint identification process based on oblique light signals in multiple directions according to an embodiment of the present application will be described below in conjunction with FIGS. 23 to 28. For ease of understanding, the fingerprint identification process is exemplified below by taking oblique light signals in three directions as an example.

When the optical signal received by the fingerprint identification device is a light signal carrying the pattern of bright and dark stripes as shown in Figure 23, and the three pixel units corresponding to each microlens in the fingerprint identification device are used to receive three target fingerprints in different directions In the case of light signals, the pixel array in the fingerprint recognition device simultaneously images the light signals of different imaging areas. Therefore, the image formed by the pixel array in the fingerprint recognition device is an image superimposed on different imaging areas, which is a blurry image. Image. For example, the image shown in Figure 24.

In some embodiments of the present application, the first image, the second image, and the third image may be obtained by extracting the original image in FIG. 24. In particular, when the optical signal received by the fingerprint identification device is a fingerprint optical signal reflected or scattered by a finger, the image formed by the pixel array is an image superimposed on different areas of the fingerprint, and it is also a fuzzy image. The electrical signals of multiple first pixel units in the pixel array can be obtained by processing the original image to form a first fingerprint image, and electrical signals of multiple second pixel units to form a second fingerprint image, and multiple third The electrical signal of the pixel unit forms a third fingerprint image.

For example, the original image generated by the multiple first pixel units in the pixel array is shown in FIG. 25. Since the multiple first pixel units all receive light signals in the same direction, there is no overlap of images in different imaging areas. Therefore, the processing unit can process and obtain the first image shown in FIG. 25 corresponding to the light signals in the first direction. For a clear image. Similarly, the processing unit may process to obtain the second image shown in FIG. 26 generated by a plurality of second pixel units, and the third image shown in FIG. 27 generated by a plurality of third pixel units.

In some embodiments of the present application, the first image, the second image, and the third image may be processed and reconstructed to form a clear image as shown in FIG. 28. Optionally, the first image and the second image may be reconstructed first to obtain clear initial target reconstructed images of the two images, and then the initial target reconstructed image and the third image are reconstructed to obtain the final The target reconstructed image. Optionally, it is also possible to process and reconstruct the three images at the same time to obtain the final target reconstructed image. Among them, the processing process includes, but is not limited to, image processing processes such as image upsampling and filtering.

For example, the first image, the second image, and the third image may be moved by a distance of several image pixels in the image respectively to form a clear image as shown in FIG. 28.

In other words, the first image can be moved a distance of several pixels to the right and down, the second image can be moved a distance of several pixels to the left and down, and the third image can be moved a distance of several pixels to the left and upwards, forming A clear image as shown in Figure 28.

In other words, when one micro lens corresponds to three pixel units, the three pixel units can receive light signals in three directions respectively through the design of the optical path. Furthermore, when the surface of the pixel array is covered with a layer of microlens array, the pixel array can perform imaging based on light signals in three directions to obtain the original image. Since the original image is an image formed by superimposing images in three directions, the original image can be reconstructed through an algorithm, and then a clear reconstructed image can be obtained.

In the embodiment of the present application, the processing unit may adjust the movement distance of the three images (for example, the first image, the second image, and the third image) through algorithms according to the quality parameters of the reconstructed image to form the target reconstructed image. .

Specifically, the above-mentioned quality parameters of the reconstructed image include, but are not limited to: the contrast of the reconstructed image, the clarity of the reconstructed image, the signal-to-noise ratio of the reconstructed image, or the similarity between the reconstructed image and three images.

Optionally, adjusting the moving distance of the three images may be adjusting the number of pixels of the moving image of the three images. When the moving distance of the three images is the distance of N image pixels, the N can be adjusted according to the quality parameter of the reconstructed image to form a target reconstructed image.

Since the thickness of the display screen is constant and the relative position of the display screen and the fingerprint identification device is basically unchanged, the original image can be collected first (for example, the image shown in Figure 24), and the image quality of the reconstructed image is the clearest At this time, the number of image pixels that need to be moved in the image corresponding to the oblique light signal in each direction is determined as the moving image parameter, and the moving image parameter is stored in the storage unit. Furthermore, in the subsequent fingerprint collection process, a clear image can be reconstructed based on the moving image parameters.

It should be understood that the above-mentioned original image may be a fingerprint image, or any original pattern covering the surface of the display screen with clear contrast. For example, the image in Figure 23 is similar to the fingerprint ridges and valleys in the fingerprint image. When the light signal received by the fingerprint recognition device is the light signal that has been reflected or scattered by the finger, the image processed by the processing unit is being processed and reconstructed. The front can be similar to the image shown in FIG. 24, and the fingerprint image after processing and reconstruction can be similar to the image shown in FIG. 28, which is a clear fingerprint image.

In addition, when an electronic device equipped with a fingerprint identification device is used by a user, the installation distance between the fingerprint identification device and the display screen will change when a strong impact is encountered, or the installation distance between the fingerprint identification device and the display screen during mass production. When the fluctuation changes, the distance of the image pixels moved by the three images changes. At this time, the distance of the image pixels moved by the three images under the change of the installation distance can be automatically calibrated to ensure the clarity of the reconstructed image. The noise ratio and contrast ratio ensure the fingerprint recognition effect of the fingerprint recognition device and improve the user experience.

In other words, if the position of the fingerprint module relative to the display screen is shifted, the distance of the image pixels to be moved for each image can be re-determined from the original image. It can also be determined that the position of the fingerprint module relative to the display screen has shifted by evaluating that the quality of the image is lower than the preset threshold or the value measured by the accelerometer exceeds the preset threshold.

In addition, by comparing the similarity between the central area of the reconstructed image and the overlapping area of a single image, it can be secondarily judged whether the clarity of the reconstructed image reaches the optimal state.

It should be understood that the drawings are only examples of embodiments of the present application, and should not be construed as limiting the present application.

For example, alternatively, the number of light-blocking layers included in at least one light-blocking layer included in the fingerprint identification device is greater than three light-blocking layers.

For another example, the above fingerprint identification device may also include an image sensor drive unit, a microprogram controller and other devices.

The embodiment of the present application also provides an electronic device, which may include a display screen and the fingerprint identification device of the above-mentioned embodiment of the present application, wherein the fingerprint identification device is disposed under the display screen to realize off-screen optical fingerprint recognition. The electronic device can be any electronic device with a display screen.

Among them, the display screen may be the display screen described above, such as an OLED display screen or other display screens. For the related description of the display screen, refer to the description of the display screen in the above description. For the sake of brevity, details are not repeated here.

In some embodiments of the present application, a foam layer may be provided below the display screen, and the foam layer may be provided with at least one opening above the fingerprint identification device. The reflected light signal is transmitted to the fingerprint recognition device.

For example, there is a layer of black foam under the display screen, and the black foam can be provided with an opening above the fingerprint identification device. When the finger is placed on top of the lit display screen, the finger will reflect the light emitted by the display screen. The reflected light reflected by the finger penetrates the display screen and is transmitted to the fingerprint identification device through at least one opening. The fingerprint is a diffuse reflector, and its reflected light exists in all directions.

At this time, the specific light path in the fingerprint recognition device can be used to make the optical sensing pixel array in the fingerprint recognition device receive oblique light signals in multiple directions. The processing unit in the fingerprint recognition device or the processing unit connected to the fingerprint recognition device The reconstructed fingerprint image can be obtained through the algorithm, and then the fingerprint identification can be performed.

In some embodiments of the present application, there may or may not be a gap between the fingerprint identification device and the display screen.

For example, there may be a gap of 0 to 1 mm between the fingerprint identification device and the display screen.

In some embodiments of the present application, the fingerprint identification device may output the collected image to a dedicated processor of a computer or a dedicated processor of an electronic device to perform fingerprint identification.

It should be understood that the processor of the embodiment of the present application may be an integrated circuit chip with signal processing capability. In the implementation process, the steps of the foregoing method embodiments can be completed by an integrated logic circuit of hardware in the processor or instructions in the form of software. The above-mentioned processor may be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (ASIC), a ready-made programmable gate array (Field Programmable Gate Array, FPGA) or other Programming logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps, and logical block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor or the like. The steps of the method disclosed in the embodiments of the present application can be directly embodied as being executed and completed by a hardware decoding processor, or executed and completed by a combination of hardware and software modules in the decoding processor. The software module can be located in a mature storage medium in the field, such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

It can be understood that the fingerprint recognition in the embodiments of the present application may further include a memory, and the memory may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. Among them, the non-volatile memory can be read-only memory (Read-Only Memory, ROM), programmable read-only memory (Programmable ROM, PROM), erasable programmable read-only memory (Erasable PROM, EPROM), and electrically available Erase programmable read-only memory (Electrically EPROM, EEPROM) or flash memory. The volatile memory may be random access memory (Random Access Memory, RAM), which is used as an external cache. By way of exemplary but not restrictive description, many forms of RAM are available, such as static random access memory (Static RAM, SRAM), dynamic random access memory (Dynamic RAM, DRAM), synchronous dynamic random access memory (Synchronous DRAM, SDRAM), Double Data Rate Synchronous Dynamic Random Access Memory (Double Data Rate SDRAM, DDR SDRAM), Enhanced Synchronous Dynamic Random Access Memory (Enhanced SDRAM, ESDRAM), Synchronous Link Dynamic Random Access Memory (Synchlink DRAM, SLDRAM) ) And Direct Rambus RAM (DR RAM). It should be noted that the memories of the systems and methods described herein are intended to include, but are not limited to, these and any other suitable types of memories.

It should be understood that the specific examples in the embodiments of the present application are only for helping those skilled in the art to better understand the embodiments of the present application, rather than limiting the scope of the embodiments of the present application.

It should be understood that the terms used in the embodiments of the present application and the appended claims are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. For example, the singular forms of "a", "above" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

A person of ordinary skill in the art may be aware that, in combination with the examples described in the embodiments disclosed herein, the units can be implemented by electronic hardware, computer software, or a combination of the two, in order to clearly illustrate the interchangeability of hardware and software. In the above description, the composition and steps of each example have been described generally in terms of function. Whether these functions are performed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of this application.

In the several embodiments provided in this application, it should be understood that the disclosed system and device may be implemented in other ways. For example, the device embodiments described above are merely illustrative, for example, the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components may be combined or It can be integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may also be electrical, mechanical or other forms of connection.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments of the present application.

In addition, the functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or three or more units may be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or software functional unit.

If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solution of this application is essentially or the part that contributes to the existing technology, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium. It includes several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory, random access memory, magnetic disk or optical disk and other media that can store program codes.

The above are only specific implementations of this application, but the protection scope of this application is not limited to this. Anyone familiar with the technical field can easily think of various equivalents within the technical scope disclosed in this application. Modifications or replacements, these modifications or replacements shall be covered within the scope of protection of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

A fingerprint identification device, characterized in that it is suitable for under the display screen to realize under-screen optical fingerprint identification. The fingerprint identification device includes a plurality of fingerprint identification units distributed in a square array, and among the plurality of fingerprint identification units Each fingerprint recognition unit includes:

Micro lens

At least two light-blocking layers are arranged under the microlens, and each of the light-blocking layers of the at least two light-blocking layers is provided with light-passing holes to form three light guide channels in different directions;

Three pixel units are arranged under the at least two light blocking layers, and the three pixel units are respectively located at the bottom of the three light guide channels;

Wherein, the fingerprint light signals returned after being reflected or scattered from the finger above the display screen are condensed by the microlens, and the three target fingerprint light signals in different directions are respectively transmitted to the said three light guide channels. Three pixel units, the three target fingerprint light signals are used to detect fingerprint information of the finger.
The fingerprint identification device according to claim 1, wherein the directions of at least two of the three light guide channels are inclined with respect to the display screen.
The fingerprint identification device according to claim 1, wherein the projection angle of the two light guide channels of the three light guide channels on the plane where the three pixel units are located is 90 degrees.
The fingerprint identification device according to claim 1, wherein the included angles of the three light guide channels and the display screen are the same.
The fingerprint identification device according to any one of claims 1 to 4, wherein each of the three pixel units includes three photosensitive areas, and the three photosensitive areas are respectively located in the three light guide channels bottom of.
5. The fingerprint identification device according to claim 5, wherein at least one of the three photosensitive areas is deviated from the center of the pixel unit in which it is located.
7. The fingerprint identification device according to claim 6, wherein at least one of the three photosensitive areas deviates in a direction away from the center of the microlens.
The fingerprint identification device according to claim 5, wherein the three pixel units form a quadrilateral pixel area, and two of the three photosensitive areas are located on one side of the pixel area at the same time.
The fingerprint identification device according to claim 5, wherein the three pixel units include a first pixel unit, the first pixel unit includes a first photosensitive area, and the first pixel unit is connected to the first pixel unit. A photosensitive area is all quadrilateral;

Wherein, the length and width of the first pixel unit are respectively L and W, the length and width of the first photosensitive area are both greater than or equal to 0.1×W, W≦L, and both W and L are positive numbers.
The fingerprint identification device according to claim 5, wherein the three target fingerprint light signals respectively form three light spots on the three pixel units, and the three photosensitive areas are quadrilateral areas and are respectively circumscribed In the three light spots.
The fingerprint identification device according to claim 5, wherein the height of the optical path between the microlens and the plane where the three pixel units are located is calculated according to a formula, and the formula is: h=x×cotθ;

Wherein, h is the height of the optical path, x is the distance between the center of the first photosensitive area in the three photosensitive areas and the projection point of the center of the microlens on the plane where the three pixel units are located, θ is the angle between the first target fingerprint optical signal received by the first photosensitive area and the vertical direction, and the angle between the first target fingerprint optical signal and the vertical direction in the three target fingerprint optical signals is greater than the three target fingerprint optical signals. The angle between the other two target fingerprint optical signals in the target fingerprint optical signal and the vertical direction, where the vertical direction is a direction perpendicular to the display screen.
The fingerprint identification device according to any one of claims 1 to 4, wherein two of the three pixel units are squares with side length a, and the other pixel unit is 2a in length, A rectangle with width a, where a is a positive number.
The fingerprint identification device according to any one of claims 1 to 4, wherein the angles between the three light guide channels and the plane where the three pixel units are located are between 30° and 90°.
The fingerprint identification device according to any one of claims 1 to 4, wherein the bottom light-blocking layer in the at least two light-blocking layers is provided with three communication channels corresponding to the three pixel units. Light small holes.
The fingerprint identification device according to claim 14, wherein the bottom light blocking layer is a metal wiring layer on the surface of the three pixel units.
The fingerprint identification device according to claim 14, wherein the apertures of the light-passing holes in the three light guide channels decrease sequentially from top to bottom.
The fingerprint identification device according to claim 14, wherein the three light guide channels overlap the light-passing holes in the top light-blocking layer of the at least two light-blocking layers.
The fingerprint identification device according to any one of claims 1 to 4, wherein the fingerprint identification unit further comprises:

Transparent medium layer;

Wherein, the lens medium layer is used to connect the microlens, the at least two light blocking layers, and the three pixel units.
The fingerprint identification device according to any one of claims 1 to 4, wherein the fingerprint identification unit further comprises:

Optical filter layer;

Wherein, the optical filter layer is arranged in the light path between the display screen and the plane where the three pixel units are located, and is used to filter light signals in non-target wavelength bands so as to transmit light signals in the target wavelength bands.
The fingerprint identification device of claim 19, wherein the optical filter layer is integrated on the surface of the three pixel units.
The fingerprint identification device of claim 19, wherein the optical filter layer is disposed between the bottom light-blocking layer of the at least two light-blocking layers and the plane where the three pixel units are located.
The fingerprint identification device according to any one of claims 1 to 4, wherein multiple groups of the three pixel units include multiple target pixel units, and the light guide channels corresponding to the multiple target pixel units A color filter layer is provided, and the color filter layer is used to pass red visible light, green visible light or blue visible light.
The fingerprint identification device according to claim 22, wherein a plurality of groups of the three pixel units are located in an area composed of a plurality of unit pixel areas, and each of the plurality of unit pixel areas is provided with one The target pixel unit.
The fingerprint identification device according to claim 22, wherein the multiple target pixel units are evenly distributed in a plurality of groups of the three pixel units.
The fingerprint identification device of claim 22, wherein the color filter layer is disposed in a light-passing hole of the target pixel unit corresponding to the light guide channel.
The fingerprint identification device according to any one of claims 1 to 4, wherein the fingerprint identification device comprises a plurality of groups of the three pixel units;

The light signals received by the plurality of first pixel units in the plurality of groups of the three pixel units are used to form the first fingerprint image of the finger, and the light signals received by the plurality of second pixel units in the plurality of groups of the three pixel units The optical signal is used to form the second fingerprint image of the finger, and the optical signals received by the plurality of third pixel units in the plurality of groups of the three pixel units are used to form the third fingerprint image of the finger. One or more of the fingerprint image, the second fingerprint image, and the third fingerprint image are used for fingerprint recognition.
The fingerprint identification device according to claim 26, wherein the pixel average value of each X first pixel units in the plurality of first pixel units is used to form a pixel value in the first fingerprint image;

The pixel average value of every X second pixel units in the plurality of second pixel units is used to form a pixel value in the second fingerprint image;

The pixel average value of every X third pixel units in the plurality of third pixel units is used to form a pixel value in the third fingerprint image, where X is a positive integer.
The fingerprint identification device of claim 26, wherein the plurality of first pixel units are not adjacent to each other, and/or the plurality of second pixel units are not adjacent to each other, and /Or, the plurality of third pixel units are not adjacent to each other.
The fingerprint identification device according to claim 26, wherein the fingerprint identification device further comprises a processing unit configured to move the first fingerprint image, the second fingerprint image, and the third fingerprint image. The fingerprint image is combined into a reconstructed image, and the moving distance of the first fingerprint image, the second fingerprint image, and the third fingerprint image is adjusted according to the quality parameters of the reconstructed image to form a target image. An image is constructed, and the target reconstructed image is used for fingerprint recognition.
The fingerprint identification device according to any one of claims 1 to 4, wherein the distance between the fingerprint identification device and the display screen is 0 to 1 mm.
An electronic device, characterized by comprising: a display screen; and

The fingerprint identification device according to any one of claims 1 to 30, wherein the fingerprint identification device is arranged below the display screen to realize off-screen optical fingerprint identification.
The electronic device according to claim 31, wherein the distance between the fingerprint identification device and the display screen is 0 to 1 mm.