CN211375615U - Fingerprint identification device and electronic equipment - Google Patents

Abstract

The embodiment of the application discloses a fingerprint identification device and electronic equipment, and the performance of the fingerprint identification device can be improved. This fingerprint identification device is applicable to the below of display screen, and every fingerprint identification unit in a plurality of fingerprint identification units includes: a microlens; at least two light blocking layers, wherein each light blocking layer is provided with light-passing small holes to form four light guide channels in different directions; the four pixel units are respectively positioned at the bottoms of the four light guide channels; after fingerprint optical signals returned from a finger above the display screen are converged by the micro lens, four target fingerprint optical signals in different directions are transmitted to the four pixel units through the four light guide channels respectively, and included angles of the four light guide channels relative to the display screen are not identical. The fingerprint identification device comprises a fingerprint identification device, a fingerprint light source and a control circuit.

Description

Fingerprint identification device and electronic equipment

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

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

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

Technical Field

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

Background

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

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

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

SUMMERY OF THE UTILITY MODEL

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

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

a microlens;

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

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

the fingerprint light signals returned after being reflected or scattered by the finger above the display screen are converged by the micro lens, wherein four target fingerprint light signals in different directions are transmitted to the four pixel units through the four light guide channels respectively, included angles of the four light guide channels relative to the display screen are not identical, and the four target fingerprint light signals are used for detecting fingerprint information of the finger.

According to the scheme, one micro lens corresponds to four pixel units, the four pixel units respectively receive target fingerprint optical signals which are converged by the micro lens and pass through four directions of four light guide channels, and the target fingerprint optical signals in the four directions are respectively received by the four pixel units. Compared with the technical scheme that one microlens corresponds to one pixel unit, the light-entering amount of the fingerprint identification device can be increased, the exposure time is shortened, and the view field of the fingerprint identification device is increased. In addition, for a technical scheme that one microlens corresponds to four pixel units, and centers of the microlens and the four pixel units coincide in a vertical direction, in the technical scheme of the present application, included angles of four light guide channels with respect to the display screen are not completely the same, angles of fingerprint light signals received by the four pixel units are determined by relative position relations of the four pixel units and the microlens, and if the pixel units are farther away from the center of the microlens, the angles of the fingerprint light signals received by the pixel units are larger. Therefore, the position of the pixel unit is flexibly set, so that the pixel unit can receive a wide-angle fingerprint optical signal, the identification problem of a dry finger is further improved, the thickness of a light path in the fingerprint identification unit can be further reduced, the thickness of the fingerprint identification device is reduced, and the process cost is reduced.

In one possible implementation, the four pixel units form a pixel region of a quadrilateral region, and a center point of the pixel region is not vertically coincident with a center of the microlens.

In a possible implementation manner, the pixel region is a square region with a side length of a, and a projection point of the center of the microlens on the plane where the four pixel units are located is at a distance d from a center point of the pixel region, wherein 0 < d < a.

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

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

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

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

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

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

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

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

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

In one possible implementation manner, the four target fingerprint light signals form four light spots on the four pixel units respectively, and the four photosensitive areas are quadrilateral areas and circumscribe the four light spots.

In one 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 the formula: h is x × cot θ;

h is the height of the light 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, θ is the included angle between the first target fingerprint optical signal received by the first photosensitive area and the vertical direction, the included angle between the first target fingerprint optical signal in the four target fingerprint optical signals and the vertical direction is greater than the included angles between the other three target fingerprint optical signals in the four target fingerprint optical signals and the vertical direction, and the vertical direction is perpendicular to the display screen.

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

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

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

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

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

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

In one possible implementation, the fingerprint identification unit further includes: a transparent dielectric layer;

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

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

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

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

In one possible implementation manner, the optical filtering 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 one possible implementation, the plurality of fingerprint identification units includes: the multi-group of four pixel units comprises a plurality of target pixel units, and color filter layers are arranged in light guide channels corresponding to the target pixel units and used for allowing red visible light, green visible light or blue visible light to pass through.

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

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

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

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

In a possible implementation manner, the optical signals received by a plurality of first pixel units in the plurality of groups of four pixel units are used to form a first fingerprint image of the finger, the optical signals received by a plurality of second pixel units in the plurality of groups of four pixel units are used to form a second fingerprint image of the finger, the optical signals received by a plurality of third pixel units in the plurality of groups of four pixel units are used to form a third fingerprint image of the finger, the optical signals received by a plurality of fourth pixel units in the plurality of groups of four pixel units are used to form a fourth fingerprint image of the finger, and one or more images of the first fingerprint image, the second fingerprint image, the third fingerprint image and the fourth fingerprint image are used for fingerprint identification.

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

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

In 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, 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 manner, the fingerprint identification device further includes a processing unit, and the processing unit is configured to move the first fingerprint image, the second fingerprint image, the third fingerprint image, and the fourth fingerprint image to combine and form a reconstructed image, and adjust the moving distances of the first fingerprint image, the second fingerprint image, the third fingerprint image, and the fourth fingerprint image according to a quality parameter of the reconstructed image to form a target reconstructed image, and the target reconstructed image is used for fingerprint identification.

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

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

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

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

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

Drawings

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

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

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

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

Fig. 7 is a schematic perspective structure diagram of a fingerprint identification unit according to an embodiment of the present application.

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

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

Fig. 10 is a schematic cross-sectional view of the fingerprint recognition unit of fig. 8 taken 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 sectional view of the fingerprint recognition unit of fig. 11 taken along the direction a-a'.

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

Fig. 17a and 17b are schematic diagrams of two pixel arrays in a fingerprint recognition 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.

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

Detailed Description

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

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

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

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

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

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

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

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

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

In another embodiment, the light guiding layer or the light path guiding structure may also be an optical Lens (Lens) layer, which has one or more Lens units, such as a Lens group composed of one or more aspheric lenses, and is used to focus the reflected light reflected from the finger to the sensing array of the light detecting portion 134 therebelow, so that the sensing array can image based on the reflected light, thereby obtaining the fingerprint image of the finger. Optionally, the optical lens layer may further be formed with a pinhole in the optical path of the lens unit, and the pinhole may cooperate with the optical lens layer to enlarge the field of view of the optical fingerprint device, so as to improve the fingerprint imaging effect of the optical fingerprint device 130.

In other embodiments, the light guide layer or the light path guiding structure may also specifically adopt a Micro-Lens (Micro-Lens) layer, the Micro-Lens layer has a Micro-Lens array formed by a plurality of Micro-lenses, which may be formed above the sensing array of the light detecting portion 134 through a semiconductor growth process or other processes, and each Micro-Lens may correspond to one of the sensing units of the sensing array. And, other optical film layers may be further formed between the microlens layer and the sensing unit, such as a dielectric layer or a passivation layer, and more specifically, a light blocking layer having micro holes may be further included between the microlens layer and the sensing unit, where the micro holes are formed between the corresponding microlenses and the sensing unit, and the light blocking layer may block optical interference between adjacent microlenses and the sensing unit, and enable light rays corresponding to the sensing unit to be converged into the micro holes through the microlenses and transmitted to the sensing unit through the micro holes to perform optical fingerprint imaging. It should be understood that several implementations of the above-described optical path directing structure may be used alone or in combination, for example, a microlens layer may be further disposed below the collimator layer or the optical lens layer. Of course, when the collimator layer or the optical lens layer is used in combination with the microlens layer, the specific lamination structure or optical path thereof may need to be adjusted according to actual needs.

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

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

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

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

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

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

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

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

As shown in fig. 2 and 3, the fingerprint recognition device 200 includes a microlens array 210, at least one light blocking layer 220, and a pixel array 230. The microlens array 210 is located right above the pixel array 230 and the at least one light-blocking layer 220, and one microlens 211 corresponds to one pixel unit 231, that is, each microlens 211 in the microlens array 210 focuses the received light to the pixel unit 231 corresponding to the same microlens 211 through the aperture 2201 of the at least one light-blocking layer 220. The optical signal received by each microlens 211 is mainly a fingerprint optical signal incident perpendicularly to the microlens array 210 after being reflected or scattered by a finger above the display screen.

As shown in fig. 3, the pixel units 231 in the pixel array 230 are arranged periodically, and the photosensitive area 2311 of each pixel unit 231 in the pixel array 230 is disposed at the center of the same pixel unit, so as to increase the duty ratio of the photosensitive area.

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

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

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

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

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

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

Alternatively, as shown in fig. 4, of the at least one light-blocking layer, the uppermost light-blocking layer is the first light-blocking layer 221, the second light-blocking layer 222 is disposed below the first light-blocking layer 221, and the third light-blocking layer 223 is disposed above the pixel array 230. Here, a first small hole 2211 corresponding to the first microlens 211 is formed in the first light-blocking layer 221, a second small hole 2221 and a third small hole 2222 corresponding to the first microlens 211 are formed in the second light-blocking layer 222, both the second small hole 2221 and the third small hole 2222 are located below the first small hole 2211, and a fourth small hole 2231 and a fifth small hole 2232 corresponding to the first microlens 211 are formed in the third light-blocking layer 223. In this structure, the first small hole 2211, the second small hole 2221, and the fourth small hole 2231 form a light guide channel corresponding to the first microlens, through which the light signal of the first direction converged by the first microlens is received by the first light sensing area 2311 in the first pixel unit 231. The first small hole 2211, the third small hole 2222 and the fifth small hole 2232 form another light guide channel corresponding to the first microlens, and the light signal of the second direction converged by the first microlens passes through the light guide channel to be received by the second photosensitive region 2321 in the second pixel unit 232.

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

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

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

However, in this embodiment, the center of one microlens coincides with the centers of the four pixel units in the vertical direction, which is limited by the fixed arrangement of the pixel array and the microlens array, the inclination angle of the optical signal received by the pixel unit is limited, the recognition performance of the dry finger is not optimal, and the overall optical path is still thick, which is not favorable for the further thinning development of the fingerprint recognition device.

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

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

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

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

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

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

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

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

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

a microlens 310;

at least two light-blocking layers disposed below the micro-lens 310, wherein each light-blocking layer of the at least two light-blocking layers is provided with a light-passing aperture to form four light-guiding channels (a first light-guiding channel, a second light-guiding channel, a third light-guiding channel and a fourth light-guiding channel) in different directions;

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

after the fingerprint optical signals returned after being reflected or scattered by the finger above the display screen are converged by the micro lens 310, four target fingerprint optical signals (a first target fingerprint optical signal, a second target fingerprint optical signal, a third target fingerprint optical signal and a fourth target fingerprint optical signal) in different directions are respectively transmitted to the four pixel units through the four light guide channels, included angles of the four light guide channels relative to the display screen are not completely the same, and the four target fingerprint optical signals are used for detecting fingerprint information of the finger.

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

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

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

Alternatively, 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 microlenses 310 and are disposed below the microlenses 310.

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

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

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

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

Optionally, as shown in fig. 7, a first light-passing aperture 3211 is formed on the first light- blocking layer 321, and 4 light-passing apertures, which are a second light-passing aperture 3221, a third light-passing aperture 3222, a fourth light-passing aperture 3223, and a fifth light-passing aperture 3224, are formed on the second light-blocking layer 322. The second light passing aperture 3221 and the first light passing aperture 3211 form a first light guiding channel for passing a first target fingerprint light signal among the fingerprint light signals converged by the microlens 310, which is received by the first pixel unit 331 located at the bottom of the first light guiding channel. Likewise, the third light passing aperture 3222 and the first light passing aperture 3211 form a second light guide channel for passing the second target fingerprint light signal, which is received by the second pixel element 332 located at the bottom of the second light guide channel. The fourth light passing aperture 3223 and the first light passing aperture 3211 form a third light guiding channel for passing a third target fingerprint light signal, which is received by the third pixel element 333 at the bottom of the third light guiding channel. The fifth light passing aperture 3224 and the first light passing aperture 3211 form a fourth light guiding channel for passing a fourth target fingerprint light signal, which is received by the fourth pixel unit 334 located at the bottom of the fourth light guiding channel, and 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 used for detecting fingerprint information.

In this embodiment, each of the light-passing apertures may be located at any position below the microlens 310, and is intended to form any four light-guiding channels in different directions, and the included angles between the four light-guiding channels in different directions and the display screen are not completely 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 may also be located at any position below the microlens 310, and are intended to receive fingerprint light signals of four different directions passing through the light guide channels of the four different directions, where the angles between the fingerprint light signals of the four different directions and the display screen are also not exactly the same.

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

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

According to the scheme of the embodiment of the application, one micro lens corresponds to four pixel units, the four pixel units respectively receive fingerprint optical signals in four directions which are converged by the micro lens and pass through four light guide channels, and the fingerprint optical signals in the four directions are respectively received by the four pixel units. Compared with the technical scheme that one microlens corresponds to one pixel unit (such as the fingerprint identification device in fig. 2 and 3), the light-entering amount of the fingerprint identification device can be increased, the exposure time can be shortened, and the field of view of the fingerprint identification device can be increased.

In addition, in the embodiment of the present application, the included angles of the four light guiding channels with respect to the display screen are not completely the same, the angles of the fingerprint light signals received by the four pixel units (the included angles of the fingerprint light signals with the direction perpendicular to the display screen) are determined by the relative position relationship between the four pixel units and the microlens, and the larger the pixel unit is, the farther the pixel unit is shifted from the center of the microlens, the larger the angle of the fingerprint light signal received by the pixel unit is. Therefore, the position of the pixel unit is flexibly set, so that the pixel unit can receive a wide-angle fingerprint optical signal, the identification problem of a dry finger is further improved, the thickness of a light path in the fingerprint identification unit can be further reduced, the thickness of the fingerprint identification device is reduced, and the process cost is reduced.

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

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

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

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

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

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

For example, as shown in fig. 7, the fingerprint identification unit includes two light-blocking layers, a top light-blocking layer of the two light-blocking layers is provided with a first light-passing aperture 3211, and a bottom light-blocking layer of the two light-blocking layers is provided with four light-passing apertures corresponding to four pixel units.

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

For example, in fig. 7, the direction of the first light guide channel corresponding to the first pixel unit 331 is a connection line direction of the first light passing pinhole 3211 and the second light passing pinhole 3221 or a direction close to the connection line direction, the direction of the second light guide channel corresponding to the second pixel unit 331 is a connection line direction of the first light passing pinhole 3211 and the third light passing pinhole 3222 or a direction close to the connection line direction, the direction of the third light guide channel corresponding to the third pixel unit 333 is a connection line direction of the first light passing pinhole 3211 and the fourth light passing pinhole 3223 or a direction close to the connection line direction, and the direction of the fourth light guide channel corresponding to the fourth pixel unit 334 is a connection line direction of the first light passing pinhole 3211 and the fifth light passing pinhole 3224 or a direction close to the connection line direction.

Optionally, the at least two light-blocking layers may also be three light-blocking layers, for example, a light-blocking layer is further disposed in the two light-blocking layers in the embodiment of the above application, and light-passing small holes corresponding to the four pixel units are also disposed in the light-blocking layer, so as to form four light-guiding 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 an intermediate light-blocking layer, a connection direction of the light-passing apertures of the bottom light-blocking layer and the top light-blocking layer in the four light-guiding channels is a direction of the light-guiding channels, and centers of the light-passing apertures in the intermediate light-blocking layer may be respectively located on the connection lines of the four light-guiding channels.

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

For example, the metal wiring layers of the four pixel units are disposed at the back focal plane position of the microlens 310, the metal wiring layers are bottom light-blocking layers of at least two light-blocking layers, and a second light-passing aperture 3221, a third light-passing aperture 3222, a fourth light-passing aperture 3223, and a fifth light-passing aperture 3224 are respectively formed above the light-sensing areas of the four pixel units.

In other words, the bottom light-blocking layer of the at least two light-blocking layers is formed on the metal wiring layer of the fingerprint sensor chip, and the corresponding light-passing small hole is formed above the photosensitive area of each pixel unit. Alternatively, the metal wiring layer of the fingerprint sensor chip may be reused as an optical path layer between the microlens and the pixel unit.

Optionally, the top light-blocking layer of the at least two light-blocking layers is provided with at least one light-passing aperture corresponding to the four pixel units. For example, a light-passing aperture may be respectively disposed for four pixel units in the top light-blocking layer, and for example, a light-passing aperture may also be disposed for four pixel units in the top light-blocking layer, such as the first light-passing aperture 3211 described above, in other words, a first light-guiding channel corresponding to the first pixel unit 321, a second light-guiding channel corresponding to the second pixel unit 322, a third light-guiding channel corresponding to the third pixel unit 333, and a fourth light-guiding channel corresponding to the fourth pixel unit 334 are overlapped with the light-passing apertures in the top light-blocking layer of at least two light-blocking layers.

Optionally, the apertures of the light passing apertures in the four light guide channels decrease from top to bottom, for example, the apertures of the second light passing aperture 3221, the third light passing aperture 3222, the fourth light passing aperture 3223, and the fifth light passing aperture 3224 are all smaller than the aperture of the first light passing aperture 3211.

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

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

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

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

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

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

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

The transparent medium layer is used to connect the microlens 310, at least two light blocking layers, and the four pixel units.

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

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

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

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

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

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

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

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

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

Optionally, the optical filter layer is configured to pass optical signals in a wavelength band range of 400nm to 650nm, in other words, a wavelength range of the target wavelength band includes 400nm to 650 nm.

Fig. 8 shows a schematic top view of the fingerprint recognition unit 301 in fig. 7.

As shown in fig. 8, the regions 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 convenience of description, the regions where the four pixel units are located are simply referred to as the pixel regions 330) may be located obliquely below the microlenses 310, and the centers of the pixel regions 330 and the centers of the microlenses 310 are not overlapped in the vertical direction. The four pixel units all receive target fingerprint optical signals in the inclined direction, namely the directions of the four light guide channels corresponding to the four pixel units are inclined relative to the display screen.

The four pixel units each include a photosensitive Area (AA) for receiving four target fingerprint optical signals respectively passing through the four light guide channels and converting the four target fingerprint optical signals into corresponding electrical signals. The photosensitive area may be an area where a photodiode is located in the pixel unit, that is, an area in the pixel unit that receives the light signal, and other areas in the pixel unit may be used for setting other circuits in the pixel unit and for arranging inter-pixel routing. Optionally, the light sensitivity of the photosensitive region to blue light, green light, red light or infrared light is greater than a first predetermined threshold, and the quantum efficiency is greater than a second predetermined threshold. For example, the first predetermined threshold may be 0.5v/lux-sec and the second predetermined threshold may be 40%. That is, the photosensitive region has high light sensitivity and high quantum efficiency for blue light (wavelength of 460 ± 30nm), green light (wavelength of 540 ± 30nm), red light or infrared light (wavelength of ≧ 610nm) so as to detect the corresponding light.

The first light sensing area 3311 of the first pixel unit 331 is located below the second light passing hole 3221, i.e., at the bottom of the first light guiding channel, and is configured to receive the first target fingerprint light signal; the second photosensitive region 3321 of the second pixel unit 332 is located below the third light-passing aperture 3222, i.e., at the bottom of the second light-guiding channel, and is configured to receive the second target fingerprint light signal; the third light sensing area 3331 of the third pixel element 333 is located below the fourth light passing aperture 3223, i.e. at the bottom of the third light guiding channel, for receiving the third target fingerprint light signal, and the fourth light sensing area 3341 of the fourth pixel element 334 is located below the fifth light passing aperture 3224, i.e. at the bottom of the fourth light guiding channel, for receiving the fourth target fingerprint light signal.

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

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

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

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

Fig. 10 shows a schematic cross-sectional view of fingerprint identification unit 301 of fig. 8 along direction B-B'.

As shown in fig. 10, a distance from the center of the second photosensitive region 3321 to the center of the microlens 310 is not equal to a distance from the center of the fourth photosensitive region 3341 to the center of the microlens 310, at this time, an included angle between the second target fingerprint optical signal 321 received by the second photosensitive region 3331 and an included angle between the fourth target fingerprint optical signal 314 received by the fourth photosensitive region 3341 and the display screen are not the same, or an included angle between the first light guide channel corresponding to the second photosensitive region 3321 and the display screen is not equal to an included angle between the fourth light guide channel corresponding to the fourth photosensitive region 3341 and the display screen.

In the embodiment of the present application, the first photosensitive area 3311 and the second photosensitive area 3321 receive the target fingerprint optical signal at the same angle with respect to the display screen, and the third photosensitive area 3321 and the fourth photosensitive area 3341 receive the target fingerprint optical signal at the same angle with respect to the display screen.

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

Fig. 8, 9, and 10 show a case where the fingerprint identification unit 301 includes two light-blocking layers, and optionally, the fingerprint identification unit 301 may further include three light-blocking layers.

Fig. 11 shows a schematic top view of a fingerprint recognition unit 301, and fig. 12 shows a schematic cross-sectional view of the fingerprint recognition unit 301 along the direction a-a' in fig. 11.

As shown in fig. 11 and 12, the fingerprint recognition unit 301 includes three light blocking layers. The top light-blocking layer is provided with the first light-passing aperture 3211, and the bottom light-blocking layer is provided with the second light-passing aperture 3221, the third light-passing aperture 3222, the fourth light-passing aperture 3223, and the fifth light-passing aperture 3224. In addition, a sixth light passing aperture 3231, a seventh light passing aperture 3232, an eighth light passing aperture 3233 and a ninth light passing aperture 3234 are arranged in the light blocking layer of the newly added intermediate layer. The first light-passing aperture 3221, the sixth light-passing aperture 3231, and the second light-passing aperture 3221 form a first light-guiding channel corresponding to the first light-sensing region 3311, and centers of the four light-passing apertures may be located on the same straight line. In addition, the first light passing aperture 3221, the seventh light passing aperture 3232, and the third light passing aperture 3222 form a second light guide channel corresponding to the second light sensing region 3321, centers of the four light passing apertures may be located on the same straight line, and the first light passing aperture 3221, the eighth light passing aperture 3233, and the fourth light passing aperture 3223 form a third light guide channel corresponding to the third light sensing region 3331, centers of the four light passing apertures may be located on the same straight line. The first light passing small hole 3221, the ninth light passing small hole 3234 and the fifth light passing small hole 3224 form a fourth light guide channel corresponding to the fourth light sensing area 3341, and centers of the four light passing small holes may also be located on the same straight line.

Optionally, in this embodiment, the aperture of the first light-passing aperture 3221 is larger than the apertures 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 3234, and the apertures 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 3234 are larger than the apertures of the second light-passing aperture 3221, the third light-passing aperture 3222, the fourth light-passing aperture 3223 and the fifth light-passing aperture 3224.

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

Referring to fig. 8 and 11, in one possible embodiment, the photosensitive areas of the four pixel cells occupy only a small portion of the area of the pixel cells to meet the requirement of receiving the optical signal.

In this embodiment, 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 on the connection line of the first light passing hole 3211 and the second light passing hole 3221. Similarly, the centers of the photosensitive regions in other pixel units can be located at the bottom of the corresponding light guide channels.

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

In order to receive the first, second, third and fourth target fingerprint light signals to the maximum, optionally, the first photosensitive area 3311 of the first pixel unit 331 may completely cover the first light spot 3301, the second photosensitive area 3321 of the second pixel unit 332 may completely cover the second light spot 3302, the third photosensitive area 3331 of the third pixel unit 333 may completely cover the third light spot 3303, and the fourth photosensitive area 3331 of the fourth pixel unit 334 may completely cover the fourth light spot 3304.

Alternatively, among the four pixel units, the first pixel unit 331 may be a quadrilateral area having a length and a width of L and W, respectively, where W ≦ L, W and L are positive numbers, and both the length and the width of the first photosensitive area 3311 in the first pixel unit 331 are 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 may also correspondingly satisfy the above conditions.

In one possible embodiment, as shown in fig. 8 and 11, the photosensitive regions of the four pixel units are quadrilateral regions and are circumscribed to the photosensitive regions.

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

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

Alternatively, in fig. 8 and 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-mentioned figures, the shape, size, and relative position of the four pixel units may be arbitrarily set, and the shape and size of the four pixels may be the same or different, which is not limited in this embodiment of the present application. For example, the first pixel unit and the third pixel unit of the four pixel units are square pixels, the second pixel unit is a rectangular pixel, or the four pixel units are square pixels, and so on.

In fig. 8 and 11, four photosensitive regions are disposed offset from the centers of four pixel cells. Since the four photosensitive regions all receive the optical signals in the oblique direction, and the larger the oblique angle is, the farther the photosensitive region in the pixel unit is from the center of the microlens, for example, the third photosensitive region and the fourth photosensitive region are from the center of the microlens, and the first photosensitive region and the second photosensitive region are closer to the center of the microlens, the angle of the target fingerprint optical signal received by the third photosensitive region and the fourth photosensitive region is larger, and the angle of the target fingerprint optical signal received by the first photosensitive region and the second photosensitive region is smaller.

In addition, the four photosensitive areas are arranged in a manner of being offset from the center of the pixel unit and are also offset towards the direction far away from the center of the micro lens, so that the target fingerprint optical signal angle received by the four photosensitive areas can be increased, and the thickness of the fingerprint identification unit can be further reduced.

It should be understood that, in the embodiment of the present application, the four photosensitive areas may also be respectively located at the centers of the four pixel units, and in order to meet the requirement of the angle for receiving the light signal by the photosensitive areas, the four pixel units may be shifted away from the center of the microlens, so as to increase the angle for receiving the target fingerprint light signal by the four photosensitive areas, and decrease the thickness of the fingerprint identification unit.

In this embodiment, the four pixel units may also be disposed at any position below the microlens, and the four photosensitive regions may be disposed at any position in the four pixel units, and are intended to receive the target fingerprint optical signal passing through the four channels.

As shown in fig. 8 and 11, an angle between the projection of the first target fingerprint light signal received by the first photosensitive region 3311 and the projection of the second target fingerprint light signal received by the second photosensitive region 3321 on the plane of the pixel region 330 is +90 °, an angle between the projection of the first target fingerprint light signal received by the first photosensitive region 3311 and the projection of the third target fingerprint light signal received by the third photosensitive region 3331 on the plane of the pixel region 330 is-90 °, and an angle between the projection of the first target fingerprint light signal received by the first photosensitive region 3311 and the projection of the fourth target fingerprint light signal received by the fourth photosensitive region 3341 on the plane of the pixel region 330 is 180 °.

Or, the projection of the first light guide channel on the plane where the pixel region 330 is located forms an included angle of +90 degrees with the projection of the second light guide channel on the plane where the pixel region 330 is located, the projection of the first light guide channel on the plane where the pixel region 330 is located forms an included angle of-90 degrees with the projection of the third light guide channel on the plane where the pixel region 330 is located, and the projection of the first light guide channel on the plane where the pixel region 330 is located forms an included angle of 180 degrees with the projection of the fourth light guide channel on the plane where the pixel region 330 is located.

Adopt the scheme of this application embodiment, the fingerprint light signal mutually perpendicular that two pixel cell of multiunit received in the four pixel cell, first pixel cell and second pixel cell wherein promptly, first pixel cell and third pixel cell, fourth pixel cell and second pixel cell, and the fingerprint light signal mutually perpendicular that fourth pixel cell and third pixel cell received, under this condition, the fingerprint light signal of ridge and valley line in the perpendicular to fingerprint of being convenient for gather, can improve the quality of the fingerprint light signal that the fingerprint identification unit received, thereby improve fingerprint image quality, promote fingerprint identification device's fingerprint identification performance.

It should be understood that, the fingerprint optical signals received by any two pixel units in the four pixel units are perpendicular, that is, the fingerprint optical signals perpendicular to ridges and valleys in the fingerprint can be collected, so as to improve the quality of the fingerprint optical signals received by the fingerprint identification unit.

In fig. 8 to 12, the connecting line between the projection point of the microlens on the four pixel units and the center point of the four pixel units is parallel to one side of the pixel units. Optionally, the micro lens may be disposed at any position above the four pixel units, and a direction of a connecting line between a projection point of the micro lens on the four pixel units and a center point of the four pixel units may be any direction.

Fig. 13 shows a schematic top view of another fingerprint recognition unit 301.

As shown in fig. 13, a line connecting a projection point of the center of the microlens 310 on the pixel region 330 and the center of the pixel region 330 is located on one diagonal line in the pixel region 330. The photosensitive areas in the four pixel units are all arranged away from the microlens, so as to receive fingerprint light signals with a larger angle, wherein the center of the microlens 310 is farthest away from the fourth pixel unit 334, the photosensitive area in the fourth pixel unit 334 is arranged on the opposite corner of the fourth pixel unit away from the microlens 310, and at this time, the angle of the fingerprint light signal received by the photosensitive area in the fourth pixel unit 334 is the largest among the four pixel units. Adopt this mode, can further reduce the light path thickness of fingerprint identification unit and fingerprint identification module.

In addition, in the embodiment of the present application, an included angle between the first target fingerprint optical signal received by the first photosensitive region 3311 and the projection of the third target fingerprint optical signal received by the third photosensitive region 3331 on the plane where the pixel region 330 is located is 90 °, or an included angle between the projection of the first light guide channel on the plane where the pixel region 330 is located and the projection of the third light guide channel on the plane where the pixel region 330 is located is 90 °. An included angle between the projection of the first light guide channel on the plane where the pixel region 330 is located and the projection of the fourth light guide channel on the plane where the pixel region 330 is located is an acute angle smaller than 90 degrees, and an included angle between the projection of the first light guide channel on the plane where the pixel region 330 is located and the projection of the second light guide channel on the plane where the pixel region 330 is located is an obtuse angle larger than 90 degrees.

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

Fig. 8, 9, 11, and 13 illustrate only schematic top views of several fingerprint identification units 301, and it should be understood that a projection of any two light guide channels in the four light guide channels on the plane where the pixel region 330 is located may form any included angle between 0 ° and 180 °, and that the respective included angles between the four light guide channels and the plane where the pixel region 330 is located may also form any angle between 0 ° and 90 °, which is not limited in this embodiment of the present application.

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

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

Alternatively, fig. 14 shows another schematic top view of the fingerprint recognition unit 301.

As shown in fig. 14, the photosensitive areas in the four pixel units are larger in area, and cover other areas besides the light spots on the pixel units. In fig. 14, the photosensitive regions in the four pixel cells occupy most of the area of the pixel cells. For example, the first photosensitive region 3311 in the first pixel unit 331 occupies 95% or more of the area in the first pixel unit 331, or the respective photosensitive regions in the other pixel units occupy 95% or more of the area.

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

Alternatively, based on the embodiments of the above-mentioned application, any two distances among the distance from the center of the first photosensitive region 3311 to the center of the microlens 310, the distance from the center of the second photosensitive region 3321 to the center of the microlens 310, the distance from the center of the third photosensitive region 3331 to the center of the microlens 310, and the distance from the center of the fourth photosensitive region 3341 to the center of the microlens 310 may not be equal, or the four distances are different, at this time, any two included angles among the four included angles between 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 and the display screen are different, or the four included angles are all different, or the first light guide channel, the second light guide channel, the third light guide channel and the fourth light guide channel are all different from any two included angles in the four included angles of the display screen, or the four included angles are all different.

The above description only illustrates several cases where the pixel region 330 where four pixel units in the fingerprint identification unit 301 are located is located obliquely below the microlens 310, and it should be understood that the pixel region 300 may also be located in any region obliquely below the microlens 310, which is not limited in this embodiment, and the photosensitive regions in the four pixel units may be located in any region in the pixel units where they are located, which is also not limited in this embodiment.

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

Specifically, in a possible light path design manner, the angle of the first target fingerprint light signal is greater than the angles of the other three target fingerprint light signals in the four target fingerprint light signals, where the angle of the light signal refers to an included angle between the light signal and a direction perpendicular to the display screen.

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

h＝x×cotθ；

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

The above application embodiment shows a case where four pixel units in the fingerprint identification unit 301 all receive oblique optical signals, optionally, one of the four pixel units may receive a target fingerprint optical signal in a vertical direction, and the other two pixel units receive the target fingerprint optical signal in an oblique direction, in other words, the direction of the light guide channel corresponding to one of the four pixel units is vertical to the display screen, and the directions of the light guide channels corresponding to the other two pixel units are all oblique to the display screen.

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.

Fig. 15 shows a top view of a fingerprint recognition unit 301 of the fingerprint recognition device 300.

As shown in fig. 15, the second photosensitive region 3321 of the second pixel unit 332 is located directly below the center of the microlens 310 in spatial position, or the center of the second photosensitive region 3321 coincides with the center of the microlens 310 in the vertical direction. At this time, the second light guide channel corresponding to the second photosensitive region 3321 is also perpendicular to the microlens 310 or the display screen. At this time, the center of the first light-passing aperture 3211, the center of the third light-passing aperture 3222, the center of the microlens 310, and the center of the second photosensitive region 3321 in the second light-guiding channel are all located on the same straight line perpendicular to the display screen.

In spatial position, the first photosensitive region 3311 of the first pixel unit 331, the third photosensitive region 3331 of the third pixel unit 333, and the fourth photosensitive region 3341 of the fourth pixel unit 334 are located obliquely below the center of the microlens 310, and receive the light signals oblique to the display panel, and the directions of the corresponding first light-guiding channel, third light-guiding channel, and fourth light-guiding channel are arranged obliquely to the display panel. Specifically, the technical features of the first pixel unit 331, the third pixel unit 333, the fourth pixel unit 334 and the related technical features thereof can refer to the technical features of the above technical scheme in which the four pixel units all receive oblique optical signals, and are not described herein again.

Fig. 15 illustrates only one case of the relative position relationship between the first pixel unit 331 and the third pixel unit 333 in the fingerprint identification unit 301 and the microlens 310, and it should be understood that, in terms of spatial position, the first pixel unit 331 and the third pixel unit 333 may also be located in any area obliquely below the microlens 310, which is not limited in this embodiment, and the photosensitive areas in the four pixel units may be located in any area in the pixel unit where the photosensitive areas are located, which is also not limited in this embodiment.

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

The fingerprint recognition unit 301 of the present application is described in detail above with reference to fig. 6 to 15.

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

Alternatively, as shown in fig. 16, in a possible implementation, four pixel units in one fingerprint identification unit 301 are quadrilateral pixel units and form a quadrilateral area, and the pixel array 302 of the fingerprint identification device 300 is represented as a pixel matrix arranged by a plurality of quadrilateral pixel unit arrays.

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

Optionally, the plurality of target pixel units 3021 may all be the first pixel unit 331, the second pixel unit 332, the third pixel unit 333, or the fourth pixel unit 334, and may also include the first pixel unit 331, the second pixel unit 332, the third pixel unit, and the fourth pixel unit 334 at the same time, which is not limited in this embodiment of the present invention.

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

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

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

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

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

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

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

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

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

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

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

For example, as shown in fig. 16, the unit pixel region 3023 may be a pixel region of 4 fingerprint recognition units, i.e., a pixel region of 16 pixel units. It should be understood that the unit pixel area may also be a pixel unit area with any other size, which is not limited in this embodiment of the application.

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

Fig. 17a to 17b show schematic diagrams of a pixel array 302 in two types of fingerprint recognition devices 300. As shown in fig. 17a to 17b, the numeral "1" denotes the first pixel unit 331, the numeral "2" denotes the second pixel unit 332, the numeral "3" denotes the third pixel unit 333, and the numeral "4" denotes the fourth pixel unit 334.

As shown in fig. 17a and 17b, none of the plurality of first pixel units 331, the plurality of second pixel units 332, the plurality of third pixel units 333, and the plurality of fourth pixel units 334 are adjacent to each other.

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

In the pixel array 302, a plurality of first pixel units 331 receive a fingerprint light signal of a direction, the fingerprint light signal is used for forming a first fingerprint image of a finger, and a first target fingerprint light signal received by one first pixel unit 331 is used for forming a pixel point in the first fingerprint image. The plurality of second pixel units 332 receive the fingerprint light signal of the other direction, the fingerprint light signal is used for forming a second fingerprint image of the finger, and the second target fingerprint light signal received by one second pixel unit 332 is used for forming one pixel point in the second fingerprint image. The plurality of third pixel units 333 receives a fingerprint light signal of a third direction, the fingerprint light signal is used for forming a third fingerprint image of the finger, and a third target fingerprint light signal received by one third pixel unit 333 is used for forming one pixel point in the third fingerprint image. The plurality of fourth pixel units 334 receives a fourth directional fingerprint light signal, the fingerprint light signal is used for forming a fourth fingerprint image of the finger, and a fourth target fingerprint light signal received by one fourth pixel unit 334 is used for forming one pixel point in the fourth fingerprint image. The first fingerprint image, the second fingerprint image, the third fingerprint image and the fourth fingerprint image can be independently used for fingerprint identification, any two or three of the first fingerprint image, the second fingerprint image, the third fingerprint image and the fourth fingerprint image can be reconstructed, and the reconstructed fingerprint images are subjected to fingerprint identification.

Alternatively, in a possible implementation, the first target fingerprint light signal received by one first pixel unit 331 is used to form one pixel point in the first fingerprint image. A second pixel unit 332 receives the second target fingerprint light signal for forming a pixel in the second fingerprint image. A third pixel unit 333 receives a third target fingerprint light signal for forming a pixel in the third fingerprint image. A fourth pixel element 334 receives the fourth target fingerprint light signal to form a pixel in the fourth fingerprint image.

Alternatively, in another possible implementation, 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 a pixel point 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 a pixel point in the second fingerprint image. The third target fingerprint light signal received by every X third pixel units 333 of 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 X fourth pixel units 334 in the plurality of fourth pixel units is used to form a pixel point in the fourth fingerprint image. Wherein X is a positive integer greater than 1.

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

Specifically, in the embodiment of the present application, the fingerprint identification device 300 further includes a processing Unit, and optionally, the processing Unit may be a processor, and the processor may be a processor in the fingerprint identification device 300, such as a Micro Controller Unit (MCU) or the like. The processor may also be a processor in the electronic device where the fingerprint identification device 300 is located, for example, a main control chip in a mobile phone, and the like, which is not limited in this embodiment of the application.

Specifically, the processing unit includes a first sub-processing unit, a second sub-processing unit, a third sub-processing unit and a fourth sub-processing unit, wherein the first sub-processing unit is configured to acquire the electrical signals of X first pixel units 331 to form one pixel value in a first fingerprint image of the finger, the second sub-processing unit is configured to acquire the electrical signals of X second pixel units 332 to form one pixel value in a second fingerprint image of the finger, the third sub-processing unit is configured to acquire the electrical signals of X third pixel units 333 to form one pixel value in a third fingerprint image of the finger, and the fourth sub-processing unit is configured to acquire the electrical signals of X second pixel units 334 to form one pixel value in a fourth fingerprint image of the finger.

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

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

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

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

Alternatively, the X first pixel units 331 may be adjacent X pixel units in the plurality of first pixel units 331 of the pixel array 302, for example, 4 first pixel units of 2 × 2, or 9 first pixel units of 3 × 3, and likewise, the X second pixel units 332 may be adjacent X pixel units in the plurality of second pixel units 332 of the pixel array 302, the X third pixel units 333 may be adjacent X pixel units in the plurality of third pixel units 333 of the pixel array 302, or the X fourth pixel units 334 may be adjacent X pixel units in the plurality of fourth pixel units 334 of the pixel array 302, which is not specifically limited in this embodiment of the application.

Fig. 18 is a schematic block diagram of an electronic device comprising 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 screen 120, and a fingerprint identification apparatus 300 located below the filter 400 and composed of a plurality of fingerprint identification units 301, wherein the pixel unit of each fingerprint identification unit 301, i.e., the pixel array 302, may be disposed on the upper surface of the substrate 500. Wherein the pixel array 302 and the substrate 500 may be referred to as a fingerprint sensor or an image sensor.

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

Specifically, the substrate may be the Circuit board 150 in fig. 1, and may specifically be a Circuit board (PCB), a Flexible Printed Circuit (FPC), a software-integrated Circuit board, or the like, which is not limited in this embodiment of the application.

The fingerprint identification process based on the oblique optical signals in multiple directions according to the embodiment of the present application is described below with reference to fig. 19 to 25. For ease of understanding, the fingerprint identification process is exemplified by the 4-directional oblique light signals.

When the optical signal received by the fingerprint identification device is an optical signal carrying an alternate pattern of bright and dark stripes as shown in fig. 19, and 4 pixel units corresponding to each microlens in the fingerprint identification device are used for receiving target fingerprint optical signals in 4 different directions, the pixel array in the fingerprint identification device simultaneously images the optical signals in different imaging areas, so that an image formed by the pixel array in the fingerprint identification device is a superimposed image of the different imaging areas, and is a blurred image. Such as the image shown in fig. 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 performing extraction processing on the original image in fig. 20. In particular, when the light signal received by the fingerprint identification device is a fingerprint light signal reflected or scattered by a finger, the image formed by the pixel array is a superimposed image of different areas of the fingerprint, and is also a blurred image. The original image can be processed to obtain electrical signals of a plurality of first pixel units in the pixel array to form a first fingerprint image, and electrical signals of a plurality of second pixel units to form a second fingerprint image, electrical signals of a plurality of third pixel units to form a third fingerprint image, and electrical signals of a plurality of fourth pixel units to form a fourth fingerprint image.

For example, the original image generated by the first pixel units in the pixel array is shown in fig. 21. Since the plurality of first pixel units all receive the optical signals in the same direction, there is no situation of overlapping images of different imaging areas, and therefore, the processing unit can process and obtain the first image corresponding to the optical signals in the first direction as shown in fig. 21, which is a clear image. Similarly, the processing unit may process the second image generated by the plurality of second pixel units as shown in fig. 22, the third image generated by the plurality of third pixel units as shown in fig. 23, and the fourth image generated by the plurality of fourth pixel units as shown in fig. 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 a first target reconstructed image, the third image and the fourth image may be reconstructed to obtain a second target reconstructed image, and the first target reconstructed image and the second target reconstructed image may be reconstructed again to obtain a final target reconstructed image. Alternatively, the four images may be processed at the same time and reconstructed to obtain a final target reconstructed image. The processing procedure includes, but is not limited to, image processing procedures such as image upsampling, filtering, and the like.

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

In other words, the first image may be shifted to the left and upward by a distance of several pixels of the image, the second image may be shifted to the right and upward by a distance of several pixels, the third image may be shifted to the left and downward by a distance of several pixels, and the fourth image may be shifted to the right and downward by a distance of several pixels, forming a sharp image as shown in fig. 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 optical path design. Furthermore, when the surface of the pixel array is covered with a layer of microlens array, the pixel array can perform imaging based on light signals in four directions to obtain an original image. Because the original image is formed by superposing the images in four directions, the original image can be reconstructed through an algorithm, and a clear reconstructed image can be obtained.

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

Specifically, the quality parameters of the reconstructed image include, but are not limited to: the contrast of the reconstructed image, the definition of the reconstructed image, the signal-to-noise ratio of the reconstructed image or the similarity between the reconstructed image and the 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 pixel points, the N can be adjusted according to the quality parameters of the reconstructed image to form a target reconstructed image.

Because the thickness of the display screen is fixed and the relative position between the display screen and the fingerprint identification device is basically unchanged, an original image (such as the image shown in fig. 20) can be collected first, the number of image pixels, which need to be moved, of the image corresponding to the oblique optical signal in each direction when the imaging quality of the reconstructed image is clearest, is determined as a moving image parameter, and the moving image parameter is stored in the storage unit. Furthermore, in the subsequent fingerprint acquisition process, a clear image can be reconstructed based on the moving image parameters.

It should be understood that the original image may be a fingerprint image, or any pattern with clear contrast originally overlaid on the surface of the display screen. For example, the image in fig. 19 is similar to the shape of the fingerprint ridges and fingerprint valleys in the fingerprint image, when the optical signal received by the fingerprint identification device is an optical signal reflected or scattered by a finger, the image processed by the processing unit may be similar to the image shown in fig. 20 before processing and reconstructing, and the fingerprint image processed and reconstructed may be similar to the image shown in fig. 25 to be a clear fingerprint image.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Claims (33)

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

a microlens;

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

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

wherein, follow fingerprint light signal that returns after the finger reflection of display screen top or scattering passes through microlens converges back, wherein four target fingerprint light signal of equidirectional not pass through respectively four light guide channel transmit extremely four pixel cell, four light guide channel are relative the contained angle of display screen is not identical, just four target fingerprint light signal are used for detecting the fingerprint information of finger.

2. The fingerprint recognition device of claim 1, wherein the four pixel units form a pixel area of a quadrilateral area, and a center point of the pixel area is not vertically coincident with a center of the microlens.

3. The fingerprint identification device of claim 1, wherein the pixel area is a square area with a side length of a, a distance between a projection point of the center of the microlens on the plane of the four pixel units and a center point of the pixel area is d, and 0 < d < a.

4. The fingerprint recognition device of claim 1, wherein at least three of the four light-conducting channels are oriented obliquely with respect to the display.

5. The fingerprint identification device according to claim 1, wherein the included angle of the projection of two of the four light guide channels on the plane of the four pixel units is 90 degrees.

6. The fingerprint identification device according to any one of claims 1 to 5, wherein each of the four pixel units comprises four photosensitive areas, and the four photosensitive areas are respectively located at the bottoms of the four light guide channels.

7. The fingerprint recognition device of claim 6, wherein at least one of the four photosensitive regions is disposed off-center from a center of a pixel cell in which it is disposed.

8. The fingerprint recognition device of claim 7, wherein the at least one photosensitive area is offset in a direction away from a center of the microlens.

9. The fingerprint identification device of 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.

10. The fingerprint identification device according to claim 6, wherein the four pixel units comprise a first pixel unit, the first pixel unit comprises a first photosensitive area, and the first pixel unit and the first photosensitive area are both quadrilateral;

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

11. The fingerprint identification device of claim 6, wherein the four target fingerprint light signals form four light spots on the four pixel units respectively, and the four light sensing areas are quadrilateral areas and circumscribe the four light spots.

12. The fingerprint recognition device according to claim 6, wherein the height of the optical path between the micro-lens and the plane of the four pixel units is calculated according to a formula:

h＝x×cotθ；

wherein, h does light path height, x do first photosensitive area's in four photosensitive area center with microlens's center is in distance between the projection point on four pixel cell place planes, theta do first target fingerprint light signal and the contained angle of vertical direction that first photosensitive area received, in four target fingerprint light signal first target fingerprint light signal is greater than in four target fingerprint light signal other three target fingerprint light signal and vertical direction's contained angle, the vertical direction is the perpendicular to the direction of display screen.

13. The fingerprint recognition device according to any one of claims 1 to 5, wherein the four pixel units are quadrilateral pixel units with the same size.

14. The fingerprint identification device according to any one of claims 1 to 5, wherein the four light guide channels respectively form an angle of 30 ° to 90 ° with the plane of the four pixel units.

15. The fingerprint identification device according to any one of claims 1 to 5, wherein the bottom light-blocking layer of the at least two light-blocking layers is provided with four light-passing small holes corresponding to the four pixel units respectively.

16. 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.

17. The fingerprint identification device of claim 15, wherein the apertures of the four light guide channels decrease from top to bottom.

18. The fingerprint identification device of claim 15, wherein the four light guide channels coincide with light passing apertures in a top light blocking layer of the at least two light blocking layers.

19. The fingerprint recognition device according to any one of claims 1 to 5, wherein the fingerprint recognition unit further comprises:

a transparent dielectric layer;

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

20. The fingerprint recognition device according to any one of claims 1 to 5, wherein the fingerprint recognition unit further comprises:

an optical filter layer;

the optical filtering layer is arranged in a light path from the display screen to the plane element where the four pixel units are located, and is used for filtering optical signals of a non-target waveband so as to penetrate through the optical signals of the target waveband.

21. The fingerprint recognition device of claim 20, wherein the optical filter layer is integrated on the four pixel cell surfaces.

22. The fingerprint recognition device according to claim 20, wherein the optical filter layer is disposed between a bottom light-blocking layer of the at least two light-blocking layers and a plane in which the four pixel units are located.

23. The fingerprint identification device according to any one of claims 1 to 5, wherein the plurality of groups of four pixel units include a plurality of target pixel units, and a color filter layer is disposed in a corresponding light guide channel of the plurality of target pixel units, and the color filter layer is configured to pass red visible light, green visible light, or blue visible light.

24. The fingerprint identification device of claim 23, wherein the area where the plurality of sets of four pixel units are located is composed of a plurality of unit pixel areas, and one target pixel unit is disposed in each of the plurality of unit pixel areas.

25. The apparatus of claim 23, wherein the plurality of target pixel units are evenly distributed among the plurality of groups of four pixel units.

26. The fingerprint identification device of claim 23, wherein the color filter layer is disposed in a light-passing aperture of the corresponding light guide channel of the target pixel unit.

27. The fingerprint recognition device according to any one of claims 1 to 5,

the optical signals received by a plurality of first pixel units in the plurality of groups of four pixel units are used for forming a first fingerprint image of the finger, the optical signals received by a plurality of second pixel units in the plurality of groups of four pixel units are used for forming a second fingerprint image of the finger, the optical signals received by a plurality of third pixel units in the plurality of groups of four pixel units are used for forming a third fingerprint image of the finger, the optical signals received by a plurality of fourth pixel units in the plurality of groups of four pixel units are used for forming a fourth fingerprint image of the finger, and 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.

28. The fingerprint recognition device of claim 27, wherein an average of pixels of every X first pixel units of the plurality of first pixel units is used to form a pixel value in the first fingerprint image;

the pixel average value of every X second pixel units in the plurality of second pixel units is used for forming a pixel value in the second fingerprint image,

the average value of the pixels of every X third pixel units in the plurality of third pixel units is used for forming 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 for forming a pixel value in the fourth fingerprint image, wherein X is a positive integer.

29. The apparatus of claim 27, wherein the first pixel units are not adjacent to each other, the second pixel units are not adjacent to each other, the third pixel units are not adjacent to each other, and the fourth pixel units are not adjacent to each other.

30. The fingerprint recognition device according to claim 27, further comprising a processing unit, wherein the processing unit is configured to move the first fingerprint image, the second fingerprint image, the third fingerprint image and the fourth fingerprint image to combine to form a reconstructed image, and adjust the moving distance of the first fingerprint image, the second fingerprint image, the third fingerprint image and the fourth fingerprint image according to the quality parameter of the reconstructed image to form a target reconstructed image, and the target reconstructed image is used for fingerprint recognition.

31. The fingerprint recognition device of any one of claims 1-5, wherein the distance between the fingerprint recognition device and the display screen is 0-1 mm.

32. An electronic device, comprising: a display screen; and

the fingerprint recognition device of any one of claims 1-31, said fingerprint recognition device being disposed below said display screen to enable off-screen optical fingerprint recognition.

33. The electronic device of claim 32, wherein a distance between the fingerprint recognition device and the display screen is 0 to 1 mm.

Images