CN110945525B

CN110945525B - Fingerprint identification method, fingerprint identification device and electronic equipment

Info

Publication number: CN110945525B
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: 2023-08-22
Anticipated expiration: 2039-10-31
Also published as: WO2021081891A1; CN110945525A

Abstract

The embodiment of the application discloses a fingerprint identification method, a fingerprint identification device and electronic equipment, which can improve the quality of fingerprint images. The method is suitable for the electronic equipment with the display screen and the 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 oblique light signal, wherein the first oblique light signal is an oblique light signal which is sent by a light-emitting unit and is directed to the fingerprint identification device; acquiring a smear image generated by the fingerprint identification device according to the received second inclined light signal, wherein the second inclined light signal is an inclined light signal which is emitted by the light-emitting unit, is directed to the surface of the fingerprint identification device, and reaches the fingerprint identification device after being reflected on the surface of the fingerprint identification device and the lower surface of the display screen; and correcting the fingerprint data collected by the fingerprint identification device according to the distance X between the original image and the smear image, wherein the corrected fingerprint data are used for fingerprint identification.

Description

Fingerprint identification method, fingerprint identification device and electronic equipment

Technical Field

The embodiment of the application relates to the field of fingerprint identification, and more particularly relates to a fingerprint identification method, a fingerprint identification device and electronic equipment.

Background

With the rapid development of the mobile phone industry, fingerprint identification technology is more and more paid attention to, and the practical application of the under-screen fingerprint identification technology is required by the public. The most applied among the fingerprint identification technology under the screen is the optical fingerprint identification technology under the screen, and the optical fingerprint identification technology under the screen can adopt the light that the screen sent as the light source, can carry the fingerprint information of finger after the light that the screen sent shines the finger above the screen, and the optical signal that carries fingerprint information can be received by fingerprint identification device to carry out fingerprint identification.

The fingerprint identification device needs to be installed below the screen to achieve the fingerprint detection function, 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 be guaranteed to be within a certain range only through a structure processing technology at the present stage. In addition, when the consumer uses the screen, the screen is pressed by different people, and the distance is fluctuated due to the difference of pressing force. 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 to be solved.

Disclosure of Invention

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

In a first aspect, a method for fingerprint identification is provided, the method being applicable to an electronic device having a display screen and a fingerprint identification apparatus arranged below the display screen, the method comprising: acquiring an original image generated by a fingerprint identification device according to a received first inclined light signal, wherein the first inclined light signal is an inclined light signal which is sent 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 light signal, wherein the second inclined light signal is an inclined light 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.

In the technical scheme provided by the embodiment of the application, the inclined optical signal is used as the incident optical signal, the fingerprint data is corrected according to the original image and the smear image generated by the inclined optical signal, and the corrected fingerprint data can more accurately reflect the fingerprint information of the finger, so that the quality of the fingerprint image can be improved, and the fingerprint identification effect is improved.

In some possible implementations, the correcting the fingerprint data collected by the fingerprint identification device according to the distance X between the original image and the smear image includes: determining 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 pre-configured according to different distances Y and corresponding different distances X.

In some possible implementations, the display screen is an organic light emitting diode OLED screen, and the first oblique light signal and the second oblique light signal are 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 region is circular in shape.

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

In some possible implementations, the at least one light emitting region includes 3 light emitting regions, and centers of the 3 light emitting regions are not on a straight line, which can improve accuracy of the measured distance X.

In some possible implementations, the first oblique optical signal and the second oblique optical signal have an oblique angle of 10 ° to 50 °.

In some possible implementations, the fingerprint recognition device includes a light path guiding structure for guiding the first oblique light signal and the second oblique light signal to a sensing array having a plurality of optical sensing units, and a fingerprint sensor.

In some possible implementations, the fingerprint recognition device includes a fingerprint sensor, and the fingerprint sensor is 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.

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

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

In some possible implementations, the light path guiding structure includes a microlens array and at least one light blocking layer, the microlens array is configured to be disposed between the display screen and the fingerprint sensor, the microlens array includes a plurality of microlenses configured to converge received light signals, the at least one light blocking layer is disposed between the microlens array and the fingerprint sensor, wherein each light blocking layer includes a plurality of openings corresponding to the plurality of microlenses, and the inclined light 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 converging surface of the microlens on a plane perpendicular to its optical axis is circular or square.

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

In some possible implementations, the curvature of the collection surface is the same in each direction.

In some possible implementations, the openings corresponding to the same microlenses in different light blocking layers decrease in order from top to bottom.

In some possible implementations, the inclination angle of the connection line of the openings corresponding to the same microlens in the different light blocking layers is the same as the inclination angle 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, where openings corresponding to the same microlens in different light-blocking layers are used to sequentially guide the first oblique optical signal and the second oblique optical signal converged by the microlens to the optical sensing unit corresponding to the microlens.

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

In some possible implementations, the optical path guiding structure includes a microlens array for being disposed between the display screen and the fingerprint sensor, the microlens array including a plurality of microlenses for converging the received optical signals, and a collimating aperture disposed between the microlens array and the fingerprint sensor, the collimating aperture for guiding the first oblique optical signals and the second oblique optical signals to the fingerprint sensor.

In some possible implementations, the collimating aperture has air or a light-transmitting material in its aperture and a light-absorbing material in its aperture wall, and the axis of the collimating aperture has the same inclination angle as the first oblique optical signal and the second oblique optical signal.

In some possible implementations, the arrangement of the inner core material and the outer core material of the collimating aperture is capable of total reflection of the first oblique optical signal and the second oblique optical signal transmitted within the optical fiber.

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

In some possible implementations, the fingerprint recognition device further includes a filter layer for transmitting an optical signal 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 glue layer is filled between the filter layer and the microlens array.

In some possible implementations, the transparent glue 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 light signal and the second oblique light signal to the fingerprint sensor, and the light emitting unit is for emitting the first oblique light signal and the second oblique light signal on an edge region of a field angle of the lens.

In some possible implementations, the light emitting units are light emitting pixels of an organic light emitting diode OLED panel, 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 panel, the at least one light emitting area being located in an edge area of an interface area with a field angle of view of the lens on the OLED panel.

In some possible implementations, 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.

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

In some possible implementations, the at least one light emitting region includes 3 light emitting regions, a center of the 3 light emitting regions not being on a straight line.

In a third aspect, there is provided an electronic device comprising: the display screen, the fingerprint identification device in any possible implementation manner of the second aspect, and the processor, configured to acquire the original image and the smear image, and correct fingerprint data acquired by the fingerprint identification device according to a distance X between the original image and the smear image, where the corrected fingerprint data is used for fingerprint identification.

In some possible implementations, the processor is configured 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 A-A'.

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

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

Fig. 5 is a schematic diagram of a fingerprint recognition device according to an embodiment of the present application.

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

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

Fig. 10 is a schematic diagram of a correspondence relationship between a distance X and a distance Y according to an embodiment of the present application.

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

Fig. 12 is a schematic view of a light emitting region according to an embodiment of the present application.

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

Fig. 14 is a schematic block diagram of a fingerprint identification apparatus according to an embodiment of the present application.

Fig. 15 is a schematic view of a circular microlens array according to 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 diagram of one possible configuration of the fingerprint recognition device shown in fig. 14.

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

Fig. 20 is a schematic diagram of one possible configuration of the fingerprint recognition device shown in fig. 14.

Fig. 21 is a schematic diagram of one possible configuration of the fingerprint recognition device shown in fig. 14.

Fig. 22 is a schematic diagram of one possible configuration of the fingerprint recognition device shown in fig. 14.

Fig. 23 is a schematic structural view of a collimation hole according to an embodiment of the present application.

Fig. 24 is a schematic structural view of another collimation hole according to an embodiment of the present application.

Fig. 25 is a schematic structural view of another collimation hole according to an embodiment of the present application.

Fig. 26 is a schematic diagram of one possible configuration of the fingerprint recognition device shown in fig. 14.

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

Detailed Description

The technical scheme of the application will be described below with reference to the accompanying drawings.

It should be understood that embodiments of the present application may be applied to fingerprint systems, including but not limited to optical, ultrasound or other fingerprint recognition systems and medical diagnostic products based on optical, ultrasound or other fingerprint imaging, and are described by way of example only with respect to optical fingerprint systems, but should not be construed as limiting the embodiments of the present application in any way, as well as other systems employing optical, ultrasound or other imaging techniques, etc.

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

The optical underscreen fingerprint identification technology uses light returned from the top surface of the device display assembly for fingerprint sensing and other sensing operations. The returned light carries information about an object (e.g., a finger) in contact with the top surface, and by collecting and detecting the returned 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 properly configuring the optical elements for collecting and detecting the returning light.

Fig. 1 and 2 show schematic diagrams of electronic devices to which embodiments of the present application may be applied. Fig. 1 is a schematic view illustrating an orientation of the electronic device 10, and fig. 2 is a schematic view illustrating a partial cross section of the electronic device 10 shown in fig. 1 along A-A'.

The electronic device 10 includes a display 120 and an optical fingerprint module 130. 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 area of the sensing array 133 or the sensing area thereof is the fingerprint detection area 103 (also referred to as 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 the display area of the display screen 120. In an alternative embodiment, the optical fingerprint module 130 may be disposed at other locations, such as a side of the display screen 120 or an edge non-transparent area of the electronic device 10, and the optical signal from at least a portion of the display area of the display screen 120 is guided to the optical fingerprint module 130 through an optical path design, so that the fingerprint detection area 103 is actually located in the display area of the display screen 120.

It should be appreciated that the area of 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 a light path design such as lens imaging, a reflective folded light path design, or other light path designs such as light converging or reflecting, the area of the fingerprint detection area 103 of the optical fingerprint module 130 may be made 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, for example, by 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.

Thus, when the user needs to unlock the electronic device 10 or perform other fingerprint verification, the user only needs to press the finger against the fingerprint detection area 103 on the display screen 120, so as to implement fingerprint input. Since fingerprint detection can be implemented in the screen, the electronic device 10 adopting the above structure does not need to have a special reserved space on the front surface to set fingerprint keys (such as Home keys), so that a comprehensive screen scheme can be adopted, that is, the display area of the display screen 120 can be basically expanded 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 detecting portion 134 and an optical component 132. The light detecting part 134 includes the sensing array 133 and a reading circuit and other auxiliary circuits electrically connected to the sensing array 133, which may be fabricated on a chip (Die) such as an optical imaging chip or an optical fingerprint sensor by a semiconductor process. The sensing array 133 is specifically a Photo detector (Photo detector) array, which includes a plurality of Photo detectors distributed in an array, which may be used as an optical sensing unit as described above. The optical component 132 may be disposed above the sensing array 133 of the light detecting portion 134, and may specifically include a Filter layer (Filter), a light guiding layer or a light path guiding structure, and other optical elements, where the Filter layer may be used to Filter out ambient light penetrating the finger, and the light guiding layer or the light path guiding structure is mainly used to guide reflected light reflected from the finger surface to the sensing array 133 for optical detection.

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

The light guiding layer or the light path guiding structure of the optical component 132 may have various implementations, for example, the light guiding layer may be a Collimator (Collimator) layer made of a semiconductor silicon wafer, which has a plurality of collimating units or a micropore array, the collimating units may be small holes, the light vertically incident to the collimating units from the reflected light reflected by the finger may pass through and be received by the optical sensing units below the collimating units, and the light with an excessively large incident angle is attenuated by multiple reflections inside the collimating units, so each optical sensing unit basically only receives the reflected light reflected by the fingerprint lines right above the optical sensing units, and the sensing array 133 may detect the fingerprint image of the finger.

In another implementation, the light guiding layer or 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, for converging the reflected light reflected from the finger to the sensing array 133 of the light detecting part 134 therebelow, so that the sensing array 133 may image based on the reflected light, thereby obtaining a fingerprint image of the finger. Optionally, the optical lens layer may further form a pinhole in the optical path of the lens unit, and the pinhole may cooperate with the optical lens layer to expand the field of view of the optical fingerprint module 130, so as to improve the fingerprint imaging effect of the optical fingerprint module 130.

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

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

As an alternative implementation manner, the display screen 120 may be a display screen with a self-luminous display unit, such as an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. Taking an OLED display as an example, the optical fingerprint module 130 may use a display unit (i.e., an OLED light source) of the OLED display 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, which light 111 is reflected at the surface of the finger 140 to form reflected light or scattered inside the finger 140 to form scattered light. In the related patent application, the above reflected light and scattered light are collectively referred to as reflected light for convenience of description. Since the ridge (ridge) 141 and the valley (valley) 142 of the fingerprint have different light reflection capacities, the reflected light 151 from the ridge and the reflected light 152 from the valley have different light intensities, and 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 after passing through the optical component 132; fingerprint image data may be obtained based on the fingerprint detection signal and further fingerprint matching verification may be performed, thereby implementing an optical fingerprint recognition function at 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 adapted to a non-self-luminous display screen, such as a liquid crystal display screen or other passive light emitting display screen. Taking the application to a liquid crystal display having a backlight module and a liquid crystal panel as an example, to support the under-screen fingerprint detection of the liquid crystal display, 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 be specifically 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 or disposed 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 by an optical path so that 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 be configured to allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint module 130 by making holes or other optical designs on the film layers such as the diffusion sheet, the brightness enhancement sheet, and the reflection sheet. When the optical fingerprint module 130 is used to provide an optical signal for fingerprint detection using an internal light source or an external light source, the detection principle is 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, that is positioned over the display screen 120 and covers the front of the electronic device 10. Thus, in the embodiment of the present application, the pressing of the finger against the display screen 120 actually means pressing 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 implementations, the optical fingerprint module 130 may include only one optical fingerprint sensor, where the area of the fingerprint detection area 103 of the optical fingerprint module 130 is smaller and the position is fixed, so that the user needs to press the finger to a specific position of the fingerprint detection area 103 when inputting the fingerprint, otherwise, the optical fingerprint module 130 may not be able to collect the fingerprint image, which may cause poor user experience. In other alternative embodiments, the optical fingerprint module 130 may specifically include a plurality of optical fingerprint sensors. The optical fingerprint sensors may be disposed side by side below the display screen 120 in a spliced manner, and the sensing areas of the optical fingerprint sensors together form the fingerprint detection area 103 of the optical fingerprint module 130. Thus, the fingerprint detection area 103 of the optical fingerprint module 130 can be extended to the main area of the lower half of the display screen, that is, to the finger usual pressing area, thereby realizing the blind press type fingerprint input operation. Further, when the number of the optical fingerprint sensors is sufficient, the fingerprint detection area 103 may be further extended to a half display area or even the whole display area, so as to implement half-screen or full-screen fingerprint detection.

For example, in the electronic device 10 shown in fig. 3 and fig. 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 disposed side by side under the display screen 120 by, for example, splicing, and 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 the plurality of optical fingerprint sensors of the optical fingerprint device 130, the optical component 132 may have a plurality of optical path guiding structures therein, where each optical path guiding structure corresponds to one optical fingerprint sensor and is respectively attached to and disposed above the corresponding optical fingerprint sensor. Alternatively, the plurality of optical fingerprint sensors may share a unitary light path guiding structure, i.e. the light path guiding structure has a sufficiently large area to cover the sensing array of the plurality of optical fingerprint sensors. In addition, the optical component 132 may further include other optical elements, such as a Filter layer (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 to isolate the influence of the external interference light on the optical fingerprint detection. The optical filter may be used to filter out ambient light that penetrates through the finger and enters the optical fingerprint sensor through the display screen 120, similar to the optical path guiding structure, and the optical filter may be separately configured for each optical fingerprint sensor to filter out interference light, or may also use a large-area optical filter to cover the plurality of optical fingerprint sensors simultaneously.

The optical path modulator can also be replaced by an optical Lens (Lens), and a small hole can be formed above the optical Lens through a shading material and matched with the optical Lens to collect fingerprint detection light to an optical fingerprint sensor below so as to realize fingerprint imaging. Similarly, each optical fingerprint sensor may be configured with one optical lens for fingerprint imaging, or the plurality of optical fingerprint sensors may use the same optical lens for light collection 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 simultaneously configured to optically image the two or more sensing arrays, thereby reducing imaging distance and enhancing imaging effect.

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

The optical fingerprint identification technology under the screen generally adopts light emitted by the screen as a light source, an optical signal emitted by the screen reaches a finger above the screen, the optical signal after reflection or scattering of the finger carries fingerprint information of the finger, and the optical signal carrying the fingerprint information can be received by a fingerprint sensor below the screen for fingerprint identification.

The existing under-screen optical fingerprint identification is realized under an OLED screen at present, and utilizes the light transmission characteristic of the OLED screen, and the light signal emitted by the screen irradiates the finger, and the reflected light signal after 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, and the fingerprint recognition device 330 includes a light path guiding structure 331 and a fingerprint sensor 332, the fingerprint sensor 332 may be electrically connected to a circuit board 333, and the circuit board 333 may be a substrate or a flexible printed circuit board (FPC flexible printed circuit, FPC). Display screen 320 may include a light-emitting layer 322, a component 321 positioned above light-emitting layer 322, and a component 323 positioned below light-emitting layer 322. In the fingerprint identification process, the finger 310 may press the fingerprint detection area on the display screen, and after the light signal emitted by the display screen 320 irradiates the finger, the light signal is received by the fingerprint sensor 332 under the display screen 320 after reflection of the finger, and the fingerprint sensor 332 may generate a 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 below the screen to achieve the fingerprint detection function, but the distance Y between the lower surface of the screen and the upper surface of the fingerprint identification device is difficult to test and accurate when leaving the factory, namely the installation position of the fingerprint identification device is difficult to test and accurate, and the distance Y can be guaranteed to be within a certain range only through a structure processing technology at the present stage. In addition, when the consumer uses, the screen is pressed by different people, and the distance Y can be fluctuated due to different pressing forces.

The size of the distance Y can affect the quality of the fingerprint image, for example, the difference between the distance Y after installation and the preconfigured distance Y can lead to the reduction of the optical signal received by the fingerprint identification device, thereby affecting the quality of the fingerprint image, for example, the size of the distance Y can also affect the size of the fingerprint image, therefore, if the accurate value of the distance Y can be obtained in real time, the fingerprint image can be corrected in real time through an algorithm, thereby ensuring that the fingerprint image cannot be degraded due to the distance Y, and further effectively improving the 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 fingerprint detection performance. The method is suitable for electronic equipment with a display screen and a 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 oblique light signal, wherein the first oblique light signal is an oblique light signal sent by the light-emitting unit and directed to the fingerprint identification device.

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

And S630, 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 are used for fingerprint identification.

In the embodiment of the present application, the first oblique light signal is an oblique light signal emitted by the light emitting unit and directly irradiated to the fingerprint recognition device, and the second oblique light signal is an oblique light signal emitted by the light emitting unit and reflected by the device surface before reaching the fingerprint recognition device, and is described in detail below 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 directed to the fingerprint recognition device, and the fingerprint recognition device may generate the original image 340 according to the received light signal 361. The other part of the light signals 362,363 (second oblique light signal) emitted from the light emitting layer 322 reaches the fingerprint recognition device after being reflected by the device surface, and the fingerprint recognition device generates the smear image 350 according to the received light signals 362, 363.

It will be appreciated that if a vertical light signal is present, there is no smear image, and therefore embodiments of the present application use a tilted light signal to generate a smear image.

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

The oblique optical signal 363 has a larger signal intensity than the oblique optical signal 362, and the smear image generated according to the oblique optical signal 363 can reflect the distance Y between the fingerprint recognition device and the display screen, so the embodiment of the 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 from the second oblique optical signal is shifted or shifted in the horizontal direction from the original image generated from the first oblique optical signal by a distance X which is actually related to a distance Y, as shown in fig. 8, and the larger the distance Y, the larger the distance X. Therefore, the embodiment of the application can utilize the positive correlation relation between the distance X and the distance Y, and can correct the fingerprint data collected by the fingerprint identification device by detecting the distance X, thereby improving the fingerprint identification performance.

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

The relative positional relationship between the smear image and the original image in fig. 7 and 8 is only one example, and does not represent an actual positional relationship. The distances in the vertical direction of the smear image and the original image shown in fig. 7 and 8 do not represent actual distances, but only in order to more clearly express the smear image and the original image, which are generally in one horizontal direction.

In the embodiment of the application, besides the OLED screen serving as the light-emitting unit, an external light source such as a light-emitting diode (light emitting diode, LED) lamp can be used as the light-emitting unit, the LED lamp can be arranged at a position between the lower part of the display screen and the upper surface of the fingerprint identification device, and the LED lamp is offset by a certain distance relative to the fingerprint identification device, so that the purpose that the LED lamp can emit inclined light signals to the fingerprint identification device is realized.

In the embodiment of the application, the fingerprint data is corrected according to the distance X between the original image and the smear image, and the fingerprint data can be corrected according to the 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 condition of the fingerprint data corresponding to different distances X is obtained through testing, and then the correction parameters corresponding to different distances X are determined. After the fingerprint recognition device is mounted on the electronic equipment, the fingerprint data is corrected by measuring the distance X.

For example, the correction of the fingerprint data according to the distance X may also be that the distance Y between the upper surface of the fingerprint recognition device and the lower surface of the display screen is determined according to the distance X, and the fingerprint data collected by the fingerprint recognition device is corrected according to the distance Y. Before the fingerprint identification device leaves the factory, a plurality of distances Y (Y1, Y2, …, yn) are adjusted on a specific screen through a jig, and corresponding smear distances X (X1, X2, …, xn) are respectively tested, so that a 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 mounted 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 relationship, and the distance X and the distance Y are in a linear relationship, where the relationship between the distance X and the distance Y may be expressed as y=k×x+b, where k and b are constants.

Before the equipment leaves the factory, a plurality of distances X corresponding to the distances Y can be obtained through the process, so that parameters k and b can be calculated, that is, k and b can be configured in advance according to different distances Y and corresponding different distances X. Since the distance Y and the distance X are linear, 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 accuracy, at least 3 groups of data can be tested, so that solutions of multiple groups of k and b can be obtained, and then the average value of the solutions is calculated.

After the test is finished, the k and b obtained by the test can be written into a flash memory (flash) or a one-time programmable (one time programmable, OTP) memory which are arranged in the fingerprint identification device, or stored in the whole machine for use when the algorithm of the whole machine is called.

Fig. 9 shows a schematic flow chart of a method of acquiring the correspondence between the distance X and the distance Y.

Before testing the distance, the fingerprint sensor may be initialized, the OLED display screen 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 the gravity center algorithm. By testing the corresponding distance X at different distances Y, the parameters k and b can be solved by taking the formula y=k x+b.

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

Fig. 11 is a schematic flowchart showing a process of actually detecting a distance. After initializing a preset pattern, calculating the center between the smear image and the original image by using a center algorithm, calculating the distance X through the centers of the two images, and then calculating the corresponding distance Y in real time according to the formula Y=k x+b. In practical applications, taking the average of the data multiple times can be considered 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 preset 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 an optical signal emitted from a preset pattern.

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

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

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

To further improve the detection accuracy, the areas of the different light emitting areas may be different, or the shapes of the different light emitting areas may be different. Taking a circular light emitting area as an example, the diameters of the different light emitting areas may be different.

In addition, in order to detect distances of the original image and the smear image in different directions, 3 light emitting areas may be included on the display screen, centers of the 3 light emitting areas are not on a straight line, that is, the centers of the 3 light emitting areas may constitute a triangle. As shown in fig. 12, the line connecting the centers of the 3 circular spots is triangular. Of course, embodiments of the present application may also employ more than 3 light emitting regions, as long as the centers of the 3 light emitting regions are not on a straight line.

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

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

The fingerprint recognition device in the embodiment of the application can comprise an optical path guiding structure and a fingerprint sensor, wherein the fingerprint sensor can comprise a sensing array with a plurality of sensing units, and the optical path guiding structure is used for guiding the first inclined optical signal and the second inclined optical signal to the sensing array.

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

It will be appreciated that the optical path guiding structure may be 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 the detection light signal emitted by the light-emitting unit, irradiated to the finger and reflected by the finger, and generating fingerprint data according to the detection light signal.

The optical signal for detecting the distance is an oblique optical signal as described above, 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 an oblique optical signal. That is, the detection light signal is perpendicular or inclined with respect to the display screen.

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

Fig. 13 shows a scheme in which a tilt light signal is used for detecting a distance, and a vertical light signal is used for fingerprint detection. The fingerprint sensor comprises 4 sensing units, wherein 3 sensing units can be used for receiving vertical light signals so as to perform fingerprint detection. And some or all of the 4 sensing units may be used to receive oblique light signals for distance detection.

The scheme can be realized by combining oblique receiving and vertical receiving of the fingerprint sensor and setting different light emitting areas and special light path guiding structures. The optical path guiding structure may guide both the vertical optical signal and the oblique optical signal.

If the optical path guiding structure can guide only one direction of the optical signal, i.e., the detected optical signal, the first oblique optical signal, and the second oblique optical signal have the same inclination angle, the fingerprint detection process and the distance detection process may be performed separately. The distance detection may be performed, for example, during periods when no fingerprint detection is 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, so that the fingerprint image can be corrected more accurately. However, in order to reduce the processing complexity, fingerprint detection and distance detection may also be performed separately.

In addition, the embodiment of the present application further provides a fingerprint recognition device for being disposed under a display screen, and as shown in fig. 14, the fingerprint recognition 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 an induction array of the fingerprint sensor, where the first oblique light signal is an oblique light signal sent by the light emitting unit and directed to the fingerprint recognition device, and the second oblique light signal is a oblique light signal sent by the light emitting unit and directed to the surface of the fingerprint recognition device, and reflected by the surface of the fingerprint recognition device and reflected by the lower surface of the display screen, and then reaches the fingerprint recognition device. The fingerprint sensor 1420 includes a sensing array having a plurality of optical sensing units, the sensing array configured to generate an original image based on a first oblique optical signal and generate a smear image based on a second oblique optical signal, the original image and the smear image being configured to correct fingerprint data collected by a fingerprint recognition device, the corrected fingerprint data being configured for fingerprint recognition.

The form of the optical path guiding structure according to the embodiment of the present application is not particularly limited, and the optical path guiding structure may be any of the forms described above.

The light path guiding structure may include, for example, a microlens array for being disposed between the display screen and the fingerprint sensor, and at least one light blocking layer, and the microlens array may include a plurality of microlenses for converging the received light signals. The at least one light blocking layer comprises a plurality of openings corresponding to the microlenses respectively, and the 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.

The projection of the converging surface of the micro lens on a plane perpendicular to the optical axis of the micro lens can be round or square, and of course, the converging surface of the micro lens can also be in other shapes; the condensing surface of the microlens may be spherical or aspherical, and the embodiment of the present application is not particularly limited thereto.

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

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 microlens 511 shown in fig. 16 has a square shape projected directly thereunder, which is also referred to as a square microlens 511. It can be seen that by closely arranging the rectangular microlenses 511, gaps do not exist between adjacent microlenses 511, so that a higher condensing area ratio can be obtained, more image information can be obtained, and thus fingerprint recognition performance can be improved.

The converging surface of the micro lens is a surface for converging light rays. The embodiment of the application does not limit the surface shape of the collecting surface, and can be spherical or aspherical. Preferably, the curvature of the collecting surface in each direction is the same, so that the imaging focuses in each direction of the microlens are at the same position, thereby ensuring the imaging quality.

Next, a fingerprint recognition device according to an embodiment of the present application will be described 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 further have two condensing surfaces, and the projection areas of the two condensing surfaces are rectangular, and the two condensing surfaces are symmetrical to form a shape similar to a convex lens, so as to achieve a better condensing effect on light.

In addition, the microlenses in the microlens array 510 according to the embodiment of the present application may be other polygonal microlenses, that is, the microlenses may be forward projected as polygons, such as hexagons, in addition to rectangular microlenses. These microlenses, once tightly spliced together, can eliminate or reduce the gap 620 described above.

Optionally, the microlens array 510 further includes a base material under the plurality of microlenses, the base material 512 having the same refractive index as the material of the microlenses, thereby reducing light loss due to abrupt refractive index changes.

Optionally, the device 500 further comprises a filter layer 530, wherein the filter layer 530 is arranged above the microlens array 510 or between the microlens array 510 and the fingerprint sensor 520, and the filter layer 530 is arranged to transmit light 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 a transparent adhesive layer 532 is filled.

The transparent adhesive layer 532 may be, for example, an optically clear adhesive (Optically Clear Adhesive, OCA), a transparent glue, a transparent adhesive film, or the like.

The transparent glue layer 532 is an optical glue with low refractive index, and compared with fig. 18, fig. 19 reduces one layer of air interface, so that stray light can be reduced, light loss is less, and better fingerprint performance is achieved.

The microlens array 510 may be surrounded by a light shielding material 534, for example, black foam may be used to perform a light shielding process, so as to prevent stray light around the microlens array 510 from entering the microlens array 510, thereby 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 mode of integrating the optical filter layer 510 with the optical fingerprint sensor 520 is not limited in this embodiment of the present application, for example, an evaporation process may be used to perform a film plating on the optical sensing unit of the optical fingerprint sensor 520 to form the optical filter layer 530, for example, a film of the optical filter material may be prepared above the optical sensing unit of the optical fingerprint sensor 520 by an atomic layer deposition, a sputtering film plating, an electron beam evaporation film plating, an ion beam film plating, or the like. Preferably, the thickness of the filter layer 530 may be 20 μm or less.

Taking fig. 18 to 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 light sensing units and a light blocking layer 551 positioned above the plurality of sensing units. The light blocking layer 551 includes a plurality of openings, for example, openings 5511, each of the openings corresponds to one of the optical sensing units, for example, the opening 5511 corresponds to the optical sensing unit 521, and the opening 5511 is configured to enable an oblique optical signal at a predetermined angle to reach the optical sensing unit 521 corresponding to the opening 5511 and block light rays in other directions from affecting the oblique optical signal. The microlens array 510 is composed of a plurality of microlenses, and the refractive index of the base material 512 located under the microlens array 510 may be equal to that of the microlenses, for example, so as to reduce light loss caused by abrupt refractive index changes.

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

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

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

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

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 recognition, but the location and type of the filter layer 530 are not limited in the present application.

The present application uses oblique light signals for distance detection, as illustrated in fig. 18 to 20, and light entering the micro lens 511 at an angle i can be converged by the micro lens 511 and reach the optical sensing unit 521 through the opening 5511. While the light rays of the remaining angles are blocked by the light blocking layer 551.

The openings in each light blocking layer, in addition to realizing optical path guiding, can also effectively prevent light crosstalk and block stray light, so that only light satisfying the above-mentioned preset angle i can pass through the light blocking layer to reach the optical fingerprint sensor 520.

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

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

As another example, fig. 21 shows a case where two light blocking layers are present. Fig. 21 adds 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 relevant components in fig. 21 may be referred to the description of fig. 20.

As another example, fig. 22 shows a case where three light blocking layers are present. Fig. 22 adds a light blocking layer 552 and a light blocking layer 553 on the basis of fig. 20, and a transparent dielectric layer 561 is filled between the light blocking layer 552 and the light blocking layer 553, and a transparent dielectric layer 562 is filled between the light blocking layer 553 and the filter layer 530. Other relevant components in fig. 22 may be referred to the description of fig. 20.

Further, optionally, the inclination angle of the connection line of the opening corresponding to the same microlens in the different light blocking layers is the same as the inclination angle of the inclined optical signal.

The openings in the different light barrier layers corresponding to the same microlens should have a lateral offset between them and the lines of the openings in the different light barrier layers should pass through the corresponding optical sensing unit so that the oblique optical signal can reach the optical sensing unit.

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

Also, the vertical distances between adjacent two light blocking layers may be equal or unequal.

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

Optionally, each microlens corresponds to one optical sensing unit of the optical fingerprint sensor 520, wherein the openings corresponding to the same microlens in different light blocking layers are used to sequentially guide the oblique optical signals converged by the microlens to the optical sensing unit corresponding to the microlens.

Further, optionally, the wires of the openings corresponding to the same microlens in different light blocking layers pass through the 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 its corresponding optical sensing unit to ensure that the oblique optical signal can reach the center region of the optical sensing unit, thereby achieving superior photoelectric conversion efficiency.

For example, as shown in fig. 22, the light that reaches the microlens 511 at the 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 of the optical fingerprint sensor 520 itself in this order, and finally reaches the optical sensing unit 521. The opening 5531 is offset to the left relative to the opening 5531 by a certain distance, the opening 5511 is offset to the left relative to the opening 5531 by a certain distance, and the central lines of the opening 5521, the opening 5531 and the opening 5511 can pass through the corresponding optical sensing unit 521, so that the oblique light can be guided.

Since the microlenses have a converging effect on light, the angle of the converging light beam becomes narrower as it travels downward. Therefore, optionally, the openings corresponding to the same micro lenses 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 receiving of the light is realized, the collimation degree is ensured, meanwhile, unnecessary light can be effectively attenuated, and the definition of the optical fingerprint image acquired by the optical fingerprint sensor 520 is further improved. For example, as shown in fig. 22, the apertures 5521, 5531, and 5511 corresponding to the same microlens 511 are sequentially reduced.

In fig. 21 and 22, the last light blocking layer, where the oblique light signal arrives, 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 can be connected through a transparent medium layer. For example, in fig. 22, the light blocking layer 551 is integrated in the optical fingerprint sensor 520, the light blocking layer 552 and the light blocking layer 553 are connected by the transparent dielectric layer 561, and the light blocking layer 553 and the filter layer 530 are connected by the transparent dielectric layer 562. Preferably, the refractive index of the transparent dielectric layer 561 and the transparent dielectric layer 562 may be the same as that of the base material 512 of the microlens array 510 and the same as that of the microlens array 510, thereby reducing light loss caused by abrupt refractive index changes.

However, the implementation of the present application is not limited to this, and other means 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 stuck together by transparent glue or an adhesive film, or the like.

Since the aperture on each light-blocking layer has a certain size, the inclination angle of the optical signal selected through the light-blocking layer is not a fixed value, but within a certain range, the collimation angle of the inclined 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 the above-described optical fiber alignment by multiple light blocking layers, embodiments of the present application provide other ways of alignment, as shown in FIGS. 23-25.

Fig. 23 shows a manner of selecting an oblique optical signal by using a collimating aperture 741, wherein a light-transmitting material or air is arranged in the aperture of the collimating aperture 741, a light-absorbing material is arranged on the aperture wall, when the collimating aperture is vertically arranged, the perpendicular incident light is guided, and when the collimating aperture is inclined according to the receiving angle, the oblique optical signal is guided. For example, when the angle of inclination of the collimation small hole 741 is β, an optical signal having the angle of inclination β can be guided.

The collimation holes 741 are disposed on the opaque substrate 740, and when the finger 710 is pressed against the display screen 730, the inclined optical signal 720 reflected by the finger can be guided to the fingerprint sensor 750 by the collimation holes 741, and the fingerprint sensor 750 can perform fingerprint identification according to the received optical signal.

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

Fig. 24 shows a collimation hole for guiding the oblique optical signal to the fingerprint sensor by total reflection, the axis of the collimation hole being perpendicular to the surface of the display screen. The refractive index of the interior and the exterior of the collimation hole are different, and only the incident light signal conforming to the total reflection angle is selected through the total reflection principle. For example, the optical signal 720 is an optical signal according to the angle of total reflection, and after the optical signal 720 reaches the collimation hole 742, total reflection occurs in the collimation hole 742, so as to form an optical signal 760, and the fingerprint sensor 750 can perform fingerprint recognition according to the optical signal 760.

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

The collimation process shown in fig. 23 to 25 may be achieved by optical fibers.

In addition to the above-described structure of the microlens array, the method of the embodiment of the present application can 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 can collect optical signals 760 reflected by a finger to a fingerprint sensor 750.

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

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

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

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

The embodiment of the application also provides electronic equipment which comprises the fingerprint identification device in the various embodiments of the application.

Fig. 27 is a schematic block diagram of an electronic device according to an embodiment of the present application. The electronic device 1000 comprises 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 fingerprint 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-emissive display such as an OLED screen.

The display may be a conventional non-folding display, which may also be a foldable display, or a so-called flexible display.

The fingerprint recognition device 1020 may be any of the fingerprint recognition devices described above, and is not described herein for simplicity.

The processor 1030 may be configured 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 noted that the terminology used in the embodiments of the application and in the appended claims is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the application.

For example, as used in the embodiments of the 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 will appreciate that the 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 solution. 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 as a software functional unit and sold or used as a stand-alone product, may be stored on a computer readable storage medium. Based on such understanding, the technical solution of the embodiments of the present application may be embodied in essence or a part contributing to the prior art or a part of the technical solution, in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method of the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a U disk, a mobile hard disk, a read-only memory, a random access memory, a magnetic disk or an optical disk.

It will be clearly understood by those skilled in the art that, for convenience and brevity of description, specific working procedures of the apparatus, device and unit described above may refer to corresponding procedures in the foregoing method embodiments, which are not repeated herein.

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 manners.

For example, the division of units or modules or components in the above-described apparatus embodiments is merely a logic function division, and there may be another division manner in actual implementation, for example, multiple 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 performed.

As another example, the units/modules/components described above as separate/display components may or may not be physically separate, i.e., may be located in one place, or may be distributed over multiple network elements. Some or all of the units/modules/components may be selected according to actual needs to achieve the objectives of the embodiments of the present application.

Finally, it is pointed out that the coupling or direct coupling or communication connection between the various elements shown or discussed above can be an indirect coupling or communication connection via interfaces, devices or elements, which can be in electrical, mechanical or other forms.

The foregoing is merely a specific implementation of the embodiment of the present application, but the protection scope of the embodiment of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the embodiment of the present application, and the changes or substitutions are covered by the protection scope of the embodiment 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 identification, the method being applicable to an electronic device having a display screen and a fingerprint identification apparatus disposed below the display screen, the method comprising:

acquiring an original image generated by a fingerprint identification device according to a received first inclined light signal, wherein the first inclined light signal is an inclined light signal which is sent 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 light signal, wherein the second inclined light signal is an inclined light 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 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 between the original image and the smear image so as to correct fingerprint data acquired by the fingerprint identification device, wherein the corrected fingerprint data are used for fingerprint identification.

2. The method of claim 1, wherein the relationship between the distance Y and the distance X is Y = k x+b, wherein k, b are both constants.

3. The method according to claim 2, wherein k and b are pre-configured according to different distances Y and corresponding different distances X.

4. The method of claim 1, 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 from light signals emitted by light emitting pixels on at least one light emitting area on the OLED screen.

5. The method of claim 4, wherein the at least one light emitting region is circular in shape.

6. The method of claim 4, wherein the areas of different ones of the at least one light emitting regions are different.

7. The method of claim 4, wherein the at least one light emitting region comprises 3 light emitting regions, the centers of the 3 light emitting regions not being on a straight line.

8. The method of claim 1, wherein the first oblique optical signal and the second oblique optical signal are at an oblique angle of 10 ° to 50 °.

9. The method of any of claims 1-8, wherein the fingerprint recognition device comprises a light path guiding structure and a fingerprint sensor, the fingerprint sensor comprising a sensing array having a plurality of optical sensing units, the light path guiding structure for guiding the first oblique light signal and the second oblique light signal to the sensing array.

10. The method of claim 9, 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.

11. The method of claim 10, wherein the detection light signal is perpendicular or oblique to a surface of the display screen.

12. A fingerprint recognition device for use in an electronic device having a display screen, the fingerprint recognition device being configured to be disposed below the display screen, the fingerprint recognition device comprising:

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

the fingerprint sensor comprises an induction array with a plurality of optical induction units, wherein the induction array is used for generating an original image according to the first inclined light signals and generating a smear image according to the second inclined light signals, the distance X between the original image and the smear image is used for determining the distance Y between the upper surface of the fingerprint identification device and the lower surface of the display screen so as to correct fingerprint data acquired by the fingerprint identification device, and the corrected fingerprint data are used for fingerprint identification.

13. The fingerprint recognition device of claim 12, wherein the light path guiding structure comprises a microlens array for positioning between the display screen and the fingerprint sensor, the microlens array comprising a plurality of microlenses for converging 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 holes corresponding to the micro lenses respectively, and inclined light signals converged by each micro lens pass through the holes corresponding to the micro lenses in different light blocking layers to reach the optical sensing unit of the fingerprint sensor.

14. The fingerprint recognition device according to claim 13, wherein the projection of the condensing surface of the microlens on a plane perpendicular to the optical axis thereof is circular or square.

15. The fingerprint recognition device of claim 13, wherein a last one of the at least one light blocking layer is integrated in the fingerprint sensor.

16. The fingerprint recognition device according to claim 13, wherein each of the microlenses corresponds to one optical sensing unit of the fingerprint sensor, wherein openings corresponding to the same microlens in different light blocking layers are used to sequentially guide the first oblique optical signal and the second oblique optical signal converged by the microlens to the optical sensing unit corresponding to the microlens.

17. The fingerprint recognition device of claim 13, further comprising a filter layer for transmitting optical signals in the visible wavelength range.

18. The fingerprint recognition device of claim 17, wherein the filter layer is integrated on the fingerprint sensor.

19. The fingerprint recognition device of claim 17, wherein 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.

20. The fingerprint identification device of claim 19, wherein the transparent glue layer is surrounded by a light shielding material.

21. The fingerprint recognition device according to claim 12, wherein the optical path guiding structure comprises a lens for converging the first oblique light signal and the second oblique light signal to the fingerprint sensor, the light emitting unit for emitting the first oblique light signal and the second oblique light signal on an edge region of a field angle of the lens.

22. The fingerprint recognition device of claim 21, wherein the light emitting unit is a light emitting pixel of an organic light emitting diode OLED screen, 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, the at least one light emitting area being located at an edge area of an interface area with a field angle of view of the lens on the OLED screen.

23. The fingerprint recognition device according to claim 12, wherein the fingerprint sensor is further configured to receive a detection light signal emitted from 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.

24. The fingerprint recognition device of claim 23, wherein the detection light signal is perpendicular or oblique to a surface of the fingerprint recognition device.

25. The fingerprint recognition device of claim 12, wherein the display screen is an organic light emitting diode, OLED, screen, the first oblique light signal and the second oblique light signal being formed by light signals emitted by light emitting pixels on at least one light emitting area on the OLED screen.

26. The fingerprint identification device of claim 25, wherein the at least one light emitting area is circular in shape.

27. The fingerprint identification device of claim 25, wherein the areas of different ones of the at least one light emitting areas are different.

28. The fingerprint identification device of claim 25, wherein said at least one light emitting area comprises 3 light emitting areas, the center of said 3 light emitting areas not being on a straight line.

29. The fingerprint identification device according to any one of claims 12-28, wherein the first oblique light signal and the second oblique light signal have an angle of inclination of 10 ° -50 °.

30. An electronic device, comprising:

a display screen;

and a fingerprint recognition device as claimed in any one of claims 12 to 29;

and the processor is used for acquiring the original image and the smear image, and determining the distance Y between the upper surface of the fingerprint identification device and the lower surface of the display screen according to the distance X between the original image and the smear image so as to correct the fingerprint data acquired by the fingerprint identification device, wherein the corrected fingerprint data are used for fingerprint identification.

31. The electronic device of claim 30, wherein the relationship between the distance Y and the distance X is Y = k X + b, wherein k, b are both constants.

32. The electronic device of claim 31, wherein k and b are pre-configured according to different distances Y and corresponding different distances X.

33. The electronic device of claim 30, 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 from light signals emitted by light emitting pixels on at least one light emitting area on the OLED screen.

34. The electronic device of claim 33, wherein the at least one light emitting region is circular in shape.

35. The electronic device of claim 33, wherein areas of different ones of the at least one light emitting regions are different.

36. The electronic device of claim 33, wherein the at least one light emitting region comprises 3 light emitting regions, the center of the 3 light emitting regions not being on a straight line.

37. The electronic device of any one of claims 30-36, wherein the first oblique light signal and the second oblique light signal are at an oblique angle of 10 ° to 50 °.