CN116935451A - Living body fingerprint identification system and fingerprint detection module - Google Patents

Abstract

The invention provides a living body fingerprint identification system and a fingerprint detection module, wherein the fingerprint detection module comprises a spectrum chip, a circuit board, an optical component and a bracket, wherein the spectrum chip is arranged on the circuit board and is electrically connected with the circuit board, the bracket is arranged on the circuit board, the optical component is fixed by the bracket and is supported on a photosensitive path of the spectrum chip through the bracket, so that reflected light of a fingerprint to be detected is received by the spectrum chip through the optical component, and fingerprint information detection is carried out by the spectrum chip based on spectrum information of the reflected light.

Description

Living body fingerprint identification system and fingerprint detection module

Technical Field

The invention relates to the field of fingerprint detection, in particular to a living body fingerprint identification system and a fingerprint detection module.

Background

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 types of terminal devices, such as smart phones for consumers, due to their small size, high performance, and high user acceptance. At present, various fingerprint sensing systems are circulated in the market, such as a sensing system based on a capacitive fingerprint module, a sensing system based on an optical fingerprint module and the like, and the fingerprint sensing system of the type can realize unlocking, but after being applied to fingerprint identification unlocking of a mobile terminal, lawless persons can crack a security system of a user by stealing the fingerprint of the user to prepare a fake fingerprint, so that the probability of the fingerprint password of the mobile terminal being recognized is increased, and the security of information of the mobile terminal is threatened greatly.

The existing fingerprint identification equipment mainly comprises optical fingerprint identification equipment and capacitance fingerprint identification equipment, wherein the optical fingerprint identification equipment is large in size and is not beneficial to equipment integration, and the capacitance fingerprint identification equipment is high in cost and is easily limited by chip productivity. In addition, the two fingerprint devices generally have no living body detection function, and the device safety is low. The existing living fingerprint identification schemes have certain defects, such as poor environmental stability, short service life and insufficient living detection capability of the capacitive module, and the optical module generally does not have the living detection capability, so that a simple and reliable fingerprint identification scheme is needed to realize living fingerprint identification.

With the development of spectroscopic technology, fingerprint identification devices based on multispectral technology gradually appear, but the existing multispectral fingerprint living detection devices are large in size and complex in algorithm. The prism and reflector structure is basically adopted in the light path to turn the light path to improve the image contrast, and the matched illumination light sources are more in variety and quantity, so that the system can complete identification and living body detection by multiple frames of images. In addition, as the spectrum precision is not high, the living body processing algorithm is complex, and the time consumption is long and the system load is large. The existing spectrum detection equipment has small volume but complex internal structure, and does not have high-precision living body identification performance.

Disclosure of Invention

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

Another advantage of the present invention is to provide a living fingerprint identification system and a fingerprint detection module, wherein the living fingerprint identification system performs living judgment according to spectral information after percutaneous reflection, thereby realizing living detection of fingerprints and improving detection accuracy.

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

Another advantage of the present invention is to provide a living fingerprint recognition system and a fingerprint detection module, wherein the living fingerprint recognition system includes a light source and a recognition module, wherein the light source is disposed at or adjacent to the recognition module, and is used by the light source for illuminating a fingerprint to be detected.

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

The invention further provides a living body fingerprint identification system and a fingerprint detection module, wherein the living body fingerprint identification system obtains original data, namely light intensity information, respectively carries out image information correction and spectrum information correction on the original data, then respectively adopts a fingerprint identification algorithm and a living body algorithm, compares fingerprint images and spectrum information with corresponding information extracted during input to obtain matching degree, and when the matching degree is higher than a threshold value, input verification is passed, otherwise output verification fails.

Another advantage of the present invention is to provide a living fingerprint identification system and a fingerprint detection module, wherein the living fingerprint detection method includes image information correction and spectrum information correction including image processing mode of surrounding mean value compensation (binding), and the accuracy of data detection is improved by weighted average.

The invention further provides a living fingerprint identification system and a fingerprint detection module, wherein the living fingerprint detection method further comprises a living algorithm flow, the effective correction spectrum parameters (or spectrum information) extracted by processing the original data (light intensity information) and the corresponding parameters of the input data form a data set, a correlation coefficient R after straight line fitting is calculated, when the correlation coefficient R is larger than a corresponding threshold value, the living body is judged, and otherwise, the living body is judged to be non-living body.

According to an aspect of the present invention, there is provided a fingerprint detection module, including:

a spectrum chip;

a circuit board, wherein the spectrum chip is arranged on the circuit board and is electrically connected with the circuit board; and

the optical component is positioned on a photosensitive path of the spectrum chip and used for receiving reflected light of the fingerprint to be detected by the spectrum chip through the optical component and detecting fingerprint information based on spectrum information of the reflected light by the spectrum chip.

According to one embodiment of the present invention, the fingerprint detection device further comprises a light source assembly, wherein the light source assembly is arranged on the circuit board and is electrically connected with the circuit board, and light generated by the light source assembly is emitted to the fingerprint to be detected.

According to one embodiment of the present invention, the optical component is fixed by the bracket, and the optical component is supported on the photosensitive path of the spectrum chip by the bracket.

According to one embodiment of the invention, further comprising a transparent cover plate, wherein the transparent cover plate is disposed on the support, wherein the transparent cover plate is located above the optical assembly.

According to one embodiment of the present invention, the support includes a first support and a second support, wherein the first support is located outside the second support, the transparent cover plate is fixed to the first support, the optical component is disposed on the second support, and the optical component is supported on the photosensitive path of the spectrum chip through the second support.

According to one embodiment of the present invention, the light source assembly further comprises at least one light source, the first bracket is further provided with at least one package cavity, wherein the light source of the light source assembly is located in the package cavity of the first bracket, and the bracket is made of transparent material.

According to an embodiment of the present invention, the fingerprint detection module further includes a heat dissipation element, wherein the heat dissipation element is disposed on the circuit board, and the temperature of the fingerprint detection module is reduced by the heat dissipation element.

According to one embodiment of the present invention, the holder includes a holder body and an extension unit integrally extended inward from the holder body, and the optical component is fixed to the photosensitive path of the spectrum chip by the extension unit of the holder.

According to one embodiment of the present invention, the holder main body further includes a holder upper end portion and a holder lower end portion integrally extending downward from the holder upper end portion, wherein the holder lower end portion is fixed to the wiring board, and the light source assembly is located outside the holder lower end portion, wherein the holder main body of the holder is a transparent material.

According to one embodiment of the present invention, the light source assembly further includes at least one light source, and the bracket body is further provided with an avoidance space, wherein the light source is located in the avoidance space of the bracket body.

According to one embodiment of the present invention, the escape space of the bracket body is formed at a lower end portion of the bracket body, wherein the escape space is a space with a one-sided opening facing downward; or the side of the avoidance space is provided with an opening which can at least partially accommodate the light source.

According to an embodiment of the present invention, the holder further includes a light shielding unit, wherein the light shielding unit is a light shielding material having a light shielding property, wherein the light shielding unit is formed at a lower end portion of the holder and a lower end of the extension unit of the holder body.

According to one embodiment of the present invention, the holder includes a holder body and an extension unit integrally extended inward from the holder body, wherein the optical assembly is fixed to the extension unit of the holder, and the transparent cover plate is fixed to an upper end of the holder body.

According to one embodiment of the present invention, the circuit board includes a first circuit board and a second circuit board, wherein the spectrum chip is disposed on the first circuit board, the light source assembly is disposed on the second circuit board, and the second circuit board is fixed to the extension unit of the bracket.

According to one embodiment of the present invention, the light source set price includes at least one light source and at least one light homogenizing member located in an emitting direction of the at least one light source, wherein the light homogenizing member is located on a light emitting path of the light source, and light emitted by the light source is homogenized by the light homogenizing member.

According to one embodiment of the present invention, the circuit board further includes a connection unit, wherein the connection unit connects the first circuit board and the second circuit board, and the light source of the light source assembly is conducted with the spectrum chip provided to the first circuit board through the connection unit.

According to one embodiment of the present invention, the device further comprises a light source component and a prism, wherein the light source component is adjacent to the prism, wherein the light emitted by the light source component reaches the area to be measured through the prism, and the reflected light of the fingerprint to be measured is refracted to the optical component through the prism and then received by the spectrum chip through the optical component.

According to an embodiment of the invention, the prism has a light incident surface, a detection surface and at least one light emergent surface, wherein the light source assembly is forward opposite to the light incident surface of the prism, and the light emitted by the light source assembly enters the prism through the light incident surface of the prism to reach the detection surface.

According to one embodiment of the present invention, the light source assembly is disposed at the bottom of the prism, wherein the light source assembly further comprises at least one light source and a light homogenizing layer, wherein the light homogenizing layer is disposed on the light incident surface of the prism, the light source is forward opposite to the light homogenizing layer, and wherein the light emitted by the light source is homogenized through the light homogenizing layer.

According to one embodiment of the invention, the optical component of the fingerprint detection module is a microstructure array, the spectrum chip comprises a light filtering structure and an image sensor, wherein the microstructure array and the light filtering structure are positioned on a photosensitive path of the image sensor, and the microstructure array, the light filtering structure and the image sensor are sequentially stacked and integrated into a whole.

According to one embodiment of the invention, the energy of the incident light emitted by the light source assembly in the 400-600nm wave band is 80% or more.

According to one embodiment of the invention, the light source assembly emits incident light having an energy in the 400-500nm band of no more than 80% of the energy in the 500-600nm band.

According to another aspect of the present invention, there is further provided a living body fingerprint recognition system including:

A main control unit;

an imaging unit, wherein the imaging unit comprises an imaging device and a spectrum chip, and the imaging device is positioned on a photosensitive path of the spectrum chip;

an illumination unit, wherein the illumination unit is located around the imaging unit; and

the algorithm unit, the imaging unit and the lighting unit are connected with the main control unit, the main control unit controls the lighting unit to emit detection light to an object to be detected, reflected light of the object to be detected is received by the spectrum chip through the imaging device, light intensity information of the reflected light is obtained, and the algorithm unit identifies fingerprint information of the object to be detected based on the light intensity information.

Drawings

Fig. 1 is a schematic diagram of a living body fingerprint recognition system according to the present invention.

Fig. 2 is a schematic diagram of a frame of the living body fingerprint recognition system according to the present invention.

Fig. 3 is a schematic diagram of a white LED luminescence spectrum of the living body fingerprint recognition system according to the present invention.

Fig. 4 is a system frame diagram of the living body fingerprint recognition system according to the present invention.

Fig. 5 is a flowchart of an identification method of the living body fingerprint identification system according to the present invention.

Fig. 6 is a schematic diagram of a spectrum chip structure of a fingerprint detection module according to the present invention.

Fig. 7 is a schematic diagram of a frame of the fingerprint detection module according to the present invention.

Fig. 8 is a schematic view of the microstructure of a sensor of the fingerprint detection module according to the present invention.

Fig. 9 is a schematic diagram of a spectral pixel structure of the sensor of the fingerprint detection module according to the present invention.

Fig. 10 is a schematic structural diagram of a spectrum chip of the sensor of the fingerprint detection module according to the present invention.

Fig. 11 is a schematic view of the microstructure of the spectrum chip of the sensor of the fingerprint detection module according to the present invention.

Fig. 12 is a schematic diagram of a physical pixel of a spectrum chip of the sensor of the fingerprint detection module according to the present invention.

Fig. 13 is a schematic structural diagram of the fingerprint detection module according to the present invention.

Fig. 14 is a schematic structural diagram of a fingerprint detection module according to a first preferred embodiment of the present invention.

Fig. 15 is a schematic diagram of another alternative implementation of the fingerprint detection module according to the first preferred embodiment of the present invention.

Fig. 16 is a schematic diagram of another alternative implementation of the fingerprint detection module according to the first preferred embodiment of the present invention.

Fig. 17 is a schematic structural diagram of a fingerprint detection module according to a second preferred embodiment of the present invention.

Fig. 18 is a schematic structural diagram of a fingerprint detection module according to a third preferred embodiment of the present invention.

Fig. 19 is a schematic diagram of another alternative implementation of the fingerprint detection module according to the above preferred embodiment of the present invention.

Fig. 20 is a schematic view of a surface structure of a microlens array of the fingerprint detection module according to the above preferred embodiment of the present invention.

Fig. 21 is a schematic structural diagram of a fingerprint detection module according to a fourth preferred embodiment of the present invention.

Fig. 22 is a schematic diagram of another alternative implementation of the fingerprint detection module according to the fourth preferred embodiment of the present invention.

Fig. 23 is a schematic diagram of a frame structure of the fingerprint detection module according to a fifth preferred embodiment of the present invention.

Fig. 24 is a schematic structural diagram of another alternative implementation of the fingerprint detection module according to the fifth preferred embodiment of the present invention.

FIG. 25 is a schematic diagram of another embodiment of the fingerprint detection module according to the fifth preferred real-time exchange rate of the present invention.

Fig. 26 is a schematic diagram of fingerprint area division according to the identification method in any of the above preferred embodiments of the present invention.

Detailed Description

The technical scheme of the embodiment of the application will be described below with reference to the accompanying drawings. It is apparent that the described embodiments relate only to some, but not all, embodiments of the application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the disclosed embodiments, are within the scope of the present application. The terms "comprising" and "having" and any variations thereof, in the description and claims of the present application, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of steps or elements is not limited to only those listed but may alternatively include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

It will be understood by those within the art that certain terms, such as those used in the specification and claims, may be used in any orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which are merely for convenience of description and to simplify the description, rather than to indicate or imply that the devices, mechanisms, structures or elements being referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore the above terms should not be construed as limiting the application. Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one implementation of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

Overview of living fingerprint identification System and fingerprint detection Module

The living fingerprint identification system of the application belongs to optical fingerprint identification, adopts a direct shooting mode, and an imaging unit of the living fingerprint identification system directly images a finger placed on a transparent cover plate, thereby greatly reducing the volume of a module. In addition, the imaging can acquire spectral information generated by reflection of an object to be detected, and accurate living body detection is carried out, so that the safety level of the system is greatly improved. The living fingerprint identification of the application also covers the identification of living palmprint.

As shown in fig. 1, due to physiological characteristics such as capillaries (blood) and sweat pores in human skin, the human skin is difficult to forge as compared with fingerprint lines, and due to the physiological characteristics, the skin has different spectral absorption/reflection degrees of different wave bands, which means that living body judgment can be performed according to spectral information reflected by the skin, so that living body detection of fingerprints is realized. Specifically, as shown by the reflection spectrum test on the real finger and the finger model material, the difference between the reflection spectrum of the real finger and the reflection spectrum of the finger model material is huge at the wavelength of 300nm-1100nm, and as shown in fig. 1, the difference between the reflection spectrum data corresponding to the real finger and the reflection spectrum data corresponding to the finger model material is large by taking the test of silica gel, paper, human skin and the like as an example. Therefore, it is possible to make a living body judgment by the received reflection spectrum.

The living body fingerprint recognition system of the present application is shown in fig. 2 to 4, wherein the living body fingerprint recognition system includes a main control unit 100, an imaging unit 200, an illumination unit 300, and an algorithm unit 400, wherein the main control unit 100 is electrically connected to the imaging unit 200, the illumination unit 300, and the algorithm unit 400, and the imaging unit 200, the illumination unit 300, and the algorithm unit 400 are controlled to operate by the main control unit 100. The illumination unit 300 emits an incident light, the incident light irradiates an object to be measured (finger, palm, etc.) and is reflected to form a reflected light with detection information, the reflected light is received by the imaging unit 200, corresponding light intensity information is obtained, and the light intensity information is processed by the algorithm unit 400, so as to identify texture and/or living body information of the object to be measured.

Preferably, the incident light emitted through the illumination unit 300 is uniform light. Thus, in the present application, the lighting unit 300 includes a light source and a light homogenizing member, which may be a light homogenizing member, for homogenizing incident light projected from the light source. The imaging unit 200 includes an imaging device and a spectrum chip, the imaging device being located on a photosensitive path of the spectrum chip, wherein the imaging device may further include a lens group, a filter, and the like. The algorithm unit 400 may provide a texture image restoration algorithm, and/or a living body recognition algorithm in the present application. The illumination unit 300 is disposed around the imaging unit, and the light source and the spectrum chip are electrically connected and fixed to the same circuit board; the light source and the spectrum chip can also be separately arranged on different circuit boards, for example, the circuit boards for arranging the light source can be independently arranged on a bracket. Preferably, the light sources are symmetrically distributed about the imaging unit, may be distributed along a circular ring, a square ring, or left-right multi-point symmetry, i.e. the identification system may have one or more light sources in the present application.

The light source is an LED, wherein the light source is a white light LED or a monochromatic LED with specific wavelength, such as an optical combination of red, green and blue plus NIR. In living body identification, the main principle is that the physiological characteristics cause the spectrum absorption/reflection degree of the skin to be different in different wave bands. Experiments have shown that skin is relatively sensitive to spectral absorption/reflection at 400-600nm, especially 500-600nm. Therefore, the light source of the present invention preferably emits incident light having a strong intensity in the 400-600nm range, while the light intensities in the other bands are relatively weak. More preferably 500-600nm has a strong light intensity. For example, the source spectrum relative intensity distribution satisfies: the energy is mainly distributed between 500nm and 600nm, the distribution in the interval is relatively flat, and no obvious peak exists; 400 nm-500 nm has a small amount of energy distribution, the energy integral of which is not higher than 80% of the interval of 500-600nm, and no significant peak exists; the light intensity is as weak as possible in the spectral range outside 400-600nm, and the energy sum in this interval is not higher than 20% of the total radiation energy sum of the light source.

As shown in fig. 4, the recognition system may further include a wake-up unit 500, wherein when the recognition system is in a standby state, the wake-up unit 500 activates the recognition system to be transferred to a normal operation state when a finger is approaching or touching. The wake-up unit 500 may use an infrared correlation mechanism or a wake-on-touch mechanism, for example, a trigger capacitor is mounted on a circuit board, and when an object to be detected contacts the recognition system, the recognition system is woken up.

As shown in fig. 5, a fingerprint recognition method of the recognition system according to the present application is illustrated according to another aspect of the present application. The fingerprint texture and the living body identification or detection flow can be processed in parallel or in series according to the system performance and actual needs, and the living body detection function can be independently switched on and off. Specifically, the finger to be measured is placed in the region to be measured, the illumination unit 300 emits an incident light to the finger to be measured, a part of the incident light is absorbed by the finger to be measured, and a part of the incident light is reflected to form a reflected light, the reflected light is collected by the imaging unit 200 to obtain corresponding light intensity information, the light intensity information comprises image information and spectrum information, the image information is used for fingerprint image identification, and the spectrum information is used for spectrum data analysis to perform living body judgment; matching the fingerprint image with a pre-stored reference fingerprint image, and judging a living body by utilizing spectrum information in parallel or in series; if both pass, the verification is successful; otherwise the system will alarm.

Referring to fig. 6 to 13 of drawings, a fingerprint detection module according to another aspect of the present application is illustrated in the following description. The fingerprint detection module comprises a spectrum chip 10 and a circuit board 20, wherein the spectrum chip 10 is electrically connected to the circuit board 20 and is used for receiving reflected light and acquiring light intensity information. Specifically, the spectrum chip 10 includes a filter structure 11 and an image sensor 12, the filter structure 11 is located on a photosensitive path of the image sensor 12, and the filter structure 11 is a broadband filter structure in a frequency domain or a wavelength domain. The passband spectra of the different wavelengths of the filter structure 11 are not exactly the same throughout. The filter structure 11 may be a structure or a material having a filter property such as a super surface, a photonic crystal, a nano-pillar, a multilayer film, a dye, a quantum dot, a MEMS (micro electro mechanical system), an FP etalon, a cavity layer, a waveguide layer, a diffraction element, or the like. For example, in the embodiment of the present application, the optical filtering structure 11 may be a light modulation layer in chinese patent CN 201921223201.2. The image sensor 12 may be a CMOS Image Sensor (CIS), CCD, array photodetector, or the like. The spectroscopic device further includes a data processing unit, which may be a processing unit such as MCU, CPU, GPU, FPGA, NPU, ASIC, that can export data generated by the image sensor 12 to the outside for processing.

The spectrum chip 10 is used for acquiring finger line image information and finger spectrum characteristic information to realize verification of finger biological characteristics, wherein the chip size range is between 1/9 'and 1/1.6', the imaging spatial resolution is above 5 ten thousand pixels, and the spectrum chip has the spectrum discrimination capability of the light to be detected, which is equivalent to the spectrum resolution below 30 nm. The spectrum chip 10 may be attached to the circuit board 20 by COB or CSP packaging, FC packaging technology.

It should be noted that, in the present application, the spectrum chip 10 records the intensity signal of the incident light at different wavelengths λ as f (λ), the transmission spectrum curve of the filtering structure as T (λ), and the spectrum chip 10 has m groups of filtering structures, each group of transmission spectrums being different from each other, which are also called "structural units", and may be collectively referred to as Ti (λ) (i=1, 2,3, …, m). And corresponding physical pixels are arranged below each group of filter structures, and the light intensity information Ii modulated by the filter structures is detected. In the present application, a group of structural units corresponding to one physical pixel is described as an example, but the present application is not limited thereto, and in other embodiments, a plurality of physical pixels may be grouped to correspond to a group of structural units.

The relationship between the spectral distribution of the 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, noted as:

Si(λ)＝Ti(λ)·R(λ)

the above equation can be extended to a matrix form:

where 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, and corresponds to the light intensity information of the m image sensors, which is also called m "physical pixels", and is a vector with a length of m. S is the optical response of the system for different wavelengths, and is determined by two factors, namely the transmissivity of the filtering structure and the quantum efficiency of the response of the image sensor. S is a matrix, each row vector corresponds to the response of a structural unit to incident light with different wavelengths, wherein the incident light is discretely and uniformly sampled, and n sampling points are all used. The number of columns of S is the same as the number of samples of the incident light. Here, f (λ) is the intensity of the incident light at different wavelengths λ, i.e. the spectrum of the incident light to be measured.

In practical applications, the response parameter S of the system is known, and the spectrum f (can be understood as spectrum recovery) of the input light can be obtained by using algorithm to back-calculate through the light intensity reading I of the image sensor, and the process can adopt different data processing modes according to the situation, including but not limited to: least squares, pseudo-inverses, equalizations, least squares, artificial neural networks, etc.

Taking one physical pixel corresponding to one group of structural units as an example, how to recover one spectrum information, which is also called as a "spectrum pixel", by using m groups of physical pixels (i.e., pixel points on an image sensor) and m groups of corresponding structural units (the same structure on a modulation layer is defined as a structural unit) are described above. It should be noted that, in the embodiment of the present application, a plurality of physical pixels may correspond to a set of structural units. It may be further defined that a group of structural elements and corresponding at least one physical pixel constitute a unit pixel, in principle at least one unit pixel constitutes one of said spectral pixels.

On the basis of the implementation mode, the spectral pixels are subjected to array processing, so that the snapshot type spectral imaging device can be realized.

As shown in fig. 8, with an image sensor of 1896×1200 pixels (fig. 8 shows a partial area of the image sensor), and m=4 is selected, i.e. 4*4 unit pixels are selected to form one spectrum pixel, 474×300 spectrum pixels independent of each other can be implemented, where each spectrum pixel can separately calculate the spectrum result by the above method. After the image sensor is matched with components such as a lens group, the object to be detected can be subjected to snapshot spectrum imaging, so that spectrum information of each point of the object to be detected can be obtained through single exposure.

On the basis, the selection mode of the optical pixels can be rearranged according to actual needs under the condition that the image sensor does not need to be adjusted, so that the spatial resolution is improved. As shown in fig. 9, the close-packed arrangement of the solid line boxes and the dashed line boxes may be selected to increase the spatial resolution from 474×300 to approximately 1896×1200 in the above example.

Further, the spatial resolution and the spectral resolution can be rearranged as required for the same image sensor. For example, in the above example, when the spectral resolution requirement is high, 8×8 unit pixels may be used to form one spectral pixel; when the spatial resolution requirement is high, 3*3 physical pixels can be used to form one spectral pixel. That is, the spectrum chip 10 may acquire light intensity information, which may be used for imaging or for spectrum recovery. For example, in a living body fingerprint identification system, the light intensity information may include image information for fingerprint line image restoration and spectrum information for judging a living body.

In the present invention, the spectrum chip 10 has a modulation area 101 and a non-modulation area 102, wherein the modulation area 101 is provided with a filtering structure on the optical path of the image sensor 12, and the non-modulation area 102 is not provided with a filtering structure correspondingly, that is, the incident light is modulated by the filtering structure in the modulation area and then received by the image sensor 12. Whereas the non-modulated regions 102 are not modulated, for example, when the image sensor is a CMOS chip, the non-modulated regions 102 are implemented directly as black and white pixels (i.e., no bayer array is provided on the CMOS chip). Preferably, the modulation region 101 may acquire spectral information, and the non-modulation region 102 acquires image information. In various embodiments, the non-modulated regions 102 may also be implemented as bayer arrays, microlens arrays, convex lenses, concave lenses, fresnel lenses, etc. to modulate the incident light.

In the present invention. The area of the modulation region 101 occupies 10% -50%, preferably 12% -25% of the area of the effective area of the spectrum chip 10. Optionally, at least a portion of the modulated regions 101 and the non-modulated regions 102 are spaced apart. Therefore, in the process of processing and analyzing, the image information of the non-modulation region 102 around the modulation region 101 can be used to combine with the spectrum information of the modulation region 101, and the spectrum information can be optimized by using the image information, for example, the image information can be used to remove noise and the like, so that the spectrum information is more accurate. Specifically, the image information of the peripheral non-modulated regions 102 may be averaged, and the value of the modulated regions 101 may be divided by or subtracted from the average value of the image information of the peripheral non-modulated regions 102 of the modulated regions 101; spectral information may also be used to assist in image recovery from image information. Thus, the spectrum information has more information, and because the modulation region 101 is provided with a structural unit, which is different from the information of the non-modulation region 102, the region has information gaps during imaging, so that the spectrum information acquired by the modulation region 101 can be used for calculating to compensate the image information of the region or correcting the image information of the adjacent region. For example, as shown in the figure, the filtering structure 11 corresponds to one physical pixel, and two adjacent filtering structures are separated by two physical pixels; i.e. 1 physical pixel with a structural unit is surrounded by 8 physical pixels.

In the present application, since the modulated regions 101 may lack image information for calculation, the image information values of the modulated regions 101 may also be calculated using the image information values obtained by the physical pixels of the surrounding non-modulated regions 102. Specifically, an average value of image information of peripheral physical pixels may be used as an image information value of the modulation region 101, so that the whole image is more complete, and for example, 8 physical pixels of the following figure surround physical pixels corresponding to 1 structural unit, the image information value of the intermediate modulation region may be calculated using the peripheral 8 physical pixels; the average value of 24 peripheral physical pixels can be used to calculate the image information value corresponding to the intermediate modulation region.

The circuit board 20 may be a Flexible Printed Circuit (FPC), a rigid Printed Circuit (PCB) or a rigid-flex board (F-PCB), a ceramic substrate, etc. The circuit board 20 is used for driving, controlling, data processing and outputting the light source and the sensor chip.

The fingerprint detection module further comprises an optical component 30, wherein the optical component 30 is located on the optical path of the spectrum chip 10. Preferably, in the present application, the optical component 30 is a lens group, i.e. the optical component 30 is composed of at least one lens. More preferably, the lens group is used for imaging the finger to be detected in the region to be detected on the spectrum chip 10, the FOV is between 80 degrees and 130 degrees, the back focal length is between 0.3mm and 5mm, and the total optical length is between 1mm and 10 mm. The optical assembly 30 further includes a filter element for filtering the reflected light, for example, the filter element cuts off the band of 650nm or 600nm or more, that is, only allows the reflected light of 650nm or 600nm or less to pass through, so as to prevent the external ambient light from interfering with the test result. It will be appreciated that the filter element may be adjusted or selected according to actual requirements.

The fingerprint detection module further comprises a support 40, the support 40 is disposed on the circuit board 20, the optical component 30 is disposed on the support 40, and the optical component 30 is supported by the support 40 and maintains the optical path of the spectrum chip 10.

The fingerprint detection module further comprises a transparent cover plate 50, wherein the region to be detected is formed on the surface of the transparent cover plate 50 for placing a finger to be detected or a palm to be detected, and the transparent cover plate 50 can be, but is not limited to, optical glass (glass cover plate) or optical plastic, and has a thickness of 0.8mm-1.2mm. The fingerprint detection module further comprises at least one light source assembly 60, wherein the light source assembly 60 is used for illuminating a finger to be detected or a palm to be detected. Preferably, the light emitted by the light source assembly 60 has a spectral width (. Gtoreq.30 nm). Preferably, in the present application, the light source assembly 60 may emit monochromatic light or mixed light according to the need. Preferably, the light source assembly 60 includes a light source 61 and a light homogenizing member 62, and the incident light emitted from the light source 61 is homogenized by the light homogenizing member 62 and then projected to the finger or palm to be measured.

The light homogenizing member 62 is located between the light source 61 and the transparent cover 50. The light homogenizing member 62 is made of transparent optical plastic, the surface of the light homogenizing member can be frosted, and a certain proportion of light scattering powder can be filled in the light homogenizing member. It should be noted that the upper and lower surfaces (the surface close to the light source and the surface close to the transparent cover plate) of the light homogenizing member 62 can be designed according to the light pattern of the light source, so as to diffuse the light to the greatest extent and improve the light homogenizing effect of the outer surface of the module cover plate. As shown in fig. 13, the included angle between the light source and the circuit board 20 can be adjusted to obtain a better light homogenizing effect.

Example 1

As shown in fig. 14 to 16, the fingerprint detection module according to the first preferred embodiment of the present invention is illustrated in the following description. The fingerprint detection module comprises a spectrum chip 10, a circuit board 20, an optical component 30 and a bracket 40, wherein the spectrum chip 10 is electrically connected with the circuit board 20, the optical component 30 is arranged on the bracket 40, and the optical component 30 is kept in a photosensitive path of the spectrum chip 10 through the bracket 40. The bracket 40 is fixed to the circuit board 20, and the bracket 40 is provided with a light-passing hole 401, wherein the light-passing hole 401 of the bracket 40 is located right above the optical assembly 30, and light to be detected is obtained through the light-passing hole 401 of the bracket 40.

The optical assembly 30 is implemented as a lens group, wherein the optical assembly 30 comprises at least one optical lens. The optical lens of the optical component 30 is fixed above the spectrum chip 10 by the bracket 40, and the light to be detected is processed by the optical component 30.

Accordingly, the holder 40 includes a holder body 41 and an extension unit 42 integrally extended inward from the holder body 41, wherein the light-passing hole 401 is formed at an upper end of the holder body 41 of the holder 40, the extension unit 42 extends inward from the holder body 41, and forms a supporting structure having a light-passing hole 402 in the middle, wherein the optical component 30 is disposed in the light-passing hole 402 formed by the extension unit 42, and the light-sensing path of the optical component 30 on the spectrum chip 10 is supported by the extension unit 42.

The fingerprint detection module further comprises a transparent cover plate 50, wherein the transparent cover plate 50 is arranged on the support body 41 of the support 40, and the transparent cover plate 50 is fixed and supported by the support body 41. The transparent cover plate 50 may be, but is not limited to, a transparent glass or a transparent plastic structure. The transparent cover 50 is covered on the photosensitive path of the spectrum chip 10, and the transparent cover 50 provides a structure suitable for fingerprint collection.

The fingerprint detection module further comprises a light source assembly 60, wherein the light source assembly 60 is electrically connected with the circuit board 20, and the light source assembly 60 provides a light source for the identification process of the fingerprint detection module.

Preferably, in the preferred embodiment of the present invention, the light source module 60 is disposed at the extension unit 42 of the stand 40, wherein the light emitting surface of the light source module 60 faces the transparent cover plate 50.

The circuit board 20 includes a first circuit board 21 and a second circuit board 22, wherein the first circuit board 21 is electrically connected to the spectrum chip 10, and the light source assembly 60 is electrically connected to the second circuit board 22; wherein the first wiring board 21 is disposed at a lower end of the bracket 40, and the second wiring board 22 is disposed at the extension unit 42 of the bracket 40. That is, the light source assembly 60 is fixed to the extension unit 42 of the bracket 40 through the second circuit board 22.

As shown in fig. 14, the light source assembly 60 includes at least one light source 61 and at least one light homogenizing member 62 disposed in a light emitting direction of the at least one light source 61, wherein the light homogenizing member 62 is disposed on a light emitting path of the light source 61, and light emitted from the light source 61 is homogenized by the light homogenizing member 62. It should be noted that the light source assembly 60 in the preferred embodiment of the present invention is the illumination unit 300 in the living body fingerprint recognition system.

As shown in fig. 15, in the preferred embodiment of the present invention, the wiring board 20 further includes a connection unit 23, wherein the connection unit 23 connects the first wiring board 21 and the second wiring board 22, and the light source 61 of the light source assembly 60 is conducted with the spectrum chip 10 provided to the first wiring board 21 through the connection unit 23.

The support 40 is further provided with at least one ventilation hole 403, wherein the ventilation hole 403 is communicated with the inside and the outside of the support 40, and heat in the support 40 is led out outwards through the ventilation hole 403, so that heat accumulation in the support 40 is avoided. It will be appreciated that the light source generates a significant amount of heat during operation, and the corresponding support 40, optical assembly 30 and transparent cover 50 form a relatively sealed space, which can easily cause excessive heating of the space and affect device lifetime. Accordingly, in the preferred embodiment of the present invention, the ventilation holes 403 of the supporter 40 are formed at the upper end portion of the supporter 40.

Preferably, in the preferred embodiment of the present invention, the ventilation holes 403 are formed at the top ends of the transparent cover 50 and the holder body 41 of the holder 40. Specifically, when the transparent cover plate 50 is adhered to the support 40 by using an adhesive such as glue, at least a part of the area is reserved in the process of drawing the glue, and when the transparent cover plate 50 is arranged on the support 40, the area without drawing the glue forms the ventilation holes, so that heat is discharged.

Alternatively, the ventilation holes 403 are formed in the bracket body 41 of the bracket 40, that is, the upper end of the bracket 40 is opened, the transparent cover 50 is fixed to the bracket 40, and the upper end of the bracket 40 is opened to form the ventilation holes with the transparent cover 50.

As shown in fig. 15, the connection unit 23 of the wiring board 20 communicates with the first wiring board 21 and the second wiring board 22, wherein the connection unit 23 extends from the first wiring board 21 to the second wiring board 22. Preferably, the connection unit 23 is a wire, and the connection unit 23 passes through the extension unit 42 of the bracket 40.

Accordingly, the bracket 40 is further provided with at least one through hole 404, wherein the through hole 404 penetrates the extension unit 42 of the bracket 40. One end of the connection unit 23 is connected to the second circuit board 22, and is connected to the first circuit board 21 through the through hole 404 of the bracket 40. Correspondingly, the first circuit board 21 is also provided with a corresponding fixing through hole, and the other end of the metal wire passes through the fixing through hole and is fixed on the first circuit board 21.

As shown in fig. 16, alternatively, in the preferred embodiment of the present invention, the wiring board 20 further includes a connection unit 23A, wherein the connection unit 23A electrically connects the first wiring board 21 and the second wiring board 22. In this preferred embodiment of the present invention, the connection unit 23A is implemented as a flexible board (FPC). Wherein the connection unit 23A is disposed outside the bracket 40 and has one end connected to the first circuit board 21 and the other end of the connection unit 23A is connected to the second circuit board 22. In other words, in the preferred embodiment of the present invention, the circuit board 20 has a flexible board structure, wherein the first circuit board 21 is fixed to the extension unit 42 of the bracket 40 after being folded.

Alternatively, in another embodiment of the present invention, the connection unit 23 is a circuit pattern formed on the surface of the support 40 based on a Laser Direct Structuring (LDS) technology, and the first circuit board 21 and the second circuit board 22 are electrically connected through the circuit pattern. In this preferred embodiment of the invention, the circuit pattern may also be implemented directly as the second wiring board 22, i.e. the light source is directly connected to the circuit pattern.

Optionally, in another embodiment of the present invention, the connection unit 23 is a conductive bracket formed by injection molding a conductive bracket on the bracket 40, where the connection unit 23 is a conductive circuit built in the bracket 40, and after the bracket 40 is fixed on the first circuit board 21, one end of the conductive circuit is connected to the first circuit board 21 to achieve circuit conduction, and the other end is formed on the extension portion, and when the second circuit board 22 is fixed on the extension portion, the second circuit board 22 is conducted to the other end of the conductive circuit, so as to achieve conduction between the first circuit board 21 and the second circuit board 22. In another embodiment of the present invention, the other end of the conductive circuit is directly connected to the light source 61, and the conductive circuit can be regarded as the second circuit board 22.

Example two

As shown in fig. 17, the fingerprint detection module according to the second preferred embodiment of the present invention is illustrated in the following description. The fingerprint detection module comprises a spectrum chip 10, a circuit board 20, an optical component 30, a support 40A, a transparent cover plate 50 and a light source component 60, wherein the spectrum chip 10 is electrically connected with the circuit board 20, the optical component 30 is arranged on the support 40A, and the optical component 30 is kept in a photosensitive path of the spectrum chip 10 through the support 40.

Unlike the above preferred embodiment, the support 40A includes a first support 43A and a second support 44A, wherein the first support 43A is located outside the second support 44A, the transparent cover 50 is fixed to the first support 43A, the optical component 30 is disposed on the second support 44A, and the optical component 30 is supported on the photosensitive path of the spectrum chip 10 by the second support 44A.

The second bracket 44A is provided with a light hole 440A, wherein the optical component 30 is fixed to the light hole 440A of the second bracket 44A by the second bracket 44A. It can be appreciated that the light-transmitting hole 440A of the second bracket 44A is opposite to the light-sensing surface of the spectrum chip 10. The first bracket 43A is supported on the outer side of the second bracket 44A, the optical assembly 30 is fixedly supported by the second bracket 44A, and the second bracket 44A forms a sealed environment with the optical assembly 30 and the wiring board 20. The spectrum chip 10 is placed in a sealed space formed by the second bracket 44A, the optical component 30 and the circuit board 20.

The light source module 60 is disposed between the first bracket 43A and the second bracket 44A, and unlike the first preferred embodiment described above, the light source module 60 shares the same wiring board 20 with the spectrum chip 10. The light source module 60 is disposed outside the second bracket 44A and electrically connected to the circuit board 20, and the first bracket 43A is disposed outside the light source module 60 and fixed to the circuit board 20. The light source assembly 60 includes a light source 61 and a light homogenizing member 62, and the light emitted from the light source 61 is homogenized by the light homogenizing member 62 and then projected to the area to be measured of the transparent cover plate 50.

Example III

As shown in fig. 18, the fingerprint detection module according to a third preferred embodiment of the present invention is illustrated in the following description. The fingerprint detection module comprises a spectrum chip 10, a circuit board 20, an optical component 30 and a support 40, wherein the spectrum chip 10 is electrically connected with the circuit board 20, the optical component 30 is arranged on the support 40, and the optical component 30 is kept in a photosensitive path of the spectrum chip 10 through the support 40. The bracket 40 is fixed to the upper end of the circuit board 20, wherein the optical assembly 30 is fixed to the bracket 40.

The fingerprint detection module further comprises a light source assembly 60B and a prism 70B, wherein the light source assembly 60B is adjacent to the prism 70B, wherein the light emitted from the light source assembly 60B reaches the area to be detected through the prism 70B, and the reflected light of the fingerprint to be detected is refracted to the optical assembly 30 through the prism 70B and then received by the spectrum chip 10 through the optical assembly 30.

In detail, the prism 70B has a light incident surface 701B, a detection surface 702B, and at least one light emergent surface 703B, wherein the light source assembly 60B is forward opposite to the light incident surface 701B of the prism 70B, and the light emitted from the light source assembly 60B enters the prism 70B through the light incident surface 701B of the prism 70B to reach the detection surface 702B. The detection face 702B of the prism 70B provides a detection area for detection of a finger or palm. The light-emitting surface 703B of the prism 70B corresponds to the optical component 30, and the reflected light to be detected is received by the spectrum chip 10 through the optical component 30.

Preferably, the prism 70B has a hexahedral structure, wherein the light incident surface 701B and the detection surface 702B of the prism 70B are surfaces formed at both ends of the prism 70B. Illustratively, in the preferred embodiment of the present invention, the light incident surface 701B is a bottom surface of the prism 70B, and the detection surface 702B is a top surface corresponding to the light incident surface 702B. More preferably, the light incident surface 701B of the prism 70B is forward opposite to the detection surface 702B, that is, the light incident surface 701B and the detection surface 702B of the prism 70B are surfaces parallel to each other.

The light exit surface 703B of the prism 70B is formed on a side surface of the prism 70B. Preferably, the side surface of the prism 70B extends from the light incident surface 701B to the detection surface 702B obliquely upward. It should be noted that, in the preferred embodiment of the present invention, the number of the light emitting surfaces 703B of the prism 70B may be one or more.

The light source assembly 60B is disposed at the bottom of the prism 70B, wherein the light source assembly 60B further comprises at least one light source 61B and a light homogenizing layer 62B, wherein the light homogenizing layer 62B is disposed on the light incident surface 701B of the prism 70B, the light source 61B is forward opposite to the light homogenizing layer 62B, and wherein the light emitted from the light source 61B is homogenized by the light homogenizing layer 62B.

It will be appreciated that in the preferred embodiment of the present invention, the light homogenizing layer 62B is a homogenizing material or a frosting material applied to the bottom end of the prism 70B so that the light emitted from the light source 61B is homogenized through the surface of the bottom surface. The homogenized incident light irradiates to a finger or palm to be measured positioned in the region to be measured in the prism, and then diffuse reflection is generated.

In the preferred embodiment of the present invention, the prism 70B has four sides, wherein the light-emitting surface 703B of the prism 70B is one side of the prism 70B. The light to be detected is emitted to the optical component 30 through the light emitting surface 703B of the prism 70B. Therefore, it can be understood that in the preferred embodiment of the present invention, the light-emitting surface 703B of the prism 70B is located in the light-sensing path of the spectrum chip 10.

Preferably, the other sides of the prism 70B are blackened, that is, light generated by diffuse reflection is absorbed by the other three sides, so that stray light can be reduced to a certain extent, and light which affects measurement accuracy can be prevented from being emitted from the first side.

Modified examples

As shown in fig. 19 and 20, another alternative implementation of the fingerprint detection module according to the above preferred embodiment of the present invention is illustrated in the following description. Since the recognition system needs to image the fingerprint texture, an optical component 30, such as an optical lens, is required, but the conventional optical lens is generally larger in size, especially in the optical path, which results in an excessively high module height, which is not beneficial to miniaturization.

Accordingly, in this preferred embodiment of the invention, the optical component 30 of the fingerprint detection module is implemented as a micro-structured array 110, and accordingly, in this preferred embodiment of the invention, the spectral chip comprises a filter structure 120 and an image sensor 130, wherein the micro-structured array 110 and the filter structure 120 are located on the photosensitive path of the image sensor 130. By way of example, the microstructure array is implemented as a pinhole array, a microlens array, a superlens array, or the like in the present embodiment, and the height of the module can be reduced to some extent. Alternatively, in another alternative variation, the aperture array, the microlens array or the superlens array may be integrated on the surface of the optical filtering structure, that is, the microstructure array 110, the optical filtering structure 120 and the image sensor 130 are stacked in sequence to form the fingerprint detection module.

It should be noted that, in the present invention, the fingerprint detection module includes a spectrum chip 10 composed of a filter structure 120 and an image sensor 130, i.e. the spectrum chip 10 is composed of the filter structure 120 and the image sensor 130. Further, the spectral chip 10 further comprises a modulated area 111 and a non-modulated area 112. The corresponding microstructure array according to the present invention needs to be designed according to the structural characteristics of the actual spectrum chip 10.

As shown in fig. 20, taking a microlens array as an example, the focal point of the microlens array corresponding to the microlens at the non-modulation region 112 is substantially located on the surface of the image sensor, and the region corresponding to the modulation region 111 does not need to consider whether the microlens is in focus, or even in an individual variant embodiment, the region corresponding to the modulation region 111 may not be provided with a microlens. That is, the microlenses of the non-modulation region 112 are in one-to-one relationship with the pixels (physical pixels) on the image sensor, and the microlenses of the modulation region 111 are substantially consistent with the size of the optical filtering structure, for example, when the structural units of the optical filtering structure of the modulation region 111 correspond to n×n physical pixels, the corresponding microlens size is substantially equal to the size of the physical pixels, and the size of the microlenses corresponding to the non-modulation region 112 is substantially equal to the size of the physical pixels. I.e. the microstructure array is not regular, the local microstructure of the array varies depending on the particularities of the picture elements of the image sensor.

In fig. 20, the large circles correspond to the microstructure array of the modulation region 111, and the small circles correspond to the microstructure array of the non-modulation region 112; the size of the single microlens corresponding to the modulation region 111 is greater than or equal to the size of the single microlens corresponding to the non-modulation region 112, and is desirably n×n, where n×n is the number of physical pixels corresponding to the structural unit.

Example IV

Referring to fig. 21 to 22 of drawings, a fingerprint detection module according to a fourth preferred embodiment of the present invention is illustrated in the following description. The fingerprint detection module comprises a spectrum chip 10, a circuit board 20, an optical component 30 and a support 40C, wherein the spectrum chip 10 is electrically connected with the circuit board 20, the optical component 30 is arranged on the support 40C, and the optical component 30 is kept in a photosensitive path of the spectrum chip 10 through the support 40.

The support 40C further includes a first support 43C and a second support 44C, wherein the first support 43C is located outside the second support 44C, and the optical component 30 is disposed on the second support 44C and is held in the photosensitive path of the spectrum chip 10 by the second support 44C. The optical assembly 30, the second bracket 44C and the circuit board 20 form a sealed space, wherein the spectrum chip 10 is located in the sealed space.

The fingerprint detection module further comprises a light source assembly 60C, wherein the light source assembly 60C is disposed on the circuit board 20 and electrically connected to the circuit board 20. The light source assembly 60C further includes at least one light source 61C, wherein the light source 61C may be, but is not limited to, an LED light source, and the light source 61C is disposed around the spectrum chip 10. As an example, 6 LED light sources are arranged symmetrically left and right outside the spectrum chip 10.

The first bracket 43C is fixed to the wiring board 20, and the light source 61C is at least partially enclosed by the first bracket 43C. Preferably, the first bracket 43C further has at least one package cavity 430C, wherein the light source 61C of the light source assembly 60C is located in the package cavity 430C of the first bracket 43C.

Preferably, in the preferred embodiment of the present invention, the first support 43C is made of a transparent material, for example, PC, PE, etc. is formed by injection molding, and the first support 43C is frosted, so that the first support 43C has a uniform light effect. The light emitted from the light source assembly 60 is radiated outward through the first bracket 43C.

The first bracket 43C includes a first bracket main body 431C and a mating member 432C integrally extending inward from the first bracket main body 431C, wherein the mating member 432C extends inward from a middle position of the first bracket main body 431C, and is configured to be snapped onto the second bracket 44C, so that when the first bracket 43C is in a device, the mating member 432C can be mated with the second bracket 44C (closely attached to the outer side of the second bracket 44C).

The fingerprint detection module further comprises a transparent cover plate 50, wherein the transparent cover plate 50 is disposed at the end of the first bracket 43C, and the transparent cover plate 50 is fixed and supported by the first bracket 43C.

The light source emits light, and then is homogenized by the first bracket 43C, and then is projected to the region to be measured of the transparent cover plate 50, the finger or palm to be measured is placed in the region to be measured to reflect part of the homogenized light, and the reflected light enters the spectrum chip 10 after passing through the optical component 30, so as to obtain corresponding light intensity information, and the light intensity information is used for judging whether the fingerprint is true or false or not or whether the fingerprint is living.

It can be appreciated that the first bracket 43C in this embodiment can support the transparent cover 50 to further provide the light-homogenizing effect. Further, in the manufacturing process of the first support 43C, scattering particles are added into the original light-transmitting material to improve the light-homogenizing effect, and the scattering particles may be titanium powder or the like. Further, the first bracket 43C is frosted, so that the light homogenizing effect is better.

The holder 40C further includes a light shielding layer (not shown) coated on the outside of the first holder 43C, by which the influence of external light on stray light is shielded.

As shown in fig. 23, the present invention further provides another alternative implementation of the fingerprint detection module according to the fourth preferred embodiment. The fingerprint detection module further comprises a heat dissipation element 80C, wherein the heat dissipation element 80C is disposed on the circuit board 20, and the temperature of the fingerprint detection module is reduced by the heat dissipation element 80C.

Preferably, the circuit board 20 is further provided with at least one heat dissipation port 202, wherein the heat dissipation port 202 corresponds to the light source 61C, and the heat dissipation element 80C is disposed at the heat dissipation port 202 of the circuit board 20. It will be appreciated that heat generated by the light source 61C may be conducted away by the heat sink 80C at the heat sink 202. It is understood that the heat sink 80C may be, but is not limited to, a filled heat sink material through which heat generated by the light source is rapidly exhausted.

Example five

Referring to fig. 23 to 25 of drawings, a fingerprint detection module according to a fourth preferred embodiment of the present invention is illustrated in the following description. The fingerprint detection module comprises a circuit board 20, a support 40, a spectrum chip 10, an optical assembly 30, a light source assembly 60 and a transparent cover plate 50, wherein the spectrum chip 10 is electrically connected to the circuit board 20, the support 40 is fixed on the circuit board 20, the optical assembly 30 is arranged on a photosensitive path of the spectrum chip 10 where the support 40 is located, and the transparent cover plate 50 is fixed on the support 40. The light source module 60 is provided to the wiring board 20 and is electrically connected to the wiring board 20.

The light source assembly 60 further includes at least one light source 61, wherein the light source 61 is located at the outer side of the holder 40, and light emitted from the light source 61 is incident to the transparent cover 50 through the holder 40, and thus, in the preferred embodiment of the present invention, the light source 61 is preferably obliquely disposed to the circuit board 20 or the light source 61 is disposed to have a specific oblique illumination angle, wherein light generated from the light source 61 is incident to the transparent cover 50 through the holder 40.

Preferably, in the preferred embodiment of the present invention, the support 40 is made of a transparent material, and the support 40 has a dodging effect. The light emitted by the light source 61 is homogenized by the bracket 40 and then projected toward the transparent cover 50.

More preferably, for better illumination of the transparent cover plate 50, the light source 61 is arranged at an angle α to the wiring board 20, wherein 5 ° < α < 35 °.

It will be appreciated that in this preferred embodiment of the present invention, unlike the first preferred embodiment described above, the light source assembly 60 shares the wiring board 20 with the spectrum chip 10, but the light sources 61 of the light source assembly 60 are located outside the holder 40.

The holder 40 includes a holder body 41 and an extension unit 42 integrally extended inward from the holder body 41, and the optical assembly 30 is fixed on the photosensitive path of the spectrum chip 10 by the extension unit 42 of the holder 40. The holder body 41 of the holder 40 is provided to the wiring board 20, wherein the transparent cover 50 is provided to an upper end of the holder body 41. The holder body 41 further includes a holder upper end 411 and a holder lower end 412 integrally extending downward from the holder upper end 411, wherein the holder lower end 412 is fixed to the circuit board 20, and the light source assembly 60 is located outside the holder lower end 412.

The stand 40 further includes a light shielding unit 45, wherein the light shielding unit 45 is a light shielding material having a light shielding property, and wherein the light shielding unit 45 is formed at the stand lower end portion 412 of the stand body 41 and the lower end of the extension unit 42. It will be appreciated that the light emitted by the light source enters the spectrum chip 10 through the lower end of the main body, which affects the imaging accuracy of the spectrum chip 10. Therefore, the present invention needs to apply a layer of light shielding unit 45 on the inner side surface of the lower end of the main body, so as to prevent the light emitted by the light source from directly entering the spectrum chip 10.

As shown in fig. 24 and 25, another preferred embodiment of the fingerprint detection module according to the present invention is further illustrated. Unlike the fifth preferred embodiment described above, at least part of the light source 61 is covered on the holder 40. The bracket main body 41 of the bracket 40 is further provided with an avoidance space 410, wherein the light source 61 is located in the avoidance space 410 of the bracket main body 41, so that the light emitted by the light source 61 is homogenized by the bracket 40 as much as possible, on one hand, the homogenizing effect of the light and the efficiency of projecting the light onto the transparent cover plate 50 can be improved, and on the other hand, the size in the horizontal direction can be reduced to a certain extent because the light source 61 is accommodated in the avoidance space 410.

The escape space 410 of the bracket body 41 is formed at a lower end portion of the bracket body 41, wherein the escape space 410 is a space with a one-side opening facing downward; or the side of the avoidance space 410 may be provided with an opening to at least partially accommodate the light source 61.

In another alternative embodiment of the present invention, the stand 40 further includes an outer stand (not shown) disposed outside the stand body 41. The outer frame of the frame 40 wraps the light source 61, the circuit board 20, etc. inside the outer frame, so that it can protect the light source and the circuit board from being exposed to the external environment.

As shown in fig. 26, according to another aspect of the present application, the present application further provides an identification method of the living body fingerprint identification system, wherein the living body detection method is as follows:

3 wavelengths are selected in the purple light section, 5 wavelengths are selected in the green light section, 8 wavelengths are selected in the red light section, 8 wavelengths are selected in the near infrared section, and 24 wave sections total. As shown in the following figure, the solid peripheral box represents the Sensor effective imaging region, the broken-line ellipse represents the fingerprint imaging region, and the broken-line box represents the specific region where the spectral data is extracted.

When the system detects a fingerprint image, the center of the area of the fingerprint is calculated. A fixed size a x a pixel is selected near the center, for example, box 1 in the figure. Four areas of fixed size B are selected around block 1, as indicated by blocks 2-5. The spectral values of 24 bands in 5 regions and the weights of five regions form a spectral feature vector of 1 x 125. The vector size varies with the number of regions, and the actual required vector dimension is selected according to the platform performance and security level.

The final vector can be expressed as: s= { (rλ1, …, rλn, R1) A1, (…) A2, …, (rλ1, …, rλn, rN) AN }, where R represents the spectral reflectance, λn represents a selected certain wavelength, AN represents a selected certain region, and rN represents the weight of the region.

After the specific optical system is built, a sample needs to be collected so as to confirm algorithm parameters. When the spectrum samples of the fingers of the real person are collected, attention is paid to the distribution of layers, and the spectrum samples of the fingers of different sexes, different age groups and different professions are required to be collected. And simultaneously collecting samples of various material finger molds. And training the positive and negative samples by using an SVM to obtain an SVM parameter model. When the device is used, the device extracts the spectral characteristics of the object to be detected and synthesizes the characteristic vectors to input the SVM, so that the living body detection can be completed.

It should be noted that, in this embodiment, the spectrum information does not necessarily need to restore the spectrum curve to perform the living body judgment, but may directly perform the living body judgment according to the spectrum response, specifically, obtain the reference spectrum response data of the image sensor of the spectrum-based analysis device to the reference object; acquiring identification spectrum response data of an object to be identified by the image sensor of the spectrum-based analysis device; and determining a recognition result of the object to be recognized based on a comparison result of the reference 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 apparatus, wherein the spectrum chip 10 obtains original data, namely light intensity information, the light intensity information includes image information and spectrum information, and image information correction and spectrum information correction are respectively performed on the original data; then, respectively adopting a fingerprint identification algorithm and a living body algorithm, and comparing the fingerprint image with spectrum information with corresponding reference information extracted during input to obtain a matching degree; when the matching degree of the two is higher than the threshold value, inputting verification is passed; otherwise, outputting verification failure.

Image information correction and spectral information correction include image processing methods of ambient mean compensation (binding). Therefore, in the 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 correction of image information, the intensity value of a spectral pixel (which can be understood as a filter structure formed in correspondence with a physical pixel) is replaced with an intensity value obtained by a weighted average of intensities of nearby ordinary physical pixels, thereby generating corrected image information (image data). The average value can be obtained by selecting a plurality of adjacent (e.g. 4, 8, 24, 80) common physical pixels for averaging, and when the number is greater than 4, the weighted kernel used for weighted averaging can be a uniform kernel (all physical pixels Ping Quan) or a gaussian kernel. For example, in the embodiment shown in fig. 12, a gaussian kernel of 5*5 may be used, as shown in table 1, where the middle 0 represents a spectrum pixel, that is, where the light intensity information (image information) needs to be obtained by gaussian kernel weighted average of the light intensity information (image information) of 24 physical pixels around, that is, the light intensity information value of the relevant material pixel is multiplied by the sum of corresponding coefficients and divided by the sum of weights.

TABLE 1

0.032755	0.15	0.242	0.15	0.032755
					0.007917	0.032755	0.054	0.032755	0.007917

For the acquisition of spectral information, it is necessary to avoid the effect of the brightness of the pattern at different positions on the spectral verification. For example, the different reflectivities of the fingerprint valleys and the fingerprint ridges cause different brightness and darkness, and thus may affect the judgment of the spectrum signal of the object to be measured. The living fingerprint detection method according to the preferred embodiment of the present invention further includes a step of correcting the spectral pixel intensities. For example, the intensity value of the current spectral pixel may be divided by or subtracted from the value of the weighted average (binning) of neighboring normal pixels to obtain the relative intensity, which may be subsequently processed as modified spectral information. Furthermore, the correction spectrum information can be screened according to a specific rule, and the oversized value and the undersized value are removed, so that the effectiveness of the correction spectrum information is improved. Taking fig. 12 as an example, the value of 8 physical pixels around the spectrum pixel may be taken as an average intensity value, and the intensity value of the spectrum pixel may be divided by or subtracted from the average intensity value of 8 physical pixels to obtain corrected spectrum information.

The living body fingerprint detection method of the present invention further includes a step of a living body judgment algorithm. The effective corrected spectrum parameter (may also be understood as corrected spectrum information) extracted from the processed raw data (light intensity information) is calculated, and a correlation coefficient R (for example, pearson correlation coefficient may be adopted) with the reference spectrum information is calculated, and when the correlation coefficient R is greater than a corresponding threshold value, it is determined as a living body, otherwise it is determined as a non-living body. Because the invention needs to calculate the correlation coefficient R, the input information and the detection information are one-dimensional vectorization.

The living fingerprint detection method of the present application further includes the steps of threshold selection and use. For different times of recording information, due to potential changes of various conditions during recording, the noise power ratio (signal to noise ratio) is different each time data are collected. When the signal-to-noise ratio is high, the correlation coefficient between the corresponding spectrum information and other recorded reference spectrum information is generally high; otherwise, when the signal-to-noise ratio is low, the corresponding correlation coefficient is generally low. Therefore, the judgment using the uniform threshold value is liable to introduce erroneous judgment. In this way, the application eliminates the dynamic selection of a threshold value and the corresponding use method, and can more accurately perform living body verification.

The above description is only illustrative of the preferred embodiments of the present application and of the principles of the technology employed. It will be appreciated by persons skilled in the art that the scope of the application referred to in the present application is not limited to the specific combinations of the technical features described above, but also covers other technical features formed by any combination of the technical features described above or their equivalents without departing from the inventive concept. Such as the above-mentioned features and the technical features disclosed in the present application but not limited to those having similar functions are replaced with each other.

Claims (23)

1. Fingerprint detection module, its characterized in that includes:

a spectrum chip;

a circuit board, wherein the spectrum chip is arranged on the circuit board and is electrically connected with the circuit board; and

the optical component is positioned on a photosensitive path of the spectrum chip and used for receiving reflected light of the fingerprint to be detected by the spectrum chip through the optical component and detecting fingerprint information based on spectrum information of the reflected light by the spectrum chip.

2. The fingerprint detection module of claim 1, further comprising a light source assembly, wherein the light source assembly is disposed on the circuit board and electrically connected to the circuit board, wherein light generated by the light source assembly is emitted to the fingerprint to be detected.

3. The fingerprint detection module of claim 2, further comprising a bracket, wherein the bracket is disposed on the circuit board, the optical component is fixed by the bracket, and the optical component is supported on the photosensitive path of the spectrum chip by the bracket.

4. The fingerprint detection module of claim 3, further comprising a transparent cover plate, wherein the transparent cover plate is disposed on the stand, wherein the transparent cover plate is positioned above the optical assembly.

5. The fingerprint detection module of claim 4, wherein the support comprises a first support and a second support, wherein the first support is located outside the second support, the transparent cover plate is fixed to the first support, the optical component is disposed on the second support, and the optical component is supported on a photosensitive path of the spectrum chip through the second support.

6. The fingerprint detection module of claim 5, wherein the light source assembly further comprises at least one light source, the first support is further provided with at least one pocket, wherein the light source of the light source assembly is located in the pocket of the first support, and the support is of transparent material.

7. The fingerprint detection module of claim 6, further comprising a heat sink, wherein the heat sink is disposed on the circuit board, and the temperature of the fingerprint detection module is reduced by the heat sink.

8. The fingerprint detection module of claim 4, wherein the holder comprises a holder body and an extension unit integrally extending inward from the holder body, the optical component being secured to the photosensitive path of the spectral chip by the extension unit of the holder.

9. The fingerprint sensing module according to claim 8, wherein said holder body further comprises a holder upper end and a holder lower end integrally extending downward from said holder upper end, wherein said holder lower end is secured to said circuit board, said light source assembly is located outside said holder lower end, wherein said holder body of said holder is of transparent material.

10. The fingerprint detection module of claim 8, wherein the light source assembly further comprises at least one light source, the holder body further comprises an avoidance space, wherein the light source is located in the avoidance space of the holder body.

11. The fingerprint detection module according to claim 10, wherein the escape space of the holder body is formed at a lower end portion of the holder body, wherein the escape space is a space with a one-sided opening facing downward; or the side of the avoidance space is provided with an opening which can at least partially accommodate the light source.

12. The fingerprint detection module according to claim 9 or 10, wherein said holder further comprises a light shielding unit, wherein said light unit is a light shielding material having a light shielding property, wherein said light shielding unit is formed at a lower end portion of said holder body and a lower end of said extension unit.

13. The fingerprint sensing module according to claim 4 wherein said bracket comprises a bracket body and an extension unit integrally extending inwardly from said bracket body, wherein said optical assembly is secured to said extension unit of said bracket, and said transparent cover plate is secured to an upper end of said bracket body.

14. The fingerprint detection module of claim 13, wherein the circuit board comprises a first circuit board and a second circuit board, wherein the spectral chip is disposed on the first circuit board, the light source assembly is disposed on the second circuit board, and the second circuit board is secured to the extension unit of the bracket.

15. The fingerprint detection module according to claim 14, wherein the light source set comprises at least one light source and at least one light homogenizing member located in a transmitting direction of the at least one light source, wherein the light homogenizing member is located on a light emitting path of the light source, and light emitted by the light source is homogenized by the light homogenizing member.

16. The fingerprint detection module of claim 15, wherein the circuit board further comprises a connection unit, wherein the connection unit connects the first circuit board and the second circuit board, and the light source of the light source assembly is conducted with the spectrum chip provided on the first circuit board through the connection unit.

17. The fingerprint detection module of claim 1, further comprising a light source assembly and a prism, wherein the light source assembly is adjacent to the prism, wherein light from the light source assembly reaches the area to be detected via the prism, and reflected light from the fingerprint to be detected is refracted by the prism to the optical assembly and received by the spectral chip via the optical assembly.

18. The fingerprint detection module of claim 17, wherein the prism has an incident surface, a detection surface and at least one emergent surface, wherein the light source assembly is forward opposite to the incident surface of the prism, and the light emitted by the light source assembly enters the prism through the incident surface of the prism to reach the detection surface.

19. The fingerprint detection module of claim 18, wherein the light source assembly is disposed at a bottom of the prism, wherein the light source assembly further comprises at least one light source and a light homogenizing layer, wherein the light homogenizing layer is disposed on the light incident surface of the prism, the light source is forward opposite to the light homogenizing layer, and wherein the light emitted from the light source is homogenized through the light homogenizing layer.

20. The fingerprint detection module of claim 1, wherein the optical component of the fingerprint detection module is a micro-structured array, the spectral chip comprises a light filtering structure and an image sensor, wherein the micro-structured array and the light filtering structure are positioned on a photosensitive path of the image sensor, and the micro-structured array, the light filtering structure and the image sensor are sequentially stacked and integrated.

21. The fingerprint detection module of claim 2, 6, 9, 14 or 17, wherein the light source assembly emits incident light having an energy of 80% or more in the 400-600nm band.

22. The fingerprint detection module of claim 21, wherein the light source assembly emits incident light having an energy in the 400-500nm band that is no more than 80% of the energy in the 500-600nm band.

23. The living body fingerprint identification system is characterized by comprising:

a main control unit;

an imaging unit, wherein the imaging unit comprises an imaging device and a spectrum chip, and the imaging device is positioned on a photosensitive path of the spectrum chip;

an illumination unit, wherein the illumination unit is located around the imaging unit; and

the algorithm unit, the imaging unit and the lighting unit are connected with the main control unit, the main control unit controls the lighting unit to emit detection light to an object to be detected, reflected light of the object to be detected is received by the spectrum chip through the imaging device, light intensity information of the reflected light is obtained, and the algorithm unit identifies fingerprint information of the object to be detected based on the light intensity information.