CN112528953A

CN112528953A - Fingerprint identification device, electronic equipment and fingerprint identification method

Info

Publication number: CN112528953A
Application number: CN202011563420.2A
Authority: CN
Inventors: 何嘉明; 丘芳芳
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2020-12-25
Filing date: 2020-12-25
Publication date: 2021-03-19
Anticipated expiration: 2040-12-25
Also published as: CN112528953B

Abstract

The embodiment of the application relates to a fingerprint identification device, electronic equipment and a fingerprint identification method. This fingerprint identification device sets up the below at electronic equipment's display screen, includes: the optical path layer is used for guiding return optical signals in N directions, which return after passing through the finger, to the optical fingerprint sensor; the optical fingerprint sensor comprises an array of optical sensing units, each optical sensing unit comprises N optical sensing pixels, each optical sensing pixel is used for receiving a return light signal in one of the N directions, the return light signals in the N directions are used for generating N fingerprint images in one-to-one correspondence, and the brightness difference of image blocks in corresponding positions of different fingerprint images is used for determining the pressing areas of the N fingerprint images to perform fingerprint identification. The fingerprint identification device, the electronic equipment and the fingerprint identification method can improve the safety of fingerprint identification.

Description

Fingerprint identification device, electronic equipment and fingerprint identification method

Technical Field

The embodiments of the present application relate to the field of biometric identification, and more particularly, to a fingerprint identification apparatus, an electronic device, and a method of fingerprint identification.

Background

The current fingerprint technology under the screen is rising, more and more manufacturers and customers select the mobile phone using the fingerprint identification under the screen, the problem that the comprehensive screen is not comprehensive enough is well solved by the fingerprint technology under the screen, but the fingerprint under the screen also faces a series of problems.

Since the principle of imaging of an off-screen fingerprint is that light emitted by the screen illuminates the finger and reflects, the reflected light is received by the sensor. When the finger does not completely cover the sensor, for the place where the finger does not cover, the external ambient light can also be directly received by the sensor through the screen, so that the fingerprint and the like remained on the screen can also be imaged on the sensor. Since the intensity of the ambient light and the intensity of the light reflected by the finger to the screen may not be very different, it is impossible to distinguish the image collected by the sensor from the fingerprint actually pressed by the finger or the trace of the screen residue, which brings a challenge to the anti-hacking attack of the fingerprint under the screen.

Disclosure of Invention

The application provides a fingerprint identification device, an electronic device and a fingerprint identification method, which can improve the safety of fingerprint identification.

In a first aspect, a fingerprint identification device is provided, which is disposed below a display screen of an electronic device, and includes: the optical path layer is used for guiding return optical signals in N directions, returning after passing through the finger, to the optical fingerprint sensor, and N is an integer larger than 1; an optical fingerprint sensor disposed below the optical path layer for receiving the return optical signals of the N directions, the optical fingerprint sensor comprises an array of optical sensing elements, the optical sensing elements comprising N optical sensing pixels, each of the N optically sensitive pixels is for receiving a return light signal in one of the N directions, wherein return light signals of the same direction of the N return light signals are used to generate the same fingerprint image, the return light signals in the N directions are used for generating N fingerprint images in one-to-one correspondence, the brightness difference of image blocks at corresponding positions of different fingerprint images in the N fingerprint images is used for determining the pressing areas of the N fingerprint images, and the pressing areas of the N fingerprint images are used for fingerprint identification.

Therefore, the fingerprint recognition device according to the embodiment of the present application can receive return light signals in a plurality of directions. Considering that when a fingerprint image is collected, aiming at the condition that a finger locally presses on the surface of a display screen, the optical fingerprint sensor corresponding to the pressing area mainly receives screen luminescence reflected by the finger, and the light intensity of return light received by the part of light from light paths in different directions is consistent with the full-pressing condition and is uniform; and the optical fingerprint sensor corresponding to the non-pressed area mainly receives ambient light, for example, the ambient light may include light leakage of the screen and external light transmitted through the screen, and since the ambient light is not isotropic light, the intensity difference of the light received from the light paths in different directions is large. According to the characteristic, a plurality of fingerprint images can be correspondingly generated aiming at return light signals in a plurality of directions received by the fingerprint identification device, the fingerprint images are divided by comparing the brightness difference of image blocks at corresponding positions of different fingerprint images so as to distinguish a part corresponding to a finger pressing area in the fingerprint images, and then the fingerprint identification is carried out on the part, so that the problems that the fingerprint identification device collects screen residual marks such as fingerprints and the like due to partial pressing of the fingers, so that cracking attack and the like are caused are solved, and the performance of the fingerprints under the screen can achieve the optimal effect.

With reference to the first aspect, in an implementation manner of the first aspect, the optical path layer includes: at least one light-blocking layer, each of the at least one light-blocking layer being provided with an array of apertures to form a plurality of light-conducting channels in the N directions for guiding return light signals in the N directions to the optical fingerprint sensor.

With reference to the first aspect and the foregoing implementation manner of the first aspect, in another implementation manner of the first aspect, each of the plurality of light guide channels corresponds to one optical sensing pixel in the optical fingerprint sensor.

With reference to the first aspect and the foregoing implementation manner of the first aspect, in another implementation manner of the first aspect, the optical path layer further includes: and the micro lens array is arranged above the at least one light blocking layer and used for converging the return light signal passing through the finger to the light guide channel of the at least one light blocking layer.

With reference to the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, one microlens in the microlens array corresponds to N light guide channels, and the N light guide channels correspond to N directions one to one.

With reference to the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, the N light guide channels respectively correspond to N optical sensing pixels included in a same optical sensing unit.

With reference to the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, projections of the N light guide channels on a horizontal plane are distributed symmetrically along a projection center of an optical axis of the microlens on the horizontal plane.

With reference to the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, included angles between the plurality of light guide channels and a horizontal plane are equal.

With reference to the first aspect and the foregoing implementation manner of the first aspect, in another implementation manner of the first aspect, the at least one light-blocking layer is two light-blocking layers.

With reference to the first aspect and the foregoing implementation manner of the first aspect, in another implementation manner of the first aspect, the optical path layer includes: n lenses, each of the N lenses for converging return light signals of one direction for generating one fingerprint image.

With reference to the first aspect and the foregoing implementations of the first aspect, in another implementation of the first aspect, N is equal to 2 or 4.

With reference to the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, it is determined whether an image block in a corresponding position of different fingerprint images in the N fingerprint images is a pressed block according to a luminance difference of the image block, where all the pressed blocks of the N fingerprint images are pressed areas of the N fingerprint images.

With reference to the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, each of the N fingerprint images includes M image blocks divided in the same manner, M is an integer greater than 1, luminance differences of image blocks at corresponding positions of different fingerprint images in the N fingerprint images include N ith difference values, the N ith difference values include differences between pixel values of an ith image block in the M image blocks of each fingerprint image and pixel values of a preset image block, i is 1,2, … …, and M, and the N ith difference values are used to determine whether an ith image block of each fingerprint image is the pressed block.

With reference to the first aspect and the foregoing implementation manner of the first aspect, in another implementation manner of the first aspect, the fingerprint identification device further includes: a processing unit to: if the N ith difference values meet a preset condition, determining an ith image block of each fingerprint image as the pressing block; or, if the N ith difference values do not satisfy the preset condition, determining that the ith image block of each fingerprint image is a non-pressing block.

With reference to the first aspect and the foregoing implementation manner of the first aspect, in another implementation manner of the first aspect, the preset condition includes: the maximum value of the absolute values of the N ith difference values is smaller than or equal to a first preset value; and/or the sum of the absolute values of the N ith difference values is less than or equal to a second preset value.

With reference to the first aspect and the foregoing implementation manner of the first aspect, in another implementation manner of the first aspect, the processing unit is configured to: determining the average value of the pixel values of all the pixel points in the ith image block as the pixel value of the ith image block; or, determining the sum of the pixel values of all the pixel points in the ith image block as the pixel value of the ith image block.

With reference to the first aspect and the foregoing implementation manner of the first aspect, in another implementation manner of the first aspect, the sizes of the M image blocks of each fingerprint image are the same.

With reference to the first aspect and the foregoing implementation manner of the first aspect, in another implementation manner of the first aspect, the preset image block is an ith image block of any one of the N fingerprint images.

With reference to the first aspect and the foregoing implementation manner of the first aspect, in another implementation manner of the first aspect, the performing fingerprint identification according to the pressing areas of the N fingerprint images includes: determining the standard deviation of all pixel points in l x l pixel arrays by taking each pixel point in the pressing area of each fingerprint image in the N fingerprint images as the center as the standard deviation of each pixel point so as to obtain the standard deviation image of the pressing area of each fingerprint image; performing binarization segmentation and morphological processing on the standard deviation image; determining a white area in the processed standard deviation image as a fingerprint identification area; and carrying out fingerprint identification on the fingerprint identification area.

In a second aspect, an electronic device is provided, the electronic device comprising: a display screen and the fingerprint identification device of the first aspect or any possible implementation manner of the first aspect.

In a third aspect, a fingerprint identification method is provided, which is applied to an electronic device having a fingerprint identification device disposed below a display screen of the electronic device, the fingerprint identification device being configured to receive return light signals in N directions returning after passing through a finger, return light signals in the same direction in the return light signals in the N directions being used for generating the same fingerprint image, where N is an integer greater than 1. The method comprises the following steps: acquiring N fingerprint images in one-to-one correspondence with the return light signals in the N directions; determining the pressing areas of the N fingerprint images according to the brightness difference of image blocks at corresponding positions of different fingerprint images in the N fingerprint images; and carrying out fingerprint identification according to the pressing areas of the N fingerprint images.

Therefore, according to the fingerprint identification method, a plurality of fingerprint images can be correspondingly generated according to return light signals in a plurality of directions received by the fingerprint identification device, the fingerprint images are divided by comparing the brightness difference of image blocks at corresponding positions of different fingerprint images, so that parts corresponding to finger pressing areas in the fingerprint images are distinguished, fingerprint identification is carried out on the parts, the problems that the fingerprint identification device collects screen residual traces such as fingerprints and the like due to partial pressing of the fingers, cracking attack and the like are caused are solved, and the performance of the fingerprints under the screen can achieve the optimal effect.

With reference to the third aspect, in an implementation manner of the third aspect, the determining, according to a luminance difference of image blocks at corresponding positions of different fingerprint images in the N fingerprint images, pressed areas of the N fingerprint images includes: determining whether the image block is a pressed block according to the brightness difference of the image blocks at the corresponding positions of different fingerprint images in the N fingerprint images; and determining all pressed blocks of the N fingerprint images as pressed areas of the N fingerprint images.

With reference to the third aspect and the foregoing implementation manner of the third aspect, in another implementation manner of the third aspect, each of the N fingerprint images includes M image blocks divided in the same manner, M is an integer greater than 1, luminance differences of image blocks at corresponding positions of different fingerprint images in the N fingerprint images include N ith difference values, the N ith difference values include differences between pixel values of an ith image block in the M image blocks of each fingerprint image and pixel values of a preset image block, where i is 1,2, … …, M; determining whether the image block is a pressed block according to the brightness difference of the image blocks at the corresponding positions of different fingerprint images in the N fingerprint images, including: and determining whether the ith image block of each fingerprint image is the pressed block according to the N ith difference values.

With reference to the third aspect and the foregoing implementation manner of the third aspect, in another implementation manner of the third aspect, the determining, according to the N ith difference values, whether an ith image block of each fingerprint image is the pressed block includes: if the N ith difference values meet a preset condition, determining an ith image block of each fingerprint image as the pressing block; or, if the N ith difference values do not satisfy the preset condition, determining that the ith image block of each fingerprint image is a non-pressing block.

With reference to the third aspect and the foregoing implementation manner of the third aspect, in another implementation manner of the third aspect, the preset condition includes: the maximum value of the absolute values of the N ith difference values is smaller than or equal to a first preset value; and/or the sum of the absolute values of the N ith difference values is less than or equal to a second preset value.

With reference to the third aspect and the foregoing implementation manner of the third aspect, in another implementation manner of the third aspect, the method further includes: determining the average value of the pixel values of all the pixel points in the ith image block as the pixel value of the ith image block; or, determining the sum of the pixel values of all the pixel points in the ith image block as the pixel value of the ith image block.

With reference to the third aspect and the foregoing implementation manner of the third aspect, in another implementation manner of the third aspect, the sizes of the M image blocks of each fingerprint image are the same.

With reference to the third aspect and the foregoing implementation manner of the third aspect, in another implementation manner of the third aspect, the preset image block is an ith image block of any one of the N fingerprint images.

With reference to the third aspect and the foregoing implementation manner of the third aspect, in another implementation manner of the third aspect, the performing fingerprint identification according to the pressed areas of the N fingerprint images includes: determining the standard deviation of all pixel points in l x l pixel arrays by taking each pixel point in the pressing area of each fingerprint image in the N fingerprint images as the center as the standard deviation of each pixel point so as to obtain the standard deviation image of the pressing area of each fingerprint image; performing binarization segmentation and morphological processing on the standard deviation image; determining a white area in the processed standard deviation image as a fingerprint identification area; and carrying out fingerprint identification on the fingerprint identification area.

With reference to the third aspect and the foregoing implementation manner of the third aspect, in another implementation manner of the third aspect, the N directions have the same included angle with the horizontal plane.

With reference to the third aspect and the foregoing implementations of the third aspect, in another implementation of the third aspect, N is equal to 2 or 4.

In a fourth aspect, a chip is provided, where the chip includes an input/output interface, at least one processor, at least one memory, and a bus, where the at least one memory is used to store instructions, and the at least one processor is used to call the instructions in the at least one memory to perform the method in the third aspect or any possible implementation manner of the third aspect.

In a fifth aspect, there is provided a computer readable medium for storing a computer program comprising instructions for performing the method of the third aspect or any possible implementation manner of the third aspect.

A sixth aspect provides a computer program product comprising instructions which, when executed by a computer, cause the computer to perform the method of fingerprint identification in the third aspect or any possible implementation form of the third aspect. In particular, the computer program product may be run on the electronic device of the second aspect described above.

Drawings

Fig. 1 is a schematic configuration diagram of an electronic apparatus to which the present application can be applied.

Fig. 2 is a schematic cross-sectional view of the electronic device shown in fig. 1.

Fig. 3 is another schematic block diagram of an electronic device to which the present application may be applied.

Fig. 4 is a schematic cross-sectional view of the electronic device shown in fig. 3.

Fig. 5 to 8 are another schematic diagrams of the electronic device according to the embodiment of the present application.

Fig. 9 is a schematic flow chart of a method of fingerprint identification of an embodiment of the present application.

Fig. 10 is a diagram illustrating the light intensity of return light signals in different directions according to an embodiment of the present application.

Fig. 11 is a schematic block diagram of an electronic device of an embodiment of the present application.

Detailed Description

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

The technical scheme of the embodiment of the application can be applied to various electronic devices. Such as portable or mobile computing devices, e.g., smart phones, laptops, tablets, gaming devices, etc., and other electronic devices, e.g., electronic databases, automobiles, Automated Teller Machines (ATMs), etc. However, the present embodiment is not limited thereto.

The technical scheme of the embodiment of the application can be used for the biological feature recognition technology. The biometric technology includes, but is not limited to, fingerprint recognition, palm print recognition, iris recognition, face recognition, and living body recognition. For convenience of explanation, the fingerprint identification technology is described as an example below.

The technical scheme of the embodiment of the application can be used for the under-screen fingerprint identification technology and the in-screen fingerprint identification technology.

Fingerprint identification technique is installed in the display screen below with fingerprint identification module under the screen to realize carrying out the fingerprint identification operation in the display area of display screen, need not set up the fingerprint collection region in the positive region except that the display area of electronic equipment. Specifically, the fingerprint identification module uses the light that returns from the top surface of electronic equipment's display module to carry out fingerprint response and other response operations. This returned light carries information about objects (e.g., fingers) in contact with or in proximity to the top surface of the display assembly, and the fingerprint recognition module located below the display assembly performs underscreen fingerprint recognition by capturing and detecting this returned light. The fingerprint identification module can be designed to realize desired optical imaging by properly configuring an optical element for collecting and detecting returned light, so as to detect fingerprint information of the finger.

Correspondingly, (In-display) fingerprint identification technique means installs inside the display screen fingerprint identification module or partial fingerprint identification module In the screen to realize carrying out the fingerprint identification operation In the display area of display screen, need not set up the fingerprint collection region In the positive region except that the display area of electronic equipment.

Fig. 1 to 4 are schematic views showing an electronic device to which the embodiment of the present application can be applied. Fig. 1 and 3 are schematic orientation diagrams of the electronic device 10, and fig. 2 and 4 are schematic cross-sectional diagrams of the electronic device 10 shown in fig. 1 and 3, respectively.

Referring to fig. 1 to 4, the electronic device 10 may include a display 120 and an optical fingerprint identification module 130.

The display 120 may be a self-luminous display employing display units having self-luminous properties as display pixels. For example, the display screen 120 may be an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. In other alternative embodiments, the Display 120 may also be a Liquid Crystal Display (LCD) or other passive light emitting Display, which is not limited in this embodiment of the present application. Further, the display screen 120 may also be specifically a touch display screen, which not only can perform image display, but also can detect a touch or pressing operation of a user, thereby providing a human-computer interaction interface for the user. For example, in one embodiment, the electronic device 10 may include a Touch sensor, which may be embodied as a Touch Panel (TP), which may be disposed on a surface of the display screen 120, or may be partially or wholly integrated within the display screen 120, thereby forming the Touch display screen.

Optical fingerprint module 130 includes an optical fingerprint sensor that includes a sensing array 133 having a plurality of optical sensing elements 131 (which may also be referred to as optical sensing pixels, light sensing pixels, pixel cells, etc.). The sensing array 133 is located in an area or a sensing area thereof, which is the fingerprint detection area 103 (also called a fingerprint collection area, a fingerprint identification area, etc.) of the optical fingerprint module 130.

Wherein, the optical fingerprint module 130 is disposed in a local area below the display screen 120.

With continued reference to fig. 1, the fingerprint detection area 103 may be located within a display area of the display screen 120. In an alternative embodiment, the optical fingerprint module 130 may be disposed at other positions, such as the side of the display screen 120 or the edge opaque area of the electronic device 10, and the optical path is designed to guide the optical signal from at least a part of the display area of the display screen 120 to the optical fingerprint module 130, so that the fingerprint detection area 103 is actually located in the display area of the display screen 120.

For the electronic device 10, when a user needs to unlock or perform other fingerprint verification on the electronic device 10, the user only needs to press a finger on the fingerprint detection area 103 of the display screen 120, so as to realize fingerprint input. Since fingerprint detection can be implemented in the screen, the electronic device 10 with the above structure does not need to reserve a special 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.

With continued reference to fig. 2, the optical fingerprint module 130 may include a light detection portion 134 and an optical assembly 132. The light detecting portion 134 includes the sensing array 133 (also referred to as an optical fingerprint sensor) and a reading circuit and other auxiliary circuits electrically connected to the sensing array 133, which can be fabricated on a chip (Die) by a semiconductor process, such as an optical imaging chip or an optical fingerprint sensor. The sensing array 133 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 as described above. The optical assembly 132 may be disposed above the sensing array 133 of the light detecting portion 134, and may specifically include a Filter (Filter) for filtering out ambient light penetrating through the finger, a light guiding layer or a light path guiding structure for guiding reflected light reflected from the surface of the finger to the sensing array 133 for optical detection, and other optical elements.

In some embodiments of the present application, 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, for example, the optical component 132 is attached to the chip, or some components of the optical component 132 are integrated into the chip.

In some embodiments of the present application, the area or the light sensing range of the sensing array 133 of the optical fingerprint module 130 corresponds to the fingerprint detection area 103 of the optical fingerprint module 130. The fingerprint collecting area 103 of the optical fingerprint module 130 may be equal to or not equal to an area or a light sensing range of an area where the sensing array 133 of the optical fingerprint module 130 is located, which is not specifically limited in the embodiment of the present application.

For example, the light path is guided by the light collimation method, and the fingerprint detection area 103 of the optical fingerprint module 130 may be designed to be substantially consistent with the area of the sensing array of the optical fingerprint module 130.

For another example, for example, through a light path design such as lens imaging, a reflective folded light path design, or other light path designs such as light convergence or reflection, the area of the fingerprint detection area 103 of the optical fingerprint module 130 may be larger than the area of the sensing array 133 of the optical fingerprint module 130.

The following is an exemplary description of the optical path guiding structure that the optical component 132 may include.

Taking the optical Collimator with the through hole array having the high aspect ratio as an example, the optical Collimator may specifically be a Collimator (collimater) layer made on a semiconductor silicon wafer, and the optical Collimator has a plurality of collimating units or micro holes, the collimating units may specifically be micro holes, and the collimating units have a specific direction, for example, the specific direction may be a vertical direction or an inclined direction with a certain angle. In the light signals returned by the finger, the return light with the specific direction can be incident into the collimation unit, the light passing through the collimation unit can pass through and be received by the sensor chip below the collimation unit, and the light of other incident angles is attenuated in the collimation unit after multiple reflections, so that each sensor chip can only receive the reflected light reflected by the fingerprint lines corresponding to the sensor chip above the sensor chip basically, the image resolution can be effectively improved, and the fingerprint identification effect is further improved.

Taking the optical path design of the optical Lens adopted by the optical path guiding structure as an example, the optical path guiding structure may 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 for converging the reflected light reflected from the finger to the sensing array 133 of the light detection portion 134 therebelow, so that the sensing array 133 may perform imaging based on the reflected light, thereby obtaining the fingerprint image of the finger. Further, the optical lens layer may further be formed with a pinhole or a micropore diaphragm in the optical path of the lens unit, for example, one or more light-shielding sheets may be formed in the optical path of the lens unit, wherein at least one light-shielding sheet may be formed with a light-transmitting micropore in the optical axis or the optical central region of the lens unit, and the light-transmitting micropore may serve as the pinhole or the micropore diaphragm. The pinhole or the micro-aperture diaphragm can cooperate with the optical lens layer and/or other optical film layers above the optical lens layer to enlarge the field of view of the optical fingerprint module 130, so as to improve the fingerprint imaging effect of the optical fingerprint module 130.

Taking the optical path design of the optical path guiding structure using a Micro-Lens (Micro-Lens) layer as an example, the optical path guiding structure may be a Micro-Lens array formed by a plurality of Micro-lenses, which may be formed above the sensing array 133 of the light detecting portion 134 through a semiconductor growth process or other processes, and each Micro-Lens may correspond to one or more sensing units of the sensing array 133, respectively. And other optical film layers, such as a dielectric layer or a passivation layer, can be formed between the microlens layer and the sensing unit. More specifically, a light blocking layer (or referred to as a light shielding layer, a light blocking layer, etc.) having micro holes (or referred to as open holes) may be further included between the microlens layer and the sensing unit, wherein 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 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 for optical fingerprint imaging.

It should be understood that several of the implementations described above for the optical path directing structure may be used alone or in combination.

For example, a microlens layer may be further disposed above or 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.

On the other hand, the optical assembly 132 may further include other optical elements, such as a Filter (Filter) or other optical film, which may be disposed between the optical path guiding structure and the optical fingerprint sensor or between the display screen 120 and the optical path guiding structure, and mainly used for isolating the influence of external interference light on the optical fingerprint detection. The filter layer may be configured to filter ambient light that penetrates through a finger and enters the optical fingerprint sensor through the display screen 120, and similar to the optical path guiding structure, the filter layer may be respectively disposed for each optical fingerprint sensor to filter interference light, or may also cover the plurality of optical fingerprint sensors simultaneously with one large-area filter layer.

Fingerprint identification module 140 may be configured to collect fingerprint information (e.g., fingerprint image information) of a user.

Taking the display screen 120 as an example, the display screen has a self-luminous display unit, such as an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. The optical fingerprint module 130 may use a display unit (i.e., an 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 120 emits a beam of light 111 towards 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 (transmitted light) is formed by scattering through the inside of the finger 140. In the related patent application, the above-mentioned reflected light and scattered light are collectively referred to as return light for convenience of description. Because the ridges (ridges) 141 and the valleys (valley)142 of the fingerprint have different light reflection capacities, the return light 151 from the ridges and the return light 152 from the valleys of the fingerprint have different light intensities, and after passing through the optical assembly 132, the return light is received by the sensing array 133 in the optical fingerprint module 130 and converted into corresponding electric signals, i.e., fingerprint detection signals; fingerprint image data can be obtained based on the fingerprint detection signal, and fingerprint matching verification can be further performed, so that an optical fingerprint identification function is realized in the electronic device 10.

In other alternatives, the optical fingerprint module 130 may also use an internal light source or an external light source to provide an optical signal for fingerprint detection and identification. In this case, the optical fingerprint module 130 may be applied to not only a self-luminous display screen such as an OLED display screen, but also a non-self-luminous display screen such as a liquid crystal display screen or other passive luminous display screens.

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 module 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 module 130; alternatively, the optical fingerprint module 130 may be disposed below the backlight module, and the backlight module may open holes or perform other optical designs on film layers such as a diffusion sheet, a brightness enhancement sheet, and a reflection sheet to allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint module 130. When the optical fingerprint module 130 is used to provide an optical signal for fingerprint detection by using an internal light source or an external light source, the detection principle is consistent with the above description.

In a specific implementation, the electronic device 10 may further include a transparent protective cover, which may be a glass cover or a sapphire cover, located above the display screen 120 and covering the front surface of the electronic device 10. Therefore, 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.

On the other hand, optics fingerprint module 130 can only include an optics fingerprint sensor, and the area of the fingerprint detection area 103 of optics fingerprint module 130 is less and the rigidity this moment, therefore the user need press the finger to the specific position of fingerprint detection area 103 when carrying out the fingerprint input, otherwise optics fingerprint module 130 probably can't gather the fingerprint image and cause user experience not good. In other alternative embodiments, the optical fingerprint module 130 may specifically include a plurality of optical fingerprint sensors. A plurality of optics fingerprint sensor can set up side by side through the concatenation mode the below of display screen 120, just a plurality of optics fingerprint sensor's response area constitutes jointly optics fingerprint module 130's fingerprint detection area 103. Thereby the fingerprint detection area 103 of optical fingerprint module 130 can extend to the main area of the lower half of display screen, extend to the finger and press the region conventionally promptly to realize blind formula fingerprint input operation of pressing. Further, when the number of the optical fingerprint sensors is sufficient, the fingerprint detection area 103 may also be extended to a half display area or even the entire display area, thereby realizing half-screen or full-screen fingerprint detection.

Referring to fig. 3 and 4, the optical fingerprint module 130 in the electronic device 10 may include a plurality of optical fingerprint sensors, the plurality of optical fingerprint sensors may be arranged below the display screen 120 side by side in a manner such as splicing, and sensing areas of the plurality of optical fingerprint sensors jointly form the fingerprint detection area 103 of the optical fingerprint device 130.

Further, the optical assembly 132 may include a plurality of optical path guiding structures, each of which corresponds to one optical fingerprint sensor (i.e., the sensing array 133) and is attached above the corresponding optical fingerprint sensor. Alternatively, the plurality of optical fingerprint sensors may share an integral optical path directing structure, i.e. the optical path directing structure has an area large enough to cover the sensing array of the plurality of optical fingerprint sensors.

Taking the optical collimator with the through hole array having the aspect ratio as an example of the optical assembly 132, when the optical fingerprint module 130 includes a plurality of optical fingerprint sensors, one or more collimating units may be configured for one optical sensing unit in the optical sensing array of each optical fingerprint sensor, and the collimating units are attached to and disposed above the corresponding optical sensing units. Of course, the plurality of optical sensing units may also share one collimating unit, i.e. the one collimating unit has a sufficiently large aperture to cover the plurality of optical sensing units. Because a collimation unit can correspond a plurality of optical sensing units or an optical sensing unit corresponds a plurality of collimation units, the spatial period of display screen 120 and optical fingerprint sensor's spatial period's correspondence has been destroyed, therefore, even the spatial structure of the luminous display array of display screen 120 and optical fingerprint sensor's optical sensing array's spatial structure are similar, also can effectively avoid optical fingerprint module 130 to utilize the optical signal through display screen 120 to carry out fingerprint imaging and generate moire fringe, optical fingerprint module 130's fingerprint identification effect has effectively been improved.

Taking the optical lens as an example of the optical component 132, when the optical fingerprint module 130 includes a plurality of sensor chips, an optical lens may be configured for each sensor chip to perform fingerprint imaging, or an optical lens may be configured for a plurality of sensor chips to implement light convergence and fingerprint imaging. Even when one sensor chip has two sensing arrays (Dual Array) or multiple sensing arrays (Multi-Array), two or more optical lenses can be configured for the sensor chip to cooperate with the two or more sensing arrays for optical imaging, so as to reduce the imaging distance and enhance the imaging effect.

It should be understood that fig. 1-4 are only examples of the present application and should not be construed as limiting the present application.

For example, the number, size and arrangement of the fingerprint sensors are not specifically limited, and may be adjusted according to actual requirements. For example, the number of the plurality of fingerprint sensors of the optical fingerprint module 130 may be 2, 3, 4 or 5, and the plurality of fingerprint sensors may be distributed in a square or circle shape.

The fingerprint identification device according to the embodiment of the present application will be described in detail below with reference to the accompanying drawings. Specifically, fig. 5 shows a schematic diagram of the electronic device 20 according to the embodiment of the application, and as shown in fig. 5, the electronic device 20 includes a display 200 and a fingerprint identification device 300 disposed below the display 200.

It should be understood that the display screen 200 of the present embodiment may be used to provide a touch interface for the finger 410. When a user needs to perform fingerprint recognition, the finger 410 touches a fingerprint detection area of the display screen 200, wherein the fingerprint detection area of the display screen 200 in fig. 5 includes an area 210 and an area 220. The display 200 may include light-emitting display pixels capable of emitting light that illuminates the finger 410, which may be reflected or scattered by the surface and interior of the finger 410 to produce return light that may be received by the fingerprint recognition device 300 below the display 200.

As shown in fig. 5, the fingerprint recognition device 300 of the embodiment of the present application includes an optical path layer 310 and an optical fingerprint sensor 320, the optical path layer 310 is used for guiding return optical signals of N directions returning after passing through a finger to the optical fingerprint sensor 320; an optical fingerprint sensor 320 is disposed below the optical path layer 310 for receiving the return optical signals of the N directions. Specifically, the optical fingerprint sensor 320 in the embodiment of the present application includes an array of optical sensing units, each of which may include N optical sensing pixels, each of the N optical sensing pixels being respectively configured to receive a return optical signal in one of the N directions.

For example, as shown in fig. 5, it is exemplified that any one of the optical sensing units 321 included in the optical fingerprint sensor 320, and that the optical sensing unit 321 includes 4 optical sensing pixels, which are respectively denoted as S1-S4, the 4 optical sensing pixels S1-S4 are respectively used for receiving return light signals of 4 directions, that is, the optical sensing pixel S1 is used for receiving the return light signal P1, the optical sensing pixel S2 is used for receiving the return light signal P2, the optical sensing pixel S3 is used for receiving the return light signal P3, and the optical sensing pixel S4 is used for receiving the return light signal P4.

It should be understood that the display screen 200 in the embodiment of the present application may correspond to the display screen 120 in the electronic device 10 in fig. 1 to 4 and is applicable to the related description of the display screen 120, and the fingerprint identification device 300 may correspond to the optical fingerprint identification module 130 in the electronic device 10 in fig. 1 to 4 and is applicable to the related description of the optical fingerprint identification module 130, for example, the optical path layer 310 in the fingerprint identification device 300 may correspond to the light detection portion 134 in the fingerprint identification module 130, and the optical fingerprint sensor 320 in the fingerprint identification device 300 may correspond to the optical element 132 in the fingerprint identification module 130, which is not repeated herein for brevity.

In the embodiment of the present application, the optical path layer 310 may have various forms, for example, the optical path layer 310 may include an optical lens, a micro lens, a collimator, or the like, which will be illustrated in the following with reference to the accompanying drawings.

Optionally, as an embodiment, the light path layer 310 of the embodiment of the present application may include at least one light-blocking layer, wherein each light-blocking layer of the at least one light-blocking layer is provided with an array of small holes to form a plurality of light guide channels in N directions, and the plurality of light guide channels are used for guiding the return light signals in the N directions to the optical fingerprint sensor 320 below. Specifically, each of the plurality of light guide channels may correspond to one or more optical sensing pixels in the optical fingerprint sensor, and it is described below that each of the plurality of light guide channels corresponds to one optical sensing pixel, that is, each of the plurality of light guide channels may be configured to transmit a return light signal in one direction and correspondingly transmit the return light signal to one optical sensing pixel.

Specifically, as shown in fig. 5, it is exemplified here that at least one light-blocking layer includes two light-blocking layers, that is, light-blocking

layers

311 and 312, and

aperture arrays

3111 and 3121 are provided on the light-blocking layer 311 and the light-blocking layer 312, respectively. Since only any one of the optical sensing units 321 included in the optical fingerprint sensor 320 is shown in fig. 5, and the optical sensing unit 321 includes 4 optical sensing pixels as an example, fig. 5 only shows a partial area of the light blocking layers 311 and 312 corresponding to the optical sensing unit 321; in order to form a light guide channel capable of passing through the return optical signals P1-P4, fig. 5 illustrates that the aperture array 3111 disposed on the light-blocking layer 311 includes 4 apertures, and the aperture array 3121 disposed on the light-blocking layer 312 also includes 4 apertures, which form 4 light guide channels as illustrated in fig. 5, for respectively guiding the return optical signals P1-P4 in 4 directions to the photo-sensitive pixels S1-S4 below, but the embodiment of the present application is not limited thereto.

It should be understood that the number of light blocking layers in the embodiment of the present application can be flexibly set according to practical applications. For example, instead of the light path layer 310 shown in fig. 5 including two light-blocking

layers

311 and 312, it may also be arranged that the light path layer 310 includes more than two light-blocking layers to form a plurality of light-guiding channels having N directions; alternatively, only one light-blocking layer may be provided. Specifically, for the case where only one light blocking layer is provided, the light blocking layer may have a certain thickness, so that each small hole in the small hole array in the light blocking layer is a light guide channel; or, when one light blocking layer is arranged, the principle of pinhole imaging may also be utilized, and the return light signals in N directions are transmitted to the optical fingerprint sensor 320 below through the N pinholes arranged on the light blocking layer in a pinhole imaging manner, so as to obtain N fingerprint images, which is not limited in the embodiment of the present application.

The size and number of the aperture arrays of each light-blocking layer in the embodiment of the present application can also be flexibly set according to practical applications, for example, the number and size of the apertures of the light-blocking layer can be set according to the direction of the return light signal that needs to be received, or according to the number and size of the optically sensitive pixels in the light fingerprint sensor 320. For example, as shown in fig. 5, the number of the apertures of the plurality of light-blocking layers may be set equal, or may be set unequal. The size of the aperture arrays of the same light-blocking layer can be the same or different, and the size of the aperture arrays of different light-blocking layers can be the same or different. For example, as shown in fig. 5, the number of the apertures of the plurality of light-blocking layers may be set to be the same, and the sizes of all the apertures included in the same light-blocking layer may be set to be the same, while the sizes of all the apertures included in the plurality of light-blocking layers may also be set to be the same; alternatively, all the apertures included in the same light-blocking layer may be set to have the same size, and the number of the apertures of the plurality of light-blocking layers may be set to be different, and the size of the apertures of the different light-blocking layers may be different, for example, in the direction from the display 200 to the underlying optical fingerprint sensor 320, the number of the apertures of each light-blocking layer increases sequentially, and the size of the aperture of each light-blocking layer decreases sequentially, but the embodiment of the present application is not limited thereto.

For example, also for guiding the return optical signals P1-P4 in 4 directions, it is also possible to provide a different number of aperture arrays than those shown in fig. 5 on the light-blocking

layers

311 and 312. For example, 4 holes on the light-blocking layer 311 in fig. 5 can be combined into one hole, while 4 holes are still disposed on the light-blocking layer 312, and the return optical signals P1-P4 in 4 directions can also be guided, which are not listed here for brevity.

It should be understood that the shape of the apertures provided in the light-blocking layers in the embodiments of the present application may be set according to the actual application, and the shape of the apertures in the same light-blocking layer may be the same or different, and the shape of the apertures in different light-blocking layers may also be the same or different. For example, as shown in fig. 5, the small holes on all the light blocking layers may be set to have the same shape, such as 5 is only a circle, or may also be set to have other shapes, such as a rectangle or a triangle, which is not limited in this application.

Optionally, as another embodiment, for the fingerprint identification device 300 shown in fig. 5, in order to improve the imaging effect, the optical path layer 310 may further include: and the micro lens array is arranged above the at least one light blocking layer and is used for converging the return light signal passing through the finger to the light guide channel of the at least one light blocking layer.

Fig. 6 shows another schematic diagram of the electronic device 20 of the embodiment of the present application. As shown in fig. 6, the optical path layer 310 further includes a microlens array 313, unlike fig. 5. Each microlens in the microlens array 313 in the embodiment of the present application may correspond to one or more optically sensitive pixels in the underlying optical fingerprint sensor 320, and each microlens may correspond to one or more light-guiding channels. For example, in the microlens array in the embodiment of the present application, one microlens may correspond to N light guide channels, and the N light guide channels correspond to N directions one to one; further, the N light guide channels respectively correspond to N optical sensing pixels included in the same optical sensing unit, but the embodiment of the present application is not limited thereto.

For example, only one microlens in the microlens array 313 is shown in fig. 6, and the one microlens corresponds to one photo-sensing unit, that is, the microlens shown in fig. 6 is used for converging the return light signals P1-P4, so that the converged return light signals P1-P4 are received by the photo-sensing pixels S1-S4 in the same photo-sensing unit after passing through 4 light guide channels in at least one light blocking layer.

It should be understood that fig. 5 and fig. 6 both illustrate return light signals in 4 directions, but the embodiment of the present application is not limited thereto, and for example, the fingerprint recognition apparatus 300 may also be configured to receive return light signals in more or less than 4 directions.

For example, fig. 7 shows a further schematic diagram of the electronic device 20 according to the embodiment of the present application, and as shown in fig. 7, the fingerprint recognition device 300 of fig. 7 is exemplified by being capable of receiving return light signals in 2 two directions, unlike the fingerprint recognition device 300 of fig. 6 which is capable of receiving return light signals in 4 directions. In contrast to fig. 6, one photo-sensing unit of fig. 7 includes two photo-sensing pixels S1 and S2 for receiving return optical signals P1 and P2, respectively. Also, one microlens in the microlens array 313 in fig. 7 corresponds to two light guide channels, and corresponds to two optically sensitive pixels S1 and S2 included in one optically sensitive unit, for converging the return light signals P1 and P2 to the optically sensitive pixels S1 and S2, respectively. Fig. 7 includes two light-blocking layers, 311 and 312, respectively, each of which is provided with an array of apertures, the apertures of the same light-blocking layer being of the same shape and size, but the apertures of different light-blocking layers being of different sizes. The number of the small holes in the light-blocking layer 311 is smaller than that of the small holes in the light-blocking layer 312, but the aperture of the small holes in the light-blocking layer 311 is larger than that of the small holes in the light-blocking layer 312.

Optionally, as a further embodiment, the optical path layer in the embodiment of the present application may include: and N lenses, wherein each lens of the N lenses is used for converging return light signals in one direction, and the return light signals in one direction are used for generating a fingerprint image, namely imaging by using the lenses.

Fig. 8 shows a further schematic diagram of the electronic device 20 according to the embodiment of the present application, and as shown in fig. 8, the optical path layer 320 may include N lenses 314, for example, two lenses 314 in fig. 8, for converging the return light signals in 2 directions to generate 2 fingerprint images.

It should be understood that the different optical path layers 320 shown in fig. 5 to 8 may be used alone or in combination with each other, and the embodiments of the present application are not limited thereto. No matter which optical path layer is used, the N directions in the embodiment of the present application can be flexibly set according to practical applications. For example, the value of N may be any integer greater than 1, for example, N may be equal to 2 or 4. For another example, each of the N directions may also be flexibly set.

Specifically, the N directions are generally set to be symmetrical. For example, taking the case of fig. 5-7 including at least one light blocking layer as an example, the N directions, i.e. the directions of the plurality of light guide channels, are equal to each other in the included angle between the N directions and the horizontal plane, or the included angles between the plurality of light guide channels and the horizontal plane are equal to each other. For another example, taking the case shown in fig. 6 or fig. 7 including the microlenses and the light blocking layer as an example, for N directions received by the same optical sensing unit, that is, the directions of N light guide channels corresponding to one microlens corresponding to the optical sensing unit, projections of the N light guide channels on a horizontal plane are symmetrically distributed along a projection center of an optical axis of the one microlens on the horizontal plane.

Therefore, the electronic device 20 of the embodiment of the present application, through the optical path layer 310 and the optical fingerprint sensor 320, can be used to receive the return optical signals of N directions, where N is an integer greater than 1. The return light signals of the same direction of the return light signals of the N directions may be used to generate the same fingerprint image, and the return light signals of the N directions may be used to generate the N fingerprint images.

The electronic device 20 according to the embodiment of the present application is described in detail above with reference to the drawings, and for convenience of description, the electronic device 20 shown in fig. 5 is mainly used as an example in the following description, but the embodiment of the present application is not limited thereto. Specifically, in the present embodiment, the surface of the display screen 200 includes a fingerprint detection area corresponding to the detection area of the optical fingerprint sensor 320 in the fingerprint recognition device 300, and the finger 410 touches the fingerprint detection area at the time of fingerprint recognition, so that the optical fingerprint sensor 320 below can receive the return light passing through the finger 410 to perform fingerprint detection.

However, when the finger 410 touches the area for fingerprint detection on the display screen 200, the finger 410 may not completely cover the area, for example, as shown in fig. 5, the finger 410 only covers a part of the fingerprint detection area, in the embodiment of the present application, the area covered by the finger 410 in the fingerprint detection area is referred to as a pressing area 220, and the area not covered by the finger 410 is referred to as a non-pressing area 210.

For the non-pressed region 210 not covered by the finger 410, the external ambient light can also directly penetrate through the screen and be received by the optical fingerprint sensor 320 below, and then the fingerprint and the like remaining on the screen can also be imaged on the optical fingerprint sensor 320. Since the intensity of the ambient light and the light reflected by the finger 410 to the screen may not be very different, it is impossible to distinguish the image acquired by the sensor from the fingerprint actually pressed by the finger or the trace of the screen residue, which makes a challenge to prevent the attack of breaking the fingerprint under the screen.

Therefore, the embodiment of the present application provides a fingerprint identification method and a fingerprint identification apparatus, which can effectively solve the above problems.

Fig. 9 shows a schematic flow chart of a method 500 of fingerprinting of an embodiment of the present application. The method 500 may be applied to an electronic device having a fingerprint recognition device disposed below a display screen of the electronic device, the fingerprint recognition device being configured to receive return light signals in N directions returned after passing through a finger, return light signals in the same direction in the return light signals in the N directions being used to generate the same fingerprint image, N being an integer greater than 1. For example, the method 500 may be applied to the electronic device 20 shown in fig. 5 to 8, but the embodiment of the present application is not limited thereto. The following description will take the example of applying the method 500 to the electronic device 20 shown in fig. 5.

As shown in fig. 9, the method 500 may include: s510, acquiring N fingerprint images in one-to-one correspondence with the return light signals in the N directions; s520, determining the pressing areas of the N fingerprint images according to the brightness difference of the image blocks at the corresponding positions of different fingerprint images in the N fingerprint images; s530, fingerprint recognition is performed according to the pressed areas of the N fingerprint images.

In the embodiment of the application, the return light signals are received from multiple directions by the fingerprint identification device, and since the ambient light generally has a certain directivity, for example, the ambient light may include indoor lamp light, and the indoor lamp light has directivity, that is, the light intensities received from different directions are not uniform. However, for the place pressed by the finger, the lower fingerprint identification device mainly receives the light returned by the finger, and the returned light received in different directions is relatively uniform, so that the collected fingerprint image can be divided into two parts, namely a finger-pressed area and a non-pressed area.

Specifically, taking fig. 5 as an example, when the finger 410 touches the pressing area 220, the area of the optical fingerprint sensor 320 in the fingerprint identification device 300 corresponding to the pressing area 220 mainly receives the screen light reflected from the finger 410, and since the screen light is reflected and transmitted by the finger and the reflection of the structure of the screen itself, the screen light can be considered to be uniform and not directional, so that the intensity difference of the return light in different directions received by the portion of the optical fingerprint sensor 320 corresponding to the pressing area is small, for example, the intensity difference may include the sensitivity of the sensing pixels of the screen structure (polarization or routing, etc.) and the sensor itself, and the difference of the portion is usually fixed or can be ignored.

However, since the non-pressed region 210 generally has directivity due to an ambient light source (for example, indoor light, sunlight, or the like), the intensity difference of the received return light is generally large for the portion of the optical fingerprint sensor 320 corresponding to the non-pressed region 210. For example, taking fig. 5 as an example, fig. 10 shows a schematic diagram of the light intensities of the return light signals in different directions for the position of the indoor lamp light 420 in fig. 5, and as shown in fig. 10, for the non-pressed region 210, the light intensity of the return light signal P1 in the same direction as the lamp light 420 is strongest, and the light intensity of the return light signal P3 in the opposite direction to the lamp light 420 is weakest, and the received light is the least.

Therefore, according to the characteristic of the multi-directional return light, a plurality of fingerprint images are correspondingly generated aiming at the received return light signals in a plurality of directions, the fingerprint images are divided by comparing the brightness difference of the image blocks at the corresponding positions of different fingerprint images, so that the parts corresponding to the finger pressing areas in the fingerprint images are distinguished, the fingerprint identification is further performed on the parts, the problem that the screen residual traces such as fingerprints and the like are collected by a fingerprint identification device due to the fact that the fingers are pressed locally, so that cracking attack and the like are caused is solved, and the performance of the fingerprint under the screen achieves the optimal effect.

It should be understood that the method 500 of the embodiments of the present application may be performed by a processing unit or a processor in the electronic device 20. In particular, fig. 11 shows a schematic block diagram of an electronic device 600 of an embodiment of the application. As shown in fig. 11, the electronic device 600 includes a display 610, a fingerprint recognition device 620, and a processing unit 630. The display screen 610 may correspond to the display screen 200 in the electronic device 20 in fig. 5 to 8, and is applicable to the related description of the display screen 200; the fingerprint identification device 620 may correspond to the fingerprint identification device 300 in the electronic device 20 of fig. 5 to 8, and is suitable for the related description of the fingerprint identification device 300, and for brevity, will not be described again. Moreover, the processing unit 630 may be configured to execute the method 500 of the embodiment of the present application, where the processing unit 630 may be a processing unit or a processor located in the electronic device 600, or the processing unit 630 may also be a processing unit or a processor located in the fingerprint identification device 620, and the embodiment of the present application is not limited thereto.

In S510, for the N-direction return light signals received by the optical fingerprint sensor 320 of the fingerprint identification device 300, N fingerprint images corresponding to the N-direction return light signals one to one, that is, one of the N-direction return light signals may be acquired for generating one fingerprint image.

In S520, the pressed areas of the N fingerprint images are determined according to the brightness difference of the image blocks at the corresponding positions of different fingerprint images in the N fingerprint images. Specifically, each of the N fingerprint images may be divided into M image blocks in the same manner, where M is an integer greater than 1, and the brightness difference of the image blocks at corresponding positions in different fingerprint images is compared to determine whether the image block belongs to a pressed area of the fingerprint image, so as to determine the pressed area of the N fingerprint images. For example, the S520 may include: determining whether the image block is a pressed block according to the brightness difference of the image blocks at the corresponding positions of different fingerprint images in the N fingerprint images; and determining all pressed blocks of the N fingerprint images as pressed areas of the N fingerprint images.

Optionally, the size of the M image blocks may be the same or different, for example, each fingerprint image may be divided into M image blocks of a size, or into image blocks of a size, a and b may take any positive integer.

In an embodiment of the present application, the method 500 may further include: and determining the brightness difference of image blocks at corresponding positions of different fingerprint images in the N fingerprint images. Specifically, the brightness difference between all fingerprint images in the N fingerprint images may be compared, or the brightness difference between some fingerprint images in the N fingerprint images may also be compared. Since it is more accurate to compare the brightness difference between all fingerprint images than to compare the brightness difference between only a part of the fingerprint images, the following description will be given taking the brightness difference between all N fingerprint images as an example.

Specifically, the luminance difference between image blocks at corresponding positions of different fingerprint images in the N fingerprint images may include N ith difference values, where the N ith difference values include a difference between a pixel value of an ith image block in the M image blocks of each fingerprint image and a pixel value of a preset image block, and i sequentially takes each integer from 1 to M.

Specifically, the method 500 may include: it is determined that each of the N fingerprint images comprises pixel values of each of the M image blocks, i.e. the pixel values Xi1, Xi2, … …, XiN of the N ith image block are determined. Specifically, the pixel value of the image in the embodiment of the present application may be an average value of pixels of all pixel points in the image, or may also be a sum of pixels of all pixel points in the image. For example, taking the determination of the ith image block of any image as an example in the embodiment of the present application, the determining may include: determining the average value of the pixel values of all the pixel points in the ith image block as the pixel value of the ith image block; or, determining the sum of the pixel values of all the pixel points in the ith image block as the pixel value of the ith image block.

The method 500 further comprises: determining differences between pixel values of the ith image block in each fingerprint image and pixel values Xi0 of the preset image blocks, namely determining N ith difference values (Xi1-Xi0), (Xi2-Xi0), … … and (XiN-Xi 0). For example, the preset image block may be an ith image block of any one of the N fingerprint images, but the embodiment of the present invention is not limited thereto.

Correspondingly, the S520 may specifically include: and determining whether the ith image block of each fingerprint image is the pressed block according to the N ith difference values. Specifically, if the N ith difference values satisfy a preset condition, determining an ith image block of each fingerprint image as the pressed block; or, if the N ith difference values do not satisfy the preset condition, determining that the ith image block of each fingerprint image is a non-pressed block.

Alternatively, the preset condition may be set according to actual applications. For example, the preset condition may include: the maximum value in the absolute values of the N ith difference values is less than or equal to a first preset value; and/or the sum of the absolute values of the N ith difference values is less than or equal to a second preset value. Specifically, the maximum value of the absolute values of the N ith difference values may be represented as MaxDi ═ max (| Xi1-Xi0|, | Xi2-Xi0|, …, | XiN-Xi0|), then when MaxDi of the ith image block is less than or equal to a first preset value, the ith image block of each fingerprint image is determined to be the pressed block, and when MaxDi of the ith image block is greater than the first preset value, the ith image block of each fingerprint image is determined to be the non-pressed block. Similarly, the sum of the absolute values of the N ith difference values may be represented as Adi ═ Xi1-Xi0| + | Xi2-Xi0| + … + | XiN-Xi0|, so that when the Adi of the ith image block is less than or equal to the second preset value, the ith image block of each fingerprint image is determined to be the pressed block, and when the Adi of the ith image block is greater than the second preset value, the ith image block of each fingerprint image is determined to be the non-pressed block.

It should be understood that the first preset value and the second preset value in the embodiment of the present application may be flexibly set according to practical applications, and may be set to any value, which is not limited in the embodiment of the present application.

In the embodiment of the present application, for the pressed blocks and non-pressed blocks determined by the above method for each fingerprint image, all the pressed blocks in each fingerprint image are determined as the pressed area of the fingerprint image, and the pressed area of the fingerprint image corresponds to the fingerprint image of the finger on the pressed area 220 as shown in fig. 5; similarly, all non-pressed blocks in each fingerprint image are determined to be non-pressed regions of the fingerprint image, which correspond to the image of the non-pressed region 210 as shown in fig. 5.

In S530, fingerprint recognition is performed based on the pressed regions of the N fingerprint images. However, in order to further accurately distinguish the portion of the fingerprint image corresponding to the pressed region 220, the above-identified pressed region of the fingerprint image may be processed. Specifically, the method 500 may further include: determining the standard deviation of all pixel points in l x l pixel arrays by taking each pixel point in the pressing area of each fingerprint image in the N fingerprint images as the center as the standard deviation of each pixel point so as to obtain the standard deviation image of the pressing area of each fingerprint image; performing binarization segmentation and morphological processing on the standard deviation image; determining a white area in the processed standard deviation image as a fingerprint identification area; and carrying out fingerprint identification on the fingerprint identification area. The morphological treatment in the embodiments of the present application may include swelling and/or erosion, but the embodiments of the present application are not limited thereto.

In the embodiment of the present application, by further dividing the pressing area of each fingerprint image, an accurate fingerprint identification area of the fingerprint image, that is, the pressing area 220 corresponding to the touch of the finger 410 in fig. 5, can be obtained, so that the fingerprint identification can be performed by using the fingerprint identification area, and the fingerprint identification performance is improved.

Alternatively, for other areas of the fingerprint image than the determined fingerprint identification area, the partial area may not be used for fingerprint identification. However, since the partial area corresponds to the non-pressed area 210 which is not touched by the fingerprint 410, the ambient light may be determined according to the image of the area, for example, the irradiation direction of the ambient light may be determined, and the embodiment of the present application is not limited thereto.

Therefore, according to the fingerprint identification method and the fingerprint identification device in the embodiment of the application, when a fingerprint image is collected, aiming at the condition that a finger is locally pressed on the surface of a display screen, the optical fingerprint sensor corresponding to the pressing area mainly receives screen light reflected by the finger, and the light intensity of return light received by the part of light from light paths in different directions is consistent with the full-pressing condition and is uniform; and the optical fingerprint sensor corresponding to the non-pressed area mainly receives ambient light, for example, the ambient light may include light leakage of the screen and external light transmitted through the screen, and since the ambient light is not isotropic light, the intensity difference of the light received from the light paths in different directions is large. Therefore, the fingerprint image can be segmented by comparing the image difference of the light path imaging in different directions, so that the fingerprint image area corresponding to the finger pressing area is determined, and the fingerprint identification is carried out on the partial area, so that the performance of the fingerprint under the screen can achieve the optimal effect.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. 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.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. 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 be in an electrical, mechanical or other form.

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 embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units 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 or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including 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: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A fingerprint identification device, characterized by, set up the below at the display screen of electronic equipment, includes:

the optical path layer is used for guiding return optical signals in N directions, returning after passing through the finger, to the optical fingerprint sensor, and N is an integer larger than 1;

an optical fingerprint sensor disposed below the optical path layer for receiving the return optical signals of the N directions, the optical fingerprint sensor comprising an array of optical sensing units, the optical sensing units comprising N optical sensing pixels, each of the N optical sensing pixels for receiving the return optical signal of one of the N directions,

the return light signals in the same direction in the return light signals in the N directions are used for generating the same fingerprint image, the return light signals in the N directions are used for generating N fingerprint images in one-to-one correspondence, the brightness difference of image blocks of corresponding positions of different fingerprint images in the N fingerprint images is used for determining the pressing areas of the N fingerprint images, and the pressing areas of the N fingerprint images are used for fingerprint identification.

2. The fingerprint recognition device of claim 1, wherein the light path layer comprises:

at least one light-blocking layer, each of the at least one light-blocking layer being provided with an array of apertures to form a plurality of light-conducting channels in the N directions for guiding return light signals in the N directions to the optical fingerprint sensor.

3. The fingerprint recognition device of claim 2, wherein each of the plurality of light-conducting channels corresponds to one optically sensitive pixel in the optical fingerprint sensor.

4. The fingerprint recognition device of claim 2, wherein the light path layer further comprises:

and the micro lens array is arranged above the at least one light blocking layer and used for converging the return light signal passing through the finger to the light guide channel of the at least one light blocking layer.

5. The fingerprint identification device of claim 4, wherein one microlens in the microlens array corresponds to N light guide channels, and the N light guide channels correspond to N directions one by one.

6. The fingerprint identification device according to claim 5, wherein the N light guide channels respectively correspond to N optically sensitive pixels included in a same optically sensitive unit.

7. The fingerprint identification device of claim 5, wherein the projections of the N light guide channels on the horizontal plane are symmetrically distributed along the projection center of the optical axis of the micro lens on the horizontal plane.

8. The fingerprint recognition device of claim 2, wherein the plurality of light guide channels are at equal angles to the horizontal plane.

9. The fingerprint recognition device according to claim 2, wherein the at least one light blocking layer is two light blocking layers.

10. The fingerprint recognition device of claim 1, wherein the light path layer comprises:

n lenses, each of the N lenses for converging return light signals of one direction for generating one fingerprint image.

11. Fingerprint recognition device according to one of claims 1 to 10, wherein N is equal to 2 or 4.

12. The fingerprint recognition device according to any one of claims 1 to 10, wherein the luminance difference of an image block at a corresponding position of a different fingerprint image in the N fingerprint images is used to determine whether the image block is a pressed block, and all pressed blocks of the N fingerprint images are pressed areas of the N fingerprint images.

13. The fingerprint recognition device according to claim 12, wherein each of the N fingerprint images includes M image blocks divided in the same manner, M is an integer greater than 1, the luminance difference of the image block at the corresponding position of different fingerprint images in the N fingerprint images includes N ith difference values, the N ith difference values include a difference between a pixel value of an ith image block in the M image blocks of each fingerprint image and a pixel value of a preset image block, i is 1,2, … …, M, and the N ith difference values are used to determine whether the ith image block of each fingerprint image is the pressed block.

14. The fingerprint recognition device of claim 13, further comprising: a processing unit to:

if the N ith difference values meet a preset condition, determining an ith image block of each fingerprint image as the pressing block; or,

and if the N ith difference values do not meet the preset condition, determining that the ith image block of each fingerprint image is a non-pressing block.

15. The fingerprint recognition device according to claim 14, wherein the preset condition comprises:

the maximum value of the absolute values of the N ith difference values is smaller than or equal to a first preset value; and/or the presence of a gas in the gas,

the sum of the absolute values of the N ith difference values is less than or equal to a second preset value.

16. The fingerprint recognition device of any one of claims 13-15, wherein the processing unit is configured to:

determining the average value of the pixel values of all the pixel points in the ith image block as the pixel value of the ith image block; or,

and determining the sum of the pixel values of all the pixel points in the ith image block as the pixel value of the ith image block.

17. The fingerprint recognition device according to any one of claims 13 to 15, wherein the size of the M image blocks of each fingerprint image is the same.

18. The fingerprint recognition device according to any one of claims 13 to 15, wherein the preset image block is an i-th image block of any one of the N fingerprint images.

19. The fingerprint recognition device according to any one of claims 13 to 15, wherein the fingerprint recognition according to the pressing areas of the N fingerprint images comprises:

determining the standard deviation of all pixel points in l x l pixel arrays by taking each pixel point in the pressing area of each fingerprint image in the N fingerprint images as the center as the standard deviation of each pixel point so as to obtain the standard deviation image of the pressing area of each fingerprint image;

performing binarization segmentation and morphological processing on the standard deviation image;

determining a white area in the processed standard deviation image as a fingerprint identification area;

and carrying out fingerprint identification on the fingerprint identification area.

20. An electronic device, comprising:

a display screen;

the fingerprint recognition of any one of claims 1 to 19.

21. A fingerprint identification method is applied to an electronic device with a fingerprint identification device, the fingerprint identification device is arranged below a display screen of the electronic device, the fingerprint identification device is used for receiving return light signals in N directions which return after passing through a finger, return light signals in the same direction in the return light signals in the N directions are used for generating the same fingerprint image, and N is an integer larger than 1, and the method comprises the following steps:

acquiring N fingerprint images in one-to-one correspondence with the return light signals in the N directions;

determining the pressing areas of the N fingerprint images according to the brightness difference of image blocks at corresponding positions of different fingerprint images in the N fingerprint images;

and carrying out fingerprint identification according to the pressing areas of the N fingerprint images.

22. The method according to claim 21, wherein determining the pressed areas of the N fingerprint images according to the brightness difference of the image blocks at the corresponding positions of different fingerprint images in the N fingerprint images comprises:

determining whether the image block is a pressed block according to the brightness difference of the image blocks at the corresponding positions of different fingerprint images in the N fingerprint images;

and determining all pressed blocks of the N fingerprint images as pressed areas of the N fingerprint images.

23. The method according to claim 22, wherein each of the N fingerprint images includes M image blocks divided in the same manner, M is an integer greater than 1, the luminance difference of the image block at the corresponding position of different fingerprint images in the N fingerprint images includes N ith difference values, the N ith difference values include the difference between the pixel value of the ith image block in the M image blocks of each fingerprint image and the pixel value of the preset image block, i is 1,2, … …, M;

determining whether the image block is a pressed block according to the brightness difference of the image blocks at the corresponding positions of different fingerprint images in the N fingerprint images, including:

and determining whether the ith image block of each fingerprint image is the pressed block according to the N ith difference values.

24. The method according to claim 23, wherein said determining whether an i-th image block of each fingerprint image is the pressed block according to the N i-th difference values comprises:

25. The method according to claim 24, wherein the preset condition comprises:

26. The method of any one of claims 23 to 25, further comprising:

27. The method according to any one of claims 23 to 25, wherein the size of the M image blocks of each fingerprint image is the same.

28. The method according to any one of claims 23 to 25, wherein the preset image block is an i-th image block of any one of the N fingerprint images.

29. The method according to any one of claims 23 to 25, wherein the performing fingerprint recognition according to the pressed areas of the N fingerprint images comprises:

30. The method of any one of claims 21 to 25, wherein the N directions are at the same angle to the horizontal.

31. The method according to any one of claims 21 to 25, wherein N is equal to 2 or 4.