CN111095285B

CN111095285B - Fingerprint identification device and electronic equipment

Info

Publication number: CN111095285B
Application number: CN201980004300.8A
Authority: CN
Inventors: 蒋鹏; 马明
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2019-08-23
Filing date: 2019-12-13
Publication date: 2021-09-17
Anticipated expiration: 2039-12-13
Also published as: CN111095285A

Abstract

The embodiment of the application discloses a fingerprint identification device and electronic equipment, and the performance of the fingerprint identification device can be improved. This fingerprint identification device is applicable to the below of display screen in order to realize optical fingerprint identification under the screen, and this fingerprint identification device includes a plurality of fingerprint identification units, and wherein every fingerprint identification unit includes: a microlens; at least two light blocking layers, wherein each light blocking layer is provided with a light through small hole to form two light guide channels in different directions; the two pixel units are respectively positioned at the bottoms of the two light guide channels; after fingerprint optical signals returned from a finger above the display screen are converged by the micro lens, two target fingerprint optical signals in different directions are transmitted to the two pixel units through the two light guide channels respectively. The fingerprint identification device is characterized in that a plurality of groups of two pixel units in the fingerprint identification device receive fingerprint optical signals in two different directions and convert the fingerprint optical signals to form two fingerprint images, the two fingerprint images are moved and reconstructed to form a reconstructed image, and the reconstructed image is used for fingerprint identification.

Description

Fingerprint identification device and electronic equipment

This application claims priority from the following applications, the entire contents of which are incorporated by reference in this application:

the PCT application with the application number of PCT/CN2019/102366 and the name of 'fingerprint detection device, method and electronic equipment' is submitted in 2019, 8 and 23 months;

the PCT application with the application number of PCT/CN2019/111978 and the name of 'fingerprint detection device and electronic equipment' is submitted in 2019, 10 and 18 months.

Technical Field

The present application relates to the field of fingerprint identification technology, and more particularly, to a fingerprint identification device and an electronic apparatus.

Background

With the rapid development of the terminal industry, people pay more and more attention to the biometric identification technology, and the practicability of the more convenient under-screen biometric identification technology, such as the under-screen fingerprint identification technology, has become a requirement of the public. The technology of fingerprint identification under the screen is to arrange a fingerprint identification device under a display screen and realize fingerprint identification by collecting fingerprint images. For example, the fingerprint recognition device may collect the received light signal to a pixel array in a photosensor through a microlens array, and the photosensor generates a fingerprint image based on the light signal received by the pixel array, thereby performing fingerprint recognition.

In some related technologies, the microlens array in the fingerprint identification device is located right above the pixel array, and one microlens corresponds to one pixel unit, that is, each microlens in the microlens array focuses received light to a pixel unit corresponding to the same microlens, and a plurality of pixel units are arranged in an array. By adopting the technical scheme, the whole light inlet quantity of the fingerprint identification device is small, the exposure time is long, the whole imaging quality is poor, and the identification performance of the dry finger is not good. Meanwhile, the thickness of the light path in the fingerprint identification device is thick, the processing difficulty and cost of the light path are increased, and the development of the light and thin fingerprint identification device is not facilitated.

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

Disclosure of Invention

The embodiment of the application provides a fingerprint identification device and electronic equipment, and the performance of the fingerprint identification device can be improved.

In a first aspect, a fingerprint identification device is provided, the fingerprint identification device is suitable for below of display screen in order to realize optical fingerprint identification under the screen, and this fingerprint identification device includes a plurality of fingerprint identification units that are square array distribution, and every fingerprint identification unit in this a plurality of fingerprint identification units includes:

a microlens;

at least two light-blocking layers arranged below the micro lens, wherein each light-blocking layer of the at least two light-blocking layers is provided with a light-passing small hole to form two light-guiding channels in different directions;

the two pixel units are arranged below the at least two light blocking layers and are respectively positioned at the bottoms of the two light guide channels;

the fingerprint light signals returned after being reflected or scattered by the finger above the display screen are converged by the micro lens, wherein two target fingerprint light signals in different directions are transmitted to the two pixel units through the two light guide channels respectively, and the two target fingerprint light signals are used for detecting fingerprint information of the finger.

According to the scheme, one micro lens corresponds to two pixel units, the two pixel units respectively receive the target fingerprint optical signals which are converged by the micro lens and pass through two directions of the two light guide channels, and the target fingerprint optical signals in the two directions are respectively received by the two pixel units. Compared with the technical scheme that one microlens corresponds to one pixel unit, the light-entering amount of the fingerprint identification device can be increased, the exposure time is shortened, and the view field of the fingerprint identification device is increased. The angle of the fingerprint light signal received by the pixel unit is determined by the relative position relationship between the pixel unit and the microlens, and the farther the pixel unit is shifted from the center of the microlens, the larger the angle of the fingerprint light signal received by the pixel unit is. Therefore, the position of the pixel unit is flexibly set, so that the pixel unit can receive a wide-angle fingerprint optical signal, the identification problem of a dry finger is greatly improved, the thickness of a light path in the fingerprint identification unit can be reduced, the thickness of the fingerprint identification device is reduced, and the process cost is reduced. In addition, compared with the technical scheme that one micro lens corresponds to four pixel units, the area of each unit pixel unit in the pixel array is increased, so that the pixel units in the pixel array can be conveniently laid out and wired, and the number of the pixel units in the pixel array is reduced, so that the data volume of fingerprint processing is reduced, and the processing speed of fingerprint identification can be improved. In conclusion, the fingerprint identification device improves the identification problem of dry fingers, reduces the thickness of the fingerprint identification device, reduces the process cost, facilitates the circuit design of a pixel array and improves the processing speed of fingerprint identification.

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

Adopt the scheme of this application embodiment, through the direction that sets up light guide channel, make two pixel unit receive vertical direction's fingerprint light signal and incline direction's fingerprint light signal respectively, when finger and display screen contact are good, vertical direction's fingerprint light signal light is powerful, the fingerprint image signal quality that corresponds is good, can carry out fingerprint identification fast, meanwhile, when doing finger and display screen contact failure, incline direction's fingerprint light signal can improve the fingerprint identification problem of doing the finger, and can reduce fingerprint identification device's thickness. If the two pixel units receive the fingerprint optical signals in the inclined directions, the fingerprint optical signals in different inclined directions are used for further optimizing the identification problem of the dry finger.

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

The scheme of adopting this application implementation mode through the direction that sets up light guide channel for the fingerprint light signal mutually perpendicular that two pixel element received, the fingerprint light signal of ridge and valley line in the perpendicular to fingerprint of being convenient for gather can improve the quality of the fingerprint light signal that fingerprint identification unit received, thereby improves fingerprint image quality, promotes fingerprint identification device's fingerprint identification performance.

In a possible implementation manner, the two light guide channels have the same included angle with the display screen.

In one possible implementation manner, the two pixel units respectively include two photosensitive regions, and the two photosensitive regions are respectively located at the bottoms of the two light guide channels.

In one possible implementation, at least one of the two photosensitive regions is disposed off-center from the pixel cell in which it is located.

In one possible implementation, the at least one photosensitive region is offset in a direction away from a center of the microlens.

By adopting the scheme of the implementation mode, under the condition that the position of the pixel unit is fixed, the angle of the target fingerprint optical signal received by the photosensitive area can be further increased.

In one possible implementation, the two pixel units form a quadrilateral pixel area, and the two photosensitive areas are respectively located on the diagonal line of the pixel area or are located on one side of the pixel area.

In one possible implementation manner, the two pixel units include a first pixel unit, the first pixel unit includes a first photosensitive area, and the first pixel unit and the first photosensitive area are both quadrilateral; the length and the width of the first pixel unit are respectively L and W, W is less than or equal to L, both W and L are positive numbers, and both the length and the width of the first photosensitive area are more than or equal to 0.1 multiplied by W.

By adopting the scheme of the implementation mode, the photosensitive area of the pixel unit is increased, the full-well capacity of the pixel unit and the dynamic range of the pixel unit can be improved, so that the overall performance of the pixel unit is improved, and high dynamic range imaging of the fingerprint identification device is realized.

In one possible implementation manner, the two target fingerprint optical signals form two light spots on the two pixel units respectively, and the two light sensing areas are quadrilateral areas and are circumscribed with the two light spots.

In a possible implementation manner, if an included angle between a first target fingerprint optical signal of the two target fingerprint optical signals and a vertical direction is greater than an included angle between a second target fingerprint optical signal of the two target fingerprint optical signals and the vertical direction, where the vertical direction is a direction perpendicular to the display screen, a first photosensitive area of the two photosensitive areas is used for receiving the first target fingerprint optical signal;

the height of the light path between the microlens and the plane where the two pixel units are located is calculated according to a formula: h is x × cot θ;

wherein h is the height of the optical path, x is the distance between the center of the first photosensitive area and the projection point of the center of the microlens on the plane where the two pixel units are located, and θ is the angle of the first target fingerprint optical signal.

In one possible implementation, the two pixel units are rectangular pixel units with the same size.

In one possible implementation, the two light guide channels respectively form an angle of 30 ° to 90 ° with respect to the plane in which the two pixel units are located.

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

In one possible implementation manner, the bottom light blocking layer is a metal wiring layer on the surfaces of the two pixel units.

In a possible implementation manner, the apertures of the two light guide channels decrease from top to bottom.

In one possible implementation, the two light guide channels coincide with each other in the light-transmitting apertures in the top light-blocking layer of the at least two light-blocking layers.

In one possible implementation, the fingerprint identification unit further includes:

a transparent dielectric layer;

the transparent medium layer is used for connecting the micro lens, the at least two light blocking layers and the two pixel units.

an optical filter layer;

the optical filtering layer is arranged in an optical path from the display screen to a plane where the two pixel units are located, and is used for filtering optical signals of non-target wave bands so as to transmit the optical signals of the target wave bands.

In one possible implementation, the optical filter layer is integrated on the surfaces of the two pixel units.

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

In one possible implementation, the plurality of fingerprint identification units includes: the two pixel units comprise a plurality of target pixel units, and color filter layers are arranged in light guide channels corresponding to the target pixel units and used for passing red visible light, green visible light or blue visible light.

Through the technical scheme of this implementation, can be through setting up a plurality of target pixel unit sensing colorama signals, according to the difference of the colorama signal that different target pixel unit received, confirm the fingerprint area that the finger on the display screen pressed and the region that the non-finger pressed, at fingerprint identification's in-process, the direct photosignal that the pixel unit sensing that corresponds to the fingerprint area that presses the finger carries out fingerprint identification and handles, and avoided the non-finger to press the pixel unit that the region corresponds and led to the fact the interference to fingerprint identification, thereby improve fingerprint identification's success rate. In addition, because the absorption and reflection performance of the finger on the colored light signals is different from the absorption and reflection performance of other materials on the colored light signals, the anti-counterfeiting function of fingerprint identification can be enhanced according to the intensity of the received colored light signals, and whether the finger is pressed by a real finger or a fake finger can also be judged.

In a possible implementation manner, the area where the two pixel units of the plurality of groups are located is composed of a plurality of unit pixel areas, and one target pixel unit is arranged in each unit pixel area in the plurality of unit pixel areas.

In one possible implementation, the plurality of target pixel units are uniformly distributed in a plurality of groups of the two pixel units.

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

In a possible implementation manner, the optical signals received by a plurality of first pixel units in the plurality of groups of two pixel units are used for forming a first fingerprint image of the finger, the optical signals received by a plurality of second pixel units in the plurality of groups of two pixel units are used for forming a second fingerprint image of the finger, and the first fingerprint image and/or the second fingerprint image are used for fingerprint identification.

In one possible implementation, the average value of pixels of every 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 pixel average value of every X second pixel units in the plurality of second pixel units is used for forming a pixel value in the second fingerprint image, wherein X is a positive integer.

By adopting the scheme of the embodiment, the number of the pixels of the fingerprint image can be further reduced, the speed of fingerprint identification is improved, and in the embodiment, if a plurality of pixel units in the X pixel units have faults, the X pixel units can still output the obtained pixel values, and the formation of the fingerprint image and the effect of fingerprint identification cannot be influenced.

In one possible implementation manner, the plurality of first pixel units and the plurality of second pixel units are alternately arranged in an alternating and alternating manner.

In a possible implementation manner, the fingerprint identification device further includes a processing unit, and the processing unit is configured to move the first fingerprint image and the second fingerprint image to form a reconstructed image in combination, and adjust a moving distance of the first fingerprint image and the second fingerprint image according to a quality parameter of the reconstructed image to form a target reconstructed image, where the target reconstructed image is used for fingerprint identification.

In one possible implementation, the distance between the fingerprint recognition device and the display screen is 0 to 1 mm.

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

the fingerprint identification device in the first aspect or any one of the possible implementation manners of the first aspect, where the fingerprint identification device is disposed below the display screen to implement optical fingerprint identification under the display screen.

The fingerprint identification device is arranged in the electronic equipment, and the fingerprint identification performance of the electronic equipment is improved by improving the fingerprint identification performance of the fingerprint identification device.

Drawings

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

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

Fig. 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 provided according to an embodiment of the present application.

Fig. 7 is a schematic perspective structure 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 of fig. 7.

Fig. 9 is a schematic sectional view of the fingerprint recognition unit of fig. 8 taken along the direction a-a'.

Fig. 10 is a schematic top view of the fingerprint identification unit of fig. 7.

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

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 sectional view of the fingerprint recognition unit of fig. 12 taken along the direction a-a'.

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 provided 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 diagram of a pixel array in a fingerprint recognition device according to an embodiment of the present application.

Fig. 21a to 21c are schematic diagrams of three 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 27 are schematic diagrams of fingerprint images in a fingerprint identification process according to an embodiment of the present application.

Detailed Description

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

It should be understood that the embodiments of the present application can be applied to optical fingerprint systems, including but not limited to optical fingerprint identification systems and products based on optical fingerprint imaging, and the embodiments of the present application are only described by way of example, but not limited to any limitation, and the embodiments of the present application are also applicable to other systems using optical imaging technology, etc.

As a common application scenario, the optical fingerprint system provided by the embodiment of the application can be applied to smart phones, tablet computers and other mobile terminals or other electronic devices with display screens; more specifically, in the above electronic device, the fingerprint recognition device may be embodied as an optical fingerprint device, which may be disposed in a partial area or an entire area below the display screen, thereby forming an Under-screen (Under-display) optical fingerprint system. Alternatively, the fingerprint identification device may be partially or completely integrated into a display screen of the electronic device, so as to form an In-display (In-display) optical fingerprint system.

Fig. 1 is a schematic structural diagram of an electronic device to which the embodiment of the present invention is applicable, where the electronic device 10 includes a display screen 120 and an optical fingerprint device 130, where the optical fingerprint device 130 is disposed in a local area below the display screen 120. The optical fingerprint device 130 comprises an optical fingerprint sensor including a sensing array 133 having a plurality of optical sensing units 131, where the sensing array 133 is located or a sensing area thereof is a fingerprint detection area 103 of the optical fingerprint device 130. As shown in fig. 1, the fingerprint detection area 103 is located in a display area of the display screen 120. In an alternative embodiment, the optical fingerprint device 130 may be disposed at other locations, such as the side of the display screen 120 or the edge opaque region of the electronic device 10, and the optical path is designed to guide the optical signal of at least a portion of the display area of the display screen 120 to the optical fingerprint device 130, such that the fingerprint detection area 103 is actually located in the display area of the display screen 120.

It should be appreciated that the area of fingerprint sensing area 103 may be different from the area of the sensing array of optical fingerprint device 130, for example, the area of fingerprint sensing area 103 of optical fingerprint device 130 may be larger than the area of the sensing array of optical fingerprint device 130 by optical path design such as lens imaging, reflective folded optical path design, or other optical path design where light is converged or reflected. In other alternative implementations, if light path guidance is performed using, for example, light collimation, fingerprint sensing area 103 of optical fingerprint device 130 may also be designed to substantially coincide with the area of the sensing array of optical fingerprint device 130.

Therefore, when the user needs to unlock or otherwise verify the fingerprint of the electronic device, the user only needs to press the finger on the fingerprint detection area 103 of the display screen 120, so as to input the fingerprint. Since fingerprint detection can be implemented in the screen, the electronic device 10 with the above structure does not need to reserve a space on the front surface thereof to set a fingerprint key (such as a Home key), so that a full-screen scheme can be adopted, that is, the display area of the display screen 120 can be substantially extended to the front surface of the whole electronic device 10.

As an alternative implementation, as shown in fig. 1, the optical fingerprint device 130 includes a light detection portion 134 and an optical component 132, where the light detection portion 134 includes a sensing array, and a reading circuit and other auxiliary circuits electrically connected to the sensing array, 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 Photo detector (Photo detector) array, which includes a plurality of Photo detectors distributed in an array, and the Photo detectors can be used as the optical sensing units; the optical assembly 132 may be disposed above the sensing array of the light detection portion 134, and may specifically include a light guiding layer or a light path guiding structure for guiding the reflected light reflected from the surface of the finger to the sensing array for optical detection, and other optical elements.

In particular implementations, the optical assembly 132 may be packaged with the same optical fingerprint component as the light detection portion 134. For example, the optical component 132 may be packaged in the same optical fingerprint chip as the light detecting portion 134, or the optical component 132 may be disposed outside the chip where the light detecting portion 134 is located, such as attaching the optical component 132 on the chip, or integrating some components of the optical component 132 into the chip.

For example, the light guide layer may be a Collimator (collimateror) layer fabricated on a semiconductor silicon wafer, and the collimater unit may be a small hole, and in the reflected light reflected from the finger, the light perpendicularly incident to the collimater unit may pass through and be received by the optical sensing unit below the collimater unit, and the light with an excessively large incident angle is attenuated by multiple reflections inside the collimater unit, so that each optical sensing unit can only receive the reflected light reflected from the fingerprint pattern directly above the optical sensing unit, and the sensing array can detect the fingerprint image of the finger.

In another embodiment, the light guiding layer or the light path guiding 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, and is used to focus the reflected light reflected from the finger to the sensing array of the light detecting portion 134 therebelow, so that the sensing array can image based on the reflected light, thereby obtaining the fingerprint image of the finger. Optionally, the optical lens layer may further be formed with a pinhole in the optical path of the lens unit, and the pinhole may cooperate with the optical lens layer to enlarge 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 guiding 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, which may be formed above the sensing array of the light detecting portion 134 through a semiconductor growth process or other processes, and each Micro-Lens may correspond to one of the sensing units of the sensing array. And, other optical film layers may be further formed between the microlens layer and the sensing unit, such as a dielectric layer or a passivation layer, and more specifically, a light blocking layer having micro holes may be further included between the microlens layer and the sensing unit, where the micro holes are formed between the corresponding microlenses and the sensing unit, and the light blocking layer may block optical interference between adjacent microlenses and the sensing unit, and enable light rays corresponding to the sensing unit to be converged into the micro holes through the microlenses and transmitted to the sensing unit through the micro holes to perform optical fingerprint imaging. It should be understood that several implementations of the above-described optical path directing structure may be used alone or in combination, for example, a microlens layer may be further disposed below 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 microlens layer, the specific lamination structure or optical path thereof may need to be adjusted according to actual needs.

As an alternative embodiment, the display screen 120 may adopt a display screen having a self-Light Emitting 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 (i.e., the OLED light source) of the OLED display screen 120 located in the fingerprint detection area 103 as an excitation light source for optical fingerprint detection. When the finger 140 is pressed against the fingerprint detection area 103, the display screen 120 emits a beam of light 111 toward the target finger 140 above the fingerprint detection area 103, and the light 111 is reflected at the surface of the finger 140 to form reflected light or scattered light by scattering through the inside of the finger 140 to form scattered light, which is collectively referred to as reflected light for convenience of description in the related patent application. Because the ridges (ridges) and valleys (valley) of the fingerprint have different light reflection capacities, the reflected light 151 from the ridges and 152 from the valleys have different light intensities, and after passing through the optical assembly 132, the reflected light is received by the sensing array 134 in the optical fingerprint device 130 and converted into corresponding electrical signals, i.e., fingerprint detection signals; based on the fingerprint detection signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed, so that an optical fingerprint identification function is realized in the electronic device 10.

In other embodiments, the optical fingerprint device 130 may also use an internal light source or an external light source to provide the light signal for fingerprint detection. In this case, the optical fingerprint device 130 may be adapted for use with a non-self-emissive display such as a liquid crystal display or other passively emissive display. Taking an application to a liquid crystal display screen with a backlight module and a liquid crystal panel as an example, to support the underscreen fingerprint detection of the liquid crystal display screen, the optical fingerprint system of the electronic device 10 may further include an excitation light source for optical fingerprint detection, where the excitation light source may specifically be an infrared light source or a light source of non-visible light with a specific wavelength, and may be disposed below the backlight module of the liquid crystal display screen or in an edge area below a protective cover plate of the electronic device 10, and the optical fingerprint device 130 may be disposed below the edge area of the liquid crystal panel or the protective cover plate and guided through a light path so that the fingerprint detection light may reach the optical fingerprint device 130; alternatively, the optical fingerprint device 130 may be disposed under the backlight module, and the backlight module is configured to allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint device 130 by perforating or performing other optical designs on the diffusion sheet, the brightness enhancement sheet, the reflection sheet, and other film layers. When the optical fingerprint device 130 is used to provide an optical signal for fingerprint detection using an internal light source or an external light source, the detection principle is the same as that described above.

It should be understood that in particular implementations, the electronic device 10 also includes a transparent protective cover plate, which may be a glass cover plate or a sapphire cover plate, positioned over the display screen 120 and covering the front face of the electronic device 10. Because, in the embodiment of the present application, the pressing of the finger on the display screen 120 actually means pressing on the cover plate above the display screen 120 or the surface of the protective layer covering the cover plate.

It should also be understood that electronic device 10 may also include a circuit board 150 disposed below optical fingerprint arrangement 130. The optical fingerprint device 130 may be adhered to the circuit board 150 by a back adhesive, and electrically connected to the circuit board 150 by soldering a pad and a wire. Optical fingerprint device 130 may be electrically interconnected and signal-transferred to other peripheral circuits or other components of electronic device 10 via circuit board 150. For example, the optical fingerprint device 130 may receive a control signal of a processing unit of the electronic apparatus 10 through the circuit board 150, and may also output a fingerprint detection signal from the optical fingerprint device 130 to the processing unit or the control unit of the electronic apparatus 10 through the circuit board 150, or the like.

On the other hand, in some embodiments, the optical fingerprint device 130 may include only one optical fingerprint sensor, where the area of the fingerprint detection area 103 of the optical fingerprint device 130 is small and the position is fixed, so that the user needs to press a finger to a specific position of the fingerprint detection area 103 when performing a fingerprint input, otherwise the optical fingerprint device 130 may not acquire a fingerprint image and the user experience is poor. In other alternative embodiments, optical fingerprint device 130 may specifically include a plurality of optical fingerprint sensors; the plurality of optical fingerprint sensors may be disposed side by side below the display screen 120 in a splicing manner, and sensing areas of the plurality of optical fingerprint sensors jointly form the fingerprint detection area 103 of the optical fingerprint device 130. That is, the fingerprint detection area 103 of the optical fingerprint device 130 may include a plurality of sub-areas, each of which corresponds to a sensing area of one of the optical fingerprint sensors, so that the fingerprint collection area 103 of the optical fingerprint device 130 may be extended to a main area of a lower half portion of the display screen, i.e., to a region where a finger is normally pressed, thereby implementing a blind-touch fingerprint input operation. Alternatively, when the number of optical fingerprint sensors is sufficient, the fingerprint detection area 103 may also be extended to half the display area or even the entire display area, thereby enabling 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 the sensing unit in the sensing array may also be referred to as a pixel unit or a pixel.

It should be noted that, optical fingerprint device in this application embodiment also can be called optical fingerprint identification module, fingerprint identification device, fingerprint identification module, fingerprint collection device etc. but above-mentioned term mutual replacement.

Fig. 2 and 3 show a schematic cross-sectional view and a schematic top view of a fingerprint recognition device.

As shown in fig. 2 and 3, the fingerprint recognition 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 right above the pixel array 230 and the at least one light-blocking layer 220, and one microlens 211 corresponds to one pixel unit 231, that is, each microlens 211 in the microlens array 210 focuses the received light to the pixel unit 231 corresponding to the same microlens 211 through the aperture 2201 of the at least one light-blocking layer 220. The optical signal received by each microlens 211 is mainly a fingerprint optical signal incident perpendicularly 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 disposed at the center of the same pixel unit, so as to increase the duty ratio of the photosensitive area.

In other words, the microlenses 211 in the microlens array 210 correspond to the pixel units 231 in the pixel array 230 one by one, and the photosensitive areas 2311 of the 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 increases the processing difficulty, the cycle time and the cost of the optical path of the fingerprint identification device 200.

In addition, in normal life scenes, such as washing hands, getting up in the morning, plastering fingers, low temperature, and the like, fingers are generally dry, the cuticle is not uniform, and when the fingers are pressed on a display screen, poor contact occurs in local areas of the fingers. When the contact between the dry finger and the display screen is not good, the contrast between the fingerprint ridges and the fingerprint valleys of the fingerprint image in the vertical direction formed by the fingerprint identification device 200 is poor, and the image is blurred to be unable to distinguish the fingerprint lines, so that the fingerprint identification performance of the fingerprint identification device 200 for the dry finger is poor.

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

As shown in fig. 4 and 5, the fingerprint recognition 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 a pixel unit is disposed at the bottom of each light guide channel in the plurality of light guide channels.

For example, as shown in fig. 4 and 5, the light blocking layer under the first microlenses 211 in the microlens array 210 is formed with 4 light guide channels, the first microlenses 211 correspond to the 4 pixels under them, and the 4 pixel units include the first pixel unit 231 and the second pixel unit 232 shown in the figure.

Alternatively, as shown in fig. 4, of the at least one light-blocking layer, the uppermost light-blocking layer is the first light-blocking layer 221, the second light-blocking layer 222 is disposed below the first light-blocking layer 221, and the third light-blocking layer 223 is disposed above the pixel array 230. Here, a first small hole 2211 corresponding to the first microlens 211 is formed in the first light-blocking layer 221, a second small hole 2221 and a third small hole 2222 corresponding to the first microlens 211 are formed in the second light-blocking layer 222, both the second small hole 2221 and the third small hole 2222 are located below the first small hole 2211, and a fourth small hole 2231 and a fifth small hole 2232 corresponding to the first microlens 211 are formed in the third light-blocking layer 223. 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, through which the light signal of the first direction converged by the first microlens is received by the first light sensing 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, and the light signal of the second direction converged by the first microlens passes through the light guide channel to be received by the second photosensitive region 2321 in the second pixel unit 232.

Fig. 4 is a schematic cross-sectional view of the fingerprint identification device 200, in which only one microlens corresponds to 2 light guide channels and 2 pixel units, it should be understood that, in the embodiment of the present application, one microlens corresponds to 4 light guide channels and 4 pixel units, and reference can be made to fig. 4 for the case of another 2 light guide channels and 2 pixel units corresponding to one microlens.

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

Through the scheme of the embodiment, through the design of the light path, 4 pixel units corresponding to a single micro lens can simultaneously receive optical signals in 4 directions, so that the light incoming amount of the fingerprint identification device is improved, the exposure time is shortened, and the field of view is increased. Meanwhile, the imaging light path matched with the multi-pixel unit through the single micro lens can carry out non-direct light imaging (namely inclined light imaging) on the object space light beam of the fingerprint, the identification effect of the dry finger can be improved, the object space numerical aperture of the optical system can be enlarged, the thickness of the light path design of the pixel array can be shortened, and finally the thickness of the fingerprint identification device can be effectively reduced.

However, in this embodiment, the pixel array includes 4 types of pixel units, each type of pixel unit receives an optical signal in one direction, and therefore, when performing fingerprint identification, the electrical signals generated by the 4 types of pixel units need to be processed to form a fingerprint image signal for fingerprint identification, which results in a large amount of data and a long time for signal processing. In addition, since one microlens corresponds to 4 pixel units, the number of pixel units in the pixel array is large, and the layout and routing of the pixel units are not facilitated. And thirdly, the light signal inclination angle received by the pixel unit is limited due to the fixed arrangement of the pixel array, the identification performance of the dry finger is not optimal, and the whole light path is still thick, so that the further light and thin development of the fingerprint identification device is not facilitated.

Based on the above problems, in the embodiments of the present application, a fingerprint identification device is provided, which can optimize the identification performance of a dry finger and reduce the thickness of the fingerprint identification device while improving the light incident amount of the fingerprint identification device, reducing the exposure time, and improving the optical resolution and the optical field of view.

Hereinafter, the fingerprint recognition device according to the embodiment of the present application will be described in detail with reference to fig. 6 to 27.

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

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

Fig. 6 is a schematic top view of a fingerprint identification device 300 according to an embodiment of the present application, where the fingerprint identification device 300 is suitable for use below a display screen to realize optical fingerprint identification below the display screen.

As shown in fig. 6, the fingerprint recognition device 300 may include a plurality of fingerprint recognition units 301 distributed in a square array. The fingerprint identification units 301 include a plurality of microlenses arranged in a square array, and if the microlenses are circular microlenses, the centers of the microlenses are arranged in a square array, and the centers of the four adjacent microlenses form a square.

Of course, the fingerprint recognition device 300 may also include a plurality of fingerprint recognition units 301 that are structurally staggered with respect to each other. For example, the microlens in each fingerprint identification unit in the fingerprint identification device 300 may converge the received oblique light signal to the pixel unit under the microlens in the adjacent plural fingerprint identification units. In other words, each microlens converges the received oblique light signal to a pixel cell under a plurality of microlenses adjacent to the same microlens.

Alternatively, fig. 7 shows a schematic perspective structure of a fingerprint recognition unit 301.

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

a microlens 310;

at least two light-blocking layers disposed under the micro-lens 310, wherein each of the at least two light-blocking layers has a light-passing aperture to form two light-guiding channels (a first light-guiding channel and a second light-guiding channel) in different directions;

two pixel units (a first pixel unit 331 and a second pixel unit 332) disposed below the at least two light-blocking layers, the two pixel units being disposed at the bottoms of the two light-guiding channels;

after the fingerprint optical signals returned after being reflected or scattered by the finger above the display screen are converged by the micro lens 310, two target fingerprint optical signals (a first target fingerprint optical signal and a second target fingerprint optical signal) in different directions are respectively transmitted to the two pixel units through the two light guide channels, and the two target fingerprint optical signals are used for detecting fingerprint information of the finger.

In the present application, the microlens 310 may be various lenses having a condensing function for increasing a field of view and increasing an amount of light signals transmitted to the pixel unit. The material of the microlens 310 may be an organic material, such as a resin. Alternatively, the surface of the microlens 310 may be spherical or aspherical. The micro lens 310 may be a circular lens, a square lens, or the like, which is not limited in the embodiments of the present application.

Alternatively, if the microlens 310 is a circular microlens, the diameter of the circular microlens is not greater than the arrangement period of two pixel units. For example, if the area where two pixel units are located is a quadrilateral area of A × B, where A ≦ B, and A and B are positive integers, the diameter of the microlens 310 is smaller than or equal to A.

In the present application, the pixel unit may be a photoelectric conversion unit. Alternatively, the pixel unit may include a Complementary Metal Oxide Semiconductor (CMOS) device, and specifically includes a Photodiode (PD), a CMOS switch tube, and the like, where the photodiode is a Semiconductor device composed of a PN junction, and has a unidirectional conductive characteristic, and may convert a received optical signal into a corresponding electrical signal, so as to convert an optical image into an electrical image, and the CMOS switch tube is configured to receive a control signal to control the operation of the photodiode, and may be configured to control an electrical signal of the output photodiode.

Alternatively, as shown in fig. 7, two pixel units in the fingerprint identification unit 301 may be rectangular, and the two rectangular pixel units correspond to the microlenses 310 and are disposed below the microlenses 310.

It should be noted here that the two pixel units disposed below the microlens 310 can also be square or other irregular patterns, so that the pixel array in the fingerprint identification device 300 has higher symmetry, higher sampling efficiency, equal distance between adjacent pixels, better angular resolution, and less aliasing effect.

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

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

Of course, the second light-blocking layer 322 may also be formed at any position between the microlens 310 and the plane of the two pixel units, for example, between the first light-blocking layer 321 and the plane of the two pixel units, which is not specifically limited in this embodiment of the application.

Alternatively, as shown in fig. 7, a first light-passing aperture 3211 is formed on the first light-

blocking layer

321, and 2 light-passing

apertures

3221 and 3222 are formed on the second light-blocking layer 322. The second light passing aperture 3221 and the first light passing aperture 3211 form a first light guiding channel, which is used for passing through a first target fingerprint light signal in the fingerprint light signals converged by the microlens 310, and is received by the first pixel unit 331 located at the bottom of the first light guiding channel, for detecting fingerprint information. Likewise, the third light passing aperture 3222 and the first light passing aperture 3211 form a second light guide channel for passing a second target fingerprint light signal, which is received by the second pixel unit 332 located at the bottom of the second light guide channel, and the first target fingerprint light signal and the second target fingerprint light signal are used for detecting fingerprint information.

In the embodiment of the present application, the first light passing aperture 3211, the second light passing aperture 3221, and the third light passing aperture 3222 may be located at any position below the microlens 310, and are intended to form light guide channels in any two different directions. In other words, the first pixel unit 331 and the second pixel unit 332 corresponding to the microlens 310 can also be located at any position below the microlens 310, and are intended to receive fingerprint light signals of two different directions passing through the light guide channels of the two different directions.

Alternatively, the light guide channel is constructed by adjusting the relative position relationship between the two pixel units and the microlens 310 and forming small holes on the light blocking layer between the pixel units and the microlens 310 to pass through fingerprint light signals in different directions, so that the light sensing areas in the two pixel units receive the fingerprint light signals in different directions.

Alternatively, the photosensitive areas in the two pixel units can receive fingerprint light signals in different directions by adjusting the areas of the photosensitive areas in the two pixel units and/or the relative position relationship of the photosensitive areas in the pixel units.

According to the scheme of the embodiment of the application, one micro lens corresponds to two pixel units, the two pixel units respectively receive fingerprint optical signals which are converged by the micro lens and pass through two directions of the two light guide channels, and the fingerprint optical signals in the two directions are respectively received by the two pixel units. Compared with the technical scheme that one microlens corresponds to one pixel unit (such as the fingerprint identification device in fig. 2 and 3), the light-entering amount of the fingerprint identification device can be increased, the exposure time can be shortened, and the field of view of the fingerprint identification device can be increased. In the embodiment of the present application, an angle of the fingerprint light signal received by the pixel unit (an included angle between the fingerprint light signal and a direction perpendicular to the display screen) is determined by a relative position relationship between the pixel unit and the microlens, and the farther the pixel unit is shifted from the center of the microlens, the larger the angle of the fingerprint light signal received by the pixel unit is. Therefore, the position of the pixel unit is flexibly set, so that the pixel unit can receive a wide-angle fingerprint optical signal, the identification problem of a dry finger is greatly improved, the thickness of a light path in the fingerprint identification unit can be reduced, the thickness of the fingerprint identification device is reduced, and the process cost is reduced.

In addition, compared with the technical scheme that one microlens corresponds to four pixel units (for example, the fingerprint identification device in fig. 4 and 5), in the embodiment of the present application, one microlens corresponds to two pixel units, so that the area of a unit pixel unit in a pixel array is increased, the pixel units in the pixel array are conveniently laid out and routed, and the number of the pixel units in the pixel array is reduced, so that the data volume of fingerprint processing is reduced, and the processing speed of fingerprint identification can be improved.

In summary, by adopting the technical scheme of the embodiment of the application, the identification problem of the dry finger is improved, the thickness of the fingerprint identification device is reduced, the process cost is reduced, meanwhile, the circuit design of the pixel array is facilitated, and the processing speed of fingerprint identification is improved.

Optionally, the target fingerprint optical signals in the two directions received by the fingerprint identification unit 301 are both optical signals inclined with respect to the display screen, or one of the target fingerprint optical signals in the two directions is an optical signal perpendicular to the display screen, and the other target fingerprint optical signal is an optical signal inclined with respect to the display screen.

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

Alternatively, the angle of the target fingerprint light signal in the two directions (the angle between the target fingerprint light signal and the direction perpendicular to the display screen) may be between 0 ° and 60 °. Alternatively, the angle of the fingerprint light signal received by the microlens 310 may be between 0 ° and 60 °.

That is, the included angles between the light guide channels in two different directions formed in the at least two light-blocking layers and the direction perpendicular to the display screen may also be between 0 ° and 60 °, or the included angles between the light guide channels in two different directions formed in the at least two light-blocking layers and the display screen may be between 30 ° and 90 °, and if the display screen is arranged in parallel to the plane where the two pixel units are located, the included angles between the light guide channels in two different directions formed in the at least two light-blocking layers and the plane where the two pixel units are located may be between 30 ° and 90 °.

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

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

Alternatively, if the at least two light-blocking layers are a plurality of light-blocking layers with more than two layers, the direction of the light-guiding channel in the plurality of light-blocking layers may be the direction of the line connecting the center of the uppermost light-passing aperture and the center of the lowermost light-passing aperture in the light-guiding channel. Or the direction of the light guide channel is a direction close to the direction of the central connecting line, for example, the direction of the light guide channel is within ± 5 ° of the direction of the central connecting line.

For example, in fig. 7, the direction of the first light guide channel corresponding to the first pixel unit 331 is a connection line direction of the first light passing aperture 3211 and the second light passing aperture 3221 or a direction close to the connection line direction, and the direction of the second light guide channel corresponding to the second pixel unit 331 is a connection line direction of the first light passing aperture 3211 and the third light passing aperture 3222 or a direction close to the connection line direction.

Optionally, the at least two light-blocking layers may also be three light-blocking layers, for example, a light-blocking layer is further disposed in the two light-blocking layers in the embodiment of the above application, and light-passing apertures corresponding to the first pixel unit 331 and the second pixel unit 332 are also disposed in the light-blocking layer, so as to form two light-guiding channels corresponding to the two pixel units.

Alternatively, if the at least two light-blocking layers are three or more light-blocking layers, the light-blocking layer between the bottom light-blocking layer and the top light-blocking layer is a middle light-blocking layer, in the two light guide channels, the direction of the connection line of the light-passing apertures of the bottom light-blocking layer and the top light-blocking layer is the direction of the light guide channels, and the centers of the light-passing apertures in the middle light-blocking layer may be respectively located on the connection line of the two light guide channels.

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

For example, the metal wiring layers of the first pixel unit 331 and the second pixel unit 332 are disposed at the back focal plane position of the microlens 310, the metal wiring layers are bottom light-blocking layers of at least two light-blocking layers, and a second light-passing aperture 3221 and a third light-passing aperture 3222 are formed above the light-sensing areas of the first pixel unit 331 and the second pixel unit 332, respectively.

In other words, the bottom light-blocking layer of the at least two light-blocking layers is formed on the metal wiring layer of the fingerprint sensor chip, and the corresponding light-passing small hole is formed above the photosensitive area of each pixel unit. Alternatively, the metal wiring layer of the fingerprint sensor chip may be reused as an 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 aperture corresponding to the first pixel unit 331 and the second pixel unit 332. For example, a light-passing aperture may be respectively disposed in the top light-blocking layer for the first pixel unit 331 and the second pixel unit 332, or for example, a light-passing aperture may also be disposed in the top light-blocking layer for the first pixel unit 331 and the second pixel unit 332, such as the above-mentioned first light-passing aperture 3211, in other words, the light-passing apertures in the top light-blocking layer of at least two light-blocking layers coincide with the light-passing apertures in the first light-guiding channels corresponding to the first pixel unit 331 and the second light-guiding channels corresponding to the second pixel unit 332.

Optionally, the apertures of the light-passing apertures in the first light guide channel and the second light guide channel decrease from top to bottom, for example, the apertures of the second light-passing aperture 3221 and the third light-passing aperture 3222 are both smaller than the aperture of the first light-passing aperture 3211.

In other words, the aperture of the light-passing apertures in the upper light-blocking layer is set larger than the aperture of the light-passing apertures in the lower light-blocking layer, thereby. At least two light-blocking layers can be enabled to guide more (a certain angle range) of light signals to the corresponding pixel units.

It should be understood that, in a specific implementation, a person skilled in the art may determine the direction of the light guide channel according to the light path design requirement, so as to determine the distribution of the light passing holes in the at least two light blocking layers, thereby forming the light guide channel meeting the light path design requirement, and the target fingerprint light signal passing through a specific direction is received by the pixel unit.

In a specific implementation, each of the at least two light-blocking layers has a transmittance for light in a specific wavelength band (such as visible light or a wavelength band above 610nm) that is less than a preset threshold (e.g., 20%) to prevent the corresponding light from passing through. The light-passing small hole can be a cylindrical through hole, and can also be a through hole with other shapes, such as a polygonal through hole. The clear aperture may have an aperture greater than a predetermined value, for example greater than 100nm, to facilitate transmission of the desired light for imaging. The aperture of the light-passing aperture is also smaller than a predetermined value to ensure that the light-blocking layer blocks unwanted light. For another example, the aperture of the clear aperture may be smaller than the diameter of the microlens.

As an example, the light-passing apertures in the at least two light-blocking layers may also comprise large-aperture apertures equivalently synthesized by a plurality of small-aperture apertures. For example, a plurality of small-aperture openings in the top light-blocking layer of the at least two light-blocking layers for transmitting the light signals converged by the same microlens may be combined into one large-aperture opening.

Alternatively, each of the at least two light-blocking layers may be a metal layer, and accordingly, the light-passing small holes provided in the light-blocking layers may be through holes formed in the metal layer. The light-blocking layer of the at least two light-blocking layers can also be a black polymer light-absorbing material. For example, the at least two light-blocking layers have a visible light band transmittance of less than 2% for light signals greater than a preset angle.

It will be appreciated that the parameter settings of the light passing apertures in the light blocking layer should be such that the light signal required for imaging is maximally transmitted to the pixel cell, while the unwanted light is maximally blocked. For example, the parameters of the light passing aperture may be set to maximize transmission of light signals incident obliquely at a certain angle (e.g., 35 degrees) to the corresponding pixel cell, while maximizing blocking of other light signals.

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

The transparent medium layer is used to connect the microlens 310, at least two light blocking layers, and two pixel units (a first pixel unit 331 and a second pixel unit 332).

For example, the transparent dielectric layer is transparent to optical signals in a target wavelength band (i.e., optical signals in a wavelength band required for fingerprint recognition). For example, the transparent dielectric layer may be an oxide or a nitride. Optionally, the transparent dielectric layer may include multiple layers to achieve the functions of protection, transition, buffering, and the like, respectively. For example, a transition layer may be disposed between the inorganic layer and the organic layer to achieve a tight connection; a protective layer may be provided over the easily oxidizable layer to provide protection.

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

The optical filter layer is disposed in an optical path from the microlens 310 to a plane where two pixel units are located or above the microlens 310, and is configured to filter optical signals in a non-target wavelength band to transmit optical signals in a target wavelength band.

For example, the transmittance of the optical filter layer for light in a target wavelength band may be greater than or equal to a preset threshold, and the cut-off rate for light in a non-target wavelength band may be greater than or equal to the preset threshold. For example, the preset threshold may be 80%. Alternatively, the optical filter layer may be a separately formed optical filter layer. For example, the optical filter layer may be formed by using blue crystal or blue glass as a carrier. Alternatively, the optical filter layer may be a plated film formed on the surface of any one of the optical paths from the microlens 310 to the plane where the two pixel units are located. For example, the optical filter layer may be formed by a plating film formed on the surface of the pixel unit, the surface of any one of the transparent dielectric layers, or the surface of the microlens.

Optionally, when the at least two light-blocking layers are both located above the pixel units, but not on the surfaces of the pixel units, 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 two 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 disposed between the bottom light-blocking layer and the light-blocking layer above the bottom light-blocking layer.

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

Alternatively, the optical filter layer may be formed by coating on the pixel unit using a Physical Vapor Deposition (PVD) process, for example, a multi-layer filter material film is prepared over the pixel unit by atomic layer Deposition, sputter coating, e-beam evaporation coating, ion beam coating, and the like.

Optionally, in an 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 are alternately grown in sequence to form the optical filter layer; or the multilayer oxide film comprises 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 an 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 configured to pass optical signals in a wavelength band range of 400nm to 650nm, in other words, a wavelength range of the target wavelength band includes 400nm to 650 nm.

Fig. 8 and 10 show two schematic top views of the fingerprint recognition unit 301 in fig. 7.

As shown in fig. 8 and 10, the areas where the first pixel unit 331 and the second pixel unit 332 are located (for convenience of description, the areas where the first pixel unit 331 and the second pixel unit 332 are located are simply referred to as the pixel area 330) may be located right below the microlens 310, and the center of the pixel area 330 coincides with the center of the microlens 310 in the vertical direction. The first pixel unit 331 and the second pixel unit 332 both receive the target fingerprint optical signal in an oblique direction, that is, the directions of the first light guide channel corresponding to the first pixel unit 331 and the second light guide channel corresponding to the second pixel unit 332 are both oblique with respect to the display screen.

The first pixel unit 331 and the second pixel unit 332 each include a photosensitive Area (Active Area, AA) for receiving the first target fingerprint optical signal and the second target fingerprint optical signal respectively, and converting the first target fingerprint optical signal and the second target fingerprint optical signal into corresponding electrical signals. The photosensitive area may be an area where a photodiode is located in the pixel unit, that is, an area in the pixel unit that receives the light signal, and other areas in the pixel unit may be used for setting other circuits in the pixel unit and for arranging inter-pixel routing. 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%. That is, the photosensitive region 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 of ≧ 610nm) so as to detect the corresponding light.

The first light sensing area 3311 of the first pixel unit 331 is located below the second light passing hole 3221, i.e., at the bottom of the first light guiding channel, for receiving the first target fingerprint light signal, and the second light sensing area 3321 of the second pixel unit 332 is located below the third light passing hole 3222, i.e., at the bottom of the second light guiding channel, for receiving the second target fingerprint light signal.

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

As shown in fig. 9, the first target fingerprint light signal 311 is received by the first light sensing area 3311 in the first pixel unit through the first light transmitting hole 3211 and the first light transmitting channel formed by the second light transmitting hole 3221, and the second target fingerprint light signal 312 is received by the second light sensing area 3321 in the second pixel unit through the second light transmitting channel formed by the first light transmitting hole 3211 and the third light transmitting hole 3222.

Alternatively, in the embodiment of the present application, the distance from the center of the first photosensitive region 3311 to the center of the microlens 310 and the distance from the center of the second photosensitive region 3321 to the center of the microlens 310 are equal.

Optionally, in this case, the included angles between the first target fingerprint optical signal 311 received by the first photosensitive region 3311 and the display screen and the second target fingerprint optical signal 312 received by the second photosensitive region 3321 are the same, or the included angle between the first light guide channel corresponding to the first photosensitive region 3311 and the display screen and the included angle between the second light guide channel corresponding to the second photosensitive region 3321 and the display screen are equal.

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

As shown in fig. 11, the distance from the center of the first photosensitive region 3311 to the center of the microlens 310 is not equal to the distance from the center of the second photosensitive region 3321 to the center of the microlens 310, and at this time, the included angles between the first target fingerprint optical signal 311 received by the first photosensitive region 3311 and the second target fingerprint optical signal 312 received by the second photosensitive region 3321 and the display screen are not the same, or the included angle between the first light guide channel corresponding to the first photosensitive region 3311 and the display screen is not equal to the included angle between the second light guide channel corresponding to the second photosensitive region 3321 and the display screen.

Fig. 8 to 11 show a case where the fingerprint identification unit 301 includes two light-blocking layers, and optionally, the fingerprint identification unit 301 may further include three light-blocking layers.

Fig. 12 shows a schematic top view of a fingerprint recognition unit 301, and fig. 13 shows a schematic cross-sectional view of the fingerprint recognition unit 301 of fig. 12 along the direction a-a'.

As shown in fig. 12 and 13, the fingerprint recognition unit 301 includes three light blocking layers. The top light-blocking layer is provided with the first light-passing aperture 3211, and the bottom light-blocking layer is provided with the second light-passing aperture 3221 and the third light-passing aperture 3222. In addition, a fourth light passing aperture 3231 and a fifth light passing aperture 3232 are disposed in the light blocking layer of the newly added middle layer. The first light-passing aperture 3211, the fourth light-passing aperture 3231 and the second light-passing aperture 3221 form a first light-guiding channel corresponding to the first light-sensing area 3311, and centers of the three light-passing apertures may be located on the same straight line. In addition, the first light passing aperture 3211, the fifth 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 centers of the three light passing apertures may also be located on the same straight line.

Optionally, in this embodiment, the aperture of the first light passing aperture 3211 is larger than the apertures of the fourth light passing aperture 3231 and the fifth light passing aperture 3232, and the apertures of the fourth light passing aperture 3231 and the fifth light passing aperture 3232 are larger than the apertures of the second light passing aperture 3221 and the third light passing aperture 3222.

It should be understood that in the present application, the fingerprint identification unit 301 may further include more light-blocking layers, hereinafter, two light-blocking layers are described as an example, and the case of more than two light-blocking layers may refer to the related description, which is not described herein again.

Referring to fig. 8, 10 and 12, in one possible embodiment, the photosensitive areas in the two pixel cells occupy only a small area in the pixel cells to meet the requirement of receiving the optical signal.

In this embodiment, the center of the first photosensitive region 3311 may be located at the bottom of the first light guide channel, and the center of the second photosensitive region 3321 may be located at the bottom of the second light guide channel. In other words, the center of the first light sensing region 3311 is located on the connection line of the first light passing aperture 3211 and the second light passing aperture 3221, and the center of the second light sensing region 3321 is located on the connection line of the first light passing aperture 3211 and the third light passing aperture 3222.

With the above arrangement, the first target fingerprint light signal forms the first light spot 3301 on the first pixel unit 331 through the first light guide channel, and the second target fingerprint light signal forms the second light spot 3302 on the second pixel unit 332 through the second light guide channel.

In order to maximize the reception of the first and second target fingerprint light signals, optionally, the first photosensitive area 3311 of the first pixel unit 331 may completely cover the first light spot 3301, and the second photosensitive area 3321 of the second pixel unit 332 may completely cover the second light spot 3302.

Optionally, the first pixel unit is a quadrilateral area, and the length and width of the quadrilateral area are L and W, respectively, where W is less than or equal to L, W and L are positive numbers, and the length and width of the first photosensitive area in the first pixel unit are greater than or equal to 0.1 × W. Of course, the size of the second pixel unit and the second photosensitive area thereof may also correspondingly satisfy the above condition.

In one possible embodiment, as shown in fig. 8, 10 and 12, the first photosensitive region 3311 is a quadrilateral region and circumscribes the first light spot 3301, and similarly, the second photosensitive region 3321 is a quadrilateral region and circumscribes the second light spot 3302.

In this case, the photosensitive area in the pixel unit is small, but the fingerprint optical signal passing through the light guide channel is sufficiently received, so that the fingerprint imaging requirement is met, and meanwhile, the area of other areas in the pixel unit is large, so that enough space is provided for the wiring of the pixel unit, the process requirement is reduced, the process manufacturing efficiency is improved, and other areas can be used for arranging other circuit structures, so that the signal processing capacity of the pixel unit can be improved.

It should be understood that when the photosensitive regions in the two pixel units occupy only a small portion of the area in the pixel unit, the centers of the photosensitive regions may not be located at the bottom of the light guide channel, but may be shifted to some extent, and at this time, the areas of the photosensitive regions may be enlarged, so that the photosensitive regions can cover the whole area of the light spots of the fingerprint light signals on the pixel units.

Alternatively, in fig. 8, 10 and 12, the first pixel unit 331 and the second pixel unit 332 are rectangular pixel units, and the first photosensitive region 3311 and the second photosensitive region 3321 are disposed offset from the centers of the two pixel units. Since the first pixel unit 331 and the second pixel unit 332 both receive the optical signal in the oblique direction, the larger the oblique angle is, the farther the photosensitive region in the pixel unit is from the center of the microlens. Thus, the first and second

photosensitive regions

3311 and 3321 are offset from the center of the pixel unit and are offset away from the center of the microlens, which can increase the angle of the target fingerprint optical signal received by the two photosensitive regions, thereby reducing the thickness of the fingerprint identification unit.

It should be understood that, in the embodiment of the present application, the first photosensitive region 3311 and the second photosensitive region 3321 may also be located at the center of the first pixel unit 331 and the second pixel unit 332, and in order to meet the requirement of the angle of receiving the light signal by the photosensitive region, the first pixel unit 331 and the second pixel unit 332 may be shifted away from the center of the microlens, so as to increase the angle of receiving the target fingerprint light signal by the two photosensitive regions and reduce the thickness of the fingerprint identification unit.

In the embodiment of the present application, the two photosensitive regions may be disposed at any position in the pixel unit, and are intended to receive the target fingerprint optical signal passing through the two channels.

As shown in fig. 8, 10 and 12, the pixel region 330 formed by the first pixel unit 331 and the second pixel unit 332 is a quadrilateral pixel region, and the first photosensitive region 3311 and the second photosensitive region 3321 may be located on a diagonal line of the pixel region 330. In this case, an included angle between the first target fingerprint optical signal received by the first photosensitive region 3311 and the projection of the second target fingerprint optical signal received by the second photosensitive region 3321 on the plane of the pixel region 330 is 180 °, or an included angle between the projection of the first light guide channel on the plane of the pixel region 330 and the projection of the second light guide channel on the plane of the pixel region 330 is 180 °.

Alternatively, the first photosensitive region 3311 and the second photosensitive region 3321 may be located on either side of the pixel region 330 at the same time.

For example, fig. 14 shows a schematic top view of another fingerprint identification unit 301. As shown in fig. 14, the first photosensitive region 3311 and the second photosensitive region 3321 are simultaneously located at an upper side of the pixel region 330. At this time, an included angle between the first target fingerprint optical signal received by the first photosensitive region 3311 and the projection of the second target fingerprint optical signal received by the second photosensitive region 3321 on the plane where the pixel region 330 is located may be 90 °, or an included angle between the projection of the first light guide channel on the plane where the pixel region 330 is located and the projection of the second light guide channel on the plane where the pixel region 330 is located is 90 °.

Adopt the scheme of this application embodiment, the fingerprint light signal mutually perpendicular that two pixel element received, the fingerprint light signal of ridge and valley line in the perpendicular to fingerprint of being convenient for gather can improve the quality of the fingerprint light signal that fingerprint identification unit received to improve fingerprint image quality, promote fingerprint identification device's fingerprint identification performance.

Fig. 8, fig. 10, fig. 12 and fig. 14 only illustrate schematic top views of several fingerprint identification units 301, wherein the projection of the first light guide channel and the second light guide channel on the plane where the pixel region 330 is located forms an included angle of 180 ° or an included angle of 90 °, it should be understood that the projection of the first light guide channel and the second light guide channel on the plane where the pixel region 330 is located may form any included angle between 0 ° and 180 °, and this is not limited in this embodiment of the present application.

It should also be understood that the implementation manner that the projection of the first light guide channel and the second light guide channel on the plane where the pixel region 330 is located forms an included angle of 180 degrees or an included angle of 90 degrees is not limited to the fingerprint identification unit shown in fig. 8 and 9, and other structures that the projection of the first light guide channel and the second light guide channel on the plane where the pixel region 330 is located forms an included angle of 180 degrees or an included angle of 90 degrees are also within the protection scope of the present application.

In the embodiment of the application, the light guide channel direction corresponding to the pixel unit can be adjusted by setting the pixel unit and the photosensitive area in the pixel unit, so that the light path requirement of the design can be met.

In the embodiments of the above application, the photosensitive regions in the two pixel units occupy only a small portion of the area of the pixel units, and in one possible implementation, the photosensitive regions in the two pixel units occupy a large portion of the area of the pixel units, so as to improve the dynamic range of the pixel units.

Alternatively, fig. 15 shows another schematic top view of the fingerprint recognition unit 301.

As shown in fig. 15, the photosensitive areas in the two pixel units are larger in area, and cover other areas besides the light spots on the pixel units. In fig. 15, the photosensitive regions in the two pixel cells occupy most of the area of the pixel cells. For example, the first photosensitive region 3311 in the first pixel unit 331 occupies more than 95% of the area in the first pixel unit 331, and/or the second photosensitive region 3321 in the second pixel unit 332 occupies more than 95% of the area in the second pixel unit 332.

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

It should be understood that the above-mentioned embodiments in fig. 8 to 15 only show the top view schematic diagram of the partial fingerprint identification unit 301 in the case that the centers of the pixel regions 330 and the centers of the microlenses coincide in the vertical direction, and the light sensing regions in the first pixel unit and the second pixel unit can be respectively arranged in any region of the pixel units to realize the purpose of receiving the target fingerprint light signals of 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 recognition device 300 is also composed of a plurality of fingerprint recognition units 301, and as shown in fig. 16, the plurality of fingerprint recognition units 301 are arranged in an array. Wherein the pixel cell in each fingerprint identification cell 301 only receives the fingerprint light signal converged by the microlens in that fingerprint identification cell 301, and does not receive the fingerprint light signal converged by the microlenses in the other fingerprint identification cells 301.

In the fingerprint recognition unit 301 of the present application, the first pixel unit 331 and the second pixel unit 332 are located obliquely below the corresponding microlens 310 in spatial position, and the center of the pixel region 330 where the first pixel unit 331 and the second pixel unit 332 are located and the center of the microlens 310 do not coincide in a direction perpendicular to the pixel region. Specifically, in the embodiment of the present application, the first photosensitive region 3311 in the first pixel unit 331 and the second photosensitive region 3321 in the second pixel unit 332 are both located obliquely below the corresponding first light guide channel and second light guide channel, so that the first photosensitive region 3311 only receives the first target fingerprint light signal passing through the first light guide channel, and the second photosensitive region 3321 only receives the second target fingerprint light signal passing through the second light guide channel, but does not receive light signals in other directions converged by other microlenses, which causes interference of fingerprint identification.

Fig. 17 shows a top view of a fingerprint recognition unit 301 of the fingerprint recognition device 300.

As shown in fig. 17, the first photosensitive area 3311 in the first pixel unit 331 is a quadrilateral area and circumscribes the first light spot 3301, and similarly, the second photosensitive area 3321 in the second pixel unit 332 is a quadrilateral area and circumscribes the second light spot 3302. The center of the first photosensitive region 3311 may be located at the bottom of the first light guide channel, and the center of the second photosensitive region 3321 may be located at the bottom of the second light guide channel.

Alternatively, the center of the first photosensitive region 3311 may be offset from the bottom of the first light guide channel, and the center of the second photosensitive region 3321 is offset from the bottom of the second light guide channel, but the first and second photosensitive regions include the first and second light spots. For example, the first photosensitive region 3311 in the first pixel unit 331 may occupy more than 95% of the area in the first pixel unit 331, and/or the second photosensitive region 3321 in the second pixel unit 332 may occupy more than 95% of the area in the second pixel unit 332.

As shown in fig. 17, the pixel region 330 formed by the first pixel unit 331 and the second pixel unit 332 is a quadrilateral pixel region, and the first photosensitive region 3311 and the second photosensitive region 3321 may be located on a diagonal line of the pixel region 330. In this case, an included angle between the first target fingerprint optical signal received by the first photosensitive region 3311 and the projection of the second target fingerprint optical signal received by the second photosensitive region 3321 on the plane where the pixel region 330 is located is 90 °, or an included angle between the projection of the first light guide channel on the plane where the pixel region 330 is located and the projection of the second light guide channel on the plane where the pixel region 330 is located is 90 °.

For example, fig. 18 shows a schematic top view of another fingerprint identification unit 301. As shown in fig. 18, the first photosensitive region 3311 and the second photosensitive region 3321 are simultaneously located at an upper side of the pixel region 330. At this time, an included angle between the first target fingerprint optical signal received by the first photosensitive region 3311 and the second target fingerprint optical signal received by the second photosensitive region 3321 in the plane of the pixel region 330 may be an acute angle smaller than 90 °, or a projection of the first light guide channel on the plane of the pixel region 330 and a projection of the second light guide channel on the plane of the pixel region 330 may be an acute angle smaller than 90 °.

It should be understood that the projection of the two light guide channels on the plane where the pixel region 330 is located may form any included angle between 0 ° and 180 °, and the included angle between the two light guide channels and the plane where the pixel region 330 is located may also form any angle between 0 ° and 90 °, which is not limited in this embodiment of the present application.

It should also be understood that, in the embodiment of the present application, the light guide channel direction corresponding to the pixel unit may be adjusted by setting the pixel unit and the photosensitive area in the pixel unit, so that the light guide channel meets the designed light path requirement.

Alternatively, based on the embodiments of the above-mentioned application, in one possible implementation, the distance from the center of the first photosensitive region 3311 in the first pixel unit 331 to the center of the microlens 310 is equal to the distance from the center of the second photosensitive region 3321 in the second pixel unit 332 to the center of the microlens 310.

Optionally, in this case, an included angle between the first target fingerprint optical signal received by the first photosensitive area 3311 and the second target fingerprint optical signal received by the second photosensitive area 3321 and the display screen is the same, or an included angle between the first light guide channel corresponding to the first photosensitive area 3311 and the display screen is equal to an included angle between the second light guide channel corresponding to the second photosensitive area 3321 and the display screen.

Certainly, the distance from the center of the first photosensitive region 3311 to the center of the microlens 310 and the distance from the center of the second photosensitive region 3321 to the center of the microlens 310 may also be unequal, at this time, the included angles between the first target fingerprint optical signal received by the first photosensitive region 3311 and the second target fingerprint optical signal received by the second photosensitive region 3321 and the display screen are different, or the included angle between the first light guide channel corresponding to the first photosensitive region 3311 and the display screen is unequal to the included angle between the second light guide channel corresponding to the second photosensitive region 3321 and the display screen.

In the spatial position, the pixel region 330 where the first pixel unit 331 and the second pixel unit 332 are located is located obliquely below the microlens 310, and fig. 17 and fig. 18 only illustrate two relative positions of the pixel region 330 where the first pixel unit 331 and the second pixel unit 332 are located in the fingerprint identification unit 301 and the microlens 310, it should be understood that, in the spatial position, the pixel region 300 may also be located in any region obliquely below the microlens 310, which is not limited in this embodiment of the present application, and the photosensitive regions in the first pixel unit 331 and the second pixel unit 332 may be located in any region in the pixel unit where they are located, which is not limited in this embodiment of the present application.

It should be understood that, whether the pixel region 330 in which the first pixel unit 331 and the second pixel unit 332 are located is located obliquely below the microlens 310 or directly below the microlens 310, as the pixel unit and the photosensitive region move, the direction of the target fingerprint light signal received by the photosensitive region and the direction of the light guide channel corresponding to the photosensitive region also change, in other words, the positions of the pixel unit and the photosensitive region relative to the microlens can also be designed according to the direction required by the target fingerprint light signal in the light path design.

Specifically, in a possible light path design manner, the angle of the first target fingerprint light signal is different from the angle of the second target fingerprint light signal, and the angle of the first target fingerprint light signal is greater than the angle of the second target fingerprint light signal, where the angle of the light signal is an included angle between the light signal and a direction perpendicular to the display screen.

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

h＝x×cotθ；

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

The above application embodiments show the case where the first pixel unit 331 and the second pixel unit in the fingerprint identification unit 301 receive the oblique light signal, alternatively, one of the first pixel unit 331 and the second pixel unit 332 can receive the target fingerprint light signal in the vertical direction, and the other 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 first pixel unit 331 and the second pixel unit 332 is vertical to the display screen, and the direction of the light guide channel corresponding to the other pixel unit is oblique to the display screen.

The following is exemplified by the first pixel unit 331 receiving a first target fingerprint light signal in an oblique direction and the second pixel unit 332 receiving a second target fingerprint light signal in a vertical direction.

Fig. 19 shows a top view of a fingerprint recognition unit 301 of the fingerprint recognition device 300.

As shown in fig. 19, the second photosensitive region 3321 in the second pixel unit 332 is located right below the center of the microlens 310, or the center of the second photosensitive region 3321 coincides with the center of the microlens 310 in the vertical direction. At this time, the second light guide channel corresponding to the second photosensitive region 3321 is also perpendicular to the microlens 310 or the display screen. At this time, the center of the first light-passing aperture 3211, the center of the third light-passing aperture 3222, the center of the microlens 310, and the center of the second photosensitive region 3321 in the second light-guiding channel are all located on the same straight line perpendicular to the display screen.

The first photosensitive area 3311 of the first pixel unit 331 is located obliquely below the center of the microlens 310, and receives the light signal obliquely from the display panel, and the direction of the corresponding first light guide channel is oblique to the display panel. Specifically, the first pixel unit 331 and the related technical features thereof can refer to the technical features of the above technical scheme in which both pixel units receive oblique optical signals, and are not described herein again.

Fig. 19 illustrates only one case where the first pixel unit 331 and the first photosensitive area 3311 of the fingerprint identification unit 301 are located obliquely below the microlens 310, and it should be understood that the first pixel unit 331 may also be located in any area obliquely below the microlens 310, which is not limited in this embodiment, and the photosensitive areas of the first pixel unit 331 and the second pixel unit 332 may be located in any area of the pixel units where they are located, which is also not limited in this embodiment.

In this application embodiment, receive the fingerprint light signal of vertical direction and the fingerprint light signal of incline direction respectively through two pixel, when finger and display screen contact are good, the fingerprint light signal light of vertical direction is powerful, and the fingerprint image signal that corresponds is of high quality, can carry out fingerprint identification fast, and meanwhile, when doing finger and display screen contact failure, the fingerprint light signal of incline direction can improve the fingerprint identification problem of doing the finger, and can reduce fingerprint identification device's thickness.

The fingerprint recognition unit 301 of the present application is described in detail above with reference to fig. 6 to 19.

Specifically, the fingerprint identification device 300 includes a plurality of fingerprint identification units 301, wherein each of the plurality of fingerprint identification units 301 includes two of the pixel units, and thus, the fingerprint identification device 300 includes a plurality of groups of two of the pixel units, which form a pixel array of the fingerprint identification device 300.

Alternatively, as shown in fig. 20, in a possible implementation, two pixel units in one fingerprint identification unit 301 are rectangular pixel units, and the pixel array 302 of the fingerprint identification device 300 is represented as a pixel matrix with a plurality of rectangular pixel unit array arrangements.

Optionally, a plurality of target pixel units 3021 are disposed in the pixel array 302, and a color filter layer is disposed in the light guide channel corresponding to the plurality of target pixel units 3021, and the color filter layer is configured to pass color light with a specific wavelength and be received by the plurality of target pixel units.

Optionally, the plurality of target pixel units 3021 may all be the first pixel unit 331, may also all be the second pixel unit 332, and may also include both the first pixel unit 331 and the second pixel unit 332, which is not limited in this embodiment of the application.

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

In one 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.

Alternatively, in the embodiment of the present application, the plurality of target pixel cells 3021 in the pixel array 302 are used for sensing one of a red signal, a blue signal or a green signal, for example, the plurality of target pixel cells 3021 sense only the red signal and form a corresponding electrical signal, but do not sense light signals other than the red signal.

When a finger presses, the plurality of target pixel units 3021 sense red light signals, some of the plurality of target pixel units can receive red light signals passing through the finger, and other some of the plurality of target pixel units cannot receive red light signals passing through the finger.

Based on the difference in the red light signals sensed by the plurality of target pixel cells 3021, the fingerprint region 303 of the finger is determined.

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

Alternatively, the green light signal and the blue light signal sensed by the plurality of target pixel units 3021 may be a complete green band light signal or a blue band light signal, for example, a green light signal with a wavelength between 490nm and 570nm or a blue light signal with a wavelength between 450nm and 475nm, or may also be a light signal of a partial band in a green band or a blue band, for example, the green light signal is a green light signal with any band range between 490nm and 570nm or any wavelength, and the blue light signal is a green light signal with any band range between 450nm and 475nm or any wavelength.

Therefore, in the technical solution of the embodiment of the present application, a plurality of target pixel units 3021 may be arranged to sense a color light signal, and a fingerprint area pressed by a finger and an area pressed by a non-finger on a display screen are determined according to a difference between color light signals received by different target pixel units, and in a fingerprint identification process, a fingerprint identification process is directly performed on an optical signal sensed by a pixel unit corresponding to the fingerprint area pressed by the finger, so that interference caused by the pixel unit corresponding to the area pressed by the non-finger on fingerprint identification is avoided, and thus a success rate of fingerprint identification is improved. In addition, because the absorption and reflection performance of the finger on the colored light signals is different from the absorption and reflection performance of other materials on the colored light signals, the anti-counterfeiting function of fingerprint identification can be enhanced according to the intensity of the received colored light signals, and whether the finger is pressed by a real finger or a fake finger can also be judged.

The fingerprint recognition device 300 includes a plurality of groups of the two pixel units, which form a pixel array of the fingerprint recognition device 300.

Optionally, the plurality of target pixel cells 3021 are uniformly or non-uniformly distributed in the pixel array 302.

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

For example, as shown in fig. 20, the unit pixel region 3023 may be a pixel region of 4 fingerprint recognition units, i.e., a pixel region of 8 pixel units. It should be understood that the unit pixel area may also be a pixel unit area with any other size, which is not limited in this embodiment of the application.

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

Fig. 21a to 21c show schematic diagrams of the pixel array 302 in three fingerprint recognition devices 300. As shown in fig. 21a to 21c, the numeral "1" denotes the first pixel unit 331, and the numeral "2" denotes the second pixel unit 332.

As shown in fig. 21a, a plurality of first pixel units 331 are arranged in a plurality of rows in the pixel array 302, a plurality of second pixel units 332 are also arranged in a plurality of rows in the pixel array 302, a row of second pixel units 332 is arranged between two rows of first pixel units 331, and the plurality of rows of first pixel units 331 and the plurality of rows of second pixel units 332 are alternately arranged in an alternating manner.

As shown in fig. 21b, the plurality of first pixel units 331 are arranged in a plurality of rows in the pixel array 302, the plurality of second pixel units 332 are also arranged in a plurality of rows in the pixel array 302, one row of second pixel units 332 is arranged between two rows of first pixel units 331, and the plurality of rows of first pixel units 331 and the plurality of rows of second pixel units 332 are alternately arranged in an interleaving manner.

As shown in fig. 21c, the plurality of first pixel units 331 and the plurality of second pixel units 332 are alternately arranged in the pixel array 302, wherein the four pixel units of the first pixel unit 331, the upper, the lower, the left, the right, and the left are the second pixel units 332, the four pixel units of the second pixel unit 332, the upper, the lower, the left, the right, and the left are the first pixel units 331, and the plurality of first pixel units 331 and the plurality of second pixel units 332 are alternately arranged.

In the pixel array 302, a plurality of first pixel units 331 receive a fingerprint light signal of one direction, which is used to form a first fingerprint image of a finger. The plurality of second pixel units 332 receive fingerprint light signals of another direction, which are used to form a second fingerprint image of the finger. The first fingerprint image and the second fingerprint image can be used for fingerprint identification independently, and can also be used for reconstructing two fingerprint images and carrying out fingerprint identification on the reconstructed fingerprint images.

Alternatively, in a possible implementation, the first target fingerprint light signal received by one first pixel unit 331 is used to form one pixel point in the first fingerprint image. A second pixel element 332 receives the second target fingerprint light signal to form a pixel in the second fingerprint image.

Alternatively, in another possible embodiment, the first target fingerprint light signals received by the X first pixel units 331 are used to form one pixel point in the first fingerprint image. The second target fingerprint light signals received by the X second pixel units 332 are used to form a pixel point in the second fingerprint image, where X is a positive integer. Specifically, in the embodiment of the present application, the fingerprint identification device 300 further includes a processing Unit, and 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 Controller Unit (MCU) or the like. The processor may also be a processor in the electronic device where the fingerprint identification device 300 is located, for example, a main control chip in a mobile phone, and the like, which is not limited in this embodiment of the application.

Specifically, the processing unit includes a first sub-processing unit for acquiring the electrical signals of X first pixel units 331 to form one pixel value in a first fingerprint image of the finger, and a second sub-processing unit for acquiring the electrical signals of X second pixel units 332 to form one pixel value in a second fingerprint image of the finger.

Optionally, the first sub-processing unit is configured to be connected to X first pixel units 331 in the pixel array 302 through metal traces, and use an average value of pixel values of the X first pixel units 331 as a pixel value in the first fingerprint image.

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

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, 4 first pixel units of 2 × 2, or 9 first pixel units of 3 × 3, and likewise, the X second pixel units 332 may be adjacent X pixel units in the plurality of second pixel units 332 of the pixel array 302, where X is not specifically limited in this embodiment of the application.

Fig. 22 is a schematic configuration 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 screen 120, and a fingerprint identification apparatus 300 located below the filter 400 and composed of a plurality of fingerprint identification units 301, wherein the pixel unit of each fingerprint identification unit 301, i.e., the pixel array 302, may be disposed on the upper surface of the substrate 500. Wherein the pixel array 302 and the substrate 500 may be referred to as a fingerprint sensor or an image sensor.

Optionally, in this 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, and may specifically be a Circuit board (PCB), a Flexible Printed Circuit (FPC), a software-integrated Circuit board, or the like, which is not limited in this embodiment.

The fingerprint identification process based on the oblique optical signals in multiple directions according to the embodiment of the present application is described below with reference to fig. 23 to 27. For ease of understanding, the fingerprint identification process is exemplified by 2-direction oblique light signals.

When the optical signal received by the fingerprint identification device is an optical signal carrying an alternate pattern of bright and dark stripes as shown in fig. 23, and 2 pixel units corresponding to each microlens in the fingerprint identification device are used for receiving target fingerprint optical signals in 2 different directions, the pixel array in the fingerprint identification device simultaneously images the optical signals in different imaging areas, so that an image formed by the pixel array in the fingerprint identification device is a superimposed image of the different imaging areas, and is a blurred image. Such as the image shown in fig. 24.

In some embodiments of the present application, the first image and the second image may be obtained by performing extraction processing on the original image in fig. 24. In particular, when the light signal received by the fingerprint identification device is a fingerprint light signal reflected or scattered by a finger, the image formed by the pixel array is a superimposed image of different areas of the fingerprint, and is also a blurred image. An electrical signal of a first fingerprint image formed by a plurality of first pixel units receiving the first target fingerprint optical signal in the pixel array and an electrical signal of a second fingerprint image formed by a plurality of second pixel units receiving the second target fingerprint optical signal can be obtained by processing the original image.

For example, as shown in fig. 25, the original image generated by the plurality of first pixel units in the pixel array is a clear image, and since the plurality of first pixel units all receive the optical signals in the same direction, there is no situation that images of different imaging areas are superimposed, and therefore, the processing unit can process the first image shown in fig. 25 corresponding to the optical signals in the first direction to obtain the clear image. Similarly, the processing unit may process a second image generated by a plurality of second pixel units as shown in fig. 26.

In some embodiments of the present application, the first image and the second image may be processed and reconstructed to form a clear image as shown in fig. 27.

For example, the first image and the second image may be respectively moved by a distance of several bit image pixels in the image to form a clear image as shown in fig. 27.

In other words, the first image may be shifted to the right and down by a distance of several image pixels and the second image may be shifted to the left and up by a distance of several pixels to form a clear image as shown in fig. 27.

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

In the embodiment of the present application, the processing unit may algorithmically adjust the moving distance of the two images (for example, the first image and the second image described above) according to the quality parameter of the reconstructed image to form the target reconstructed image.

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

Alternatively, adjusting the moving distance of the two images may be adjusting the number of pixels of the moving image of the two images. When the moving distance of the two images is the distance of N image pixel points, the N can be adjusted according to the quality parameters of the reconstructed image to form a target reconstructed image.

Because the thickness of the display screen is fixed and the relative position between the display screen and the fingerprint identification device is basically unchanged, an original image (such as the image shown in fig. 24) can be collected first, the number of image pixels, which need to be moved, of the image corresponding to the oblique optical signal in each direction when the imaging quality of the reconstructed image is clearest, is determined as a moving image parameter, and the moving image parameter is stored in the storage unit. Furthermore, in the subsequent fingerprint acquisition process, a clear image can be reconstructed based on the moving image parameters.

It should be understood that the original image may be a fingerprint image, or any pattern with clear contrast originally overlaid on the surface of the display screen. For example, the image in fig. 23 is similar to the shape of the fingerprint ridges and fingerprint valleys in the fingerprint image, when the optical signal received by the fingerprint identification device is an optical signal reflected or scattered by a finger, the image processed by the processing unit may be similar to the image shown in fig. 24 before processing and reconstruction, and the fingerprint image processed and reconstructed may be similar to the image shown in fig. 27 to be a clear fingerprint image.

In addition, when the electronic equipment who installs fingerprint identification device is used by the user, run into strong impact, fingerprint identification device changes or at the volume production in-process with the installation distance of display screen, when installation distance is undulant between fingerprint identification device and the display screen changes, the image pixel distance of two image movements changes, at this moment, can the automatic calibration at the distance of the image pixel of two image movements under the installation distance change condition, and then guarantee the definition of the image after the reconsitution, SNR and contrast, thereby guarantee fingerprint identification device's fingerprint identification effect, improve user experience.

In other words, if the position of the fingerprint module group relative to the display screen is shifted, the distance of the image pixel to be moved of each image can be determined again through the original image. The position of the fingerprint module relative to the display screen can be determined to have shifted when the quality of the image is lower than a preset threshold value or the value measured by the accelerometer exceeds the preset threshold value.

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

It is to be understood that the drawings are merely exemplary of embodiments of the application and are not to be construed as limiting the application.

For example, alternatively, the at least one light-blocking layer included in the fingerprint identification device includes more light-blocking layers than 3 light-blocking layers.

For another example, the fingerprint recognition device may further include an image sensor driving unit, a micro-program controller, and the like.

The embodiment of the application also provides electronic equipment which can comprise a display screen and the fingerprint identification device, wherein the fingerprint identification device is arranged below the display screen to realize optical fingerprint identification under the screen. The electronic device may be any electronic device having a display screen.

The display screen may be the display screen described above, for example, an OLED display screen or other display screens, and the description of the display screen in the above description may be referred to for the relevant description of the display screen, and for brevity, the description is not repeated here.

In some embodiments of the present application, a layer of foam may be disposed below the display screen, and the layer of foam may be disposed above the fingerprint recognition device with at least one opening for transmitting the light signal reflected by the finger to the fingerprint recognition device.

For example, there is the cotton black bubble of one deck below the display screen, and this black bubble is cotton can be provided with an trompil in fingerprint identification device's top, and when the finger was put in the display screen top of lighting up, the light that the display screen sent will be reflected to the finger, and the reverberation via finger reflection can pierce through the display screen and transmit to fingerprint identification device through at least one trompil. A fingerprint is a diffuse reflector whose reflected light is present in all directions.

At this time, a specific optical path in the fingerprint identification device may be used, so that the optical sensing pixel array in the fingerprint identification device receives oblique optical signals in multiple directions, and the processing unit in the fingerprint identification device or the processing unit connected to the fingerprint identification device may acquire a reconstructed fingerprint image through an algorithm, so as to perform fingerprint identification.

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

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

In some embodiments of the present application, the fingerprint recognition device may output the collected image to a special processor of a computer or a special processor of an electronic device, so as to perform fingerprint recognition.

It should be understood that the processor of the embodiments of the present application may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The Processor may be a general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, or discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

It will be appreciated that the fingerprinting of embodiments of the present application may also include memory, which may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile Memory may be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash Memory. Volatile Memory can be Random Access Memory (RAM), which acts as external cache Memory. By way of example, but not limitation, many forms of RAM are available, such as Static random access memory (Static RAM, SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic random access memory (Synchronous DRAM, SDRAM), Double Data Rate Synchronous Dynamic random access memory (DDR SDRAM), Enhanced Synchronous SDRAM (ESDRAM), Synchronous link SDRAM (SLDRAM), and Direct Rambus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It should be understood that the specific examples in the embodiments of the present application are for the purpose of promoting a better understanding of the embodiments of the present application and are not intended to limit the scope of the embodiments of the present application.

It is to be understood that the terminology used in the embodiments of the present application and the appended claims is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the present application. For example, as used in the examples of this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Those of ordinary skill in the art will appreciate that the elements of the examples described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the components and steps of the examples have been described above generally in terms of their functionality in order to clearly illustrate the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the several embodiments provided in the present application, it should be understood that the disclosed system and apparatus may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may also be an electric, mechanical or other form of connection.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments of the present application.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially or partially contributed by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: u disk, removable hard disk, read only memory, random access memory, magnetic or optical disk, etc. for storing program codes.

While the invention has been described with reference to specific embodiments, the scope of the invention is not limited thereto, and those skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the invention. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. The utility model provides a fingerprint identification device which characterized in that is applicable to the below of display screen in order to realize optical fingerprint identification under the screen, fingerprint identification device is including being a plurality of fingerprint identification units of square array distribution, every fingerprint identification unit in a plurality of fingerprint identification units includes:

a microlens;

at least two light blocking layers arranged below the micro lens, wherein each light blocking layer of the at least two light blocking layers is provided with a light passing small hole to form two light guide channels in different directions;

the two pixel units are arranged below the at least two light blocking layers and are respectively positioned at the bottoms of the two light guide channels, the bottom light blocking layer in the at least two light blocking layers is provided with two light through small holes respectively corresponding to the two pixel units, each pixel unit in the two pixel units comprises a photosensitive area, and the photosensitive area is positioned at the bottom of the light guide channel;

the included angle of the projections of the two light guide channels on the plane where the two pixel units are located is 90 degrees, two target fingerprint optical signals in different directions in the fingerprint optical signals returned after being reflected or scattered by a finger above the display screen are converged by the micro lens and then are transmitted to the two pixel units through the two light guide channels, the two target fingerprint optical signals are used for detecting fingerprint information of the finger, and non-target fingerprint optical signals in the fingerprint optical signals are blocked by the light blocking layer;

at least one photosensitive area of two photosensitive areas in the two pixel units is arranged in a manner of deviating from the center of the pixel unit where the photosensitive area is located, and the at least one photosensitive area deviates in a direction far away from the center of the micro lens;

the plurality of fingerprint recognition units include: the pixel structure comprises a plurality of groups of two pixel units, wherein the area where the two pixel units are located is composed of a plurality of unit pixel areas, each unit pixel area in the unit pixel areas comprises a plurality of pixel units, and the pixel units comprise a target pixel unit;

the light guide channel corresponding to the target pixel unit is provided with a color filter layer, the color filter layer is used for passing red visible light, green visible light or blue visible light, the target pixel unit is used for sensing the red visible light, the green visible light or the blue visible light so as to determine a fingerprint area of the finger or judge whether the finger is a real finger, and an optical signal sensed by the pixel unit corresponding to the fingerprint area is used for fingerprint identification.

2. The fingerprint recognition device of claim 1, wherein at least one of the two light guide channels is oriented in a direction that is oblique with respect to the display.

3. The fingerprint identification device of claim 1, wherein the two light guide channels are at the same angle with respect to the display screen.

4. The fingerprint recognition device according to any one of claims 1 to 3, wherein the two pixel units form a quadrilateral pixel area, and the two photosensitive areas are respectively located on the diagonal line of the pixel area or are located on one side of the pixel area.

5. The fingerprint recognition device according to any one of claims 1 to 3, wherein the two pixel units comprise a first pixel unit, the first pixel unit comprises a first photosensitive area, and the first pixel unit and the first photosensitive area are both quadrilateral;

the length and the width of the first pixel unit are L and W respectively, the length and the width of the first photosensitive area are both larger than or equal to 0.1 xW, W is smaller than or equal to L, and W and L are positive numbers.

6. The fingerprint identification device according to any one of claims 1 to 3, wherein the two target fingerprint light signals form two light spots on the two pixel units respectively, and the two light sensing areas are quadrilateral areas and circumscribe the two light spots.

7. The fingerprint identification device according to any one of claims 1 to 3, wherein if an angle between a first target fingerprint optical signal of the two target fingerprint optical signals and a vertical direction is larger than an angle between a second target fingerprint optical signal of the two target fingerprint optical signals and the vertical direction, the vertical direction being a direction perpendicular to the display screen, a first photosensitive area of the two photosensitive areas is configured to receive the first target fingerprint optical signal;

the height of the optical path between the micro lens and the plane where the two pixel units are located is calculated according to a formula, wherein the formula is as follows: h is x × cot θ;

wherein h is the optical path height, x is a distance between the center of the first photosensitive area and a projection point of the center of the microlens on a plane where the two pixel units are located, and θ is an angle of the first target fingerprint optical signal.

8. The fingerprint recognition device according to any one of claims 1 to 3, wherein the two pixel units are rectangular pixel units with the same size.

9. The fingerprint identification device according to any one of claims 1 to 3, wherein the two light guide channels respectively form an angle of 30 ° to 90 ° with the plane of the two pixel units.

10. The fingerprint identification device according to any one of claims 1 to 3, wherein the bottom light blocking layer is a metal wiring layer on the surface of the two pixel units.

11. The fingerprint identification device according to any one of claims 1 to 3, wherein the light-passing apertures in the two light guide channels decrease in aperture from top to bottom.

12. The fingerprint identification device according to any one of claims 1 to 3, wherein the two light guide channels coincide with a light passing aperture in a top light barrier layer of the at least two light barrier layers.

13. The fingerprint recognition device according to any one of claims 1 to 3, wherein the fingerprint recognition unit further comprises:

a transparent dielectric layer;

14. The fingerprint recognition device according to any one of claims 1 to 3, wherein the fingerprint recognition unit further comprises:

an optical filter layer;

15. The fingerprint recognition device of claim 14, wherein the optical filter layer is integrated on the surfaces of the two pixel units.

16. The fingerprint recognition device according to claim 14, wherein the optical filter layer is disposed between a bottom light-blocking layer of the at least two light-blocking layers and a plane in which the two pixel units are located.

17. The fingerprint recognition device according to any one of claims 1 to 3, wherein the plurality of target pixel units are uniformly distributed in a plurality of groups of the two pixel units.

18. The fingerprint identification device according to any one of claims 1 to 3, wherein the color filter layer is disposed in the light-passing aperture of the corresponding light guide channel of the target pixel unit.

19. The fingerprint recognition device according to any one of claims 1 to 3, wherein the optical signals received by a plurality of first pixel units in a plurality of groups of said two pixel units are used for forming a first fingerprint image of said finger, the optical signals received by a plurality of second pixel units in a plurality of groups of said two pixel units are used for forming a second fingerprint image of said finger, and said first fingerprint image and/or said second fingerprint image are used for fingerprint recognition.

20. The fingerprint recognition device of claim 19, wherein an average of pixels of every X first pixel units of the plurality of first pixel units is used to form a pixel value in the first fingerprint image; and/or the presence of a gas in the gas,

and the pixel average value of every X second pixel units in the plurality of second pixel units is used for forming one pixel value in the second fingerprint image, wherein X is a positive integer.

21. The fingerprint recognition device of claim 19, wherein the plurality of first pixel units and the plurality of second pixel units are alternately arranged in an alternating and alternating manner; or,

the plurality of first pixel units are arranged in a plurality of rows of first pixel units, the plurality of second pixel units are arranged in a plurality of rows of second pixel units, and the plurality of rows of first pixel units and the plurality of rows of second pixel units are alternately arranged in an alternating and penetrating manner; or,

the plurality of first pixel units are arranged in a plurality of rows of first pixel units, the plurality of second pixel units are arranged in a plurality of rows of second pixel units, and the plurality of rows of first pixel units and the plurality of rows of second pixel units are alternately arranged in an interleaving manner.

22. The fingerprint recognition device according to claim 19, further comprising a processing unit, wherein the processing unit is configured to move the first fingerprint image and the second fingerprint image to combine to form a reconstructed image, and adjust a moving distance of the first fingerprint image and the second fingerprint image according to a quality parameter of the reconstructed image to form a target reconstructed image, and the target reconstructed image is used for fingerprint recognition.

23. The fingerprint recognition device according to any one of claims 1 to 3, wherein the distance between the fingerprint recognition device and the display screen is 0 to 1 mm.

24. An electronic device, comprising:

a display screen; and

the fingerprint recognition device of any one of claims 1-23, said fingerprint recognition device disposed below said display screen to enable off-screen optical fingerprint recognition.