WO2022107905A1

WO2022107905A1 - Fingerprint sensing system for noise reduction

Info

Publication number: WO2022107905A1
Application number: PCT/KR2020/016250
Authority: WO
Inventors: 강성희; 임용식
Original assignee: 주식회사 바이오로그디바이스
Priority date: 2020-11-18
Filing date: 2020-11-18
Publication date: 2022-05-27
Also published as: KR102627219B1; KR20220067723A

Abstract

Disclosed is a fingerprint sensing system for noise reduction. The fingerprint sensing system for noise reduction of the present invention may comprise: a fingerprint sensing unit (100) for acquiring a user's fingerprint image through one or more sensor pixel (110) units that are spaced apart; and an encryption unit (200) for encrypting the fingerprint image through a scrambling technique. In addition, rather than sensing a plurality of adjacent pixels, the present invention minimizes noise by collecting and simultaneously amplifying pixels that are spaced considerably apart from each other so that interference does not occur therebetween.

Description

Fingerprint sensing system for noise reduction

The present invention relates to a fingerprint sensing system for noise reduction, and more particularly, it does not sense a large number of adjacent pixels in order to minimize noise, and collects pixels that are considerably spaced apart so that they do not interfere with each other due to a high amplification rate. It relates to a fingerprint sensing system for simultaneously amplifying noise reduction.

In the case of the prior art, high-speed processing is impossible in the case of serial processing in a single pixel unit from Pixel Amplifier to Analog-to-digital converter (ADC). It is necessary to solve the problem of high power consumption and the occurrence of serious noise due to interference between adjacent pixels when the amplification factor reaches a certain threshold value by collecting and driving adjacent pixels even when a large number of pixels are amplified.

An object of the present invention is to provide a fingerprint sensing system that minimizes noise by collecting and simultaneously amplifying pixels that are considerably spaced apart so as not to sense a plurality of adjacent pixels and to prevent interference with each other due to a high amplification rate.

In order to solve the above problems, in the fingerprint sensing system for noise reduction according to an embodiment of the present invention, the fingerprint sensor unit 100 for acquiring a user's fingerprint image through one or more spaced apart sensor pixels 110 units ); and an encryption unit 200 that encrypts the fingerprint image using a scrambling technique.

At this time, the fingerprint sensor unit 100, one or more sensor pixels 110 in contact with the user's fingerprint; one or more pixel sensing units 120 connected to an output terminal of the sensor pixel 110 to detect and output distance information of the fingerprint in contact with the sensor pixel 100 through the sensor pixel 110; a pixel coordinate unit 130 for controlling an operation range and an output order of the pixel sensing unit 120; a pixel switch 140 for controlling an output order of the pixel sensing unit 120 based on the control information of the pixel coordinate unit 130; a gain amplifier 150 for sequentially amplifying the output of the pixel sensing unit 120 through the pixel switch 140; and a conversion unit 160 for converting the output of the pixel sensing unit 120 amplified through the gain amplifier 150 into a digital signal.

In addition, at this time, the pixel coordinate unit 130 controls all one or more sensor pixels 110 in the same column spaced apart by N (natural number) columns to sequentially operate row by row through the pixel sensing unit 120. .

According to an embodiment of the present invention, there is an effect that noise can be minimized by collecting and simultaneously amplifying pixels that are considerably spaced apart so that interference between a plurality of adjacent pixels does not occur.

1 is a block diagram illustrating a fingerprint sensing system for encrypting fingerprint image data according to an embodiment of the present invention.

2 is a block diagram illustrating the encryption unit 200 of the fingerprint sensing system for encrypting fingerprint image data according to an embodiment of the present invention.

3 is a circuit diagram illustrating a random number generator 210 of a fingerprint sensing system for encrypting fingerprint image data according to an embodiment of the present invention.

4 is a serial circuit diagram illustrating the scrambler 220 of the fingerprint sensing system for encrypting fingerprint image data according to an embodiment of the present invention.

5 is a parallel circuit diagram illustrating the scrambler 220 of the fingerprint sensing system for encrypting fingerprint image data according to an embodiment of the present invention.

6 is a flowchart illustrating a fingerprint sensing system for encrypting fingerprint image data according to an embodiment of the present invention.

7 is a flowchart illustrating the scrambler 220 of the fingerprint sensing system for encrypting fingerprint image data according to an embodiment of the present invention.

8 is a flowchart illustrating the random number generator 210 of the fingerprint sensing system for encrypting fingerprint image data according to an embodiment of the present invention.

9 is an exemplary view for explaining the structure of the sensor pixel 110 of the fingerprint sensor unit 100 of the fingerprint sensing system for noise reduction according to an embodiment of the present invention.

10 is a circuit diagram illustrating the fingerprint sensor unit 100 of the fingerprint sensing system for noise reduction according to an embodiment of the present invention.

11 is a flowchart illustrating a fingerprint sensing system for noise reduction according to an embodiment of the present invention.

12 is a flowchart illustrating the pixel coordinate unit 130 of the fingerprint sensing system for noise reduction according to an embodiment of the present invention.

In a fingerprint sensing system for noise reduction according to an embodiment of the present invention, the fingerprint sensor unit 100 for acquiring a user's fingerprint image through one or more spaced apart sensor pixels (110); and an encryption unit 200 that encrypts the fingerprint image using a scrambling technique.

Hereinafter, detailed contents for carrying out the present invention will be described based on the embodiments with reference to the drawings. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention. It should be understood that various embodiments of the present invention are different but need not be mutually exclusive. For example, certain shapes, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in relation to one embodiment. In addition, it should be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the present invention. Accordingly, the following detailed description is not intended to be taken in a limiting sense, and the scope of the present invention, if properly described, is limited only by the appended claims, along with all scope equivalents to those claimed. Like reference numerals in the drawings refer to the same or similar functions throughout the various aspects.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless specifically defined explicitly.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to enable those of ordinary skill in the art to easily practice the present invention.

As shown in FIG. 1, the fingerprint sensing system for encrypting fingerprint image data of the present invention includes a fingerprint sensor unit 100 for acquiring a user's fingerprint image and an encryption unit for encrypting the fingerprint image using a scrambling technique. (200).

In addition, a preferred embodiment of the fingerprint sensor unit 100 is driven in a capacitive manner, and the encryption unit 200 outputs the encrypted fingerprint image.

At this time, as shown in FIG. 2, the encryption unit 200 includes a random number generator 210 that generates a random number and a scrambler 220 that encrypts the fingerprint image using a scrambling technique using the random number. is made of

In addition, the random number generator 210 generates a second seed value (Key) and a coefficient value that are random numbers, and a preferred embodiment of the design of the random number generator 210 is as shown in FIG. 3 . , LFSR (Liner Feed-back Shift Register) is used to generate a pseudo-random number, and the first initial (Seed) value of FSR (Feed-Back Shift Register) is used to minimize the deviation (OCV) between the fingerprint sensor units 100 . The irregularity between chips is ensured by acquiring the first seed value from an embedded ROM in which a calibration value for the purpose of a calibration is stored and combining the bits between bits.

In addition, the first initial (Seed) value is changed every time the fingerprint sensor unit 100 acquires a fingerprint image, and the number of feedback loops is also changed.

In this case, the scrambler 220 uses the random number generated by the random number generator 210 as a polynomial coefficient and a second seed value (Key) in the scrambling technique.

In addition, a preferred embodiment of the scrambler 220, as shown in FIG. 4, applies a scrambling polynomial composed of 8 bits, and is composed of an 8-bit shift register and XOR, and a fingerprint 8-bit data generated from the sensor unit 100 is applied to a shift register by 1 bit, and the XOR-processed data is used as scrambled data.

In addition, as shown in FIG. 4 , in order to configure the shift registers in series, the output ADC_OUT of the fingerprint sensor unit 100 should output a valid value at least every 8 cycles. Therefore, when the output (ADC_OUT) of the fingerprint sensor unit 100 does not satisfy 8 cycles, as shown in FIG. 5 , a circuit is configured to process a shift register and XOR in parallel, and the It can be applied in a structure in which the output (ADC_OUT) of the fingerprint sensor unit 100 is output at every cycle.

In addition, in the scrambler 220 , the output ADC_OUT of the fingerprint sensor unit 100 is output once every 8 clocks, and when the shift operation is completed, a new output ADC_OUT is supplied. In addition, when the shift operation is completed for 8 cycles, a scrambling and encrypted 1 byte value is stored in the shift register, and the output (ADC_OUT) data of the fingerprint sensor unit 100 is all scrambled. It is repeated until it is scrambled and encrypted.

In addition, based on the logic circuit diagrams of the random number generator 210 and the scrambler 220 shown in FIGS. 3 to 5 , it can be designed to process various bits.

In addition, the second initial (Seed) value (Key) is used as an initial value of the shift register, specifically generated by the random number generator 220 and obtained by the fingerprint sensor unit 100 It is stored in the shift register in the start section of the fingerprint image frame.

In the fingerprint sensing system for encrypting fingerprint image data of the present invention, as shown in FIG. 6 , applying power to the fingerprint sensing system (S601) and putting the fingerprint sensor unit 100 into a standby state and performing an 8-bit counter The step of always executing (Counter) (S620) and the step of delivering a fingerprint sensing command and extracting the value of the counter (Counter) in an unspecified section (S630) and the scrambler 220 is the random number generator ( Step S640 of receiving the coefficients of the polynomial, which is a random number generated from 210) and a second seed value (Key), and confirming that the second seed value (Key) is generated and provided (S650), acquiring the 1-byte fingerprint image after sensing through the fingerprint sensor unit 110 (S660), and 8-bit scrambling of the 1-byte fingerprint image through the scrambler 220 (S670) ) and a serial communication channel (Serial Peripheral Interface, SPI) to transmit the data scrambled in step S670 (S680) and the one-byte fingerprint image obtained through step S660, after the fingerprint image data is It is checked whether it exists, and if it exists, the step S660 of performing the above step (S690) is performed.

In addition, as shown in FIG. 7 , the random number generator 210 of the fingerprint sensing system applies the polynomial coefficients provided in the step S640 ( S710 ) and the steps received in the step S640 . After the step (S720) of storing the second seed value (Key) as an initial value in the shift register of the scrambler 220 and the first XOR operation on the output of the register (register) The step of shifting the register (S730) and the step of sequentially performing a 1-bit secondary XOR operation on the first XOR operation result of step S730 and the 1-byte fingerprint image of step S660 (S740) and the In order to perform all of the operations of step S740 on the 1-byte fingerprint image in step S660, an 8-clock operation is checked, and if it is less than 8 clocks, the step S730 is performed (S750).

In addition, in the step S710, when the coefficient of the polynominal is 0, the input of the XOR to which the corresponding register output is directed is set to 0 (S711) and when the coefficient of the polynominal is 1 A step (S712) of inputting the corresponding register output to the XOR is performed.

In addition, as shown in FIG. 8 , the scrambler 220 of the fingerprint sensing system stores a calibration value for the purpose of minimizing the deviation (OCV) between the fingerprint sensor units 100. The built-in ROM Acquiring the first seed value from (Embedded ROM) (S810) and applying the first seed value of step S810 to a Feed-Back Shift Register (FSR) (S820) and For one clock, it is determined whether the shift operation of the FSR (Feed-Back Shift Register) and the XOR operation are performed (S830) and whether the step S840 is performed as many times as the corresponding feedback loop (Feed-Back Loop), and the corresponding feedback loop (Feed-Back Loop) If the step S840 is performed less than the number of times, the step S840 is performed (S840).

In addition, as shown in FIGS. 1 and 9, the fingerprint sensing system for noise reduction of the present invention includes a fingerprint sensor unit 100 that acquires a user's fingerprint image through one or more spaced apart sensor pixels 110 and the It consists of an encryption unit 200 that encrypts the fingerprint image using a scrambling technique.

In addition, a preferred embodiment of the one or more sensor pixels 110 spaced apart in the fingerprint sensor unit 100 is, as shown in FIG. 9, the sensor pixels 110 spaced apart in N columns. Also, N is a natural number.

At this time, as shown in FIG. 10 , the fingerprint sensor unit 100 is connected to one or more sensor pixels 110 that come into contact with the user's fingerprint and an output terminal of the sensor pixel 110 to connect the sensor pixels 100 . ) at least one pixel sensing unit 120 that detects and outputs the distance information of the fingerprint in contact with the sensor pixel 110, and a pixel coordinate unit that controls the operation range and output order of the pixel sensing unit 120 The pixel sensing unit 120 through the pixel switch 140 and the pixel switch 140 for controlling the output order of the pixel sensing unit 120 based on the control information of 130 and the pixel coordinate unit 130 ) includes a gain amplifier 150 that sequentially amplifies the output and a converter 160 that converts the output of the pixel sensing unit 120 amplified through the gain amplifier 150 into a digital signal.

In addition, in a preferred embodiment of the pixel sensing unit 120 , it is connected 1:1 with the sensor pixel 110 . Accordingly, the user's fingerprint image can be obtained by measuring and synthesizing the distance of the fingerprint in contact with the sensor pixel 110 .

In addition, in a preferred embodiment in which the pixel switch 140 controls the output order of the pixel sensing unit 120, a switch configured at an output terminal of the pixel sensing unit 120 is turned on or off according to the output order. (OFF) to control the output order of the pixel sensing unit 120.

In addition, the pixel coordinate unit 130 transmits distance information of the fingerprint contacting the sensor pixel 110 sequentially in a row unit in the same column spaced apart by N (natural number) columns through the pixel sensing unit 120 . In order to recognize and recognize the distance information of the fingerprint in contact with all the sensor pixels 110 through the pixel sensing unit 120, the sensor pixels 110 are spaced apart in N (natural number) columns and sequentially and parallel to all the columns. The distance information of the fingerprint in contact with is recognized through the pixel sensing unit 120 .

In addition, as shown in FIG. 11 , the fingerprint sensing system for noise reduction of the present invention controls the operation sequence of the sensor pixel 110 and the pixel sensing unit 120 through the pixel coordinate unit 130 . Steps (S1110) and the control of steps S1110, sequentially (#1 to #M) in row units through the pixel sensing unit 120, fingerprints on all one or more sensor pixels 110 in the same column spaced apart column by column. ) and controlling the output order of the pixel sensing unit 120 in the step S1120 according to the control of the step S1120 and S1110 (S1130) and sequentially amplifying the output of the step S1130 ( Step S1140) and step S1140 of digitally converting the amplified output (S1150), checking whether the sensor pixel 110 is the last, and performing the step S1110 if it is not the last step (S1160) are performed.

In addition, the step S1110 includes, as shown in FIG. 12 , a step of initializing a row index value to 0 (S1210) and generating a column index value from 1 to N in the column direction of the sensor pixel (110) Preparing to drive the sensor pixel 110 and the pixel sensing unit 120 in the same column of index values as in the step (S1220) of allocating coordinates from 1 to N (S1230) and the column Increasing the index value by 1 (S1240) and performing the above step S1230 when the column index value is not N, and performing the following step S1260 when the column index value is N (S1250) ) and increasing the row index value to M (S1260) and designating the row index value of the sensor pixel 110 as the row index value of the step S1260 (S1270) is done

Finally, since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the specific embodiments of the present invention, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

Terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

The spatially relative terms below (below, beneath, lower), above (above, upper), etc. facilitate the correlation between one element or components and other elements or components, as shown in the drawings. can be used to describe The spatially relative terms should be understood as terms including different orientations of the device during use or operation in addition to the orientation shown in the drawings. For example, when an element shown in the drawings is turned over, an element described as below (below, beneath) another element may be placed above and above the other element. Accordingly, the example term below may include both downward and upward directions. The device may also be oriented in other orientations, and thus spatially relative terms may be interpreted according to orientation.

As used in the present invention, an expression indicating a part such as "part" or "part" means a device in which the component may include a specific function, software that may include a specific function, or a device that may include the corresponding function. And it means that it can represent a combination of software, but it is not necessarily limited to the expressed function, which is provided to help a more general understanding of the present invention, and a person with ordinary knowledge in the field to which the present invention belongs If it is, various modifications and variations are possible from these base materials.

The invention has been described above for the purpose of method steps presenting the performance of specific functions and their relationships. The boundaries and order of these functional components and method steps have been arbitrarily defined herein for convenience of description. Alternative boundaries and orders may be defined so long as the specific functions and relationships are properly performed. Any such alternative boundaries and orders are therefore within the scope and spirit of the claimed invention. Additionally, boundaries of these functional components have been arbitrarily defined for convenience of description. Alternative boundaries can be defined as long as any important functions are properly performed. Likewise, flowchart blocks may also be arbitrarily defined herein to represent any significant functionality. For extended use, the flowchart block boundaries and order may have been defined and still perform some important function. Alternative definitions of both functional components and flowchart blocks and sequences are therefore within the scope and spirit of the claimed invention.

The invention may also have been described, at least in part, in terms of one or more embodiments. Embodiments of the present invention are used herein to represent the present invention, aspects thereof, features thereof, concepts thereof, and/or examples thereof. A physical embodiment of an apparatus, article of manufacture, machine, and/or process embodying the present invention may employ one or more aspects, features, concepts, examples, etc. described with reference to one or more embodiments described herein. may include Moreover, throughout the drawings, embodiments may incorporate the same or similarly named functions, steps, modules, etc., which may use the same or different reference numbers, as such, the functions, The steps, modules, etc. may be the same or similar functions, steps, modules, etc. or others.

As described above, in the present invention, specific matters such as specific components, etc., and limited embodiments and drawings have been described, but these are provided to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. , various modifications and variations are possible from these descriptions by those of ordinary skill in the art to which the present invention pertains.

The above-described embodiments are examples for explaining the present invention, and the present invention is not limited thereto. Those of ordinary skill in the art to which the present invention pertains will be able to practice the present invention with various modifications therefrom, so the technical protection scope of the present invention should be defined by the appended claims.

Claims

In the fingerprint sensing system,

a fingerprint sensor unit 100 for obtaining a user's fingerprint image through one or more spaced-apart sensor pixels 110; and

an encryption unit 200 for encrypting the fingerprint image using a scrambling technique;

Fingerprint sensing system comprising a
According to claim 1,

The fingerprint sensor unit 100,

one or more sensor pixels (110) in contact with the user's fingerprint;

one or more pixel sensing units 120 connected to an output terminal of the sensor pixel 110 to detect and output distance information of the fingerprint in contact with the sensor pixel 100 through the sensor pixel 110;

a pixel coordinate unit 130 for controlling an operation range and an output order of the pixel sensing unit 120;

a pixel switch 140 for controlling an output order of the pixel sensing unit 120 based on the control information of the pixel coordinate unit 130;

a gain amplifier 150 sequentially amplifying the output of the pixel sensing unit 120 through the pixel switch 140 ; and

a conversion unit 160 for converting the output of the pixel sensing unit 120 amplified through the gain amplifier 150 into a digital signal;

Fingerprint sensing system comprising a
3. The method of claim 2,

The pixel coordinate unit 130,

Fingerprint sensing system, characterized in that the one or more sensor pixels 110 in the same column spaced by N (natural number) columns are controlled to sequentially operate row by row through the pixel sensing unit 120