ANTI-BLUR INFRARED LENS FOR PANORAMIC CAMERA SYSTEM USING HD RESOLUTION SENSOR
20230168475 · 2023-06-01
Assignee
Inventors
- Van Dat Nguyen (Thai Binh Province, VN)
- Xuan Du Dang (Pho Yen Town, VN)
- Thanh Dat Vu (Ha Noi City, VA)
Cpc classification
G02B13/06
PHYSICS
G02B13/18
PHYSICS
International classification
G02B13/18
PHYSICS
Abstract
The disclosure refers to the anti-blur infrared lens for the panoramic camera system, also known as Infrared Search and Track (IRST), using a 1280×1024 resolution sensor with a working F-number of 2. The lens operates in the mid-infrared wavelength range of 3-5 μm, using a fast steering mirror (FSM) and a pair of lenses with extended polynomial surfaces to prevent image blur during integration time. The optical image captured by the lens always maintains sharpness during the change of rotation angle of the device by changing the angular position of FSM. The lens is capable of observing with wide angle-of-view and large rotation angle compensation ability, ensuring long detection distance.
Claims
1. An anti-blur infrared lens for panoramic camera system using HD resolution sensor with folding structure consists of ten main lenses and two reflectors, one of reflector is a fast steering mirror; in a direction from an object plane to an image plane, the lens consists of: lenses (L1), (L2), (L3), (L4), (L5), (L6) forming an outermost angular magnification lens group (G1); a fast steering mirror group (M1); lenses (L7), (L8) forming a converging lens group (G2); a fixed mirror group (M2); and lenses (L9), (L10) forming an intermediate image magnification lens group (G3).
2. The anti-blur infrared lens for panoramic camera system using HD resolution sensor, according to claim 1, wherein in the direction from the object plane to the image plane, the magnification group (G1) includes 6 single lens elements; in which: three lenses (L1),(L2),(L3) including two positive power lenses combined with negative power (L3) lens are responsible for receiving incident parallel light beams and focusing them at an intermediate image plane; a focal length of the optical part generated by these three lenses satisfies 200 mm>f(L1,L2,L3)>150 mm; the next three lenses of the magnification group (G1) are (L4), (L5), (L6) consisting of two positive power lenses (L4, L6) combined with one negative power lens (L5) to convert an intermediate image into parallel beams; a focal length of the optical part created by these three lenses satisfies 100 mm<f(L4,L5,L6)<150 mm; group (G1) has the effect of magnifying a focal length of the optical part created by groups (G2,G3) to a ratio (A), this magnification ratio satisfies 1.2≤f(L1,L2,L3)/f(L4,L5,L6)=A≤2.0.
3. The anti-blur infrared lens for panoramic camera system using HD resolution sensor, according to claim 1, wherein in the direction from the object plane to the image plane, the lenses (L3), (L4) are those with anti-blur effect when scanning; in which: lens (L3) is made of germanium with negative power, consisting of a concave surface (S5) with an aspherical profile and a convex surface (S6) with extended polynomial profile; lens (L4) is made of zinc selenide with negative power, consisting of a concave surface (S7) with an extended polynomial profile and a surface (S8) with a spherical profile with the convex face towards the image plane; surfaces of the lenses (L3), (L4) are optimized so that when the fast steering mirror group (M1) rotates, an image point position corresponding to each field of view remains the same, ensuring an overall spot size of the lens is always smaller than a pixel pitch when the mirror group rotates continuously.
4. The anti-blur infrared lens for panoramic camera system using HD resolution sensor, according to claim 1, wherein in the direction from the object plane to the image plane, using a fast steering mirror group (M1) located in an exit pupil position of the magnification group (G1) between the lenses (L6) and (L7); the anti-blur infrared lens for panoramic camera system using HD resolution sensor uses a fast steering mirror and is designed to satisfy a compensation of rotation angle and meets:
5. The anti-blur infrared lens for panoramic camera system using HD resolution sensor, according to claim 1, wherein in the direction from the object plane to the image plane, converging lens group (G2) consisting of two lenses positive focal lengths (L7), (L8) focus a light beam coming out of the group (G1) to create an intermediate image plane; single lens element (L8) which helps the lens have focus ability in different distance and temperature, is made of silicon, with positive power, and two curved surfaces of aspherical profile, the focus group helps the lens compensate the image sharpness at a distance from 20 m to infinity in a temperature range from −20° C. to 65° C.
6. The anti-blur infrared lens for panoramic camera system using HD resolution sensor, according to claim 1, wherein in the direction from the object plane to the image plane, the reflector (M2) is placed in between the lens elements (L8) and (L9) to create a double fold structure for the lens; a position of the arranged mirror is not on the intermediate image plane.
7. The anti-blur infrared lens for panoramic camera system using HD resolution sensor, according to claim 1, wherein intermediate image magnification group (G3) is designed to magnify an intermediate image created by the convergent lens group (G2); whereby the image magnification ratio is from 1.1 to 2.5, equivalent to 1.1≤|f(G1,G2,G3)/f(G1,G2)|≤2.5.
8. The anti-blur infrared lens for panoramic camera system using HD resolution sensor, according to claim 5, wherein intermediate image magnification group (G3) is designed to magnify an intermediate image created by the convergent lens group (G2); whereby the image magnification ratio is from 1.1 to 2.5, equivalent to 1.1≤|f(G1,G2,G3)/f(G1,G2)|≤2.5.
9. The anti-blur infrared lens for the panoramic camera system using the HD resolution sensor, according to claim 1, optimized so that an exit pupil with diameter D is located directly in front of the sensor with a distance d; whereby the ratio between distance d and diameter D has a value d/D<2, ensuring that the lens is compatible with F/#2 detectors.
10. The anti-blur infrared lens for panoramic camera system using HD resolution sensor, according to the points from claim 1, is designed to satisfy the following conditions:
11. The anti-blur infrared lens for panoramic camera system using HD resolution sensor, according to claim 1, with a working F-number of 2 has detailed parameters as shown in the table below: TABLE-US-00005 Radius of No. Surface type curvature Thickness Material 1 Spherical 55.55 14.91 Silicon 2 Aspherical 118.44 5.39 3 Aspherical 75.84 9.91 Germanium 4 Aspherical 33.96 76.96 5 Aspherical −47.25 11.00 Germanium 6 Extended polynomial −44.58 20.00 7 Extended polynomial −331.64 8.00 ZnSe 8 Spherical −69.98 43.79 9 Aspherical −218.83 3.50 Germanium 10 Aspherical −807.21 49.02 11 Spherical −79.12 8.00 Silicon 12 Spherical −63.50 25.50 13 Plane −42.20 Mirror 13 Diffractive −297.42 −4.57 Germanium 14 Spherical −404.39 −17.23 15 Aspherical −28.32 −10.01 Silicon 16 Aspherical −25.21 −27.21 17 Plane 26.50 Mirror 18 Aspherical −18.54 9.17 Germanium 19 Diffractive −22.10 34.35 20 Aspherical 60.49 5.10 Silicon 21 Aspherical 1887.42 The unit of measurement used in the tables is “mm”; The aspherical surfaces are defined by the following polynomial:
Description
BRIEF DESCRIPTION OF FIGURES
[0022]
[0023]
[0024]
[0025]
[0026]
[0027]
[0028]
[0029]
[0030]
[0031]
[0032]
DETAILED DESCRIPTION OF THE OPTIONS OF THE INVENTION
[0033] The invention of an anti-blur infrared lens for an anti-blur scanning system using an HD resolution sensor whose structure is illustrated in
[0034] Referring to
[0035] According to this structure, the group (G1) has the effect of magnifying the focal length of the optical part created by the group (G2, G3) to a certain magnification ratio (A). In order to ensure the magnification of the group (G1), the focal ratio f(L1,L2,L3)/f(L4,L5,L6)=A. In addition, the magnification ratio is between 1.2 and 2.0 therefore 1.2≤f(L1,L2,L3)/f(L4,L5,L6)=A≤2.0.
[0036] Referring to
[0037] In conformity with this structure, referring to
[0038] In which α is the rotation angle of the mirror, β is the rotation angle of the device in the integration time for each frame, A is the magnification ratio of the group (G1).
[0039]
[0040] Referring to
[0041] Referring to
[0042] Referring to
[0043] Referring to
1.1≤f(G1,G2,G3)/f(G1,G2)≤2.5
In which:
[0044] f(G1,G2,G3) is the focal length of an optical part formed by groups G1,G2,G3;
[0045] f(G1,G2) is the focal length of the optical part formed by groups G1,G2.
[0046] Referring to
[0047] Referring to
[0048] Referring to
[0049] Referring to
[0050] According to this structure, the invention of an anti-blur infrared lens for a panoramic camera system using an HD resolution sensor is designed to satisfy the following conditions:
[0051] In which:
[0052] f(L1,L2,L3) is the focal length of the optical part formed by the lenses (L1), (L2), (L3);
[0053] f(L4,L5,L6) is the focal length of the optical part formed by the lenses (L4), (L5), (L6);
[0054] f(G1,G2,G3) is the focal length of the optical part formed groups (G1), (G2), (G3);
[0055] f(G1,G2) is the focal length of the optical part formed by the groups (G1), (G2);
[0056] β is the rotation angle of the device each time it takes one frame;
[0057] d is the distance from exit pupil to image plane;
[0058] D is the diameter of the exit pupil of the lens.
[0059] An example is made for the invention of an anti-blur infrared lens for a panoramic camera system using an HD resolution sensor 1280×1024 F/#2 sensors, with detailed parameters are as follows:
TABLE-US-00001 TABLE 1 Radius of No. Surface type curvature Thickness Material 1 Spherical 55.55 14.91 Silicon 2 Aspherical 118.44 5.39 3 Aspherical 75.84 9.91 Germanium 4 Aspherical 33.96 76.96 5 Aspherical −47.25 11.00 Germanium 6 Extended polynomial −44.58 20.00 7 Extended polynomial −331.64 8.00 ZnSe 8 Spherical −69.98 43.79 9 Aspherical −218.83 3.50 Germanium 10 Aspherical −807.21 49.02 11 Spherical −79.12 8.00 Silicon 12 Spherical −63.50 25.50 13 Plane −42.20 Mirror 13 Diffractive −297.42 −4.57 Germanium 14 Spherical −404.39 −17.23 15 Aspherical −28.32 −10.01 Silicon 16 Aspherical −25.21 −27.21 17 Plane 26.50 Mirror 18 Aspherical −18.54 9.17 Germanium 19 Diffractive −22.10 34.35 20 Aspherical 60.49 5.10 Silicon 21 Aspherical 1887.42
[0060] The unit of measure used in the tables is ‘mm’
[0061] The aspherical surfaces are defined by the following formula:
[0062] In which:
[0063] R is the radius of curvature of the aspherical surface
[0064] y is the axial height from the optical axis
[0065] k is the conic constant of the aspherical surface
[0066] A.sub.2i are respectively the even order aspherical coefficients of 2, 4, 6, 8,10, 12, . . .
[0067] The table below lists the aspherical parameters of some lens surfaces:
TABLE-US-00002 TABLE 2 Surface Conic A4 A6 A8 A10 2 7.328e−7 −2.500e−10 9.839e−14 −1.980e−17 3 8.393e−7 −1.355e−10 9.406e−14 −9.804e−17 4 8.223e−6 1.309e−9 1.727e−12 2.924e−16 5 −9.755e−6 −6.764e−9 −3.271e−12 9 −8.236e−7 −2.829e−9 −2.640e−12 4.495e−16 10 −6.667e−7 −1.944e−9 −2.859e−12 2.740e−15 14 −1.164e−6 7.962e−10 −5.056e−13 2.144e−16 16 4.326e−6 7.200e−9 4.918e−12 6.318e−15 17 7.237e−6 2.657e−8 9.476e−13 2.034e−15 19 −7.873e−6 3.356e−8 1.358e−9 −2.936e−12 20 1.169e−6 1.462e−8 2.943e−11 1.994e−13 21 −3.269e−6 2.327e−8 −1.710e11 .sup. 4.535e14 22 −2.721e6 3.304e−8 −4.688e−11 8.700e−14
[0068] The diffractive surfaces used in the design are described by the following polynomial expansion:
[0069] In which:
[0070] Φ is the phase added to the ray at the coordinates defined by ρ,
[0071] A.sub.i are the coefficients of the polynomial that are optimized during the design process.
[0072] ρ là the normalized coordinate at the diffractive surface.
The table below lists the diffraction coefficients at the S14 and S20 surfaces:
TABLE-US-00003 TABLE 3 S14 S20 A.sub.1 −9.5986e−5 −1.3571e−4 A.sub.2 8.6280e−10 −5.6461e−8
The extended polynomial surfaces are defined by the following polynomial:
[0073] In which:
[0074] z is the sag at the calculated point
[0075] k is the conic constant of the surface
[0076] c is the curvature of the surface
[0077] r is the radius at coordinates x,y
[0078] N is the number of coefficients of the polynomial
[0079] A.sub.i is the coefficient corresponding to the monomial of order i
[0080] Ei(x,y) is the monomial of x and y corresponding to order i
[0081] The following table lists the coefficients corresponding to the respective monomials of the surfaces S6 and S7:
TABLE-US-00004 TABLE 4 Coefficient Monomial S6 S7 X1Y0 0.000E+00 0.000E+00 X0Y1 −1.543E−03 2.834E−03 X2Y0 7.210E−01 −1.160E−01 X1Y1 0.000E+00 0.000E+00 X0Y2 6.680E−01 −2.600E−02 X3Y0 0.000E+00 0.000E+00 X2Y1 7.511E−04 −4.387E−03 X1Y2 0.000E+00 0.000E+00 X0Y3 −2.163E−04 2.907E−03 X4Y0 −1.222E+00 −2.440E−01 X3Y1 0.000E+00 0.000E+00 X2Y2 −2.466E+00 −5.280E−01 X1Y3 0.000E+00 0.000E+00 X0Y4 −1.257E+00 −1.270E−01
[0082] The detailed description of this invention has been specifically explained above, however it should also be understood that the descriptions presented are merely a model of the invention, it can be expressed in many different forms. Therefore, the details of the parameters presented here should not be considered as a limitation, they are only the basis for other proposals.