WO2016070781A1

WO2016070781A1 - Mobile terminal visible light and biometric identification combination opto-electronic imaging system and method

Info

Publication number: WO2016070781A1
Application number: PCT/CN2015/093647
Authority: WO
Inventors: 倪蔚民; 金城
Original assignee: 苏州思源科安信息技术有限公司
Priority date: 2014-11-03
Filing date: 2015-11-03
Publication date: 2016-05-12
Also published as: CN105376469B; CN104301633B; CN104301633A; CN105357426A; CN105354557B; CN105357426B; CN105426848A; CN105426848B; CN105354557A; CN105376469A

Abstract

Provided are a mobile terminal visible light and biometric identification combination opto-electronic imaging system and method. The system comprises an LED light source, an optical filter, an optical imaging lens and an image sensor; the image sensor is configured such that a unit pixel has a broadband imaging wavelength distribution spectrum capable of receiving visible light to infrared light; the LED light source is configured to radiate light having an imaging wavelength of visible light or infrared light, and has a radiation wavelength range matching the visible light to infrared light broadband imaging wavelength distribution of the image sensor; the optical filter is configured to be a visible light and infrared light changeable wavelength optical filter, and the visible light and infrared light changeable wavelength optical filter is configured to have a filtration wavelength range matching the visible light to infrared light broadband imaging wavelength distribution of the image sensor; the optical imaging lens is configured to have a focus wavelength range matching the visible light to infrared light broadband imaging wavelength distribution of the image sensor.

Description

Mobile terminal visible light and biometric combined photoelectric imaging system and method

Technical field

The invention relates to the field of biometric photoelectric, in particular to a visible light and biometric combined photoelectric imaging system and method for mobile terminals with high security.

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, WeChat, and bank account management, although in their use, for life. It has brought great convenience, 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, and even be copied, so with the use of fingerprint technology on mobile terminals More and more extensive, its security will also decline accordingly, so bio-identification, which is more advantageous in terms of security, is a very effective method to solve the mobile identity authentication process, and the biometric system is an existing creature. The most accurate in recognition.

Currently, in the biometric system technology and products of all mobile terminals, the combination of the visible light photoelectric imaging system and the iris vein biometric photoelectric imaging system for the self-photographing function is not realized. However, if the self-photographing visible light photoelectric imaging system and the iris vein biometric photoelectric imaging system are separately and independently implemented, the cost thereof is greatly increased, and the volume of the more important mobile terminal cannot provide a mounting space for accommodating three or more separate independent optical imaging systems.

In addition, although the iris vein has more advantages in biosecurity and fingerprint recognition in terms of anti-counterfeiting safety, if it is applied to important occasions such as mobile phone large-value payment, it is still necessary to further upgrade the security technology of anti-counterfeiting in vivo detection. To eliminate the threat of security risks. After all, biometrics itself is designed to be safe, and its own security is the most basic and important.

And how to obtain high-quality image photoelectric imaging methods and imaging methods for improving the success rate of biometric recognition in mobile terminal applications.

It should be pointed out that the RGB-IR independent channel optoelectronic imaging system can realize the combined imaging of visible light and biometrics. However, due to the production cost and process, the mutual wavelength background isolation or cut-off depth between independent channels has not yet met the actual demand.

Further, the high-security mobile terminal visible light and biometric combined photoelectric imaging system and method need to solve the following serious problems:

1. A visible light and biometric combined photoelectric imaging system for mobile terminal applications, which is visible to the self-timer function. The photo-electric imaging system and the iris vein bio-identification photoelectric imaging system are combined, and the volume is controlled within 8.5 mm*8.5 mm*6 mm, and the power consumption is low.

2. In the mobile terminal application, the visible light and biometric combined photoelectric imaging system requires a set of high-security anti-counterfeiting living body detection methods to ensure the safety of the biometric identification itself.

3. In the mobile terminal application, the visible light and biometric combined photoelectric imaging system needs to obtain high quality image photoelectric imaging method.

4. In the mobile terminal application, the visible light and biometric combined photoelectric imaging system requires a set of imaging methods to improve the success rate of biometric recognition.

5. In the mobile terminal application, the visible light and biometric combined photoelectric imaging system 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.

Summary of the invention

The technical problem to be solved by the present invention is to provide a visible light and biometric combined photoelectric imaging system for mobile terminals with high security.

In particular, the biometrics described in the present invention are designated as irises and veins.

In order to solve the above technical problem, the present invention provides a visible light and biometric combined photoelectric imaging system for a mobile terminal, including a visible light photoelectric imaging and a biometric photoelectric imaging system; the visible light photoelectric imaging and the biometric photoelectric imaging are both performed by a processor chip and an LED. An illumination source, an optical filter, an optical imaging lens, an image sensor; the imaging array of the image sensor is configured such that the unit pixel has an imaging wavelength spectrum that receives a broadband distribution of visible-infrared light; the LED illumination source is configured to pass the LED a current driver controlled radiation illumination source of a visible light-infrared light imaging wavelength, and the LED illumination source has a range of radiation wavelengths that match the visible light-infrared broadband imaging wavelength distribution of the image sensor;

The optical filter is configured to control a driver-controlled visible-infrared variable wavelength optical filter through an optical filter; the visible-infrared variable wavelength optical filter is configured to have visible-infrared light with an image sensor Broadband imaging wavelength distributions are matched filter wavelength ranges; the optical imaging lens is configured as an autofocus optical imaging lens controlled by an optical imaging lens focus driver; the autofocus optical imaging lens is configured to have visible light with an image sensor Infrared light broadband imaging wavelength range in which the wavelength distributions are matched; the visible-infrared variable wavelength optical filter, an autofocus optical imaging lens, the optical center of the image sensor being configured as a coaxial optical path position of the optical axis of the imaging system; The optical center of the LED illumination source is configured as an off-axis optical path position of the optical axis of the imaging system.

As an improvement of the visible light and biometric combined photoelectric imaging system of the mobile terminal according to the present invention: the visible light imaging wavelength is radiated by the LED illumination source, and the visible light-infrared variable wavelength optical filter is switched to filter the infrared light imaging wavelength. Autofocus optical imaging lens physical refraction focusing visible light imaging wavelength and imaging array of image sensor receiving visible light wavelength constitute optical path of visible light photoelectric imaging; infrared light imaging wavelength is radiated by said LED illumination source, visible light-infrared variable wavelength optical filter Switching to filtering visible light imaging wavelengths, autofocusing optical imaging lens physical refraction focusing infrared light imaging wavelength, and imaging array of image sensor receiving infrared light wavelength constitutes optical path of biometric photoelectric imaging; the visible light photoelectric imaging adopts visible light imaging wavelength of 400- 650 nm, the focusing work distance WD is at least in the range of 30-100 cm; the biometric photoelectric imaging adopts infrared light imaging wavelength of 750-950 nm, and the focusing work distance WD is at least 30-100 cm; the coaxial Optical path The visible-infrared variable wavelength optical filter, the autofocus optical imaging lens, the angle between the optical center line of the image sensor and the optical axis of the imaging system has an angle of 0 degrees; the off-axis optical path position is the radiation optics of the illumination source The angle between the centerline and the optical axis of the imaging system has an angle of 5-30 degrees.

As a mobile terminal visible light and biometric combined photoelectric imaging system of the present invention Step improvement: The biometric photoelectric imaging has the following optical imaging requirements: the imaging wavelength WI of the biometric photoelectric imaging satisfies: 750 nm ≤ WI ≤ 950 nm; the focused work object distance WD of the biometric photoelectric imaging satisfies: 10 cm ≤ WD ≤ 30 cm; The pixel spatial resolution PSR of the biometric photoelectric imaging satisfies: PSR ≥ 10 pixels/mm; the optical magnification OM of the biometric photoelectric imaging satisfies: OM=PS*PSR; wherein the PS is the physics of each imaging pixel unit of the image sensor Scale; PSR is the pixel spatial resolution of biometric photoelectric imaging; the optical spatial resolution OSRI of the biometric photoelectric imaging satisfies in the image plane: when the modulation transfer function is equal to 60%, 1/(4*PS) ≤ OSRI ≤1/(2*PS); the visible light photoelectric imaging has the following optical imaging requirements: the imaging wavelength WI of visible light photoelectric imaging satisfies: 400 nm ≤ WI ≤ 650 nm; the focused work object distance WD of visible light photoelectric imaging satisfies: 30 cm ≤ WD ≤ 100cm; Pixel spatial resolution PSR of visible light photoelectric imaging should satisfy: PSR≤3pixel/mm; optical magnification OM of visible light photoelectric imaging should satisfy: OM=PS*PSR; wherein, PS is the physical scale of each imaging pixel unit of the image sensor; PSR is the pixel spatial resolution of visible light photoelectric imaging;

The optical spatial resolution OSRI of the visible light photoelectric imaging satisfies in the image plane: when the modulation transfer function is equal to 60%, 1/(4*PS) ≤ OSRI ≤ 1/(2*PS).

Preferably, the image sensor, the LED current driver, the autofocus optical imaging lens focus driver, and the optical filter control driver are each controlled by a processor chip;

The processor chip is configured to connect an image sensor, control image pixel value data output by the image sensor imaging array; connect the LED current driver to drive the LED illumination source radiation intensity, radiation angle and position, radiation time; connect autofocus optics An imaging lens focus driver is used to drive the autofocus optical imaging lens to physically focus; and an optical filter control driver is coupled to drive the visible-infrared variable wavelength optical filter wavelength range change.

A further improvement of the visible light and biometric combined optoelectronic imaging system of the mobile terminal according to the present invention: the physical scale PS of the imaging pixel unit receiving the visible light-infrared light wavelength in the imaging array of the image sensor satisfies the following condition: 1 um / Pixel ≤ PS ≤ 3 um / pixel; the wavelength pixel unit received by the image sensor imaging array has a photoelectrically converted value Y, and its value Y is:

Y=Q*GAIN*EXP*ADCG*E*PSU EQ1

Wherein: the EXP is an integration time or exposure time of the image sensor imaging array; EXP synchronization is equal to the LED illumination source radiation time; EXP≤33.3ms; GAIN is the digital and analog gain of the image sensor imaging array; the maximum GAIN satisfies the image sensor Signal-to-noise ratio SNR, SNR ≥ 36db decibel; ADCG is the ADC voltage analog-to-digital conversion quantization resolution of the image sensor imaging array; E is the radiance or irradiance received by the image sensor imaging array;

E=C*β*I/WD ² *cos ² ψ*(1/FNO) ²

Where: I is the radiation intensity of the LED illumination source 106; the minimum value of I satisfies I ≥ 100 mw / sr; ψ is the radiation angle of the LED illumination source, that is, the off-axis clamp between the radiation optical center line of the LED illumination source and the optical axis of the imaging system Angle; ψ satisfied: 5 degrees ≤ ψ ≤ 30 degrees; WD is the focus working distance of the optical imaging system; FNO is the numerical aperture of the autofocus optical imaging lens, that is, the relative aperture distance reciprocal; FNO meets: 0.5*PS/(1.22 *λ)≤FNO≤2.0*PS/(1.22*λ);

λ is the imaging wavelength; β is the biological tissue optical effect reflectivity of the imaged object; C is the optical coefficient of the optical imaging system;

C=1/16*cos ⁴ ω/(1+OM) ² ;

Where: ω is the object angle of view of the incident light; ω satisfies: 0 ≤ ω ≤ FOV/2, FOV is the full field of view of the photoelectric imaging system; OM is the optical magnification of the photoelectric imaging system; PSU is the image sensor imaging The physical scale area ratio of the imaging pixel unit of the array;

PSU = (PS * PS) / cm ² ;

Q is a photoelectric conversion constant of the photoelectric imaging system; the digital value Y of the image sensor imaging array receiving pixel unit photoelectric conversion is output as the imaged image raw RAW pixel data I{Y}; the imaging array of the image sensor is configured as a global frame An imaging mode or a scroll line imaging mode; the image sensor is configured as a RAW RGB pixel output format, using RGB channel compensation gain or RGB channel balance gain;

G channel compensation or balanced gain is the normalization standard, G_GC=1.0; R channel compensation or balance gain R_GC=G/R; B channel compensation or balance gain B_GC=G/B; the [λl, λh] is the imaging wavelength range The g(λ), r(λ), b(λ) are photoelectric quantum conversion efficiency sensitivity wavelength distribution functions of the RGB spectrum of the image sensor, respectively, and f(λ) is a visible light-infrared variable wavelength optical filter Transmittance wavelength distribution function, S(λ) is the radiance wavelength distribution function of the LED illumination source; L(λ) is the transmittance wavelength distribution function of the autofocus optical imaging lens; the equivalent is to compensate the gain by the R channel or The B channel compensation gain is a normalized standard; the image resolution ROI of the image sensor is configured to be: ROI ≥ 2560 pixels * 1280 pixels; the image sensor has a chief ray incident angle CRA (Chief Ray Angle) ≥ 25 degrees.

Further improvement of a visible light and biometric combined photoelectric imaging system for a mobile terminal according to the present invention: the LED illumination source has: visible light and infrared light imaging wavelengths of independent or mixed radiation; half-peak radiation field of view angle Ω; The half-peak radiation field of view angle Ω satisfies:

Ω ≥ FOV;

The FOV is a full field of view of the imaging system;

FOV ≥ 2 * arctan ((DI * PS) / (2 * EFL));

Where: EFL is the equivalent focal length of the autofocus optical imaging lens; DI is the number of image-facing pixel units of the image sensor imaging array; PS is the physical scale of the pixel unit of the image sensor imaging array; used to optimize the photoelectric imaging system One or more different radiation angles and positions of the imaging field of view and imaging quality effects; continuous or pulsed radiation time and radiation intensity synchronized with image sensor imaging for jointly optimizing the imaging quality effects of the optoelectronic imaging system; said LED illumination The light source is packaged in an SMD surface mount package.

A further improvement of a visible light and biometric combined optoelectronic imaging system for a mobile terminal according to the present invention: the visible light-infrared variable wavelength optical filter has: when changed to a visible light imaging wavelength:

The light cutoff rate Fi≤10.0% in the visible light imaging wavelength range, and the light cutoff ratio outside the visible light imaging wavelength range is Fo≥99.0%,

Equivalent

The light transmittance in the visible light imaging wavelength range is Ti≥90.0%, and the light transmittance outside the visible light imaging wavelength range is To≤1.0%;

When changing to infrared light imaging wavelength:

The optical cutoff rate Fi≤10.0% in the infrared imaging wavelength range, and the optical cutoff ratio outside the infrared imaging wavelength range is Fo≥99.0%,

Equivalent

The light transmittance in the infrared light imaging wavelength range is Ti≥90.0%, and the light transmittance outside the infrared light imaging wavelength range is To≤1.0%.

As a mobile terminal visible light and biometric combined photoelectric imaging system of the present invention Step improvement: The autofocus optical imaging lens is configured to have a fixed focal length, and any of a liquid driving lens, a liquid crystal driving lens, a VCM voice coil driving lens, a MEMS driving lens, an EDOF wavefront phase modulation lens, or a wafer level array microlens One type;

And it has:

The surface maximum reflectance Rmax ≤ 1.0%, the surface average reflectance Ravg ≤ 0.3%,

Equivalent

The surface minimum transmittance Tmin ≥ 99.0%, the surface average transmittance Tavg ≥ 99.7%;

The autofocus optical imaging lens has a focal length EFL, and the numerical aperture FNO satisfies:

2mm ≤ EFL ≤ 5mm, 1.4 ≤ FNO ≤ 2.8;

The optical distortion DOL absolute value of the autofocus optical imaging lens is configured as: DOL absolute value ≤ 1%;

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

The IOR = edge field of view brightness of the optical imaging lens / central field of view brightness of the optical imaging lens;

The autofocus optical imaging lens and image sensor are configured to match the principal ray incident angle CRA with each other.

An imaging method for visible light photoelectric imaging, comprising the following steps: 1 processor chip performs optical filter control driver, LED current driver, image sensor, autofocus optical imaging lens focus driver initialization working state configuration; 2 processor chip Control optical filter control driver, LED current driver, image sensor, autofocus optical imaging lens focus driver enters low power standby or shutdown mode; processor chip determines whether it needs to acquire visible image, turn to step 4, continue to step 3 The 4 processor chip controls the visible light-infrared variable wavelength optical filter to be a visible light imaging wavelength through an optical filter control driver; the processor chip controls the LED current driver to drive the LED illumination source to generate visible light imaging wavelength continuous or synchronous pulse mode radiation; The processor chip controls the imaging array of the image sensor to receive the original image RAW RGB pixel data I{Y} of the global frame imaging mode or the scroll line imaging mode output; 5 processor chip according to the imaging original image RAW pixel data I{Y} Pixel unit photoelectric conversion relationship, driving image sensor and LED current driver and autofocus optical imaging lens focus driver to realize feedback control; 6 processor chip for original image RAW pixel data I{Y} interpolation reconstruction and image processing; 7 processor The chip outputs the interpolated reconstructed and image processed image I{r, g, b}; 8 returns to step 2 loop.

An imaging method for biometric photoelectric imaging, comprising the steps of: 1. processor chip performing optical filter control driver, LED current driver, image sensor, autofocus optical imaging lens focus driver initializing working state Configuration; 2. Processor chip control optical filter control driver, LED current driver, image sensor, autofocus optical imaging lens focus driver enters low power standby or shutdown mode; 3. Processor chip determines whether it needs to acquire biological imaging image, Is the step (4), continue to step (3); 4. The processor chip changes the visible-infrared variable wavelength optical filter to the infrared light imaging wavelength through the optical filter control driver; 5. The processor chip controls the LED current driver to drive the LED illumination The light source generates infrared radiation imaging wavelength continuous or synchronous pulse mode radiation; 6. The processor chip controls the image sensor's imaging array to receive the global frame imaging mode or the scroll line imaging mode output of the original image RAW RGB pixel data I{Y}; Processor chip based on imaged raw image RAW The pixel data I{Y} and the pixel unit photoelectric conversion relationship drive the image sensor and the LED current driver and the autofocus optical imaging lens focus driver to realize the feedback control; 8. The processor chip outputs the image I{Y}; 9. returns to the step (2) cycle.

As an improvement of the imaging method for biometric photoelectric imaging according to the present invention, the image sensor initialization working state is configured as a RAW RGB pixel output format, and the RGB channel compensation gain or the RGB channel balance gain processing can be configured by initializing the working state. Setting a corresponding RGB channel digital and/or analog gain simplification of the image sensor; the feedback control includes the following steps: First, the processor chip can According to the imaged raw image RAW pixel data I{Y} output by the image sensor and the corresponding formula EQ1, feedback control image sensor reset integration time, digital and/or analog gain setting, feedback control LED current driver to drive the radiation intensity of the LED illumination source And radiation time, used to control image brightness, signal-to-noise ratio and motion blur to improve image quality; secondly, the processor chip can calculate the mirror total reflection interference in the image based on the imaged raw image RAW pixel data I{Y} output by the image sensor Degree and relative illumination brightness balance, feedback control LED current driver drives LED illumination source to control radiation angle and position to improve imaging quality; finally, the processor chip can calculate the focus quality of the original RAW pixel data I{Y} of the imaged image Value feedback control Autofocus optical imaging lens Focus drive drive autofocus optical imaging lens to achieve biometric optoelectronic imaging focus work distance WD at least in the range of 10cm-30cm.

A driving autofocus method comprises the following steps: 1. defining a local region of interest to be searched and a search parameter according to a predetermined focus working object range; 2. processor chip controlling autofocus optical imaging lens focusing driver according to step 1 Defining a local region of interest to be searched and search parameters, driving the autofocus optical imaging lens to perform a continuous focus position search in a monotonic direction; 3. processor chip controlling the image sensor acquisition step 2 in a monotonous direction in a continuous focus position Searching for the output of the original image RAW RGB pixel data; 4. The processor chip calculates the focus quality of the focus position search image in real time; 5. The processor determines that the image corresponding to the best focus quality is the best focus image.

A biometric anti-counterfeiting bio-detection method: a real-time detection method for biological tissue spectroscopy activity characteristics generated by visible-infrared light imaging wavelength radiation.

As an improvement of the biometric anti-forgery living body detection method according to the present invention, the real-time detection method of the biological tissue spectral activity characteristic generated by the visible light-infrared light imaging wavelength radiation comprises the following steps: 1) processor chip through optical The filter control driver changes the visible-infrared variable wavelength optical filter to visible light imaging wavelength; the processor chip drives the LED current driver to drive the LED illumination source to generate visible imaging wavelength radiation; the processor chip acquires the visible imaging wavelength of the image sensor imaging array Image Ivs; 2) the processor chip controls the driver to change the visible-infrared variable wavelength optical filter to the infrared light imaging wavelength through the optical filter control driver; the processor chip drive controls the LED current driver to drive the LED illumination source to generate the infrared light imaging wavelength radiation; The processor chip acquires the infrared light imaging wavelength image Iir of the image sensor imaging array; 3) the processor chip calculates the contrast C data of the visible light imaging wavelength image Ivs and the infrared light imaging wavelength image Iir in steps a and b, respectively, Ivs_C, and Iir_C ; among them:

C is the contrast between the iris area and the outer area of the iris;

or

C is the contrast between the vein area and the extra-venous area;

C=S(Yiris)/S(Youtiris);

or

C=S(Youtvein)/S(Yvein);

Yiris represents the iris area pixel; Youtiris represents the iris area pixel; Yvein represents the vein area pixel;

Youtvein represents the extra-venous region pixel; the function S is the corresponding region pixel statistical evaluation function, and the pixel statistical evaluation function includes: histogram statistics, frequency statistics, average statistics, weighted average statistics, median statistics , energy value statistics, variance statistics, gradient statistics or space-frequency domain filters; 4) processor chip real-time calculation of visible image imaging wavelength radiation and infrared light imaging wavelength radiation image contrast Ivs_C and Iir_C activity change rate Δρ;

among them:

Δρ=Iir_C/Ivs_C*100%;

5) Preset values of the spectral properties of the biological tissue according to the visible light-infrared light imaging wavelength, and step 4 The active contrast ratio of the data value Δρ is correspondingly changed, and the judgment condition Δρ>300% realizes real-time detection of the biological living state; the above-mentioned steps 1 and 2 are equivalent and can be swapped.

An imaging method for improving the success rate of biometric recognition includes the following steps: I. acquiring infrared light imaging wavelength biological image Iir{Pψenroll} generated by at least two or more LED illumination sources at different radiation angles and positions during registration; II At least two or more biometric template Template{Pψenroll} are obtained by using the biological image Iir{Pψenroll}, and the cross-matching of the feature templates is successful, and then saved as a registered bio-feature template; III. One or more acquisitions are recognized. The infrared light imaging wavelength biological image Iir{Pψrecogn} generated by the LED illumination source at different radiation angles and positions; IV, using one or more biological images Iir{Pψrecogn} to calculate the generated feature template Template{Pψrecogn} and the registered creature The feature template Template{Pψenroll} performs cross comparison and obtains the recognition result.

An imaging method for improving the success rate of biometric recognition, comprising: the following steps: i. acquiring infrared light imaging wavelength biological image generated by at least two or more LED illumination sources at different radiation intensities when registering Iir{Renroll} ;ii, using the biological image Iir{Renroll} to obtain at least two or more biometric templates Template{Renroll}, after the cross-matching of the feature templates is successful, save as a registered bio-feature template; iii, collect one when identifying Or the above-mentioned LED illumination source, the infrared light imaging wavelength biological image Iir{Rrecogn} generated at different radiation intensities; iv, using one or more biological images Iir{Rrecogn} to calculate the generated feature template Template{Rrecogn} and the registered creature Cross-aligning between feature templates Template{Renroll} and obtaining recognition results.

An imaging method for improving the success rate of biometric recognition includes the following steps: a registration of at least two or more LED illumination sources generated at different radiation wavelength ranges of infrared light imaging wavelength biological images Iir{Wenroll}; b using biological The image Iir{Wenroll} calculates at least two or more biometric template Template{Wenroll}, and after the cross-matching between the feature templates is successful, saves as a registered bio-feature template; c collects one or more LED illumination sources when recognizing Infrared light imaging wavelength biological image Iir{Wrecogn} generated at different radiation wavelength ranges; d uses one or more biological images Iir{Wrecogn} to calculate the generated feature template Template{Wrecogn} and registered biometric template Template{Wenroll} Cross-aligning and obtaining recognition results.

Summarizing the above description, the present invention realizes a high security mobile terminal visible light and biometric combined photoelectric imaging system and a method thereof:

1. The visible light and biometric combined photoelectric imaging system in mobile terminal application realizes the visible light photoelectric imaging satisfying the self-timer function and the photoelectric imaging combination of various iris vein biometrics, and its volume is controlled within 8.5mm*8.5mm*6mm, low power consumption .

2. The visible light and biometric combined photoelectric imaging system in the mobile terminal application realizes a set of high-security anti-counterfeiting living body detection methods to ensure the safety of the biometric identification itself.

3. The visible light and biometric combined photoelectric imaging system in mobile terminal application realizes obtaining high quality image photoelectric imaging method.

4. A combination of visible light and biometric imaging photoelectric imaging systems in mobile terminal applications to achieve an imaging method that improves the success rate of biometric recognition.

5. In the mobile terminal application, the visible light and biometric combined photoelectric imaging system can greatly reduce the cost, and the cost can be reduced to less than 10 dollars to be applied on a large scale.

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 view of a visible light and biometric combined photoelectric imaging system of the present invention;

detailed description

Embodiment 1 A mobile terminal visible light and biometric combined photoelectric imaging system and method are provided. The method comprises an imaging method with visible light photoelectric imaging, an imaging method for biometric photoelectric imaging, a biological anti-counterfeiting living body detecting method, and an imaging method for improving the success rate of biometric recognition.

As shown in FIG. 1, the combined optoelectronic imaging system sequentially sets a visible-infrared variable wavelength optical filter (101 or 104) (for filtering visible or infrared light imaging wavelengths) from top to bottom along the optical axis 100 of the imaging system. a fixed mount 103 for autofocus optical imaging lens 102 (for refracting focused imaging wavelengths), an autofocus optical imaging lens (for fixed mounting of autofocus optical imaging lenses), Image sensor 105 (for photoelectric conversion output imaging image), illumination source 106 (including visible light and infrared light - LED illumination source for generating visible light imaging wavelength radiation for visible light photoimaging and for generating infrared light imaging for biometric photoelectric imaging) Wavelength radiation) and imaging system fixed mounting substrate 107 (for providing visible light and biometric photoelectric imaging fixed mounting carrier), imaging system fixed mounting substrate 107 connected to mobile terminal motherboard 110 (for implementing mobile terminal function circuit carrier), in mobile terminal Integrated LED current driver 108 on the main board 110 (for driving and controlling the illumination of the LED illumination source 106 Degree, radiation angle and position, and radiation time), autofocus optical imaging lens focus driver 111 (for driving autofocus optical imaging lens 102 autofocus), optical filter control driver 112 (for driving visible light-infrared light variable The wavelength optical filter changes the wavelength range), and a processor chip 109 (for driving control of the LED current driver 108, autofocus optical imaging lens focus driver 111, optical filter control driver 112 and image sensor 105).

The visible light and biometric combined optoelectronic imaging system of Embodiment 1 of the present invention includes an optical pathway for visible light photo imaging and an optical pathway for biometric photoelectric imaging.

The optical pathways for visible light imaging include the following:

The LED illumination source 106 radiates the visible light imaging wavelength, the visible-infrared variable wavelength optical filter (101 or 104) switches to the filtered infrared light imaging wavelength, the autofocus optical imaging lens 102 physically refracts the focused visible imaging wavelength, and the image sensor 105 is imaged. The array receives visible wavelengths.

The optical pathways for biometric optoelectronic imaging include the following:

The LED illumination source 106 radiates the infrared light imaging wavelength, the visible-infrared variable wavelength optical filter (101 or 104) is switched to filter the visible light imaging wavelength, and the autofocus optical imaging lens 102 physically refracts the focused infrared light imaging wavelength, the image sensor 105 The imaging array receives the wavelength of the infrared light.

In a specific embodiment 1 of the present invention, the imaging array of the image sensor 105 is configured such that the unit pixel has an imaging wavelength spectrum that receives a broadband distribution of visible-infrared light; the LED illumination source 106 (visible light and infrared LED illumination source) is configured to have a radiation wavelength range that matches the visible-infrared broadband imaging wavelength distribution of the image sensor 105; the visible-infrared variable wavelength optical filter (101 or 104) is configured to have a visible-infrared broadband imaging wavelength with the image sensor 105 The filter wavelength ranges that match each other are distributed; the autofocus optical imaging lens 102 is configured to have a range of focus wavelengths that match the visible-infrared broadband imaging wavelength distribution of the image sensor 105.

A visible-infrared variable wavelength optical filter (101 or 104), autofocusing optical imaging lens 102, the optical center of image sensor 105 being configured as an on-axis optical path position of imaging system optical axis 100. The on-axis optical path position is at an angle between the optical center line of the visible-infrared variable wavelength optical filter (101 or 104), the autofocus optical imaging lens 102, and the image sensor 105 and the optical axis 100 of the imaging system. 0 degree angle.

The optical center of the LED illumination source 106 is configured as an off-axis optical path position of the imaging system optical axis 100. The off-axis optical path position is an angle of 5-30 degrees between the radiation optical centerline of the illumination source 106 and the imaging system optical axis 100.

[The processor chip 109 has the following functions:

For connecting the image sensor 105, controlling the image pixel value data output by the image sensor 105 imaging array;

Connecting the LED current driver 108 to drive the radiation intensity, radiation angle and position, and radiation time of the LED illumination source 106;

Connecting the autofocus optical imaging lens focus driver 111 to achieve physical focus of driving the autofocus optical imaging lens 102;

Connecting the optical filter control driver 112 effects a wavelength range change of the visible light-infrared variable wavelength optical filter.

The autofocus optical imaging lens 102 is configured to have a fixed focal length, and may be any one of a liquid driving lens, a liquid crystal driving lens, a VCM voice coil driving lens, a MEMS driving lens, an EDOF wavefront phase modulation lens, or a wafer level array microlens. .

The visible-infrared variable wavelength optical filter (101 or 104) described above controls the driver 112, and can drive two independent (visible and infrared) optical filters, such as VCM voice coil electromagnetic force, respectively. Achieve wavelength range changes. Specifically, the electromagnetic force is applied to the voice coil cavity to realize the electromagnetic force to push the elastic mechanical transmission mechanism to shift the displacement of the two independent filters (visible light or infrared light) to the coaxial optical path position of the imaging system optical axis 100. The drive wavelength range changes. Further, the visible-infrared variable wavelength optical filter (101 or 104) described above may employ a dielectric thin film tunable wavelength optical filter. The optical filter wavelength filter range change is achieved by the optical filter control driver 112 applying different sized film dielectric value tunings. The visible-infrared variable wavelength optical filter of the present invention is not limited to the above examples, and other types should be equally understood.

The imaging wavelength of the invention includes a visible light imaging wavelength of 400-650 nm and an infrared light imaging wavelength of 750-950 nm; the imaging wavelength in the specific embodiment 1 includes a visible light imaging wavelength of 400-650 nm and an infrared light imaging wavelength of 810-880 nm. In the specific embodiment 1 of the present invention, the infrared light imaging wavelength range, in essence, the imaging wavelength range is a bandwidth characteristic, which can also be equivalently interpreted as being represented by an imaging wavelength center (wavelengthcenter) and a half-peak bandwidth (FWHM), such as 810-880 nm. The range can be expressed as a central wavelength of 850 nm ± 30 nm half-peak bandwidth. Further, as an example of the variation of the imaging wavelength range, a narrow band may be used as a center wavelength of 850 nm ± 15 nm half-peak bandwidth. The variation of the imaging wavelength range of the present invention is not limited to the above examples, and other ranges should be equally understood.

The visible light photoelectric imaging adopts the visible light imaging wavelength, the focusing work object distance is at least 30-100 cm, and the photoelectric imaging system adopts the infrared light imaging wavelength, and the focusing work object distance WD is at least 10-30 cm.

Biometric optoelectronic imaging has the following optical imaging requirements:

The imaging wavelength WI of the biometric photoelectric imaging satisfies: 750 nm ≤ WI ≤ 950 nm;

Focusing work distance WD of biometric photoelectric imaging meets: 10cm ≤ WD ≤ 30cm;

The pixel spatial resolution (PSR) of biometric photoelectric imaging should satisfy: PSR ≥ 10 pixels/mm;

The optical magnification OM (optical magnification) of biometric photoelectric imaging should satisfy: OM=PS*PSR;

Wherein, the PS described above is a physical scale of each imaging pixel unit of the image sensor 105; the PSR is a pixel spatial resolution of the biometric photoelectric imaging;

The optical spatial resolution of image of plane (ISORI) should be satisfied in the image plane: when the modulation transfer function is equal to 60% (MTF=0.6), 1/(4*PS)≤OSRI≤ 1/(2*PS) lp/mm (line pair per mm).

Visible light imaging has the following optical imaging requirements:

The imaging wavelength WI of visible light photoelectric imaging satisfies: 400 nm ≤ WI ≤ 650 nm;

The focused work distance WD of visible light photoelectric imaging satisfies: 30cm ≤ WD ≤ 100cm;

The pixel spatial resolution PSR (pixel spatial resolution) of visible light photoelectric imaging should satisfy: PSR≤3pixel/mm;

Optical magnification OM (optical magnification) of visible light photoelectric imaging, should meet: OM = PS * PSR;

Wherein, the PS described above is a physical scale of each imaging pixel unit of the image sensor 105; the PSR is a pixel spatial resolution of visible light photoelectric imaging;

The optical spatial resolution of image of plane (ISORI) should be satisfied in the image plane: when the modulation transfer function is equal to 60% (MTF=0.6), 1/(4*PS)≤OSRI≤1 /(2*PS) lp/mm (line pair per mm).

The physical scale PS of the imaging pixel unit receiving the visible-infrared light wavelength in the imaging array of the image sensor 105 satisfies the following condition: 1 um / pixel ≤ PS ≤ 3 um / pixel (micron per pixel);

The value Y of the photoelectric conversion of the wavelength pixel unit received by the image sensor 105 imaging array is:

Y=Q*GAIN*EXP*ADCG*E*PSU EQ1

Of which: the above

EXP is the integration time integration time or exposure time of the imaging array of the image sensor 105, unit: S seconds; EXP synchronization is equal to the radiation time of the LED illumination source 106;

EXP≤33.3ms

GAIN is the digital and analog gain of the image sensor 105 imaging array, no unit;

The maximum value GAIN satisfies the signal-to-noise ratio SNR of the image sensor 105, and the SNR ≥ 36db decibel

ADCG is the ADC voltage analog-to-digital conversion quantization resolution of the image sensor 105 imaging array, unit: LSB/V, numerical position per volt;

E is the radiance or irradiance received by the image sensor 105 imaging array, in units of lux (lux) or mw/cm 2 (per milliwatt per square centimeter);

E=C*β*I/WD ² *cos ² ψ*(1/FNO) ²

Where: I is the radiation intensity of the LED illumination source 106, unit milliwatts per sphericity (mw/sr);

I minimum value satisfies I≥100mw/sr;

ψ is the radiation angle of the LED illumination source 106, that is, the off-axis angle between the radiation optical center line of the LED illumination source 106 and the imaging system optical axis 100;

ψ satisfied: 5 degrees ≤ ψ ≤ 30 degrees; more recently limited to 7 degrees ≤ ψ ≤ 22.5 degrees;

WD is the focus working distance of the optical imaging system;

FNO is the numerical aperture of the autofocus optical imaging lens 102, that is, the relative aperture distance reciprocal;

FNO is satisfied: 0.5*PS/(1.22*λ)≤FNO≤2.0*PS/(1.22*λ)

λ is the imaging wavelength;

β is the optical reflectance of the biological tissue of the imaged object (iris or vein) (the wavelength of the radiation from the LED illumination source is absorbed by the iris or vein biological tissue, and the reflection and scattering produce the optical reflectance of the biological tissue);

C is the optical coefficient of the optical imaging system;

C=1/16*cos ⁴ ω/(1+OM) ²

Where: ω is the object angle of view of the incident light;

ω satisfies: 0 ≤ ω ≤ FOV/2, FOV is the full field of view of the photoelectric imaging system;

OM is the optical magnification of the photoelectric imaging system;

The PSU is a physical scale area ratio of the imaging pixel unit of the imaging array of the image sensor 105;

PSU = (PS * PS) / cm ² ;

Q is the photoelectric conversion constant of the photoelectric imaging system; the unit is volts per milliwatt per square centimeter per second, V / (mw / cm ² - sec) or ke - / (mw / cm ^{2 -} sec);

The digital value Y of the image sensor 105 imaging array receiving pixel unit photoelectric conversion is further output as the imaged image raw RAW pixel data I{Y}.

The imaging array of image sensor 105 is configured as a global frame imaging mode (Global Shutter) or a rolling line imaging mode (Rolling Shutter).

The Global Shutter mode described in Embodiment 1 of the present invention includes an imaging mode of global frame integration and global frame readout, or an imaging mode of global frame integration and scroll line readout.

The rolling line imaging mode (Rolling Shutter) described in Embodiment 1 of the present invention includes an imaging mode of rolling line integration and rolling line reading.

Image sensor 105 is configured as a RAW RGB pixel output format, using RGB channel compensation gain or RGB channel balance gain.

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

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

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

The above [λ1, λh] is an imaging wavelength range, and the preferred visible light imaging wavelength in the specific embodiment 1 of the present invention is [400 nm, 650 nm], and the infrared imaging wavelength is [800 nm, 900 nm], as an equivalent understanding, further The infrared imaging wavelength range can also be changed to [810 nm, 880 nm].

g(λ), r(λ), b(λ) are the photoelectric quantum conversion efficiency sensitivity wavelength distribution functions of the RGB spectrum of the image sensor 105, respectively, and f(λ) is a visible-infrared variable wavelength optical filter (101) Or 104) a transmittance wavelength distribution function, S(λ) is a radiance wavelength distribution function of the LED illumination source 106; L(λ) is a transmittance wavelength distribution function of the autofocus optical imaging lens 102.

Equivalently understood, the R channel compensation gain or the B channel compensation gain can be equivalently used as a normal standard.

When the special image imaging sensor 105 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;

The image resolution ROI of the image sensor 105 is configured to:

ROI ≥ 2560 pixels * 1280 pixels.

The image sensor 105 has a chief ray incident angle CRA (Chief Ray Angle) ≥ 25 degrees.

The image sensor 105 according to the first embodiment of the present invention can further reduce the volume by using a package such as Bare Die (COB), ShellUT CSP, NeoPAC CSP, TSV CSP or the like.

The LED illumination source 106 of the embodiment 1 of the present invention has visible and infrared imaging wavelengths of independent or mixed radiation. Furthermore, the LED illumination source (106 visible light and infrared light LED) according to the embodiment 1 of the present invention has a half-peak radiation viewing angle Ω. The half-peak radiation field of view angle Ω satisfies:

Ω ≥ FOV;

The FOV is a full field of view of the imaging system;

FOV ≥ 2 * arctan ((DI * PS) / (2 * EFL));

Wherein: EFL is the equivalent focal length of the autofocus optical imaging lens 102; DI is the image sensor 105 The number of image-facing pixel units of the array image; PS is the physical scale of the pixel unit of the imaging array of the image sensor 105;

LED (the above-mentioned LED illumination source) is theoretically a Lambertian point source with 360-degree angle radiation. The convex lens or concave mirror can refract or reflect the light radiated by the LED point source to control the convergence of light. The effect of the half-peak radiation field of view of the LED illumination source. The convex lens can be made of an optical matrix material such as high refractive and transmittance optical plastic, and the concave mirror can be made of a high optical reflectivity metal matrix material. Further ideally, the LED can adopt an epoxy resin matrix material with high refractive index and high transmittance, and incorporate a scattering color agent that absorbs the wavelength of visible light transmitted infrared light to perform lens functional encapsulation, thereby realizing LED half-peak radiation field of view angle control convergence light energy. And the surface is black to achieve visual aesthetic requirements.

The LED illumination source 106 of the embodiment 1 of the present invention has one or more different radiation angles and positions for optimizing the imaging field of view and imaging quality effects of the optoelectronic imaging system. If using different radiation positions and different radiation angles on the left and/or right side of the optical axis 100 of the imaging system (left side Pl, right side Pr, left and right sides Pl & Pr, [5-30] radiation angle any one or more Such angles as 5 degrees, 20 degrees), as an example of different radiation angles and position changes can also be used (upper side Pt, lower side Pb, upper and lower sides Pt & Pb, [5-30] radiation angle any one or more angles Such as 10 degrees, 30 degrees). A variety of radiation angles can optimize the degree of specular total reflected light interference and improve the imaging quality of the photoelectric imaging system. A variety of radiation locations can optimize the relative illumination brightness balance of the imaging field of view and improve the imaging quality of the optoelectronic imaging system. The different radiation angles and positional variations of the present invention are not limited to the above examples, and other different radiation angles and positions should be equally understood.

The LED illumination source 106 of the embodiment 1 of the present invention has continuous or pulsed radiation time and radiation intensity synchronized with imaging of the image sensor 105 for jointly optimizing the imaging quality effects of the optoelectronic imaging system. The continuous or pulsed radiation time and radiation intensity of the LED illumination source 106 in synchronism with the image sensor 105 can optimize image brightness, signal to noise ratio and motion blur, and improve the imaging quality of the optoelectronic imaging system. The LED illumination source 106 can be further reduced in size by encapsulation such as SMD surface patches.

The visible-infrared variable wavelength optical filter (101 or 104) according to the first embodiment of the present invention has a range of visible light and infrared light imaging wavelengths. Furthermore, the visible-infrared variable wavelength optical filter (101 or 104) described in Embodiment 1 of the present invention has:

When changing to visible light imaging wavelength:

The light cutoff rate in the visible light imaging wavelength range is Fi≤10.0%,

The light cutoff ratio outside the visible light imaging wavelength range is Fo ≥ 99.0%,

Equivalent

The light transmittance in the visible light imaging wavelength range is Ti≥90.0%,

The light transmittance outside the visible light imaging wavelength range is To ≤ 1.0%.

When changing to infrared light imaging wavelength:

The optical cutoff rate in the wavelength range of infrared light imaging is Fi≤10.0%,

The optical cutoff rate outside the wavelength range of infrared light imaging is Fo ≥ 99.0%,

Equivalent

[The light transmittance in the wavelength range of infrared light imaging is Ti≥90.0%,

The light transmittance outside the wavelength range of the infrared light imaging is To ≤ 1.0%.

The autofocus optical imaging lens 102 of the embodiment 1 of the present invention has physical refractive focused visible light and infrared light imaging wavelengths. Furthermore, the autofocus optical imaging lens 102 of the embodiment 1 of the present invention has imaging wavelengths for visible light and infrared light:

The surface maximum reflectance Rmax ≤ 1.0%, the surface average reflectance Ravg ≤ 0.3%;

Equivalent

The surface minimum transmittance Tmin ≥ 99.0%, and the surface average transmittance Tavg ≥ 99.7%.

The autofocus optical imaging lens 102 described above can be implemented by surface multi-layer anti-reflection or anti-reflection coating on an aspheric optical plastic such as optical grade PMMA, optical grade PC and other optical matrix materials; and can pass 3-5P aspherical optics The plastic injection molding process is realized, and the total length of TTL optics is ≤6mm.

2mm ≤ EFL ≤ 5mm, 1.4 ≤ FNO ≤ 2.8.

Furthermore, the optical distortion DOL (distortion of lens) absolute value of the autofocus optical imaging lens 102 described above is configured as:

The absolute value of DOL is ≤1%.

The relative illumination rate IOR of the autofocus optical imaging lens 102 described above is configured to:

IOR ≥ 50%.

The IOR = edge field brightness of the optical imaging lens / central field of view brightness of the optical imaging lens.

The autofocus optical imaging lens 102 and the image sensor 105 described above are configured to match the principal ray incident angle CRA, that is, theoretically, the CRA is equal, and the absolute value of the control error range is 3 degrees or less in practical applications.

The autofocus optical imaging lens 102 is configured to have a fixed focal length including any one of a liquid drive lens, a liquid crystal drive lens, a VCM voice coil drive lens, a MEMS drive lens, an EDOF wavefront phase modulation lens, or a wafer level microarray lens. The liquid-driven lens described above includes a fixed focus lens, a liquid lens, and a voltage driver 111 for controlling the liquid lens; the liquid crystal drive lens described above includes a fixed focus lens, a liquid crystal lens, and a voltage driver 111 for controlling the liquid crystal lens; The liquid driving lens and the liquid crystal driving lens described above both adjust the optical power by changing the dioptric power of the incident light to realize the autofocus function. The VCM voice coil drive lens described above includes a fixed focus lens, a VCM voice coil, and a current driver 111 for controlling the VCM voice coil; the VCM voice coil drive lens described above is realized by changing the optical back focus and optical image distance adjustment. Auto focus function. The MEMS (Micro Electro Mechanical System) driving lens described above includes a fixed focus lens, a MEMS lens, and an electrostatic actuator 111 for controlling the MEMS lens. The MEMS drive lens described above achieves an autofocus function by changing the optical position of the MEMS lens. The wafer-level array microlens described above implements 3D panoramic deep reconstruction through Computational Imaging. The EDOF wavefront phase modulation lens described above includes a lens and a wavefront phase modulation optical element; the EDOF wavefront phase modulation described above is modulated by the wavefront phase modulation optical element, and the inverse filter demodulation reconstruction realizes the extended depth of field function.

Embodiment 1 of the present invention further includes an OSI optical image stabilization driver for the imaging system, and a motion vector information feedback optical image stabilization driver provided by a sensor such as a gyroscope integrated by the mobile terminal is used to control the optical motion blur of the compensation imaging system, which can further Optimize the imaging quality effects of photoelectric imaging systems.

Specifically, the motion vector information provided by the gyroscope, the linear velocity meter or the like according to the embodiment 1 of the present invention is used for feedback optical image stabilization driver OIS control to compensate optical motion blur of the imaging system, or for feedback 3-axis motion vector information That is, the angular velocity and/or the linear velocity is less than the predetermined threshold to control the optical motion blur of the imaging system, and the imaging quality effect of the photoelectric imaging system can be further optimized.

In order to remove the imaging interference of the specular total reflected light, the LED illumination source 106 of the embodiment 1 of the present invention is configured with an optical linear polarizer, and an orthogonal state 90 corresponding to the configuration in the imaging optical path (before or after the autofocus optical imaging lens 102) The optical linear polarizer can completely remove the imaging interference of the specular total reflected light by forming orthogonal polarization linear polarization at the transmitting and receiving ends. Further, an optical polarizer capable of tunable polarization can be disposed in the imaging optical path (before or after the autofocus optical imaging lens 102), and the specular total reflected light can be completely removed by controlling the polarization state of the tunable optical polarizer. Imaging interference.

Embodiment 1 of the present invention has different optical imaging requirements due to biometric photoelectric imaging and visible light photoelectric imaging, imaging wavelength, pixel spatial resolution, optical magnification, optical spatial resolution, focusing Crop distance range.

The biometric optoelectronic imaging described above has the following optical imaging requirements:

The imaging wavelength WI of biometric photoelectric imaging satisfies:

750nm ≤ WI ≤ 950;

Biofocus photoelectric imaging's focused work distance WD meets:

10cm ≤ WD ≤ 30cm.

The optical magnification OM (optical magnification) of biometric photoelectric imaging should satisfy:

OM=PS*PSR;

Wherein: PS is the physical scale of each imaging pixel unit of the image sensor; PSR is the pixel spatial resolution of the biometric photoelectric imaging;

The optical imaging requirements of biometric photoelectric imaging described in Embodiment 1 of the present invention enable high-resolution extraction of iris and vein biometric details to improve combined biometric performance.

The visible light photoimaging has the following optical imaging requirements:

The imaging wavelength WI of visible light photoelectric imaging satisfies:

400nm ≤ WI ≤ 650nm;

The focused work distance WD of visible light photoelectric imaging satisfies:

30cm ≤ WD ≤ 100cm.

The optical magnification OM (optical magnification) of visible light photoelectric imaging should satisfy:

OM=PS*PSR;

Wherein: PS is a physical scale of each imaging pixel unit of the image sensor; PSR is a pixel spatial resolution of visible light photoelectric imaging;

Through the above-described mobile terminal visible light and biometric combined photoelectric imaging system, the present invention provides an imaging method for visible light photoelectric imaging, comprising the following steps:

1. The processor chip 109 configures the optical filter, the LED illumination source, the image sensor and the optical imaging lens to be in an initial working state, in particular, to perform an optical filter control driver 112, an LED current driver 108, the image sensor 105, the autofocus optical imaging lens focus driver 111 initializes the working state configuration;

2. Processor chip 109 controls control of said optical filter, said LED illumination source, said image sensor and said optical imaging lens into a low power standby or shutdown mode, optical filter control driver 112, LED current driver 108 , the image sensor 105, the autofocus optical imaging lens focus driver 111 enters a low power standby or shutdown mode;

3. The processor chip determines whether it is necessary to acquire the visible light imaging image, and proceeds to step 4, and proceeds to step 3;

4. The processor chip 109 changes the visible-infrared variable wavelength optical filter (101 or 104) through the optical filter control driver 112 to allow imaging wavelengths through visible light;

5. The processor chip 109 controls the LED current driver 108 to drive the LED illumination source 106 to produce radiation in a visible light imaging wavelength continuous or sync pulse mode;

6. The processor chip 109 controls the imaging array of the image sensor 105 to receive the original image RAW RGB pixel data I{Y} output in the global frame imaging mode or the scroll line imaging mode;

7. The processor chip 109 drives the image sensor 105 and the LED current driver 108 and the autofocus optical imaging lens focus driver 111 according to the imaging original image RAW pixel data I{Y} and the pixel unit photoelectric conversion relationship to implement feedback control;

8. The processor chip 109 interpolates and reconstructs the original image RAW pixel data I{Y};

9. The processor chip 109 outputs the interpolated reconstructed and image processed image I{r, g, b};

10. Return to step 2 loop.

The feedback control in step 7 of the imaging method for visible light photoelectric imaging described above includes:

1. The processor chip 109 can feedback control the reset integration time of the image sensor 105, the digital and/or analog gain setting, and the feedback control LED according to the imaged raw image RAW pixel data I{Y} output by the image sensor 105 and the corresponding formula EQ1. The current driver 108 drives the radiation intensity of the LED illumination source 106, and the radiation time is used to improve imaging quality.

2. The processor chip 109 can calculate the degree of specular total reflection interference in the image according to the imaged raw image RAW pixel data I{Y} output by the image sensor 105. The feedback control LED current driver 108 drives the LED illumination source 106 for controlling the radiation angle and position. To improve the quality of the image.

3. The processor chip 109 can control the autofocus optical imaging lens focus driver 111 to drive the autofocus optical imaging lens 102 to achieve visible light photoimage focusing work object distance WD according to the focus quality value feedback control of the calculated imaged raw RAW pixel data I{Y}. 30cm-100cm. A conventionally known autofocus method such as maximum focus peak blurring to accurate iterative search can be employed.

The processor chip 109 can pass the light sensor (depending on the use, a separate device can be provided on the processor chip 109, the method of which is set as the prior art, or the corresponding processing can be purchased in the market. The chip implements such a light sensor function to control the intensity of the radiation of the visible light of the LED illumination source 106 by the LED current driver 108 based on the current ambient light level. Furthermore, in the specific embodiment 1 of the present invention, if the light sensor is judged to be greater than 500-1000 lux or more according to the current ambient light brightness, the LED current driver is turned off to drive the visible light of the LED illumination source 106.

It is further explained that the interpolation reconstruction described in the step 8 of the imaging method for visible light photoelectric imaging described above may employ a conventionally known interpolation algorithm.

The image processing described in step 8 of the imaging method of visible light photoelectric imaging includes image optical black level correction BLC, automatic white balance AWB, color matrix correction CCM, lens edge shading correction lens shading correction, automatic exposure feedback control AEC, automatic gain Feedback control AGC, etc.

Through the above-described mobile terminal visible light and biometric combined photoelectric imaging system, the present invention provides an imaging method for biometric photoelectric imaging, comprising the following steps:

2. The processor chip 109 controls the optical filter, the LED illumination source, the image sensor and the optical imaging lens to enter a low power standby or shutdown mode, in particular, an optical filter control driver 112, LED The current driver 108, the image sensor 105, the autofocus optical imaging lens focus driver 111 enters a low power standby or shutdown mode;

3. The processor chip determines whether it is necessary to acquire the biological imaging image, and proceeds to step 4, and proceeds to step 3;

4. The processor chip 109 changes the visible-infrared variable wavelength optical filter (101 or 104) through the optical filter control driver 112 to allow imaging of the wavelength by infrared light;

5. The processor chip 109 controls the LED current driver 108 to drive the LED illumination source 106 to generate infrared radiation imaging wavelength continuous or synchronous pulse mode radiation;

8. The processor chip 109 outputs an image I{Y};

9. Return to step 2 loop.

In the first step of the embodiment 1 of the present invention, the image sensor 105 initializing operation state is configured as a RAW RGB pixel output format, and the RGB channel compensation gain or RGB channel balance gain processing can set the corresponding RGB channel number of the image sensor 105 by initializing the working state configuration. And/or analog gain simplification implementation. Further image imaging sensor 105, disable color matrix correction CCM, disable interpolation interpolation, disable gamma correction, disable automatic white balance AWB, use these functions to reduce the contrast of biological images, especially texture high frequency edge parts, affecting biological image quality.

The feedback control in step 7 of the imaging method for biometric photoelectric imaging described above includes:

1. The processor chip 109 can feedback control the reset integration time of the image sensor 105, the digital and/or analog gain setting, and the feedback control LED according to the imaged raw image RAW pixel data I{Y} output by the image sensor 105 and the corresponding formula EQ1. The current driver 108 drives the radiation intensity of the LED illumination source 106, and the radiation time, which is used to control image brightness, signal to noise ratio, and motion blur to improve image quality.

2. The processor chip 109 can calculate the degree of specular total reflection interference and the relative illumination brightness balance in the image according to the imaged raw image RAW pixel data I{Y} output by the image sensor 105, and the feedback control LED current driver 108 drives the LED illumination source 106. Control the radiation angle and position to improve image quality.

3. The processor chip 109 can control the autofocus optical imaging lens. The focus driver 111 drives the autofocus optical imaging lens 102 to realize the biometric photoelectric imaging focusing work distance WD according to the focus quality value feedback control of the calculated imaged raw RAW pixel data I{Y}. At least 10cm-30cm. A conventionally known autofocus method such as maximum focus peak blurring to accurate iterative search can be employed.

Further, the processor chip 109 can perform optical black level correction BLC of the image sensor, automatic exposure feedback control AEC, and automatic gain feedback control AGC through the imaged raw RAW pixel data output by the image sensor 105.

Considering biometric focus requirements, high pixel spatial resolution, large optical magnification, and macro focus working object range, conventionally known autofocus methods such as maximum focus peak blurring to accurate iterative search take more than 1 second.

In order to achieve fast and stable autofocus within 100ms, the specific embodiment 1 of the present invention provides a fast autofocus method by the above-mentioned mobile terminal visible light and biometric combined photoelectric imaging system, comprising the following steps:

1. Defining a local region of interest ROI and a search parameter to be searched according to a predetermined focused work distance range WD;

Defining the local interest area ROI to be searched can be determined by the following formula;

1/EFL=1/ROI+1/WD;

Wherein: the EFL is a fixed focal length of the autofocus optical imaging lens;

WD is the predetermined biological focus work distance range, 10-30cm;

The ROI is the corresponding local area of interest to be searched;

Defining search parameters includes:

The search step size SStep and the number of searches SNO can be determined by the following formula:

SStep=k*PS;

SNO=ROI/SStep;

Wherein: the PS is a physical scale of the imaging pixel unit of the image sensor 105;

k is a fuzzy circle diameter scale acceptable to the biometric algorithm;

2. Processor Chip 109 Controls Autofocus Optical Imaging Lens The focus driver 111 drives the autofocus optical imaging lens 102 to perform a continuous focus position search in a monotonic direction in accordance with the local region of interest ROI and search parameters defined in step 1 to be searched. That is, the continuous focus position {Pi, i=1, SNO} search in the monotonous direction is performed;

The monotonous direction continuous focus position search can avoid the conventional well-known autofocus method such as the maximum focus peak blur to accurate iterative search, which leads to the repetition of the forward and reverse directions, with high efficiency, stability and fast focusing speed.

3. The processor chip 109 controls the image sensor 105 to acquire the imaged original image RAW RGB pixel data I{Pi, i=1, NO of the continuous focus position {Pi, i=1, SNO} searched in the monotonous direction in step 2. };

4. The processor 109 chip calculates the focus quality QS (I{Pi}) of the focus position search image I{Pi, i=1, NO} in real time; the function QS is a focus quality evaluation function, and the focus quality evaluation function The methods used include: gradient statistics, frequency statistics, high-pass or band-pass spatial filters, high-frequency energy value statistics, variance statistics, spatial-frequency domain filters, etc.; the focus quality evaluation function QS of the present invention is not limited to the above examples. Other methods should be interpreted equally.

5. The processor 109 determines that the image corresponding to the best focus quality arg{QS(I{Pi})} is the best focus image;

The focus quality maximum image corresponding to arg{QS(I{Pi})}=max{QS(I{Pi})} is the best focus image;

Further,

The focus quality maximum image corresponding to arg{QS(I{Pi})}={QS(I{Pi-1})QS(I{Pi+1})} is the best focus image;

Can also be used

Arg{QS(I{Pi})}={QS(I{Pi})>EI)} corresponding focus quality image is the best focus image;

EI is the image focus quality threshold acceptable for biometric algorithms.

The method of determining the focus quality of the present invention is not limited to the above examples, and other methods should be equivalently understood.

The invention provides a high-safety biometric anti-counterfeiting biological detection method, which has real-time detection capability for biometric forgery, and is used for ensuring the safety of the biometric identification itself, and adopts the following methods:

A real-time detection method for the spectral properties of biological tissues produced by visible-infrared light imaging wavelength radiation.

Through the above-mentioned mobile terminal visible light and biometric combined photoelectric imaging system, the present invention provides a real-time detection method for biological tissue spectral activity characteristics generated by visible light-infrared light imaging wavelength radiation, comprising the following steps:

1. The processor chip 109 changes the visible-infrared variable wavelength optical filter (101 or 104) to a visible light imaging wavelength through an optical filter control driver 112;

The processor chip 109 drives the LED current driver 108 to drive the LED illumination source 106 to generate visible imaging wavelength radiation;

The processor chip 109 acquires the visible light imaging wavelength image Ivs of the imaging array of the image sensor 105;

2. The processor chip 109 changes the visible-infrared variable wavelength optical filter (101 or 104) to the infrared light imaging wavelength through the optical filter control driver 112;

The processor chip 109 drives the LED current driver 108 to drive the LED illumination source 106 to generate infrared light imaging wavelength radiation;

The processor chip 109 acquires an infrared light imaging wavelength image Iir of the imaging array of the image sensor 105;

3. The processor chip 109 calculates the contrast C data of the visible light imaging wavelength image Ivs and the infrared light imaging wavelength image Iir in steps 1, 2, respectively Ivs_C, and Iir_C;

among them:

C is the contrast between the iris area and the outer area of the iris;

or

C is the contrast between the vein area and the extra-venous area;

C=S(Yiris)/S(Youtiris);

or

C=S(Youtvein)/S(Yvein);

Yiris represents the iris area pixel;

Youtiris represents the pixels outside the iris;

Yvein represents the vein area pixel;

Youtvein indicates the pixel outside the vein;

The function S is a corresponding area pixel statistical evaluation function, and the method used by the pixel statistical evaluation function includes: histogram statistics, frequency statistics, average statistics, weighted average statistics, median statistics, energy value statistics, variance statistics The gradient statistic, the space-frequency domain filter, etc.; the corresponding region pixel statistical evaluation function S of the present invention is not limited to the above examples, and other methods should be equivalently understood.

4. The processor chip 109 calculates the image contrast Ivs_C and the Iir_C activity change rate Δρ of the visible light imaging wavelength radiation and the infrared light imaging wavelength radiation, respectively, in real time;

among them:

Δρ=Iir_C/Ivs_C*100%;

5. According to the visible light-infrared light imaging wavelength, the preset value of the spectral activity of the biological tissue is irradiated, and the corresponding change rate of the active contrast of the data value Δρ in the step 4 is determined, and the condition Δρ>300% is judged to realize the real-time detection of the biological living state.

It is equally understood that the steps 1 and 2 in the real-time detection method of the biological tissue spectroscopy activity characteristic generated by the above visible light-infrared light imaging wavelength radiation are equivalent and can be reversed.

In order to improve the biometric success rate, the specific embodiment 1 (according to the mobile terminal visible light and biometric combined photoelectric imaging system) provides an imaging method for improving the biometric success rate, comprising the following steps:

1. Infrared light imaging wavelength biological image Iir{Pψenroll} generated when at least two or more LED illumination sources 106 are acquired at different radiation angles and positions during registration;

The specific embodiment 1 of the present invention uses different radiation angles and positions, for example, the left side P1, the right side Pr, the left and right sides P1 & Pr, the upper side Pt, the lower side Pb, the upper and lower sides Pt & Pb, [5-30] radiation angle One or more angles such as 5 degrees, 10 degrees, 20 degrees, 30 degrees).

2. Using the biological image Iir{Pψenroll} to obtain at least two or more biometric template Template{Pψenroll}, and after performing cross-matching between the feature templates, save as a registered bio-feature template;

For example, the cross-alignment is obtained by performing the cross-matching of the three biometric templates Template{1, 2, 3} as Template1-Template2, Template1-Template3, and Template2-Template3 respectively; only when the above feature templates are cross-aligned Once successful, the stability and recognition rate of the registered biometric template for subsequent identification can be guaranteed.

3. Collecting one or more LED illumination sources 106 at different radiation angles and positions when identifying Infrared light imaging wavelength biological image Iir{Pψrecogn};

4. Cross-aligning the generated feature template Template{Pψrecogn} with the registered biometric template Template{Pψenroll} using one or more biological images Iir{Pψrecogn} and obtaining the recognition result;

In order to improve the biometric success rate, the specific embodiment 1 (according to the mobile terminal visible light and biometric combined photoelectric imaging system) further provides an imaging method for improving the biometric success rate, comprising the following steps:

1. Infrared light imaging wavelength biological image Iir{Renroll} generated by at least two or more LED illumination sources 106 at different radiation intensities when registering;

Specific embodiment 1 of the present invention exemplifies the use of different visible light and infrared light radiation intensity to generate biological tissue such as pupil stimulation

Active infrared light imaging wavelength biological images, such as producing 1x, 2x, 4x or more different visible and/or infrared light intensity;

2. Using the biological image Iir{Renroll} to obtain at least two or more biometric templates Template{Renroll}, and after performing cross-matching between the feature templates, save as a registered bio-feature template;

3. Infrared light imaging wavelength biological image Iir{Rrecogn} generated when one or more LED illumination sources 106 are generated at different radiation intensities;

4. Cross-aligning the generated feature template Template{Rrecogn} with the registered biometric template Template{Renroll} using one or more biological images Iir{Rrecogn} and obtaining the recognition result;

In order to improve the biometric success rate, the specific embodiment 1 (according to the mobile terminal visible light and biometric combined photoelectric imaging system) further provides another imaging method for improving the biometric success rate, comprising the following steps:

1. Infrared light imaging wavelength biological image Iir{Wenroll} generated when at least two or more LED illumination sources 106 are generated in different radiation wavelength ranges during registration;

The specific embodiment 1 of the present invention exemplifies the use of the LED illumination source 106 to generate infrared light imaging wavelength biological images of different radiation wavelength ranges, for example, 750 nm-800 nm, 800 nm-850 nm, 850 nm-900 nm, 900 nm-950 nm, 750 nm-850 nm, 850 nm, respectively. Different radiation wavelength ranges or combinations of -950 nm.

2. Using the biological image Iir{Wenroll} to obtain at least two or more biometric template Template{Wenroll}, and after performing the cross-matching between the feature templates, save as a registered bio-feature template;

3. Infrared light imaging wavelength biological image Iir{Wrecogn} generated when one or more LED illumination sources 106 are generated at different radiation wavelength ranges;

4. Cross-aligning the generated feature template Template{Wrecogn} with the registered biometric template Template{Wenroll} using one or more biological images Iir{Wrecogn} and obtaining the recognition result;

The specific content and technical features described in the present invention can be implemented within the scope of the same or equivalent understanding, such as changes in imaging wavelength range, image sensor changes, LED illumination source changes, optical filter changes. Modification, autofocus optical imaging lens changes, optical path transformation, and device replacement should also be equally understood.

By way of example, the visible light wavelength radiation of the LED illumination source of the specific embodiment of the present invention can also be replaced by a display screen provided by the mobile terminal itself, such as an RGB backlight source with an adjustable brightness of the LCD display screen, or an organic substance having RGB radiation. Light-emitting OLED.

As a further example, the optical filter control driver can be replaced by a manual controller such as a manual switcher.

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

A mobile terminal visible light and biometric combined photoelectric imaging system, the system comprising an LED illumination source, an optical filter, an optical imaging lens, and an image sensor, wherein:

The image sensor is configured to have a unit pixel having an imaging wavelength spectrum that receives a broadband distribution of visible light-infrared light;

The LED illumination source is configured to radiate light of a visible or infrared light imaging wavelength, and the LED illumination source has a range of radiation wavelengths that match a visible light-infrared broadband imaging wavelength distribution of the image sensor;

The optical filter is configured to have a filtered wavelength range that matches a visible light-infrared broadband imaging wavelength distribution of the image sensor;

The optical imaging lens is configured to have a range of focus wavelengths that match a visible light-infrared broadband imaging wavelength distribution of the image sensor;

An optical center of the optical filter, the optical imaging lens, and the image sensor is configured as a coaxial optical path position of an optical axis of the imaging system, and an optical center of the LED illumination source is configured as the imaging system Off-axis optical path position of the optical axis.
The visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 1, wherein: the visible light imaging wavelength is radiated by the LED illumination source, and the optical filter is switched to filter the infrared light imaging wavelength, The optical imaging lens physically refracts the focused visible imaging wavelength, and the imaging array of the image sensor receives the visible wavelength to form an optical path for visible light imaging; or

Irradiating the infrared light imaging wavelength by the LED illumination source, the optical filter is switched to filter the visible light imaging wavelength, the optical imaging lens physically refracts the focused infrared light imaging wavelength, and the imaging array of the image sensor receives the infrared light wavelength, forming Optical pathway for biometric imaging.
A visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 1, wherein:

The coaxial optical path position is an angle of 0 degree between the optical filter, the optical imaging lens, an optical center line of the image sensor, and an optical axis of the imaging system.
A visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 1, wherein:

The off-axis optical path position is an angle of 5-30 degrees between an angle between a radiation optical center line of the LED illumination source and an optical axis of the imaging system.
A visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 1, wherein the biometric photoelectric imaging has the following optical imaging requirements:

The imaging wavelength WI of the biometric photoelectric imaging satisfies: 750 nm ≤ WI ≤ 950 nm;

Focusing work distance WD of biometric photoelectric imaging meets: 10cm ≤ WD ≤ 30cm;

Pixel spatial resolution PSR of biometric photoelectric imaging satisfies: PSR ≥ 10 pixels/mm;

The optical magnification OM of biometric photoelectric imaging satisfies: OM=PS*PSR;

Wherein, the PS is a physical scale of each imaging pixel unit of the image sensor; and the PSR is a pixel spatial resolution of the biometric photoelectric imaging;

The optical spatial resolution OSRI of the biometric photoelectric imaging satisfies in the image plane: when the modulation transfer function is equal to 60%, 1/(4*PS) ≤ OSRI ≤ 1/(2*PS).
A visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 1, It is characterized by: Visible light imaging has the following optical imaging requirements:

The imaging wavelength WI of visible light photoelectric imaging satisfies: 400 nm ≤ WI ≤ 650 nm;

The focused work distance WD of visible light photoelectric imaging satisfies: 30cm ≤ WD ≤ 100cm;

The pixel spatial resolution PSR of visible light photoelectric imaging should satisfy: PSR≤3pixel/mm;

The optical magnification OM of visible light photoelectric imaging should satisfy: OM=PS*PSR;

Wherein, the above PS is a physical scale of each imaging pixel unit of the image sensor; PSR is a pixel spatial resolution of visible light photoelectric imaging;

The optical spatial resolution OSRI of the visible light photoelectric imaging satisfies in the image plane: when the modulation transfer function is equal to 60%, 1/(4*PS) ≤ OSRI ≤ 1/(2*PS).
A visible light and biometric combined optoelectronic imaging system for a mobile terminal according to claim 1, wherein said system further comprises a processor chip, said processor chip controlling said image sensor, LED current driver, auto focus Optical imaging lens focus driver and optical filter control driver;

The processor chip is configured to connect the image sensor, control image pixel value data output by the imaging array of the image sensor; connect the LED current driver to drive the LED illumination source to control radiation intensity, radiation angle, and Positioning, radiant time; connecting the autofocus optical imaging lens focus driver to achieve physical focus of driving the autofocus optical imaging lens; and connecting the optical filter control driver to drive a wavelength range change of the visible light-infrared variable wavelength optical filter.
A visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 1, wherein:

The wavelength pixel unit received by the image sensor imaging array has a photoelectrically converted value Y, and the value Y is:

Y=Q*GAIN*EXP*ADCG*E*PSU

Wherein: the EXP is an integration time or an exposure time of the image sensor imaging array; the EXP synchronization is equal to the radiation time of the LED illumination source;

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

The maximum value GAIN satisfies the signal-to-noise ratio SNR of the image sensor;

ADCG is the ADC voltage analog-to-digital conversion quantization resolution of the image sensor imaging array;

E is the radiance or irradiance received by the image sensor imaging array;

E=C*β*I/WD 2 *cos 2 ψ*(1/FNO) 2

Where: I is the radiation intensity of the LED illumination source;

ψ is the radiation angle of the LED illumination source, that is, the off-axis angle between the radiation optical center line of the LED illumination source and the optical axis of the imaging system;

WD is the focus working distance of the optical imaging system;

FNO is the numerical aperture of the autofocus optical imaging lens, that is, the relative aperture distance reciprocal;

λ is the imaging wavelength;

β is the optical reflectance of the biological tissue of the imaged object;

C is the optical coefficient of the optical imaging system;

C=1/16*cos 4 ω/(1+OM) 2 ;

Where: ω is the object angle of view of the incident light;

OM is the optical magnification of the photoelectric imaging system;

The PSU is a physical scale area ratio of the imaging pixel unit of the image sensor imaging array;

PSU = (PS * PS) / cm 2 ;

Q is the photoelectric conversion constant of the photoelectric imaging system.
A visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 8 Its characteristics are:

The EXP≤33.3ms;

The SNR ≥ 36db decibels;

The minimum value of I satisfies I≥100mw/sr;

The ψ meets: 5 degrees ≤ ψ ≤ 30 degrees;

The FNO satisfies: 0.5*PS/(1.22*λ)≤FNO≤2.0*PS/(1.22*λ);

The ω satisfies: 0 ≤ ω ≤ FOV/2, and the FOV is the full field of view of the photoelectric imaging system.
A visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 8, wherein:

The digital value Y of the image sensor imaging array receiving pixel unit photoelectric conversion is output as the imaged image raw RAW pixel data I{Y};

The imaging array of the image sensor is configured as a global frame imaging mode or a rolling line imaging mode;

The image sensor uses RGB channel compensation gain or RGB channel balance gain;

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

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

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

The [λl, λh] is an imaging wavelength range;

The g(λ), r(λ), b(λ) are photoelectric quantum conversion efficiency sensitivity wavelength distribution functions of the RGB spectrum of the image sensor, respectively, and f(λ) is a transmittance wavelength distribution function of the optical filter , S(λ) is the radiance wavelength distribution function of the LED illumination source; L(λ) is the transmittance wavelength distribution function of the autofocus optical imaging lens.
The mobile terminal visible light and biometric combined photoelectric imaging system according to claim 1, wherein the image resolution ROI of the image sensor is configured as:

ROI ≥ 2560 pixels * 1280 pixels;

The image sensor has a chief ray incidence angle CRA (Chief Ray Angle) ≥ 25 degrees.
A visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 1, wherein said LED illumination source has:

Independent or mixed radiation visible and infrared light imaging wavelengths;

Half-peak radiation field of view angle Ω;

The half-peak radiation field of view angle Ω satisfies:

Ω ≥ FOV;

The FOV is a full field of view of the imaging system;

FOV ≥ 2 * arctan ((DI * PS) / (2 * EFL));

Wherein: EFL is the equivalent focal length of the autofocus optical imaging lens; DI is the number of image-facing angular pixel units of the image sensor imaging array; and PS is the physical dimension of the pixel unit of the image sensor imaging array.
A visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 1 or 12, wherein the LED illumination source is used to control an imaging field of view of the photoelectric imaging system and one or more different radiation angles and Position and for continuous control of the continuous synchronization of the photoelectric imaging system with the imaging of the image sensor Or pulsed radiation time and radiation intensity.
A combined visible light and biometric photoelectric imaging system for a mobile terminal according to claim 1 or 12, wherein the LED illumination source is packaged with an SMD surface mount.
A visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 1, wherein:

The optical filter has:

When changing to visible light imaging wavelength:

The light cutoff rate in the visible light imaging wavelength range is Fi≤10.0%,

The light cutoff ratio outside the visible light imaging wavelength range is Fo ≥ 99.0%,

Equivalent

The light transmittance in the visible light imaging wavelength range is Ti≥90.0%,

Light transmittance outside the wavelength range of visible light imaging To ≤ 1.0%;

When changing to infrared light imaging wavelength:

The optical cutoff rate in the wavelength range of infrared light imaging is Fi≤10.0%,

The optical cutoff rate outside the wavelength range of infrared light imaging is Fo ≥ 99.0%,

Equivalent

The light transmittance in the wavelength range of infrared light imaging is Ti≥90.0%,

The light transmittance outside the wavelength range of the infrared light imaging is To ≤ 1.0%.
A visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 1, wherein:

The optical imaging lens is configured to have a fixed focal length, and employs any one of a liquid drive lens, a liquid crystal drive lens, a VCM voice coil drive lens, a MEMS drive lens, an EDOF wavefront phase modulation lens, or a wafer level array microlens.
A combined visible light and biometric imaging photoelectric imaging system for a mobile terminal according to claim 16, wherein said optical imaging lens has:

The surface maximum reflectance Rmax ≤ 1.0%, the surface average reflectance Ravg ≤ 0.3%,

Equivalent

The surface minimum transmittance Tmin ≥ 99.0%, the surface average transmittance Tavg ≥ 99.7%;

The optical imaging lens has a focal length EFL, and the numerical aperture FNO satisfies:

2mm ≤ EFL ≤ 5mm, 1.4 ≤ FNO ≤ 2.8;

The optical distortion DOL absolute value of the optical imaging lens is configured to:

DOL absolute value ≤ 1%;

The relative illumination rate IOR of the optical imaging lens is configured to:

IOR ≥ 50%;

The IOR = edge field of view brightness of the optical imaging lens / central field of view brightness of the optical imaging lens;

The optical imaging lens and the image sensor are configured to match a principal ray incident angle CRA with each other.
A visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 1, wherein said system further comprises a gyroscope for providing a motion vector information feedback optical image stabilization driver for controlling compensation imaging. The optical motion of the system is blurred.
A visible light and biometric combined optoelectronic imaging system for a mobile terminal according to claim 1, wherein said system further comprises an optical linear polarizer configured for said LED illumination source, and orthogonally configured in said imaging optical path. A 90 degree optical linear polarizer for forming an orthogonal state of linear polarization through the transmitting and receiving ends to remove imaging interference of specularly totally reflected light.
A visible light and biometric combined photoelectric imaging system for a mobile terminal according to claim 1, It is characterized in that the system further comprises an optical polarizer of tunable polarization state configured in the imaging optical path for controlling imaging interference of the specularly totally reflected light by controlling the polarization state of the tunable optical polarizer.
An imaging method for realizing visible light photoelectric imaging using the mobile terminal visible light and biometric combined photoelectric imaging system according to claim 1, comprising the steps of:

1 configuring the optical filter, the LED illumination source, the image sensor and the optical imaging lens to be in an initial working state;

2 controlling the optical filter, the LED illumination source, the image sensor, and the optical imaging lens to enter a low power standby or shutdown mode;

3 to determine whether it is necessary to obtain a visible light imaging image, is to step 4, or continue to step 3;

4 changing the optical filter to allow imaging wavelengths through visible light;

5 driving the LED illumination source to generate radiation in a visible light imaging wavelength continuous or synchronous pulse mode;

6 controlling the image sensor to receive the original image data of the global frame imaging mode or the scroll line imaging mode output I{Y};

7 driving the image sensor and the LED illumination source and the optical imaging lens according to the imaging original image data I{Y} and the pixel unit photoelectric conversion relationship to implement feedback control;

8 interpolating reconstruction and image processing of the original image data I{Y};

9 outputting the interpolated reconstructed and image processed image I{r, g, b};

10 returns to step 2 loop.
An imaging method for realizing biometric photoelectric imaging using the mobile terminal visible light and biometric combined photoelectric imaging system according to claim 1, characterized in that the method comprises the following steps:

(1) configuring the optical filter, the LED illumination source, the image sensor, and the optical imaging lens to be in an initial working state;

(2) controlling the optical filter, the LED illumination source, the image sensor, and the optical imaging lens to enter a low power standby or shutdown mode;

(3) judging whether it is necessary to acquire a biological imaging image, is to go to step (4), and to continue step (3);

(4) changing the optical filter to allow imaging of wavelengths by infrared light;

(5) driving the LED illumination source to generate infrared radiation imaging wavelength continuous or synchronous pulse mode radiation;

(6) controlling the image sensor to receive the original image data I{Y} output in the global frame imaging mode or the scroll line imaging mode;

(7) driving the image sensor and the LED illumination source and the optical imaging lens according to the imaging original image data I{Y} and the pixel unit photoelectric conversion relationship to implement feedback control;

(8) output image I{Y};

(9) Return to step (2) cycle.
The imaging method according to claim 21 or 22, wherein the image sensor initializing operation state is configured as a RAW RGB pixel output format, and the RGB channel compensation gain or the RGB channel balance gain processing can set the image sensor by initializing the working state configuration. The corresponding RGB channel digital and / or analog gain implementation.
The imaging method according to claim 21 or 22, wherein said feedback control comprises the following steps:

a) feedback controlling the reset integration time of the image sensor, digital and/or analog gain setting, feedback control driving LED according to the imaged raw image data I{Y} output by the image sensor and the corresponding wavelength pixel unit photoelectric conversion formula Radiation intensity and radiation time of the illumination source;

b) calculating the degree of specular total reflection interference and the relative illumination brightness balance in the image according to the imaged raw image data I{Y} output by the image sensor, and the feedback control driving the LED illumination source for controlling the radiation angle And location;

c) controlling the optical imaging lens according to the calculation of the focus quality value feedback of the imaged image raw image data I{Y} to achieve a biometric photoelectric imaging focusing work distance WD of at least 10 cm-30 cm.
A method for driving automatic focus using the mobile terminal visible light and biometric combined photoelectric imaging system according to claim 1, comprising the steps of:

1) defining a local region of interest to be searched and a search parameter according to a predetermined focused work distance range;

2) controlling the optical imaging lens to perform a continuous focus position search in a monotonous direction according to the local region of interest and the search parameter defined in step 1);

3) controlling the image sensor to acquire the imaged raw image pixel data of the continuous focus position search output in the monotonous direction in step 2);

4) calculating the focus quality of the focus position search image I{Pi, i=1, NO} in real time, and evaluating the focus quality;

5) Determine the image corresponding to the best focus quality as the best focus image.
A driving autofocus method according to claim 25, wherein said local interest region ROI defined in said step 1) to be searched is determined by the following formula;

1/EFL=1/ROI+1/WD;

Wherein: the EFL is a fixed focal length of the optical imaging lens;

WD is a predetermined biological focus work distance range;

The ROI is the corresponding local area of interest to be searched.
A method of driving an autofocus according to claim 26, wherein said predetermined biofocus work distance is in the range of 10-30 cm.
The driving autofocus method according to claim 26, wherein said search parameter in said step 2) includes a search step SStep and a search count SNO, which are determined by the following formula:

SStep=k*PS;

SNO=ROI/SStep;

Wherein: the PS is a physical scale of an imaging pixel unit of the image sensor;

k is a fuzzy circle diameter scale acceptable to the biometric algorithm;

The ROI is the corresponding local area of interest to be searched.
The driving autofocus method according to claim 26, wherein said focus quality evaluation function QS of said step 4) is selected from at least one of the following methods: gradient statistic, frequency statistic, high pass or band pass spatial filter , high frequency energy value statistics, variance statistics, space-frequency domain filters.
A method of driving an autofocus according to claim 26, wherein said step 5) determining the best focus quality is: arg {QS(I{Pi})}=max{QS(I{Pi})} The focus quality maximum image is the best focus image, wherein the QS is an evaluation function of the focus quality.
The method of driving an autofocus according to claim 26, wherein said step 5) determining the best focus quality is: arg {QS(I{Pi})}={QS(I{Pi-1}) QS( The corresponding focus quality maximum image of I{Pi+1})} is the best focus image, wherein the QS is an evaluation function of the focus quality.
The method of driving an autofocus according to claim 26, wherein said step 5) determining the best focus quality is: arg {QS(I{Pi})}={QS(I{Pi})>EI)} The corresponding focus quality image is the best focus image, wherein the QS is an evaluation function of the focus quality, and EI is an image focus quality threshold acceptable by the biometric algorithm.
An imaging method for improving a biometric success rate by using a mobile terminal visible light and biometric combined photoelectric imaging system according to claim 1, comprising the steps of:

I. Infrared light imaging wavelength biological image generated when at least two or more LED illumination sources are collected under different radiation conditions during registration;

II. Using biological image calculation to obtain at least two or more biometric templates, and performing feature template After the cross comparison is successful, save as a registered biometric template;

III. Collecting infrared light imaging wavelength biological images generated by one or more LED illumination sources under different radiation conditions during identification;

IV. Cross-aligning the feature template generated by using one or more biological image calculations with the registered biometric template and obtaining the recognition result.
The image forming method according to claim 33, wherein said radiation condition in step I is that the LED illumination source is at a different radiation angle.
The image forming method according to claim 34, wherein said radiation angle ranges from 5 to 30 degrees.
The image forming method according to claim 33, wherein said radiation condition in step I is that the LED illumination source is at a different radiation position.
The image forming method according to claim 36, wherein said radiation position is at least any one selected from the left side, the right side, the left and right sides, the upper side, the lower side, and the upper and lower sides.
The image forming method according to claim 33, wherein said radiation condition in said step I is that the LED illumination source is at a different radiation intensity.
The image forming method according to claim 38, wherein said radiation intensity is 1 time, 2 times, 4 times or more of different visible light and/or infrared light radiation intensity.
The image forming method according to claim 33, wherein said radiation condition in step I is that the LED illumination source is in a different radiation wavelength range.
The image forming method according to claim 40, wherein said radiation wavelength ranges from 750 nm to 800 nm, 800 nm to 850 nm, 850 nm to 900 nm, 900 nm to 950 nm, 750 nm to 850 nm, and 850 nm to 950 nm of different radiation wavelength ranges or combinations.
A method for detecting a biometric anti-counterfeiting living body using the visible light and biometric combined photoelectric imaging system of the mobile terminal according to claim 1, wherein the method is biological tissue spectroscopy generated by visible light-infrared light imaging wavelength radiation. Real-time detection of active characteristics, including the following steps:

1) changing the optical filter to generate visible light imaging wavelength radiation by the visible light imaging wavelength, driving the LED illumination source, and acquiring the visible light imaging wavelength image Ivs of the image sensor imaging array;

2) changing the optical filter by imaging the wavelength of the infrared light, driving the LED illumination source to generate infrared light imaging wavelength radiation, and acquiring the infrared light imaging wavelength image Iir of the image sensor imaging array;

3) respectively calculating the contrast C data of the visible light imaging wavelength image Ivs and the infrared light imaging wavelength image I ir in steps 1) and 2), respectively Ivs_C, and I ir_C;

4) calculating the image contrast Ivs_C and Iir_C activity change rate Δρ of visible light imaging wavelength radiation and infrared light imaging wavelength radiation in real time respectively;

among them:

Δρ=Iir_C/Ivs_C*100%;

5) According to the visible light-infrared light imaging wavelength, the preset value of the spectral activity characteristic of the biological tissue is irradiated, and the corresponding change rate of the activity contrast of the data value Δρ in the step 4) is judged whether the threshold condition is satisfied, and the biological living state is detected in real time.
The living body detecting method according to claim 42, wherein said contrast C is a contrast between an iris area and an out-of-iris area, C = S (Yiris) / S (Youtiris), wherein Yiris represents an iris area pixel, and Youtiris represents an iris outside The area pixel, the function S is a corresponding area pixel statistical evaluation function.
The living body detecting method according to claim 42, wherein said contrast C is a contrast between a vein region and an extravascular region, C = S (Youtvein) / S (Yvein), wherein Yvein represents a vein region pixel, and Youtvein represents an intravenous vein The area pixel, the function S is a corresponding area pixel statistical evaluation function.
The living body detecting method according to claim 43 or 44, wherein said pixel statistical evaluation function S The method employed is selected from at least one of the following: histogram statistics, frequency statistics, mean statistics, weighted average statistics, median statistics, energy value statistics, variance statistics, gradient statistics, spatial-frequency domain filters.
The living body detecting method according to claim 42, wherein said steps 1) and 2) can be performed alternately or simultaneously.
The living body detecting method according to claim 42, wherein said threshold condition is whether Δρ > 300% is satisfied, and if it is satisfied, it is determined to be a living state.