WO2021051737A1 - 指纹识别装置、背光模组、液晶显示屏和电子设备 - Google Patents

指纹识别装置、背光模组、液晶显示屏和电子设备 Download PDF

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Publication number
WO2021051737A1
WO2021051737A1 PCT/CN2020/074011 CN2020074011W WO2021051737A1 WO 2021051737 A1 WO2021051737 A1 WO 2021051737A1 CN 2020074011 W CN2020074011 W CN 2020074011W WO 2021051737 A1 WO2021051737 A1 WO 2021051737A1
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WIPO (PCT)
Prior art keywords
prism film
fingerprint
liquid crystal
angle
prism
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PCT/CN2020/074011
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English (en)
French (fr)
Inventor
葛丛
刘杨赞
蔡斐欣
何毅
皮波
Original Assignee
深圳市汇顶科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by 深圳市汇顶科技股份有限公司 filed Critical 深圳市汇顶科技股份有限公司
Priority to CN202080001558.5A priority Critical patent/CN111837130A/zh
Publication of WO2021051737A1 publication Critical patent/WO2021051737A1/zh

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    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V40/00—Recognition of biometric, human-related or animal-related patterns in image or video data
    • G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
    • G06V40/12—Fingerprints or palmprints
    • G06V40/13—Sensors therefor
    • G06V40/1324—Sensors therefor by using geometrical optics, e.g. using prisms
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133606—Direct backlight including a specially adapted diffusing, scattering or light controlling members

Definitions

  • This application relates to the field of optical fingerprint technology, and more specifically, to a fingerprint identification device, a backlight module, a liquid crystal display, and electronic equipment.
  • the embodiments of the present application provide a fingerprint identification device, a backlight module, a liquid crystal display and electronic equipment, which can improve the performance of optical fingerprint identification under the LCD screen.
  • a fingerprint identification device which is used to perform under-screen fingerprint identification under a backlight module of a liquid crystal display.
  • the backlight module includes a first prism film and a second prism film.
  • the first prism Both the film and the second prism film face the liquid crystal panel of the liquid crystal display
  • the fingerprint identification device includes: a fingerprint recognition module located obliquely below the fingerprint detection area in the liquid crystal display for receiving the first fingerprint light signal ,
  • the first fingerprint light signal is used for fingerprint recognition, where the first fingerprint light signal is the fingerprint light signal after passing through one of the prism film sides of the first prism film and one of the prism film sides of the second prism film
  • the fingerprint optical signal is the optical signal returned by the reflection or scattering of the finger above the fingerprint detection area; the two bottom angles in the first prism film are not equal to each other, and the two in the second prism film The bottom angles are not equal to each other.
  • the two bottom angles in the first prism film are the angles between the two sides of the prism film in the first prism film and the plane where the liquid crystal display is located.
  • the bottom angle is the angle between the two sides of the prism film in the second prism film and the plane where the liquid crystal display screen is located.
  • the prism film in the backlight module of the liquid crystal display is improved into a first prism film and a second prism film.
  • the two bottom corners of the first prism film and the two prism films of the second prism film The bottom angle is different, the area of the corresponding two prism film sides is also different.
  • the fingerprint recognition module is placed obliquely below the fingerprint detection area in the LCD screen, not directly below, so that the fingerprint recognition module only receives the second
  • the light signal refracted by a prism film side surface in a prism film and a prism film side surface in a second prism film realizes fingerprint recognition under the liquid crystal display screen.
  • the first base angle ⁇ 1 in the first prism film is smaller than the second base angle ⁇ 2 , 30° ⁇ 1 ⁇ 45°, and the first base angle is the first prism film The included angle between the side surface of the first prism film and the plane where the liquid crystal display screen is located, and the second bottom angle is the included angle between the side surface of the second prism film in the first prism film and the plane where the liquid crystal display screen is located.
  • the first fingerprint optical signal is an optical signal after the fingerprint optical signal passes through one of the side surfaces of the first prism film and the second prism film.
  • the fingerprint recognition module is located such that it cannot receive the fingerprint light signal after passing through the second prism film side surface and another prism film side surface of the second prism film.
  • the third base angle ⁇ 1 in the second prism film is smaller than the fourth base angle ⁇ 2 , 30° ⁇ 1 ⁇ 45°, and the third base angle is the second prism film The angle between the side surface of the third prism film and the plane where the liquid crystal display screen is located, and the fourth bottom angle is the angle between the side surface of the fourth prism film in the second prism film and the plane where the liquid crystal display screen is located.
  • the first fingerprint optical signal is an optical signal after the fingerprint optical signal passes through the side surface of the first prism film and the side surface of the third prism film.
  • the fingerprint identification module is located such that it cannot receive the fingerprint optical signal after passing through the side surface of the first prism film and the fourth prism film.
  • the angle between the two prism film side surfaces in the first prism film is the apex angle ⁇ 1 of the first prism film
  • the angle between the two prism film side surfaces in the second prism film is The apex angle ⁇ 2 of the second prism film is 70° ⁇ 1 ⁇ 110°, and 70° ⁇ 2 ⁇ 110°.
  • the first prism film and the second prism film have the same structure.
  • the projection angle between the ridge of a prism in the second prism film and the ridge of a prism in the first prism film on the first plane is ⁇ , 70° ⁇ 90 °, wherein the first plane is a plane parallel to the liquid crystal display screen.
  • the fingerprint identification module includes: an optical component and a light detection array; the optical component is used to receive the first fingerprint light signal, and transmit the first fingerprint light signal to the light detection The light detection array is used to convert the first fingerprint light signal into a fingerprint image signal for fingerprint identification.
  • the optical component includes at least one optical lens, and the at least one optical lens is a spherical or aspherical lens.
  • the light detection array includes at least one optical fingerprint sensor.
  • a backlight module which is suitable for an electronic device with a liquid crystal display screen, comprising: a first prism film and a second prism film, the first prism film and the second prism film both face the liquid crystal display screen
  • the liquid crystal panel ; the two bottom angles in the first prism film are not equal to each other, and the two bottom angles in the second prism film are not equal to each other, the two bottom angles in the first prism film are the first prism
  • the angle between the two sides of the prism film in the film and the plane where the liquid crystal display is located, and the two bottom angles in the second prism film are the plane where the two sides of the prism film in the second prism film and the liquid crystal display are located ⁇ The included angle.
  • the fingerprint optical signal forms a first fingerprint optical signal after passing through one of the prism film side surfaces in the first prism film and one of the prism film side surfaces in the second prism film, and the first fingerprint optical signal
  • the fingerprint light signal is the light signal returned by the reflection or scattering of the finger above the fingerprint detection area.
  • the original backlight module is improved, and the fingerprint recognition function under the liquid crystal display can be realized.
  • the first base angle ⁇ 1 in the first prism film is smaller than the second base angle ⁇ 2 , 30° ⁇ 1 ⁇ 45°, and the first base angle is the first prism film The included angle between the side surface of the first prism film and the plane where the liquid crystal display screen is located, and the second bottom angle is the included angle between the side surface of the second prism film in the first prism film and the plane where the liquid crystal display screen is located.
  • the first fingerprint optical signal is an optical signal after the fingerprint optical signal passes through one of the side surfaces of the first prism film and the second prism film.
  • the third base angle ⁇ 1 in the second prism film is smaller than the fourth base angle ⁇ 2 , 30° ⁇ 1 ⁇ 45°, and the third base angle is the second prism film The angle between the side surface of the third prism film and the plane where the liquid crystal display screen is located, and the fourth bottom angle is the angle between the side surface of the fourth prism film in the second prism film and the plane where the liquid crystal display screen is located.
  • the first fingerprint optical signal is an optical signal after the fingerprint optical signal passes through the side surface of the first prism film and the side surface of the third prism film.
  • the angle between the two prism film side surfaces in the first prism film is the apex angle ⁇ 1 of the first prism film
  • the angle between the two prism film side surfaces in the second prism film is The apex angle ⁇ 2 of the second prism film is 70° ⁇ 1 ⁇ 110°, and 70° ⁇ 2 ⁇ 110°.
  • the first prism film and the second prism film have the same structure.
  • the projection angle between the ridge of a prism in the second prism film and the ridge of a prism in the first prism film on the first plane is ⁇ , 70° ⁇ 90 °, wherein the first plane is a plane parallel to the liquid crystal display screen.
  • an electronic device including: a liquid crystal display screen and, according to the first aspect and the fingerprint identification device in any one of the possible implementation manners of the first aspect, the liquid crystal display screen includes a backlight module, the The fingerprint identification module is arranged under the backlight module.
  • the electronic device further includes: an infrared light source for providing infrared excitation light for fingerprint detection of the fingerprint recognition module, and the infrared excitation light irradiates at least a part of the display area of the liquid crystal display screen, The at least part of the display area at least partially covers the fingerprint detection area of the fingerprint identification module; wherein, the first fingerprint light signal includes the first fingerprint infrared light signal of the infrared light source that passes through the backlight module after the infrared excitation light of the infrared light source is reflected by the finger .
  • the first fingerprint infrared light signal is generated by using an infrared light source, and optical fingerprint detection is performed based on the first fingerprint infrared light signal, which can reduce the interference of visible light on the screen to infrared light fingerprint detection, and balance the infrared light fingerprint image
  • the optical illuminance further improves the quality of fingerprint imaging.
  • the infrared light source is a single or multiple infrared light-emitting diodes; the single or multiple infrared light-emitting diodes are distributed around the fingerprint detection area.
  • the infrared light source is arranged under the glass cover of the liquid crystal display screen, and is arranged side by side with the liquid crystal panel of the liquid crystal display screen.
  • the infrared light source is obliquely attached below the glass cover plate.
  • the electronic device further includes: an infrared light transmission layer, which is arranged between the infrared light source and the glass cover and/or between the infrared light source and the liquid crystal display, for transmitting Pass the infrared excitation light and block visible light.
  • an infrared light transmission layer which is arranged between the infrared light source and the glass cover and/or between the infrared light source and the liquid crystal display, for transmitting Pass the infrared excitation light and block visible light.
  • a liquid crystal display screen including: the backlight module in the second aspect or any possible implementation of the second aspect.
  • an electronic device including: the liquid crystal display of the fourth aspect.
  • the electronic device can realize the fingerprint recognition function of the large field of view under the liquid crystal display screen.
  • 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 diagram of a three-dimensional structure of a backlight module according to an embodiment of the present application.
  • Fig. 3 is a schematic structural diagram of a prism film according to an embodiment of the present application.
  • Fig. 4 is a schematic diagram of an optical path when a fingerprint recognition device under a liquid crystal display screen performs fingerprint recognition according to an embodiment of the present application.
  • Fig. 5 is a schematic diagram of a fingerprint image according to an embodiment of the present application.
  • Fig. 6 is a schematic diagram of another fingerprint image according to an embodiment of the present application.
  • Fig. 7 is a schematic structural diagram of a fingerprint identification device according to an embodiment of the present application.
  • Fig. 8 is a schematic cross-sectional view of an enlarged first prism film according to an embodiment of the present application.
  • Fig. 9 is a schematic diagram of another fingerprint image according to an embodiment of the present application.
  • FIG. 10 is a cross-sectional view of the relative positional relationship between the optical field of view and the fingerprint detection area of a fingerprint identification module according to an embodiment of the present application.
  • FIG. 11 is a cross-sectional view of the relative positional relationship between the optical field of view and the fingerprint detection area of another fingerprint identification module according to an embodiment of the present application.
  • FIG. 12 is a schematic diagram of a three-dimensional structure of two prism films in a backlight module according to an embodiment of the present application.
  • Fig. 13 is a schematic cross-sectional view of Fig. 12 in the XZ plane.
  • FIG. 14 is another schematic cross-sectional view of two prism films in a backlight module according to an embodiment of the present application.
  • Fig. 15 is a schematic diagram of a fingerprint image according to an embodiment of the present application.
  • Fig. 16 is a schematic diagram of another fingerprint image according to an embodiment of the present application.
  • FIG. 17 is a top view of an optical field of view area and fingerprint detection area of a fingerprint identification module in a liquid crystal display according to an embodiment of the present application.
  • FIG. 18 is a top view of the optical field of view area and fingerprint detection area of another fingerprint identification module in a liquid crystal display according to an embodiment of the present application.
  • Fig. 19 is a schematic structural diagram of another fingerprint identification device according to an embodiment of the present application.
  • FIG. 20 is a schematic cross-sectional view of an enlarged second prism film according to an embodiment of the present application.
  • Fig. 21 is a schematic diagram of a fingerprint image according to an embodiment of the present application.
  • FIG. 22 is a top view of the optical field of view area and fingerprint detection area of another fingerprint identification module in a liquid crystal display according to an embodiment of the present application.
  • Fig. 23 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
  • Under-screen fingerprint recognition technology refers to the installation of a fingerprint recognition device (such as a fingerprint recognition module) below the display screen, so that fingerprint recognition operations are performed inside the display area of the display screen, without the need for areas other than the display area on the front of the electronic device Set the fingerprint collection area.
  • a fingerprint recognition device such as a fingerprint recognition module
  • the under-screen fingerprint identification technology may include under-screen optical fingerprint identification technology, under-screen ultrasonic fingerprint identification technology, or other types of under-screen fingerprint identification technology.
  • the under-screen optical fingerprint recognition technology uses light returned from the top surface of the device display component to perform fingerprint sensing and other sensing operations.
  • the returned light carries information about the object (for example, a finger) in contact with the top surface.
  • a specific optical sensor module located below the display screen is used to perform under-screen optical fingerprint recognition.
  • the design of the specific optical sensor module can be such that the desired optical imaging can be achieved by appropriately configuring the optical elements for capturing and detecting the returned light.
  • the technical solution of the embodiment of the present application can also perform other biometric recognition, such as living body recognition, palmprint recognition, etc., which is not limited in the embodiment of the present application.
  • FIG. 1 is a schematic structural diagram of an electronic device to which the embodiment of the application can be applied.
  • the electronic device 1 includes a display screen 10 and a fingerprint identification device 20, wherein the fingerprint identification device 20 is arranged in a partial area below the display screen 10.
  • the fingerprint identification device 20 includes an optical assembly 300 and a light detection array 400, the light detection array 400, and a reading circuit and other auxiliary circuits electrically connected to the light detection array.
  • It can be fabricated on a chip (De) such as an optical imaging chip or an optical fingerprint sensor through a semiconductor process, and the light detection array can specifically be a photodetector array on the optical fingerprint sensor, which includes a plurality of arrays
  • the optical detector can be called a pixel unit or a pixel; the optical assembly 300 can be arranged above the light detection array 400, and can specifically include a light guide layer or a light path guide structure and other optical elements.
  • the optical layer or optical path guiding structure is mainly used to guide the reflected light reflected from the surface of the finger to the sensing array for optical detection.
  • the area where the light detection array 400 is located or its sensing area is the fingerprint detection area 103 of the fingerprint identification device 20. As shown in FIG. 1, the fingerprint detection area 103 is located in the display area of the display screen 10.
  • the fingerprint identification device 20 can also be arranged in other positions, such as the side of the display screen 10 or the non-transmissive area at the edge of the electronic device 1, and at least part of the display area of the display screen 10 is designed through the optical path.
  • the light signal of ⁇ is guided to the fingerprint identification device 20, so that the fingerprint detection area 103 is actually located in the display area of the display screen 10.
  • the area of the fingerprint detection area 103 may be different from the area of the light detection array 400 of the fingerprint identification device 20.
  • a light path design such as lens imaging, a reflective folding light path design, or other light convergence or reflection light path design, it can make The area of the fingerprint detection area 103 of the fingerprint identification device 20 is larger than the area of the light detection array 400.
  • the fingerprint detection area 103 of the fingerprint identification device 20 can also be designed to be substantially the same as the area of the sensing array of the fingerprint identification device 20.
  • the electronic device 1 with the above structure does not require special reserved space on the front 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 10 can be basically Extend to the front of the entire electronic device 1.
  • the optical assembly 300 and the light detection array 400 may be packaged in the same optical fingerprint component.
  • the optical component 300 can be packaged in the same optical fingerprint chip as the photodetection array 400, or the optical component 300 can be arranged outside the chip where the photodetection array 400 is located.
  • the optical component 300 can be attached to the top of the chip, or the optical component 300 can be attached to the top of the chip. Part of the components of the assembly 300 are integrated in the above-mentioned chip.
  • the light guide layer or light path guiding structure of the optical component 300 has multiple implementation solutions.
  • the light guide layer may be specifically a collimator layer made on a semiconductor silicon wafer, which has multiple collimators.
  • 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.
  • 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.
  • 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 fingerprint identification device 20.
  • 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.
  • 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.
  • a microlens layer can be further provided under the collimator layer or the optical lens layer.
  • 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.
  • the electronic device 1 further includes a transparent protective cover 130, which may be a glass cover or a sapphire cover, which is located above the display screen 10 and covers the front surface of the electronic device 1.
  • a transparent protective cover 130 which may be a glass cover or a sapphire cover, which is located above the display screen 10 and covers the front surface of the electronic device 1.
  • a circuit board 150 may also be provided under the fingerprint identification device 20.
  • the fingerprint identification device 20 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 fingerprint identification device 20 can realize electrical interconnection and signal transmission with other peripheral circuits or other components of the electronic device 1 through the circuit board 150.
  • the fingerprint identification device 20 can receive the control signal of the processing unit of the electronic device 1 through the circuit board 150, and can also output the fingerprint image signal from the fingerprint identification device 20 to the processing unit or the control unit of the electronic device 1 through the circuit board 150 Wait.
  • the fingerprint identification device 20 may only include an optical fingerprint sensor.
  • the fingerprint detection area 103 of the fingerprint identification device 20 has a small area and a fixed position. Therefore, the user needs to input fingerprints. Press the finger to a specific position of the fingerprint detection area 103, otherwise the fingerprint identification device 20 may not be able to collect the fingerprint image, resulting in poor user experience.
  • the fingerprint identification device 20 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 fingerprint recognition device 20 is constituted.
  • the fingerprint detection area 103 of the fingerprint identification device 20 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 fingerprint identification device 20 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.
  • 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.
  • optical fingerprint device in the embodiments of the present application can also be referred to as an optical fingerprint recognition module, fingerprint recognition device, fingerprint recognition module, fingerprint module, fingerprint acquisition device, etc., and the above terms can be replaced with each other.
  • the display screen 10 is 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.
  • OLED Organic Light Emitting Diode
  • Micro-LED Micro-LED
  • the fingerprint identification device 20 can use the display unit (ie, an OLED light source) of the OLED display screen 10 located in the fingerprint detection area 103 as an excitation light source for optical fingerprint detection.
  • the display screen 10 emits a beam of light to the target finger 140 above the fingerprint detection area 103.
  • the light is reflected on the surface of the finger 140 to form reflected light or scattered inside the finger 140 to form scattered light.
  • the above-mentioned reflected light and scattered light are collectively referred to as reflected light. Because the ridge and valley of the fingerprint have different light reflection capabilities, the reflected light from the fingerprint ridge and the reflected light from the fingerprint valley have different light intensities. After the reflected light passes through the optical component 300, it is affected by the fingerprint.
  • the light detection array 400 in the identification device 20 receives and converts it into a corresponding electrical signal, that is, a fingerprint image signal; based on the fingerprint image signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed, thereby realizing optical Fingerprint recognition function.
  • the display screen 10 When the display screen 10 is a display screen without a self-luminous display unit, such as a liquid crystal display screen or other passive light-emitting display screens, a backlight module needs to be used as the light source of the display screen 10.
  • the display screen 10 includes a liquid crystal panel 110 and a backlight module 120.
  • the backlight module The group 120 is used to send a light signal to the liquid crystal panel 110.
  • the liquid crystal panel 110 includes a liquid crystal layer and a control circuit for controlling the deflection of the liquid crystal to transmit the light signal.
  • the electronic device 1 may further include an excitation light source 160 for optical fingerprint detection.
  • the fingerprint identification device 20 is arranged under the backlight module 120.
  • the excitation light source 160 emits excitation light 111 to the target finger 140 above the fingerprint detection area 103.
  • the excitation light 111 is reflected on the surface of the finger 140 to form the first reflected light 151 of the fingerprint ridge and the second reflected light 152 of the fingerprint valley.
  • the reflected light 151 and the second reflected light 152 need to pass through the liquid crystal panel 110 and the backlight module 120, and then pass through the optical assembly 300, and are received by the light detection array 400 in the fingerprint identification device 20 and converted into fingerprint image signals.
  • the excitation light source is an infrared light source, which will not affect the normal display of the liquid crystal display, and fingerprint recognition is performed based on infrared light signals to remove interference from ambient light and improve the effect of fingerprint recognition.
  • the film structure in the backlight module 120 especially the prism film, will cause a great interference to the imaging of the fingerprint identification device 20.
  • the backlight module 120 includes a light source (Light Source), a light guide plate (Light Guide Plate), a diffuser (Diffuser), a prism film (Brightness Enhancement Film, BEF), a reflector (Reflector), etc., among which,
  • the light signal of the light source enters the light guide plate from the side, is converted into a uniformly distributed surface light source through the scattering of the light guide plate, and then enters the prism film through the uniform light effect of the lower diffuser. Due to the light-gathering effect of the prism film, the light conforming to a certain angle is emitted, and the non-conforming light is again reflected in the light guide plate and the diffuser plate. After the function of the light guide plate and the diffuser plate, it is received by the prism film again and is The light that meets the angle requirements is emitted.
  • the backlight module there are usually two prism films, namely the vertical prism film and the horizontal prism film described in FIG. 2.
  • the two prism films have the same structure, but the prism film has the same structure.
  • the directions of the ridges are different, and the projection angle of the ridges of the two prism films on the same plane is 90°, which is parallel to the plane of the liquid crystal panel in the display screen.
  • the two prism films work together to ensure that the light signals in the 360° range on the horizontal plane are effectively converged to the liquid crystal panel.
  • the light after passing through the prism film is condensed to 70°, that is, the angle between the light signal after passing through the prism film and the direction perpendicular to the display screen is between 0 and 70°, and it is in the display screen.
  • the projection on can be any angle from 0 to 360°. Therefore, by arranging the prism film in the backlight module, the brightness of the front view is effectively increased, and the brightness of the liquid crystal display is increased by 70% compared with the case where the prism film is not provided.
  • the two prism films in the backlight module may also be referred to as brightness enhancement prism films.
  • Fig. 3(a) and Fig. 3(b) show a three-dimensional structure diagram and a cross-sectional view of a prism film 1200 in the backlight module 120 in an embodiment of the present application, wherein Fig. 3(b) is Fig. 3 (a) is a schematic cross-sectional view on the XZ plane.
  • the prism film 1200 may be any one of the two prism films in FIG. 2.
  • the prism film 1200 is a plurality of identical triangular prisms 1210 regularly arranged in a row on a base 1220, wherein each triangular prism 1210 is formed by protruding upward from the base 1220, and each triangular prism 1210 has two There are two inclined side surfaces. The angle between the two inclined side surfaces is the apex angle (Apex Angle) of the prism 1210. Since all the prisms in the prism film have the same structure, for the convenience of description, in this application, the following is also The vertex angle of any triangular prism in the prism film is called the vertex angle of the prism film.
  • angles between the two inclined sides of a triangular prism 1210 and the horizontal plane are the two base angles of the triangular prism, respectively.
  • the two inclined sides of the prism 1210 are the first side 1211 and the second side 1212, respectively, and the angle between the first side 1211 and the horizontal direction is the first bottom angle of the prism 1210 ⁇ , the angle between the second side surface 1212 and the horizontal direction is the second base angle ⁇ of the triangular prism 1210.
  • the two base angles of any triangular prism in the prism film are also referred to as the two base angles of the prism film, and the first side surface of each triangular prism in the prism film is referred to as the first side.
  • the side of the prism film, and the second side of each triangular prism in the prism film is called the side of the second prism film.
  • the apex angle of the prism film in the prior art is generally 90°, and the light-gathering effect of the prism film is the best at this angle. If the apex angle is not 90°, part of the optical signal may be lost, affecting the display brightness of the LCD screen.
  • the two base angles in the prism film are generally equal, that is, the multiple triangle prisms in the prism film The areas of the two sides are the same. If the apex angle of the prism film is 90°, the prism film is composed of a plurality of isosceles right-angle prisms arranged on the base.
  • the prism film is set in the LCD screen to improve the brightness of the LCD screen, but the finger is pressed on the surface of the LCD screen, when the fingerprint identification device is set under the finger for fingerprint identification, the light signal reflected or scattered from the finger will pass through the prism. The film will be refracted into two light signals in different directions, thereby affecting the fingerprint recognition function under the LCD screen.
  • the liquid crystal display screen 10 includes a liquid crystal panel 110 and a backlight module 120.
  • the backlight module 120 includes a prism film 1200 and others.
  • the film layer 124, the other film layer 124 includes, but is not limited to, the film structure of the light guide plate, the reflective film, and the diffuser film in FIG. 2 above.
  • the third reflected light 153 is a fingerprint detection light signal reflected or transmitted through the central area of the finger.
  • the central area of the finger corresponds to the central area of the fingerprint detection area 103, and the fingerprint identification device 20 is set in the central area of the fingerprint detection area 103.
  • the third reflected light 153 is refracted by the side surfaces of the prism film in two directions in the prism film 1200 into first refracted light 161 and second refracted light 162 in different directions.
  • the first refracted light 161 and the second refracted light 162 cannot enter
  • the optical assembly 300 in the fingerprint identification device 20 performs imaging.
  • the light signal at the center of the finger cannot be received by the fingerprint recognition device 20, and the fingerprint image detected by the light detection array 400 will form a dark area as shown in FIG. 5, and the field of view of the fingerprint recognition device 20 is divided into two. Two equal fields of view are formed, resulting in severe field loss and image distortion.
  • the fourth optical signal 154 is the ambient light signal or stray light signal of other areas outside the fingerprint detection area 103. After the fourth optical signal 154 is refracted by the prism film, a large-angle refracted light signal enters the optical assembly 300 and is optically transmitted. The component 300 is transmitted to the light detection array 400 and forms images in the light detection array 400, which affects the quality of the fingerprint image.
  • a prism film is taken as an example to illustrate the influence of the prism film on the fingerprint light signal.
  • the liquid crystal display includes two prism films as shown in FIG. 2, the other prism film will affect the fingerprint light.
  • the signal interference situation can also refer to the above description.
  • the two prism films are composed of isosceles right-angled prisms, the center of the fingerprint image detected by the light detection array 400 will form a dark area as shown in FIG. 6, and the field of view of the fingerprint identification device 20 is divided into four, forming an equal Four parts of the field of view, resulting in a more serious loss of field of view.
  • This application proposes a fingerprint identification device suitable for liquid crystal display screens, which is arranged obliquely below the fingerprint detection area, so that the fingerprint identification device receives the refracted light refracted by one side surface of the prism film, and improves the liquid crystal display
  • the prism film structure in the backlight module of the screen increases the effective field of view for the fingerprint identification device to receive the fingerprint light signal, thereby forming a continuous fingerprint image with a larger area, and realizing fingerprint identification under the LCD screen.
  • FIG. 7 is a schematic structural diagram of a fingerprint identification device 200 provided by an embodiment of the present application, which is suitable for electronic equipment with a liquid crystal display, and is used for setting under the backlight module of the liquid crystal display for under-screen fingerprint recognition.
  • the backlight module includes a first prism film.
  • the fingerprint identification device 200 includes:
  • the fingerprint identification module 201 is located obliquely below the fingerprint detection area 103 in the liquid crystal display 10, and is used to receive the first fingerprint optical signal 102, and the first fingerprint optical signal 101 is used for fingerprint identification, wherein the first fingerprint
  • the optical signal 102 is the optical signal refracted by the fingerprint optical signal 101 through the side surface of the first prism film in the first prism film 121, and the fingerprint optical signal 101 is the optical signal returned by the reflection or scattering of the finger above the fingerprint detection area 103;
  • the first bottom angle and the second bottom angle of the first prism film 121 are not equal.
  • the first bottom angle is the angle between the side surface of the first prism film in the first prism film 121 and the plane where the liquid crystal display is located.
  • the angle is the angle between the side surface of the second prism film in the first prism film 121 and the plane where the liquid crystal display screen is located.
  • the fingerprint identification module 201 may be the fingerprint identification device 20 in FIG. 1, which may include an optical assembly 300 and a light detection array 400.
  • the optical component 300 is used to receive the first fingerprint light signal 101, and transmit the first fingerprint light signal to the light detection array 400, and the light detection array 400 is used to convert the first fingerprint light signal 101 into a fingerprint Image signal for fingerprint recognition.
  • the optical component 300 may be an optical lens (Lens) layer, which has one or more lens units, such as a lens group composed of one or more optical lenses.
  • the surface of the optical lens in the optical lens layer may be a spherical surface or an aspheric surface, and the material of the optical lens may be a transparent material such as glass or resin.
  • the light detection array 400 includes a plurality of sensing units.
  • the sensing unit may use a photodiode (Photo Diode), a metal oxide semiconductor field effect transistor (Metal Oxide Semiconductor Field Effect Transistor, MOSFET) and other devices to detect light signals and output fingerprint image signals.
  • the sensing unit has higher optical sensitivity and higher quantum efficiency for light of a specific wavelength, so as to facilitate detection of optical signals of corresponding wavelengths.
  • the fingerprint detection area 103 is the sensing area of the light detection array 400 in the liquid crystal display 10, that is, when the user's finger presses on the fingerprint detection area 103, the light signal is reflected by the finger above the fingerprint detection area 103 or The fingerprint light signal is scattered and returned.
  • the fingerprint detection signal is used to detect the fingerprint information of the finger.
  • the light detection array 400 performs fingerprint imaging on the finger above the fingerprint detection area 103.
  • the fingerprint identification module 201 may include only one optical fingerprint sensor. At this time, the fingerprint detection area 103 of the fingerprint identification module 201 has a small area and a fixed position.
  • the fingerprint identification module 201 may specifically include a plurality of optical fingerprint sensors; the plurality of optical fingerprint sensors may be arranged side by side under the liquid crystal display in a splicing manner, and the sensing area of the plurality of optical fingerprint sensors Together, the fingerprint detection area 103 of the fingerprint identification module 201 is formed.
  • the fingerprint identification device 200 may be applied to the above-mentioned electronic device 1, and it may be specifically arranged under the backlight module 120 of the above-mentioned liquid crystal display 10.
  • the related features of the liquid crystal display screen 10 and the backlight module 120 can refer to the related description of the liquid crystal display screen 10 and the backlight module 120 above.
  • the first prism film 121 of the embodiment of the present application is also a prism film structure, which is also formed by arranging a plurality of triangular prisms on a substrate.
  • the first prism film 121 can be understood as an improvement formed on the prism film 1200 described above. Improved prism film structure.
  • FIG. 8 shows an enlarged schematic cross-sectional view of the first prism film 121.
  • the base of the first prism film 121 is below, and the first prism film side surface 1211 and the second prism film side surface 1212 protrude toward the upper side of the base.
  • the first prism film side surface 1211 and the second prism film side surface 1211 The film sides 1212 all face the liquid crystal panel 110 of the liquid crystal display, and the base of the first prism film 121 is parallel to the plane where the liquid crystal panel 110 is located.
  • the first side surfaces of the multiple triangular prisms in the first prism film 121 are all referred to as the first prism film side surface 1211
  • the second side surfaces of the multiple triangular prisms are all referred to as the second prism film side surface 1212.
  • the plane where the liquid crystal panel in the liquid crystal display is located is also referred to as the first plane, and the direction perpendicular to the first plane is referred to as the vertical direction.
  • the first plane is also a horizontal plane, and the vertical direction is the vertical direction.
  • the angle between the side surface of the first prism film 1211 and its base that is, the angle between the side surface of the first prism film 1211 and the first plane is the first base angle ⁇ 1
  • the angle between the side surface of the second prism film 1212 and its base is the second base angle ⁇ 2 , ⁇ 1 ⁇ 2
  • the area of the first prism film side surface 1211 is different from the area of the second prism film side surface 1212 equal.
  • the difference between the first prism film 121 and the aforementioned prism film 1200 is that the area of the two prism film sides of the prism film 1200 are equal, and the two base angles are equal.
  • the first prism film 121 has the same area. The side areas of the two prism films are not equal, and the two bottom angles are not equal.
  • ⁇ 1 ⁇ 2 correspondingly, the area of the first prism film side surface 1211 in the first prism film 121 is larger than the area of the second prism film side surface 1212.
  • the first prism film side surface 1211 receives the optical signal a
  • the second prism film side surface 1212 receives the optical signal b.
  • the optical signal a and the optical signal b are parallel optical signals, in particular, the optical signal a and the optical signal b All are optical signals perpendicular to the first plane.
  • the optical signal a and the optical signal b are both optical signals returned by reflection or scattering of the finger above the fingerprint detection area, and carry fingerprint information. And it can be understood that the light intensity of the light signal in the direction perpendicular to the finger is larger, which is beneficial to improve the quality of the fingerprint image and improve the effect of fingerprint recognition.
  • the optical signal a After the optical signal a is received by the first prism film side surface 1211, after being refracted by the first prism film 121, it is emitted as the optical signal c.
  • the optical signal b After the optical signal b is received by the second prism film side surface 1212, after being refracted by the first prism film 121, the optical signal b is emitted as the optical signal d. Since ⁇ 1 ⁇ 2 , the incident angle of the optical signal a on the side surface 1211 of the first prism film is smaller than the incident angle of the optical signal b on the side surface of the second prism film. According to the law of refraction, the optical signal c is sandwiched between the vertical direction The angle is smaller than the angle between the optical signal d and the vertical direction.
  • the angle between the optical signal c and the vertical direction is also referred to as the exit angle of the optical signal c
  • the angle between the optical signal d and the vertical direction is also referred to as the angle of the optical signal d. Exit angle.
  • the optical signal a may be the fingerprint optical signal 101 in FIG. 7, and the optical signal c may be the first fingerprint optical signal 102 in FIG. 7.
  • FIG. 8 only uses the optical signal a and the optical signal b in the vertical direction for illustration.
  • the fingerprint optical signal 101 in the embodiment of the present application may also be the optical signal in other directions received by the side surface of the first prism film.
  • the application embodiment does not specifically limit the direction of the fingerprint light signal received by the side of the first prism film, and it may include the fingerprint light signal in any direction.
  • the fingerprint recognition module is set directly below the fingerprint detection area, as shown in Figure 9, the fingerprint image of the fingerprint recognition module also has dark areas. The image is divided into two.
  • the imaging area S 1 in the fingerprint recognition module is larger, while the light signal received by the side of the second prism film is refraction Later, the imaging area S 2 in the fingerprint recognition module is relatively small.
  • the fingerprint detection area 103 is arranged on the side of the field of view (FOV) of the fingerprint identification module 201, so that the fingerprint identification
  • the module 201 only receives the light signal refracted by the side of the first prism film, which can solve the problem of dark areas in the fingerprint image and realize the fingerprint recognition function under the liquid crystal display, and it can also make the fingerprint recognition module have a relatively large effective optical vision. Field, corresponding to a larger area of fingerprint detection area.
  • the smaller the ⁇ 1 is the larger the area of the side surface 1211 of the first prism film is, so that the fingerprint identification module has a larger effective optical field of view, and the fingerprint identification effect is better.
  • the smaller the ⁇ 1 is the greater the impact on the brightness of the LCD screen.
  • the value of the first bottom angle ⁇ 1 ranges from 30° to Between 45°, that is, 30° ⁇ 1 ⁇ 45°.
  • the angle between the first prism film side surface 1211 and the second prism film side surface 1212 can be referred to as the apex angle of the first prism film 121, and the apex angle of the first prism film 121 is ⁇ 1 .
  • the pitch (Pitch) between the ridges of two adjacent triangular prisms in the first prism film 121 is P 1.
  • the optical field of view of the fingerprint recognition module 201 may be the optical field of view of the optical component 300 in the fingerprint recognition module 201.
  • the field of view area of the fingerprint recognition module 201 This is the field of view area of the fingerprint identification module 201 in the liquid crystal display, and the field of view area may be larger than the fingerprint detection area 103 described above.
  • the fingerprint detection area 103 and the fingerprint identification module 201 are also The area where the field of view of the fingerprint identification module 201 overlaps is referred to as the effective optical field of view area of the fingerprint identification module 201, and the area under the fingerprint detection area 103 that overlaps the field of view of the fingerprint identification module 201 is referred to as the The effective optical field of view of the fingerprint recognition module 201.
  • FIG. 10 shows a cross-sectional view of the relative positional relationship between the optical field of view of the fingerprint identification module 201 and the fingerprint detection area.
  • the fingerprint identification module 201 is arranged at the bottom left of the fingerprint detection area 103, and the dotted line above the fingerprint identification module 201 represents its optical field of view, which is related to the structure of the optical components in the fingerprint identification module Related to optical parameters.
  • the optical field of view can form a circular field of view area on the liquid crystal panel 110, wherein the fingerprint detection area 103 is located on the right side of the circular field of view area, and the fingerprint light reflected or scattered by the finger above the fingerprint detection area 103
  • the signal is received by the fingerprint recognition module 201 after being refracted by the side of the first prism film in the first prism film 121.
  • the fingerprint light signal reflected or scattered by the finger above the fingerprint detection area 103 (for example, the optical signal 103 in FIG. 10) is refracted by the side surface of the second prism film in the first prism film 121 (for example, in FIG.
  • the optical signal 104) cannot be received by the fingerprint recognition module 201.
  • FIG. 11 shows a cross-sectional view of the relative positional relationship between the field of view of another fingerprint recognition module and the fingerprint detection area.
  • the fingerprint identification module 201 is arranged at the lower right of the fingerprint detection area 103, where the fingerprint detection area 103 is located on the left side of the optical field of view of the fingerprint identification module 201, and the fingerprint detection area 103 is reflected or scattered by the finger.
  • the fingerprint light signal of the first prism film 121 is refracted by the second prism film side surface and then received by the fingerprint recognition module.
  • the fingerprint optical signal reflected or scattered by the finger above the fingerprint detection area 103 (for example, the optical signal 101 in FIG. 11) is refracted by the side surface of the first prism film in the first prism film 121 (for example, in FIG.
  • the optical signal 102) cannot be received by the fingerprint recognition module.
  • the fingerprint detection area 103 in FIG. 11 has a smaller area than the fingerprint detection area 103 in FIG. 10. If the fingerprint identification module is performed according to FIG. 11 Set, the fingerprint recognition module only receives the light signal refracted from the side of the second prism film in the first prism film. Although the dark area problem can also be solved, the effective optical field of view of the fingerprint recognition module is relatively small at this time, and only It can correspond to a small fingerprint detection area, and the fingerprint recognition effect is not good.
  • the fingerprint identification module 201 is arranged obliquely below the fingerprint detection area 103, rather than directly below, so that the fingerprint identification module 201 only receives the larger area of the first prism film side refracted. Instead of receiving the light signal refracted by the side of the second prism film with a smaller area, the effective field of view of the fingerprint recognition module is improved, and fingerprint recognition is performed on the finger above the fingerprint detection area with a larger area.
  • the side surface of the first prism film can receive more light signals and the light intensity is larger, which improves the effective field of view of the fingerprint recognition module. It also helps to improve the quality of fingerprint images.
  • the structure of the first prism film 121 and the position of the fingerprint recognition module 201 are described above with reference to FIGS. 7 to 11 when only one first prism film 121 is included in the backlight module.
  • the backlight module may also include two prism films, that is, two prism films in different directions as shown in FIG. 2.
  • the included angle of the projection of the ridges of the two prism films on the first plane is ⁇ , 70° ⁇ 90°, wherein the ridges of the prism film may be the ridges of any triangular prism in the prism film .
  • the distance between the two prism films may be less than 1 ⁇ m or any other value, which is not limited in the embodiment of the present application.
  • other optical film layers in the backlight module may be provided between the two prism films, and other film layers may not be provided between the two prism films. Nor does it make specific restrictions.
  • one of the two prism films may have the same structure as the improved first prism film 121, and the other prism film may be the original prism film 1200 without improvement.
  • An example of the second prism film has the same structure.
  • FIG. 12 shows a schematic diagram of the three-dimensional structure of two prism films in the backlight module in this case.
  • Fig. 13 shows a schematic cross-sectional view of the perspective view of Fig. 12 in the XZ plane.
  • the upper prism film is the aforementioned first prism film 121
  • the lower prism film is the aforementioned prism film 1200.
  • the prism film 1200 may also be located above the first prism film 121.
  • the fingerprint recognition module is arranged below the fingerprint detection area, the fingerprint light signal passing through the first prism film 121 is refracted into two parts, and the fingerprint light signal passing through the first prism film 121 is refracted into two parts.
  • the fingerprint image area formed by the first fingerprint light signal refracted by the side surface of the first prism film 121 is larger than the fingerprint image area formed by the second fingerprint light signal refracted by the side surface of the second prism film in the first prism film 121.
  • the fingerprint image After being refracted by the first prism film 121, as shown in FIG. 15, the fingerprint image is divided into two in the Y direction to form two left and right parts, and the areas of the two parts are not equal.
  • the optical signal refracted by the first prism film 121 passes through the two prism film sides of the prism film 1200 again and is refracted into two parts.
  • the fingerprint image is again divided into two in the X direction to form four parts.
  • the fingerprint recognition module is arranged below the fingerprint detection area, it is similar to the above situation.
  • the fingerprint image is divided in the X direction. It is two, and is equally divided into left and right parts.
  • the light signal refracted by the prism film 1200 again passes through the two prism film sides of the first prism film 121 and is refracted into two parts.
  • the fingerprint image is again divided into two in the Y direction, and is divided into four parts with different areas. section.
  • the fingerprint image is divided into 2 larger areas and 2 smaller areas, where the two larger areas correspond to the first prism in the first prism film.
  • the fingerprint recognition module In order to improve the effective field of view of the fingerprint recognition module while removing the dark areas of the image, it is necessary to move the fingerprint recognition module, and the fingerprint recognition module can receive one of the side surfaces of the first prism film and the prism film. The light signal refracted by the side of the prism film. At this time, the fingerprint detection area is located at a corner of the field of view of the fingerprint recognition module.
  • the backlight module when the backlight module has only one first prism film, move the fingerprint recognition module from directly below the fingerprint detection area to one side, and it can translate along the X direction of the plane where it is located. .
  • the fingerprint identification module in addition to the translation of the fingerprint identification module in the X direction from directly below the fingerprint detection area, the fingerprint identification module needs to be translated in the Y direction. After the movement, the fingerprint detection area is located in the fingerprint identification module. A corner of the field of view of the group, where the X direction and the Y direction are directions perpendicular to each other in the same plane.
  • FIG. 17 shows a top view of the optical field of view area and fingerprint detection area of the fingerprint recognition module in the liquid crystal display when the backlight module includes only one first prism film 121.
  • FIG. 18 shows a top view of the optical field of view area and fingerprint detection area of the fingerprint recognition module in the liquid crystal display when the backlight module includes the first prism film 121 and the original prism film 1200.
  • the circular dashed line indicates the optical field of view of the fingerprint recognition module in the liquid crystal display. Comparing Figures 17 and 18, it can be seen that compared to the backlight module with only one first prism film In the case that the backlight module has the first prism film and the original prism film, the area of the fingerprint detection area 103 is reduced by half. In other words, the effective field of view of the fingerprint recognition module is also reduced by half.
  • the brightness of the liquid crystal display is also improved compared to the case of a prism film.
  • both of the two prism films may be improved prism films.
  • both of the two prism films may have the same structure as the improved first prism film 121 described above, that is, the two prism films have the same structure.
  • one of the two prism films may have the same structure as the improved first prism film 121, and the other may also be an improved prism film, that is, the side areas of the two prism films of the prism film. Not equal, but the structure of the prism film is different from the structure of the first prism film described above.
  • one prism film in the backlight module is the first prism film 121 described above, and the other prism film is called the second prism film 122.
  • the second prism film 122 is arranged in parallel below the first prism film 121.
  • the second prism film 122 of the embodiment of the present application is also a prism film structure, which is also formed by arranging a plurality of triangular prisms on a substrate.
  • the second prism film 122 can also be understood as an improved form after the above-mentioned prism film 1200 is improved. ⁇ prism film structure.
  • FIG. 19 is a schematic structural diagram of another fingerprint identification device 200 provided by an embodiment of the present application, which is suitable for electronic equipment with a liquid crystal display, and is used to set under the backlight module of the liquid crystal display for under-screen fingerprint recognition ,
  • the backlight module includes a first prism film and a second prism film, and both the first prism film and the second prism film face the liquid crystal panel of the liquid crystal display.
  • the fingerprint identification device 200 includes:
  • the fingerprint recognition module 201 is located obliquely below the fingerprint detection area 103 in the liquid crystal display 10, and is used to receive a first fingerprint light signal, which is used for fingerprint recognition, wherein the first fingerprint light signal
  • the signal is the optical signal after the fingerprint light signal passes through one of the prism film side surfaces of the first prism film 121 and one of the prism film side surfaces of the second prism film 122, and the fingerprint light signal is reflected by the finger above the fingerprint detection area or Scattered and returned light signal;
  • the two bottom angles in the first prism film 121 are not equal to each other, and the two bottom angles in the second prism film 122 are not equal to each other.
  • the two bottom angles in the first prism film 121 are the two bottom angles in the first prism film 121.
  • the angle between the side surface of the prism film and the plane where the liquid crystal display screen 10 is located, and the two bottom angles in the second prism film 122 are the angles between the two side surfaces of the prism film in the second prism film 122 and the plane where the liquid crystal display screen 10 is located.
  • FIG. 20 shows an enlarged schematic cross-sectional view of the second prism film 122.
  • the base of the second prism film 122 is below, and the third prism film side surface 1221 and the fourth prism film side surface 1222 protrude toward the upper side of the base.
  • the third prism film side surface 1221 and the fourth prism film side surface 1221 All 1222 face the liquid crystal panel 110 of the liquid crystal display, and the base of the second prism film 122 is parallel to the plane where the liquid crystal panel 110 is located.
  • the first side surfaces of the multiple triangular prisms in the second prism film 122 are all referred to as the third prism film side surface 1221
  • the second side surfaces of the multiple triangular prisms are all referred to as the fourth prism film side surface 1222.
  • the angle between the third prism film side surface 1221 and its base that is, the angle between the third prism film side surface 1221 and the first plane is the third base angle ⁇ 1
  • the angle between the fourth prism film side surface 1222 and its base That is, the angle between the fourth prism film side surface 1222 and the first plane is the fourth base angle ⁇ 2 , ⁇ 1 ⁇ ⁇ 2
  • the area of the third prism film side surface 1221 and the area of the fourth prism film side surface 1222 are not equal.
  • ⁇ 1 ⁇ 2 correspondingly, the area of the third prism film side surface 1221 in the second prism film 122 is larger than the area of the fourth prism film side surface 1222.
  • ⁇ 1 is smaller in the embodiment of the present application, the greater the area of the third side surface of the prism film 1221, so that the fingerprint module may have a greater effective optical field of view, a better effect fingerprint recognition.
  • ⁇ 1 is, the greater the brightness of the liquid crystal display panel, in order to balance the effect of the fingerprint recognition luminance liquid crystal display panel, further, in some embodiments, the range of the third base angle ⁇ 1 at 30 ° to 45°, that is, 30° ⁇ 1 ⁇ 45°.
  • ⁇ 1 ⁇ 1 .
  • the angle between the third prism film side surface 1221 and the fourth prism film side surface 1222 can be referred to as the apex angle of the second prism film 122, and the apex angle of the second prism film 122 is ⁇ 2 .
  • the apex angle of the second prism film 122 is ⁇ 2 .
  • ⁇ 1 ⁇ 2 .
  • the brightness of the liquid crystal display screen can be maximized while realizing fingerprint recognition.
  • the pitch (Pitch) between the ridges of two adjacent triangular prisms in the second prism film 122 is P 2.
  • the value range of P 1 may be between 15 ⁇ m and 40 ⁇ m.
  • P 2 and P 1 may not be equal.
  • the embodiment of the present application does not specifically limit the pitch values of the two prism films.
  • the second prism film 122 is arranged below the first prism film 121, a part of the second prism film 122 receives the light signal refracted by the first prism film side surface 1211 in the first prism film 121, such as the above The optical signal c, and another partial area receives the optical signal refracted by the second prism film side surface 1212 of the first prism film 121, such as the above-mentioned optical signal d.
  • the third prism film side surface 1221 on the second prism film 122 receives the optical signal c 1
  • the fourth prism film side surface 1222 receives the optical signal c 2.
  • the optical signal c 1 and the optical signal c 2 both pass through the first prism The light signal refracted by the first prism film side surface 1211 in the film 121.
  • the optical signal c 1 is received by the third prism film side surface 1221, after being refracted by the second prism film 122, it is emitted as the optical signal e.
  • the optical signal c 2 is received by the side surface 1222 of the fourth prism film, and after being refracted by the second prism film 122, it is emitted as the optical signal f. Since ⁇ 1 ⁇ 2 , the incident angle of the optical signal c 1 on the side surface of the third prism film 1221 is smaller than the incident angle of the optical signal c 2 on the side surface of the second prism film. According to the law of refraction, the optical signal e and the vertical direction The included angle is smaller than the included angle between the optical signal f and the vertical direction.
  • the optical signal e in FIG. 20 may be the first fingerprint optical signal 102 in FIG. 7, which is received by the fingerprint identification module 201 for fingerprint identification.
  • the optical signal f in FIG. 20 may also be the first fingerprint optical signal 102 in FIG. 7, which is received by the fingerprint identification module 201 for fingerprint identification.
  • the first fingerprint optical signal is the optical signal after the fingerprint optical signal passes through one of the first prism film side surface 1211 and the second prism film 122 of the first prism film 121.
  • the position of the fingerprint identification module 201 is such that it cannot receive the fingerprint light signal after passing through the second prism film side surface 1212 of the first prism film 121 and the other prism film side surface of the second prism film 122.
  • FIG. 20 only uses the optical signals c 1 and c 2 in the vertical direction for illustration.
  • the embodiment of the present application does not specifically limit the direction of the fingerprint optical signal received by the side surface of the third prism film, which may include any Direction of the fingerprint light signal.
  • the light signal received by the side of the third prism film is refracted by the second prism film, and the angle of the emitted light signal is smaller, while the fourth prism film After the light signal received on the side is refracted by the second prism film, the angle of the emitted light signal is relatively large. If the fingerprint identification module is arranged directly below the fingerprint detection area, on the basis of the fingerprint image in FIG. 9, the fingerprint image is divided into four again to form the fingerprint image in FIG. 21.
  • S 1 corresponds to the optical signal after refraction through the first prism film side surface 1211 and the third prism film side surface 1221
  • S 2 corresponds to the optical signal after refraction through the second prism film side surface 1212 and the third prism film side surface 1221
  • S 3 corresponding to the side surface through the first prism film 1211 and the fourth prism film side of the light refracted signals 1222
  • S 4 corresponding to the optical signal through the second refractive prism film 1212 and the fourth side surface of the prism film 1222 side.
  • the fingerprint detection area is set at a corner of the optical field of view of the fingerprint recognition module, so that the fingerprint recognition module only receives the side surface of the first prism film and the third prism
  • the light signal refracted by the side of the film (corresponding to S 1 in Figure 20), but the light signal refracted by the side of other prism films is not received, which can solve the problem of dark areas in the fingerprint image and realize fingerprint recognition under the LCD screen.
  • the function can also make the fingerprint identification module have a relatively large effective optical field of view, corresponding to a larger fingerprint detection area.
  • FIG. 22 shows a top view of the optical field of view area and fingerprint detection area of the fingerprint recognition module when the backlight module includes the first prism film 121 and the second prism film 121.
  • the circular dashed line indicates the optical field of view of the fingerprint recognition module in the liquid crystal panel. It can be seen from the comparison of FIG. 18 and FIG. 22 that compared with the backlight module including the first prism film 121 and the original prism film 1200 In other words, when the backlight module includes the first prism film 121 and the second prism film 122, the area of the fingerprint detection area 103 is increased. In other words, the effective field of view of the fingerprint recognition module is also increased.
  • sampling the embodiments of this application while taking into account the brightness of the liquid crystal display, it can further increase the effective field of view of the fingerprint recognition module and increase the area of the fingerprint detection area 103, thereby collecting fingerprint images of a larger area. Improve the fingerprint recognition performance under the LCD screen.
  • the embodiment of the present application also provides a backlight module, which is suitable for electronic equipment with a liquid crystal display, and the liquid crystal display includes a backlight module 120;
  • the backlight module 120 includes a first prism film 121 and a second prism film 122, and both the first prism film 121 and the second prism film 122 face the liquid crystal panel of the liquid crystal display;
  • the two bottom angles in the first prism film 121 are not equal to each other, and the two bottom angles in the second prism film 122 are not equal to each other.
  • the two bottom angles in the first prism film 121 are the two bottom angles in the first prism film 121.
  • the angle between the side surface of the prism film and the plane where the liquid crystal display is located, and the two bottom angles of the second prism film 122 are the angles between the two side surfaces of the prism film and the plane where the liquid crystal display is located.
  • the fingerprint optical signal forms a first fingerprint optical signal after passing through one of the prism film side surfaces of the first prism film 121 and one of the prism film side surfaces of the second prism film 122, and the first fingerprint optical signal is used to perform Fingerprint recognition, the fingerprint light signal is the light signal returned by the reflection or scattering of the finger above the fingerprint detection area.
  • the first base angle ⁇ 1 in the first prism film 121 is smaller than the second base angle ⁇ 2 , 30° ⁇ 1 ⁇ 45°, and the first base angle is the side surface of the first prism film in the first prism film 121 The included angle between 1211 and the plane where the liquid crystal display is located, and the second bottom angle is the included angle between the second prism film side surface 1212 of the first prism film 121 and the plane where the liquid crystal display is located.
  • the first fingerprint optical signal is the optical signal after the fingerprint optical signal passes through one of the first prism film side surface 1211 and the second prism film side surface 122.
  • the third bottom angle ⁇ 1 in the second prism film 122 is smaller than the fourth bottom angle ⁇ 2 , 30° ⁇ 1 ⁇ 45°, and the third bottom angle is the side surface 1221 of the third prism film in the second prism film 122 The included angle with the plane where the liquid crystal display is located, and the fourth bottom angle is the included angle between the side surface 1222 of the fourth prism film in the second prism film 122 and the plane where the liquid crystal display is located.
  • the first fingerprint optical signal is the optical signal after the fingerprint optical signal passes through the first prism film side surface 1211 and the third prism film side surface 1221.
  • the included angle between the two prism film side surfaces in the first prism film 121 is the apex angle ⁇ 1 of the first prism film 121
  • the included angle between the two prism film side surfaces in the second prism film 122 is the second prism film 122
  • the apex angle ⁇ 2 70° ⁇ 1 ⁇ 110°, 70° ⁇ 2 ⁇ 110°.
  • the structures of the first prism film 121 and the second prism film 122 are the same.
  • the angle between the projection of the ridge of a prism in the second prism film 122 and the ridge of a prism in the first prism film 121 on the first plane is ⁇ , 70° ⁇ 90°, wherein A plane is a plane parallel to the liquid crystal display screen.
  • Using the backlight module of the embodiment of the present application can realize the fingerprint recognition function of the large field of view under the liquid crystal display while ensuring the brightness of the liquid crystal display.
  • an embodiment of the present application also provides an electronic device 2.
  • the electronic device 2 may include the above-mentioned liquid crystal display 10 and the fingerprint identification device 200 of the above-mentioned application embodiment, wherein the liquid crystal display 10 includes the above-mentioned In the backlight module 120 in the application embodiment, the fingerprint identification device 200 is disposed under the backlight module 120.
  • the electronic device 2 can be any electronic device with a liquid crystal display screen and a backlight module.
  • the electronic device 2 may also include an infrared light source 30.
  • the infrared light source 30 may be arranged under the glass cover 130 of the electronic device, and arranged side by side with the liquid crystal panel of the liquid crystal display.
  • the infrared light source 30 is arranged under the glass cover 130 of the electronic device 2, and is arranged side by side with the liquid crystal panel 110 of the liquid crystal display screen 10, and is arranged on the liquid crystal display screen. 10 diagonally above the backlight module 120.
  • the backlight module 120 includes a first prism film 121 and/or a second prism film 122, and other structures 124 of the backlight module.
  • the infrared light source 30 is arranged under the glass cover 130 of the electronic device 2 and arranged side by side with the liquid crystal panel 110 and the backlight module 120 in the liquid crystal display 10.
  • the infrared light source 30 can be obliquely attached below the glass cover 130.
  • the infrared light source 30 can be obliquely attached to the bottom of the display screen 10 through optical glue.
  • the optical glue may be any kind of optical liquid glue or optical solid glue.
  • an infrared light transmitting layer 301 may be provided between the infrared light source 30 and the glass cover plate, and/or between the infrared light source 30 and the liquid crystal display screen 10, and the infrared light transmitting layer 301 may be provided between the infrared light source 30 and the glass cover plate.
  • the over layer 301 is used to transmit the infrared excitation light and block visible light.
  • the infrared light transmission layer 301 may be an infrared transmission ink.
  • a light-blocking foam 302 may be provided between the infrared light source 30 and the liquid crystal panel 110 in the liquid crystal display 10 to block visible light.
  • the infrared light source 30 may be arranged in a non-display area at the edge of the electronic device 2.
  • the electronic device 2 is a mobile phone
  • the non-display area is the mobile phone frame area where the image is not displayed on the surface of the mobile phone.
  • the infrared light source 30 is arranged in the lower area corresponding to the mobile phone frame area where the image is not displayed.
  • the infrared light source 30 may be a single or multiple light-emitting diodes (Light-Emitting Diode, LED).
  • a plurality of infrared light-emitting diodes may form a band-shaped infrared light-emitting source, which is distributed around the fingerprint detection area 103.
  • the present application by using an infrared light source to generate the first fingerprint infrared light signal, and performing optical fingerprint detection based on the first fingerprint infrared light signal, it is possible to reduce the interference of the screen visible light on the infrared light fingerprint detection, and to balance the infrared light fingerprint
  • the optical illuminance of the image further improves the quality of fingerprint imaging.
  • the disclosed system, device, and method may be implemented in other ways.
  • 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.
  • 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 be in electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, 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.
  • 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 function 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.
  • the technical solution of the present application essentially or the part that contributes to the existing technology or the 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, including Several instructions are used 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 (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disks or optical disks and other media that can store program codes. .

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Abstract

一种指纹识别装置（20、200）、背光模组（120）、显示屏（10）和电子设备（1、2），能够提升LCD屏下光学指纹识别性能。指纹识别装置（20、200）用于设置在液晶显示屏（10）的背光模组（120）下方以进行屏下指纹识别，背光模组（120）包括第一棱镜膜（121）和第二棱镜膜（122），第一棱镜膜（121）和第二棱镜膜（122）均朝向液晶显示屏（10）的液晶面板（110），指纹识别装置（20、200）包括：指纹识别模组（201），位于在液晶显示屏（10）中指纹检测区域（103）的斜下方，用于接收第一指纹光信号（102），第一指纹光信号（102）用于进行指纹识别，其中，第一指纹光信号（102）为指纹光信号（101）经过第一棱镜膜（121）中其中一个棱镜膜侧面（1211）和第二棱镜膜（122）中其中一个棱镜膜侧面（1221）后的光信号，指纹光信号（101）为经指纹检测区域（103）上方的手指（140）反射或散射而返回的光信号；第一棱镜膜（121）中的两个底角（α 1、α 2）互不相等，且第二棱镜膜（122）中两个底角（β 1、β 2）互不相等。

Description

指纹识别装置、背光模组、液晶显示屏和电子设备
本申请要求以下申请的优先权，其全部内容通过应用结合在本申请中：2019年9月20日提交美国专利局、申请号为62/903,672、发明名称为“UNDER-DISPLAY OPTICAL SENSOR WITH COMPENSATED LIGHT PATHS AND COMPENSATION PARTS OPTIMIZATION”的临时申请。
技术领域
本申请涉及光学指纹技术领域，并且更具体地，涉及一种指纹识别装置、背光模组、液晶显示屏和电子设备。
背景技术
随着生物识别技术的发展，屏下指纹识别技术在手机等便携式终端的应用越来越广泛。目前，液晶显示(Liquid Crystal Display，LCD)屏等被动式显示屏幕通过背光模组提供光源，背光模组中各种膜层结构会对屏下指纹识别装置的指纹光学成像有严重干扰，导致基于LCD显示屏的屏下指纹识别技术的商用受阻。
因此，如何提升LCD屏下光学指纹识别性能是本领域急需解决的技术难题。
发明内容
本申请实施例提供了一种指纹识别装置、背光模组、液晶显示屏和电子设备，能够提升LCD屏下光学指纹识别性能。
第一方面，提供了一种指纹识别装置，用于设置在液晶显示屏的背光模组下方以进行屏下指纹识别，该背光模组包括第一棱镜膜和第二棱镜膜，该第一棱镜膜和该第二棱镜膜均朝向该液晶显示屏的液晶面板，该指纹识别装置包括：指纹识别模组，位于在该液晶显示屏中指纹检测区域的斜下方，用于接收第一指纹光信号，该第一指纹光信号用于进行指纹识别，其中，该第一指纹光信号为指纹光信号经过该第一棱镜膜中其中一个棱镜膜侧面和该第二棱镜膜中其中一个棱镜膜侧面后的光信号，该指纹光信号为经该指纹检测区域上方的手指反射或散射而返回的光信号；该第一棱镜膜中的两个底角 互不相等，且该第二棱镜膜中两个底角互不相等，该第一棱镜膜中的两个底角为该第一棱镜膜中两个棱镜膜侧面与该液晶显示屏所在的平面的夹角，该第二棱镜膜中的两个底角为该第二棱镜膜中两个棱镜膜侧面与该液晶显示屏所在的平面的夹角。
通过本申请实施例的方案，将液晶显示屏的背光模组中的棱镜膜改进为第一棱镜膜和第二棱镜膜，该第一棱镜膜的两个底角和第二棱镜膜的两个底角不同，对应的两个棱镜膜侧面的面积也不同，将指纹识别模组设置在液晶显示屏中的指纹检测区域的斜下方，而不是正下方，旨在使得指纹识别模组仅接收第一棱镜膜中的一个棱镜膜侧面和第二棱镜膜中一个棱镜膜侧面折射的光信号，实现液晶显示屏下的指纹识别。
在一种可能的实现方式中，该第一棱镜膜中的第一底角α 1小于第二底角α 2，30°≤α 1<45°，该第一底角为该第一棱镜膜中第一棱镜膜侧面与该液晶显示屏所在的平面的夹角，该第二底角为该第一棱镜膜中第二棱镜膜侧面与该液晶显示屏所在的平面的夹角。
在一种可能的实现方式中，该第一指纹光信号为该指纹光信号经过该第一棱镜膜侧面和该第二棱镜膜中其中一个棱镜膜侧面后的光信号。
在一种可能的实现方式中，该指纹识别模组的位置使得其接收不到该指纹光信号经过该第二棱镜膜侧面和该第二棱镜膜中另一个棱镜膜侧面后的光信号。
在一种可能的实现方式中，该第二棱镜膜中的第三底角β 1小于第四底角β 2，30°≤β 1<45°，该第三底角为该第二棱镜膜中第三棱镜膜侧面与该液晶显示屏所在的平面的夹角，该第四底角为该第二棱镜膜中第四棱镜膜侧面与该液晶显示屏所在的平面的夹角。
在一种可能的实现方式中，该第一指纹光信号为该指纹光信号经过该第一棱镜膜侧面和该第三棱镜膜侧面后的光信号。
在一种可能的实现方式中，该指纹识别模组的位置使得其接收不到该指纹光信号经过该第一棱镜膜侧面和该第四棱镜膜后的光信号。
在一种可能的实现方式中，该第一棱镜膜中两个棱镜膜侧面的夹角为该第一棱镜膜的顶角γ 1，该第二棱镜膜中两个棱镜膜侧面的夹角为该第二棱镜膜的顶角γ 2，70°＜γ 1＜110°，70°＜γ 2＜110°。
在一种可能的实现方式中，γ 1＝γ 2＝90°。
在一种可能的实现方式中，该第一棱镜膜和该第二棱镜膜的结构相同。
在一种可能的实现方式中，该第二棱镜膜中一个棱镜的棱脊与该第一棱镜膜中一个棱镜的棱脊在第一平面的投影的夹角为θ，70°≤θ≤90°，其中，该第一平面为平行于该液晶显示屏的平面。
在一种可能的实现方式中，该指纹识别模组包括：光学组件以及光检测阵列；该光学组件用于接收该第一指纹光信号，并将该第一指纹光信号至传输至该光检测阵列，该光检测阵列用于将该第一指纹光信号并转换为指纹图像信号，以进行指纹识别。
在一种可能的实现方式中，该光学组件包括至少一个光学透镜，该至少一个光学透镜为球面或者非球面透镜。
在一种可能的实现方式中，该光检测阵列包括至少一个光学指纹传感器。
第二方面，提供一种背光模组，适用于具有液晶显示屏的电子设备，包括：第一棱镜膜和第二棱镜膜，该第一棱镜膜和该第二棱镜膜均朝向该液晶显示屏的液晶面板；该第一棱镜膜中的两个底角互不相等，且该第二棱镜膜中两个底角互不相等，该第一棱镜膜中的两个底角为该第一棱镜膜中两个棱镜膜侧面与该液晶显示屏所在的平面的夹角，该第二棱镜膜中的两个底角为该第二棱镜膜中两个棱镜膜侧面与该液晶显示屏所在的平面的夹角。
在一种可能的实现方式中，指纹光信号经过该第一棱镜膜中其中一个棱镜膜侧面和该第二棱镜膜中其中一个棱镜膜侧面后形成第一指纹光信号，该第一指纹光信号用于进行指纹识别，该指纹光信号为经该指纹检测区域上方的手指反射或散射而返回的光信号。
通过本申请中的背光模组，对原始的背光模组进行改进，能够实现液晶显示屏下的指纹识别功能。
在一种可能的实现方式中，该第一棱镜膜中的第一底角α 1小于第二底角α 2，30°≤α 1<45°，该第一底角为该第一棱镜膜中第一棱镜膜侧面与该液晶显示屏所在的平面的夹角，该第二底角为该第一棱镜膜中第二棱镜膜侧面与该液晶显示屏所在的平面的夹角。
在一种可能的实现方式中，该第一指纹光信号为该指纹光信号经过该第一棱镜膜侧面和该第二棱镜膜中其中一个棱镜膜侧面后的光信号。
在一种可能的实现方式中，该第二棱镜膜中的第三底角β 1小于第四底角 β 2，30°≤β 1<45°，该第三底角为该第二棱镜膜中第三棱镜膜侧面与该液晶显示屏所在的平面的夹角，该第四底角为该第二棱镜膜中第四棱镜膜侧面与该液晶显示屏所在的平面的夹角。
在一种可能的实现方式中，该第一指纹光信号为该指纹光信号经过该第一棱镜膜侧面和该第三棱镜膜侧面后的光信号。
在一种可能的实现方式中，该第一棱镜膜中两个棱镜膜侧面的夹角为该第一棱镜膜的顶角γ 1，该第二棱镜膜中两个棱镜膜侧面的夹角为该第二棱镜膜的顶角γ 2，70°＜γ 1＜110°，70°＜γ 2＜110°。
在一种可能的实现方式中，γ 1＝γ 2＝90°。
在一种可能的实现方式中，该第一棱镜膜和该第二棱镜膜的结构相同。
在一种可能的实现方式中，该第二棱镜膜中一个棱镜的棱脊与该第一棱镜膜中一个棱镜的棱脊在第一平面的投影的夹角为θ，70°≤θ≤90°，其中，该第一平面为平行于该液晶显示屏的平面。
第三方面，提供一种电子设备，包括：液晶显示屏以及，根据第一方面以及第一方面中任一可能实现的方式中的指纹识别装置，其中，该液晶显示屏包括背光模组，该指纹识别模组设置于该背光模组下方。
在一种可能的实现方式中，该电子设备还包括：红外光源，用于为该指纹识别模组的指纹检测提供红外激励光，该红外激励光照射到该液晶显示屏的至少部分显示区域，该至少部分显示区域至少部分覆盖该指纹识别模组的指纹检测区域；其中，该第一指纹光信号包括该红外光源的红外激励光经过手指反射后经过该背光模组的第一指纹红外光信号。
在本实现方式中，通过采用红外光源产生第一指纹红外光信号，并基于该第一指纹红外光信号进行光学指纹检测，能够减少屏幕可见光对于红外光指纹检测的干扰，且均衡红外光指纹图像的光学照度，进一步提高指纹成像的质量。
在一种可能的实现方式中，该红外光源为单颗或者多颗红外发光二极管；该单颗或多颗红外发光二极管分布在该指纹检测区域的四周。
在一种可能的实现方式中，该红外光源设置在该液晶显示屏的玻璃盖板的下方，且与该液晶显示屏的液晶面板并排设置。
在一种可能的实现方式中，该红外光源斜贴在该玻璃盖板的下方。
在一种可能的实现方式中，该电子设备还包括：红外光透过层，设置于 该红外光源与该玻璃盖板之间和/或该红外光源与该液晶显示屏之间，用于透过该红外激励光且阻挡可见光。
第四方面，提供一种液晶显示屏，包括：第二方面或者第二方面中任一可能实现方式中的背光模组。
第五方面，提供一种电子设备，包括：第四方面的液晶显示屏。
采用本申请的方案，该电子设备能够实现液晶显示屏下的大视场的指纹识别功能。
附图说明
图1是本申请实施例所适用的电子设备的结构示意图。
图2是根据本申请实施例的背光模组的立体结构示意图。
图3是根据本申请实施例的棱镜膜的结构示意图。
图4是根据本申请实施例的一种液晶显示屏下指纹识别装置进行指纹识别时的光路示意图。
图5是根据本申请实施例的一种指纹图像示意图。
图6是根据本申请实施例的另一指纹图像示意图。
图7是根据本申请实施例的一种指纹识别装置的示意性结构图。
图8是根据本申请实施例的一种放大后的第一棱镜膜的截面示意图。
图9是根据本申请实施例的另一指纹图像示意图。
图10是根据本申请实施例的一种指纹识别模组的光学视场和指纹检测区域的相对位置关系的截面图。
图11是根据本申请实施例的另一指纹识别模组的光学视场和指纹检测区域的相对位置关系的截面图。
图12是根据本申请实施例的背光模组中两个棱镜膜的立体结构示意图。
图13是图12在XZ平面中的截面示意图。
图14是根据本申请实施例的背光模组中两个棱镜膜的另一种截面示意图。
图15是根据本申请实施例的一种指纹图像示意图。
图16是根据本申请实施例的另一指纹图像示意图。
图17是根据本申请实施例的一种指纹识别模组在液晶显示屏中的光学视场区域与指纹检测区域俯视图。
图18是根据本申请实施例的另一指纹识别模组在液晶显示屏中的光学视场区域与指纹检测区域俯视图。
图19是根据本申请实施例的另一指纹识别装置的示意性结构图。
图20是根据本申请实施例的一种放大后的第二棱镜膜的截面示意图。
图21是根据本申请实施例的一种指纹图像示意图。
图22是根据本申请实施例的另一指纹识别模组在液晶显示屏中的光学视场区域与指纹检测区域俯视图。
图23是根据本申请实施例的一种电子设备的结构示意图。
具体实施方式
随着智能终端步入全面屏时代，电子设备正面指纹采集区域受到全面屏的挤压，因此屏下(Under-display或者Under-screen)指纹识别技术越来越受到关注。屏下指纹识别技术是指将指纹识别装置(比如指纹识别模组)安装在显示屏下方，从而实现在显示屏的显示区域内部进行指纹识别操作，不需要在电子设备正面除显示区域外的区域设置指纹采集区域。
屏下指纹识别技术可以包括屏下光学指纹识别技术、屏下超声波指纹识别技术或者其他类型的屏下指纹识别技术。
以屏下光学指纹识别技术为例，屏下光学指纹识别技术使用从设备显示组件的顶面返回的光来进行指纹感应和其他感应操作。该返回的光携带与顶面接触的物体(例如手指)的信息，通过捕获和检测该返回的光实现位于显示屏幕下方的特定光学传感器模块进行屏下光学指纹识别。该特定光学传感器模块的设计可以为通过恰当地配置用于捕获和检测返回的光的光学元件来实现期望的光学成像。
应理解，本申请实施例的技术方案可以应用于各种电子设备，更具体地，可以应用于具有显示屏的电子设备。例如智能手机、笔记本电脑、平板电脑、游戏设备等便携式或移动计算设备，以及电子数据库、汽车、银行自动柜员机(Automated Teller Machine，ATM)等其他电子设备，但本申请实施例对此并不限定。
还应理解，本申请实施例的技术方案除了可以进行指纹识别外，还可以进行其他生物特征识别，例如，活体识别，掌纹识别等，本申请实施例对此也不限定。
下面将结合附图，对本申请实施例中的技术方案进行描述。
需要说明的是，为便于说明，在本申请的实施例中，相同的附图标记表示相同的部件，并且为了简洁，在不同实施例中，省略对相同部件的详细说明。
应理解，附图示出的本申请实施例中的各种部件的厚度、长宽等尺寸，以及指纹识别装置的整体厚度、长宽等尺寸仅为示例性说明，而不应对本申请构成任何限定。
如图1所示为本申请实施例可以适用的电子设备的结构示意图，电子设备1包括显示屏10和指纹识别装置20，其中，指纹识别装置20设置在显示屏10下方的局部区域。
作为一种可选的实现方式，如图1所示，指纹识别装置20包括光学组件300和光检测阵列400，该光检测阵列400以及与该光检测阵列电性连接的读取电路及其他辅助电路，其可以在通过半导体工艺制作在一个芯片(De)比如光学成像芯片或者光学指纹传感器，该光检测阵列具体可以为光学指纹传感器上的光探测器(Photo detector)阵列，其包括多个呈阵列式分布的光探测器，该光探测器可以称为像素单元或者像素；该光学组件300可以设置在光检测阵列400的上方，可以具体包括导光层或光路引导结构以及其他光学元件，该导光层或光路引导结构主要用于从手指表面反射回来的反射光导引至感应阵列进行光学检测。光检测阵列400所在区域或者其感应区域为指纹识别装置20的指纹检测区域103。如图1所示，指纹检测区域103位于显示屏10的显示区域之中。
在一种替代实施例中，指纹识别装置20还可以设置在其他位置，比如显示屏10的侧面或者电子设备1的边缘非透光区域，并通过光路设计来将显示屏10的至少部分显示区域的光信号导引到指纹识别装置20，从而使得指纹检测区域103实际上位于显示屏10的显示区域。
应当理解，指纹检测区域103的面积可以与指纹识别装置20的光检测阵列400的面积不同，例如通过例如透镜成像的光路设计、反射式折叠光路设计或者其他光线汇聚或者反射等光路设计，可以使得指纹识别装置20的指纹检测区域103的面积大于光检测阵列400的面积。在其他替代实现方式中，如果采用例如光线准直方式进行光路引导，指纹识别装置20的指纹检测区域103也可以设计成与指纹识别装置20的感应阵列的面积基本一致。
因此，使用者在需要对电子设备进行解锁或者其他指纹验证的时候，只需要将手指按压在位于显示屏10的指纹检测区域103，便可以实现指纹输入。由于指纹检测可以在屏下实现，因此采用上述结构的电子设备1无需其正面专门预留空间来设置指纹按键(比如Home键)，从而可以采用全面屏方案，即显示屏10的显示区域可以基本扩展到整个电子设备1的正面。
在具体实现上，光学组件300可以与光检测阵列400封装在同一个光学指纹部件。比如，光学组件300可以与光检测阵列400封装在同一个光学指纹芯片，也可以将光学组件300设置在光检测阵列400所在的芯片外部，比如将光学组件300贴合在芯片上方，或者将光学组件300的部分元件集成在上述芯片之中。
其中，光学组件300的导光层或者光路引导结构有多种实现方案，比如，该导光层可以具体为在半导体硅片制作而成的准直器(Collimator)层，其具有多个准直单元或者微孔阵列，该准直单元可以具体为小孔，从手指反射回来的反射光中，垂直入射到该准直单元的光线可以穿过并被其下方的光学感应单元接收，而入射角度过大的光线在该准直单元内部经过多次反射被衰减掉，因此每一个光学感应单元基本只能接收到其正上方的指纹纹路反射回来的反射光，从而感应阵列便可以检测出手指的指纹图像。
在另一种实施例中，导光层或者光路引导结构也可以为光学透镜(Lens)层，其具有一个或多个透镜单元，比如一个或多个非球面透镜组成的透镜组，其用于将从手指反射回来的反射光汇聚到其下方的光检测部分134的感应阵列，以使得该感应阵列可以基于该反射光进行成像，从而得到该手指的指纹图像。可选地，该光学透镜层在该透镜单元的光路中还可以形成有针孔，该针孔可以配合该光学透镜层扩大光学指纹装置的视场，以提高指纹识别装置20的指纹成像效果。
在其他实施例中，导光层或者光路引导结构也可以具体采用微透镜(Micro-Lens)层，该微透镜层具有由多个微透镜形成的微透镜阵列，其可以通过半导体生长工艺或者其他工艺形成在光检测部分134的感应阵列上方，并且每一个微透镜可以分别对应于感应阵列的其中一个感应单元。并且，微透镜层和感应单元之间还可以形成其他光学膜层，比如介质层或者钝化层，更具体地，微透镜层和感应单元之间还可以包括具有微孔的挡光层，其中该微孔形成在其对应的微透镜和感应单元之间，挡光层可以阻挡相邻微透镜和 感应单元之间的光学干扰，并使得感应单元所对应的光线通过微透镜汇聚到微孔内部并经由该微孔传输到该感应单元以进行光学指纹成像。应当理解，上述光路引导结构的几种实现方案可以单独使用也可以结合使用，比如，可以在准直器层或者光学透镜层下方进一步设置微透镜层。当然，在准直器层或者光学透镜层与微透镜层结合使用时，其具体叠层结构或者光路可能需要按照实际需要进行调整。
应理解，在具体实现上，电子设备1还包括透明保护盖板130，该盖板可以为玻璃盖板或者蓝宝石盖板，其位于显示屏10的上方并覆盖电子设备1的正面。因为，本申请实施例中，所谓的手指按压在显示屏10实际上是指按压在显示屏10上方的盖板或者覆盖盖板的保护层表面。
还应理解，指纹识别装置20的下方还可以设置有电路板150。指纹识别装置20可以通过背胶粘接在该电路板150上，并通过焊盘及金属线焊接与该电路板150实现电性连接。指纹识别装置20可以通过电路板150实现与其他外围电路或者电子设备1的其他元件的电性互连和信号传输。比如，指纹识别装置20可以通过电路板150接收电子设备1的处理单元的控制信号，并且还可以通过电路板150将来自指纹识别装置20的指纹图像信号输出给电子设备1的处理单元或者控制单元等。
另一方面，在某些实施例中，指纹识别装置20可以仅包括一个光学指纹传感器，此时指纹识别装置20的指纹检测区域103的面积较小且位置固定，因此用户在进行指纹输入时需要将手指按压到指纹检测区域103的特定位置，否则指纹识别装置20可能无法采集到指纹图像而造成用户体验不佳。在其他替代实施例中，指纹识别装置20可以具体包括多个光学指纹传感器；该多个光学指纹传感器可以通过拼接方式并排设置在显示屏120的下方，且该多个光学指纹传感器的感应区域共同构成指纹识别装置20的指纹检测区域103。也即是说，指纹识别装置20的指纹检测区域103可以包括多个子区域，每个子区域分别对应于其中一个光学指纹传感器的感应区域，从而将指纹识别装置20的指纹采集区域103可以扩展到显示屏的下半部分的主要区域，即扩展到手指惯常按压区域，从而实现盲按式指纹输入操作。可替代地，当光学指纹传感器数量足够时，指纹检测区域103还可以扩展到半个显示区域甚至整个显示区域，从而实现半屏或者全屏指纹检测。
需要说明的是，本申请实施例中的光学指纹装置也可以称为光学指纹识 别模组、指纹识别装置、指纹识别模组、指纹模组、指纹采集装置等，上述术语可相互替换。
需要注意的是，显示屏10为具有自发光显示单元的显示屏时，比如有机发光二极管(Organic Light Emitting Diode，OLED)显示屏或者微型发光二极管(Micro-LED)显示屏。以采用OLED显示屏为例，指纹识别装置20可以利用OLED显示屏10位于指纹检测区域103的显示单元(即OLED光源)来作为光学指纹检测的激励光源。显示屏10向指纹检测区域103上方的目标手指140发出一束光，该光在手指140的表面发生反射形成反射光或者经过手指140内部散射而形成散射光，在相关专利申请中，为便于描述，上述反射光和散射光统称为反射光。由于指纹的脊(ridge)与谷(valley)对于光的反射能力不同，因此，来自指纹脊的反射光和来自指纹谷的反射光具有不同的光强，反射光经过光学组件300后，被指纹识别装置20中的光检测阵列400所接收并转换为相应的电信号，即指纹图像信号；基于指纹图像信号便可以获得指纹图像数据，并且可以进一步进行指纹匹配验证，从而在电子设备1实现光学指纹识别功能。
而当显示屏10为不具有自发光显示单元的显示屏时，比如液晶显示屏或者其他的被动发光显示屏，需要采用背光模组作为显示屏10的光源。以应用在具有背光模组和液晶面板的液晶显示屏为例，为支持液晶显示屏的屏下指纹识别，如图1所示，显示屏10包括液晶面板110和背光模组120，该背光模组120用于向液晶面板110发出光信号，该液晶面板110包括液晶层以及控制电路，用于控制液晶的偏转以透过光信号。
可选地，本申请实施例中，该电子设备1还可以包括用于光学指纹检测的激励光源160，指纹识别装置20设置在背光模组120下方，当手指140按压在指纹检测区域103时，激励光源160向指纹检测区域103上方的目标手指140发出激励光111，该激励光111在手指140的表面发生反射形成指纹脊的第一反射光151和指纹谷的第二反射光152，第一反射光151和第二反射光152需经过液晶面板110和背光模组120后，再经过光学组件300后，被指纹识别装置20中的光检测阵列400所接收并转换为指纹图像信号。可选地，在一些实施方式中，该激励光源为红外光源，不会影响液晶显示屏的正常显示，并基于红外光信号进行指纹识别，去除环境光的干扰，提高指纹识别的效果。
但在此过程中，背光模组120中的膜层结构，尤其是棱镜膜，会对指纹识别装置20的成像造成较大干扰。
为了便于理解，首先结合图2对液晶显示屏中的背光模组120进行一个简单的说明。
如图2所示，背光模组120包括光源(Light Source)、导光板(Light Guide Plate)、扩散片(Diffuser)、棱镜膜(Brightness Enhancement Film，BEF)、反射板(Reflector)等，其中，光源的光信号从侧面进入导光板，经导光板的散射转化为均匀分布的面光源，然后经过下扩散片的均光作用入射至棱镜膜。由于棱镜膜的聚光作用，符合某种角度的光线被射出，不符合的光线再次被反射值导光板和扩散板中，经过导光板和扩散板的作用后，重新被棱镜膜接收，并以符合角度要求的光线射出。
一般而言，在背光模组中，通常设置有两个棱镜膜，即图2中所述的垂直方向的棱镜膜以及水平方向的棱镜膜，该两个棱镜膜的结构相同，但棱镜膜的棱脊的方向不同，两个棱镜膜的棱脊在同一平面上的投影的夹角呈90°，该平面为平行于显示屏中液晶面板的平面。该两个棱镜膜共同作用，保证水平面上360°范围内的光信号，均被有效会聚至液晶面板。
在一些实施方式中，经过棱镜膜后的光线被收拢至70°，即经过棱镜膜后的光信号，与垂直于显示屏的方向的夹角在0至70°之间，而其在显示屏上的投影可以为0至360°中任意的角度。因此，通过在背光模组中设置棱镜膜，有效的增加了正视的亮度，较于不设置棱镜膜的情况，液晶显示屏的亮度增加了70％。在本申请的一些实施例中，背光模组中的两个棱镜膜也可以称为增亮棱镜膜。
图3中的(a)和图3中的(b)示出了本申请实施例中背光模组120中一个棱镜膜1200的立体结构图以及截面图，其中，图3中的(b)为图3中的(a)在XZ平面上的截面示意图。该棱镜膜1200可以为图2中两个棱镜膜中的任意一个。
具体地，该棱镜膜1200为多个相同的三棱镜1210在基底1220上规律地排成一排，其中，每一个三棱镜1210是从基底1220向上凸出而形成的，且每一个三棱镜1210为具有两个倾斜侧面的结构，两个倾斜侧面之间具有夹角，为三棱镜1210的顶角(Apex Angle)，由于棱镜膜中所有的三棱镜结构相同，因此，为了方便描述，在本申请中，下文也将棱镜膜中任意一个三 棱镜的顶角称之为棱镜膜的顶角。
此外，一个三棱镜1210的两个倾斜侧面与水平面的夹角分别为该三棱镜的两个底角。例如，图3中的(b)所示，三棱镜1210中两个倾斜侧面分别为第一侧面1211和第二侧面1212，该第一侧面1211与水平方向的夹角为三棱镜1210的第一底角α，该第二侧面1212与水平方向的夹角为三棱镜1210的第二底角β。同样为了方便描述，在本申请中，下文也将棱镜膜中任意一个三棱镜的两个底角称之为棱镜膜的两个底角，棱镜膜中每个三棱镜的第一侧面称之为第一棱镜膜侧面，棱镜膜中每个三棱镜的第二侧面称之为第二棱镜膜侧面。
为了提高棱镜膜的聚光作用，经过试验数据统计，目前现有技术中棱镜膜的顶角一般为90°，该角度下，棱镜膜的聚光效果最优。若顶角不为90°，则可能会损失部分光信号，影响液晶显示屏的显示亮度。
此外，也为了保证棱镜膜聚光的均匀性，即各个角度的光信号均能够有良好的聚光效果，一般而言，棱镜膜中两个底角一般相等，即棱镜膜中多个三棱镜的两个侧面的面积相同，若棱镜膜的顶角为90°，则棱镜膜由多个等腰直角三棱镜在基底上排列组成。
由于液晶显示屏中设置棱镜膜提高液晶显示屏的亮度，但手指按压在液晶显示屏的表面，指纹识别装置设置在手指下方进行指纹识别时，从手指反射或散射返回后的光信号，经过棱镜膜会被折射为不同方向的两个光信号，从而影响液晶显示屏下的指纹识别功能。
图4示出了一种液晶显示屏下指纹识别装置进行指纹识别时的光路示意图，其中，液晶显示屏10包括液晶面板110以及背光模组120，该背光模组120中包括棱镜膜1200以及其他膜层124，该其他膜层124包括但不限于是以上图2中的导光板、反射膜以及扩散膜等膜层结构。
如图4所示，第三反射光153为经过手指中心区域反射或透射的指纹检测光信号，手指中心区域对应指纹检测区域103的中心区域，指纹识别装置20设置于指纹检测区域103的中心区域下方，第三反射光153被棱镜膜1200中两个方向的棱镜膜侧面折射为方向不同的第一折射光161和第二折射光162，该第一折射光线161和第二折射光162无法进入指纹识别装置20中的光学组件300进行成像。因此，手指中心的光信号无法被指纹识别装置20接收，光检测阵列400检测得到的指纹图像中会形成一个如图5所示的暗区， 指纹识别装置20的视场被一分为二，形成均等的两部分视场，导致严重的视场损失和图像畸变。
另外，第四光信号154为指纹检测区域103外的其它区域的环境光信号或者杂散光信号，该第四光信号154经过棱镜膜折射后形成大角度的折射光信号进入光学组件300并被光学组件300传输至光检测阵列400，在光检测阵列400中成像，影响指纹图像的质量。
应理解，图4中以一个棱镜膜作为举例说明了该棱镜膜对于指纹光信号的影响，若液晶显示屏中包括如图2中所示的两个棱镜膜，则另一个棱镜膜对于指纹光信号的干扰情况也可以参见以上描述。若两个棱镜膜均由等腰直角三棱镜构成，光检测阵列400检测得到的指纹图像中心会形成如图6所示的暗区，指纹识别装置20的视场被一分为四，形成均等的四部分视场，造成更为严重的视场的损失。
综上，由于液晶显示屏中的棱镜膜对于指纹检测光信号的影响，造成指纹识别装置的视场损失和指纹图像的图像畸变，因而无法实现屏下指纹识别。
本申请提出一种适用于液晶显示屏的指纹识别装置，将该指纹装置设置于指纹检测区域的斜下方，使得指纹识别装置接收被棱镜膜中的一个侧面折射后的折射光，并改进液晶显示屏的背光模组中的棱镜膜结构，增大指纹识别装置接收指纹光信号的有效视场，从而形成较大面积的连续的指纹图像，实现液晶显示屏下指纹识别。
以下，结合图7至图21，详细介绍本申请实施例的指纹识别装置。
图7是本申请实施例提供的一种指纹识别装置200的示意性结构图，适用于具有液晶显示屏的电子设备，并用于设置在液晶显示屏的背光模组下方以进行屏下指纹识别，其中，该背光模组包括第一棱镜膜。
如图7所示，该指纹识别装置200包括：
指纹识别模组201，位于在液晶显示屏10中指纹检测区域103的斜下方，用于接收第一指纹光信号102，该第一指纹光信号101用于进行指纹识别，其中，该第一指纹光信号102为指纹光信号101经过第一棱镜膜121中第一棱镜膜侧面折射的光信号，该指纹光信号101为经指纹检测区域103上方的手指反射或散射而返回的光信号；
第一棱镜膜121中的第一底角与第二底角不相等，该第一底角为第一棱 镜膜121中第一棱镜膜侧面与液晶显示屏所在的平面的夹角，第二底角为第一棱镜膜121中第二棱镜膜侧面与所述液晶显示屏所在的平面的夹角。
可选地，在本申请实施例中，指纹识别模组201可以为图1中指纹识别装置20，其可以包括光学组件300和光检测阵列400。
其中，光学组件300用于接收第一指纹光信号101，并将该第一指纹光信号至传输至光检测阵列400，该光检测阵列400用于将该第一指纹光信号101并转换为指纹图像信号，以进行指纹识别。
具体地，在本申请实施例中，光学组件300可以为光学透镜(Lens)层，其具有一个或多个透镜单元，比如一个或多个光学透镜组成的透镜组。可选地，该光学透镜层中的光学透镜的表面可以为球面或者非球面，光学透镜的材料可以为玻璃，树脂等透明材料。
具体地，在本申请实施例中，光检测阵列400包括多个感应单元。其中，该感应单元可以采用光电二极管(Photo Diode)、金属氧化物半导体场效应管(Metal Oxide Semiconductor Field Effect Transistor，MOSFET)等器件进行光信号的检测以及指纹图像信号的输出。可选地，该感应单元对于特定波长光具有较高的光灵敏度和较高的量子效率，以便于检测相应波长的光信号。
在本申请实施例中，指纹检测区域103为光检测阵列400在液晶显示屏10中的感应区域，即用户手指按压在指纹检测区域103上方时，光信号经过指纹检测区域103上方的手指反射或散射而返回指纹光信号，该指纹检测信号用来检测所述手指的指纹信息，该光检测阵列400对该指纹检测区域103上方的手指进行指纹成像。
可选地，指纹识别模组201可以仅包括一个光学指纹传感器，此时指纹识别模组201的指纹检测区域103的面积较小且位置固定。在其他替代实施例中，指纹识别模组201可以具体包括多个光学指纹传感器；该多个光学指纹传感器可以通过拼接方式并排设置在液晶显示屏的下方，且该多个光学指纹传感器的感应区域共同构成指纹识别模组201的指纹检测区域103。
在一种可能的实施方式中，该指纹识别装置200可以适用于上述电子设备1中，其具体可以设置在上述液晶显示屏10的背光模组120的下方。在本申请实施例中，液晶显示屏10和背光模组120的相关特征可以参考上文中液晶显示屏10和背光模组120的相关描述。
具体地，本申请实施例的第一棱镜膜121也为棱镜膜结构，其同样由多个三棱镜在基底上排列形成，该第一棱镜膜121可以理解为在上述棱镜膜1200上进行改进形成的改进后的棱镜膜结构。
为了更清楚的说明该改进后的第一棱镜膜121的结构，图8示出了一种放大后的第一棱镜膜121的截面示意图。
如图8所示，该第一棱镜膜121的基底在下方，其第一棱镜膜侧面1211以及第二棱镜膜侧面1212均朝基底的上方凸出，该第一棱镜膜侧面1211和第二棱镜膜侧面1212均朝向液晶显示屏的液晶面板110，该第一棱镜膜121的基底平行于液晶面板110所在的平面。在本申请实施例中，第一棱镜膜121中多个三棱镜的第一侧面均称之为第一棱镜膜侧面1211，多个三棱镜的第二侧面均称之为第二棱镜膜侧面1212。
为了方便描述，在本申请中，将液晶显示屏中液晶面板所在平面也称为第一平面，将垂直于该第一平面的方向称为垂直方向。一般情况下，若液晶显示屏水平放置，则该第一平面也为水平面，垂直方向为竖直方向。
如图8所示，第一棱镜膜侧面1211与其基底的夹角，也即第一棱镜膜侧面1211与第一平面的夹角为第一底角α 1，第二棱镜膜侧面1212与其基底的夹角，也即第二棱镜膜侧面1212与第一平面的夹角为第二底角α 2，α 1≠α 2，第一棱镜膜侧面1211的面积与第二棱镜膜侧面1212的面积不相等。
换言之，该第一棱镜膜121与上述棱镜膜1200的区别在于，上述棱镜膜1200的两个棱镜膜侧面的面积相等，两个底角相等，而本申请实施例中，第一棱镜膜121的两个棱镜膜侧面的面积不等，两个底角也不相等。
可选地，α 1＜α 2，对应的，第一棱镜膜121中第一棱镜膜侧面1211的面积大于第二棱镜膜侧面1212的面积。
如图8所示，第一棱镜膜侧面1211接收光信号a，第二棱镜膜侧面1212接收光信号b，该光信号a和光信号b为平行光信号，特别地，该光信号a和光信号b均为垂直于第一平面的光信号。在指纹识别的过程中，该光信号a和光信号b均为经过指纹检测区域上方手指反射或者散射而返回的光信号，携带有指纹信息。且可以理解的是，垂直于手指的方向上光信号的光强较大，有利于提高指纹图像的质量以提高指纹识别的效果。
光信号a被第一棱镜膜侧面1211接收后，经过第一棱镜膜121的折射后，出射为光信号c。光信号b被第二棱镜膜侧面1212接收后，经过第一棱 镜膜121的折射后，出射为光信号d。由于α 1＜α 2，则光信号a在第一棱镜膜侧面1211上的入射角小于光信号b在第二棱镜膜侧面上的入射角，由折射定律可知，光信号c与垂直方向的夹角小于光信号d与垂直方向的夹角，下文也将光信号c与垂直方向的夹角也称为光信号c的出射角度，光信号d与垂直方向的夹角也称为光信号d的出射角度。
可选地，在图8的实施例中，光信号a可以为图7中的指纹光信号101，光信号c可以为图7中的第一指纹光信号102。
应理解，上述图8仅以垂直方向的光信号a和光信号b进行举例进行了说明，本申请实施例中的指纹光信号101还可以为第一棱镜膜侧面接收的其它方向的光信号，本申请实施例对该第一棱镜膜侧面接收的指纹光信号的方向不做具体限定，其可以包括任意方向的指纹光信号。
通过上述说明可知，对于平行光信号而言，第一棱镜膜侧面接收的光信号经过第一棱镜膜折射后，出射的光信号角度较小，而第二棱镜膜侧面接收的光信号经过第一棱镜膜折射后，出射的光信号角度较大，因而，若指纹识别模组设置在指纹检测区域的正下方，如图9所示，指纹识别模组的指纹图像中同样出现暗区，将指纹图像一分为二，第一棱镜膜中第一棱镜膜侧面接收的光信号经过折射后，在指纹识别模组中的成像面积S 1较大，而第二棱镜膜侧面接收的光信号经过折射后，在指纹识别模组中的成像面积S 2较小。
此时，若将指纹识别模组201设置在指纹检测区域103的斜下方，该指纹检测区域103设置在指纹识别模组201的光学视场(Field of View，FOV)的一侧，使得指纹识别模组201仅接收第一棱镜膜侧面折射的光信号，既可以解决指纹图像中的暗区问题，实现液晶显示屏下的指纹识别功能，也可以使得指纹识别模组具有相对大的有效光学视场，对应较大面积的指纹检测区域。
在本申请实施例中，α 1越小，第一棱镜膜侧面1211的面积越大，可以使得指纹识别模组具有更大的有效光学视场，指纹识别的效果更佳。但α 1越小，对液晶显示屏的亮度影响越大，为了均衡液晶显示屏的亮度与指纹识别的效果，在一些实施方式中，上述第一底角α 1的取值范围在30°至45°之间，即30°≤α 1＜45°。
如图8所示，上述第一棱镜膜侧面1211与第二棱镜膜侧面1212的夹角可以称为第一棱镜膜121的顶角，该第一棱镜膜121的顶角为γ 1，在一些实 施方式中，70°＜γ 1＜110°。
此外，在图8中，第一棱镜膜121中两个相邻的三棱镜的棱脊之间的间距(Pitch)为P 1，可选地，P 1的取值范围可以在15μm至40μm之间，一些实施方式中，P 1＝24μm。
可选地，在本申请实施例中，指纹识别模组201的光学视场可以为指纹识别模组201中光学组件300的光学视场，可选地，该指纹识别模组201的视场区域为该指纹识别模组201在液晶显示屏中的视场区域，该视场区域可以大于上述指纹检测区域103。
此外，指纹识别模组201的视场区域中，除了部分区域为指纹检测区域外，其它区域无手指覆盖，为无效视场区域，因此，也将该指纹检测区域103与该指纹识别模组201的视场区域重合的区域称之为该指纹识别模组201的有效光学视场区域，该指纹检测区域103下方的空间区域与该指纹识别模组201的视场空间重合的区域称之为该指纹识别模组201的有效光学视场。
图10示出了一种指纹识别模组201的光学视场和指纹检测区域的相对位置关系的截面图。
如图10所示，指纹识别模组201设置在指纹检测区域103的左下方，指纹识别模组201上方的虚线表示其光学视场，该光学视场与指纹识别模组中的光学组件的结构和光学参数相关。该光学视场在液晶面板110上可以形成一个圆形的视场区域，其中，该指纹检测区域103位于该圆形视场区域的右侧，指纹检测区域103上方手指反射或散射后的指纹光信号，经过第一棱镜膜121中的第一棱镜膜侧面折射后被指纹识别模组201接收。而经过该指纹检测区域103上方手指反射或散射后的指纹光信号(例如，图10中的光信号103)，经过第一棱镜膜121中的第二棱镜膜侧面折射后(例如，图10中的光信号104)无法被指纹识别模组201接收。
图11示出了另一种指纹识别模组的视场和指纹检测区域的相对位置关系的截面图。
图11所示，指纹识别模组201设置在指纹检测区域103的右下方，其中，指纹检测区域103位于指纹识别模组201的光学视场的左侧，指纹检测区域103上方手指反射或散射后的指纹光信号，经过第一棱镜膜121中的第二棱镜膜侧面折射后被指纹识别模组接收。而经过该指纹检测区域103上方手指反射或散射后的指纹光信号(例如，图11中的光信号101)，经过第一 棱镜膜121中的第一棱镜膜侧面折射后(例如，图11中的光信号102)无法被指纹识别模组接收。
由于第一棱镜膜121中不同侧面对光信号的折射角度不同，图11中的指纹检测区域103与图10中的指纹检测区域103相比，面积较小，若指纹识别模组按照图11进行设置，则指纹识别模组仅接收第一棱镜膜中第二棱镜膜侧面折射的光信号，虽然也可以解决暗区问题，但此时指纹识别模组的有效光学视场相对较小，也只能对应较小面积的指纹检测区域，指纹识别效果不佳。
因此，在本申请实施例中，将指纹识别模组201设置在指纹检测区域103的斜下方，而不是正下方，旨在使得指纹识别模组201仅接收面积较大的第一棱镜膜侧面折射的光信号，而不接收面积较小的第二棱镜膜侧面折射的光信号，提高指纹识别模组的有效视场，对较大面积的指纹检测区域上方的手指进行指纹识别。
此外，又由于第一棱镜膜侧面的面积大于第二棱镜膜侧面的面积，第一棱镜膜侧面能够接收的光信号较多，光强较大，在提高指纹识别模组的有效视场外，也有利于提高指纹图像的质量。
以上结合图7至图11说明了背光模组中仅包括一个第一棱镜膜121时，第一棱镜膜121的结构以及指纹识别模组201的位置。
可选地，背光模组中还可以包括两个棱镜膜，即如图2所示的两个不同方向的棱镜膜。
可选地，该两个棱镜膜的棱脊在第一平面的投影的夹角为θ，70°≤θ≤90°，其中棱镜膜的棱脊可以为棱脊膜中任意一个三棱镜的棱脊。
可选地，该两个棱镜膜之间的距离可以小于1μm或者其它任意数值，本申请实施例对此不做限定。
此外，在本申请实施例中，该两个棱镜膜之间可以设置有背光模组中的其它光学膜层，该两个棱镜膜之间也可以不设置其它膜层，本申请实施例对此也不做具体限定。
在一种实施方式中，该两个棱镜膜中的其中一个棱镜膜可以与上述经过改进后的第一棱镜膜121的结构相同，而另一个棱镜膜可以为未经过改进的原始棱镜膜1200(第二棱镜膜的一例)的结构相同。
图12示出了该情况下，背光模组中两个棱镜膜的立体结构示意图。图 13示出了图12的立体图在XZ平面中的截面示意图。如图12和图13所示，其上方的棱镜膜为上述第一棱镜膜121，下方的棱镜膜为上述棱镜膜1200。当然，在本实施方式中，例如，如图14所示，棱镜膜1200也可以位于第一棱镜膜121的上方。
在图12和图13所示的棱镜膜结构下，若指纹识别模组设置在指纹检测区域的下方，经过第一棱镜膜121的指纹光信号被折射为两部分，其中，经过第一棱镜膜121中第一棱镜膜侧面折射后的第一指纹光信号形成的指纹图像面积大于经过第一棱镜膜121中第二棱镜膜侧面折射后的第二指纹光信号形成的指纹图像面积。经过第一棱镜膜121折射后，如图15所示，指纹图像在Y方向上一分为二，形成左右两部分，且两部分的面积不等。经过第一棱镜膜121折射后的光信号再次经过棱镜膜1200的两个棱镜膜侧面，被折射为两部分，指纹图像在X方向上再次被一分为二，形成四部分。
在图14所示的棱镜膜结构下，若指纹识别模组设置在指纹检测区域的下方，同上述情况类似，如图16所示，经过棱镜膜1200折射后，指纹图像在X方向上一分为二，且均等划分为左右两部分。经过棱镜膜1200折射后的光信号再次经过第一棱镜膜121的两个棱镜膜侧面，被折射为两部分，指纹图像在Y方向上再次被一分为二，且划分为面积不等的四部分。
因此，在上述两种情况下，指纹图像被划分为2个较大面积的区域以及2个较小面积的区域，其中，两个较大面积的区域对应于经过第一棱镜膜中第一棱镜膜侧面折射的光信号。
为了能够在去除图像暗区的同时，提高指纹识别模组的有效视场，需要移动指纹识别模组，且指纹识别模组能够接收经过第一棱镜膜中第一棱镜膜侧面以及棱镜膜中一个棱镜膜侧面折射后的光信号，此时，指纹检测区域位于指纹识别模组的视场的一角。
具体地，在上文中，背光模组仅有一个第一棱镜膜的情况下，将指纹识别模组从指纹检测区域的正下方，向一侧移动，其可以沿其所在平面的X方向进行平移。在本申请实施例中，除了将指纹识别模组从指纹检测区域的正下方向X方向进行平移以外，还需要将指纹识别模组向Y方向进行平移，移动之后，指纹检测区域位于指纹识别模组的视场的一角，其中，X方向和Y方向为同一平面中相互垂直的方向。
例如，图17示出了背光模组仅包括一个第一棱镜膜121的情况下，指 纹识别模组在液晶显示屏中的光学视场区域与指纹检测区域俯视图。图18示出了背光模组包括第一棱镜膜121以及原始棱镜膜1200的情况下，指纹识别模组在液晶显示屏中的光学视场区域与指纹检测区域俯视图。
图17和图18中，圆形虚线表示指纹识别模组在液晶显示屏中的光学视场区域，比较图17和图18可以看出，相较于背光模组仅有一个第一棱镜膜的情况，在背光模组具有第一棱镜膜以及原始棱镜膜的情况下，指纹检测区域103的面积减小一半，该换言之，指纹识别模组的有效视场也减小一半。
但在该方式下，由于增加了一个棱镜膜，相比于一个棱镜膜的情况，液晶显示屏的亮度也得到的提高。
为了综合考虑液晶显示屏的亮度以及指纹识别模组的有效视场，在另一种实施方式中，该两个棱镜膜均可以为经过改进的棱镜膜。
可选地，该两个棱镜膜均可以与上述经过改进后的第一棱镜膜121的结构相同，即两个棱镜膜的结构相同。
可选地，该两个棱镜膜中的一个棱镜膜可以与上述经过改进后的第一棱镜膜121的结构相同，另一个同样为经过改进的棱镜膜，即棱镜膜的两个棱镜膜侧面面积不等，但该棱镜膜的结构与上述第一棱镜膜的结构不同。
为了方便描述，下文的实施例中，背光模组中的一个棱镜膜为上文中的第一棱镜膜121，另一个棱镜膜称之为第二棱镜膜122。可选地，该第二棱镜膜122平行设置于第一棱镜膜121的下方。
本申请实施例的第二棱镜膜122也为棱镜膜结构，其同样由多个三棱镜在基底上排列形成，该第二棱镜膜122也可以理解为在上述棱镜膜1200上进行改进形成的改进后的棱镜膜结构。
图19是本申请实施例提供的另一种指纹识别装置200的示意性结构图，适用于具有液晶显示屏的电子设备，并用于设置在液晶显示屏的背光模组下方以进行屏下指纹识别，其中，该背光模组包括第一棱镜膜和第二棱镜膜，该第一棱镜膜和第二棱镜膜均朝向液晶显示屏的液晶面板。
如图19所示，该指纹识别装置200包括：
指纹识别模组201，位于在所述液晶显示屏10中指纹检测区域103的斜下方，用于接收第一指纹光信号，该第一指纹光信号用于进行指纹识别，其中，第一指纹光信号为指纹光信号经过第一棱镜膜121中其中一个棱镜膜侧面和第二棱镜膜122中其中一个棱镜膜侧面后的光信号，该指纹光信号为经 所述指纹检测区域上方的手指反射或散射而返回的光信号；
第一棱镜膜121中的两个底角互不相等，且第二棱镜膜122中两个底角互不相等，第一棱镜膜121中的两个底角为第一棱镜膜121中两个棱镜膜侧面与液晶显示屏10所在的平面的夹角，第二棱镜膜122中的两个底角为第二棱镜膜122中两个棱镜膜侧面与液晶显示屏10所在的平面的夹角。
图20示出了一种放大后的第二棱镜膜122的截面示意图。
如图20所示，该第二棱镜膜122的基底在下方，其第三棱镜膜侧面1221以及第四棱镜膜侧面1222均朝基底的上方凸出，该第三棱镜膜侧面1221和第四棱镜膜侧面1222均朝向液晶显示屏的液晶面板110，该第二棱镜膜122的基底平行于液晶面板110所在的平面。在本申请实施例中，第二棱镜膜122中多个三棱镜的第一侧面均称之为第三棱镜膜侧面1221，多个三棱镜的第二侧面均称之为第四棱镜膜侧面1222。
如图20所示，第三棱镜膜侧面1221与其基底的夹角，也即第三棱镜膜侧面1221与第一平面的夹角为第三底角β 1，第四棱镜膜侧面1222与其基底的夹角，也即第四棱镜膜侧面1222与第一平面的夹角为第四底角β 2，β 1≠β 2，第三棱镜膜侧面1221的面积与第四棱镜膜侧面1222的面积不相等。
可选地，β 1＜β 2，对应的，第二棱镜膜122中第三棱镜膜侧面1221的面积大于第四棱镜膜侧面1222的面积。
在本申请实施例中，β 1越小，第三棱镜膜侧面1221的面积越大，可以使得指纹识别模组具有更大的有效光学视场，指纹识别的效果更佳。但β 1越小，对液晶显示屏的亮度影响越大，为了均衡液晶显示屏的亮度与指纹识别的效果，进一步地，在一些实施方式中，上述第三底角β1的取值范围在30°至45°之间，即30°＜β 1≤45°。可选地，β 1＝α 1。
如图20所示，上述第三棱镜膜侧面1221与第四棱镜膜侧面1222的夹角可以称为第二棱镜膜122的顶角，该第二棱镜膜122的顶角为γ 2，在一些实施方式中，70°＜γ 2＜110°。可选地，γ 1＝γ 2。
可选地，在一些实施方式中，γ 1＝γ 2＝90°，采用该实施方式，可以在实现指纹识别的同时，最大化的保证液晶显示屏的亮度。
此外，在图20中，第二棱镜膜122中两个相邻的三棱镜的棱脊之间的间距(Pitch)为P 2，可选地，P 1的取值范围可以在15μm至40μm之间，一些实施方式中，P 2＝P 1＝24μm，在另一些实施方式中，P 2和P 1也可以不相等， 本申请实施例对两个棱镜膜的Pitch值不做具体限定。
若第二棱镜膜122设置在上述第一棱镜膜121的下方，则该第二棱镜膜122中的部分区域接收的是第一棱镜膜121中第一棱镜膜侧面1211折射的光信号，例如上述光信号c，而另一部分区域接收的是第一棱镜膜121中第二棱镜膜侧面1212折射的光信号，例如上述光信号d。
如图20所示，第二棱镜膜122上第三棱镜膜侧面1221接收光信号c 1，第四棱镜膜侧面1222接收光信号c 2，该光信号c 1和光信号c 2均为经过第一棱镜膜121中的第一棱镜膜侧面1211折射后的光信号。
光信号c 1被第三棱镜膜侧面1221接收后，经过第二棱镜膜122的折射后，出射为光信号e。光信号c 2被第四棱镜膜侧面1222接收后，经过第二棱镜膜122的折射后，出射为光信号f。由于β 1＜β 2，则光信号c 1在第三棱镜膜侧面1221上的入射角小于光信号c 2在第二棱镜膜侧面上的入射角，由折射定律可知，光信号e与垂直方向的夹角小于光信号f与垂直方向的夹角。
可选地，在一种实施方式中，图20中的光信号e可以为图7中的第一指纹光信号102，被指纹识别模组201接收以进行指纹识别。
可选地，在另一种实施方式中，图20中的光信号f也可以为图7中的第一指纹光信号102，被指纹识别模组201接收以进行指纹识别。
换言之，在本申请实施例中，第一指纹光信号为指纹光信号经过第一棱镜膜121中第一棱镜膜侧面1211和第二棱镜膜122中其中一个棱镜膜侧面后的光信号。指纹识别模组201的位置使得其接收不到指纹光信号经过第一棱镜膜121中第二棱镜膜侧面1212和第二棱镜膜122中另一个棱镜膜侧面后的光信号。
应理解，上述图20仅以垂直方向的光信号c 1和c 2进行举例进行了说明，本申请实施例对该第三棱镜膜侧面接收的指纹光信号的方向不做具体限定，其可以包括任意方向的指纹光信号。
与上文对于第一棱镜膜中经过两个侧面的光信号的成像分析类似，第三棱镜膜侧面接收的光信号经过第二棱镜膜折射后，出射的光信号角度较小，而第四棱镜膜侧面接收的光信号经过第二棱镜膜折射后，出射的光信号角度较大。若指纹识别模组设置在指纹检测区域的正下方，在图9的指纹图像的基础上，将指纹图像再次一分为四，形成图21中的指纹图像。其中，S 1对应经过第一棱镜膜侧面1211以及第三棱镜膜侧面1221的折射后的光信号， S 2对应经过第二棱镜膜侧面1212以及第三棱镜膜侧面1221的折射后的光信号，S 3对应经过第一棱镜膜侧面1211以及第四棱镜膜侧面1222的折射后的光信号，S 4对应经过第二棱镜膜侧面1212以及第四棱镜膜侧面1222的折射后的光信号。
此时，若将指纹识别模组设置在指纹检测区域的斜下方，该指纹检测区域设置在指纹识别模组的光学视场的一角，使得指纹识别模组仅接收第一棱镜膜侧面以及第三棱镜膜侧面折射的光信号(对应于图20中的S 1)，而接收不到其它棱镜膜侧面折射的光信号，既可以解决指纹图像中的暗区问题，可实现液晶显示屏下的指纹识别功能，也可以使得指纹识别模组具有相对大的有效光学视场，对应较大面积的指纹检测区域。
图22示出了背光模组包括第一棱镜膜121以及第二棱镜膜121的情况下，指纹识别模组的光学视场区域与指纹检测区域俯视图。
图22中，圆形虚线表示指纹识别模组在液晶面板中的光学视场区域，比较图18和图22可以看出，相较于背光模组包括第一棱镜膜121以及原始棱镜膜1200的情况，在背光模组包括第一棱镜膜121以及第二棱镜膜122的情况下，指纹检测区域103的面积增大，该换言之，指纹识别模组的有效视场也增大。
因此，采样本申请实施例，在兼顾液晶显示屏的亮度的同时，还能进一步增大指纹识别模组的有效视场，增加指纹检测区域103的面积，从而采集到较大面积的指纹图像，提高液晶显示屏下的指纹识别性能。
另外，本申请实施例还提供了一种背光模组，适用于具有液晶显示屏的电子设备，该液晶显示屏包括背光模组120；
可选地，本申请实施例中的背光模组120的相关特征可以参见上述实施例中的背光模组120的相关描述。
具体地，背光模组120包括第一棱镜膜121和第二棱镜膜122，第一棱镜膜121和第二棱镜膜122均朝向液晶显示屏的液晶面板；
第一棱镜膜121中的两个底角互不相等，且第二棱镜膜122中两个底角互不相等，第一棱镜膜121中的两个底角为第一棱镜膜121中两个棱镜膜侧面与液晶显示屏所在的平面的夹角，第二棱镜膜122中的两个底角为第二棱镜膜122中两个棱镜膜侧面与液晶显示屏所在的平面的夹角。
在一种实施方式中，指纹光信号经过第一棱镜膜121中其中一个棱镜膜 侧面和第二棱镜膜122中其中一个棱镜膜侧面后形成第一指纹光信号，第一指纹光信号用于进行指纹识别，指纹光信号为经指纹检测区域上方的手指反射或散射而返回的光信号。
可选地，第一棱镜膜121中的第一底角α 1小于第二底角α 2，30°≤α 1<45°，第一底角为第一棱镜膜121中第一棱镜膜侧面1211与液晶显示屏所在的平面的夹角，第二底角为第一棱镜膜121中第二棱镜膜侧面1212与液晶显示屏所在的平面的夹角。
在一种实施方式中，第一指纹光信号为指纹光信号经过第一棱镜膜侧面1211和第二棱镜膜122中其中一个棱镜膜侧面后的光信号。
可选地，第二棱镜膜122中的第三底角β 1小于第四底角β 2，30°≤β 1<45°，第三底角为第二棱镜膜122中第三棱镜膜侧面1221与液晶显示屏所在的平面的夹角，第四底角为第二棱镜膜122中第四棱镜膜侧面1222与液晶显示屏所在的平面的夹角。
在一种实施方式中，第一指纹光信号为指纹光信号经过第一棱镜膜侧面1211和第三棱镜膜侧面1221后的光信号。
可选地，第一棱镜膜121中两个棱镜膜侧面的夹角为第一棱镜膜121的顶角γ 1，第二棱镜膜122中两个棱镜膜侧面的夹角为第二棱镜膜122的顶角γ 2，70°＜γ 1＜110°，70°＜γ 2＜110°。可选地，γ 1＝γ 2＝90°。
在一些实施方式中，第一棱镜膜121和第二棱镜膜122的结构相同。
可选地，第二棱镜膜122中一个棱镜的棱脊与第一棱镜膜121中一个棱镜的棱脊在第一平面的投影的夹角为θ，70°≤θ≤90°，其中，第一平面为平行于液晶显示屏的平面。
采用本申请实施例的背光模组，可以在保证液晶显示屏亮度的同时，实现液晶显示屏下的大视场的指纹识别功能。
如图23所示，本申请实施例还提供了一种电子设备2，该电子设备2可以包括上述液晶显示屏10以及上述申请实施例的指纹识别装置200，其中，该液晶显示屏10包括上述申请实施例中的背光模组120，该指纹识别装置200设置于背光模组120下方。
可选地，该电子设备2可以为任何具有液晶显示屏和背光模组的电子设备。
可选地，该电子设备2还可以包括红外光源30。
可选地，该红外光源30可以设置在电子设备的玻璃盖板130的下方，且与该液晶显示屏的液晶面板并排设置。
在一种可能的实施方式中，如图23所示，该红外光源30设置在电子设备2的玻璃盖板130的下方，与液晶显示屏10的液晶面板110并排设置，且设置于液晶显示屏10的背光模组120的斜上方。具体地，该背光模组120包括第一棱镜膜121和/或第二棱镜膜122，以及背光模组其他结构124。
在另一种可能的实施方式中，该红外光源30设置在电子设备2的玻璃盖板130的下方，与液晶显示屏10中的液晶面板110以及背光模组120并排设置。
可选地，该红外光源30可以斜贴在该玻璃盖板130的下方。例如，该红外光源30可以通过光学胶斜贴在该显示屏10的下方。可选地，该光学胶可以是任一种光学液态胶或者光学固态胶。
可选地，如图23所示，该红外光源30与该玻璃盖板之间，和/或该红外光源30与该液晶显示屏10之间可以设置红外光透过层301，该红外光透过层301用于透过该红外激励光且阻挡可见光。可选地，该红外光透过层301可以为透红外油墨。
可选地，如图23所示，该红外光源30与该液晶显示屏10中的液晶面板110之间可以设置阻光泡棉302，用于阻挡可见光。
此外，在本申请实施例中，该红外光源30可以设置在该电子设备2边缘的非显示区域。例如，电子设备2为手机，非显示区域为手机表面非显示图像的手机边框区域，具体地，该红外光源30设置在非显示图像的手机边框区域对应的下方区域中。
在一些实施方式中，该红外光源30可以为单颗或者多颗发光二极管(Light-Emitting Diode，LED)。可选地，多颗红外发光二极管可以组成带状红外发光源，分布在指纹检测区域103的四周。
在本申请实施例中，通过采用红外光源产生第一指纹红外光信号，并基于该第一指纹红外光信号进行光学指纹检测，能够减少屏幕可见光对于红外光指纹检测的干扰，且均衡红外光指纹图像的光学照度，进一步提高指纹成像的质量。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，能够以电子硬件、或者计算机软件和电子硬件的结 合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，上述描述的系统、装置和单元的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
在本申请所提供的几个实施例中，应该理解到，所揭露的系统、装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。
所述功能如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本申请的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本申请各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(ROM，Read-Only Memory)、随机存取存储器(RAM，Random Access Memory)、磁碟或者光盘等各种可以存储程序代码的介质。
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易 想到变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应所述以权利要求的保护范围为准。

Claims (32)

  1. 一种指纹识别装置，其特征在于，用于设置在液晶显示屏的背光模组下方以进行屏下指纹识别，所述背光模组包括第一棱镜膜和第二棱镜膜，所述第一棱镜膜和所述第二棱镜膜均朝向所述液晶显示屏的液晶面板，所述指纹识别装置包括：
    指纹识别模组，位于在所述液晶显示屏中指纹检测区域的斜下方，用于接收第一指纹光信号，所述第一指纹光信号用于进行指纹识别，其中，所述第一指纹光信号为指纹光信号经过所述第一棱镜膜中其中一个棱镜膜侧面和所述第二棱镜膜中其中一个棱镜膜侧面后的光信号，所述指纹光信号为经所述指纹检测区域上方的手指反射或散射而返回的光信号；
    所述第一棱镜膜中的两个底角互不相等，且所述第二棱镜膜中两个底角互不相等，所述第一棱镜膜中的两个底角为所述第一棱镜膜中两个棱镜膜侧面与所述液晶显示屏所在的平面的夹角，所述第二棱镜膜中的两个底角为所述第二棱镜膜中两个棱镜膜侧面与所述液晶显示屏所在的平面的夹角。
  2. 根据权利要求1所述的指纹识别装置，其特征在于，所述第一棱镜膜中的第一底角α 1小于第二底角α 2，30°≤α 1<45°，所述第一底角为所述第一棱镜膜中第一棱镜膜侧面与所述液晶显示屏所在的平面的夹角，所述第二底角为所述第一棱镜膜中第二棱镜膜侧面与所述液晶显示屏所在的平面的夹角。
  3. 根据权利要求2所述的指纹识别装置，其特征在于，所述第一指纹光信号为所述指纹光信号经过所述第一棱镜膜侧面和所述第二棱镜膜中其中一个棱镜膜侧面后的光信号。
  4. 根据权利要求3所述的指纹识别装置，其特征在于，所述指纹识别模组的位置使得其接收不到所述指纹光信号经过所述第二棱镜膜侧面和所述第二棱镜膜中另一个棱镜膜侧面后的光信号。
  5. 根据权利要求3或4所述的指纹识别装置，其特征在于，所述第二棱镜膜中的第三底角β 1小于第四底角β 2，30°≤β 1<45°，所述第三底角为所述第二棱镜膜中第三棱镜膜侧面与所述液晶显示屏所在的平面的夹角，所述第四底角为所述第二棱镜膜中第四棱镜膜侧面与所述液晶显示屏所在的平面的夹角。
  6. 根据权利要求5所述的指纹识别装置，其特征在于，所述第一指纹 光信号为所述指纹光信号经过所述第一棱镜膜侧面和所述第三棱镜膜侧面后的光信号。
  7. 根据权利要求6所述的指纹识别装置，其特征在于，所述指纹识别模组的位置使得其接收不到所述指纹光信号经过所述第一棱镜膜侧面和所述第四棱镜膜后的光信号。
  8. 根据权利要求1至7中任一项所述的指纹识别装置，其特征在于，所述第一棱镜膜中两个棱镜膜侧面的夹角为所述第一棱镜膜的顶角γ 1，所述第二棱镜膜中两个棱镜膜侧面的夹角为所述第二棱镜膜的顶角γ 2，70°＜γ 1＜110°，70°＜γ 2＜110°。
  9. 根据权利要求8所述的指纹识别装置，其特征在于，γ 1＝γ 2＝90°。
  10. 根据权利要求1至9中任一项所述的指纹识别装置，其特征在于，所述第一棱镜膜和所述第二棱镜膜的结构相同。
  11. 根据权利要求1至10中任一项所述的指纹识别装置，其特征在于，所述第二棱镜膜中一个棱镜的棱脊与所述第一棱镜膜中一个棱镜的棱脊在第一平面的投影的夹角为θ，70°≤θ≤90°，其中，所述第一平面为平行于所述液晶显示屏的平面。
  12. 根据权利要求1至11中任一项所述的指纹识别装置，其特征在于，所述指纹识别模组包括：光学组件以及光检测阵列；
    所述光学组件用于接收所述第一指纹光信号，并将所述第一指纹光信号至传输至所述光检测阵列，所述光检测阵列用于将所述第一指纹光信号并转换为指纹图像信号，以进行指纹识别。
  13. 根据权利要求12所述的指纹识别装置，其特征在于，所述光学组件包括至少一个光学透镜，所述至少一个光学透镜为球面或者非球面透镜。
  14. 根据权利要求12或13所述的指纹识别装置，其特征在于，所述光检测阵列包括至少一个光学指纹传感器。
  15. 一种背光模组，其特征在于，适用于具有液晶显示屏的电子设备，包括：第一棱镜膜和第二棱镜膜，所述第一棱镜膜和所述第二棱镜膜均朝向所述液晶显示屏的液晶面板；
    所述第一棱镜膜中的两个底角互不相等，且所述第二棱镜膜中两个底角互不相等，所述第一棱镜膜中的两个底角为所述第一棱镜膜中两个棱镜膜侧面与所述液晶显示屏所在的平面的夹角，所述第二棱镜膜中的两个底角为所 述第二棱镜膜中两个棱镜膜侧面与所述液晶显示屏所在的平面的夹角。
  16. 根据权利要求15所述的背光模组，其特征在于，指纹光信号经过所述第一棱镜膜中其中一个棱镜膜侧面和所述第二棱镜膜中其中一个棱镜膜侧面后形成第一指纹光信号，所述第一指纹光信号用于进行指纹识别，所述指纹光信号为经所述指纹检测区域上方的手指反射或散射而返回的光信号。
  17. 根据权利要求16所述的背光模组，其特征在于，所述第一棱镜膜中的第一底角α 1小于第二底角α 2，30°≤α 1<45°，所述第一底角为所述第一棱镜膜中第一棱镜膜侧面与所述液晶显示屏所在的平面的夹角，所述第二底角为所述第一棱镜膜中第二棱镜膜侧面与所述液晶显示屏所在的平面的夹角。
  18. 根据权利要求17所述的背光模组，其特征在于，所述第一指纹光信号为所述指纹光信号经过所述第一棱镜膜侧面和所述第二棱镜膜中其中一个棱镜膜侧面后的光信号。
  19. 根据权利要求18所述的背光模组，其特征在于，所述第二棱镜膜中的第三底角β 1小于第四底角β 2，30°≤β 1<45°，所述第三底角为所述第二棱镜膜中第三棱镜膜侧面与所述液晶显示屏所在的平面的夹角，所述第四底角为所述第二棱镜膜中第四棱镜膜侧面与所述液晶显示屏所在的平面的夹角。
  20. 根据权利要求19所述的背光模组，其特征在于，所述第一指纹光信号为所述指纹光信号经过所述第一棱镜膜侧面和所述第三棱镜膜侧面后的光信号。
  21. 根据权利要求15至20中任一项所述的背光模组，其特征在于，所述第一棱镜膜中两个棱镜膜侧面的夹角为所述第一棱镜膜的顶角γ 1，所述第二棱镜膜中两个棱镜膜侧面的夹角为所述第二棱镜膜的顶角γ 2，70°＜γ 1＜110°，70°＜γ 2＜110°。
  22. 根据权利要求21所述的背光模组，其特征在于，γ 1＝γ 2＝90°。
  23. 根据权利要求15至22中任一项所述的背光模组，其特征在于，所述第一棱镜膜和所述第二棱镜膜的结构相同。
  24. 根据权利要求15至23中任一项所述的背光模组，其特征在于，所述第二棱镜膜中一个棱镜的棱脊与所述第一棱镜膜中一个棱镜的棱脊在第 一平面的投影的夹角为θ，70°≤θ≤90°，其中，所述第一平面为平行于所述液晶显示屏的平面。
  25. 一种电子设备，其特征在于，包括：液晶显示屏以及，
    根据权利要求1至14中任一项所述的指纹识别装置，其中，所述液晶显示屏包括背光模组，所述指纹识别模组设置于所述背光模组下方。
  26. 根据权利要求25所述的电子设备，其特征在于，还包括：红外光源，用于为所述指纹识别模组的指纹检测提供红外激励光，所述红外激励光照射到所述液晶显示屏的至少部分显示区域，所述至少部分显示区域至少部分覆盖所述指纹识别模组的指纹检测区域；
    其中，所述第一指纹光信号包括所述红外光源的红外激励光经过手指反射后经过所述背光模组的第一指纹红外光信号。
  27. 根据权利要求25所述的电子设备，其特征在于，所述红外光源为单颗或者多颗红外发光二极管；
    所述单颗或多颗红外发光二极管分布在所述指纹检测区域的四周。
  28. 根据权利要求25至27中任一项所述的电子设备，其特征在于，所述红外光源设置在所述液晶显示屏的玻璃盖板的下方，且与所述液晶显示屏的液晶面板并排设置。
  29. 根据权利要求28所述的电子设备，其特征在于，所述红外光源斜贴在所述玻璃盖板的下方。
  30. 根据权利要求28或29所述的电子设备，其特征在于，还包括：红外光透过层，设置于所述红外光源与所述玻璃盖板之间和/或所述红外光源与所述液晶显示屏之间，用于透过所述红外激励光且阻挡可见光。
  31. 一种液晶显示屏，其特征在于，包括：
    根据权利要求15至24中任一项所述的背光模组。
  32. 一种电子设备，其特征在于，包括：根据权利要求31所述的液晶显示屏。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20230267761A1 (en) * 2020-07-23 2023-08-24 3M Innovative Properties Company Electronic device with optical sensor module

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN211319247U (zh) * 2019-09-20 2020-08-21 深圳市汇顶科技股份有限公司 指纹识别装置、背光模组、液晶显示屏和电子设备
US10936847B1 (en) * 2019-09-20 2021-03-02 Shenzhen GOODIX Technology Co., Ltd. Under-display optical sensor with compensated light paths
WO2021146965A1 (zh) * 2020-01-21 2021-07-29 深圳市汇顶科技股份有限公司 指纹检测装置、背光模组、显示屏和电子设备
CN114002769A (zh) * 2021-10-20 2022-02-01 武汉华星光电技术有限公司 滤光准直复合膜及其制造方法、显示装置

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102105833A (zh) * 2008-07-22 2011-06-22 日立麦克赛尔株式会社 液晶显示装置
KR20140079681A (ko) * 2012-12-19 2014-06-27 엘지디스플레이 주식회사 프리즘시트와 이를 포함하는 백라이트 유닛 및 디스플레이 장치
CN107610590A (zh) * 2017-09-25 2018-01-19 深圳市华星光电技术有限公司 多功能广告显示屏
CN208173153U (zh) * 2018-05-11 2018-11-30 印象认知（北京）科技有限公司 一种显示屏及电子设备
CN108957768A (zh) * 2018-06-22 2018-12-07 张家港康得新光电材料有限公司 实现裸眼3d、2d/3d切换的结构及方法
CN109863508A (zh) * 2019-01-23 2019-06-07 深圳市汇顶科技股份有限公司 Lcd屏下指纹识别模组、lcd装置和终端设备
CN110235143A (zh) * 2019-04-30 2019-09-13 深圳市汇顶科技股份有限公司 屏下指纹识别装置和电子设备

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101042378B1 (ko) * 2009-02-12 2011-06-17 인제대학교 산학협력단 광학식 지문인식 시스템
US10635878B2 (en) * 2015-10-23 2020-04-28 Shenzhen GOODIX Technology Co., Ltd. Optical fingerprint sensor with force sensing capability
WO2020133479A1 (zh) * 2018-12-29 2020-07-02 深圳市汇顶科技股份有限公司 光学指纹识别模组及电子设备
CN109613756B (zh) * 2019-01-29 2021-08-10 华勤技术股份有限公司 Lcd显示屏、电子设备以及控制系统
EP3731133B8 (en) * 2019-03-12 2022-04-20 Shenzhen Goodix Technology Co., Ltd. Under-screen fingerprint recognition apparatus and electronic device
CN211319247U (zh) * 2019-09-20 2020-08-21 深圳市汇顶科技股份有限公司 指纹识别装置、背光模组、液晶显示屏和电子设备

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102105833A (zh) * 2008-07-22 2011-06-22 日立麦克赛尔株式会社 液晶显示装置
KR20140079681A (ko) * 2012-12-19 2014-06-27 엘지디스플레이 주식회사 프리즘시트와 이를 포함하는 백라이트 유닛 및 디스플레이 장치
CN107610590A (zh) * 2017-09-25 2018-01-19 深圳市华星光电技术有限公司 多功能广告显示屏
CN208173153U (zh) * 2018-05-11 2018-11-30 印象认知（北京）科技有限公司 一种显示屏及电子设备
CN108957768A (zh) * 2018-06-22 2018-12-07 张家港康得新光电材料有限公司 实现裸眼3d、2d/3d切换的结构及方法
CN109863508A (zh) * 2019-01-23 2019-06-07 深圳市汇顶科技股份有限公司 Lcd屏下指纹识别模组、lcd装置和终端设备
CN110235143A (zh) * 2019-04-30 2019-09-13 深圳市汇顶科技股份有限公司 屏下指纹识别装置和电子设备

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20230267761A1 (en) * 2020-07-23 2023-08-24 3M Innovative Properties Company Electronic device with optical sensor module
US11954939B2 (en) * 2020-07-23 2024-04-09 3M Innovative Properties Company Electronic device with optical sensor module

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