TWI791964B - Fingerprint reading method, fingerprint reading device and information processing device using same - Google Patents

Abstract

A fingerprint reading method, suitable for an optical fingerprint collection panel and realized by a control circuit, the fingerprint reading method is characterized in that it includes: measuring a temperature of the optical fingerprint collection panel and mapping a temperature-deformation rate according to the temperature Comparing the table to obtain an optical path deformation rate; performing a texture compensation process on a pre-stored shading image according to the optical path deformation rate to obtain a new shading image; and according to the new shading image for the optical fingerprint collection panel A shading removal process is performed on the collected first fingerprint image to obtain a second fingerprint image.

Description

Fingerprint reading method, fingerprint reading device and information processing device using same

The present invention relates to a fingerprint reading method, in particular to a fingerprint reading method which can obtain a clear and correct fingerprint image by correcting the shading image (background texture image) by temperature.

Fingerprint recognition is a technology that is widely used on portable computers or smart phones. Generally speaking, when the user's finger presses the touch panel on the above-mentioned smart device, the device will send image information including fingerprints and shading to the application processor (Application Processor, AP) or microcontroller The processor (Micro Control Unit, MCU) and other computing units are used to reduce or remove the shading information, so as to obtain image information including only fingerprints.

However, in the prior art, the above-mentioned shading information is collected by R&D personnel at a specific temperature when the touch panel leaves the factory, and applied to the fingerprint collection process at any time. When fingerprints are collected under low temperature conditions, the optical path layer in the panel will be affected by temperature changes and cause thermal expansion and contraction. At this time, the applied shading will be different from the shading information in the actually collected fingerprints. , resulting in misalignment or pixel deviation in the final output fingerprint image.

In order to solve the above problems, there is an urgent need in the art for a novel fingerprint reading scheme.

One purpose of the present invention is to disclose a fingerprint reading method, which can calculate the deformed shading image by measuring the temperature, thereby effectively improving the accuracy of the fingerprint image.

Another object of the present invention is to disclose a fingerprint reading device, which can calculate the deformed shading image by measuring the temperature, thereby effectively improving the accuracy of the fingerprint image.

Another object of the present invention is to disclose an information processing device, the fingerprint reading device included in it can calculate the deformed shading image by measuring the temperature, so as to effectively improve the accuracy of the fingerprint image.

In order to achieve the above purpose, a fingerprint reading method is proposed, which is suitable for an optical fingerprint collection panel and is realized by a control circuit. The fingerprint reading method is characterized in that it includes:

Measuring a temperature of the optical fingerprint collection panel and mapping a temperature-deformation rate comparison table according to the temperature to obtain an optical path deformation rate;

performing a texture compensation process on a prestored texture image according to the optical path deformation rate to obtain a new texture image; and

Perform a shading removal process on a first fingerprint image collected by the optical fingerprint collection panel according to the new shading image to obtain a second fingerprint image.

In one embodiment, the optical path deformation rate is the texture deformation rate of an optical path layer in the optical fingerprint collection panel affected by temperature.

In possible embodiments, the temperature can be measured by a temperature sensor on the optical fingerprint collection panel or by a temperature sensing circuit in a readout chip of the control circuit.

To achieve the above purpose, the present invention further proposes a fingerprint reading device, which includes an optical fingerprint collection panel and a control circuit, the control circuit is used to drive the optical fingerprint collection panel to perform a fingerprint reading method, and the fingerprint The read method is characterized by comprising:

The control circuit measures a temperature of the optical fingerprint collection panel and maps a temperature-deformation rate comparison table according to the temperature to obtain an optical path deformation rate;

performing a texture compensation process on a prestored texture image according to the optical path deformation rate to obtain a new texture image; and

Perform a shading removal process on a first fingerprint image collected by the optical fingerprint collection panel according to the new shading image to obtain a second fingerprint image.

In one embodiment, the optical path deformation rate is the texture deformation rate of an optical path layer in the optical fingerprint collection panel affected by temperature.

In possible embodiments, the temperature can be measured by a temperature sensor on the optical fingerprint collection panel or by a temperature sensing circuit in a readout chip of the control circuit.

To achieve the above object, the present invention further proposes an information processing device, which has a central processing unit and a display screen, wherein the display screen has the fingerprint reading device as mentioned above, and the central processing unit is used to communicate with the display screen communication.

In a possible embodiment, the information processing device may be a smart phone, a portable computer, an access control security system or a vehicle electronic system.

In possible embodiments, the display screen may include a liquid crystal display, a light emitting diode display, an organic light emitting diode display or a quantum dot light emitting diode display.

In a possible embodiment, the fingerprint reading device may be a plug-in module of the display screen or embedded in the display screen.

Please refer to Fig. 1 and Fig. 2 together, wherein, Fig. 1 depicts the block diagram of an embodiment of a fingerprint reading device applicable to the fingerprint reading method of the present invention; Fig. 2 depicts an implementation of the fingerprint reading method Example flowchart. As shown in FIG. 1 , a fingerprint reading device 100 includes an optical fingerprint collection panel 110 and a control circuit 120 , and the control circuit 120 is used to drive the optical fingerprint collection panel 110 to execute a fingerprint reading method. As shown in Figure 2, the fingerprint reading method includes: storing a collected first fingerprint image (step a); measuring a temperature of the optical fingerprint collection panel and mapping a temperature-deformation rate comparison table according to the temperature to Obtain an optical path deformation rate (step b); perform a texture compensation process on a prestored shading image according to the optical path deformation rate to obtain a new shading image (step c); The first fingerprint image is subjected to a shading removal process to obtain a second fingerprint image (step d).

Specifically, please refer to FIG. 3 , the optical fingerprint collection panel 110 may include a light emitting layer 111, a conversion layer 112, an optical path layer 113 and a glass cover 114 from bottom to top, wherein the light emitting layer 111 includes at least one light emitting element , such as but not limited to LED elements; the conversion layer 112 includes a plurality of photoelectric conversion elements, such as but not limited to photodiodes; the optical path layer 113 is a medium layer that allows light to pass through, which may include air, water or collimators; And the glass cover 114 is used for pressing by a finger to perform a fingerprint collection operation. During operation, the user presses the finger on the glass cover 114; the light emitted by the light-emitting elements of the light-emitting layer 111 will pass through the optical path layer 113 and irradiate the finger on the glass cover 114; reflected by the finger The light will pass through the optical path layer 113 and after reaching the conversion layer 112, it will be converted into an electrical signal and read by a readout chip 121 in the control circuit 120 to obtain the fingerprint containing the finger and the shading produced by the optical path layer 113 An original fingerprint image, that is, the first fingerprint image.

In addition, the temperature can be measured by a temperature sensor (not shown in the figure) on the optical fingerprint collection panel 110 or by a temperature sensing circuit (not shown in the figure) in the readout chip 121 of the control circuit 120 . Since the optical fingerprint collection panel 110 and the control circuit 120 are structurally separated from each other, there may be a temperature difference, so the two can be designed as close as possible to reduce the temperature difference between the two.

Please refer to FIG. 4 , which shows a temperature-deformation rate relationship diagram of the optical path layer 113 . After obtaining the temperature, the temperature-deformation rate relation diagram can be mapped according to the temperature to obtain the optical path deformation rate.

In addition, please refer to FIG. 5a, which shows an original shading image generated by the optical path layer 113; and FIG. 5b, which shows a deformed shading image generated from the original shading image in FIG. 5a. It can be seen from FIG. 5 a and FIG. 5 b that the texture size of the deformed shading image is smaller than that of the original shading image.

After obtaining the optical path deformation rate corresponding to the temperature, the texture compensation process can be performed on the pre-stored shading image according to the optical path deformation rate to obtain the new shading image, wherein the The texture compensation process includes a texture resizing operation to enlarge or reduce the pre-stored texture image. Specifically, the control circuit 120 stores the pre-stored shading image when it leaves the factory.

After obtaining the new shading image, the original fingerprint image can be subjected to shading removal processing according to the new shading image to obtain an image containing only the fingerprint, that is, the second Fingerprint image to eliminate deformation caused by temperature changes, thereby reducing misalignment or pixel deviation to improve the accuracy of fingerprint reading.

According to the above description, the present invention further provides an information processing device. Please refer to FIG. 6, which shows a block diagram of an embodiment of an information processing device of the present invention, wherein an information processing device 200 has a central processing unit 210 and a display screen 220, wherein the display screen 220 may include a liquid crystal display (liquid-crystal display, LCD), a light emitting diode display (light emitting diode, led), an organic light emitting diode display (organic light emitting diode, OLED) or a quantum dot light emitting diode display (quantum light emitting diode, QLED), and it has the aforementioned fingerprint reading device 100, and the fingerprint reading device can be a plug-in module of the display screen 220 or embedded in the display screen 220, and the central processing unit 210 Then it is used to communicate with the display screen 220 . In addition, in a possible embodiment, the information processing device 200 can be a smart phone, a portable computer, an access control security system or a vehicle electronic system.

With the design disclosed above, the present invention has the following advantages:

1. The fingerprint reading method of the present invention can calculate the deformed shading image by measuring the temperature, thereby effectively improving the accuracy of the fingerprint image.

2. The fingerprint reading device of the present invention can calculate the deformed shading image by measuring the temperature, thereby effectively improving the accuracy of the fingerprint image.

3. The fingerprint reading device contained in the information processing device of the present invention can calculate the deformed shading image by measuring the temperature, thereby effectively improving the accuracy of the fingerprint image. What is disclosed in this case is a preferred embodiment. For example, any partial changes or modifications derived from the technical ideas of this case and easily deduced by those who are familiar with the technology are within the scope of the patent right of this case.

To sum up, regardless of the purpose, means and efficacy of this case, it shows 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. I implore your review committee to understand it clearly and grant a patent as soon as possible. Society is for the Most Prayer.

Step a: store a first fingerprint image collected Step b: Measure a temperature of the optical fingerprint collection panel and map a temperature-deformation value comparison table according to the temperature to obtain an optical path deformation rate Step c: Perform a texture compensation process on a prestored shading image according to the optical path deformation rate to obtain a new shading image Step d: Perform a shading removal process on the first fingerprint image according to the new shading image to obtain a second fingerprint image 100: Fingerprint reading device 110:Optical fingerprint acquisition panel 111: luminescent layer 112: conversion layer 113: Optical path layer 114: glass cover 120: control circuit 121: read chip 200: information processing device 210: central processing unit 220: display screen

FIG. 1 shows a block diagram of an embodiment of a fingerprint reading device applicable to the fingerprint reading method of the present invention. FIG. 2 is a flowchart of an embodiment of the fingerprint reading method of the present invention. FIG. 3 is a cross-sectional view of an embodiment of an optical fingerprint collection panel of the fingerprint reading device of FIG. 1 . FIG. 4 is a graph showing the relationship between temperature and deformation rate of the optical path layer of the optical fingerprint collection panel of FIG. 3 . FIG. 5 a shows an original shading image of the optical path layer in FIG. 3 . Fig. 5b shows the deformed shading image from the original shading image in Fig. 5a. FIG. 6 is a block diagram of an embodiment of an information processing device of the present invention.

Step a: store a first fingerprint image collected

Step b: Measure a temperature of the optical fingerprint collection panel and map a temperature-deformation value comparison table according to the temperature to obtain an optical path deformation rate

Step c: Perform a texture compensation process on a prestored shading image according to the optical path deformation rate to obtain a new shading image

Step d: Perform a shading removal process on the first fingerprint image according to the new shading image to obtain a second fingerprint image

Claims (8)

A fingerprint reading method, suitable for an optical fingerprint collection panel and realized by a control circuit, the fingerprint reading method is characterized in that it includes: measuring a temperature of the optical fingerprint collection panel and mapping a temperature-deformation rate according to the temperature Check the table to obtain an optical path deformation rate, wherein the optical path deformation rate is the texture deformation rate of an optical path layer in the optical fingerprint collection panel affected by temperature; perform a pre-stored shading image according to the optical path deformation rate Texture compensation processing to obtain a new shading image, wherein the pre-stored shading image is an initial background texture image of the optical fingerprint collection panel, and the new shading image represents an updated background texture image and performing a shading removal process on a first fingerprint image collected by the optical fingerprint collection panel according to the new shading image to obtain a second fingerprint image. The fingerprint reading method described in item 1 of the scope of patent application, wherein the temperature is measured by a temperature sensor on the optical fingerprint collection panel or by a temperature sensing circuit in a readout chip of the control circuit have to. A fingerprint reading device, comprising an optical fingerprint collection panel and a control circuit, the control circuit is used to drive the optical fingerprint collection panel to execute a fingerprint reading method, the fingerprint reading method is characterized by comprising: the control circuit Measuring a temperature of the optical fingerprint collection panel and mapping a temperature-deformation rate comparison table according to the temperature to obtain an optical path deformation rate, wherein the optical path deformation rate is produced by an optical path layer in the optical fingerprint collection panel affected by temperature Texture deformation rate; perform a texture compensation process on a pre-stored shading image according to the optical path deformation rate to obtain a new shading image, wherein the pre-stored shading image is an initial background texture of the optical fingerprint collection panel image, and the new shading image represents an updated background texture image; and a shading removal process is performed on a first fingerprint image collected by the optical fingerprint collection panel according to the new shading image to A second fingerprint image is obtained. The fingerprint reading device as described in item 3 of the scope of the patent application, wherein the temperature is measured by a temperature sensor on the optical fingerprint collection panel or by a temperature sensing circuit in a readout chip of the control circuit have to. An information processing device, which has a central processing unit and a display screen, wherein the display screen has a fingerprint reading device as described in any one of items 3 to 4 of the scope of the patent application, and the central processing unit is used for Communicate with the display. The information processing device described in item 5 of the scope of the patent application is an electronic device selected from a group consisting of a smart phone, a portable computer, an access control security system and a vehicle electronic system. The information processing device as described in item 5 of the scope of the patent application, wherein the display screen includes a group consisting of a liquid crystal display, a light emitting diode display, an organic light emitting diode display and a quantum dot light emitting diode display A display selected by the group. The information processing device as described in item 7 of the patent application, wherein the fingerprint reading device is an external module of the display screen or embedded in the display screen.

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