CN110945527A

CN110945527A - Fingerprint identification device and electronic equipment

Info

Publication number: CN110945527A
Application number: CN201980002486.3A
Authority: CN
Inventors: 王文轩; 沈健; 纪登鑫
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2019-10-25
Filing date: 2019-10-25
Publication date: 2020-03-31
Anticipated expiration: 2039-10-25
Also published as: WO2021077406A1; CN110945527B

Abstract

The utility model provides a fingerprint identification device and electronic equipment, can improve the light semaphore when receiving slope light signal to promote fingerprint imaging effect and fingerprint identification effect. This fingerprint identification device is applicable to the electronic equipment that has the display screen and in order to carry out optical fingerprint detection under the screen, and this fingerprint identification device includes: the optical fingerprint sensor is arranged below the display screen in a non-parallel mode; the optical component is arranged above the optical fingerprint sensor and comprises at least one lens, the optical component is used for transmitting a fingerprint optical signal returned after being reflected or scattered by a finger above the display screen to the optical fingerprint sensor for fingerprint identification, and the fingerprint optical signal is an optical signal inclined relative to the display screen.

Description

Fingerprint identification device and electronic equipment

Technical Field

The present application relates to the field of optical fingerprint technology, and more particularly, to a fingerprint identification device and an electronic apparatus.

Background

With the development of biometric identification technology, the application of the underscreen fingerprint identification technology in portable terminals such as mobile phones is more and more extensive.

In some specific scenarios, the underscreen fingerprint identification device may receive the optical signal in the oblique direction to perform fingerprint identification so as to meet specific requirements, for example, the optical path distance in the fingerprint identification device is reduced by receiving the oblique optical signal, so as to reduce the thickness of the fingerprint identification device; or the fingerprint detection effect of the dry finger can be improved by receiving the inclined optical signal, and the like. However, when the fingerprint identification device receives the optical signal in the inclined direction, the optical signal quantity can be attenuated, so that the optical signal quantity received by the fingerprint identification device is insufficient, the fingerprint imaging effect is influenced, and the fingerprint identification effect is finally influenced.

Therefore, how to improve the light signal amount while receiving the inclined light signal by the fingerprint identification device, so as to improve the fingerprint imaging effect and the fingerprint identification effect, is a problem to be solved urgently.

Disclosure of Invention

The embodiment of the application provides a fingerprint identification device and electronic equipment, can improve the light semaphore when receiving slope light signal to promote fingerprint formation of image effect and fingerprint identification effect.

In a first aspect, a fingerprint identification device is provided, which is suitable for an electronic device having a display screen to perform optical fingerprint detection under the screen, and comprises:

the optical fingerprint sensor is arranged below the display screen in a non-parallel mode;

the optical component is arranged above the optical fingerprint sensor and comprises at least one lens, the optical component is used for transmitting a fingerprint optical signal returned after being reflected or scattered by a finger above the display screen to the optical fingerprint sensor for fingerprint identification, and the fingerprint optical signal is an optical signal inclined relative to the display screen.

In this application, when fingerprint identification device received for the fingerprint light signal of display screen slope, place through being certain contained angle with optics fingerprint sensor and display screen place plane, optics fingerprint sensor non-level places promptly, can reduce the contained angle of fingerprint light signal and optics fingerprint sensor perpendicular, make optics fingerprint sensor received light signal vertical incidence or be close vertical incidence in optics fingerprint sensor, thereby when fingerprint identification device received the fingerprint light signal of slope, also can increase the light intensity of the light signal that optics fingerprint sensor received, improve fingerprint image quality and fingerprint identification effect.

In one possible implementation, the display screen includes a fingerprint detection area, and the optical component is configured to transmit the fingerprint optical signal returned after being reflected or scattered by a finger above the fingerprint detection area;

the optical fingerprint sensor faces the fingerprint detection area and is arranged obliquely below the fingerprint detection area.

In one possible implementation, the plane of the optical fingerprint sensor is at an angle ω to the plane of the display screen, wherein 0 ° < ω <90 °.

In one possible implementation, 0 ° < ω < 30 °.

In a possible implementation manner, an incident angle of the fingerprint light signal with respect to the optical fingerprint sensor is θ - ω, where θ - ω is an angle between the fingerprint light signal and a vertical plane of the optical fingerprint sensor, and θ is an angle between the fingerprint light signal and a vertical plane of the display screen.

In one possible implementation, ω ═ θ, where θ is the angle between the fingerprint light signal and the vertical plane of the display screen.

In one possible implementation, the optical assembly includes: at least one optical lens for receiving the fingerprint light signal to image the fingerprint, wherein the optical lens is a spherical or aspheric lens.

In one possible implementation, the optical assembly further includes: an aperture stop formed in an optical path of the at least one optical lens.

In one possible implementation, the focal plane of the optical lens is parallel to the optical fingerprint sensor.

In one possible implementation, the direction of the fingerprint light signal is parallel to the optical axis of the optical lens.

In a possible implementation manner, the at least one optical lens is fixed on the optical fingerprint sensor through a fixing component, and the at least one optical lens and the optical fingerprint sensor are both arranged below the display screen in a non-parallel mode.

In one possible implementation, the optical assembly includes: a microlens array and at least one light blocking layer;

the at least one light blocking layer is positioned below the micro lens array and is provided with a plurality of light passing small holes;

the micro lens array is used for receiving the fingerprint optical signal and converging the fingerprint optical signal to the plurality of light-transmitting small holes;

the plurality of light-passing small holes are used for transmitting the fingerprint light signal to the optical fingerprint sensor.

In one possible implementation, the fingerprint light signal is incident perpendicularly to the microlens array.

In one possible implementation, the microlens array and the at least one light blocking layer are integrally disposed over the optical fingerprint sensor through a semiconductor process;

the micro-lens array, the at least one light-blocking layer and the optical fingerprint sensor are all arranged below the display screen in a non-parallel mode.

In one possible implementation, the optical fingerprint sensor is disposed non-parallel below the display screen by a support structure;

the supporting structure is made of injection molding materials, plastic materials or metal materials.

In a possible implementation manner, the display screen is an organic light emitting diode display screen, wherein the fingerprint light signal is a light signal formed by reflection or scattering of excitation light emitted by a part of display units of the organic light emitting diode display screen by a finger above the organic light emitting diode display screen and returned.

In one possible implementation manner, the display screen is a liquid crystal display screen with a backlight module, and the liquid crystal display screen comprises the backlight module;

the fingerprint optical signal is an optical signal formed after infrared excitation light emitted by an external light source irradiates a finger above the liquid crystal display screen to be reflected or scattered and then returns, and is refracted by one of the first prism film side surface and the second prism film side surface of the prism film of the backlight module.

In this implementation, place optics fingerprint sensor slope, can be so that optics fingerprint sensor detects the fingerprint image that obtains and does not have the dark stripe to realize the fingerprint identification under the liquid crystal display, in addition, can also increase the light intensity of the fingerprint light signal that optics fingerprint sensor received, can further improve fingerprint image quality and fingerprint identification effect.

In a possible implementation manner, the optical assembly includes at least one optical lens and an aperture stop, the plane of the optical fingerprint sensor is at an angle ω with the plane of the display screen, where 90 ° > ω > β/2+ arctan (l/d), l is 1/2 of the length of the optical fingerprint sensor, d is the distance from the aperture stop to the optical fingerprint sensor, and β is the divergence angle of the shadow area determined according to the prism film.

In one possible implementation, the optical assembly is positioned such that an optical signal refracted through a side of another one of the prismatic films deviates from the optical assembly and is not transmitted to the optical fingerprint sensor.

In one possible implementation, the optical fingerprint sensor is positioned such that an optical signal refracted through a side of another one of the prismatic films deviates from the optical fingerprint sensor.

In a possible implementation manner, the fingerprint identification apparatus further includes:

and the filtering layer is arranged in a light path between the display screen and the optical fingerprint sensor and is used for filtering optical signals of non-target wave bands and transmitting the optical signals of the target wave bands.

In a second aspect, an electronic device is provided, which includes a display screen and a fingerprint identification device as in the first aspect or any possible implementation manner of the first aspect, wherein the fingerprint identification device is disposed below the display screen for performing an off-screen optical fingerprint detection.

In one possible implementation manner, the display screen is a liquid crystal display screen, and the electronic device further includes:

and the infrared light source is used for providing infrared excitation light for fingerprint detection of the fingerprint identification device, the infrared excitation light irradiates at least part of the display area of the liquid crystal display screen, and the at least part of the display area at least partially covers the fingerprint detection area of the fingerprint identification device.

Through set up above-mentioned fingerprint identification device in electronic equipment for this electronic equipment has good fingerprint identification performance, promotes the fingerprint identification success rate, improves user experience.

Drawings

Fig. 1 is a schematic structural diagram of an electronic device to which the embodiment of the present application is applied.

Fig. 2 is a schematic structural diagram of a fingerprint identification device according to an embodiment of the present application.

Fig. 3 is a schematic block diagram of another fingerprint identification device according to an embodiment of the present application.

Fig. 4 is a schematic block diagram of another fingerprint identification device according to an embodiment of the present application.

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

Fig. 6 is a schematic block diagram of another fingerprint identification device according to an embodiment of the present application.

Fig. 7 is a schematic block diagram of another fingerprint identification device according to an embodiment of the present application.

Fig. 8 is a schematic structural diagram of a fingerprint recognition device under a liquid crystal display according to an embodiment of the present application.

Fig. 9a and 9b are a perspective view and a cross-sectional view of a prism film in a liquid crystal display panel.

Fig. 10 is a schematic diagram of a fingerprint image shadow formed by detection of an optical fingerprint sensor under a liquid crystal display according to an embodiment of the application.

Fig. 11 is a schematic structural diagram of a fingerprint recognition device according to an embodiment of the present application.

Fig. 12 is a schematic block diagram of another fingerprint identification device according to an embodiment of the present application.

Fig. 13 is a schematic diagram illustrating calculation of a tilt angle of an optical fingerprint sensor under a liquid crystal display according to an embodiment of the present application.

Fig. 14 is a schematic diagram illustrating calculation of a translation distance of an optical fingerprint sensor under a liquid crystal display according to an embodiment of the present application.

Fig. 15 is a schematic structural diagram of another fingerprint identification device according to an embodiment of the present application.

FIG. 16 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 with reference to the accompanying drawings.

It should be understood that the embodiments of the present application can be applied to optical fingerprint systems, including but not limited to optical fingerprint identification systems and products based on optical fingerprint imaging, and the embodiments of the present application are only described by way of example, but not limited to any limitation, and the embodiments of the present application are also applicable to other systems using optical imaging technology, 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 recognition device may be embodied as an optical fingerprint device, which may be disposed in a partial area or an entire area below the display screen, thereby forming an Under-screen (Under-display) optical fingerprint system. Alternatively, the fingerprint identification device may be partially or completely integrated into a display screen of the electronic device, so as to form an In-display (In-display) optical fingerprint system.

Fig. 1 is a schematic structural diagram of an electronic device to which the embodiment of the present invention is applicable, where the electronic device 10 includes a display screen 120 and an optical fingerprint device 130, where the optical fingerprint device 130 is disposed in a local area below the display screen 120. The optical fingerprint device 130 comprises an optical fingerprint sensor including a sensing array 133 having a plurality of optical sensing units 131, where the sensing array 133 is located or a sensing area thereof is a fingerprint detection area 103 of the optical fingerprint device 130. As shown in fig. 1, the fingerprint detection area 103 is located in a display area of the display screen 120. In an alternative embodiment, the optical fingerprint device 130 may be disposed at other locations, such as the side of the display screen 120 or the edge opaque region of the electronic device 10, and the optical path is designed to guide the optical signal of at least a portion of the display area of the display screen 120 to the optical fingerprint device 130, such 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 fingerprint sensing area 103 may be different from the area of the sensing array of optical fingerprint device 130, for example, the area of fingerprint sensing area 103 of optical fingerprint device 130 may be larger than the area of the sensing array of optical fingerprint device 130 by optical path design such as lens imaging, reflective folded optical path design, or other optical path design where light is converged or reflected. In other alternative implementations, if light path guidance is performed using, for example, light collimation, fingerprint sensing area 103 of optical fingerprint device 130 may also be designed to substantially coincide with the area of the sensing array of optical fingerprint device 130.

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

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

In particular implementations, the optical assembly 132 may be packaged with the same optical fingerprint component as the light detection portion 134. For example, the optical component 132 may be packaged in the same optical fingerprint chip as the optical detection portion 134, or the optical component 132 may be disposed outside the chip where the optical detection portion 134 is located, such as attaching the optical component 132 on the chip, or integrating some components of the optical component 132 into the chip.

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

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

In other embodiments, the light guide layer or the light path guiding structure may also specifically adopt a Micro-Lens (Micro-Lens) layer, the Micro-Lens layer has a Micro-Lens array formed by a plurality of Micro-lenses, which may be formed above the sensing array of the light detecting portion 134 through a semiconductor growth process or other processes, and each Micro-Lens may correspond to one of the sensing units of the sensing array. And, other optical film layers may be further formed between the microlens layer and the sensing unit, such as a dielectric layer or a passivation layer, and more specifically, a light blocking layer having micro holes may be further included between the microlens layer and the sensing unit, where the micro holes are formed between the corresponding microlenses and the sensing unit, and the light blocking layer may block optical interference between adjacent microlenses and the sensing unit, and enable light rays corresponding to the sensing unit to be converged into the micro holes through the microlenses and transmitted to the sensing unit through the micro holes to perform optical fingerprint imaging. It should be understood that several implementations of the above-described optical path directing structure may be used alone or in combination, for example, a microlens layer may be further disposed below the collimator layer or the optical lens layer. Of course, when the collimator layer or the optical lens layer is used in combination with the microlens layer, the specific lamination structure or optical path thereof may need to be adjusted according to actual needs.

As an alternative embodiment, the display screen 120 may adopt a display screen having a self-Light Emitting display unit, such as an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. Taking the OLED display screen as an example, the optical fingerprint device 130 may use the display unit (i.e., the OLED light source) of the OLED display screen 120 located in the fingerprint detection area 103 as an excitation light source for optical fingerprint detection. When the finger 140 is pressed against the fingerprint detection area 103, the display screen 120 emits a beam of light 111 toward the target finger 140 above the fingerprint detection area 103, and the light 111 is reflected at the surface of the finger 140 to form reflected light or scattered light by scattering through the inside of the finger 140 to form scattered light, which is collectively referred to as reflected light for convenience of description in the related patent application. Because ridges (ridges) and valleys (valley) of the fingerprint have different light reflection capacities, reflected light 151 from the ridges and 152 from the valleys have different light intensities, and the reflected light is received by the sensor array 134 in the optical fingerprint device 130 and converted into corresponding electric signals, i.e., fingerprint detection signals, after passing through the optical assembly 132; based on the fingerprint detection signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed, so that an optical fingerprint identification function is realized in the electronic device 10.

In other embodiments, the optical fingerprint device 130 may also use an internal light source or an external light source to provide the light signal for fingerprint detection. In this case, the optical fingerprint device 130 may be adapted for use with a non-self-emissive Display screen, such as a Liquid Crystal Display (LCD) or other passive emissive Display screen. Taking an application to a liquid crystal display screen with a backlight module and a liquid crystal panel as an example, to support the underscreen fingerprint detection of the liquid crystal display screen, the optical fingerprint system of the electronic device 10 may further include an excitation light source for optical fingerprint detection, where the excitation light source may specifically be an infrared light source or a light source of non-visible light with a specific wavelength, and may be disposed below the backlight module of the liquid crystal display screen or in an edge area below a protective cover plate of the electronic device 10, and the optical fingerprint device 130 may be disposed below the edge area of the liquid crystal panel or the protective cover plate and guided through a light path so that the fingerprint detection light may reach the optical fingerprint device 130; alternatively, the optical fingerprint device 130 may be disposed under the backlight module, and the backlight module is configured to allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint device 130 by perforating or performing other optical designs on the diffusion sheet, the brightness enhancement sheet, the reflection sheet, and other film layers. When the optical fingerprint device 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 the same as that described above.

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

It should also be understood that electronic device 10 may also include a circuit board 150 disposed below optical fingerprint arrangement 130. The optical fingerprint device 130 may be adhered to the circuit board 150 by a back adhesive, and electrically connected to the circuit board 150 by soldering a pad and a wire. Optical fingerprint device 130 may be electrically interconnected and signal-transferred to other peripheral circuits or other components of electronic device 10 via circuit board 150. For example, the optical fingerprint device 130 may receive a control signal of a processing unit of the electronic apparatus 10 through the circuit board 150, and may also output a fingerprint detection signal from the optical fingerprint device 130 to the processing unit or the control unit of the electronic apparatus 10 through the circuit board 150, or the like.

On the other hand, in some embodiments, the optical fingerprint device 130 may include only one optical fingerprint sensor, where the area of the fingerprint detection area 103 of the optical fingerprint device 130 is small and the position is fixed, so that the user needs to press a finger to a specific position of the fingerprint detection area 103 when performing a fingerprint input, otherwise the optical fingerprint device 130 may not acquire a fingerprint image and the user experience is poor. In other alternative embodiments, optical fingerprint device 130 may specifically include a plurality of optical fingerprint sensors; the plurality of optical fingerprint sensors may be disposed side by side below the display screen 120 in a splicing manner, and sensing areas of the plurality of optical fingerprint sensors jointly form the fingerprint detection area 103 of the optical fingerprint device 130. That is, the fingerprint detection area 103 of the optical fingerprint device 130 may include a plurality of sub-areas, each of which corresponds to a sensing area of one of the optical fingerprint sensors, so that the fingerprint collection area 103 of the optical fingerprint device 130 may be extended to a main area of a lower half portion of the display screen, i.e., to a region where a finger is normally pressed, thereby implementing a blind-touch fingerprint input operation. Alternatively, when the number of optical fingerprint sensors is sufficient, the fingerprint detection area 103 may also be extended to half the display area or even the entire display area, thereby enabling half-screen or full-screen fingerprint detection.

It should also be understood that in the embodiments of the present application, the sensing array in the optical fingerprint device may also be referred to as a pixel array, and the optical sensing unit or the sensing unit in the sensing array may also be referred to as a pixel unit.

It should be noted that, optical fingerprint device in this application embodiment also can be called optical fingerprint identification module, fingerprint identification device, fingerprint identification module, fingerprint collection device etc. but above-mentioned term mutual replacement.

Fig. 2 shows a schematic block diagram of a fingerprint recognition device 200.

As shown in fig. 2, the fingerprint recognition device 200 includes: an optical assembly 210 and an optical fingerprint sensor 220, wherein the optical assembly 210 is configured to receive a fingerprint light signal reflected or scattered by a finger 140 over the display screen 120 and direct the fingerprint light signal to the optical fingerprint sensor 220. The surface of the optical fingerprint sensor 220 is provided with a light detection array 221 to detect a fingerprint light signal for fingerprint recognition.

Alternatively, the light detecting array 221 may be the same as the sensing array 133 of FIG. 1, and the optical assembly 210 may be the same as the optical assembly 132 of FIG. 1.

Optionally, as shown in fig. 2, the optical assembly 210 may include at least one optical lens for optically imaging the optical signal and transmitting the optical signal to the light detection array.

Optionally, the optical assembly 210 may also include a collimating layer, as described above for the optical assembly 132 in fig. 1, having a plurality of collimating units for passing optical signals incident perpendicular to the collimating units; a micro-lens layer and a light blocking layer with micro-holes can also be included for conducting optical signals in a specific direction; any other optical element for transmitting optical signals may be used, and the embodiment of the present application is not limited thereto.

In the embodiment of the present application, the optical component 210 is disposed below the display screen 120 of the electronic device, and the optical fingerprint sensor 220 is disposed below the optical component 210, wherein the optical fingerprint sensor 220 is disposed parallel to the display screen 120, that is, the light receiving surface of the light detecting array 221 in the optical fingerprint sensor 220 is disposed parallel to the display screen 120.

As shown in fig. 2, the light signal reflected or scattered by the finger 140 above the display screen 120 and passing through the optical element 210 is an oblique fingerprint light signal 201, and the light detecting array 221 receives the oblique fingerprint light signal 201.

It should be noted here that the tilted fingerprint optical signal 201 refers to an optical signal that is not perpendicular to the surface of the display screen, in other words, the angle between the propagation direction of the tilted fingerprint optical signal 201 and the surface of the display screen is not 90 °.

For example, when the display screen 120 and the light detecting array 221 are both disposed in a horizontal direction, a vertical plane perpendicular to the surface of the display screen is a vertical direction, and the angle between the tilted fingerprint light signal 201 and the vertical direction, i.e., the tilt angle of the tilted fingerprint light signal, is θ, wherein 0 ° < θ <90 °. If the light intensity of the inclined fingerprint light signal 201 is I₀According to the cosine fourth power theorem of the optical system, the light intensity I of the fingerprint light signal received by the light detection array 221_eThe calculation formula (1) is:

I_e＝I₀×cos⁴theta equation (1)

From the above formulaWhen θ increases, the intensity of the optical signal I received by the photo detector array 221_eThe light intensity of the fingerprint light signal received by the light detecting array 221 is rapidly reduced, in other words, when the inclination angle of the inclined fingerprint light signal is increased, thereby affecting the fingerprint imaging and fingerprint identification effects of the fingerprint identification device.

Based on this, this application provides a fingerprint identification device, set up the optics fingerprint sensor among the fingerprint identification device through the slope, can reduce the contained angle of slope light signal and fingerprint identification device perpendicular for the slope light signal vertical incidence that fingerprint identification device received or be close vertical incidence in optics fingerprint sensor, thereby when fingerprint identification device received the slope light signal, also can increase the light intensity of the light signal that optics fingerprint sensor received, improve fingerprint image quality and fingerprint identification effect.

Hereinafter, the fingerprint recognition device according to the embodiment of the present application will be described in detail with reference to fig. 3 to 15.

It should be noted that, for the sake of understanding, the same structures are denoted by the same reference numerals in the embodiments shown below, and detailed descriptions of the same structures are omitted for the sake of brevity.

Fig. 3 is a schematic structural diagram of a fingerprint identification device 300 according to an embodiment of the present application, where the fingerprint identification device 300 is configured to be disposed below a display screen 120 of an electronic device for fingerprint identification.

As shown in fig. 3, the fingerprint recognition device 300 includes: an optical assembly 310 and an optical fingerprint sensor 320;

an optical fingerprint sensor 320 disposed non-parallel below the display screen 120;

an optical component 310 comprising at least one lens, the optical component 310 being configured to transmit a fingerprint light signal 301 reflected or scattered by a finger above the display screen 120 to the optical fingerprint sensor 320 for fingerprint recognition, wherein the fingerprint light signal 301 is a light signal tilted with respect to the display screen.

In particular, the optical fingerprint sensor 320 may include a light detecting array 321, and the light detecting array 321 is grown on the surface of the optical fingerprint sensor 320 for receiving light signals and converting the light signals into corresponding electrical signals. The plane in which the light sensing array 321 is located, i.e. the light receiving surface, is at the same angle as the plane in which the optical fingerprint sensor 320 is located.

Specifically, the fingerprint optical signal 301 may be an optical signal returned after being reflected or scattered by the finger 140 above the fingerprint detection area 203 in the display screen 120. The fingerprint detection area 203 is a sensing area of the light detection array 321 in the display screen 120. Optionally, the light detection array 321 and the fingerprint detection area 203 may be the same as the sensor array 133 and the fingerprint detection area 103 in fig. 1, and the related description may refer to the above technical solutions, which are not described herein again.

Specifically, when the fingerprint light signal 301 received by the fingerprint identification device 300 is an optical signal inclined with respect to the display screen, the fingerprint identification device 300 may be disposed obliquely below the fingerprint detection area 203.

Optionally, when the optical fingerprint sensor 320 is disposed non-parallel below the display screen 120, or when the optical fingerprint sensor 320 is disposed obliquely below the display screen 120, the optical fingerprint sensor 320 is disposed obliquely below the fingerprint detection area 203, and the light receiving surface of the optical fingerprint sensor 320, i.e., the surface of the light detecting array 321, is disposed toward the fingerprint detection area 203, in this case, the fingerprint light signal reflected or scattered by the fingerprint detection area 203 can be received to the greatest extent, so as to improve the fingerprint imaging quality and fingerprint identification effect.

Alternatively, the optical assembly 310 may be disposed parallel to and below the display screen 120, or similarly, obliquely below the display screen 120, similar to the optical fingerprint sensor. Alternatively, the optical element 310 may be disposed obliquely below the fingerprint detection area 203.

For example, as shown in FIG. 3, the fingerprint detection area 203 is located at the upper right of the optical assembly 310 and the optical fingerprint sensor 320, where the left end of the optical fingerprint sensor 320 is higher than the right end, and the light receiving surface thereof is disposed toward the upper right, i.e., toward the fingerprint detection area 203.

When the optical fingerprint sensor 320 is disposed with its light receiving surface facing upward and leftward with its right end higher than the left end, the fingerprint detection area 203 is located on the fingerprint recognition device 300, i.e., on the optical assembly 310 and the optical fingerprint sensor 320.

Optionally, as shown in fig. 3, an included angle between a plane where the optical fingerprint sensor 320 is located and a plane where the display screen is located is ω, that is, an included angle between a plane where the light detection array 321 is located and a plane where the display screen is located is ω, and when the display screen is located on a horizontal plane, an included angle between the optical fingerprint sensor 320 and the horizontal plane is ω, where ω is greater than 0 ° and less than 90 °. For convenience of description, an included angle between a plane where the optical fingerprint sensor 320 is located and a plane where the display screen is located is also referred to as an inclination angle of the optical fingerprint sensor hereinafter.

Alternatively, as shown in fig. 3, the fingerprint optical signal 301 is an optical signal inclined by an angle θ relative to the display screen, where the inclination angle θ is an angle between a propagation direction of the fingerprint optical signal 301 and a first direction, the first direction is a direction perpendicular to the display screen, and 0 ° < θ <90 °. For convenience of description, the tilted fingerprint optical signals in the following description refer to optical signals that are not perpendicular to the plane of the display screen, and the tilt angle of the tilted fingerprint optical signals is the angle between the propagation direction of the optical signals and the perpendicular direction perpendicular to the surface of the display screen.

As shown in fig. 3, when the display 120 is located on a horizontal plane, the inclination angle of the fingerprint light signal is θ, the inclination angle of the optical fingerprint sensor 320 is ω, and θ > ω, the incident angle of the fingerprint light signal 301 with respect to the optical fingerprint sensor 320 is θ - ω, which is the angle between the fingerprint light signal 301 and a second direction perpendicular to the optical fingerprint sensor 320.

According to the above formula (1), the light intensity of the fingerprint light signal 301 is I₀The light intensity I of the optical signal received by the optical fingerprint sensor 320_eThe calculation formula (2) is:

I_e′＝I₀×cos⁴(theta-omega) formula (2)

For the fingerprint light signal with the inclination angle theta, when the optical fingerprint sensor is not obliquely arranged, namely as shown in figure 2, the optical fingerprint sensor is arranged in parallel on the displayThe intensity of the optical signal received by the optical fingerprint sensor when under the screen is shown in formula (1), I_e＝I₀×cos⁴Theta. When the optical fingerprint sensor is placed obliquely (the inclination angle is omega), the intensity of the optical signal received by the optical fingerprint sensor is shown in formula (2), I_e＝I₀×cos⁴(theta-omega) due to theta>ω, and ω>0 deg., so that the intensity of the optical signal received by the optical fingerprint sensor after being tilted is greater than the intensity of the optical signal received by the optical fingerprint sensor before being tilted.

For example, when the inclination angle θ of the fingerprint light signal is 50 °, the optical fingerprint sensor is not placed obliquely, i.e., ω is 0 °, I_e＝0.17×I₀. When the optical fingerprint sensor is placed at 30 degrees of inclination, i.e. omega is 30 degrees, I_e＝0.78×I₀. Therefore, after the optical fingerprint sensor is placed at an inclination of 30 °, the intensity of the optical signal received by the optical fingerprint sensor increases by about 4.6 times.

As shown in fig. 4, when the display screen 120 is located on a horizontal plane, the inclination angle of the fingerprint light signal is θ, the inclination angle of the optical fingerprint sensor 320 is ω, and θ is ω, the fingerprint light signal 301 has an incident angle of 0 ° with respect to the optical fingerprint sensor 320, i.e. the fingerprint light signal 301 is incident perpendicular to the optical fingerprint sensor 320, and at this time, the light intensity I of the light signal received by the optical fingerprint sensor 320 is_e＝I₀。

For example, when the inclination angle θ of the fingerprint light signal is 50 ° and the optical fingerprint sensor is not placed obliquely, I_e＝0.17×I₀When the optical fingerprint sensor is placed at an inclination of 50 ° (ω ═ 50 °), I_e＝I₀At this time, the intensity of the optical signal received by the optical fingerprint sensor increases by about 5.88 times.

As shown in fig. 5, when the display 120 is located on a horizontal plane, the inclination angle of the fingerprint light signal is θ, the inclination angle of the optical fingerprint sensor 320 is ω, and θ < ω, the incident angle of the fingerprint light signal 301 with respect to the optical fingerprint sensor 320 is ω - θ, which is also the angle of the fingerprint light signal 301 with respect to the second direction, wherein the second direction is the direction perpendicular to the optical fingerprint sensor 320.

According to the formula (1), the light intensity of the fingerprint light signal is I₀Light intensity I of optical signal received by optical fingerprint sensor_eThe calculation formula (3) is:

I_e″＝I₀×cos⁴(ω-θ)＝I₀×cos⁴(theta-omega) formula (3)

Since cos (ω - θ) ═ cos (θ - ω), the calculation formula (3) of the intensity of the optical signal received by the optical fingerprint sensor may be the same as the calculation formula (2) when θ < ω. Based on the above analysis, for the same fingerprint light signal (with an inclination angle θ), the intensity of the light signal received by the optical fingerprint sensor after being placed obliquely is greater than the intensity of the light signal received by the optical fingerprint sensor before being placed obliquely.

Therefore, when optical fingerprint sensor and display screen place the plane and be certain contained angle and place, non-parallel placement is in the display screen below promptly, to the slope light signal of same light intensity, compares in parallel placement in the display screen below, and optical fingerprint sensor received light signal's intensity can improve by a wide margin to improve fingerprint imaging quality and fingerprint identification effect.

When 0 ° < ω ≦ θ, the light intensity of the optical signal received by the optical fingerprint sensor is increased compared to the optical fingerprint sensor arranged in parallel (ω ═ 0 °), and the thickness variation of the optical fingerprint sensor is not large, improving the performance of the fingerprint recognition device without affecting the thickness of the fingerprint recognition device 300.

Particularly, when ω ═ θ, the fingerprint light signal is perpendicularly incident to the optical fingerprint sensor, the light intensity of the light signal received by the optical fingerprint sensor is maximum, and the fingerprint imaging quality and the fingerprint identification effect are optimal.

It should be noted here that the inclination angle ω of the optical fingerprint sensor 320 is set in relation to the inclination angle θ of the fingerprint light signal that the fingerprint identification device 300 needs to receive, and in the fingerprint identification system, various factors such as the structure and position of the optical element in the optical assembly 310 of the fingerprint identification device 300, the distance between the optical assembly 310 and the optical fingerprint sensor 320, and the distance between the optical assembly 310 and the screen all affect the angle of the fingerprint light signal received by the fingerprint identification device 300. Alternatively, when the fingerprint light signal received by the fingerprint identification device is inclined at an angle θ ≦ 30 °, 0 ° < ω ≦ 30 °.

Optionally, as shown in fig. 3, the fingerprint identification device 300 may further include a supporting structure 330, and the optical fingerprint sensor 320 may be disposed below the display screen in a non-parallel manner through the supporting structure 330, i.e., at an angle with respect to a plane where the display screen is located.

Alternatively, the support structure 330 may be an injection molded material, including but not limited to polycarbonate, resin, polymethylmethacrylate, and the like.

Optionally, the support structure 330 may also be a metal material, including but not limited to copper, aluminum, or other alloy materials.

Optionally, the supporting structure 330 may also be a plastic material or any other solid material having a supporting function, and the material of the supporting structure is not particularly limited in the embodiments of the present application.

Specifically, the supporting structure 330 can be disposed on a substrate fixedly supporting the fingerprint recognition device 300, including but not limited to a middle frame of a mobile phone. The support structure 330 may be disposed on the substrate by processes including, but not limited to: injection molding, fine engraving, photoetching, etching, laser processing and the like.

Optionally, the supporting structure 330 may be integrally processed with the substrate to form a whole, or may be processed independently, and is connected and fixed on the substrate through a connecting device.

Alternatively, in one possible implementation, as shown in fig. 6, the optical assembly 310 may include: the lens assembly comprises at least one optical lens and is used for receiving the fingerprint optical signal 301 for fingerprint imaging, and the optical fingerprint sensor is used for receiving the imaged optical signal and forming a corresponding electric signal for fingerprint identification.

Alternatively, the surface of the optical lens may be spherical or aspherical. Alternatively, the material of the optical lens may be a transparent material such as glass, resin, or the like.

Optionally, when the lens assembly includes a plurality of optical lenses, the plurality of optical lenses may all be spherical lenses or all be aspheric lenses, or may include both spherical lenses and aspheric lenses, which is not limited in this application.

Optionally, the lens assembly further comprises an aperture stop. The aperture diaphragm is formed in an optical path with the at least one optical lens and is used for being matched with the at least one optical lens to carry out optical fingerprint imaging.

Alternatively, the aperture stop may be located on the primary optical axis of the optical lens.

Alternatively, the aperture stop may be located at the object-side focus or the image-side focus of the optical lens.

Optionally, the plurality of optical lenses in the lens assembly are arranged parallel to each other, that is, the focal planes of the plurality of optical lenses are parallel to each other, and the main optical axes of the plurality of optical lenses are located on the same straight line.

Alternatively, the lens assembly may be fixed on the optical fingerprint sensor by a fixing assembly, for example, the fixing assembly may include a lens holder and a lens barrel, the lens assembly is configured and fixed in the lens barrel, and the lens holder is configured and arranged to connect with the lens barrel and fix the lens barrel on the optical fingerprint sensor. Alternatively, the fixing component may further include a bracket, an adhesive layer, and the like, which is not limited in this application.

Optionally, in the present embodiment, the optical axis of the optical lens is perpendicular to the optical fingerprint sensor 320, in other words, the focal plane of the optical lens is parallel to the optical fingerprint sensor 320.

When the plane where the optical fingerprint sensor 320 is located and the plane where the display screen 120 is located are set to be ω, the included angle between the focal plane of the optical lens and the display screen 120 is also ω.

When the number of the optical lenses is multiple, the included angles between the focal planes of the optical lenses and the display screen 120 may be ω, that is, the optical lenses and the optical fingerprint sensor 320 are disposed under the display screen 120 in a non-parallel manner.

Alternatively, the direction of the fingerprint light signal 301 received by the optical lens may be parallel to the direction of the main optical axis of the lens. If the fingerprint optical signal 301 is transmitted to the optical fingerprint sensor 320 through the optical center of the optical lens, the direction of the optical signal received by the optical fingerprint sensor 320 is the same as the direction of the fingerprint optical signal 301, and the inclination angles are all θ.

Alternatively, in another possible implementation, as shown in fig. 7, the optical assembly 310 may include: a microlens array 311 and at least one light blocking layer 312.

The at least one light blocking layer 312 is located below the microlens array 311, and is provided with a plurality of light passing apertures;

the micro lens array 311 is used for receiving the fingerprint optical signal 301 and converging the fingerprint optical signal 301 to a plurality of light-passing pinholes;

the plurality of light passing apertures is used to transmit the fingerprint light signal 301 to the optical fingerprint sensor 320, in particular, to transmit the fingerprint light signal 301 to the light detecting array 321 in the optical fingerprint sensor 320.

Alternatively, the microlens array 311 includes a plurality of microlenses, which may be spherical or aspherical lenses.

Optionally, the light detection array 321 includes a plurality of pixel units, and the microlenses in the microlens array 311 correspond to the pixel units in the light detection array 321 one by one, that is, one microlens is used to receive the optical signal above the microlens and transmit the optical signal to one pixel unit corresponding to the microlens through a light-passing aperture on at least one light-blocking layer.

Alternatively, when the optical assembly 310 includes a light blocking layer, one microlens corresponds to one light passing aperture and one pixel unit. The center of the microlens, the center of the light passing aperture, and the center of the pixel unit may coincide in a direction perpendicular to the pixel unit.

Alternatively, when the optical assembly 310 includes at least two light-blocking layers, for example, two light-blocking layers including a first light-blocking layer and a second light-blocking layer, one microlens in the microlens array corresponds to one first light-passing aperture on the first light-blocking layer and one second light-passing aperture on the second light-blocking layer, and one pixel unit. Similarly, the center of the microlens, the center of the first light passing aperture, the center of the second light passing aperture, and the center of the pixel unit may coincide in a direction perpendicular to the pixel unit.

Alternatively, the microlens array 311 may be used to receive an optical signal incident perpendicular to the microlens array 311. The fingerprint light signal 301 returning after reflection or scattering by the finger above the display screen may be a light signal incident perpendicular to the microlens array 311.

Optionally, the material of the microlens array 311 is a transparent medium having a light transmittance of more than 99%, such as resin.

Alternatively, the microlenses in the microlens array 311 are polygonal lenses, such as square lenses or hexagonal lenses, and may also be circular lenses. For example, when the microlens is a quadrangular lens, the upper surface of the quadrangular lens is a spherical surface or an aspherical surface, and the lower surface thereof is a quadrangular lens.

Specifically, the transmittance of the at least one light blocking layer 312 to light in a specific wavelength band (such as visible light or a wavelength band over 610 nm) is less than 20%, so as to prevent the corresponding light from passing through. Optionally, the material of the at least one light-blocking layer 312 may be a metal and/or a black opaque material.

Alternatively, the light-passing apertures in the at least one light-blocking layer 312 are circular apertures having a diameter of less than 10 μm for optical imaging, and the resolution of the optical imaging can be increased by reducing the size of the light-passing apertures, thereby increasing the resolution of the fingerprint image.

Optionally, the shape of the light passing aperture on the at least one light blocking layer may also be a polygon or other shapes, which is not limited in this application.

Optionally, the microlens array 311 and the at least one light blocking layer 312 may be packaged together with the light detection array 321 in an optical fingerprint sensor, and specifically, the at least one light blocking layer 312 may be prepared on a plurality of pixel units of the light detection array 321 by a micro-nano processing process or a nano-printing process, for example, a layer of non-transparent material film is prepared above the plurality of pixel units by atomic layer deposition, sputter coating, electron beam evaporation coating, ion beam coating, and the like by the micro-nano processing process, and then the small hole pattern lithography and etching are performed to form a plurality of light passing small holes.

Optionally, the light detection array 321 is isolated from the light blocking layer and the multiple light blocking layers by transparent medium layers. The transparent dielectric layer is an organic or inorganic transparent dielectric material, such as resin or silicon oxide.

In the embodiment of the present application, the microlens array 311 and the at least one light blocking layer 312 are both disposed in parallel above the optical fingerprint sensor, i.e. the microlens array 311 and the at least one light blocking layer 312 are both disposed in non-parallel, i.e. obliquely below the display screen.

Optionally, an angle between a plane of each of the at least one light blocking layer 312 and a plane of the display screen is ω. The lower surface of the microlens array 311 also forms an angle ω with the plane of the display screen.

Optionally, in various embodiments described above, the apparatus 300 for fingerprint recognition may further include: the filtering layer is used for filtering optical signals of non-target wave bands, transmitting the optical signals of the target wave bands (namely the optical signals of the wave bands required by fingerprint image acquisition), and is beneficial to reducing the influence of the environment optical signals of the non-target wave bands, so that the fingerprint identification performance can be improved.

Optionally, a filter layer is disposed in the optical path between the display screen 120 and the optical fingerprint sensor 320. For example, a filter layer may be disposed between the display screen 120 and the optical assembly 310, or in the optical assembly 310, or may also be disposed between the optical assembly 310 and the optical fingerprint sensor 320.

When the optical assembly 310 includes the microlens array 311 and the at least one light blocking layer 312, optionally, the lower surface of the filter layer is completely attached to the upper surface of the microlens array 311 by an adhesive layer, and there is no air layer between the filter layer and the microlens array 310. Alternatively, the adhesive layer may be a low refractive index glue having a refractive index of less than 1.25.

Optionally, the filter layer may also be fixed above the microlens array 310 by a low refractive index glue or other fixing device, and a certain air gap exists between the lower surface of the filter layer and the upper surface of the microlens array 310.

Alternatively, the filter layer may be attached over the optical fingerprint sensor 320 by an adhesive having a high transmittance and a low refractive index.

Alternatively, the filter layer may also be integrated in the chip of the optical fingerprint sensor 320, and specifically, the filter layer may be formed by coating on the plurality of pixel units of the optical fingerprint sensor 320 by an evaporation process, for example, a filter material film is prepared on the plurality of pixel units by atomic layer deposition, sputtering coating, electron beam evaporation coating, ion beam coating, or the like.

In the embodiment of the present application, the filter layer may be a visible light filter, and may be specifically configured to filter visible light wavelengths, for example, visible light used for image display. The visible light filter may particularly comprise one or more optical filters, which may be configured, for example, as band pass filters, to filter out light emitted by the visible light source while not filtering out infrared light signals. The one or more optical filters may be implemented, for example, as an optical filter coating formed on one or more continuous interfaces, or may be implemented as one or more discrete interfaces.

It should be understood that the filter layer may be fabricated on the surface of any optical component or along the optical path to the optical fingerprint sensor 320 to the reflected light formed via finger reflection. Optionally, the filter layer may also be disposed in a film layer structure in the display screen 120.

Optionally, in various embodiments described above in the present application, the display screen may be an organic light emitting diode display screen (OLED) or a liquid crystal display screen (LCD). If the display screen is an OLED display screen, the fingerprint optical signal is an optical signal formed by reflecting or scattering excitation light emitted by part of display units of the OLED display screen by a finger above the OLED display screen and returning. If the display screen is an LCD display screen comprising a backlight module, the fingerprint optical signal is an optical signal formed by reflecting or scattering infrared excitation light emitted by an external light source by a finger above the LCD display screen and returning the infrared excitation light to one of the first prism film side and the second prism film side of the prism film of the backlight module after the infrared excitation light irradiates the upper part of the LCD display screen and is refracted.

Specifically, as shown in fig. 8, the lcd 120 includes a liquid crystal panel 122, a backlight module 123 and a glass cover 124. Specifically, the backlight module 123 includes a prism film 124 and other structures 125 of the backlight module, wherein the other structures 125 of the backlight module include, but are not limited to, polarizer, diffuser, light guide plate, and reflector. Specifically, fig. 9a and 9b show a perspective view and a cross-sectional view of a prism film 124 in an embodiment of the present application, in which the prism film 124 is formed by regularly arranging a plurality of identical prism units 1240 on a substrate 1243 in a row, wherein each prism unit 1240 is formed by protruding upward from the substrate 1243, and each prism unit 1240 has a single source structure with two inclined side surfaces, and an included angle is formed between the two inclined side surfaces, which is an apex angle (apex angle) of the prism unit 1240. For example, as shown in fig. 9b, prism unit 1240 has a triangular cross-section, and prism unit 1240 has a structure similar to a triangular prism. Specifically, the inclined sides of the plurality of prism cells 1240 are connected to form the upper surface of the prism film 124, wherein, as shown in fig. 9a and 9b, two inclined sides of the prism cells 1240 are a first inclined side unit 1241 and a second inclined side unit 1242, respectively, and the plurality of first inclined side units 1241 and the plurality of second inclined side units 1242 are disposed to be spaced apart from each other, forming a plurality of first inclined side units 1241 parallel to each other and a plurality of second inclined side units 1242 parallel to each other in the prism film 124. The plurality of parallel first inclined side units 1241 are first prism film sides of the prism film 124, and the plurality of parallel second inclined side units 1242 are second prism film sides of the prism film 124.

As shown in fig. 8, the fingerprint recognition device 200 includes an optical lens, an aperture stop, and an optical fingerprint sensor. When the fingerprint recognition device 200 is disposed in parallel below the lcd 120, the fingerprint light signal reflected or scattered by the finger is refracted by the first prism film side and the second prism film side of the prism film 124 into light signals of different directions, wherein, after the fingerprint light signal at the edge of the fingerprint detection area 203 is refracted by the prism film, for example the fingerprint light signal 204 enters the optical fingerprint sensor through the aperture stop for imaging, after the fingerprint light signal at the center of the fingerprint detection area 203 is refracted by the prism film, for example, the fingerprint light signal 205 cannot enter the optical fingerprint sensor through the aperture stop for imaging, therefore, shadow stripes as shown in fig. 10 are formed in the fingerprint image detected and formed in the optical fingerprint sensor, resulting in a serious field loss and distortion of the fingerprint image, and thus the fingerprint recognition function under the liquid crystal display screen cannot be realized.

Consequently, be the liquid crystal display's the condition to in the display screen, fingerprint identification device in this application embodiment, through non-parallel arrangement in the liquid crystal display below for all regional fingerprint light signals in the fingerprint detection area all can all pass through the aperture diaphragm after passing through in the prism membrane one prism membrane side refraction in first prism membrane side and the second prism membrane side, thereby make no shadow in the fingerprint image that optics fingerprint sensor detected the formation, the fingerprint identification device who is convenient for to be located the liquid crystal display below carries out fingerprint identification.

Fig. 11 shows a schematic structural diagram of another fingerprint identification device 300, wherein the fingerprint identification device 300 is arranged below a liquid crystal display screen and comprises: an optical assembly 310 and an optical fingerprint sensor 320.

The optical assembly 310 includes, among other things, an aperture stop 313 and an optical lens 314. Alternatively, as shown in fig. 11, the aperture stop 313 is located above the optical lens 314, performs optical fingerprint imaging together with the optical lens, and transmits a fingerprint light signal to the optical fingerprint sensor 320.

Optionally, the aperture stop 313 is located on the primary optical axis of the optical lens 314.

Alternatively, the aperture stop 313 may be located at the object focus of the optical lens 314.

Specifically, the optical fingerprint sensor 320 is disposed obliquely below the liquid crystal display, for example, as shown in fig. 11, the inclination angle of the optical fingerprint sensor 320 is ω, 0 ° < ω <90 °.

Optionally, as shown in fig. 11, the fingerprint recognition device 300 further includes: and a support structure 330 for supporting and fixing the optical fingerprint sensor 320 to be disposed under the display screen in a non-parallel manner. Specifically, the specific implementation manner of the supporting structure 330 may refer to the description of the supporting structure 330 in the above application embodiments, and is not described herein again.

Optionally, the optical assembly 310 is also disposed obliquely below the liquid crystal display. For example, as shown in FIG. 11, the focal plane of the optical lens 314 is parallel to the optical fingerprint sensor 320, or the tilt angle of the optical lens 314 is also ω.

Optionally, in this embodiment, the optical assembly 310 may further include a plurality of optical lenses, which may be spherical lenses or aspheric lenses, and the aperture stop 314 is formed in optical paths of the plurality of optical lenses.

Alternatively, the optical assembly 310 is positioned such that the optical assembly 310 receives only the optical signal formed after being refracted through one of the first and second prism film sides of the prism film 124, and does not receive the optical signal refracted through the other prism film side of the prism film 124.

Specifically, the aperture stop 313 in the optical assembly 310 is located such that the aperture stop 313 reflects or scatters only by a finger above the fingerprint detection area 203, and then passes through a side of one of the prism films to refract the formed fingerprint optical signal. For example, as shown in fig. 11, the fingerprint light signal 301 refracted by the second prism film side surface can enter the optical lens 314 and the optical fingerprint sensor 320 through the aperture stop 313 to be imaged, while the fingerprint light signal refracted by the first prism film side surface cannot be imaged through the aperture stop 313.

Alternatively, the optical fingerprint sensor 320 may be positioned such that the optical fingerprint sensor 320 receives only the optical signal formed after being refracted through one of the first and second prism film sides of the prism film 124 and does not receive the optical signal refracted through the other prism film side of the prism film 124.

Through the scheme of this application embodiment, place optics fingerprint sensor 320 slope, can make optics fingerprint sensor 320 can receive all regional fingerprint light signal in the fingerprint detection region, and carry out fingerprint formation of image to the fingerprint detection region, and do not have the dark stripe in the fingerprint image that obtains of detection, can realize the fingerprint identification under liquid crystal display, in addition, can also increase the light intensity of the fingerprint light signal that optics fingerprint sensor 320 received, can further improve fingerprint image quality and fingerprint identification effect.

Fig. 12 is a schematic view showing another fingerprint recognition device 300, wherein the fingerprint recognition device 300 is also arranged below the liquid crystal display screen, and comprises: an optical assembly 310 and an optical fingerprint sensor 320.

The optical assembly 310 is disposed in parallel below the liquid crystal display. For example, the optical lens 314 in the optical assembly 310 has a principal optical axis perpendicular to the surface of the liquid crystal display panel, and the aperture stop 314 is located on the principal optical axis of the optical lens 314.

The optical fingerprint sensor 320 is also disposed in parallel below the liquid crystal display 120, but obliquely below the optical assembly 310. For example, as shown in fig. 12, when the optical fingerprint sensor 320 is located at the lower left of the optical assembly 310, the fingerprint detection area 203 corresponding to the optical fingerprint sensor 320 is located at the upper right of the optical assembly, the optical fingerprint sensor 320 is configured to receive a fingerprint light signal in the fingerprint detection area 203, the fingerprint light signal enters the aperture stop 313 after being refracted by the second prism film side surface of the prism film 124, and the fingerprint light signal cannot enter the aperture stop 313 after being refracted by the first prism film side surface of the prism film 124.

Similarly, when the optical fingerprint sensor 320 is located at the lower right of the optical assembly 310, the fingerprint detection area 203 corresponding to the optical fingerprint sensor 320 is located at the upper left of the optical assembly, the optical fingerprint sensor 320 is configured to receive a fingerprint light signal in the fingerprint detection area 203, the fingerprint light signal enters the aperture stop 313 after being refracted by the first prism film side of the prism film 124, and the fingerprint light signal cannot enter the aperture stop 313 after being refracted by the second prism film side of the prism film 124.

Alternatively, as shown in fig. 12, the fingerprint detection area 203 is located on one side of the optical axis of the optical component 310.

Optionally, a Field Of View (FOV) area Of the optical assembly 310 is larger than the fingerprint detection area 203, and the fingerprint light signal received by the optical fingerprint sensor 320 is a portion Of the light signal transmitted by the optical assembly 310. Specifically, in the embodiment of the present application, the field of view area of the optical component 310 is the field of view area of the optical component 310 in the liquid crystal display screen.

Optionally, the fingerprint detection area 203 is located at an edge region of the field of view of the optical assembly 310. The edge area of the field of view of the optical assembly 310 is located within the field of view area of the optical assembly 310, and the distance between the center of the edge area of the field of view and the center of the field of view area is greater than or equal to a first threshold, for example, the first threshold is 4/5 of the radius of the field of view area, it should be understood that the first threshold may also be 3/4 or any other value of the radius of the field of view area, which is not limited in this embodiment of the present application.

Optionally, the optical component 310 does not overlap with a projection of the fingerprint detection area 203 onto a plane in which the optical fingerprint sensor 320 is located.

It should be understood that the optical assembly 310 and the fingerprint detection area 203 may also have an overlapping area in projection on the plane of the optical fingerprint sensor 320, but the optical fingerprint sensor 320 cannot simultaneously receive the fingerprint light signals refracted through the two prism film sides of the prism films.

Optionally, the fingerprint detection area 203 is located on one side of the optical axis of the optical assembly 310, and the optical fingerprint sensor 320 is disposed on the other side of the optical axis of the optical assembly 310.

Optionally, in one possible embodiment, optical assembly 310 is a super wide angle lens group including one or more super wide angle lenses. Optionally, the field of view of the ultra-wide angle lens group is larger than the fingerprint detection area 203. Optionally, the ultra-wide angle lens group has a field angle ranging from 120 ° to 180 °.

Optionally, the fingerprint detection area 203 is a square of 5cm x 5cm or more.

Optionally, the object focal length of the optical assembly 310, also called the front focal length of the optical assembly 310, is increased, thereby increasing the distance from the optical assembly 310 to the fingerprint detection area 203 to enlarge the field of view of the optical assembly 310. By enlarging the field of view of the optical assembly 310 and increasing the area of the optical fingerprint sensor 320, the area of the fingerprint detection area 203 can be increased, thereby increasing the area of the fingerprint image and improving the performance of the fingerprint recognition.

Specifically, fig. 13 shows a schematic diagram of the calculation of the inclination angle ω of the optical fingerprint sensor 320 when the optical fingerprint sensor 320 is placed obliquely below the liquid crystal display. The optical fingerprint sensor 320 in fig. 13 may be the optical fingerprint sensor 320 in fig. 11, and the aperture stop 313 may be the aperture stop 313 in fig. 11.

As shown in fig. 13, the optical fingerprint sensor 320' is disposed parallel to the lcd, and the corresponding fingerprint identification area is located right above the optical fingerprint sensor 320', in which case, a shadow area appears in the center of the fingerprint image formed by the optical fingerprint sensor 320', for the specific reason, see the related description of fig. 8, which is not repeated herein.

Wherein, the distance from the aperture stop 313 to the optical fingerprint sensor 320 'is d, d > 0. l is the length or width of the sensing region in the optical fingerprint sensor, l >0, specifically, l can be the length or width of the light detection array 321. β is the divergence angle of the shadow region in the fingerprint image generated by the optical fingerprint sensor 320', β >0, the divergence angle is related to the structure of the optical assembly 310, the distance from the optical assembly 310 to the optical fingerprint sensor, the structure of the prism film and other factors.

To avoid the appearance of shadows in the fingerprint image formed by the optical fingerprint sensor, the optical fingerprint sensor is rotated to the position of the optical fingerprint sensor 320 in fig. 13, where the tilt angle of the optical fingerprint sensor 320 is ω, when 90^°>ω>β/2+ arctan (l/d), optical fingerNo shadows will appear in the fingerprint image formed by the fingerprint sensor 320.

It should be understood that fig. 13 shows only one direction of rotation of the optical fingerprint sensor, and the fingerprint sensor may also rotate in other directions with the aperture stop 313 as the center of rotation, so that no shadow appears in the fingerprint image formed by the optical fingerprint sensor.

It should also be understood that in the embodiments of the present application, when the optical fingerprint sensor is rotated, the optical component in the fingerprint identification device rotates together with the optical fingerprint sensor, in other words, the optical component in the fingerprint identification device is disposed parallel to the optical fingerprint sensor, and when the optical fingerprint sensor is disposed at an angle with respect to the display screen, the optical component is also disposed at an angle with respect to the display screen.

Specifically, fig. 14 shows a schematic diagram of the calculation of the moving distance c of the optical fingerprint sensor 320 when the optical fingerprint sensor 320 below the lcd is placed obliquely below the optical assembly 310. The optical fingerprint sensor 320 in fig. 14 may be the optical fingerprint sensor 320 in fig. 12, and the aperture stop 313 may be the aperture stop 313 in fig. 12.

As shown in fig. 14, the optical fingerprint sensor 320' is disposed parallel to the lcd, and the corresponding fingerprint identification area is located right above the optical fingerprint sensor 320', in which case, a shadow area appears in the center of the fingerprint image formed by the optical fingerprint sensor 320', for the specific reason, see the description of fig. 8, which is not repeated herein.

Wherein the distance from the aperture stop 313 to the optical fingerprint sensor 320 'is d, d > 0. l is the length or width of the light sensing area in the optical fingerprint sensor, l >0, specifically l may be the length or width of the light sensing array 321. β is the divergence angle of the shaded area in the fingerprint image generated by the optical fingerprint sensor 320', β > 0.

In order to avoid shadows in the fingerprint image formed by the optical fingerprint sensor, the optical fingerprint sensor is translated to the position of the optical fingerprint sensor 320 in fig. 14, where the translation distance of the optical fingerprint sensor 320 is c, and no shadows are present in the fingerprint image formed by the optical fingerprint sensor 320 when c > l + d × arctan (β/2).

It should be noted here that in the embodiment of the present application, when the position of the optical assembly in the fingerprint identification device is kept unchanged, the optical fingerprint sensor is translated by the distance c, so that the optical fingerprint sensor is located obliquely below the optical assembly, but not directly below the optical assembly.

It should be understood that while only a translation schematic of the optical fingerprint sensor is shown in fig. 14 in one direction, the fingerprint sensor may also be translated in other directions so that no shadows appear in the fingerprint image formed by the optical fingerprint sensor.

Alternatively, when the display is a liquid crystal display, as shown in fig. 15, the fingerprint recognition device 300 further includes: the infrared light source 340 is used for providing infrared excitation light for fingerprint detection of the fingerprint identification device 300, the infrared excitation light irradiates at least part of the display area of the liquid crystal display screen, and the at least part of the display area at least partially covers the fingerprint detection area of the fingerprint identification device 300.

Alternatively, the infrared light source 340 may be disposed below the glass cover 121 of the electronic device, and disposed side by side with the liquid crystal panel 122 of the liquid crystal display, and disposed obliquely above the backlight module 123 of the liquid crystal display.

Alternatively, the infrared light source 340 may be attached obliquely below the glass cover plate 121. For example, the infrared light source 340 may be attached to the underside of the display screen by optical glue. Alternatively, the optical glue may be any one of an optical liquid glue or an optical solid glue.

Alternatively, an infrared light transmitting layer 341 may be disposed between the infrared light source and the glass cover plate and/or between the infrared light source and the liquid crystal display screen, and the infrared light transmitting layer 341 may be configured to transmit the infrared excitation light and block the visible light. Alternatively, the infrared light transmitting layer 341 may be an infrared light transmitting ink.

Alternatively, as shown in fig. 15, a light blocking foam 342 may be disposed between the infrared light source 340 and the liquid crystal panel 122 in the liquid crystal display for blocking visible light.

Optionally, the infrared light source is disposed in a non-display area at an edge of the electronic device.

Alternatively, the infrared light source may be a single or multiple light-emitting diodes (LEDs). Alternatively, a plurality of infrared light emitting diodes may constitute a strip-shaped infrared light emitting source, which is distributed around the fingerprint identification device 300.

As shown in fig. 16, an electronic device 30 is further provided in the embodiment of the present application, and the electronic device 30 may include the fingerprint identification device 300 in the embodiment of the present application.

Optionally, the electronic device 30 may further include a display screen 120. Alternatively, the display 120 may be a liquid crystal display or an organic light emitting diode display.

Optionally, when the display screen is a liquid crystal display screen, the electronic device 30 may further include an infrared light source. The infrared light source may be the same as the infrared light source 340 in fig. 15, and the related technical solutions may refer to the above description, which is not described herein again.

It should be understood that the specific examples in the embodiments of the present application are for the purpose of promoting a better understanding of the embodiments of the present application and are not intended to limit the scope of the embodiments of the present application.

It is to be understood that the terminology used in the embodiments of the present application and the appended claims is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the present application. For example, as used in the examples of this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Those of ordinary skill in the art will appreciate that the elements of the examples described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the components and steps of the examples have been described above generally in terms of their functionality in order to clearly illustrate the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the several embodiments provided in the present application, it should be understood that the disclosed system and apparatus may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may also be an electric, mechanical or other form of connection.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments of the present application.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially or partially contributed by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

While the invention has been described with reference to specific embodiments, the scope of the invention is not limited thereto, and those skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the invention. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A fingerprint identification device is suitable for the electronic equipment that has the display screen in order to carry out optical fingerprint detection under the screen, its characterized in that, fingerprint identification device includes:

the optical component is arranged above the optical fingerprint sensor and comprises at least one lens, the optical component is used for transmitting a fingerprint optical signal returned after the reflection or scattering of a finger above the display screen to the optical fingerprint sensor for fingerprint identification, and the fingerprint optical signal is an optical signal inclined relative to the display screen.

2. The fingerprint recognition device of claim 1, wherein the display screen includes a fingerprint detection area, and the optical assembly is configured to transmit the fingerprint light signal returned after reflection or scattering by a finger above the fingerprint detection area;

3. The fingerprint recognition device according to claim 1 or 2, wherein the plane of the optical fingerprint sensor is at an angle ω to the plane of the display screen, wherein 0 ° < ω <90 °.

4. The fingerprint recognition device of claim 3, wherein 0 ° < ω < 30 °.

5. The fingerprint recognition device according to claim 3 or 4, wherein the incident angle of the fingerprint light signal with respect to the optical fingerprint sensor is θ - ω, where θ - ω is the angle between the fingerprint light signal and the vertical plane of the optical fingerprint sensor, θ is the angle between the fingerprint light signal and the vertical plane of the display screen, and 0 ° < θ <90 °.

6. The fingerprint recognition device according to claim 3 or 4, wherein ω is θ, where θ is an angle between the fingerprint light signal and a vertical plane of the display screen, and 0 ° < θ <90 °.

7. The fingerprint recognition device of any one of claims 1-6, wherein the optical assembly comprises: at least one optical lens for receiving the fingerprint optical signal to perform fingerprint imaging, wherein the optical lens is a spherical lens or an aspheric lens.

8. The fingerprint recognition device of claim 7, wherein the optical assembly further comprises: an aperture stop formed in an optical path of the at least one optical lens.

9. The fingerprint recognition device of claim 7 or 8, wherein the focal plane of the optical lens is parallel to the optical fingerprint sensor.

10. The fingerprint recognition device according to any one of claims 7-9, wherein the direction of the fingerprint light signal is parallel to the optical axis of the optical lens.

11. The fingerprint recognition device of any one of claims 7-10, wherein the at least one optical lens is secured to the optical fingerprint sensor by a securing assembly, and wherein the at least one optical lens is disposed non-parallel to the optical fingerprint sensor below the display screen.

12. The fingerprint recognition device of any one of claims 1-6, wherein the optical assembly comprises: a microlens array and at least one light blocking layer;

the micro lens array is used for receiving the fingerprint optical signals and converging the fingerprint optical signals to the plurality of light-transmitting small holes;

the plurality of light-passing small holes are used for transmitting the fingerprint light signals to the optical fingerprint sensor.

13. The fingerprint recognition device of claim 12, wherein the fingerprint light signal is incident perpendicularly to the microlens array.

14. The fingerprint recognition device according to claim 12 or 13, wherein the microlens array and the at least one light blocking layer are integrally disposed over the optical fingerprint sensor by a semiconductor process;

the micro lens array, the at least one light blocking layer and the optical fingerprint sensor are all arranged below the display screen in a non-parallel mode.

15. The fingerprint recognition device of any one of claims 1-14, wherein the optical fingerprint sensor is disposed non-parallel below the display screen via a support structure;

16. The fingerprint recognition device according to any one of claims 1-15, wherein the display screen is an organic light emitting diode display screen;

the fingerprint optical signal is an optical signal formed by reflecting or scattering excitation light emitted by part of display units of the organic light-emitting diode display screen by a finger above the organic light-emitting diode display screen and returning.

17. The fingerprint identification device of any one of claims 1-15, wherein the display is a liquid crystal display having a backlight module;

18. The fingerprint recognition device of claim 17, wherein the optical assembly comprises at least one optical lens and an aperture stop, and the plane of the optical fingerprint sensor is at an angle ω with respect to the plane of the display screen, wherein 90 ° > ω > β/2+ arctan (l/d), l is 1/2 of the length of the optical fingerprint sensor, d is the distance from the aperture stop to the optical fingerprint sensor, and β is the divergence angle of the shadow region determined by the prism film.

19. The fingerprint recognition device of claim 17 or 18, wherein the optical assembly is positioned such that an optical signal refracted through a side of another one of the prismatic films is deflected away from the optical assembly and not transmitted to the optical fingerprint sensor.

20. The fingerprint identification device of any one of claims 17-19, wherein the optical fingerprint sensor is positioned such that the light signal refracted through the side of the other of the prismatic films is deflected away from the optical fingerprint sensor.

21. The fingerprint recognition device according to any one of claims 1-20, wherein the fingerprint recognition device further comprises:

and the filtering layer is arranged in a light path between the display screen and the optical fingerprint sensor and used for filtering optical signals of non-target wave bands and transmitting the optical signals of the target wave bands.

22. An electronic device, comprising:

a display and a fingerprint recognition device according to any one of claims 1 to 21, wherein said fingerprint recognition device is arranged below said display for off-screen optical fingerprint detection.

23. The electronic device of claim 22, wherein the display screen is an organic light emitting diode display screen, and wherein the fingerprint light signal is a light signal formed by reflection or scattering of excitation light emitted from a portion of display units of the organic light emitting diode display screen by a finger above the organic light emitting diode display screen and returned.

24. The electronic device of claim 22, wherein the display is a liquid crystal display, the electronic device further comprising:

the infrared light source is used for providing infrared excitation light for fingerprint detection of the fingerprint identification device, the infrared excitation light irradiates to at least part of display area of the liquid crystal display screen, and at least part of the display area at least partially covers the fingerprint detection area of the fingerprint identification device.