TWI759014B - Optical fingerprint identification method for overcoming strong light interference and touch display and information processing device using the same - Google Patents

Abstract

An optical fingerprint identification method for overcoming strong light interference, the method comprises: displaying an initial image on a touch screen; displaying a first image on the touch screen, and receiving a set of image data to obtain a first fingerprint image image; display a second image on the touch screen, and receive another set of the image data to obtain a second fingerprint image; and display the initial image on the touch screen, the first fingerprint image Perform a subtraction operation with the second fingerprint image to generate a third fingerprint image, and perform a comparison procedure on the third fingerprint image with a sample image, if the result of the comparison procedure is a match, then Unlock, if the result of the comparison procedure is mismatch, it will prompt failure.

Description

Optical fingerprint identification method for overcoming strong light interference and touch display and information processing device using the same

The present invention relates to an optical fingerprint identification method, in particular to an optical fingerprint identification method which can improve the identification rate in a strong light environment.

After the popularity of full-screen mobile phones, under-screen optical fingerprint recognition has gradually become standard equipment. The principle of optical fingerprint recognition is briefly described as follows: use the mobile phone screen to provide a light source so that the light emitted by the finger is reflected to an optical acquisition module below the screen. The optical signals collected by the groups are also different; a processing circuit is used to photoelectrically convert the optical signals, then amplify and digitize them; finally, upload the data representing the fingerprint image to an application processor for identification.

Generally, the indoor light is about 100lx, which has little effect on the optical fingerprint recognition under the screen. However, when the phone is moved outside, the light outside may reach 100,000 lx in sunny sunlight. Although the ambient light will be greatly attenuated after being filtered by the finger, such a strong light will still penetrate the finger and interfere with the optical fingerprint recognition under the screen. Please refer to FIG. 1a and FIG. 1b together, wherein, FIG. 1a is a schematic diagram of obtaining fingerprint information by means of reflection without ambient light; FIG. As shown in FIG. 1a, the light 11a emitted by a light source 11 is reflected after reaching a finger 13 on a glass cover 12 to form a fingerprint information 14a under the light source 11; and as shown in FIG. 1b, a strong light 15a forms an interference information 14b under the light source 11 after penetrating the finger 13, wherein the interference information 14b and the fingerprint information 14a are in opposite phases. Therefore, the overlapping of the interference information 14b and the fingerprint information 14a will cause the captured image to be attenuated. On the other hand, the finger is not a uniform material, and a new image is formed during the projection process, which also interferes with the real fingerprint image.

In order to solve the above problems, some existing technologies insert a filter film between the screen and the capture device to attenuate light in a frequency band different from the light source. However, this method cannot filter out the external light in the same frequency band as the light source.

In addition, in the process of fingerprint identification in the general prior art, when the identification of the first frame image fails, the second frame or even more frame images are usually collected and retried to improve the identification rate. However, this method still cannot improve the fingerprint recognition rate when encountering strong ambient light.

Therefore, a novel optical fingerprint identification method is urgently needed in the art.

One objective of the present invention is to provide an optical fingerprint identification method that overcomes the interference of strong light, which can improve the success rate of fingerprint identification by switching images with different brightness in the fingerprint sensing area.

Another object of the present invention is to provide a touch display, which can improve the success rate of fingerprint identification by switching images with different brightness in the fingerprint sensing area.

Another object of the present invention is to provide an information processing device, which can improve the success rate of fingerprint identification by switching images with different brightness in the fingerprint sensing area.

In order to achieve the aforementioned purpose, an optical fingerprint identification method for overcoming the interference of strong light is proposed. The method includes:

Utilizing a control unit to output a first frame of display data to display an initial frame on a touch screen;

The control unit outputs a second frame of the display data to display a first frame on the touch screen, and receives a set of image data to obtain a first fingerprint image;

The control unit outputs a third frame of the display data to display a second frame on the touch screen, and receives another set of the image data to obtain a second fingerprint image; and

The control unit outputs the first frame of the display data to display the initial image on the touch screen, performs a subtraction operation on the first fingerprint image and the second fingerprint image to generate a third fingerprint image, and performing a comparison procedure on the third fingerprint image with the sample image, if the result of the comparison procedure is a match, then unlocking is performed, and if the result of the comparison procedure is a mismatch, a failure is prompted.

In one embodiment, the image data is sensed from the touch screen by an optical capture module.

In one embodiment, the first picture and the second picture are relatively a high-brightness picture and a low-brightness picture.

In one embodiment, the initial picture, the first picture and the second picture differ only in a fingerprint identification area.

In order to achieve the aforementioned object, the present invention further provides a touch display, which has a touch screen and a control unit, and the control unit is used for performing the following steps to improve the fingerprint recognition rate under strong light:

outputting a first frame of display data to display an initial frame on the touch screen;

outputting a second frame of the display data to display a first frame on the touch screen, and receiving a set of image data to obtain a first fingerprint image;

outputting a third frame of the display data to display a second frame on the touch screen, and receiving another set of the image data to obtain a second fingerprint image; and

Outputting the display data of the first frame to display the initial image on the touch screen, performing a subtraction operation on the first fingerprint image and the second fingerprint image to generate a third fingerprint image, and in the same way This image performs a comparison procedure on the third fingerprint image, if the result of the comparison procedure is a match, then unlocking is performed, and if the result of the comparison procedure is a mismatch, it will prompt failure.

In one embodiment, the image data is sensed from the touch screen by an optical capture module.

In one embodiment, the first picture and the second picture are relatively a high-brightness picture and a low-brightness picture.

In one embodiment, the initial picture, the first picture and the second picture differ only in a fingerprint identification area.

In order to achieve the aforementioned object, the present invention further provides an information processing device, which has a central processing unit and the aforementioned touch display, wherein the central processing unit is used for communication with the touch display.

In a possible embodiment, the information processing device may be a portable computer or a smart handheld device.

Please refer to FIG. 2 , which shows a block diagram of a touch display for realizing the optical fingerprint identification method of the present invention. As shown in FIG. 2 , a touch display 100 has a touch screen 110 , an optical capture module 120 and a control unit 130 .

The touch screen 110 is used for displaying a picture on a transparent cover plate according to the display data D _DISP , and can provide a full-screen fingerprint identification area on the transparent cover plate for the user to perform fingerprint identification operations.

The optical acquisition module 120 is used for acquiring the optical signal transmitted from the touch screen 110 when the user performs the fingerprint identification operation, and converts the optical signal into the image data D _IMG .

The control unit 130 is used for outputting the display data D _DISP , receiving the image data D _IMG , and performing the following steps according to the ambient light intensity signal S _AL to improve the fingerprint recognition rate under strong light:

(1) outputting a first frame of display data D _DISP to display an initial image on the touch screen 110;

(2) outputting a second frame of display data D _DISP to display a first frame on the touch screen 110, and receiving a set of image data D _IMG to obtain a first fingerprint image;

(3) outputting a third frame of display data D _DISP to display a second frame on the touch screen 110, and receiving another set of image data D _IMG to obtain a second fingerprint image; and

(4) outputting the first frame of display data D _DISP to display the initial image on the touch screen 110, performing a subtraction operation on the first fingerprint image and the second fingerprint image to generate a third fingerprint image, and performing a comparison procedure on the third fingerprint image with a sample image, if the result of the comparison procedure is a match, then unlocking is performed, and if the result of the comparison procedure is a mismatch, a failure is prompted. In addition, the brightness of the second picture is different from the brightness of the first picture, and preferably, the first picture and the second picture are relatively a high-brightness picture and a low-brightness picture.

From the above description, the present invention proposes an optical fingerprint identification method for overcoming the interference of strong light. Please refer to FIG. 3 , which shows a flow chart of an embodiment of an optical fingerprint identification method for overcoming strong light interference according to the present invention. As shown in FIG. 3 , the method includes: using a control unit to output a first frame of display data to display an initial image on a touch screen (step a); the control unit to output a second frame of the display data to The touch screen displays a first frame, and receives a set of image data to obtain a first fingerprint image (step b); the control unit outputs a third frame of the display data to display an image on the touch screen The second frame, and receiving another set of the image data to obtain a second fingerprint image (step c); and the control unit outputting the first frame of the display data to display the initial frame on the touch screen , perform a subtraction operation on the first fingerprint image and the second fingerprint image to generate a third fingerprint image, and perform a comparison procedure on the third fingerprint image with a sample image, if the comparison If the result of the comparison program is a match, then unlocking is performed, and if the result of the comparison program is a mismatch, a failure is indicated (step d).

According to this method, the present invention can effectively improve the fingerprint recognition rate without changing the hardware. In addition, in the process of taking pictures, the present invention can only switch the screen in the area where the finger is pressed, that is, the initial screen, the first screen and the second screen are only different in a fingerprint identification area, so that the user can use The user will not have obvious feeling during the operation. That is, the method of the present invention can make the image collected by the optical fingerprint device less susceptible to the influence of ambient light, thereby improving the unlocking experience.

In addition, according to the above description, the present invention further provides an information processing device. Please refer to FIG. 4 , which shows a block diagram of an embodiment of the information processing apparatus of the present invention. As shown in FIG. 4 , an information processing device 200 has a central processing unit 210 and a touch display 220 , wherein the central processing unit 210 is used for communicating with the touch display 220 and the touch display 220 is connected by the touch display 100 accomplish. In addition, the information processing device 200 can be a portable computer or a smart handheld device.

According to the above description, the present invention can provide the following advantages:

1. The optical fingerprint identification method for overcoming the interference of strong light of the present invention can improve the success rate of fingerprint identification by switching images with different brightness in the fingerprint sensing area.

2. The touch display of the present invention can improve the success rate of fingerprint identification by switching between images with different brightness in the fingerprint sensing area.

3. The information processing device of the present invention can improve the success rate of fingerprint identification by switching between screens with different brightness in the fingerprint sensing area.

What is disclosed in the present invention is one of the preferred embodiments, and any partial changes or modifications originating from the technical idea of the present invention and easily inferred by those skilled in the art are within the scope of the patent right of the present invention.

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 suitable for practical use, and indeed meets the patent requirements of the invention. Society is to pray for the best.

11: Light source 11a: Light 12: Glass cover 13: Fingers 14a: Fingerprint information 14b: Interference information 15a: Strong light 100: Touch Monitor 110: Touch screen 120: Optical acquisition module 130: Control unit 200: Information processing device 210: Central Processing Unit 220: Touch Monitor Step a: use a control unit to output a first frame of display data to display an initial frame on a touch screen Step b: the control unit outputs a second frame of the display data to display a first frame on the touch screen, and receives a set of image data to obtain a first fingerprint image Step c: The control unit outputs a third frame of the display data to display a second frame on the touch screen, and receives another set of the image data to obtain a second fingerprint image Step d: The control unit outputs the display data of the first frame to display the initial image on the touch screen, and performs a subtraction operation on the first fingerprint image and the second fingerprint image to generate a third fingerprint image, and perform a comparison procedure on the third fingerprint image with a sample image, if the result of the comparison procedure is a match, then unlock, if the result of the comparison procedure is a mismatch, it will prompt failure

In order to further disclose the specific technical content of the present invention, please refer to the drawings first, wherein: FIG. 1a is a schematic diagram of obtaining fingerprint information by reflection in the absence of ambient light. Fig. 1b is a schematic diagram of the interference of the fingerprint collection operation caused by strong ambient light penetrating the finger. FIG. 2 is a block diagram of a touch display for realizing the optical fingerprint identification method of the present invention. FIG. 3 is a flowchart illustrating an embodiment of an optical fingerprint identification method for overcoming strong light interference according to the present invention. FIG. 4 is a block diagram illustrating an embodiment of the information processing apparatus of the present invention.

Step a: use a control unit to output a first frame of display data to display an initial frame on a touch screen

Step b: The control unit outputs a second frame of the display data to display a first frame on the touch screen, and receives a set of image data to obtain a first fingerprint image

Step c: the control unit outputs a third frame of the display data to display a second frame on the touch screen, and receives another set of the image data to obtain a second fingerprint image

Step d: the control unit outputs the display data of the first frame to display the initial image on the touch screen, and performs a subtraction operation on the first fingerprint image and the second fingerprint image to generate a third fingerprint image, and perform a comparison procedure on the third fingerprint image with a sample image, if the result of the comparison procedure is a match, the unlocking is performed; if the result of the comparison procedure is a mismatch, it will prompt failure

Claims (4)

An optical fingerprint identification method for overcoming strong light interference, the method comprises: using a control unit to output a first frame of display data to display an initial image on a touch screen; the control unit to output a second frame of the display data to A first frame is displayed on the touch screen, and a set of image data is received to obtain a first fingerprint image; the control unit outputs a third frame of the display data to display a second frame on the touch screen , and receive another set of the image data to obtain a second fingerprint image; and the control unit outputs the first frame of the display data to display the initial image on the touch screen, the first fingerprint image Perform a subtraction operation with the second fingerprint image to generate a third fingerprint image, and perform a comparison procedure on the third fingerprint image with the sample image, if the result of the comparison procedure is a match, Then unlock, if the result of the comparison procedure is not matching, it will prompt failure; wherein, the image data is obtained by an optical capture module from the touch screen sensing, the first frame and the second frame The pictures are relatively a high-brightness picture and a low-brightness picture, and the initial picture, the first picture and the second picture are only different in a fingerprint identification area. A touch display has a touch screen and a control unit, the control unit is used for performing the following steps to improve the fingerprint recognition rate under strong light: outputting a first frame of display data to display a touch screen on the touch screen an initial image; outputting a second frame of the display data to display a first frame on the touch screen, and receiving a set of image data to obtain a first fingerprint image; outputting a third frame of the display data to Display a second frame on the touch screen, and receive another set of the image data to obtain a second fingerprint image; and output the first frame of the display data to display the initial frame on the touch screen , perform a subtraction operation on the first fingerprint image and the second fingerprint image to generate a third fingerprint image, and perform a comparison procedure on the third fingerprint image with a sample image, if the comparison If the result of the comparison procedure is a match, then unlocking is performed, and if the result of the comparison procedure is no match, it will prompt failure; wherein, the image data is obtained from the touch screen by an optical acquisition module, and the The first picture and the second picture are relatively a high-brightness picture and a low-brightness picture, and the initial picture, the first picture There is only a fingerprint identification area difference between the picture and the second picture. An information processing device has a central processing unit and the touch display as described in claim 2, wherein the central processing unit is used for communication with the touch display. The information processing device described in item 3 of the scope of the application is a portable computer or a smart handheld device.

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