CN112083562B - Off-axis two-mirror imaging system with real exit pupil - Google Patents

Off-axis two-mirror imaging system with real exit pupil Download PDF

Info

Publication number
CN112083562B
CN112083562B CN202010817889.8A CN202010817889A CN112083562B CN 112083562 B CN112083562 B CN 112083562B CN 202010817889 A CN202010817889 A CN 202010817889A CN 112083562 B CN112083562 B CN 112083562B
Authority
CN
China
Prior art keywords
axis
mirror
exit pupil
light beam
imaging system
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202010817889.8A
Other languages
Chinese (zh)
Other versions
CN112083562A (en
Inventor
朱钧
吴玮琛
金国藩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tsinghua University
Original Assignee
Tsinghua University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tsinghua University filed Critical Tsinghua University
Priority to CN202010817889.8A priority Critical patent/CN112083562B/en
Publication of CN112083562A publication Critical patent/CN112083562A/en
Application granted granted Critical
Publication of CN112083562B publication Critical patent/CN112083562B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B17/00Systems with reflecting surfaces, with or without refracting elements
    • G02B17/02Catoptric systems, e.g. image erecting and reversing system
    • G02B17/06Catoptric systems, e.g. image erecting and reversing system using mirrors only, i.e. having only one curved mirror
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/0025Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for optical correction, e.g. distorsion, aberration

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Lenses (AREA)

Abstract

The invention relates to an off-axis two-mirror imaging system with a real exit pupil, which comprises a main reflector, a primary reflector, a lens and a real exit pupil, wherein the main reflector is positioned on an incident light path of an incident light beam and reflects the incident light beam to form a first reflected light beam, the secondary reflector is positioned on a reflected light path of the main reflector and is used for reflecting the first reflected light beam to form a second reflected light beam, the second reflected light beam passes through the lens and the real exit pupil after passing through the incident light beam and reaches an image plane, and the secondary reflector and the lens are respectively positioned at two sides of the incident light beam.

Description

Off-axis two-mirror imaging system with real exit pupil
Technical Field
The invention relates to the field of optical design, in particular to an off-axis two-mirror imaging system.
Background
The off-axis reflection type optical imaging system has the advantages of high transmittance, wide imaging waveband range, no chromatic aberration and the like, and has a plurality of applications in the imaging field. To avoid reducing imaging efficiency by avoiding beam obscuration, the symmetry of off-axis systems is disrupted, some non-conventional and field-of-view dependent aberrations are introduced, and spherical and aspherical surfaces with rotational symmetry have less ability to correct such aberrations. The optical free-form surface is an optical surface which has no rotation symmetry and high design freedom degree, and can be used for correcting off-axis aberration and improving optical performance. In recent years, free-form surfaces have been increasingly used for off-axis reflective imaging systems, and many imaging systems with high performance have been realized.
At present, off-axis reflection type systems are also increasingly applied to infrared imaging, and have important application in vehicle-mounted obstacle avoidance systems and monitoring security systems. However, the off-axis reflective optical system has the problem of too large system volume to avoid beam blocking.
Disclosure of Invention
In view of the foregoing, it is desirable to provide an off-axis reflective imaging system with a compact and small size.
An off-axis two-mirror imaging system with an actual exit pupil comprises a main reflector, a primary reflector, a lens and an actual exit pupil, wherein the main reflector is positioned on an incident light path of an incident light beam and reflects the incident light beam to form a first reflected light beam, the secondary reflector is positioned on a reflected light path of the main reflector and is used for reflecting the first reflected light beam to form a second reflected light beam, the second reflected light beam passes through the lens and the actual exit pupil after passing through the incident light beam and reaches an image plane, and the secondary reflector and the lens are respectively positioned on two sides of the incident light beam.
Compared with the prior art, the off-axis two-mirror imaging system provided by the invention only uses two reflectors, has compact and simple structure and low cost, and can reduce the volume, weight and the like of the system; moreover, the imaging system is additionally provided with a lens in front of an image surface, so that the width of partial beams of the reflector can be reduced, the aberration can be corrected by a free-form surface, the F number of the imaging system can be reduced, the field of view of the imaging system is improved, and higher imaging resolution and a wider observation range can be obtained; in addition, the imaging system further comprises a real exit pupil, which can improve the sensitivity of the system.
Drawings
Fig. 1 is an optical path diagram of an off-axis two-mirror imaging system with a real exit pupil according to an embodiment of the present invention.
Figure 2 is an MTF curve for each field of view of an off-axis two-mirror imaging system with a real exit pupil provided by an embodiment of the present invention.
Figure 3 is a graph of the average RMS wave aberration for each field of view of an off-axis two-mirror imaging system with a real exit pupil according to an embodiment of the present invention.
Description of the main elements
Off-axis two-mirror imaging system 100 with real exit pupil
Main mirror 102
Secondary reflector 104
Lens 106
First surface 1061 of the lens
Second surface 1062 of the lens
Real exit pupil 108
Image plane 110
The following detailed description will further illustrate the invention in conjunction with the above-described figures.
Detailed Description
The technical scheme of the invention is further detailed in the following description and the accompanying drawings in combination with specific embodiments.
Referring to fig. 1, an embodiment of the invention provides an off-axis two-mirror imaging system 100 with a real exit pupil. The off-axis two-mirror imaging system 100 with a real exit pupil includes a primary mirror 102, a secondary mirror 104, a lens 106 and a real exit pupil 108, which are disposed adjacent to each other and spaced apart from each other. The main reflector 102 is located on an incident light path of the incident light beam and reflects the incident light beam to form a first reflected light beam. The secondary mirror 104 is located on the reflection optical path of the primary mirror 102, and is used for reflecting the first reflection optical beam to form a second reflection optical beam. The lens 106 and the real exit pupil 108 are located in the reflected light path of the secondary mirror 104. The second reflected light beam passes through the incident light beam, passes through the lens 106 and the real exit pupil 108, and reaches the image plane 110. The secondary mirror 104 and the lens 106 are located on both sides of the incident light beam, respectively. The entrance pupil and the primary mirror 102 are located on either side of the second reflected beam.
The optical path of the off-axis two-mirror imaging system 100 with a real exit pupil when in operation is as follows: when the object is at infinity, the light beam emitted from the object first enters the reflective surface of the primary mirror 102, and is reflected by the reflective surface of the primary mirror 102 to form a first reflected light beam, which is then irradiated onto the reflective surface of the secondary mirror 104, and is then reflected by the reflective surface of the secondary mirror 104 to form a second reflected light beam, which finally reaches the image plane 110 through the lens 106 and the exit pupil 108. The light path of the second reflected light beam is crossed and partially overlapped with the light path of the incident light beam, so that the space can be fully utilized, and the volume of the system is reduced.
The reflecting surfaces of the primary mirror 102 and the secondary mirror 104 may be spherical, aspheric or free-form surfaces, and in this embodiment, the reflecting surfaces of the primary mirror 102 and the secondary mirror 104 are both free-form surfaces. The materials of the primary mirror 102 and the secondary mirror 104 are not limited as long as they have high reflectivity. The primary mirror 102 and the secondary mirror 104 may be made of metal materials such as aluminum, copper, and the like, or inorganic non-metal materials such as silicon carbide, silicon dioxide, and the like. To further increase the reflectivity of the primary and secondary mirrors 102, 104, an antireflection film, which may be a gold film, may be coated on the respective reflective surfaces. The dimensions of the primary mirror 102 and the secondary mirror 104 are not limited.
For convenience of description, the space in which the off-axis two-mirror imaging system 100 with real exit pupil is located defines a global three-dimensional rectangular coordinate system (X, Y, Z), the space in which the primary mirror 102 is located defines a first local three-dimensional rectangular coordinate system (X ', Y ', Z '), and the space in which the secondary mirror 104 is located defines a second local three-dimensional rectangular coordinate system (X ", Y", Z "). In this embodiment, the center of the entrance pupil position of the off-axis two-mirror imaging system 100 with a real exit pupil is the origin of the global three-dimensional rectangular coordinate system, please refer to fig. 1, a horizontal straight line passing through the center of the entrance pupil is the Z axis, which is negative to the left and positive to the right, the Y axis is in the plane shown in fig. 1, which is positive to the bottom in the direction perpendicular to the Z axis, the X axis is perpendicular to the YZ plane, and the inward direction is positive to the outward direction in the direction perpendicular to the YZ plane.
In the global three-dimensional rectangular coordinate system (X, Y, Z), a first local three-dimensional rectangular coordinate system (X ', Y', Z ') is defined with a point on the main mirror 102 as an origin, and the reflection surface of the main mirror 102 and the position thereof are described by the first local three-dimensional rectangular coordinate system (X', Y ', Z'). In the global three-dimensional rectangular coordinate system (X, Y, Z), a second local three-dimensional rectangular coordinate system (X ", Y", Z ") is defined with a point on the sub-mirror 104 as an origin, and the reflecting surface of the sub-mirror 104 and the position thereof are described by the second local three-dimensional rectangular coordinate system (X", Y ", Z").
The origins of the first local three-dimensional rectangular coordinate system (X ', Y', Z ') and the second local three-dimensional rectangular coordinate system (X', Y ', Z') are located at different positions in the global three-dimensional rectangular coordinate system (X, Y, Z). Each of the first local coordinate system (X ', Y ', Z ') and the second local coordinate system (X ", Y", Z ") may be regarded as a result of the global coordinate system (X, Y, Z) being first translated such that an origin of the global coordinate system (X, Y, Z) coincides with an origin of the local coordinate system, and then rotated about an X-axis of the global coordinate system (X, Y, Z).
The first local three-dimensional rectangular coordinate system (X ', Y ', Z ') is obtained by translating the global three-dimensional rectangular coordinate system (X, Y, Z) along the positive direction of the Y axis and the positive direction of the Z axis, and the translation distance can be selected and set according to actual requirements. In this embodiment, the first local three-dimensional rectangular coordinate system (X ', Y ', Z ') is obtained by translating the global three-dimensional rectangular coordinate system (X, Y, Z) by about 140mm in the positive direction of the Y axis, then translating by about 82mm in the positive direction of the Z axis, and finally rotating by about 50 ° counterclockwise by using the X axis as a rotation axis; the origin of the first local three-dimensional rectangular coordinate system has coordinates (0, 140, 82) in the global three-dimensional rectangular coordinate system.
In the first local rectangular three-dimensional coordinate system (X ', Y ', Z '), the reflection surface of the main mirror 102 is a polynomial free-form surface of X ' Y ', and the equation of the polynomial free-form surface of X ' Y ' can be expressed as:
Figure BDA0002633394200000051
wherein z ' is the rise of the curved surface, c ' is the curvature of the curved surface, k ' is the coefficient of the quadric surface, A i ' is a coefficient of the i-th term in the polynomial. Since the off-axis two-mirror imaging system 100 is symmetric about the Y ' Z ' plane, only the even term of X ' may be retained. Preferably, the reflecting surface of the main mirror 102 is an x ' y ' polynomial free-form surface with an even-order term of x ' with the order of 6, and the equation of the x ' y ' polynomial free-form surface can be expressed as:
Figure BDA0002633394200000061
it should be noted that the degree of the highest order of the x 'y' polynomial free-form surface is not limited to 6, but may be 4, 8, 10, etc., and those skilled in the art can optimize the design according to the actual situation.
In this embodiment, the curvature c ', the conic coefficient k' and the coefficients A in the x 'y' polynomial of the reflection surface of the main mirror 102 i ' ofSee table 1 for values. It will be understood that the curvature c ', the conic coefficient k', and the coefficients A i The value of' is also not limited to that described in table 1 and can be adjusted by those skilled in the art according to actual needs.
TABLE 1 values of coefficients in the x 'y' polynomial of the reflection surface of the primary mirror
c' -7.010E-06
k' 1796500.188
A 3 ' 5.097
A 4 ' -3.947E-04
A 6 ' -0.728E-03
A 8 ' 9.930E-07
A 10 ' 2.958E-06
A 11 ' -1.987E-09
A 13 ' -2.159E-08
A 15 ' -5.642E-08
A 17 ' -5.109E-11
A 19 ' -7.645E-10
A 21 ' -9.073E-10
A 22 ' 7.512E-14
A 24 ' -5.502E-13
A 26 ' -0.929E-12
A 28 ' 5.644E-12
In the global three-dimensional rectangular coordinate system (X, Y, Z), the second local three-dimensional rectangular coordinate system (X ', Y', Z ') is obtained by translating the first local three-dimensional rectangular coordinate system (X', Y ', Z') along the positive direction of the Y axis and the negative direction of the Z axis, and the translation distance can be selected and set according to actual needs. In this embodiment, the second local three-dimensional rectangular coordinate system (X ", Y", Z ") is obtained by translating the first local three-dimensional rectangular coordinate system (X ', Y ', Z ') by about 75mm in the positive direction of the Y axis, then by translating by about 54mm in the negative direction of the Z axis, and then by rotating by about 163 ° clockwise with the X axis as the rotation axis; the origin of the second local three-dimensional rectangular coordinate system is (0, 215, 28) in the global three-dimensional rectangular coordinate system.
In the second local rectangular three-dimensional coordinate system (X ", Y", Z "), the reflection surface of the secondary reflector 104 is a polynomial free-form surface of X" Y ", and the equation of the polynomial free-form surface of X" Y "can be expressed as:
Figure BDA0002633394200000071
wherein z ' is the rise of the curved surface, c ' is the curvature of the curved surface, k ' is the coefficient of the quadric surface, A i "is a coefficient of the i-th term in the polynomial. Since the off-axis two-mirror imaging system 100 is symmetric about the Y "Z" plane, only the even term of X "may be retained. Preferably, the reflecting surface of the secondary mirror 104 is an X "y" polynomial free-form surface with an even-order term of X "with the order of 8, and the equation of the X" y "polynomial free-form surface can be expressed as:
Figure BDA0002633394200000072
it should be noted that the degree of the highest degree of the x "y" polynomial free-form surface is not limited to 8, but may be 4, 6, or 10, and the like, and those skilled in the art can optimize the design according to the actual situation.
In this embodiment, the curvature c, the conic coefficient k and the coefficients A of the x "y" polynomial of the reflecting surface of the secondary reflector 104 i See table 2 for values of. It will be appreciated that the curvature c ", the conic coefficient k" and the coefficients A i The value of "is not limited to that described in table 2, and can be adjusted by those skilled in the art according to actual needs.
TABLE 2 values of the coefficients in the x "y" polynomial of the reflecting surface of the subreflector
c” 2.785E-03
k” -25.690
A 3 -1.504
A 4 -7.782E-06
A 6 1.994E-06
A 8 -0.773E-06
A 10 -2.557E-06
A 11 1.591E-09
A 13 6.336E-09
A 15 3.260E-09
A 17 0.292E-11
A 19 -1.342E-11
A 21 0.272E-11
A 22 -2.464E-13
A 24 -3.364E-12
A 26 -1.903E-12
A 28 -5.049E-13
A 30 -2.383E-15
A 32 7.351E-15
A 34 6.224E-15
A 36 5.471E-16
A 37 0.581E-18
A 39 6.608E-18
A 41 -2.978E-17
A 43 -5.415E-17
A 45 -0.465E-17
The lens 106, the real exit pupil 108 and the image plane 110 are all disposed on the light path of the second reflected light beam. The secondary reflector 104 is disposed at one side of the incident light path, and the lens 106, the real exit pupil 108 and the image plane 110 are disposed at the other side of the incident light path. The arrangement order of the lens 106 and the real exit pupil 108 on the optical path of the second reflected light beam is not limited; in one embodiment, the second reflected light passes through the lens 106, then passes through the real exit pupil 108, and finally reaches the image plane 110; in another embodiment, the second reflected light passes through the real exit pupil 108, then passes through the lens 106, and finally reaches the image plane 110.
The lens 106 is used for converging the second reflected light beam onto the image plane 110. The lens 106 includes a first surface 1061 and a second surface 1062, the first surface 1061 and the second surface 1062 are disposed opposite to each other, the first surface 1061 of the lens is an incident surface of the second reflected light, and the second surface 1062 of the lens is an exit surface of the second reflected light. In a global three-dimensional rectangular coordinate system (X, Y, Z), the lens 106 is offset from the secondary mirror 104 along the negative direction of the Y-axis, and the offset can be set according to actual requirements. In this embodiment, in the global three-dimensional rectangular coordinate system (X, Y, Z), the lens 106 is offset from the secondary mirror 104 along the Y-axis negative direction by about 156mm, that is, the distance between the center of the first surface 1061 of the lens 106 and the origin of the second local three-dimensional rectangular coordinate system where the secondary mirror 104 is located along the Y-axis negative direction is about 237 mm; the lens 106 is offset from the secondary mirror 104 along the negative Z-axis by about 17mm, i.e., the distance between the center of the first surface 1061 of the lens 106 and the origin of the second local three-dimensional rectangular coordinate system of the secondary mirror 104 along the negative Z-axis is about 67 mm; the center of the first surface 1061 of the lens 106 has coordinates (0, -22, 11) in the global coordinate system.
The shape of the first surface 1061 and the second surface 1062 is not limited, and may be a spherical surface, an aspherical surface, or a free-form surface, and it is understood that the spherical surface and the aspherical surface are easier to machine than the free-form surface. Preferably, the first surface 1061 and the second surface 1062 are spherical or aspherical in shape. In this embodiment, the first surface 1061 and the second surface 1062 are both spherical surfaces, and the equation of the spherical surfaces can be expressed as:
Figure BDA0002633394200000101
wherein z is the high vector of the curved surface, and c is the curvature of the curved surface. In this embodiment, the radius of curvature of the first surface 1061 of the lens 106 is-126.23 mm, and in the spherical equation of the first surface 1061, c is-7.92205467E-3; the radius of curvature of the second surface 1062 of the lens 106 is-226.57 mm, and in the spherical equation of the second surface 1062, c is-4.41345335E-3. It is understood that the value of the curvature c is not limited to the embodiment, and can be adjusted by those skilled in the art according to the actual requirement.
The material and specification of the lens 106 are not limited, and can be selected according to actual requirements. When the operating wavelength of the off-axis two-mirror imaging system 100 is in the visible range, the material of the lens 106 may be glass, plastic, etc.; when the operating wavelength of the off-axis two-mirror imaging system 100 is in the infrared range, the material of the lens 106 may be germanium, zinc sulfide, zinc selenide, or the like. The thickness of the lens 106 can be reduced as much as possible during design, so that the influence of chromatic aberration on the imaging quality can be reduced. In this embodiment, the central thickness of the lens is 3.0mm, the diameter of the lens is 40mm, and the lens is made of germanium.
The real exit pupil 108 is parallel to and opposite to the lens 106. The distance between the real exit pupil 108 and the lens 106 is not limited, and can be set according to actual needs; in this embodiment, the distance between the real exit pupil 108 and the second surface 1062 of the lens 106 is 10 mm. The specification of the real exit pupil 108 is not limited, and can be selected and set according to actual needs; in this embodiment, the radius of the real exit pupil 108 is 13 mm. The real exit pupil 108 can significantly suppress stray light, and diffracted light, thereby improving the signal-to-noise ratio of the imaging system 100 and enabling the imaging system 100 to have higher sensitivity.
After entering, the light beam is reflected by the primary mirror 102 and reaches the secondary mirror 104, and after being reflected by the secondary mirror 104, the light beam is received and imaged by the image plane 110 through the lens 106 and the real exit pupil 108. The image plane 110 is parallel to and opposite to the real exit pupil 108. The distance between the image plane 110 and the real exit pupil 108 is not limited, and can be set according to actual needs; in this embodiment, the distance from the real exit pupil 108 to the image plane is 33 mm. The image plane 110 may be disposed with any optical imaging device, or may be used as an entrance pupil of another optical system. In this embodiment, a photo detector is disposed at the position of the image plane 110.
In addition, the off-axis two-mirror imaging system 100 with a real exit pupil may further include an aperture stop, and the aperture stop may be located at the entrance pupil, on the primary mirror 102, on the secondary mirror 104, on the lens 106, at the real exit pupil 108 or at the image plane 110, or may be disposed in the incident light path of the incident light beam, the reflected light path of the primary mirror 102, the reflected light path of the secondary mirror 104 or between the lens 106 and the image plane 110. The aperture and the shape of the aperture diaphragm are not limited, and the aperture diaphragm can be specifically selected and arranged according to actual needs. In this embodiment, the aperture is disposed on the secondary reflector 104, and the aperture is a circle whose outer edge coincides with the outer edge of the secondary reflector.
The parameters of the off-axis two-mirror imaging system 100 with the real exit pupil, such as the field angle, the equivalent focal length, the entrance pupil diameter, and the F-number, can be set according to the actual situation. In this embodiment, the field angle of the off-axis two-mirror imaging system 100 is 5.8 ° × 4.2 °, the equivalent focal length is 150mm, and the F-number of the off-axis two-mirror imaging system 100 is 1.5. Of course, it should be understood that the values of the parameters of the off-axis two-mirror imaging system are not limited to those listed in the present embodiment, and other values of the parameters obtained according to the present invention should also be within the scope of the present invention.
The operating band of the off-axis two-mirror imaging system 100 with a real exit pupil is not limited, and may be a visible light band or an infrared band. In this embodiment, the off-axis two-mirror imaging system has an operating wavelength in the range of 8 microns to 16 microns. Of course, the operating wavelength of the off-axis two-mirror imaging system 100 is not limited to this embodiment, and can be adjusted according to actual needs.
Referring to fig. 2, for the modulation transfer function MTF of the partial field angle of the off-axis two-mirror imaging system 100 with the real exit pupil in the infrared band, it can be seen from the figure that the modulation degree of each field is at least 0.30 at 30lp/mm, and the MTF curve of each field substantially reaches the diffraction limit, indicating that the off-axis two-mirror imaging system 100 with the real exit pupil has high imaging quality.
Referring to fig. 3, the average RMS wave aberration diagram of each field of view of the off-axis two-mirror imaging system 100 with a real exit pupil, with an average value of 0.061 λ, where λ is 9110.9nm, shows that the imaging quality of the off-axis two-mirror imaging system 100 with a real exit pupil is very good.
The off-axis two-mirror imaging system with the real exit pupil provided by the invention adopts an off-axis two-mirror system, only two reflectors are used, the structure is compact, and the volume and the weight of the system can be reduced; the off-axis two-mirror imaging system is simple in structure, easy to design and process and easy to produce in batches; a thin common spherical lens is added in front of an image surface of the imaging system, so that the width of partial light beams of the reflector can be reduced, the free-form surface can be favorably used for correcting aberration, the F number of the imaging system can be further reduced, and the field of view of the system can be improved; the imaging system provides an actual exit pupil at the exit pupil location, which can significantly limit unwanted background radiation and improve signal-to-noise ratio.
The invention provides an off-axis two-mirror imaging system 100 with a real exit pupil, which can be applied to the fields of earth observation, space target detection, astronomical observation, multispectral thermal imaging, stereo mapping, aerospace, unmanned driving and the like. The off-axis two-mirror imaging system 100 with the real exit pupil provided by the invention reaches the diffraction limit in the infrared band, and can be used under visible light or in the infrared band.
In addition, other modifications within the spirit of the invention will occur to those skilled in the art, and it is understood that such modifications are included within the scope of the invention as claimed.

Claims (8)

1. An off-axis two-mirror imaging system with an actual exit pupil comprises a main reflector, a primary reflector, a single lens and an actual exit pupil, wherein the main reflector is positioned on an incident light path of an incident light beam and reflects the incident light beam to form a first reflected light beam, the secondary reflector is positioned on a reflected light path of the main reflector and is used for reflecting the first reflected light beam to form a second reflected light beam, the second reflected light beam passes through the incident light beam and reaches an image plane through the lens and the actual exit pupil, the secondary reflector and the lens are respectively positioned on two sides of the incident light beam, the reflecting surfaces of the main reflector and the secondary reflector are both free curved surfaces, the F number of the off-axis two-mirror imaging system with the actual exit pupil is 1.5, the single lens comprises a first surface and a second surface, and the first surface and the second surface are arranged oppositely, and the second reflected light beam enters the lens from a first surface, wherein the first surface is a convex surface, and the second surface is a concave surface.
2. The off-axis two-mirror imaging system with a real exit pupil of claim 1, wherein the primary mirror and the entrance pupil are located on either side of the second reflected beam.
3. The off-axis two-mirror imaging system with a real exit pupil of claim 1 wherein the optical path of the second reflected light beam intersects and partially overlaps with the optical path of the incident light beam.
4. An off-axis two-mirror imaging system with real exit pupil as claimed in claim 1, wherein a global three-dimensional rectangular coordinate system is defined with the center of the entrance pupil position of the off-axis two-mirror imaging system with real exit pupil as the origin, wherein a first local three-dimensional rectangular coordinate system (X ', Y ', Z ') is defined with a point on the primary mirror as the origin, wherein a second local three-dimensional rectangular coordinate system (X ', Y ', Z ') is defined with a point on the secondary mirror as the origin, wherein the first local three-dimensional rectangular coordinate system (X ', Y ', Z ') is translated by the global three-dimensional rectangular coordinate system (X, Y, Z) in the positive Y-axis direction and the positive Z-axis direction, and wherein the second local three-dimensional rectangular coordinate system (X ', Y Z ') is translated by the first local three-dimensional rectangular coordinate system (X ', Y ', Z) in the positive Y-axis direction and the positive Z-axis direction, y ', Z') is translated in the positive Y-axis direction and the negative Z-axis direction, and the lens is deviated from the secondary mirror in the negative Y-axis direction.
5. An off-axis two-mirror imaging system with a real exit pupil according to claim 1, wherein a first local three-dimensional rectangular coordinate system (X ', Y', Z ') is defined with a point on the primary mirror as the origin, the reflecting surface of the primary mirror being a free-form surface of X' Y 'polynomial of even-order term of X' of order 6, the equation for the free-form surface of X 'Y' polynomial being expressed as:
Figure FDF0000017635590000021
wherein z ' is the rise of the curved surface, c ' is the curvature of the curved surface, k ' is the coefficient of the quadric surface, A i ' is a coefficient of the i-th term in the polynomial.
6. Tool according to claim 5An off-axis two-mirror imaging system with a real exit pupil, characterized in that c '-7.010E-06, k' -1796500.188, a 3 ′=5.097,A 4 ′=-3.947E-04,A 6 ′=-0.728E-03,A 8 ′=9.930E-07,A 10 ′=2.958E-06,A 11 ′=-1.987E-09,A 13 ′=-2.159E-08,A 15 ′=-5.642E-08,A 17 ′=-5.109E-11,A 19 ′=-7.645E-10,A 21 ′=-9.073E-10,A 22 ′=7.512E-14,A 24 ′=-5.502E-13,A 26 ′=-0.929E-12,A 28 ′=5.644E-12。
7. An off-axis two-mirror imaging system with a real exit pupil according to claim 1, characterized in that a second local three-dimensional rectangular coordinate system (X ", Y", Z ") is defined with a point on the secondary mirror as the origin, the reflecting surface of the secondary mirror is an X" Y "polynomial free-form surface of an even-order term of X' of order 8, the equation of the X" Y "polynomial free-form surface is expressed as:
Figure FDF0000017635590000022
Figure FDF0000017635590000031
wherein z ' is the rise of the curved surface, c ' is the curvature of the curved surface, k ' is the coefficient of the quadric surface, A i "is the coefficient of the i-th term in the polynomial.
8. The off-axis two-mirror imaging system with a real exit pupil of claim 7, wherein c "-2.785E-03, k" -25.690, a 3 ″=-1.504,A 4 ″=-7.782E-06,A 6 ″=1.994E-06,A 8 ″=-0.773E-06,A 10 ″=-2.557E-06,A 11 ″=1.591E-09,A 13 ″=6.336E-09,A 15 ″=3.260E-09,A 17 ″=0.292E-11,A 19 ″=-1.342E-11,A 21 ″=0.272E-11,A 22 ″=-2.464E-13,A 24 ″=-3.364E-12,A 26 ″=-1.903E-12,A 28 ″=-5.049E-13,A 30 ″=-2.383E-15,A 32 ″=7.351E-15,A 34 ″=6.224E-15,A 36 ″=5.471E-16,A 37 ″=0.581E-18,A 39 ″=6.608E-18,A 41 ″=-2.978E-17,A 43 ″=-5.415E-17,A 45 ″=-0.465E-17。
CN202010817889.8A 2020-08-14 2020-08-14 Off-axis two-mirror imaging system with real exit pupil Active CN112083562B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010817889.8A CN112083562B (en) 2020-08-14 2020-08-14 Off-axis two-mirror imaging system with real exit pupil

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010817889.8A CN112083562B (en) 2020-08-14 2020-08-14 Off-axis two-mirror imaging system with real exit pupil

Publications (2)

Publication Number Publication Date
CN112083562A CN112083562A (en) 2020-12-15
CN112083562B true CN112083562B (en) 2022-09-23

Family

ID=73728953

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010817889.8A Active CN112083562B (en) 2020-08-14 2020-08-14 Off-axis two-mirror imaging system with real exit pupil

Country Status (1)

Country Link
CN (1) CN112083562B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114488497B (en) * 2021-12-31 2023-04-07 清华大学 Real exit pupil off-axis reflective optical system

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4265510A (en) * 1979-05-16 1981-05-05 Hughes Aircraft Company Three mirror anastigmatic optical system
JP3486465B2 (en) * 1994-09-05 2004-01-13 オリンパス株式会社 Visual display device
JP3486468B2 (en) * 1994-10-21 2004-01-13 オリンパス株式会社 Prism optical system
US6612701B2 (en) * 2001-08-20 2003-09-02 Optical Products Development Corporation Image enhancement in a real image projection system, using on-axis reflectors, at least one of which is aspheric in shape
JP4422432B2 (en) * 2003-05-26 2010-02-24 オリンパス株式会社 Decentered optical system and optical system using the same
US7390101B2 (en) * 2005-01-31 2008-06-24 The Boeing Company Off-axis two-mirror re-imaging infrared telescope
CN103226237A (en) * 2013-04-19 2013-07-31 中国科学院长春光学精密机械与物理研究所 Unblocked catadioptric infrared optical system
EP3004965B1 (en) * 2013-05-24 2019-08-07 University Of Rochester Head-worn display of the see-through type
CN104714297B (en) * 2013-12-11 2017-02-15 清华大学 Free surface reflection-type scanning system
CN104765151B (en) * 2015-03-30 2017-03-15 中国科学院长春光学精密机械与物理研究所 Big visual field helmet display optical system using double free-form surface mirrors
CN107367833B (en) * 2017-07-27 2019-09-13 北京海鲸科技有限公司 A kind of goggle structure and augmented reality system
CN107300777A (en) * 2017-08-18 2017-10-27 深圳惠牛科技有限公司 A kind of imaging system reflected based on double free form surfaces
CN109471260A (en) * 2017-09-08 2019-03-15 塔普翊海(上海)智能科技有限公司 Eyepiece formula imaging optical device and wear-type image formation optical device and its manufacturing method and imaging method
CN108051908B (en) * 2017-12-01 2019-10-15 中国科学院长春光学精密机械与物理研究所 A kind of imaging optical system
CN108227195B (en) * 2017-12-29 2020-05-19 南京信息工程大学 Off-axis two-mirror free-form surface optical system
CN108519677A (en) * 2018-04-17 2018-09-11 北京理工大学 Off-axis dual reflective wears glasses display optical system
CN108732734B (en) * 2018-05-30 2020-12-25 南京信息工程大学 Free-form surface-based fast-focus ratio reflection type long-wave infrared viewfinder optical system
CN109917535B (en) * 2019-02-24 2021-03-30 西安应用光学研究所 Refrigeration type compact non-blocking free-form surface optical system

Also Published As

Publication number Publication date
CN112083562A (en) 2020-12-15

Similar Documents

Publication Publication Date Title
US9846298B2 (en) Off-axis three-mirror optical system with freeform surfaces
US9405109B2 (en) Off-axial three-mirror optical system with freeform surfaces
TWI485427B (en) Off-axial three-mirror system
CN110132411B (en) Free-form surface imaging spectrometer system
CN112305738B (en) Free-form surface reflection type infrared imaging system
TWI748620B (en) Optical imaging system
TWI622801B (en) An off-axial telecentric optical system with three freeform surfaces
US11221471B2 (en) Freeform surface off-axis three-mirror optical system
CN112083562B (en) Off-axis two-mirror imaging system with real exit pupil
CN113126271A (en) Free-form surface optical telescopic system
CN111487754B (en) Free-form surface off-axis three-mirror imaging system
CN114488497B (en) Real exit pupil off-axis reflective optical system
CN114077044A (en) Off-axis two-mirror imaging system
TWI761923B (en) Off-axis two-mirror infrared imaging system
CN111487753B (en) Free-form surface off-axis three-mirror imaging system
CN111487755B (en) Free-form surface off-axis three-mirror imaging system
CN117092801A (en) Off-axis catadioptric hybrid optical system
CN114236797A (en) Catadioptric afocal optical system
CN118259438A (en) Coaxial reflection type optical telescopic system

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant