TW202028935A - Optical fingerprint sensing apparatus and information processing apparatus being provided with an optical sensor array and a signal readout circuit - Google Patents

Abstract

Provided is an optical fingerprint sensing apparatus provided with an optical sensor array having at least one background fringe sensing region, wherein a light shield is arranged above the background fringe sensing region, and the optical sensor array is used for outputting a plurality of first pixel sensing signals in a fingerprint sensing region and at least one second pixel sensing signal in the at least one background fringe sensing region; and a signal readout circuit used for acquiring the plurality of first pixel sensing signals and the at least one second pixel sensing signal, wherein a frame of a first fingerprint image is generated according to the plurality of first pixel sensing signals, and a frame of a fringe image according to the at least one second pixel sensing signal is generated, so that the frame of the first fingerprint image and the frame of the fringe image are subjected to a subtraction computation to obtain a frame of a second fingerprint image.

Description

Optical fingerprint sensing device and information processing device

The present invention relates to an optical fingerprint sensing device, in particular to an optical fingerprint sensing device capable of eliminating fringe patterns.

Today's technology is changing with each passing day. In addition to watching TV, movies, or taking photos, smartphones can also be used to make payments or investment transactions. However, as life becomes more convenient, the importance of information security is also increasing. In order to effectively prevent information or related electronic equipment from being stolen or misappropriated, many security software or devices related to information security have been proposed one after another. Among them, fingerprint recognition technology is one of the important information security technologies.

At present, optical fingerprint recognition technology has gradually been recognized by the market, and the demand is increasing. Among them, a photodiode array (photodiode array) is used as the sensing element (sensor), and then an external signal readout circuit (Read out IC, hereinafter referred to as ROIC) architecture, with easy assembly and large recognition area (can be used as a full-screen fingerprint Recognition scheme), the cost does not increase significantly with the increase of the recognition area, etc., has become one of the better technologies in the field of optical fingerprint recognition. However, although the optical fingerprint recognition technology has many advantages, compared with the current more mature complementary metal oxide semiconductor image sensor (CMOS image sensor), the image quality is still not comparable. The problem of channel stripes in the image is one of the defects.

In the optical fingerprint recognition architecture, the signal readout circuit is usually driven row by row when reading the sensing signal, and the signal collection time of each row is independent. Because there will be noise or fluctuations when the drive signal is output, and there will be crosstalk between the adjacent layers of the photodiode array on the panel, and these factors will be superimposed on the signal collected by the signal readout circuit in the form of noise Medium, causing the image quality to deteriorate. Fortunately, although these noises are time-varying, for the channel signal collected by the signal readout circuit at the same time, it is a fixed deviation, so it will eventually show a fixed gate direction fringe (that is, the gate Drive lines with parallel stripes). Please refer to FIG. 1, which is a photodiode array sensing image 10 with a plurality of gate stripes 11.

For gate fringes, the first traditional solution is to perform some filtering processing on the software side, such as mean filtering. Although the average filter can improve the fringe problem to a certain extent, the average filter itself has inherent defects, that is, it cannot protect the image details well, that is to say, it will destroy the image details while denoising the image. Part, so that the image becomes blurred. The second traditional solution is to average the pixels in all gate directions, and then subtract the average value from all the pixels in the row. Please refer to FIG. 2, which is a schematic diagram showing the effect of processing a photodiode array sensing image 10 with a plurality of gate stripes 11 by the second traditional solution. The second traditional solution is better for regular images, such as fake fingers. However, since the fingerprints of real users are more random, the changes in application scenarios are more complicated. Different pressing forces, pressing angles, and finger directions will affect the effect of the algorithm. Therefore, for real users’ fingerprints, each There is a deviation in the average value of the stripes in the gate direction, so the second traditional solution will still leave some stripes on the final calibrated image.

Therefore, in order to solve the above problems, a novel optical fingerprint sensing solution is urgently needed in the art.

One purpose of the present invention is to disclose an optical fingerprint sensing device, which can effectively remove the fringe noise of a fingerprint image through a simple auxiliary sensing structure and a simple subtraction operation.

Another object of the present invention is to disclose an optical fingerprint sensing device, which can improve the reliability of fingerprint recognition by using a simple auxiliary sensing structure and a simple subtraction operation.

In order to achieve the aforementioned purpose, an optical fingerprint sensing device is proposed, which has:

An optical sensor array has a gate drive input side and a source output side perpendicular to the gate drive input side, and it has a fingerprint sensing area and at least one background stripe sensing area, wherein, The at least one background stripe sensing area is correspondingly adjacent to at least one side of two opposite sides of the fingerprint sensing area, and the two opposite sides are parallel to the gate drive input side, and each of the background stripe senses A light shield is provided above the sensing area, and the source output side is used to output a plurality of first pixel sensing signals of the fingerprint sensing area and at least one second of the at least one background stripe sensing area Pixel sensing signal;

A signal readout circuit, coupled to the source output side, for collecting the plurality of first pixel sensing signals and the at least one second pixel sensing signal, and sensing according to the plurality of first pixels The signal generates a frame of a first fingerprint image, generates a frame of stripe image according to the at least one second pixel sensing signal, and performs a subtraction operation on the frame of the first fingerprint image and the frame of stripe image to obtain a Frame a second fingerprint image; and

A processing unit coupled to the signal readout circuit to receive the frame of the second fingerprint image.

In one embodiment, the light shield is a screen frame.

In one embodiment, the optical fingerprint sensing device further has a gate drive unit to drive the gate drive input side, wherein the gate drive unit is a gate drive chip or an on-board integrated gate Drive circuit (gate driver on array; GOA).

To achieve the foregoing objective, the present invention further provides an optical fingerprint sensing device, which has:

An optical sensor array has a gate drive input side and a source output side perpendicular to the gate drive input side, and it has a fingerprint sensing area and at least one background stripe sensing area, wherein, The at least one background stripe sensing area is correspondingly adjacent to at least one side of two opposite sides of the fingerprint sensing area, and the two opposite sides are parallel to the gate drive input side, and each of the background stripe senses A light shield is provided above the sensing area, and the source output side is used to output a plurality of first pixel sensing signals of the fingerprint sensing area and at least one second of the at least one background stripe sensing area Pixel sensing signal;

A signal readout circuit, coupled to the source output side, for collecting the plurality of first pixel sensing signals and the at least one second pixel sensing signal, and sensing according to the plurality of first pixels Signal to generate a frame of a first fingerprint image, and generate a frame of stripe image according to the at least one second pixel sensing signal; and

A processing unit that receives the frame of the first fingerprint image and the frame of stripe image from the signal readout circuit, and performs a subtraction operation on the frame of the first fingerprint image and the frame of stripe image to obtain a frame of second Fingerprint image.

In one embodiment, the light shield is a screen frame.

In one embodiment, the optical fingerprint sensing device further has a gate drive unit to drive the gate drive input side, wherein the gate drive unit is a gate drive chip or an on-board integrated gate Drive circuit.

In addition, the present invention also discloses an information processing device, which has a central processing unit and the aforementioned optical fingerprint sensing device, wherein the central processing unit is used to communicate with the processing unit to receive the frame of the second fingerprint image .

In possible embodiments, the information processing device can be a smart phone or a portable computer device.

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

Please refer to FIG. 3, which illustrates a schematic diagram of an embodiment of the optical fingerprint sensing device of the present invention. As shown in FIG. 3, the optical fingerprint sensing device includes an optical sensor array 100, a gate driving unit 110, a signal readout circuit 120, and a processing unit 130. The optical sensor array 100 has a The fingerprint sensing area 100a and at least one background stripe sensing area 100b. The fingerprint sensing area 100a and the background stripe sensing area 100b each have a plurality of sensing elements, and each of the sensing elements has a switch 101 and a light sensor. Test a diode 102 and a capacitor 103.

In addition, the optical sensor array 100 has a gate drive input side and a source output side perpendicular to the gate drive input side, wherein the at least one background stripe sensing area 100b is correspondingly adjacent to the fingerprint sensor At least one side of the two opposite sides of the area 100a (in FIG. 3, only a background stripe sensing area 100b is shown, and the background stripe sensing area 100b is correspondingly adjacent to the left side of the fingerprint sensing area 100a) , And the two opposite sides are parallel to the gate drive input side; each of the background stripe sensing regions 100b has a light shield (such as but not limited to a screen frame); and the source output side It is used to output a plurality of first pixel sensing signals of the fingerprint sensing area 100a and at least one second pixel sensing signal of the at least one background stripe sensing area 100b.

The gate driving unit 110 is used to drive the gate driving input side, wherein the gate driving unit 110 can be a gate driver chip or an on-board integrated gate driver circuit (gate driver on array; GOA), so The integrated gate drive circuit on the board is a gate drive circuit integrated on the panel (such as but not limited to a glass substrate).

The signal readout circuit 120 is coupled to the source output side for: collecting the plurality of first pixel sensing signals and the at least one second pixel sensing signal; according to the plurality of first pixel sensing signals The detection signal generates a frame of a first fingerprint image, and generates a frame of stripe image according to the at least one second pixel sensing signal; and performs a subtraction operation on the frame of the first fingerprint image and the frame of stripe image to Obtain a second fingerprint image.

The processing unit 130 is coupled to the signal readout circuit 120 to receive the frame of the second fingerprint image. In this way, the fringe noise of the fingerprint image can be effectively removed.

In addition, in a possible variant embodiment, the signal readout circuit 120 generates a first fingerprint image based on the plurality of first pixel sensing signals, and generates a first fingerprint image based on the at least one second pixel sensing signal After the frame of the fringe image, the frame of the first fingerprint image and the frame of fringe image are transmitted to the processing unit 130, so that the processing unit 130 performs a subtraction on the frame of the first fingerprint image and the frame of fringe image Operate to obtain a second fingerprint image, thereby effectively removing the fringe noise of the fingerprint image.

Please refer to FIG. 4, which is a schematic diagram illustrating the processing effect of the optical fingerprint sensing device of FIG. 3 on a photodiode array sensing image 10 having a plurality of gate stripes 11 and a fingerprint image 12. As shown in FIG. 4, the processed photodiode array sensing image can effectively remove the gate stripe 11 and present a clear fingerprint image 12.

Based on the above description, the present invention further provides an information processing device. Please refer to FIG. 5, which shows a block diagram of an embodiment of the processing device of the present invention. As shown in FIG. 5, an information processing device 200 has a central processing unit 210 and an optical fingerprint sensing device 220. The optical fingerprint sensing device 220 is implemented by the optical fingerprint sensing device shown in FIG. The processing unit 210 is used to communicate with a processing unit (same as the processing unit 130 shown in FIG. 3) inside the optical fingerprint sensing device 220 to receive the second fingerprint image, so as to effectively remove the fingerprint image fringe noise To improve the reliability of fingerprint recognition.

Therefore, with the technical solutions disclosed above, the present invention has the following advantages:

(1) The optical fingerprint sensing device of the present invention can effectively remove the fringe noise of a fingerprint image through a simple auxiliary sensing structure and a simple subtraction operation.

(2) The optical fingerprint sensing device of the present invention can improve the reliability of fingerprint recognition by using a simple auxiliary sensing structure and a simple subtraction operation.

The disclosure in this case is a preferred embodiment, and any partial changes or modifications that are derived from the technical ideas of the case and can be easily inferred by those who are familiar with the art do not deviate from the scope of the patent right of the case.

In summary, regardless of the purpose, means, and effects of this case, it is shown that it is very different from the conventional technology, and its first invention is practical, and it does meet the patent requirements of the invention. Please check it out and grant the patent as soon as possible. Society is for the best prayer.

10: Photodiode array sensing image 11: Brake direction stripes 12: Fingerprint image 100: Optical sensor array 100a: Fingerprint sensing area 100b: background stripe sensing area 101: switch 102: light sensing diode 103: Capacitance 110: Gate drive unit 120: signal readout circuit 130: processing unit 200: Information processing device 210: Central Processing Unit 220: Optical fingerprint sensor

Figure 1 is a photodiode array sensing image with a plurality of gate stripes. FIG. 2 is a schematic diagram showing the effect of the second traditional solution on a photodiode array sensing image with multiple gate stripes. FIG. 3 is a schematic diagram of an embodiment of the optical fingerprint sensing device of the present invention. 4 is a schematic diagram showing the effect of the optical fingerprint sensing device of FIG. 3 on a photodiode array sensing image with a plurality of gate stripes and a fingerprint image after processing. FIG. 5 is a block diagram of an embodiment of the processing device of the present invention.

100: Optical sensor array

100a: Fingerprint sensing area

100b: background stripe sensing area

101: switch

102: light sensing diode

103: Capacitance

110: Gate drive unit

120: signal readout circuit

130: processing unit

Claims (10)

An optical fingerprint sensing device has: an optical sensor array with a gate drive input side and a source output side, and it has a fingerprint sensing area and at least one background stripe sensing area, wherein, The at least one background stripe sensing area is correspondingly adjacent to at least one side of two opposite sides of the fingerprint sensing area, each of the background stripe sensing areas has a light shield above it, and the source electrode The output side is used to output a plurality of first pixel sensing signals in the fingerprint sensing area and at least one second pixel sensing signal in the at least one background stripe sensing area; a signal readout circuit, and the source The output side is coupled to collect the plurality of first pixel sensing signals and the at least one second pixel sensing signal, and generate a frame of first fingerprint image according to the plurality of first pixel sensing signals, Generating a frame of fringe image according to the at least one second pixel sensing signal, and performing a subtraction operation on the frame of the first fingerprint image and the frame of fringe image to obtain a frame of second fingerprint image; and a process The unit is coupled to the signal readout circuit to receive the frame of the second fingerprint image. According to the optical fingerprint sensing device described in claim 1, wherein the light shielding object is a screen frame. The optical fingerprint sensing device described in the first item of the patent application further has a gate drive unit to drive the gate drive input side, wherein the gate drive unit is a gate drive chip or a board Integrated gate drive circuit. An optical fingerprint sensing device has: an optical sensor array with a gate drive input side and a source output side, and it has a fingerprint sensing area and at least one background stripe sensing area, wherein, The at least one background stripe sensing area is correspondingly adjacent to at least one side of two opposite sides of the fingerprint sensing area, each of the background stripe sensing areas has a light shield above it, and the source electrode The output side is used to output a plurality of first pixel sensing signals of the fingerprint sensing area and at least one second pixel sensing signal of the at least one background stripe sensing area; a signal readout circuit, and the source The output side is coupled to collect the plurality of first pixel sensing signals and the at least one second pixel sensing signal, and generate a frame of first fingerprint image according to the plurality of first pixel sensing signals, And generating a frame of stripe image according to the at least one second pixel sensing signal; and a processing unit that receives the frame of the first fingerprint image and the frame of stripe image from the signal readout circuit, and the frame A fingerprint image and the frame of the stripe image are subjected to a subtraction operation to obtain a frame of the second fingerprint image. According to the optical fingerprint sensing device described in claim 4, the light shielding object is a screen frame. For example, the optical fingerprint sensing device described in claim 4 further has a gate drive unit to drive the gate drive input side, wherein the gate drive unit is a gate drive chip or a board Integrated gate drive circuit. An optical fingerprint sensing device, which has: an optical sensor array, which has a background stripe sensing area on at least one of two opposite sides, and a light shield is provided above the background stripe sensing area , And the optical sensor array is used to output a plurality of first pixel sensing signals in a fingerprint sensing area and at least one second pixel sensing signal in at least one of the background stripe sensing areas; and a signal reading An output circuit for collecting the plurality of first pixel sensing signals and the at least one second pixel sensing signal to generate a first fingerprint image according to the plurality of first pixel sensing signals, The at least one second pixel sensing signal generates a frame of fringe image, and performing a subtraction operation on the frame of the first fingerprint image and the frame of fringe image to obtain a frame of second fingerprint image. An optical fingerprint sensing device, which has: an optical sensor array, which has a background stripe sensing area on at least one of two opposite sides, and a light shield is provided above the background stripe sensing area , And the optical sensor array is used to output a plurality of first pixel sensing signals in a fingerprint sensing area and at least one second pixel sensing signal in at least one of the background stripe sensing areas; a signal readout A circuit for collecting the plurality of first pixel sensing signals and the at least one second pixel sensing signal to generate a first fingerprint image according to the plurality of first pixel sensing signals, and The at least one second pixel sensing signal generates a frame of fringe images; and a processing unit that receives the frame of the first fingerprint image and the frame of fringe image from the signal readout circuit, and the frame of the first fingerprint image A subtraction operation is performed between the image and the frame of the fringe image to obtain a frame of the second fingerprint image. An information processing device having a central processing unit and the optical fingerprint sensing device as described in any one of items 1-8 of the scope of patent application, wherein the central processing unit is used to communicate with the processing unit to receive The second fingerprint image of this frame. For example, the information processing device described in item 7 of the scope of patent application is a smart phone or a portable computer device.

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