WO2023143242A1

WO2023143242A1 - Fingerprint detection module, and living body fingerprint detection apparatus and method

Info

Publication number: WO2023143242A1
Application number: PCT/CN2023/072590
Authority: WO
Inventors: 张鸿; 程松; 郭明江; 李情情; 黄志雷; 黄乾友; 李丽
Original assignee: 北京与光科技有限公司
Priority date: 2022-01-27
Filing date: 2023-01-17
Publication date: 2023-08-03

Abstract

Provided in the present invention are a fingerprint detection module, and a living body fingerprint detection apparatus and method. The living body fingerprint detection apparatus comprises a light source and an identification module, wherein light generated by the light source is transmitted to a fingerprint to be detected, the identification module comprises at least one sensor and an optical assembly, the optical assembly is located on an optical path of the at least one sensor, reflected light of said fingerprint reaches the at least one sensor through the optical assembly, and the at least one sensor performs living body fingerprint determination on the basis of spectral information of received reflected light.

Description

Fingerprint detection module, live fingerprint detection device and detection method

technical field

The invention relates to the field of fingerprint detection, in particular to a fingerprint detection module, a living fingerprint detection device and a detection method.

Background technique

Various types of biometric systems are increasingly used to provide greater security and/or enhanced user convenience. For example, fingerprint sensing systems have been widely used in various terminal devices, such as consumer smartphones, due to their small size, high performance, and high user acceptance. At present, there are many kinds of fingerprint sensing systems in the market, such as sensing systems based on capacitive fingerprint modules, sensing systems based on optical fingerprint modules, etc. Although the above-mentioned types of fingerprint sensing systems can realize unlocking, they are still being used After the fingerprint identification of the mobile terminal is unlocked, criminals can steal the user's fingerprint to make a fake fingerprint to crack the user's security system, which instead increases the probability of the mobile terminal's fingerprint password being discovered, and has caused a great impact on the information security of the mobile terminal. threat.

However, the existing living fingerprint identification schemes have certain defects. For example, the capacitive module has the disadvantages of poor environmental stability, low lifespan, and insufficient living detection ability, while the optical type usually does not have the living detection ability. Therefore, there is an urgent need for a simple , Reliable fingerprint identification scheme to realize living fingerprint identification.

Existing fingerprint recognition devices mainly include optical fingerprint recognition devices and capacitive fingerprint recognition devices. Among them, optical fingerprint recognition devices are generally large in size, which is not conducive to device integration, while capacitive fingerprint recognition devices are expensive and easily restricted by chip production capacity. In addition, these two fingerprint devices generally do not have the function of liveness detection, and the security of the devices is low. Existing live fingerprint identification schemes have certain defects. For example, the capacitive module has the disadvantages of poor environmental stability, low lifespan, and insufficient live detection ability, while the optical type usually does not have the live detection ability. Therefore, a simple, Reliable fingerprint identification scheme realizes living fingerprint identification.

With the development of spectral technology, fingerprint identification devices based on multi-spectral technology gradually appear, but the existing multi-spectral fingerprint liveness detection devices are bulky and have complex algorithms. Prism and reflector structures are basically used in the optical path to turn the optical path to improve image contrast, and there are many types and quantities of supporting lighting sources, and the system often requires multiple frames of images to complete recognition and liveness detection. In addition, due to the low spectral accuracy, the living body processing algorithm is relatively complicated, which takes a long time and the system load is heavy. Although the existing spectral detection equipment is small in size, its internal structure is complex, and it does not have high-precision living body recognition performance.

The fingerprint identification device in the prior art needs to irradiate the fingerprint to be tested with light emitted by a light source, wherein the reflected light of the fingerprint will carry detection information. The light source of the fingerprint identification device in the prior art is usually arranged under the fingerprint collection lens, wherein the light emitted by the light source will pass through the fingerprint collection lens and then irradiate the surface of the fingerprint to be tested. In this process, due to the smooth surface of the fingerprint collection lens, it is inevitable that part of the light will be reflected, and this reflected light will be used as a noise signal in the fingerprint identification process, thereby affecting the accuracy of the identification result.

Contents of the invention

A main advantage of the present invention is to provide a living fingerprint detection device and a detection method, wherein the living fingerprint detection device is suitable for living body detection, which improves the applicability of the fingerprint detection device.

Another advantage of the present invention is to provide a living fingerprint detection device and detection method, wherein the living fingerprint detection device performs living body judgment according to the spectral information reflected by the skin, thereby realizing the living body detection of fingerprints and improving the detection accuracy.

Another advantage of the present invention is to provide a living fingerprint detection device and detection method, wherein the living fingerprint detection device determines the recognition result of the object to be recognized based on the comparison result of the reference spectral response data and the identification spectral response data, which is beneficial to improve The accuracy of fingerprint detection and identification.

Another advantage of the present invention is to provide a living fingerprint detection device and a detection method, wherein the living fingerprint detection device includes a light source and an identification module, wherein the light source is arranged at the identification module or adjacent to the identification module. The module is set, and the light source is used for illuminating the fingerprint to be tested.

Another advantage of the present invention is to provide a living fingerprint detection device and detection method, wherein the light source is arranged on the circuit board or frame of the identification module, which is beneficial to the miniaturization of the living fingerprint detection device.

Another advantage of the present invention is to provide a living fingerprint detection device and detection method, wherein the living fingerprint detection device obtains raw data, that is, light intensity information, respectively performs image information correction and spectrum information correction on the raw data, and then respectively Using the fingerprint recognition algorithm and the living body algorithm, the fingerprint image and spectral information are compared with the corresponding information extracted during entry to obtain the matching degree. When the matching degree of both is higher than the threshold, the input verification passes, otherwise the output verification fails.

Another advantage of the present invention is to provide a living fingerprint detection device and detection method, wherein the living fingerprint detection method includes image information correction and spectral information correction including the image processing method of surrounding mean value compensation (binning), through weighted average to improve data detection accuracy.

Another advantage of the present invention is to provide a living fingerprint detection device and detection method, wherein the living fingerprint detection method further includes the flow of the living body algorithm, and the raw data (light intensity information) is extracted after processing. Effectively correct spectral parameters (or spectral information), form a data set with the corresponding parameters of the input data, and calculate the correlation coefficient R after the straight line fitting, when the correlation coefficient R is greater than the corresponding threshold, it is judged as a living body, otherwise it is judged as a non-living body .

A main advantage of the present invention is to provide a fingerprint detection module and a living body fingerprint recognition system, wherein the living body fingerprint recognition system is suitable for living body detection and improves the applicability of the fingerprint detection device.

Another advantage of the present invention is to provide a fingerprint detection module and a living fingerprint identification system, wherein the fingerprint identification module collects the fingerprint information of the fingerprint to be tested by means of side lighting, which is beneficial to reduce the noise signal caused by light reflection , which is conducive to improving the accuracy of fingerprint recognition.

Another advantage of the present invention is to provide a fingerprint detection module and a living fingerprint identification system, wherein the fingerprint identification module determines the identification result of the object to be identified based on the comparison result of the reference spectral response data and the identification spectral response data, and has It is beneficial to improve the accuracy of fingerprint detection and identification.

Another advantage of the present invention is to provide a fingerprint detection module and a living fingerprint identification system, wherein the light source is arranged outside the transparent cover, and the light emitted by the light source enters the The transparent cover is beneficial to simplify the structure of the fingerprint identification module.

Another advantage of the present invention is to provide a fingerprint detection module and a living fingerprint recognition system, wherein the living fingerprint recognition system based on the fingerprint recognition module obtains raw data, that is, light intensity information, and performs image information on the raw data respectively. Correction and spectral information correction, and then use the fingerprint recognition algorithm and the living body algorithm respectively to compare the fingerprint image and spectral information with the corresponding information extracted during entry to obtain the matching degree. When the matching degree of both is higher than the threshold, input verification Pass, otherwise the output validation fails.

Another advantage of the present invention is to provide a fingerprint detection module and a living fingerprint identification system, wherein the fingerprint identification module further includes a light-shielding layer, wherein the light-shielding layer is arranged on the lower surface of the transparent cover, which is beneficial to The direct emission of the light emitted by the light source through the lower surface of the transparent cover plate is reduced, so as to improve the light intensity of the detection light.

Another advantage of the present invention is to provide a fingerprint detection module and a living fingerprint identification system, wherein the fingerprint identification module further includes a light-gathering layer, wherein the light-gathering layer is arranged on the upper surface of the transparent cover, In order to increase the energy of the incident light reaching the area to be measured on the transparent cover, and at the same time use the total reflection caused by the refractive index of the light-gathering layer being greater than that of the transparent cover to filter out some incident light with larger angles .

According to one aspect of the present invention, a living fingerprint detection device of the present invention capable of achieving the foregoing and other purposes and advantages includes:

a light source, wherein the light generated by the light source is emitted to the fingerprint to be tested; and

An identification module, wherein the identification module includes at least one sensor and an optical component, the optical component Located on the optical path of the at least one sensor, the reflected light of the fingerprint to be tested reaches the at least one sensor through the optical component, wherein the at least one sensor performs living fingerprint judgment based on the spectral information of the received reflected light.

According to an embodiment of the present invention, the identification module further includes a bracket and a circuit board, wherein the sensor is electrically connected to the circuit board, the bracket is arranged on the circuit board, and the optical assembly It is arranged on the bracket, the bracket supports the optical assembly, and keeps the optical assembly in the photosensitive path of the sensor.

According to an embodiment of the present invention, the light source is arranged on the circuit board, and is connected to the sensor through the circuit board.

According to an embodiment of the present invention, the identification module further includes a transparent cover and a support, wherein the transparent cover is supported by the support on the photosensitive path of the sensor.

According to an embodiment of the present invention, the circuit board further includes a first circuit board and a second circuit board, wherein the sensor is arranged on the first circuit board, and the light source is arranged on the second circuit board. circuit board.

According to an embodiment of the present invention, the circuit board further includes at least one connecting wire, wherein the connecting wire electrically connects the first circuit board and the second circuit board.

According to an embodiment of the present invention, the circuit board further includes a flexible board, wherein the flexible board is arranged on the first circuit board and the second circuit board, and is electrically connected to the The first circuit board and the second circuit board.

According to one embodiment of the present invention, the sensor is a spectral sensor.

According to an embodiment of the present invention, the recognition module includes a spectral sensor, an imaging sensor, and a spectroscopic element, wherein the spectroscopic element is located on the optical path between the spectroscopic sensor and the imaging sensor, and the detected light is captured by the The spectroscopic element is divided into a first detection light and a second detection light, wherein the first detection light reaches the spectrum sensor after being deflected by the spectroscopic element, and the second detection light reaches the spectral sensor after being transmitted by the spectroscopic element In the imaging sensor, the spectrum sensor obtains spectral information of the object under test through the first detection light, and the imaging sensor obtains image information of the object under test through detection of the second detection light.

According to an embodiment of the present invention, the identification module further includes a dodging element, wherein the dodging element is arranged between the light splitting element and the spectral sensor, and the light is homogenized by the dodging element. Then, the spectral information is obtained by the spectral sensor for living body discrimination.

According to an embodiment of the present invention, the recognition module further includes a lens group, the lens group is located between the imaging sensor and the light splitting element, and adjusts the light to be received by the imaging chip.

According to an embodiment of the present invention, the imaging sensor and the lens group are arranged along a horizontal direction, wherein the spectral sensor and the dodging sheet are arranged along a height direction.

According to one aspect of the present invention, the present invention provides a fingerprint detection module, comprising:

Spectrum chip;

A circuit board, wherein the spectrum chip is arranged on the circuit board and electrically connected to the circuit board;

bracket;

A transparent cover, wherein the transparent cover is supported by the support on the photosensitive path of the spectrum chip, the transparent cover includes a collection part and a non-collection part integrally extending outward from the collection part; and

A light source assembly, wherein the light source assembly is located at the side of the transparent cover, and the light emitted by the light source assembly is incident on the collection portion from the non-collection portion of the transparent cover.

According to an embodiment of the present invention, the transparent cover further has an upper surface and a lower surface, wherein the upper surface is opposite to the lower surface, and the light source assembly is mounted on the non-contact surface of the transparent cover. The outer side of the collection part emits light toward the direction of the transparent cover, and forms at least one incident light path between the upper surface and the lower surface of the transparent cover.

According to an embodiment of the present invention, the light source assembly includes at least one light source and at least one light uniform member, and the light uniform member is located between the light source and the transparent cover plate.

According to an embodiment of the present invention, the light dodging member is integrally formed on the outside of the non-collecting portion of the transparent cover plate.

According to an embodiment of the present invention, the light source and the homogenizing element surround the transparent cover plate, and the light emitted by the light source can be understood as entering the homogenizing element vertically, and then passing through the homogenizing element along the incident on the transparent cover in the horizontal direction.

According to an embodiment of the present invention, it further includes an optical assembly, the optical assembly is arranged in the photosensitive path of the spectrum chip, wherein the optical assembly is supported by the bracket between the transparent cover plate and the spectrum chip between.

According to an embodiment of the present invention, the bracket includes a bracket body and an extension unit integrally extending inward from the bracket body, wherein the light source assembly and the transparent cover are supported on the upper end of the bracket body, so The optical assembly is fixedly supported by the extension unit.

According to an embodiment of the present invention, the bracket includes a first bracket and a second bracket, wherein the first bracket is located outside the second bracket, and the transparent cover plate and the light source assembly are supported on the The upper end of the first bracket, the optical assembly is fixed and supported by the second bracket.

According to an embodiment of the present invention, the transparent cover further includes a light-shielding layer, wherein the light-shielding layer is disposed on the lower surface of the transparent cover.

According to an embodiment of the present invention, the light-shielding layer is selected from a material combination consisting of a reflective film and an absorbing film.

According to an embodiment of the present invention, it further includes a light-gathering layer, wherein the light-gathering layer is arranged on the upper surface of the transparent cover, and the refractive index of the light-gathering layer is greater than that of the transparent cover. refractive index.

According to an embodiment of the present invention, the spectrum chip has a modulation area and a non-modulation area, the modulation area is concentratively arranged at the four corners or the peripheral area of the spectrum chip, and the non-modulation area is located at the Central region.

According to an embodiment of the present invention, the optical component of the fingerprint detection module is a microstructure array, and the spectrum chip includes a filter structure and an image sensor, wherein the microstructure array and the filter structure are located at the On the photosensitive path of the image sensor, the microstructure array, the filter structure and the image sensor are sequentially stacked and integrated.

According to an embodiment of the present invention, the energy of the incident light emitted by the light source component in the 400-600nm band is greater than or equal to 80%.

According to another aspect of the present invention, the present invention further provides a living fingerprint identification system, comprising:

control unit;

A fingerprint detection module as described above; and

A processing unit, wherein the processing unit and the fingerprint detection module are electrically connected to the control unit, the fingerprint detection module obtains the identification spectral response data of the object to be identified, and based on the set reference spectral response data A recognition result of the object to be recognized is determined by a comparison result with the recognition spectral response data.

According to another aspect of the present invention, the present invention further provides a living fingerprint detection method, comprising:

(a) Obtain light intensity information for fingerprint collection;

(b) obtaining fingerprint images and spectral information based on the obtained light intensity information; and

(c) comparing the fingerprint image and the spectral information with the entered reference information, and when the matching degree is higher than a threshold, the input verification is passed; otherwise, the output verification fails.

According to an embodiment of the present invention, the detection method further includes: correcting the light intensity information, wherein the correction of the light intensity information includes an image processing method of surrounding average value compensation.

According to an embodiment of the present invention, in the correction of image information, the intensity value of the spectral pixel will be replaced by The intensity value of the weighted average of the intensity of the common physical pixels nearby is used to generate the corrected image parameters to obtain the fingerprint image.

According to an embodiment of the present invention, the detection method further includes: the step of correcting the spectral information corresponding to the spectral pixel, dividing or subtracting the intensity value of the current spectral pixel by the weighted average intensity value of adjacent ordinary pixels to obtain the relative intensity , as the corrected spectral information for subsequent processing.

According to an embodiment of the present invention, the detection method further includes: the step of judging the living body, calculating the correlation coefficient R formed by the effective corrected spectral information extracted after the original data is processed and the entered reference spectral information, when the correlation coefficient R is greater than the corresponding When the threshold is reached, it is judged as a living body; otherwise, it is judged as a non-living body.

According to one embodiment of the present invention, the detection method further includes the following steps:

In the case of n valid entries, calculate the correlation coefficient R between the spectral characteristic parameters of each time and the other n-1 times, take the lowest correlation coefficient R_min, and perform specific formula calculations with the system setting parameter k to obtain the Enter the comparative decision threshold R_t, when there are n-1 or more than the corresponding decision threshold, it is considered that the test is a live body, otherwise it is judged as a non-living body, wherein the specific formula is: R_t=max(R_min, k).

According to an embodiment of the present invention, the detection method further includes the step of judging the consistency of spectral features:

During each entry, the entered spectral information is processed according to the comparison process, and the correlation coefficient between the entered data and the already entered spectral information is calculated. If the coefficient is less than the system setting value m, the entry fails.

According to an embodiment of the present invention, the detection method further includes the step of entering data update:

After each successful detection, calculate the correlation coefficient between the spectral information of this judgment and the n input data, and obtain the corresponding average value R_atest, and compare it with the average value R_a1~n of the correlation coefficient between the n input data, If R_atest is greater than one or more of R_a1~n, use the data of this test to replace the smallest data among R_a1~n in the input data.

Further objects and advantages of the invention will fully appear from an understanding of the ensuing description and accompanying drawings.

These and other objects, features and advantages of the present invention will be fully realized by the following detailed description and accompanying drawings.

Description of drawings

FIG. 1 is a schematic diagram of a living fingerprint detection device according to a first preferred embodiment of the present invention.

Fig. 2 is a schematic frame diagram of the living fingerprint detection device according to the first preferred embodiment of the present invention.

Fig. 3 is a partial structural diagram of the living fingerprint detection device according to the above-mentioned first preferred embodiment of the present invention.

Fig. 4 is a schematic diagram of the overall structure of the living fingerprint detection device according to the first preferred embodiment of the present invention.

5A to 5C are the whole of the living fingerprint detection device according to the above-mentioned first preferred embodiment of the present invention Schematic representation of an alternative embodiment of the structure.

FIG. 6A to FIG. 6D are schematic diagrams of alternative implementations of the overall structure of the living fingerprint detection device according to the above-mentioned first preferred embodiment of the present invention.

Fig. 7 is a schematic structural frame diagram of a sensor of the living fingerprint detection device according to the above-mentioned first preferred embodiment of the present invention.

FIG. 8A and FIG. 8B are microstructure schematic diagrams of a sensor of the living fingerprint detection device according to the above-mentioned first preferred embodiment of the present invention.

Fig. 9 is a schematic diagram of the frame structure of the spectral sensor of the living fingerprint detection device according to the first preferred embodiment of the present invention.

Fig. 10 is a cross-sectional view of the spectral sensor of the living fingerprint detection device according to the first preferred embodiment of the present invention.

Fig. 11 is a schematic diagram of physical pixels of the spectrum sensor of the living fingerprint detection device according to the first preferred embodiment of the present invention.

Fig. 12 is a schematic frame diagram of a living fingerprint detection device according to a second preferred embodiment of the present invention.

Fig. 13 is a method block diagram of a living fingerprint detection method according to another preferred embodiment of the present invention.

FIG. 14 is a schematic diagram of a correlation coefficient after straight line fitting in a live fingerprint detection method according to another preferred embodiment of the present invention.

Fig. 15 is a schematic diagram of a method framework of a living fingerprint detection method according to another preferred embodiment of the present invention.

Fig. 16 is a schematic frame diagram of the living fingerprint identification system according to the present invention.

Fig. 17 is a schematic diagram of the white light LED emission spectrum of the living fingerprint identification system according to the present invention.

Fig. 18 is a schematic diagram of the system framework of the living fingerprint identification system according to the present invention.

Fig. 19 is a schematic diagram of the framework of the fingerprint detection module according to the present invention.

Fig. 20 is a schematic structural diagram of the spectrum chip of the sensor of the fingerprint detection module according to the present invention.

Fig. 21 is a schematic diagram of the physical pixels of the spectrum chip of the sensor of the fingerprint detection module according to the present invention.

Fig. 22 is a schematic diagram of the microstructure of the spectrum chip of the sensor of the fingerprint detection module according to the present invention.

Fig. 23 is a schematic diagram of the microstructure of the spectrum chip of the sensor of the fingerprint detection module according to the present invention, which shows the modulation area structure of the spectrum chip.

Fig. 24 is a schematic diagram of the microstructure of the physical pixels of the spectrum chip of the sensor of the fingerprint detection module according to the present invention.

FIG. 25 is a schematic structural diagram of a fingerprint detection module according to a third preferred embodiment of the present invention.

Fig. 26 is a schematic diagram of another optional implementation of the fingerprint detection module according to the third preferred embodiment of the present invention.

27A and 27B are schematic diagrams of the optical path of the fingerprint detection module according to another preferred embodiment of the present invention.

Fig. 28 is a schematic diagram of another optional implementation of the fingerprint identification module according to another preferred embodiment of the present invention.

FIG. 29A and FIG. 29B are schematic diagrams of the simulation results of the total number of collisions of the fingerprint recognition module according to the above-mentioned preferred embodiment of the present invention when the light-gathering layer is provided.

Detailed ways

The following description serves to disclose the present invention to enable those skilled in the art to carry out the present invention. The preferred embodiments described below are only examples, and those skilled in the art can devise other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents and other technical solutions without departing from the spirit and scope of the present invention.

Those skilled in the art should understand that in the disclosure of the present invention, the terms "vertical", "transverse", "upper", "lower", "front", "rear", "left", "right", " The orientation or positional relationship indicated by "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present invention and simplified description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, so the above terms should not be construed as limiting the present invention.

It can be understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element The quantity can be multiple, and the term "a" cannot be understood as a limitation on the quantity.

Overview of the detection principle of the living fingerprint detection device in the present invention

As shown in Figure 1, due to the physiological characteristics such as capillaries (blood) and sweat pores in human skin, it is difficult to be forged compared with fingerprint lines, and the existence of physiological characteristics will lead to the spectral absorption/reflection of the skin in different bands It is different, which also shows that the living body judgment can be made according to the spectral information reflected by the skin, so as to realize the living body detection of fingerprints. Specifically, through the reflection spectrum test of real fingers and fingerprint materials, it can be known that at the wavelength of 300nm-1100nm, there is a huge difference between the reflection spectrum of real fingers and the reflection spectrum of fingerprint materials, as shown in Figure 1. Tests on silica gel, paper and human skin For example, the reflection spectrum data corresponding to real fingers and fingerprint materials are quite different. Therefore, it is possible to judge the living body through the received reflection spectrum.

Referring to Figures 1 to 15 of the accompanying drawings of the present invention, a living fingerprint detection device and detection method according to the present invention are explained in the following description. The living fingerprint detection device includes a light source 10 and a recognition module 20, wherein the light source 10 emits illuminating light to the finger to be tested, and the recognition module 20 detects the fingerprint to be tested by detecting the light reflected from the finger. The recognition module 20 includes an optical component 21 and at least one sensor 22 , wherein the optical component 21 is located on the optical path of the sensor 22 . It is worth mentioning that, in this preferred embodiment of the present invention, the sensor 22 is an image sensor or a spectral sensor. Preferably, the optical component 21 is a lens group, and the optical component 21 further includes at least one lens. More preferably, the optical component 21 is used to transmit the imaging information of the finger print to the sensor 22, wherein the FOV of the optical component 21 is between 80 degrees and 130 degrees, and the back focus is between 0.3 mm and 5 mm , The total optical length is between 1mm and 10mm.

The light source 10 is used to illuminate the finger to be tested, and it needs to be selected to have a certain spectral width (>30nm). Wherein, the light source can emit monochromatic light or mixed light according to requirements.

It is worth mentioning that, in this preferred embodiment of the present invention, the light source 10 is arranged at the identification module 20 or the light source 10 is arranged adjacent to the identification module 20, and the light emitted by the light source 10 The light reaches the finger to be tested, and the detection light reflected by the finger to be tested passes through the optical component 21 of the identification module 20 to the sensor 22, and then the sensor 22 performs liveness judgment, thereby realizing fingerprint identification. liveness detection.

As shown in FIG. 3 , in the preferred embodiment of the present invention, the identification module 20 further includes a bracket 23 and a circuit board 24 , wherein the sensor 22 is electrically connected to the circuit board 24 . Preferably, the bracket 23 is arranged on the circuit board 24, the optical assembly 21 is arranged on the bracket 23, the optical assembly 21 is supported by the bracket 23, and the optical assembly 21 is kept on the The photosensitive path of the sensor 22 . It is worth mentioning that the circuit board 24 may be, but not limited to, a flexible board (FPC), a rigid board (PCB), a rigid-flex board (F-PCB), a ceramic substrate, and the like. The circuit board 24 can be used for driving, controlling, data processing and output of light sources and sensors.

In at least one embodiment of the present invention, since the living fingerprint detection device needs to be miniaturized, the light source 10 can be integrated into the circuit board 24 , as shown in FIG. 4 , or integrated into the bracket 23 . That is to say, the light source 10 is fixed on the circuit board 24 , or the light source 10 is fixed on the bracket 23 . Preferably, the light emitting path of the light source 10 is not parallel to the photosensitive path of the sensor 22 .

Figure 5A and Figure 5B show a specific implementation of the identification module 20 of the present invention, in this preferred embodiment of the present invention, the identification module 20 further includes a transparent cover plate 25 and a support 26 , wherein the transparent cover 25 is supported by the support 26 on the photosensitive path of the sensor 22 . The transparent cover 25 is used to place the object to be tested, such as a finger, and the reflected light information of the object to be tested is acquired through the transparent cover 25 . As an example, the light emitted by the light source 10 passes through the transparent cover 25 to irradiate the finger print, and the reflected light is reflected by the transparent cover 25 and enters the sensor 22 .

It is worth mentioning that, in this preferred embodiment of the present invention, the identification module 20 is a double bracket structure, wherein the support 26 supports the transparent cover 25, and the support 26 and the The transparent cover plate 25 covers the bracket 23 and the optical assembly 21 fixed by the bracket 23 inside. The support 26 is an outer support structure, and the support 23 is an inner support structure fixed inside the support 26 .

Preferably, the support 26 is arranged on the circuit board 24, wherein the upper end of the support 26 fixes the transparent cover 25, and the other end of the support 26 is fixed on the circuit board 24, And the support member 26 , the circuit board 24 and the transparent cover 25 form a closed space to prevent dust from entering. Preferably, in this preferred embodiment of the present invention, the transparent cover 25 is supported by the support 26 , and the distance between the transparent cover 25 and the circuit board 24 is less than 7 mm. In individual embodiments of the present invention, the supporting member 26 and the bracket 23 are integrated, that is, the two are integrated into an integral structural member for fixing and supporting the optical assembly 21 and the transparent cover 25 .

The light source 10 is disposed on the circuit board 24 and electrically connected to the circuit board 24 . Preferably, in this preferred embodiment of the present invention, the light source 10 is located inside the support member 26, wherein the light source 10 is adjacently arranged on the outside of the bracket 23, and the light of the light source 10 The path is not parallel to the photosensitive path of the sensor. Optionally, in other optional embodiments of the present invention, the light source 10 is disposed on the bracket 23 , and the light source 10 is electrically connected to the circuit board 24 .

As shown in FIG. 5B, according to another aspect of the present invention, the present invention further provides another optional implementation of an identification module, wherein the circuit board 24 further includes a first circuit board 241 and a second circuit board 242 , wherein the sensor 241 is disposed on the first circuit board 241 , and the light source 10 is disposed on the second circuit board 242 . The bracket 23 is fixed on the first circuit board 241 , and the optical assembly 21 is fixed on the bracket 23 and located in the photosensitive path of the sensor 22 .

The circuit board 24 further includes a flexible board 244, wherein the flexible board 244 is arranged on the first circuit board 241 and the second circuit board 242, and is electrically connected to the first circuit board 242 through the flexible board 244. A circuit board 241 and the second circuit board 242 are used to realize the conduction of the circuit board 24 .

As shown in FIG. 5C , in an optional implementation manner of the present invention, the identification module 20 further includes at least one homogenizing element 28 , wherein the homogenizing element 28 is arranged on the photosensitive path of the light source 10 , used to homogenize the light emitted by the light source. The light homogenizing element 28 is disposed at the emitting end of the light source 10 , wherein the light emitted by the light source 10 irradiates to the transparent cover plate 25 through the light homogenizing element 28 .

As shown in FIG. 6A to FIG. 6C of the accompanying drawings of the present invention, an identification module 20 according to another preferred embodiment of the present invention is illustrated. The difference from the above-mentioned preferred embodiment is that in this preferred embodiment of the present invention, the transparent cover 25 of the identification module is arranged on the bracket 23 . The bracket 23 includes a bracket body 231 , a lens support portion 232 and a cover support portion 233 , wherein the lens support portion 232 is located at an upper end of the cover support portion 233 . That is to say, the transparent cover 25 is supported above the optical assembly 21 by the bracket 23 . The lens support part 232 extends inward from the lens main body 231 and forms a support structure with a light hole inside the bracket 23 , wherein the cover support part 233 is integrally upward from the bracket main body 231 extending to fix and support the transparent cover 25 . In short, in this preferred embodiment of the present invention, the support 23 is a support structure with upper and lower double layers, wherein the transparent cover 25 is supported by the cover support portion 233 of the support 23 Above the optical assembly 21 , the optical assembly 21 is supported by the lens support portion 232 of the bracket 23 below the transparent cover 25 .

The lens support portion 232 of the bracket 23 divides the inner space of the bracket 23 into an upper accommodating space 234 and a lower accommodating space 235, wherein the optical assembly 21 is held on the bracket 23. The upper accommodating space 234 , the sensor 22 is held in the lower accommodating space 235 of the bracket 23 . The light source 10 and the sensor 22 are disposed on the circuit board 24 and electrically connected to the circuit board 24 . The circuit board 24 further includes a first circuit board 241 and a second circuit board 242, wherein the sensor 241 is arranged on the first circuit board 241, and the light source 10 is arranged on the second circuit board 242. The bracket 23 is fixed on the first circuit board 241 , and the optical assembly 21 is fixed on the bracket 23 and located in the photosensitive path of the sensor 22 .

As shown in FIG. 6A , different from the above-mentioned preferred embodiment, the light source 10 is disposed on the lens support portion 232 of the bracket 23 , wherein the light source 10 is located above the sensor 22 . Preferably, the light source 10 is disposed on the bracket lens portion 232 of the bracket 23 , and the light emitting path of the light source is not parallel to the photosensitive path of the sensor.

Preferably, in this preferred embodiment of the present invention, the first circuit board 241 and the second circuit board 242 are electrically connected; the transparent cover 25 is arranged on the upper end of the bracket 23 and held on the on the photosensitive path of the sensor 22. The sensor 22, the bracket 23 and the optical assembly 22 supported by the bracket 23 form a substantially sealed space; the transparent cover 25, the bracket 23 and the optical assembly 21 form a substantially sealed space .

As shown in Figure 6B, the identification module 20 of the living fingerprint detection device of the present invention is further provided with at least one heat dissipation hole 201, wherein the at least one heat dissipation hole 201 communicates the internal space of the identification module with the external environment , The internal temperature of the identification module 20 is reduced through the cooling holes. As an example, the support 23 is provided with an opening, or when the transparent cover 25 is fixed, the transparent cover 25 and the support 26 form the heat dissipation hole 201 on the At the connection position between the transparent cover plate 25 and the support member 26 , the upper space is not completely closed and there is a gap for ventilation and heat dissipation.

As shown in FIG. 6C , according to another aspect of the present invention, the first circuit board 241 and the second circuit board 242 of the present invention are connected. The first circuit board 241 and the second circuit board 242 are connected through pins. Specifically, the circuit board 24 further includes at least one connecting wire 243 , wherein the connecting wire 243 electrically connects the first circuit board 241 and the second circuit board 242 . It can be understood that the connecting wires can be but not limited to metal pins, wherein one end of the connecting wire 243 is connected to the second circuit board 242, and the other end of the connecting wire 243 is connected to the first circuit board 241, so as to realize the conduction between the first circuit board and the second circuit board.

Since the bracket 23 , the optical assembly 21 and the first circuit board 241 form a closed space, it is difficult to fix the connecting wire 243 to the first circuit board 241 in a conductive manner from a technical point of view. . Preferably, the bracket 23 is provided with a corresponding communication hole 230, wherein the communication hole 230 of the bracket 23 is facing the connection position of the first circuit board 241, so that the second circuit board 242 is set In the case of the bracket 23, the connecting wire 243 can be connected to the first circuit board 241 through the communication hole 230 of the bracket 23, and then the connecting wire 243 can be fixed to the first circuit board 241 by welding, gluing and other processes. A circuit board 241 . Further, since the bracket 23 is fixed on the first circuit board 241 , the connecting wire 243 is connected to the first circuit board 241 . Therefore, preferably, the first circuit board 241 has a connecting through hole, and the connecting wire 243 at least partially passes through the connecting through hole, so that the connecting wire 243 can be connected from the back side of the first circuit board 241 It is fixed and connected with the first circuit board 241 .

As shown in FIG. 6D , in an optional implementation manner of the present invention, the identification module 20 further includes at least one uniform member 28, wherein the uniform member 28 is located in the photosensitive path of the light source 10 for to homogenize the light emitted by the light source. The light homogenizing element 28 is disposed at the emitting end of the light source 10 , wherein the light emitted by the light source 10 irradiates to the transparent cover plate 25 through the light homogenizing element 28 .

Preferably, for the scheme of disposing the light source on the first circuit board, the living fingerprint detection device further includes a heat sink, and the heat sink is disposed under the light source so as to rapidly dissipate the heat generated by the light source.

As shown in Figures 6 to 11, the sensor 22 is a spectral sensor, the spectral sensor includes a filter structure and an image sensor, the filter structure is located on the photosensitive path of the image sensor, and the filter structure is a frequency domain Or a broadband filter structure in the wavelength domain. The pass spectra of different wavelengths of the filter structures are not exactly the same. Filtering structures can be metasurfaces, photonic crystals, nanopillars, multilayer films, dyes, quantum dots, MEMS (micro-electromechanical systems), FP etalon (FP etalon), cavity layer (resonant cavity layer), waveguide layer (waveguide layer), diffraction elements and other structures or materials with filtering properties. For example, in the embodiment of the present application, the light filtering structure may be the light modulation layer in Chinese patent CN201921223201.2. The image sensor may be a CMOS image sensor (CIS), a CCD, an array photodetector, or the like. In addition, the spectrum device further includes a data processing unit, which may be a processing unit such as MCU, CPU, GPU, FPGA, NPU, ASIC, etc., which can export the data generated by the image sensor to the outside for processing.

The spectral sensor is used to acquire fingerprint image information and spectral feature information of the finger, so as to verify the biological characteristics of the finger. The chip size ranges from 1/9' to 1/1.6', the imaging spatial resolution is above 50,000 pixels, and it has the ability to identify the spectrum of the light to be measured which is equivalent to the spectral resolution below 30nm. The spectral sensor can be attached to the circuit board by COB or CSP packaging or FC packaging technology.

Specifically, the working principle of the spectral sensor is that the intensity signals of incident light at different wavelengths λ are denoted as f(λ), the transmission spectrum curve of the filter structure is denoted as T(λ), and the spectral sensor has m groups of filter Optical structure, each group of transmission spectra is different, also known as "structural unit", the whole can be recorded as Ti(λ) (i=1,2,3,...,m). There are corresponding physical pixels under each group of filter structures to detect the light intensity information Ii modulated by the filter structures. . In a specific embodiment of the present application, it is described by taking one physical pixel corresponding to a group of structural units as an example, but it is not limited thereto. In other embodiments, a group of multiple physical pixels may also correspond to a group of structures unit.

The relationship between the spectral distribution of incident light and the measured value of the image sensor can be expressed by the following equation:

Ii=Σ(f(λ) Ti(λ) R(λ))

Where R(λ) is the response of the image sensor, recorded as:

Si(λ)=Ti(λ) R(λ)

Then the above formula can be expanded into matrix form:

Among them, Ii (i=1,2,3,...,m) is the response of the image sensor after the light to be measured passes through the broadband filter structure, corresponding to the light intensity information of m image sensors, also known as m "physical pixels" ”, which is a vector of length m. S is the light response of the system to different wavelengths, which is determined by two factors: the transmittance of the filter structure and the quantum efficiency of the image sensor response. S is a matrix, each row vector corresponds to the response of a structural unit to incident light of different wavelengths, Here, the incident light is discretely and uniformly sampled, and there are n sampling points in total. The number of columns of S is the same as the number of sampling points of the incident light. Here, f(λ) is the light intensity of the incident light at different wavelengths λ, that is, the spectrum of the incident light to be measured.

In practical applications, the response parameter S of the system is known. Through the light intensity reading I of the image sensor, the spectrum f of the input light can be obtained by using the algorithm inversion (which can be understood as spectrum restoration). The process can be different according to the specific situation. Data processing methods, including but not limited to: least squares, pseudo-inverse, equalization, least square norm, artificial neural network, etc.

Taking one physical pixel corresponding to a group of structural units as an example, the above describes how to use m groups of physical pixels (that is, pixels on the image sensor) and their corresponding m groups of structural units (the same structure on the modulation layer is defined as a structural unit ) to restore a spectral information, also known as "spectral pixel". It should be noted that, in the embodiment of the present application, multiple physical pixels may also correspond to a group of structural units. It can be further defined that a group of structural units and at least one corresponding physical pixel constitute a unit pixel, and in principle, at least one unit pixel constitutes a spectral pixel.

On the basis of the above implementation manner, the spectral pixels are arrayed to realize a snapshot spectral imaging device.

For example, as shown in FIG. 8A and FIG. 8B, an image sensor with 1896*1200 pixels is used (FIG. 8A shows a part of the image sensor area), and m=4 is selected at the same time, that is, 4*4 unit pixels are selected to form a spectral pixel, then this 474*300 mutually independent spectral pixels can be realized at the same time, and each spectral pixel can calculate the spectral result independently by the above method. After the image sensor is combined with the lens group and other components, snapshot spectral imaging of the object to be measured can be performed, so that the spectral information of each point of the object to be measured can be obtained in a single exposure.

On this basis, according to actual needs, without any adjustment to the image sensor, the selection method of spectral pixels can be rearranged to improve the spatial resolution. As shown in FIG. 8B , the close arrangement of solid-line boxes and dotted-line boxes can be selected to increase the spatial resolution in the above example from 474*300 to close to 1896*1200.

Further, for the same image sensor, spatial resolution and spectral resolution can be rearranged as required. For example, in the above example, when the spectral resolution is required to be high, 8*8 unit pixels can be used to form a spectral pixel; when the spatial resolution is required to be high, 3*3 physical pixels can be used to form a spectral pixel.

That is to say, the spectral sensor can obtain light intensity information, which can be used for both imaging and spectral restoration. For example, in a living fingerprint detection device, the light intensity information may include image information and spectral information, the image information is used for fingerprint texture image recovery, and the spectral information is used for judging a living body.

In an embodiment of the present invention, preferably, the spectral sensor has a modulation area and a non-modulation area. The modulation area means that the optical path of the image sensor is provided with a filter structure, and the non-modulation area corresponds to no filter structure. The light structure, that is, the incident light in the modulation area will be modulated by the filtered light structure and then received by the image sensor. The non-modulation area will not be modulated. For example, when the image sensor is a CMOS chip, the non-modulation area is directly implemented as black and white pixels (that is, no Bayer array is provided on the CMOS chip). Preferably, the modulation area is mainly used to acquire spectral information, and the non-modulation area is used to acquire image information. In individual embodiments, the non-modulation area can also be implemented as a Bayer array, a microlens array, a convex lens, a concave lens, a Fresnel lens, etc., to adjust the incident light.

Preferably, in this preferred embodiment of the present invention, the area of the modulation region accounts for 10%-50% of the effective area of the spectrum chip, preferably 12%-25%, and optionally at least a part of the modulation region and the The interval setting of the non-modulation area; therefore, in the processing and analysis process, the image information of the non-modulation area around the modulation area can be combined with the spectral information of the modulation area, and the image information can be used to optimize the spectral information. For example, it can be used to remove background noise, etc., so that the spectral information is more accurate; specifically, the image information of the surrounding non-modulation area can be averaged, and then the value of the modulation area can be divided or subtracted by the surrounding non-modulation area of the modulation area The average value of the image information of the area; spectral information can also be used to assist image information for image restoration. Generally speaking, spectral information will have more information. At the same time, since the modulation area has structural units, it is different from the non-modulation area information. Therefore, there will be information gaps in this area during imaging, so the spectral information obtained in the modulation area can be used for calculation to compensate for the image information of this area, or to correct the image information of its adjacent areas. For example, as shown in Figure 11, taking the filter structure corresponding to one physical pixel as an example, there are two physical pixels between two adjacent filter structures; that is, one physical pixel with a structural unit is surrounded by eight physical pixels .

In at least one embodiment of the present invention, since the modulation area may lack the image information used for calculation, it can also use the image information values obtained by the physical pixels of the surrounding non-modulation area to calculate the image of the modulation area Information value, specifically, the average value of the image information of the surrounding physical pixels can be used as the image information value of the modulation area, so as to make the whole image more complete. The 8 physical pixels in the figure below surround the physical pixel corresponding to a structural unit For example, the image information value of the middle modulation area can be calculated by using the surrounding 8 physical pixels; the image information value corresponding to the middle modulation area can also be calculated by using the average value of the surrounding 24 physical pixels.

It is worth mentioning that, in this embodiment, the spectral information does not necessarily need to recover the spectral curve before the living body judgment can be made, but the living body judgment can be made directly according to the response. Specifically, acquiring the reference spectral response data of the image sensor of the spectrum-based analysis device to a reference object; acquiring the recognition spectral response data of the image sensor of the spectrum-based analysis device for the object to be identified; and based on the The recognition result of the object to be recognized is determined with reference to a comparison result of the spectral response data and the recognition spectral response data.

Referring to FIG. 12 of the accompanying drawings of the present invention, a living fingerprint detection device according to another aspect of the present invention is clarified in the following description. The identification module 20 of the living fingerprint detection device includes a spectral sensor 221A, an imaging sensor 222A, and a spectroscopic element 27A, wherein the spectroscopic element 30 is located in the optical path between the spectroscopic sensor 221A and the imaging sensor 222A, that is, the incident light enters the spectroscopic element 27A. The detection light is divided into a first detection light and a second detection light by the light splitting element 27A, wherein the first detection light is deflected by the light splitting element 27A and reaches the spectrum sensor 221A, and the second detection light is The light splitting element 27A passes through and reaches the imaging sensor 222A. The spectral sensor 221A obtains spectral information of the object under test through the first detection light, and the imaging sensor 222A obtains image information of the object under test through detection of the second detection light.

Preferably, the identification module 20 further includes a homogenizing element 28A, wherein the homogenizing element 28A is arranged between the light splitting element 27A and the spectral sensor 221A, and the light is controlled by the homogenizing element 28A. Homogenize, and then obtain spectral information by the spectral sensor 221A for living body discrimination. It should be noted that since the surface to be tested is often uneven, such as fingerprints with valleys and ridges, the change of the corresponding area during the test will lead to different spectral responses in different areas, making it more difficult to judge the living body. Therefore, after the light is uniformed by using the light homogenizing member 28A, even if the area changes during the test, the overall spectral information remains unchanged.

For example, in the process of fingerprint live identification, if the tester deflects at a certain angle when placing the finger, the fingerprint valleys and ridges corresponding to the spectral sensor will also change, which will lead to changes in the spectral information reaching the spectral sensor. At this time, additional processing is required to achieve accuracy. Judgment, after homogenization, since the light source does not move, the valleys and ridges as a whole remain unchanged, so the deflection will not cause a large change in spectral information, so that living body judgment can be realized relatively simply and efficiently. Preferably, the identification module 20 of the living fingerprint detection device further includes a lens group 29A, the lens group 29A is located between the imaging sensor 222A and the light splitting element 27A, and is imaged after adjusting the light Chip reception is beneficial to improve imaging quality, such as clearer.

In view of the size requirements in practical applications, such as mobile phones and wearable devices, it is necessary to limit the size in a certain direction. Taking the height direction as an example, when the imaging sensor 222A is matched with the lens group 29A, there is generally a requirement for focal length, and the size of the lens group is generally larger. Preferably, the imaging sensor 222A and the lens group 29A are arranged along the horizontal direction, wherein the spectral sensor 221A is arranged along the height direction (vertical direction) together with the dodging sheet 28A. That is to say, after the incident light enters the light splitting element 27A along the height direction, the transmitted part enters the homogenizing element 28A, and reaches the spectral sensor 221A after being homogenized; while the turning part enters the lens group along the horizontal direction 29A is adjusted and then received by the imaging sensor 222A.

It is worth mentioning that, since the identification module of this preferred embodiment of the present invention uses a spectral sensor, spectral information can be obtained, and spectral information can be used to determine whether the object to be detected is a living body, thereby making the security performance of fingerprint identification more effective. high. Figure 16 and Figure 17 show the living fingerprint identification system of the present invention, wherein the living The body fingerprint identification system includes a control unit 100C, an imaging unit 200C, a lighting unit 300C, and a processing unit 400C, wherein the control unit 100C is electrically connected to the imaging unit 200C, the lighting unit 300C, and the processing unit 400C, and through the The control unit 100C controls the imaging unit 200C, the lighting unit 300C and the processing unit 400C to work. The illumination unit 300C emits an incident light, and the incident light irradiates the object to be measured (finger, palm, etc.) and is reflected to form reflected light with detection information, and the reflected light is received by the imaging unit 200C, Obtain the corresponding light intensity information, and then process the light intensity information through the processing unit 400C, so as to identify the texture and/or living body information of the object to be measured.

Preferably, the incident light emitted by the lighting unit 300C is uniform light. Therefore, in the present application, the lighting unit 300C includes a light source and a dodging element, and the dodging element homogenizes the incident light projected by the light source, wherein the dodging element may be a dodging element. The imaging unit 200C includes an imaging device and a spectrum chip, and the imaging device is located on a photosensitive path of the spectrum chip, wherein the imaging device may further include a lens group, a filter, and the like. In the present invention, the processing unit 400C may provide a texture image restoration algorithm, and/or a living body recognition algorithm. The lighting unit 300C is arranged around the imaging unit, and the light source and the spectrum chip are electrically connected and fixed on the same circuit board; the light source and the spectrum chip can also be separately arranged on different circuit boards, for example, the circuit board used to set the light source can be independently arranged on the a stand. Preferably, the light sources are symmetrically distributed with respect to the imaging unit, and may be symmetrically distributed along a circular ring, a square ring, or multiple left and right points, that is, the identification system in the present invention may have one or more light sources.

The light source is LED, wherein the light source is a white LED, or a monochromatic LED of a specific wavelength or a combination of multiple lights, such as an optical combination of red, green and blue + NIR. It should be noted that in the living body recognition, the main principle is that the existence of physiological characteristics will cause the skin to have different spectral absorption/reflection degrees for different bands. According to experiments, the skin is more sensitive to spectral absorption/reflection at 400-600nm, especially 500-600nm. Therefore, the incident light preferably emitted by the light source of the present invention has a stronger light intensity at 400-600 nm, while the light intensity in other wavelength bands is relatively weak. Even better is that 500-600nm has stronger light intensity. For example, the relative intensity distribution of the source spectrum satisfies: the energy is mainly distributed between 500nm and 600nm, and the distribution in this interval is relatively flat, and there can be no significant peak; 400nm~500nm has a small amount of energy distribution, and its energy integral is not higher than 500~600nm 80% of the interval, and there should be no significant peaks; the light intensity in the spectral range beyond 400-600nm should be as weak as possible, and the total energy in this interval should not be higher than 20% of the total radiant energy of the light source.

As shown in FIG. 18, according to another aspect of the present invention, the fingerprint recognition method of the recognition system of the present invention is clarified. The fingerprint texture and liveness recognition or detection process can be processed in parallel or serially according to system performance and actual needs, and the liveness detection function can be switched on and off separately. Specifically, the finger to be tested is placed in the area to be tested, and the illumination unit 300C emits an incident light to the finger to be tested, and the incident light is partially absorbed by the finger to be tested, and partially absorbed by the finger to be tested. Generate reflection to form a reflected light, the reflected light is collected by the imaging unit 200C to obtain corresponding light intensity information, the light intensity information includes image information and spectrum information, the image information is used for fingerprint image identification, the The spectral information is used for spectral data analysis to judge the living body; then the fingerprint image is matched with the pre-stored reference fingerprint image, and the spectral information can be used in parallel or serially to judge the living body; if both pass, the verification is successful; otherwise The system will give an alarm.

Referring to Figures 19 to 24 of the accompanying drawings of the present invention, according to another aspect of the present invention, the lighting unit 300C and the imaging unit 200C of the fingerprint identification system are integrated into a fingerprint detection module. In the following description be illuminated. The fingerprint detection module includes a spectrum chip 10C and a circuit board 20C, and the spectrum chip 10C is electrically connected to the circuit board 20C to receive the detection light with fingerprint detection information reflected from the living fingerprint to be tested. , to obtain light intensity information. Specifically, the spectrum chip 10C is the same as the sensor in the above-mentioned preferred embodiment, and details are not repeated here.

In the present invention, the spectrum chip 10C has a modulation area 101C and a non-modulation area 102C, wherein the modulation area 101C is provided with a filter structure on the optical path of the image sensor 12C, and the non-modulation area 102C corresponds to The filter structure is set, that is, the incident light in the modulation area will be modulated by the filter structure and then received by the image sensor 12C. The non-modulation area 102C will not be modulated. For example, when the image sensor is a CMOS chip, the non-modulation area 102C is directly implemented as black and white pixels (that is, no Bayer array is provided on the CMOS chip). Preferably, the modulation area 101C can acquire spectral information, and the non-modulation area 102C can acquire image information. In individual embodiments, the non-modulation region 102C can also be implemented as a Bayer array, a microlens array, a convex lens, a concave lens, a Fresnel lens, etc., to adjust the incident light.

As shown in FIG. 21 , in another embodiment of the present invention, the modulation area 101C of the spectrum chip 10C can be set according to requirements. For example, it can be located at the four corners and/or the periphery of the spectrum chip 10C; preferably, in a specific example of the present application, the modulation area 101C and the non-modulation area 101C can be designed according to the application scenario of the spectrum chip 10C Area 102C. Taking fingerprint recognition as an example, the modulation area 101C is mainly used to obtain spectral information, which is used to determine whether it is a living body, while the non-modulation area 102C is used to obtain images. Therefore, the modulation area 101C is concentratedly arranged in the characteristic area of the spectrum chip 10C. The four corners or the surrounding area of the chip 10C are only used to obtain spectral information. Correspondingly, the non-modulation area 102C is located in the central area of the spectrum chip 10C. Since the fingerprint texture comparison needs to capture the feature points of the fingerprint, the feature points of the fingerprint are generally concentrated in the center of the finger. Therefore, setting the central area of the spectrum chip 10C as the non-modulation area 102C can improve the imaging quality, thereby The accuracy of the obtained fingerprint texture can be improved, so that the accuracy of fingerprint comparison is higher. At the same time, compared to the space between the modulation area 101C and the non-modulation area 102C in the previous embodiment, the middle area of the spectrum chip 10C in this embodiment is set as the non-modulation area 102C, which can also be Improve image quality. It should be noted that the central area in the present invention is not strictly limited to the centermost area of the spectrum center, which can be a regular area close to the center of the effective area of the spectrum chip or close to the center of the effective area of the spectrum chip An irregular area.

Further, it can be understood that, as mentioned above, the modulation area 101C is the area provided with the filter structure 11, while the non-modulation area 102C is implemented as a conventional pixel area, that is, the filter structure mentioned in the present invention is not provided. light structure. In order to better process the spectral signal of the modulation area 101C in the present invention, optionally, black and white pixels for calibration are set in the modulation area 101C or adjacent to the modulation area, and the black and white pixels of the calibration function After the light intensity information is acquired by the pixel, the spectrum information acquired by the modulation area is calibrated. It should be noted that, in this preferred embodiment of the present invention, the black pixel is a pixel unit with a filter structure, and the white pixel is a pixel unit without a filter structure.

It should be noted that the modulation region 101C and the non-modulation region 102C of the spectrum chip 10C in the present invention are regions that actually participate in obtaining light intensity information, and are not completely limited to image sensors and/or filter structures. area. Therefore, in other embodiments, as shown in FIG. 13 , the modulation area 101C can also be concentrated in the central area of the spectrum chip 10C, and the non-modulation area 102C is located around and/or at the four corners; thus the modulation area 101C More intense and more precise spectral information can be received.

In the present invention, since the image information used for calculation may be missing in the modulation area 101C, it can also use the image information values acquired by the physical pixels of the surrounding non-modulation area 102C to calculate the image information value of the modulation area 101C . Specifically, the average value of the image information of the surrounding physical pixels can be used as the image information value of the modulation area 101C, so as to make the entire image more complete, as shown in the spectrum chip in Figure 11, that is, 8 physical pixels surround a structural unit corresponding to Taking physical pixels as an example, the image information value of the middle modulation area can be calculated by using the surrounding 8 physical pixels; the image information value corresponding to the middle modulation area can also be calculated by using the average value of the surrounding 24 physical pixels.

The circuit board 20C may be a flexible board (FPC), a rigid board (PCB), a rigid-flex board (F-PCB), a ceramic substrate, and the like. The circuit board 20C is used for driving, controlling, data processing and output of the light source and the sensor chip.

The fingerprint detection module further includes an optical component 60C, and the optical component 60C is located on the optical path of the spectrum chip 10C. Preferably, in this application, the optical assembly 60C is a lens group, that is, the Optical assembly 60C is composed of at least one lens. More preferably, the lens group is used to image the finger to be tested in the area to be tested onto the spectrum chip 10C, its FOV is between 80 degrees and 130 degrees, the back focus is between 0.3 mm and 5 mm, and the total optical length is Between 1mm and 10mm. The optical assembly 60C further includes a filter element to filter the reflected light. For example, the filter element cuts off the wavelength band above 650nm or 600nm, that is, only allows the reflected light below 650nm or 600nm to pass through, preventing external ambient light from affecting the The test results are interfering. It can be understood that the filter element can be adjusted or selected according to actual requirements.

The fingerprint detection module further includes a bracket 30C, the bracket 30C is arranged on the circuit board 20C, the optical assembly 60C is arranged on the bracket 30C, and the optical assembly is supported and held by the bracket 30C 60C is in the optical path of the spectrum chip 10C.

The fingerprint detection module further includes a transparent cover 40C, and the area to be tested is formed on the surface of the transparent cover 40C for placing a finger or a palm to be tested. The transparent cover 40C can be but not limited to optical glass ( glass cover) or optical plastic, with a thickness of 0.8mm-1.2mm. The fingerprint detection module further includes at least one light source assembly 50C, and the light source assembly 50C is used for illuminating the finger or the palm to be tested. Preferably, the light emitted by the light source assembly 50C has a certain spectral width (≥30nm). Preferably, in this application, the light source assembly 50C can emit monochromatic light and/or mixed light according to requirements. Preferably, the light source assembly 50C includes a light source 51C and a homogenizing element 52C, the incident light emitted by the light source 51C is homogenized by the homogenizing element 52C, and then enters the to-be-treated light through the transparent cover plate 40C. Measure the finger or the palm to be tested.

The dodging member 52C is located between the light source 51C and the transparent cover 40C. The homogenizing member 52C is made of transparent optical plastic, the surface can be frosted, and the inside can be filled with a certain proportion of astigmatizing powder. It should be noted that, in the prior art fingerprint recognition equipment, the light source is located under the fingerprint collection panel, such as transparent glass, wherein the light emitted by the light source reaches the surface of the fingerprint to be tested through the collection panel, wherein the fingerprint to be tested The reflected light to be measured passes through the fingerprint collection panel and then passes through the optical component 60C to the spectrum chip 10C. It is worth mentioning that part of the light emitted by the light source of the fingerprint identification device in the prior art will inevitably be reflected by the lower surface of the fingerprint collection panel, and directly reach the spectrum chip 10C through the optical component 60C. , and the light reflected by the fingerprint collection panel will affect the detection result of the fingerprint identification device as an interference signal.

Embodiment Three

As shown in FIG. 25, the fingerprint detection module according to the third preferred embodiment of the present invention is explained in the following description. The fingerprint detection module includes a spectrum chip 10C, a circuit board 20C, a bracket 30C, a transparent cover 40C and at least one light source assembly 50C, wherein the spectrum chip 10C is arranged on the circuit board 20C, and is connected with the The circuit board 20C is electrically connected, the transparent cover 40C is arranged on the support 30C, and the transparent cover 40C is supported by the support 30C on the photosensitive path of the spectrum chip 10C. The light source assembly 50C is arranged outside the transparent cover plate 40C, and the light generated by the light source assembly 50C is incident from the side of the transparent cover plate 40C, and forms a belt to be treated through the transparent cover plate 40C. Measure the reflected light of fingerprint information.

In detail, the transparent cover 40C can be but not limited to transparent glass, wherein the transparent cover 40C includes a collection part 41C and a non-collection part 42C integrally extending outward from the collection part 41C, wherein the non-collection The portion 42C is provided along the outer edge of the collecting portion 41C. The light source assembly 50C is disposed on the non-collection portion 42C of the transparent cover plate 40C, or the light source assembly 50C is located outside the non-collection portion 42C, wherein the light generated by the light source assembly 50C comes from the The non-collection portion 42C of the transparent cover 40C is incident to the collection portion 41C of the transparent cover 40C. The collection part 41C of the transparent cover 40C is used to collect the fingerprint of the subject to be tested, that is, to provide an area for collecting the fingerprint of the subject to be tested, and the subject to be tested places his finger or palm on the transparent cover 40C. The acquisition unit 41C is described above. The light generated by the light source assembly 50C reaches the collection part 41C from the non-collection part 42C, and forms reflection on the upper surface of the collection part 41C, wherein the reflected light with the fingerprint information to be tested comes from the transparent cover The collection part 41C of the board 40C is reflected to the spectrum chip 10C, so that the spectrum chip 10C can judge the live fingerprint information based on the reflected light of the fingerprint information to be tested. It should be understood that the non-collection part 42C and the collection part 41C of the present invention constitute the transparent cover plate 40C, and the non-collection part 42C and the collection part 41C are divided according to actual applications, and in individual embodiments The non-collection part 42C can also be equivalent to the collection part 41C, that is, this part of the area (non-collection part) can also be used to collect the fingerprint of the subject.

The transparent cover plate 40C further has an upper surface 401C and a lower surface 402C, wherein the upper surface 401C is opposite to the lower surface 402C, wherein the upper surface 401C of the transparent cover plate 40C is facing outward, for Place the finger or palm to be tested, and the light incident on the transparent cover plate 40C by the light source assembly 50C is reflected on the upper surface 401C of the transparent cover plate 40C, that is, part of the incident light is reflected by the finger or palm to be tested. Absorption, partial reflection will generate reflected light with fingerprint information to be tested, and the reflected light with fingerprint information to be tested will reach the spectrum chip 10C through the lower surface 402C.

It is worth mentioning that, as shown in FIGS. 27A to 28 , in this preferred embodiment of the present invention, the light source assembly 50C emits light from the outside of the transparent cover 40C toward the direction of the transparent cover 40C. , and at least one incident light path 410C is formed between the upper surface 401C and the lower surface 402C of the transparent cover 40C, wherein the light emitted by the light source assembly 50C passes from the transparent cover along the incident light path 410C The non-collection portion 42C of 40C enters the collection portion 41C of the transparent cover plate 40C. Preferably, in this preferred embodiment of the present invention, the light emitted by the light source assembly 50C forms the incident light path 410C along the horizontal direction.

The light emitted by the light source assembly 50C reaches the upper surface 401C of the transparent cover 40C along the incident light path 410C, and the light is reflected by the object to be tested to form a reflected light path 420C, which contains the reflection of the fingerprint information to be tested. The light enters the spectrum chip 10C through the lower surface 402C of the transparent cover plate 40C along the reflection optical path 420C.

It can be understood that, in this preferred embodiment of the present invention, the light source assembly 50C of the fingerprint identification module is located outside the transparent cover 40C, and the light generated by the light source assembly 50C is incident on the side The pattern enters the transparent cover 40C, and forms reflected light with the fingerprint information to be tested on the collection part 41C of the transparent cover 40C. In short, in this preferred embodiment of the present application, the fingerprint recognition module is side-lit, that is, the light source assembly 50C irradiates light from the side of the transparent cover 40C.

Preferably, in this preferred embodiment of the present invention, the incident light path 410C generated by the light source assembly 50C is not lower than the lower surface 402C of the transparent cover 40C, that is, the light generated by the light source assembly 50C Above the lower surface 402C of the transparent cover 40C, along the incident light path 410C, enters the collecting part 41C from the non-collecting part 42C, and forms reflection on the upper surface 401C of the collecting part 41C. It can be understood that, the light source 50 forms the reflective light path 420C above the lower surface 402C of the transparent cover 40C, so that the light source 50 can avoid The influence of stray light formed by specular reflection on the detection results.

As shown in FIG. 25 , the light source assembly 50C includes at least one light source 51C and at least one dodging member 52C, wherein the dodging member 52C is located at the front end of the light emitting direction of the light source 51C, and the light generated by the light source 51C It reaches the transparent cover plate 40C through the light homogenizing member 52C. The light source 51C of the light source assembly 50C is outside the transparent cover plate 40C, wherein the light homogenizing member 52C is located between the light source 51C and the transparent cover plate 40C.

Preferably, in one embodiment of the present invention, the dodging member 52C of the light source assembly 50C is integrated with the transparent cover 40C, that is, the dodging member is formed on the transparent cover The side of the light source 51C is pasted on the light homogenizing member 52C, so that the light emitted by the light source 51C can enter the light homogenizing member 52C as much as possible to be homogenized, and then projected to the transparent cover plate 40C. measurement area. That is, the non-collecting portion 42C is implemented as a dodging member 52C. As an example, the side of the transparent cover 40C can be frosted, so that the side of the transparent cover 40C has a dodging effect, that is, the side of the transparent cover 40C is frosted to form a dodging layer of the light source assembly 50C , to homogenize the light from the light source 51C. Therefore, the dodging element can be replaced, that is, the dodging layer is the dodging element in the foregoing embodiment; or it can be used together with the dodging element to homogenize the light, so that the dodging effect is better.

Preferably, the light source 51C and the dodging member 52C surround the transparent cover plate 40C, and the light source It can be understood that the light emitted by 51C enters the homogenizing member 52C substantially perpendicular to the optical axis, and then is homogenized by the homogenizing member 52C and then enters the transparent cover 40C along the horizontal direction. It can be understood that the incident light enters the light homogenizing element substantially vertically without considering the scattering angle of the light.

As shown in FIG. 25, the fingerprint recognition module further includes an optical assembly 60C, wherein the optical assembly 60C is arranged in the photosensitive path of the spectrum chip 10C, wherein the optical assembly 60C is supported by the bracket 30C on the between the transparent cover plate 40C and the spectrum chip 10C. The support 30C is fixed on the circuit board 20C, and the support 30C is provided with a light transmission hole 302C, wherein the light transmission hole 302C of the support 30C is located on the photosensitive path of the spectrum chip 10C, the The spectrum chip 10C can obtain the light to be detected through the light transmission hole 302C of the bracket 30C.

The optical assembly 60C is implemented as a lens group, wherein the optical assembly 60C includes at least one optical lens. The optical lens of the optical assembly 60C is fixed above the spectrum chip 10C by the bracket 30C, and the light to be detected is processed by the optical assembly 60C.

Correspondingly, the bracket 30C includes a bracket body 31C and an extension unit 32C integrally extending inward from the bracket body 31C, wherein the upper end of the bracket body 31C of the bracket 30C forms the light-transmitting hole 302C, so The extension unit 32C extends inward from the bracket main body 31C, and forms a support structure with a light transmission hole 302C in the middle, wherein the optical component 60C is disposed in the light transmission hole 302C formed by the extension unit 32C, and The optical assembly 60C is supported by the extension unit 32C on the light-sensing path of the spectrum chip 10C.

The transparent cover 40C and the light source assembly 50C are disposed on the bracket main body 31C of the bracket 30C, and the transparent cover 40C and the light source assembly 50C are fixed and supported by the bracket main body 31C. The transparent cover 40C may be, but not limited to, a transparent glass or transparent plastic structure. The transparent cover 40C is covered on the photosensitive path of the spectrum chip 10C, and the transparent cover 40C provides an area to be tested suitable for collecting fingerprints. Preferably, in this preferred embodiment of the present invention, the light source assembly 50C is disposed at the end of the bracket body 31C of the bracket 30C, wherein the light emitting surface of the light source assembly 50C faces the transparent cover 40C.

It is worth mentioning that the light source assembly 50C in this preferred embodiment of the present invention is the lighting unit 300C in the living fingerprint identification system.

Embodiment Four

As shown in FIG. 26, the fingerprint detection module according to the fourth preferred embodiment of the present invention is explained in the following description. The fingerprint detection module includes a spectrum chip 10C, a circuit board 20C, a bracket 30D, an optical assembly 60C, a transparent cover 40C and a light source assembly 50C, wherein the spectrum chip 10C is electrically connected to the circuit board 20C, The optical assembly 60C is arranged on the support 30D, and the optical assembly 60C is held in the photosensitive path of the spectrum chip 10C through the support 30D. The light source assembly 50C and the transparent cover 40C are arranged on the top of the support 30D, and the light source assembly 50C is located outside the transparent cover 40C, and the light generated by the light source assembly 50C comes from the transparent The outer side of the cover plate 40C enters the transparent cover plate 40C. It is worth mentioning that, in this preferred embodiment of the present application, the structures of the transparent cover 40C and the light source assembly 50C are the same as those of the third preferred embodiment above, and will not be repeated here.

The difference from the above-mentioned preferred embodiment is the structure of the bracket 30D, specifically, the bracket 30D includes a first bracket 33A and a second bracket 34A, wherein the first bracket 33A is located on the side of the second bracket 34A. Outside, the transparent cover plate 40C is fixed on the first bracket 33A, the optical assembly 60C is arranged on the second bracket 34A, and the optical assembly 60C is supported on the second bracket 34A. The light-sensing path of the spectrum chip 10C is described.

The second bracket 34A is provided with a first light transmission hole 340A, wherein the optical component 60C is fixed to the first light transmission hole 340A of the second bracket 34A by the second bracket 34A. It can be understood that the first light transmission hole 340A of the second bracket 34A is facing the photosensitive surface of the spectrum chip 10C. The first bracket 33A is supported on the outside of the second bracket 34A, the optical assembly 60C is fixedly supported by the second bracket 34A, and the second bracket 34A is connected to the optical assembly 60C and the circuit board 20C forms a sealed environment. The spectrum chip 10C is placed in a sealed space formed by the second bracket 34A, the optical assembly 60C and the circuit board 20C.

Embodiment five

As shown in FIG. 27A to FIG. 28 , according to another aspect of the present application, the present invention further provides another preferred implementation of the fingerprint identification module. The working principle of the present invention is to place the finger or palm to be tested on the collection part 41C of the transparent cover 40C, that is, the region to be measured of the transparent cover 40C, and the light source assembly 50C emits an incident light (as shown in FIG. The incident light A) reaches the finger to be tested, part of the incident light is absorbed by the finger to be tested, and part of the incident light is reflected to form a reflected light, and the reflected light is collected by the imaging unit to obtain corresponding light intensity information, The light intensity information includes image information and spectral information, the image information is used for fingerprint image identification, and the spectral information is used for spectral data analysis to perform living body judgment, that is, the light intensity information received by the spectrum chip through the reflected light is removed Identify fingerprints. After the light generated by the light source 51C is homogenized, part of the incident light entering the transparent cover 40C (as shown in the incident light B) may directly pass through the lower surface 402C of the transparent cover 40C and enter the transparent cover 40C. The spectrum chip 10C mentioned above will bring recognition noise, resulting in inaccurate results.

It should be noted that, during the fingerprint identification process, when the incident light reaches the collection part 41C in the transparent cover 40C, if the incident light hits the contact area between the finger and the transparent cover 40C, diffuse reflection will occur. Light will enter the spectrum chip 10C; and due to the existence of fingerprint valleys and ridges, there will be a gap area between the finger and the transparent cover (this area is filled with air), and this part of the incident light will produce specular reflection. Therefore, to a certain extent, the stronger the energy of the incident light irradiating the object to be measured, the better the recognition accuracy will be.

As shown in FIG. 27A and FIG. 27B , different from the above preferred embodiment, the transparent cover 40C further includes a light-shielding layer 43C, wherein the light-shielding layer 43C is arranged on the lower surface 402C of the transparent cover 40C , wherein the light-shielding layer 43C may be but not limited to a reflective film or an absorbing film, for reflecting or absorbing light passing through the lower surface 402C of the transparent cover 40C. Preferably, in this preferred embodiment of the present invention, the light shielding layer 43C is attached or coated on the non-collection portion 42C of the transparent cover plate 40C.

As shown in FIG. 27B , without affecting the incident light A from entering the spectrum chip, part of the incident light B can be prevented from entering the spectrum chip 10C.

Preferably, in this preferred embodiment of the present invention, the light-shielding layer 43C is a reflective film formed on the non-collecting portion 42C of the transparent cover plate 40C, wherein the light emitted by the light source assembly 50C travels along the The incident light path 410C enters the transparent cover plate 40C. It can be understood that, part of the light (ray B) emitted by the light source assembly 50C is projected to the light-shielding layer 43C of the transparent cover 40C, and is projected by the light (light A) formed by reflection of the light-shielding layer 43C. to the upper surface 401C of the collecting portion 41C of the transparent cover 40C. When the incident light B reaches the lower surface, the incident light B will be reflected due to the provision of the reflective film, and the corresponding light will reach the object under test due to the reflection, increasing the energy reaching the object under test.

As shown in Figure 28, different from the above-mentioned preferred embodiment, the fingerprint recognition module further includes a light-gathering layer 70C, wherein the light-gathering layer 70C is arranged on the upper surface of the transparent cover 40C 401C. It is worth mentioning that the light-gathering layer 70C is a material with a high refractive index, and the refractive index of the light-gathering layer 70C is greater than that of the transparent cover 40C, and the light of the transparent cover 40C will Concentrating more on the light concentrating layer 70C, the light signal entering the inner side of the identification module through the lower surface of the transparent cover 40C is stronger, resulting in a higher signal-to-noise ratio. The light concentrating layer 70C is disposed on the collecting portion 41C of the transparent cover 40C, preferably, the light concentrating layer 70C covers the upper surface 401C of the transparent cover 40C.

As shown in FIG. 28, when the incident light emitted by the light source 51C is homogenized by the homogenizing member 52C, it enters the transparent cover 40C, and then enters the light concentrating layer 70C. The layer 70C is low, so it can be considered that the incident light enters the optically denser material from the optically thinner material, and the refraction angle becomes smaller. As shown by the incident light A indicated by the dotted line, the incident light A enters the light concentrating layer 70C and then reaches the gap area, where it is specularly reflected, and then passes through the transparent cover plate 40C Enter the interior of the fingerprint module. The incident light B is reflected by the light-shielding layer 43C as shown in the dotted line in the figure, enters the light-collecting layer 70C, and reaches the contact area to generate diffuse reflection. When the incident light angle of diffuse reflection is smaller than the critical value, this part of the incident light It will enter the transparent cover, such as the incident light B1; while the incident light B2 corresponds to a larger diffuse reflection angle, exceeding the critical angle to generate total reflection, and will not enter the transparent cover 40C. As shown by the solid line, the incident light C has a relatively large refraction angle after entering the light-gathering layer, and total reflection will occur when the incident light C is larger than the critical angle.

It can be understood that the light concentrating layer 70C can increase the energy of the incident light reaching the collecting portion 41C of the transparent cover 40C, and at the same time, the refractive index of the light concentrating layer 70C is greater than that of the transparent cover 40C. The total reflection brought by the high efficiency filters out some incident light with large angles.

As shown in Fig. 29A and Fig. 29B, it is the optical simulation after setting the light-gathering layer. Under the same circumstances, the total number of impacts on the side where the light-gathering layer 70C is set will increase, which is increased by nearly 3.6% as shown in the simulation. , to a certain extent, it can be understood that the design of the light-gathering layer 70C allows more light to be gathered in the light-gathering layer 70C, so that more light energy reaches the finger to be tested, and the overall test effect will be better.

In addition, the living fingerprint identification system in the present invention further includes a trigger unit, and when the object to be tested approaches the living fingerprint identification system, the trigger unit sends an instruction to make the living fingerprint identification system start working. The trigger unit may be a trigger capacitor or the like, which is arranged on the circuit board and electrically connected to the circuit board.

According to another aspect of the present invention, the present invention further provides a living body fingerprint identification method, wherein in this embodiment, the spectral information does not necessarily need to restore the spectral curve before performing living body judgment, but can be directly based on the spectral response Make liveness judgments.

In detail, acquiring the reference spectral response data of the image sensor of the spectrum-based analysis device to a reference object; acquiring the recognition spectral response data of the image sensor of the spectrum-based analysis device for the object to be identified; and based on the The recognition result of the object to be recognized is determined with reference to a comparison result of the spectral response data and the recognition spectral response data.

The present invention further provides a living fingerprint detection method based on the living fingerprint identification device above, wherein the spectrum chip obtains original data, that is, light intensity information, and the light intensity information includes image information and spectral information, and the original data are respectively Carry out image information correction and spectral information correction; then use the fingerprint recognition algorithm and the living body algorithm respectively to compare the fingerprint image and spectral information with the corresponding reference information extracted during entry to obtain the matching degree; when the matching degrees of both are higher than When the threshold is reached, the input validation passes; otherwise, the output validation fails.

Referring to Figure 13, the present invention further provides a living fingerprint detection method based on the above-mentioned living fingerprint detection device, wherein the spectral sensor 221A obtains raw data, that is, light intensity information, and the light intensity information includes image information and spectrum information, respectively performing image information correction and spectral information correction on the original data; and then The fingerprint recognition algorithm and the living body algorithm are respectively used to compare the fingerprint image and spectral information with the corresponding reference information extracted during entry to obtain the matching degree; when the matching degree of both is higher than the threshold, the input verification is passed; otherwise, the output verification fail.

Image information correction and spectrum information correction include an image processing method of surrounding mean value compensation (binning). Therefore, in this preferred embodiment of the present invention, the living fingerprint detection method further includes the steps of image information correction and spectral information correction. In the image information correction, the intensity value of the spectral pixel (which can be understood as the corresponding formation of the filter structure and the physical pixel) will be replaced by the intensity value of the weighted average of the intensity of the nearby ordinary physical pixels, thereby generating the corrected image information (image data) . The average value can be averaged by selecting a number of adjacent (such as 4, 8, 24, 80) ordinary physical pixels. When the number is greater than 4, the weighted kernel used in the weighted average can use a uniform kernel (all physical pixels pixel equal weight) or a Gaussian kernel. For example, in the embodiment shown in Figure 11, a 5*5 Gaussian kernel can be used, as shown in Table 1, the middle 0 represents a spectral pixel, that is, the light intensity information (image information) at this place needs the light intensity information of the surrounding 24 physical pixels (Image information) Gaussian kernel weighted average is obtained, that is, the light intensity information value of the relevant material pixel is multiplied by the sum of the corresponding coefficients, and then divided by the sum of the weights.

Table 1

For the acquisition of spectral information, it is necessary to avoid the influence of bright patterns at different positions on spectral verification. For example, the reflectivity of fingerprint valleys and fingerprint ridges is different, resulting in different degrees of brightness and darkness, which may affect the judgment of the spectral signal of the object to be measured. Therefore, the living fingerprint detection method in this preferred embodiment of the present invention further includes a step of correcting the spectral pixel intensity. For example, the intensity value of the current spectral pixel may be divided or subtracted by the weighted average (binning) value of adjacent common pixels to obtain the relative intensity, which may be used as the corrected spectral information for subsequent processing. Further, the corrected spectral information can be screened by specific rules, and values that are too large and too small can be eliminated, so as to improve the effectiveness of the corrected spectral information. Taking Figure 11 as an example, the values of the 8 physical pixels around the spectral pixel can be taken as the average intensity value, and then the intensity value of the spectral pixel can be divided or subtracted by the average intensity value of the 8 physical pixels to obtain the corrected Correct spectral information.

Referring to Fig. 14, the living body fingerprint detection method of the present invention further includes the step of living body judgment algorithm. The effective corrected spectral parameters extracted after processing the original data (light intensity information) (also can be understood as corrected Positive spectral information), and calculate the correlation coefficient R between it and the reference spectral information (for example, Pearson correlation coefficient can be used). When the correlation coefficient R is greater than the corresponding threshold, it is determined as a living body, otherwise it is determined as a non-living body. Since the correlation coefficient R needs to be calculated in the present invention, both the input information and the detection information will be vectorized in one dimension.

Further, the living fingerprint detection method of the present invention further includes the steps of threshold selection and use. For different times of input information, due to the potential changes of various conditions during the input, the noise power ratio (signal-to-noise ratio) has a certain difference each time the data is collected. When the signal-to-noise ratio is high, the correlation coefficient between the corresponding spectral information and other recorded reference spectral information is generally high; on the contrary, when the signal-to-noise ratio is low, the corresponding correlation coefficient is generally low. Therefore, using a unified threshold for judgment is easy to introduce misjudgment. In this regard, the present application excludes a dynamic selection of a threshold and a corresponding usage method, so that biometric verification can be performed more accurately.

In the case of n valid entries (for example, a set of valid entries is 10 entries), calculate the correlation coefficient R between the spectral information entered this time and the spectral information entered in other n-1 times, and take the lowest correlation coefficient R_min, and The system sets the parameter k to perform specific formula calculations to obtain the judgment threshold R_t for this input comparison. In actual use, calculate the correlation coefficient of the data to be tested and n times of data that have been entered, and compare them with the corresponding judgment threshold R_t (1~10). When there are n-1 or more than the corresponding judgment threshold, it is considered that the The test is living, otherwise it is judged as non-living.

Further, the living fingerprint detection method of the present invention further includes the step of fingerprint entry. When entering, judge the consistency of the entered spectral features. Due to the interference of random factors such as potential ambient light or the state of the finger to be recorded, it may cause instability to the recorded spectral information, which in turn affects the experience of using accuracy. Therefore, it is necessary to judge the consistency of spectral information when entering.

For example, the input requires a group of N times (2-20 times) continuous input with the same finger. For each entry, process the entered spectral parameters according to the comparison process, and calculate the correlation coefficient between the entered data and the corresponding spectral parameter data that has already been entered. If the coefficient is less than the system setting value m, the entry fails. .

Optionally, the correlation coefficients of the data entered each time can be compared with the data entered in the database corresponding to the specific prosthetic material in the system, if the correlation coefficients of multiple (n=1-3) data are greater than the system threshold q , the entry fails. If the input fails for several consecutive times (n=2~5), the input of this group fails, and a new set of input needs to be performed.

Further, the living fingerprint detection method of the present invention further includes the step of updating the input data. Considering that the system or the DUT may have changes in the long term, the entered data needs to be updated. For example, after each determination that the detection is successful, the average value R_atest of the correlation coefficient between the spectral parameters determined this time and the comparison of the 10 input data stored in the system is calculated, and the average value R_a1 of the correlation coefficient between it and the 10 input data is calculated. 10 for comparison, if R_atest is greater than one or more of R_a1~10, select the smallest one among R_a1~10, and use the The data replaces the corresponding input data. It should be noted that the 10 input data are only used as an example and do not constitute a limitation. It does not necessarily have to be 10, but can also be greater than 10 or less than 10, which can be adjusted according to needs.

Referring to Fig. 15 of the accompanying drawings of the present invention, the living fingerprint detection method according to the above-mentioned preferred embodiment of the present invention is explained in the following description. Described live fingerprint detection method comprises the steps:

(a) Obtain light intensity information for fingerprint collection;

In the above living fingerprint detection method, the detection method further includes: modifying the light intensity information, wherein the light intensity information correction includes an image processing method of surrounding average value compensation (binning). In the correction of image information, the intensity of the spectral pixel is replaced by the intensity value of the weighted average of the intensity of the nearby ordinary physical pixels, so as to generate the corrected image parameters.

In the above living fingerprint detection method, the detection method further includes: correcting the spectral information corresponding to the spectral pixel, that is, the intensity value of the current spectral pixel, dividing or subtracting the intensity value of the weighted average (binning) of adjacent ordinary pixels to obtain Relative intensity for subsequent processing as corrected spectral information.

In the above living fingerprint detection method, the detection method further includes: the step of living body judgment, calculating the correlation coefficient R formed by the effective corrected spectral information extracted after the original data is processed and the entered reference spectral information, when the correlation coefficient R is greater than the corresponding When the threshold is reached, it is judged as a living body; otherwise, it is judged as a non-living body.

In the above-mentioned live fingerprint detection method, the detection method further comprises the following steps:

In the case of n valid entries, calculate the correlation coefficient R between the spectral information of each entry and the other n-1 entries, take the lowest correlation coefficient R_min, and perform a specific formula calculation with the system setting parameter k to obtain the entry Compared with the decision threshold R_t, when there are n-1 or more than the corresponding decision threshold, it is considered that the test is a living body, otherwise it is judged as a non-living body, wherein the specific formula is: R_t=max(R_min, k).

In the above-mentioned live fingerprint detection method, the detection method further includes the step of consistency judgment of spectral features:

During each entry, the entered spectral information is processed according to the comparison process, and the correlation coefficient between the entered data and the already entered spectral information is calculated. If the correlation coefficient is less than the system setting value m, the entry fails. Optionally, compare the correlation coefficients between the spectral parameters of each entry and the spectral parameters of specific prosthetic materials already in the system, and if there is a data correlation coefficient greater than the system threshold q, the entry fails.

In the above-mentioned live fingerprint detection method, the detection method further includes the step of entering data update:

It should be understood by those skilled in the art that the embodiments of the present invention shown in the foregoing description and drawings are only examples and do not limit the present invention. The objects of the present invention have been fully and effectively accomplished. The functions and structural principles of the present invention have been shown and described in the embodiments, and the embodiments of the present invention may have any deformation or modification without departing from the principles.

Claims

A live fingerprint detection device, characterized in that it comprises:

a light source, wherein the light generated by the light source is emitted to the fingerprint to be tested; and

An identification module, wherein the identification module includes at least one sensor and an optical component, the optical component is located in the optical path of the at least one sensor, and the reflected light of the fingerprint to be tested reaches the At least one sensor, wherein the at least one sensor performs live fingerprint judgment based on the spectral information of the received reflected light.
The living fingerprint detection device according to claim 1, wherein the identification module further comprises a bracket and a circuit board, wherein the sensor is electrically connected to the circuit board, and the bracket is arranged on the circuit board , the optical assembly is arranged on the bracket, the optical assembly is supported by the bracket, and the optical assembly is kept in the photosensitive path of the sensor.
The living fingerprint detection device according to claim 2, wherein the light source is arranged on the circuit board.
The living fingerprint detection device according to claim 3, wherein the identification module further includes a transparent cover and a support, wherein the support is sleeved on the outside of the bracket and supported by the support The transparent cover is above the optical assembly.
The living fingerprint detection device according to claim 3, wherein the identification module further includes a transparent cover, wherein the transparent cover is arranged on the bracket, and the transparent cover is supported by the bracket on the above the optical assembly.
The live fingerprint detection device according to claim 2, wherein the bracket includes a bracket main body, a lens support part and a cover support part, wherein the lens support part is located at the upper end of the cover support part, the The light source and the second circuit board are arranged on the lens supporting part of the bracket.
The living fingerprint detection device according to claim 4 or 5, wherein said circuit board further comprises a first circuit board and a second circuit board, wherein said sensor is arranged on said first circuit board, said light source It is arranged on the second circuit board.
The living fingerprint detection device according to claim 7, wherein the circuit board further comprises at least one connection line, wherein the connection line electrically connects the first circuit board and the second circuit board.
The living fingerprint detection device according to claim 7, wherein the circuit board further includes a soft board, wherein the soft board is arranged on the first circuit board and the second circuit board, and passes through the flexible board. A board electrically connects the first wiring board and the second wiring board.
The living fingerprint detection device according to claim 1, wherein the identification module further comprises to There is at least one homogenizing element, wherein the at least one homogenizing element is arranged on the light-emitting path of the light source.
The living fingerprint detection device according to any one of claims 1 to 10, wherein the sensor is a spectral sensor.
The living fingerprint detection device according to claim 1, wherein the identification module includes a spectral sensor, an imaging sensor, and a spectroscopic element, wherein the spectroscopic element is located in the optical path of the spectral sensor and the imaging sensor, The detection light is divided into a first detection light and a second detection light by the spectroscopic element, wherein the first detection light is deflected by the spectroscopic element and reaches the spectrum sensor, and the second detection light is split by the spectroscopic The element passes through and reaches the imaging sensor, the spectrum sensor obtains the spectral information of the object under test through the first detection light, and the imaging sensor obtains the image information of the object under test through detecting the second detection light.
The fingerprint detection module is characterized in that it includes:

Spectrum chip;

A circuit board, wherein the spectrum chip is arranged on the circuit board and electrically connected to the circuit board;

bracket;

A transparent cover, wherein the transparent cover is supported by the support on the photosensitive path of the spectrum chip, the transparent cover includes a collection part and a non-collection part integrally extending outward from the collection part; and

A light source assembly, wherein the light source assembly is located at the side of the transparent cover, and the light emitted by the light source assembly is incident on the collection portion from the non-collection portion of the transparent cover.
The fingerprint detection module according to claim 13, wherein the transparent cover further has an upper surface and a lower surface, wherein the upper surface is opposite to the lower surface, and the light source assembly is mounted on the transparent cover The outer side of the non-collecting portion of the plate emits light toward the direction of the transparent cover, and forms at least one incident light path between the upper surface and the lower surface of the transparent cover.
The fingerprint detection module according to claim 14, wherein the light source assembly comprises at least one light source and at least one light uniformity member, and the light uniformity member is located between the light source and the transparent cover.
The fingerprint detection module according to claim 15, wherein the dodging element is integrally formed on the outside of the non-collecting portion of the transparent cover.
The fingerprint detection module according to claim 15, wherein the light source and the dodging member surround the transparent cover, and the light emitted by the light source enters the dodging member vertically, and then passes through the dodging member. The component is incident to the transparent cover plate along the horizontal direction.
The fingerprint detection module according to claim 15, further comprising an optical assembly, said optical assembly It is arranged in the photosensitive path of the spectrum chip, wherein the optical component is supported by the support between the transparent cover plate and the spectrum chip.
The fingerprint detection module according to claim 18, wherein the bracket comprises a bracket body and an extension unit integrally extending inward from the bracket body, wherein the light source assembly and the transparent cover are supported on the bracket The upper end of the main body, the optical assembly is fixedly supported by the extension unit.
The fingerprint detection module according to claim 18, wherein the support includes a first support and a second support, wherein the first support is located outside the second support, the transparent cover and the light source assembly Being supported on the upper end of the first bracket, the optical assembly is fixed and supported by the second bracket.
The fingerprint detection module according to any one of claims 14 to 20, wherein the transparent cover further comprises a light-shielding layer, wherein the light-shielding layer is disposed on the lower surface of the transparent cover.
The fingerprint detection module according to claim 21, wherein the light-shielding layer is selected from a material combination consisting of a reflective film and an absorbing film.
The fingerprint detection module according to any one of claims 14 to 20, further comprising a light-gathering layer, wherein the light-gathering layer is arranged on the upper surface of the transparent cover, and the refraction of the light-gathering layer The index is greater than the refractive index of the transparent cover.
The fingerprint detection module according to claim 21, further comprising a light-gathering layer, wherein the light-gathering layer is arranged on the upper surface of the transparent cover, and the refractive index of the light-gathering layer is greater than that of the The refractive index of the transparent cover.
The fingerprint detection module according to claim 13, wherein the spectrum chip has a modulation area and a non-modulation area, the modulation area is concentratively arranged at the four corners or the peripheral area of the spectrum chip, and the non-modulation area is located at The central area of the spectrum chip.
The fingerprint detection module according to claim 13, wherein the optical component of the fingerprint detection module is a microstructure array, and the spectrum chip includes a filter structure and an image sensor, wherein the microstructure array and the filter The optical structure is located on the light-sensing path of the image sensor, and the microstructure array, the filter structure and the image sensor are sequentially stacked and integrated.
The fingerprint detection module according to claim 13, wherein the energy of the incident light emitted by the light source component in the 400-600nm band is greater than or equal to 80%.
The live fingerprint identification system is characterized in that it includes:

control unit;

The fingerprint detection module as claimed in any one of claims 13 to 27; and

A processing unit, wherein the processing unit and the fingerprint detection module are electrically connected to the control unit, the fingerprint detection module obtains the identification spectral response data of the object to be identified, and based on the set reference spectral response data A recognition result of the object to be recognized is determined by a comparison result with the recognition spectral response data.
A living fingerprint detection method, characterized in that, comprising:

(a) Obtain light intensity information for fingerprint collection;

(b) obtaining fingerprint images and spectral information based on the obtained light intensity information; and

(c) comparing the fingerprint image and the spectral information with the entered reference information, and when the matching degree is higher than a threshold, the input verification is passed; otherwise, the output verification fails.
The living fingerprint detection method according to claim 29, wherein the detection method further comprises: modifying light intensity information, wherein the light intensity information correction includes an image processing method of surrounding average value compensation.
The living fingerprint detection method according to claim 30, wherein in the image information correction, the intensity value of the spectral pixel will be replaced by the intensity value of the weighted average of the intensity of the nearby ordinary physical pixels, thereby generating the corrected picture parameters for obtaining fingerprint image.
The living fingerprint detection method according to claim 30, wherein the detection method further includes: the step of correcting the spectral information corresponding to the spectral pixel, dividing or subtracting the intensity value of the current spectral pixel by the weighted average intensity of adjacent ordinary pixels value, and obtain the relative intensity, which can be used as the corrected spectral information for subsequent processing.
The living fingerprint detection method according to claim 32, wherein the detection method further comprises: the step of determining the living body, calculating the correlation coefficient R formed by the effective corrected spectral information extracted after the original data is processed and the entered reference spectral information, when When the correlation coefficient R is greater than the corresponding threshold, it is determined as a living body; otherwise, it is determined as a non-living body.
The living fingerprint detection method according to claim 32, wherein said detection method further comprises the following steps:

In the case of n valid entries, calculate the correlation coefficient R between the spectral information of each entry and the other n-1 entries, take the lowest correlation coefficient R_min, and perform a specific formula calculation with the system setting parameter k to obtain the entry Compared with the decision threshold R_t, when there are n-1 or more than the corresponding decision threshold, it is considered that the test is a living body, otherwise it is judged as a non-living body, wherein the specific formula is: R_t=max(R_min, k).
The living fingerprint detection method according to claim 129, wherein said detection method further comprises the step of judging the consistency of spectral features:

During each entry, the entered spectral information is processed according to the comparison process, and the correlation coefficient between the entered data and the already entered spectral information is calculated. If the coefficient is less than the system setting value m, the entry fails.
The living fingerprint detection method according to claim 29, wherein said detection method further comprises the step of entering data update:

After each successful detection, calculate the correlation coefficient between the spectral information of this judgment and the n input data, and obtain the corresponding average value R_atest, and compare it with the average value R_a1~n of the correlation coefficient between the n input data, If R_atest is greater than one or more of R_a1~n, use the data of this test to replace the smallest data among R_a1~n in the input data.