TWI771829B - Optical fingerprint recognition method for improving recognition rate under strong light and touch display and information processing device using the same - Google Patents

Abstract

An optical fingerprint identification method for improving the recognition rate under strong light, the method includes: displaying a first image on a touch screen, receiving a set of image data to obtain a first fingerprint image, and judging an ambient light intensity signal Whether it is greater than a threshold, if so, determine that the ambient light is strong light; perform a comparison procedure on the first fingerprint image with a sample image and receive another set of the image data to obtain a second fingerprint image , if the result of the comparison procedure is a match, then unlock, if the result of the comparison procedure is a mismatch, proceed to the next stage; perform the comparison procedure on the second fingerprint image with the sample image, A second image is displayed on the touch screen, and another set of the image data is received to obtain a third fingerprint image. If the result of the comparison procedure is a match, unlocking is performed. If the result is no match, proceed to the next stage; and display the first frame on the touch screen, and perform the comparison procedure on the third fingerprint image with the sample image, if the result of the comparison procedure is If there is a match, it will be unlocked, and if the result of the comparison procedure is no match, it will prompt failure.

Description

Optical fingerprint recognition method for improving recognition rate under strong light 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 will reach an optical acquisition module below the screen after being reflected by the finger. 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, there is an urgent need for a novel optical fingerprint identification method in the art.

One object of the present invention is to provide an optical fingerprint identification method for improving the identification rate under 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 improving the recognition rate under strong light is proposed, and the method includes:

utilize a control unit to output a first frame of display data to display a first frame on a touch screen, receive a set of image data to obtain a first fingerprint image, and determine whether an ambient light intensity signal is greater than a threshold, If so, the ambient light is determined to be strong light;

The control unit performs a comparison procedure on the first fingerprint image with a sample image and receives another set of the image data to obtain a second fingerprint image. If the result of the comparison procedure is a match, then Unlock, if the result of the comparison procedure is mismatched, proceed to the next stage;

The control unit performs the comparison procedure on the second fingerprint image with the sample image, outputs a second frame of the display data to display a second image on the touch screen, and receives another set of the images image data to obtain a 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, then proceed to the next stage; and

The control unit outputs the first frame of display data to display the first frame on the touch screen, and performs the 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 mismatch, it will prompt failure.

In one embodiment, the ambient light intensity signal is provided by an ambient light sensing unit.

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 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 a first frame on the touch screen, receiving a set of image data to obtain a first fingerprint image, and determining whether an ambient light intensity signal is greater than a threshold, if so, determining Ambient light is strong light;

Perform a comparison procedure on the first fingerprint image with a sample image and receive another set of the image data to obtain a second fingerprint image, if the result of the comparison procedure is a match, then unlock, If the result of the comparison procedure is a mismatch, proceed to the next step;

Perform the comparison procedure on the second fingerprint image with the sample image, output a second frame of the display data to display a second frame on the touch screen, and receive another set of the image data for Obtaining a third fingerprint image, if the result of the comparison procedure is a match, then unlocking, and if the result of the comparison procedure is a mismatch, then proceed to the next step; and

Outputting the first frame of display data to display the first frame on the touch screen, and performing the comparison procedure on the third fingerprint image with the sample image, if the result of the comparison procedure is a match, perform the comparison procedure Unlock, if the result of the comparison procedure is a mismatch, it will prompt failure.

In one embodiment, the ambient light intensity signal is provided by an ambient light sensing unit.

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 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 ambient light sensing unit 120 , an optical capture module 130 and a control unit 140 .

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

The ambient light sensing unit 120 is used for sensing the intensity of ambient light to generate an ambient light intensity signal S _AL .

The optical capture module 130 is used to capture the light signal transmitted from the touch screen 110 when the user performs the fingerprint identification operation, and convert the light signal into the image data D _IMG .

The control unit 140 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 a first frame on the touch screen 110; receiving a set of image data D _IMG to obtain a first fingerprint image; and determining whether the ambient light intensity signal S _AL is greater than a threshold, if so, the ambient light is determined to be strong light;

(2) Perform a comparison procedure on the first fingerprint image with a sample image and receive another set of image data D _IMG to obtain a second fingerprint image, if the result of the comparison procedure is a match, then Unlock, if the result of the comparison procedure is mismatched, proceed to the next stage;

(3) performing the comparison procedure on the second fingerprint image with the sample image; outputting a second frame of display data D _DISP to display a second frame on the touch screen 110 and receiving another set of image data _DIMG obtains a 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, then proceed to the next stage;

(4) Outputting the first frame of display data D _DISP to display the first frame on the touch screen 110, and performing the comparison procedure on the third fingerprint image with the sample image, if the result of the comparison procedure is If it is a match, it will be unlocked, and if the result of the comparison procedure is no match, it will prompt failure. 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 improving the identification rate under strong light. Please refer to FIG. 3 , which shows a flow chart of an embodiment of the optical fingerprint identification method for improving the identification rate under strong light 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 a first frame on a touch screen, receiving a set of image data to obtain a first fingerprint image, and determining Whether an ambient light intensity signal is greater than a threshold, if yes, then determine that the ambient light is strong light (step a); the control unit performs a comparison procedure on the first fingerprint image with a sample image and receives another set of Describe the image data to obtain a second fingerprint image, if the result of the comparison procedure is a match, then unlock, if the result of the comparison procedure is a mismatch, then proceed to the next stage (step b); the control The unit performs the comparison procedure on the second fingerprint image with the sample image, outputs a second 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 third fingerprint image, if the result of the comparison procedure is a match, then unlock, if the result of the comparison procedure is a mismatch, then proceed to the next stage (step c); and the control unit outputs the The first frame of display data is used to display the first frame on the touch screen, and perform the 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 alignment procedure is no match, 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, during the image capturing process of the present invention, the screen can be switched only in the area where the finger is pressed, so that the user does 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 recognition method for improving the recognition rate under strong light of the present invention can improve the success rate of fingerprint recognition by switching between 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: Ambient light sensing unit 130: Optical acquisition module 140: 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 a first frame on a touch screen, receive a set of image data to obtain a first fingerprint image, and determine whether an ambient light intensity signal is greater than A threshold value, if it is, it is determined that the ambient light is strong light Step b: The control unit performs a comparison procedure on the first fingerprint image with a sample image and receives another set of the image data to obtain a second fingerprint image, if the result of the comparison procedure is If there is a match, it will be unlocked. If the result of the comparison program is not a match, the next stage will be carried out. Step c: The control unit performs the comparison procedure on the second fingerprint image with the sample image, outputs a second frame of the display data to display a second image on the touch screen, and receives another set of The image data obtains a 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, then proceed to the next stage Step d: The control unit outputs the first frame of display data to display the first frame on the touch screen, and performs the comparison procedure on the third fingerprint image with the sample image. If the result is a match, it will be unlocked. If the result of the comparison program is not a match, 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 improving the identification rate under strong light 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 a first frame on a touch screen, receive a set of image data to obtain a first fingerprint image, and determine whether an ambient light intensity signal is greater than A threshold value, if it is, it is determined that the ambient light is strong light Step b: The control unit performs a comparison procedure on the first fingerprint image with a sample image and receives another set of the image data to obtain a second fingerprint image, if the result of the comparison procedure is If there is a match, it will be unlocked. If the result of the comparison program is not a match, the next stage will be performed. Step c: The control unit performs the comparison procedure on the second fingerprint image with the sample image, outputs a second frame of the display data to display a second image on the touch screen, and receives another set of The image data obtains a 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, then proceed to the next stage Step d: The control unit outputs the first frame of display data to display the first frame on the touch screen, and performs the comparison procedure on the third fingerprint image with the sample image. If the result is a match, it will be unlocked. If the result of the comparison program is not a match, it will prompt failure.

Claims (10)

An optical fingerprint recognition method for improving the recognition rate under strong light, the method comprises: using a control unit to output a first frame of display data to display a first picture on a touch screen, and receiving a set of image data to obtain a first frame a fingerprint image, and determine whether an ambient light intensity signal is greater than a threshold, if so, determine that the ambient light is strong light; the control unit performs a comparison procedure on the first fingerprint image with a sample image and receives another A set of said image data to obtain a second fingerprint image, if the result of the comparison procedure is a match, then unlocking, if the result of the comparison procedure is a mismatch, then proceed to the next stage; the control unit Perform the comparison procedure on the second fingerprint image with the sample image, output a second frame of the display data to display a second frame on the touch screen, and receive another set of the image data for Obtaining a third fingerprint image, if the result of the comparison procedure is a match, then unlocking, if the result of the comparison procedure is a mismatch, then proceed to the next stage; and the control unit outputs the first frame of display data The first screen is displayed on the touch screen, and the comparison procedure is performed on the third fingerprint image with the sample image. If the result of the comparison procedure is a match, unlocking is performed. If the result is no match, it indicates failure; wherein, the brightness of the second picture is different from the brightness of the first picture. The optical fingerprint identification method for improving the recognition rate under strong light as described in item 1 of the scope of the patent application, wherein the ambient light intensity signal is provided by an ambient light sensing unit. The optical fingerprint identification method for improving the recognition rate under strong light as described in item 1 of the claimed scope, wherein the image data is sensed from the touch screen by an optical acquisition module. The optical fingerprint identification method for improving the recognition rate under strong light as described in item 1 of the scope of the patent application, wherein the first picture and the second picture are relatively a high-brightness picture and a low-brightness picture. A touch display has a touch screen and a control unit, the control unit is used for executing 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 The first screen, receiving a set of image data to obtain a first fingerprint image, and determining whether an ambient light intensity signal is greater than a threshold, and if so, determining that the ambient light is strong light; Perform a comparison procedure on the first fingerprint image with a sample image and receive another set of the image data to obtain a second fingerprint image, if the result of the comparison procedure is a match, then unlock, If the result of the comparison procedure is no match, proceed to the next step; perform the comparison procedure on the second fingerprint image with the sample image, and output a second frame of the display data for displaying on the touch screen Displaying a second screen, and receiving another set of the image data to obtain a third fingerprint image, if the result of the comparison procedure is a match, then unlocking, and if the result of the comparison procedure is a mismatch, Then proceed to the next step; and output the first frame of display data to display the first frame on the touch screen, and perform the comparison procedure on the third fingerprint image with the sample image, if the comparison procedure If the result of the comparison procedure is a match, it will be unlocked, and if the result of the comparison procedure is a mismatch, it will prompt failure; wherein, the brightness of the second picture is different from the brightness of the first picture. The touch display of claim 5, wherein the ambient light intensity signal is provided by an ambient light sensing unit. The touch display as described in claim 5, wherein the image data is sensed from the touch screen by an optical acquisition module. The touch display according to claim 5, wherein the first picture and the second picture are relatively a high-brightness picture and a low-brightness picture. An information processing device has a central processing unit and the touch display according to any one of claims 5 to 8 of the patent application scope, wherein the central processing unit is used for communicating with the touch display. The information processing device described in item 9 of the scope of the application is a portable computer or a smart handheld device.

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