WO2020181489A1

WO2020181489A1 - Fingerprint recognition device, fingerprint recognition method and electronic device

Info

Publication number: WO2020181489A1
Application number: PCT/CN2019/077831
Authority: WO
Inventors: 姚国峰; 沈健
Original assignee: 深圳市汇顶科技股份有限公司
Priority date: 2019-03-12
Filing date: 2019-03-12
Publication date: 2020-09-17
Also published as: CN110062931A; CN110062931B

Abstract

Provided are a fingerprint recognition device and a fingerprint recognition method, which may improve the performance of fingerprint recognition. The device comprises: an optical path guiding structure, that is disposed below a display screen and that is used to guide an inclined optical signal, which is reflected from a finger when the finger is illuminated in a pressing area of the display screen and which has a certain angle, to a sensing unit located below a first area of the display screen in an image acquisition module, the first area being located within a non-pressing area of the display screen; and the image acquisition module, which is disposed below the optical path guiding structure and which is used to acquire a fingerprint image of the finger according to the inclined optical signal.

Description

Fingerprint identification device, fingerprint identification method and electronic equipment

Technical field

This application relates to the field of information technology, and more specifically, to a fingerprint identification device, a fingerprint identification method, and electronic equipment.

Background technique

The fingerprint recognition technology under the optical screen is the reflected light formed by collecting the light emitted by the light source and reflected on the finger, and the reflected light carries the fingerprint information of the finger, so as to realize the fingerprint recognition under the screen. For special fingers, such as relatively dry fingers, there is an air gap between the valley of the fingerprint and the display screen. This air gap will cause severe diffuse scattering of light, which will affect the difference in the reflection of light by the ridges and valleys of the fingerprint. The contrast of the fingerprint image obtained by the reflected light imaging will decrease, which affects the performance of fingerprint recognition.

Summary of the invention

The embodiments of the present application provide a fingerprint identification device, a fingerprint identification method, and an electronic device, which can improve fingerprint identification performance.

In a first aspect, a fingerprint identification device is provided, including: a light path guide structure, which is arranged under the display screen, and is used to irradiate the finger from the pressing area of the display screen with an oblique light signal with a specific angle reflected from the finger , Guide to the sensing unit in the image acquisition module located below the first area of the display screen, the first area is located in the non-pressing area of the display screen; the image acquisition module is arranged in the light path guiding structure The lower part is used to obtain the fingerprint image of the finger according to the oblique light signal.

In a possible implementation, the light path guiding structure is further used to guide the vertical light signal reflected from the finger when the finger is irradiated from the pressing area to the image acquisition module located in the pressing area. A sensing unit below the area; wherein the image acquisition module is configured to: if acquiring the fingerprint image according to the vertical light signal fails, acquire the fingerprint image according to the oblique light signal.

In a possible implementation manner, the exposure time used by the image acquisition module to collect the oblique light signal is greater than the exposure time used to collect the vertical light signal.

In a possible implementation manner, the light path guiding structure includes: a microlens array, wherein a microlens located under the pressing area is used to converge the vertical optical signal, and a microlens located under the first area The microlens is used to converge the oblique light signal; a light blocking layer is arranged below the microlens array, and the light blocking layer includes a plurality of openings corresponding to the plurality of microlenses, wherein each opening It is used to guide the light signal condensed by the corresponding micro lens to the image acquisition module.

In a possible implementation manner, the device further includes a processing module configured to obtain information about the pressing area and the first area, wherein the pressing area and the first area The distance between is determined according to the following information: the height between the display screen and the image acquisition module, the distance between adjacent openings in the light blocking layer, and the focal length of the microlens.

In a possible implementation manner, the distance between the pressing area and the first area is d, d=h×s/f, where h is between the display screen and the image acquisition module The height of, s is the distance between adjacent openings in the light blocking layer, and f is the focal length of the micro lens.

In a possible implementation manner, the first area is located in a shadow area covered by the finger and not in contact with the finger in the non-pressing area.

In a possible implementation manner, the area of the first area is equal to the area of the pressing area.

In a possible implementation manner, the image acquisition module is formed by splicing multiple optical fingerprint sensors.

In a possible implementation manner, the image acquisition module includes an optical fingerprint sensor.

In a second aspect, a fingerprint identification method is provided, the method is executed by a fingerprint identification device, the device includes a light path guide structure and an image acquisition module sequentially arranged below the display screen, and the method includes: the light path guide structure The oblique light signal with a specific angle reflected from the finger when the finger is irradiated from the pressing area of the display screen is guided to the sensing unit in the image acquisition module located below the first area of the display screen, so The first area is located in a non-pressing area of the display screen; the image acquisition module obtains a fingerprint image of the finger according to the oblique light signal.

In a possible implementation, the method further includes: the optical path guide junction will guide the vertical light signal reflected from the finger when the finger is irradiated in the pressing area to the image acquisition module located in the The sensing unit below the pressing area; wherein the image acquisition module acquires the fingerprint image of the finger according to the oblique light signal, including: if the image acquisition module fails to acquire the fingerprint image according to the vertical light signal , The fingerprint image is acquired according to the oblique light signal.

In a possible implementation, the light path guiding structure includes: a microlens array, wherein a microlens located under the pressing area is used to converge the vertical optical signal, and a microlens located under the first area The microlens is used to converge the oblique light signal; a light blocking layer is arranged below the microlens array, and the light blocking layer includes a plurality of openings corresponding to the plurality of microlenses, wherein each opening It is used to guide the light signal condensed by the corresponding micro lens to the image acquisition module.

In a possible implementation manner, the fingerprint identification device further includes a processing module configured to obtain information about the pressing area and the first area, wherein the pressing area and the first area The distance between a region is determined according to the following information: the height between the display screen and the image acquisition module, the distance between adjacent openings in the light blocking layer, and the focal length of the microlens.

In a third aspect, a terminal device is provided, including the fingerprint identification device in the first aspect or any possible implementation of the first aspect.

Based on the above technical solution, the optical path guide structure in the fingerprint identification device can guide the light source to illuminate the finger in the finger pressing area and the oblique light signal reflected by the finger to the sensor located below the specific area in the finger non-press area in the image acquisition module Unit, so that the image acquisition module acquires the fingerprint image of the finger according to the oblique light signal. Since the diffuse reflection intensity of oblique light on the finger is lower than the diffuse reflection intensity of vertical light, special fingers that are prone to diffuse reflection during fingerprint recognition, such as dry fingers, can improve the contrast of the captured fingerprint image. Improve fingerprint detection performance.

Description of the drawings

Fig. 1 is a schematic diagram of the structure of an electronic device to which this application can be applied.

Fig. 2 is a schematic diagram of a fingerprint identification device adopting a multi-sensor splicing method.

Figure 3 is a schematic diagram of a normal finger when performing fingerprint detection.

Figure 4 is a schematic diagram of a dry finger when performing fingerprint detection.

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

FIG. 6 is a schematic diagram of the principle of fingerprint recognition in an embodiment of the present application.

FIG. 7 is a schematic diagram of the principle of fingerprint recognition in an embodiment of the present application.

Fig. 8 is a schematic structural diagram of an optical path guide structure of an embodiment of the present application.

FIG. 9 is a schematic flowchart of a fingerprint identification method according to an embodiment of the present application.

FIG. 10 is a schematic flowchart of a specific implementation manner of the fingerprint identification method according to an embodiment of the present application.

FIG. 11 is a schematic block diagram of an electronic device according to an embodiment of the present application.

detailed description

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

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

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

As shown in FIG. 1 is a schematic structural diagram of a terminal device to which the embodiment of the application can be applied. The terminal device 10 includes a display screen 120 and an optical fingerprint device 130, wherein the optical fingerprint device 130 is disposed under the display screen 120 Local area. The optical fingerprint device 130 includes an optical fingerprint sensor, and the optical fingerprint sensor includes a sensing array 133 having a plurality of optical sensing units 131. The area where the sensing array is located or its sensing area is the fingerprint collection area 121 of the optical fingerprint device 130. As shown in FIG. 1, the fingerprint collection area 121 is located in the display area of the display screen 120. In an alternative embodiment, the optical fingerprint device 130 may also be arranged in other positions, such as the side of the display screen 120 or the non-transparent area of the edge of the terminal device 10, and the optical fingerprint device 130 may be designed to The optical signal of at least a part of the display area of the display screen 120 is guided to the optical fingerprint device 130, so that the fingerprint collection area 121 is actually located in the display area of the display screen 120. In an alternative embodiment, the optical fingerprint device 130 may also be arranged in other positions, such as the side of the display screen 120 or the non-transparent area of the edge of the terminal device 10, and the optical fingerprint device 130 may be designed to The optical signal of at least part of the display area of the display screen 120 is guided to the optical fingerprint device 130, so that the fingerprint collection area 121 is actually located in the display area of the display screen 120.

It should be understood that the area of the fingerprint collection area 121 may be different from the area of the sensing array of the optical fingerprint device 130, for example, through a light path design such as lens imaging, a reflective folding light path design, or other light path design such as light convergence or reflection, The area of the fingerprint collection area 121 of the optical fingerprint device 130 can be made larger than the area of the sensing array of the optical fingerprint device 130. In other alternative implementations, if for example, light collimation is used for light path guidance, the fingerprint collection area 121 of the optical fingerprint device 130 may also be designed to be substantially the same as the area of the sensing array of the optical fingerprint device 130.

Therefore, when the user needs to unlock the terminal device or perform other fingerprint verification, he only needs to press his finger on the fingerprint collection area 121 located on the display screen 120 to realize fingerprint input. Since fingerprint detection can be implemented in the screen, the terminal device 10 adopting the above structure does not need to reserve a space on the front side for the fingerprint button (such as the Home button), so that a full screen solution can be adopted, that is, the display area of the display screen 120 It can be basically extended to the front of the entire terminal device 10.

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

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

Wherein, the light guide layer or the light path guide structure in the optical component 132 has multiple implementation solutions. For example, the light guide layer may specifically be a collimator (Collimator) layer made on a semiconductor silicon wafer, which has A plurality of collimating units or micro-hole arrays, the collimating unit may be specifically a small hole, among the reflected light reflected from the finger, the light that is perpendicularly incident on the collimating unit can pass through and be sensed by the light below it The unit receives, and the light whose incident angle is too large is attenuated by multiple reflections inside the collimating unit. Therefore, each optical sensor unit can basically only receive the reflected light reflected by the fingerprint pattern directly above it. The sensor array can detect the fingerprint image of the finger.

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

In other implementations, the light guide layer or the light path guide structure may also specifically adopt a micro-lens (Micro-Lens) layer. The micro-lens layer has a micro-lens array formed by a plurality of micro-lenses, which can be grown by semiconductors. A process or other processes are formed above the sensing array of the light detecting part 134, and each microlens may correspond to one of the sensing units of the sensing array. In addition, other optical film layers may be formed between the microlens layer and the sensing unit, such as a dielectric layer or a passivation layer. More specifically, between the microlens layer and the sensing unit, a light blocking layer (or called a light shielding layer) with microholes may also be included, wherein the microholes are formed between the corresponding microlens and the sensing unit. In between, the light blocking layer can block the optical interference between the adjacent microlens and the sensing unit, and make the light corresponding to the sensing unit converge into the microhole through the microlens and pass through the microhole. It is transmitted to the sensing unit for optical fingerprint imaging.

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

As an optional implementation manner, the display screen 120 may adopt a display screen with a self-luminous display unit, such as an organic light-emitting diode (Organic Light-Emitting Diode, OLED) display or a micro-LED (Micro-LED) display. Screen. Taking an OLED display screen as an example, the optical fingerprint device 130 may use the display unit (ie, OLED light source) of the OLED display screen 120 located in the fingerprint collection area 121 as an excitation light source for optical fingerprint detection. When the finger 140 is pressed on the fingerprint collection area 121, the display screen 120 emits a beam of light 111 to the target finger 140 above the fingerprint collection area 121. The light 111 is reflected on the surface of the finger 140 to form reflected light or pass through all the fingers. The finger 140 scatters to form scattered light. In related patent applications, for ease of description, the above-mentioned reflected light and scattered light are collectively referred to as reflected light. Because the ridge 141 and valley 142 of the fingerprint have different light reflection capabilities, the reflected light 151 from the fingerprint ridge and the reflected light 152 from the fingerprint valley have different light intensities, and the reflected light passes through the optical component 132. After that, it is received by the sensing array 133 in the optical fingerprint device 130 and converted into a corresponding electrical signal, that is, a fingerprint detection signal; based on the fingerprint detection signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed, thereby The terminal device 10 implements an optical fingerprint recognition function.

In other implementations, the optical fingerprint device 130 may also use a built-in light source or an external light source to provide an optical signal for fingerprint detection. In this case, the optical fingerprint device 130 may be suitable for non-self-luminous display screens, such as liquid crystal display screens or other passively-luminous display screens. Taking a liquid crystal display with a backlight module and a liquid crystal panel as an example, in order to support the under-screen fingerprint detection of the liquid crystal display, the optical fingerprint system of the terminal device 10 may also include an excitation light source for optical fingerprint detection. The excitation light source may specifically be an infrared light source or a light source of invisible light of a specific wavelength, which may be arranged under the backlight module of the liquid crystal display or arranged in the edge area under the protective cover of the terminal device 10, and the The optical fingerprint device 130 can be arranged under the edge area of the liquid crystal panel or the protective cover and guided by the light path so that the fingerprint detection light can reach the optical fingerprint device 130; or, the optical fingerprint device 130 can also be arranged in the backlight module. Under the group, and the backlight module is designed to allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint device 130 through openings or other optical designs on the film layers such as diffuser, brightness enhancement film, and reflective film. . When the optical fingerprint device 130 adopts a built-in light source or an external light source to provide an optical signal for fingerprint detection, the detection principle is the same as that described above.

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

In some embodiments, the optical fingerprint device 130 may include only one optical fingerprint sensor. At this time, the fingerprint collection area 121 of the optical fingerprint device 130 has a small area and a fixed position. Therefore, the user needs to touch the finger when performing fingerprint input. Press to a specific position of the fingerprint collection area 121, otherwise the optical fingerprint device 130 may not be able to collect fingerprint images, resulting in poor user experience.

In other embodiments, the optical fingerprint device 130 may specifically include multiple optical fingerprint sensors. The multiple optical fingerprint sensors may be arranged side by side under the display screen 120 in a splicing manner, and the sensing areas of the multiple optical fingerprint sensors collectively constitute the fingerprint collection area 121 of the optical fingerprint device 130. In other words, the fingerprint collection area 121 of the optical fingerprint device 130 may include multiple sub-areas, and each sub-area corresponds to the sensing area of one of the optical fingerprint sensors, so that the fingerprint collection area 121 of the optical fingerprint module 130 It can be extended to the main area of the lower half of the display screen, that is, extended to the area where the finger is habitually pressed, so as to realize the blind fingerprint input operation. Alternatively, when the number of optical fingerprint sensors is sufficient, the fingerprint collection area 130 can also be extended to half of the display area or even the entire display area, thereby realizing half-screen or full-screen fingerprint detection.

FIG. 2 shows a schematic diagram of the optical fingerprint device 130 including multiple optical fingerprint sensors. The multiple optical fingerprint sensors may be arranged side by side under the display screen 120 by means such as splicing, and the sensing areas of the multiple optical fingerprint sensors collectively constitute the fingerprint collection area 121 of the optical fingerprint device 130. In other words, the fingerprint collection area 121 of the optical fingerprint device 130 may include multiple sub-areas, and each sub-area corresponds to one of the optical fingerprint sensors, or in other words, each sub-area corresponds to one of the optical sensor arrays 133. Sensing area.

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

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

In the embodiments of the present application, the above-mentioned optical fingerprint device may also be called an optical fingerprint identification device, a fingerprint identification device, etc.; the optical detection part may also be called an image acquisition module, an image sensor, an optical fingerprint sensor, etc.; fingerprint acquisition of an image acquisition module The area can also be called the fingerprint recognition area, the fingerprint detection area, the sensing area of the image acquisition module, etc.; the light path guiding structure can also be called the angle screening structure, the angle screening component, etc.; the sensing unit can also be called the photosensitive unit, the optical sensing unit, etc. ; Sensing array can also be called sensing unit array, photosensitive single array and so on.

The embodiments of the present application can be applied to the detection of various types of fingers, and are particularly suitable for the detection of dry fingers. The so-called dry fingers refer to relatively dry fingers or relatively clean fingers, such as the fingers that have just washed their hands, and the fingers that have just gotten up. At this time, the oil secretion content of the finger epidermis is low. When a dry finger is in contact with the display screen, there is a large amount of air in the gap between the finger and the display screen (the valley of the fingerprint), which causes serious diffuse reflection of light, which makes the effective light that carries fingerprint information collected by the image acquisition module. The signal is interfered by the diffuse reflected light, which leads to the poor contrast of the fingerprint image collected, and it is difficult to perform effective fingerprint matching.

This will be described in detail with reference to FIGS. 3 and 4. Figure 3 shows the fingerprint recognition of a normal finger. When the finger 140 is in contact with the display screen 120, due to the presence of grease in the valley of the finger, when the incident light 111 is incident on the finger 140, normal patterns are formed on the ridges 141 and valleys 142 of the fingerprint. The reflected light signals 151 and 152, and the fingerprint images obtained by imaging based on the reflected light signals 151 and 152 are shown as 30 in FIG. 3. In Figure 4, the finger 140 is a dry finger. When the finger 140 is in contact with the display screen 120, the valley 142 of the fingerprint forms diffuse reflection light 152a due to the large amount of air, which affects the contrast of the fingerprint image collected by the image acquisition module 130. , The fingerprint image obtained by imaging according to the reflected light signals 151 and 152a is shown as 40 in FIG. 4. It can be seen that, due to the diffuse reflection effect caused by the valley 142 of the fingerprint in FIG. 4, the sharpness of the fingerprint image 40 is obviously worse than that of the fingerprint image 30.

In order to solve the problems existing in fingerprint recognition of dry fingers, the oblique light signal is used in the embodiment of the present application to collect fingerprint images of the fingers. That is, the image acquisition module collects the light signal obliquely incident on the finger and reflected by the finger, and acquires the fingerprint image of the finger according to the oblique light signal. This is because the diffuse reflection intensity of light incident at a larger angle is lower than that of light incident at a small angle.

Take an example from life as an illustration. When scanning the QR code of a shared bicycle at night, if the mobile phone is scanning the QR code directly, the flash of the mobile phone will cause serious reflection, which is the diffuse reflection effect. At this time, you only need to tilt the phone appropriately so that the light from the flash illuminates the QR code obliquely, and you can scan a relatively clear QR code pattern.

The embodiment of the present application proposes a fingerprint identification solution, which acquires a fingerprint image of a finger by collecting oblique light signals reflected by the finger, thereby improving fingerprint identification performance for special fingers such as dry fingers.

FIG. 5 is a schematic block diagram of a fingerprint identification device 500 according to an embodiment of the present application. The fingerprint collection area of the device 500 is located in the display screen. As shown in FIG. 5, the device 500 includes a light path guiding structure 510 and an image acquisition module 520.

The light path guide structure 510 is arranged under the display screen, and is used to guide the oblique light signal with a specific angle reflected from the finger when the finger is irradiated from the pressing area of the display screen to the image acquisition module 520 located under the first area of the display The first area is located in the non-pressing area of the display screen.

The image acquisition module 520 is arranged under the light path guiding structure 510, and is used to acquire a fingerprint image of the finger according to the oblique light signal.

The "pressing area" here is the pressing area when the finger performs the fingerprint recognition operation in the fingerprint collecting area of the image collecting module 520 located in the display screen; the "non-pressing area" is the area in the fingerprint collecting area except the pressing area .

The first area is located in the non-pressing area. For example, preferably, the first area is located in a shadow area covered by the finger and not in contact with the finger in the non-pressing area.

The area of the first area and the area of the pressing area may be equal or not equal.

The “below the pressing area” may refer to, for example, being directly under the pressing area. The term "located under the first area" may refer to, for example, being located directly under the first area. However, a certain degree of offset is allowed, and the offset will not have a significant impact on the collection of fingerprint images.

It should be noted that there is a distance d between the first area and the collection area, and the distance d is related to the specific angle θ of the oblique light signal reflected by the finger. Generally, if the first area is located in the shadow area under the finger, there is no overlap between the first area and the collection area. However, in some special cases, for example, when the specific angle θ is small, there may be overlap between the first area and the pressing area. The specific angle θ is determined by the internal structural parameters of the fingerprint recognition device 500, which will be further described later.

Hereinafter, this specific angle is also referred to as a tilt angle.

The image acquisition module 520 may be composed of at least one optical fingerprint sensor. For example, the multi-sensor splicing method shown in FIG. 2 is spliced into a 2×3, 2×4, or 3×3 optical fingerprint sensor array. The fingerprint sensor includes an array of sensing units, and each sensing array includes a plurality of sensing units. That is, the image acquisition module 520 is formed by splicing multiple optical fingerprint sensors with a smaller area.

The image acquisition module 520 may also be composed of an optical fingerprint sensor, and the optical fingerprint sensor may include a sensing unit array or multiple sensing unit arrays, wherein each sensing array includes multiple sensing units. That is, the image acquisition module 520 may be a single optical fingerprint sensor with a larger area.

The light source illuminates the finger in the pressing area of the finger, and the oblique light signal reflected by the finger is transmitted to the image acquisition module 520 through the optical path guide structure 510. The sensing unit located below the first area in the image acquisition module 520 collects the oblique light signal, thereby acquiring a fingerprint image. The intensity of diffuse reflection produced by oblique light on the finger is lower than that of vertical light. Therefore, for those special fingers that are prone to diffuse reflection during the fingerprint recognition process, such as dry fingers, the contrast of the collected fingerprint images can be improved, and the fingerprint detection performance can be improved.

The image acquisition module 520 of the embodiment of the present application has a large fingerprint acquisition area, and the fingerprint acquisition area can cover the pressing area of the finger and the first area. Fingers can be pressed anywhere in the fingerprint collection area to perform fingerprint recognition.

The image acquisition module 520 may be a complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS), a charge-coupled device (Charge-coupled Device, CCD), a thin film transistor (Thin Film Transistor, TFT), an avalanche diode, etc., in the embodiment of the application There is no restriction on this.

The display screen in the embodiment of the present application may adopt various display screens described above, such as an LCD display screen or an OLED display screen. Wherein, when the display screen is an OLED display screen, the light emitting layer of the display screen includes a plurality of organic light emitting diode light sources, and the fingerprint identification device 500 uses at least part of the organic light emitting diode light sources as excitation light sources for fingerprint recognition.

Optionally, when a finger performs a pressing operation in the fingerprint collection area, a part of the light-emitting layer located in the pressing area emits light. In other words, the light source only illuminates the finger in the pressed area, and does not emit light in the non-pressed area.

On the one hand, because it is not necessary to emit light in the entire large fingerprint collection area, the power consumption of the display screen can be reduced; on the other hand, it can avoid the light that does not carry fingerprint information from the non-pressing area, and collects light from the image collection module 520. The oblique light signal causes interference.

Optionally, the light path guiding structure 510 can also be used to guide the vertical light signal reflected from the finger when the finger is irradiated from the pressing area to the sensing unit located under the pressing area in the image acquisition module 520.

Wherein, optionally, the vertical light signal may be collected by a sensing unit located below the pressing area in the image collecting module 520 first, and the fingerprint image of the finger may be acquired according to the vertical light signal. If the fingerprint image fails to be acquired according to the vertical light signal, for example, when the sharpness of the fingerprint image cannot achieve fingerprint matching, the sensing unit located under the first area in the image acquisition module 520 then collects the oblique light signal with a specific angle, and according to the Oblique the light signal to obtain the fingerprint image.

Since the intensity of the oblique light signal is lower than the intensity of the vertical light signal, the responsiveness of the sensing unit of the image acquisition module 520 to the oblique light signal decreases, and the exposure time needs to be appropriately extended to ensure sufficient signal output. Therefore, optionally, the exposure time used by the image acquisition module 520 to collect the oblique light signal may be greater than the exposure time used to collect the vertical light signal.

In one implementation, the light path guiding structure 510 may include a micro lens array 511 and a light blocking layer 512 disposed under the micro lens array 511.

In the microlens array 511, the microlens located under the pressing area is used to converge the vertical light signal reflected by the finger, and the microlens located under the first area is used to converge the oblique light signal at a specific angle reflected by the finger.

The light blocking layer 512 includes a plurality of openings respectively corresponding to the plurality of microlenses, wherein each opening is used for guiding the light signal condensed by its corresponding microlens to the image acquisition module 520.

The light blocking layer 512 is disposed at the back focal plane of the micro lens array 511. Each of the openings in the light blocking layer 512 can be arranged at the focal point of the microlens corresponding to the opening, so as to filter out stray light and achieve screening of light in a specific direction.

The opening corresponding to the same microlens for guiding the vertical optical signal, and the opening corresponding to the microlens for guiding the oblique optical signal may be a different opening. For example, for a microlens located below the pressing area, its corresponding opening is located at its focal point, that is, the corresponding opening of the microlens is located directly below the microlens; while for the microlens located below the first area, its corresponding opening is The hole is located at the focal point of its adjacent lens, that is, the corresponding opening of the micro lens is located obliquely below the micro lens.

The image acquisition module 520 includes multiple sensing units. Optionally, each sensing unit may correspond to a microlens for receiving the light signal condensed by the microlens.

The inclination angle θ of the oblique light signal that can be collected by the sensing unit located below the first area in the image acquisition module 520 is determined by the optical path guiding structure and the structural parameters of the image acquisition module. For example, the angle θ is the reflection angle of the light reflected by the finger, and the angle θ is determined by the distance between adjacent openings in the light blocking layer 512 and the focal length of the micro lens.

The following takes FIG. 6 and FIG. 7 as examples to describe in detail the principle of fingerprint recognition in the embodiment of the present application.

As shown in FIGS. 6 and 7, the fingerprint collection area 121 in the display screen 120 includes a finger pressing area 1211 and a non-pressing area. The non-pressing area includes a first area 1212, and the first area 1212 is located in the non-pressing area. In the shaded area covered and not touched by the finger. This is because in the area outside the shadow area of the finger, the sensing unit in the image acquisition module 520 is very likely to saturate the signal under the illumination of ambient light such as sunlight, light, etc., which will cause the phenomenon of blooming and reduce the acquisition. The quality of the fingerprint image. The portion of the finger 140 that is not in contact with the display screen 120 can just play a role in shielding the ambient light.

As shown in FIG. 6, the sensing unit located below the pressing area 1211 in the image capture module 520 is used to capture the vertical light signal reflected by the finger, and the sensing unit located below the first area 1212 in the image capture module 520 is used to capture the tilt of the finger reflection. Light signal.

FIG. 6 only shows the reflected light from the finger, and does not show the incident light. The light emitting unit located in the finger pressing area emits light. The emitted incident light may include light directed in various directions. The reflected light reflected by the finger includes the light reflected vertically and the oblique light reflected at a specific angle.

The light path guiding structure 510 under the display screen 120 includes a microlens array 511 and a light blocking layer 512. The center of any opening in the light blocking layer 512 is located at the focal point of the corresponding microlens, and the incident light outside the opening cannot pass through防光层512。 Light blocking layer 512.

Take the opening 5121 and the opening 5122 as examples. According to the convergence principle of the convex lens, only the light incident vertically or nearly collimated below the pressing area 1211 can be condensed at the focal point of the microlens 5111 and pass through the corresponding opening 5121 to be received by the sensing unit under the pressing area 1211. The light incident below the first area 1212 at a specific angle θ can be condensed at the focal point of the micro lens 5112 and pass through the corresponding opening 5122 to be received by the sensing unit under the first area 1212.

An image acquisition module 520 is provided under the light path guiding structure 510, and the image acquisition module 520 includes a plurality of sensing units 521. Wherein, when imaging is performed according to the vertical light signal, the sensing unit located below the pressing area 1211 works; when imaging is performed based on the oblique light signal, the sensing unit located below the first area 1212 works. This can reduce the power consumption of the image acquisition module.

Of course, it can also work with all the sensing units holding the image acquisition module 520. At this time, when processing the collected optical signals, you can first process the vertical optical signals collected by the sensing unit under the pressing area 1211 to obtain the fingerprint image. When the fingerprint image is not clear, then the first area 1212 The oblique light signal collected by the sensing unit is processed to obtain a fingerprint image.

The light-emitting unit in the light-emitting layer 123 in FIG. 6 below the pressing area 1211 emits light. The light illuminates the part of the finger 140 in the pressing area 1211. The vertical light signal 161 reflected by the finger 140 from the pressing area is incident into the microlens array 511. A part of the microlens located under the pressing area 1211 is collected by the photosensitive unit 521 in the image capturing module 520 under the pressing area 1211 after being converged by the partial microlens. The vertical light signal 161 carries fingerprint information of the finger, so that the fingerprint image of the finger can be obtained according to the vertical light signal 161 to perform fingerprint matching. However, the vertical optical signal 161 will be affected by severe diffuse reflection. Therefore, for special fingers such as dry fingers, it may not be possible to obtain a clear fingerprint image, which may result in failure of fingerprint recognition.

At this time, the light-sensing unit 521 located under the first area 1212 in the image acquisition module 520 is turned on, and the light-emitting unit under the pressing area 1211 in the light-emitting layer 123 still emits light. The light irradiates the part of the finger 140 in the pressing area 1211, and the finger 140 The oblique light signal 162 reflected from the pressing area is incident on a part of the microlens under the first area 1212 in the microlens array 511, and is condensed by the part of the microlens by the image acquisition module 520 under the first area 1212. The photosensitive unit 521 collects. The tilt light signal 162 carries fingerprint information of the finger, so that the fingerprint image of the finger can be obtained according to the tilt light signal 162 to perform fingerprint matching. Since the oblique light signal 162 is less affected by diffuse reflection light, a clear fingerprint image can be obtained.

The touch control module (also referred to as a touch layer or a touch screen) 122 in FIG. 6 can be used to determine the position of the pressing area 1211 of the finger 140 and the position of the shadow area of the finger 140. Therefore, the position of the first area 1212 can be determined in the shaded area according to the relationship satisfied between the pressing area 1211 and the first area 1212.

The touch layer 122 may be integrated in the display screen 120 or may be a separate component relative to the display screen 120. The touch layer 122 can be a capacitive touch that detects the position of a finger based on the principle of sensing changes in the electric field on the surface of the display screen; it can also be an infrared light touch that locates the position of the finger based on scanning whether infrared rays are blocked by the finger. Not limited.

Optionally, the processing module 530 may obtain information about the pressing area and the first area, where the distance between the pressing area and the first area is determined according to the following information: the height between the display screen and the image acquisition module 520 , The distance between adjacent openings in the light blocking layer, and the focal length of the microlens.

It should be understood that the processing module 530 may be a processing module in a device to which the apparatus 500 is applied, for example, the main control of a terminal device. Alternatively, the processing module 530 may also be integrated with the fingerprint identification device 500 as a part of the fingerprint identification device 500, that is, the fingerprint identification device includes the processing module 530.

The distance between the pressing area and the first area may be determined by the following formula, for example: d=h×s/f.

Wherein, d is the distance between the pressing area and the first area, h is the height between the display screen and the image acquisition module, and s is the distance between adjacent openings in the light blocking layer (pitch ), f is the focal length of the micro lens.

Still taking FIG. 6 as an example, below the first area 1212, the distance between the opening 5122 and the adjacent opening on the left is s, and the focal length of the corresponding microlens 5112 is f. It can be seen that tanθ=s/ f. The angle θ of the oblique light signal collected by the image collection module 520 is determined by the structural parameters of the optical path guiding structure.

In addition, the size of the opening on the light blocking layer determines the ability to filter the angle of light. The smaller the opening size, the stronger the ability to screen the angle.

In order to explain how the distance between the pressing area and the first area is determined, the fingerprint identification device shown in FIG. 6 is now simplified as shown in FIG. 8 for description.

FIG. 8 shows the display screen 120 and the fingerprint identification device 500, where it can be known based on FIG. 7 that the tilt angle θ of the tilt light signal collected by the fingerprint identification device 500 should satisfy tanθ=s/f. Based on Figure 8, the angle θ also satisfies tanθ=h/d. Therefore, it can be obtained from tanθ=s/f=h/d, and d=hs/f. That is, the distance between the first area 1212 and the pressing area 1211 is d=hs/f.

Because the touch layer 122 can obtain the overall position of the finger above the fingerprint collection area and the position of the finger pressing area 1211. Therefore, the position of the first area 1212 can be determined according to the position of the shadow area of the finger on the fingerprint collection area and the distance d between the first area 1212 and the pressing area 1211. Therefore, when fingerprint recognition fails based on the vertical light signal reflected by the finger, fingerprint recognition can be performed based on the inclined light signal with an angle θ reflected by the finger.

The diffuse reflection effect of the oblique optical signal at the angle θ is smaller than the diffuse reflection effect of the vertical optical signal. Therefore, for special fingers, such as dry fingers, which are prone to diffuse reflection, the fingerprint information of the finger can be collected by using the oblique light signal of angle θ to obtain a clearer fingerprint image.

It should be noted that due to the difference in refractive index, light refraction may occur between the display screen 120 and the contact interface of the fingerprint identification device 500, which is not shown in FIG. 8. At this time, the calculated distance of the first area relative to the pressing area may deviate from the calculated d=hs/f when no refraction occurs. However, when the deflection angle is small, the influence on the distance can be ignored, and it can be considered that the slight deviation of the position of the first region 1212 will not affect the fingerprint image collection. At this time, d=hs/f can be used to determine the position of the first region 1212. In actual use, this difference in refractive index can be reduced by using suitable materials. In the embodiments of the present application, it is assumed that the refractive index difference is small enough to not affect the fingerprint image collection.

The display screen 120 and the fingerprint identification device 500 shown in FIGS. 6 and 8 are bonded together. In practical applications, there may be a certain interval, such as an air gap, between the display screen 120 and the fingerprint identification device 500 for optical transmission. For example, the fingerprint identification device 500 may be fixed under the display screen 120 through the middle frame of the mobile phone, and a certain interval is reserved between the fingerprint identification device 500 and the display screen 120. The installation positions of the fingerprint identification device 500 shown in FIG. 6 and FIG. 8 are merely illustrative, and should not limit the scope of the embodiments of the present application.

FIG. 9 is a schematic flowchart of a fingerprint identification method 900 according to an embodiment of the present application. The method shown in FIG. 9 may be executed by the aforementioned fingerprint identification device 500. The fingerprint identification device 500 includes an optical path guide structure 510 and an image acquisition module 520. The fingerprint collection area of the fingerprint identification device 500 is located in the display screen. Wherein, the method 900 includes:

In 910, the light path guiding structure 510 will guide the oblique light signal with a specific angle reflected from the finger when the finger is irradiated in the pressing area of the display screen to the sensing unit located under the first area of the display screen in the image acquisition module 520 .

Wherein, the first area is located in a non-pressing area of the display screen;

In 920, the image acquisition module 520 acquires a fingerprint image of the finger according to the acquired oblique light signal.

The light source illuminates the finger in the finger pressing area and the oblique light signal reflected by the finger is guided to the image acquisition module, and the image acquisition module obtains the fingerprint image of the finger according to the oblique light signal. Since the diffuse reflection intensity of oblique light on the finger is lower than the diffuse reflection intensity of vertical light, special fingers that are prone to diffuse reflection during fingerprint recognition, such as dry fingers, can improve the contrast of the captured fingerprint image. Improve fingerprint detection performance.

For the specific description of the fingerprint identification device 500 that executes the method 900, reference may be made to the description on the device side described above, and for brevity, details are not repeated here.

Optionally, the method further includes: the light path guiding structure 510 guides the vertical light signal reflected from the finger when the finger is irradiated in the pressing area to the sensing unit located below the pressing area in the image acquisition module 520. Wherein, in 920, if the image acquisition module 520 fails to acquire the fingerprint image according to the vertical light signal, it acquires the fingerprint image according to the oblique light signal.

Specifically, the sensing unit in the image acquisition module 520 below the pressing area can be controlled to work, and the vertical light signal reflected from the finger when the finger is irradiated from the pressing area is collected. The image acquisition module 520 acquires a fingerprint image according to the vertical light signal. If the sharpness of the fingerprint image obtained by vertical optical signal imaging is poor, it is difficult to match the fingerprint template in the fingerprint library. Then, the sensing unit located under the first area in the image acquisition module 520 is controlled to work, and the oblique light signal with a specific angle reflected from the finger when the finger is irradiated from the pressing area is collected. Since the intensity of the diffuse reflection of the oblique light on the finger is lower than that of the vertical light, the fingerprint image obtained by imaging based on the oblique light signal will be clearer.

Since the intensity of the oblique light signal is lower than the intensity of the vertical light signal, compared to collecting the vertical light signal, the image acquisition module 520 requires a longer exposure time when collecting the oblique light signal. Because of this, in this embodiment, the fingerprint image is first collected according to the vertical light signal, and the fingerprint image can be obtained efficiently. When no clear fingerprint image is obtained, the fingerprint image is collected according to the oblique light signal. Thus, both the efficiency and effect of fingerprint recognition are taken into consideration, and the user experience is improved.

Optionally, the light path guiding structure 510 of the embodiment of the present application may include a micro lens array 511 and a light blocking layer 512 disposed under the micro lens array 511.

Optionally, the processing module 530 is configured to obtain information about the pressing area and the first area, where the distance between the pressing area and the first area is determined according to the following information: the display screen to the image acquisition module 520 The height between, the distance s between adjacent openings in the light blocking layer, and the focal length f of the microlens.

The processing module 530 may be a processing module in a device to which the apparatus 500 is applied, for example, the main control of a terminal device. Alternatively, the processing module 530 may also be integrated with the fingerprint identification device 500 as a part of the fingerprint identification device 500.

For example, the processing module 530 may obtain information on the pressing area of the finger on the display screen and information on the overall orientation of the finger from the touch screen. When the image acquisition module 520 cannot obtain a clear fingerprint image according to the collected vertical light signal, the processing module 530 calculates the distance d between the pressing area and the first area according to the formula d=h×s/f, where h is The height between the display screen and the image acquisition module 520, s is the distance between adjacent openings in the light blocking layer, and f is the focal length of the micro lens. According to the distance d and the information of the overall orientation of the finger reported on the touch screen, the position of the first area can be calculated. Wherein, the first area is located in the shadow area of the finger, and the distance from the pressing area is d. Preferably, the area of the first area is equal to the area of the pressing area.

For the description of the calculation principle of the distance d between the pressing area and the first area, reference may be made to the foregoing description of FIG. 6 to FIG. 8. For brevity, details are not repeated here.

The following describes in detail a specific implementation manner of the fingerprint identification method of the embodiment of the present application with reference to FIG. 10. This method may be executed by a terminal device, which may include the aforementioned fingerprint identification device, display screen, touch screen, processing module, and the like. Take the OLED display as an example. As shown in Figure 10, the method includes:

Step 1001, fingerprint recognition starts.

The finger performs a pressing operation in the fingerprint collection area in the display screen.

Step 1002: The touch screen detects the pressing area of the finger and the overall position of the finger.

The touch screen acquires the pressing area of the finger and the overall position of the finger, and the shadow area of the finger can be determined based on the overall position of the finger.

Step 1003, the light-emitting unit in the pressing area of the display screen emits light.

The light-emitting units in the fingerprint collection area of the display screen are all excitation light sources for fingerprint recognition. However, in step 1003, only the light-emitting unit in the pressing area in the display screen emits light, so that the finger is illuminated only in the pressing area.

Wherein, the optical signal reflected by the finger includes a vertical optical signal and an oblique optical signal with a specific angle.

Step 1004: The image acquisition module collects the vertical light signal reflected by the finger with the standard exposure time.

At this time, the sensing unit located below the pressing area in the image acquisition module works to collect the vertical light signal reflected by the finger, and obtain the fingerprint image of the finger in the pressing area based on the vertical light signal.

Step 1005: The processing module determines whether the fingerprint image is clear.

If the sharpness of the fingerprint image does not meet the requirements, step 1006 is executed; if the sharpness of the fingerprint image meets the requirements, step 1007 is executed.

Step 1006: The image acquisition module collects the oblique light signal with a specific angle reflected by the finger with a long exposure time.

At this time, the sensing unit located below the first area in the image acquisition module works to collect the oblique light signal reflected by the finger, and based on the oblique light signal, obtain a fingerprint image of the finger in the pressing area.

The position of the first area may be determined by the processing module according to the position of the pressing area, the position of the shadow area, and the distance between the pressing area and the first area. The distance between the pressing area and the first area may be determined according to, for example, d=h×s/f. After the processing module obtains the position of the first area, it can control the sensing unit under the first area in the image acquisition module to turn on, so as to collect the oblique light signal.

Step 1007: The processing module performs fingerprint image matching.

The processing module matches the fingerprint image of the finger in the pressing area with the pre-registered fingerprint information according to the fingerprint algorithm.

Step 1008: The processing module judges whether the matching is successful.

If the matching is successful, step 1009 is executed; if the matching fails, step 1010 is executed.

Step 1009: Pass fingerprint authentication.

Step 1010: The fingerprint authentication fails.

For example, the user can be prompted to try again or to deny access.

Since the fingerprint recognition device has a large fingerprint collection area, the part of the fingerprint recognition device located below the shadow area of the finger can collect the oblique light signal reflected by the finger and borrow the shadow formed by the finger above the fingerprint collection area. Reduce the interference of ambient light on the oblique light signal, thereby improving the performance of the fingerprint identification device and increasing the user experience.

An embodiment of the present application also provides an electronic device. FIG. 11 is a schematic block diagram of an electronic device 1100 according to an embodiment of the present application. The electronic device 1100 includes a touch screen 1110, a display screen 1120, a fingerprint identification device 1130, and a processing module 1140.

The fingerprint identification device 1130 may be the fingerprint identification device described in any embodiment of this application.

The display screen may adopt the display screen described above, such as an OLED display screen. The light-emitting layer of the OLED display screen includes a plurality of light-emitting units, and the fingerprint identification device 1130 uses at least part of the light-emitting units as an excitation light source for fingerprint identification.

The processing module 1140 has a communication connection with the touch screen 1110, the display screen 1120, and the fingerprint identification device 1130, respectively, to perform data and instruction transmission.

The four parts of the touch screen 1110, the display screen 1120, the fingerprint identification device 1130, and the processing module 1140 can jointly complete the fingerprint identification method in the embodiment of the present application.

For example, taking FIG. 10 as an example, step 1002 is mainly performed by the touch screen 1110 and the processing module 1140; step 1003 is mainly performed by the display screen 1120 and the processing module 1140; and the remaining steps are mainly performed by the fingerprint identification device 1130 and the processing module 1140.

As an example and not a limitation, the electronic device may be a portable or mobile computing device such as a terminal device, a mobile phone, a tablet computer, a notebook computer, a desktop computer, a game device, an in-vehicle electronic device, or a wearable smart device, as well as an electronic database, a car , Bank automatic teller machine (Automated Teller Machine, ATM) and other electronic equipment. The wearable smart device includes full-featured, large-sized, complete or partial functions that can be achieved without relying on smart phones, such as smart watches or smart glasses, etc., and only focus on a certain type of application function, and need to cooperate with other devices such as smart phones Use, such as various types of smart bracelets, smart jewelry and other equipment for physical sign monitoring.

It should be understood that the specific examples in the embodiments of the present application are only to help those skilled in the art to better understand the embodiments of the present application, rather than limiting the scope of the embodiments of the present application. Those skilled in the art can base on the above-mentioned embodiments. Various improvements and modifications are made, and these improvements or modifications fall within the scope of protection of the present application.

Claims

A fingerprint identification device, characterized by comprising:

The light path guide structure is arranged under the display screen, and is used to guide the oblique light signal with a specific angle reflected from the finger when the finger is irradiated from the pressing area of the display screen to the second part of the display screen in the image acquisition module. A sensing unit below an area, the first area is located in a non-pressing area of the display screen;

The image acquisition module is arranged under the light path guiding structure, and is used to acquire a fingerprint image of the finger according to the oblique light signal.
The device according to claim 1, wherein the optical path guiding structure is further used for:

Guiding the vertical light signal reflected from the finger when the finger is irradiated in the pressing area to a sensing unit located below the pressing area in the image acquisition module;

Wherein, the image acquisition module is specifically used for:

If acquiring the fingerprint image according to the vertical light signal fails, acquiring the fingerprint image according to the oblique light signal.
3. The device according to claim 2, wherein the exposure time used by the image acquisition module to collect the oblique light signal is greater than the exposure time used to collect the vertical light signal.
The device according to any one of claims 1 to 3, wherein the optical path guiding structure comprises:

A microlens array, wherein a microlens located under the pressing area is used to converge the vertical optical signal, and a microlens located under the first area is used to converge the oblique optical signal;

The light-blocking layer is arranged under the microlens array, and the light-blocking layer includes a plurality of openings corresponding to the plurality of microlenses, wherein each opening is used to condense the light signal of its corresponding microlens Lead to the image acquisition module.
The device according to claim 4, wherein the device further comprises a processing module, and the processing module is configured to:

Acquire information about the pressing area and the first area, wherein the distance between the pressing area and the first area is determined according to the following information:

The height between the display screen and the image acquisition module, the distance between adjacent openings in the light blocking layer, and the focal length of the microlens.
The device according to claim 5, wherein the distance between the pressing area and the first area is d, d=h×s/f, where h is the display screen to the image The height between the collection modules, s is the distance between adjacent openings in the light blocking layer, and f is the focal length of the microlens.
The device according to any one of claims 1 to 6, wherein the first area is located in a shadow area covered by the finger and not in contact with the finger in the non-pressing area.
The device according to any one of claims 1 to 7, wherein the area of the first area is equal to the area of the pressing area.
The device according to any one of claims 1 to 8, wherein the image acquisition module is formed by splicing multiple optical fingerprint sensors.
The device according to any one of claims 1 to 8, wherein the image acquisition module comprises an optical fingerprint sensor.
A fingerprint identification method, characterized in that the method is executed by a fingerprint identification device, and the device includes a light path guiding structure and an image acquisition module sequentially arranged below a display screen, and the method includes:

The light path guiding structure will guide the oblique light signal with a specific angle reflected from the finger when the finger is irradiated in the pressing area of the display screen to the image acquisition module located below the first area of the display screen In the sensing unit, the first area is located in a non-press area of the display screen;

The image acquisition module acquires a fingerprint image of the finger according to the oblique light signal.
The method of claim 11, wherein the method further comprises:

The light path guiding knot guides the vertical light signal reflected from the finger when the finger is irradiated in the pressing area to the sensing unit located below the pressing area in the image acquisition module;

Wherein, the image acquisition module acquiring the fingerprint image of the finger according to the oblique light signal includes:

If the image acquisition module fails to acquire the fingerprint image according to the vertical light signal, acquire the fingerprint image according to the oblique light signal.
The method according to claim 11 or 12, wherein the exposure time used by the image acquisition module to collect the oblique light signal is greater than the exposure time used to collect the vertical light signal.
The method according to any one of claims 11 to 13, wherein the optical path guiding structure comprises:

A microlens array, wherein a microlens located under the pressing area is used to converge the vertical optical signal, and a microlens located under the first area is used to converge the oblique optical signal;

The light-blocking layer is arranged under the microlens array, and the light-blocking layer includes a plurality of openings corresponding to the plurality of microlenses, wherein each opening is used to condense the light signal of its corresponding microlens Lead to the image acquisition module.
The method according to claim 14, wherein the fingerprint identification device further comprises a processing module, and the processing module is configured to:

Acquire information about the pressing area and the first area, wherein the distance between the pressing area and the first area is determined according to the following information:

The height between the display screen and the image acquisition module, the distance between adjacent openings in the light blocking layer, and the focal length of the micro lens.
The method according to claim 15, wherein the distance between the pressing area and the first area is d, d=h×s/f, where h is the display screen to the image The height between the collection modules, s is the distance between adjacent openings in the light blocking layer, and f is the focal length of the microlens.
The method according to any one of claims 11 to 16, wherein the first area is located in a shadow area covered by the finger and not in contact with the finger in the non-pressing area.
The method according to any one of claims 11 to 17, wherein the area of the first area is equal to the area of the pressing area.
The method according to any one of claims 11 to 18, wherein the image acquisition module is formed by splicing multiple optical fingerprint sensors.
The method according to any one of claims 11 to 18, wherein the image acquisition module includes an optical fingerprint sensor.
An electronic device, characterized by comprising a display screen and the fingerprint identification device according to any one of claims 1 to 10.