WO2021081891A1

WO2021081891A1 - Method for fingerprint recognition, fingerprint recognition apparatus and electronic device

Info

Publication number: WO2021081891A1
Application number: PCT/CN2019/114707
Authority: WO
Inventors: 谢浩
Original assignee: 深圳市汇顶科技股份有限公司
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2021-05-06
Also published as: CN110945525A; CN110945525B

Abstract

Disclosed are a method for fingerprint recognition, a fingerprint recognition apparatus and an electronic device, wherein same can improve the quality of a fingerprint image. The method is applicable to an electronic device with a display screen and a fingerprint recognition apparatus, which is arranged under the display screen. The method comprises: acquiring an original image generated by a fingerprint recognition apparatus according to a received first tilt optical signal, wherein the first tilt optical signal is a tilt optical signal that is emitted from a light-emitting unit and directed toward the fingerprint recognition apparatus; acquiring a smear image generated by the fingerprint recognition apparatus according to a received second tilt optical signal, wherein the second tilt optical signal is a tilt optical signal that is emitted from the light-emitting unit, directed toward a surface of the fingerprint recognition apparatus, and reaches the fingerprint recognition apparatus after being reflected by the surface of the fingerprint recognition apparatus and reflected by a lower surface of the display screen; and according to the distance X between the original image and the smear image, correcting fingerprint data collected by the fingerprint recognition apparatus, wherein the corrected fingerprint data is used for fingerprint recognition.

Description

Method for fingerprint identification, fingerprint identification device and electronic equipment

Technical field

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

Background technique

With the rapid development of the mobile phone industry, fingerprint recognition technology has attracted more and more attention, and the practical application of fingerprint recognition technology under the screen has become a popular demand. The most widely used in the under-screen fingerprint recognition technology is the under-screen optical fingerprint recognition technology. The under-screen optical fingerprint recognition technology can use the light emitted by the screen as the light source. The light emitted by the screen will carry the fingerprint information of the finger after it shines on the finger above the screen. The optical signal carrying fingerprint information will be received by the fingerprint identification device for fingerprint identification.

The fingerprint identification device needs to be installed under the screen to achieve the function of fingerprint detection, but the distance between the bottom surface of the screen and the upper surface of the fingerprint identification device is difficult to test when it leaves the factory, that is, the installation position of the fingerprint identification device is difficult to test accurately. The stage can only ensure that the distance is within a certain range through the structure processing technology. In addition, when consumers use the screen, different people press on the screen very differently, and the difference in pressing force will also cause the distance to fluctuate. The size of the distance will affect the quality of the fingerprint image. Therefore, in this case, how to improve the quality of the fingerprint image becomes an urgent problem to be solved.

Summary of the invention

The embodiments of the present application provide a method for fingerprint identification, a fingerprint identification device, and electronic equipment, which can improve the quality of fingerprint images.

In the first aspect, a method for fingerprint identification is provided, the method is suitable for an electronic device having a display screen and a fingerprint identification device arranged below the display screen, and the method includes: acquiring the fingerprint identification device according to the received The original image generated by the first oblique light signal received, the first oblique light signal is the oblique light signal sent by the light-emitting unit pointing to the fingerprint identification device; the fingerprint identification device is acquired according to the received second oblique light signal The generated smear image, the second oblique light signal is emitted by the light-emitting unit pointing to the surface of the fingerprint recognition device, and arrives after reflection on the surface of the fingerprint recognition device and the bottom surface of the display screen. The oblique light signal of the fingerprint identification device; according to the distance X between the original image and the smear image, the fingerprint data collected by the fingerprint identification device is corrected, wherein the corrected fingerprint data is used for fingerprints Recognition.

In the technical solution provided by the embodiments of this application, the oblique light signal is used as the incident light signal, and the fingerprint data is corrected according to the original image and the smear image generated by the oblique light signal, and the corrected fingerprint data can reflect more accurately The fingerprint information of the finger can therefore improve the quality of the fingerprint image and improve the fingerprint recognition effect.

In some possible implementation manners, the correcting the fingerprint data collected by the fingerprint identification device according to the distance X between the original image and the smear image includes: determining the distance X according to the distance X The distance Y between the upper surface of the fingerprint identification device and the lower surface of the display screen; according to the distance Y, the fingerprint data collected by the fingerprint identification device is corrected.

In some possible implementation manners, the relationship between the distance Y and the distance X is Y=k*X+b, where k and b are both constants.

In some possible implementations, k and b are pre-configured according to different distances Y and corresponding different distances X.

In some possible implementations, the display screen is an organic light-emitting diode OLED screen, and the first oblique light signal and the second oblique light signal are generated by light-emitting pixels on at least one light-emitting area on the OLED screen. Formed by the emitted light signal.

In some possible implementation manners, the shape of the at least one light-emitting area is a circle.

In some possible implementation manners, the areas of different light-emitting regions in the at least one light-emitting region are different.

In some possible implementation manners, the at least one light-emitting area includes three light-emitting areas, and the centers of the three light-emitting areas are not on a straight line, which can improve the accuracy of the measured distance X.

In some possible implementation manners, the inclination angle of the first oblique optical signal and the second oblique optical signal is 10°-50°.

In some possible implementations, the fingerprint identification device includes an optical path guide structure and a fingerprint sensor, the fingerprint sensor includes a sensing array with a plurality of optical sensing units, and the optical path guide structure is used to transfer the first oblique light The signal and the second oblique optical signal are guided to the sensing array.

In some possible implementations, the fingerprint identification device includes a fingerprint sensor, and the fingerprint sensor is configured to receive a detection light signal emitted by the light-emitting unit that is irradiated on the finger and reflected by the finger, and based on the detection The optical signal generates the fingerprint data.

In some possible implementation manners, the detection light signal is perpendicular or inclined with respect to the surface of the display screen.

In a second aspect, a fingerprint identification device is provided, the fingerprint identification device is configured to be arranged below the display screen, and the fingerprint identification device includes: an optical path guide structure for converting the first tilt light signal and the second tilt The light signal is guided to the sensing array of the fingerprint sensor, wherein the first oblique light signal is the oblique light signal issued by the light-emitting unit pointing to the fingerprint identification device, and the second oblique light signal is the direction light emitted by the light-emitting unit. The surface of the fingerprint recognition device, and the oblique light signal that reaches the fingerprint recognition device after being reflected on the surface of the fingerprint recognition device and the bottom surface of the display screen; the fingerprint sensor includes a plurality of optical sensing units A sensing array for generating an original image according to the first oblique light signal, and generating a smear image according to the second oblique light signal, the original image and the smear image are used to compare The fingerprint data collected by the fingerprint identification device is corrected, and the corrected fingerprint data is used for fingerprint identification.

In some possible implementation manners, the light path guiding structure includes a microlens array and at least one light blocking layer, the microlens array is configured to be disposed between the display screen and the fingerprint sensor, and the microlens array It includes a plurality of micro lenses, the micro lenses are used to converge the received light signals, the at least one light blocking layer is arranged between the micro lens array and the fingerprint sensor, wherein each light blocking layer includes A plurality of openings corresponding to the plurality of microlenses respectively, the oblique light signal converged by each microlens passes through the openings corresponding to the microlens in different light-blocking layers to reach the optical fiber of the fingerprint sensor Induction unit.

In some possible implementations, the projection of the condensing surface of the microlens on a plane perpendicular to its optical axis is a circle or a square.

In some possible implementation manners, the light-concentrating surface is a spherical surface or an aspherical surface.

In some possible implementation manners, the curvature of the light-concentrating surface in all directions is the same.

In some possible implementations, the apertures corresponding to the same microlens in different light blocking layers are sequentially reduced from top to bottom.

In some possible implementation manners, the inclination angles of the connecting lines of the openings corresponding to the same microlens in different light blocking layers are the same as the inclination angles of the first oblique light signal and the second oblique light signal.

In some possible implementation manners, the last light blocking layer of the at least one light blocking layer is integrated in the fingerprint sensor.

In some possible implementation manners, each of the microlenses corresponds to an optical sensing unit of the fingerprint sensor, wherein the openings in different light blocking layers corresponding to the same microlens are used to pass through the microlens The converged first oblique light signal and the second oblique light signal are sequentially guided to the optical sensing unit corresponding to the microlens.

In some possible implementations, the lines connecting the centers of the openings corresponding to the same microlens in different light blocking layers pass through the central area of the optical sensing unit corresponding to the microlens.

In some possible implementation manners, the optical path guiding structure includes a microlens array and collimating holes, the microlens array is configured to be disposed between the display screen and the fingerprint sensor, and the microlens array includes A plurality of microlenses, the microlenses are used to converge the received optical signals, the collimation apertures are arranged between the microlens array and the fingerprint sensor, and the collimation apertures are used to converge The first oblique light signal and the second oblique light signal are guided to the fingerprint sensor.

In some possible implementations, the hole of the collimating hole is air or light-transmitting material, the wall of the hole is light-absorbing material, and the inclination angle of the axis of the collimating hole is the sum of the first inclined optical signal. The tilt angles of the second tilted optical signals are the same.

In some possible implementations, the arrangement of the inner core material and the outer core material of the collimating aperture can totally reflect the first oblique optical signal and the second oblique optical signal transmitted in the optical fiber .

In some possible implementation manners, the collimating aperture is an optical fiber.

In some possible implementation manners, the fingerprint identification device further includes a filter layer, and the filter layer is used to transmit optical signals in a specific wavelength range.

In some possible implementations, the filter layer is integrated on the fingerprint sensor.

In some possible implementation manners, the filter layer is disposed above the microlens array, and an air layer or a transparent glue layer is filled between the filter layer and the microlens array.

In some possible implementations, the transparent adhesive layer is surrounded by a light-shielding material.

In some possible implementations, the optical path guiding structure includes a lens, the lens is used to converge the first oblique light signal and the second oblique light signal to the fingerprint sensor, and the light emitting unit is used to The first oblique light signal and the second oblique light signal are emitted on an edge area of the field angle of the lens.

In some possible implementations, the light-emitting unit is a light-emitting pixel of an organic light-emitting diode OLED screen, and the first oblique light signal and the second oblique light signal are generated from at least one light-emitting area on the OLED screen. The at least one light-emitting area is located on the edge area of the boundary area of the field of view of the lens on the OLED screen formed by the light signal emitted by the light-emitting pixel.

In some possible implementation manners, the fingerprint sensor is further configured to receive a detection light signal emitted by the light-emitting unit that is irradiated on the finger and reflected by the finger, and generates the fingerprint data according to the detection light signal.

In some possible implementation manners, the detection light signal is perpendicular or inclined with respect to the surface of the fingerprint identification device.

In some possible implementation manners, the at least one light-emitting area includes three light-emitting areas, and the centers of the three light-emitting areas are not on a straight line.

In a third aspect, an electronic device is provided, including: a display screen, the fingerprint identification device in the second aspect and any one of its possible implementations, and a processor, configured to obtain the original image and the smear Image, and according to the distance X between the original image and the smear image, the fingerprint data collected by the fingerprint identification device is corrected, wherein the corrected fingerprint data is used for fingerprint identification.

In some possible implementation manners, the processor is configured to: determine the distance Y between the upper surface of the fingerprint identification device and the lower surface of the display screen according to the distance X; The fingerprint data collected by the fingerprint identification device is corrected.

Description of the drawings

Fig. 1 is a schematic structural diagram of an electronic device used in an embodiment of the present application.

Fig. 2 is a schematic cross-sectional view of the electronic device shown in Fig. 1 along the A-A' direction.

FIG. 3 is a schematic diagram of another structure of an electronic device used in an embodiment of the present application.

Fig. 4 is a schematic cross-sectional view of the electronic device shown in Fig. 3 along the A-A' direction.

FIG. 5 is a structural diagram of a fingerprint identification device used in an embodiment of the present application.

FIG. 6 is a schematic flowchart of a method for fingerprint identification provided by an embodiment of the present application.

FIG. 7 is a schematic diagram of an original image and a smear image generation method provided by an embodiment of the present application.

FIG. 8 is a schematic diagram of the distance X provided by an embodiment of the present application.

FIG. 9 is a schematic flowchart for determining the correspondence between the distance X and the distance Y according to an embodiment of the present application.

FIG. 10 is a schematic diagram of a corresponding relationship between a distance X and a distance Y provided by an embodiment of the present application.

FIG. 11 is a schematic flowchart of a method for determining a distance Y according to an embodiment of the present application.

FIG. 12 is a schematic diagram of a light-emitting area provided by an embodiment of the present application.

FIG. 13 is a schematic diagram of the receiving area of the fingerprint sensor provided by an embodiment of the present application.

FIG. 14 is a schematic block diagram of a fingerprint identification device provided by an embodiment of the present application.

FIG. 15 is a schematic diagram of a circular microlens array provided by an embodiment of the present application.

16 and 17 are schematic diagrams of a rectangular microlens array according to an embodiment of the present application.

FIG. 18 is a schematic diagram of a possible structure of the fingerprint recognition device shown in FIG. 14.

FIG. 19 is a schematic diagram of a possible structure of the fingerprint identification device shown in FIG. 14.

FIG. 20 is a schematic diagram of a possible structure of the fingerprint recognition device shown in FIG. 14.

FIG. 21 is a schematic diagram of a possible structure of the fingerprint recognition device shown in FIG. 14.

FIG. 22 is a schematic diagram of a possible structure of the fingerprint recognition device shown in FIG. 14.

FIG. 23 is a schematic structural diagram of a collimating hole provided by an embodiment of the present application.

Fig. 24 is a schematic structural diagram of another collimating hole provided by an embodiment of the present application.

FIG. 25 is a schematic structural diagram of another collimating hole provided by an embodiment of the present application.

FIG. 26 is a schematic diagram of a possible structure of the fingerprint recognition device shown in FIG. 14.

FIG. 27 is a schematic block diagram of an electronic device according to an embodiment of the present application.

Detailed ways

The technical solution in this application will be described below in conjunction with the accompanying drawings.

It should be understood that the embodiments of this application can be applied to fingerprint systems, including but not limited to optical, ultrasonic or other fingerprint identification systems and medical diagnostic products based on optical, ultrasonic or other fingerprint imaging. The embodiments of this application only take optical fingerprint systems as an example For illustration, the embodiments of the present application should not constitute any limitation, and the embodiments of the present application are also applicable to other systems that use optical, ultrasonic, or other imaging technologies.

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

The fingerprint recognition technology under the optical screen uses the light returned from the top surface of the device display component to perform fingerprint sensing and other sensing operations. The returned light carries information about the object (for example, a finger) in contact with the top surface. By collecting and detecting the returned light, a specific optical sensor module located under the display screen is realized. The design of the optical sensor module can be to achieve desired optical imaging by appropriately configuring optical elements for collecting and detecting the returned light.

Figures 1 and 2 show schematic diagrams of electronic devices to which the embodiments of the present application can be applied. 1 is a schematic view of the orientation of the electronic device 10, and FIG. 2 is a schematic partial cross-sectional view of the electronic device 10 shown in FIG. 1 along the direction A-A'.

The electronic device 10 includes a display screen 120 and an optical fingerprint module 130. Wherein, the optical fingerprint module 130 is arranged in a partial area below the display screen 120. The optical fingerprint module 130 includes an optical fingerprint sensor, and the optical fingerprint sensor includes a sensing array 133 having a plurality of optical sensing units 131 (also referred to as photosensitive pixels, pixel units, etc.). The area where the sensing array 133 is located or its sensing area is the fingerprint detection area 103 of the optical fingerprint module 130 (also referred to as a fingerprint collection area, a fingerprint recognition area, etc.). As shown in FIG. 1, the fingerprint detection area 103 is located in the display area of the display screen 120. In an alternative embodiment, the optical fingerprint module 130 may also be arranged in other positions, such as the side of the display screen 120 or the non-transmissive area at the edge of the electronic device 10, and the optical fingerprint module 130 The optical signal of at least a part of the display area of the display screen 120 is guided 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.

It should be understood that the area of the fingerprint detection area 103 may be different from the area of the sensing array 133 of the optical fingerprint module 130, for example, through an optical path design such as lens imaging, a reflective folding optical path design, or other optical paths such as light convergence or reflection. The design can make the area of the fingerprint detection area 103 of the optical fingerprint module 130 larger than the area of the sensing array 133 of the optical fingerprint module 130. In other alternative implementations, if for example, light collimation is used for light path guidance, the fingerprint detection area 103 of the optical fingerprint module 130 may also be designed to be substantially the same as the area of the sensing array of the optical fingerprint module 130.

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

As an optional implementation manner, as shown in FIG. 1, the optical fingerprint module 130 includes a light detecting part 134 and an optical component 132. The light detection part 134 includes the sensor array 133, a reading circuit electrically connected to the sensor array 133, and other auxiliary circuits, 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 photodetector (photodetector) array, which includes a plurality of photodetectors distributed in an array, and the photodetectors can be used as the optical sensing unit as described above. The optical component 132 may be disposed above the sensing array 133 of the light detecting part 134, and it may specifically include a filter layer (Filter), a light guide layer or a light path guiding structure, and other optical elements. It can be used to filter out ambient light penetrating the finger, and the light guide layer or light path guiding structure is mainly used to guide the reflected light reflected from the surface of the finger to the sensing array 133 for optical detection.

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

Wherein, the light guide layer or light path guiding structure of the optical component 132 has multiple implementation schemes. For example, the light guide layer may specifically be a collimator layer made on a semiconductor silicon wafer, which has multiple solutions. A collimating unit or a micro-hole array, the collimating unit may be specifically a small hole. Among the reflected light reflected from the finger, the light that is perpendicularly incident on the collimating unit can pass through and be passed by the optical sensing unit below it. The light with an excessively large incident angle is attenuated by multiple reflections inside the collimating unit. Therefore, each optical sensor unit can basically only receive the reflected light reflected by the fingerprint pattern directly above it. The sensing array 133 can detect the fingerprint image of the finger.

In another implementation manner, the light guide layer or the light path guide structure may also be an optical lens (Lens) layer, which has one or more lens units, such as a lens group composed of one or more aspheric lenses, which The sensing array 133 of the light detecting part 134 is used to converge the reflected light reflected from the finger to the sensing array 133 of the light detection part 134 below, so that the sensing array 133 can perform imaging based on the reflected light, thereby obtaining a fingerprint image of the finger. Optionally, the optical lens layer may further have a pinhole formed in the optical path of the lens unit, and the pinhole may cooperate with the optical lens layer to expand the field of view of the optical fingerprint module 130 to improve The fingerprint imaging effect of the optical fingerprint module 130 is described.

In other implementations, the light guide layer or the light path guide structure may also specifically adopt a micro-lens (Micro-Lens) layer. The micro-lens layer has a micro-lens array formed by a plurality of micro-lens, which can be grown by a semiconductor. A process or other processes are formed above the sensing array 133 of the light detecting part 134, and each microlens may correspond to one of the sensing units of the sensing array 133, respectively. In addition, other optical film layers may be formed between the micro lens layer and the sensing unit, such as a dielectric layer or a passivation layer. More specifically, a light blocking layer (or called a light blocking layer, a light blocking layer, etc.) with micro holes (or called openings) may also be included between the micro lens layer and the sensing unit, wherein the micro The hole is formed between the corresponding micro lens and the sensing unit, the light blocking layer can block the optical interference between the adjacent micro lens and the sensing unit, and make the light corresponding to the sensing unit converge through the micro lens To the inside of the micropore and transfer to the sensing unit through the micropore for optical fingerprint imaging.

It should be understood that several implementation solutions of the above-mentioned light guide layer or light path guide structure can be used alone or in combination. For example, a micro lens layer may be further provided 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, its specific laminated structure or optical path may need to be adjusted according to actual needs.

As an optional implementation manner, the display screen 120 may be a display screen with a self-luminous display unit, such as an organic light-emitting diode (Organic Light-Emitting Diode, OLED) display or a micro-LED (Micro-LED) display Screen. Taking an OLED display screen as an example, the optical fingerprint module 130 can use the display unit (ie, 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 on the fingerprint detection area 103, the display screen 120 emits a beam of light 111 to the target finger 140 above the fingerprint detection area 103. The light 111 is reflected on the surface of the finger 140 to form reflected light or pass through all the fingers. The finger 140 scatters inside to form scattered light. In related patent applications, for ease of description, the above-mentioned reflected light and scattered light are collectively referred to as reflected light. Since the ridge 141 and valley 142 of the fingerprint have different light reflection capabilities, the reflected light 151 from the fingerprint ridge and the reflected light 152 from the fingerprint valley have different light intensities, and the reflected light passes through the optical component 132 Then, it is received by the sensing array 133 in the optical fingerprint module 130 and converted into a corresponding electrical signal, that is, a fingerprint detection signal; based on the fingerprint detection signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed, thereby The electronic device 10 realizes the optical fingerprint recognition function.

In other implementations, the optical fingerprint module 130 may also use a built-in light source or an external light source to provide an optical signal for fingerprint detection. In this case, the optical fingerprint module 130 may be suitable for non-self-luminous display screens, such as liquid crystal display screens or other passively-luminous display screens. Taking a liquid crystal display with a backlight module and a liquid crystal panel as an example, in order to support the under-screen fingerprint detection of the liquid crystal display, the optical fingerprint system of the electronic device 10 may also include an excitation light source for optical fingerprint detection. The excitation light source may specifically be an infrared light source or a light source of non-visible light of a specific wavelength, which may be arranged under the backlight module of the liquid crystal display or arranged in the edge area under the protective cover of the electronic device 10, and the The optical fingerprint module 130 can be arranged under the edge area of the liquid crystal panel or the protective cover and guided by the light path so that the fingerprint detection light can reach the optical fingerprint module 130; or, the optical fingerprint module 130 can also be arranged in all areas. Below the backlight module, and the backlight module is designed 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 adopts a built-in light source or an external light source to provide an optical signal for fingerprint detection, the detection principle is the same as that described above.

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

On the other hand, in some implementations, the optical fingerprint module 130 may include only one optical fingerprint sensor. At this time, the fingerprint detection area 103 of the optical fingerprint module 130 has a small area and a fixed position, so the user is performing During fingerprint input, it is necessary to press the finger to a specific position of the fingerprint detection area 103, otherwise the optical fingerprint module 130 may not be able to collect the fingerprint image, resulting in poor user experience. In other alternative embodiments, the optical fingerprint module 130 may specifically include a plurality of optical fingerprint sensors. The multiple optical fingerprint sensors may be arranged side by side under the display screen 120 in a splicing manner, and the sensing areas of the multiple optical fingerprint sensors collectively constitute the fingerprint detection area 103 of the optical fingerprint module 130. Therefore, the fingerprint detection area 103 of the optical fingerprint module 130 can be extended to the main area of the lower half of the display screen, that is, to the area where the finger is habitually pressed, so as to realize the blind fingerprint input operation. Further, when the number of optical fingerprint sensors is sufficient, the fingerprint detection area 103 can also be extended to half of the display area or even the entire display area, thereby realizing half-screen or full-screen fingerprint detection.

For example, in the electronic device 10 shown in FIGS. 3 and 4, when the optical fingerprint device 130 in the electronic device 10 includes multiple optical fingerprint sensors, the multiple optical fingerprint sensors may be arranged side by side in the Below the display screen 120 and the sensing areas of the multiple optical fingerprint sensors collectively constitute the fingerprint detection area 103 of the optical fingerprint device 130.

Optionally, corresponding to the multiple optical fingerprint sensors of the optical fingerprint device 130, the optical component 132 may have multiple light path guiding structures, and each light path guiding structure corresponds to an optical fingerprint sensor, and is attached to the optical fingerprint sensor. Set above the corresponding optical fingerprint sensor. Alternatively, the plurality of optical fingerprint sensors may also share an overall optical path guiding structure, that is, the optical path guiding structure has an area large enough to cover the sensing array of the plurality of optical fingerprint sensors. In addition, the optical component 132 may also include other optical elements, such as filters or other optical films, which may be arranged between the optical path guiding structure and the optical fingerprint sensor or arranged on the display. The screen 120 and the optical path guiding structure are mainly used to isolate the influence of external interference light on the optical fingerprint detection. Wherein, the filter can be used to filter out the ambient light that penetrates the finger and enters the optical fingerprint sensor through the display screen 120. Similar to the optical path guide structure, the filter can be specific to each The optical fingerprint sensors are separately arranged to filter out interference light, or a large-area filter can also be used to cover the multiple optical fingerprint sensors at the same time.

The optical path modulator may also be replaced by an optical lens (Lens), and a small hole formed by a light-shielding material above the optical lens can cooperate with the optical lens to converge fingerprint detection light to an optical fingerprint sensor below to realize fingerprint imaging. Similarly, each optical fingerprint sensor may be separately configured with an optical lens to perform fingerprint imaging, or the multiple optical fingerprint sensors may also use the same optical lens to achieve light convergence and fingerprint imaging. In other alternative embodiments, each optical fingerprint sensor may even have two sensing arrays (Dual Array) or multiple sensing arrays (Multi-Array), and two or more optical lenses are configured to cooperate with the two at the same time. Or multiple sensing arrays perform optical imaging, thereby reducing the imaging distance and enhancing the imaging effect.

The number, size, and arrangement of the fingerprint sensors shown above are only examples, and can be adjusted according to actual needs. For example, the number of the plurality of fingerprint sensors may be 2, 3, 4, 5, etc., and the plurality of fingerprint sensors may be distributed in a square or circular shape.

The under-screen optical fingerprint recognition technology generally uses the light emitted by the screen as the light source. The light signal emitted by the screen reaches the finger above the screen, and the light signal after the reflection or scattering of the finger carries the fingerprint information of the finger. The light signal carrying the fingerprint information can be Received by the fingerprint sensor at the bottom of the screen for fingerprint identification.

The existing under-screen optical fingerprint recognition has been mass-produced under the OLED screen. It uses the light transmission characteristics of the OLED screen itself, and the light signal emitted by the screen itself illuminates the finger, and the light signal reflected by the finger can be Received by the fingerprint identification device for fingerprint detection.

As shown in FIG. 5, the fingerprint identification device 330 is arranged under the display screen 320. The fingerprint identification device 330 includes a light path guiding structure 331 and a fingerprint sensor 332. The fingerprint sensor 332 can be electrically connected to the circuit board 333, which can be a substrate. Or flexible printed circuit board (fpc flexible printed circuit, FPC). The display screen 320 may include a light emitting layer 322, a component part 321 located above the light emitting layer 322, and a component part 323 located below the light emitting layer 322. During the fingerprint identification process, the finger 310 can press the fingerprint detection area on the display screen. After the light signal emitted by the display screen 320 illuminates the finger, the reflection of the finger is received by the fingerprint sensor 332 under the display screen 320. The fingerprint sensor 332 can A fingerprint image of the finger 310 is generated according to the received light signal to perform fingerprint recognition.

The fingerprint identification device needs to be installed under the screen to realize the function of fingerprint detection, but the distance Y between the bottom surface of the screen and the upper surface of the fingerprint identification device is difficult to test accurately when leaving the factory, that is, the installation position of the fingerprint identification device is difficult to test accurately. At this stage, only the structural processing technology can be used to ensure that the distance Y is within a certain range. In addition, when consumers use it, different people press on the screen very differently, and the difference in pressing force will also cause the distance Y to fluctuate.

The size of the distance Y will affect the quality of the fingerprint image. For example, the distance Y after installation is different from the pre-configured distance Y, which will reduce the light signal received by the fingerprint identification device, thereby affecting the quality of the fingerprint image. For example, The size of the distance Y also affects the size of the fingerprint image. Therefore, if the accurate value of the distance Y can be obtained in real time, the fingerprint image can be corrected in real time through the algorithm to ensure that the fingerprint image will not deteriorate due to the distance Y. Can effectively improve the performance of optical fingerprints.

The embodiment of the present application provides a method for fingerprint identification, which can correct the obtained fingerprint image to improve fingerprint detection performance. The method is suitable for electronic equipment with a display screen and a fingerprint identification device arranged under the display screen. As shown in Fig. 6, the method includes steps S610 to S630.

S610. Obtain an original image generated by the fingerprint identification device according to the received first oblique light signal, where the first oblique light signal is an oblique light signal sent by the light-emitting unit directed to the fingerprint identification device.

S620. Obtain a smear image generated by the fingerprint identification device according to the received second oblique light signal. The second oblique light signal is emitted by the light-emitting unit and directed to the surface of the fingerprint identification device, and is reflected on the surface of the fingerprint identification device and the display screen The oblique light signal that reaches the fingerprint identification device after reflection on the bottom surface.

S630: Correct the fingerprint data collected by the fingerprint identification device according to the distance X between the original image and the smear image, and the corrected fingerprint data is used for fingerprint identification.

In the embodiments of the present application, the first oblique light signal is the oblique light signal emitted by the light-emitting unit that directly illuminates the fingerprint identification device, and the second oblique light signal is the light emitted by the light-emitting unit that reaches the fingerprint identification device after being reflected on the surface of the device. The oblique light signal will be described in detail below with reference to FIG. 7.

The light-emitting layer 322 in the display screen 320 can emit a light signal with a preset pattern. A part of the light signal 361 (first oblique light signal) emitted by the light-emitting layer 322 directly points to the fingerprint identification device, which can be based on the received light. The signal 361 generates the original image 340. Another part of the light signal 362,363 (second oblique light signal) emitted by the light-emitting layer 322 reaches the fingerprint recognition device after being reflected on the surface of the device, and the fingerprint recognition device generates a smear image 350 according to the received light signal 362,363.

It is understandable that if it is a vertical light signal, there is no smear image. Therefore, the embodiment of the present application uses the oblique light signal to generate the smear image.

The second oblique optical signal shown in FIG. 7 may include two types of optical signals, one is the oblique optical signal 362 and the other is the oblique optical signal 363. The oblique light signal 362 is the oblique light signal emitted by the light-emitting layer 362 that reaches the fingerprint identification device 330 after being reflected at the interface between the upper surface of the display screen and the air. The upper surface of the recognition device reflects the oblique light signal that reaches the lower surface of the display screen, and then reaches the fingerprint recognition device again after being reflected on the lower surface of the display screen. That is, the oblique light signal 363 is the light emitting layer 322 that has passed twice. Oblique light signal that reaches the fingerprint recognition device after reflection.

The oblique light signal 363 has a higher signal strength than the oblique light signal 362, and the smear image generated according to the oblique light signal 363 can better reflect the distance Y between the fingerprint identification device and the display screen. Therefore, the embodiment of the present application mainly considers the oblique light The influence of signal 363 on smear image.

It can be seen from FIG. 7 that the smear image 350 generated according to the second oblique light signal is shifted or offset in the horizontal direction from the original image generated according to the first oblique light signal, as shown in FIG. 8, The distance X of the shift or offset is actually related to the distance Y, and the distance X and the distance Y are in a positive correlation. The greater the distance Y, the greater the distance X. Therefore, the embodiment of the present application can use this positive correlation between the distance X and the distance Y, and by detecting the distance X, the fingerprint data collected by the fingerprint identification device can be corrected, thereby improving the fingerprint identification performance.

The distance X can be understood as the offset distance of the smear image relative to the original image.

The relative positional relationship between the smear image and the original image in FIGS. 7 and 8 is only an example, and does not represent the actual positional relationship. The distance between the smear image and the original image in the vertical direction shown in Figs. 7 and 8 does not indicate the actual distance, but only to express the smear image and the original image more clearly. The actual smear image and the original image Usually in a horizontal direction.

In the embodiments of the present application, in addition to the OLED screen as the light-emitting unit, an external light source can also be used as the light-emitting unit, such as a light emitting diode (LED) lamp, which can be set under the display screen and used for fingerprint recognition. The position between the upper surfaces of the device, the LED light is offset by a certain distance relative to the fingerprint identification device, so as to achieve the purpose of the LED light being able to emit a tilt light signal to the fingerprint identification device.

In the embodiment of the present application, correcting the fingerprint data according to the distance X between the original image and the smear image may also include correcting the fingerprint data according to the coordinates or other parameters of the original image and the smear image.

For example, the embodiment of the present application may directly correct the fingerprint data according to the distance X. For example, before the fingerprint identification device leaves the factory, the fingerprint data corresponding to different distances X are obtained through tests, and then the correction parameters corresponding to the different distances X are determined. After the fingerprint identification device is installed in the electronic device, the fingerprint data is corrected by measuring the distance X.

For another example, correcting the fingerprint data according to the distance X may also refer to determining the distance Y between the upper surface of the fingerprint identification device and the lower surface of the display screen according to the distance X, and correcting the fingerprint data collected by the fingerprint identification device according to the distance Y . Before the fingerprint identification device leaves the factory, adjust multiple distances Y (Y1, Y2,..., Yn) on a specific screen through a fixture, and test the corresponding smear distance X (X1, X2,..., Xn) respectively to establish Correspondence between X and Y, where n is an integer greater than or equal to 2. After the fingerprint identification device is installed in the electronic device, the distance X is measured, the distance Y is determined according to the corresponding relationship, and then the fingerprint data is corrected according to the distance Y.

In the embodiment of the present application, the distance X and the distance Y are in a positive correlation, and the distance X and the distance Y are basically a linear relationship. The relationship between the distance X and the distance Y can be expressed as Y=k*X+b, where, Both k and b are constants.

Before the device leaves the factory, multiple distances X corresponding to multiple distances Y can be obtained through the above process, so that the parameters k and b can be calculated, that is, k and b can be based on different distances Y and corresponding different distances in advance. Configured from X. Since the distance Y and the distance X have a linear relationship, in theory, k and b can be obtained through two sets of data, but in order to eliminate the test error as much as possible and improve the accuracy, at least three sets of data can be tested to obtain multiple sets of k and b. Solution of b, and then find the average value.

After the test is completed, the k and b obtained from the test can be written into the built-in flash memory (flash) or one-time programmable (OTP) memory of the fingerprint identification device, or stored in the whole machine for use in the whole machine algorithm Used when calling.

FIG. 9 shows a schematic flowchart of a method for obtaining the correspondence between the distance X and the distance Y.

Before testing the distance, the fingerprint sensor can be initialized, and the OLED display shows a preset pattern and emits light signals toward the fingerprint sensor. By setting the distance Yn, measure the corresponding distance Xn under the distance Yn, where n is an integer greater than or equal to 3. The distance Xn can be obtained by calculating the distance between the original image and the smear image through the center of gravity algorithm. The parameters k and b can be solved by testing the corresponding distance X at different distances Y and entering the formula Y=k*X+b.

The corresponding relationship between the distance Y and the distance X can be shown in Fig. 10, and the parameters k and b can be calculated through three calibration points.

FIG. 11 shows a schematic flowchart of the process of actually detecting the distance. After initializing the preset pattern, the center algorithm is used to calculate the center between the smear image and the original image, and the distance X is calculated through the centers of the two images, and then the corresponding distance Y is calculated in real time according to the formula Y=k*X+b. In practical applications, you can consider collecting multiple data and averaging to minimize errors.

If the display screen is an OLED screen, the first oblique light signal and the second oblique light signal may be formed by light signals emitted by light-emitting pixels on at least one light-emitting area on the OLED screen. The preset pattern mentioned above refers to the pattern formed by the at least one light-emitting area.

The original image and the smear image are formed according to the light signal emitted by the preset pattern.

The embodiment of the present application does not limit the shape of the at least one light-emitting area displayed on the display screen, and may be any shape, for example, a circle, a square, a polygon, and the like.

Figure 12 shows that the shape of the light-emitting area is circular, and a circular pattern can be displayed on the display screen. According to the light signal emitted by the light-emitting area, the fingerprint sensor can generate the original image (or original round spot) and the smear image (Or smear round spot), the distance between the original image and the smear image is calculated by the center of gravity algorithm, so as to correct the obtained fingerprint data.

In order to improve the accuracy of detection, there can be multiple light-emitting areas on the display screen. As shown in Figure 12, 2 or 3 round spots can be displayed on the display screen, so that the fingerprint sensor can generate multiple original images and corresponding multiple drag areas. For the shadow image, the calculated distance Y is more accurate according to the distance between the multiple original images and the corresponding multiple shadow images.

In order to further improve the detection accuracy, the areas of different light-emitting areas may be different, or the shapes of different light-emitting areas may be different. Taking a circular light-emitting area as an example, the diameter of different light-emitting areas can be different.

In addition, in order to detect the distance between the original image and the smear image in different directions, the display screen may include three light-emitting areas, and the centers of the three light-emitting areas are not on a straight line, that is, the centers of the three light-emitting areas Can form a triangle. As shown in Figure 12, the line connecting the centers of the three round spots is a triangle. Of course, the embodiment of the present application may also use more than three light-emitting areas, as long as the centers of the three light-emitting areas are not on a straight line.

FIG. 7 shows a schematic diagram of the image generated on the fingerprint sensor when the three round spots on the light-emitting area 322 emit light. The fingerprint sensor can generate 3 original images 340 and 3 smear images 350 corresponding to the 3 original images 340. Then respectively calculate the distance between the 3 original images and the 3 smear images, determine the distance Y, and then correct the fingerprint data.

The embodiment of the present application does not limit the inclination angles of the first oblique optical signal and the second oblique optical signal. For example, the inclination angle may be 10°-50°.

The fingerprint identification device in the embodiment of the present application may include a light path guiding structure and a fingerprint sensor. The fingerprint sensor may include a sensing array with a plurality of sensing units. The light path guiding structure is used to guide the first tilt light signal and the second tilt light signal. To the sensing array.

The arrangement of the optical path guiding structure in the embodiment of the present application can enable only a specific angle of the optical signal from the optical signal emitted by the at least one light-emitting area to be guided to the fingerprint sensor, and the optical signal in the vertical direction cannot be guided to the fingerprint sensor.

It can be understood that the arrangement of the optical path guide structure can make the first tilt light signal and the second tilt light signal received by the fingerprint sensor substantially parallel, that is, the tilt light signal 361 and the tilt light signal 362 shown in FIG. 7 It is substantially parallel, and the oblique light signal 361 and the oblique light signal 363 are substantially parallel.

The fingerprint sensor can also be used to receive the detection light signal emitted by the light-emitting unit that is irradiated on the finger and reflected by the finger, and generates fingerprint data according to the detection light signal.

The optical signal used to detect the distance described above is an oblique optical signal, but the embodiment of the present application does not specifically limit the detected optical signal. The detected optical signal may be a vertical optical signal or an oblique optical signal. That is, the detection light signal is vertical or inclined with respect to the display screen.

When the detection light signal is tilted relative to the display screen, the tilt angle of the detection light signal may be the same as or different from the tilt angles of the first tilt light signal and the second tilt light signal.

Figure 13 shows a scheme in which the detection distance adopts the oblique light signal and the fingerprint detection adopts the vertical light signal. The fingerprint sensor includes 4 sensing units, of which 3 sensing units can be used to receive vertical light signals for fingerprint detection. And part or all of the areas of the 4 sensing units can be used to receive tilt light signals for distance detection.

The fingerprint sensor combines upward oblique reception and vertical reception. This solution can be realized by setting different light-emitting areas and special light path guiding structures. The optical path guiding structure can guide both vertical optical signals and oblique optical signals.

If the optical path guiding structure can only guide the optical signal in one direction, that is, the detection optical signal, the first oblique optical signal, and the second oblique optical signal have the same inclination angle, the fingerprint detection process and the distance detection process can be performed separately. If fingerprint detection is not performed, distance detection can be performed. The distance detection may be performed periodically or before each fingerprint detection, which is not specifically limited in the embodiment of the present application.

If the detection light signal and the oblique light signal used to detect the distance do not interfere with each other, the fingerprint detection and the distance detection can be performed at the same time, so that the fingerprint image can be corrected more accurately. But in order to reduce processing complexity, fingerprint detection and distance detection can also be performed separately.

In addition, an embodiment of the present application also provides a fingerprint identification device, which is configured to be arranged below the display screen. As shown in FIG. 14, the fingerprint identification device 1400 includes an optical path guide structure 1410 and a fingerprint sensor 1420.

The optical path guiding structure 1410 is used to guide the first oblique light signal and the second oblique light signal to the sensing array of the fingerprint sensor, where the first oblique light signal is the oblique light signal emitted by the light-emitting unit pointing to the fingerprint identification device, and the second oblique light signal is The oblique light signal is the oblique light signal emitted by the light-emitting unit that points to the surface of the fingerprint identification device and reaches the fingerprint identification device after being reflected on the surface of the fingerprint identification device and the bottom surface of the display screen. The fingerprint sensor 1420 includes a sensing array with a plurality of optical sensing units, and the sensing array is used to generate an original image according to a first oblique light signal, and generate a smear image according to a second oblique light signal, the original image and the drag The shadow image is used to correct the fingerprint data collected by the fingerprint identification device, and the corrected fingerprint data is used for fingerprint identification.

The embodiment of the present application does not specifically limit the form of the optical path guiding structure, and the optical path guiding structure may be any form described above.

The optical path guiding structure may include, for example, a microlens array and at least one light blocking layer. The microlens array is used to be arranged between the display screen and the fingerprint sensor. The microlens array may include a plurality of microlenses. The microlens array is used for alignment. The received optical signals are converged. The at least one light blocking layer includes a plurality of openings corresponding to the plurality of microlenses, and the oblique light signal collected by each microlens passes through the openings corresponding to the microlenses in the different light blocking layers to reach the fingerprint sensor. Optical sensing unit.

The projection of the condensing surface of the microlens on the plane perpendicular to its optical axis can be circular, square, or other shapes; the condensing surface of the microlens can be spherical or aspherical. The application embodiment does not specifically limit this.

FIG. 15 is a top view of a microlens array composed of conventional circular microlenses. It can be seen that there is a gap 420 between adjacent microlenses 410, and the optical signal reflected by the finger and entering the gap 420 cannot be collected by the optical fingerprint sensor 520 As a result, although this part of the optical signal also carries image information, it has not been used.

16 and 17 are respectively a top view and a side view of a microlens array composed of rectangular microlenses according to an embodiment of the application. The projection of the microlens 511 shown in FIG. 16 directly below it is a square, which is also called a square microlens 511. It can be seen that by densely arranging these rectangular microlenses 511, there is no gap between adjacent microlenses 511, so a higher proportion of light-collecting area can be obtained, more image information can be obtained, and fingerprint recognition can be improved. performance.

Wherein, the condensing surface of the microlens is a surface used to converge light. The embodiment of the present application does not make any limitation on the surface shape of the condensing surface, for example, it may be a spherical surface or an aspherical surface. Preferably, the curvature of the condensing surface in all directions is the same, so that the imaging focus of each direction of the microlens can be at the same position, thereby ensuring the imaging quality.

The fingerprint identification device in the embodiment of the present application will be described below with reference to FIGS. 18-22.

It should be understood that each microlens in the microlens array 510 in the embodiment of the present application may also have two condensing surfaces, the projected areas of the two condensing surfaces are both rectangular, and the two condensing surfaces are symmetrical, forming a similar shape. Because of the shape of the convex lens, it can achieve a better convergence effect of light.

In addition, the microlenses in the microlens array 510 of the embodiment of the present application may be rectangular microlenses, but also other polygonal microlenses, that is, the front projection of the microlenses is a polygon, such as a hexagon. These microlenses only need to be tightly spliced together to eliminate or reduce the aforementioned gap 620.

Optionally, the microlens array 510 further includes a base material under the plurality of microlenses, and the base material 512 has the same refractive index as the material of the microlenses, thereby reducing light loss caused by a sudden change in refractive index.

Optionally, the device 500 further includes a filter layer 530, wherein the filter layer 530 is arranged above the microlens array 510, or between the microlens array 510 and the fingerprint sensor 520, and the filter layer 530 is used for To transmit optical signals within a specific wavelength range.

For example, when the filter layer 530 is disposed above the micro lens array 510, the space between the filter layer 530 and the micro lens array 510 is air 531, or a transparent glue layer 532 is filled.

The transparent adhesive layer 532 may be, for example, an optically clear adhesive (OCA), transparent glue, or transparent adhesive film.

The transparent adhesive layer 532 is an optical adhesive with a low refractive index. Compared with FIG. 18, the transparent adhesive layer 532 has a reduced air interface, which can reduce stray light, has less light loss, and has better fingerprint performance.

The microlens array 510 can be surrounded by a light-shielding material 534, for example, black foam is used for light-shielding, so as to prevent the stray light around the microlens array 510 from entering the microlens array 510 and affect the fingerprint recognition performance.

For another example, when the filter layer 530 is disposed between the microlens array 510 and the optical fingerprint sensor 520, the filter layer 510 and the optical fingerprint sensor 520 are integrated together.

The embodiment of the present application does not limit the way the filter layer 510 is integrated with the optical fingerprint sensor 520. For example, an evaporation process may be used to coat the optical sensing unit of the optical fingerprint sensor 520 to form the filter layer 530, such as by atomic Layer deposition, sputtering coating, electron beam evaporation coating, ion beam coating and other methods prepare a thin film of filter material above the optical sensing unit of the optical fingerprint sensor 520. Preferably, the thickness of the filter layer 530 may be less than or equal to 20 μm.

Taking FIGS. 18 to 20 as an example, the micro lens array 510, the optical fingerprint sensor 520, and the filter layer 530 are shown. The optical fingerprint sensor 520 includes a plurality of photosensitive units and a light blocking layer 551 located above the plurality of sensing units. The light-blocking layer 551 includes a plurality of openings, such as openings 5511, each opening corresponding to an optical sensing unit, for example, the opening 5511 corresponds to the optical sensing unit 521, and the opening 5511 is used for oblique light signals at a predetermined angle. Reaching the optical sensing unit 521 corresponding to the opening 5511 and blocking light from other directions affects the oblique light signal. The microlens array 510 is composed of a plurality of microlenses, and the refractive index of the base material 512 located under the microlens array 510 may be equal to the refractive index of the microlenses, thereby reducing light loss caused by a sudden change in refractive index.

For example, as shown in FIG. 18, the filter layer 530 may be disposed above the micro lens array 510, and there is an air gap 531 between the filter layer 530 and the micro lens array 510. A light-shielding material 540 is arranged around the micro lens array 510.

For example, as shown in FIG. 19, the filter layer 530 may be disposed above the micro lens array 510, and there is a transparent glue layer 532 between the filter layer 530 and the micro lens array 510. The transparent adhesive layer 532 can be a low refractive index optical adhesive. A light-shielding material 540 is provided around the transparent glue layer 532.

For example, as shown in FIG. 20, the filter layer 530 is integrated with the optical fingerprint sensor 520, and the filter layer 530 is located above the optical sensing unit 521 of the optical fingerprint sensor 520, so that light meeting the wavelength condition can reach the optical sensing unit 521. The light that does not meet the wavelength condition is filtered out.

The above-mentioned filter layer 530 can filter light in the infrared waveband, and transmit light in the visible light waveband, for example.

In the three implementations of the filter layer 530 shown in FIG. 18 to FIG. 20, the filter layer 530 and the optical fingerprint sensor 520 can be integrated together to better ensure the reliability of fingerprint recognition. There are no restrictions on the location and type of the 530.

This application uses oblique light signals for distance detection. Taking FIGS. 18 to 20 as examples, light entering the microlens 511 at an angle i can be condensed by the microlens 511 and reach the optical sensing unit 521 through the opening 5511. The light at other angles will be blocked by the light blocking layer 551.

The openings in each light-blocking layer can effectively prevent light crosstalk and block stray light in addition to realizing light path guidance, so that only light that meets the aforementioned preset angle i can reach the optical fingerprint sensor 520 through the light-blocking layer.

The embodiment of the present application does not limit the number of light blocking layers. Too many light blocking layers will increase the thickness and complexity of the fingerprint identification device, while too few light blocking layers will bring more interference light and affect the imaging effect. In actual use, a reasonable number of light-blocking layers can be set according to requirements.

For example, FIGS. 18 to 20 show the case where there is only one light blocking layer, that is, the light blocking layer 551.

For another example, FIG. 21 shows a situation where there are two light blocking layers. In FIG. 21, a light blocking layer 552 is added on the basis of FIG. 20, and a transparent medium layer 561 is filled between the light blocking layer 552 and the filter layer 530. For other related components in FIG. 21, reference may be made to the description of FIG. 20.

For another example, FIG. 22 shows a situation where there are three light blocking layers. FIG. 22 adds a light blocking layer 552 and a light blocking layer 553 on the basis of FIG. 20, and a transparent medium layer 561 is filled between the light blocking layer 552 and the light blocking layer 553. A transparent medium layer 562 is filled in between. For other related components in FIG. 22, reference may be made to the description of FIG. 20.

Further, optionally, the inclination angle of the connecting line of the openings corresponding to the same microlens in different light blocking layers is the same as the inclination angle of the oblique light signal.

The openings in different light-blocking layers corresponding to the same microlens should have a lateral offset, and the connection lines of these openings in different light-blocking layers should pass through the corresponding optical sensing unit, so that the The oblique light signal can reach the optical sensing unit.

Wherein, the lateral spacing between two openings corresponding to the same microlens and located in two adjacent light-blocking layers may be equal or unequal.

Moreover, the vertical distance between two adjacent light blocking layers may also be equal or unequal.

For example, when the vertical distance between two adjacent light-blocking layers is equal, the lateral spacing between the openings in the two adjacent light-blocking layers corresponding to the same microlens is also equal.

Optionally, each microlens corresponds to an optical sensing unit of the optical fingerprint sensor 520, wherein the openings in different light blocking layers corresponding to the same microlens are used to collect the oblique light signal after being condensed by the microlens. Lead to the optical sensing unit corresponding to the microlens in turn.

Further, optionally, the connecting lines of the openings corresponding to the same microlens in different light blocking layers pass through the central area of the optical sensing unit corresponding to the microlens.

For example, the opening of the last light blocking layer can be arranged above the center of the corresponding optical sensing unit to ensure that the oblique light signal can reach the central area of the optical sensing unit, thereby achieving better photoelectric conversion efficiency.

For example, as shown in FIG. 22, the light reaching the microlens 511 at an angle i sequentially passes through the opening 5521 in the light-blocking layer 552, the opening 5531 in the light-blocking layer 553, and the block of the optical fingerprint sensor 520. The opening 5511 in the optical layer 551 finally reaches the optical sensing unit 521. Wherein, the opening 5531 is offset to the left by a certain distance relative to the opening 5521, and the opening 5511 is further offset to the left by a certain distance relative to the opening 5531, and the center of the opening 5521, the opening 5531 and the opening 5511 The wires can pass through the corresponding optical sensing unit 521, so that the oblique light can be guided.

Since the microlens has a condensing effect on the light, the more downward it is transmitted, the narrower the angle of the converged beam. Therefore, optionally, the apertures corresponding to the same microlens in different light-blocking layers are sequentially reduced from top to bottom, so that the light beam reaching the optical fingerprint sensor 520 is a narrow light beam, which realizes narrow-angle light reception. While ensuring the collimation, it can also effectively attenuate unnecessary light, and further improve the clarity of the optical fingerprint image collected by the optical fingerprint sensor 520. For example, as shown in FIG. 22, the apertures of the opening 5521, the opening 5531, and the opening 5511 corresponding to the same microlens 511 are sequentially reduced.

In Figure 21 and Figure 22, the last light-blocking layer reached by the oblique light signal is integrated in the optical fingerprint sensor 520, thereby ensuring the reliability of fingerprint recognition, and the remaining light-blocking layers can pass between adjacent light-blocking layers. Transparent media layer connection. For example, in FIG. 22, the light blocking layer 551 is integrated in the optical fingerprint sensor 520, the light blocking layer 552 and the light blocking layer 553 are connected by a transparent medium layer 561, and the light blocking layer 553 and the filter layer 530 are connected by a transparent medium layer 561. The dielectric layer 562 is connected. Preferably, the refractive index of the transparent medium layer 561 and the transparent medium layer 562 may be the same as the refractive index of the base material 512 of the microlens array 510, and the same as the refractive index of the microlens array 510, thereby reducing light rays caused by a sudden change in refractive index. loss.

However, the implementation of this application is not limited to this, and other methods can also be used to connect and fix the light blocking layer. For example, the light-blocking layer is fixed by a mechanical structure such as a bracket, or multiple light-blocking layers are pasted together by transparent glue or film.

Since the small holes on each light-blocking layer have a certain size, the tilt angle of the optical signal selected by the light-blocking layer is not a fixed value, but within a certain range, the collimation angle of the tilted light signal is preferably It is -4°～4°. For example, if the preset tilt angle is 30°, the tilt angle of the light signal actually received by the fingerprint sensor is 26°-34°.

In addition to the above-mentioned optical fiber collimation through the multi-layer light-blocking layer, the embodiment of the present application also provides other collimation methods, as shown in FIGS. 23-25.

Figure 23 shows the method of selecting the tilted light signal through the collimating hole 741. The hole of the collimating hole 741 is made of light-transmitting material or air, the wall of the hole is made of light-absorbing material, and the collimating hole is arranged vertically. When the vertical incident light is guided, when the collimating hole is inclined according to the receiving angle, the oblique light signal can be guided. For example, when the inclination angle of the collimating aperture 741 is β, the optical signal with the inclination angle β can be guided.

The collimation hole 741 is provided on the opaque substrate 740. When the finger 710 is pressed on the display screen 730, the oblique light signal 720 reflected by the finger can be guided to the fingerprint sensor 750 by the collimation hole 741. The fingerprint sensor 750 Fingerprint identification can be performed based on the received light signal.

Of course, the collimating hole 741 can also guide the first oblique light signal and the second oblique light signal described above to the fingerprint sensor 750.

The collimating hole shown in FIG. 24 guides the oblique light signal to the fingerprint sensor through total reflection, and the axis of the collimating hole is perpendicular to the surface of the display screen. The refractive index of the inside and outside of the collimating hole is different, and only the incident light signal conforming to the angle of total reflection is selected through the principle of total reflection. For example, the optical signal 720 is an optical signal conforming to the total reflection angle. After the optical signal 720 reaches the collimating aperture 742, total reflection occurs in the collimating aperture 742 to form an optical signal 760. The fingerprint sensor 750 can be based on the optical signal 760. Perform fingerprint recognition.

The selection of the tilted optical signal in the embodiment of the present application can also be achieved by tilting the collimator received vertically at a specific angle. As shown in FIG. 25, after the collimator 740 is tilted, the collimating aperture 743 can only pass oblique light signals at a specific angle, and light signals at other angles are blocked from the collimator. In this case, the fingerprint sensor 750 also needs to be tilted at a specific angle to receive the optical signal selected by the collimator 740.

The collimation process shown in FIG. 23 to FIG. 25 can all be implemented by optical fiber.

In addition to the structure of the microlens array described above, the method of the embodiment of the present application can also be applied to a fingerprint identification device with a large lens. As shown in FIG. 26, the fingerprint identification device includes a lens 770, and the lens 770 can converge the light signal 760 reflected by the finger to the fingerprint sensor 750.

It can be seen from FIG. 26 that in the range of the light-receiving angle of the lens 770, the image of the edge is actually generated by the oblique light signal. Therefore, the embodiment of the present application can emit the light signal within the edge of the field of view of the lens 770. Generate original image and smear image to achieve the purpose of distance detection.

In the structure shown in FIG. 26, the light emitting unit may be used to emit the first oblique light signal and the second oblique light signal on the edge area of the field angle of the lens 770.

If the light-emitting unit is a light-emitting pixel on an OLED screen, the first oblique light signal and the second oblique light signal may be formed by light signals emitted by light-emitting pixels on at least one light-emitting area 780 on the OLED screen, and the at least one light-emitting The area 780 is located at the edge area of the intersection area of the field of view of the lens 770 on the OLED screen.

The correction of fingerprint data mentioned in the embodiment of the present application may include increasing the signal strength or adjusting the size of the fingerprint image.

An embodiment of the present application also provides an electronic device, which includes the fingerprint recognition device in the various embodiments of the present application described above.

FIG. 27 is a schematic block diagram of an electronic device according to an embodiment of the present application. The electronic device 1000 includes a display screen 1010, a fingerprint identification device 1020, and a processor 1030. The fingerprint identification device 1020 can be arranged below the display screen 1010 to perform fingerprint identification on the fingers above the display screen 1010.

The display screen 1010 may be any display screen described above, and the display screen 1010 may be, for example, a self-luminous display screen, such as an OLED screen.

The display screen may be an ordinary non-folding display screen, and the display screen may also be a foldable display screen, or referred to as a flexible display screen.

The fingerprint identification device 1020 may be any of the fingerprint identification devices described above. To simplify the description, the details will not be repeated here.

The processor 1030 can be used to execute any of the above methods.

It should be noted that the sensor chip in the embodiment of the present application may also be referred to as a fingerprint sensor.

It should be noted that the terms used in the embodiments of the present application and the appended claims are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application.

For example, the singular forms of "a", "said", "above" and "the" used in the embodiments of this application and the appended claims are also intended to include plural forms, unless the context clearly indicates other forms. meaning.

Those skilled in the art may realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed in this document can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of the embodiments of the present application.

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

Those skilled in the art can clearly understand that, for the convenience and conciseness of description, the specific working process of the equipment, device and unit described above can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed electronic equipment, apparatus, and method may be implemented in other ways.

For example, the division of units or modules or components in the device embodiments described above is only a logical function division, and there may be other divisions in actual implementation. For example, multiple units or modules or components can be combined or integrated. To another system, or some units or modules or components can be ignored or not executed.

For another example, the aforementioned units/modules/components described as separate/display components may or may not be physically separated, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units/modules/components may be selected according to actual needs to achieve the objectives of the embodiments of the present application.

Finally, it should be noted that the mutual coupling or direct coupling or communication connection shown or discussed above may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms. .

The above content is only the specific implementation manners of the embodiments of the present application, but the protection scope of the embodiments of the present application is not limited thereto. Any person skilled in the art can easily think of within the technical scope disclosed in the embodiments of the present application. The change or replacement shall be covered within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of the present application should be subject to the protection scope of the claims.

Claims

A method for fingerprint identification, characterized in that the method is suitable for electronic equipment having a display screen and a fingerprint identification device arranged under the display screen, and the method includes:

Acquiring an original image generated by the fingerprint identification device according to the received first oblique light signal, where the first oblique light signal is an oblique light signal emitted by a light-emitting unit directed to the fingerprint identification device;

Obtain the smear image generated by the fingerprint identification device according to the received second oblique light signal, the second oblique light signal is the surface of the fingerprint identification device emitted by the light-emitting unit, and the fingerprint identification The oblique light signal reflected by the surface of the device and reflected by the lower surface of the display screen and reaching the fingerprint identification device;

The fingerprint data collected by the fingerprint identification device is corrected according to the distance X between the original image and the smear image, wherein the corrected fingerprint data is used for fingerprint identification.
The method according to claim 1, wherein the correcting the fingerprint data collected by the fingerprint identification device according to the distance X between the original image and the smear image comprises:

According to the distance X, determine the distance Y between the upper surface of the fingerprint identification device and the lower surface of the display screen;

According to the distance Y, the fingerprint data collected by the fingerprint identification device is corrected.
The method according to claim 2, wherein the relationship between the distance Y and the distance X is Y=k*X+b, wherein both k and b are constants.
The method according to claim 3, wherein k and b are pre-configured according to different distances Y and corresponding different distances X.
The method according to any one of claims 1 to 4, wherein the display screen is an organic light emitting diode OLED screen, and the first oblique light signal and the second oblique light signal are generated by the OLED It is formed by the light signals emitted by the light-emitting pixels on at least one light-emitting area on the screen.
The method according to claim 5, wherein the shape of the at least one light-emitting area is a circle.
The method according to claim 5 or 6, wherein the areas of different light-emitting regions in the at least one light-emitting region are different.
The method according to any one of claims 5-7, wherein the at least one light-emitting area includes three light-emitting areas, and the centers of the three light-emitting areas are not on a straight line.
The method according to any one of claims 1-8, wherein the inclination angle of the first oblique optical signal and the second oblique optical signal is 10°-50°.
The method according to any one of claims 1-9, wherein the fingerprint identification device comprises a light path guiding structure and a fingerprint sensor, and the fingerprint sensor comprises a sensing array with a plurality of optical sensing units, and the light path The guiding structure is used for guiding the first oblique light signal and the second oblique light signal to the sensing array.
The method according to claim 10, wherein the fingerprint sensor is further configured to receive the detection light signal emitted by the light-emitting unit that is irradiated on the finger and reflected by the finger, and generates the detection light signal according to the detection light signal. The fingerprint data.
The method according to claim 11, wherein the detection light signal is perpendicular or inclined with respect to the surface of the display screen.
A fingerprint identification device applied to an electronic device with a display screen, characterized in that the fingerprint identification device is configured to be arranged below the display screen, and the fingerprint identification device includes:

The optical path guiding structure is used to guide the first oblique light signal and the second oblique light signal to the sensing array of the fingerprint sensor, wherein the first oblique light signal is the oblique light signal emitted by the light-emitting unit directed to the fingerprint identification device The second oblique light signal is emitted by the light-emitting unit pointing to the surface of the fingerprint identification device, and reaches the fingerprint identification device after reflection on the surface of the fingerprint identification device and the bottom surface of the display screen Oblique light signal;

The fingerprint sensor includes a sensing array with a plurality of optical sensing units, the sensing array is used to generate an original image according to the first oblique light signal, and to generate a smear image according to the second oblique light signal, the The original image and the smear image are used to correct the fingerprint data collected by the fingerprint identification device, and the corrected fingerprint data is used for fingerprint identification.
The fingerprint identification device according to claim 13, wherein the light path guiding structure comprises a microlens array and at least one light blocking layer, and the microlens array is configured to be arranged between the display screen and the fingerprint sensor. Meanwhile, the microlens array includes a plurality of microlenses, and the microlenses are used to converge the received optical signals,

The at least one light-blocking layer is arranged between the microlens array and the fingerprint sensor, wherein each light-blocking layer includes a plurality of openings corresponding to the plurality of microlenses, and is converged by each microlens. The latter oblique light signal passes through the openings corresponding to the microlenses in different light-blocking layers, and reaches the optical sensing unit of the fingerprint sensor.
The fingerprint identification device according to claim 14, wherein the projection of the condensing surface of the microlens on a plane perpendicular to the optical axis is a circle or a square.
The fingerprint identification device according to claim 14 or 15, wherein the last light-blocking layer in the at least one light-blocking layer is integrated in the fingerprint sensor.
The fingerprint identification device according to any one of claims 14-16, wherein each of the microlenses corresponds to an optical sensing unit of the fingerprint sensor, wherein the same microlens in different light-blocking layers The opening corresponding to the lens is used for guiding the first oblique light signal and the second oblique light signal collected by the microlens to the optical sensing unit corresponding to the microlens in sequence.
The fingerprint identification device according to any one of claims 13-17, wherein the fingerprint identification device further comprises a filter layer, and the filter layer is used to transmit light signals in a specific wavelength range.
The fingerprint identification device of claim 18, wherein the filter layer is integrated on the fingerprint sensor.
The fingerprint identification device of claim 18, wherein the filter layer is arranged above the microlens array, and an air layer or a transparent layer is filled between the filter layer and the microlens array. Glue layer.
22. The fingerprint identification device of claim 20, wherein the transparent adhesive layer is surrounded by a light-shielding material.
The fingerprint identification device according to claim 13, wherein the optical path guiding structure comprises a lens, and the lens is used to converge the first oblique light signal and the second oblique light signal to the fingerprint sensor The light emitting unit is configured to emit the first oblique light signal and the second oblique light signal on the edge area of the field angle of the lens.
The fingerprint identification device according to claim 22, wherein the light-emitting unit is a light-emitting pixel of an organic light-emitting diode OLED screen, and the first oblique light signal and the second oblique light signal are generated by the OLED screen. The at least one light-emitting area is formed by the light signal emitted by the light-emitting pixel on the at least one light-emitting area, and the at least one light-emitting area is located at the edge area of the boundary area of the field angle of the lens on the OLED screen.
The fingerprint identification device according to any one of claims 13-23, wherein the fingerprint sensor is further configured to receive a detection light signal emitted by the light-emitting unit that is irradiated on the finger and reflected by the finger, And generate the fingerprint data according to the detected light signal.
The fingerprint identification device according to claim 24, wherein the detection light signal is perpendicular or inclined with respect to the surface of the fingerprint identification device.
The fingerprint identification device according to any one of claims 13-25, wherein the display screen is an organic light emitting diode OLED screen, and the first oblique light signal and the second oblique light signal are The OLED screen is formed by light signals emitted by light-emitting pixels on at least one light-emitting area.
The fingerprint identification device of claim 26, wherein the shape of the at least one light-emitting area is a circle.
The fingerprint identification device according to claim 26 or 27, wherein the areas of different light-emitting areas in the at least one light-emitting area are different.
The fingerprint identification device according to any one of claims 26-28, wherein the at least one light-emitting area includes three light-emitting areas, and the centers of the three light-emitting areas are not on a straight line.
The fingerprint identification device according to any one of claims 13-29, wherein the inclination angle of the first oblique light signal and the second oblique light signal is 10°-50°.
An electronic device, characterized in that it comprises:

Display screen

And the fingerprint identification device according to any one of claims 13 to 30;

The processor is configured to obtain the original image and the smear image, and correct the fingerprint data collected by the fingerprint identification device according to the distance X between the original image and the smear image, wherein: The corrected fingerprint data is used for fingerprint identification.
The electronic device according to claim 31, wherein the processor is configured to:

According to the distance X, determine the distance Y between the upper surface of the fingerprint identification device and the lower surface of the display screen;

According to the distance Y, the fingerprint data collected by the fingerprint identification device is corrected.
The electronic device according to claim 32, wherein the relationship between the distance Y and the distance X is Y=k*X+b, wherein both k and b are constants.
The electronic device according to claim 33, wherein k and b are pre-configured according to different distances Y and corresponding different distances X.
The electronic device according to any one of claims 31-34, wherein the display screen is an organic light emitting diode OLED screen, and the first oblique light signal and the second oblique light signal are generated by the It is formed by the light signal emitted by the light-emitting pixel on at least one light-emitting area on the OLED screen.
The electronic device according to claim 35, wherein the shape of the at least one light-emitting area is a circle.
The electronic device according to claim 35 or 36, wherein the areas of different light-emitting areas in the at least one light-emitting area are different.
The electronic device according to any one of claims 35-37, wherein the at least one light-emitting area comprises three light-emitting areas, and the centers of the three light-emitting areas are not on a straight line.
The electronic device according to any one of claims 31-38, wherein the inclination angle of the first oblique optical signal and the second oblique optical signal is 10°-50°.