WO2021036101A1 - Fingerprint recognition apparatus and electronic device - Google Patents

Abstract

A fingerprint recognition apparatus (300) and an electronic device (30), capable of improving the performance of the fingerprint recognition apparatus (300). The fingerprint recognition apparatus (300) is applied to a lower portion of a display screen (120). Each of a plurality of fingerprint recognition units (301) comprises: a microlens (310); at least two light shielding layers (220), each light shielding layer (220) being provided with light passing pores (2211, 2221, 2222, 2231) to form four light guide channels in different directions; and four pixel units (331, 332, 333, 334) respectively located at the bottoms of the four light guide channels. After fingerprint optical signals returned from a fingerprint above the display screen (120) are converged by means of the microlens (310), four target fingerprint optical signals in different directions are respectively transmitted to the four pixel units (331, 332, 333, 334) by means of the four light guide channels. Included angles of the four light guide channels relative to the display screen (120) are not completely the same. A plurality of groups of the four pixel units (331, 332, 333, 334) in the fingerprint recognition apparatus (300) receives fingerprint optical signals in four different directions and converts same into four fingerprint images, and the four fingerprint images are moved and reconstructed into a reconstructed image for fingerprint recognition.

Description

Fingerprint identification device and electronic equipment

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

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

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

Technical field

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

Background technique

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

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

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

Summary of the invention

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

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

Micro lens

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

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

Wherein, the fingerprint light signals returned after being reflected or scattered from the finger above the display screen are condensed by the microlens, and the four target fingerprint light signals in different directions are respectively transmitted to the four pixel units through the four light guide channels , The angles of the four light guide channels relative to the display screen are not completely the same, and the four target fingerprint light signals are used to detect the fingerprint information of the finger.

According to the solution of the present application, one microlens corresponds to four pixel units, and the four pixel units respectively receive the target fingerprint light signals in four directions condensed by the microlens and passed through the four light guide channels. The fingerprint light signal is received by the four pixel units respectively. Compared with the technical solution that one microlens corresponds to one pixel unit, the amount of light entering the fingerprint identification device can be increased, the exposure time can be reduced, and the field of view of the fingerprint identification device can be increased. In addition, with respect to the technical solution in which one microlens corresponds to four pixel units, and the center of the microlens and the centers of the four pixel units overlap in the vertical direction, in the technical solution of the present application, the four light guide channels are relative to the display screen. The angles are not exactly the same. The angle of the fingerprint light signal received by the four pixel units is determined by the relative positional relationship between the four pixel units and the microlens. If the pixel unit shifts farther from the center of the microlens, the fingerprint received by the pixel unit The greater the angle of the optical signal. Therefore, by flexibly setting the position of the pixel unit, the pixel unit can receive a large-angle fingerprint light signal, which further improves the identification problem of dry fingers, and can further reduce the thickness of the light path in the fingerprint identification unit, thereby reducing the fingerprint identification device Thickness, reduce process cost.

In a possible implementation manner, the four pixel units form a pixel area of a quadrilateral area, and the center point of the pixel area does not coincide with the center of the microlens in the vertical direction.

In a possible implementation, the pixel area is a square area with side length a, and the distance between the projection point of the center of the microlens on the plane where the four pixel units is located and the center point of the pixel area is d, Where 0<d<a.

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

By adopting the solution of the embodiment of this application, by setting the direction of the light guide channel, the pixel units in the four pixel units can respectively receive the fingerprint light signal in the vertical direction and the fingerprint light signal in the oblique direction. When the finger is in good contact with the display screen When the fingerprint light signal in the vertical direction is strong, the corresponding fingerprint image signal quality is good, and fingerprint recognition can be performed quickly. At the same time, when the dry finger is in poor contact with the display, the fingerprint light signal in the oblique direction can improve the fingerprint of the dry finger Identify the problem, and can reduce the thickness of the fingerprint identification device. If the four pixel units all receive the fingerprint light signals in the oblique direction, the fingerprint light signals in different oblique directions are used to further optimize the identification problem of dry fingers.

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

By adopting the solution of the implementation of the present application, by setting the direction of the light guide channel, the fingerprint light signals received by the two pixel units of the four pixel units are perpendicular to each other, which facilitates the collection of fingerprint light perpendicular to the ridge and valley lines of the fingerprint. The signal can improve the quality of the fingerprint optical signal received by the fingerprint identification unit, thereby improving the quality of the fingerprint image and improving the fingerprint identification performance of the fingerprint identification device.

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

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

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

In a possible implementation manner, the four pixel units form a quadrilateral pixel area, and the four photosensitive areas are respectively located at four corners of the pixel area.

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

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

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

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

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

In a possible implementation manner, the four pixel units are quadrilateral pixel units with the same size.

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

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

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

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

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

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

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

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

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

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

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

In a possible implementation manner, the plurality of fingerprint identification units includes: a plurality of groups of the four pixel units include a plurality of target pixel units, and the light guide channels corresponding to the plurality of target pixel units are provided with a color filter layer, The color filter layer is used to pass red visible light, green visible light or blue visible light.

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

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

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

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

In a possible implementation, multiple groups of light signals received by a plurality of first pixel units of the four pixel units are used to form a first fingerprint image of the finger, and multiple groups of light signals received by multiple first pixel units of the four pixel units are used to form the first fingerprint image of the finger. The light signal received by the second pixel unit is used to form a second fingerprint image of the finger, and the light signals received by a plurality of third pixel units of the four pixel units are used to form a third fingerprint image of the finger. The light signals received by a plurality of fourth pixel units among the four pixel units are used to form a fourth fingerprint image of the finger, the first fingerprint image, the second fingerprint image, the third fingerprint image, and the fourth fingerprint One or more images in the image are used for fingerprint recognition.

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

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

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

In a possible implementation, the fingerprint identification device further includes a processing unit configured to move the first fingerprint image, the second fingerprint image, the third fingerprint image, and the fourth fingerprint image to form a combination Is a reconstructed image, and the moving distances of the first fingerprint image, the second fingerprint image, the third fingerprint image, and the fourth fingerprint image are adjusted according to the quality parameters of the reconstructed image to form a target reconstructed image, The reconstructed image of the target is used for fingerprint recognition.

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

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

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

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

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

Description of the drawings

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

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

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

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

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

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

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

Fig. 10 is a schematic cross-sectional view of the fingerprint identification unit in Fig. 8 along the direction B-B'.

Fig. 11 is a schematic top view of another fingerprint identification unit according to an embodiment of the present application.

Fig. 12 is a schematic cross-sectional view of the fingerprint identification unit in Fig. 11 along the A-A' direction.

Fig. 13 is a schematic top view of another fingerprint identification unit according to an embodiment of the present application.

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

Figures 17a and 17b are schematic diagrams of two types of pixel arrays in a fingerprint identification device according to an embodiment of the present application.

Fig. 18 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Figures 19 to 25 are schematic diagrams of fingerprint images in the fingerprint identification process of an embodiment of the present application.

detailed description

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

For example, as shown in FIGS. 4 and 5, the light blocking layer under the first microlens 211 in the microlens array 210 is formed with 4 light guide channels, and the first microlens 211 corresponds to the 4 pixels below it. The four pixel units include the first pixel unit 231 and the second pixel unit 232 shown in the figure.

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

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

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

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

However, in this embodiment, the center of one microlens and the centers of the four pixel units coincide in the vertical direction, which is limited by the fixed arrangement of the pixel array and the microlens array, and the inclination angle of the light signal received by the pixel unit is limited. The recognition performance of dry fingers is not optimal, and the overall optical path is still thick, which is not conducive to the further development of thinner and lighter fingerprint recognition devices.

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

Hereinafter, the fingerprint identification device of the embodiment of the present application will be described in detail with reference to FIGS. 6 to 25.

It should be noted that, for ease of understanding, in the embodiments shown below, the same structure uses the same reference numerals, and for the sake of brevity, a detailed description of the same structure is omitted.

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

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

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

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

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

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

Micro lens 310;

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

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

Among them, the fingerprint light signal returned from the finger above the display screen is reflected or scattered after being condensed by the above-mentioned microlens 310. Among them, four target fingerprint light signals in different directions (the first target fingerprint light signal, the second target fingerprint light signal, The third target fingerprint light signal and the fourth target fingerprint light signal) are respectively transmitted to the above four pixel units through the above four light guide channels, the angles of the four light guide channels with respect to the display screen are not completely the same, and the four light guide channels A target fingerprint light signal is used to detect fingerprint information of the finger.

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

Optionally, if the microlens 310 is a circular microlens, its diameter is not greater than the arrangement period of four pixel units. For example, if the area where the four pixel units are located is an A×B quadrilateral area, where A≤B, and A and B are positive integers, the diameter of the microlens 310 is less than or equal to A.

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

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

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

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

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

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

Optionally, as shown in FIG. 7, a first light-passing hole 3211 is formed on the first light-blocking layer 321, and four light-passing holes are formed on the second light-blocking layer 322, which are respectively the second light-passing holes. The hole 3221, the third light-passing hole 3222, the fourth light-passing hole 3223, and the fifth light-passing hole 3224. The second light-passing hole 3221 and the first light-passing hole 3211 form a first light guide channel for passing the first target fingerprint light signal in the fingerprint light signal condensed by the microlens 310, which is located in the first light guide. The first pixel unit 331 at the bottom of the light guide channel receives it. Similarly, the third light-passing hole 3222 and the first light-passing hole 3211 form a second light guide channel for passing the second target fingerprint light signal, which is located at the second pixel unit 332 at the bottom of the second light guide channel. receive. The fourth light-passing hole 3223 and the first light-passing hole 3211 form a third light guide channel for passing the third target fingerprint light signal, which is received by the third pixel unit 333 at the bottom of the third light guide channel. The fifth light-passing hole 3224 and the first light-passing hole 3211 form a fourth light guide channel for passing the fourth target fingerprint light signal, which is received by the fourth pixel unit 334 at the bottom of the fourth light guide channel. The first target fingerprint optical signal, the second target fingerprint optical signal, the third target fingerprint optical signal, and the fourth target fingerprint optical signal are used to detect fingerprint information.

In the embodiment of the present application, each of the above-mentioned light-passing holes can be located at any position under the microlens 310 to form any four light-guiding channels in different directions, and the light-guiding channels in different directions are the same as those of the display screen. The angles are not exactly the same. In other words, the first pixel unit 331, the second pixel unit 332, the third pixel unit 333, and the fourth pixel unit 334 corresponding to the microlens 310 can also be located at any position below the microlens 310, and are intended to receive the signals passing through four different directions. The four different directions of the fingerprint light signals of the light guide channel, the four different directions of the fingerprint light signals are also not completely the same as the angles of the display screen.

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

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

Through the solution of the embodiment of the present application, one microlens corresponds to four pixel units, and the four pixel units respectively receive fingerprint light signals in four directions condensed by the microlens and passed through the four light guide channels. The fingerprint light signal is received by the four pixel units respectively. Compared with the technical solution of one microlens corresponding to one pixel unit (such as the fingerprint identification device in Figure 2 and Figure 3), it can increase the amount of light entering the fingerprint identification device, reduce the exposure time, and increase the field of view of the fingerprint identification device .

In addition, with respect to a technical solution in which one microlens corresponds to four pixel units, and the center of the microlens and the center of the four pixel units overlap in the vertical direction (for example, the fingerprint identification device in FIG. 4 and FIG. 5), the embodiment of the present application The angles of the four light guide channels with respect to the display screen are not completely the same. The angle of the fingerprint light signal received by the four pixel units (the angle between the fingerprint light signal and the direction perpendicular to the display screen) is determined by the four pixel units. The relative positional relationship with the micro lens determines that if the pixel unit shifts farther from the center of the micro lens, the greater the angle of the fingerprint light signal received by the pixel unit. Therefore, by flexibly setting the position of the pixel unit, the pixel unit can receive a large-angle fingerprint light signal, which further improves the identification problem of dry fingers, and can further reduce the thickness of the light path in the fingerprint identification unit, thereby reducing the fingerprint identification device Thickness, reduce process cost.

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

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

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

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

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

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

For example, as shown in Fig. 7, the fingerprint identification unit includes two light-blocking layers, the top light-blocking layer of the two-layer light-blocking layer is provided with a first light-passing hole 3211, and the bottom layer of the two-layer light-blocking layer blocks light Four light-passing holes corresponding to four pixel units are arranged on the layer.

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

For example, in FIG. 7, the direction of the first light guide channel corresponding to the first pixel unit 331 is the connecting direction of the first light-passing hole 3211 and the second light-passing hole 3221 or a direction close to the connecting direction. , The direction of the second light guide channel corresponding to the second pixel unit 331 is the connecting direction of the first light-passing hole 3211 and the third light-passing hole 3222 or a direction close to the connecting direction, and the third pixel unit The direction of the third light guide channel corresponding to 333 is the connecting direction of the first light-passing hole 3211 and the fourth light-passing hole 3223 or a direction close to the connecting direction. The fourth pixel unit 334 corresponds to the fourth pixel unit 334. The direction of the light guide channel is the connecting direction of the first light-passing hole 3211 and the fifth light-passing hole 3224 or a direction close to the connecting direction.

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

Optionally, 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 the middle light-blocking layer, and four light-guiding channels The connection direction of the light-passing holes of the bottom light-shielding layer and the top light-shielding layer is the direction of the light guide channel, and the center of the light-passing hole in the middle light-shielding layer can be located at the connection line of the four light guide channels. on.

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

For example, the metal wiring layer of four pixel units is arranged at the back focal plane position of the microlens 310, and the metal wiring layer is the bottom light-shielding layer of at least two light-shielding layers, and is respectively above the photosensitive regions of the four pixel units. A second light passage hole 3221, a third light passage hole 3222, a fourth light passage hole 3223, and a fifth light passage hole 3224 are formed.

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

Optionally, the top light-blocking layer of the at least two light-blocking layers is provided with at least one light-passing hole corresponding to the four pixel units. For example, four pixel units can be provided with a light-passing hole in the top light-blocking layer. For example, four pixel units can also be provided with a light-passing hole in the top light-shielding layer, such as the above-mentioned first pass. The light aperture 3211, in other words, the first light guide channel corresponding to the first pixel unit 321, the second light guide channel corresponding to the second pixel unit 322, the third light guide channel corresponding to the third pixel unit 333, and the fourth pixel unit The fourth light guide channel corresponding to 334 coincides with the light passing holes in the top light blocking layer of the at least two light blocking layers.

Optionally, the apertures of the light-passing holes in the four light guide channels are sequentially reduced from top to bottom, for example, the second light-passing aperture 3221, the third light-passing aperture 3222, and the fourth light-passing aperture 3223. And the aperture of the fifth light-passing hole 3224 is smaller than the aperture of the first light-passing hole 3211.

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

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

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

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

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

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

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

Wherein, the lens medium layer is used to connect the aforementioned microlens 310, at least two light-blocking layers, and the aforementioned four pixel units.

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

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

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

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

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

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

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

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

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

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

FIG. 8 shows a schematic top view of the fingerprint identification unit 301 in FIG. 7.

As shown in FIG. 8, the area where the first pixel unit 331, the second pixel unit 332, the third pixel unit 333, and the fourth pixel unit 334 are located (for ease of description, the area where the four pixel units are located is referred to as the pixel area 330 for short) It may be located obliquely below the microlens 310, and the center of the pixel area 330 and the center of the microlens 310 do not overlap in the vertical direction. Wherein, the four pixel units all receive the target fingerprint light signal in the oblique direction, that is, the directions of the four light guide channels corresponding to the four pixel units are all inclined with respect to the display screen.

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

The first photosensitive area 3311 of the first pixel unit 331 is located below the second light-passing hole 3221, that is, at the bottom of the first light guide channel, and is used to receive the first target fingerprint light signal; the second pixel unit 332 The photosensitive area 3321 is located below the third light-passing hole 3222, that is, at the bottom of the second light guide channel, for receiving the second target fingerprint light signal; the third photosensitive area 3331 of the third pixel unit 333 is located at the fourth light-passing Below the small hole 3223, that is, at the bottom of the third light guide channel, is used to receive the third target fingerprint light signal. The fourth photosensitive area 3341 of the fourth pixel unit 334 is located below the fifth light-passing hole 3224, that is, located The bottom of the fourth light guide channel is used to receive the fourth target fingerprint optical signal.

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

As shown in FIG. 9, the first target fingerprint light signal 311 is received by the first photosensitive area 3311 in the first pixel unit through the first light guide channel formed by the first light-passing hole 3211 and the second light-passing hole 3221, The second target fingerprint light signal 312 is received by the second photosensitive area 3321 in the second pixel unit through the second light guide channel formed by the first light-passing hole 3211 and the third light-passing hole 3222.

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

Optionally, in this case, the first target fingerprint optical signal 311 received by the first photosensitive area 3311 and the second target fingerprint optical signal 312 received by the second photosensitive area 3321 have the same angle with the display screen, or in other words, the first target fingerprint optical signal 311 received by the first photosensitive area 3311 and the second target fingerprint optical signal 312 received by the second photosensitive area 3321. The angle between the first light guide channel corresponding to a photosensitive area 3311 and the display screen is equal to the angle between the second light guide channel corresponding to the second photosensitive area 3321 and the display screen.

Fig. 10 shows a schematic cross-sectional view of the fingerprint recognition unit 301 in Fig. 8 along the B-B' direction.

As shown in FIG. 10, the distance from the center of the second photosensitive area 3321 to the center of the microlens 310 and the distance from the center of the fourth photosensitive area 3341 to the center of the microlens 310 are not equal. At this time, the second photosensitive area 3331 receives the second The angle between the target fingerprint light signal 321 and the fourth target fingerprint light signal 314 received by the fourth photosensitive area 3341 and the display screen is different, in other words, the angle between the first light guide channel corresponding to the second photosensitive area 3321 and the display screen The angle between the fourth light guide channel corresponding to the fourth photosensitive area 3341 and the display screen is not equal.

In the embodiment of the present application, the target fingerprint light signal received by the first photosensitive area 3311 and the second photosensitive area 3321 has the same angle with the display screen, and the target fingerprint light signal received by the third photosensitive area 3321 and the fourth photosensitive area 3341 is the same as The angles of the displays are the same.

It should be understood that the included angles between the fingerprint light signals received by the four photosensitive areas and the display screen may be partly the same or all different, which is not limited in the embodiment of the present application.

The above-mentioned FIG. 8 and FIG. 9 and FIG. 10 show the case where the fingerprint identification unit 301 includes two layers of light blocking layers. Optionally, the fingerprint identification unit 301 may also include three layers of light blocking layers.

FIG. 11 shows a schematic top view of a fingerprint identification unit 301, and FIG. 12 shows a schematic cross-sectional view of the fingerprint identification unit 301 in FIG. 11 along the direction A-A'.

As shown in FIGS. 11 and 12, the fingerprint identification unit 301 includes three light-blocking layers. Wherein, the top light blocking layer is provided with the first light-passing hole 3211, and the bottom light-shielding layer is provided with the second light-passing hole 3221, the third light-passing hole 3222, the fourth light-passing hole 3223, and the bottom light-shielding layer. The fifth light-passing hole 3224 described above. In addition, a sixth light-passing hole 3231, a seventh light-passing hole 3232, an eighth light-passing hole 3233, and a ninth light-passing hole 3234 are provided in the newly added light blocking layer of the intermediate layer. Among them, the first light-passing hole 3221, the sixth light-passing hole 3231, and the second light-passing hole 3221 form the first light guide channel corresponding to the first photosensitive area 3311 unit, and the center of the four light-passing holes can be Located on the same line. In addition, the first light-passing hole 3221, the seventh light-passing hole 3232, and the third light-passing hole 3222 form a second light guide channel corresponding to the second photosensitive area 3321, and the center of the four light-passing holes can also be Are located on the same straight line, and the first light-passing hole 3221, the eighth light-passing hole 3233, and the fourth light-passing hole 3223 form a third light guide channel corresponding to the third photosensitive area 3331, and the four light-passing holes The centers of the holes can also be on the same straight line. The first light-passing aperture 3221, the ninth light-passing aperture 3234, and the fifth light-passing aperture 3224 form a fourth light guide channel corresponding to the fourth photosensitive area 3341. The centers of the four light-passing apertures may also be located at the same In a straight line.

Optionally, in the embodiment of the present application, the aperture of the first light-passing aperture 3221 is larger than that of the sixth light-passing aperture 3231, the seventh light-passing aperture 3232, the eighth light-passing aperture 3233, and the ninth light-passing aperture. The aperture of the hole 3234, and the sixth aperture 3231, the seventh aperture 3232, the eighth aperture 3233, and the ninth aperture 3234 are larger than the second aperture 3221 The apertures of the three light-passing holes 3222, the fourth light-passing holes 3223, and the fifth light-passing holes 3224.

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

Referring to FIG. 8 and FIG. 11, in a possible implementation manner, the photosensitive area in the four pixel units only occupies a small part of the area in the pixel unit, so as to meet the requirements of receiving light signals.

In the embodiment of this application, the center of the first photosensitive area 3311 may be located at the bottom of the first light guide channel. In other words, the center of the first photosensitive area 3311 may be located at the first light-passing aperture 3211 and the second light-passing aperture. On the 3221 line. Similarly, the center of the photosensitive area in other pixel units can also be located at the bottom of the corresponding light guide channel.

Through the above arrangement, the first target fingerprint light signal forms a first light spot 3301 on the first pixel unit 331 through the first light guide channel, and the second target fingerprint light signal forms a first light spot 3301 on the second pixel unit 332 through the second light guide channel. Two light spots 3302, the third target fingerprint light signal forms a third light spot 3303 on the third pixel unit 333 through the third light guide channel, and the fourth target fingerprint light signal forms a third light spot on the fourth pixel unit 334 through the fourth light guide channel Three light spots 3304.

In order to maximize the reception of the first target fingerprint optical signal, the second target fingerprint optical signal, the third target fingerprint optical signal, and the fourth target fingerprint optical signal, optionally, the first photosensitive area 3311 on the first pixel unit 331 may be The first light spot 3301 is completely covered, the second light-sensitive area 3321 on the second pixel unit 332 can completely cover the second light spot 3302, and the third light-sensitive area 3331 on the third pixel unit 333 can completely cover the third light spot 3303, In addition, the fourth photosensitive area 3331 on the fourth pixel unit 334 can completely cover the fourth light spot 3304.

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

In a possible implementation, as shown in FIG. 8 and FIG. 11, the photosensitive area in the four pixel units is a quadrilateral area and circumscribes the photosensitive area.

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

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

Optionally, in FIG. 8 and FIG. 11, the four pixel units are all quadrilateral pixel units with the same size.

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

In FIG. 8 and FIG. 11, the four photosensitive regions are offset from the center of the four pixel units. Since the four photosensitive areas all receive light signals in the oblique direction, and the greater the tilt angle, the farther the photosensitive area in the pixel unit is from the center of the microlens, for example, the third and fourth photosensitive areas are farther away from the microlens. The center distance is farther, and the first photosensitive area and the second photosensitive area are closer to the center of the microlens. Therefore, the angle of the target fingerprint light signal received by the third photosensitive area and the fourth photosensitive area is larger, and the first photosensitive area and The angle of the target fingerprint light signal received by the second photosensitive area is relatively small.

In addition, the four photosensitive areas are not only offset from the center of the pixel unit, but also offset away from the center of the microlens, which can increase the angle of the target fingerprint light signal received by the four photosensitive areas, thereby further reducing fingerprint recognition. The thickness of the unit.

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

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

As shown in Figures 8 and 11, the projection of the first target fingerprint light signal received by the first photosensitive area 3311 and the second target fingerprint light signal received by the second photosensitive area 3321 on the plane where the pixel area 330 is located is +90. °, the first target fingerprint light signal received by the first photosensitive area 3311 and the third target fingerprint light signal received by the third photosensitive area 3331 are projected on the plane of the pixel area 330 at an angle of -90°, and the first photosensitive area 3311 The projection angle of the first target fingerprint light signal received by the area 3311 and the fourth target fingerprint light signal received by the fourth photosensitive area 3341 on the plane where the pixel area 330 is located is 180°.

In other words, the projection of the first light guide channel on the plane where the pixel area 330 is located and the projection of the second light guide channel on the plane where the pixel area 330 is located are at an angle of +90°, and the projection of the first light guide channel on the plane where the pixel area 330 is located It forms an angle of -90° with the projection of the third light guide channel on the plane where the pixel area 330 is located, and the projection of the first light guide channel on the plane where the pixel area 330 is located is the same as the projection of the fourth light guide channel on the plane where the pixel area 330 is located. 180° included angle.

Using the solution of the embodiment of the present application, the fingerprint light signals received by multiple groups of two pixel units in the four pixel units are perpendicular to each other, that is, the first pixel unit and the second pixel unit, the first pixel unit and the third pixel unit, The fingerprint light signals received by the fourth pixel unit and the second pixel unit, and the fourth pixel unit and the third pixel unit are perpendicular to each other. In this case, it is convenient to collect the fingerprint light signals perpendicular to the ridges and valleys of the fingerprint. The quality of the fingerprint light signal received by the fingerprint identification unit can be improved, thereby improving the quality of the fingerprint image and improving the fingerprint identification performance of the fingerprint identification device.

It should be understood that the fingerprint light signal received by any two of the four pixel units is vertical, that is, the fingerprint light signal that can be collected perpendicular to the ridge and valley lines of the fingerprint, which improves the quality of the fingerprint light signal received by the fingerprint identification unit. The angles of the fingerprint light signals received by the other two pixel units of the four pixel units are not limited in this embodiment of the application.

In the above FIGS. 8 to 12, the connection direction between the projection points of the microlens on the four pixel units and the center points of the four pixel units is parallel to one side of the pixel unit. Optionally, the microlens can also be arranged at any position above the four pixel units, and the connection direction between its projection points on the four pixel units and the center points of the four pixel units can be any direction.

FIG. 13 shows a schematic top view of another fingerprint identification unit 301.

As shown in FIG. 13, the line connecting the projection point of the center of the microlens 310 on the pixel area 330 and the center of the pixel area 330 is located on a diagonal line in the pixel area 330. Among them, the photosensitive areas in the four pixel units are all set far away from the microlens to facilitate receiving fingerprint light signals at a larger angle. Among them, the center of the microlens 310 is the farthest from the fourth pixel unit 334, and the fourth pixel unit 334 The photosensitive area of the fourth pixel unit is disposed on the opposite corner away from the microlens 310. At this time, among the four pixel units, the photosensitive area of the fourth pixel unit 334 receives the largest angle of the fingerprint light signal. In this way, the optical path thickness of the fingerprint identification unit and the fingerprint identification module can be further reduced.

In addition, in the embodiment of the present application, the projection angle of the first target fingerprint light signal received by the first photosensitive area 3311 and the third target fingerprint light signal received by the third photosensitive area 3331 on the plane where the pixel area 330 is located is 90° In other words, the projection of the first light guide channel on the plane of the pixel area 330 and the projection of the third light guide channel on the plane of the pixel area 330 form an angle of 90°. The projection of the first light guide channel on the plane where the pixel area 330 is located and the projection of the fourth light guide channel on the plane where the pixel area 330 is located is an acute angle less than 90°, and the first light guide channel is on the plane where the pixel area 330 is located. The angle between the projection and the projection of the second light guide channel on the plane where the pixel area 330 is located is an obtuse angle greater than 90°.

Optionally, if the pixel area 330 where the four pixel units are located is a square area with side length a, the center of the microlens 310 is at the projection point on the plane where the four pixel units are located and the center point of the pixel area 330 The distance of is d, where 0<d<a.

The above-mentioned Figures 8, 9, 11 and 13 only illustrate the top-view schematic diagrams of several fingerprint identification units 301. It should be understood that the projection of any two of the four light guide channels on the plane where the pixel area 330 is located can be At any angle between 0° and 180°, and the angle between the four light guide channels and the plane where the pixel area 330 is located can also be at any angle between 0° and 90°. This embodiment of the application does not make this Any restrictions.

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

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

Optionally, FIG. 14 shows another schematic top view of the fingerprint identification unit 301.

As shown in FIG. 14, the photosensitive area in the four pixel units has a larger area, and in addition to covering the light spot on the pixel unit, it also covers other areas. In FIG. 14, the photosensitive area in the four pixel units occupies most of the area of the pixel unit. For example, the first photosensitive region 3311 in the first pixel unit 331 occupies more than 95% of the area of the first pixel unit 331, or the respective photosensitive regions in other pixel units occupies more than 95% of the area.

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

Optionally, based on the above application examples, the distance from the center of the first photosensitive area 3311 to the center of the microlens 310, the distance from the center of the second photosensitive area 3321 to the center of the microlens 310, and the distance from the center of the third photosensitive area 3331 to the microlens 310 Any two of the distance between the center of the lens 310 and the distance between the center of the fourth photosensitive area 3341 and the center of the microlens 310 may not be equal, or the four distances may not be equal. At this time, the first target fingerprint optical signal, the second The target fingerprint optical signal, the third target fingerprint optical signal, and the fourth target fingerprint optical signal are not equal to any two of the four included angles of the display screen, or the four included angles are not equal, or in other words, the first guide Any two of the four included angles between the light channel, the second light guide channel, the third light guide channel, and the fourth light guide channel and the display screen are not equal, or none of the four included angles are equal.

The above only exemplifies several cases where the pixel area 330 where the four pixel units in the fingerprint identification unit 301 are located is located obliquely below the microlens 310. It should be understood that the pixel area 300 may also be located at any area obliquely below the microlens 310. The embodiment of the application does not make any limitation on this, and the photosensitive area in the four pixel units can be located in any area of the pixel unit where it is located, and the embodiment of the application does not make any limitation on this.

It should be understood that as the pixel unit and the photosensitive area move, the direction of the target fingerprint light signal received by the photosensitive area and the direction of the light guide channel corresponding to the photosensitive area also change accordingly. In other words, it can also be designed according to the light path, Design the position of the pixel unit and the photosensitive area relative to the microlens in the direction of the target fingerprint light signal demand.

Specifically, in a possible optical path design method, the angle of the first target fingerprint optical signal is greater than the angles of the other three target fingerprint optical signals in the four target fingerprint optical signals, where the angle of the optical signal refers to the optical signal and The angle perpendicular to the direction of the display.

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

h=x×cotθ;

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

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

Hereinafter, the first pixel unit 331, the third pixel unit 333, and the fourth pixel unit 334 receive the target fingerprint light signal in the oblique direction, and the second pixel unit 332 receives the target fingerprint light signal in the vertical direction for example.

FIG. 15 shows a top view of a fingerprint identification unit 301 of the fingerprint identification device 300.

As shown in FIG. 15, in the spatial position, the second photosensitive area 3321 in the second pixel unit 332 is located directly below the center of the microlens 310, or in other words, the center of the second photosensitive area 3321 is perpendicular to the center of the microlens 310. The directions coincide. At this time, the second light guide channel corresponding to the second photosensitive area 3321 is also correspondingly perpendicular to the microlens 310 or perpendicular to the display screen. At this time, the center of the first light-passing hole 3211, the center of the third light-passing hole 3222, the center of the microlens 310, and the center of the second photosensitive area 3321 in the second light guide channel are all located at the same vertical to the display screen. On the straight line.

In terms of spatial position, the first photosensitive area 3311 in the first pixel unit 331, the third photosensitive area 3331 in the third pixel unit 333, and the fourth photosensitive area 3341 in the fourth pixel unit 334 are located at the center of the microlens 310. Obliquely below, receiving light signals inclined to the display screen, and the corresponding directions of the first light guide channel, the third light guide channel, and the fourth light guide channel are arranged obliquely to the display screen. Specifically, the first pixel unit 331, the third pixel unit 333, and the fourth pixel unit 334 and their related technical features can refer to the technical features in the technical solution for receiving the oblique light signal by the four pixel units, which will not be omitted here. Go into details.

The above-mentioned FIG. 15 only exemplifies a situation of the relative positional relationship between the first pixel unit 331 and the third pixel unit 333 in the fingerprint identification unit 301 and the microlens 310. It should be understood that in the spatial position, the first pixel unit 331 The third pixel unit 333 and the third pixel unit 333 can also be located in any area obliquely below the microlens 310. The embodiment of the present application does not make any limitation on this, and the photosensitive area of the four pixel units can be located in any area of the pixel unit where it is located. The embodiments of the application do not make any limitation on this.

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

The fingerprint identification unit 301 in this application is described in detail above with reference to FIGS. 6-15.

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

Optionally, as shown in FIG. 16, in a possible implementation manner, four pixel units in a fingerprint recognition unit 301 are quadrilateral pixel units and form a quadrilateral area, and the pixel array 302 of the fingerprint recognition device 300 appears as A pixel matrix in which a plurality of quadrilateral pixel unit arrays are arranged.

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

Optionally, the multiple target pixel units 3021 may all be the aforementioned first pixel unit 331, or the aforementioned second pixel unit 332, or the aforementioned third pixel unit 333, or the aforementioned fourth pixel unit 334, and can also include the aforementioned The first pixel unit 331, the second pixel unit 332, the third pixel unit, and the fourth pixel unit 334 are not limited in the embodiment of the present application.

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

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

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

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

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

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

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

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

The fingerprint identification device 300 includes a plurality of groups of the aforementioned four pixel units, and the plurality of groups of the aforementioned four pixel units form a pixel array of the fingerprint identification device 300.

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

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

For example, as shown in FIG. 16, the unit pixel area 3023 may be a pixel area of 4 fingerprint identification units, that is, a pixel area of 16 pixel units. It should be understood that the unit pixel area may also be a pixel unit area of any size, which is not limited in the embodiment of the present application.

Optionally, in each unit pixel area, the relative positional relationship of the target pixel unit in the unit pixel area is the same. For example, as shown in FIG. 16, in each unit pixel area, the target pixel unit is located at the lower right corner of the unit pixel area. It should be understood that, in each unit pixel area, the relative positional relationship of the target pixel unit in the unit pixel area may also be different, and the target pixel unit is arbitrarily set in the unit pixel area, which is not limited in the embodiment of the present application.

17a to 17b show schematic diagrams of the pixel array 302 in two types of fingerprint identification devices 300. As shown in Figures 17a to 17b, the number "1" represents the first pixel unit 331, the number "2" represents the second pixel unit 332, the number "3" represents the third pixel unit 333, and the number "4" represents The fourth pixel unit 334 described above.

As shown in FIGS. 17a and 17b, between the plurality of first pixel units 331, between the plurality of second pixel units 332, between the plurality of third pixel units 333, and between the plurality of fourth pixel units 334. They are not adjacent.

It should be understood that the foregoing FIGS. 17a and 17b are only schematic diagrams of two pixel arrays 302, in which the relative positional relationship of the first pixel unit 331, the second pixel unit 332, the third pixel unit 333, and the fourth pixel unit 334 can be set arbitrarily For example, the position of the first pixel unit 331 in the figure may also be the second pixel unit 332 or the third pixel unit 333 or the fourth pixel unit 334, which is not limited in the embodiment of the present application.

In the pixel array 302, a plurality of first pixel units 331 receive fingerprint light signals in one direction, and the fingerprint light signals are used to form the first fingerprint image of the finger, and the first target fingerprint light received by one first pixel unit 331 The signal is used to form a pixel in the first fingerprint image. A plurality of second pixel units 332 receive the fingerprint light signal in another direction, and the fingerprint light signal is used to form a second fingerprint image of the finger, and the second target fingerprint light signal received by one second pixel unit 332 is used to form a second fingerprint image. A pixel in the fingerprint image. The plurality of third pixel units 333 receive the fingerprint light signal in the third direction, the fingerprint light signal is used to form the third fingerprint image of the finger, and the third target fingerprint light signal received by one third pixel unit 333 is used to form the third fingerprint light signal. A pixel in the three fingerprint image. A plurality of fourth pixel units 334 receive the fingerprint light signal in the fourth direction, and the fingerprint light signal is used to form a fourth fingerprint image of the finger, and the fourth target fingerprint light signal received by one fourth pixel unit 334 is used to form a fourth fingerprint light signal. A pixel in the four fingerprint image. The first fingerprint image, the second fingerprint image, the third fingerprint image, and the fourth fingerprint image can be used for fingerprint identification alone, or any two or three fingerprint images can be reconstructed, and the reconstructed fingerprint The image is fingerprinted.

Optionally, in a possible implementation manner, the first target fingerprint light signal received by one first pixel unit 331 is used to form one pixel in the first fingerprint image. The second target fingerprint light signal received by a second pixel unit 332 is used to form a pixel in the second fingerprint image. The third target fingerprint light signal received by a third pixel unit 333 is used to form a pixel in the third fingerprint image. The fourth target fingerprint light signal received by a fourth pixel unit 334 is used to form a pixel in the fourth fingerprint image.

Optionally, in another possible implementation manner, the first target fingerprint light signal received by every X first pixel units 331 in the plurality of first pixel units is used to form one pixel in the first fingerprint image. The second target fingerprint light signal received by every X second pixel units 332 in the plurality of second pixel units is used to form one pixel in the second fingerprint image. The third target fingerprint light signal received by every X third pixel units 333 in the plurality of third pixel units is used to form one pixel in the third fingerprint image. The fourth target fingerprint light signal received by every X fourth pixel units 334 in the plurality of fourth pixel units is used to form one pixel in the fourth fingerprint image. Among them, X is a positive integer greater than 1.

Of course, in addition to the foregoing embodiments, the first target fingerprint light signal received by each A first pixel unit 331 in the plurality of first pixel units may be used to form one pixel in the first fingerprint image. The second target fingerprint light signal received by every B second pixel units 332 in the plurality of second pixel units is used to form one pixel in the second fingerprint image. The third target fingerprint light signal received by every C third pixel units 333 in the plurality of third pixel units is used to form a pixel point in the third fingerprint image. The fourth target fingerprint light signal received by every D fourth pixel units 334 in the plurality of fourth pixel units is used to form one pixel in the fourth fingerprint image. Among them, A, B, C, and D are positive integers, and at least two of them are not equal to each other.

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

Specifically, the processing unit includes a first sub-processing unit, a second sub-processing unit, a third sub-processing unit, and a fourth sub-processing unit. The first sub-processing unit is used to obtain the electrical power of the X first pixel units 331. The signal is used to form a pixel value in the first fingerprint image of the finger, and the second sub-processing unit is used to obtain the electrical signals of X second pixel units 332 to form a pixel value in the second fingerprint image of the finger. The processing unit is used to obtain the electrical signals of the X third pixel units 333 to form a pixel value in the third fingerprint image of the finger, and the fourth sub-processing unit is used to obtain the electrical signals of the X second pixel units 334 to form the finger The value of a pixel in the fourth fingerprint image.

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

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

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

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

Optionally, the X first pixel units 331 may be adjacent X pixel units in the plurality of first pixel units 331 of the pixel array 302, for example, may be 4 first pixel units of 2×2, or There are 9 first pixel units of 3×3. Similarly, the X second pixel units 332 may be adjacent X pixel units among the plurality of second pixel units 332 of the pixel array 302, and the X third pixel units The pixel unit 333 may be adjacent X pixel units among the plurality of third pixel units 333 of the pixel array 302, or the X fourth pixel units 334 may be adjacent among the plurality of fourth pixel units 334 of the pixel array 302 For X pixel units, the embodiment of the present application does not specifically limit X.

Fig. 18 is a schematic block diagram of an electronic device including a plurality of fingerprint detection units.

As shown in FIG. 18, the electronic device 30 may include a display screen 120, a filter 400 located below the display 120, and a fingerprint identification device 300 composed of a plurality of fingerprint identification units 301 located below the filter 400 Each of the pixel units of the fingerprint identification unit 301, that is, the aforementioned pixel array 302, may be arranged on the upper surface of the substrate 500. The pixel array 302 and the substrate 500 may be referred to as a fingerprint sensor or an image sensor.

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

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

The fingerprint identification process based on oblique light signals in multiple directions according to an embodiment of the present application will be described below with reference to FIGS. 19-25. For ease of understanding, the following takes the inclined light signal in four directions as an example to illustrate the fingerprint identification process.

When the optical signal received by the fingerprint identification device is a light signal carrying the pattern of bright and dark stripes as shown in Figure 19, and the four pixel units corresponding to each microlens in the fingerprint identification device are used to receive four target fingerprints in different directions In the case of light signals, the pixel array in the fingerprint recognition device simultaneously images the light signals of different imaging areas. Therefore, the image formed by the pixel array in the fingerprint recognition device is an image superimposed on different imaging areas, which is a blurry image. Image. For example, the image shown in Figure 20.

In some embodiments of the present application, the processing unit may obtain the first image, the second image, the third image, and the fourth image by extracting the original image in FIG. 20. In particular, when the optical signal received by the fingerprint identification device is a fingerprint optical signal reflected or scattered by a finger, the image formed by the pixel array is an image superimposed on different areas of the fingerprint, and it is also a fuzzy image. The original image can be processed to obtain electrical signals of multiple first pixel units in the pixel array to form a first fingerprint image, and electrical signals of multiple second pixel units to form a second fingerprint image, multiple third pixels The electrical signals of the unit form a third fingerprint image, and the electrical signals of a plurality of fourth pixel units form a fourth fingerprint image.

For example, the original image generated by the multiple first pixel units in the pixel array is shown in FIG. 21. Since the multiple first pixel units all receive the light signals in the same direction, there is no situation where images of different imaging areas are superimposed. Therefore, the processing unit can process and obtain the first image shown in FIG. 21 corresponding to the light signals in the first direction. For a clear image. Similarly, the processing unit can process the second image shown in FIG. 22 generated by multiple second pixel units, the third image shown in FIG. 23 generated by multiple third pixel units, and multiple fourth pixels. The fourth image produced by the unit is shown in Figure 24.

In some embodiments of the present application, the first image, the second image, and the third image may be processed and reconstructed to form a clear image as shown in FIG. 25. Optionally, the first image and the second image may be reconstructed to obtain the first target reconstructed image, and the third image and the fourth image may be reconstructed to obtain the second target reconstructed image, and then the first image is reconstructed. The target reconstructed image and the second target reconstructed image are reconstructed again to obtain the final target reconstructed image. Optionally, it is also possible to process and reconstruct the four images at the same time to obtain the final target reconstructed image. Among them, the processing process includes, but is not limited to, image processing processes such as image upsampling and filtering.

For example, the first image, the second image, the third image, and the fourth image may be moved by a distance of several image pixels in the image to form a clear image as shown in FIG. 25.

In other words, the first image can be moved a distance of a few pixels to the left and up, the second image can be moved a distance of a few pixels to the right and up, and the third image can be moved a distance of a few pixels to the left and down. The four images move a few pixels to the right and down to form a clear image as shown in Figure 25.

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

In the embodiment of the present application, the processing unit may adjust the movement distances of the four images (for example, the above-mentioned first image, second image, third image, and fourth image) through algorithms according to the quality parameters of the reconstructed image to form The target reconstructs the image.

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

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

Since the thickness of the display screen is constant, and the relative position of the display screen and the fingerprint identification device is basically unchanged, the original image can be collected first (such as the image shown in Figure 20), and the image quality of the reconstructed image is the clearest At this time, the number of image pixels that need to be moved in the image corresponding to the oblique light signal in each direction is determined as the moving image parameter, and the moving image parameter is stored in the storage unit. Furthermore, in the subsequent fingerprint collection process, a clear image can be reconstructed based on the moving image parameters.

It should be understood that the above-mentioned original image may be a fingerprint image, or any original pattern covering the surface of the display screen with clear contrast. For example, the image in Figure 19 is similar to the fingerprint ridges and fingerprint valleys in the fingerprint image. When the light signal received by the fingerprint recognition device is the light signal that has been reflected or scattered by the finger, the image processed by the processing unit is being processed and reconstructed. The previous image may be similar to the image shown in FIG. 20, and the fingerprint image after processing and reconstruction may be similar to the image shown in FIG. 25, which is a clear fingerprint image.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Claims (33)

A fingerprint identification device, characterized in that it is suitable for under the display screen to realize under-screen optical fingerprint identification. The fingerprint identification device includes a plurality of fingerprint identification units distributed in a square array, and among the plurality of fingerprint identification units Each fingerprint recognition unit includes: Micro lens At least two light-blocking layers are arranged under the microlens, and each of the light-blocking layers of the at least two light-blocking layers is provided with light-passing holes to form four light guide channels in different directions; Four pixel units are arranged under the at least two light blocking layers, and the four pixel units are respectively located at the bottom of the four light guide channels; Wherein, the fingerprint light signals returned after being reflected or scattered from the finger above the display screen are condensed by the microlens, and the four target fingerprint light signals in different directions are respectively transmitted to the said four light guide channels. With four pixel units, the angles of the four light guide channels relative to the display screen are not completely the same, and the four target fingerprint light signals are used to detect fingerprint information of the finger. The fingerprint identification device according to claim 1, wherein the four pixel units form a pixel area of a quadrilateral area, and the center point of the pixel area does not coincide with the center of the microlens in the vertical direction. The fingerprint identification device according to claim 1, wherein the pixel area is a square area with side length a, and the center of the microlens is on the plane where the four pixel units are located. The distance between the center point of the pixel area is d, where 0<d<a. The fingerprint identification device according to claim 1, wherein the directions of at least three of the four light guide channels are inclined with respect to the display screen. The fingerprint identification device according to claim 1, wherein the projection angle of the two light guide channels of the four light guide channels on the plane where the four pixel units are located is 90 degrees. The fingerprint identification device according to any one of claims 1 to 5, wherein each of the four pixel units includes four photosensitive areas, and the four photosensitive areas are respectively located in the four light guide channels bottom of. 7. The fingerprint identification device according to claim 6, wherein at least one of the four photosensitive areas is deviated from the center of the pixel unit where it is located. 8. The fingerprint identification device of claim 7, wherein the at least one photosensitive area deviates in a direction away from the center of the microlens. The fingerprint identification device according to claim 6, wherein the four pixel units form a quadrilateral pixel area, and the four photosensitive areas are respectively located at four corners of the pixel area. The fingerprint identification device according to claim 6, wherein the four pixel units include a first pixel unit, the first pixel unit includes a first photosensitive area, and the first pixel unit is connected to the first pixel unit. A photosensitive area is all quadrilateral; Wherein, the length and width of the first pixel unit are respectively L and W, the length and width of the first photosensitive area are both greater than or equal to 0.1×W, W≦L, and both W and L are positive numbers. The fingerprint identification device according to claim 6, wherein the four target fingerprint light signals respectively form four light spots on the four pixel units, and the four photosensitive areas are quadrilateral areas and are circumscribed to The four light spots. The fingerprint identification device according to claim 6, wherein the height of the optical path between the microlens and the plane where the four pixel units are located is calculated according to a formula: h=x×cotθ; Wherein, h is the height of the optical path, x is the distance between the center of the first photosensitive area among the four photosensitive areas and the projection point of the center of the microlens on the plane where the four pixel units are located, θ is the angle between the first target fingerprint optical signal received by the first photosensitive area and the vertical direction, and the angle between the first target fingerprint optical signal and the vertical direction in the four target fingerprint optical signals is greater than the four target fingerprint optical signals. The angle between the other three target fingerprint optical signals in the target fingerprint optical signal and the vertical direction, where the vertical direction is a direction perpendicular to the display screen. The fingerprint identification device according to any one of claims 1 to 5, wherein the four pixel units are quadrilateral pixel units with the same size. The fingerprint identification device according to any one of claims 1 to 5, wherein the angles between the four light guide channels and the plane where the four pixel units are located are between 30° and 90°. The fingerprint identification device according to any one of claims 1 to 5, wherein the bottom light-blocking layer in the at least two light-blocking layers is provided with four communication channels corresponding to the four pixel units respectively. Light small holes. 15. The fingerprint identification device of claim 15, wherein the bottom light blocking layer is a metal wiring layer on the surface of the four pixel units. The fingerprint identification device according to claim 15, wherein the apertures of the light-passing holes in the four light guide channels decrease sequentially from top to bottom. The fingerprint identification device according to claim 15, wherein the four light guide channels are overlapped with the light-passing holes in the top light-blocking layer of the at least two light-blocking layers. The fingerprint identification device according to any one of claims 1 to 5, wherein the fingerprint identification unit further comprises: Transparent medium layer; Wherein, the lens medium layer is used to connect the microlens, the at least two light blocking layers, and the four pixel units. The fingerprint identification device according to any one of claims 1 to 5, wherein the fingerprint identification unit further comprises: Optical filter layer; Wherein, the optical filter layer is arranged in the optical path between the display screen and the plane element where the four pixel units are located, and is used to filter the optical signal in the non-target wavelength band so as to transmit the optical signal in the target wavelength band. 22. The fingerprint identification device of claim 20, wherein the optical filter layer is integrated on the surface of the four pixel units. 22. The fingerprint identification device of claim 20, wherein the optical filter layer is disposed between the bottom light-blocking layer of the at least two light-blocking layers and the plane where the four pixel units are located. The fingerprint identification device according to any one of claims 1 to 5, wherein multiple groups of the four pixel units include multiple target pixel units, and light guide channels corresponding to the multiple target pixel units are provided There is a color filter layer, and the color filter layer is used to pass red visible light, green visible light or blue visible light. The fingerprint identification device according to claim 23, wherein a plurality of groups of the four pixel units are located in an area composed of a plurality of unit pixel areas, and each of the plurality of unit pixel areas is provided with one The target pixel unit. The fingerprint identification device according to claim 23, wherein the multiple target pixel units are evenly distributed in a plurality of groups of the four pixel units. 23. The fingerprint identification device of claim 23, wherein the color filter layer is disposed in a light-passing hole of the target pixel unit corresponding to the light guide channel. The fingerprint identification device according to any one of claims 1 to 5, wherein the light signals received by a plurality of first pixel units in a plurality of groups of the four pixel units are used to form the first image of the finger. A fingerprint image, a plurality of groups of light signals received by a plurality of second pixel units in the four pixel units are used to form a second fingerprint image of the finger, and a plurality of groups of third pixels in the four pixel units The light signal received by the unit is used to form a third fingerprint image of the finger, and the light signals received by a plurality of fourth pixel units in a plurality of groups of the four pixel units are used to form a fourth fingerprint image of the finger, so One or more of the first fingerprint image, the second fingerprint image, the third fingerprint image, and the fourth fingerprint image are used for fingerprint identification. The fingerprint identification device according to claim 27, wherein the pixel average value of each X first pixel units in the plurality of first pixel units is used to form a pixel value in the first fingerprint image; The pixel average value of each X second pixel units in the plurality of second pixel units is used to form a pixel value in the second fingerprint image, The pixel average value of every X third pixel units in the plurality of third pixel units is used to form a pixel value in the third fingerprint image; The pixel average value of every X fourth pixel units in the plurality of fourth pixel units is used to form a pixel value in the fourth fingerprint image, where X is a positive integer. The fingerprint identification device of claim 27, wherein the plurality of first pixel units are not adjacent to each other, the plurality of second pixel units are not adjacent to each other, and the plurality of first pixel units are not adjacent to each other. The three pixel units are not adjacent to each other, and the plurality of fourth pixel units are not adjacent to each other. The fingerprint identification device according to claim 27, wherein the fingerprint identification device further comprises a processing unit configured to move the first fingerprint image, the second fingerprint image, and the third fingerprint image. The fingerprint image and the fourth fingerprint image are combined to form a reconstructed image, and the first fingerprint image, the second fingerprint image, and the third fingerprint image are adjusted according to the quality parameters of the reconstructed image. The moving distance of the fourth fingerprint image to form a target reconstructed image, and the target reconstructed image is used for fingerprint recognition. The fingerprint identification device according to any one of claims 1 to 5, wherein the distance between the fingerprint identification device and the display screen is 0 to 1 mm. An electronic device, characterized by comprising: a display screen; and The fingerprint identification device according to any one of claims 1 to 31, wherein the fingerprint identification device is arranged below the display screen to realize under-screen optical fingerprint identification. The electronic device according to claim 32, wherein the distance between the fingerprint identification device and the display screen is 0 to 1 mm.

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