TWI678637B - Fingerprint identification systems - Google Patents

Abstract

A fingerprint recognition system includes a fingerprint sensing device and a controller. The fingerprint sensing device samples the fingerprint and generates a sampling signal, and converts the sampling signal into a first fingerprint image signal according to a first set of parameters, or converts the sampling signal into a second fingerprint image signal according to a second set of parameters. The controller selects a first set of setting parameters from the plurality of set parameters for the fingerprint sensing device to perform signal conversion. When the first fingerprint image signal does not meet the registered fingerprint characteristics, it selects a second set of settings from the plurality of set parameters. The parameters are used by the fingerprint sensing device to perform signal conversion, and when the first fingerprint image signal or the second fingerprint image signal meets the registered fingerprint characteristics, it is determined that the fingerprint is a legitimate fingerprint.

Description

Fingerprint recognition system

This application is mainly related to fingerprint recognition technology, and more particularly, to a fingerprint recognition system and method capable of dynamically adjusting gain parameters and offset parameters.

In recent years, the application of security management has gradually received attention, such as: portal security management, electronic device authentication, financial system authentication, and crime detection. Fingerprint identification, the biometric identification technology, is currently the most commonly used in security. Management technology.

Generally, fingerprint recognition devices use a fixed set of parameters to obtain fingerprint images for comparison. However, the input conditions of fingerprints are usually not the same. The input conditions include the detected area of the finger (re-press / Tap), how dry and wet your fingers are, etc. Therefore, under the different input conditions of the same fingerprint, the fingerprint images obtained according to the fixed setting parameters will have obvious differences, which will affect the probability of successful fingerprint comparison.

For example, when the user touches his finger on the fingerprint recognition device, the obtained fingerprint image may be too light to easily find the fingerprint characteristics, or when the user touches his finger on the fingerprint recognition device again, or If there is moisture on the contacting fingers, the fingerprint image obtained may be too dark to easily find the fingerprint features.

In order to solve the above problem, the present application provides a fingerprint recognition system with multiple sets of setting parameters, which can dynamically select suitable setting parameters for processing fingerprint sampling signals to increase the probability of successful fingerprint comparison (lower the false rejection rate (False Rejection Rate (FRR)).

An embodiment of the present application provides a fingerprint recognition system, which includes a fingerprint sensing device and a controller. The fingerprint sensing device is used for sampling a fingerprint and generating a sampling signal, and converting the sampling signal into a first fingerprint image signal according to a first set of setting parameters. The controller is used to select the first set of setting parameters from a plurality of set parameters for the fingerprint sensing device to perform the signal conversion to determine whether the first fingerprint image signal meets one or more registered fingerprint characteristics. When the first fingerprint image signal meets the registered fingerprint characteristics, it is determined that the fingerprint is a valid fingerprint. When the first fingerprint image signal does not meet the registered fingerprint characteristics, select one from the multiple array setting parameters. A second set of parameters and instructing the fingerprint sensing device to convert the sampling signal into a second fingerprint image signal according to the second set of parameters, determine whether the second fingerprint image signal meets the registered fingerprint characteristics, and when the When the second fingerprint image signal meets the characteristics of the registered fingerprint, it is determined that the fingerprint is a legitimate fingerprint.

Regarding other additional features and advantages of this application, those skilled in the art can make some modifications and retouches based on the gesture-based fingerprint recognition system disclosed in the implementation method of the present application without departing from the spirit and scope of this application. And get.

100‧‧‧ Fingerprint Identification System

10‧‧‧Fingerprint sensing device

11‧‧‧Fingerprint sensor

12‧‧‧Signal Amplifier

13‧‧‧ Analog Digital Converter

14‧‧‧Microprocessor

15‧‧‧Temporary storage device

20‧‧‧ touch sensing device

30‧‧‧controller

40‧‧‧Storage device

50‧‧‧ reminder device

S210 ~ S280, S310 ~ S370‧‧‧Method steps

FIG. 1 is a structural diagram of a fingerprint recognition system according to an embodiment of the present application.

FIG. 2 is a flowchart of a fingerprint identification method according to an embodiment of the present application.

FIG. 3 is a flowchart of a fingerprint identification method according to another embodiment of the present application.

This section describes the best way to implement this application. The purpose is to explain the spirit of this application and not to limit the scope of protection of this application. When it is understood that the terms "include" and "include "And other words are used to indicate the existence of specific technical features, values, method steps, operations, components, and / or components, but it does not exclude the addition of more technical features, values, method steps, operations, components , Components, or any combination of the above.

FIG. 1 is a structural diagram of a fingerprint recognition system according to an embodiment of the present application. The fingerprint recognition system 100 includes a fingerprint sensing device 10, a touch sensing device 20, a controller 30, a storage device 40, and a reminder device 50.

For example, the fingerprint identification system 100 may be an electronic computing device such as a smart phone, a tablet computer, a notebook computer, a personal computer, a workstation, an ATM, or an electronic lock that can support the fingerprint identification function.

The fingerprint sensing device 10 is mainly responsible for sampling fingerprints and generating sampling signals according to specific set parameters, and the principle of fingerprint sampling may be optical, capacitive, or temperature sensitive, and is not limited to a specific type. Specifically, the setting parameters include a gain parameter and an offset parameter.

The fingerprint sensing device 10 may be an area type fingerprint sensor. Sensor, or swipe type sensor, where a full-frame fingerprint sensor takes a complete fingerprint image each time, and a swipe sensor only samples a portion of the fingerprint image at a time After the continuous sampling, the sampling result is stitched into a complete fingerprint image.

To further explain, the fingerprint sensing device 10 may be an integrated integrated circuit (IC), which includes a fingerprint sensor 11, one or more signal amplifiers 12, and an analog-to-digital converter (Analog-to -Digital Converter (ADC) 13, microprocessor (Micro Control Unit, MCU) 14, and temporary storage device 15 (such as memory).

Generally speaking, the fingerprint sensor 11 may include a sensing element configured with a specific resolution (eg, 500 DPI (Dots Per Inch)) to constitute image pixels, to sample the fingerprint of its corresponding position, and generate the original fingerprint. Image signal.

Then, the signal amplifier 12 can amplify the original fingerprint image signal into a gain fingerprint image signal according to the gain parameter. In this way, the original fingerprint image signal with weak signal strength can be used for subsequent signal processing after gain amplification.

After that, the analog-to-digital converter 13 converts the gain fingerprint image signal into a digital image signal, and then according to the offset parameter, the digital image signals of various intensities correspond to specific grayscale values, respectively, thereby generating a converted fingerprint image signal.

The microprocessor 14 is used to set gain parameters and offset parameters used by the signal amplifier 12 and the analog digital converter 13, and receives the converted fingerprint image signal from the analog digital converter 13, and then converts the converted fingerprint image signal It is transmitted to the controller 30 for subsequent fingerprint comparison operations.

In addition, the temporary storage device 15 can store the original fingerprint image signal. When the microprocessor 14 wants to use the new gain parameter and offset parameter, the original fingerprint image signal can be taken out from the temporary storage device 15 and transmitted to the signal amplifier 12, The signal amplifier 12 and the analog digital converter 13 are set to use the new gain parameters and offset parameters. The signal amplifier 12 uses the new gain parameters to gain amplification of the original fingerprint image signal, and the analog digital converter 13 uses the new The offset parameter converts the gain fingerprint image signal. That is, the fingerprint sensing device 10 can dynamically process the sampling signal according to different setting parameters.

In this embodiment, the touch sensing device 20 is configured to detect the approach or touch of a conductive object (such as a finger) and generate a touch signal. The principle of touch detection may be resistive, capacitive, Or optical, not limited to a specific type.

In another embodiment, the fingerprint sensing device 10 and the touch sensing device 20 may be integrated into a single component, such as an integrated sensing chip. Alternatively, the fingerprint sensing device 10 and the touch sensing device 20 may be integrated in a display panel, so that the touch panel has functions of displaying visual content, fingerprint sampling, and touch detection at the same time.

The controller 30 may be a general-purpose processor, a microprocessor, an application processor (AP), a digital signal processor (DSP), a graphics processing unit (GPU), or a hologram processing (Holographic Processing Unit, HPU), or any processor that can provide data processing and image analysis. The controller 30 may include various types of circuit logic, in addition to providing data processing and image analysis functions, it is also used to: receive the converted fingerprint image signal from the fingerprint sensing device 10, and receive the touch signal from the touch sensing device 20 2.Set the setting parameters used by the fingerprint sensing device 10. Data, reading or storing data from the storage device 40, and controlling the prompt device 50 to output a prompt message to inform the user as to whether the fingerprint comparison result is successful or failed.

The controller 30 is used to coordinate the operations of the fingerprint sensing device 10, the touch sensing device 20, the storage device 40, and the input / output device 50 to execute the fingerprint identification method of the present application.

The storage device 40 is a non-transitory computer-readable storage medium, including: memory (eg, flash memory, non-volatile random access memory (NVRAM)) ), Or magnetic storage devices (such as: hard disks, magnetic tapes), or optical disks, or any combination of the above media, which are mainly used to store data, including: registered fingerprint characteristics, optimal setting parameters corresponding to different pressing pressure channels, And computer-readable instructions or code (for example, application / communication protocol code and / or code for the fingerprint identification method of this application).

The prompting device 50 is mainly responsible for outputting a prompting message to inform the user when the fingerprint comparison fails. For example, the prompt message can be specific visual content (such as image, text), sound content, or vibration. The prompting device 50 may include a display device (such as a Liquid-Crystal Display (LCD), a Light-Emitting Diode (LED) display, an Organic Light-Emitting Diode (Organic LED, OLED), and electronic paper A display (Electronic Paper Display, EPD), or a cathode ray tube (CRT) display, etc.), a speaker, and / or a vibrator, for generating the visual content, sound content, and / or vibration.

It can be understood that the components shown in FIG. 1 are only used to provide an illustrative example, and are not intended to limit the protection scope of the present application. In another embodiment, The fingerprint recognition system 100 may further include other components. For example, when the fingerprint recognition system 100 is a smart phone or a tablet, it may further include a button, a microphone, a power supply, a wireless communication device, and / or a global positioning system. (Global Positioning System, GPS), etc. Buttons and microphones can be used to provide input and output functions as an interface for human-computer interaction. The power supply can be a portable / replaceable rechargeable battery that is responsible for providing power to the operation of other components. The wireless communication device can provide the function of wireless communication to obtain mobile services. The global positioning system can provide the location information of the fingerprint identification system 100 for mobile positioning services / applications.

FIG. 2 is a flowchart of a fingerprint identification method according to an embodiment of the present application. In this embodiment, the fingerprint recognition method is applicable to the fingerprint recognition system 100, and the sampling signal conversion and fingerprint feature comparison can be repeatedly performed according to different setting parameters to increase the probability of successful fingerprint comparison and reduce the false rejection rate.

First, the fingerprint recognition system 100 samples the user's finger fingerprint through the fingerprint sensing device 10 to generate a sampling signal (step S210), that is, the fingerprint sensor 11 detects the fingerprint to generate an original fingerprint image signal.

Then, the fingerprint recognition system 100 selects a set of setting parameters from the plurality of setting parameters (step S220), wherein each set of setting parameters includes a gain parameter and an offset parameter.

In one embodiment, the fingerprint recognition system 100 can collect fingerprint signals pressed by the user with different forces in advance, and individually determine a set of setting parameters according to the fingerprint signals generated by the different forces. Preferably, each set of setting parameters can be used to Process individual corresponding fingerprint signals to obtain high-quality fingerprint images signal. These setting parameters are the complex array setting parameters described in step S220.

For example, the first fingerprint signal is generated by a gravitational pressure, the second fingerprint signal is generated by a moderate pressure, and the third fingerprint signal is generated by a light pressure. Therefore, the first fingerprint signal needs to be used accordingly. The setting parameter of can be set to a small value, so that the first fingerprint signal can obtain a clearer fingerprint image after signal conversion. Similarly, in order to make the second and third fingerprint signals get clearer after signal conversion, For the fingerprint image, the setting parameter corresponding to the second fingerprint signal can be set to a medium value, and the setting parameter corresponding to the third fingerprint signal can be set to a larger value.

Next, the fingerprint recognition system 100 converts the sampling signal into a fingerprint image signal according to the selected setting parameters (step S230), and then determines whether the fingerprint image signal conforms to the registered fingerprint feature (step S240). The registered fingerprint feature may include at least the following One: bifurcation information, ridge endpoint information, core point information, dot information, eye information, crossover information, and bridges (bridge) information. For the format and detailed description of the above fingerprint characteristics, please refer to the standard specification ISO / IEC 19794.

In one embodiment, the fingerprint recognition system 100 may collect a fingerprint image signal of a user as a registered fingerprint in advance, and analyze the registered fingerprint to obtain fingerprint characteristics.

Continuing from step S240, if the fingerprint image signal matches the registered fingerprint characteristics, it is determined that the fingerprint is a valid fingerprint (step S250), and the process ends.

In one embodiment, when it is determined that the fingerprint is a legal fingerprint, the finger The pattern recognition system 100 can further release its locked state and / or launch a specific application.

Continuing from step S240, if the fingerprint image signal does not meet the registered fingerprint characteristics, it is determined whether there are any unselected ones in the multiple array setting parameters (step S260), and if so, another set of setting parameters is selected from the multiple array setting parameters. (Step S270), and then the process receives step S230 to perform the conversion of the sampling signal and the comparison of the fingerprint image signal again according to the newly selected setting parameters.

Continuing with step S260, if the multiple array setting parameters have been selected, it is determined that the fingerprint is an invalid fingerprint (step S280), and the flow ends.

In one embodiment, when it is determined that the fingerprint is an illegal fingerprint, the fingerprint recognition system 100 may maintain its locked state, and further output a prompt message (such as visual / sound content, or vibration) through the prompt device 50 to inform the user of the fingerprint ratio. Failed.

FIG. 3 is a flowchart of a fingerprint identification method according to an embodiment of the present application. In this embodiment, the fingerprint recognition method is applicable to the fingerprint recognition system 100, and the appropriate setting parameters are selected according to the pressure of the user's finger to perform one-time conversion of the sampling signal and comparison of the fingerprint characteristics, which can reduce the signal conversion. The time and power consumption required for the comparison of fingerprints and fingerprint characteristics. In addition, it can increase the probability of successful fingerprint comparison and reduce the false rejection rate.

First, the fingerprint recognition system 100 samples a user's finger fingerprint through the fingerprint sensing device 10 to generate a sampling signal (step S310), that is, the fingerprint sensor 11 detects the fingerprint to generate an original fingerprint image signal.

In addition, the user's finger is also detected by the touch sensing device 20 Touch to generate a touch signal and determine the contact area of the finger according to the touch signal (step S320). It is further explained that since the contact area of the finger is positively related to the pressing pressure channel, the contact area can be understood as a kind of Parameters of the pressure channel. For example, when the size of the contact area is within the first predetermined range, it can represent the pressure channel 1; when the size of the contact area is within the second predetermined range, it can represent the pressure channel 2, where the first predetermined range is smaller than the second The predetermined range, and the pressing pressure channel 1 is smaller than the pressing pressure channel 2.

Then, the fingerprint recognition system 100 selects a set of setting parameters from the complex array of setting parameters according to the contact area of the finger (ie, pressing pressure) (step S330), wherein each set of setting parameters includes a gain parameter and an offset parameter.

In one embodiment, the fingerprint recognition system 100 can collect fingerprint signals pressed by the user with different forces in advance, and individually determine a set of setting parameters according to the fingerprint signals generated by the different forces. Preferably, each set of setting parameters can be used to Individual fingerprint signals are processed to obtain high-quality fingerprint image signals. These setting parameters are the complex array setting parameters described in step S330.

Next, the fingerprint recognition system 100 converts the sampling signal into a fingerprint image signal according to the selected setting parameters (step S340), and then determines whether the fingerprint image signal conforms to the registered fingerprint feature (step S350). The registered fingerprint feature may include at least the following One: ridge bifurcation information, ridge end information, center point information, single point information, eye diagram information, interlaced line information, and bridge information.

In one embodiment, the fingerprint recognition system 100 may collect a fingerprint image signal of a user as a registered fingerprint in advance, and analyze the registered fingerprint to obtain fingerprint characteristics.

Continuing with step S350, if the fingerprint image signal matches the registered fingerprint characteristics, it means that the fingerprint is a legitimate fingerprint. Therefore, the fingerprint identification system 100 is unlocked and / or a specific application is started (step S360), and then the process ends.

Continuing step S350, if the fingerprint image signal does not meet the registered fingerprint characteristics, it means that the fingerprint is an illegal fingerprint, so the fingerprint recognition system 100 is maintained in a locked state, and / or a prompt message (such as visual / sound) is output through the prompt device 50 Content, or vibration) to inform the user that the fingerprint comparison failed (step S370), and then the process ends.

According to the above embodiment, when it is understood that the fingerprint recognition system proposed in the present application can dynamically select a suitable set of setting parameters from the complex array setting parameters for processing fingerprint sampling signals and comparing fingerprint characteristics, Each set of parameters can correspond to different conditions during fingerprint input (such as the degree of wetness and dryness of the finger, re-press / light-press, etc.). Therefore, it can effectively increase the probability of successful fingerprint comparison and reduce the false rejection rate. Furthermore, since the probability of successful fingerprint comparison is improved, the number of times the user presses the fingerprint sensor can be reduced, thereby reducing the chance of wear of the fingerprint sensor.

Although the present application is disclosed in various embodiments as above, it is only for reference and is not intended to limit the scope of the application. Any person skilled in the art can make some changes without departing from the spirit and scope of the application. With retouch. Therefore, the above embodiments are not used to limit the scope of the present application, and the protection scope of the present application shall be determined by the scope of the attached patent application.

The terms "first" and "second" used in the scope of patent applications are used to modify elements in claims and are not used to indicate that there is a priority between Weight order, antecedent relationship, or one element precedes another element, or the chronological order in which method steps are performed, is only used to distinguish elements with the same name.

Claims (3)

A fingerprint recognition system includes: a touch sensing device for detecting a finger touch and generating a touch signal; a fingerprint sensing device for sampling a fingerprint and generating a sampling signal; A first set of parameters for converting the sampling signal into a first fingerprint image signal, and a second set of parameters for converting the sampling signal into a second fingerprint image signal; and a controller for The touch signal determines a contact area to reflect the pressing pressure channel, and selects the first set of setting parameters from the complex array setting parameters according to the contact area for the fingerprint sensing device to perform the conversion of the first fingerprint image signal, and decides Whether the first fingerprint image signal meets one or more registered fingerprint characteristics. When the first fingerprint image signal meets the registered fingerprint characteristics, it is determined that the fingerprint is a legitimate fingerprint. When the first fingerprint image signal does not meet the registered fingerprint characteristics, When registering fingerprint characteristics, select the second set of setting parameters from the above-mentioned multiple array setting parameters for uploading The fingerprint sensing device performs the conversion of the second fingerprint image signal to determine whether the second fingerprint image signal meets the registered fingerprint characteristics, and determines that the fingerprint is legal when the second fingerprint image signal meets the registered fingerprint characteristics. Fingerprint; where each set of the above-mentioned multiple array setting parameters corresponds to different conditions when the fingerprint is input, including the degree of wetness and dryness of the finger, and the pressure channel; wherein the controller dynamically selects different setting parameter pairs The sampled signals are processed to generate different fingerprint image signals. The fingerprint identification system according to item 1 of the scope of patent application, wherein the controller is further configured to determine that the fingerprint is an invalid fingerprint when the first fingerprint image signal does not meet the registered fingerprint characteristics, and determine the fingerprint When the fingerprint is a legitimate fingerprint, a first prompt message is generated to indicate that the fingerprint comparison is successful, or a predetermined application is started, and when the fingerprint is determined to be illegal, a second prompt message is generated to indicate that the fingerprint comparison has failed, or ordered One of the above-mentioned fingerprint recognition systems generates vibration. According to the fingerprint recognition system described in the first item of the patent application scope, wherein each of the above-mentioned set parameters includes a gain parameter and an offset parameter.