CN114430481B

CN114430481B - Iris zooming focusing optical imaging system for iris optical imaging device

Info

Publication number: CN114430481B
Application number: CN202111532984.4A
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: 2019-11-21
Filing date: 2020-04-18
Publication date: 2023-07-11
Anticipated expiration: 2040-04-18
Also published as: CN111447430B; CN114430481A; CN114500976A; CN114500976B; CN114302126A; CN111556306B; CN114302126B; CN114442312A; CN111556306A; CN111447430A

Abstract

The invention provides an iris zooming and focusing optical imaging system for a long-distance large-view-field iris optical imaging device, which is characterized by comprising the following components: the system comprises an optical zoom focusing lens group, an optical filter and an image imaging sensor, wherein the optical zoom focusing lens group is used for synchronously executing focal length and focusing position adjustment of iris imaging, the optical filter is used for filtering visible light to improve interference of an iris zoom focusing optical imaging system on stray light of external non-imaging wavelength, and improve signal-to-noise ratio SNR of imaging quality.

Description

Iris zooming focusing optical imaging system for iris optical imaging device

The application is a divisional application of 'a device and a method for long-distance large-field iris optical imaging' with application number 202010308691.7, wherein the application number is 18, 4 and 2020.

Technical Field

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

Background

Known iris imaging devices suffer from the disadvantage that the imaging time to obtain images at long working distances and large working field of view scenes exceeds 1-3s, and the user cannot remain consistently relatively stationary for such long periods of time due to the large magnification requirement of the image iris diameter requirement >200pixel, resulting in even very slight movements that can result in the need to readjust the field of view, zoom focus, illumination beyond that of the iris imaging system.

In addition, the traditional distance measurement comprises software mapping of iris diameters or binocular distances, because the error is too large to provide accurate working distance information due to the fact that the variation difference in the crowd is larger than 20%, the overall performance is directly affected, the error is too large to provide accurate working distance information under the conditions of long working distance and large working view field, meanwhile, the known technology has the depth of field, image brightness, image relative illuminance, illumination source radiation intensity, image quality such as the eye iris radiated illuminance and the like can not guarantee consistency under the conditions of long working distance and large working view field, even the difference is several times, the traditional illumination source adopts the condition that the square inverse ratio of the working distance changes, the radiation intensity of a non-constant light source (such as the working distance is 2-3 times, the view field angle changes by 2-3 times and the radiation intensity changes by 4-9 times), and the requirement that the view field angle and the radiation illuminance are constant under a large range can not be met at the same time.

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

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 comprises a 3D depth imaging unit for performing 3D physical space point coordinate acquisition,

and a direction axis rotation unit for performing object-side imaging region adjustment of the iris-zoom-focus optical imaging system according to the 3D physical space point coordinates;

the iris zooming and focusing optical imaging system comprises an optical zooming and 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 combination control of matching relations between the field angles of the iris zooming 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 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 illumination light source radiation system and the image display feedback system, and realizes driving and feedback control among all system units.

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

Preferably, the direction axis rotation 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 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 and 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 and focusing optical imaging system, and R is the working radius of the iris zooming and focusing optical imaging system.

Preferably, the solid angle of radiation intensity of the LED illumination light source radiation system satisfies the relationship: Ω (ω) =4pi×sin ² (ω) unit sphericity sr, wherein,

ω＝arctan((PXiris ² +PYiris ² ) ^1/2 /2*PSiris/((1+β)*EFLiris))

＝arctan((PXiris ² +PYiris ² ) ^1/2 psiris/(beta R)), ω is the half field angle of the iris zoom focusing optical imaging system,

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

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

EFLiris is the focal length position and,

p=pr PSiris, PR is the iris physical diameter image space resolution,

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

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

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

a combined imaging mode of global pixel exposure (integration) and illumination radiation in either an off-or on-sync triggering mode with a combination of filters, wherein:

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

speed is the speed of movement of a predetermined control, in m/s,

PR is the iris physical diameter image space resolution,

m is the pixel scale of a motion blur image controlled in advance, and the unit pixel;

the combined imaging mode synchronous pulse exposure (integration) frequency and synchronous pulse illumination radiation frequency Fpulse, the synchronous pulse illumination radiation frequency fpulse= [10, 30] hz,

the LED illumination source radiation system generates radiation illuminance Tpulse Eiris (omega) of synchronous pulse illumination radiation on the iris surface <10mw/cm ² ，

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

Another aspect of the present invention is to provide a method of remote large field of view iris optical imaging, the method comprising:

the image processing and driving control system executes driving and feedback control processes among an iris optical tracking system, an iris zooming focusing optical imaging system, an LED illumination light source radiation system and an 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, the relative coordinates are converted into 3D physical space points, and the angle of the direction axis rotating unit is adjusted in a feedback mode, so that real-time synchronous iris optical imaging tracking is achieved;

b. the iris zooming focusing optical imaging system is controlled in a feedback mode, and feedback control of the focal length and the focusing position of the optical zooming focusing lens group is achieved in real time according to the 3D physical space point coordinates;

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

d. The feedback control image display feedback system displays the current image and/or state information in real time;

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

Preferably, the feedback control iris imaging tracking system comprises:

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

EFLface＝[(PXface ² +PYface ² ) ^1/2 *PSface/2]/tan(FOVface/2)

pxface is the X horizontal pixel resolution of the 3D depth imaging unit;

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

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

fovvace is the field angle of the 3D depth imaging unit, fovvace = FOV;

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

a2, defining a 3D depth imaging unit to control and 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 area in the brightness image Ii (x, y), and further positioning left and right eye center coordinates (xl, yl) and (xr, yr) in the face area;

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

z＝[Iz(xl，yl)+lz(xr，yr)]/2

or (b)

z＝Iz((xl+xr)/2，(yl+yr)/2)；

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

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 side of the 3D depth imaging unit, wherein KPface (Xe, ye, ze) =KPface (Xe x z/EFLface, ye x z/EFLface, z).

a3, establishing the coordinate transformation of the object side key reference point coordinate KPface (Xe, xe, ze) of the 3D depth imaging unit relative to the 3D physical space point Piris (X, Y, Z) of the iris zooming focusing optical imaging system, piris (X, Y, Z) = (Xe-XOffset, xe-Yoffset, ze-Zoffset),

(Xoffset, yoffset, zoffset) is the 3D physical position coordinate offset of the 3D depth imaging unit relative to the iris-zoom-focus optical imaging system.

a4, executing synchronous control of the direction axis rotating unit, comprising:

a rotation angle θv=arcsin (X/R) of the vertical direction rotation shaft is performed,

performing a rotation angle θh=arcsin (Y/R) of the horizontal direction rotation shaft;

R＝(X ² +Y ² +Z ² ) ^1/2

alternatively, performing the directional axis rotation unit asynchronous control includes:

a rotation angle θv=arctan (X/Z) of the vertical direction rotation shaft is performed,

an equivalent to the above-mentioned one,

Executing a rotation angle θh=arctan (Y/Z) of the horizontal direction rotation shaft

The rotation angle θv=arcsin (X/R) of the vertical direction rotation shaft is performed.

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

b1, executing zoom focusing parameter synchronous control of an iris zoom focusing optical imaging system;

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

focal length position efliris=r×β/(1+β) r= (X) ² +Y ² +Z ² ) ^1/2 ，

Where, β=pr×psiris, PR is the iris physical diameter image space resolution,

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

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

b2, executing focusing parameter control on the iris zooming focusing optical imaging system to realize that the focusing position is in the field depth range of the image space,

focal position FOCUS=β [ R-kDOF, R+kDOF ],

wherein, k steps control range, dof=2×fno×soc×1+β/β ² Wherein FNO is aperture parameter of iris zooming focusing optical imaging system,

SOC is the smallest physical spot resolution parameter for an iris-zoom focused optical imaging system.

Preferably, the feedback control LED illumination source radiation system comprises:

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

the LED illumination source radiation direction angle ψ = 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 and 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 and focusing optical imaging system, and R is the working radius of the iris zooming and focusing optical imaging system;

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

solid angle omega (omega) =4pi×sin of radiation intensity of LED illumination light source ² (ω) unit sphericity sr, wherein,

ω＝arctan((PXiris ² +PYiris ² ) ^1/2 /2*PSiris/((1+β)*EFLiris))＝arctan((PXiris ² +PYiris ² ) ^1/2 PSiris/(beta. R)), omega is iris zoom focusing opticsThe half field angle of the image system,

EFLiris is the focal length position and,

p=pr PSiris, PR is the iris physical diameter image space resolution,

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

The device and the method for long-distance large-view-field iris optical imaging provided by the invention have the advantages that the constant view angle and the constant radiation illuminance in a large range are realized, and the device and the method have the following advantages:

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

2. The imaging speed is within 0.1s in response to the field of view and the working distance and depth of field.

3. A constant depth of field for imaging.

4. Constant imaging image brightness.

5. Constant imaging image relative illuminance.

6. A constant LED illumination source system radiates the total light power.

7. The iris of the eye is constantly irradiated with illumination and meets the eye biosafety radiation upper limit.

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

9. The working distance is more than 1m, and the field of view range is more 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, functions and advantages of the present invention will be clarified by the following description of embodiments of the present 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 invention.

Fig. 2 schematically illustrates a schematic diagram of an apparatus for remote large field of view iris optical imaging in accordance with another embodiment of the invention.

Reference numerals:

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

110 The 3D depth imaging unit is an infrared VCSEL light source,

111. a depth imaging unit, an infrared imaging lens and an image imaging sensor,

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

113. the horizontal rotation axis of the iris optical tracking system,

114. a visible light RGB image-forming unit,

115 The field angle of the 3D depth imaging unit is a predetermined working field angle fovfarm,

116. a predetermined proximal working radius Rnear,

117. a predetermined near-end 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 the iris zoom-focus optical imaging system,

121. an optical filter of an iris zoom focusing optical imaging system,

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

123. the window is protected and the window is protected,

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

125. The far end working radius of the iris zoom focusing optical imaging system/the field angle FOViris-far of the distance Rfar/Zfar,

126. the near-end working radius/distance Rnear/Znear of the iris zoom focusing optical imaging system,

127. the far-end working radius/distance Rfar/Zfar object plane imaging region of the iris zoom focusing optical imaging system,

130L/130R at the distal working radius/distance Rfar/Zfar,

131L/131R at the proximal working radius/distance Rnear/Znear,

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

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

134L/134R at a proximal working radius/distance Rnear/Znear, the left/right side illumination source radiation intensity direction angle of the LED illumination source radiation system matches the proximal working radius/distance Rnear/Znear of the iris zoom focus optical imaging system,

135L/135R at the distal working radius/distance Rfar/Zfar, the left/right side illumination source radiation intensity direction angle of the LED illumination source radiation system matches the distal working radius/distance Rfar/Zfar of the iris zoom focus optical imaging system,

150. an image processing and driving control system,

160. an image display feedback system.

200. A long-distance large-field iris optical imaging device,

210 The 3D depth imaging unit is an infrared VCSEL light source,

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

214. a visible light RGB image-forming unit,

215 The field angle of the 3D depth imaging unit is a predetermined working field angle fovfarm,

216. a predetermined proximal working radius Rnear,

217. a predetermined near-end working distance Znear,

218. a predetermined distal working radius Rfar,

219. a predetermined distal working distance Zfar,

228. a 2-axis MEMS rotary mirror unit of the iris optical tracking system,

220. a zoom-focus imaging lens group of the iris zoom-focus optical imaging system,

221. an optical filter of an iris zoom focusing optical imaging system,

222. an image imaging sensor of the iris zoom focusing optical imaging system,

223. the window is protected and the window is protected,

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

225. The far end working radius of the iris zoom focusing optical imaging system/the field angle FOViris-far of the distance Rfar/Zfar,

226. the near-end working radius/distance Rnear/Znear of the iris zoom focusing optical imaging system,

227. the far-end working radius/distance Rfar/Zfar object plane imaging region of the iris zoom focusing optical imaging system,

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

232L/232R at the distal 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 matches the field angle fovir-far of the distal working radius/distance Rfar/Zfar of the iris zoom focus optical imaging system,

233L/233R at the proximal working radius/distance Rnear/Znear, the radiation intensity solid angle of the left/right side illumination light source of the LED illumination light source radiation system matches the field angle FOViris-near of the proximal working radius/distance Rnear/Znear of the iris zoom focus optical imaging system,

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

235L/235R, the left/right side illumination source radiation intensity direction angle of the LED illumination source radiation system at the distal working radius/distance Rfar/Zfar, matches the distal working radius/distance Rfar/Zfar of the iris zoom focus optical imaging system,

236L/236R LED illumination source radiation system,

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

250. an image processing and driving control system,

260. an image display feedback system.

Detailed Description

The objects and functions of the present invention and methods for achieving these objects and functions will be elucidated by referring to exemplary embodiments. However, the present invention is not limited to the exemplary embodiments disclosed below; this may be implemented in different forms. The essence of the description is merely to aid one skilled in the relevant art in comprehensively understanding 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 represent the same or similar components, or the same or similar steps.

Embodiment one:

the schematic diagram of the apparatus for remote large field iris optical imaging in one embodiment of the present invention shown in fig. 1, an apparatus 100 for remote large field iris optical imaging in this embodiment of the present invention includes: an iris optical tracking system, an iris zoom focusing 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 and a 2-direction axis rotating unit: a vertical rotation axis 112 of the iris optical tracking system and a horizontal 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 stereoscopic imaging (LED illumination light source, fixed spaced-apart 2 sets of parametrically symmetric imaging lens and image imaging sensor).

The iris-zoom-focus optical imaging system includes an optical zoom-focus lens group 120, an optical filter 121, and an image-forming sensor 122.

The LED illumination source radiation system comprises LED illumination source radiation intensity solid angle and/or radiation intensity direction angle combination control.

The image display feedback system 160 includes a display screen for displaying current images 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 zooming focusing optical imaging system, the LED illumination light source radiation system and the image display feedback system, and realizes driving and feedback control among the system units.

According to the embodiment of the invention, a method for long-distance large-field iris optical imaging comprises the following steps:

the image processing and driving control system performs driving and feedback control procedures between the system units as follows:

a. and the iris imaging tracking system is controlled by feedback, 3D coordinates of key points of the iris are obtained through the 3D depth imaging unit, the relative coordinates are converted into 3D physical space points, the angle of the 2-axis rotating unit is controlled by feedback, and real-time synchronous iris optical imaging tracking is realized.

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

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

d. Feedback control image display the feedback system displays the current image and/or status information in real time.

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

According to an embodiment of the invention, the specific steps include:

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

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

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

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

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

fovvace is the field angle of the 3D depth imaging unit, fovvace = FOV;

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

Typical parameters are calculated as follows:

pxface=640 pixels, pyface=480 pixels, psface=5.6 um/pixel, fovface=fov=77 degrees, eflface=2.8 mm.

and a2, defining a 3D depth imaging unit to control and 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 brightness image Ii (x, y), and further locating left and right eye center coordinates (xl, yl) and (xr, yr) in the face region.

The known convolutional neural network CNN cascade model based on deep learning can reliably and accurately realize the functions of face region detection and human eye positioning.

In particular, in order to improve the performance of detecting and positioning eyes, the embodiment adopts an independent or combined visible light RGB image imaging unit 114, performs calibration registration of the 3D depth imaging unit and the visible light RGB image imaging unit 114 in advance, and then further detects the face area and the positioning of eyes in the RGB image to improve the accuracy and reliability. In addition, the RGB imaging unit can be used for detecting that the face triggers the system to enter a normal working state when the device is in a standby state, so that the standby power consumption of the system is reduced. Further, the imaging image of 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)。

In particular, in order to improve the accuracy and reliability of distance information measurement, the embodiment adopts effective pixels in the local area for extracting the center coordinates of the left and right eyes to filter the interference pixels, such as median filtering, or filtering the pixels with too high brightness or too low brightness in the gray brightness image, or the pixels with too far distance or too near distance in the depth distance image, and the like.

a24, generating key reference points KPface (xe, ye, z) of the image side of the 3D depth imaging unit, wherein KPface (xe, ye, z) =KPface ((xl+xr-PXface)/2 x PSface, (yl+yr-PYface)/2 x PSface, z).

a3, establishing coordinate transformation of object side key reference point coordinates KPface (Xe, xe, ze) of the 3D depth imaging unit relative to 3D physical space points Piris (X, Y, Z) of the iris zooming focusing optical imaging system,

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

where (Xoffset, yoffset, zoffset) is the 3D physical position coordinate offset of the 3D depth imaging unit relative to the iris-zoom-focus optical imaging system.

R＝(X ² +Y ² +Z ² ) ^1/2

an equivalent to the above-mentioned one,

In the embodiment of the present invention, the synchronization control of the direction axis rotation unit is performed, and the synchronization can be achieved by adopting the angular rotation speed ratio K of the vertical/horizontal direction rotation axis, k=θv/θh.

In the specific embodiment of the invention, the asynchronous control of the direction axis rotating unit is implemented, and the asynchronization can be realized by adopting the sequential time sequence of the angle rotation of the vertical/horizontal direction rotating shafts, such as the rotation angle thetav of the vertical direction rotating shaft and then the rotation angle thetah of the horizontal direction rotating shaft; or equivalently, the rotation angle θh of the rotation shaft in the horizontal direction and then the rotation angle θv of the rotation shaft in the vertical direction are first performed.

In particular, as a simplification, when Xoffset < < X, yoffset < < Y, zoffset < < Z, that is, the 3D physical position coordinate shift of the 3D depth imaging unit with respect to the iris zoom focus optical imaging system is ignored, the rotation angle of the vertical/horizontal direction rotation axis is approximately irrelevant to Z.

Still further preferably, the 3D depth imaging unit and the iris optical tracking system are integrated to maintain synchronous rotation control, providing an ideal accuracy feedback measurement when the iris optical tracking system adjusts the 2-axis rotation angle by comparing the rotated expected object side key reference points KP (Xp, yp, zp):

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

or an equivalent thereof,

KP((Xe ² +Ze ² ) ^1/2 *sin(θv-arctan(Xe/Ze))，(Ye ² +Ze ² ) ^1/2 *sin(θh-arctan(Ye/Ze))，(Xe ² +Ye ² +Ze ² ) ^1/2 )，θv＝X/Z，θh＝Y/Z。

and (3) repeating the step a3 to establish 3D physical space point Piris (X, Y, Z) coordinate transformation according to the actual object side key reference point KPface (Xe, ye, ze) if the actual object side key reference point KPface (Xe, ye, ze) output by the 3D depth imaging unit after the iterative step a1-a2 is judged whether to be in a preset error range of the system, if the error range is exceeded, the step a4 is fed back to control the step a4, and the rotation angle is readjusted. Further, the 3D depth imaging unit and the iris tracking system are integrated to maintain synchronous rotation control, and a working view angle of 360 degrees is expanded.

Performing zoom focus parameter synchronization control of an iris zoom focus optical imaging system, comprising:

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

Focal length position efliris=r×β/(1+β) r= (X) ² +Y ² +Z ² ) ^1/2

Where β=pr is the pixel unit resolution um/pixel of the image imaging sensor of the PSiris iris zoom focusing optical imaging system, such as typical 3um/pixel, and β=0.06, where β=pr is the iris physical diameter image space resolution pixel/mm, such as typical 20 pixels/mm.

R is shown in fig. 1 as 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 near working distance Znear117 and a predetermined far working distance Zfar119.

As typical parameters proximal working radius rnear=1m, distal working radius rfar=2m, efliris=56.6 mm and 113.2mm, respectively.

In consideration of the fact that the 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. If the same focal length is kept in the range of 5-10cm, the design is reasonable, and the iris diameter itself is different from person to person.

focal position FOCUS=β [ R-kDOF, R+kDOF ]

Wherein, k steps control the range, k= [1,2]STEP size is step=β DOF, e.g. k=2, including-2 STEP, -STEP,0, +step,2STEP total 5 ranges, dof=2×fno×soc (1+β)/β ² Wherein FNO is aperture parameter of iris zooming focusing optical imaging system, parameter range [ PF,2PF]Pf=psiris/(1 um/pixel); SOC is a minimum physical spot resolution parameter of the iris zoom focusing optical imaging system, and a typical value of the parameter is soc=2×psiris×1pixel, and the maximum dof=21.2 mm.

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

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

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

Meanwhile, the device does not have any mechanical transmission part driven by the traditional screw or gear connection, has no service life limitation, and has substantial improvement on control precision and repeatability.

In practice, the present liquid lens has a limited clear aperture, typically 6-10mm, and a limited refractive range of-10 to +20 diopters, and the wavefront error increases to lambda/10 at large diopters, but due to the depth of field versus FNO value, the long focal length application requirements are suitable for iris-zoom-focus optical imaging systems. The optical designer can solve the problem by optimizing the design of the optical path by utilizing the characteristic skill of the liquid lens, such as selecting a proper exit pupil in the optical path to design FNO to solve the clear aperture, the initial design of the optical system of the zooming part adopts the setting of the maximum focal length of the zooming liquid lens when working at the far-end working radius/distance at the optical power of 0 diopter, and the initial design of the optical system of the focusing part adopts the setting of the image surface position of the focusing liquid lens when working at the far-end working radius/distance at the optical power of 0 diopter.

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

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

LED illumination source radiation direction angle ψ=arctan (D/R)

Equivalent definition, included angles phi 'between a central line corresponding to the radiation intensity peak direction of the LED illumination light source radiation system and an object plane of the iris zoom focusing optical imaging system are phi=90-phi'.

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

Solid angle omega (omega) =4pi×sin of radiation intensity of LED illumination light source ² (omega) unit sphericity sr

ω＝arctan((PXiris ² +PYiris ² ) ^1/2 /2*PSiris/((1+β)*EFLiris))

＝arctan((PXiris ² +PYiris ² ) ^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 pixel resolution, pixel, of the iris-zoom-focus optical imaging system.

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

Since real physical optics such as convex lenses and or concave reflectors cannot produce a uniform light field distribution of light energy (light power) respectively, i.e. a unit step function distribution, with equal density at a given solid angle Ω (ω) of the radiation intensity of the LED illumination source, a specific function distribution is provided.

Wherein:

i (omega) is the radiation intensity of the LED illumination light source radiation system, and the unit is mw/sr

I(Ω)＝Ipeak*f(Ω)。

Omega is the solid angle of the LED illumination light source radiation system, and the unit sr sphericity.

Ipak is the peak radiation intensity of the LED illumination source radiation system, in mW/sr.

f (omega) is the radiation intensity normalized distribution function of the LED illumination light source radiation system.

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

From the deduction that f (Ω (ω))=i (Ω (ω))/Ipeak,

therefore, when the radiation intensity solid angle Ω (ω) of the LED illumination light source radiation system, the LED illumination light source radiation system has the radiation intensity I (Ω (ω))=ipeak×f (Ω (ω)), the closer f (Ω (ω)) to 1, the more the unit step function distribution characteristic is exhibited.

Defining ρ=i ρ/ipeak=i (Ω (ω))/ipeak=f (Ω (ω)), ρ being the relative illuminance of the light radiation received by the imaging image plane of the predetermined custom iris focus optical imaging system, e.g. 0.5 or 0.707, higher meaning a more uniform relative illuminance distribution.

Essentially the solid angle of the radiant intensity of the LED illumination source produces the irradiance Eiris on the iris surface,

Eiris(ω，ψ)＝OP/(Ω(ω)*R ² )*cos ³ (ψ)＝Ipeak/R ² *cos ³ (ψ)。

satisfying sin when ω is small enough ² (ω)＝tan ² (ω)。

As shown in FIG. 1, the field angle FOViris-near124 of the near working radius/distance Rnear/Znear of the iris zoom focusing optical imaging system. The field angle FOViris-far125 of the iris zoom focusing optical imaging system distal working radius/distance Rfar/Zfar. The iris zoom focuses on an object plane imaging region 126 of the optical imaging system's proximal working radius/distance Rnear/Znear. The iris zoom focuses on the object plane imaging region 127 of the optical imaging system's distal working radius/distance Rfar/Zfar. The LED illumination sources radiate left and right side LED illumination sources 130L/130R of the system at a distal working radius/distance Rfar/Zfar. The LED illumination sources radiate left and right side LED illumination sources 131L/131R of the system at a near working radius/distance Rnear/Znear. The solid angle of radiation intensity of the left/right side illumination light source of the LED illumination light source radiation system at the far-end working radius/distance Rfar/Zfar is matched with the far-end working radius/distance Rfar/Zfar's field angle FOViris-far132L/132R of the iris zoom focusing optical imaging system. The radiation intensity solid angle of the left/right side illumination light source of the LED illumination light source radiation system at the near-end working radius/distance Rnear/Znear is matched with the field angle FOViris-near133L/133R at the near-end 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 Rnear/Znear matches the near-end working radius/distance Rnear/Znear134L/134R 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 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 the irradiation intensity of the iris surface is changed by changing the irradiation intensity of the light distributed by the solid angle of the irradiation intensity of the LED illumination light source in an equivalent way for the LED illumination light source irradiation system with constant total light power basically, no matter how the working radius [ Rfar, rnear ]/distance [ Zfar, znear ] and the corresponding field angle [ FOViris-far, FOViris-near ] of the iris zoom focusing optical imaging system are changed at the far end/near end, the working radius/distance and the field angle of the corresponding iris optical zoom focusing optical imaging system can be completely matched according to the formula Eiris (omega, phi).

It can be demonstrated that the illuminance Eimage of light is received for an imaging image plane having an iris zoom focus optical imaging system.

According to the formula Eimage (ω, ψ) =t 1/8/(1+β) ² *cos ⁴ (Φ)*μ*Eiris(ω，ψ)/FNO ² ，

Satisfying cos when ω is small enough ⁴ (Φ) =1, Φ is the imaging incidence angle of the iris zoom focusing optical imaging system, Φ= [0, ω]，

Mu is the optical constant coefficient of the reflectivity of the iris biological tissue, 0.12 to 0.15,

and t is a transmittance constant coefficient of the iris zooming focusing optical imaging system.

Eimage is constant, i.e., the imaged image brightness limage is constant.

limage＝QE*Tpulse*Eimage*ADC*G*S

QE is the photon-electron quantum conversion efficiency unit e-/(mw um) ² ) S, G is unit conversion gain unit mv/e-, ADC is analog voltage/digital brightness conversion unit LSB/mv, S is unit pixel area unit um ² 。

At present, the traditional CMOS SENSOR technology performs photon-electron quantum conversion, namely the PD silicon-based photodiode has the advantages of non-ideal efficiency, a front QF quantum film or an OPF organic photosensitive film and the like, and has the characteristics of natural high quantum conversion efficiency to infrared photons and global shutter which are ideal and optimal.

It can also be demonstrated that the relative illuminance ρ of the light radiation received by the imaging image plane of the iris-zoom focusing optical imaging system is constant, ρ=eidge/eclter=i ρ/Ipeak, eidge is the radiated illuminance at the edge of the imaging image plane (field of view edge) =eimage (ω, ψ), eclter is the radiated illuminance at the center of the imaging image plane (field of view center), and eclter=eimage (ω, ψ) is the relative illuminance at which the imaging image brightness is constant.

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

The invention responds to the corresponding solid angle of the LED illumination source radiation intensity in the corresponding field angle range [ FOViris-far, FOViris-near ], the working radius range [ Rfar, rnear ], or the working distance range [ Zfar, znfar ] by realizing the weight value redistribution of the LED illumination source radiation system for the constant total light power.

∑OPi＝OP

OPi＝Wi*OP，∑Wi＝1

OPi is the optical power of the LED illumination light source radiation system with different radiation direction angles and radiation intensity solid angles, and Wi is the weight value of the corresponding OPi.

i is the number of LED illumination source radiation systems having different radiation direction angles and radiation intensity solid angles.

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

The invention achieves a constant total radiated illuminance Eiris on the iris surface after combined control of the optical powers of the LED illumination source radiation systems having different radiation direction angles and radiation intensity solid angles.

∑Ei＝Eiris

Ei＝Wi*Eiris，∑Wi＝1

Ei is the irradiance produced on the iris surface by the optical power OPi of the LED illumination source radiation system having different radiation direction angles and radiation intensity solid angles.

According to a specific embodiment of the present invention, the combined control of the corresponding LED illumination source radiation intensity solid angle and the constant total optical power OP when the optical power OPfar and OPnear allocation of the LED illumination source radiation system at i=2, i.e. at different radiation direction angles and radiation intensity solid angles of the distal working radius Rfar and the proximal working radius Rnear, achieves any given working radius R is exemplified.

Op1+op2=op or opfar+opnear=op, opfar=wfar=wpop, opnear=wnear=op.

OP is defined as the constant total optical power of the LED illumination source radiation system corresponding to the working radius R.

OPfar is defined as the optical power of the LED illumination source radiation system corresponding to the distal working radius Rfar.

Wfar is the weight value of the corresponding OPfar.

OPnear is defined as the optical power of the proximal LED illumination source radiation system corresponding to the proximal working radius Rnear.

Wnear is the weight value of the corresponding OPnear.

Under the condition of wfar+wnear=1, the following deductions are made according to the above formula:

Wfar＝[cos ³ (ψR)*R ² -cos ³ (ψnear)*Rnear ² ]/[cos ³ (ψfar)*Rfar ² -cos ³ (ψnear)*Rnear ² ]。

Wnear]＝[cos ³ (ψfar)*Rfar ² -cos ³ (ψR)*R ² ]/[cos ³ (ψfar)*Rfar ² -cos ³ (ψhear)*Rnear ² ]。

wherein, psi R is the radiation direction angle of the R working radius LED illumination light source radiation system.

Wherein, psi far is the radiation direction angle of the far-end LED illumination light source radiation system.

Wherein ψnear is the radiation direction angle of the proximal LED illumination source radiation system.

In particular, at cos ³ (ψfar)/cos ³ (ψR) =1 and cos ³ (ψhear)/cos ³ Under the simplified condition of (ψr) =1, the above formula is simplified to

Wfar＝[R ² -Rnear ² ]/[Rfar ² -Rnear ² ]

Wnear＝[Rfar ² -R ² ]/[Rfar ² -Rnear ² ]。

The optical powers OPfar and OPnear of the LED illumination light source radiation system, which are used for distributing the weight value ratios Wfar and Wnear at different radiation direction angles and radiation intensity solid angles of the far-end working radius Rfar and the near-end working radius Rnear, are combined to realize the corresponding LED illumination light source radiation intensity solid angle and constant total light power when any given working radius R.

According to a specific embodiment of the present invention, the i=2 embodiment, that is, the combination control of the corresponding LED illumination source radiation intensity solid angle and the constant total optical power OP when the optical powers OPfar and OPnear of the LED illumination source radiation system at different radiation direction angles and radiation intensity solid angles of the distal working radius Rfar and the proximal working radius Rnear are allocated to realize any given working radius R is also exemplified.

Meanwhile, adding boundary conditions of a radiation intensity normalization distribution function of the LED illumination light source radiation system:

f(Ω)-°β*OPfar+f(Ω)near*OPnear＝f(Ω)R*OP

OPfar+OPnear＝OP，

OPfar＝Wfar*OP，OPnear＝Wnear**OP

OP is defined as the constant total optical power of the LED illumination source radiation system corresponding to the working radius R, and f (Ω) R is the radiation intensity normalized distribution function corresponding to OP.

Wfar is the weight value of the corresponding OPfar, and f (Ω) far is the radiation intensity normalized distribution function of the corresponding OPfar.

Wnear is the weight value of the corresponding OPnear, and f (Ω) near is the corresponding OPnear radiation intensity normalized distribution function.

Wfar＝[cos ³ (ψR)*f(Ω)R*R ² -cos ³ (ψnear)*f(Ω)near*Rnear ² ]/[cos ³ (ψfar)*f(Ω)far*Rfar ² -cos ³ (ψnear)*f(Ω)near*Rnear ² ]。

Wnear＝[cos ³ (ψfar)*f(Ω)far*Rfar ² -cos ³ (ψR)*f(Ω)R*R ² ]/[cos ³ (ψfar)*f(Ω)far*Rfar ² -cos ³ (ψnear)*f(Ω)near*Rnear ² ]。

in particular, under the condition Ω=Ω (ω), wfar+wnear=1, the following deductions are made according to the above formula:

Wfar＝[cos ³ (ψR)*f(Ω(ω))R*R ² -cos ³ (ψnear)*f(Ω(ω))near*Rnear ² ]/[cos ³ (ψfar)*f(Ω(ω))far*Rfar ² -cos ³ (ψnear)*f(Ω(ω))near*Rnear ² ]。

Wnear＝[cos ³ (ψfar)*f(Ω(ω))far*Rfar ² -cos ³ (ψR)*f(Ω(ω))R*R ² ]/[cos ³ (ψfar)*f(Ω(ω))far*Rfar ² -cos ³ (ψnear)*f(Ω(ω))near*Rnear ² ]。

wherein, psi R is the radiation direction angle of R working radius LED illumination light source radiation system.

Wherein, ψfar is the radiation direction angle of the far-end LED illumination light source radiation system.

Wherein, psi near is the radiation direction angle of the near-end LED illumination light source radiation system.

Wherein f (omega) R is a corresponding radiation intensity normalization distribution function value of the R working radius LED illumination light source radiation system when the omega radiation intensity solid angle is formed.

Wherein f (omega) far is a corresponding radiation intensity normalization distribution function value of the far-end working radius LED illumination light source radiation system when the omega radiation intensity solid angle is formed.

Wherein f (omega) near is a corresponding radiation intensity normalized distribution function value of the near-end working radius LED illumination light source radiation system at an omega radiation intensity solid angle.

In particular, at cos ³ (ψfar)/cos ³ (ψR) =1 and cos ³ (ψnear)/cos ³ Under the simplified condition of (ψr) =1, the above formula is simplified as:

Wfar＝[f(Ω(ω))R*R ² -f(Ω(ω))near*Rnear ² ]/[f(Ω(ω))far*Rfar ² -f(Ω(ω))near*Rnear ² ]。

Wnear＝[f(Ω(ω))far*Rfar ² -f(Ω(ω))R*R ² ]/[f(Ω(ω))far*Rfar ² -f(Ω(ω))near*Rnear ² ]。

The irradiation illuminance of the iris surface is changed by the same amount by combining the irradiation power of the LED illumination light source with the irradiation intensity solid angle combination control weight value reassigned in the field angle range of the iris zooming focusing optical imaging system corresponding to the far-end working radius/distance and the near-end working radius/distance, the irradiation illuminance is kept nearly constant according to a formula, and the field angle of the corresponding iris zooming focusing optical imaging system can be completely matched.

As an equivalent extension of the invention, the combined control of the optical powers of the radiation system with more LED illumination sources with different radiation direction angles and radiation intensity solid angles should be equally understood and equivalent.

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

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

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

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

The synchronous pulse exposure (integration) frequency and the synchronous pulse illumination radiation frequency fpulse= [10, 30] hz, and the LED illumination light source radiation system generates the radiation illuminance Tpulse Eiris (omega) <10mw/cm2 of synchronous pulse illumination radiation on the iris surface so as to ensure that the biological safety of eye radiation is met.

Furthermore, the iris zoom 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 filters, and can have anti-interference performance on various light interference conditions in an external uncontrolled environment. Such as up to 10,000 lux or more.

The protection window 123 can adopt full transmission toughened optical glass, or more preferably adopts a filter which reflects visible light below 700nm and transmits 700-900nm infrared light, so that the optical filter can protect an internal optical component, and meanwhile, a user can not observe that an internal structure provides a visual feedback effect for use in a natural state of the user through reflecting the visible light, and further, the interference of the iris zoom focusing optical imaging system on stray light of external non-imaging wavelength can be eliminated by filtering the visible light, and the signal-to-noise ratio SNR of imaging quality is further improved.

Embodiment two:

the schematic diagram of the apparatus for remote large field iris optical imaging in one embodiment of the invention shown in fig. 2, an apparatus 200 for remote large field iris optical imaging in the embodiment of the invention, includes: an iris optical tracking system, an iris zoom focusing optical imaging system, an LED illumination source radiation system, an image display feedback system 260, 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 stereoscopic imaging (LED illumination light source, fixed spaced-apart 2 sets of parametrically symmetric imaging lens and image imaging sensor).

The iris-zoom-focus optical imaging system includes an optical zoom-focus lens group 220, an optical filter 221, and an image-forming 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 driving and feedback control among system units.

According to an embodiment of the invention, the specific steps include:

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

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

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

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

fovvace is the field angle of the 3D depth imaging unit, fovvace = FOV;

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

Typical parameters are calculated as follows:

z= [ Iz (xl, yl) +lz (xr, yr) ]/2, or z=iz ((xl+xr)/2, (yl+yr)/2).

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

a4, performing rotation angle synchronization control of the 2-axis MEMS rotary mirror unit 228 to adjust the vertical/horizontal direction, comprising:

the rotation angle θv=arcsin (X/R)/2 of the vertical direction rotation shaft is performed,

performing a rotation angle θh=arcsin (Y/R)/2 of the horizontal direction rotation shaft;

R＝(X ² +Y ² +Z ² ) ^1/2

or alternatively, the process may be performed,

performing directional axis rotation unit asynchronous control, comprising:

a rotation angle θv=arctan (X/Z)/2 of the vertical direction rotation shaft is performed,

an equivalent to the above-mentioned one,

performing a rotation angle θh=arctan (Y/Z)/2 of the horizontal direction rotation shaft

The rotation angle θv=arcsin (X/R)/2 of the vertical direction rotation shaft is performed.

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-based MEMS brake device 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 adopting MEMS brakes in piezoelectric, electromagnetic, electrostatic, ultrasonic, thermoelectric modes and the like.

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

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

2. Operating frequency >10Hz full scale rotation,

3. the angular precision is <0.1 degrees,

4. the working mode is a point to point 2 axis static vector,

5. the response time is <50ms,

6. the operating voltage is 5vDC and,

7. mirror surface coating, namely, metal medium, gold/aluminum film or enhanced gold/aluminum film, the reflectivity of 700-900nm wavelength is more than 92%,

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

9. optical window, no or antireflection film protective window,

11. service life >100,000,000 full scale rotations,

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

Focal length position efliris=r×β/(1+β) r= (X) ² +Y ² +Z ² ) ^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 near working distance Znear217 and a predetermined far working distance Zfar219.

focal position FOCUS=β [ R-kDOF, R+kDOF ]

Wherein, k steps control the range, k= [1,2]STEP size is step=β DOF, e.g. k=2, including-2 STEP, -STEP,0, +step,2STEP total 5 ranges, dof=2×fno×soc (1+β)/β ² Wherein FNO is aperture parameter of iris zooming focusing optical imaging system, parameter range [ PF,2PF]Pf=psiris/(1 um/pixel); SOC is the minimum physical spot resolution parameter for an iris-zoom focused optical imaging system,typical values for parameters are soc=2×psiris×1pixel, maximum dof=21.2 mm.

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

LED illumination source radiation direction angle ψ=arctan (D/R)

ω＝arctan((PXiris ² +PYiris ² ) ^1/2 /2*PSiris/((1+β)*EFLiris))

＝arctan((PXiris ² +PYiris ² ) ^1/2 /2*PSiris/(β*R))

ω is the half field angle of the iris-zoom-focus optical imaging system.

Wherein:

I(Ω)＝Ipeak*f(Ω)。

From the deduction that f (Ω (ω))=i (Ω (ω))/Ipeak,

therefore, at the solid angle Ω (ω) of the radiation intensity of the LED illumination light source radiation system, the LED illumination light source radiation system has the radiation intensity I (Ω (ω))=ipeak×f (Ω (ω)).

Essentially, the solid angle of the radiation intensity of the LED illumination source generates the radiated illuminance Eiris, eiris (omega, phi) =OP/(omega) R on the iris surface ² )*cos ³ (ψ)＝Ipeak/R ² *cos ³ (ψ)。

Satisfying sin when ω is small enough ² (ω)＝tan ² (ω)。

As shown in FIG. 2, the field angle FOViris-near224 of the near working radius/distance Rnear/Znear of the iris zoom focusing optical imaging system. The field angle FOViris-far225 of the iris zoom focusing optical imaging system distal working radius/distance Rfar/Zfar. The iris zoom focuses on an object plane imaging region 226 of the optical imaging system's proximal working radius/distance Rnear/Znear. The iris zooms the object plane imaging region 227 of the focal length/distance Rfar/Zfar at the distal end of the optical imaging system. Left and right side LED illumination sources 230L/230R of the LED illumination source radiation system. The solid angle of radiation intensity of the left/right side illumination light source of the LED illumination light source radiation system at the far-end working radius/distance Rfar/Zfar is matched with the far-end working radius/distance Rfar/Zfar of the iris zoom focusing optical imaging system FOViris-far232L/232R. The radiation intensity solid angle of the left/right side illumination light source of the LED illumination light source radiation system at the near-end working radius/distance Rnear/Znear is matched with the field angle FOViris-near233L/233R at the near-end 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 Rnear/Znear matches the near-end working radius/distance Rnear/Znear234L/234R 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 far-end working radius/distance Rfar/Zfar matches the far-end working radius/distance Rfar/Zfar235L/235R of the iris zoom focusing optical imaging system. The LED illumination source irradiates the left/right side liquid lenses 236L/236R of the system. The left/right side 2-axis MEMS rotating mirror 237L/237R of the LED illumination source radiation system.

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

Iimage＝QE*Tpulse*Eimage*ADC*G*S

The embodiment is realized through the combination control of the liquid lens and the 2-axis MEMS rotary reflecting mirror by the LED illumination light source radiation system, and the matching of the field angle range [ FOViris-far, FOViris-near ], the working radius range [ Rfar, rnear ], or the working distance range [ Zfar, znear ] of the corresponding iris zoom focusing optical imaging system is realized.

The preferred solid angle of the radiation intensity of the LED illumination light source in the embodiment is realized by placing a liquid lens at the position of the emergent light path of the LED illumination light source to control diopter, namely refractive angle, and the solid angle of the radiation intensity of the illumination light source is changed by controlling the emergent light diopter through the liquid lens essentially to respond to the field angle of the iris zooming focusing optical imaging system corresponding to different working radiuses/distances. It is designed to realize the matching relation between the solid angle of the radiation intensity of the LED illumination light source and the field angle of the iris zooming focusing optical imaging system corresponding to different working radiuses/distances.

The radiation intensity direction angle of the LED illumination light source of the preferred embodiment is realized by synchronously controlling the rotation angle of the vertical/horizontal direction by arranging a 2-axis MEMS rotary reflector at the position of the emergent light path of the LED illumination light source, and the radiation intensity direction angle of the LED illumination light source is changed by basically controlling the rotation angle of the vertical/horizontal direction by the 2-axis MEMS rotary reflector, so that the radiation intensity direction angle of the LED illumination light source responds to the field angle of an iris zooming focusing optical imaging system corresponding to different working radiuses/distances. It is designed to realize the matching relation between the radiation intensity direction angle of the LED illumination light source and the field angle of the iris zooming focusing optical imaging system corresponding to different working radiuses/distances.

Specifically, the method for controlling the rotation angle of the vertical/horizontal direction of the 2-axis MEMS rotary reflector for controlling the radiation intensity direction angle of the LED illumination light source comprises the following steps:

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

a32, establishing coordinate transformation of object side key reference point coordinates KPface (Xe, xe, ze) of the 3D depth imaging unit relative to 3D physical space points 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, a 2-axis MEMS rotary mirror unit for performing radiation intensity direction angle control of an LED illumination light source adjusts the rotation angle synchronous control of the vertical/horizontal direction, comprising:

the rotation angle thetav=arcsin (X '/R')/2 of the vertical direction rotation shaft is performed,

performing a rotation angle θh=arcsin (Y '/R')/2 of the horizontal direction rotation shaft;

R'＝(X' ² +Y' ² +Z' ² ) ^1/2

or alternatively, the process may be performed,

performing directional axis rotation unit asynchronous control, comprising:

the rotation angle thetav=arctan (X '/Z')/2 of the vertical direction rotation shaft is performed,

an equivalent to the above-mentioned one,

The rotation angle θh=arctan (Y '/Z')/2 of the horizontal direction rotation shaft is performed

The rotation angle θv=arcsin (X '/R')/2 of the vertical direction rotation shaft is performed.

Specifically, the LED illumination light source radiation system of this embodiment is realized by controlling the combination of the liquid lens and the 2-axis MEMS rotating mirror, the light paths of the LED illumination light sources are sequential, the outgoing light paths sequentially pass through the liquid lens to control diopter, and then the 2-axis MEMS rotating mirror unit is used to adjust the rotation angle in the vertical/horizontal direction to realize synchronous control.

The protection window 223 may be made of fully transmissive toughened optical glass, or more preferably, an optical filter that reflects visible light below 700nm and transmits infrared light between 700nm and 900nm is used, which can protect the internal optical component, and the user can not observe that the internal structure provides the visual feedback effect of the natural state of the user through reflecting the visible light.

The invention provides a device and a method for long-distance large-view-field iris optical imaging, which can realize constant view angle and constant radiation illuminance in a large range.

The present invention is not limited to the exemplary embodiments disclosed below, and as an equivalent transformation or simplification of the embodiments of the present invention, for example, the use of a universal ball as the direction axis rotation should be equally understood, for example, the simplification of the 2-axis direction axis rotation to the single-axis direction axis rotation should be equally understood, and other functional substitutions including optical/mechanical/electronic elements should be equally understood.

Other embodiments of the invention will be apparent to and understood by 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 iris zoom focusing optical imaging system for a long-distance large-field iris optical imaging apparatus, the iris zoom focusing optical imaging system comprising: the optical zoom focusing lens group is used for synchronously executing focal length and focusing position adjustment of iris imaging, the optical filter is used for filtering visible light to enable the iris zoom focusing optical imaging system to eliminate interference on stray light of external non-imaging wavelength, and the signal-to-noise ratio SNR of imaging quality is improved;

The focal length parameter of the iris zooming focusing optical imaging system is controlled to realize the preset magnification of keeping the focal length position constant, namely the same imaging iris diameter,

focal length position efliris=r x beta/(1 + beta),

wherein: beta=pr x PSiris,

PR is the iris physical diameter image space resolution, in pixels/mm,

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

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

the focusing parameter control of the iris zooming focusing optical imaging system realizes that the focusing position is in the depth of field of the image space,

focal position FOCUS=β [ R-kDOF, R+kDOF ]

Wherein: k is the step number control range, k= [1,2];

DOF=2*FNO*SOC*(1+β)/β2，

wherein:

FNO is aperture parameter of iris zooming focusing optical imaging system,

SOC is the minimum physical spot resolution parameter of the iris zoom focusing optical imaging system, soc=2×psiris×1pixel

Generating 2k+1 times of step length control position through a parameter k, wherein the step length is beta DOF so as to ensure that the focusing position is in the object field depth range of + -DOF/2;

the iris zoom focus optical imaging system further comprises an LED illumination source radiation system for combined imaging mode configuration, the LED illumination source radiation system and the iris zoom focus optical imaging system configured to: a combined imaging mode of global pixel exposure and illumination radiation in either a simultaneous off-pulse or in-pulse triggering mode with the combination of filters,

Wherein:

the combined imaging mode synchronous pulse exposure time and synchronous pulse illumination radiation time Tpulse < m/(PR x speed),

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

PR is the iris physical diameter image space resolution,

m is a predetermined motion blurred image pixel scale, a unit pixel;

Tpulse*Fpulse*Eiris(ω)<10mw/cm2，

fpulse is the synchronous pulse exposure frequency and synchronous pulse illumination radiation frequency of the combined imaging modality,

eiris (ω) generates a irradiance of simultaneous pulsed illumination radiation at the iris surface for the LED illumination source radiation system.

2. Iris-zoom-focus optical imaging system according to claim 1, characterized in that the FNO ranges from [ PF,2PF ], pf=psiris/(1 um/pixel).

3. The iris-zoom-FOCUS optical imaging system according to claim 1, wherein the optical zoom-FOCUS lens group of the iris-zoom-FOCUS optical imaging system controls the focal length efliis and the FOCUS independently, respectively, by an aspherical optical glass/plastic hybrid 2-sheet liquid lens.

4. The iris zoom focusing optical imaging system according to claim 3, wherein the focal length and focal position of the optical zoom focusing lens group of the iris zoom focusing optical imaging system are converted into values of unit specification of diopter of 2 liquid lenses of the imaging optical system which are designed correspondingly, and the liquid lenses have linear response optical property relation of diopter and voltage/current correspondence.

5. The iris zoom focusing optical imaging system of claim 3, wherein the optical zoom focusing lens group of the iris zoom focusing optical imaging system selects an exit pupil in the optical path to design an FNO clear aperture, the zoom portion optical system is initially designed to set a maximum focal length for the zoom liquid lens to operate at a distal working radius/distance at 0 diopter optical power, and the focusing portion optical system is initially designed to set an image plane position for the focus liquid lens to operate at a distal working radius/distance at 0 diopter optical power.

6. The iris zoom focusing optical imaging system according to claim 1, wherein fpulse= [10, 30] hz.

7. The iris zoom focusing optical imaging system of claim 1, wherein m <10.