WO2021077406A1

WO2021077406A1 - Fingerprint recognition apparatus and electronic device

Info

Publication number: WO2021077406A1
Application number: PCT/CN2019/113305
Authority: WO
Inventors: 王文轩; 沈健; 纪登鑫
Original assignee: 深圳市汇顶科技股份有限公司
Priority date: 2019-10-25
Filing date: 2019-10-25
Publication date: 2021-04-29
Also published as: CN110945527B; CN110945527A

Abstract

A fingerprint recognition apparatus and an electronic device. The fingerprint recognition apparatus may increase the amount of optical signals while receiving an inclined optical signal, thereby improving an fingerprint imaging effect and fingerprint recognition effect. The fingerprint recognition apparatus is applied to an electronic device having a display screen so as to carry out under-screen optical fingerprint detection, the fingerprint recognition apparatus comprising: an optical fingerprint sensor, which is provided below a display screen using a means by which same is not parallel to the display screen; and an optical assembly, which is provided above the optical fingerprint sensor and comprises at least one lens, the optical assembly being used for transmitting to the optical fingerprint sensor a fingerprint optical signal returned after being reflected or scattered by a finger above the display screen so as to perform fingerprint recognition, the fingerprint optical signal being an optical signal which is inclined relative to the display screen.

Description

Fingerprint identification device and electronic equipment

Technical field

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

Background technique

With the development of biometric technology, under-screen fingerprint recognition technology has become more and more widely used in portable terminals such as mobile phones.

In some specific scenarios, the under-screen fingerprint identification device can receive oblique light signals to perform fingerprint identification to meet specific needs. For example, by receiving oblique light signals to reduce the optical path distance in the fingerprint identification device, thereby reducing The thickness of the fingerprint identification device; or by receiving oblique light signals, the fingerprint detection effect of dry fingers can be improved, and so on. However, when the fingerprint identification device receives the optical signal in the oblique direction, the amount of the optical signal will be attenuated, so that the amount of the optical signal received by the fingerprint identification device is insufficient, which affects the fingerprint imaging effect and ultimately affects the fingerprint identification effect.

Therefore, how the fingerprint identification device can increase the amount of the light signal while receiving the oblique light signal, so as to improve the fingerprint imaging effect and the fingerprint recognition effect, is a problem to be solved urgently.

Summary of the invention

The embodiments of the present application provide a fingerprint identification device and electronic equipment, which can increase the amount of the light signal while receiving the oblique light signal, thereby improving the fingerprint imaging effect and the fingerprint recognition effect.

In the first aspect, a fingerprint identification device is provided, which is suitable for electronic equipment with a display screen to perform under-screen optical fingerprint detection. The fingerprint identification device includes:

An optical fingerprint sensor, configured to be arranged under the display screen in a manner not parallel to the display screen;

The optical component is arranged above the optical fingerprint sensor and includes at least one lens, and the optical component is used to transmit the fingerprint light signal reflected or scattered by the finger above the display screen to the optical fingerprint sensor for fingerprint identification, wherein, The fingerprint optical signal is an optical signal inclined with respect to the display screen.

In this application, when the fingerprint identification device receives the fingerprint light signal inclined with respect to the display screen, the optical fingerprint sensor is placed at a certain angle with the plane where the display screen is located, that is, the optical fingerprint sensor is placed non-horizontally, which can reduce the fingerprint light signal The angle between the vertical surface of the optical fingerprint sensor and the optical fingerprint sensor makes the light signal received by the optical fingerprint sensor incident vertically or nearly vertically incident on the optical fingerprint sensor, so that the fingerprint identification device can also increase the optical fingerprint sensor while receiving the oblique fingerprint light signal. The light intensity of the received light signal improves the fingerprint image quality and fingerprint recognition effect.

In a possible implementation manner, the display screen includes a fingerprint detection area, and the optical component is used to transmit the fingerprint light 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 a possible implementation, the angle between the plane where the optical fingerprint sensor is located and the plane where the display screen is located is ω, where 0°<ω<90°.

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

In a possible implementation, the incident angle of the fingerprint light signal relative 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.

In a possible implementation, ω=θ, where θ is the angle between the fingerprint optical signal and the vertical plane of the display screen.

In a possible implementation manner, the optical component includes: at least one optical lens for receiving the fingerprint optical signal to perform fingerprint imaging, and the optical lens is a spherical or aspherical lens.

In a possible implementation manner, the optical assembly further includes: a small aperture diaphragm formed in the optical path of the at least one optical lens.

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

In a possible implementation, the direction of the fingerprint optical 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 non-parallel under the display screen.

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

The at least one light-blocking layer is located under the micro lens array and is provided with a plurality of light-passing holes;

The micro lens array is used to receive the fingerprint optical signal, and converge the fingerprint optical signal to the plurality of light-passing holes;

The multiple light-passing holes are used to transmit the fingerprint light signal to the optical fingerprint sensor.

In a possible implementation manner, the fingerprint optical signal is perpendicularly incident on the microlens array.

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

The microlens array, the at least one light blocking layer and the optical fingerprint sensor are all arranged non-parallel under the display screen.

In a possible implementation manner, the optical fingerprint sensor is arranged non-parallel under the display screen through a supporting structure;

The supporting structure is made of injection molding material, plastic material or metal material.

In a possible implementation, the display screen is an organic light emitting diode display screen, and the fingerprint light signal is the reflection of the excitation light emitted by a part of the display unit of the organic light emitting diode display screen on the finger above the organic light emitting diode display screen. Or scattered and returned light signal.

In a possible implementation, the display is a liquid crystal display with a backlight module, and the liquid crystal display includes a backlight module;

The fingerprint light signal is the infrared excitation light emitted by the external light source irradiated by the finger above the liquid crystal display, reflected or scattered, and then returned, and passed through one of the first prism film side surface and the second prism film side surface of the prism film of the backlight module The optical signal formed after refracting on the side of the prism film.

In this implementation, the optical fingerprint sensor is placed obliquely, so that there are no dark stripes in the fingerprint image detected by the optical fingerprint sensor, thereby realizing fingerprint recognition under the LCD screen. In addition, it can also increase the fingerprints received by the optical fingerprint sensor. The light intensity of the optical signal can further improve the fingerprint image quality and fingerprint recognition effect.

In a possible implementation, the optical assembly includes at least one optical lens and a small aperture stop, and the angle between the plane where the optical fingerprint sensor is located and the plane where the display screen is located is ω, 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 diaphragm to the optical fingerprint sensor, β is the divergence angle of the shadow area determined according to the prism film .

In a possible implementation manner, the position of the optical component makes the optical signal refracted by the side of another prism film in the prism film deviate from the optical component and cannot be transmitted to the optical fingerprint sensor.

In a possible implementation manner, the position of the optical fingerprint sensor makes the optical signal refracted by the side surface of another prism film in the prism film deviate from the optical fingerprint sensor.

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

The filter layer is arranged in the light path between the display screen and the optical fingerprint sensor, and is used to filter out the light signal of the non-target waveband and transmit the light signal of the target waveband.

In a second aspect, an electronic device is provided, including a display screen and a fingerprint identification device such as the first aspect or any possible implementation of the first aspect, wherein the fingerprint identification device is arranged under the display screen for screen Under optical fingerprint detection.

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

The infrared light source is used to provide 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 .

By providing the above-mentioned fingerprint identification device in the electronic device, the electronic device has good fingerprint identification performance, improves the fingerprint identification success rate, and improves the user experience.

Description of the drawings

FIG. 1 is a schematic diagram of the structure of an electronic device to which an 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 structural diagram of another fingerprint identification device according to an embodiment of the present application.

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

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

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

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

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

9a and 9b are a three-dimensional structural view and a cross-sectional view of a prism film in a liquid crystal display screen.

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

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

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

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

14 is a schematic diagram of calculating the translation distance of an optical fingerprint sensor under the 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 ways

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

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

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

1 is a schematic structural diagram of an electronic device to which the embodiment of the application can be applied. The electronic device 10 includes a display screen 120 and an optical fingerprint device 130, wherein the optical fingerprint device 130 is disposed in a partial area under the display screen 120. The optical fingerprint device 130 includes an optical fingerprint sensor, and the optical fingerprint sensor includes a sensing array 133 having a plurality of optical sensing units 131, and the area where the sensing array 133 is located or its sensing area is the fingerprint detection area 103 of the optical fingerprint device 130. As shown in FIG. 1, the fingerprint detection area 103 is located in the display area of the display screen 120. In an alternative embodiment, the optical fingerprint device 130 can also be arranged in other positions, such as the side of the display screen 120 or the non-transmissive area at the edge of the electronic device 10, and at least part of the display area of the display screen 120 is designed through the optical path. The optical signal is guided to the optical fingerprint device 130, so that the fingerprint detection area 103 is actually located in the display area of the display screen 120.

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

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

As an optional implementation, as shown in FIG. 1, the optical fingerprint device 130 includes a light detecting portion 134 and an optical component 132. The light detecting portion 134 includes a sensing array and a reading circuit electrically connected to the sensing array. Other auxiliary circuits, 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 photodetector array, which includes a plurality of arrays distributed The photodetector can be used as the above-mentioned optical sensing unit; the optical component 132 can be arranged above the sensing array of the light detecting part 134, and it can specifically include a light guide layer or a light path guide structure and other optical elements. The light guide layer or light path guide structure is mainly used to guide the reflected light reflected from the surface of the finger to the sensing array for optical detection.

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

Among them, the light guide layer or light path guiding structure of the optical component 132 has multiple implementation schemes. For example, the light guide layer may be specifically a collimator layer made on a semiconductor silicon wafer, which has multiple collimators. Unit or micro-hole array, the collimating unit can be specifically a small hole, the reflected light reflected from the finger, the light that is perpendicularly incident on the collimating unit can pass through and be received by the optical sensor unit below it, and the incident angle Excessive light is attenuated by multiple reflections inside the collimating unit, so each optical sensor unit can basically only receive the reflected light reflected by the fingerprint pattern directly above it, so the sensor array can detect the finger Fingerprint image.

In another embodiment, the light guide layer or the light path guide structure may also be an optical lens (Lens) layer, which has one or more lens units, such as a lens group composed of one or more aspheric lenses, which is used for The reflected light reflected from the finger is condensed to the sensing array of the light detection part 134 below it, so that the sensing array can perform imaging based on the reflected light, thereby obtaining a fingerprint image of the finger. Optionally, the optical lens layer may further have a pinhole formed in the optical path of the lens unit, and the pinhole may cooperate with the optical lens layer to expand the field of view of the optical fingerprint device, 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 guide structure may also specifically adopt a micro-lens (Micro-Lens) layer. The micro-lens layer has a micro-lens array formed by a plurality of micro-lenses. The process is formed above the sensing array of the light detecting part 134, and each microlens may correspond to one of the sensing units of the sensing array, respectively. In addition, other optical film layers may be formed between the micro lens layer and the sensing unit, such as a dielectric layer or a passivation layer. More specifically, a light blocking layer with micro holes may also be formed between the micro lens layer and the sensing unit. The micro-hole is formed between the corresponding micro-lens and the sensing unit. The light blocking layer can block the optical interference between the adjacent micro-lens and the sensing unit, and make the light corresponding to the sensing unit converge into the micro-hole through the micro-lens And it is transmitted to the sensing unit through the micro-hole for optical fingerprint imaging. It should be understood that several implementation solutions of the above-mentioned light path guiding structure can be used alone or in combination. For example, a microlens layer can be further provided under the collimator layer or the optical lens layer. Of course, when the collimator layer or the optical lens layer is used in combination with the micro lens layer, the specific laminated structure or optical path may need to be adjusted according to actual needs.

As an optional embodiment, the display screen 120 may adopt a display screen with a self-luminous display unit, such as an organic light-emitting diode (OLED) display screen or a micro-LED (Micro-LED) display screen. Taking the OLED display screen as an example, the optical fingerprint device 130 may use the display unit (ie, OLED light source) of the OLED display screen 120 located in the fingerprint detection area 103 as the excitation light source for optical fingerprint detection. When the finger 140 is pressed on the fingerprint detection area 103, the display screen 120 emits a beam of light 111 to the target finger 140 above the fingerprint detection area 103. The light 111 is reflected on the surface of the finger 140 to form reflected light or scattered inside the finger 140. The scattered light is formed. In related patent applications, for ease of description, the above-mentioned reflected light and scattered light are collectively referred to as reflected light. Since the ridge and valley of the fingerprint have different light reflection capabilities, the reflected light 151 from the fingerprint ridge and the reflected light 152 from the fingerprint ridge have different light intensities. After the reflected light passes through the optical component 132, It is received by the sensor array 134 in the optical fingerprint device 130 and converted into a corresponding electrical signal, that is, a fingerprint detection signal; based on the fingerprint detection signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed, so that the electronic device 10 Realize the optical fingerprint recognition function.

In other embodiments, the optical fingerprint device 130 may also use a built-in light source or an external light source to provide an optical signal for fingerprint detection. In this case, the optical fingerprint device 130 can be applied to a non-self-luminous display screen, such as a liquid crystal display (LCD) or other passive light-emitting display screens. Taking a liquid crystal display with a backlight module and a liquid crystal panel as an example, in order to support the under-screen fingerprint detection of the liquid crystal display, the optical fingerprint system of the electronic device 10 may also include an excitation light source for optical fingerprint detection. It can be specifically an infrared light source or a light source of invisible light of a specific wavelength, which can be arranged under the backlight module of the liquid crystal display or arranged in the edge area under the protective cover of the electronic device 10, and the optical fingerprint device 130 can be arranged with a liquid crystal panel or Under the edge area of the protective cover and guided by the light path so that the fingerprint detection light can reach the optical fingerprint device 130; or, the optical fingerprint device 130 can also be arranged under the backlight module, and the backlight module passes through the diffusion sheet, the brightness enhancement sheet, The film layer such as the reflective sheet has holes or other optical designs to allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint device 130. When the optical fingerprint device 130 adopts a built-in light source or an external light source to provide an optical signal for fingerprint detection, the detection principle is the same as that described above.

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

It should also be understood that the electronic device 10 may further include a circuit board 150 disposed under the optical fingerprint device 130. The optical fingerprint device 130 can be adhered to the circuit board 150 through adhesive, and is electrically connected to the circuit board 150 through soldering pads and metal wires. The optical fingerprint device 130 can realize electrical interconnection and signal transmission with other peripheral circuits or other components of the electronic device 10 through the circuit board 150. For example, the optical fingerprint device 130 can receive the control signal of the processing unit of the electronic device 10 through the circuit board 150, and can also output the fingerprint detection signal from the optical fingerprint device 130 to the processing unit or the control unit of the electronic device 10 through the circuit board 150 Wait.

On the other hand, in some embodiments, the optical fingerprint device 130 may include only one optical fingerprint sensor. At this time, the fingerprint detection area 103 of the optical fingerprint device 130 has a small area and a fixed position. Therefore, the user needs to perform fingerprint input Press the finger to a specific position of the fingerprint detection area 103, otherwise the optical fingerprint device 130 may not be able to collect fingerprint images, resulting in poor user experience. In other alternative embodiments, the optical fingerprint device 130 may specifically include a plurality of optical fingerprint sensors; the plurality of optical fingerprint sensors may be arranged side by side under the display screen 120 in a splicing manner, and the sensing areas of the plurality of optical fingerprint sensors are common The fingerprint detection area 103 of the optical fingerprint device 130 is constituted. In other words, the fingerprint detection area 103 of the optical fingerprint device 130 may include multiple sub-areas, and each sub-area corresponds to the sensing area of one of the optical fingerprint sensors, so that the fingerprint collection area 103 of the optical fingerprint device 130 can be extended to display The main area of the lower half of the screen is extended to the area where the finger is habitually pressed, so as to realize the blind fingerprint input operation. Alternatively, when the number of optical fingerprint sensors is sufficient, the fingerprint detection area 103 can also be extended to half of the display area or even the entire display area, thereby realizing half-screen or full-screen fingerprint detection.

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 sensing unit in the sensing array may also be referred to as a pixel unit.

It should be noted that the optical fingerprint device in the embodiments of the present application may also be referred to as an optical fingerprint identification module, a fingerprint identification device, a fingerprint identification module, a fingerprint module, a fingerprint acquisition device, etc., and the above terms can be replaced with each other.

FIG. 2 shows a schematic structural diagram of a fingerprint identification device 200.

As shown in FIG. 2, the fingerprint identification device 200 includes an optical component 210 and an optical fingerprint sensor 220. The optical component 210 is used to receive the fingerprint light signal reflected or scattered by the finger 140 above the display screen 120, and to transfer the fingerprint The optical signal is guided and transmitted to the optical fingerprint sensor 220. The surface of the optical fingerprint sensor 220 is provided with a light detection array 221 to detect fingerprint light signals for fingerprint identification.

Optionally, the light detection array 221 may be the same as the sensing array 133 in FIG. 1, and the optical assembly 210 may be the same as the optical assembly 132 in 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 optical detection array.

Optionally, the optical component 210 may also include a collimating layer as described in the above-mentioned optical component 132 in FIG. 1 with a plurality of collimating units for passing optical signals incident perpendicular to the collimating unit; or It includes a micro-lens layer and a light-blocking layer with micro-holes, which are used to transmit optical signals in a specific direction; it can also be any other optical element used to transmit optical signals, which is not limited in the embodiment of the present application.

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

As shown in FIG. 2, the optical signal reflected or scattered by the finger 140 above the display screen 120 and then passed through the optical component 210 is the oblique fingerprint optical signal 201, and the optical detection array 221 receives the oblique fingerprint optical signal 201.

It should be noted here that the oblique 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 oblique fingerprint optical signal 201 and the surface of the display screen is not 90°. angle.

For example, when the display screen 120 and the light detection array 221 are both placed in the horizontal direction, the vertical plane perpendicular to the surface of the display screen is the vertical direction. The angle between the tilted fingerprint light signal 201 and the vertical direction is the tilted fingerprint light signal The inclination angle of is θ, where 0°<θ<90°. If the light intensity of the oblique fingerprint light signal 201 is I ₀ , according to the cosine fourth power theorem of the optical system, the calculation formula (1) of the _{light intensity I e of the fingerprint light signal received by the light detection array 221 is:}

I _e ＝I ₀ ×cos ⁴ θ Formula (1)

It can be seen from the above formula that when θ increases, the light intensity I _e of the optical signal received by the light detection array 221 decreases rapidly. In other words, when the tilt angle of the tilted fingerprint light signal increases, the fingerprint received by the light detection array 221 The light intensity of the light signal decreases rapidly, which affects the fingerprint imaging and fingerprint recognition effect of the fingerprint identification device.

Based on this, this application proposes a fingerprint recognition device. By obliquely setting the optical fingerprint sensor in the fingerprint recognition device, the angle between the tilt light signal and the vertical plane of the fingerprint recognition device can be reduced, so that the tilt light signal received by the fingerprint recognition device is vertical. Incident or nearly perpendicularly incident on the optical fingerprint sensor, so that while the fingerprint identification device receives the oblique light signal, it can also increase the light intensity of the light signal received by the optical fingerprint sensor, and improve the fingerprint image quality and fingerprint recognition effect.

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

It should be noted that, for ease of understanding, in the embodiments shown below, the same structure uses the same reference numerals, and for the sake of brevity, a detailed description of the same structure is omitted.

FIG. 3 is a schematic structural diagram of a fingerprint identification device 300 provided by an embodiment of the present application. The fingerprint identification device 300 is configured to be installed under the display screen 120 of an electronic device for fingerprint identification.

As shown in FIG. 3, the fingerprint identification device 300 includes: an optical component 310 and an optical fingerprint sensor 320;

The optical fingerprint sensor 320 is arranged non-parallel under the display screen 120;

The optical component 310 includes at least one lens. The optical component 310 is used to transmit the fingerprint light signal 301 that is reflected or scattered by the finger above the display 120 to the optical fingerprint sensor 320 for fingerprint identification, wherein the fingerprint light signal 301 It is an optical signal tilted with respect to the display screen.

Specifically, the optical fingerprint sensor 320 may include a light detection array 321 that is grown on the surface of the optical fingerprint sensor 320 to receive light signals and convert the light signals into corresponding electrical signals. The plane where the light detection array 321 is located, that is, the light receiving surface, has the same angle as the plane where the optical fingerprint sensor 320 is located.

Specifically, the aforementioned 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 the 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 sensing array 133 and the fingerprint detection area 103 in FIG.

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

Optionally, when the optical fingerprint sensor 320 is arranged non-parallel under the display screen 120, or when the optical fingerprint sensor 320 is arranged obliquely under the display screen 120, the optical fingerprint sensor 320 is arranged obliquely under the fingerprint detection area 203, The light receiving surface of the optical fingerprint sensor 320, that is, the surface of the light detection array 321 is set toward the fingerprint detection area 203. At this time, the fingerprint light signal reflected or scattered by the fingerprint detection area 203 can be received to the greatest extent, thereby improving the quality of fingerprint imaging and fingerprinting. Recognition effect.

Optionally, the optical component 310 may be arranged in parallel under the display screen 120, or similar to the optical fingerprint sensor, and also arranged obliquely under the display screen 120. Optionally, the optical component 310 can also be arranged 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. At this time, the left end of the optical fingerprint sensor 320 is higher than the right end, and its light receiving surface faces the upper right, that is, it faces the fingerprint detection. Area 203 is set.

It should be noted here that when the right end of the optical fingerprint sensor 320 is higher than the left end and its light receiving surface is set toward the upper left, the fingerprint detection area 203 is located on the fingerprint identification device 300, that is, located on the upper left of the optical assembly 310 and the optical fingerprint sensor 320 square.

Optionally, as shown in FIG. 3, the angle between the plane where the optical fingerprint sensor 320 is located and the plane where the display screen is located is ω, that is, the angle between the plane where the light detection array 321 is located and the plane where the display screen is located is ω, when the display When located on a horizontal plane, the included angle between the optical fingerprint sensor 320 and the horizontal plane is ω, where 0°<ω<90°. For the convenience of description, the angle between the plane where the optical fingerprint sensor 320 is located and the plane where the display screen is located is also referred to as the tilt angle of the optical fingerprint sensor below.

Optionally, as shown in FIG. 3, the fingerprint optical signal 301 is an optical signal with an inclination angle θ relative to the display screen, where the inclination angle θ is the angle between the propagation direction of the fingerprint optical signal 301 and the first direction. The first direction is the direction perpendicular to the display screen, 0°<θ<90°. For the convenience of description, the slanted fingerprint light signal hereinafter refers to the light signal that is not perpendicular to the plane where the display screen is located. The tilt angle of the slanted fingerprint light signal is the clamp between the propagation direction of the light signal and the vertical direction perpendicular to the surface of the display screen. angle.

As shown in FIG. 3, when the display screen 120 is 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 fingerprint light signal 301 is incident with respect to the optical fingerprint sensor 320 The angle is θ-ω, and the incident angle θ-ω is the included angle of the fingerprint optical signal 301 with respect to the second direction, where the second direction is a direction perpendicular to the optical fingerprint sensor 320.

According to the above formula (1), when the light intensity of the fingerprint light signal 301 is I ₀ , the calculation formula (2) of _{the light intensity I e} of the light signal received by the optical fingerprint sensor 320 is:

I _e ′=I ₀ ×cos ⁴ (θ-ω) formula (2)

For a fingerprint light signal with a tilt angle of θ, when the optical fingerprint sensor is not placed at an angle, that is, as shown in Figure 2, when it is arranged parallel to the bottom of the display screen, the intensity of the light signal received by the optical fingerprint sensor is as shown in formula (1), I _e =I ₀ ×cos ⁴ θ. When the optical fingerprint sensor is placed obliquely (the tilt angle is ω), the intensity of the optical signal received by the optical fingerprint sensor is as shown in formula (2), I _e = I ₀ × cos ⁴ (θ-ω), since θ>ω, And ω>0°, therefore, the intensity of the light signal received by the optical fingerprint sensor is greater than the intensity of the light signal received by the optical fingerprint sensor before the tilt.

For example, when the inclination angle θ of the fingerprint light signal is θ=50°, and the optical fingerprint sensor is not placed at an angle, that is, when ω=0°, I _e =0.17×I ₀ . The optical fingerprint sensor is placed at an angle of 30°, that is, when ω=30°, I _e =0.78×I ₀ . Therefore, after the optical fingerprint sensor is placed at an angle of 30°, the intensity of the light signal received by the optical fingerprint sensor increases by about 4.6 times.

As shown in Figure 4, when the display screen 120 is 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 fingerprint light signal 301 is incident with respect to the optical fingerprint sensor 320 The angle is 0°, that is, the fingerprint light signal 301 is incident perpendicular to the optical fingerprint sensor 320. At this time, the light intensity of the light signal received by the optical fingerprint sensor 320 is I _e =I ₀ .

For example, when the inclination angle of the fingerprint light signal is θ=50° and the optical fingerprint sensor is not placed at an angle, I _e =0.17×I ₀ , and when the optical fingerprint sensor is placed at an angle of 50° (ω=50°), I _e =I ₀ At this time, the intensity of the light signal received by the optical fingerprint sensor has increased by about 5.88 times.

As shown in FIG. 5, when the display screen 120 is 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 fingerprint light signal 301 is incident with respect to the optical fingerprint sensor 320 The angle is ω-θ, and the incident angle ω-θ is also the included angle of the fingerprint optical signal 301 with respect to the second direction, where the second direction is a direction perpendicular to the optical fingerprint sensor 320.

According to the above formula (1), when the light intensity of the fingerprint light signal is I ₀ , the calculation formula (3) of _{the light intensity I e} of the light signal received by the optical fingerprint sensor is:

I _e ″=I ₀ ×cos ⁴ (ω-θ)=I ₀ ×cos ⁴ (θ-ω) formula (3)

Since cos(ω-θ)=cos(θ-ω), when θ<ω, the calculation formula (3) of the intensity of the optical signal received by the optical fingerprint sensor can be the same as the calculation formula (2). Based on the above analysis, for the same fingerprint light signal (the tilt angle is θ), the intensity of the light signal received by the optical fingerprint sensor after tilting is greater than the intensity of the light signal received by the optical fingerprint sensor before tilting.

Therefore, when the optical fingerprint sensor is placed at a certain angle with the plane where the display screen is located, that is, when it is placed non-parallel under the display screen, the optical fingerprint sensor receives a tilted light signal of the same light intensity compared to when it is placed parallel under the display screen. The intensity of the optical signal can be greatly improved, thereby improving the fingerprint imaging quality and fingerprint recognition effect.

When 0°<ω≤θ, compared with the parallel arrangement of the optical fingerprint sensor (ω=0°), the light intensity of the optical signal received by the optical fingerprint sensor increases, and the thickness of the optical fingerprint sensor does not change much, which will not affect The thickness of the fingerprint identification device 300 also improves the performance of the fingerprint identification device.

In particular, when ω=θ, the fingerprint light signal is incident on the optical fingerprint sensor perpendicularly, and the light intensity of the light signal received by the optical fingerprint sensor is the largest, and the fingerprint imaging quality and fingerprint recognition effect are the best.

It should be noted here that the setting of the tilt angle ω of the optical fingerprint sensor 320 is related to the tilt angle θ of the fingerprint light signal that the fingerprint recognition device 300 needs to receive. In the fingerprint recognition system, the optical component 310 in the fingerprint recognition device 300 The structure and position of the optical element, the distance of the optical component 310 from the optical fingerprint sensor 320, the distance of the optical component 310 from the screen, and other factors all affect the angle of the fingerprint light signal received by the fingerprint identification device 300. Optionally, when the inclination angle θ of the fingerprint light signal received by the fingerprint identification device is 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 non-parallel through the supporting structure 330, that is, set at a certain angle with the plane where the display screen is located. Below the display.

Optionally, the support structure 330 may be an injection molding material, including but not limited to polycarbonate, resin, polymethyl methacrylate, 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 with a supporting function, and the embodiment of the present application does not specifically limit the material of the supporting structure.

Specifically, the supporting structure 330 may be disposed on a substrate that fixedly supports the fingerprint identification device 300, and the substrate includes, but is not limited to, a middle frame of a mobile phone. The support structure 330 may be arranged on the substrate through a processing technology, which includes but is not limited to: injection molding, precision carving, photolithography, etching, laser processing, and the like.

Optionally, the support structure 330 can be integrated with the substrate to form a whole, or can be processed independently, and connected and fixed on the substrate by a connecting device. The embodiment of the present application also does not specify the processing technology and specific form of the support structure. limited.

Optionally, in a possible implementation, as shown in FIG. 6, the optical assembly 310 may include: a lens assembly, the lens assembly includes at least one optical lens for receiving fingerprint optical signals 301 for fingerprint imaging, optical The fingerprint sensor is used to receive the imaged optical signal and form a corresponding electrical signal for fingerprint identification.

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

Optionally, when the lens assembly includes a plurality of optical lenses, the plurality of optical lenses may all be spherical lenses or all aspheric lenses, or may include both spherical lenses and aspheric lenses. Not limited.

Optionally, the lens assembly further includes a small aperture stop. The small aperture diaphragm is formed in the optical path with the at least one optical lens, and is used to cooperate with the at least one optical lens to perform optical fingerprint imaging.

Optionally, the aperture stop may be located on the main optical axis of the optical lens.

Optionally, the aperture stop may be located at the object-side focal point or the image-side focal point of the optical lens.

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

Optionally, 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 to be fixed in the lens barrel, and the lens holder is used to connect the lens holder. And fix the lens barrel on the optical fingerprint sensor. Alternatively, the fixing component may also include a bracket, an adhesive layer, etc., which are not limited in the embodiment of the present application.

Optionally, in the embodiment of the present application, 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 of the optical fingerprint sensor 320 and the plane of the display screen 120 are set at ω, the angle between the focal plane of the optical lens and the display screen 120 is also ω.

When the number of optical lenses is multiple, the angles between the focal planes of the multiple optical lenses and the display screen 120 may all be ω, that is, the multiple optical lenses and the optical fingerprint sensor 320 are not arranged in parallel under the display screen 120.

Optionally, the direction of the fingerprint optical signal 301 received by the optical lens may be parallel to the direction of the main optical axis of the lens. If the fingerprint light signal 301 is transmitted to the optical fingerprint sensor 320 through the optical center of the optical lens, the direction of the light signal received by the optical fingerprint sensor 320 is the same as the direction of the fingerprint light signal 301, and the tilt angle is θ.

Optionally, 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 under the micro lens array 311, and is provided with a plurality of light-passing holes;

The micro lens array 311 is used to receive the fingerprint optical signal 301, and converge the fingerprint optical signal 301 to a plurality of light-passing holes;

The multiple light-passing holes are used to transmit the fingerprint light signal 301 to the optical fingerprint sensor 320, specifically, to transmit the fingerprint light signal 301 to the light detection array 321 in the optical fingerprint sensor 320.

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

Optionally, the photodetection array 321 includes a plurality of pixel units, and the microlenses in the microlens array 311 correspond to the pixel units in the photodetection array 321 one-to-one, that is, one microlens is used to receive the light signal above it, and The light signal is transmitted to a pixel unit corresponding to the microlens through the light-passing hole on at least one light-blocking layer.

Optionally, when the optical component 310 includes a light-blocking layer, one microlens corresponds to one light-passing hole and one pixel unit. The center of the microlens, the center of the light-passing hole, and the center of the pixel unit may coincide in a direction perpendicular to the pixel unit.

Optionally, when the optical component 310 includes at least two light-blocking layers, for example, when it includes two light-blocking layers, a first light-blocking layer and a second light-blocking layer, one microlens in the microlens array corresponds to the first light-blocking layer A first light-passing hole on the layer, a second light-passing hole on the second light-blocking layer, and a 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.

Optionally, the micro lens array 311 may be used to receive light signals incident perpendicular to the micro lens array 311. The fingerprint optical signal 301 returned after being reflected or scattered by the finger above the display screen may be an optical signal incident perpendicular to the microlens array 311.

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

Optionally, the microlenses in the microlens array 311 are polygonal lenses, such as square lenses or hexagonal lenses, or circular lenses. For example, when the microlens is a quadrilateral lens, the upper surface of the quadrilateral lens is spherical or aspherical, and the lower surface is quadrilateral.

Specifically, the transmittance of at least one light-blocking layer 312 to light in a specific wavelength band (for example, visible light or a wavelength band above 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 metal and/or black opaque material.

Optionally, the light-passing hole on the at least one light-blocking layer 312 is a circular hole with a diameter of less than 10 μm for optical imaging, and the resolution of the optical imaging can be improved by reducing the size of the light-passing hole. Thereby improving the resolution of the fingerprint image.

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

Optionally, the microlens array 311 and the at least one light-blocking layer 312 can be packaged in the optical fingerprint sensor together with the photodetection array 321. Specifically, the at least one light-blocking layer 312 can adopt a micro-nano processing technology or a nano-printing process in the optical fingerprint sensor. The detection array 321 is prepared on a plurality of pixel units. For example, a micro-nano processing technology is used to prepare a non-volatile layer on top of the multiple pixel units by atomic layer deposition, sputtering coating, electron beam evaporation coating, ion beam coating and other methods. The light-transmitting material film is then subjected to small hole pattern photolithography and etching to form a plurality of light-passing small holes.

Optionally, the light detection array 321 is isolated from the light blocking layer and the multilayer light blocking layer by a transparent medium layer. The transparent medium layer is an organic or inorganic transparent medium 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 arranged in parallel above the optical fingerprint sensor, that is, the microlens array 311 and the at least one light-blocking layer 312 are not parallel, that is, they are arranged obliquely on the display. Bottom of the screen.

Optionally, the angle between the plane of each light-blocking layer in the at least one light-blocking layer 312 and the plane of the display screen is ω. The angle between the lower surface of the microlens array 311 and the plane where the display screen is located is also ω.

Optionally, in the above-mentioned various embodiments, the fingerprint recognition device 300 may further include: a filter layer, which is used to filter out the optical signal of the non-target wavelength band, and transmit the optical signal of the target wavelength band (that is, the wavelength band required for fingerprint image collection). The optical signal), which is beneficial to reduce the influence of the ambient light signal in the non-target band, thereby improving the fingerprint recognition performance.

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

When the optical component 310 includes a microlens array 311 and 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 through an adhesive layer, and the filter layer and the microlens array 310 There is no air layer in between. Optionally, the adhesive layer may be a low refractive index glue, and the refractive index of the low refractive index glue is less than 1.25.

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

Optionally, the filter layer may be pasted on the optical fingerprint sensor 320 through a bonding glue, which has a high transmittance and a low refractive index.

Optionally, the filter layer can also be integrated in the chip of the optical fingerprint sensor 320. Specifically, the filter layer can be formed by coating a plurality of pixel units of the optical fingerprint sensor 320 by using an evaporation process, for example, through an atomic layer. Deposition, sputtering coating, electron beam evaporation coating, ion beam coating and other methods prepare a thin film of filter material over multiple pixel units.

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

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

Optionally, in the foregoing various embodiments of the present application, the display screen may be an organic light emitting diode display (OLED) or a liquid crystal display (LCD). If the display screen is an OLED display screen, the fingerprint light signal is a light signal formed and returned by the excitation light emitted by part of the display unit of the OLED display screen reflected or scattered by the finger above the OLED display screen. If the display screen is an LCD display screen that includes a backlight module, the fingerprint light signal is the infrared excitation light emitted by an external light source irradiated by the finger above the LCD display screen, reflected or scattered, and then returned, and passes through the first prism of the prism film of the backlight module The optical signal formed after being refracted by one of the film side surface and the second prism film side surface.

Specifically, as shown in FIG. 8, the liquid crystal display 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 backlight module structures 125. The other structures 125 of the backlight module include, but are not limited to, backlight module structures such as polarizers, diffusers, light guide plates, and reflectors. Specifically, FIGS. 9a and 9b show a three-dimensional structure diagram and a cross-sectional view of a prism film 124 in an embodiment of the present application. The prism film 124 is a plurality of identical prism units 1240 arranged in a row on a substrate 1243 regularly. Among them, each prism unit 1240 is formed by protruding upward from the base 1243, and each prism unit 1240 has a single source structure with two inclined sides, and the angle between the two inclined sides is the angle of the prism unit 1240. Apex angle. For example, as shown in FIG. 9b, the cross section of the prism unit 1240 is triangular, and the prism unit 1240 has a structure similar to a triangular prism. Specifically, the inclined side surfaces of a plurality of prism units 1240 are connected to form the upper surface of the prism film 124, wherein, as shown in FIG. 9a and FIG. 9b, the two inclined side surfaces in the prism unit 1240 are the first inclined side surface unit 1241 and the second inclined side surface unit 1241, respectively. Two inclined side surface units 1242, a plurality of first inclined side surface units 1241 and a plurality of second inclined side surface units 1242 are spaced apart from each other, forming a plurality of first inclined side surface units 1241 parallel to each other in the prism film 124, and a plurality of parallel parallel sides. One second inclined side unit 1242. The plurality of mutually parallel first inclined side surface units 1241 are the first prism film side surfaces of the prism film 124, and the plurality of mutually parallel second inclined side surface units 1242 are the second prism film side surfaces of the prism film 124.

As shown in FIG. 8, the fingerprint identification device 200 includes an optical lens, a small aperture diaphragm, and an optical fingerprint sensor. When the fingerprint identification device 200 is arranged in parallel under the liquid crystal display 120, the fingerprint light signal returned after being reflected or scattered by the finger is respectively refracted by the side surface of the first prism film and the side surface of the second prism film in the prism film 124 into light in different directions. 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 a small aperture for imaging, and the fingerprint light signal at the center of the fingerprint detection area 203 passes through the prism After the film is refracted, for example, the fingerprint light signal 205 cannot enter the optical fingerprint sensor through the aperture diaphragm for imaging. Therefore, the fingerprint image formed by the detection in the optical fingerprint sensor will form shadow stripes as shown in Figure 10, resulting in a serious field of view Loss and distortion of the fingerprint image make it impossible to realize the fingerprint recognition function under the LCD screen.

Therefore, for the case that the display screen is a liquid crystal display screen, the fingerprint identification device in the embodiment of the present application is arranged non-parallel under the liquid crystal display screen, so that the fingerprint light signals of all areas in the fingerprint detection area pass through the first in the prism film. Both the side of the prism film and the side of the second prism film can pass through the small aperture after being refracted, so that there is no shadow in the fingerprint image detected by the optical fingerprint sensor, which is convenient for the fingerprint identification device located under the LCD screen. Fingerprint recognition.

FIG. 11 shows a schematic structural diagram of another fingerprint identification device 300. The fingerprint identification device 300 is arranged under the liquid crystal display and includes an optical component 310 and an optical fingerprint sensor 320.

Among them, the optical assembly 310 includes a small aperture stop 313 and an optical lens 314. Optionally, as shown in FIG. 11, the aperture stop 313 is located above the optical lens 314, and performs optical fingerprint imaging together with the optical lens, and transmits the fingerprint light signal to the optical fingerprint sensor 320.

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

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

Specifically, the optical fingerprint sensor 320 is arranged 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 identification device 300 further includes: a supporting structure 330 for supporting and fixing the optical fingerprint sensor 320 arranged non-parallel below the display screen. Specifically, for the specific implementation of the supporting structure 330, reference may be made to the related description of the supporting structure 330 in the above-mentioned application embodiment, which will not be repeated here.

Optionally, the optical assembly 310 is also arranged 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 in other words, the tilt angle of the optical lens 314 is also ω.

Optionally, in the embodiment of the present application, the optical assembly 310 may further include a plurality of optical lenses, the plurality of optical lenses may be spherical lenses or aspheric lenses, and the aperture stop 314 is formed in the plurality of optical lenses. In the light path.

Optionally, the position of the optical component 310 is such that the optical component 310 only receives the optical signal formed after being refracted by one of the first prism film side surface and the second prism film side surface of the prism film 124, and cannot receive the light signal that passes through. The optical signal refracted by the side of the other prism film in the prism film 124.

Specifically, the position of the small aperture diaphragm 313 in the optical assembly 310 is such that the small aperture diaphragm 313 is only reflected or scattered by the finger above the fingerprint detection area 203, and then passes through the fingerprint light signal formed by refraction on the side surface of a prism film in the prism film. . For example, as shown in FIG. 11, the fingerprint light signal 301 refracted by the side surface of the second prism film can enter the optical lens 314 and the optical fingerprint sensor 320 through the aperture stop 313 for imaging, and the fingerprint light signal 301 refracted by the side surface of the first prism film can be imaged. The fingerprint light signal cannot pass through the aperture diaphragm 313 for imaging.

Optionally, the position of the optical fingerprint sensor 320 can also be such that the optical fingerprint sensor 320 only receives the optical signal formed after being refracted by one of the first prism film side surface and the second prism film side surface of the prism film 124, and The light signal refracted by the side of the other prism film in the prism film 124 is not received.

Through the solution of the embodiment of the present application, the optical fingerprint sensor 320 is placed obliquely, so that the optical fingerprint sensor 320 can receive fingerprint light signals of all areas in the fingerprint detection area, and perform fingerprint imaging on the fingerprint detection area, and the fingerprint image obtained by the detection There are no dark stripes, which can realize fingerprint recognition under the liquid crystal display. In addition, it can increase the light intensity of the fingerprint light signal received by the optical fingerprint sensor 320, which can further improve the fingerprint image quality and fingerprint recognition effect.

FIG. 12 shows a schematic structural diagram of another fingerprint identification device 300. The fingerprint identification device 300 is also arranged under the liquid crystal display screen, and includes an optical component 310 and an optical fingerprint sensor 320.

Wherein, the optical assembly 310 is arranged in parallel below the liquid crystal display screen. For example, the main optical axis of the optical lens 314 in the optical assembly 310 is perpendicular to the surface of the liquid crystal display screen, and the aperture stop 314 is located on the main optical axis of the optical lens 314.

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

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

Optionally, as shown in FIG. 12, the fingerprint detection area 203 is located on one side of the optical axis of the optical assembly 310.

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

Optionally, the fingerprint detection area 203 is located at the edge area of the field of view of the optical component 310. The edge area of the field of view of the optical component 310 is located within the field of view area of the optical component 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 the radius of the field of view. 4/5. It should be understood that the first threshold may also be 3/4 of the radius of the field of view or any other value, which is not limited in the embodiment of the present application.

Optionally, there is no overlap between the projections of the optical component 310 and the fingerprint detection area 203 on the plane where the optical fingerprint sensor 320 is located.

It should be understood that the projection of the optical component 310 and the fingerprint detection area 203 on the plane where the optical fingerprint sensor 320 is located may also have an overlapping area, but the optical fingerprint sensor 320 cannot receive the fingerprint light refracted by the two sides of the prism film at the same time. signal.

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 arranged on the other side of the optical axis of the optical assembly 310.

Optionally, in a possible implementation manner, the optical component 310 is an ultra-wide-angle lens group, and the ultra-wide-angle lens group includes one or more ultra-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 field of view of the ultra-wide-angle lens group ranges from 120° to 180°.

Optionally, the fingerprint detection area 203 is a square greater than or equal to 5 cm*5 cm.

Optionally, increase the object focal length of the optical assembly 310, also called the front focal length of the optical assembly 310, so as to increase the distance from the optical assembly 310 to the fingerprint detection area 203, so as to expand the field of view of the optical assembly 310. By expanding the field of view of the optical component 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 fingerprint recognition performance.

Specifically, FIG. 13 shows a schematic diagram of calculating the tilt angle ω of the optical fingerprint sensor 320 when the optical fingerprint sensor 320 under the liquid crystal display screen is placed obliquely. 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 placed parallel to the liquid crystal display, and its corresponding fingerprint recognition area is located directly above the optical fingerprint sensor 320'. In this case, the optical fingerprint sensor 320' forms the center of the fingerprint image A shaded area will appear. For specific reasons, refer to the related description in FIG. 8 and will not be repeated here.

Wherein, the distance between the aperture stop 313 and the optical fingerprint sensor 320' is d, and d>0. l is the length or width of the photosensitive area in the optical fingerprint sensor, l>0, specifically, l may be the length or width of the light detection array 321. β is the divergence angle of the shadow area in the fingerprint image generated by the optical fingerprint sensor 320', β>0, the divergence angle is related to the structure of the optical component 310, the distance from the optical component 310 to the optical fingerprint sensor, the structure of the prism film, etc. Related. After determining the relevant parameters of the fingerprint identification system, when the optical fingerprint sensor 320' is placed in parallel, the width of the shadow area in the fingerprint image and the distance from the aperture 313 to the optical fingerprint sensor 320' can be used to determine the divergence angle of the shadow area .

In order to avoid 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. At this time, the tilt angle of the optical fingerprint sensor 320 is ω, when 90°>ω>β/ When 2+arctan (l/d), no shadow appears in the fingerprint image formed by the optical fingerprint sensor 320.

It should be understood that FIG. 13 only shows a schematic diagram of the rotation of the optical fingerprint sensor in one direction. The fingerprint sensor can also rotate in other directions with the small aperture diaphragm 313 as the center of rotation, so that the fingerprint image formed by the optical fingerprint sensor does not appear in the fingerprint image. shadow.

It should also be understood that, in the embodiments of the present application, when the optical fingerprint sensor rotates, 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 and the optical fingerprint sensor are arranged in parallel. When the optical fingerprint sensor and the display screen are set at a certain angle, the optical components therein are also set at a certain angle with the display screen.

Specifically, FIG. 14 shows a schematic diagram of calculating the moving distance c of the optical fingerprint sensor 320 when the optical fingerprint sensor 320 under the liquid crystal display is placed obliquely below the optical component 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 placed parallel to the liquid crystal display, and its corresponding fingerprint recognition area is located directly above the optical fingerprint sensor 320'. In this case, the center of the fingerprint image formed by the optical fingerprint sensor 320' A shaded area will appear. For specific reasons, refer to the related description in FIG. 8 and will not be repeated here.

Wherein, the distance between the aperture stop 313 and the optical fingerprint sensor 320' is d, and d>0. l is the length or width of the photosensitive area in the optical fingerprint sensor, l>0, specifically, l may be the length or width of the light detection array 321. β is the divergence angle of the shadow 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. At this time, the translation distance of the optical fingerprint sensor 320 is c, when c>l+d×arctan When (β/2), no shadow appears in the fingerprint image formed by the optical fingerprint sensor 320.

It should be noted here that, in the embodiment of the present application, when the position of the optical component in the fingerprint identification device remains unchanged, the optical fingerprint sensor is translated by a distance c, so that the optical fingerprint sensor is located obliquely below the optical component, not at Directly below the optical components.

It should be understood that FIG. 14 only shows a schematic diagram of translation in one direction of the optical fingerprint sensor, and the fingerprint sensor can also be translated in other directions, so that shadows do not appear in the fingerprint image formed by the optical fingerprint sensor.

Optionally, when the display screen is a liquid crystal display, as shown in FIG. 15, the fingerprint identification device 300 further includes: an infrared light source 340 for providing infrared excitation light for fingerprint detection of the fingerprint identification device 300, and the infrared excitation light It is irradiated to at least part of the display area of the liquid crystal display, and the at least part of the display area at least partially covers the fingerprint detection area of the fingerprint identification device 300.

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

Optionally, the infrared light source 340 may be obliquely attached under the glass cover 121. For example, the infrared light source 340 may be obliquely attached to the bottom of the display screen through optical glue. Optionally, the optical glue may be any kind of optical liquid glue or optical solid glue.

Optionally, an infrared light transmission layer 341 may be provided between the infrared light source and the glass cover and/or between the infrared light source and the liquid crystal display screen. The infrared light transmission layer 341 is used to transmit infrared excitation light and block visible light. Optionally, the infrared light transmission layer 341 may be an infrared transmission ink.

Optionally, as shown in FIG. 15, a light-blocking foam 342 may be provided between the infrared light source 340 and the liquid crystal panel 122 in the liquid crystal display screen to block visible light.

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

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

As shown in FIG. 16, an embodiment of the present application also provides an electronic device 30, which may include the fingerprint identification device 300 of the foregoing application embodiment.

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

Optionally, when the display screen is a liquid crystal display screen, the electronic device 30 may also include an infrared light source. The infrared light source can be the same as the infrared light source 340 in FIG. 15, and the related technical solutions can be referred to the above description, which will not be repeated here.

It should be understood that the specific examples in the embodiments of the present application are only for helping those skilled in the art to better understand the embodiments of the present application, rather than limiting the scope of the embodiments of the present application.

It should be understood that the terms used in the embodiments of the present application and the appended claims are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. For example, the singular forms of "a", "above" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

A person of ordinary skill in the art may be aware that, in combination with the examples described in the embodiments disclosed herein, the units can be implemented by electronic hardware, computer software, or a combination of the two, in order to clearly illustrate the interchangeability of hardware and software. In the above description, the composition and steps of each example have been described generally in terms of function. Whether these functions are performed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of this application.

In the several embodiments provided in this application, it should be understood that the disclosed system and device may be implemented in other ways. For example, the device embodiments described above are merely illustrative, for example, the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components may be combined or It can be integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may also be electrical, mechanical or other forms of connection.

The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments of the present application.

In addition, the functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or software functional unit.

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

The above are only specific implementations of this application, but the protection scope of this application is not limited to this. Anyone familiar with the technical field can easily think of various equivalents within the technical scope disclosed in this application. Modifications or replacements, these modifications or replacements shall be covered within the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

A fingerprint identification device is suitable for electronic equipment with a display screen to perform under-screen optical fingerprint detection, characterized in that the fingerprint identification device includes:

An optical fingerprint sensor, configured to be arranged under the display screen in a manner that is not parallel to the display screen;

The optical component is arranged above the optical fingerprint sensor and includes at least one lens, and the optical component is used to transmit the fingerprint light signal returned after being reflected or scattered by the finger above the display screen to the optical fingerprint sensor for fingerprinting Identification, wherein the fingerprint optical signal is an optical signal inclined with respect to the display screen.
The fingerprint identification device according to claim 1, wherein the display screen comprises a fingerprint detection area, and the optical component is used to transmit the fingerprint light 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.
The fingerprint identification device according to claim 1 or 2, wherein the angle between the plane where the optical fingerprint sensor is located and the plane where the display screen is located is ω, where 0°<ω<90°.
The fingerprint identification device according to claim 3, wherein 0°<ω<30°.
The fingerprint identification device according to claim 3 or 4, wherein the incident angle of the fingerprint optical signal with respect to the optical fingerprint sensor is θ-ω, wherein θ-ω is the fingerprint optical signal and the optical fingerprint sensor. The included angle of the vertical plane of the optical fingerprint sensor, θ is the included angle of the fingerprint light signal and the vertical plane of the display screen, 0°<θ<90°.
The fingerprint identification device according to claim 3 or 4, wherein ω=θ, where θ is the angle between the fingerprint light signal and the vertical plane of the display screen, 0°<θ<90°.
The fingerprint identification device according to any one of claims 1-6, wherein the optical component comprises: at least one optical lens for receiving the fingerprint light signal to perform fingerprint imaging, and the optical lens is Spherical or aspheric lens.
7. The fingerprint identification device according to claim 7, wherein the optical assembly further comprises a small aperture diaphragm formed in the optical path of the at least one optical lens.
The fingerprint identification device according to claim 7 or 8, wherein the focal plane of the optical lens is parallel to the optical fingerprint sensor.
The fingerprint identification device according to any one of claims 7-9, wherein the direction of the fingerprint optical signal is parallel to the optical axis of the optical lens.
The fingerprint identification device according to any one of claims 7-10, wherein the at least one optical lens is fixed on the optical fingerprint sensor by a fixing component, and the at least one optical lens is connected to the optical fingerprint sensor. The sensors are not arranged in parallel under the display screen.
The fingerprint identification device according to any one of claims 1-6, wherein the optical component comprises: a microlens array and at least one light blocking layer;

The at least one light-blocking layer is located under the microlens array, and is provided with a plurality of light-passing holes;

The microlens array is used to receive the fingerprint optical signal, and converge the fingerprint optical signal to the plurality of light-passing holes;

The multiple light-passing holes are used to transmit the fingerprint light signal to the optical fingerprint sensor.
The fingerprint identification device of claim 12, wherein the fingerprint optical signal is incident on the microlens array perpendicularly.
The fingerprint identification device according to claim 12 or 13, wherein the microlens array and the at least one light blocking layer are integrated and disposed above the optical fingerprint sensor through a semiconductor process;

The microlens array, the at least one light blocking layer and the optical fingerprint sensor are all arranged non-parallel under the display screen.
The fingerprint identification device according to any one of claims 1-14, wherein the optical fingerprint sensor is arranged non-parallel below the display screen through a supporting structure;

The supporting structure is made of injection molding material, plastic material or metal material.
The fingerprint identification device according to any one of claims 1-15, wherein the display screen is an organic light emitting diode display screen;

The fingerprint light signal is a light signal formed and returned by the excitation light emitted by a part of the display unit of the organic light emitting diode display screen reflected or scattered by a finger above the organic light emitting diode display screen.
The fingerprint identification device according to any one of claims 1-15, wherein the display screen is a liquid crystal display screen with a backlight module;

The fingerprint light signal is the infrared excitation light emitted by the external light source irradiated by the finger above the liquid crystal display screen, reflected or scattered, and then returned, and passes through the first prism film side surface and the second prism film of the prism film of the backlight module One of the side surfaces of the prism film side refracts the optical signal formed after it is refracted.
The fingerprint identification device according to claim 17, wherein the optical component comprises at least one optical lens and a small aperture stop, and the angle between the plane where the optical fingerprint sensor is located and the plane where the display screen is located is ω, 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 diaphragm to the optical fingerprint sensor, β Is the divergence angle of the shadow area determined according to the prism film.
The fingerprint identification device according to claim 17 or 18, wherein the position of the optical component is such that the optical signal refracted by the side surface of another prism film in the prism film deviates from the optical component and cannot be transmitted to the optical component.述optical fingerprint sensor.
The fingerprint identification device according to any one of claims 17-19, wherein the position of the optical fingerprint sensor is such that the optical signal refracted by the side surface of another prism film in the prism film deviates from the optical fingerprint sensor.
The fingerprint identification device according to any one of claims 1-20, wherein the fingerprint identification device further comprises:

The filter layer is arranged in the optical path between the display screen and the optical fingerprint sensor, and is used to filter out the light signal of the non-target waveband and transmit the light signal of the target waveband.
An electronic device, characterized in that it comprises:

A display screen and the fingerprint identification device according to any one of claims 1 to 21, wherein the fingerprint identification device is arranged below the display screen for under-screen optical fingerprint detection.
The electronic device according to claim 22, wherein the display screen is an organic light emitting diode display screen, wherein the fingerprint light signal is the excitation light emitted by a part of the display unit of the organic light emitting diode display screen. The light signal formed and returned by the reflection or scattering of the finger above the organic light emitting diode display screen.
The electronic device according to claim 22, wherein the display screen is a liquid crystal display screen, and the electronic device further comprises:

The infrared light source is used to provide 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 identification The fingerprint detection area of the device.