TW202226155A - Large-area under-screen optical fingerprint collection method, fingerprint identification device, and information processing device capable of effectively avoiding fingerprint image segmentation caused by stacking multiple afterimages, thereby greatly improving the quality of the collected fingerprint images - Google Patents

Abstract

The present invention discloses a large-area under-screen optical fingerprint collection method, which is realized by a control unit for controlling a fingerprint collection circuit to execute a fingerprint collection program. When executing the large-area under-screen optical fingerprint collection method of the present invention, a fingerprint collection area is divided into a plurality of first sub-collection blocks, and a fingerprint coverage range of a finger on a mobile phone screen is divided into a plurality of second sub-collection blocks. As a result, after fingerprint collection is performed on the plurality of second sub-collection blocks sequentially according to a block collection program, a plurality of second sub-fingerprint images can be obtained. Finally, after performing a subtraction operation on the gray-scale value of each pixel in each of the sub-fingerprint images and an average gray-scale value, an image tiling process is performed on the plurality of second sub-fingerprint images, so as to obtain a fingerprint image. After applying the method of the present invention to the fingerprint identification device, it is able to effectively overcome the problem of fingerprint image segmentation caused by stacking multiple afterimages, thereby greatly improving the quality of the fingerprint images collected by the fingerprint collection circuit.

Description

Optical fingerprint collection method under large-area screen, fingerprint identification device, and information processing device

The present invention relates to the field of optical fingerprint detection, in particular to a large-area under-screen optical fingerprint collection method applied to an optical fingerprint identification chip.

At present, optical fingerprint identification chips have been widely used in various electronic devices, such as smart phones, and mainly include an optical fingerprint acquisition circuit and a fingerprint identification operation function. As shown in the structure diagram of a conventional under-screen optical fingerprint collection circuit shown in FIG. 1 , the conventional under-screen optical fingerprint collection circuit is integrated into the smart phone 3a, and includes an optical fingerprint collection panel 10a and an optical fingerprint collection panel 10a. A readout integrated circuit (ROIC) 12a. In more detail, the conventional optical fingerprint collecting panel 10a includes a photodetector array, wherein the photodetector array is composed of a plurality of photodetectors 11a, and each of the photodetectors 11a includes a photodiode 111a, A charge storage capacitor 112a and a switch element 113a. In more detail, the photodiode 111a included in each of the photodetectors 11a is an organic photodetector (OPD), so that the optical fingerprint collecting panel 10a includes a planar photodetector array ( Flat panel photodetector array, FPD array).

FIG. 2 shows a schematic diagram of fingerprint acquisition performed by a conventional under-screen optical fingerprint acquisition circuit. As shown in FIG. 2 , the conventional under-screen optical fingerprint collection circuit provides a large-area fingerprint collection area 101a, for example, the area size is M×N, where M and N are both pixel numbers. Users who have used the fingerprint capture function must know that when using the fingerprint recognition function to unlock the phone screen or make mobile payments, it is usually necessary to press once or twice to successfully complete the fingerprint recognition. In other words, in order to successfully complete the fingerprint identification, the user usually presses the fingerprint at the first position on the screen, and then presses the fingerprint at the second position. Therefore, as shown in FIG. 2 , for the under-screen optical fingerprint collection circuit, it will perform one fingerprint collection at the first fingerprint pressing position, and then perform another fingerprint collection at the second fingerprint pressing position.

Unfortunately, the fingerprints collected by the conventional under-screen optical fingerprint collection circuit have the problem of insufficient accuracy. FIG. 3 and FIG. 4 both show fingerprint images collected by a conventional under-screen optical fingerprint collection circuit. As shown in FIG. 3 , the size of the collected fingerprint image is m×n, where both m and n are pixel numbers, usually between 80 and 300. In more detail, as shown in FIG. 2 and FIG. 3 , when the user presses the fingerprint at the first position on the screen of the mobile phone, more or less fingerprints (afterimages) are left on the screen. Therefore, when the under-screen optical fingerprint collection circuit performs fingerprint collection at the position where the fingerprint is pressed for the second time, the fingerprint afterimage will affect the accuracy of fingerprint collection. It is conceivable that the more times the user performs fingerprint imprinting on the screen, the stacking of multiple afterimages will lead to the problem of image segmentation, resulting in poor fingerprint image quality, as shown in Figure 4.

It can be seen from the above description that there is an urgent need in the art for a novel large-area under-screen optical fingerprint collection method.

The main purpose of the present invention is to provide a large-area under-screen optical fingerprint collection method, which is realized by a control unit for controlling a fingerprint collection circuit to execute a fingerprint collection program. When implementing the large-area under-screen optical fingerprint collection method of the present invention, a fingerprint collection area is divided into a first plurality of sub-collection blocks, and a fingerprint coverage area of a finger on a mobile phone screen is divided into a second plurality of sub-collections block. In this way, after fingerprint collection is performed on the second plurality of sub-collection blocks one by one according to a block collection procedure, a second plurality of first sub-fingerprint images can be obtained. Finally, after performing a subtraction operation on each pixel grayscale value and an average grayscale value in each of the first sub-fingerprint images, a second sub-fingerprint image is generated, and then a second plurality of the first sub-fingerprint images are generated. A fingerprint image can be obtained by performing an image splicing process on the two sub-fingerprint images. After the method of the present invention is applied to the fingerprint identification device, the problem of fingerprint image segmentation caused by stacking multiple afterimages can be effectively overcome, thereby greatly improving the quality of the fingerprint image collected by the fingerprint collection circuit.

After the method of the present invention is applied to a fingerprint identification device including a fingerprint acquisition circuit and a control unit, the problem of fingerprint image segmentation caused by stacking of multiple afterimages can be effectively overcome, thereby greatly improving the performance of the fingerprint acquisition circuit. The quality of the captured fingerprint image.

In order to achieve the above object, the present invention proposes an embodiment of the large-area under-screen optical fingerprint collection method, which includes the following steps:

dividing a fingerprint collection area into a first plurality of sub-collection blocks;

A finger is imprinted on the fingerprint collection area to occupy a fingerprint coverage area in the fingerprint collection area, and the fingerprint coverage area has a second plurality of sub-collection blocks. According to a block collection procedure, along the second The plurality of sub-collection blocks perform fingerprint collection one by one to obtain a first sub-fingerprint image;

performing a grayscale value averaging process on the second plurality of the first sub-fingerprint images to obtain an average grayscale value;

performing a subtraction operation on the gray-scale value of each pixel in each of the first sub-fingerprint images and the average gray-scale value to obtain a second sub-fingerprint image; and

An image stitching process is performed on the second plurality of second sub-fingerprint images to obtain a fingerprint image.

In one embodiment, the aforementioned large-area under-screen optical fingerprint collection method of the present invention further includes the following steps:

A smoothing process is performed on the fingerprint image, thereby eliminating image seams between any two of the second sub-fingerprint images.

In one embodiment, the second plurality of the sub-collection blocks form a square array.

In a possible embodiment, the block collection procedure can be any of the following:

The first sub-collection block in the first row and the last sub-collection block in the last row are respectively a start-point collection block and an end-point collection block, according to the order from left to right and top to bottom along the second A plurality of described sub-collection blocks carry out fingerprint collection one by one;

The last sub-collection block in the first row and the first sub-collection block in the last row are respectively a start-point collection block and an end-point collection block, according to the order from right to left and from top to bottom along the second complex number Each of the sub-collection blocks performs fingerprint collection one by one;

The first sub-collection block in the last row and the last sub-collection block in the first row are respectively a start-point collection block and an end-point collection block, according to the order from left to right and bottom to top along the second A plurality of described sub-collection blocks carry out fingerprint collection one by one;

The last sub-collection block in the last row and the first sub-collection block in the first row are respectively a start point collection block and an end point collection block, according to the order from right to left and from bottom to top, along the first Two or more of the sub-collection blocks carry out fingerprint collection one by one;

Take the center and the first sub-collection block in the first row as a start-point collection block and an end-point collection block, respectively, according to from center to top, from left to right, from top to bottom, and from right to left , and carry out fingerprint collection one by one along the second plurality of described sub-collection blocks in the order from bottom to top;

Take the center and the last sub-collection block of the first row as a start-point collection block and an end-point collection block, respectively, according to from center to top, from right to left, from top to bottom, from left to right, And the fingerprint collection is carried out one by one along the second plurality of said sub-collection blocks in order from bottom to top;

The center and the first sub-collection block in the last row are respectively a start-point collection block and an end-point collection block, according to from center to bottom, from left to right, from bottom to top, from right to left, and fingerprint collection is performed one by one along the second plurality of said sub-collection blocks in an order from top to bottom; and

The center and the last sub-collection block of the last row are respectively a start-point collection block and an end-point collection block, according to from center to bottom, from right to left, from bottom to top, from left to right, and The fingerprint collection is performed one by one along the second plurality of the sub-collection blocks in order from top to bottom.

The present invention also provides a fingerprint identification device, which includes an under-screen optical fingerprint collection circuit and a control unit, characterized in that the control unit controls the under-screen optical fingerprint collection circuit according to a large-area under-screen optical fingerprint collection method to realize an under-screen optical fingerprint collection circuit. A fingerprint collection program; the large-area under-screen optical fingerprint collection method includes the following steps:

dividing a fingerprint collection area into a first plurality of sub-collection blocks;

A finger is imprinted on the fingerprint collection area to occupy a fingerprint coverage area in the fingerprint collection area, and the fingerprint coverage area has a second plurality of sub-collection blocks. According to a block collection procedure, along the second The plurality of sub-collection blocks perform fingerprint collection one by one to obtain a first sub-fingerprint image;

performing a grayscale value averaging process on the second plurality of the first sub-fingerprint images to obtain an average grayscale value;

performing a subtraction operation on the gray-scale value of each pixel in each of the first sub-fingerprint images and the average gray-scale value to obtain a second sub-fingerprint image; and

An image stitching process is performed on the second plurality of second sub-fingerprint images to obtain a fingerprint image.

In one embodiment, the aforementioned large-area under-screen optical fingerprint collection method further includes the following steps:

A smoothing process is performed on the fingerprint image, thereby eliminating the image seam between any two of the sub-fingerprint images.

In one embodiment, the second plurality of the sub-collection blocks form a square array.

In one embodiment, the block collection procedure is any of the following:

The first sub-collection block in the first row and the last sub-collection block in the last row are respectively a start-point collection block and an end-point collection block, according to the order from left to right and top to bottom along the second A plurality of described sub-collection blocks carry out fingerprint collection one by one;

The last sub-collection block in the first row and the first sub-collection block in the last row are respectively a start-point collection block and an end-point collection block, according to the order from right to left and from top to bottom along the second complex number Each of the sub-collection blocks performs fingerprint collection one by one;

The first sub-collection block in the last row and the last sub-collection block in the first row are respectively a start-point collection block and an end-point collection block, according to the order from left to right and bottom to top along the second A plurality of described sub-collection blocks carry out fingerprint collection one by one;

The last sub-collection block in the last row and the first sub-collection block in the first row are respectively a start point collection block and an end point collection block, according to the order from right to left and from bottom to top, along the first Two or more of the sub-collection blocks carry out fingerprint collection one by one;

Take the center and the first sub-collection block in the first row as a start-point collection block and an end-point collection block, respectively, according to from center to top, from left to right, from top to bottom, and from right to left , and carry out fingerprint collection one by one along the second plurality of described sub-collection blocks in the order from bottom to top;

Take the center and the last sub-collection block of the first row as a start-point collection block and an end-point collection block, respectively, according to from center to top, from right to left, from top to bottom, from left to right, And the fingerprint collection is carried out one by one along the second plurality of said sub-collection blocks in order from bottom to top;

The center and the first sub-collection block in the last row are respectively a start-point collection block and an end-point collection block, according to from center to bottom, from left to right, from bottom to top, from right to left, and fingerprint collection is performed one by one along the second plurality of said sub-collection blocks in an order from top to bottom; and

The center and the last sub-collection block of the last row are respectively a start-point collection block and an end-point collection block, according to from center to bottom, from right to left, from bottom to top, from left to right, and The fingerprint collection is performed one by one along the second plurality of the sub-collection blocks in order from top to bottom.

The present invention also provides an information processing device having the fingerprint identification device of the present invention as described above.

In one embodiment, the information processing device is selected from the group consisting of smart phones, smart TVs, smart watches, smart bracelets, tablet computers, notebook computers, all-in-one computers, access control devices, desktop computers, and An electronic device in a group of industrial computers.

In order to enable your examiners to further understand the structure, characteristics, purpose, and advantages of the present invention, drawings and detailed descriptions of preferred embodiments are attached as follows.

The present invention mainly discloses a large-area under-screen optical fingerprint collection method, which is realized by a control unit and used to control a fingerprint collection circuit to execute a fingerprint collection program. When implementing the large-area under-screen optical fingerprint collection method of the present invention, a fingerprint collection area is divided into a first plurality of sub-collection blocks, and a fingerprint coverage area of a finger on a mobile phone screen is divided into a second plurality of sub-collections block. In this way, after fingerprint collection is performed on the second plurality of sub-collection blocks one by one according to a block collection procedure, a second plurality of sub-fingerprint images can be obtained. Finally, after performing a subtraction operation on the gray-scale value of each pixel in each of the sub-fingerprint images and an average gray-scale value, an image splicing process is performed on the second plurality of the sub-fingerprint images, so that A fingerprint image can be obtained. After the method of the present invention is applied to the fingerprint identification device, the problem of fingerprint image segmentation caused by stacking multiple afterimages can be effectively overcome, thereby greatly improving the quality of the fingerprint image collected by the fingerprint collection circuit.

FIG. 5 shows a flow chart of a large-area under-screen optical fingerprint collection method of the present invention, and FIG. 6 shows a top view of a mobile phone screen. As shown in FIG. 5 and FIG. 6 , the method flow first executes step S1 : dividing a fingerprint collection area 101 with a size of M×N into a first plurality of sub-collection blocks 1011 , wherein the size of each of the sub-collection blocks is s×t. After step S1 is performed, as shown in FIG. 6 , the under-screen optical fingerprint collection circuit provides a fingerprint collection area 101 with a size of M×N on the screen 10 of the mobile phone, and the fingerprint collection area 101 includes a first plurality of sub-collection areas In block 1011, the user can press his finger on the screen 10 of the mobile phone to use the fingerprint recognition function to unlock the screen of the mobile phone or perform mobile payment.

Continue to refer to the top view of the fingerprint collection area 101 shown in FIG. 7 . As shown in FIG. 5 and FIG. 7 , the method flow then executes step S2 : when a finger is imprinted on the fingerprint collection area 101 to occupy a fingerprint coverage area 102 with a size of m×n in the fingerprint collection area 101 In the following, a total of a second plurality of sub-collection blocks 1011 are located within the fingerprint coverage area 102. At this time, according to a block collection procedure, fingerprint collection is performed one by one along the second plurality of said sub-collection blocks 1011, so as to obtain a second plurality of sub-collection blocks 1011 the first sub-fingerprint image. Wherein, M, N, s, t, m, and n are all pixel numbers.

8 to 15 show schematic diagrams of block acquisition procedures for the second plurality of sub-acquisition blocks 1011 . According to the design of the present invention, the second plurality of the sub-collection blocks 1011 form a square array, so when the block collection procedure in step S2 is performed, the order from left to right and top to bottom can be adopted. In more detail, as shown in FIG. 8 , the first sub-collection block 1011 in the first row and the last sub-collection block in the last row are respectively a start point collection block and an end point collection block. Fingerprints are collected one by one along the second plurality of the sub-collection blocks 1011 in the order from top to bottom.

In another feasible embodiment, when the block collection procedure in step S2 is executed, the sequence from right to left and from top to bottom may also be adopted. In more detail, as shown in FIG. 9 , the sub-collection blocks 1011 in the last row of the first row and the first sub-collection block in the last row are respectively a start point collection block and an end point collection block, and then according to the Fingerprints are collected one by one along the second plurality of the sub-collection blocks 1011 in the order from left to top to bottom.

In yet another feasible embodiment, when the block collection procedure in step S2 is executed, the sequence from left to right and bottom to top can also be adopted. In more detail, as shown in FIG. 10 , the first sub-collection block 1011 of the last row and the last sub-collection block 1011 of the first row are respectively a start point collection block and an end point collection block, according to the order from left to right. And fingerprint collection is performed one by one along the second plurality of the sub-collection blocks 1011 in the order from bottom to top.

In yet another feasible embodiment, when executing the block collection procedure in step S2, the sequence from right to left and bottom to top may also be adopted. In more detail, as shown in FIG. 11 , the sub-collection block 1011 in the last row of the last row and the sub-collection block 1011 of the first row in the first row are respectively a start point collection block and an end point collection block. Fingerprints are collected one by one along the second plurality of the sub-collection blocks 1011 in the order from the left to the bottom.

In yet another feasible embodiment, when executing the block collection procedure in step S2, the sequence from the center to the periphery can also be used. In more detail, as shown in FIG. 12 , the center and the first sub-collection block 1011 in the first row are respectively a start-point collection block and an end-point collection block. Fingerprint collection is performed one by one along the second plurality of the sub-collection blocks 1011 in the order of right, top to bottom, right to left, and bottom to top. As shown in FIG. 13 , the sequence from the center to the periphery can also be performed as follows: the center and the last sub-collection block 1011 in the first row are respectively a start-point collection block and an end-point collection block, Fingerprint collection is performed one by one along the second plurality of the sub-collection blocks 1011 according to the sequence from center to top, right to left, top to bottom, left to right, and bottom to top.

According to the above description, as shown in FIG. 14 , the sequence from the center to the periphery can also be operated as follows, with the center and the first sub-collection block 1011 in the last row as the first point collection block and the end point, respectively The acquisition block, according to the order from center to bottom, from left to right, bottom to top, right to left, and top to bottom, along the second plurality of said sub-collection blocks 1011 to perform fingerprint collection one by one . Furthermore, as shown in FIG. 15 , the sequence from the center to the periphery can also be performed as follows: the center and the last sub-collection block 1011 in the first row are respectively a start point collection block and an end point collection block. For the blocks, fingerprints are collected one by one along the second plurality of the sub-collection blocks 1011 according to the sequence from center to bottom, from right to left, from bottom to top, from left to right, and from top to bottom.

FIG. 16 shows a top view of the second plurality of fingerprint images collected by the under-screen optical fingerprint collection circuit. As shown in FIG. 5 and FIG. 16 , after step S2 is completed, the method flow then executes steps S3 and S4 : performing a grayscale value averaging process on the second plurality of the first sub-fingerprint images 10P1 to obtain an average grayscale value level value, and perform a subtraction operation on the gray level value of each pixel in each of the first sub-fingerprint images 10P1 and the average gray level value to obtain a second sub-fingerprint image. It is worth explaining that when using the fingerprint recognition function to unlock the mobile phone screen or perform mobile payment, the user usually has to press one or two times on the fingerprint acquisition area 101 with a size of M×N provided by the under-screen optical fingerprint acquisition circuit. It takes time to successfully complete fingerprint identification, resulting in fingerprint imprinting (afterimage) on the screen. Wherein, the stacking of multiple afterimages will cause the pixel grayscale value (ie, grayscale) of each sub-fingerprint image 10P1 to have a high and low level difference. For this reason, the present invention utilizes the execution of steps S3 and S4 to reduce the gray level difference between the pixel gray level values of each first sub-fingerprint image 10P1 as much as possible.

Figure 17 shows a top view of a fingerprint image captured by an under-screen optical fingerprint capture circuit. As shown in FIG. 5 and FIG. 17 , after performing a subtraction operation on the gray-scale value of each pixel in each of the first sub-fingerprint images 10P1 and the average gray-scale value, the second plurality of all The second sub-fingerprint image is subjected to an image splicing process to obtain a fingerprint image 10P. Further, a smoothing process can also be performed on the fingerprint image 10P, so as to eliminate image seams existing between any two of the second sub-fingerprint images.

In this way, the above has completely and clearly explained a large-area under-screen optical fingerprint collection method of the present invention; and, from the above, it can be known that the present invention has the following advantages:

(1) The present invention discloses a large-area under-screen optical fingerprint collection method, which is applied in a fingerprint identification device and implemented by a control unit to control a fingerprint collection circuit to execute a fingerprint collection program. When implementing the large-area under-screen optical fingerprint collection method of the present invention, a fingerprint collection area is divided into a first plurality of sub-collection blocks, and a fingerprint coverage area of a finger on a mobile phone screen is divided into a second plurality of sub-collections block. In this way, after fingerprint collection is performed on the second plurality of sub-collection blocks one by one according to a block collection procedure, a second plurality of first sub-fingerprint images can be obtained. Finally, after performing a subtraction operation on each pixel grayscale value and an average grayscale value in each of the first sub-fingerprint images, a second sub-fingerprint image is generated, and then a second plurality of the first sub-fingerprint images are generated. A fingerprint image can be obtained by performing an image splicing process on the two sub-fingerprint images. After the method of the present invention is applied to the fingerprint identification device, the problem of fingerprint image segmentation caused by stacking multiple afterimages can be effectively overcome, thereby greatly improving the quality of the fingerprint image collected by the fingerprint collection circuit.

(2) The present invention also provides an information processing device having the fingerprint identification device of the present invention as described above. Moreover, the information processing device is selected from the group consisting of smart TVs, smart phones, smart watches, smart bracelets, tablet computers, notebook computers, all-in-one computers, access control devices, desktop computers, and industrial computers. An electronic device in a group.

It must be emphasized that the above-mentioned disclosure in this case is a preferred embodiment, and any partial changes or modifications originating from the technical ideas of this case and easily inferred by those who are familiar with the art are within the scope of the patent of this case. category of rights.

To sum up, regardless of the purpose, means and effect of this case, it shows that it is completely different from the conventional technology, and its first invention is practical, and it does meet the patent requirements of the invention. Society is to pray for the best.

10a: Optical fingerprint collection panel 101a: Fingerprint collection area 11a: Photodetector 111a: Photodiode 112a: charge storage capacitor 113a: Switching elements 12a: Read circuit chip 3a: Smartphone 10: Screen 101: Fingerprint collection area 102: Fingerprint Coverage 1011: Sub-collection block 10P: Fingerprint Image 10P1: Sub-fingerprint image S1: Divide a fingerprint collection area with a size of M×N into a first plurality of sub-collection blocks, wherein the size of each of the sub-collection blocks is s×t S2: Under the circumstance that a finger is imprinted on the fingerprint collection area so as to occupy a fingerprint coverage area with a size of m×n in the fingerprint collection area, a total of a second plurality of sub-collection blocks are located within the fingerprint coverage area , at this time, according to a block collection program, fingerprint collection is performed one by one along the second plurality of the sub-collection blocks, so as to obtain a second plurality of first sub-fingerprint images S3: Perform a grayscale value averaging process on the second plurality of the first sub-fingerprint images to obtain an average grayscale value S4: Perform a subtraction operation on the gray-scale value of each pixel in each of the first sub-fingerprint images and the average gray-scale value to obtain a second sub-fingerprint image respectively S5: Perform an image stitching process on the second plurality of the second sub-fingerprint images to obtain a fingerprint image

1 is a schematic diagram of a conventional under-screen optical fingerprint collection circuit; 2 is a schematic diagram of a conventional under-screen optical fingerprint collection circuit performing fingerprint collection; 3 is a fingerprint image diagram collected by a conventional under-screen optical fingerprint collection circuit; 4 is a fingerprint image diagram collected by a conventional under-screen optical fingerprint collection circuit; FIG. 5 is a flow chart of a method for collecting optical fingerprints under a large-area screen according to the present invention; Figure 6 is a top view of a mobile phone screen; 7 is a top view of a fingerprint collection area; 8 is a schematic diagram of a block collection procedure for a second plurality of sub-collection blocks; 9 is a schematic diagram of a block collection procedure for a second plurality of sub-collection blocks; 10 is a schematic diagram of a block collection procedure for a second plurality of sub-collection blocks; 11 is a schematic diagram of a block collection procedure for a second plurality of sub-collection blocks; 12 is a schematic diagram of a block collection procedure for a second plurality of sub-collection blocks; 13 is a schematic diagram of a block collection procedure for a second plurality of sub-collection blocks; 14 is a schematic diagram of a block collection procedure for a second plurality of sub-collection blocks; 15 is a schematic diagram of a block collection procedure for a second plurality of sub-collection blocks; 16 is a top view of a second plurality of fingerprint images collected by the under-screen optical fingerprint collection circuit; and FIG. 17 is a top view of a fingerprint image collected by the under-screen optical fingerprint collection circuit.

S1: Divide a fingerprint collection area with a size of M×N into a first plurality of sub-collection blocks, wherein the size of each of the sub-collection blocks is s×t

S2: Under the circumstance that a finger is imprinted on the fingerprint collection area so as to occupy a fingerprint coverage area with a size of m×n in the fingerprint collection area, a total of a second plurality of sub-collection blocks are located within the fingerprint coverage area , at this time, according to a block collection program, fingerprint collection is performed one by one along the second plurality of the sub-collection blocks, so as to obtain a second plurality of first sub-fingerprint images

S3: Perform a gray-scale value averaging process on the second plurality of the first sub-fingerprint images to obtain an average gray-scale value

S4: Perform a subtraction operation on the gray-scale value of each pixel in each of the first sub-fingerprint images and the average gray-scale value to obtain a second sub-fingerprint image respectively

S5: Perform an image stitching process on the second plurality of the second sub-fingerprint images to obtain a fingerprint image

Claims (10)

A method for collecting optical fingerprints under a large-area screen, comprising the following steps: dividing a fingerprint collection area into a first plurality of sub-collection blocks; A finger is imprinted on the fingerprint collection area to occupy a fingerprint coverage area in the fingerprint collection area, and the fingerprint coverage area has a second plurality of sub-collection blocks. According to a block collection procedure, along the second The plurality of sub-collection blocks perform fingerprint collection one by one to obtain a first sub-fingerprint image; performing a grayscale value averaging process on the second plurality of the first sub-fingerprint images to obtain an average grayscale value; performing a subtraction operation on the gray-scale value of each pixel in each of the first sub-fingerprint images and the average gray-scale value to obtain a second sub-fingerprint image; and An image stitching process is performed on the second plurality of second sub-fingerprint images to obtain a fingerprint image. The optical fingerprint collection method under a large-area screen as described in claim 1, further comprising the following steps: A smoothing process is performed on the fingerprint image, thereby eliminating image seams between any two of the second sub-fingerprint images. The large-area under-screen optical fingerprint collection method according to claim 1, wherein the second plurality of the sub-collection blocks form a square array. The optical fingerprint collection method under a large-area screen according to claim 3, wherein the block collection procedure is any of the following: The first sub-collection block in the first row and the last sub-collection block in the last row are respectively a start-point collection block and an end-point collection block, and follow the sequence from left to right and top to bottom. The second plurality of described sub-collection blocks perform fingerprint collection one by one; The last sub-collection block in the first row and the first sub-collection block in the last row are respectively a start-point collection block and an end-point collection block, and follow the sequence from right to left and from top to bottom. Two or more of the sub-collection blocks carry out fingerprint collection one by one; The first sub-collection block in the last row and the last sub-collection block in the first row are respectively a start point collection block and an end point collection block, and follow the sequence from left to right and bottom to top. The second plurality of described sub-collection blocks perform fingerprint collection one by one; The last sub-collection block in the last row and the first sub-collection block in the first row are respectively a start-point collection block and an end-point collection block, according to the order from right to left and from bottom to top. The second plurality of described sub-collection blocks carry out fingerprint collection one by one; Take the center and the first sub-collection block in the first row as a start-point collection block and an end-point collection block, respectively, according to from center to top, from left to right, from top to bottom, and from right to left , and perform fingerprint collection one by one along the second plurality of the sub-collection blocks in the order from bottom to top; Take the center and the last sub-collection block of the first row as a start-point collection block and an end-point collection block, respectively, according to from center to top, from right to left, from top to bottom, from left to right, And the fingerprint collection is performed one by one along the second plurality of the sub-collection blocks in order from bottom to top; The center and the first sub-collection block in the last row are respectively a start-point collection block and an end-point collection block, according to from center to bottom, from left to right, from bottom to top, from right to left, and fingerprint collection is performed one by one along the second plurality of the sub-collection blocks in an order from top to bottom; and Take the center and the last sub-collection block of the first row as a start-point collection block and an end-point collection block, respectively, according to from center to bottom, from right to left, from bottom to top, from left to right, And fingerprint collection is performed one by one along the second plurality of the sub-collection blocks in order from top to bottom. A fingerprint identification device, comprising an under-screen optical fingerprint collection circuit and a control unit, characterized in that the control unit controls the under-screen optical fingerprint collection circuit to implement a fingerprint collection program according to a large-area under-screen optical fingerprint collection method; The optical fingerprint collection method under the large-area screen includes the following steps: dividing a fingerprint collection area into a first plurality of sub-collection blocks; A finger is imprinted on the fingerprint collection area to occupy a fingerprint coverage area in the fingerprint collection area, and the fingerprint coverage area has a second plurality of sub-collection blocks. According to a block collection procedure, along the second The plurality of sub-collection blocks perform fingerprint collection one by one to obtain a first sub-fingerprint image; performing a grayscale value averaging process on the second plurality of the first sub-fingerprint images to obtain an average grayscale value; performing a subtraction operation on the gray-scale value of each pixel in each of the first sub-fingerprint images and the average gray-scale value to obtain a second sub-fingerprint image; and An image stitching process is performed on the second plurality of the second sub-fingerprint images to obtain a fingerprint image. The fingerprint identification device according to claim 5, wherein the large-area under-screen optical fingerprint collection method further comprises the following steps: A smoothing process is performed on the fingerprint image, thereby eliminating image seams between any two of the second sub-fingerprint images. The fingerprint identification device according to claim 5, wherein the second plurality of the sub-collection blocks form a square array. The fingerprint identification device as claimed in claim 7, wherein the block collection procedure is any one of the following: The first sub-collection block in the first row and the last sub-collection block in the last row are respectively a start-point collection block and an end-point collection block, according to the order from left to right and top to bottom along the second A plurality of described sub-collection blocks carry out fingerprint collection one by one; The last sub-collection block in the first row and the first sub-collection block in the last row are respectively a start-point collection block and an end-point collection block, according to the order from right to left and from top to bottom along the second complex number Each of the sub-collection blocks performs fingerprint collection one by one; The first sub-collection block in the last row and the last sub-collection block in the first row are respectively a start-point collection block and an end-point collection block, according to the order from left to right and bottom to top along the second A plurality of described sub-collection blocks carry out fingerprint collection one by one; The last sub-collection block in the last row and the first sub-collection block in the first row are respectively a start point collection block and an end point collection block, according to the order from right to left and from bottom to top, along the first Two or more of the sub-collection blocks carry out fingerprint collection one by one; Take the center and the first sub-collection block in the first row as a start-point collection block and an end-point collection block, respectively, according to from center to top, from left to right, from top to bottom, and from right to left , and carry out fingerprint collection one by one along the second plurality of described sub-collection blocks in the order from bottom to top; Take the center and the last sub-collection block of the first row as a start-point collection block and an end-point collection block, respectively, according to from center to top, from right to left, from top to bottom, from left to right, And the fingerprint collection is carried out one by one along the second plurality of said sub-collection blocks in order from bottom to top; The center and the first sub-collection block in the last row are respectively a start-point collection block and an end-point collection block, according to from center to bottom, from left to right, from bottom to top, from right to left, and fingerprint collection is performed one by one along the second plurality of said sub-collection blocks in an order from top to bottom; and The center and the last sub-collection block of the last row are respectively a start-point collection block and an end-point collection block, according to from center to bottom, from right to left, from bottom to top, from left to right, and The fingerprint collection is performed one by one along the second plurality of the sub-collection blocks in order from top to bottom. An information processing device having the fingerprint identification device according to any one of claim 5 to claim 8. The information processing device according to claim 9, wherein the information processing device is selected from the group consisting of smart phones, smart TVs, smart watches, smart bracelets, tablet computers, notebook computers, all-in-one computers, access control An electronic device in the group consisting of devices, desktop computers, and industrial computers.

Images