WO2021138781A1

WO2021138781A1 - Fingerprint detection device and electronic device

Info

Publication number: WO2021138781A1
Application number: PCT/CN2020/070538
Authority: WO
Inventors: 王文轩; 沈健; 纪登鑫
Original assignee: 深圳市汇顶科技股份有限公司
Priority date: 2020-01-06
Filing date: 2020-01-06
Publication date: 2021-07-15
Also published as: CN111837126A

Abstract

Provided are a fingerprint detection device and an electronic device. The fingerprint detection device is suitable for an electronic device with a display screen to realize fingerprint identification under the screen, the display screen sequentially comprising a transparent cover plate, a first transparent dielectric layer, an optical adhesive layer and a display layer from top to bottom; and the fingerprint detection device comprises a fingerprint sensor chip arranged below the display screen and used for receiving an optical signal emitted by an external light source and returned, by a finger, over the display screen so as to detect fingerprint information of the finger, wherein the refractive index of the first transparent dielectric layer is smaller than the refractive index of the optical adhesive layer and the refractive index of the transparent cover plate, respectively, such that the optical signal emitted by the external light source can be totally reflected in the transparent cover plate. The first transparent dielectric layer can improve the quality of a fingerprint image and the fingerprint identification effect.

Description

Fingerprint detection device and electronic equipment

Technical field

The embodiments of the present application relate to the field of fingerprint detection, and more specifically, to fingerprint detection devices and electronic equipment.

Background technique

At present, fingerprint recognition under the screen is mainly used in Organic Light-Emitting Diode (OLED) screens. The principle is that the fingerprint recognition module under the OLED screen uses the light transmission characteristics of the OLED screen to receive the light emitted by the OLED screen itself. The reflected light formed by the reflection of the finger detects the fingerprint. However, because the light-emitting principle and specific structure of liquid crystal display (LCD) screens are different from those of OLED screens, the fingerprint recognition scheme under OLED screens is not suitable for LCD screens. For the LCD screen, it is necessary to separately set up a supplementary light, and the supplementary light is used to generate a light signal for fingerprint identification. In addition, for the OLED screen, a fill light can also be provided, and accordingly, the light emitted by the OLED screen and the light emitted by the fill light can be combined for fingerprint identification.

Normally, the fill light can be arranged on the side of the glass cover, so that the light signal emitted by the fill light is transmitted to the finger through the glass cover, and then returns to fingerprint recognition after being reflected or scattered by the finger. Module. For example, as an expectation, the glass cover can be attached to the display layer by optical glue. When the light emitting direction of the fill light is adjusted to a certain angle range with the glass cover, the light emitted by the fill light will be in The inside of the glass cover plate propagates in a manner of approximate total reflection.

However, since the refractive index of the glass cover is about 1.5, the refractive index of the optical glue is generally 1.47 to 1.5, and the refractive indexes of the two are very close. When the surface of the glass cover and the air reach the condition of total reflection, the glass cover The interface between the lower surface and the optical glue cannot achieve the condition of total reflection of light. Correspondingly, it is difficult to achieve the condition of total reflection even if the light emitting angle is continuously adjusted.

Therefore, how to propagate the light signal emitted by the supplementary light in the glass cover of the display screen in a manner of approximate total reflection is a technical problem urgently needed to be solved by those skilled in the art.

Summary of the invention

A fingerprint detection device and electronic equipment are provided, which can make the light signal emitted by an external light source propagate in a manner of approximate total reflection in a glass cover plate in a display screen, thereby improving the quality of fingerprint images and the effect of fingerprint recognition.

In a first aspect, a fingerprint detection device is provided. The fingerprint detection device is suitable for electronic equipment with a display screen to realize fingerprint recognition under the screen. The display screen includes a transparent cover and a first transparent medium in order from top to bottom. Layer, optical adhesive layer and display layer;

The fingerprint detection device includes:

Fingerprint sensor chip, the fingerprint sensor chip is used to be arranged below the display screen, the fingerprint sensor chip is used to receive the light signal sent by the external light source through the finger above the display screen to detect the finger Fingerprint information;

Wherein, the refractive index of the first transparent medium layer is respectively smaller than the refractive index of the optical adhesive layer and the refractive index of the transparent cover, so that the optical signal emitted by the external light source can be inside the transparent cover. Perform total reflection.

By arranging the first transparent medium layer on the transparent cover plate and the optical adhesive layer, and making the refractive index of the first transparent medium layer smaller than the refractive index of the optical adhesive layer and the transparent cover plate, respectively The index of refraction can make the interface between the transparent cover and the first transparent medium layer meet the condition of total reflection, and then make the transparent cover and the transparent cover at a certain angle (incidence angle greater than the critical angle) The optical signal of the interface between the first transparent medium layers can be transmitted in the transparent cover plate in a manner of total reflection, thereby improving the quality of the fingerprint image and the fingerprint recognition effect.

In some possible implementations, the refractive index of the first transparent medium layer is greater than the refractive index of air.

The refractive index of the first transparent medium layer is greater than the refractive index of air, so that the optical signal directed at the interface between the transparent cover plate and the first transparent medium layer at a certain angle (incidence angle greater than the critical angle) can be It spreads in the transparent cover plate in a way of total reflection, thereby improving the quality of the fingerprint image and the fingerprint recognition effect; moreover, by controlling the refractive index of the first transparent medium layer, it is possible to avoid targeting the first transparent medium The critical angle (that is, the total reflection angle) of the interface between the optical adhesive layer and the optical adhesive layer is too small, which is conducive to the transmission of the optical signal with a certain radiation angle emitted by the display layer to the first optical adhesive layer through the optical adhesive layer. The transparent medium layer, correspondingly, will increase the amount of light signals received by the finger and increase the brightness of the screen.

In some possible implementation manners, different refractive indexes of the first transparent medium layer correspond to different wavelength ranges, and the wavelength range is a wavelength range of an optical signal emitted by the external light source.

By associating the refractive index of the first transparent medium layer with the wavelength range of the optical signal emitted by the external light source, it is not only guaranteed that the optical signal emitted by the external light source is fully reflected in the transparent cover, but also Reducing the possibility or probability of total reflection of the light signal emitted by the display layer on the transparent cover is beneficial to improving the performance of the electronic device.

In some possible implementation manners, the refractive index of the first transparent medium layer ranges from 1.1 to 1.3.

In some possible implementation manners, the light transmittance of the first transparent medium layer is greater than 90%.

In some possible implementation manners, the material of the first transparent medium layer includes at least one of the following materials:

Organic coating materials, inorganic oxides, inorganic fluorides, and inorganic nitrides.

By setting the material of the first transparent medium layer to the above-mentioned material, it is not only convenient to dispose the first transparent medium layer between the transparent cover plate and the optical adhesive layer, but also does not affect the disposition of the first transparent medium layer. The transparent cover plate of the first transparent medium layer is attached or adhered to the upper surface of the display layer through the optical adhesive layer.

In some possible implementations, the first transparent medium layer is bonded to the display layer through the optical adhesive layer.

In some possible implementation manners, the display screen further includes a second transparent medium layer, the second transparent medium layer is disposed under the first transparent medium layer, and the second transparent medium layer passes through the optical The adhesive layer is attached to the display layer, wherein the refractive index of the second transparent medium layer is less than the refractive index of the optical adhesive layer to reduce the optical signal emitted by the display screen when entering the transparent cover. The resulting loss.

By arranging a second transparent medium layer between the first transparent medium layer and the optical adhesive layer, it is equivalent to transmitting the optical signal from the display layer to the transparent cover plate. The interface of the total reflection angle (that is, the interface between the optical adhesive layer and the first transparent medium layer) is transformed into two interfaces with a large total reflection angle (that is, the optical adhesive layer and the second The interface between the transparent medium layers, and the interface between the second transparent medium layer and the first transparent medium layer), which is equivalent to increasing the total reflection angle of the optical signal emitted by the display layer as a whole , Thereby increasing the luminous flux of the light signal emitted by the display layer, which not only ensures that the finger can receive enough light signal, but also can ensure that there is enough light signal to display the image, and accordingly, can improve the fingerprint image quality and fingerprint recognition effect , It can also ensure the performance of the electronic device.

In some possible implementations, the refractive index of the second transparent medium layer is greater than the refractive index of the first transparent medium layer.

Constructing the refractive index of the second transparent medium layer to be greater than the refractive index of the first transparent medium layer can ensure that the total reflection angle for the interface between the second transparent medium layer and the optical adhesive layer is greater than When the second transparent medium layer is not provided, the total reflection angle of the interface between the first transparent medium layer and the optical adhesive layer, correspondingly, can improve the fingerprint image quality and fingerprint recognition effect at the same time , To ensure the performance of the electronic equipment.

In some possible implementation manners, the material of the second transparent medium layer includes at least one of the following materials:

Constructing the material of the second transparent medium layer as the above-mentioned material not only facilitates the placement of the second transparent medium layer, but also ensures the connection and stability between the first transparent medium layer and the optical adhesive layer.

In some possible implementations, the second transparent medium layer includes at least one medium layer, and at least one refractive index corresponding to the at least one medium layer is the same, or the at least one refractive index is partially the same, or the at least one The refractive index is different from each other.

Therefore, as a whole, the total reflection angle of the light signal emitted by the display layer can be effectively increased, which is beneficial to increase the luminous flux.

In some possible implementations, the external light source is arranged below the transparent cover plate and located on one side of the display layer; or, the external light source is arranged inside the transparent cover plate.

In some possible implementation manners, the fingerprint sensor chip is further configured to receive the light signal sent by the display screen and returned via the finger, so as to detect fingerprint information of the finger.

In some possible implementation manners, the transparent cover plate is a glass cover plate, or the material of the transparent cover plate is a flexible material.

In the second aspect, an electronic device is provided, including:

Display screen; and

In the fingerprint detection device described in the first aspect or any one of the possible implementations of the first aspect, the fingerprint detection device is arranged below the display screen, the fingerprint detection device includes a fingerprint sensor chip, and the fingerprint The sensor chip is configured to be arranged below the display screen, and the fingerprint sensor chip is configured to receive light signals sent by an external light source and returned via a finger above the display screen to detect fingerprint information of the finger;

Wherein, the display screen includes a transparent cover plate, a first transparent medium layer, an optical adhesive layer, and a display layer in order from top to bottom, and the refractive index of the first transparent medium layer is smaller than the refractive index and the refractive index of the optical adhesive layer. The refractive index of the transparent cover allows the light signal emitted by the external light source to be totally reflected inside the transparent cover.

In some possible implementations, the display screen further includes a rear panel located below the display layer, the material of the rear panel is an opaque material, the rear panel is provided with an opening, and the fingerprint detection device It is arranged below the opening, so that the fingerprint sensor chip in the fingerprint detection device receives the light signal returned via the finger through the opening.

Description of the drawings

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

Fig. 2 is a schematic cross-sectional view of the electronic device shown in Fig. 1.

Fig. 3 is another schematic structural diagram of an electronic device to which the present application can be applied.

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

5 to 9 are schematic structural diagrams of the relationship between the fingerprint detection device and the display screen of the electronic device according to an embodiment of the present application.

FIG. 10 is a schematic diagram of the relationship between the luminous flux and the radiation angle in the embodiment of the present application.

Detailed ways

The technical solution in this application will be described below in conjunction with the accompanying drawings.

The technical solutions of the embodiments of the present application can be applied to various electronic devices. For example, portable or mobile computing devices such as smartphones, notebook computers, tablet computers, and gaming devices, as well as other electronic devices such as electronic databases, automobiles, and bank automated teller machines (ATM). However, the embodiment of the present application does not limit this.

The technical solutions of the embodiments of the present application can be used in biometric identification technology. Among them, biometric recognition technologies include, but are not limited to, fingerprint recognition, palmprint recognition, iris recognition, face recognition, and living body recognition. For ease of description, the following uses fingerprint recognition technology as an example for description.

The technical solutions of the embodiments of the present application can be used for off-screen fingerprint identification technology and in-screen fingerprint identification technology.

The under-screen fingerprint recognition technology refers to the installation of the fingerprint recognition module below the display screen, so as to realize the fingerprint recognition operation in the display area of the display screen, and there is no need to set a fingerprint collection area on the front of the electronic device except for the display area. Specifically, the fingerprint identification module uses light returned from the top surface of the display assembly of the electronic device to perform fingerprint sensing and other sensing operations. This returned light carries information about objects (such as fingers) that are in contact with or close to the top surface of the display assembly, and the fingerprint recognition module located below the display assembly collects and detects this returned light to realize fingerprint recognition under the screen. Among them, the fingerprint recognition module can be designed to achieve desired optical imaging by appropriately configuring optical elements for collecting and detecting the returned light, so as to detect the fingerprint information of the finger.

Correspondingly, in-display fingerprint recognition technology refers to the installation of fingerprint recognition modules or part of fingerprint recognition modules inside the display screen, so that fingerprint recognition operations can be performed in the display area of the display screen, without the need for electronic The fingerprint collection area is set in the area on the front of the device except the display area.

Figures 1 to 4 show schematic diagrams of electronic devices to which the embodiments of the present application can be applied. 1 and FIG. 3 are schematic diagrams of the orientation of the electronic device 10, and FIG. 2 and FIG. 4 are schematic cross-sectional diagrams of the electronic device 10 shown in FIG. 1 and FIG. 3, respectively.

Referring to FIGS. 1 to 4, the electronic device 10 may include a display screen 120 and an optical fingerprint recognition module 130.

Wherein, the display screen 120 may be a self-luminous display screen, which uses a self-luminous display unit as a display pixel. For example, the display screen 120 may be an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. In other alternative embodiments, the display screen 120 may also be a liquid crystal display (LCD) or other passive light-emitting display, which is not limited in the embodiment of the present application. Further, the display screen 120 may also be specifically a touch-sensitive display screen, which can not only perform screen display, but also detect a user's touch or pressing operation, so as to provide the user with a human-computer interaction interface. For example, in an embodiment, the electronic device 10 may include a touch sensor, and the touch sensor may specifically be a touch panel (TP), which may be provided on the surface of the display screen 120, or may be partially integrated or The whole is integrated into the display screen 120 to form the touch display screen.

The optical fingerprint module 130 includes an optical fingerprint sensor, and the optical fingerprint sensor includes an optical sensing pixel array 133 (also referred to as an optical sensing unit, a photosensitive pixel, or a pixel unit, etc.) having a plurality of optical sensing pixels 131 Optical sensing unit array, sensing pixel array or pixel unit array, etc.). The area where the optical sensing pixel array 133 is located or the photosensitive area of the optical fingerprint module 130 (also referred to as the sensing area) corresponds to the fingerprint detection area 103 (also referred to as fingerprint collection area, fingerprint recognition area) of the optical fingerprint module 130 Wait).

It should be noted that each optical sensing pixel array in the optical sensing pixel array may include a photosensitive area and a non-photosensitive area, where the photosensitive area may be provided with a device for converting optical signals into electrical signals, such as photodetectors, The non-photosensitive area may be not provided with a device that converts light signals into electrical signals, and the non-photosensitive area may be provided with at least one metal wiring layer to realize the transmission of electrical signals from the photosensitive area to other devices.

Of course, at least one metal wiring layer for transmitting electrical signals can also be provided on the surface of the photosensitive area that is unlikely to receive optical signals, which is not limited in this application.

In other words, the optical sensing pixel 131 may include a photodetector, that is, the optical sensing pixel array 133 may specifically include a photodetector array, which includes a plurality of photodetectors distributed in an array.

Wherein, the optical fingerprint module 130 is arranged in a partial area below the display screen 120.

Please continue to refer to FIG. 1, the fingerprint detection area 103 may be located in the display area of the display screen 120. In an alternative embodiment, the optical fingerprint module 130 can also be arranged in other positions, such as the side of the display screen 120 or the non-transmissive area of the edge of the electronic device 10, and the optical fingerprint module 130 can be designed to The optical signal from at least a part of the display area of the display screen 120 is guided to the optical fingerprint module 130, so that the fingerprint detection area 103 is actually located in the display area of the display screen 120.

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

Please continue to refer to FIG. 2, the optical fingerprint module 130 may include a light detecting part 134 and an optical component 132. The light detection part 134 includes an optical fingerprint sensor (also referred to as the optical sensing pixel array 133), a reading circuit electrically connected to the optical sensing pixel array 133, and other auxiliary circuits, which can be used in semiconductor technology. Made on a chip (Die), such as an optical imaging chip or an optical fingerprint sensor. The optical component 132 may be disposed above the optical sensing pixel array 133 of the light detecting part 134, and it may specifically include a filter layer, a light guide layer or a light path guiding structure, and other optical elements. The light layer can be used to filter out ambient light penetrating the finger, and the light guide layer or light path guiding structure is mainly used to guide the reflected light reflected from the surface of the finger to the optical sensing pixel array 133 for optical detection.

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

In some embodiments of the present application, the area or light sensing range of the optical sensing pixel array 133 of the optical fingerprint module 130 corresponds to the fingerprint detection area 103 of the optical fingerprint module 130. Wherein, the fingerprint collection area 103 of the optical fingerprint module 130 may be equal to or not equal to the area or the light sensing range of the optical sensing pixel array 133 of the optical fingerprint module 130, which is not done in this embodiment of the application. Specific restrictions.

For example, the light path is guided by light collimation, the fingerprint detection area 103 of the optical fingerprint module 130 can be designed to be substantially the same as the area of the optical sensing pixel array 133 of the optical fingerprint module 130.

For another example, for example, through optical path design such as lens imaging, reflective folding optical path design, or other light converging or reflection optical path design, the area of the fingerprint detection area 103 of the optical fingerprint module 130 can be made larger than that of the optical fingerprint module. 130 optically senses the area of the pixel array 133.

The light path guiding structure that the optical assembly 132 may include is exemplarily described below.

Taking an optical collimator with a high-aspect-ratio through hole array in the optical path guiding structure as an example, the optical collimator may specifically be a collimator (Collimator) layer fabricated on a semiconductor silicon wafer, which has A plurality of collimating units or micro-holes, the collimating unit may be specifically a small hole, among the reflected light reflected from the finger, the light perpendicularly incident to the collimating unit can pass through and be received by the sensor chip below it , And the light whose incident angle is too large is attenuated by multiple reflections inside the collimating unit. Therefore, each sensor chip can basically only receive the reflected light reflected by the fingerprint pattern directly above it, which can effectively improve image resolution. Rate, and then improve the fingerprint recognition effect.

Taking the optical path design of the optical lens as an example of the optical path guiding structure, the optical path guiding structure may 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 to converge the reflected light reflected from the finger to the optical sensing pixel array 133 of the light detecting part 134 below it, so that the optical sensing pixel array 133 can perform imaging based on the reflected light, thereby obtaining the Finger fingerprint image. Further, the optical lens layer may also have a pinhole or a micro-aperture formed in the optical path of the lens unit, for example, one or more light-shielding sheets may be formed in the optical path of the lens unit, of which at least A light-shielding sheet may be formed with light-transmitting micro-holes in the optical axis or optical center area of the lens unit, and the light-transmitting micro-holes may serve as the aforementioned pinholes or micro-apertures. The pinhole or micro-aperture diaphragm can cooperate with the optical lens layer and/or other optical film layers above the optical lens layer to expand the field of view of the optical fingerprint module 130 to improve the optical fingerprint module 130 Fingerprint imaging effect.

Taking the light path design of the light path guiding structure using a micro-lens layer as an example, the light path guiding structure may include a micro lens array formed by a plurality of micro lenses, which may be formed by a semiconductor growth process or other processes Above the optical sensing pixel array 133 of the light detecting part 134, and each microlens may correspond to one of the sensing units of the optical sensing pixel array 133, respectively. In addition, other optical film layers may be formed between the micro lens layer and the sensing unit, such as a dielectric layer or a passivation layer. More specifically, a light blocking layer (or called a light blocking layer, a light blocking layer, etc.) with micro holes (or called openings) may also be included between the micro lens layer and the sensing unit, wherein the micro A hole is formed between the corresponding microlens and the sensing unit, the light blocking layer can block the optical interference between the adjacent microlens and the sensing unit, and make the light corresponding to the sensing unit converge through the microlens To the inside of the micropore and transfer to the sensing unit through the micropore for optical fingerprint imaging.

It should be understood that the foregoing several implementation solutions for the optical path guiding structure can be used alone or in combination.

For example, a micro lens layer may be further provided above or below the collimator layer or the optical lens layer. Of course, when the collimator layer or the optical lens layer is used in combination with the micro lens layer, its specific laminated structure or optical path may need to be adjusted according to actual needs.

On the other hand, the optical component 132 may also include other optical elements, such as filters or other optical films, which may be arranged between the optical path guiding structure and the optical fingerprint sensor or arranged at all. The display screen 120 and the optical path guide structure are mainly used to isolate the influence of external interference light on the optical fingerprint detection. Wherein, the filter layer may be used to filter out the ambient light that penetrates the finger and enters the optical fingerprint sensor through the display screen 120. Similar to the light path guiding structure, the filter layer may be specific to each The optical fingerprint sensors are separately arranged to filter out interference light, or a large-area filter layer can also be used to simultaneously cover the multiple optical fingerprint sensors.

The fingerprint identification module 140 may be used to collect user fingerprint information (such as fingerprint image information).

Take the display screen 120 with a self-luminous display unit as an example, such as an Organic Light-Emitting Diode (OLED) display or a Micro-LED (Micro-LED) display. The optical fingerprint module 130 can use the display unit of the OLED display 120 located in the fingerprint detection area 103 (i.e., an OLED light source) as an excitation light source for optical fingerprint detection. When the finger 140 is pressed on the fingerprint detection area 103, the display screen 120 emits a beam of light 111 to the target finger 140 above the fingerprint detection area 103. The light 111 is reflected on the surface of the finger 140 to form reflected light or pass through all the fingers. The finger 140 scatters inside to form scattered light (transmitted light). In related patent applications, for ease of description, the above-mentioned reflected light and scattered light are collectively referred to as reflected light. Since the ridge 141 and valley 142 of the fingerprint have different light reflection capabilities, the reflected light 151 from the fingerprint ridge and the reflected light 152 from the fingerprint valley have different light intensities, and the reflected light passes through the optical component 132 Then, it is received by the optical sensor pixel array 133 in the optical fingerprint module 130 and converted into a corresponding electrical signal, that is, a fingerprint detection signal; based on the fingerprint detection signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed , So as to realize the optical fingerprint recognition function in the electronic device 10.

In other alternatives, the optical fingerprint module 130 may also use a built-in light source or an external light source to provide an optical signal for fingerprint detection and identification. In this case, the optical fingerprint module 130 can be applied not only to self-luminous displays such as OLED displays, but also to non-self-luminous displays, such as liquid crystal displays or other passive light-emitting displays.

Taking a liquid crystal display with a backlight module and a liquid crystal panel as an example, in order to support the under-screen fingerprint detection of the liquid crystal display, the optical fingerprint system of the electronic device 10 may also include an excitation light source for optical fingerprint detection. The light source may specifically be an infrared light source or a light source of invisible light of a specific wavelength, which may be arranged under the backlight module of the liquid crystal display or arranged in the edge area under the protective cover of the electronic device 10, and the optical fingerprint module 130 can be arranged under the edge area of the liquid crystal panel or the protective cover and guided by the light path so that the fingerprint detection light can reach the optical fingerprint module 130; or, the optical fingerprint module 130 can also be arranged on the backlight module Below, and the backlight module is designed to allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint module 130 by perforating film layers such as diffuser, brightness enhancement film, reflective film, etc. . When the optical fingerprint module 130 adopts a built-in light source or an external light source to provide an optical signal for fingerprint detection, the detection principle is the same as that described above.

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

On the other hand, the optical fingerprint module 130 may include only one optical fingerprint sensor. At this time, the fingerprint detection area 103 of the optical fingerprint module 130 has a small area and a fixed position. Therefore, the user needs to press his finger when performing fingerprint input. Go to the specific position of the fingerprint detection area 103, otherwise the optical fingerprint module 130 may not be able to collect fingerprint images, resulting in poor user experience. In other alternative embodiments, the optical fingerprint module 130 may specifically include a plurality of optical fingerprint sensors. The multiple optical fingerprint sensors may be arranged side by side under the display screen 120 in a splicing manner, and the fingerprint detection areas of the multiple optical fingerprint sensors collectively constitute the fingerprint detection area 103 of the optical fingerprint module 130. Therefore, the fingerprint detection area 103 of the optical fingerprint module 130 can be extended to the main area of the lower half of the display screen, that is, to the area where the finger is habitually pressed, so as to realize the blind fingerprint input operation. Further, when the number of optical fingerprint sensors is sufficient, the fingerprint detection area 103 can also be extended to half of the display area or even the entire display area, thereby realizing half-screen or full-screen fingerprint detection.

Referring to FIGS. 3 and 4, the optical fingerprint module 130 in the electronic device 10 may include a plurality of optical fingerprint sensors, and the plurality of optical fingerprint sensors may be arranged side by side on the display screen 120 by means such as splicing. Below, and the fingerprint detection areas of the multiple optical fingerprint sensors collectively constitute the fingerprint detection area 103 of the optical fingerprint device 130.

Further, the optical component 132 may include a plurality of light path guiding structures, and each light path guiding structure corresponds to an optical fingerprint sensor (that is, the optical sensing pixel array 133), and is attached and arranged above the corresponding optical fingerprint sensor. . Alternatively, the multiple optical fingerprint sensors may also share an overall light path guiding structure, that is, the light path guiding structure has an area large enough to cover the optical sensing pixel array 133 of the multiple optical fingerprint sensors.

Taking the optical component 132 using an optical collimator with a high-aspect-ratio through hole array as an example, when the optical fingerprint module 130 includes multiple optical fingerprint sensors, it may be an optical sensor pixel of each optical fingerprint sensor. One optical sensing pixel in the array 133 is configured with one or more collimating units, and is attached and arranged above the corresponding optical sensing pixel. Of course, the plurality of optical sensing pixels may also share one collimating unit, that is, the one collimating unit has an aperture large enough to cover the plurality of optical sensing pixels. Since one collimating unit can correspond to multiple optical sensing pixels or one optical sensing pixel corresponds to multiple collimating units, the correspondence between the spatial period of the display screen 120 and the spatial period of the optical fingerprint sensor is destroyed. Therefore, even if the display screen 120 is The spatial structure of the light-emitting display array is similar to the spatial structure of the optical sensing pixel array 133 of the optical fingerprint sensor. It can also effectively prevent the optical fingerprint module 130 from using the light signal passing through the display 120 to perform fingerprint imaging to generate moiré fringes, which effectively improves the optical The fingerprint recognition effect of the fingerprint module 130.

Taking the optical component 132 using an optical lens as an example, when the optical fingerprint module 130 includes multiple sensor chips, one optical lens can be configured for each sensor chip to perform fingerprint imaging, or one optical lens can be configured for multiple sensor chips. Realize light convergence and fingerprint imaging. Even when a sensor chip has two optical sensing pixel arrays (Dual Array) or multiple optical sensing pixel arrays (Multi-Array), it is also possible to configure two or more optical lenses for the sensor chip to cooperate with the two optical sensing pixel arrays (Dual Array) or multiple optical sensing pixel arrays (Multi-Array). One optical sensing pixel array or multiple optical sensing pixel arrays perform optical imaging, thereby reducing the imaging distance and enhancing the imaging effect.

It should be understood that FIGS. 1 to 4 are only examples of the present application, and should not be construed as limiting the present application.

For example, this application does not specifically limit the number, size, and arrangement of fingerprint sensors, which can be adjusted according to actual needs. For example, the optical fingerprint module 130 may include a plurality of fingerprint sensors distributed in a square or circular shape.

For another example, the optical fingerprint module 130 or the electronic device 10 may also include an external light source (similar to the above-mentioned excitation light source). The light signal emitted by the external light source is used to reinforce the light signal emitted by the display screen 120. The light signal emitted by the external light source can be used for fingerprint detection or for displaying images. The light signal emitted by the external light source can be transmitted in the transparent cover of the display screen 120 in a manner of approximately total reflection, thereby improving the quality of the fingerprint image and the fingerprint recognition effect. For ease of description, the following uses a schematic diagram of the relationship between the fingerprint detection device and the display screen as an example to describe the structure and optical transmission principle of the display screen.

5 to 9 are the relationship between the fingerprint detection device 205 (similar to the above-mentioned optical module 130) and the display screen (similar to the above-mentioned 120) of the electronic device 200 (similar to the above-mentioned electronic device 10) according to an embodiment of the present application Schematic structure diagram. The fingerprint detection device 205 is suitable for an electronic device 20 with a display screen to realize fingerprint recognition under the screen.

As shown in FIG. 5, under normal circumstances, the display screen may include a transparent cover 201, an optical adhesive layer 202, and a display layer 203 in order from top to bottom. Wherein, the transparent cover 201 can be used as a touch interface for fingerprint detection or fingerprint recognition, and can also be used as a display interface for displaying images. The optical adhesive layer 202 may be an optical clear adhesive (OCA), and the optical adhesive layer 202 may be a solid adhesive or a liquid adhesive. The display layer 203 may be a self-luminous display layer or a non-self-luminous display layer. For example, the display layer 203 may also be called a display panel. The display panel may include a plurality of light-emitting pixels. The light signals emitted by the plurality of light-emitting pixels are used to display an image, and in addition, the light signals sensed by at least a part of the light-emitting pixels of the plurality of light-emitting pixels are used for fingerprint detection or fingerprint recognition.

Wherein, the fingerprint detection device 205 or the electronic device 200 may further include an external light source 204. Optionally, the external light source 204 may be arranged under the transparent cover 201, or may be arranged at the bottom edge of the electronic device 200. The transmission path of the light signal emitted by the external light source 204 can be configured as: when the light exit direction of the external light source 204 and the glass cover are adjusted to be within a specific angle range, the light emitted by the external light source 204 is as shown in FIG. 5 It will propagate in the transparent cover 201 in a manner of approximate total reflection.

Further, as shown in FIG. 6, when the finger 206 touches the transparent cover 201, the interface between the transparent cover 201 and the air to achieve the condition of total reflection is destroyed by the finger 206 (the refractive index of the finger stratum corneum is generally about 1.55). , Larger than air); correspondingly, the light signal transmitted in the transparent cover 201 enters the finger 206 and illuminates the finger 206; after the light carrying the fingerprint signal passes through the entire display screen, it is The fingerprint detection device 205 (for example, an overall module structure including a fingerprint recognition sensor and an optical path system) receives and processes the fingerprint detection device, thereby performing fingerprint recognition.

It should be noted that the external light source 204 can be used as a separate fingerprint recognition light source, or can be used as a reinforcing light source for an existing light source (the existing light source can be provided by the OLED screen).

In some embodiments of the present application, the electronic device 200 may further include a first transparent medium layer disposed between the transparent cover 201 and the optical adhesive layer 202.

For example, as shown in FIG. 7, the display screen includes a transparent cover 201, a first transparent medium layer 207, an optical adhesive layer 202, and a display layer 203 from top to bottom; wherein, the fingerprint detection device 205 includes a fingerprint sensor Chip, the fingerprint sensor chip is used to be arranged under the display screen, the fingerprint sensor chip is used to receive the light signal sent by the external light source 204 through the finger above the display screen to detect the finger Fingerprint information; wherein, the refractive index of the first transparent medium layer 207 may be smaller than the refractive index of the optical adhesive layer 202 and the transparent cover 201, so that the optical signal emitted by the external light source 204 can be in the transparent cover The inside of the board 201 performs total reflection. Optionally, the first transparent medium layer 207 is bonded to the display layer 203 through the optical adhesive layer 202.

It should be noted that the first transparent medium layer 207 may be attached to the lower surface of the transparent cover plate 201. At this time, the first transparent medium layer 207 is attached to the display through the optical adhesive layer 202. The layer 203 is equivalent to that the transparent cover 201 is bonded to the optical adhesive layer 202 through the first transparent medium layer 207.

In other words, during the preparation process, the first transparent medium layer 207 can be directly prepared on the lower surface of the transparent cover plate 201, and during installation, the transparent cover plate 201 is directly prepared with the first transparent medium layer The surface where 207 is located is bonded to the display layer 203 through the optical adhesive layer 202.

Of course, during the preparation and installation process, the first transparent medium layer 207 can also be used as a medium layer physically separated from the transparent cover plate 201, which is not specifically limited in this application.

By arranging the first transparent medium layer 207 on the transparent cover 201 and the optical adhesive layer 202, and making the refractive index of the first transparent medium layer 207 smaller than the refractive index of the optical adhesive layer 202, So that the interface between the transparent cover 201 and the first transparent medium layer 207 can meet the condition of total reflection, thereby making it irradiate at a certain angle (incident angle greater than the critical angle) to the transparent cover 201 and the first transparent medium layer. The optical signal of the interface between a transparent medium layer 207 can be transmitted in the transparent cover 201 in a manner of total reflection, thereby improving the quality of the fingerprint image and the fingerprint recognition effect.

In other alternative embodiments, the refractive index of the optical adhesive layer 202 can also be directly reduced, so that the refractive index of the optical adhesive layer 202 is close to the refractive index of air.

However, because the refractive index of the optical adhesive layer 202 is too low, the luminous flux of the display layer 203 will be affected, that is, the light signal emitted by the display layer 203 through the optical adhesive layer 202 will be reduced. By setting the first transparent medium layer 207, the refractive index of the first transparent medium layer can be set only to the refractive index for the wavelength of the external light source, which is then distinguished from the wavelength of the optical signal emitted by the display layer 203 Open to improve the fingerprint image quality and fingerprint detection or recognition effect while ensuring the luminous flux.

In some possible implementations, the refractive index of the first transparent medium layer 207 is greater than the refractive index of air.

In other words, the refractive index of the first transparent medium layer 207 is greater than the refractive index of air and smaller than the refractive index of the optical adhesive layer 202.

By the refractive index of the first transparent medium layer 207 being greater than the refractive index of air, it can be shot at a certain angle (incidence angle greater than the critical angle) between the transparent cover 201 and the first transparent medium layer 207 The optical signal of the interface can propagate in the transparent cover 201 in a way of total reflection, thereby improving the quality of fingerprint images and the effect of fingerprint recognition; moreover, by controlling the refractive index of the first transparent medium layer 207, it can be avoided For the critical angle (that is, the total reflection angle) of the interface between the first transparent medium layer 207 and the optical adhesive layer 202 is too small, it is beneficial for the optical signal with a certain radiation angle emitted by the display layer 203 to pass through The optical adhesive layer 202 is transmitted to the first transparent medium layer 207, and accordingly, the signal amount of the optical signal received by the finger is increased and the screen brightness is improved.

In some possible implementations, different refractive indexes of the first transparent medium layer 207 correspond to different wavelength ranges, and the wavelength range is the wavelength range of the optical signal emitted by the external light source 204.

In other words, the refractive index of the first transparent medium layer 207 has a corresponding relationship with the wavelength range of the optical signal emitted by the external light source 204. For example, assuming that the wavelength of the optical signal emitted by the external light source 204 is 550 nm, the refractive index of the first transparent medium layer 207 refers to the refractive index corresponding to 550 nm. For another example, assuming that the wavelength range of the optical signal emitted by the external light source 204 is 800 nm to 900 nm, the refractive index of the first transparent medium layer 207 refers to the refractive index corresponding to the wavelength range of 800 nm to 900 nm.

By associating the refractive index of the first transparent medium layer 207 with the wavelength range of the light signal emitted by the external light source 204, it not only ensures that the light emitted by the external light source 204 is totally reflected in the transparent cover 201 Signal, and can reduce the possibility or probability of total reflection of the light signal emitted by the display layer 203 on the transparent cover 201, which is beneficial to improve the performance of the electronic device.

In some possible implementations, the refractive index of the first transparent medium layer 207 ranges from 1.1 to 1.3. For example, the refractive index of the first transparent medium layer 207 may be 1.2. At this time, according to the law of total reflection, when the refractive index of the transparent cover 201 is 1.5 and the refractive index of air is 1, the critical angle of total reflection at the interface between the transparent cover 201 and the air is 41.8°. At the interface between 201 and the low refractive index material, the critical angle of total reflection is 53.1°. In other words, when the incident angle of light at the interface between the transparent cover plate 201 and the first transparent medium layer 207 is greater than 53.1°, the upper and lower surfaces of the transparent cover plate 201 meet the condition of total reflection, which results in the phenomenon of total reflection. The total reflection propagation is performed in the transparent cover 201. When a finger touches the surface of the transparent cover plate 201, the condition of the total reflection interface between the transparent cover plate 201 and the air is destroyed, and light can propagate into the finger, thereby illuminating the finger.

It should be noted that the present application does not limit the material and specific structure of the first transparent medium layer 207, which enables the optical signal emitted by the external light source 204 to be totally reflected in the transparent cover 201. Any medium can be used as the first lens medium layer 207.

For example, the light transmittance of the first transparent medium layer 207 is greater than 90%.

For another example, the material of the first transparent medium layer 207 includes at least one of the following materials:

By setting the material of the first transparent medium layer 207 to the above-mentioned materials, it is not only convenient to arrange the first transparent medium layer 207 between the transparent cover plate 201 and the optical adhesive layer 202, but also does not affect the The transparent cover 201 provided with the first transparent medium layer 207 is bonded or adhered to the upper surface of the display layer 203 through the optical adhesive layer 202.

In some possible implementation manners, the electronic device 200 may further include a second transparent medium layer disposed between the first transparent medium layer 207 and the optical adhesive layer 202.

For example, as shown in FIG. 7, the display screen may further include a second transparent medium layer 208, the second transparent medium layer 208 is disposed under the first transparent medium layer 207, and the second transparent medium layer 208 is bonded to the display layer 203 through the optical adhesive layer 202, wherein the refractive index of the second transparent medium layer 208 is smaller than the refractive index of the optical adhesive layer 202 to reduce the light emitted by the display screen. The loss caused when a signal enters the transparent cover 201.

By installing a second transparent medium layer 208 between the first transparent medium layer 207 and the optical adhesive layer 202, it is equivalent to transmitting the optical signal from the display layer 203 to the path of the transparent cover 201 , Convert an interface with a small total reflection angle (as shown in FIG. 8, the interface between the optical adhesive layer 202 and the first transparent medium layer 207) into two interfaces with a large total reflection angle (As shown in FIG. 9, the interface between the optical adhesive layer 202 and the second transparent medium layer 208, and the interface between the second transparent medium layer 208 and the first transparent medium layer 207) , Which is equivalent to increasing the total reflection angle of the light signal emitted by the display layer 203 as a whole, thereby increasing the luminous flux of the light signal emitted by the display layer 203, which not only ensures that the finger can receive enough light signals, It can also ensure that there are enough light signals to display the image, and correspondingly, the quality of the fingerprint image and the fingerprint recognition effect can be improved, and the performance of the electronic device can also be guaranteed.

When the first transparent medium layer 207 is arranged under the transparent cover plate 201, the material of the optical adhesive layer 202 and the material of the first transparent medium layer 207 have a relatively large difference in refractive index. When the refractive index of 202 is 1.47 and the refractive index of the first transparent medium layer 207 is 1.2, according to the law of total reflection, when the light emitted by the display layer 203 reaches the optical adhesive layer 202 and the first transparent medium layer At the interface of 207, if the incident angle is greater than or equal to 54.2°, the light will be totally reflected. For example, as shown in Figure 10, based on the relationship between the radiation angle of the light signal emitted by the light-emitting layer in the OLED screen and the luminous flux, when the radiation angle θ is greater than 54.2°, the luminous flux accounts for approximately 10.8% of the total amount of light emitted by the display layer. . In other words, considering the total reflection loss, when the first transparent medium layer 207 is disposed under the transparent cover 201, the luminous flux loss of the OLED is estimated to be greater than 10.8%.

However, if at least one second transparent medium with a refractive index between the first transparent medium layer 207 and the optical adhesive layer 202 is provided between the first transparent medium layer 207 and the optical adhesive layer 202 Layer 208. That is, the refractive index of the optical adhesive layer 202>the refractive index of the second transparent medium layer 208>the refractive index of the first transparent medium layer 207. Assuming that the refractive index of the second transparent medium layer 208 is 1.38, considering the interface between the optical adhesive layer 202 and the second transparent medium layer 208, and the second transparent medium layer 208 and the first transparent medium layer 208 Affected by the total reflection occurring at the interface between the transparent medium layers 207, the luminous flux loss of the OLED is estimated to be 4.1%, which greatly reduces the luminous flux loss of the OLED.

In some possible implementations, the refractive index of the second transparent medium layer 208 is greater than the refractive index of the first transparent medium layer 207.

The refractive index of the second transparent medium layer 208 is configured to be greater than the refractive index of the first transparent medium layer 207, which can ensure that the interface between the second transparent medium layer 208 and the optical adhesive layer 202 is The total reflection angle is greater than the total reflection angle of the interface between the first transparent medium layer 207 and the optical adhesive layer 202 when the second transparent medium layer 208 is not provided. Accordingly, it can improve the fingerprint image. The quality and fingerprint recognition effect ensure the performance of the electronic device.

Similar to the first transparent medium layer 207, the transparent medium that can increase the total reflection angle of the display screen as a whole can be used as the second lens medium layer 208.

For example, the material of the second transparent medium layer 208 includes at least one of the following materials:

Constructing the material of the second transparent medium layer 208 as the above-mentioned material not only facilitates the arrangement of the second transparent medium layer 208, but also ensures the connection between the first transparent medium layer 207 and the optical adhesive layer 202 And stability.

In some possible implementations, the second transparent medium layer 208 includes at least one medium layer, and at least one refractive index corresponding to the at least one medium layer is the same, or the at least one refractive index is partially the same, or the at least one A refractive index is different from each other.

Therefore, as a whole, the total reflection angle of the light signal emitted by the display layer 203 can be effectively increased, which is beneficial to increase the luminous flux.

In some possible implementations, the external light source 204 is disposed under the transparent cover plate 201 and located on one side of the display layer 203; or, the external light source 204 is disposed on the transparent cover plate 201 internal.

In some possible implementations, the transparent cover 201 is a glass cover, or the material of the transparent cover 201 is a flexible material.

In addition, an embodiment of the present application also provides an electronic device (similar to the above-mentioned electronic device 10 or electronic device 200). The electronic device may include a display screen and the fingerprint detection device described above, and the fingerprint detection device is set at Below the display screen, the fingerprint detection device includes a fingerprint sensor chip, the fingerprint sensor chip is configured to be arranged below the display screen, and the fingerprint sensor chip is configured to receive signals emitted by an external light source through the display screen. The optical signal returned by the upper finger to detect the fingerprint information of the finger;

Wherein, the display screen includes a transparent cover plate, a first transparent medium layer, an optical adhesive layer, and a display layer in order from top to bottom, and the refractive index of the first transparent medium layer is smaller than the refractive index of the optical adhesive layer, so that the The light signal emitted by the external light source can be totally reflected inside the transparent cover plate.

Optionally, the electronic equipment includes, but is not limited to, mobile phones, computers, multimedia machines, and game consoles.

It should be noted that the terms used in the embodiments of the application and the appended claims are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the application.

For example, the singular forms of "a", "said", "above" and "the" used in the embodiments of this application and the appended claims are also intended to include plural forms, unless the context clearly indicates other forms. meaning.

Those skilled in the art may be aware that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered as going beyond the scope of the embodiments of the present application.

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

Those skilled in the art can clearly understand that, for the convenience and conciseness of the description, the specific working process of the equipment, device and unit described above can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed electronic equipment, apparatus, and method may be implemented in other ways.

For example, the division of units or modules or components in the device embodiments described above is only a logical function division, and there may be other divisions in actual implementation. For example, multiple units or modules or components can be combined or integrated. To another system, or some units or modules or components can be ignored or not executed.

For another example, the aforementioned units/modules/components described as separate/display components may or may not be physically separated, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units/modules/components may be selected according to actual needs to achieve the objectives of the embodiments of the present application.

Finally, it should be noted that the mutual coupling or direct coupling or communication connection shown or discussed above may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms. .

The above content is only specific implementations of the embodiments of the application, but the scope of protection of the embodiments of the application is not limited thereto. Any person skilled in the art can easily think of the technical scope disclosed in the embodiments of the application. The change or replacement shall be covered within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of the present application should be subject to the protection scope of the claims.

Claims

A fingerprint detection device, characterized in that the fingerprint detection device is suitable for electronic equipment with a display screen to realize fingerprint recognition under the screen, and the display screen includes a transparent cover plate, a first transparent medium layer, Optical adhesive layer and display layer;

The fingerprint detection device includes:

Fingerprint sensor chip, the fingerprint sensor chip is used to be arranged below the display screen, the fingerprint sensor chip is used to receive the light signal sent by the external light source through the finger above the display screen to detect the finger Fingerprint information;

Wherein, the refractive index of the first transparent medium layer is respectively smaller than the refractive index of the optical adhesive layer and the refractive index of the transparent cover, so that the optical signal emitted by the external light source can be inside the transparent cover. Perform total reflection.
The fingerprint detection device according to claim 1, wherein the refractive index of the first transparent medium layer is greater than the refractive index of air.
The fingerprint detection device according to claim 1 or 2, wherein the different refractive indexes of the first transparent medium layer correspond to different wavelength ranges, and the wavelength range is the wavelength range of the optical signal emitted by the external light source .
The fingerprint detection device according to any one of claims 1 to 3, wherein the refractive index of the first transparent medium layer is in the range of 1.1-1.3.
The fingerprint detection device according to any one of claims 1 to 4, wherein the light transmittance of the first transparent medium layer is greater than 90%.
The fingerprint detection device according to any one of claims 1 to 5, wherein the material of the first transparent medium layer comprises at least one of the following materials:

Organic coating materials, inorganic oxides, inorganic fluorides, and inorganic nitrides.
The fingerprint detection device according to any one of claims 1 to 6, wherein the first transparent medium layer is bonded to the display layer through the optical adhesive layer.
The fingerprint detection device according to any one of claims 1 to 6, wherein the display screen further comprises a second transparent medium layer, and the second transparent medium layer is disposed on the surface of the first transparent medium layer. Below, the second transparent medium layer is bonded to the display layer through the optical adhesive layer, wherein the refractive index of the second transparent medium layer is less than the refractive index of the optical adhesive layer to reduce the display The loss caused when the light signal emitted by the screen enters the transparent cover.
8. The fingerprint detection device according to claim 8, wherein the refractive index of the second transparent medium layer is greater than the refractive index of the first transparent medium layer.
The fingerprint detection device according to claim 8 or 9, wherein the material of the second transparent medium layer comprises at least one of the following materials:

Organic coating materials, inorganic oxides, inorganic fluorides, and inorganic nitrides.
The fingerprint detection device according to any one of claims 8 to 10, wherein the second transparent medium layer comprises at least one medium layer, and at least one refractive index corresponding to the at least one medium layer is the same, or The at least one refractive index is partially the same, or the at least one refractive index is different from each other.
The fingerprint detection device according to any one of claims 1 to 11, wherein the external light source is arranged under the transparent cover plate and located on one side of the display layer; or, the external light source The light source is arranged inside the transparent cover plate.
The fingerprint detection device according to any one of claims 1 to 12, wherein the fingerprint sensor chip is further configured to receive the light signal returned by the finger from the display screen to detect the finger Fingerprint information.
The fingerprint detection device according to any one of claims 1 to 13, wherein the transparent cover is a glass cover, or a material of the transparent cover is a flexible material.
An electronic device, characterized in that it comprises:

Display screen; and

The fingerprint detection device according to any one of claims 1 to 14, wherein the fingerprint detection device is arranged below the display screen, the fingerprint detection device comprises a fingerprint sensor chip, and the fingerprint sensor chip is configured to be arranged at Below the display screen, the fingerprint sensor chip is configured to receive light signals sent by an external light source and returned via a finger above the display screen, so as to detect fingerprint information of the finger;

Wherein, the display screen includes a transparent cover plate, a first transparent medium layer, an optical adhesive layer, and a display layer in order from top to bottom, and the refractive index of the first transparent medium layer is smaller than the refractive index and the refractive index of the optical adhesive layer. The refractive index of the transparent cover allows the light signal emitted by the external light source to be totally reflected inside the transparent cover.
The electronic device according to claim 15, wherein the display screen further comprises a rear panel located below the display layer, a material of the rear panel is an opaque material, and the rear panel is provided with openings The fingerprint detection device is arranged below the opening, so that the fingerprint sensor chip in the fingerprint detection device receives the light signal returned via the finger through the opening.