CN110502177B

CN110502177B - Screen unlocking method and device for synchronously verifying fingerprint information

Info

Publication number: CN110502177B
Application number: CN201810475509.XA
Authority: CN
Inventors: 黄建东
Original assignee: Shanghai Harvest Intelligence Tech Co Ltd
Current assignee: Shanghai Harvest Intelligence Tech Co Ltd
Priority date: 2018-05-17
Filing date: 2018-05-17
Publication date: 2021-06-11
Anticipated expiration: 2038-05-17
Also published as: TW202213138A; CN113535049A; WO2019219061A1; CN110502177A; TWI750473B; TWI790848B; TW202004542A

Abstract

The invention provides a screen unlocking method and a screen unlocking device for synchronously verifying fingerprint information, wherein the method is applied to the screen unlocking device for synchronously verifying the fingerprint information, the device comprises a display unit and a sensing unit, a fingerprint identification area is arranged on the display unit, and the sensing unit is positioned below the fingerprint identification area and is used for acquiring the fingerprint information on the fingerprint identification area; the method comprises the following steps: receiving a sliding track of a user on the fingerprint identification area, and synchronously acquiring fingerprint information corresponding to the user finger; and when the sliding track of the user on the fingerprint identification area is matched with the preset sliding track, judging whether the synchronously acquired fingerprint information is matched with the preset fingerprint information, if so, completing screen unlocking, and otherwise, failing to unlock the screen. Therefore, the safety of screen unlocking is effectively improved, and the operation experience of a user is enhanced.

Description

Screen unlocking method and device for synchronously verifying fingerprint information

Technical Field

The invention relates to the field of electronic equipment, in particular to a screen unlocking method and device for synchronously verifying fingerprint information.

Background

With the development of technology and technology, touch display panels have been widely used in devices requiring human-computer interaction interfaces, such as operation screens of industrial computers, tablet computers, touch screens of smart phones, and the like. Since these devices are usually accompanied by a large amount of user information during the use process, the protection of user information security is very important. Among the many ways of securing information, fingerprint identification encryption is an important item.

Currently, the power-on unlocking of the electronic device generally comprises a screen sliding unlocking mode and a fingerprint unlocking mode. The screen sliding unlocking is realized by comparing a sliding track input by a user with a preset sliding track, and if the sliding track is matched with the preset sliding track, the electronic equipment is unlocked. The fingerprint unlocking is to compare the currently collected user fingerprint information with the pre-stored fingerprint information, and if the user fingerprint information is matched with the pre-stored fingerprint information, the electronic equipment is unlocked.

However, in the current display panel technology, no matter a Liquid Crystal Display (LCD), an Active Matrix Organic Light Emitting Diode (AMOLED) display, or a micro-LED display, a Thin Film Transistor (TFT) structure is used to scan and drive a single pixel, so as to realize the display function of the on-screen pixel array. The main structure forming the switching function of the TFT is a semiconductor Field Effect Transistor (FET), in which the well-known main materials of the semiconductor layer are amorphous silicon, polycrystalline silicon, Indium Gallium Zinc Oxide (IGZO), or organic compounds mixed with carbon nanomaterials, and the like. Since the structure of the Photo Diode (Photo Diode) can also be made of such semiconductor material, and the manufacturing equipment is compatible with the TFT array manufacturing equipment, and the manufactured photodiode can be directly integrated with the TFT and scan and drive the photodiode by using the TFT, the TFT Photo Diode has recently been manufactured by the TFT array manufacturing method and is widely used in the X-ray sensing flat panel device, as described in the patent CN103829959B and CN 102903721B.

Compared with the image sensor device prepared by the traditional crystal material, the light forbidden Band width (Band gap) of the TFT photodetection array film material takes visible light as the main absorption range, so that the TFT photodetection array film material is more easily interfered by the ambient visible light to form noise, and the signal-to-noise ratio (SNR) is lower. The primary application of TFT light sensing array is mainly the application of X-ray sensing flat panel device, mainly because X-ray is short wavelength light and has high collimation, the X-ray image firstly enters the light wavelength conversion material configured on the sensing flat panel, and the visible light with longer wavelength converted from the X-ray image is then directly transmitted to the TFT light sensing array film inside the sensing flat panel, so as to avoid the noise interference caused by the visible light of the surrounding environment, as described in the above-mentioned patents CN103829959B and CN 102903721B.

Such a well-known TFT visible light detection array film can be used as an implementation solution for integrating the light detection function into the display panel if it is disposed in the display panel structure. However, due to the thickness of the display screen and the aperture of the display pixel opening, the real image sensed by the photo diode array is an image with optical distortion such as diffraction, and the optical signal penetrates through the multi-layer structure of the display screen, and under the condition that the optical display signal and the touch sensing signal coexist, the difficulty level of extracting the useful optical signal from the low signal-to-noise ratio scene is very high, the technical difficulty level reaches the level of nearly single photon imaging, and the original image must be analyzed by the related algorithm based on the light wave theory operation reconstruction. To avoid this difficulty, it is known that disposing the visible light sensor film in the original display structure requires additional optical enhancement devices, or disposing the light sensor film only in the side of the display, and performing light image reconstruction by using light reaching the side in non-perpendicular reflection, for example: the patent of the people's republic of china CN 101359369B. However, although the technology can avoid the technical difficulty of low-light imaging, the additional optical device increases the thickness of the light detection display screen, and the configuration mode at the side of the display screen cannot meet the full-screen experience of the user.

In short, the current electronic device still collects the user fingerprint information through a corresponding sensor, and the user can only place a finger at a specific position (for example, a HOME key of an apple cell phone) outside a screen, so that the user fingerprint information can be collected by the sensor below, the operation position is fixed, and the user sensory experience is poor.

In summary, it is very necessary to provide a screen unlocking scheme for synchronously authenticating user fingerprint information while a user performs screen sliding unlocking.

Disclosure of Invention

Therefore, a technical scheme for synchronously verifying the screen unlocking of the fingerprint information needs to be provided, and the problems of low safety, limited user operation space, poor experience and the like in the existing screen unlocking mode are solved.

In order to achieve the above object, the inventor provides a screen unlocking method for synchronously verifying fingerprint information, which is applied to a device for synchronously unlocking a screen for verifying fingerprint information, wherein the device comprises a display unit and a sensing unit, a fingerprint identification area is arranged on the display unit, and the sensing unit is positioned below the fingerprint identification area and is used for acquiring the fingerprint information on the fingerprint identification area; the method comprises the following steps:

receiving a sliding track of a user on the fingerprint identification area, and synchronously acquiring fingerprint information corresponding to the user finger;

and when the sliding track of the user on the fingerprint identification area is matched with the preset sliding track, judging whether the synchronously acquired fingerprint information is matched with the preset fingerprint information, if so, completing screen unlocking, and otherwise, failing to unlock the screen.

Furthermore, the sensing unit is a light detection array film, the light detection array film comprises PxQ pixel detection areas, each pixel detection area is correspondingly provided with a pixel detection structure, and each pixel detection structure comprises a group of pixel thin film circuits and a light detection unit, wherein the group of pixel thin film circuits is composed of more than one thin film transistor; the light detection unit comprises a photosensitive diode or a photosensitive transistor.

Further, the light detection array film is an array formed by a photosensitive diode, the photosensitive diode comprises a photosensitive diode induction area, a photosensitive diode layer is arranged in the photosensitive diode induction area, the photosensitive diode layer comprises a p-type semiconductor layer, an i-type semiconductor layer and an n-type semiconductor layer, the p-type semiconductor layer, the i-type semiconductor layer and the n-type semiconductor layer are stacked from top to bottom, and the i-type semiconductor layer is of a microcrystalline silicon structure or a non-crystalline silicon germanium structure.

Further, the light detection array film is an array formed by a photosensitive transistor, the photosensitive transistor comprises a photosensitive transistor sensing area, the photosensitive transistor sensing area is provided with a photosensitive thin film transistor, and the photosensitive thin film transistor comprises a grid electrode, a source electrode, a drain electrode, an insulating layer and a light absorption semiconductor layer; the photosensitive thin film transistor is an inverted coplanar structure, and the inverted coplanar structure comprises: the grid electrode, the insulating layer and the source electrode are longitudinally arranged from bottom to top, and the drain electrode and the source electrode are transversely arranged in a coplanar manner; the insulating layer wraps the grid so that the grid is not in contact with the source electrode and the drain electrode; the source electrode and the drain electrode are in clearance fit, a photosensitive leakage current channel is formed between the source electrode and the drain electrode in the transverse direction, and the light absorption semiconductor layer is arranged in the photosensitive leakage current channel.

Furthermore, the fingerprint identification area comprises a plurality of fingerprint identification sub-areas, and a sensing unit is correspondingly arranged below each fingerprint identification sub-area; the method comprises the following steps:

receiving a starting instruction of a user to the fingerprint identification sub-area, and starting a sensing unit below the fingerprint identification sub-area;

or receiving a closing instruction of a user to the fingerprint identification sub-area, and closing the sensing unit below the fingerprint identification sub-area.

Furthermore, the display unit is a self-luminous diode display screen, and the device further comprises cover plate glass, a touch screen, optical cement and an optical device;

the cover plate glass, the touch screen, the self-luminous diode display screen, the optical cement, the optical device and the sensing unit are arranged from top to bottom; the touch screen is attached to the lower surface of the cover plate glass, and the optical adhesive is attached to the lower surface of the self-luminous diode display screen; the refractive index of the optical cement is smaller than that of the cover plate glass, and the self-luminous diode display screen comprises a plurality of display pixels; the apparatus also includes a processor;

the receiving of the sliding track of the user on the fingerprint identification area and the synchronous acquisition of the fingerprint information corresponding to the user finger include:

when the touch screen detects a touch signal of a finger of a user, the processor sends a display driving signal to the self-luminous diode display screen;

when the display pixels receive the display driving signals of the processor, the display pixels send out optical signals, and the optical signals are reflected on the upper surface of the cover plate glass to form reflected optical signals;

the optical adhesive changes the light path of the reflected light signal, the reflected light signal with the incident angle larger than a first critical angle in the reflected light signal is filtered to obtain a first reflected light signal, and the first reflected light signal enters the optical device; the first critical angle is a critical angle at which the reflected light signal can be totally reflected on the surface of the optical cement;

the optical device changes the light path of the first reflected light signal, filters the first reflected light signal of which the incident angle on the surface of the optical device is smaller than a second critical angle in the first reflected light signal to obtain a second reflected light signal, and enables the second reflected light signal to enter the sensing unit at the incident angle smaller than a preset angle; the second critical angle is a critical angle at which the reflected light signal can be totally reflected on the upper surface of the cover glass;

the processor generates fingerprint information according to the second reflected light signal received by the sensing unit and outputs the fingerprint information.

Further, the self-luminous diode display screen comprises MxN display pixels; the method comprises the following steps:

the processor sequentially drives a single display pixel or a display pixel array on the display screen to send out light signals according to the preset time sequence electric signals so as to form light spots or light spot combination on the upper surface of the cover glass to scan the finger part of a user and form reflected light signals.

The inventor also provides a screen unlocking device for synchronously verifying fingerprint information, which comprises a display unit, a sensing unit, a processor and a computer program, wherein the display unit is provided with a fingerprint identification area, and the sensing unit is positioned below the fingerprint identification area and is used for acquiring the fingerprint information on the fingerprint identification area;

the sensing unit is used for receiving a sliding track of a user on the fingerprint identification area and synchronously acquiring fingerprint information corresponding to the finger of the user;

the computer program when executed by a processor implementing the steps of:

the cover plate glass, the touch screen, the self-luminous diode display screen, the optical cement, the optical device and the sensing unit are arranged from top to bottom; the touch screen is attached to the lower surface of the cover plate glass, and the optical adhesive is attached to the lower surface of the self-luminous diode display screen; the refractive index of the optical cement is smaller than that of the cover plate glass, and the self-luminous diode display screen comprises a plurality of display pixels;

the processor is used for sending a display driving signal to the self-luminous diode display screen when the touch screen detects a touch signal of a finger of a user;

the display pixels are used for sending out optical signals when receiving display driving signals of the processor, and the optical signals are reflected on the upper surface of the cover plate glass to form reflected optical signals;

the optical adhesive is used for changing the light path of the reflected light signal, and filtering the reflected light signal of which the incident angle of the optical adhesive is larger than a first critical angle in the reflected light signal to obtain a first reflected light signal, so that the first reflected light signal enters the optical device; the first critical angle is a critical angle at which the reflected light signal can be totally reflected on the surface of the optical cement;

the optical device is used for changing the optical path of the first reflected light signal, filtering the first reflected light signal of which the incident angle on the surface of the optical device is smaller than a second critical angle in the first reflected light signal to obtain a second reflected light signal, and enabling the second reflected light signal to enter the sensing unit at the incident angle smaller than a preset angle; the second critical angle is a critical angle at which the reflected light signal can be totally reflected on the upper surface of the cover glass;

the processor is used for generating fingerprint information according to the second reflected light signal received by the sensing unit and outputting the fingerprint information.

Further, the optical device comprises a light shielding type optical device and a phase change type optical device, wherein the light shielding type optical device comprises a periodic pinhole array or a non-periodic pinhole array, and the phase change type optical device comprises a photonic crystal structure or a micro-lens array structure with a periodically changed refractive index or a diffuse scattering structure with a non-periodic changed refractive index.

Different from the prior art, the screen unlocking method and device for synchronously verifying the fingerprint information in the technical scheme are applied to the screen unlocking device for synchronously verifying the fingerprint information, the device comprises a display unit and a sensing unit, a fingerprint identification area is arranged on the display unit, and the sensing unit is positioned below the fingerprint identification area and used for acquiring the fingerprint information on the fingerprint identification area; the method comprises the following steps: receiving a sliding track of a user on the fingerprint identification area, and synchronously acquiring fingerprint information corresponding to the user finger; and when the sliding track of the user on the fingerprint identification area is matched with the preset sliding track, judging whether the synchronously acquired fingerprint information is matched with the preset fingerprint information, if so, completing screen unlocking, and otherwise, failing to unlock the screen. Like this, when the user carries out the screen sliding unblock operation, carry out user's fingerprint information's collection and authentication in step, adopt the mode of dual authentication effectively to promote the security of screen unblock on the one hand, on the other hand the user need not to operate on specific button and can realize fingerprint information's collection, has effectively promoted user experience.

Drawings

FIG. 1 is a schematic diagram of a thin film application structure of a photodetector array according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a display pixel of a self-emissive diode display panel according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating the variation of the light path of the reflection of the emitted light of a single display pixel according to an embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating the variation of the light path of the light emission and reflection of a single display pixel after disposing an optical adhesive according to an embodiment of the present invention;

FIG. 5 is a schematic diagram illustrating the variation of the light path of the reflection of the emitted light of a single display pixel after the placement of the optical glue and the optical device according to one embodiment of the present invention;

FIG. 6 is a schematic diagram of an effective light-emitting area corresponding to a single display pixel according to an embodiment of the invention;

fig. 7 is a schematic structural diagram of a screen unlocking device for synchronously verifying fingerprint information according to an embodiment of the present invention;

FIG. 8 is a flowchart of a method for collecting fingerprint information according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a light detection unit according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a light detection unit according to another embodiment of the present invention;

FIG. 11 is a schematic diagram of a source and a drain according to another embodiment of the present invention;

FIG. 12 is a flow chart illustrating a process for fabricating a light detecting unit according to another embodiment of the present invention;

fig. 13 is a flowchart of a screen unlocking method for synchronously verifying fingerprint information according to an embodiment of the present invention.

Reference numerals:

1. cover glass/touch screen;

2. a self-luminous diode display screen; 21. a display pixel;

3. a photodetecting array film; 31. a photosensitive pixel;

4. optical cement;

5. an optical device;

101. a gate electrode; 102. a source electrode; 103. a drain electrode; 104. an insulating layer; 105. a light-absorbing semiconductor layer.

Detailed Description

To explain technical contents, structural features, and objects and effects of the technical solutions in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.

Fig. 13 is a flowchart of a screen unlocking method for synchronously verifying fingerprint information according to an embodiment of the present invention. The method is applied to a device for synchronously verifying screen unlocking of fingerprint information, and the device comprises a display unit and a sensing unit. The device is an electronic device with a touch display screen, such as an intelligent mobile device like a mobile phone, a tablet computer and a personal digital assistant, and also can be an electronic device like a personal computer and an industrial device computer.

The display unit is provided with a fingerprint identification area, and the sensing unit is located below the fingerprint identification area and used for acquiring fingerprint information on the fingerprint identification area. The display unit is a display screen which takes an active array thin film transistor as scanning driving and data transmission, and comprises an AMOLED display screen, an LCD liquid crystal display screen, a micro light-emitting diode display screen, a quantum dot display screen or an electronic ink display screen.

In this embodiment, the coverage area of the sensing unit is adapted to the size of the touch display screen, so that the sensing unit can capture the fingerprint information of the user no matter how the finger of the user slides on the display screen. The sliding track is a motion track of a finger of a user on the display unit, and can be single-finger operation or multi-finger operation. The motion track of the user's finger includes but is not limited to lines, figures, Chinese characters, etc. When the sliding track is operated by a user through a plurality of fingers, if the plurality of fingers are simultaneously positioned in the fingerprint identification area in the sliding process, the sensing unit collects fingerprint information corresponding to the fingers.

In other embodiments, the number of the sensing units can be multiple, and the sensing units are only required to be spliced into a size matched with the display unit and arranged below the display unit. Compared with a large-area sensing unit, the small-area sensing unit is easier to produce and process, so that the production cost is saved.

In other embodiments, the fingerprint identification area may be an area smaller than the size of the display screen, such as 1/2 or 1/4, preferably, the fingerprint identification area is rectangular, the size of the rectangle is located at the center of the display unit, and the size of the sensing unit is matched with the size of the fingerprint identification area. In this embodiment, when the user's finger slides on the display screen, if the finger is located outside the fingerprint identification area, the fingerprint information will not be identified because the sensing unit is not disposed in the area outside the fingerprint identification area; when the finger of the user slides into the fingerprint identification area, the sensing unit captures the fingerprint information of the user. Because the sensing unit only occupies partial area of the display unit, compared with a full-screen covering mode, the production cost can be effectively saved.

The method comprises the following steps:

firstly, the method enters step S1301 to receive a sliding track of the user on the fingerprint identification area, and synchronously acquire fingerprint information corresponding to the user finger.

In some embodiments, the display unit comprises a touch unit; the step of receiving a sliding track of a user's finger on the display unit includes: the sensing unit or the touch unit receives a sliding track of a finger of a user on the display unit, generates sliding track information, and stores the sliding track information. The touch control unit may be a touch screen, and the touch screen may be configured to sense a touch operation of a user thereon, where the touch operation includes a sliding track operation. The sliding track information and the fingerprint information can be obtained by the sensing unit, or the sliding track information can be obtained by the touch unit through identification, and the fingerprint information is obtained by the sensing unit through capture. In short, for a terminal with a touch screen, the sliding track information is captured by a sensing unit or a touch unit, and the application range of the device is effectively improved.

And then, step S1302 is performed to determine whether the sliding track of the user on the fingerprint identification area is detected to be matched with a preset sliding track, if so, step S1303 is performed to determine whether the synchronously acquired fingerprint information is matched with the preset fingerprint information, and if so, step S1304 is performed to complete screen unlocking. If the sliding track is not matched with the preset sliding track, or the collected fingerprint information is not matched with the preset fingerprint information, the screen unlocking in step S1305 fails.

The preset fingerprint information is stored fingerprint information which is input by a user in advance and is used for comparing with fingerprint information which is acquired when the user executes screen unlocking operation. The preset fingerprint information can be stored in a storage unit of the device, such as a memory of a mobile phone and a hard disk of a computer, or in a storage unit of a server. The communication connection comprises a wired communication connection or a wireless communication connection.

The comparison of the fingerprint information can be realized through a fingerprint identification algorithm, the fingerprint identification algorithm can be stored in a storage unit of the device, after the sensing unit collects the fingerprint information on the fingerprint identification area, a processor of the device calls the fingerprint identification algorithm in the storage unit, the fingerprint information collected synchronously is compared with the preset fingerprint information, and then whether the fingerprint information is matched with the preset fingerprint information is judged. The fingerprint identification algorithm comprises the steps of preprocessing a fingerprint image, extracting data features, matching the features, identifying the fingerprint and the like, can be realized by various algorithms, is mature in the prior art, is applied to various encryption and decryption fields at present, and is not described in detail herein.

In this embodiment, the method further comprises: and sending prompt information when the sliding track is judged not to be matched with the preset sliding track or the acquired fingerprint information is judged not to be matched with the preset fingerprint information. The prompt message comprises one or more of sound prompt message, image prompt message, light prompt message and video prompt message. Taking the example of the mismatch of the fingerprint information, the "the collected fingerprint information does not match the preset fingerprint information" generally includes the following two cases: one is that the fingerprint identification fails, namely the storage unit has stored this fingerprint information in advance, but when gathering the fingerprint information of users synchronously, because the end of user's finger is not very sufficient with the screen contact, make the fingerprint information gathered not very complete, cause the fingerprint identification to fail; in another case, the storage unit does not store therein the preset fingerprint information matching the fingerprint information.

For the first case, the device may emit a sound prompt or an image prompt when the preset fingerprint information matching the synchronously collected fingerprint information is not recognized. The voice prompt message comprises a voice prompt message for prompting the user to input the fingerprint again (such as performing the screen sliding operation again), and the image prompt message comprises a popup prompt message for prompting the user to input the fingerprint again (such as performing the screen sliding operation again). When the number of times of synchronously acquiring the fingerprint information input by the user exceeds the preset number of times and no preset fingerprint information matched with the synchronously acquired fingerprint information is identified, the preset fingerprint information matched with the fingerprint information is determined not to be stored in the storage unit, namely the other condition is determined.

For the second case, that is, when the preset fingerprint information matched with the fingerprint information is not stored in the storage unit, the device can also send out image prompt information, for example, a pop-up window prompts the user that the current fingerprint information is not input; and video prompt information can be sent, the video prompt information contains a tutorial on how to enter new fingerprint information, and a user can complete the entry of the new fingerprint information according to the video prompt information. Of course, the prompt information can also be realized by vibration, light sensation prompt and the like. In short, the prompt information is only for the user to know the condition of "no fingerprint information matching with the fingerprint information synchronously acquired this time" as soon as possible, and the selection of the prompt information form can be adjusted correspondingly according to the settings of different manufacturers.

In some embodiments, when the display unit is an LCD liquid crystal display or an electronic ink display, a backlight unit is further disposed below the sensing unit, and the sensing unit is disposed between the backlight unit and the LCD liquid crystal display or between the backlight unit and the electronic ink display. Since the LCD liquid crystal display does not belong to a self-luminous element, a backlight unit needs to be added below the sensing unit at the time of installation. The backlight unit can be an LCD backlight module, and can also be other electronic elements with self-luminous function. In other embodiments, when the display unit is an AMOLED display screen, the OLED display screen is a self-luminous element, and thus a backlight unit is not required. Through the arrangement of the two schemes, the production requirements of different manufacturers can be effectively met, and the application range of the terminal is widened.

In some embodiments, the fingerprint identification area includes a plurality of fingerprint identification sub-areas, and a sensing unit is correspondingly disposed below each fingerprint identification sub-area. The apparatus further comprises a sensing unit control circuit, the method further comprising: the method comprises the steps of receiving a starting instruction of a user to a fingerprint identification subregion, starting a sensing unit below the fingerprint identification subregion by a sensing unit control circuit, receiving a closing instruction of the user to the fingerprint identification subregion, and closing the sensing unit below the fingerprint identification subregion by the sensing unit control circuit.

Taking the number of the fingerprint identification areas as two as an example, the two fingerprint identification sub-areas may be uniformly distributed in the screen one above the other or one left and one right, or may be distributed in other arrangement manners. The following is a detailed description of the application process of a terminal with two sub-regions for fingerprint identification: in the using process, a starting signal triggered by a user is received, and the light detection devices (namely the sensing units) below the two fingerprint identification sub-areas are set to be in an opening state. In a preferred embodiment, the range formed by the two fingerprint identification sub-regions covers the whole display screen, so that when the light detection devices below the two fingerprint identification sub-regions are set to be in an on state, light signals entering the display screen can be absorbed by the TFT image sensing array film (i.e., the sensing unit) below the light detection devices, and thus fingerprint information of a user can be captured.

In other embodiments, the two fingerprint identification sub-regions may also span 2/3, 3/4, etc. of the entire display area. Certainly, the user may set the light detection device below one fingerprint identification sub-area to be turned on and the light detection device below another fingerprint identification sub-area to be turned off according to the preference of the user. When the terminal does not need to be operated, the light detection devices below the two fingerprint identification sub-regions can be set to be in a closed state. In short, the light detection devices under the fingerprint identification sub-regions are turned on or off, and can be set according to the preference of the user.

As shown in fig. 1, the touch display screen includes a cover glass, a touch screen, and a display pixel assembly of a self-emitting diode from top to bottom, and a light detection array film (i.e., a sensing unit) can be disposed below the touch display screen, so as to detect and identify physiological characteristics (e.g., fingerprint information) of a user. Taking fingerprint identification as an example, the structure shown in fig. 1 has at least the following problems when fingerprint information acquisition is realized: after the display pixels positioned right below the fingers irradiate the fingers, different optical phenomena such as light penetration, light reflection, light scattering and the like can occur on the upper surface of the cover plate glass, no matter whether the ridges or the grooves of the fingerprints are adopted, bright and dark effective reflected light signals can be really formed to be very weak, and the ridge or the groove of the fingerprints is difficult to distinguish; (2) the light intensity is seriously weakened (usually reduced by more than 95%) after the reflected light signal passes through the cover plate glass, the touch screen and the display screen and reaches the light detection array film, and meanwhile, the reflected light signal also has an optical distortion phenomenon after passing through a TFT opening of the display screen, so that the collection of fingerprint information is influenced; (3) each display pixel of the self-luminous diode display screen has low luminous collimation, namely the luminous angle is wide, and the large-angle light emission is easy to interfere with fingerprints to be irradiated by adjacent or spaced pixel light sources, so that the acquired fingerprint information is inaccurate.

In order to solve the problems that when the light detection structure detects physiological characteristic information, the strength of a reflected light signal entering the light detection array film is seriously reduced, so that the lines of the captured physiological characteristic information are not obviously distinguished, and the information acquisition is not accurate, the invention provides the screen unlocking device for synchronously verifying the fingerprint information, and the device can be applied to detecting and identifying the physiological characteristic information, such as fingerprints, palm prints and the like.

As shown in fig. 7, the device comprises a cover glass, a touch screen, a self-luminous diode display screen 2, an optical adhesive 4, an optical device 5 and a light detection array film 3 from top to bottom; the touch screen is attached to the lower surface of the cover plate glass, and the optical adhesive 4 is attached to the lower surface of the self-luminous diode display screen 2; the refractive index of the optical cement 4 is smaller than that of the cover glass, and the self-luminous diode display screen comprises a plurality of display pixels. For convenience of explanation, all the drawings of the present invention simplify the cover glass and the touch screen into a whole, which is denoted as cover glass/touch screen 1, and when describing the change of the optical path, the change of the optical path on the surface of the cover glass/touch screen 1 is simplified into the change of the optical path on the surface of the cover glass.

When the photodetection array film is disposed under the display screen structure, light is reflected after a single display pixel or a display pixel array (which may be a row or a column of display pixels, or a plurality of display pixels arranged in a periodic or non-periodic manner) is used as a light source to irradiate the fingerprint above the cover glass. Because most of the light irradiated to the fingerprint convex is absorbed by the convex skin, and the air gap between the concave and the cover plate glass can partially reflect the light irradiated to the concave, the photosensitive pixel of the light detection array film can receive different bright and dark characteristics of the concave and convex of the fingerprint, and the light detection array film can reconstruct the convex and concave images of the fingerprint according to the bright and dark characteristics represented by the reflected light signals.

Referring to fig. 2, the display panel of the present invention is a self-luminous diode display panel, which is a display panel composed of a self-luminous diode pixel array, such as an Organic Light Emitting Diode (OLED) display panel, a micro-LED display panel, etc., as its name implies. The display screen comprises MxN display pixels, in order to facilitate detailed description of the optical path change of the optical signal emitted by each display pixel, the display pixels in the Nth row and the Mth column on the display screen are marked as Pmn, and the optical path changes of other display pixels can be obtained in the same way. In order to better describe the optical path change of the display pixels, the thickness of the self-luminous diode display screen related by the invention is smaller than 1/10 of the thickness of the cover glass, and the refractive indexes of the display screen and the cover glass are closer, so that when the optical path change is calculated, the change of the reflected light signal on the surface of the display screen is negligible compared with the cover glass, so as to simplify the description.

Fig. 3 is a schematic diagram illustrating a change of light paths of light emission and reflection of a single display pixel according to an embodiment of the present invention. The upper circle in fig. 3 indicates that the radius of the emission cross-section of a single display pixel Pmn is smaller than R_CA top view of the light beam of (1), radius R_CThe incident angle of the light rays to the upper surface of the cover glass is θ c, as shown by the position corresponding to the broken line in fig. 3.

Since the refractive index n2 of the cover glass is about 1.5 and the refractive index n1 of the air is about 1.0, when the light source of the (m, n) -th display pixel is irradiated upward at a large angle, the total reflection occurs for the light rays with the incident angle θ greater than θ c (θ c = sin-1(n1/n 2)) irradiated to the surface of the cover glass. Assuming that the projection length of θ c to the r-axis of the circular coordinate is Rc, the light rays outside the dotted circle with Rc as the radius with the origin at the (m, n) -th light-emitting display pixel position Pmn are light rays that can be totally reflected on the upper surface of the cover glass. When the light rays with the incident angle larger than theta c are irradiated on the convex patterns of the fingerprints contacted with the upper surface of the cover plate glass, the refractive index of the skin of the convex patterns destroys the original total reflection condition, so that the reflection signals at the positions corresponding to the convex patterns cannot be totally reflected in the cover plate glass, and part of the reflection signals enter the light detection array film through the lower surface of the cover plate glass to form bright patterns. In contrast, since an air gap exists between the concave pattern of the fingerprint and the cover glass, the reflected light signal at the concave pattern position maintains total reflection and cannot reach the photodetection array film to form a dark pattern.

In short, the light rays within the dotted circle of fig. 3, i.e., the light rays with the incident angle of the upper surface of the cover glass greater than θ c, can be used as fingerprint valley areas for detecting air gaps. Therefore, an effective technology for identifying the fingerprint under the optical display screen needs to use Rc as the characteristic dimension and use an effective illumination combination to illuminate or scan the finger portion on the cover glass to obtain a highly sensitive reflection area for the fingerprint image. Assuming that the thickness of the touch cover glass is h, Rc = h ‧ tan-1(θ c).

When the light beam emitted by the light source of the (m, n) -th display pixel on the display screen is irradiated upwards at a large angle, although the incident angle theta irradiated on the upper surface of the cover glass is larger than the ray of thetac (thetac = sin-1(n1/n 2)), the light beam can be relatively accurately totally reflected to the fingerprint concave veins spaced by the air gap, the light transmission path totally reflected back to the light detection array film is longer and longer when the incident angle irradiated on the cover glass surface is too large, which leads to more serious attenuation of useful light image information, and when the part of the reflected light signal reaches the light detection array film, the part of the reflected light signal becomes noise interference without reference value. Therefore, it is also necessary to define the light detection range of the maximum available information when the (m, n) -th display pixel is used as the light source to illuminate the fingerprint above the cover glass.

Referring to fig. 4 and 5, since the refractive index of the optical paste (n 3) is smaller than the refractive index of the cover glass (n 2), among the light rays entering the surface of the optical paste by the first total reflection (hereinafter referred to as "total reflection 1") occurring on the upper surface of the cover glass, the rays having an incident angle of phi greater than phi c will undergo the second total reflection (hereinafter referred to as "total reflection 2") occurring on the surface of the optical paste, and phi c = sin-1(n3/n 2). Assuming that the projection length of Φ c corresponding to the r-axis of the circular coordinate is Rc' = h ‧ tan-1(Φ c), the light rays outside the dotted circle with the (m, n) -th display pixel position Pmn as the origin and 2Rc as the radius are the light rays capable of generating the total reflection 2 on the surface of the optical cement. On the other hand, the optical rays that can be totally reflected 2 on the surface of the optical cement are filtered out by the optical cement with refractive index n3 < n2 as total reflection 2 because the reflected light signal path is too long and does not carry the optical rays with high-precision fingerprint information, compared with the optical rays within the dotted circle with radius 2 Rc'.

As can be seen from fig. 4 and 5, for a single display pixel, the light beams that can be totally reflected 1 and 2 are optical signals corresponding to fingerprint information with high accuracy. Accordingly, it can be defined that, in implementing the under-screen fingerprint recognition technology, after the (m, n) -th display pixel of the self-luminous diode display screen is used as the light source to illuminate the fingerprint, the photo-detection array film can acquire the relatively sensitive and effective fingerprint area, that is, the dotted concentric circular ring shaped light beam area with the (m, n) -th display pixel position Pmn as the origin and the range of Rc to 2Rc as the radius, if projected to the direction of the circular coordinate r, the area range of Rc < r < 2Rc is the most suitable fingerprint optical information that the photo-detection array film can acquire from the light source emitted from the single display pixel of the self-luminous diode display screen, as shown in fig. 6.

For the light rays outside the region larger than 2Rc ', as mentioned above, the light rays outside the region larger than 2Rc ' can be filtered by the optical adhesive with the corresponding refractive index, i.e. the light rays outside the region larger than 2Rc ' are totally reflected on the surface of the optical adhesive and do not enter the light detection array film, thereby affecting the collection of the fingerprint information image. For light rays smaller than the Rc region, the invention filters the light rays by disposing optics above the light detecting array film. In the present embodiment, the optical device 4 includes a light-shielding optical device including a periodic pinhole array or an aperiodic pinhole array, and a phase-change optical device including a photonic crystal structure or a microlens array structure in which a refractive index changes periodically, or a diffuse scattering structure in which a refractive index changes aperiodically.

Preferably, the shape of the pinhole may be a circular hole or a square hole, the optical device may be obtained by a compressed sampling method of a coded aperture (coded aperture), taking fingerprint identification as an example, fingerprint information identification only requires application requirements of light and dark gray scales, by a filter design of spatial frequency (in this embodiment, specifically, light rays of display pixels irradiated on the cover glass surface θ < θ c and θ > Φ c need to be filtered), the coded aperture of the optical device is designed to be a device with a light guiding function, high-resolution light and dark light signal acquisition in an Rc < r < 2 Rc' region can be realized, and a reflected light signal passing through the optical device is incident into the photodetection array film in a vertical direction as much as possible (an incident angle is smaller than a preset angle). References to a compressed sampling method of coded aperture (coded aperture) are as follows: stephen r. Gottesman, "Coded alerts: past, present, and future application and design, "(Proceeding of SPIE, vol. 6714, 2007), this article describes a method for designing a thin optical device with a simple one-dimensional model, in which the coded aperture can be widely applied to a thin optical device requiring high resolution and wide viewing angle. In short, by a coded aperture (coded aperture) compressive sampling method, a corresponding optical device can be designed according to a predetermined parameter requirement (i.e. a light ray in an r < Rc region range is required to be filtered after passing through the optical device), and specific steps are the prior art and are not described herein again.

In other embodiments, the optical device may also be designed by using digital holography, and by using digital holography (or computer generated holography), the optical device may be designed according to predetermined parameter requirements (i.e. it is required to filter out the light ray in the r < Rc region range after passing through the optical device), and the specific steps may be referred to the following documents: M.A. Seldowitz, J.P. Allebach, and D.W. Sweeney, "Synthesis of digital lipids by direct binding search," appl. Opt. 26, 2788-. This document proposes that a corresponding digital holography optic can be designed with a specific algorithm using a calculator to achieve an output image with high resolution.

In this embodiment, the device comprises, from top to bottom, a cover glass, a touch screen, a self-emissive diode display screen, an optical adhesive, an optical device, and a photo-detection array film; the touch screen is attached to the lower surface of the cover plate glass, and the optical adhesive is attached to the lower surface of the self-luminous diode display screen; the refractive index of the optical cement is smaller than that of the cover plate glass, and the self-luminous diode display screen comprises a plurality of display pixels; the apparatus also includes a processor; the method comprises the following steps:

the method first enters step S801, when the touch screen detects a touch signal of a finger of a user, the processor sends a display driving signal to the self-emitting diode display screen. Taking fingerprint information identification as an example, when the touch screen detects that a finger of a user is placed on the upper surface of the cover glass, the touch signal is triggered.

And then, in step S802, when the display pixels receive the display driving signals of the processor, light signals are sent out, and the light signals are reflected on the upper surface of the cover plate glass to form reflected light signals. Because the display screen and the cover glass have certain light transmittance, light signals emitted by the display pixels can be reflected and transmitted on the upper surface of the cover glass, namely, the light signals directly penetrate through the upper surface of the cover glass and enter the air, and only the light signals reflected on the upper surface of the cover glass finally enter the light detection array film to form corresponding image signals.

Then, in step 803, the optical glue changes the optical path of the reflected optical signal, and filters the reflected optical signal of which the incident angle of the optical glue is greater than the first critical angle in the reflected optical signal to obtain a first reflected optical signal, and the first reflected optical signal enters the optical device. The first critical angle is a critical angle at which the reflected light signal can be totally reflected on the surface of the optical cement. In short, the optical signal with long light path, namely the light ray in the r >2 Rc' area, is filtered by the optical cement with the refractive index smaller than that of the cover glass.

Then, in step S804, the optical device changes the optical path of the first reflected light signal, and filters the first reflected light signal, of which the incident angle on the surface of the optical device is smaller than the second critical angle, in the first reflected light signal to obtain a second reflected light signal, and the second reflected light signal enters the sensing unit (i.e., the photo-detection array film) at the incident angle smaller than the preset angle. The second critical angle is a critical angle at which the reflected light signal can be totally reflected on the upper surface of the cover glass. In short, the light ray in the r < Rc region is filtered by the optical device, and the light ray passing through the optical device (the radius r of the light ray on the coordinate axis satisfies Rc < r < 2 Rc') is incident on the light detecting array film as perpendicular as possible, so that the light flux is increased to better capture the fingerprint feature information.

Then, the process proceeds to step S805, and the processor generates and outputs fingerprint information according to the second reflected light signal received by the photo detection array film. The light beams emitted by each display pixel are captured to meet the condition that Rc < r < 2 Rc' in the range, then the optical signals of each display pixel in the region are superposed, and complete physiological characteristic identification image information (such as fingerprint image information) is reconstructed and output.

In some embodiments, the displayThe screen includes MxN display pixels, the method comprising: the processor sequentially drives a single display pixel or a display pixel array on the display screen to send out optical signals according to the preset time sequence electric signals so as to form light spots or light spot combination scanning fingerprint characteristic parts on the upper surface of the cover plate glass and form reflected optical signals. E.g. a first behavior P of display pixels on a display screen₁₁，P₁₂ … P_1NSecond behavior P₂₁，P₂₂ … P_2NBy analogy, the Nth behavior P_M1，P_M2 … P_MN. By presetting the timing electrical signal, the processor can drive the display pixels on the display screen row by row and column by column, or can drive the periodically-changed discrete display pixels (for example, the first row P is driven first_11、P_13、P_15，Redrive the second row P_21、P_23、P₂₅And then drives the third row P_31、P_33、P₃₅And so on) it is of course also possible to drive a plurality of display pixels in a non-periodically varying arrangement in turn. In short, the sequence of driving each display pixel on the display screen to emit light can be selected according to actual needs.

In some embodiments, the photo detection array film comprises PxQ pixel detection regions, each pixel detection region is correspondingly provided with a pixel detection structure, and each pixel detection structure comprises a group of more than one thin film transistors for pixel thin film circuits and a photo detection unit; the light detection unit comprises a photosensitive diode or a photosensitive transistor. For each photo-detection unit, there are several implementations as follows:

the first embodiment is as follows:

the TFT image sensor array film (i.e., the photo-sensing array film) is an array of photodiodes, which include a photodiode sensing region. The existing Liquid Crystal Display (LCD) panel or Organic Light Emitting Diode (OLED) display panel is driven and scanned by a TFT structure to realize the display function of the pixel array on the panel. The main structure forming the TFT switching function is a semiconductor Field Effect Transistor (FET), in which the well-known semiconductor layer materials mainly include amorphous silicon, polysilicon, Indium Gallium Zinc Oxide (IGZO), or organic compounds mixed with carbon nanomaterials, etc. Since the structure of the photo sensing diode can also be prepared by using such semiconductor material, and the production equipment is compatible with the production equipment of the TFT array, in recent years, the TFT photo sensing diode (i.e. photodiode) is beginning to be produced by using the TFT array preparation method. For the specific structure of the conventional photodiode, reference may be made to the description of the photodetector array thin film structure in U.S. Pat. No. 6943070B2 and the patent CN204808361U of the people's republic of china. The production process of the TFT image sensing array film is different from the TFT structure of the display panel in that: originally, the pixel opening area of the display panel is changed into a light sensing area in the production process. The TFT can be prepared by using thin glass as a substrate, or by using a high temperature resistant plastic material as a substrate, as described in US6943070B 2.

In order to improve the signal-to-noise ratio (SNR), as shown in fig. 9, the light detection unit of the present invention is further improved so that the improved TFT image sensing array film can detect and identify the infrared signal reflected back from the body part of the user. The concrete structure is as follows:

the photosensitive diode layer comprises a p-type semiconductor layer, an i-type semiconductor layer and an n-type semiconductor layer, the p-type semiconductor layer, the i-type semiconductor layer and the n-type semiconductor layer are stacked from top to bottom, and the i-type semiconductor layer is of a microcrystalline silicon structure or a non-crystalline silicon germanium structure. The microcrystalline silicon structure is a semiconductor layer formed by chemical vapor deposition of silane and hydrogen, the crystallinity of the microcrystalline silicon structure is more than 40%, and the forbidden bandwidth of the microcrystalline silicon structure is less than 1.7 eV. The amorphous germanium silicide structure is an amorphous semiconductor layer formed by chemical vapor deposition of silane, hydrogen and germane, and the forbidden bandwidth of the amorphous semiconductor layer is less than 1.7 eV.

The forbidden Band width (Band gap) refers to a Band gap width (unit is electron volts (eV)), the energy of electrons in a solid cannot be continuously taken, but discontinuous energy bands exist, free electrons exist for conduction, the energy Band in which the free electrons exist is called a conduction Band (energy conduction), the bound electrons need to obtain enough energy for transition from a valence Band to the conduction Band, and the minimum value of the energy is the forbidden Band width. The forbidden band width is an important characteristic parameter of a semiconductor, and the size of the forbidden band width is mainly determined by the energy band structure of the semiconductor, namely, the forbidden band width is related to the combination property of a crystal structure and atoms and the like.

At room temperature (300K), the forbidden bandwidth of germanium is about 0.66eV, and the silane contains germanium element, so that the forbidden bandwidth of the i-type semiconductor layer is reduced after the germanium element is doped, and when the forbidden bandwidth is less than 1.7 eV, the i-type semiconductor layer can receive optical signals in the wavelength range from visible light to infrared light (or near infrared light). The operating wavelength range of a photodiode containing amorphous or microcrystalline germanium silicide structures can be extended to the wavelength range of 600nm to 2000 nm by adjusting the concentration of GeH4 in a chemical vapor deposition.

Example two:

in addition to the first embodiment, in order to improve the quantum efficiency of photoelectric conversion, the amorphous silicon photodiode may also be formed by stacking more than two p-type/i-type/n-type structures. The p-type/i-type/n-type material of the first junction layer of the photodiode still has an amorphous silicon structure, and the p-type/i-type/n-type material above the second junction layer can be a microcrystalline structure, a polycrystalline structure or a compound material doped with a scalable photosensitive wavelength range. In short, the photodiode structure can be formed by stacking a plurality of p-type/i-type/n-type structures one on top of the other, and the photodiode structure described in the first embodiment is used for each p-type/i-type/n-type structure.

Example three:

based on the first embodiment or the second embodiment, for each p-type/i-type/n-type structure, the p-type semiconductor layer included in the p-type/i-type/n-type structure may be a multilayer structure with more than two layers. For example, the p-type semiconductor layer has a three-layer structure including, from top to bottom, a first p-type semiconductor layer (p 1 layer), a second p-type semiconductor layer (p 2 layer), and a third p-type semiconductor layer (p 3 layer). The p1 layer can adopt an amorphous structure and is heavily doped with boron (the boron concentration is more than twice of that of the standard process); the p2 and the p3 adopt a microcrystalline structure and are doped with boron normally (doped according to standard process concentration), and the absorption of light is reduced by virtue of the p2 layer and the p3 layer with reduced thickness, so that the light enters the i layer as much as possible and is absorbed by the i layer, and the photoelectric conversion rate is improved; on the other hand, the p2 layer and the p3 layer are doped with normal boron, so that the degradation of the built-in potential caused by heavy doping of the p1 layer can be effectively avoided. When the p-type semiconductor layer includes a multi-layer structure with other layers, the description is omitted here.

Similarly, the n-type semiconductor layer may have a multilayer structure of more than two layers. For example, the n-type semiconductor layer has a three-layer structure including, from top to bottom, a first n-type semiconductor layer (n1 layer), a second n-type semiconductor layer (n 2 layer), and a third n-type semiconductor layer (n3 layer). Wherein, the n3 layer can adopt an amorphous structure and is heavily doped with phosphorus (the phosphorus content is more than twice of that of the standard process); the n1 and the n2 adopt microcrystalline structures and are normally doped with phosphorus (according to a standard production process), and the absorption of light is reduced by virtue of the n1 layer and the n2 layer with reduced thicknesses, so that the light enters the i layer as much as possible and is absorbed by the i layer, and the photoelectric conversion rate is improved; on the other hand, the n1 layer and the n2 layer are doped with normal phosphorus, so that the degradation of the built-in potential caused by heavy doping of the n3 layer can be effectively avoided. When the n-type semiconductor layer includes a multi-layer structure with other layers, the description is omitted here.

Example four:

the TFT image sensing array film (i.e. the light detection array film) is an array formed by photosensitive transistor tubes, the array formed by the photosensitive transistor tubes comprises a photosensitive transistor tube sensing area, and the photosensitive transistor tube sensing area is provided with photosensitive thin film transistors. As shown in fig. 10, the photosensitive thin film transistor includes a gate electrode 101, a source electrode 102, a drain electrode 103, an insulating layer 104, a light-absorbing semiconductor layer 105; the photosensitive thin film transistor is an inverted coplanar structure, and the inverted coplanar structure comprises: the gate 101, the insulating layer 104 and the source 102 are arranged from bottom to top longitudinally, and the drain 103 and the source 102 are arranged in a horizontal coplanar manner; the insulating layer 104 wraps the gate 101, so that the gate 101 is not in contact with the source 102 and the drain 101 and the drain 103; the source electrode 102 and the drain electrode 103 are in clearance fit, a photosensitive leakage current channel is formed between the source electrode 102 and the drain electrode 103 in the transverse direction, and the light absorption semiconductor layer 105 is arranged in the photosensitive leakage current channel.

When the TFT is controlled to be operated in an off state by the grid voltage, no current passes between a source electrode and a drain electrode; however, when the TFT is irradiated by a light source, the energy of the light excites electron-hole pairs in the semiconductor, and the electron-hole pairs are separated by the field effect of the TFT structure, thereby causing photosensitive leakage current in the TFT. Such photosensitive leakage current characteristics allow the TFT array to be used in photodetection or photodetection technologies. Compared with the common device adopting TFT leakage current as the photosensitive thin film transistor, the invention uses the inverted coplanar field effect transistor structure to arrange the light absorption semiconductor layer on the uppermost light absorption layer, thereby greatly increasing the excitation of photoelectrons and improving the photoelectric conversion efficiency.

Fig. 12 is a flowchart illustrating a method for manufacturing a light detecting unit according to an embodiment of the present invention. The method is used for preparing the photosensitive thin film transistor (namely, the light detection unit) of the sixth embodiment, and specifically comprises the following steps:

firstly, step S1201 is carried out to coat a grid electrode on the substrate of the pixel thin film transistor through magnetron sputtering. The substrate of the pixel thin film transistor can adopt a hard board, and can also adopt a flexible material (such as polyimide);

then step S1202 is carried out to coat a film on the upper part of the grid electrode by chemical vapor deposition or magnetron sputtering to form an insulating layer;

then, in step S1203, forming an n-type doped semiconductor layer of the source and the drain on the insulating layer by chemical vapor deposition coating, forming metal layers of the source and the drain by magnetron sputtering coating, defining the source and the drain with a preset structure by a yellow light etching process, obtaining that the source and the drain are transversely coplanar and in clearance fit, and forming a photosensitive leakage current channel between the source and the drain transversely;

and then step S1204 is carried out to deposit a film in the photosensitive leakage current channel by chemical vapor deposition to form a light-absorbing semiconductor layer.

Example five:

with the well-known field effect transistor structure, the TFT used as a switch for scan driving and data transmission does not need to be designed specifically for the structure for collecting photocurrent between the source and the drain; however, when the field effect transistor is applied to the detection of photosensitive leakage current, if the electron-hole pairs excited by light are separated by the field effect, the Drift (Drift) path driven by the electric field is too long, and there is a high possibility that the photoelectrons are recombined with holes (Recombination) before they can not reach the electrode successfully, or are captured by Dangling bonding (Dangling Bond) defects of the light absorption semiconductor layer itself, and thus cannot contribute to the photocurrent output for photodetection effectively. In order to improve the photosensitive leakage current affected by the channel length between the source and the drain, so as to increase the area of the light-absorbing semiconductor without deteriorating the photoelectric conversion efficiency, the source and the drain of the fourth embodiment are further improved in this embodiment, and a novel structure of the source and the drain is proposed.

As shown in fig. 11, the number of the source electrodes and the drain electrodes is multiple, the source electrodes and the source electrodes are connected in parallel, and the drain electrodes are connected in parallel; the source electrode and the drain electrode are in clearance fit, and a photosensitive leakage current channel is formed between the source electrode and the drain electrode in the transverse direction and comprises: a first gap is formed between adjacent source electrodes, one drain electrode is arranged in the first gap, a second gap is formed between adjacent drain electrodes, one source electrode is arranged in the second gap, and the source electrodes and the drain electrodes are arranged in a staggered mode and are in clearance fit. The distance between each source and the adjacent drain is less than the electron drift distance, which is the distance that an electron can survive under the effect of a field effect. Therefore, in each detection pixel, a plurality of source electrodes of the same pixel are connected in parallel, and a plurality of drain electrodes of the same pixel are also connected in parallel, so that the recombination probability of photoexcited electrons and holes can be effectively reduced, the success probability of collecting photoelectrons by the electrodes under the action of a field effect is improved, and the photosensitivity of the TFT leakage current photosensitive thin film transistor is improved to the maximum extent.

In the step-by-step process for fabricating the photosensitive thin film transistor (i.e., the light detecting unit) of the fifth embodiment, the general steps are similar to those for fabricating the photosensitive thin film transistor of the fourth embodiment. The difference is that in the step S1203, "defining the source and the drain with a predetermined structure by photolithography and etching process, so that the source and the drain are laterally coplanar and are in clearance fit, and a photosensitive leakage current channel is formed between the source and the drain laterally" includes: defining a source electrode group and a drain electrode group by a yellow light etching process, wherein each source electrode group comprises a plurality of source electrodes, and the source electrodes and the drain electrodes are mutually connected in parallel; each drain electrode group comprises a plurality of drain electrodes, and the drain electrodes are mutually connected in parallel; a first gap is formed between adjacent source electrodes, one drain electrode is arranged in the first gap, a second gap is formed between adjacent drain electrodes, one source electrode is arranged in the second gap, and the source electrodes and the drain electrodes are arranged in a staggered mode and are in clearance fit.

In some embodiments, the photodetection array film is configured to receive a detection trigger signal, is in a photodetection state, and receives a light signal reflected by a detection portion (e.g., a fingerprint, an eyeball, an iris, etc.) to capture detection portion information of a user; and is used for receiving the light source trigger signal and is in a state of emitting a light source (such as an infrared light source). Preferably, the light source trigger signal and the detection trigger signal are alternately switched and meet a preset frequency. Taking the photo-sensing array film as an array formed by photodiodes as an example, in practical application, a bias voltage (including a forward bias voltage, or a zero bias voltage or a negative bias voltage) can be applied between the p-type/i-type/n-type photodiodes by scanning driving through the TFT, so as to realize the function of emitting infrared light by the TFT image sensing array film.

Specifically, a forward bias, or a zero bias or a negative bias, may be alternately applied between the p-type/i-type/n-type infrared photodiodes to trigger the first trigger signal or the second trigger signal. Taking an example that an array formed by the infrared photosensitive diodes has 10 rows of pixel dot matrixes, applying forward bias to the p-type/i-type/n-type infrared photosensitive diodes in a first period to enable the 10 rows of pixel dot matrixes to be in an infrared light emitting state; applying zero bias or negative bias to the p-type/i-type/n-type infrared photosensitive diode in a second period to enable the 10-row pixel dot matrix to be in an infrared light detection state, and the pixel dot matrix is used for capturing infrared light information reflected by eyeballs of a user and generating corresponding infrared images for output; and applying forward bias to the p-type/i-type/n-type infrared photosensitive diode in the third period to enable the 10-column pixel dot matrix to be in an infrared light emitting state, and repeating the alternation and the like. Further, the light source trigger signal (i.e., the first trigger signal) and the detection trigger signal (i.e., the second trigger signal) are alternately switched at a frequency consistent with a predetermined frequency. The time interval between adjacent periods can be set according to actual needs, and preferably, the time interval can be set to be the time required for the TFT array to drive and scan the infrared photodiode array for each Frame (Frame) to receive at least one complete image signal, that is, the preset frequency is to perform switching once every time interval.

The screen unlocking method and device for synchronously verifying the fingerprint information in the technical scheme are applied to a screen unlocking device for synchronously verifying the fingerprint information, the device comprises a display unit and a sensing unit, a fingerprint identification area is arranged on the display unit, and the sensing unit is located below the fingerprint identification area and used for acquiring the fingerprint information on the fingerprint identification area; the method comprises the following steps: receiving a sliding track of a user on the fingerprint identification area, and synchronously acquiring fingerprint information corresponding to the user finger; and when the sliding track of the user on the fingerprint identification area is matched with the preset sliding track, judging whether the synchronously acquired fingerprint information is matched with the preset fingerprint information, if so, completing screen unlocking, and otherwise, failing to unlock the screen. Like this, when the user carries out the screen sliding unblock operation, carry out user's fingerprint information's collection and authentication in step, adopt the mode of dual authentication effectively to promote the security of screen unblock on the one hand, on the other hand the user need not to operate on specific button and can realize fingerprint information's collection, has effectively promoted user experience.

It should be noted that, although the above embodiments have been described herein, the invention is not limited thereto. Therefore, based on the innovative concepts of the present invention, the technical solutions of the present invention can be directly or indirectly applied to other related technical fields by making changes and modifications to the embodiments described herein, or by using equivalent structures or equivalent processes performed in the content of the present specification and the attached drawings, which are included in the scope of the present invention.

Claims

1. A screen unlocking method for synchronously verifying fingerprint information is characterized in that the method is applied to a device for synchronously verifying screen unlocking of fingerprint information, the device comprises a display unit and a sensing unit, a fingerprint identification area is arranged on the display unit, and the sensing unit is positioned below the fingerprint identification area and used for acquiring the fingerprint information on the fingerprint identification area; the method comprises the following steps:

when the sliding track of the user on the fingerprint identification area is matched with a preset sliding track, judging whether the synchronously acquired fingerprint information is matched with the preset fingerprint information or not, if so, completing screen unlocking, otherwise, failing to unlock the screen;

the device also comprises a light-transmitting cover plate, optical cement and an optical device, wherein the light-transmitting cover plate, the display unit, the optical cement, the optical device and the sensing unit are arranged from top to bottom; the display unit includes a plurality of display pixels;

the synchronously collecting the fingerprint information corresponding to the user finger comprises the following steps:

the display pixels send out optical signals, and the optical signals are reflected on the upper surface of the light-transmitting cover plate to form reflected optical signals;

the optical adhesive changes the optical path of the reflected light signal, the reflected light signal with the incident angle larger than a first critical angle in the reflected light signal is filtered to obtain a first reflected light signal, and the first reflected light signal enters the optical device; the first critical angle is a critical angle at which the reflected light signal can be totally reflected on the surface of the optical cement;

the optical device changes the optical path of the first reflected light signal, filters the first reflected light signal of which the incident angle on the surface of the optical device is smaller than a second critical angle in the first reflected light signal to obtain a second reflected light signal, and enables the second reflected light signal to enter the sensing unit; the second critical angle is a critical angle at which optical signals emitted by the display pixels can be totally reflected on the upper surface of the light-transmitting cover plate.

2. The method as claimed in claim 1, wherein the sensor unit is a photo-detection array film, the photo-detection array film includes PxQ pixel detection areas, each pixel detection area is correspondingly configured with a pixel detection structure, each pixel detection structure includes a group of pixel thin-film circuits and a photo-detection unit composed of more than one thin-film transistors; the light detection unit comprises a photosensitive diode or a photosensitive transistor.

3. The method as claimed in claim 2, wherein the photo-detecting array film is an array of photodiodes, each of the photodiodes includes a photodiode sensing region, a photodiode layer is disposed in the photodiode sensing region, the photodiode layer includes a p-type semiconductor layer, an i-type semiconductor layer, and an n-type semiconductor layer, the p-type semiconductor layer, the i-type semiconductor layer, and the n-type semiconductor layer are stacked from top to bottom, and the i-type semiconductor layer is a microcrystalline silicon structure or a non-crystalline silicon germanium structure.

4. The screen unlocking method for synchronously verifying fingerprint information according to claim 2, wherein the photodetection array film is an array formed by photosensitive transistors, the photosensitive transistors comprise photosensitive transistor sensing areas, the photosensitive transistor sensing areas are provided with photosensitive thin film transistors, and the photosensitive thin film transistors comprise grid electrodes, source electrodes, drain electrodes, insulating layers and light absorption semiconductor layers; the photosensitive thin film transistor is an inverted coplanar structure, and the inverted coplanar structure comprises: the grid electrode, the insulating layer and the source electrode are longitudinally arranged from bottom to top, and the drain electrode and the source electrode are transversely arranged in a coplanar manner; the insulating layer wraps the grid so that the grid is not in contact with the source electrode and the drain electrode; the source electrode and the drain electrode are in clearance fit, a photosensitive leakage current channel is formed between the source electrode and the drain electrode in the transverse direction, and the light absorption semiconductor layer is arranged in the photosensitive leakage current channel.

5. The screen unlocking method for synchronously verifying the fingerprint information as claimed in claim 1, wherein the fingerprint identification area comprises a plurality of fingerprint identification sub-areas, and a sensing unit is correspondingly arranged below each fingerprint identification sub-area; the method comprises the following steps:

6. The screen unlocking method of synchronously verifying fingerprint information according to claim 1 or 2, wherein said display unit is a self-luminous diode display screen, said apparatus further comprising a touch screen;

the light-transmitting cover plate, the touch screen, the self-luminous diode display screen, the optical cement, the optical device and the sensing unit are arranged from top to bottom; the touch screen is attached to the lower surface of the light-transmitting cover plate, and the optical adhesive is attached to the lower surface of the self-luminous diode display screen; the refractive index of the optical cement is smaller than that of the light-transmitting cover plate; the apparatus also includes a processor;

the display pixel sends out optical signals, and the display pixel comprises: when the touch screen detects a touch signal of a finger of a user, the processor sends a display driving signal to the self-luminous diode display screen; when the display pixels receive the display driving signals of the processor, the display pixels send out optical signals;

the optical device is further adapted to cause the second reflected light signal to enter the sensing unit at an angle of incidence less than a preset angle; the processor generates fingerprint information according to the second reflected light signal received by the sensing unit.

7. The screen unlocking method of synchronously verifying fingerprint information of claim 6, wherein said self-luminous diode display screen includes MxN display pixels; the method comprises the following steps:

the processor sequentially drives a single display pixel or a display pixel array on the display screen to send out light signals according to the preset time sequence electric signals so as to form light spots or light spot combination on the upper surface of the light-transmitting cover plate to scan the finger part of the user and form reflected light signals.

8. A screen unlocking device for synchronously verifying fingerprint information is characterized by comprising a display unit, a sensing unit, a processor and a computer program, wherein a fingerprint identification area is arranged on the display unit, and the sensing unit is positioned below the fingerprint identification area and used for acquiring the fingerprint information on the fingerprint identification area;

the computer program when executed by a processor implementing the steps of:

the display pixels are used for emitting optical signals, and the optical signals are reflected on the upper surface of the light-transmitting cover plate to form reflected optical signals;

the optical adhesive is used for changing the optical path of the reflected light signal, filtering the reflected light signal of which the incident angle of the optical adhesive is larger than a first critical angle in the reflected light signal to obtain a first reflected light signal, and enabling the first reflected light signal to enter an optical device; the first critical angle is a critical angle at which the reflected light signal can be totally reflected on the surface of the optical cement;

the optical device is used for changing the optical path of the first reflected light signal, filtering the first reflected light signal of which the incident angle on the surface of the optical device is smaller than a second critical angle in the first reflected light signal to obtain a second reflected light signal, and enabling the second reflected light signal to enter the sensing unit; the second critical angle is a critical angle at which optical signals emitted by the display pixels can be totally reflected on the upper surface of the light-transmitting cover plate;

the processor is used for generating fingerprint information according to the second reflected light signal received by the sensing unit.

9. The screen unlocking apparatus for synchronously verifying fingerprint information according to claim 8, wherein said display unit is a self-luminous diode display screen, said apparatus further comprising a touch screen;

the light-transmitting cover plate, the touch screen, the self-luminous diode display screen, the optical cement, the optical device and the sensing unit are arranged from top to bottom; the touch screen is attached to the lower surface of the light-transmitting cover plate, and the optical adhesive is attached to the lower surface of the self-luminous diode display screen; the refractive index of the optical adhesive is smaller than that of the light-transmitting cover plate, and the self-luminous diode display screen comprises a plurality of display pixels;

the display pixels are used for sending out optical signals when receiving display driving signals of the processor;

the optical device is further adapted such that the second reflected light signal enters the sensing unit at an angle of incidence smaller than a preset angle.

10. The screen unlocking device for synchronously verifying fingerprint information of claim 9, wherein the optical device comprises a light-shielding type optical device and a phase-change type optical device, the light-shielding type optical device comprises a periodic pinhole array or a non-periodic pinhole array, and the phase-change type optical device comprises a photonic crystal structure or a micro-lens array structure with a periodic variation of refractive index or a diffuse scattering structure with a non-periodic variation of refractive index.