CN110674798A - Optical fingerprint identification device and touch terminal - Google Patents

Abstract

The present invention provides an optical fingerprint identification device and a touch terminal, which relate to the technical field of display terminals, so as to alleviate the technical problem of high process complexity of the existing touch terminal with fingerprint identification function. The optical fingerprint identification device is used to be installed at the bottom of an OLED display device; the optical fingerprint identification device comprises a photosensitive sensor array and an optical film layer, and the optical film layer and the photosensitive sensor array are fixedly arranged; The light signal incident in a preset angle range, after passing through the optical film layer, is incident on the photosensitive sensor array.

Description

Optical fingerprint identification device and touch terminal

technical field

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

Background technique

Full screen is the mainstream configuration of current mobile phones, and the use of full screen mobile phones also makes organic light-emitting diode (Organic Light-Emitting Diode, OLED) fingerprints a popular research direction. As shown in FIG. 1 , the basic structure is that a fingerprint identification assembly 2 is placed under the OLED panel 1 , and the fingerprint identification assembly 2 includes two parts, an integrated optical imaging structure and an image sensor array.

In the current products, most of the optical imaging structures use an optical lens structure. In order to meet the requirements of the lens structure and optical path, there is an optical lens 3 above each photosensitive sensor 4 in the photosensitive sensor array. This requires The photosensitive sensor 4 and the optical lens 3 have extremely high precision alignment (the error is within a few μm). In order to achieve the above-mentioned accuracy, in a general implementation scheme, the photosensitive sensor 4 and the optical lens 3 are made by a CMOS silicon-based compatible process. However, such a manufacturing process has many processes and high complexity in the manufacturing process.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an optical fingerprint identification device and a touch terminal, so as to alleviate the technical problem of high process complexity of the existing touch terminal with fingerprint identification function.

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

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

The light signal incident from the direction of the OLED display device with a preset angle range, after passing through the optical film layer, enters the photosensitive sensor array.

Further, the optical film layer includes a microlens layer and at least one diaphragm layer;

The central axis of the microlenses in the microlens layer is aligned with the light-transmitting area of the diaphragm in each layer of the diaphragm layer;

The light signal incident from the direction of the OLED display device with a preset angle range, after being focused by the microlens layer, passes through the at least one diaphragm layer, and is received by the photosensor array.

Further, the light 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 microlens layer.

Further, one photosensitive sensor in the photosensitive sensor array is aligned with 4 to 16 of the microlenses.

Further, the optical film layer includes a transparent base layer and an optical wavelength band;

The photosensitive sensor array is covered with a light-shielding layer, and the light-shielding layer is provided with through holes;

The light signal incident from the direction of the OLED display device with a preset angle range, after being focused by the light wavelength band, passes through the through hole of the light shielding layer, and is received by the photosensor array.

Further, the light signal incident from the direction of the OLED display device outside the preset angle range is absorbed by the non-through hole portion of the light shielding layer after passing through the light wavelength band.

Further, each photosensitive sensor in the photosensitive sensor array is aligned with one of the through holes.

Further, a Fresnel grating in the optical wavelength band is aligned with one of the through holes.

Further, a light-blocking wall is vertically disposed in the transparent base layer, and the light-blocking wall blocks and forms a plurality of light channels;

Each photosensitive sensor is aligned with one of the light channels.

Further, a Fresnel grating in the optical wavelength band aligns a plurality of the through holes.

Further, the optical film layer includes a transparent base layer and an optical wavelength band;

A Fresnel grating in the optical waveband is aligned with a plurality of photosensors in the photosensor array;

The light signal incident from the direction of the OLED display device with a preset angle range is received by the plurality of photosensitive sensors after passing through one of the Fresnel gratings.

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

The light blocking wall blocks and forms a plurality of light channels, and one of the light channels is aligned with one or more photosensors in the photosensor array;

The light signal incident from the direction of the OLED display device with a preset angle range is received by one or more of the light sensitive sensors after passing through the light channel.

Further, the optical fingerprint identification device further includes an infrared filter film disposed above the photosensitive sensor array.

In a second aspect, the present invention also provides a touch terminal, including an OLED display device and the above-mentioned optical fingerprint identification device;

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

The optical fingerprint identification device provided by the present invention includes a photosensitive sensor array and an optical film layer, and can be installed at the bottom of an OLED display device. When a finger touches the top of the OLED display device and fingerprint identification is required, the light emitted by the OLED display device will illuminate the valleys and ridges of the fingerprint. Since the part of the valley is the interface between the glass and the air, that is, it propagates from the optically dense medium to the optically sparser medium; larger, so that the fingerprint pattern can be identified according to the intensity of the reflected light received by the photosensitive sensor array.

The light signal incident from the direction of the OLED display device with a preset angle range, that is, the above-mentioned reflected light can enter the photosensitive sensor array after passing through the optical film layer, so the reflected light entering the optical film layer and the photosensitive sensor array comes from There is a small fixed range above it, so there is no need for very precise alignment between the photosensitive sensor array and the optical film layer. Therefore, in the optical fingerprint identification device provided by the present invention, the optical film layer and the photosensitive sensor array can be manufactured independently, which reduces the complexity of the manufacturing process and can alleviate the high manufacturing process complexity of the existing touch terminal with fingerprint identification function. technical issues.

Description of drawings

In order to illustrate the specific embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the specific embodiments or the prior art. Obviously, the accompanying drawings in the following description The drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

1 is a schematic diagram of an existing fingerprint identification device;

2 is a schematic diagram of an optical fingerprint identification device according to an embodiment of the present invention;

3 is a schematic diagram of a first implementation manner of an optical fingerprint identification device provided by an embodiment of the present invention;

4 is a schematic diagram of a first implementation manner of an optical film layer in an optical fingerprint identification device provided by an embodiment of the present invention;

5 is a schematic diagram of size parameters of an optical film layer in an optical fingerprint identification device provided by an embodiment of the present invention;

6 is a schematic diagram of a second implementation manner of an optical film layer in an optical fingerprint identification device provided by an embodiment of the present invention;

7 is a schematic diagram of a third embodiment of an optical film layer in an optical fingerprint identification device provided by an embodiment of the present invention;

8 is a schematic diagram of a fourth embodiment of an optical film layer in an optical fingerprint identification device provided by an embodiment of the present invention;

9 is a schematic diagram of a fifth implementation manner of an optical film layer in an optical fingerprint identification device provided by an embodiment of the present invention;

10 is a schematic diagram of a sixth embodiment of an optical film layer in an optical fingerprint identification device provided by an embodiment of the present invention;

11 is a schematic diagram of a second implementation manner of an optical fingerprint identification device provided by an embodiment of the present invention;

12 is a schematic diagram of a third implementation manner of an optical fingerprint identification device provided by an embodiment of the present invention;

13 is a schematic diagram of a fourth implementation manner of an optical fingerprint identification device provided by an embodiment of the present invention;

14 is a schematic diagram of a fifth implementation manner of an optical fingerprint identification device provided by an embodiment of the present invention;

15 is a schematic diagram of a sixth implementation manner of an optical fingerprint identification device provided by an embodiment of the present invention;

16 is a schematic diagram of a seventh implementation manner of an optical fingerprint identification device provided by an embodiment of the present invention;

FIG. 17 is a schematic diagram of a Fresnel grating in an embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Most of the existing optical imaging structures use an optical lens structure. In order to meet the requirements of the lens structure and optical path, there is an optical lens 3 above each photosensitive sensor in the photosensitive sensor array, which requires the photosensitive sensor and the optical lens. It has extremely high precision alignment. In order to achieve the above-mentioned accuracy, in a general implementation scheme, the photosensitive sensor and the optical lens are made by a CMOS silicon-based compatible process, resulting in numerous process steps and high process complexity. In addition, to realize under-screen fingerprint imaging, the photosensitive sensor has high requirements on the angle of light received, and it is difficult to achieve an accurate light angle in the prior art.

Embodiments of the present invention provide an optical fingerprint recognition device and a touch terminal, which can be applied to touch terminals such as mobile phones and tablet computers, and are especially suitable for full-screen mobile phones, which can alleviate the existing manufacturing process of touch terminals with fingerprint recognition functions. Technical issues of high complexity.

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 layer 200 . The optical film layer 200 and the photosensitive sensor array 100 are fixedly arranged. In this embodiment, the optical glue 300 is used for bonding. The optical fingerprint identification device can be installed at the bottom of the OLED display device 400 , and the light signal from the direction of the OLED display device 400 with a predetermined angle range enters the photosensitive sensor array 100 after passing through the optical film layer 200 .

When a finger touches the top of the OLED display device 400 and fingerprint identification is required, the light emitted by the OLED display device 400 will illuminate the valleys and ridges of the fingerprint. Since the part of the valley is the interface between the glass and the air, that is, it propagates from the optically dense medium to the optically sparser medium; larger, so that the fingerprint pattern can be identified according to the intensity of the reflected light received by the photosensitive sensor array 100 .

The light signal incident from the direction of the OLED display device 400 with a predetermined angle range, that is, the above-mentioned reflected light, can be incident on the photosensor array 100 after passing through the optical film layer 200 . In the best case, the preset angle is 90° with the optical film layer 200 , that is, it is perpendicular to the optical film layer 200 . The reflected light of each photosensitive sensor (sensor) in the layer 200 and the photosensitive sensor array 100 comes from a small fixed range above it, so very precise alignment between the photosensitive sensor array 100 and the optical film layer 200 is not required. Therefore, in the optical fingerprint identification device provided by the embodiment of the present invention, the optical film layer 200 and the photosensitive sensor array 100 can be fabricated separately, and then bonded together by the optical glue 300, or fixedly arranged in other ways, which reduces the complexity of the process. It can alleviate the technical problem of high process complexity of the existing touch terminal with a fingerprint recognition function, and by simplifying the process of the touch terminal, the yield of the touch terminal can also be improved.

In addition to the use of optical glue, the fixed setting method of the optical film layer and the photosensitive sensor array can also be: using the photosensitive sensor array as the substrate, making the optical film layer on it, and realizing the fixed setting of the two, of course, the production of the optical film layer The process does not require very precise alignment with the photosensitive sensor array.

For example, on the one hand, a plurality of photosensitive sensor arrays 100 can be fabricated on an 8-inch wafer by using the COMS process, and on the other hand, an 8-inch optical film layer 200 can be fabricated, and the two are fabricated independently. Then, the 8-inch wafer and the 8-inch optical film layer 200 are bonded and fixed by the optical glue 300, and then cut into small pieces to obtain the optical fingerprint identification device provided by the embodiment of the present invention. The technical solution provided by the embodiment of the present invention does not require the optical film layer 200 to be continuously fabricated on the fabricated CMOS photosensitive sensor array 100, which can significantly reduce fabrication difficulty and fabrication cost. Then, the two separately prepared devices can be bonded together by using the optical adhesive 300, which is easier to mass-produce.

Alternatively, the wafer can be cut into small pieces first, and each piece can be made into a single array of photosensors. At the same time, a small piece of glass is cut out as a transparent base layer of the optical film layer, and a single optical film layer is made. Then, the photosensitive sensor array and the optical film layer are separately bonded, and the optical fingerprint identification device is fabricated by means of small-piece bonding.

As shown in FIG. 3 , in an embodiment of the present invention, the optical film layer 200 includes a microlens layer, a second diaphragm layer and a first diaphragm layer located below the microlens layer, and may also include a transparent base layer 210 , a first transparent layer 212 and a second transparent layer 213 . Specifically, the first diaphragm layer is formed on the transparent base layer 210, the first transparent layer 212 is filled between the diaphragms 211 of the first diaphragm layer and the upper part of the second diaphragm layer, and the second diaphragm layer is formed On the first transparent layer 212, the second transparent layer 213 is filled between the respective diaphragms 211 of the second diaphragm layer and on the upper part of the second diaphragm layer. The transparent base layer 210 can be made of glass, polyimide (PI for short) or other transparent materials.

The microlens layer includes many microlenses 214 for focusing, each diaphragm layer includes many diaphragms 211, the central axis of each microlens 214 and the light transmission of the diaphragm 211 in each diaphragm layer Area alignment. The light signal incident from the direction of the OLED display device 400 with a preset angle range, after being focused by the microlens layer, passes through two diaphragm layers, and then enters the photosensor array 100 and is received by the photosensor array 100 .

In addition to using the optical glue 300, the fixed arrangement of the optical film layer 200 and the photosensitive sensor array 100 can also be as follows: the photosensitive sensor array 100 is used as a substrate, and the first aperture layer, the first transparent layer 212, the first diaphragm layer, the first transparent layer 212, the The two diaphragm layers, the second transparent layer 213 , the microlens layer and other parts form the optical film layer 200 to realize the fixed arrangement of the optical film layer 200 and the photosensitive sensor array 100 . Of course, the production process of each part of the optical film layer 200 does not require It is precisely aligned with the photosensitive sensor array 100 .

As an optional solution, one photosensor 101 in the photosensor array 100 may be aligned with a plurality of microlenses 214 . As shown in FIG. 3 , one microlens 214 and two diaphragms 211 below it can be regarded as one optical pixel group, and the photosensor 101 can be aligned with multiple optical pixel groups. That is, the positions of one optical pixel group and the plurality of microlenses 214 correspond to each other, so that the light signal incident from the direction of the OLED display device 400 with a preset angle range is focused by the aligned microlenses 214, and then passes through the aligned microlenses 214. The two apertures 211 are received by the photosensitive sensor 101 .

For example, one photosensitive sensor 101 corresponds to 2×2 or 3×3 or 4×4 optical pixel groups, so that the photosensitive sensor array 100 does not need to be precisely aligned with the optical film layer 200 . Even if the photosensitive sensor 101 deviates from the optical pixel group, there are always many other optical pixel groups aligned with the photosensitive sensor 101 , which further improves the fault tolerance rate when the photosensitive sensor array 100 is assembled with the optical film layer 200 .

Because one photosensor is aligned with 4 to 16 microlenses in this embodiment, the silicon-based photosensor array 100 can be made into a low PPI (Pixels Per Inch, pixel density per inch) product, a conventional silicon-based product It can reach thousands of PPI (eg, 4000 PPI), while the range of PPI used in this embodiment is 250-500, which increases the area of each individual photosensor 101 and has better photosensitivity characteristics. In other embodiments, the photosensitive sensor and the microlens can also be aligned in a one-to-one manner.

When performing fingerprint image recognition, it can be seen that the valley and ridge of the fingerprint each have a position for light to reflect. The light depicted by the solid line in Figure 3 represents the light within the preset angle range, and the light depicted by the solid line Represents rays outside the preset angle range. It can be seen that, after passing through the OLED film layer, the nearly vertical solid line light is focused by the microlens 214 of the optical film layer 200, and then passes through the two apertures 211 to reach the photosensitive sensor 101, where it is converted into a corresponding electrical signal and read out. Although the dashed rays of other angles also pass through the microlens 214 , they are all blocked by the diaphragm 211 and absorbed by the black material of the diaphragm 211 . Such valleys or ridges of the fingerprint can only reach the photosensitive sensor 101 with solid light rays. In this way, it is ensured that the light reflected by the part of the valley is received by the photosensitive sensor 101 below the corresponding valley, the light reflected by the part of the ridge is received by the photosensitive sensor 101 below the corresponding ridge, and the mixed light at other angles is easily blocked. Thus, valleys and ridges can be distinguished.

Further, as shown in FIG. 4 , the optical fingerprint identification device provided by the embodiment of the present invention further includes an infrared filter film (IR-Cut Filter, IRCF for short) 215 disposed above the photosensitive sensor array 100, and the infrared filter film 215 Specifically, it is disposed between the first diaphragm layer of the optical film layer 200 and the transparent base layer 210 to block interfering light from the external environment. When there is external light, since the external light passes through the finger, only the light with a wavelength above 600 nm can pass through the finger, so the external light is filtered by the infrared filter film 215 before reaching the photosensitive sensor 101, and will not affect the fingerprint image. recognition has an impact.

The infrared filter film 215 is directly fabricated on the transparent base layer 210, and then the diaphragm 211 and the microlens 214 and other components are fabricated, so that the infrared filter function and the function of limiting the light angle can be better integrated, which is conducive to reducing the thickness of the overall device. .

As shown in Figure 5, the optional dimensions of each part in this embodiment are as follows:

The optional size of the microlens 214 aperture D is in the order of several μm to several tens of μm;

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

The optional size of aperture d of aperture 211 is in the order of several μm;

The optional size of the thickness d1 of the diaphragm 211 is in the order of several μm;

The optional size of the transparent layer d2 between the two diaphragm layers is in the order of several μm;

The optional size of the infrared filter film d3 is several μm;

The thickness d4 of the transparent base layer can be selected in the order of several μm to several hundreds of μm;

The optional size of the top d5 of the microlens 214 to the top of the second diaphragm layer is in the order of tens of μm;

The optional dimension from the top of the microlens 214 to the bottom d6 of the first diaphragm layer is in the order of tens of μm.

As shown in FIG. 6 , in another embodiment, the microlenses 214 may also be arranged in a continuous structure.

In addition, the specific position of the infrared filter film can also be selected in various ways. As shown in FIG. 7 , the infrared filter film 215 can be used as the base layer of the optical film layer 200 . Alternatively, as shown in FIG. 8 , the infrared filter film 215 can be substituted for the first transparent layer. Alternatively, as shown in FIG. 9 , the infrared filter film 215 can be fabricated separately and attached to the bottom of the transparent base layer 210 by using the optical glue 301 .

As shown in FIG. 10 , in other embodiments, only one layer of diaphragm 211 may be provided in the optical film layer 200 . Compared with two diaphragm layers, using one diaphragm layer can make the thickness of the optical film layer 200 thinner.

In another embodiment, three or more layers of diaphragms can also be arranged in the optical film layer, and more diaphragms have a better effect on limiting the light angle, that is, only light in a small angle range will enter the photosensitive sensor array.

As shown in FIG. 11 , in one embodiment of the present invention, the optical film layer 200 includes a transparent base layer 221 and an optical wavelength band. The photosensitive sensor array 100 is covered with a light shielding layer 121 , and the light shielding layer 121 is provided with through holes.

As shown in FIG. 17 , the black part of the Fresnel grating 222 is the light-shielding part, and the white part is the light-transmitting part. Each Fresnel grating 222 is composed of many concentric black and white rings, and its optical properties are determined by the radius of the concentric circles and the number of rings at the intersection of black and white. In the optical wavelength band, there are many such Fresnel gratings 222 in an array.

The light signal incident from the direction of the OLED display device 400 with a preset angle range, after being focused by the light wave 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 many concentric rings, wherein the light-shielding part and the light-transmitting part are spaced apart from each other, and its optical characteristics are determined by the radius of these concentric rings and the number of the rings. Because the Fresnel grating 222 has a focusing function, very precise alignment between the photosensor array 100 and the optical film layer 200 is not required.

Therefore, the optical film layer 200 and the photosensitive sensor array 100 can be fabricated separately, and then bonded together by the optical glue 300, which simplifies the complexity of the process and can alleviate the complexity of the existing touch terminal with fingerprint recognition function. high-level technical issues.

In addition to using the optical glue 300, the fixed arrangement of the optical film layer 200 and the photosensitive sensor array 100 can also be as follows: the photosensitive sensor array 100 is used as the substrate, and the transparent base layer 221 and the light wave band and other parts are fabricated on it to form the optical film The layer 200 realizes the fixed arrangement of the optical film layer 200 and the photosensor array 100 . Of course, each part of the optical film layer 200 does not need to be precisely aligned with the photosensor array 100 during the fabrication process.

然后按照光敏传感器122对应的位置，对阻光材料进行图形化，形成菲涅尔光栅222的图形，即完成了光学膜层200的制作。The manufacturing process of the optical film layer 200 is roughly as follows: forming a layer of light-blocking material on the transparent base layer 221, such as metal or other materials with low transmittance and low reflectivity, if a metal material is used, the thickness should not be less than

Then, the light blocking material is patterned according to the position corresponding to the photosensitive sensor 122 to form the pattern of the Fresnel grating 222 , that is, the fabrication of the optical film layer 200 is completed.

On the other hand, a light-shielding layer 121 also needs to be formed on the photosensitive sensor array 100. At the same time, in order to ensure that the photosensitive sensor 122 can receive light without mixing light, a through hole is opened in the light-shielding layer 121 corresponding to the position above each photosensitive sensor 122, To allow light to enter, each photosensor 122 in the photosensor array 100 is aligned with a through hole.

Then, the optical film layer 200 and the photosensitive sensor array 100 are bonded together by using the optical glue 300 , and each Fresnel grating 222 is corresponding to each photosensitive sensor 122 respectively. As an implementation, a Fresnel grating 222 in the optical band is aligned with a through hole.

When 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 photosensitive sensor 122 passes through the Fresnel grating, and then converges to the corresponding through hole on each photosensitive sensor 122 . Other light rays with larger angles (dotted lines in the figure) converge to the non-through holes of the light shielding layer 121 and are absorbed by the light shielding layer 121 .

In another implementation manner, a plurality of Fresnel gratings 222 in the optical wavelength band may also be aligned with one through hole.

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

The light blocking wall 223 blocks and forms a plurality of light channels 224 , and each photosensitive sensor 122 is aligned with one light channel 224 . It can be seen from FIG. 11 that the light channel 224 is located between the two light blocking walls 223 adjacent to the left and right. In fact, there are also two light blocking walls in the front and rear directions that are not shown in the figure, that is to say The light channel 224 is formed by being blocked and surrounded by four light blocking walls 223 at the front, rear, left and right.

The light blocking wall 223 is formed in the transparent base layer 221 , which can block more light with a large angle, and thus can further reduce the influence of the light with a large angle on the adjacent photosensors 122 .

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

Photosensitive sensor 122PPI can be selected as 250~500PPI;

The diameter of the Fresnel grating 222 is smaller than or equal to the size of a single photosensitive sensor 122;

The through holes of the light shielding layer 121 can be selected as several μm levels;

The center-to-center spacing of the Fresnel grating 222 can be selected as hundreds of μm;

The diameter of the Fresnel grating 222 can be selected as tens of μm;

The thickness of the optical layer can be selected in the order of hundreds of microns.

As shown in FIG. 13 , in an embodiment of the present invention, a Fresnel grating 222 in an optical wavelength band is aligned with a plurality of through holes, and each photosensor 122 corresponds to one through hole. In this way, there is no need for precise alignment between the optical film layer 200 and the photosensitive sensor array 100. Because the number of Fresnel gratings 222 is less, there is always a photosensitive sensor 122 closest to the Fresnel grating 222, which receives the The optical signal transmitted and focused by the Fresnel grating 222 .

As shown in FIG. 14 , in another embodiment, the optical film layer 200 includes a transparent base layer 221 and an optical wavelength band. One Fresnel grating 222 in the optical wavelength band is aligned with the plurality of photosensors 122 in the photosensor array 100 , which is equivalent to omitting the light shielding layer 121 in the embodiment shown in FIG. 13 . The light signal from the direction of the OLED display device is received by a plurality of photosensitive sensors 122 after passing through a Fresnel grating 222 .

If the light-converging angle of the Fresnel gratings 222 is sufficiently small and the distance between adjacent Fresnel gratings 222 is sufficiently large, the light shielding layer can be omitted. When light with a small angle passes through the Fresnel grating 222 , it will be focused by the Fresnel grating 222 and then enter the photosensitive sensor 122 that is closest to the Fresnel grating 222 . When light rays with slightly larger angles pass through the Fresnel grating 222 , they will pass through (unfocused) in a manner similar to the imaging of a pinhole, and enter the photosensitive sensors 122 around the closest photosensitive sensor 122 . In this way, a plurality of photosensitive sensors 122 are combined and used as a fingerprint pixel, and the light signal is projected onto the photosensitive sensor array 100 in the form of light spots, which is not the imaging method similar to the previous embodiment.

This embodiment also does not need to consider the alignment of the optical film layer 200 and the photosensor array 100 , and light from different angles can reach different photosensors 122 to realize long-distance identification of fingerprints.

As shown in FIG. 15 , in an embodiment of the present invention, every two photosensors 122 can be used as a unit, one of which is corresponding to the Fresnel grating 222 , and the light shielding layer 121 above the light-shielding layer 121 is provided with a through hole, which can be used as a unit. The other one is covered by the light shielding layer 121 and does not receive light, but can reduce the dark current or the noise signal of the photosensitive sensor 122 , so it is used as the reference photosensitive sensor 122 .

In this embodiment, in order to realize fingerprint recognition, the total size of two adjacent pixels needs to reach 70 μm. Compared with 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 an embodiment of the present invention, the optical film layer 200 includes a transparent base layer 230 and a light blocking wall 231 vertically arranged in the transparent base layer 230 , and one end of the light blocking wall 231 is located on the transparent base layer 230 . The top of the bottom layer 230 and the other end of the light blocking wall 231 are located at the bottom of the transparent base layer 230 . The light blocking wall 231 blocks and forms a plurality of light channels 232 , and one light channel 232 is aligned with the multiple (or one) photosensors 131 in the photosensor array 100 . The light signal from the direction of the OLED display device 400 is received by a plurality of (or one) light sensitive sensors 131 after passing through the light channel 232 .

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

In this embodiment, an array of light channels 232 is implemented in the transparent base layer 230, and each photosensitive sensor 131 can correspond to multiple light channels 232, so that because the light channels 232 are relatively narrow, only a small angle of light can pass through to reach the photosensitive sensor 131, so as to realize long-distance valley and ridge identification and prevent crosstalk. In addition, in other embodiments, there may also be a one-to-one correspondence between the photosensors 131 and the optical channels.

By forming the optical channel 232 in the optical film layer 200, the optical signal entering the optical film layer 200 and each photosensitive sensor 131 in the photosensitive sensor array 100 comes from a small fixed range above it, so the photosensitive sensor array 100 and the photosensitive sensor array 100 are connected with each other. Very precise alignment between the optical film layers 200 is not required. Therefore, the optical film layer 200 and the photosensitive sensor array 100 can be fabricated separately, and then bonded together by the optical glue 301, which simplifies the complexity of the process and can alleviate the complexity of the existing touch terminals with fingerprint recognition function. In addition, by simplifying the manufacturing process of the touch terminal, the yield of the touch terminal can also be improved.

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

Optical glue 301 can be selected to be 25μm or thinner;

The transparent base layer can be 400μm or thinner;

The optical glue 302 can be selected to be 25μm or thinner;

The center spacing of the optical channel can be selected as tens of μm level;

The inner diameter of the optical channel can be selected to be in the order of tens of μm.

In addition to the use of the optical glue 301, the optical film layer 200 and the photosensitive sensor array 100 can also be fixedly arranged by using the photosensitive sensor array 100 as a substrate, on which the transparent base layer 230 and the light-blocking wall 231 and other parts are fabricated to form The optical film layer 200 realizes the fixed arrangement of the optical film layer 200 and the photosensor array 100 . Of course, each part of the optical film layer 200 does not need to be precisely aligned with the photosensor array 100 during the fabrication process.

In other embodiments, the optical channel can also be realized by using a material without a substrate such as an optical fiber, and then adding a light-shielding material to the outer wall of the optical fiber to form an optical channel with a large aspect ratio.

In each of the above-mentioned embodiments, an infrared filter film located above the photosensitive sensor array 100 may also be included, and the specific arrangement method can be referred to as shown in FIG. 6 to FIG. 9 , or other feasible methods.

The embodiment of the present invention also provides a touch terminal, which can be a mobile phone, a tablet computer, etc., and is especially suitable for a full-screen mobile phone. The touch terminal includes an OLED display device and an optical fingerprint identification device provided in any of the above-mentioned embodiments. The optical fingerprint identification device is installed at the bottom of the OLED display device, and the two can be fixed by a frame-mounted gasket, with air or low refraction in the middle. rate material filling.

Because the touch terminal provided by the embodiment of the present invention includes all the technical features of the optical fingerprint identification device provided by the above embodiment, the same technical problem can be solved and the same technical effect can be achieved.

It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further definition and explanation 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. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of the invention is usually placed in use, only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying The device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first", "second", "third", etc. are only used to differentiate the description and should not be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless otherwise expressly specified and limited, the terms "arranged", "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection, It can also be a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or the internal communication between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. scope.

Claims (14)

1. An optical fingerprint identification device, characterized in that, for being installed at the bottom of an OLED display device; The optical fingerprint identification device includes a photosensitive sensor array and an optical film layer, and the optical film layer and the photosensitive sensor array are fixedly arranged; The light signal incident from the direction of the OLED display device with a preset angle range, after passing through the optical film layer, enters the photosensitive sensor array. 2. The device according to claim 1, wherein the optical film layer comprises a microlens layer and at least one diaphragm layer; The central axis of the microlenses in the microlens layer is aligned with the light-transmitting area of the diaphragm in each layer of the diaphragm layer; The light signal incident from the direction of the OLED display device with a preset angle range, after being focused by the microlens layer, passes through the at least one diaphragm layer, and is received by the photosensor array. 3 . The device according to claim 2 , wherein the light signal incident from the direction of the OLED display device outside the preset angle range, after passing through the microlens layer, is blocked by the at least one layer of diaphragms. 4 . layer absorption. 4 . The device according to claim 2 , wherein one photosensitive sensor in the photosensitive sensor array is aligned with 4 to 16 of the microlenses. 5 . 5. The device according to claim 1, wherein the optical film layer comprises a transparent base layer and an optical wavelength band; The photosensitive sensor array is covered with a light-shielding layer, and the light-shielding layer is provided with through holes; The light signal incident from the direction of the OLED display device with a preset angle range, after being focused by the light wavelength band, passes through the through hole of the light shielding layer, and is received by the photosensor array. 6 . The device according to claim 5 , wherein the light signal incident from the direction of the OLED display device outside the preset angle range, after passing through the light wavelength band, is blocked by the non-through hole of the light shielding layer. 7 . Partially absorbed. 7 . The device according to claim 5 , wherein each photosensor in the photosensor array is aligned with one of the through holes. 8 . 8 . The device of claim 7 , wherein one Fresnel grating in the optical wavelength band is aligned with one of the through holes. 9 . 9 . The device according to claim 8 , wherein a light-blocking wall is vertically disposed in the transparent base layer, and the light-blocking wall blocks and forms a plurality of light channels; 10 . Each photosensitive sensor is aligned with one of the light channels. 10 . The device of claim 7 , wherein a Fresnel grating in the optical wavelength band aligns a plurality of the through holes. 11 . 11. The device of claim 1, wherein the optical film layer comprises a transparent base layer and an optical wavelength band; A Fresnel grating in the optical waveband is aligned with a plurality of photosensors in the photosensor array; The light signal incident from the direction of the OLED display device with a preset angle range is received by the plurality of photosensitive sensors after passing through one of the Fresnel gratings. 12. The device according to claim 1, wherein the optical film layer comprises a transparent base layer and a light blocking wall vertically disposed in the transparent base layer; The light blocking wall blocks and forms a plurality of light channels, and one of the light channels is aligned with one or more photosensors in the photosensor array; The light signal incident from the direction of the OLED display device with a preset angle range is received by one or more of the light sensitive sensors after passing through the light channel. 13. The device according to any one of claims 1 to 12, further comprising an infrared filter film disposed above the photosensitive sensor array. 14. A touch terminal, comprising an OLED display device and the optical fingerprint identification device according to any one of claims 1 to 13; The optical fingerprint identification device is installed at the bottom of the OLED display device.

Images