CN110945525A

CN110945525A - Method for fingerprint identification, fingerprint identification device and electronic equipment

Info

Publication number: CN110945525A
Application number: CN201980002446.9A
Authority: CN
Inventors: 谢浩
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2020-03-31
Anticipated expiration: 2039-10-31
Also published as: WO2021081891A1; CN110945525B

Abstract

The embodiment of the application discloses a method for fingerprint identification, a fingerprint identification device and electronic equipment, which can improve the quality of a fingerprint image. The method is suitable for the electronic equipment with a display screen and a fingerprint identification device arranged below the display screen, and comprises the following steps: acquiring an original image generated by the fingerprint identification device according to a received first inclined optical signal, wherein the first inclined optical signal is an inclined optical signal which is emitted by a light-emitting unit and points to the fingerprint identification device; acquiring a smear image generated by the fingerprint identification device according to a received second inclined optical signal, wherein the second inclined optical signal is an inclined optical signal which is emitted by the light-emitting unit, points to the surface of the fingerprint identification device, and reaches the fingerprint identification device after being reflected by the surface of the fingerprint identification device and the lower surface of the display screen; and correcting the fingerprint data acquired 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.

Description

Method for fingerprint identification, fingerprint identification device and electronic equipment

Technical Field

The present invention relates to the field of fingerprint identification, and more particularly, to a method for fingerprint identification, a fingerprint identification apparatus, and an electronic device.

Background

With the rapid development of the mobile phone industry, the fingerprint identification technology is more and more emphasized by people, and the practicability of the under-screen fingerprint identification technology becomes a requirement of the public. The most applied of the technology of fingerprint identification under the screen is the technology of optical fingerprint identification under the screen, the technology of optical fingerprint identification under the screen can adopt the light that the screen sent as the light source, the light that the screen sent can carry the fingerprint information of finger behind the finger of screen top, and the light signal that carries fingerprint information can be received by the fingerprint identification device to carry out fingerprint identification.

The fingerprint identification device needs to be installed below the screen to realize the function of fingerprint detection, but the distance between the lower surface of the screen and the upper surface of the fingerprint identification device is difficult to test accurately when leaving the factory, namely the installation position of the fingerprint identification device is difficult to test accurately, and the distance can only be ensured within a certain range through a structure processing technology at the present stage. In addition, when consumers use the screen, different people press the screen very differently, and the distance fluctuates due to different pressing forces. Since the size of the distance affects the quality of the fingerprint image, how to improve the quality of the fingerprint image in this case is a problem that needs to be solved.

Disclosure of Invention

The embodiment of the application provides a method for fingerprint identification, a fingerprint identification device and electronic equipment, which can improve the quality of a fingerprint image.

In a first aspect, a method for fingerprint identification is provided, the method being applied to an electronic device having a display screen and a fingerprint identification device disposed below the display screen, the method comprising: acquiring an original image generated by a fingerprint identification device according to a received first inclined optical signal, wherein the first inclined optical signal is an inclined optical signal which is emitted by a light-emitting unit and points to the fingerprint identification device; acquiring a smear image generated by the fingerprint identification device according to a received second inclined optical signal, wherein the second inclined optical signal is an inclined optical signal which is emitted by the light-emitting unit, points to the surface of the fingerprint identification device, and reaches the fingerprint identification device after being reflected by the surface of the fingerprint identification device and the lower surface of the display screen; and correcting the fingerprint data acquired 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.

According to the technical scheme, the inclined light signals are used as the incident light signals, the fingerprint data are corrected according to the original images and the smear images generated by the inclined light signals, and the corrected fingerprint data can reflect the fingerprint information of the finger more accurately, so that the quality of the fingerprint image can be improved, and the fingerprint identification effect is improved.

In some possible implementations, the modifying the fingerprint data collected by the fingerprint identification device according to the distance X between the original image and the smear image includes: determining a 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.

In some possible implementations, 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 configured in advance 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 formed by light signals emitted by light emitting pixels on at least one light emitting area on the OLED screen.

In some possible implementations, the at least one light emitting area is circular in shape.

In some possible implementations, the areas of different light emitting areas in the at least one light emitting area are different.

In some possible implementations, the at least one light-emitting area includes 3 light-emitting areas, and centers of the 3 light-emitting areas are not in a straight line, so that the accuracy of the measured distance X can be improved.

In some possible implementations, the first and second tilted optical signals have a tilt angle of 10 ° to 50 °.

In some possible implementations, the fingerprint identification device includes an optical path guiding structure and a fingerprint sensor, the fingerprint sensor includes a sensing array having a plurality of optical sensing units, and the optical path guiding structure is configured to guide the first oblique optical signal and the second oblique optical signal 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 optical signal emitted by the light emitting unit, where the detection optical signal is emitted by the light emitting unit, and then the detection optical signal is reflected by the finger, and generate the fingerprint data according to the detection optical signal.

In some possible implementations, the detected light signal is perpendicular or oblique to a surface of the display screen.

In a second aspect, a fingerprint recognition device is provided, the fingerprint recognition device is configured to be disposed below the display screen, and the fingerprint recognition device includes: the light path guiding structure is used for guiding a first inclined light signal and a second inclined light signal to an induction array of a fingerprint sensor, wherein the first inclined light signal is an inclined light signal which is emitted by a light emitting unit and points to the fingerprint identification device, the second inclined light signal is an inclined light signal which is emitted by the light emitting unit and points to the surface of the fingerprint identification device, and the inclined light signal reaches the fingerprint identification device after being reflected by the surface of the fingerprint identification device and the lower surface of the display screen; the fingerprint sensor comprises a sensing array with a plurality of optical sensing units, wherein the sensing array is used for generating an original image according to the first inclined optical signal and generating a smear image according to the second inclined optical signal, the original image and the smear image are used for correcting fingerprint data collected by the fingerprint identification device, and the corrected fingerprint data are used for fingerprint identification.

In some possible implementations, the optical path guiding structure includes a microlens array and at least one light blocking layer, the microlens array is disposed between the display screen and the fingerprint sensor, the microlens array includes a plurality of microlenses for converging received optical signals, and the at least one light blocking layer is disposed between the microlens array and the fingerprint sensor, where each light blocking layer includes a plurality of openings corresponding to the microlenses, respectively, and oblique optical signals converged by each microlens pass through the openings corresponding to the microlenses in different light blocking layers to reach the optical sensing unit of the fingerprint sensor.

In some possible implementations, the projection of the light-gathering surface of the microlens on a plane perpendicular to its optical axis is circular or square.

In some possible implementations, the light collection surface is spherical or aspherical.

In some possible implementations, the curvatures of the light-condensing surfaces in the respective directions are the same.

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

In some possible implementations, 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 optical signal and the second oblique optical signal.

In some possible implementations, a last light-blocking layer of the at least one light-blocking layer is integrated in the fingerprint sensor.

In some possible implementations, each of the microlenses corresponds to one optical sensing unit of the fingerprint sensor, wherein the openings corresponding to the same microlens in different light blocking layers are used for sequentially guiding the first oblique optical signal and the second oblique optical signal converged by the microlenses to the optical sensing unit corresponding to the microlens.

In some possible implementations, a line connecting centers of the openings corresponding to the same microlens in different light blocking layers passes through a central region of the optical sensing unit corresponding to the microlens.

In some possible implementations, the optical path guiding structure includes a microlens array and a collimating aperture, the microlens array is configured to be disposed between the display screen and the fingerprint sensor, the microlens array includes a plurality of microlenses, the microlenses are configured to converge the received optical signals, the collimating aperture is disposed between the microlens array and the fingerprint sensor, and the collimating aperture is configured to guide the first oblique optical signal and the second oblique optical signal to the fingerprint sensor.

In some possible implementations, the collimating aperture has a hole therein made of air or a light-transmitting material, a hole wall made of a light-absorbing material, and an axis of the collimating aperture has an inclination angle equal to an inclination angle of the first inclined optical signal and the second inclined optical signal.

In some possible implementations, the inner core material and the outer core material of the collimating aperture are configured to totally reflect the first tilted optical signal and the second tilted optical signal transmitted within the optical fiber.

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

In some possible implementations, the fingerprint identification device further includes a filter layer for transmitting optical signals within a specific wavelength range.

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

In some possible implementations, the filter layer is disposed above the microlens array, and an air layer or a transparent adhesive 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 for converging the first oblique optical signal and the second oblique optical signal to the fingerprint sensor, and the light emitting unit is configured to emit the first oblique optical signal and the second oblique optical signal on an edge area of a 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 formed by light signals emitted by the light emitting pixel on at least one light emitting area on the OLED screen, where the at least one light emitting area is located at an edge area of an intersection area with a field angle of the lens on the OLED screen.

In some possible implementations, the fingerprint sensor is further configured to receive a detection optical signal emitted by the light emitting unit, wherein the detection optical signal is emitted by the light emitting unit, irradiates the finger and is reflected by the finger, and generate the fingerprint data according to the detection optical signal.

In some possible implementations, the detected light signal is perpendicular or oblique to the surface of the fingerprint recognition device.

In some possible implementations, the at least one light-emitting area includes 3 light-emitting areas, and centers of the 3 light-emitting areas are not on a straight line.

In a third aspect, an electronic device is provided, including: the fingerprint recognition device comprises a display screen, a fingerprint recognition device in the second aspect and any one of the possible implementation manners of the second aspect, and a processor, wherein the processor is used for acquiring the original image and the smear image, and correcting fingerprint data collected by the fingerprint recognition device according to a distance X between the original image and the smear image, and the corrected fingerprint data is used for fingerprint recognition.

In some possible implementations, the processor is to: determining a 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.

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 direction a-a'.

Fig. 3 is another schematic structural diagram 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 direction a-a'.

Fig. 5 is an architecture diagram of a fingerprint recognition device applied in accordance with an embodiment of the present application.

Fig. 6 is a schematic flow chart of a method for fingerprint identification according to an embodiment of the present application.

Fig. 7 is a schematic diagram of a generation manner of an original image and a smear image according to an embodiment of the present application.

Fig. 8 is a schematic diagram of the distance X provided in the embodiment of the present application.

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

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

Fig. 12 is a schematic diagram of a light-emitting region according to an embodiment of the present disclosure.

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

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

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

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

Fig. 18 is a schematic view of a possible structure of the fingerprint recognition apparatus shown in fig. 14.

Fig. 19 is a schematic diagram of a possible structure of the fingerprint recognition apparatus shown in fig. 14.

Fig. 20 is a schematic diagram of a possible structure of the fingerprint recognition apparatus shown in fig. 14.

Fig. 21 is a schematic diagram of a possible structure of the fingerprint recognition apparatus shown in fig. 14.

Fig. 22 is a schematic diagram of a possible structure of the fingerprint recognition apparatus shown in fig. 14.

Fig. 23 is a schematic structural view of a collimating aperture provided in an embodiment of the present application.

FIG. 24 is a schematic view of another collimating aperture provided in embodiments of the present application.

FIG. 25 is a schematic diagram of another collimating aperture provided in embodiments of the present application.

Fig. 26 is a schematic diagram of a possible structure of the fingerprint recognition apparatus shown in fig. 14.

Fig. 27 is a schematic block diagram of an electronic device provided in an embodiment of the present application.

Detailed Description

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

It should be understood that the embodiments of the present 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, and the embodiments of the present application are only illustrated by way of example of an optical fingerprint system, but should not constitute any limitation to the embodiments of the present application, and the embodiments of the present application are also applicable to other systems using optical, ultrasonic or other imaging technologies, and the like.

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

Optical underscreen fingerprint identification technology uses light returned from the top surface of a device display assembly for fingerprint sensing and other sensing operations. The returning light carries information about an object (e.g., a finger) in contact with the top surface, and by collecting and detecting the returning light, a specific optical sensor module located below the display screen is realized. The design of the optical sensor module may be such that the desired optical imaging is achieved by appropriately configuring the optical elements for collecting and detecting the returned light.

Fig. 1 and 2 show schematic views of electronic devices to which embodiments of the present application may be applied. Fig. 1 is an orientation diagram of an electronic device 10, and fig. 2 is a partial cross-sectional diagram of the electronic device 10 shown in fig. 1 along a 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 disposed in a local area below the display screen 120. The optical fingerprint module 130 includes an optical fingerprint sensor including a sensing array 133 having a plurality of optical sensing units 131 (which may also be referred to as photosensitive pixels, pixel units, etc.). The sensing array 133 is located in an area or a sensing area thereof, which is the fingerprint detection area 103 (also called a fingerprint collection area, a fingerprint identification area, etc.) of the optical fingerprint module 130. As shown in fig. 1, the fingerprint detection area 103 is located in a display area of the display screen 120. In an alternative embodiment, the optical fingerprint module 130 may be disposed at other positions, such as the side of the display screen 120 or the edge opaque region of the electronic device 10, and the optical path is designed to guide the optical signal from at least a part of the display region of the display screen 120 to the optical fingerprint module 130, so that the fingerprint detection region 103 is actually located in the display region 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, by designing an optical path such as lens imaging, a reflective folded optical path, or other optical path designs such as light converging or reflecting, the area of the fingerprint detection area 103 of the optical fingerprint module 130 may be larger than the area of the sensing array 133 of the optical fingerprint module 130. In other alternative implementations, if the light path is guided by, for example, light collimation, the fingerprint detection area 103 of the optical fingerprint module 130 may be designed to substantially coincide with the area of the sensing array of the optical fingerprint module 130.

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

As an alternative implementation, as shown in FIG. 1, the optical fingerprint module 130 includes a light detection portion 134 and an optical assembly 132. The light detecting portion 134 includes the sensing array 133 and a reading circuit and other auxiliary circuits electrically connected to the sensing array 133, which can be fabricated on a chip (Die) by a semiconductor process, such as an optical imaging chip or an optical fingerprint sensor. The sensing array 133 is specifically a Photo detector (Photo detector) array, which includes a plurality of Photo detectors distributed in an array, and the Photo detectors can be used as the optical sensing units as described above. The optical assembly 132 may be disposed above the sensing array 133 of the light detecting portion 134, and may specifically include a Filter (Filter) for filtering out ambient light penetrating through the finger, a light guiding layer or a light path guiding structure for guiding reflected light reflected from the surface of the finger to the sensing array 133 for optical detection, and other optical elements.

In particular implementations, the optical assembly 132 may be packaged with the same optical fingerprint component as the light detection portion 134. For example, the optical component 132 may be packaged in the same optical fingerprint chip as the optical detection portion 134, or the optical component 132 may be disposed outside the chip where the optical detection portion 134 is located, for example, the optical component 132 is attached to the chip, or some components of the optical component 132 are integrated into the chip.

For example, the light guide layer may specifically be a Collimator (collimater) layer manufactured on a semiconductor silicon wafer, and the collimater unit may specifically be a small hole, and in reflected light reflected from a finger, light perpendicularly incident to the collimater unit may pass through and be received by an optical sensing unit below the collimater unit, and light with an excessively large incident angle is attenuated by multiple reflections inside the collimater unit, so that each optical sensing unit can basically only receive reflected light reflected from a fingerprint pattern directly above the optical sensing unit, and the sensing array 133 can detect a fingerprint image of the finger.

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

In other implementations, the light guide layer or the light path guiding structure may also specifically adopt a Micro-Lens (Micro-Lens) layer, the Micro-Lens layer has a Micro-Lens array formed by a plurality of Micro-lenses, which may be formed above the sensing array 133 of the light detecting portion 134 through a semiconductor growth process or other processes, and each Micro-Lens may respectively correspond to one of the sensing units of the sensing array 133. And other optical film layers, such as a dielectric layer or a passivation layer, can be formed between the microlens layer and the sensing unit. More specifically, a light blocking layer (or referred to as a light shielding layer, a light blocking layer, etc.) having micro holes (or referred to as open holes) may be further included between the microlens layer and the sensing unit, wherein the micro holes are formed between the corresponding microlenses and the sensing unit, and the light blocking layer may block optical interference between adjacent microlenses and the sensing unit, and enable light corresponding to the sensing unit to be converged into the micro holes through the microlenses and transmitted to the sensing unit through the micro holes for optical fingerprint imaging.

It should be understood that several implementations of the light guiding layer or the light path guiding structure described above may be used alone or in combination. For example, a microlens layer may be further disposed above or below the collimator layer or the optical lens layer. Of course, when the collimator layer or the optical lens layer is used in combination with the microlens layer, the specific lamination structure or optical path thereof may need to be adjusted according to actual needs.

As an alternative implementation manner, the display screen 120 may adopt a display screen having a self-Light Emitting display unit, such as an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. Taking an OLED display screen as an example, the optical fingerprint module 130 may use a display unit (i.e., an OLED light source) of the OLED display screen 120 located in the fingerprint detection area 103 as an excitation light source for optical fingerprint detection. When the finger 140 is pressed against the fingerprint detection area 103, the display 120 emits a beam of light 111 towards the target finger 140 above the fingerprint detection area 103, and the light 111 is reflected at the surface of the finger 140 to form reflected light or scattered light by scattering inside the finger 140. In the related patent application, the above-mentioned reflected light and scattered light are collectively referred to as reflected light for convenience of description. Because the ridges (ridges) 141 and the valleys (valley)142 of the fingerprint have different light reflection capabilities, the reflected light 151 from the ridges and the reflected light 152 from the valleys of the fingerprint have different light intensities, and after passing through the optical assembly 132, the reflected light is received by the sensing array 133 in the optical fingerprint module 130 and converted into corresponding electrical signals, i.e., fingerprint detection signals; fingerprint image data can be obtained based on the fingerprint detection signal, and fingerprint matching verification can be further performed, so that an optical fingerprint identification function is realized in the electronic device 10.

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

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

On the other hand, in some implementation manners, the optical fingerprint module 130 may only include one optical fingerprint sensor, and the area of the fingerprint detection area 103 of the optical fingerprint module 130 is small and the position is fixed, so that the user needs to press the finger to the specific position of the fingerprint detection area 103 when inputting the fingerprint, otherwise the optical fingerprint module 130 may not collect the fingerprint image and cause the user experience to be poor. In other alternative embodiments, the optical fingerprint module 130 may specifically include a plurality of optical fingerprint sensors. A plurality of optics fingerprint sensor can set up side by side through the concatenation mode the below of display screen 120, just a plurality of optics fingerprint sensor's response area constitutes jointly optics fingerprint module 130's fingerprint detection area 103. Thereby the fingerprint detection area 103 of optical fingerprint module 130 can extend to the main area of the lower half of display screen, extend to the finger and press the region conventionally promptly to realize blind formula fingerprint input operation of pressing. Further, when the number of the optical fingerprint sensors is sufficient, the fingerprint detection area 103 may also be extended to a half display area or even the entire display area, thereby realizing half-screen or full-screen fingerprint detection.

For example, in the electronic device 10 shown in fig. 3 and 4, when the optical fingerprint device 130 in the electronic device 10 includes a plurality of optical fingerprint sensors, the plurality of optical fingerprint sensors may be arranged side by side below the display screen 120 by, for example, splicing, and the sensing areas of the plurality of optical fingerprint sensors together form the fingerprint detection area 103 of the optical fingerprint device 130.

Optionally, corresponding to a plurality of optical fingerprint sensors of the optical fingerprint apparatus 130, there may be a plurality of optical path guiding structures in the optical component 132, where each optical path guiding structure corresponds to one optical fingerprint sensor, and is attached to and disposed above the corresponding optical fingerprint sensor. Alternatively, the plurality of optical fingerprint sensors may share an integral optical path directing structure, i.e. the optical path directing structure has an area large enough to cover the sensing array of the plurality of optical fingerprint sensors. In addition, the optical assembly 132 may further include other optical elements, such as a Filter (Filter) or other optical film, which may be disposed between the optical path guiding structure and the optical fingerprint sensor or between the display screen 120 and the optical path guiding structure, and is mainly used for isolating the influence of external interference light on the optical fingerprint detection. The optical filter may be configured to filter ambient light that penetrates through a finger and enters the optical fingerprint sensors through the display screen 120, and similar to the optical path guiding structure, the optical filter may be respectively disposed for each optical fingerprint sensor to filter interference light, or may also cover the plurality of optical fingerprint sensors simultaneously with one large-area optical filter.

The light path modulator can also be replaced by an optical Lens (Lens), and a small hole formed by a shading material above the optical Lens is matched with the optical Lens to converge fingerprint detection light to an optical fingerprint sensor below the optical Lens so as to realize fingerprint imaging. Similarly, each optical fingerprint sensor may be respectively configured with an optical lens to perform fingerprint imaging, or the 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 or more sensing arrays to perform optical imaging, so as to reduce the imaging distance and enhance the imaging effect.

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

The optical fingerprint identification technology under the screen generally adopts light emitted by the screen as a light source, light signals emitted by the screen reach a finger above the screen, the light signals reflected or scattered by the finger carry fingerprint information of the finger, and the light signals carrying the fingerprint information can be received by a fingerprint sensor below the screen so as to carry out fingerprint identification.

The existing optical fingerprint identification under the screen is realized in mass production under the OLED screen at present, the OLED screen utilizes the light transmission characteristic of the OLED screen, and the light signal emitted by the screen is irradiated to a 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 recognition device 330 is disposed below the display screen 320, the fingerprint recognition device 330 includes a light path guiding structure 331 and a fingerprint sensor 332, the fingerprint sensor 332 can be electrically connected to a circuit board 333, and the circuit board 333 can be a substrate or a Flexible Printed Circuit (FPC). The display screen 320 may include a light emitting layer 322, a component 321 located above the light emitting layer 322, and a component 323 located below the light emitting layer 322. In the fingerprint identification process, the finger 310 may press the fingerprint detection area on the display screen, after the light signal emitted by the display screen 320 irradiates the finger, the light signal is reflected by the finger and received by the fingerprint sensor 332 below the display screen 320, and the fingerprint sensor 332 may generate the fingerprint image of the finger 310 according to the received light signal, so as to perform fingerprint identification.

The fingerprint identification device needs to be installed in the below of screen in order to realize the function of fingerprint detection, but the distance Y between screen lower surface and the fingerprint identification device upper surface is difficult to test accurately when dispatching from the factory, and fingerprint identification device's mounted position is difficult to test accurately promptly, can only guarantee distance Y at a certain within range through structure processing technology at present stage. In addition, when consumers use the screen, different people press the screen very differently, and the distance Y fluctuates due to different pressing forces.

Distance Y's size can exert an influence to fingerprint image's quality, for example, distance Y after the installation is different with the distance Y of preconfiguration, can lead to the light signal that fingerprint identification device received to reduce, thereby influence fingerprint image's quality, for example, distance Y's size still can influence fingerprint image's size again, consequently, if can acquire distance Y's accurate value in real time, just can carry out real-time correction to fingerprint image through the algorithm, thereby guarantee that fingerprint image can not worsen because of distance Y, and then can effectively promote optical fingerprint performance.

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

S610, acquiring an original image generated by the fingerprint identification device according to the received first inclined optical signal, wherein the first inclined optical signal is an inclined optical signal which is emitted by the light emitting unit and points to the fingerprint identification device.

And S620, acquiring a smear image generated by the fingerprint identification device according to a received second inclined optical signal, wherein the second inclined optical signal is an inclined optical signal which is emitted by the light-emitting unit, points to the surface of the fingerprint identification device, and reaches the fingerprint identification device after being reflected by the surface of the fingerprint identification device and the lower surface of the display screen.

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

In the embodiment of the present application, the first oblique optical signal is an oblique optical signal emitted by the light emitting unit and directly irradiated to the fingerprint identification device, and the second oblique optical signal is an oblique optical signal emitted by the light emitting unit and reflected by the surface of the device before reaching the fingerprint identification device, which will be described in detail with reference to fig. 7.

The light-emitting layer 322 in the display screen 320 may emit a light signal of a preset pattern, wherein a portion of the light signal 361 (first oblique light signal) emitted by the light-emitting layer 322 is directly directed to the fingerprint identification device, and the fingerprint identification device may generate the original image 340 according to the received light signal 361. Another portion of the light signals 362,363 (second oblique light signals) emitted by the luminescent layer 322 are reflected off the device surface and reach the fingerprint identification device, which generates a smear image 350 based on the received

light signals

362, 363.

It can be understood that if it is a vertical light signal, there is no smear image, and thus, the embodiment of the present application generates a smear image using a tilted light signal.

The second tilted optical signal shown in fig. 7 may include two types of optical signals, one is tilted optical signal 362 and the other is tilted optical signal 363. The oblique optical signal 362 is an oblique optical signal emitted by the light emitting layer 362 and reflected at the interface between the upper surface of the display screen and the air to reach the fingerprint identification device 330, and the oblique optical signal 363 is an oblique optical signal emitted by the light emitting layer to be directed to the fingerprint identification device 330, reflected at the upper surface of the fingerprint identification device to reach the lower surface of the display screen, reflected at the lower surface of the display screen to reach the fingerprint identification device again, that is, the oblique optical signal 363 is an oblique optical signal emitted by the light emitting layer 322 and reflected twice to reach the fingerprint identification device.

The signal intensity of the oblique optical signal 363 is greater than that of the oblique optical signal 362, and the smear image generated according to the oblique optical signal 363 can better reflect the distance Y between the fingerprint identification device and the display screen, so the embodiment of the present application mainly considers the influence of the oblique optical signal 363 on the smear image.

As can be seen from fig. 7, the smear image 350 generated according to the second oblique light signal has a shift or offset in the horizontal direction with respect to 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, the distance X is in positive correlation with the distance Y, and the larger the distance Y is, the larger the distance X is. Therefore, the embodiment of the application can utilize the positive correlation between the distance X and the distance Y, and can correct the fingerprint data acquired by the fingerprint identification device by detecting the distance X, thereby improving the fingerprint identification performance.

The distance X may be understood as the offset distance of the smear image with respect to the original image.

The relative positional relationship between the smear image and the original image in fig. 7 and 8 is merely an example, and does not represent an actual positional relationship. The distance between the smear image and the original image in the vertical direction shown in fig. 7 and 8 does not represent the actual distance, but rather represents the smear image and the original image more clearly, and the smear image and the original image are generally in a horizontal direction in practice.

In the embodiment of the present application, besides the OLED screen may be used as the light emitting unit, an external light source may also be used as the light emitting unit, such as a Light Emitting Diode (LED) lamp, the LED lamp may be disposed between the lower side of the display screen and the upper surface of the fingerprint identification device, and the LED lamp is offset by a certain distance with respect to the fingerprint identification device, so as to achieve the purpose that the LED lamp can emit an oblique light signal to the fingerprint identification device.

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

The embodiment of the application can directly correct the fingerprint data according to the distance X, for example, before the fingerprint identification device leaves a factory, the fingerprint data corresponding to different distances X are obtained through testing, and then correction parameters corresponding to different distances X are determined. After the fingerprint identification device is installed in the electronic equipment, the fingerprint data is corrected by measuring the distance X.

For another example, the fingerprint data is corrected according to the distance X, and the distance Y between the upper surface of the fingerprint identification device and the lower surface of the display screen is determined according to the distance X, and the fingerprint data collected by the fingerprint identification device is corrected according to the distance Y. Before the fingerprint identification device leaves a factory, a plurality of distances Y (Y1, Y2, … and Yn) are adjusted through a jig on a specific screen, and corresponding smear distances X (X1, X2, … and Xn) are respectively tested, so that the corresponding relation between X and Y is established, wherein n is an integer greater than or equal to 2. After the fingerprint identification device is installed on the electronic equipment, the distance X is measured, the distance Y is determined according to the corresponding relation, 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 in a substantially linear relationship, and the relationship between the distance X and the distance Y may be represented as Y ═ k × X + b, where k and b are constants.

Before the device leaves the factory, the plurality of distances X corresponding to the plurality of distances Y may be obtained through the above process, so that the parameters k and b may be obtained through calculation, that is, k and b may be configured in advance according to different distances Y and corresponding different distances X. Because the distance Y and the distance X are in a linear relation, k and b can be obtained theoretically through two groups of data, but in order to eliminate test errors as much as possible and improve the accuracy, at least 3 groups of data can be tested to obtain solutions of a plurality of groups of k and b, and then the average value of the solutions is calculated.

After the test is completed, k and b obtained by the test can be written into a flash memory or a One Time Programmable (OTP) memory built in the fingerprint identification device, or stored into the whole machine for use when a whole machine algorithm is called.

Fig. 9 is a schematic flowchart of a method of acquiring the correspondence between the distance X and the distance Y.

Before the distance is tested, the fingerprint sensor may be initialized, and the OLED display displays a preset pattern and emits an optical signal toward the fingerprint sensor. By setting the distance Yn, the corresponding distance Xn at the distance Yn is measured, n being 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 by a barycentric algorithm. By testing the corresponding distance X under different distances Y, the parameters k and b can be solved by substituting the formula Y ═ k × X + b.

The correspondence between the distance Y and the distance X can be calculated from three calibration points as shown in fig. 10, and the parameters k and b can be calculated.

Fig. 11 is a schematic flowchart showing a process of actually detecting a distance. After the preset pattern is initialized, the center between the smear image and the original image is calculated by using a center algorithm, 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, it is considered to average the data collected multiple times to minimize the error.

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 above-mentioned predetermined pattern refers to a pattern formed by the at least one light emitting region.

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

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

In the case that the light emitting area shown in fig. 12 is circular, a circular pattern may be displayed on the display screen, and based on the light signal emitted from the light emitting area, the fingerprint sensor may generate an original image (or an original circle spot) and a smear image (or a smear circle spot), and calculate the distance between the original image and the smear image through a centroid algorithm, thereby correcting the obtained fingerprint data.

In order to improve the detection accuracy, a plurality of light emitting areas may be formed on the display screen, as shown in fig. 12, 2 or 3 circular spots may be displayed on the display screen, so that the fingerprint sensor may generate a plurality of original images and a plurality of corresponding smear images, and the calculated distance Y is more accurate according to the distance between the plurality of original images and the plurality of corresponding smear images.

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 diameters of different light emitting areas may be different.

In addition, in order to detect the distances between the original image and the smear image in different directions, the display screen may include 3 light-emitting areas, and the centers of the 3 light-emitting areas are not in a straight line, that is, the centers of the 3 light-emitting areas may form a triangle. As shown in fig. 12, the connection line of the centers of the 3 circular spots is a triangle. Of course, the embodiment of the present application may also adopt more than 3 light emitting areas as long as the centers of the 3 light emitting areas are not in a straight line.

Fig. 7 shows a schematic view of the image generated on the fingerprint sensor when 3 circular spot areas on the light emitting area 322 are illuminated. The fingerprint sensor may generate 3 raw images 340 and 3 smear images 350 corresponding to the 3 raw images 340. And then, respectively calculating the distance between the 3 original images and the 3 smear images, determining the distance Y, and further correcting the fingerprint data.

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

The fingerprint identification device in the embodiment of the present application may include an optical path guiding structure and a fingerprint sensor, and the fingerprint sensor may include a sensing array having a plurality of sensing units, and the optical path guiding structure is configured to guide the first oblique optical signal and the second oblique optical signal to the sensing array.

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

It is understood that the optical path directing structure is configured such that the first oblique optical signal and the second oblique optical signal received by the fingerprint sensor are substantially parallel, that is, the oblique optical signal 361 and the oblique optical signal 362 shown in fig. 7 are substantially parallel, and the oblique optical signal 361 and the oblique optical signal 363 are substantially parallel.

The fingerprint sensor can also be used for receiving detection optical signals which are emitted by the light-emitting unit, irradiate the finger and are reflected by the finger, and generating fingerprint data according to the detection optical signals.

The optical signal for detecting the distance is described above as a tilted optical signal, but the embodiment of the present application does not specifically limit the detection optical signal, and the detection optical signal may be a vertical optical signal or a tilted optical signal. That is, the detected light signal is perpendicular or oblique to the display screen.

When the detection optical signal is inclined with respect to the display screen, the inclination angle of the detection optical signal may be the same as or different from the inclination angles of the first inclined optical signal and the second inclined optical signal.

Fig. 13 shows a scheme in which the distance detection uses oblique light signals and the fingerprint detection uses perpendicular light signals. The fingerprint sensor comprises 4 sensing units, wherein 3 sensing units can be used for receiving vertical light signals to detect fingerprints. And part or all of the 4 sensing units can be used for receiving the oblique light signals for distance detection.

The combination of oblique reception and vertical reception on the fingerprint sensor can be realized by arranging different light-emitting areas and a special light path guiding structure. The optical path guiding structure can guide both vertical optical signals and oblique optical signals.

If the light path guiding structure can only guide the light signal in one direction, that is, the light signal is detected, the first oblique light signal and the second oblique light signal have the same inclination angle, the fingerprint detection process and the distance detection process can be performed separately. Such as during periods when fingerprint detection is not being performed, distance detection may be performed. The distance detection may be performed periodically or before each fingerprint detection, which is not particularly limited in the embodiments of the present application.

If the detection light signal and the oblique light signal for detecting the distance do not interfere with each other, fingerprint detection and distance detection can be performed simultaneously, which enables more accurate correction of the fingerprint image. However, in order to reduce the processing complexity, fingerprint detection and distance detection may be performed separately.

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

The light path guiding structure 1410 is configured to guide a first oblique light signal and a second oblique light signal to the sensing array of the fingerprint sensor, where the first oblique light signal is an oblique light signal emitted by the light emitting unit and directed to the fingerprint identification device, and the second oblique light signal is an oblique light signal emitted by the light emitting unit and directed to the surface of the fingerprint identification device, and reaches the fingerprint identification device after being reflected by the surface of the fingerprint identification device and reflected by the lower surface of the display screen. The fingerprint sensor 1420 includes a sensing array having a plurality of optical sensing units, the sensing array is configured to generate an original image according to the first oblique optical signal, and generate a smear image according to the second oblique optical signal, the original image and the smear image are used to correct fingerprint data collected by the fingerprint recognition device, and the corrected fingerprint data is used for fingerprint recognition.

The form of the optical path guiding structure is not particularly limited in the embodiments of the present application, and the optical path guiding structure may be any one of the forms described above.

The optical path directing structure may, for example, comprise a microlens array for being arranged between the display screen and the fingerprint sensor, the microlens array may comprise a plurality of microlenses for converging the received optical signals, and at least one light blocking layer. The at least one light blocking layer comprises a plurality of openings corresponding to the plurality of micro lenses respectively, and the oblique light signals converged by each micro lens pass through the openings corresponding to the micro lenses in different light blocking layers and reach the optical sensing unit of the fingerprint sensor.

The projection of the light-gathering surface of the micro lens on a plane perpendicular to the optical axis of the micro lens can be circular or square, and of course, the projection can be in other shapes; the light-collecting surface of the microlens may be a spherical surface or an aspherical surface, which is not particularly limited in this embodiment of the present application.

Fig. 15 is a top view of a microlens array composed of conventional circular microlenses, and it can be seen that a gap 420 exists between adjacent microlenses 410, and an optical signal reflected by a finger and entering the gap 420 is not collected by the optical fingerprint sensor 520, although this portion of the optical signal also carries image information, but is not utilized.

Fig. 16 and 17 are a top view and a side view, respectively, of a microlens array composed of rectangular microlenses according to an embodiment of the present application. The projection of the microlens 511 shown in fig. 16 right below it is a square, also referred to as a square microlens 511. It can be seen that, by closely arranging the rectangular microlenses 511, there is no gap between adjacent microlenses 511, so that a higher light-gathering area ratio can be obtained, more image information can be obtained, and the fingerprint recognition performance can be improved.

The light-gathering surface of the micro lens is a surface for gathering light. The surface type of the light-condensing surface is not limited in this embodiment, and may be, for example, a spherical surface or an aspherical surface. Preferably, the curvatures of the light-condensing surfaces in all directions are the same, so that the imaging focuses of all directions of the micro lens can be at the same position, and the imaging quality is guaranteed.

The fingerprint recognition device in the embodiment of the present application will be described below with reference to fig. 18 to 22.

It should be understood that each microlens in the microlens array 510 in the embodiment of the present application may also have two light-collecting surfaces, the projection areas of the two light-collecting surfaces are both rectangular, and the two light-collecting surfaces are symmetrical and form a shape similar to a convex lens, so as to achieve a better light-collecting effect.

In addition, the microlenses in the microlens array 510 of the embodiment of the present application may be rectangular microlenses, or may be other polygonal microlenses, that is, the forward projection of the microlenses is polygonal, for example, hexagonal. The microlenses need only be closely joined together to eliminate or reduce the gap 620 described above.

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 due to abrupt changes in refractive index.

Optionally, the apparatus 500 further comprises a filter layer 530, wherein the filter layer 530 is disposed above the microlens array 510 or between the microlens array 510 and the optical fingerprint sensor 520, and the filter layer 530 is configured to transmit optical signals in a specific wavelength range.

For example, when the filter layer 530 is disposed over the microlens array 510, air 531 is between the filter layer 530 and the microlens array 510, or the filter layer 530 is filled with a transparent adhesive layer 532.

The Clear Adhesive layer 532 may be, for example, Optically Clear Adhesive (OCA), Clear glue, or Clear Adhesive film.

This transparent adhesive layer 532 is the optical cement of low refractive index, and figure 19 compares in figure 18, has reduced one deck air interface to can reduce stray light, and light loss is less, possesses better fingerprint performance.

The microlens array 510 may be surrounded by a light blocking material 534, for example, black foam, to block light, thereby preventing stray light around the microlens array 510 from entering the microlens array 510 and affecting 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 is integrated with the optical fingerprint sensor 520.

The embodiment of the present disclosure does not limit the integration manner of the filter layer 510 and the optical fingerprint sensor 520, for example, an evaporation process may be used to perform a film coating on the optical sensing unit of the optical fingerprint sensor 520 to form the filter layer 530, for example, a filter material film is prepared above the optical sensing unit of the optical fingerprint sensor 520 by methods such as atomic layer deposition, sputter coating, electron beam evaporation coating, and ion beam coating. Preferably, the thickness of the filter layer 530 may be 20 μm or less.

Taking fig. 18-20 as an example, a microlens array 510, an optical fingerprint sensor 520, and a filter layer 530 are shown. The optical fingerprint sensor 520 includes a plurality of sensing units and a light blocking layer 551 over the sensing units. The light blocking layer 551 includes a plurality of openings, such as an opening 5511, each opening corresponds to one optical sensing unit, such as the opening 5511 corresponds to the optical sensing unit 521, and the opening 5511 is used for allowing the oblique light signal of a predetermined angle to reach the optical sensing unit 521 corresponding to the opening 5511 and blocking the light of other directions from affecting the oblique light signal. The microlens array 510 is composed of a plurality of microlenses, and the refractive index of the substrate material 512 under the microlens array 510 may be equal to that of the microlenses, for example, so as to reduce light loss caused by abrupt changes in refractive index.

For example, as shown in fig. 18, the filter layer 530 may be disposed over the microlens array 510 with an air gap 531 between it and the microlens array 510. The microlens array 510 is provided with a light blocking material 540 around the periphery thereof.

For example, as shown in fig. 19, the filter layer 530 may be disposed over the microlens array 510 with a transparent glue layer 532 interposed between the microlens array 510. The transparent adhesive layer 532 may be a low refractive index optical adhesive. The transparent adhesive layer 532 is provided with a light shielding material 540 at the periphery.

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 satisfying the wavelength condition can reach the optical sensing unit 521, and light not satisfying the wavelength condition is filtered out.

The filter layer 530 can filter light in the infrared band and transmit light in the visible band.

In the three implementations of the filter layer 530 shown in fig. 18 to 20, the filter layer 530 is integrated with the optical fingerprint sensor 520 to better ensure the reliability of fingerprint identification, but the present application does not limit the location and type of the filter layer 530.

In the present application, the distance detection is performed by using the oblique light signal, and in fig. 18 to 20 as an example, the light entering the micro lens 511 at the angle i can be converged by the micro lens 511 and reach the optical sensing unit 521 through the opening 5511. While the remaining angles of light are blocked by the light blocking layer 551.

The openings in each light blocking layer can effectively prevent light crosstalk and block stray light except for realizing light path guiding, so that only light rays meeting the preset angle i can pass through the light blocking layer to reach the optical fingerprint sensor 520.

The number of light blocking layers is not limited in the embodiments of the present application. Too many light blocking layers can increase the thickness and complexity of the fingerprint identification device, and too few light blocking layers can bring more interference light and influence the imaging effect. When in actual use, a reasonable number of light blocking layers can be arranged according to requirements.

For example, fig. 18 to 20 show the case where only one light-blocking layer, that is, the light-blocking layer 551, is present.

For another example, fig. 21 shows a case where two light-blocking layers are present. Fig. 21 is added with a light-blocking layer 552 on the basis of fig. 20, and a transparent dielectric layer 561 is filled between the light-blocking layer 552 and the filter layer 530. Other related components in fig. 21 may be referred to in the description of fig. 20.

For another example, fig. 22 shows a case where three light-blocking layers are present. Fig. 22 is added with 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, and a transparent medium layer 562 is filled between the light-blocking layer 553 and the filter layer 530. Other related components in fig. 22 may be referred to in 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 inclined optical signal.

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

The lateral distances between two openings corresponding to the same microlens and respectively located in two adjacent light blocking layers can be equal or unequal.

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

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

Optionally, each microlens corresponds to an optical sensing unit of the optical fingerprint sensor 520, wherein the openings corresponding to the same microlens in different light blocking layers are used for guiding the oblique light signal converged by the microlens to the optical sensing unit corresponding to the microlens in sequence.

Further, optionally, a connection line of the openings corresponding to the same microlens in different light blocking layers passes through a central region of the optical sensing unit corresponding to the microlens.

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

For example, as shown in fig. 22, light reaching the microlens 511 at an angle i passes through the opening 5521 in the light blocking layer 552, the opening 5531 in the light blocking layer 553, and the opening 5511 in the light blocking layer 551 carried by the optical fingerprint sensor 520 in sequence, and finally reaches the optical sensing unit 521. The opening 5531 is shifted to the left by a certain distance relative to the opening 5521, the opening 5511 is shifted to the left by a certain distance relative to the opening 5531, and a central connection line of the opening 5521, the opening 5531 and the opening 5511 can pass through the corresponding optical sensing unit 521, so that the guiding of the oblique light can be realized.

Since the micro-lens has a converging effect on light, the more downward the light is transmitted, the narrower the angle of the light beam formed by converging the light beam. Therefore, optionally, the apertures of the openings corresponding to the same microlenses 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, narrow-angle reception of the light beam is realized, the light beam which is not needed can be effectively attenuated while the collimation degree is ensured, and the definition of the optical fingerprint image collected by the optical fingerprint sensor 520 is further improved. 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 fig. 21 and 22, the last light blocking layer reached by the oblique light signal is integrated in the optical fingerprint sensor 520, so that the reliability of fingerprint recognition is ensured, and adjacent light blocking layers among the remaining light blocking layers may be connected through a transparent dielectric layer. For example, in FIG. 22, the light blocking layer 551 is integrated into the optical fingerprint sensor 520, the light blocking layer 552 and the light blocking layer 553 are connected by a transparent dielectric layer 561, and the light blocking layer 553 and the filter layer 530 are connected by a transparent dielectric layer 562. Preferably, the refractive indexes of the transparent

medium layers

561 and 562 may be the same as the refractive index of the substrate material 512 of the microlens array 510 and the refractive index of the microlens array 510, so as to reduce light loss caused by abrupt change of the refractive index.

However, the application is not limited to this, and other methods may 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 a plurality of light blocking layers are pasted together by transparent glue or an adhesive film.

Since the apertures in each light-blocking layer are of 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 optical signal is preferably-4 ° to-4 °. For example, if the preset inclination angle is 30 °, the inclination angle of the optical signal actually received by the fingerprint sensor is 26 ° to 34 °.

In addition to fiber alignment via multiple light blocking layers as described above, other alignment means are provided in embodiments of the present application, as shown in fig. 23-25.

FIG. 23 illustrates the way to select the tilted light signal through the collimating aperture 741. the collimating aperture 741 has a light transmissive material or air in the aperture, a light absorbing material in the wall, and guides the vertically incident light when the collimating aperture is vertically disposed, and guides the tilted light signal when the collimating aperture is tilted according to the receiving angle, for example, when the angle of tilt of the collimating aperture 741 is β, the light signal with the tilt angle β can be guided.

The collimating aperture 741 is disposed on the opaque substrate 740, and when the finger 710 presses the display screen 730, the oblique optical signal 720 reflected by the finger can be guided to the fingerprint sensor 750 by the collimating aperture 741, and the fingerprint sensor 750 can perform fingerprint identification according to the received optical signal.

Of course, the collimating aperture 741 can also direct the first oblique optical signal and the second oblique optical signal described above to the fingerprint sensor 750.

Fig. 24 shows a collimating aperture whose axis is perpendicular to the surface of the display screen, which directs the oblique light signal to the fingerprint sensor by total reflection. The refractive indexes of the inside and the outside of the collimating aperture are different, and only the incident light signal which accords with the total reflection angle is selected through the total reflection principle. For example, the optical signal 720 is an optical signal corresponding to a total reflection angle, and the optical signal 720 reaches the collimator hole 742, and then is totally reflected in the collimator hole 742 to form an optical signal 760, so that the fingerprint sensor 750 can perform fingerprint recognition based on the optical signal 760.

The selection of the tilted optical signal in the embodiments of the present application may also be achieved by tilting the vertically received collimator by a certain angle. As shown in fig. 25, when the collimator 740 is tilted, the collimating apertures 743 can only allow the tilted optical signals of a specific angle to pass through, and the optical signals of other angles are all blocked outside the collimator. In this case, the fingerprint sensor 750 also needs to be tilted by a certain angle to receive the optical signal selected by the collimator 740.

The collimation process shown in fig. 23 to 25 can be realized by optical fibers.

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 recognition device having a large lens. As shown in fig. 26, the fingerprint recognition device includes a lens 770, and the lens 770 focuses an optical signal 760 reflected from a finger to a fingerprint sensor 750.

As can be seen from fig. 26, in the light-narrowing angle range of the lens 770, the image of the edge is actually generated by the oblique light signal, so that the embodiment of the present application may emit the light signal in the edge of the field angle of the lens 770 to generate the original image and the smear image for the purpose of distance detection.

In the structure shown in fig. 26, the light emitting unit may be configured to emit the first and second oblique optical signals on an edge area of the angle of field of the lens 770.

If the light emitting unit is a light emitting pixel on the OLED panel, the first oblique light signal and the second oblique light signal may be formed by light signals emitted by the light emitting pixel on at least one light emitting region 780 on the OLED panel, where the at least one light emitting region 780 is located at an edge region of an intersection region of the at least one light emitting region 780 and the viewing angle of the lens 770 on the OLED panel.

Modifying fingerprint data as referred to in embodiments of the present application may include increasing signal strength or resizing the fingerprint image.

The embodiment of the present application further provides an electronic device, which includes the fingerprint identification apparatus in the various embodiments of the present application.

Fig. 27 is a schematic block diagram of an electronic device provided in an embodiment of the present application. The electronic device 1000 includes a display 1010, a fingerprint recognition device 1020, and a processor 1030. The fingerprint recognition device 1020 may be disposed below the display screen 1010 to perform fingerprint recognition on a finger above the display screen 1010.

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

The display screen can be a common non-folding display screen, and the display screen can also be a folding display screen or a flexible display screen.

The fingerprint recognition device 1020 may be any one of the fingerprint recognition devices described above, and for simplicity, the description thereof is omitted here.

The processor 1030 is operable to perform any of the methods described above.

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 is to be understood that the terminology used in the embodiments of the present application and the appended claims is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the present application.

For example, as used in the examples of this application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Those of skill in the art would appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the embodiments of the present application.

If implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application may be essentially implemented or make a contribution to the prior art, or may be implemented in the form of a software product stored in a storage medium and including several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: u disk, removable hard disk, read only memory, random access memory, magnetic or optical disk, etc. for storing program codes.

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

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

For example, the division of a unit or a module or a component in the above-described device embodiments is only one logical function division, and there may be other divisions in actual implementation, for example, a plurality of units or modules or components may be combined or may be integrated into another system, or some units or modules or components may be omitted, or not executed.

Also for example, the units/modules/components described above as separate/display components may or may not be physically separate, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the units/modules/components can be selected according to actual needs to achieve the purposes of the embodiments of the present application.

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

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

Claims

1. A method for fingerprint recognition, the method being adapted to an electronic device having a display screen and a fingerprint recognition device disposed below the display screen, the method comprising:

acquiring an original image generated by a fingerprint identification device according to a received first inclined optical signal, wherein the first inclined optical signal is an inclined optical signal which is emitted by a light-emitting unit and points to the fingerprint identification device;

acquiring a smear image generated by the fingerprint identification device according to a received second inclined optical signal, wherein the second inclined optical signal is an inclined optical signal which is emitted by the light-emitting unit, points to the surface of the fingerprint identification device, and reaches the fingerprint identification device after being reflected by the surface of the fingerprint identification device and the lower surface of the display screen;

and correcting the fingerprint data acquired 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.

2. The method according to claim 1, wherein the modifying the fingerprint data collected by the fingerprint identification device according to the distance X between the original image and the smear image comprises:

determining a 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.

3. The method according to claim 2, wherein the relationship between the distance Y and the distance X is Y ═ k X + b, where k and b are both constants.

4. The method of claim 3, wherein k and b are pre-configured according to different distances Y and corresponding different distances X.

5. The method according to any of claims 1-4, 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 formed by light signals emitted by light emitting pixels on at least one light emitting area on the OLED screen.

6. The method of claim 5, wherein the at least one light emitting area is circular in shape.

7. A method according to claim 5 or 6, wherein the areas of different light emitting areas in the at least one light emitting area are different.

8. The method of any of claims 5-7, wherein the at least one light emitting area comprises 3 light emitting areas, and the centers of the 3 light emitting areas are not in a straight line.

9. The method of any of claims 1-8, wherein the first and second tilted optical signals are tilted at an angle of 10 ° to 50 °.

10. The method according to any one of claims 1-9, wherein the fingerprint recognition device comprises an optical path directing structure and a fingerprint sensor, the fingerprint sensor comprising a sensing array having a plurality of optical sensing elements, the optical path directing structure for directing the first oblique light signal and the second oblique light signal to the sensing array.

11. The method of claim 10, wherein the fingerprint sensor is further configured to receive a detection light signal emitted by the light emitting unit after being irradiated to a finger and reflected by the finger, and generate the fingerprint data according to the detection light signal.

12. The method of claim 11, wherein the detected light signal is normal or oblique to the surface of the display screen.

13. A fingerprint identification device is applied to an electronic device with a display screen, and is characterized in that the fingerprint identification device is arranged below the display screen and comprises:

the light path guiding structure is used for guiding a first inclined light signal and a second inclined light signal to an induction array of a fingerprint sensor, wherein the first inclined light signal is an inclined light signal which is emitted by a light emitting unit and points to the fingerprint identification device, the second inclined light signal is an inclined light signal which is emitted by the light emitting unit and points to the surface of the fingerprint identification device, and the inclined light signal reaches the fingerprint identification device after being reflected by the surface of the fingerprint identification device and the lower surface of the display screen;

the fingerprint sensor comprises a sensing array with a plurality of optical sensing units, wherein the sensing array is used for generating an original image according to the first inclined optical signal and generating a smear image according to the second inclined optical signal, the original image and the smear image are used for correcting fingerprint data collected by the fingerprint identification device, and the corrected fingerprint data are used for fingerprint identification.

14. The fingerprint recognition device of claim 13, wherein the optical path directing structure comprises a micro-lens array and at least one light blocking layer, the micro-lens array is configured to be disposed between the display screen and the fingerprint sensor, the micro-lens array comprises a plurality of micro-lenses, the micro-lenses are configured to focus the received light signals,

the at least one light blocking layer is arranged between the micro lens array and the fingerprint sensor, each light blocking layer comprises a plurality of openings corresponding to the micro lenses, and oblique light signals converged by the micro lenses pass through the openings corresponding to the micro lenses in different light blocking layers and reach the optical sensing unit of the fingerprint sensor.

15. The fingerprint recognition device according to claim 14, wherein the projection of the light-condensing surface of the micro lens on a plane perpendicular to the optical axis thereof is circular or square.

16. The fingerprint recognition device according to claim 14 or 15, wherein a last light blocking layer of the at least one light blocking layer is integrated in the fingerprint sensor.

17. The fingerprint recognition device according to any one of claims 14 to 16, wherein each of the microlenses corresponds to one optical sensing unit of the fingerprint sensor, wherein the openings corresponding to the same microlens in different light blocking layers are used for sequentially guiding the first oblique light signal and the second oblique light signal after being converged by the microlenses to the optical sensing unit corresponding to the microlens.

18. The fingerprint recognition device of any one of claims 13-17, further comprising a filter layer configured to transmit optical signals within a specific wavelength range.

19. The fingerprint recognition device of claim 18, wherein the filter layer is integrated on the fingerprint sensor.

20. The fingerprint recognition device of claim 18, wherein the filter layer is disposed over the microlens array, and wherein an air layer or a transparent adhesive layer is filled between the filter layer and the microlens array.

21. The fingerprint recognition device of claim 20, wherein the transparent adhesive layer is surrounded by a light blocking material.

22. The fingerprint recognition device according to claim 13, wherein the optical path directing structure comprises a lens for converging the first oblique optical signal and the second oblique optical signal to the fingerprint sensor, and the light emitting unit is configured to emit the first oblique optical signal and the second oblique optical signal on an edge area of a field angle of the lens.

23. The fingerprint recognition 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 formed by light signals emitted from the light-emitting pixel on at least one light-emitting area on the OLED screen, the at least one light-emitting area being located at an edge area of an intersection area with a field angle of the lens on the OLED screen.

24. The fingerprint recognition 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 and reflected by the finger after being irradiated to the finger, and generate the fingerprint data according to the detection light signal.

25. The fingerprint recognition device of claim 24, wherein the detection light signal is perpendicular or oblique to a surface of the fingerprint recognition device.

26. The fingerprint recognition 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 formed by light signals emitted by light emitting pixels on at least one light emitting area of the OLED screen.

27. The fingerprint recognition device of claim 26, wherein the at least one light-emitting area is circular in shape.

28. The fingerprint recognition device of claim 26 or 27, wherein the areas of different light-emitting areas in the at least one light-emitting area are different.

29. The fingerprint identification device of any one of claims 26-28, wherein the at least one light emitting area comprises 3 light emitting areas, the 3 light emitting areas not having centers that are aligned.

30. The fingerprint recognition device according to any one of claims 13-29, wherein the first inclined optical signal and the second inclined optical signal are inclined at an angle of 10 ° to 50 °.

31. An electronic device, comprising:

a display screen;

and a fingerprint recognition device according to any one of claims 13 to 30;

and the processor is used for acquiring the original image and the smear image, and correcting the fingerprint data acquired 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.

32. The electronic device of claim 31, wherein the processor is configured to:

33. The electronic device of claim 32, wherein the distance Y is related to the distance X by Y ═ k X + b, where k and b are both constants.

34. The electronic device of claim 33, wherein k and b are pre-configured according to different distances Y and corresponding different distances X.

35. The electronic device of any one of claims 31-34, wherein the display screen is an Organic Light Emitting Diode (OLED) screen, and wherein the first oblique light signal and the second oblique light signal are formed from light signals emitted by light emitting pixels on at least one light emitting area of the OLED screen.

36. The electronic device of claim 35, wherein the at least one light emitting area is circular in shape.

37. An 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.

38. The electronic device of any of claims 35-37, wherein the at least one light-emitting area comprises 3 light-emitting areas, and wherein centers of the 3 light-emitting areas are not in a straight line.

39. The electronic device of any of claims 31-38, wherein the first tilted optical signal and the second tilted optical signal are tilted at an angle of 10 ° to 50 °.