WO2016041437A1 - Iris recognition imaging module for mobile terminal and image acquisition method - Google Patents

Abstract

The present invention provides an iris recognition imaging module for a mobile terminal. The mobile terminal comprises an iris recognition imaging module consisting of a mobile terminal mainboard, a processor chip integrated with a security function, a near infrared LED current driver, a memory having a secure read and write access function, a storage having a secure read and write access function, a power management module and a display screen. The iris recognition imaging module consists of a near infrared LED illuminating light source and an iris recognition imaging module optical component. The iris recognition imaging module optical component comprises a front and/or rear near infrared optical filter, an optical imaging lens, and an imaging sensor connecting line. The processor chip integrated with the security function is connected to the near infrared LED current driver and the iris recognition imaging module by means of connecting lines, thereby realizing feedback control. The near infrared LED current driver performs drive control on the radiation intensity and radiation period of the near infrared LED illuminating light source of the iris recognition imaging module.

Description

Iris recognition imaging module and image acquisition method for mobile terminal Technical field

The invention relates to an iris recognition imaging module and an image acquisition method for a mobile terminal, belonging to the field of biometrics and optoelectronics.

Background technique

Mobile terminals include smart phones, tablets, wearable devices, etc. In the current trend of information technology mobileization, mobile terminal devices are inevitably the most widely used devices in the future.

At present, mobile terminals in real-world applications have been widely used in mobile secure payment, account secure login, and online banking, such as the application of balance treasure (APP), WeChat (APP), and credit card management (APP). In the course of its use, it has brought great convenience to life, but a new type of economic crime caused by the weak security features of mobile terminals has gradually emerged.

In mobile terminals, the conventional method for identity verification in the prior art is password input, but the means of identity verification is very low in security, and only a simple virus program needs to be implanted on the mobile terminal to leak the password. , causing corresponding losses. In order to solve this problem, the biometric identification method is used for mobile terminal security identity authentication; for example, the fingerprint recognition technology developed by Apple based on AuthenTec, which is applied to mobile phone terminals, greatly improves the mobile terminal. Identity verification security; however, in the process of fingerprint technology recognition, since the fingerprint is static, although unique, it is extremely easy to obtain fingerprint information, even being copied, etc., so, with the fingerprint technology on the mobile terminal As the application becomes more and more extensive, its security will also decline accordingly. Therefore, iris recognition, which is more advantageous in terms of security, is a very effective method to solve the security identity authentication process of mobile terminals, and the iris recognition system is existing. The safe and secure anti-counterfeiting features of biometrics are the safest.

At present, most of the iris recognition system technologies and products are used in large-scale access control or customs clearance applications, and the power consumption is abnormally up to 10 watts or more. The control is extremely complicated, the volume is abnormally large 20cm*20cm*10cm, and the cost is extremely high above 1000 dollars. Basic characteristics cannot meet the usage standards on mobile terminals.

Further, the application to mobile terminals needs to solve the following serious problems:

1. In the mobile terminal application, the iris recognition system needs a set of miniaturized iris recognition imaging modules, full The foot mobile terminal is becoming thinner and thinner, and its volume is controlled within 8mm*8mm*6mm.

2. In the mobile terminal application, the iris recognition system needs a set of micro-power iris recognition imaging module to meet the requirements of the increasingly thin and low power consumption of the mobile terminal, and the power consumption control within 300 mW during the identification process.

3. In the mobile terminal application, the iris recognition system needs a set of simplified and efficient image acquisition methods to meet the high-quality iris image acquisition in 1 second.

4. The iris recognition imaging module for the mobile terminal, each component and parameters need to be optimally combined and configured.

5. In the mobile terminal application, the iris recognition imaging module needs to greatly reduce the cost, and the cost can be reduced to less than 10 dollars to be applied on a large scale.

Solving the above problems is the biggest challenge currently facing the application of iris recognition system technology in mobile terminals.

Summary of the invention

The technical problem to be solved by the present invention is to provide an iris recognition imaging module and an image acquisition method for mobile terminal security identity authentication.

In order to solve the above technical problem, the present invention provides an iris recognition imaging module for a mobile terminal, comprising an iris recognition imaging module disposed on the mobile terminal; the mobile terminal includes a mobile terminal motherboard and a processor chip integrated with a safety function , near-infrared LED current driver driver, memory for secure read/write access function, memory for secure read/write access function, power management module, and display screen; the processor chip is used to perform PKI encryption and digital signature algorithm to protect iris recognition code and The iris template and the iris recognition result; the image imaging sensor is configured with an encryption function module for the image signal, and correspondingly, the processor chip is configured with a decryption function module for the encrypted image signal. The processor chip is further connected to the memory and the memory, respectively, to perform safe calculation of the iris recognition code and the iris template, and to perform a safe storage function of the iris recognition code and the iris template; the iris recognition imaging module is composed of a near-infrared LED illumination source And an iris recognition imaging module optical component; the iris recognition imaging module optical component includes a front-end and/or a rear-near-infrared optical filter for imaging wavelength filtering, and filtering after filtering by the near-infrared optical filter An optical imaging lens that focuses a wavelength of light, an image imaging sensor that images an imaging wavelength ray that is focused by an optical imaging lens, and a connection that signals an image of the image imaging sensor; the processor chip and the near-infrared LED current, respectively The driver and the iris recognition imaging module are connected to each other by a connection line to realize feedback control; the near-infrared LED current driver drives and controls the radiation intensity and the radiation period of the near-infrared LED illumination source of the iris recognition imaging module.

As an improvement of the iris recognition imaging module for a mobile terminal according to the present invention, the image imaging sensor and the near-infrared LED illumination source are combined and configured as follows: a near-infrared LED illumination source and an image imaging transmission The sensor implements a synchronized pulse period radiation/exposure mode and/or a synchronized continuous period radiation/exposure mode; the near-infrared optical filter is combined with a near-infrared LED illumination source and an optical imaging lens as follows: near-infrared optics The center peak wavelength of the filter is equal to the center peak wavelength of the near-infrared LED illumination source and the central chromatic aberration correction wavelength of the optical imaging lens; the half-peak transmission wavelength bandwidth FWHM of the near-infrared optical filter effectively matches or covers the near-infrared LED illumination source The half-peak radiation wavelength bandwidth FWHM and the chromatic aberration correction wavelength range of the optical imaging lens; the image imaging sensor and the optical imaging lens are combined and configured as follows: a matching principal ray incident angle CRA ≥ 20 degrees; the near-infrared LED illumination source And the optical imaging lens and the image imaging sensor are combined and configured as follows: the brightness half-peak radiation angle of the near-infrared LED illumination source is greater than or equal to the field of view angle of the optical imaging lens, and the field of view angle of the optical imaging lens is greater than or equal to the image plane physics of the image imaging sensor scale.

Further improvement of the iris recognition imaging module for a mobile terminal according to the present invention: the near-infrared LED illumination source radiation is synchronized with a pulse period of an image imaging sensor image frame exposure and/or a near-infrared LED illumination source radiation and image Continuous period synchronization of image sensor frame exposure; the radiation/exposure period T is configured to: 3.33 ms milliseconds ≤ T ≤ 33.33 ms milliseconds; the near-infrared LED illumination source radiation intensity I is configured to: I ≥ 100 mW/sr The image imaging sensor image readout frame rate R is configured to: R ≥ 30 fps frames per second; the near-infrared LED illumination source has a center peak wavelength range of 750-880 nm, and a half-peak bandwidth FWHM of 10-60 nm; The infrared optical filter has a center peak wavelength range of 750-880 nm, a half-peak bandwidth FWHM of 10-60 nm; the optical imaging lens has a chromatic aberration correction wavelength range of 750-880 nm; and the near-infrared optical filter is for reflecting visible light and transmission. Near-infrared light at an imaging wavelength, or absorbing visible light and transmitting near-infrared light for imaging wavelength; the near-infrared optical filter is a narrow-band near-infrared optical filter Or any of the band pass near-infrared optical filters; the image plane physical scale SOI of the image imaging sensor is configured to: SOI=DOI*SOP; the DOI is an image facing angle of the image imaging sensor The number of pixels; SOP is the physical scale of the image imaging sensor unit pixel; the field of view angle FOV of the optical imaging lens is configured to be: FOV ≥ 2 * arctan ((SOI) / (2 * EFL)); EFL is an optical imaging lens The equivalent focal length value; the near-infrared LED illumination source brightness half-peak radiation angle AOR is configured to: AOR ≥ FOV; the FOV is the field of view angle of the optical imaging lens.

A further improvement of the iris recognition imaging module for a mobile terminal according to the present invention: the iris recognition imaging module optical component is configured with an outer surface protection window composed of tempered glass or sapphire glass, and the outer surface is provided with an anti-defense a surface protective coating contaminated by external impurities; the guiding indication of the iris recognition imaging module is configured as follows: a near-infrared optical filter reflects visible light for specular visual feedback and a guiding indication formed by a visible light guiding indicator, and/or a display A guidance indication formed by imaging image feedback is displayed.

A further improvement of the iris recognition imaging module for a mobile terminal according to the present invention: the image imaging sensor is configured as a RAW RGB Bayer pixel output format, using RGB channel compensation gain or RGB channel balance gain,

G channel compensation or balance gain is the normalization standard, G_CGC=1.0; R channel compensation or balance gain R_CGC=G/R; B channel compensation or balance gain B_CGC=G/B; λ is the peak wavelength of near-infrared LED illumination source , Δλ is the peak wavelength half-peak bandwidth FWHM, g(λ), r(λ), b(λ) of the near-infrared LED illumination source, respectively, is the photoelectric quantum conversion efficiency or spectral sensitivity function of the image imaging sensor RGB channel, f(λ Is a wavelength distribution function; the maximum value of the analog and/or digital gain GAIN of the image imaging sensor is configured as: image imaging sensor signal to noise ratio SNR ≥ 36db generated by the maximum GAIN; image resolution of the image imaging sensor The ROI is configured to: ROI ≥ 1920 pixels * 1080 pixels.

Further improvement of the iris recognition imaging module for a mobile terminal according to the present invention: the optical distortion DOL absolute value of the optical imaging lens is configured to: DOL absolute value ≤ 1%; EFL of the optical imaging lens, etc. The focal length value is configured as: SOP*1000pixel≤EFL≤3*SOP*1000pixel; the SOP is a physical scale of a unit pixel of the image imaging sensor, unit um/pixel; the pixel is a pixel unit; the optical imaging lens The relative illumination rate IOR is configured to: IOR ≥ 50%; the IOR is the edge field of view brightness of the optical imaging lens / the central field of view brightness of the optical imaging lens; the fixed constant aperture or relative aperture reciprocal F of the optical imaging lens is The configuration is: F=EFL/D; 0.5*SOP/(1.22*λ)≤F≤2.0*SOP/(1.22*λ); the D is the diameter of the aperture or clear aperture of the optical imaging lens, and the EFL is The equivalent focal length value of the optical imaging lens, SOP is the physical scale of the image imaging sensor unit pixel, λ is the peak wavelength of the near-infrared LED illumination source; the optical imaging lens adopts the plastic aspheric optical lens injection molding process, using 3-5P lens Correct all aberrations.

An image acquisition method for iris recognition of a mobile terminal: comprising the following steps: initial configuration of an iris recognition imaging module;

1. Near-infrared LED current driver and image imaging sensor enter the low-power mode of Shutdown or standby standby to save most of the power consumption;

2. The processor chip detects whether it is necessary to acquire an iris image, and proceeds to step 4, and proceeds to step 3;

3. The near-infrared LED current driver and image imaging sensor are switched from the Shutdown or standby standby low-power mode to the normal working mode, and the near-infrared LED current driver turns on the near-infrared LED illumination source;

4. The image imaging sensor outputs pulse period radiation/exposure and/or synchronized continuous period radiation/exposure image data synchronized with the near-infrared LED illumination source;

5. The processor chip feedback-controls the iris recognition imaging module according to the iris image data until the acquisition acquires a high-quality iris image;

6. End the acquisition of the iris image and return to step 2 for a loop.

8. The iris recognition image acquisition method for a mobile terminal according to claim 7, wherein:

The iris recognition imaging module initial configuration includes the following steps:

1. Near-infrared LED current driver reset reset, image imaging sensor reset reset;

2. The near-infrared LED current driver mode is configured with synchronized pulse period radiation and/or continuous period radiation mode;

3. Image imaging sensor configuration MIPI or parallel interface, configuration data output bit width 8/10/12bit, image imaging sensor configuration clock PLL and frame readout rate R, image imaging sensor configuration image resolution ROI;

4. The image imaging sensor is configured with a RAW RGB Bayer pixel output format, the image imaging sensor is configured with an RGB channel compensation gain or an RGB channel balance gain, and the image imaging sensor is configured with an analog and/or digital gain GAIN;

5. The image imaging sensor is configured with a pulse period exposure mode synchronized with a near infrared LED illumination source radiation pattern and/or a synchronized continuous period exposure mode.

An improvement of the iris recognition image acquisition method for a mobile terminal according to the present invention: the processor chip feedback-controls the iris recognition imaging module according to the iris image data until the acquisition of the high-quality iris image, including for the iris recognition image Obtaining the control of the near-infrared LED illumination source, including the following steps:

(1) The processor chip integrated with the safety function obtains the brightness distribution uniformity and the degree of specular reflection interference of the iris image source illumination according to the iris image data;

(2) judging whether the current brightness distribution uniformity and the degree of specular reflection interference satisfy the iris image quality; if it is step 1, go to step 3;

(3) Selecting to switch the near-infrared LED illumination source on either side or left and right sides;

(4) Return to step 1 cycle.

A further improvement of the iris recognition image acquisition method for a mobile terminal according to the present invention: the processor chip feedbacks and controls the iris recognition imaging module according to the iris image data until the acquisition of the high quality iris image, including for iris recognition Guided indication control for image acquisition, including the following steps:

i. determining whether the guiding indication mode is a specular visual feedback or a display screen displaying an imaging image feedback;

Ii. When the guiding indication is specular visual feedback, the display state prompts the visible light VSLED guiding indicator to indicate that the user uses the appropriate range, indicating that the identification fails, indicating that the identification is successful;

Iii. when the guiding instruction displays the imaged image feedback for the display screen, indicating on the display that the user uses the appropriate range, indicating that the identification fails, indicating that the identification is successful;

Iv, return to step 1 cycle.

A further improvement of the iris recognition image acquisition method for a mobile terminal according to the present invention: the processor chip feedbacks and controls the iris recognition imaging module according to the iris image data until the acquisition of the high quality iris image, including for iris recognition The image captures the visible light VSLED indicator and/or the brightness control of the display, including the following steps:

I, the processor chip obtains a pupil-iris diameter ratio value ρ according to the iris image data;

II, judging whether the current pupil to iris diameter ratio value is within the predetermined upper and lower limits [ρh, ρl], is to step 1, or to step 3;

III. Judging when ρ≥ρh, the brightness of the visible light VSLED indicator light and/or the display screen is increased, and the degree of brightness increase is linearly related to ρ-ρh;

It is judged that when ρ≤ρl, the brightness of the visible light VSLED indicator light and/or the display screen is decreased, and the degree of brightness reduction is linearly related to ρl-ρ;

IV, return to step 1 cycle.

A further improvement of the iris recognition image acquisition method for the mobile terminal according to the present invention: the processor chip with integrated security function feeds back and controls the iris recognition imaging module according to the iris image data until the high-quality iris image is acquired, Including automatic image brightness control for iris recognition image acquisition, including the following steps:

a, defining the photoelectric signal of the original unit pixel luminance value Yraw of the iris image;

Yraw=C*T*GAIN*I*(1/F) ² ;

T is a pulsed radiation/exposure period and/or a synchronized continuous radiation/exposure period in which the image imaging sensor is synchronized with the near-infrared LED illumination source;

F is the constant of the optical imaging lens fixed aperture or the inverse of the relative aperture;

I is the radiation intensity of the near-infrared LED illumination source;

GAIN is the analog and/or digital gain of the image imaging sensor;

C is a fixed photoelectric signal conversion rate constant of the iris recognition imaging module;

The synchronized image imaging sensor transmits the exposure period T and the near-infrared LED illumination source radiation period T is full Foot: 3.33ms milliseconds ≤ T ≤ 33.33ms milliseconds;

The near-infrared LED illumination source has a radiation intensity I≥100mW/sr;

The maximum value of the analog and digital gain GAIN is obtained by an image imaging sensor with a signal-to-noise ratio SNR ≥ 36db;

The F=EFL/D is satisfied:

0.5*SOP/(1.22*λ)≤F≤2.0*SOP/(1.22*λ),

The D is the diameter of the pupil or the aperture of the optical imaging lens, the EFL is the equivalent focal length value of the optical imaging lens, the SOP is the physical scale of the image imaging sensor unit pixel, and λ is the peak wavelength of the near-infrared LED illumination source;

b, defining an iris image area pixel brightness statistical evaluation value Ysp;

The S(Yraw) is an iris image region pixel brightness statistical evaluation function, and the pixel brightness statistical evaluation function includes a pixel brightness histogram statistics, a pixel brightness spectrum statistics, and a pixel brightness. Average value, pixel brightness weighted average value, or pixel brightness median value, etc.;

c. Realizing the iris image area pixel brightness evaluation value Ysp in the preset [Yll, Yhl] brightness range by photoelectric signal feedback control;

The photoelectric signal feedback control by T, I, and GAIN, the iris brightness value of the iris image area is estimated to be Yll ≤ Ysp ≤ Yhl; the Yll is the iris brightness of the iris image area. Lower limit, Yhl is the upper limit of the pixel brightness of the iris image area; the photoelectric signal processing feedback control is based on the linear product control relationship of the formula in step 1, and the feedback control changes the photoelectric signal to realize the original unit pixel brightness value Yraw change, so that the corresponding The iris image region pixel luminance statistical evaluation value Ysp satisfies a preset condition of Yll ≤ Ysp ≤ Yhl.

Summarizing the above description, the present invention achieves the following effects required by the mobile terminal usage scenario:

1. The iris recognition imaging module for the mobile terminal, whose volume is controlled within 8mm*8mm*6mm.

2. The iris recognition imaging module for the mobile terminal satisfies the power consumption control within 300 mW during the identification process, and the power consumption control within 1 mW when not working.

3. The iris recognition image acquisition method for the mobile terminal satisfies the completion of high quality iris image acquisition in 1 second.

4. The iris recognition imaging module for the mobile terminal, each component and parameters are optimized and configured.

5. The iris recognition imaging module for the mobile terminal greatly reduces the cost and the cost is reduced to less than 10 dollars.

DRAWINGS

The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

1 is a general structural diagram of an iris recognition imaging module according to a specific embodiment of the present invention;

2 is a structural diagram of an optical component of an iris recognition imaging module according to a specific embodiment of the present invention.

detailed description

Embodiment 1 FIG. 1 shows an overall structure diagram of an iris recognition imaging module for a mobile terminal, including an iris recognition imaging module optical component 1 disposed on a mobile terminal, and a near-infrared LED illumination source 3L, 3R and The iris recognition imaging module connection line 4; the mobile terminal comprises a mobile terminal motherboard 10, a near-infrared LED current driver 2, a processor chip integrated with a safety function, a memory for a secure read/write access function, and a memory 7 for a secure read/write access function. , power management 8, display 100 and wireless baseband module 9.

The integrated security function processor chip 5 is configured with the TrustZone security isolation mode of the ARM CORTEX-A series of integrated security features for single or multi-core processor chips, and its TrustZone security isolation mode is used throughout the iris recognition process.

The above mobile terminal motherboard 10, near-infrared LED current driver 2, processor chip 5 integrated with safety function, memory 6 for secure read/write access function, memory 7 for secure read/write access function, power management 8 and wireless baseband module 9, Components such as display screen 100 can be purchased from commercial products and combined in accordance with the functional and purpose requirements of the present invention.

Mobile terminal board 10 integrated with TrustZone's secure isolation mode ARM CORTEX-A integrated security function processor chip 5 (for performing all feedback control, iris recognition code and iris template for secure computing and secure storage, PKI encryption and digital signature) , near-infrared LED current driver 2 (for driving control of near-infrared LED illumination source current), memory for safe read and write access function 6 (processor chip 5 for integrated safety function performs iris calculation code and safe calculation of iris template) Memory 7 with secure read/write access function (processor chip 5 for security functions performs secure storage of iris recognition code and iris template), PMIC power management 8 (provides optical components for mobile terminal board 10 and iris recognition imaging module) All components of 1 are powered by power) and wireless baseband module 9 (for wireless communication applications), display screen 100 (for displaying image information); and each functional part is connected to each other, and the mobile terminal motherboard 10 realizes iris recognition imaging according to the present invention. Module feedback control and image acquisition methods.

The memory 6 of the secure read/write access function and the memory 7 of the secure read/write access function are used to ensure that only the processor chip 5 of the security isolation mode ARM CORTEX-A integrated security function of the TrustZone is configured to be read and written during the identity authentication process of the mobile terminal. Access rights to achieve complete and secure authentication process without external attacks.

The processor chip 5 integrated with the security function in the mobile terminal identity authentication process protects the iris recognition code and the iris template and iris recognition by performing PKI encryption and digital signature algorithms (such as AES, 3DES, IDEA, RSA, ECC, MD5, SHA, etc.) result. It is used to further improve the security and reliability of the authentication process and is not subject to external attacks. The image imaging sensor of the present invention configures an encryption function module for an image signal, and correspondingly, the processor chip configures a decryption function module for the encrypted image signal.

The mobile terminal board 10 and the iris recognition imaging module are mutually signal-connected through the iris recognition imaging module connection line 4; the implementation includes a digital core voltage VDD, an analog voltage AVDD, an IO voltage IOVDD, a main clock input MCLK, a pixel clock output PCLK, MIPI or parallel interface data and synchronization signal output, I ² C communication, low power shutdown Shutdown or standby standby mode signal (also available in software), FLASH synchronization signal, near-infrared LED illumination source 3L, 3R drive current, further visible light The signal of the drive current of the pilot indicator 3VS is controlled.

The signals of the processor chip 5 integrated with the safety function are respectively connected with the near-infrared LED current driver 2 and the connection line 4 to realize the iris recognition imaging module feedback control; the near-infrared LED current driver 2 further controls the driving of the near-infrared LED illumination source 3L, 3R Radiation intensity and radiation period. Further, the near-infrared LED current driver 2 also controls the radiation intensity and the radiation period of the visible light guiding indicator 3VS.

As in the first embodiment, the commercial product LED current driver Maxim MAX8834Y/MAX8834Z is used, which provides independently controllable two-way high-current Flash/Movie mode driving near-infrared LED illumination sources 3L and 3R, LED and a small current LED indicator to drive visible light guiding indication. Light 3VS.

In accordance with the combination of functions and purposes of the present invention, the pulse period radiation and the continuous period radiation pattern in which the Flash and Movie modes are configured to be synchronized are designed.

The iris recognition imaging module of Embodiment 1 is composed of a near-infrared LED illumination source and an iris recognition imaging module optical component;

As shown in FIG. 2, the specific structure of the iris recognition imaging module optical component 1 comprises the following components: a front near-infrared optical filter 11, a fixed focal length optical imaging lens 12, a fixed mount of the optical imaging lens 13, and a rear. The near-infrared optical filter 14, the image imaging sensor 15, and the iris recognition imaging module substrate 16 are disposed. The image recognition sensor 15, the rear near-infrared optical filter 14, the fixed mount 13 of the optical imaging lens, the optical imaging lens 12 with fixed focal length, and the front near-infrared optics are disposed on the iris recognition imaging module substrate 16 from bottom to top. Filter 11. The iris recognition imaging module substrate 16 is composed of a printed circuit board, a flexible circuit board or a soft and hard bonding board, and is used for providing a fixed structure carrier for integrally mounting the optical component 1 of the iris recognition imaging module. The fixed mount 13 of the optical imaging lens is used to mount a fixed focal length optical imaging lens 12. The iris recognition imaging module optical component 1 is used for non-contact physical imaging to acquire an iris image.

The near-infrared light radiated by the near-infrared LED illumination source (3L, 3R) enters the front near-infrared optical filter 11 and/or the rear near-infrared optical filter after the optical biological effect of absorption, scattering, and reflection of the object iris. The optical device 14 performs non-imaging interference light filtering, and the filtered imaging wavelength light enters the fixed focal length optical imaging lens 12; the fixed focal length optical imaging lens 12 is an autofocus AF optical imaging lens or a fixed focus optical imaging lens for realizing non- The contact optical optical focus is applied to the image imaging sensor 15 located at the image side, and the image imaging sensor 15 converts the image optical signal to the image electrical signal output. Finally, the iris recognition imaging module is connected to the mobile terminal motherboard 10 through the connection line 4, thereby achieving integrated security. The functional processor chip 5 feedbackly controls the iris recognition imaging module of the present invention.

At present, the highly mature mobile terminal component design and manufacturing process can realize the miniaturization of each optical component in the optical component 1 of the iris recognition imaging module, and adopt the mature technical field of the prior art to design and manufacture the COB or CSP packaging process iris recognition imaging module. It can fully meet the general standard size of mobile terminal 8mm*8mm*6mm.

The optical component 1 of the iris recognition imaging module according to Embodiment 1 of the present invention adopts a tempered glass or sapphire glass outer surface protection window, and adopts a surface protection coating which is resistant to external impurities. Adapt to a variety of harmful use scenarios such as avoiding scratches, impact marks, fingerprints, impurities and other pollution.

The near-infrared LED illumination source (3L, 3R) according to Embodiment 1 of the present invention is a surface mount SMD package, and its volume is less than 3 mm*3 mm*3 mm.

The image imaging sensor 15 and the near-infrared LED illumination source (3L, 3R) are configured in combination to: pulse-period radiation/exposure (integration) and/or synchronization of the near-infrared LED illumination source (3L, 3R) and the image imaging sensor 15 Continuous cycle radiation/exposure (integration). Near-infrared LED illumination source (3L, 3R) radiation and image imaging sensor 15 image light (integration) pulse period synchronization and / or near-infrared LED illumination source (3L, 3R) radiation and image imaging sensor 15 frame exposure (integration) Continuous cycle synchronization. According to the present invention, the near-infrared LED illumination source radiation and the image imaging sensor image frame exposure employ duty cycle parameter control to achieve a synchronization pulse period. It is particularly emphasized that the synchronous continuous period radiation/exposure method is a special case of the sync pulse period radiation/exposure method of the present invention, with radiation and exposure equal to continuous period radiation and exposure when the pulse period is 100% duty cycle. The radiation/exposure (integration) period T is configured to be: 3.33 ms milliseconds ≤ T ≤ 33.33 ms milliseconds; the near-infrared LED illumination source (3L, 3R) radiation intensity I is configured to be: I ≥ 100 mW/sr (milliwatts) The image imaging sensor 15 readout frame rate R is configured to be R ≥ 30 fps frames per second.

Embodiment 1 of the present invention is used to guide an indication configuration when a user uses an iris recognition imaging module: a near-infrared optical filter reflects visible light to perform specular visual feedback and a guiding instruction formed by a visible light guiding indicator, and/or a display screen displays an imaging image. Guidance instructions formed by feedback.

The image imaging sensor 15 described in Embodiment 1 of the present invention is configured as a RAW RGB Bayer pixel output format using RGB channel gain compensation or RGB channel gain balance.

G channel compensation or balance gain is the normalization standard, G_CGC=1.0; R channel compensation or balance gain R_CGC=G/R; B channel compensation or balance gain B_CGC=G/B; λ is the peak wavelength of near-infrared LED illumination source , Δλ is the peak wavelength half-peak bandwidth FWHM, g(λ), r(λ), b(λ) of the near-infrared LED illumination source, respectively, is the photoelectric quantum conversion efficiency or spectral sensitivity function of the image imaging sensor RGB channel, f(λ ) is the wavelength distribution function.

When a general image imaging sensor is of a color type, it can be greatly reduced in cost due to its mass production.

As in Example 1, the commercial product OmniVision OV4688 was used, and the Aptina AR0330 cost less than $5. However, because the color-type image imaging sensor has different photoelectric quantum conversion efficiency or spectral sensitivity for the RGB channel of the imaged near-infrared light wavelength, the compensation or balance is inconsistent, so that the RGB channel is identical. The RGB channel gain compensation must be used. Or RGB channel gain balance. Equivalently understood, it is also equivalent to adopt R channel gain compensation or B channel gain compensation as the normalization standard. When the special image imaging sensor adopts the monochrome type, the RGB channel gain compensation or the RGB channel gain balance can be simplified to G_CGC=R_CGC=B_CGC=1.0; further, when the image imaging sensor is used with the color type, the color matrix correction CCM is disabled, and the pixel is disabled. Interpolating PI (pixel interpolation), disabling Gamma correction, disabling auto white balance AWB, using these functions results in reduced contrast of the iris image, especially the high-frequency edge portion of the texture, which affects the iris image quality. Further, the image imaging sensor is configured to have an optical black level correction BLC (Black Level Correction) and a noise correction NC (Noise Correction). Further, the maximum value of the analog and/or digital gain GAIN of the image imaging sensor 15 is configured as: the image imaging sensor signal-to-noise ratio SNR ≥ 36 db generated by the GAIN maximum value; the image resolution ROI of the image imaging sensor 15 is configured For: ROI ≥ 1920 pixels * 1080 pixels. It is equivalent to understand that under the same conditions, the higher the image resolution ROI of the image imaging sensor, the larger the imaging range of the iris recognition imaging module, and the larger the user's use range, the easier to use. Near-infrared optical filter (11, 14) and near-infrared LED illumination source (3L, 3R), optical imaging lens 12 is configured such that the center-peak wavelength of the near-infrared optical filter (11, 14) is equal to the near-infrared LED Lighting source (3L, 3R) Center peak wavelength and center chromatic aberration correction wavelength of optical imaging lens 12; near-infrared optical filter (11, 14) half-peak transmission wavelength bandwidth FWHM effectively matches or covers half-peak of near-infrared LED illumination source (3L, 3R) The radiation wavelength bandwidth FWHM and the chromatic aberration correction wavelength range of the optical imaging lens 12.

The near-infrared LED illumination source (3L, 3R) according to Embodiment 1 of the present invention has a center peak wavelength range of 750-880 nm and a half-peak bandwidth FWHM of 10-60 nm; the front-end near-infrared optical filter 11 and/or the rear The near-infrared optical filter 14 has a center peak wavelength range of 750-880 nm and a FWHM of 10-60 nm; the optical imaging lens 12 has a chromatic aberration correction wavelength range of 750-880 nm; and the front and/or rear near infrared The optical filters (11, 14) are near-infrared light that reflects visible light and transmits for imaging wavelengths. The front and/or rear near-infrared optical filters (11, 14) are near-infrared light that absorbs visible light and transmits for imaging wavelengths. The front and/or rear near-infrared optical filters (11, 14) are any one of a narrow-band near-infrared optical filter or a band-pass near-infrared optical filter; front-near-infrared optical filtering The device 11 and/or the rear near-infrared optical filter 14 are optically transparent glass, such as BK7 or optical materials such as colored glass or optical plastic for surface multi-layer coating. The current coating process and technology can achieve background depth cut-off rate or letter The SNR (signal-to-noise ratio) is ≥60 dB (1000:1). The front near-infrared optical filter 11 and/or the rear near-infrared optical filter 14 filters the wavelength used for imaging to make the signal-to-noise ratio (SNR: signal-to-SNR) of the imaging wavelength and the non-imaged background interference stray light. -noise ratio) Satisfaction: ≥60dB (1000:1). It is equally understood that the front near-infrared optical filter 11 and/or the rear near-infrared optical filter 14 can also be equivalently used for multi-layer coating on the surface of the optical imaging lens 12.

The half-peak transmission wavelength bandwidth FWHM of the front near-infrared optical filter 11 and/or the rear near-infrared optical filter 14 effectively matches or covers the half-peak radiation wavelength bandwidth FWHM of the near-infrared LED illumination source (3L, 3R) and The chromatic aberration correction wavelength range of the optical imaging lens 12 is designed to achieve maximum imaging wavelength utilization and image high quality iris images.

When the image imaging sensor of Embodiment 1 adopts a color type, the near-infrared LED illumination source (3L, 3R) has a center peak wavelength of 850 nm and a half-peak bandwidth FWHM of 10-60 nm; the front-end near-infrared optical filter The center peak wavelength of the 11 and/or the rear near-infrared optical filter 14 is 850 nm, and the FWHM is 10-60 nm; and the chromatic aberration correction wavelength range of the optical imaging lens 12 is 750-880 nm.

The optical distortion DOL (distortion of lens) absolute value of the optical imaging lens 12 according to Embodiment 1 of the present invention is configured as: DOL absolute value ≤ 1%; the EFL equivalent focal length value of the optical imaging lens 12 is configured as: SOP*1000pixel≤EFL≤3*SOP*1000pixel; the SOP is the physical scale of the image imaging sensor 15 unit pixels, unit um/pixel; the pixel is a pixel unit; the relative illumination rate IOR of the optical imaging lens 12 is The configuration is: IOR ≥ 50%; the IOR is the edge field of the optical imaging lens 12 is bright The central field of view brightness of the degree/optical imaging lens. The fixed constant aperture or relative aperture reciprocal F of the optical imaging lens 12 is configured as: F = EFL / D, 0.5 * SOP / (1.22 * λ) ≤ F ≤ 2.0 * SOP / (1.22 * λ), the D For the diameter of the pupil or clear aperture of the optical imaging lens 12, the EFL is the equivalent focal length value of the optical imaging lens 12, the SOP is the physical scale of the image imaging sensor 15 unit pixels, and the λ is the near-infrared LED illumination source (3L, 3R) ) Peak wavelength. The optical imaging lens 12 adopts a plastic aspheric optical lens injection molding process, and uses 3-5P lenses to correct all aberrations. The plastic aspheric optical lens injection molding process costs less than $2 in mass production.

The optical imaging lens 12 according to Embodiment 1 of the present invention adopts a near-infrared light anti-reflection or anti-reflection coating. The near-infrared LED illumination source (3L, 3R) and the optical imaging lens 12 and the image imaging sensor 15 according to Embodiment 1 of the present invention are configured in combination as follows: a half-degree luminance angle of brightness of the near-infrared LED illumination source (3L, 3R) ( Or the divergence angle AOR is greater than or equal to the field of view angle FOV of the optical imaging lens 12, the field of view angle FOV of the optical imaging lens 12 is greater than or equal to the image plane physical dimension SOI of the image imaging sensor 15; the image imaging sensor 15 The image plane physical scale SOI is configured to: SOI = DOI * SOP; the DOI is the number of image facing pixels of the image imaging sensor 15; the SOP is the physical scale of the image imaging sensor 15 unit pixels; the optical imaging lens 12 The field of view FOV is configured to be: FOV ≥ 2 * arctan ((SOI) / (2 * EFL)); EFL is the equivalent focal length value of the optical imaging lens 12. The near-infrared LED illumination source (3L, 3R) brightness half-peak radiation angle (or divergence angle) AOR is configured as: AOR ≥ FOV; the FOV is the field of view angle of the optical imaging lens 12.

The image imaging sensor 15 and the optical imaging lens 12 according to Embodiment 1 of the present invention are combined to be configured such that the principal ray incident angles CRA (Chief Ray Angle) ≥ 20 degrees. The mutual matching is such that the principal ray incident angle CRA of the optical imaging lens in the light path (field of view) is less than or equal to the chief ray incident angle CRA of the image imaging sensor. Optical design software such as ZEMAX and CODEC can be used to simulate the design to achieve the above-mentioned matching principal ray incidence angles. The principal ray incident angles CRA of the image imaging sensor 15 and the optical imaging lens 12, which are mutually matched as in Embodiment 1, are combinedly configured to be 25-35 degrees, and the image forming sensor 15 principal ray incident angle CRA and the chief ray of the optical imaging lens 12 The incident angle CRA is the same. It is equivalent to understand that under the same conditions, the larger the chief ray incident angle CRA of the image imaging sensor, the optical total length TTL of the optical imaging lens can be further shortened, and the iris recognition imaging module is thinner and can meet the standard 6mm requirement of the mobile terminal. It is equivalent to understand that under the same conditions, the larger the chief ray incident angle CRA of the image imaging sensor, the larger the equivalent focal length EFL of the optical imaging lens, and the iris recognition imaging module has a larger working distance.

The configuration distance sensor according to Embodiment 1 of the present invention is used for indicating the distance and near-information information prompting by the user, and when the user exceeds the distance, such as within 10 cm, the near-infrared LED illumination source is turned off to avoid excessive light source spokes. Shoot. The configuration environment visible light sensor is used to change the brightness of the visible light indicator and/or the display according to the current ambient visible light brightness.

The above description describes the specific composition, function, and configuration of the iris recognition imaging module for the mobile terminal in Embodiment 1 of the present invention. In order to obtain a high-quality iris image, Embodiment 1 of the present invention further includes an iris recognition for a mobile terminal. Image acquisition method:

Includes the following steps:

1. Iris recognition imaging module initialization configuration.

2. The near-infrared LED current driver 2 and the image imaging sensor 15 enter a low-power mode of shutting down the Shutdown or standby standby to save most of the power consumption.

3. The processor chip 5 integrated with the security function detects whether it is necessary to acquire the iris image, and proceeds to step 4, and does not continue to step 3.

4. The near-infrared LED current driver 2 and the image imaging sensor 15 are switched from the shutdown Shutdown or standby standby low power mode to the normal working mode, and the near-infrared LED current driver 2 turns on the near-infrared LED illumination source (3L, 3R).

5. The image imaging sensor 15 outputs pulse period radiation/exposure (integration) and/or synchronized continuous period radiation/exposure (integration) image data synchronized with the near-infrared LED illumination source (3L, 3R).

6. The processor chip 5 integrated with the safety function feeds back the iris recognition imaging module according to the iris image data until the acquisition of the high quality iris image.

7. End the acquisition of the iris image and return to step 2 for a loop.

The iris recognition image acquisition method for the mobile terminal according to Embodiment 1 of the present invention satisfies that the power consumption of the near-infrared LED illumination source is greater than or equal to 100 mW and the image imaging sensor power consumption is less than 100 mW within 300 mW of the power consumption control during the identification process. Low-power mode power control with Shutdown or standby standby is less than 1mW, and high-quality iris image acquisition is achieved through feedback control within 1 second.

The iris recognition imaging module initialization configuration includes the following steps:

1. Near-infrared LED current driver reset reset, image imaging sensor reset reset.

2. The near-infrared LED current driver mode is configured for synchronized pulse period radiation and/or continuous period radiation mode.

3. Image imaging sensor configuration MIPI or parallel interface, data output bit width 8, 10, 12 bit, image imaging sensor configuration clock PLL and frame readout rate R, image imaging sensor configuration image resolution ROI.

4. Image imaging sensor configuration RAW RGB Bayer pixel output format, image imaging sensor configuration RGB channel compensation gain or RGB channel balance gain, image imaging sensor configuration analog and / or digital gain GAIN.

5. The image imaging sensor is configured with a pulse period exposure (integration) and/or a synchronized continuous period exposure (integration) mode synchronized with the radiation pattern of the near infrared LED illumination source.

The integrated security function processor chip feeds back the iris recognition imaging module according to the iris image data until the acquisition of the high quality iris image, including the near infrared LED illumination source control for the iris recognition image acquisition, including the following steps:

1. The processor chip with integrated safety function obtains the brightness distribution uniformity and the degree of specular reflection interference of the iris image source illumination according to the iris image data.

2. Determine whether the current brightness distribution uniformity and the degree of specular reflection interference satisfy the iris image quality. Go to step 1, or go to step 3.

3. Select to switch the near-infrared LED illumination source on either side or left and right.

4. Return to step 1 cycle.

The integrated security function processor chip feeds back the iris recognition imaging module according to the iris image data until the acquisition of the high quality iris image, including the guidance indication control for the iris recognition image acquisition, including the following steps:

1. Determine the guidance indication method.

2. When the guiding indication is specular visual feedback, the display state prompts the visible light VSLED guiding indicator to indicate that the user uses the appropriate range, indicating that the identification fails, indicating that the identification is successful.

3. When the guidance indicator shows the imaging image feedback for the display. Instructing the user to use the appropriate range on the display indicates that the recognition has failed, indicating that the recognition was successful.

4. Return to step 1 cycle.

The processor chip with integrated safety function feeds back the iris recognition imaging module according to the iris image data until the acquisition of the high quality iris image, including the visible light VSLED indicator light for iris recognition image acquisition and/or the brightness control of the display screen, including the following step:

1. The processor chip with integrated safety function obtains the pupil-iris diameter ratio value ρ based on the iris image data.

2. Determine whether the current pupil-iris diameter ratio value is within the predetermined upper and lower limits [ρh, ρl], and turn to step 1, or go to step 3.

3. Judging when ρ≥ρh, the brightness of the visible light VSLED indicator light and/or the display screen increases, and the brightness increase degree is linear with ρ-ρh; when ρ≤ρl, visible light VSLED indicator light and/or display The brightness of the screen is reduced, and the degree of brightness reduction is further linear with ρl-ρ.

4. Return to step 1 cycle.

The integrated security function processor chip feeds back the iris recognition imaging module according to the iris image data until the acquisition of the high quality iris image, including the automatic image brightness control for iris recognition image acquisition: including the following steps:

1. Define the photoelectric signal of the original unit pixel luminance value Yraw of the iris image;

Yraw=C*T*GAIN*I*(1/F) ² ;

T is a pulsed radiation/exposure (integration) period and/or a synchronized continuous radiation/exposure (integration) period in which the image imaging sensor is synchronized with the near-infrared LED illumination source;

F is the constant of the optical imaging lens fixed aperture or the inverse of the relative aperture;

I is the radiation intensity of the near-infrared LED illumination source;

GAIN is the analog and/or digital gain of the image imaging sensor;

C is a fixed photoelectric signal conversion rate constant of the iris recognition imaging module;

The synchronized image imaging sensor transmission exposure period T and the near-infrared LED illumination source radiation period T satisfy: 3.33 ms milliseconds ≤ T ≤ 33.33 ms milliseconds;

The near-infrared LED illumination source has a radiation intensity I≥100mW/sr;

The image imaging sensor having a maximum value of the analog and/or digital gain GAIN produces a signal-to-noise ratio SNR ≥ 36 db;

The F satisfies: F=EFL/D is: 0.5*SOP/(1.22*λ)≤F≤2.0*SOP/(1.22*λ),

The D is the diameter of the pupil or clear aperture of the optical imaging lens, the EFL is the equivalent focal length value of the optical imaging lens, the SOP is the physical scale of the unit imaging pixel of the image imaging sensor, and λ is the peak wavelength of the near-infrared LED illumination source.

2. Defining the iris image statistical evaluation value Ysp of the iris image area;

The S(Yraw) is an iris image region pixel brightness statistical evaluation function, and the pixel brightness statistical evaluation function includes a pixel brightness histogram statistics, a pixel brightness spectrum statistics, and a pixel brightness. Average value, pixel brightness weighted average or pixel brightness median, etc.

3. The iris image area pixel brightness evaluation value Ysp is in the preset [Yll, Yhl] brightness range by photoelectric signal feedback control;

The photoelectric signal feedback control by T, I, and GAIN, the iris brightness value of the iris image area is estimated to be Yll ≤ Ysp ≤ Yhl; the Yll is the iris brightness of the iris image area. The lower limit, Yhl is the upper limit of the pixel brightness of the iris image area; the photoelectric signal processing control is based on the linear product control relationship of the formula in step 1, and the feedback control changes the photoelectric signal to realize the original unit pixel brightness value. Yraw is changed so that the corresponding iris image region pixel luminance statistical evaluation value Ysp satisfies the preset condition of Yll ≤ Ysp ≤ Yhl.

The specific content and technical features of the present invention can be implemented within the scope of the same or equivalent understanding, such as image imaging sensor type, optical imaging lens type, optical path conversion, and device replacement, which should be equally understood.

Finally, it should also be noted that the above list is only a few specific embodiments of the invention. It is apparent that the present invention is not limited to the above embodiment, and many variations are possible. All modifications that can be directly derived or conceived by those of ordinary skill in the art from the disclosure of the present invention are considered to be the scope of the present invention.

Claims (18)

1. An iris recognition imaging module for a mobile terminal, comprising an iris recognition imaging module disposed on the mobile terminal; the mobile terminal comprises a mobile terminal motherboard, a processor chip integrated with safety functions, a near-infrared LED current driver driver, and a power supply The management module and the display screen are characterized in that: a memory including a secure read/write access function and a memory for a secure read/write access function; the processor chip is also respectively connected with the memory and the memory to complete the security of executing the iris recognition code and the iris template. Calculate and execute the secure storage function of the iris recognition code and iris template;

   The iris recognition imaging module is composed of a near-infrared LED illumination source and an iris recognition imaging module optical component;

   The iris recognition imaging module optical component includes a front and/or a rear near-infrared optical filter for imaging wavelength filtering, and an optical imaging lens for focusing the imaged wavelength light filtered by the near-infrared optical filter, An image imaging sensor imaged by an imaging wavelength light focused by an optical imaging lens, and a connecting line for signalling an image of the image imaging sensor;

   The processor chip is respectively connected with the near-infrared LED current driver and the iris recognition imaging module through a connection line to implement feedback control;

   The near-infrared LED current driver drives and controls the radiation intensity and radiation period of the near-infrared LED illumination source of the iris recognition imaging module.
2. The iris recognition imaging module for a mobile terminal according to claim 1, wherein the processor chip is configured to perform PKI encryption and a digital signature algorithm to protect an iris recognition code and an iris template and an iris recognition result; The image imaging sensor configures an encryption function module for the image signal, and correspondingly, the processor chip configures a decryption function module for the encrypted image signal.
3. The iris recognition imaging module for a mobile terminal according to claim 1, wherein the image imaging sensor and the near-infrared LED illumination source are combined and configured as follows:

   The near-infrared LED illumination source and image imaging sensor implement synchronized pulse period radiation/exposure mode and/or synchronized continuous period radiation/exposure mode;

   The near-infrared LED illumination source radiation is synchronized with a pulse period synchronization of the image imaging sensor image frame exposure and/or a near-infrared LED illumination source radiation is synchronized with a continuous period of image imaging sensor image frame exposure.

   The radiation/exposure (integration) period T is configured to be: 3.33 ms milliseconds ≤ T ≤ 33.33 ms milliseconds.
4. The iris recognition imaging module for a mobile terminal according to claim 1, wherein:

   The combination of the near-infrared optical filter and the near-infrared LED illumination source and the optical imaging lens is configured as follows:

   The center-peak wavelength of the near-infrared optical filter is equal to the center peak wavelength of the near-infrared LED illumination source and the central chromatic aberration correction wavelength of the optical imaging lens; the half-peak transmission wavelength bandwidth FWHM of the near-infrared optical filter effectively matches or covers the near-infrared LED a half-peak radiation wavelength bandwidth FWHM of the illumination source and a chromatic aberration correction wavelength range of the optical imaging lens;
5. The iris recognition imaging module for a mobile terminal according to claim 1, wherein the image imaging sensor and the optical imaging lens are combined and configured as follows:

   The matching principal ray incident angle CRA ≥ 20 degrees;

   The near-infrared LED illumination source and the optical imaging lens are combined with the image imaging sensor to be configured as follows:

   The half-peak radiation angle of the near-infrared LED illumination source is greater than or equal to the field of view of the optical imaging lens, and the field of view of the optical imaging lens is greater than or equal to the image plane physical size of the image imaging sensor.
6. The iris recognition imaging module for a mobile terminal according to claim 3, wherein:

   The near-infrared LED illumination source radiation intensity I is configured as: I ≤ 100 mW / sr;

   The image imaging sensor image readout frame rate R is configured to be R ≥ 30 fps frames per second.
7. The iris recognition imaging module for a mobile terminal according to claim 4, wherein the near-infrared LED illumination source has a center peak wavelength range of 750-880 nm and a half-peak bandwidth FWHM of 10-60 nm;

   The near-infrared optical filter has a center peak wavelength range of 750-880 nm and a half-peak bandwidth FWHM of 10-60 nm;

   The chromatic aberration correction wavelength range of the optical imaging lens is 750-880 nm;

   The near-infrared optical filter is a near-infrared light that reflects visible light and transmits for imaging wavelengths, or absorbs visible light and transmits near-infrared light for imaging wavelengths;

   The near-infrared optical filter is any one of a narrowband near-infrared optical filter or a bandpass near-infrared optical filter.
8. The iris recognition imaging module for a mobile terminal according to claim 1, wherein the image plane physical scale SOI of the image imaging sensor is configured to:

   SOI=DOI*SOP; the DOI is the number of image-facing pixels of the image imaging sensor; SOP is the physical scale of the image imaging sensor unit pixel;

   The field of view angle FOV of the optical imaging lens is configured to be: FOV ≥ 2 * arctan ((SOI) / (2 * EFL)); EFL is the equivalent focal length value of the optical imaging lens;

   The near-infrared LED illumination source brightness half-peak radiation angle AOR is configured to be: AOR ≥ FOV; the FOV is the field of view angle of the optical imaging lens.
9. The iris recognition imaging module for a mobile terminal according to claim 1, wherein the iris recognition imaging module optical component is configured with an outer surface protection window made of tempered glass or sapphire glass, and the outer surface is disposed. A surface protective coating that is resistant to contamination by external impurities.
10. The iris recognition imaging module for a mobile terminal according to claim 1, wherein: The guidance indication of the iris recognition imaging module is configured as follows:

    The near-infrared optical filter reflects visible light for specular visual feedback and a guidance indication formed by the visible light guiding indicator, and/or the display screen displays a guiding indication formed by the imaging image feedback.
11. The iris recognition imaging module for a mobile terminal according to claim 1, wherein:

    The image imaging sensor is configured as a RAW RGB Bayer pixel output format, using RGB channel compensation gain or RGB channel balance gain,

    

    

    

    G channel compensation or balance gain is the standardization standard, G_CGC=1.0;

    R channel compensation or balance gain R_CGC=G/R;

    B channel compensation or balance gain B_CGC=G/B;

    The λ is the peak wavelength of the near-infrared LED illumination source, and Δλ is the peak wavelength half-peak bandwidth FWHM, g(λ), r(λ), b(λ) of the near-infrared LED illumination source, respectively, is the photoelectric quantum of the RGB channel of the image imaging sensor. Conversion efficiency or spectral sensitivity function, f(λ) is a wavelength distribution function;

    The maximum value of the analog and/or digital gain GAIN of the image imaging sensor is configured as: the image imaging sensor SNR ≥ 36db generated by the GAIN maximum value;

    The image resolution ROI of the image imaging sensor is configured to be: ROI ≥ 1920 pixels * 1080 pixels.
12. The iris recognition imaging module for a mobile terminal according to claim 1, wherein the optical distortion DOL absolute value of the optical imaging lens is configured as: DOL absolute value ≤ 1%;

    The EFL equivalent focal length value of the optical imaging lens is configured to:

    SOP*1000pixel≤EFL≤3*SOP*1000pixel;

    The SOP is a physical scale of a unit pixel of the image imaging sensor, in units of um/pixel;

    The pixel is a pixel unit;

    The relative illumination rate IOR of the optical imaging lens is configured to: IOR ≥ 50%;

    The IOR is an edge field of view brightness of the optical imaging lens / a central field of view brightness of the optical imaging lens;

    The fixed constant aperture or relative aperture reciprocal F of the optical imaging lens is configured as: F = EFL / D;

    0.5*SOP/(1.22*λ)≤F≤2.0*SOP/(1.22*λ);

    The D is the diameter of the pupil or clear aperture of the optical imaging lens, and the EFL is the equivalent focal length value of the optical imaging lens.

    SOP is the physical scale of the image imaging sensor unit pixel, and λ is the peak wavelength of the near-infrared LED illumination source;

    The optical imaging lens adopts a plastic aspheric optical lens injection molding process, and uses 3-5P lenses to correct all aberrations.
13. An image acquisition method for iris recognition of a mobile terminal, the mobile terminal comprising a processor chip, a near-infrared LED current driver and an iris recognition imaging module, which are connected to each other via a connection line to implement feedback control; the near-infrared LED The current driver drives the near-infrared LED illumination source radiation intensity and radiation period of the iris recognition imaging module, the method comprising the steps of:

    1 iris recognition imaging module initial configuration;

    2 near-infrared LED current driver and image imaging sensor enter the low-power mode of Shutdown or standby standby to save most of the power consumption;

    3 processor chip to detect whether it is necessary to obtain an iris image, is to step 4, or continue to step 3;

    4 near-infrared LED current driver and image imaging sensor switch from the Shutdown or standby standby low-power mode to the normal working mode, and the near-infrared LED current driver turns on the near-infrared LED illumination source;

    5 image imaging sensor outputs pulse period radiation/exposure and/or synchronized continuous period radiation/exposure image data synchronized with the near-infrared LED illumination source;

    The 6 processor chip feedbacks and controls the iris recognition imaging module according to the iris image data until the acquisition of the high quality iris image;

    7 End the acquisition of the iris image and return to step 2 for a loop.
14. The iris recognition image acquisition method for a mobile terminal according to claim 7, wherein:

    The iris recognition imaging module initial configuration includes the following steps:

    (1) Near-infrared LED current driver reset reset, image imaging sensor reset reset;

    (2) The near-infrared LED current driver mode is configured with synchronized pulse period radiation and/or continuous period radiation mode;

    (3) image imaging sensor configuration MIPI or parallel interface, configuration data output bit width 8/10/12bit, image imaging sensor configuration clock PLL and frame readout rate R, image imaging sensor configuration image resolution ROI;

    (4) The image imaging sensor is configured with a RAW RGB Bayer pixel output format, the image imaging sensor is configured with an RGB channel compensation gain or an RGB channel balance gain, and the image imaging sensor is configured with an analog and/or digital gain GAIN;

    (5) The image imaging sensor is configured with a pulse period exposure mode synchronized with a radiation pattern of the near-infrared LED illumination source and/or a synchronized continuous period exposure mode.
15. The iris recognition image acquisition method for a mobile terminal according to claim 7, wherein the processor chip feedback-controls the iris recognition imaging module according to the iris image data until the high-quality iris image is acquired.

    Including near-infrared LED illumination source control for iris recognition image acquisition, including the following steps:

    (1) The processor chip integrated with the safety function obtains the brightness distribution uniformity and the degree of specular reflection interference of the iris image source illumination according to the iris image data;

    (2) judging whether the current brightness distribution uniformity and the degree of specular reflection interference satisfy the iris image quality; whether it is a step (1) or a step (3);

    (3) Selecting to switch the near-infrared LED illumination source on either side or left and right sides;

    (4) Return to step (a) cycle.
16. The iris recognition image acquisition method for a mobile terminal according to claim 7, wherein the processor chip feedback-controls the iris recognition imaging module according to the iris image data until the high-quality iris image is acquired.

    Including guidance indication control for iris recognition image acquisition, including the following steps:

    i. determining whether the guiding indication mode is a specular visual feedback or a display screen displaying an imaging image feedback;

    Ii. When the guiding indication is specular visual feedback, the display state prompts the visible light VSLED guiding indicator to indicate that the user uses the appropriate range, indicating that the identification fails, indicating that the identification is successful;

    Iii. when the guiding instruction displays the imaged image feedback for the display screen, indicating on the display that the user uses the appropriate range, indicating that the identification fails, indicating that the identification is successful;

    Iv, return to step 1 cycle.
17. The iris recognition image acquisition method for a mobile terminal according to claim 7, wherein the processor chip feedback-controls the iris recognition imaging module according to the iris image data until the high-quality iris image is acquired.

    Including the visible light VSLED indicator for iris recognition image acquisition and/or brightness control of the display, including the following steps:

    I, the processor chip obtains a pupil-iris diameter ratio value ρ according to the iris image data;

    II, judging whether the current pupil to iris diameter ratio value is within the predetermined upper and lower limits [ρh, ρl], is to step 1, or to step 3;

    III. Judging when ρ≥ρh, the brightness of the visible light VSLED indicator light and/or the display screen is increased, and the degree of brightness increase is linearly related to ρ-ρh;

    It is judged that when ρ≤ρl, the brightness of the visible light VSLED indicator light and/or the display screen is decreased, and the degree of brightness reduction is linearly related to ρl-ρ;

    IV, return to step 1 cycle.
18. The iris recognition image acquisition method for a mobile terminal according to claim 7, wherein the integrated security function processor chip feeds back and controls the iris recognition imaging module according to the iris image data until the acquisition of the high quality iris The image, including automatic image brightness control for iris recognition image acquisition, includes the following steps:

    a, defining the photoelectric signal of the original unit pixel luminance value Yraw of the iris image;

    Yraw=C*T*GAIN*I*(1/F) ² ;

    T is a pulsed radiation/exposure period and/or a synchronized continuous radiation/exposure period in which the image imaging sensor is synchronized with the near-infrared LED illumination source;

    F is the constant of the optical imaging lens fixed aperture or the inverse of the relative aperture;

    I is the radiation intensity of the near-infrared LED illumination source;

    GAIN is the analog and/or digital gain of the image imaging sensor;

    C is a fixed photoelectric signal conversion rate constant of the iris recognition imaging module;

    The synchronized image imaging sensor transmission exposure period T and the near-infrared LED illumination source radiation period T satisfy:

    3.33ms milliseconds ≤ T ≤ 33.33ms milliseconds;

    The near-infrared LED illumination source has a radiation intensity I≤100mW/sr;

    The maximum value of the analog and digital gain GAIN is obtained by an image imaging sensor with a signal-to-noise ratio SNR ≥ 36db;

    The F=EFL/D is satisfied:

    0.5*SOP/(1.22*λ)≤F≤2.0*SOP/(1.22*λ),

    The D is the diameter of the pupil or clear aperture of the optical imaging lens, and the EFL is the equivalent focal length value of the optical imaging lens.

    SOP is the physical scale of the image imaging sensor unit pixel, and λ is the peak wavelength of the near-infrared LED illumination source;

    b, defining an iris image area pixel brightness statistical evaluation value Ysp;

    The S(Yraw) is an iris image region pixel brightness statistical evaluation function, and the pixel brightness statistical evaluation function includes a pixel brightness histogram statistics, a pixel brightness spectrum statistics, and a pixel brightness. Average value, pixel brightness weighted average value, or pixel brightness median value, etc.;

    c. Realizing the iris image area pixel brightness evaluation value Ysp in the preset [Yll, Yhl] brightness range by photoelectric signal feedback control;

    The photoelectric signal feedback control by T, I, and GAIN, the iris brightness value of the iris image area is estimated to be Yll ≤ Ysp ≤ Yhl; the Yll is the iris brightness of the iris image area. Lower limit,

    Yhl is the upper limit of the pixel brightness of the iris image area; the photoelectric signal processing feedback control is based on the linear product control relationship of the formula in step 1, the feedback control changes the photoelectric signal, and the original unit pixel brightness value Yraw is changed to make the corresponding iris image The regional pixel luminance statistical evaluation value Ysp satisfies a preset condition of Yll ≤ Ysp ≤ Yhl.

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