CN111079552A

CN111079552A - Device and method for long-distance large-field iris optical imaging

Info

Publication number: CN111079552A
Application number: CN201911163811.2A
Authority: CN
Inventors: 倪蔚民
Original assignee: Suzhou Siyuan Kean Information Technology Co ltd
Current assignee: Suzhou Siyuan Kean Information Technology Co ltd
Priority date: 2019-11-25
Filing date: 2019-11-25
Publication date: 2020-04-28

Abstract

The invention provides a device for remote large-field-of-view iris optical imaging, which comprises: the iris optical tracking system comprises a 3D depth imaging unit and a direction axis rotating unit; the iris zooming focusing optical imaging system comprises an optical zooming focusing lens group and is used for adjusting the focal length and the focusing position of iris imaging according to the 3D physical space point coordinates; the LED illumination light source radiation system comprises a radiation intensity solid angle and/or a radiation intensity direction angle and is used for executing combined control of the matching relation between the field angles of the iris zoom focusing optical imaging system corresponding to different working radiuses/distances according to the 3D physical space point coordinates; and image processing and driving control are carried out, and driving and feedback control among all system units are realized. The invention provides a device and a method for iris optical imaging with a long distance and a large field of view, which simultaneously realize constant field angle and constant radiation illumination in a large range.

Description

Device and method for long-distance large-field iris optical imaging

Technical Field

The invention relates to the technical field of optical imaging, in particular to a device and a method for remote large-field-of-view iris optical imaging.

Background

Known iris imaging devices suffer from the drawback that the imaging time for obtaining images at far working distances and large working field scenes exceeds 1-3s, and the user cannot remain consistent and relatively stationary for such a long time due to the large magnification requirement of the image iris diameter requirement >200 pixels, resulting in the need to readjust the field of view, zoom focus, illumination beyond the field of view of the iris imaging system even if moved very slightly.

In addition, the traditional distance measurement includes software mapping of iris diameter or binocular distance, because the error is too large to provide accurate working distance information due to the fact that the variation difference in people is larger than 20%, the overall performance is directly influenced, meanwhile, the physical distance measurement of infrared, ultrasound, tof and the like has too large error to provide accurate working distance information under the scenes of far working distance and large working field, meanwhile, the known technology has the defects that the depth of field, the image brightness, the image relative illumination, the radiation intensity of an illumination light source, the image quality of the iris of an eye under the radiation illumination and the like can not guarantee the consistency even the difference is several times under the scenes of far working distance and large working field, the traditional illumination light source adopts the adjustment along with the inverse square ratio of the working distance, the radiation intensity of a non-constant light source (such as the range of 2-3 times of the working distance, the angular change of the field 2-3 times, and, so that the requirements of constant field angle and radiation illumination over a wide range cannot be satisfied at the same time.

Therefore, in order to solve the above technical problems in the prior art under the remote working distance and large working field of view, there is a need for a remote large field of view iris optical imaging apparatus and method.

Disclosure of Invention

One aspect of the present invention provides an apparatus for remote large field-of-view iris optical imaging, the apparatus comprising:

the system comprises an iris optical tracking system, an iris zooming focusing optical imaging system, an LED illumination light source radiation system, an image display feedback system and an image processing and driving control system;

the iris optical tracking system includes a 3D depth imaging unit for performing 3D physical space point coordinate acquisition,

the direction axis rotating unit is used for adjusting an object imaging area of the iris zooming focusing optical imaging system according to the 3D physical space point coordinates;

the iris zooming focusing optical imaging system comprises an optical zooming focusing lens group used for adjusting the focal length and the focusing position of iris imaging according to the 3D physical space point coordinates;

the LED illumination light source radiation system comprises a radiation intensity solid angle and/or a radiation intensity direction angle and is used for executing combined control of the matching relation between the field angles of the iris zoom focusing optical imaging system corresponding to different working radiuses/distances according to the 3D physical space point coordinates;

the image display feedback system comprises a display screen for displaying the current image and/or the state information in real time;

the image processing and driving control system is connected with the iris optical tracking system, the iris zooming focusing optical imaging system, the LED illuminating light source radiation system and the image display feedback system, and realizes the driving and feedback control among all the system units.

Preferably, the 3D depth imaging unit comprises using 3D TOF depth imaging or structured light depth imaging, or binocular stereo vision imaging.

Preferably, the direction axis rotating unit includes a rotation angle performing a vertical and/or horizontal direction rotation axis.

Preferably, the radiation intensity direction angle of the LED illumination light source radiation system satisfies the relationship: ψ ═ arctan (D/R), wherein,

an included angle between a center line corresponding to the radiation intensity peak direction of the LED illumination light source radiation system and the optical axis of the iris zooming focusing optical imaging system is defined, D is the distance between the optical center of the LED illumination light source radiation system and the optical center of the iris zooming focusing optical imaging system, and R is the working radius of the iris zooming focusing optical imaging system.

Preferably, the solid angle of the radiation intensity of the LED illumination source radiation system satisfies the relationship: omega (omega) 4 pi sin²(ω) a unit sphericity sr, wherein,

ω＝arctan((PXiris²+PYiris²)^1/2/2*PSiris/((1+β)*EFLiris))

＝arctan((PXiris²+PYiris²)^1/2/2 × PSiris/(β × R)), ω is the half field angle of the iris zoom focus optical imaging system,

PXiris is the X horizontal direction pixel resolution of an iris zoom focus optical imaging system,

PYiris is the Y-vertical pixel resolution of the iris zoom focus optical imaging system,

EFLiris is the position of the focal length,

β, (PR) PSiris, PR is the image-side resolution of the physical diameter of the iris,

PSiris is the pixel unit resolution of the image imaging sensor of the iris zoom focus optical imaging system,

and R is the working radius of the iris zoom focusing optical imaging system.

Preferably, the LED illumination source radiation system and the iris focal length focusing optical imaging system are configured to:

a combined imaging mode of global pixel exposure (integration) and illumination radiation triggered in either a synchronized out-of-pulse or synchronized in-pulse fashion with a filter, wherein:

the synchronized pulse exposure (integration) time and the synchronized pulse illumination radiation time Tpulse < m/(PR × speed) of the combined imaging mode,

speed is the speed of movement, in m/s,

PR is the iris physical diameter image-space resolution,

m is the pixel scale of the motion blurred image under preset control and is a unit pixel;

the combined imaging mode has a synchronized pulsed exposure (integration) frequency and a synchronized pulsed illumination radiation frequency, Fpulse, which is [10, 30] Hz,

the LED illumination light source radiation system generates synchronous pulse illumination radiation, and the radiated illuminance Tpulse Fpulse Eiris (omega) of the illumination radiation on the iris surface<10mw/cm²/s，

Eiris (ω) is the irradiance on the iris surface.

Another aspect of the invention provides a method for remote large field of view iris optical imaging, the method comprising:

the image processing and driving control system executes the driving and feedback control processes among the iris optical tracking system, the iris zooming focusing optical imaging system, the LED illumination light source radiation system and the image display feedback system:

a. the iris optical tracking system is controlled in a feedback mode, 3D coordinates of key points of the iris are obtained through a 3D depth imaging unit of the iris optical tracking system, relative coordinates are converted into 3D physical space points, a direction axis rotating unit is controlled in a feedback mode to adjust the angle, and real-time synchronous iris optical imaging tracking is achieved;

b. the iris zooming focusing optical imaging system is subjected to feedback control, and the feedback control of the focal length and the focusing position of the real-time synchronous optical zooming focusing lens group is realized according to the 3D physical space point coordinates;

c. the feedback control of the LED illumination light source radiation system realizes the feedback control of the LED illumination light source radiation intensity direction angle and/or the LED illumination light source radiation intensity solid angle synchronously responding to the matching relation between the field angles of the iris zoom focusing optical imaging system corresponding to different working radiuses/distances in real time according to the 3D physical space point coordinates;

d. controlling a feedback image display feedback system to display the current image and/or state information in real time through feedback;

the image display feedback system realizes real-time synchronous display of the current image as an infrared image imaged by the 3D depth imaging unit, an RGB visible light unit imaging image or an iris zooming focusing optical imaging image.

Preferably, the feedback controlled iris imaging tracking system comprises:

a1, defining the field angle FOVface and the effective imaging focal length EFLface of the 3D depth imaging unit according to the preset working field range FOV:

EFLface＝[(PXface²+PYface²)^1/2*PSface/2]/tan(FOVface/2)

PXface is the pixel resolution in the X horizontal direction of the 3D depth imaging unit;

PYface is the pixel resolution in the Y vertical direction of the 3D depth imaging unit;

PSface is the pixel unit resolution of the 3D depth imaging unit;

the FOVface is the view field angle of the 3D depth imaging unit, and the FOVface is equal to FOV;

the EFLface is an effective imaging focal length of the 3D depth imaging unit.

a2, defining 3D depth imaging unit to control and acquire key points of iris:

a21, acquiring a brightness (infrared gray scale) image Ii (x, y) and a depth distance image Iz (x, y) of the 3D depth imaging unit;

a22, detecting a face area in the luminance image Ii (x, y), and further locating left and right eye center coordinates (xl, yl) and (xr, yr) in the face area;

a23, acquiring the depth distance information of the position of the coordinates corresponding to the centers of the left and right eyes in the depth distance image Iz (x, y),

z＝[Iz(xl，yl)+lz(xr，yr)]/2

or

z＝Iz((xl+xr)/2，(yl+yr)/2)；

a24, generating a 3D depth imaging unit image side key reference point,

KPface(xe,ye,z):KPface(xe,ye,z)＝KPface((xl+xr-PXface)/2*PSface，(yl+yr-PYface)/2*PSface,z)；

a25, generating a key reference point KPface (Xe, Ye, Ze) of the object space of the 3D depth imaging unit, wherein KPface (Xe, Ye, Ze) is KPface (Xe z/EFLface, Ye z/EFLface, z).

a3, establishing object-side key reference point coordinates KPface (Xe, Xe, Ze) of the 3D depth imaging unit, and performing coordinate transformation relative to 3D physical space points Piris (X, Y, Z) of the iris zoom focusing optical imaging system, wherein Piris (X, Y, Z) is (Xe-Xoffset, Xe-Yoffset, Ze-Zooffset),

(Xoffset, Yoffset, zaffset) is a 3D physical position coordinate offset of the 3D depth imaging unit with respect to the iris zoom focus optical imaging system.

a4, performing directional axis rotation unit synchronization control, comprising:

the rotation angle θ v of the rotation axis in the vertical direction is performed as arctan (X/Z),

the rotation angle θ h of the horizontal rotation axis is executed as arctan (Y/Z).

Preferably, the feedback-controlled iris zoom-focus optical imaging system comprises:

b1, performing focal length focusing parameter synchronous control of the iris zooming focusing optical imaging system;

b11, executing the focal length parameter control of the iris zooming focusing optical imaging system, realizing the preset magnification that the focal length position keeps constant, namely the same imaging iris diameter,

the focal position EFLiris (R) β/(1+ β) R (X)²+Y²+Z²)^1/2，

Wherein β is PR PSiris, PR is the image-space resolution of the iris physical diameter,

pixel unit resolution of an image imaging sensor of a PSiris iris zoom focus optical imaging system,

r is the working radius of the iris zooming focusing optical imaging system;

b2, executing the focusing parameter control of the iris zooming focusing optical imaging system, realizing the focusing position within the range of the depth of field of the image,

the FOCUS position FOCUS β x R-kdef, R + kdef,

wherein, the k step number control range, DOF 2 FNO SOC (1+ β)/β²Wherein FNO is the aperture parameter of the iris zoom focusing optical imaging system,

the SOC is a minimum physical light spot resolution parameter of the iris zooming focusing optical imaging system.

Preferably, the feedback-controlled LED illumination source radiation system comprises:

c1, executing the control of the illumination source radiation intensity direction angle parameters of the LED illumination source radiation system,

the radiation direction angle psi of the LED illumination light source is arctan (D/R),

defining an included angle between a central line corresponding to the radiation intensity peak direction of the LED illumination light source radiation system and an optical axis of the iris zooming focusing optical imaging system, wherein D is the distance between the optical center of the LED illumination light source radiation system and the optical center of the iris zooming focusing optical imaging system, and R is the working radius of the iris zooming focusing optical imaging system;

c2, performing parameter control of the solid angle of the LED illumination source radiation intensity of the LED illumination source radiation system,

solid angle omega (omega) 4 pi sin of radiation intensity of LED illumination light source²(ω) a unit sphericity sr, wherein,

ω＝arctan((PXiris²+PYiris²)^1/2/2*PSiris/((1+β)*EFLiris))＝arctan((PXiris²+PYiris²)^1/2/2 × PSiris/(β × R)), ω is the half field angle of the iris zoom focus optical imaging system,

EFLiris is the position of the focal length,

and R is the working radius of the iris zoom focusing optical imaging system.

The device and the method for iris optical imaging with long distance and large field of view provided by the invention can simultaneously realize constant field angle and constant radiation illumination in a large range, and have the following advantages:

1. constant magnification, i.e. the same diameter of the iris of the imaged image.

2. In response to the field of view and within 0.1s of imaging speed within the working distance and depth of field range.

3. Constant imaging depth of field.

4. Constant imaged image brightness.

5. Constant imaged image relative illumination.

6. A constant LED illumination source system radiates total optical power.

7. The constant radiation illumination of the iris of the eye meets the upper limit of the biological safe radiation of the eye.

8. The moving speed to 1m/s is not affected by motion blur, countering the interference of various ambient light >10,000 lux noise conditions.

9. The working distance is larger than 1m, and the field range is larger than 60 degrees.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

Further objects, features and advantages of the present invention will become apparent from the following description of embodiments of the invention, with reference to the accompanying drawings, in which:

fig. 1 schematically illustrates a schematic diagram of an apparatus for remote large field-of-view iris optical imaging in one embodiment of the present invention.

Fig. 2 schematically shows a schematic view of an apparatus for remote large field-of-view iris optical imaging in another embodiment of the present invention.

Reference numerals:

100 a device for long-distance large-field iris optical imaging,

1103D depth imaging unit infrared VCSEL light source,

111 depth imaging unit infrared imaging lens and image imaging sensor,

112 vertical direction rotation axis of the iris optical tracking system,

113 horizontal direction rotation axis of iris optical tracking system,

114 a visible light RGB image-forming unit,

the 1153D depth imaging unit has a predetermined working field angle FOVface,

116 a predetermined proximal working radius Rnear,

117 a predetermined proximal working distance Znear,

118 a predetermined distal working radius Rfar,

119 a predetermined distal working distance Zfar,

120 a zoom focus imaging lens group of an iris zoom focus optical imaging system,

121 an optical filter of an iris zoom focus optical imaging system,

122 an image imaging sensor of the iris zoom focus optical imaging system,

123 to protect the window from the outside and to protect the window,

124 field angle FOViris-near of proximal working radius/distance Rnear/Znear of iris zoom focusing optical imaging system,

125 field angle FOViris-far of distal working radius/distance Rfar/Zfar of the iris zoom focus optical imaging system,

126 near working radius/distance Rpeak/Znpeak of the iris zoom focusing optical imaging system,

127 object plane imaging region of distal working radius/distance Rfar/Zfar of iris zoom focusing optical imaging system,

130L/130R at the distal working radius/distance Rfar/Zfar the left and right LED illumination sources of the LED illumination source radiation system,

131L/131R at the proximal working radius/distance Rnear/Znear LED illumination sources to the left and right of the LED illumination source radiation system,

132L/132R at the distal working radius/distance Rfar/Zfar, the solid angle of radiation intensity of the left/right side illumination sources of the LED illumination source radiation system, the field angle FOViris-far matching the distal working radius/distance Rfar/Zfar of the iris zoom focusing optical imaging system,

133L/133R the solid angle of radiation intensity of the left/right illumination sources of the LED illumination source radiation system at the proximal working radius/distance Rnear/Znear, the field angle FOViris-near matching the proximal working radius/distance Rnear/Znear of the iris zoom focusing optical imaging system,

134L/134R at the near end working radius/distance Rpeak/Znpeak the left/right side illumination light source radiation intensity direction angle of the LED illumination light source radiation system, matching the near end working radius/distance Rpeak/Znpeak of the iris zoom focusing optical imaging system,

135L/135R at the far end working radius/distance Rfar/Zfar, the left/right side illumination light source radiation intensity direction angle of the LED illumination light source radiation system is matched with the far end working radius/distance Rfar/Zfar of the iris zoom focusing optical imaging system,

150 an image processing and drive control system for the image processing and drive control system,

160 image display feedback system.

200 a device for long-distance large-field iris optical imaging,

2103D depth imaging unit infrared VCSEL light source,

211 a depth imaging unit infrared imaging lens and an image imaging sensor,

214 a visible light RGB image imaging unit,

the field angle of the 2153D depth imaging unit is the predetermined working field angle FOVface,

216 a predetermined proximal working radius Rnear,

217 a predetermined proximal working distance Znear,

218 a predetermined distal working radius Rfar,

219 a predetermined distal working distance Zfar,

228 2-axis MEMS rotating mirror unit of an iris optical tracking system,

220 a zoom focusing imaging lens group of the iris zoom focusing optical imaging system,

221 a filter of an iris zoom focus optical imaging system,

222 an image imaging sensor of an iris zoom focus optical imaging system,

223 the window is to be protected by the protection window,

224 field angle FOViris-near of proximal working radius/distance Rnear/Znear of iris zoom focusing optical imaging system,

225 field angle FOViris-far of distal working radius/distance Rfar/Zfar of the iris zoom focus optical imaging system,

226 near working radius/distance Rpeak/Znpeak of iris zoom focusing optical imaging system,

227 object plane imaging area of far end working radius/distance Rfar/Zfar of iris zoom focusing optical imaging system,

the 230L/230R LED illumination source radiates the left and right side LED illumination sources of the system,

232L/232R at the far end working radius/distance Rfar/Zfar, the radiation intensity solid angle of the left/right side illumination light source of the LED illumination light source radiation system is matched with the visual field angle FOViris-far of the far end working radius/distance Rfar/Zfar of the iris zoom focusing optical imaging system,

233L/233R at the proximal working radius/distance Rpeak/Znpeak the solid angle of the radiation intensity of the left/right side illumination source of the LED illumination source radiation system, the field angle FOViris-near matching the proximal working radius/distance Rpeak/Znpeak of the iris zoom focusing optical imaging system,

234L/234R at the proximal working radius/distance Rpeak/Znear the left/right side illumination source radiation intensity direction angle of the LED illumination source radiation system, matching the proximal working radius/distance Rpeak/Znear of the iris zoom focusing optical imaging system,

235L/235R at the far end working radius/distance Rfar/Zfar, the left/right side illuminating light source radiation intensity direction angle of the LED illuminating light source radiation system is matched with the far end working radius/distance Rfar/Zfar of the iris zoom focusing optical imaging system,

the 236L/236R LED illumination source radiates the liquid lens on the left/right side of the system,

the 237L/237R LED illumination source radiation system left/right 2-axis MEMS turning mirror,

250 an image processing and drive control system for the image processing system,

260 image display feedback system.

Detailed Description

The objects and functions of the present invention and methods for accomplishing the same will be apparent by reference to the exemplary embodiments. However, the present invention is not limited to the exemplary embodiments disclosed below; it can be implemented in different forms. The nature of the description is merely to assist those skilled in the relevant art in a comprehensive understanding of the specific details of the invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals denote the same or similar parts, or the same or similar steps.

The first embodiment is as follows:

referring to fig. 1, a schematic diagram of an apparatus for remote large field iris optical imaging in an embodiment of the present invention is shown, and in an embodiment of the present invention, an apparatus 100 for remote large field iris optical imaging comprises: an iris optical tracking system, an iris zoom focus optical imaging system, an LED illumination source radiation system, an image display feedback system 160, an image processing and drive control system 150.

The iris optical tracking system comprises a 3D depth imaging unit, a 2-direction axis rotating unit: a vertical direction rotation axis 112 of the iris optical tracking system and a horizontal direction rotation axis 113 of the iris optical tracking system.

The 3D depth imaging unit may provide depth image information using 3D TOF depth imaging or structured light depth imaging (e.g., 940nm infrared VCSEL light source 110, imaging lens and image imaging sensor 111), or binocular stereo imaging (LED illumination light source, fixed-distance-mounted 2 sets of parameter-symmetric imaging lens and image imaging sensor).

The iris zoom focusing optical imaging system comprises an optical zoom focusing lens group 120, an optical filter 121 and an image imaging sensor 122.

The LED illumination light source radiation system comprises the combined control of the radiation intensity solid angle and/or the radiation intensity direction angle of the LED illumination light source.

The image display feedback system 160 includes a display screen for displaying the current image and/or status information in real time.

The image processing and driving control system 150 is connected with the iris optical tracking system, the iris zoom focusing optical imaging system, the LED illumination light source radiation system and the image display feedback system, and realizes the driving and feedback control among all the system units.

According to the embodiment of the invention, the method for remote large-field-of-view iris optical imaging comprises the following steps: the image processing and drive control system performs the following drive and feedback control processes between the system units:

a. the feedback control iris imaging tracking system acquires 3D coordinates of key points of an iris through a 3D depth imaging unit, converts relative coordinates into 3D physical space points, and performs feedback control on a 2-axis rotating unit to adjust angles, so that real-time synchronous iris optical imaging tracking is realized.

b. And the feedback control of the focal length and the focusing position of the optical zoom focusing lens group is realized in real time according to the 3D physical space point coordinates by the feedback control iris zoom focusing optical imaging system.

c. And the feedback control of the LED illumination light source radiation system realizes the feedback control of the LED illumination light source radiation intensity direction angle and/or the LED illumination light source radiation intensity solid angle synchronously responding to the matching relation between the field angles of the iris zoom focusing optical imaging systems corresponding to different working radiuses/distances in real time according to the 3D physical space point coordinates.

d. And controlling the image display feedback system to display the current image and/or the state information in real time through feedback.

The image display feedback system realizes real-time synchronous display of the current image as an infrared brightness image imaged by the 3D depth imaging unit, an RGB visible light unit imaging image or an iris zooming focusing optical imaging image.

According to the embodiment of the invention, the specific steps comprise:

a1, defining the field angle FOVface115 and the effective imaging focal length EFLface of the 3D depth imaging unit according to the predetermined working field of view range FOV.

EFLface＝[(PXface²+PYface²)^1/2*PSface/2]/tan(FOVface/2)，

PXface is the X horizontal direction pixel resolution, pixel, of the 3D depth imaging unit;

PYface is the pixel resolution, pixel, in the Y vertical direction of the 3D depth imaging unit;

PSface is the pixel unit resolution of the 3D depth imaging unit, um/pixel;

the FOVface is the field angle of the 3D depth imaging unit, and the FOVface is the FOV;

EFLface is the effective imaging focal length of 3D depth imaging unit, mm.

Typical parameters are calculated as follows:

PXface 640pixels, PYface 480pixels, PSface 5.6um/pixel, FOVface 77 degrees, EFLface 2.8 mm.

a2, and defining 3D depth imaging unit control to acquire iris key points.

a21, acquiring a brightness (infrared gray scale) image Ii (x, y) and a depth distance image Iz (x, y) of the 3D depth imaging unit.

a22, detecting a face region in the luminance image Ii (x, y), and further locating the left and right eye center coordinates (xl, yl) and (xr, yr) in the face region.

At present, the well-known convolutional neural network CNN cascade model based on deep learning can reliably and accurately realize the functions of face region detection and eye positioning.

Specifically, in order to improve the performance of detecting and positioning the eyes, the visible light RGB image imaging unit 114 is used independently or jointly, calibration and registration of the 3D depth imaging unit and the visible light RGB image imaging unit 114 are performed in advance, and then the face region and the eye positioning in the RGB image are further detected, so that the accuracy and the reliability are improved. In addition, the RGB imaging unit can be used for detecting the human face when the device is in a standby state to trigger the system to enter a normal working state, so that the standby power consumption of the system is reduced. Further, the image imaged by the visible light RGB image imaging unit is used for displaying the current image in real time by the image display feedback system.

z＝[Iz(xl，yl)+lz(xr，yr)]/2，

or

z＝Iz((xl+xr)/2，(yl+yr)/2)。

a24, generating a 3D depth imaging unit image side key reference point KPface (xe, ye, z):

KPface(xe,ye,z)＝KPface((xl+xr-PXface)/2*PSface，(yl+yr-PYface)/2*PSface,z)。

a25, generating a 3D depth imaging unit object space key reference point KPface (Xe, Ye, Ze):

KPface(Xe,Ye,Ze)＝KPface(xe*z/EFLface，ye*z/EFLface，z)。

a3, establishing object-side key reference point coordinates KPface (Xe, Xe, Ze) of the 3D depth imaging unit and transforming the coordinates of the 3D physical space points Piris (X, Y, Z) of the iris zoom focusing optical imaging system,

Piris(X，Y，Z)＝(Xe-Xoffset，Xe-Yoffset，Ze-Zoffset)，

wherein, (Xoffset, Yoffset, Zoffset) is a 3D physical position coordinate offset of the 3D depth imaging unit with respect to the iris zoom focus optical imaging system.

a4, performing 2-axis rotation unit synchronization control, comprising:

Still further preferably, the 3D depth imaging unit and the iris optical tracking system are integrated to maintain synchronous rotation control, and provide an ideal accuracy feedback measurement after the iris optical tracking system adjusts the 2-axis rotation angle, by comparing the expected object key reference point KP (Xp, Yp, Zp):

KP(Xp，Yp，Zp)＝KP((Ze*tan(θv)-Xe)*cos(θv)，(Ze*tan(θh)-Ye)*cos(θh)，(Xe²+Ye²+Ze²)^1/2)，

or an equivalent thereof, may be used,

KP((Xe²+Ze²)^1/2*sin(θv-arctan(Xe/Ze))，(Ye²+Ze²)^1/2*sin(θh-arctan(Ye/Ze))，(Xe²+Ye²+Ze²)^1/2)。

and repeating the iteration steps a1-a2 to obtain the actual object key reference point KPface (Xe, Ye, Ze) output by the 3D depth imaging unit, judging whether the actual object key reference point KPface (Xe, Ye, Ze) is within a preset error range of the system, if the error range exceeds the preset error range, repeating the step a3 to establish the coordinate transformation of the 3D physical space point Piris (X, Y, Z) according to the actual object key reference point KPface (Xe, Ye, Ze), feeding back the control step a4, and readjusting the rotation angle. More recently, the 3D depth imaging unit and the iris tracking system are integrated to maintain synchronous rotation control, and a larger 360-degree working field angle is expanded.

Performing focal length focusing parameter synchronization control of an iris zoom focusing optical imaging system, comprising:

b1, executing the focal length parameter control of the iris zooming focusing optical imaging system, and realizing the preset magnification that the focal length position is kept constant, namely the same imaging iris diameter.

The focal position EFLiris (R) β/(1+ β) R (X)²+Y²+Z²)^1/2

Wherein β PR PSiris PR is the physical diameter image-side resolution pixel/mm of the iris, such as 20pixels/mm, and the unit pixel resolution um/pixel of the image imaging sensor of the PSiris iris zoom focus optical imaging system, such as 3um/pixel, β 0.06.

As shown in fig. 1, R is a predetermined working radius, including a predetermined proximal working radius Rnear116, a predetermined distal working radius Rfar118,

the predetermined working distance Z, includes a predetermined proximal working distance Znear117 and a predetermined distal working distance Zfar 119.

For example, the typical parameters include a proximal working radius Rnear of 1m, a distal working radius Rfar of 2m, and EFLiris of 56.6mm and 113.2mm, respectively.

Considering that the actual user does not move autonomously while securing the speed and the adjustment frequency, the optical zoom operation may be performed after the R interval is changed by a certain predetermined range. Such a design is reasonable if the same focal length is maintained for a range of 5-10cm, and the iris diameter itself varies from person to person.

focus position FOCUS β R-kDOF, R + kDOF

Wherein k is the control range of the number of steps, k is [1, 2 ]]The STEP size is STEP β DOF, e.g. k 2, including-2 STEP, -STEP, 0, + STEP, 2STEP for 5 ranges, DOF 2 FNO SOC (1+ β)/β²Wherein FNO is aperture parameter of iris zoom focusing optical imaging system, and parameter range [ PF, 2PF]，PF＝PSiris/(1um/pixel); the SOC is the minimum physical spot resolution parameter of the iris zoom focus optical imaging system, and typical values of the parameters are SOC 2 × PSiris 1pixel and maximum DOF 21.2 mm.

Due to the error of the depth information, the iris zoom focusing optical imaging system generates 2k +1 times step control position in the precision mechanical error, individual deviation and the like of the actual production and manufacturing process, the step is β DOF, the general 3-5 step range is completely within the preset image space focusing position, the focusing position is ensured to be within the object space depth range of + -DOF/2 (equivalent image space depth range of + - β DOF/2), and meanwhile, the small number of control steps can be ensured to be completed within 0.1 s.

The design of the invention ensures that the field depth range is constant, and simultaneously realizes that the focusing position is within the field depth range of the image surface.

The ideal aspheric optical glass/plastic mixed 2-piece liquid lens respectively and independently controls the focal length EFLiris and the focusing FOCUS, the design requires that the focal length and the focusing position are converted into numerical values with the diopter of the imaging optical system 2-piece liquid lens of the corresponding design as a unit specification, compared with the traditional complex cam curve control driven by a stepping motor, the driving control process can be greatly simplified due to the fact that the liquid lens has the linear response optical property relation corresponding to the diopter and the voltage/current, and meanwhile, the design can greatly reduce the number of the components of the whole imaging system (3-4 groups of 12-16 pieces).

Meanwhile, no mechanical transmission part for connecting and driving a traditional screw or a gear is arranged, the service life is not limited, and the control precision and the repeatability are substantially improved.

In practice, the present invention is currently practiced with liquid lenses having a limited clear aperture, typically 6-10mm, and a limited diopter range of-10 to +20 diopters, with wavefront error increasing to λ/10 at large diopters, but due to depth of field for FNO values, long focal length application requirements, suitable for iris zoom focusing optical imaging systems. The optical designer can solve the problem by optimizing the optical path design by utilizing the characteristic skill of the liquid lens, for example, the optical path is selected to be suitable for designing FNO for solving the clear aperture, the initial design of the optical system of the zooming part adopts the mode of setting the zoom liquid lens to work at the maximum focal length when the optical power of 0 diopter is at the far-end working radius/distance, and the initial design of the optical system of the focusing part adopts the mode of setting the image surface position corresponding to the focusing liquid lens to work at the far-end working radius/distance when the optical power of 0 diopter is at the far-end working.

And performing parameter control on the direction angle of the radiation intensity direction of the LED illumination light source radiation system and/or the radiation intensity solid angle of the LED illumination light source to realize the matching of the relation between the field angle ranges of the iris focal length focusing optical imaging system corresponding to different working radiuses/distances in response to different 3D physical space point coordinates, as shown in FIG. 1.

c1, executing the control of the illumination light source radiation intensity direction angle parameter of the LED illumination light source radiation system.

LED lighting source radiation direction angle psi ═ arctan (D/R)

Equivalently, the central line corresponding to the radiation intensity peak direction of the radiation system of the LED illumination light source and the object plane of the iris zoom focusing optical imaging system form an included angle psi ', phi, 90-psi'.

C2, performing parameter control of the solid angle of LED illumination source radiation intensity of the LED illumination source radiation system.

Solid angle omega (omega) 4 pi sin of radiation intensity of LED illumination light source²(omega) unit sphericity sr

ω＝arctan((PXiris²+PYiris²)^1/2/2*PSiris/((1+β)*EFLiris))

＝arctan((PXiris²+PYiris²)^1/2/2*PSiris/(β*R))

Omega is the half field angle of the iris zoom focusing optical imaging system.

PXiris is the X horizontal direction pixel resolution, pixel, of the iris zoom focusing optical imaging system.

PYiris is the Y-vertical pixel resolution, pixel, of the iris zoom focus optical imaging system.

The peak value of the radiation intensity of the radiation system Ipeak of the LED illumination source is equal to OP/Ω (ω) unit mw/sr.

OP is the total optical power, mw, of the LED illumination source radiation system.

The LED illumination source radiation intensity solid angle Ω (ω) defines the solid angle of the distribution of the corresponding ranges centered in the direction of the radiation intensity peak when the ratio of the radiation intensity I ρ to the radiation intensity peak Ipeak of the LED illumination source radiation system is equal to ρ.

ρ is I ρ/Ipeak, ρ is the relative illuminance of the optical radiation received by the imaging surface of the predetermined custom iris focal length focusing optical imaging system, such as 0.5 or 0.707, and higher means the relative illuminance distribution is more uniform.

Essentially, the solid angle of radiation intensity of the LED illumination source generates the radiated illumination Eiris on the iris surface, wherein Eiris (omega, psi) is OP/(omega) R²)*cos³(ψ)。

Sin is satisfied when ω is sufficiently small²(ω)＝tan²(ω)。

As shown in fig. 1, the field angle FOViris-near124 of the proximal working radius/distance Rnear/Znear of the iris zoom focusing optical imaging system. The far end working radius/distance Rfar/Zfar of the iris zoom focusing optical imaging system FOViris-far 125. And an object space plane imaging region 126 of a near working radius/distance Rpeak/Znpeak of the iris zoom focusing optical imaging system. An object plane imaging region 127 of the distal working radius/distance Rfar/Zfar of the iris zoom focus optical imaging system. The left and right LED illumination sources 130L/130R of the LED illumination source radiation system at the distal working radius/distance Rfar/Zfar. The left and right LED illumination sources 131L/131R of the LED illumination source radiation system at the proximal working radius/distance Rpeak/Znpeak. The solid angle of radiation intensity of the left/right side illumination sources of the LED illumination source radiation system at the distal working radius/distance Rfar/Zfar matches the field angle FOViris-far132L/132R of the distal working radius/distance Rfar/Zfar of the iris zoom focusing optical imaging system. The solid angle of radiation intensity of the left/right illumination sources of the LED illumination source radiation system at the proximal working radius/distance Rnear/Znear matches the field angle FOViris-near133L/133R of the proximal working radius/distance Rnear/Znear of the iris zoom focusing optical imaging system. The angle of the radiation intensity directions of the left/right illumination sources of the LED illumination source radiation system at the near-end working radius/distance Rpeak/Znpeak matches the near-end working radius/distance Rpeak/Znpeak 134L/134R of the iris zoom focusing optical imaging system. The left/right illumination source radiation intensity direction angle of the LED illumination source radiation system at the far end working radius/distance Rfar/Zfar matches the far end working radius/distance Rfar/Zfar135L/135R of the iris zoom focusing optical imaging system.

The invention can realize that for an LED illumination light source radiation system with constant total optical power, the radiation illumination intensity of the iris surface is changed by the same amount through dynamically changing the light radiation intensity distributed by the solid angle of the radiation intensity of the LED illumination light source, no matter how the far end/near end working radius [ Rfar, Rpeak ]/distance [ Zfar, Znear ] and the corresponding field angle [ FOViris-far, FOViris-near ] of the iris zoom focusing optical imaging system are changed, the iris zoom focusing optical imaging system keeps close to constant according to the formula Eiris (omega, psi), and can completely match the working radius/distance and the corresponding field angle of the iris optical zoom focusing optical imaging system.

The light radiation illuminance Eimage can be proved to be received for an imaging image plane of a focusing optical imaging system with an iris focal length.

According to the formula Eimage (omega, psi) ═ 1/16/(1+ β)²*cos⁴(Φ)*μ*Eiris(ω，ψ)/FNO²，

When ω is sufficiently small to satisfy cos⁴(phi) is 1, phi is the imaging incidence angle of the iris focal length focusing optical imaging system, and phi is 0, omega]And mu is the optical reflectivity of the iris biological tissue.

Eimage is constant, i.e. the image brightness Iimage is constant.

Iimage＝QE*Tpulse*Eimage*ADC*G

QE is the photon-electron quantum conversion efficiency unit e-/(mw. mu. m)²) G is unit conversion gain unit mv/e-, ADC is analog voltage/digital brightnessThe degree conversion unit LSB/mv.

At present, the traditional CMOS SENSOR technology performs photon-electron quantum conversion, the efficiency of a PD silicon-based photodiode is not ideal, the technology of a QF quantum film or an OPF organic photosensitive film and the like at the leading edge has natural high quantum conversion efficiency for infrared photons, and the property of a global shutter of global shutter is ideal and preferable.

Meanwhile, it can be proved that the relative illuminance ρ of receiving optical radiation at the imaging image plane of the iris focal length focusing optical imaging system is constant, ρ is equal to ee/enter, ee is the radiated illuminance eege (ω, ψ) ρ at the edge of the imaging image plane (edge of field of view), enter is the radiated illuminance at the center of the imaging image plane (center of field of view), and ec is the relative illuminance with constant image brightness.

The invention realizes the matching of the field angle range [ FOViris-far, FOViris-near ], the working radius range [ Rfar, Rpeak ] or the working distance range [ Zfar, Znear ] of the corresponding iris focal length focusing optical imaging system by the array combination control of solid angles with different radiation direction angles and radiation intensities through the LED illumination light source radiation system.

The LED illumination light source radiation system and the iris focal length focusing optical imaging system are combined and configured to have combined control responding to a synchronous radiation intensity direction angle and a radiation intensity solid angle, so that the LED illumination light source radiation system can respond to the corresponding field angle of the iris zooming focusing optical imaging system with different working radiuses/distances in different 3D physical space point coordinates and achieve the corresponding matching relation between the constant imaging image brightness, the constant imaging image relative illumination, the constant LED illumination light source system radiation light power and the constant eye iris radiated illumination in the preset working field and working distance.

To eliminate motion blur caused by user motion in actual use, even a moving speed of 10cm/s or less can cause very significant image motion blur disturbance due to such a large optical magnification, resulting in an influence on recognition performance.

The invention is configured to a global pixel exposure (integration) and illumination radiation combined imaging mode in a synchronous pulse external triggering mode or a synchronous pulse internal triggering mode through an LED illumination light source radiation system and an iris focal length focusing optical imaging system.

Wherein the sync pulse exposure (integration) time and the sync pulse illumination radiation time Tpulse < m/(PR × speed), speed is a predetermined controlled motion speed such as 1m/s, m is a predetermined controlled motion blur image pixel scale, and m <10 pxiels.

The synchronous pulse exposure (integral) frequency and the synchronous pulse illuminating radiation frequency Fpulse, the Fpulse is 10, 30 Hz, the LED illuminating light source radiation system generates the synchronous pulse illuminating radiation, the radiated illuminance Tpulse of the synchronous pulse illuminating radiation on the iris surface is Eiris (omega), and the radiated illuminance is less than 10mw/cm2/s, so as to ensure the eye radiation biosafety is satisfied.

Furthermore, the iris focal length focusing optical imaging system realizes a global pixel exposure (integration) and illumination radiation combined imaging mode of a synchronous pulse external triggering mode or a synchronous pulse internal triggering mode under the combination of the optical filter, and has anti-interference performance on various light interference conditions in an external uncontrolled environment. Such as outdoor solar environments up to 10,000 lux or more.

The protection window 123 can be made of full-transmission toughened optical glass, or more preferably, a filter which reflects visible light below 700nm and transmits infrared light of 700-900nm is adopted, so that the internal optical component can be protected, meanwhile, a user cannot observe the internal structure and provide the user with a natural use visual feedback effect by reflecting the visible light, furthermore, the visible light is filtered, the iris focal length focusing optical imaging system can be improved, the interference of stray light of external non-imaging wavelength can be eliminated, and the signal-to-noise ratio (SNR) of imaging quality is further improved.

Example two:

referring to fig. 2, a schematic diagram of an apparatus for remote large field iris optical imaging in an embodiment of the present invention is shown, in which an apparatus 200 for remote large field iris optical imaging in accordance with an embodiment of the present invention comprises: an iris optical tracking system, an iris zoom focusing optical imaging system, an LED illumination source radiation system, an image display feedback system 260, and an image processing and drive control system 250.

The iris optical tracking system includes a 3D depth imaging unit, a 2-axis MEMS rotating mirror unit 228.

The 3D depth imaging unit may provide depth image information using 3D TOF depth imaging or structured light depth imaging (e.g., 940nm infrared VCSEL light source 210, imaging lens and image imaging sensor 211), or binocular stereo imaging (LED illumination light source, fixed-spaced distance mounted 2 sets of parameter symmetric imaging lens and image imaging sensor).

The iris zoom focusing optical imaging system includes an optical zoom focusing lens group 220, an optical filter 221, and an image imaging sensor 222.

The image display feedback system 260 includes a display screen for displaying the current image and status information in real time.

The image processing and driving control system 250 is connected with the iris optical tracking system, the iris zooming focusing optical imaging system, the LED illumination light source radiation system and the image display feedback system, and realizes the driving and feedback control among all the system units.

According to the embodiment of the invention, the specific steps comprise:

a1, defining the field angle FOVface215 and the effective imaging focal length EFLface of the 3D depth imaging unit according to the predetermined working field of view range FOV.

EFLface＝[(PXface²+PYface²)^1/2*PSface/2]/tan(FOVface/2)，

PSface is the pixel unit resolution of the 3D depth imaging unit, um/pixel;

EFLface is the effective imaging focal length of 3D depth imaging unit, mm.

Typical parameters are calculated as follows:

a2, and defining 3D depth imaging unit control to acquire iris key points.

z＝[Iz(xl，yl)+lz(xr，yr)]/2，

or

z＝Iz((xl+xr)/2，(yl+yr)/2)。

KPface(Xe,Ye,Ze)＝KPface(xe*z/EFLface，ye*z/EFLface，z)。

Piris(X，Y，Z)＝(Xe-Xoffset，Xe-Yoffset，Ze-Zoffset)，

a4, performing synchronous control of the rotation angle of the 2-axis MEMS turning mirror unit 228 for adjusting the vertical/horizontal direction, comprising:

the rotation angle θ v of the rotation axis in the vertical direction is performed to be arctan (X/Z)/2,

the rotation angle θ h of the rotation axis in the horizontal direction is performed to be arctan (Y/Z)/2.

According to the invention, the rotation angle in the vertical/horizontal direction is adjusted by adopting the 2-axis MEMS rotary mirror unit, and the MEMS rotary mirror has the advantages of high reliability and stability, quick response, small volume, high accuracy, good repeatability and the like, and the preferred embodiment 2 of the invention is realized by the MEMS brakes in piezoelectric, electromagnetic, electrostatic, thermoelectric modes and the like.

Further, the present embodiment employs a 2-axis MEMS rotary mirror unit having typical parameters:

1. mechanical rotation angle >70 degrees, optical rotation angle >35 degrees,

2. operating frequency >10Hz full scale rotation,

3. the angular accuracy is <0.1 degrees,

4. working mode point to point 2 axis vector,

5. the response time is <50ms,

6. the operating voltage is 5vDC,

7. the mirror surface is coated with a metal medium, a gold/aluminum film or an enhanced gold/aluminum film, the 700-900nm wavelength reflectivity is more than 92 percent,

8. quality of the mirror, wavefront error WFERms <20nm RMS (lamda/50),

9. the optical window is a protective window without or with an antireflection film,

11. the service life is more than 100, 000, 000 times of full-scale rotation,

12. the working temperature is-20 to +60 degrees.

The focal position EFLiris (R) β/(1+ β) R (X)²+Y²+Z²)^1/2

As shown in fig. 2, R is a predetermined working radius, including a predetermined proximal working radius Rnear216, a predetermined distal working radius Rfar218,

the predetermined working distance Z, includes a predetermined proximal working distance Znear217 and a predetermined distal working distance Zfar 219.

focus position FOCUS β R-kDOF, R + kDOF

Wherein k is the control range of the number of steps, k is [1, 2 ]]The STEP size is STEP β DOF, e.g. k 2, including-2 STEP, -STEP, 0, + STEP, 2STEP for 5 ranges, DOF 2 FNO SOC (1+ β)/β²Wherein FNO is aperture parameter of iris zoom focusing optical imaging system, and parameter range [ PF, 2PF]PF ═ PSiris/(1 um/pixel); the SOC is the minimum physical spot resolution parameter of the iris zoom focus optical imaging system, and typical values of the parameters are SOC 2 × PSiris 1pixel and maximum DOF 21.2 mm.

And performing parameter control on the direction angle of the radiation intensity direction of the LED illumination light source radiation system and/or the radiation intensity solid angle of the LED illumination light source to realize the matching of the relationship between the field angle ranges of the iris focal length focusing optical imaging system corresponding to different working radiuses/distances in response to different 3D physical space point coordinates, as shown in FIG. 2.

LED lighting source radiation direction angle psi ═ arctan (D/R)

c2, performing parameter control on the solid angle of the LED illumination light source radiation intensity of the LED illumination light source radiation system.

ω＝arctan((PXiris²+PYiris²)^1/2/2*PSiris/((1+β)*EFLiris))

＝arctan((PXiris²+PYiris²)^1/2/2*PSiris/(β*R))

Omega is the half field angle of the iris zoom focusing optical imaging system.

Sin is satisfied when ω is sufficiently small²(ω)＝tan²(ω)。

As shown in fig. 2, the field angle FOViris-near224 of the proximal working radius/distance Rnear/Znear of the iris zoom focusing optical imaging system. The field angle FOViris-far225 of the far end working radius/distance Rfar/Zfar of the iris zoom focusing optical imaging system. And an object space plane imaging region 226 of a near working radius/distance Rpeak/Znpeak of the iris zoom focusing optical imaging system. An object plane imaging region 227 of the distal working radius/distance Rfar/Zfar of the iris zoom focus optical imaging system. The LED illumination light sources radiate the left and right LED illumination light sources 230L/230R of the system. The solid angle of radiation intensity of the left/right side illumination sources of the LED illumination source radiation system at the distal working radius/distance Rfar/Zfar matches the field angle FOViris-far232L/232R of the distal working radius/distance Rfar/Zfar of the iris zoom focusing optical imaging system. The solid angle of radiation intensity of the left/right side illumination sources of the LED illumination source radiation system at the proximal working radius/distance Rnear/Znear matches the field angle FOViris-near233L/233R of the proximal working radius/distance Rnear/Znear of the iris zoom focusing optical imaging system. The left/right side illumination source radiation intensity direction angle of the LED illumination source radiation system at the near end working radius/distance Rpeak/Znpeak matches the near end working radius/distance Rpeak/Znpeak 234L/234R of the iris zoom focusing optical imaging system. The angle of the radiation intensity directions of the left/right illumination sources of the LED illumination source radiation system at the far-end working radius/distance Rfar/Zfar is matched with the far-end working radius/distance Rfar/Zfar235L/235R of the iris zoom focusing optical imaging system. The LED illumination source radiates the left/right side liquid lenses 236L/236R of the system. The LED illumination source radiates the left/right 2-axis MEMS rotating mirror 237L/237R of the system.

Eimage is constant, i.e. the image brightness Iimage is constant.

Iimage＝QE*Tpulse*Eimage*ADC*G

QE is the photon-electron quantum conversion efficiency unit e-/(mw. mu. m)²) And G is a unit conversion gain unit mv/e-, and the ADC is an analog voltage/digital brightness conversion unit LSB/mv.

In the embodiment, the matching of the field angle range [ FOViris-far, FOViris-near ], the working radius range [ Rfar, Rpeak ] or the working distance range [ Zfar, Znear ] of the corresponding iris focal length focusing optical imaging system is realized by the combined control of the liquid lens and the 2-axis MEMS rotating reflector through the LED illumination light source radiation system.

The preferred solid angle of the radiation intensity of the LED illumination light source of the present embodiment is realized by placing a liquid lens at the position of the light exit optical path of the LED illumination light source to control the diopter, i.e. the refraction angle, and essentially, the solid angle of the radiation intensity of the illumination light source is changed by controlling the refraction angle of the exit light through the liquid lens to respond to the field angle of the iris zoom focusing optical imaging system corresponding to different working radii/distances. The design can realize the matching relation between the radiation intensity solid angles of the LED illumination light source responding to the field angles of the iris zoom focusing optical imaging system corresponding to different working radiuses/distances.

The preferred radiation intensity direction angle of the LED illumination source of the present embodiment is implemented by placing a 2-axis MEMS rotating mirror at the position of the emitting light path of the LED illumination source to control the rotation angle synchronous control of the vertical/horizontal direction, and essentially, the radiation intensity direction angle of the LED illumination source is changed by controlling the rotation angle of the vertical/horizontal direction through the 2-axis MEMS rotating mirror, so that the radiation intensity direction angle of the LED illumination source responds to the field angle of the iris zoom focusing optical imaging system corresponding to different working radii/distances. The design can realize the matching relation between the radiation intensity direction angles of the LED illumination light sources and the field angles of the iris zoom focusing optical imaging system corresponding to different working radiuses/distances.

In particular, the vertical/horizontal rotation angle method of the 2-axis MEMS rotating mirror for the LED illumination source radiation intensity direction angle control:

a3, object-side key reference point coordinates KPface (Xe, Ze) of the 3D depth imaging unit are acquired based on the same steps a1 and a 2.

a32, establishing the coordinate transformation of the key reference point KPface (Xe, Xe, Ze) of the object space of the 3D depth imaging unit relative to the 3D physical space point Piris (X ', Y ', Z ') of the LED illumination light source radiation system,

Piris(X'，Y'，Z')＝(Xe-X'offset，Xe-Y'offset，Ze-Z'offset)

(X ' offset, Y ' offset, Z ' offset) is the 3D physical position coordinate offset of the 3D depth imaging unit relative to the LED illumination source radiation system.

a33, 2-axis MEMS rotary mirror unit for performing angle control of radiation intensity direction of LED illumination light source for adjusting rotation angle synchronous control of vertical/horizontal direction, comprising:

the rotation angle θ ' v of the rotation axis in the vertical direction is performed to be arctan (X '/Z ')/2,

the rotation angle θ ' h of the rotation axis in the horizontal direction is executed as arctan (Y '/Z ')/2.

In particular, the LED illumination light source radiation system of the present embodiment is implemented by combining and controlling the liquid lens and the 2-axis MEMS rotating mirror, and the light path sequence of the LED illumination light source, the emergent light path sequentially passes through the liquid lens to control diopter, and then passes through the 2-axis MEMS rotating mirror unit to adjust the rotation angle in the vertical/horizontal direction for synchronous control.

The protection window 223 can be made of full-transmission toughened optical glass, or more preferably made of an optical filter which reflects visible light below 700nm and transmits infrared light of 700-900nm, so that the internal optical component can be protected, meanwhile, a user cannot observe the internal structure and provide the user with a natural use visual feedback effect by reflecting the visible light, furthermore, the visible light is filtered, the iris focal length focusing optical imaging system can be improved, the interference of stray light of external non-imaging wavelength can be eliminated, and the signal-to-noise ratio (SNR) of imaging quality is further improved.

The invention provides a device and a method for iris optical imaging with a long distance and a large field of view, which simultaneously realize constant field angle and constant radiation illumination in a large range.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

Claims

1. An apparatus for remote large field of view iris optical imaging, said apparatus comprising:

2. The apparatus of claim 1, wherein the 3D depth imaging unit comprises using 3D TOF depth imaging or structured light depth imaging, or binocular stereo vision imaging.

3. The apparatus of claim 1, wherein the directional axis rotation unit includes a rotation angle performing a vertical and/or horizontal direction rotation axis.

4. The apparatus of claim 1, wherein the direction angle of the radiation intensity of the LED illumination source radiation system satisfies the relationship: ψ ═ arctan (D/R), wherein,

5. The apparatus of claim 1, wherein the solid angle of radiation intensity of the LED illumination source radiation system satisfies the relationship: omega (omega) 4 pi sin²(ω) a unit sphericity sr, wherein,

ω＝arctan((PXiris²+PYiris²)^1/2/2*PSiris/((1+β)*EFLiris))

EFLiris is the position of the focal length,

and R is the working radius of the iris zoom focusing optical imaging system.

6. The apparatus of claim 1, wherein the LED illumination source radiation system and iris focus focusing optical imaging system are configured to:

speed is the speed of movement, in m/s,

PR is the iris physical diameter image-space resolution,

Eiris (ω) is the irradiance on the iris surface.

7. A method of remote large field of view iris optical imaging, said method comprising:

8. The method of claim 7, wherein feedback controlling an iris imaging tracking system comprises:

EFLface＝[(PXface²+PYface²)^1/2*PSface/2]/tan(FOVface/2)

PSface is the pixel unit resolution of the 3D depth imaging unit;

the EFLface is an effective imaging focal length of the 3D depth imaging unit.

a2, defining 3D depth imaging unit to control and acquire key points of iris:

z＝[Iz(xl，yl)+lz(xr，yr)]/2

or

z＝Iz((xl+xr)/2，(yl+yr)/2)；

a24, generating a 3D depth imaging unit image side key reference point,

KPface(xe,ye,z):KPface(xe,ye,z)＝KPface((xl+xr-PXface)/2*PS face，(yl+yr-PYface)/2*PSface,z)；

KPface(Xe,Ye,Ze)＝KPface(xe*z/EFLface，ye*z/EFLface,z)。

9. The method of claim 7, wherein feedback controlling the iris zoom focus optical imaging system comprises:

the focal position EFLiris (R) β/(1+ β) R (X)²+Y²+Z²)^1/2，

r is the working radius of the iris zooming focusing optical imaging system;

the FOCUS position FOCUS β x R-kdef, R + kdef,

10. The method of claim 7, wherein the feedback-controlled LED illumination source radiation system comprises:

ω＝arctan((PXiris²+PYiris²)^1/2/2*PSiris/((1+β)*EFLiris))

EFLiris is the position of the focal length,

and R is the working radius of the iris zoom focusing optical imaging system.