CN110674798A

CN110674798A - Optical fingerprint identification device and touch terminal

Info

Publication number: CN110674798A
Application number: CN201911099210.XA
Authority: CN
Inventors: 杨沐; 曹志日; 杨喆; 范浩强
Original assignee: Beijing Maigewei Technology Co Ltd
Current assignee: Beijing Megvii Technology Co Ltd; Beijing Maigewei Technology Co Ltd
Priority date: 2019-11-11
Filing date: 2019-11-11
Publication date: 2020-01-10
Also published as: CN211087279U; CN111160325A

Abstract

The invention provides an optical fingerprint identification device and a touch terminal, relates to the technical field of display terminals, and aims to solve the technical problem that the existing touch terminal with a fingerprint identification function is high in process complexity. The optical fingerprint identification device is used for being installed at the bottom of an OLED display device; the optical fingerprint identification device comprises a photosensitive sensor array and an optical film layer, wherein the optical film layer and the photosensitive sensor array are fixedly arranged; and light signals emitted from the direction of the OLED display device in a preset angle range pass through the optical film layer and then are emitted into the photosensitive sensor array.

Description

Optical fingerprint identification device and touch terminal

Technical Field

The invention relates to the technical field of display terminals, in particular to an optical fingerprint identification device and a touch terminal.

Background

The full-screen mobile phone is a mainstream configuration of the current mobile phone, and the use of the full-screen mobile phone also makes the Organic Light-Emitting Diode (OLED) underscreen fingerprint become a popular research direction. As shown in fig. 1, the basic structure is that a fingerprint identification component 2 is placed under an OLED panel 1, and the fingerprint identification component 2 comprises two parts of an optical imaging structure and an image sensor array which are integrated together.

In current products, most of optical imaging structures adopt an optical lens (lens) structure, and in order to meet the requirements of the lens structure and the optical path, an optical lens 3 is aligned above each photosensitive sensor 4 in the photosensitive sensor array, which requires extremely high accurate alignment (within a few μm) between the photosensitive sensor 4 and the optical lens 3. In order to achieve the above precision, in a general implementation scheme, the photosensitive sensor 4 and the optical lens 3 are both made by using a CMOS silicon-based compatible process. However, such a process is complicated and complicated.

Disclosure of Invention

The invention aims to provide an optical fingerprint identification device and a touch terminal, so as to solve the technical problem that the existing touch terminal with a fingerprint identification function has high process complexity.

In a first aspect, the present invention provides an optical fingerprint identification device, for being mounted at the bottom of an OLED display device;

the optical fingerprint identification device comprises a photosensitive sensor array and an optical film layer, wherein the optical film layer and the photosensitive sensor array are fixedly arranged;

and light signals emitted from the direction of the OLED display device in a preset angle range pass through the optical film layer and then are emitted into the photosensitive sensor array.

Further, the optical film layer comprises a micro-lens layer and at least one diaphragm layer;

the central axis of the micro lens in the micro lens layer is aligned with the light-transmitting area of the diaphragm in each diaphragm layer;

and light signals emitted from the direction of the OLED display device within a preset angle range are focused by the micro-lens layer, pass through the at least one diaphragm layer and are received by the photosensitive sensor array.

Furthermore, the optical signal incident from the direction of the OLED display device outside the preset angle range is absorbed by the at least one diaphragm layer after passing through the micro-lens layer.

Further, one of the photosensors in the photosensor array is aligned with 4 to 16 of the microlenses.

Further, the optical film layer includes a transparent base layer and a band of light;

a shading layer covers the photosensitive sensor array, and the shading layer is provided with a through hole;

and light signals emitted from the direction of the OLED display device within a preset angle range are focused by the optical wave band, pass through the through hole of the shading layer and are received by the photosensitive sensor array.

Further, the light signals incident from the direction of the OLED display device outside the preset angle range are absorbed by the non-through hole part of the light shielding layer after passing through the light wave band.

Further, each photosensor in the photosensor array is aligned to one via.

Further, one fresnel grating in the optical waveband aligns to one through hole.

Further, a light blocking wall is vertically arranged in the transparent substrate layer, and the light blocking wall blocks a plurality of light channels;

each photosensor is aligned to one of the light channels.

Further, one fresnel grating in the optical waveband aligns the plurality of through holes.

one Fresnel grating in the optical waveband is aligned with a plurality of photosensitive sensors in the photosensitive sensor array;

and light signals emitted from the direction of the OLED display device in a preset angle range are received by the plurality of photosensitive sensors after passing through one Fresnel grating.

Further, the optical film layer comprises a transparent substrate layer and a light blocking wall vertically arranged in the transparent substrate layer;

the light blocking walls block to form a plurality of light channels, and one light channel is aligned with one or more light sensors in the light sensor array;

and light signals emitted from the direction of the OLED display device in a preset angle range pass through the light channel and are received by the one or more photosensitive sensors.

Furthermore, the optical fingerprint identification device also comprises an infrared filter film arranged above the photosensitive sensor array.

In a second aspect, the present invention further provides a touch terminal, including an OLED display device and the optical fingerprint identification apparatus;

the optical fingerprint identification device is arranged at the bottom of the OLED display device.

The optical fingerprint identification device provided by the invention comprises a photosensitive sensor array and an optical film layer, and can be arranged at the bottom of an OLED display device. When a finger touches the top of the OLED display device and fingerprint identification is required, light emitted by the OLED display device can irradiate valleys and ridges of the fingerprint. The valley part is the interface between glass and air, namely the light-tight medium is transmitted to the light-sparse medium; the ridge is partially a glass-skin interface, i.e. the light from the optically thinner medium propagates towards the optically denser medium, so that the intensity of the reflected light from the valleys relative to the ridges is greater, so that the fingerprint pattern can be identified from the intensity of the reflected light received by the photosensor array.

The light signal from the direction of the OLED display device and emitted in the preset angle range, namely the reflected light can be emitted into the photosensitive sensor array after passing through the optical film layer, so that the reflected light emitted into the optical film layer and the photosensitive sensor array is from a small fixed range above the optical film layer, and the photosensitive sensor array and the optical film layer do not need to be aligned accurately. Therefore, in the optical fingerprint identification device provided by the invention, the optical film layer and the photosensitive sensor array can be manufactured independently, the complexity of the manufacturing process is reduced, and the technical problem of high complexity of the manufacturing process of the existing touch terminal with the fingerprint identification function can be solved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of a conventional fingerprint recognition device;

FIG. 2 is a schematic diagram of an optical fingerprint recognition apparatus according to an embodiment of the present invention;

FIG. 3 is a diagram illustrating a first implementation of an optical fingerprint identification apparatus according to an embodiment of the present invention;

FIG. 4 is a diagram illustrating a first implementation of an optical film layer of an optical fingerprint identification device according to an embodiment of the present invention;

FIG. 5 is a schematic diagram illustrating dimensional parameters of an optical film layer of an optical fingerprint identification device according to an embodiment of the present invention;

FIG. 6 is a diagram illustrating a second implementation of an optical film layer of an optical fingerprint identification device according to an embodiment of the present invention;

FIG. 7 is a diagram illustrating a third implementation of an optical film layer of an optical fingerprint identification device according to an embodiment of the present invention;

FIG. 8 is a diagram illustrating a fourth implementation of an optical film layer in an optical fingerprint identification device according to an embodiment of the present invention;

FIG. 9 is a diagram illustrating a fifth implementation of an optical film layer of an optical fingerprint identification device according to an embodiment of the present invention;

FIG. 10 is a diagram illustrating a sixth implementation of an optical film layer in an optical fingerprint recognition device according to an embodiment of the present invention;

FIG. 11 is a diagram illustrating a second implementation of an optical fingerprint identification device according to an embodiment of the present invention;

FIG. 12 is a diagram illustrating a third implementation of an optical fingerprint identification device according to an embodiment of the present invention;

FIG. 13 is a diagram illustrating a fourth implementation of an optical fingerprint identification device according to an embodiment of the present invention;

FIG. 14 is a diagram illustrating a fifth implementation of an optical fingerprint identification device according to an embodiment of the invention;

FIG. 15 is a diagram illustrating a sixth implementation of an optical fingerprint identification device according to an embodiment of the present invention;

FIG. 16 is a diagram illustrating a seventh implementation of an optical fingerprint identification device according to an embodiment of the present invention;

fig. 17 is a schematic diagram of a fresnel grating according to an embodiment of the present invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Most of the existing optical imaging structures adopt optical lens structures, in order to meet the requirements of the lens structures and light paths, an optical lens 3 is arranged above each photosensitive sensor in the photosensitive sensor array in a contraposition mode, and extremely high accurate contraposition between the photosensitive sensors and the optical lenses is required. In order to achieve the above accuracy, in a general implementation scheme, both the photosensitive sensor and the optical lens are made by using a CMOS silicon-based compatible process, which results in a large number of process steps and high complexity of the process. In addition, to realize the finger print imaging under the screen, the photosensitive sensor has high requirements on the angle of the received light, and the precise light angle is difficult to realize in the prior art.

The embodiment of the invention provides an optical fingerprint identification device and a touch terminal, which can be applied to touch terminals such as mobile phones and tablet computers, are particularly suitable for full-screen mobile phones, and can solve the technical problem of high process complexity of the existing touch terminal with a fingerprint identification function.

As shown in fig. 2, the optical fingerprint identification device provided by the present invention includes a photosensitive sensor array 100 and an optical film 200, wherein the optical film 200 is fixedly disposed with the photosensitive sensor array 100, and the optical film is bonded with the photosensitive sensor array by an optical adhesive 300. The optical fingerprint recognition device can be installed at the bottom of the OLED display device 400, and light signals emitted from the OLED display device 400 in the direction of a preset angle range are emitted into the photosensitive sensor array 100 after passing through the optical film 200.

When a finger touches the top of the OLED display device 400 and fingerprint recognition is required, light emitted from the OLED display device 400 may irradiate valleys and ridges of a fingerprint. The valley part is the interface between glass and air, namely the light-tight medium is transmitted to the light-sparse medium; the ridges are in part a glass-to-skin interface, i.e., propagating from the optically thinner medium to the optically denser medium, so that the intensity of light reflected by the valleys relative to the ridges is greater, thereby allowing the fingerprint pattern to be identified based on the intensity of the reflected light received by the photosensor array 100.

The light signals incident from the OLED display device 400 in the predetermined angle range, that is, the reflected light can be incident to the photosensor array 100 through the optical film 200. The predetermined angle is preferably 90 ° from the optical film 200, i.e. perpendicular to the optical film 200, and more preferably 85 to 95 °, so that the reflected light from each of the photosensors (sensors) in the photosensor array 100 and the optical film 200 comes from a small fixed range above the predetermined angle, and thus the photosensor array 100 and the optical film 200 do not need to be aligned precisely. Therefore, in the optical fingerprint identification device provided by the embodiment of the invention, the optical film layer 200 and the photosensitive sensor array 100 can be manufactured separately and then bonded by the optical adhesive 300 or fixedly arranged by other methods, so that the complexity of the manufacturing process is reduced, the technical problem of high complexity of the manufacturing process of the existing touch terminal with the fingerprint identification function can be solved, and the yield of the touch terminal can be improved by simplifying the manufacturing process of the touch terminal.

Besides using optical cement, the fixed arrangement mode of the optical film layer and the photosensitive sensor array can also be as follows: the photosensitive sensor array is used as a substrate, the optical film layer is manufactured on the substrate, the optical film layer and the photosensitive sensor array are fixedly arranged, and the optical film layer and the photosensitive sensor array do not need to be aligned accurately in the manufacturing process.

For example, a plurality of photosensor arrays 100 can be fabricated on an 8-inch wafer using a cmos process, and an 8-inch optical film layer 200 can be fabricated independently. And then, the 8-inch wafer and the 8-inch optical film layer 200 are bonded and fixed by using the optical adhesive 300, and then the wafer is cut into small pieces to obtain the optical fingerprint identification device provided by the embodiment of the invention. According to the technical scheme provided by the embodiment of the invention, the optical film layer 200 does not need to be continuously manufactured on the manufactured CMOS photosensitive sensor array 100, the manufacturing difficulty and the manufacturing cost can be obviously reduced, the CMOS and the optical film layer 200 are manufactured respectively by independent processes, and then two manufactured devices are bonded by using the optical cement 300, so that the mass production is easier.

Alternatively, the wafer may be diced first and each diced into individual photosensor arrays. Meanwhile, a small piece of glass is cut out to serve as a transparent substrate layer of the optical film layer, and a single optical film layer is manufactured. And then the photosensitive sensor array and the optical film layer are independently bonded, and the optical fingerprint identification device is manufactured in a small-piece bonding mode.

As shown in fig. 3, in one embodiment of the present invention, the optical film layer 200 includes a microlens layer and a second and a first aperture layers below the microlens layer, and may further include a transparent substrate layer 210, a first transparent layer 212, and a second transparent layer 213. Specifically, a first diaphragm layer is formed on the transparent base layer 210, a first transparent layer 212 is filled between respective diaphragms 211 of the first diaphragm layer and on top of the second diaphragm layer, a second diaphragm layer is formed on the first transparent layer 212, and a second transparent layer 213 is filled between respective diaphragms 211 of the second diaphragm layer and on top of the second diaphragm layer. The transparent substrate layer 210 may be made of glass, Polyimide (PI), or other transparent materials.

The microlens layer includes a plurality of focusing microlenses 214, each of the plurality of apertures 211 includes a plurality of central axes, and the central axes of the microlenses 214 are aligned with the light-transmitting areas of the apertures 211 in each of the plurality of aperture layers. The light signal emitted from the OLED display device 400 in the predetermined angle range is focused by the micro-lens layer, passes through the two diaphragm layers, is emitted into the photosensor array 100, and is received by the photosensor array 100.

Besides using the optical adhesive 300, the fixing manner of the optical film layer 200 and the photosensor array 100 may also be: the photosensor array 100 is used as a substrate, and a first diaphragm layer, a first transparent layer 212, a second diaphragm layer, a second transparent layer 213, a microlens layer and the like are manufactured on the substrate to form the optical film layer 200, so that the optical film layer 200 and the photosensor array 100 are fixedly arranged, and the optical film layer 200 does not need to be accurately aligned with the photosensor array 100 in the manufacturing process of each part.

As an alternative, one photosensor 101 in the photosensor array 100 can be aligned with the plurality of microlenses 214. As shown in fig. 3, one microlens 214 and two diaphragms 211 thereunder can be regarded as one optical pixel group, and the photosensitive sensor 101 can be aligned with a plurality of optical pixel groups. That is, one optical pixel group corresponds to a plurality of microlenses 214, so that the optical signal incident from the OLED display device 400 in the predetermined angle range is focused by the aligned microlenses 214, passes through the aligned two diaphragms 211, and is received by the photosensor 101.

For example, one photosensor 101 may correspond to 2 × 2, 3 × 3, or 4 × 4 groups of optical pixels, such that photosensor array 100 need not be precisely aligned with optical film layer 200. Even if the photosensitive sensor 101 deviates from the optical pixel group, there are many other optical pixel groups and pairs of photosensitive sensors 101, which further improves the fault tolerance when assembling the photosensitive sensor array 100 and the optical film layer 200.

Since one photosensor is aligned with 4-16 microlenses in this embodiment, the silicon-based photosensor array 100 can be made into a low PPI (Pixels Per Inch, pixel density) product, which can reach thousands of PPIs (e.g. 4000PPI) in a conventional silicon-based product, and the PPI range adopted in this embodiment is 250-500, so that the area of each individual photosensor 101 is increased and the photosensitivity is better. In other embodiments, the photosensitive sensor and the microlens can be aligned in a one-to-one manner.

In the case of fingerprint image recognition, it can be considered that light having one position in each of the valleys and ridges of the fingerprint is reflected, and the light rays depicted by the solid lines in fig. 3 represent light rays within the preset angle range and the light rays depicted by the solid lines represent light rays outside the preset angle range. It can be seen that the nearly vertical solid line light passes through the OLED film, is focused by the micro-lens 214 of the optical film 200, passes through the two diaphragms 211, and reaches the photosensitive sensor 101, and is converted into corresponding electrical signals and read out. The broken-line rays of other angles, although also transmitted through the microlens 214, are blocked by the diaphragm 211 and absorbed by the black material of the diaphragm 211. So that only solid line light from the valleys or ridges of the fingerprint reaches the light sensitive sensor 101. Therefore, the fact that the light rays partially reflected by the valleys are received by the photosensitive sensors 101 below the corresponding valleys and the light rays partially reflected by the ridges are received by the photosensitive sensors 101 below the corresponding ridges is guaranteed, and the light rays which are mixed easily at other angles are shielded, so that the valleys and the ridges can be distinguished.

Further, as shown in fig. 4, the optical fingerprint identification apparatus according to the embodiment of the present invention further includes an infrared Filter (IR-Cut Filter, IRCF for short) 215 disposed above the photosensor array 100, where the infrared Filter 215 is specifically disposed between the first aperture layer of the optical film 200 and the transparent substrate layer 210, and is used for blocking interference light from an external environment. When external light exists, only light with the wavelength of more than 600nm can penetrate through the finger after the external light passes through the finger, so that the external light is filtered by the infrared filter film 215 before reaching the photosensitive sensor 101, and the recognition of the fingerprint image cannot be influenced.

The infrared filter film 215 is directly manufactured on the transparent substrate layer 210, and then parts such as the diaphragm 211, the micro lens 214 and the like are manufactured, so that the infrared filtering function and the light angle limiting function can be integrated better, and the thickness reduction of the whole device is facilitated.

As shown in fig. 5, the selectable sizes of the parts in this embodiment are as follows:

the optional size of the aperture D of the micro lens 214 is several mum to dozens of mum;

the optional size of the microlens 214 arch height h is in the order of several μm;

the optional size of the aperture d of the diaphragm 211 is several mum orders;

the optional size of the diaphragm 211 thickness d1 is in the order of a few μm;

the transparent layer d2 between the two diaphragm layers may be chosen to be of the order of a few μm in size;

the optional size of the infrared filter film d3 is in the order of several mum;

the thickness d4 of the transparent substrate layer can be selected to be several mum to hundreds mum in magnitude;

the optional size of the top of the microlens 214 to the top of the second stop layer d5 is on the order of tens of μm;

the optional size of the top of the microlens 214 to the bottom of the first stop layer d6 is on the order of tens of μm.

In another embodiment, as shown in fig. 6, the microlenses 214 can also be a continuous arrangement.

In addition, the specific position of the infrared filter film can be selected in various ways. As shown in fig. 7, an infrared filter 215 may be used as a substrate layer of the optical film layer 200. Alternatively, as shown in fig. 8, the infrared filter film 215 may be substituted for the first transparent layer. Alternatively, as shown in fig. 9, the infrared filter 215 may be separately formed and attached to the bottom of the transparent base layer 210 by the optical adhesive 301.

In other embodiments, as shown in fig. 10, only one stop 211 may be disposed in the optical film layer 200. The use of one stop layer enables the thickness of the optical film layer 200 to be thinner than two stop layers.

In another embodiment, three or more layers of diaphragms may be disposed in the optical film layer, and the more layers of diaphragms have better effect on limiting the light angle, that is, only light in a small angle range is incident on the photosensor array.

In one embodiment of the present invention, as shown in fig. 11, the optical film layer 200 includes a transparent substrate layer 221 and a wavelength band of light. The light-shielding layer 121 covers the photosensor array 100, and the light-shielding layer 121 is provided with a through hole.

As shown in fig. 17, the black portion in the fresnel grating 222 is a light-shielding portion, and the white portion is a light-transmitting portion. Each fresnel grating 222 is composed of many concentric black and white rings, and its optical characteristics are determined by the radius of the concentric rings and the number of the rings at a black-white boundary. There are a number of such fresnel gratings 222 arrayed across the optical band.

The light signal emitted from the OLED display device 400 in the predetermined angle range is focused by the optical band, passes through the through hole of the light shielding layer 121, and is received by the photosensor array 100. The fresnel grating 222 is composed of a plurality of concentric rings, in which the light-shielding portion and the light-transmitting portion are spaced from each other, and the optical characteristics thereof are determined by the radii of the concentric rings and the number of rings. Because the fresnel grating 222 has a focusing function, there is no need for precise alignment between the photosensor array 100 and the optical film layer 200.

Therefore, the optical film 200 and the photosensitive sensor array 100 can be separately manufactured and then bonded by the optical adhesive 300, which simplifies the complexity of the manufacturing process and can alleviate the technical problem of high complexity of the manufacturing process of the existing touch terminal with the fingerprint identification function.

Besides using the optical adhesive 300, the fixing manner of the optical film layer 200 and the photosensor array 100 may also be: the photosensitive sensor array 100 is used as a substrate, and the transparent substrate layer 221, the optical wave band and other parts are manufactured on the photosensitive sensor array 100 to form the optical film layer 200, so that the optical film layer 200 and the photosensitive sensor array 100 are fixedly arranged, and certainly, the optical film layer 200 does not need to be accurately aligned with the photosensitive sensor array 100 in the manufacturing process of each part.

The manufacturing process of the optical film layer 200 is roughly as follows: a layer of light-blocking material, such as metal or other material with low transmittance and low reflectivity, is formed on the transparent substrate layer 221, and if the metal material is used, the thickness should be not less than

Then, the light blocking material is patterned according to the position corresponding to the photosensitive sensor 122 to form a pattern of the fresnel grating 222, and the optical film 200 is manufactured.

On the other hand, a light shielding layer 121 is also required to be formed on the photosensor array 100, and in order to ensure that the photosensors 122 can enter light and do not mix light, a through hole is formed in a position of the light shielding layer 121 corresponding to the upper portion of each photosensor 122, so that light can enter, and each photosensor 122 in the photosensor array 100 is aligned to one through hole.

Then, the optical film layer 200 and the photosensor array 100 are bonded by using the optical adhesive 300, and each fresnel grating 222 corresponds to each photosensor 122. As one implementation, one fresnel grating 222 in the optical band is aligned to one via.

After the external light passes through the fresnel grating 222, it can be ensured that the small-angle light (solid line in the figure) above each photosensor 122 passes through the fresnel grating and then converges to the corresponding through hole on each photosensor 122. Other light rays with larger angles (dotted lines in the figure) are converged at the non-through holes of the light shielding layer 121 and are absorbed by the light shielding layer 121.

In another implementation, it is also possible to align a plurality of fresnel gratings 222 in the optical band to one through hole.

Further, as shown in fig. 12, in another embodiment, a light blocking wall 223 may be vertically disposed in the transparent substrate layer 221, one end of the light blocking wall 223 is located at the top of the transparent substrate layer 221, and the other end of the light blocking wall 223 is located at the bottom of the transparent substrate layer 221.

The light blocking walls 223 block the formation of a plurality of light channels 224, and each photosensor 122 is aligned with one light channel 224. As can be seen from fig. 11, the light tunnel 224 is located between the two light blocking walls 223 adjacent to each other on the left and right, and there are actually two light blocking walls in the front-back direction which cannot be shown in the figure, that is, the light tunnel 224 is formed by being blocked and surrounded by the four light blocking walls 223 on the front-back and left-right.

The light blocking walls 223 formed in the transparent substrate layer 221 can block more light rays with large angles, so that the influence of the light rays with large angles on the adjacent photosensitive sensor 122 can be further reduced.

The optional parameters of each part in this embodiment are as follows:

the photosensitive sensor 122PPI can be selected to be 250-500 PPI;

the fresnel grating 222 diameter is less than or equal to the individual photosensor 122 size;

the through holes of the light-shielding layer 121 can be selected to be several μm level;

the circle center spacing of the Fresnel grating 222 can be selected to be in the order of hundreds of micrometers;

the diameter of the Fresnel grating 222 can be selected to be in the order of tens of μm;

the optical layer thickness may be selected to be on the order of hundreds of microns.

In one embodiment of the invention, as shown in fig. 13, one fresnel grating 222 in the optical band is aligned with a plurality of through holes, one for each photosensor 122. Thus, the optical film 200 and the photosensor array 100 do not need to be aligned precisely, and because the number of fresnel gratings 222 is smaller, there is always one photosensor 122 closest to the fresnel grating 222, which receives the light signal transmitted and focused by the fresnel grating 222.

In another embodiment, as shown in fig. 14, the optical film layer 200 includes a transparent substrate layer 221 and a wavelength band of light. One fresnel grating 222 in the optical band is aligned with the plurality of photosensors 122 in the photosensor array 100, which corresponds to the omission of the light shielding layer 121 in the embodiment shown in fig. 13. The light signals from the OLED display direction are received by the plurality of photosensors 122 after passing through a fresnel grating 222.

If the light-gathering angle of the fresnel grating 222 is small enough and the pitch between adjacent fresnel gratings 222 is large enough, the light-shielding layer can be omitted. When light with a small angle passes through the fresnel grating 222, it is focused by the fresnel grating 222 and enters the photosensor 122 closest to the fresnel grating 222. Other light rays with slightly larger angles will pass through the fresnel grating 222 (unfocused) in a manner similar to pinhole imaging and strike the photosensors 122 around the nearest photosensor 122. This combines multiple photosensors 122 for use as a fingerprint pixel, and the light signal is projected as a light spot onto the photosensor array 100, rather than being imaged in a manner similar to the previous embodiment.

This embodiment also does not need to consider the alignment of the optical film 200 with the photosensor array 100, and different angles of light can reach different photosensors 122 to achieve long-range fingerprint identification.

As shown in fig. 15, in an embodiment of the present invention, each two photosensors 122 may be used as a unit, one of which corresponds to the fresnel grating 222, and the light shielding layer 121 above the corresponding fresnel grating is provided with a through hole for receiving a light signal; the other is covered with the light-shielding layer 121, does not receive light, but can absorb dark current or a noise signal of the photosensor 122, and thus serves as a reference photosensor 122.

In this embodiment, in order to be able to realize fingerprint identification, the total size of two adjacent pixels needs to reach 70 μm effect, and compared to the previous solution, the PPI of the photosensitive sensor 122 is doubled because half of the photosensitive sensor 122 is lost as a reference.

As shown in fig. 16, in one embodiment of the present invention, the optical film layer 200 includes a transparent substrate layer 230 and a light blocking wall 231 vertically disposed in the transparent substrate layer 230, one end of the light blocking wall 231 is located at the top of the transparent substrate layer 230, and the other end of the light blocking wall 231 is located at the bottom of the transparent substrate layer 230. The light blocking walls 231 block the formation of a plurality of light channels 232, and one light channel 232 is aligned with a plurality of (or one) photosensors 131 in the photosensor array 100. The optical signal from the OLED display device 400 is received by the plurality (or one) of the photo sensors 131 after passing through the optical channel 232.

In another embodiment, the cross-sectional area of the optical channel may be smaller than that of the photosensitive sensor, so that a plurality of optical channels correspond to one photosensitive sensor, and thus, the alignment problem of the optical film layer and the photosensitive sensor array may not be considered.

In this embodiment, the array-type optical channels 232 are implemented in the transparent substrate layer 230, and each of the photosensors 131 may correspond to a plurality of the optical channels 232, so that the optical channels 232 are relatively narrow, and only light with a small angle can pass through to the photosensors 131, thereby implementing long-distance ridge and valley recognition and preventing crosstalk. In addition, in other embodiments, the photo sensors 131 and the optical channels may correspond to each other one by one.

By forming the optical channel 232 in the optical film 200, the optical signal incident to the optical film 200 and each of the photosensors 131 in the photosensor array 100 comes from a small fixed range above the optical film, so that the photosensor array 100 and the optical film 200 do not need to be aligned precisely. Therefore, the optical film layer 200 and the photosensitive sensor array 100 can be separately manufactured and then bonded by the optical adhesive 301, so that the complexity of the manufacturing process is simplified, the technical problem of high complexity of the manufacturing process of the existing touch terminal with the fingerprint identification function can be solved, and the yield of the touch terminal can be improved by simplifying the manufacturing process of the touch terminal.

The optional parameters of each part in this embodiment are as follows:

the optical glue 301 may be selected to be 25 μm or less;

the transparent base layer may be selected to be 400 μm or less;

the optical glue 302 may be selected to be 25 μm or less;

the center-to-center distance of the optical channels can be selected to be in the order of tens of micrometers;

the inner diameter of the optical channel may be selected to be on the order of tens of μm.

Besides using the optical adhesive 301, the fixing manner of the optical film layer 200 and the photosensor array 100 may also be: the photosensitive sensor array 100 is used as a substrate, and the transparent substrate layer 230, the light blocking wall 231 and the like are fabricated on the substrate to form the optical film layer 200, so that the optical film layer 200 and the photosensitive sensor array 100 are fixedly arranged, and certainly, the optical film layer 200 does not need to be accurately aligned with the photosensitive sensor array 100 in the fabrication process of each part.

In other embodiments, the optical channel may be implemented by using a material without a substrate, such as an optical fiber, and a light-shielding material is added to the outer wall of the optical fiber to form an optical channel with a large depth-width ratio.

In each of the above embodiments, an infrared filter film may be further included above the photosensor array 100, which may be specifically disposed as shown in fig. 6 to 9, or other feasible manners.

The embodiment of the invention also provides a touch terminal which can be a touch terminal such as a mobile phone, a tablet computer and the like, and is particularly suitable for a full-screen mobile phone. The touch terminal comprises an OLED display device and the optical fingerprint identification device provided by any one of the embodiments, the optical fingerprint identification device is installed at the bottom of the OLED display device, the optical fingerprint identification device and the OLED display device are fixed through a frame pasting gasket, and the middle of the optical fingerprint identification device is filled with air or low-refractive-index substances.

Because the touch terminal provided by the embodiment of the invention comprises all technical features of the optical fingerprint identification device provided by the embodiment, the same technical problems can be solved, and the same technical effects can be achieved.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or the orientations or positional relationships that the products of the present invention are conventionally placed in use, and are only used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. The optical fingerprint identification device is characterized by being used for being installed at the bottom of an OLED display device;

2. The device of claim 1, wherein the optical film layer comprises a microlens layer and at least one diaphragm layer;

3. The apparatus of claim 2, wherein the light signals incident from the OLED display device outside the predetermined angle range are absorbed by the at least one light stop layer after passing through the microlens layer.

4. The apparatus of claim 2, wherein one photosensor in the photosensor array is aligned with 4 to 16 microlenses.

5. The device of claim 1, wherein the optical film layer comprises a transparent substrate layer and a band of light;

6. The apparatus of claim 5, wherein the light signal incident from the direction of the OLED display device outside the predetermined angular range is absorbed by the non-through hole portion of the light shielding layer after the light wavelength band.

7. The apparatus of claim 5, wherein each photosensor in the photosensor array is aligned to one via.

8. The apparatus of claim 7 wherein one fresnel grating in the optical waveband aligns to one of the through holes.

9. The device according to claim 8, wherein light blocking walls are vertically arranged in the transparent substrate layer, and the light blocking walls block a plurality of light channels;

each photosensor is aligned to one of the light channels.

10. The apparatus of claim 7 wherein one fresnel grating in the optical waveband aligns a plurality of the through holes.

11. The device of claim 1, wherein the optical film layer comprises a transparent substrate layer and a band of light;

12. The device of claim 1, wherein the optical film layer comprises a transparent substrate layer and light blocking walls vertically disposed in the transparent substrate layer;

13. The device of any one of claims 1 to 12, further comprising an infrared filter disposed over the array of light sensitive sensors.

14. A touch terminal, comprising an OLED display device and the optical fingerprint recognition apparatus of any one of claims 1 to 13;