A new optical system based on multi-wedges

Abstract

The present invention discloses a novel optical system based on multiple optical wedges, belonging to the field of optical system design technology. The device comprises an optical wedge assembly and an infrared lens assembly, wherein the optical wedge assembly includes three optical wedge pairs, which are sequentially mounted within the optical wedge barrel; and the infrared lens assembly includes five lenses, which are sequentially mounted within the infrared barrel. Compared with existing technologies, the device can be configured with multiple independently rotating optical wedge pairs and infrared lenses. By optimizing their optical parameters and layout dimensions, the device achieves higher degrees of freedom and precise control of beam pointing, preventing the occurrence of large-angle total internal reflection. In addition, the use of two materials to manufacture the optical wedge pairs can eliminate chromatic aberration. The device can resolve the singularity and blind spot problems caused by rotating dual optical wedges, and has a wide range of applications in free-space optical communications, optical interconnection, optoelectronic countermeasures, optoelectronic detection, laser weapons, interferometry, and other fields.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical system design, and in particular relates to a novel optical system based on multiple optical wedges. Background Art

[0002] An optical wedge is an optical component used in infrared imaging optical systems to change the direction of outgoing light. By rotating the optical wedge, controlling the relative angle of the wedges and changing the position of the optical axis, rapid, wide-range scanning of the object field of view can be achieved. Due to its compact structure, fast response speed, high precision, large field of view, and strong adaptability to the working environment, the system has great application prospects in target search and positioning, and can be widely used in large-scale imaging and recognition, biomedical observation, laser communications, vision-based microassembly and other fields. However, optical wedge optical scanning devices encounter multiple problems in practical applications, such as beam shape distortion, dispersion, scanning blind spots, and control singularities. How to design the optical path parameters and positional relationships based on multi-optical wedge optical systems to solve these problems has become a technical challenge in this field. Summary of the Invention

[0003] In response to the above technical problems, the present invention provides a new optical system based on multiple optical wedges. The device can be configured with multiple independently rotating optical wedge pairs and infrared lenses. By optimizing its optical parameters and layout dimensions, its degrees of freedom and precise control of beam pointing are improved, which can prevent the occurrence of large-angle total reflection. In addition, the use of two materials to make the optical wedge pairs can eliminate chromatic aberration. The device can solve the problems of singular points and blind spots caused by rotating double optical wedges.

[0004] The present invention solves the above problems through the following technical means:

[0005] A novel optical system based on multiple optical wedges is characterized by comprising an optical wedge group and an infrared lens group, wherein: the optical wedge group comprises a first optical wedge pair, a second optical wedge pair, and a third optical wedge pair, which are sequentially installed in an optical wedge barrel from the outside to the inside; the infrared lens group comprises a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, which are sequentially installed in the infrared barrel from the inside to the outside; the optical wedge barrel and the infrared barrel are detachably connected by bolts or screws, and three groups of rotation drive devices are provided on the outside of the optical wedge barrel, which are used to drive the first optical wedge pair, the second optical wedge pair, and the third optical wedge pair to rotate independently and precisely.

[0006] Preferably, the first optical wedge pair, the second optical wedge pair and the third optical wedge pair are respectively composed of two, three or four optical wedges.

[0007] Preferably, the first optical wedge pair, the second optical wedge pair, and the third optical wedge pair each consist of two optical wedges: a first optical wedge and a second optical wedge, wherein: the wedge angle of the first optical wedge ranges from 7° to 9°, the effective optical aperture of the outer surface of the first optical wedge ranges from 76 mm to 80 mm, and the effective optical aperture of the inner surface of the first optical wedge ranges from 73 mm to 76 mm; the wedge angle of the second optical wedge ranges from 2° to 4°, the effective optical aperture of the outer surface of the second optical wedge ranges from 73 mm to 76 mm, and the effective optical aperture of the inner surface of the second optical wedge ranges from 72 mm to 75 mm;

[0008] The first optical wedge and the second optical wedge are spaced apart from each other by 0.5 mm to 2.5 mm.

[0009] Preferably, the front surface of the first lens is a spherical surface, and the radius of the front surface ranges from 45 mm to 52 mm; the rear surface of the first lens is a spherical surface, and the radius of the rear surface ranges from -95 mm to -105 mm.

[0010] Preferably, the front surface of the second lens is a spherical surface, and the radius of the front surface ranges from 120 mm to 125 mm; the rear surface of the second lens is a spherical surface, and the radius of the rear surface ranges from -45 mm to -55 mm.

[0011] Preferably, the front surface of the third lens is aspherical, and the aspherical surface equation of the front surface is: R=15mm to 17mm, K=0, A=0, B=-2.5e-6 to -3.1e-6, C=-1.8e-8 to -2.2e-8, D=8.0e-11 to -8.5e-11; the back surface of the third lens is spherical, and the radius range of the back surface is -15mm to -20mm.

[0012] Preferably, the front surface of the fourth lens is aspherical, and the aspherical surface equation of the front surface is: R=-8mm to -10mm, K=0, A=0, B=-2.5e-4 to -3.0e-4, C=-6.5e-7 to -7.2e-7, D=-1.6e-7 to -2.0e-7; the rear surface of the fourth lens is spherical, and the radius of the rear surface ranges from 11mm to 15mm.

[0013] Preferably, the front surface of the fifth lens is aspherical, and the aspherical surface equation of the front surface is: R=85mm to 90mm, K=0, A=0, B=5.1e-6 to 5.2e-6, C=-2.5e-8 to -3.0e-8, D=1.8e-11 to 2.1e-11; the rear surface of the fifth lens is spherical, and the radius range of the rear surface is 75mm to 80mm.

[0014] Preferably, the distance between the first optical wedge pair and the second optical wedge pair ranges from 7.5 mm to 8.5 mm; the distance between the second optical wedge pair and the third optical wedge pair ranges from 7.5 mm to 8.5 mm; the distance between the third optical wedge pair and the first lens ranges from 4.5 mm to 7.5 mm; the distance between the first lens and the second lens ranges from 4.0 mm to 5.0 mm; the distance between the second lens and the third lens ranges from 52.0 mm to 60.0 mm; the distance between the third lens and the fourth lens ranges from 15.0 mm to 20.0 mm; and the distance between the fourth lens and the fifth lens ranges from 8.0 mm to 10.0 mm.

[0015] Preferably, the rotation drive device includes a motor, a reducer, a gear, a ring gear and an encoder, wherein: the motor is detachably mounted on the outer wall of the optical wedge barrel through a housing, the output shaft of the motor is connected to the input shaft of the reducer, and the output shaft of the reducer is fitted with a gear; a transmission opening is provided near the gear in the optical wedge barrel, and the outer end of the gear can pass through the transmission opening, penetrate into the interior of the optical wedge barrel, and cooperate with the ring gear fitted on the optical wedge pair for transmission; the encoder is mounted on the motor and is used to detect the position of the motor.

[0016] The novel optical system based on multiple optical wedges of the present invention has the following beneficial effects:

[0017] 1) The device can be configured with multiple independently rotating optical wedge pairs and infrared lenses. By optimizing their optical parameters and layout dimensions, the device achieves a higher degree of freedom and precise control of beam pointing, preventing large-angle total reflection. In addition, the use of two materials to make the optical wedge pairs can eliminate chromatic aberration. The device can solve the singularity and blind spot problems caused by rotating dual optical wedges. The device can serve as a supplement to the field of view of infrared optical lenses with a small field of view, achieving the capture of targets in the field of view of infrared optical lenses.

[0018] 2) The device can precisely control the independent rotation of the optical wedge through a motor, ensuring the lens group positioning accuracy required by the optical design and meeting various mechanical, thermal and other environmental requirements.

[0019] 3) The scanning and tracking field of the device is ≥±35° and the light transmission area is ≥28cm 2 The diameter of the circle containing 80% of the energy in the full field of view is no more than 30μm, and the athermal design is achieved in the range of -45°~-60°, which can solve the singularity and blind spot problems caused by the rotating double optical wedge. It has high pointing accuracy, good dynamic performance and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 is a schematic diagram of the lens structure of the present invention;

[0023] Figure 3 Schematic diagram of the optical wedge pair structure of the present invention;

[0024] Figure 4 It is a schematic diagram of the layout of the infrared lens group of the present invention.

[0025] Among them, 1-optical wedge group, 101-first optical wedge pair, 102-second optical wedge pair, 103-third optical wedge pair, 104-first optical wedge, 105-second optical wedge, 2-infrared lens group, 201-first lens, 202-second lens, 203-third lens, 204-fourth lens, 205-fifth lens, 3-optical wedge barrel, 4-infrared barrel, 5-rotation drive device. DETAILED DESCRIPTION

[0026] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0027] The present invention will be described in detail below with reference to the accompanying drawings.

[0028] Example 1

[0029] like Figure 1 and Figure 2As shown, the novel optical system based on multiple optical wedges includes an optical wedge group 1 and an infrared lens group 2, wherein: the optical wedge group 1 includes a first optical wedge pair 101, a second optical wedge pair 102, and a third optical wedge pair 103, which are sequentially installed from the outside to the inside in the optical wedge barrel 3; the infrared lens group 2 includes a first lens 201, a second lens 202, a third lens 203, a fourth lens 204, and a fifth lens 205, which are sequentially installed from the inside to the outside in the infrared lens barrel 4.

[0030] Specifically, after the three sets of optical wedges are assembled, they are installed in series in the lens barrel. The axial length inside the lens barrel is adjusted by a spacer, and the axial length tolerance is controlled within 0.1mm. The five lenses are fixed by a pressure ring and an annular table. In addition, the outer surface of the above-mentioned lens is coated with a three-proof film, which can play a role in moisture-proof, fog-proof and mildew-proof. A sealing ring and GD414 silicone rubber filling are used between the optical window and the metal structural parts. Under high-precision precision machine tool processing, the concentricity tolerance of the mounting and positioning surfaces of each lens is guaranteed to be less than 0.02, and the axial tolerance is less than ±0.03. During the design process, adjustment and beveling spacers are installed between the lenses to ensure further adjustment during the lens assembly process. After the adjustment is completed, the thread glue is applied with a pressure ring to tighten and fix it.

[0031] In the figure, the optical wedge barrel 3 and the infrared lens barrel 4 are detachably connected via bolts, screws, and flanges. Three sets of rotation drive devices 5 are installed on the outside of the optical wedge barrel 3. These drive devices 5 are used to drive the independent and precise rotation of the first optical wedge pair 101, the second optical wedge pair 102, and the third optical wedge pair 103.

[0032] It should be noted that the optical wedge barrel 3 and infrared lens barrel 4 are constructed from 2A12 aluminum alloy, a high-strength, hard aluminum alloy that can be heat-treated and hardened, exhibiting excellent machinability. The anodized surface provides high corrosion resistance. High-precision machining ensures that the concentricity tolerance of each lens mounting surface is less than 0.02.

[0033] Example 2

[0034] like Figure 1 As shown, the rotation drive device 5 includes a motor, a reducer, a gear, a ring gear and an encoder, wherein: the motor is detachably mounted on the outer wall of the optical wedge barrel 3 through a housing, the output shaft of the motor is connected to the input shaft of the reducer, and the output shaft of the reducer is sleeved with a gear; a transmission opening is provided near the gear on the optical wedge barrel 3, and the outer end of the gear can pass through the transmission opening, penetrate into the interior of the optical wedge barrel 3, and cooperate with the ring gear sleeved on the optical wedge pair for transmission; the encoder is mounted on the motor and is used to detect the position of the motor.

[0035] In this embodiment, three independent motor control systems control the rotation of the motor-reducer according to the optical design requirements. The motor-reducer drives the optical wedge through a gear transmission, rotating it within a 360-degree range with a transmission ratio of 3.2:1. In practical applications, a brushless DC motor, reducer, and encoder are selected based on the requirements, meeting the -40 to +55° ambient temperature range. The average no-load backlash of the reducer is ≤1.6°.

[0036] It should be noted that the optical wedge pair's mounting base is fitted with a pair of thin-walled, equal-section ball bearings made of bearing steel, which minimizes deformation. Seal caps on both sides ensure long-term, stable operation of the bearings. They contain Great Wall 7008 grease, which is resistant to temperatures ranging from -40°C to +100°C, ensuring leak-proof and effective sealing.

[0037] Example 3

[0038] like Figures 1 to 4 As shown, first optical wedge pair 101, second optical wedge pair 102, and third optical wedge pair 103 can be composed of two, three, or four optical wedges. In this embodiment, first optical wedge pair 101, second optical wedge pair 102, and third optical wedge pair 103 each consist of two optical wedges: a first optical wedge 104 and a second optical wedge 105. The wedge angle of first optical wedge 104 ranges from 7° to 9°, the effective optical aperture of the outer surface of first optical wedge 104 ranges from 76 mm to 80 mm, and the effective optical aperture of the inner surface of first optical wedge 104 ranges from 73 mm to 76 mm. The wedge angle of second optical wedge 105 ranges from 2° to 4°, the effective optical aperture of the outer surface of second optical wedge 105 ranges from 73 mm to 76 mm, and the effective optical aperture of the inner surface of second optical wedge 105 ranges from 72 mm to 75 mm. The distance between first optical wedge 104 and second optical wedge 105 ranges from 0.5 mm to 2.5 mm.

[0039] In this example, because both the optical wedge and the prism have dispersion characteristics, the chromatic aberration of the system must be considered when deflection occurs. Since this problem can be reduced by using a combined optical wedge pair, that is, a combination of optical wedges made of two different materials, this device selects Si and Ge as the two materials for the combined optical wedge pair. The optical wedge with a large wedge angle is made of silicon material with low dispersion, while the optical wedge with a small wedge angle is made of germanium material with high dispersion.

[0040] It should be noted that the radial clearance of the optical wedge assembly is controlled within 0~0.05mm. The bearing precision ensures that the coaxiality error of the three sets of optical wedges is within 0.05mm, and ensures the smooth and reliable operation of the optical wedge assembly.

[0041] Example 4

[0042] like Figures 1 to 4As shown, the front surface of the first lens 201 is spherical, with a radius ranging from 45mm to 52mm; the back surface of the first lens 201 is spherical, with a radius ranging from -95mm to -105mm. The front surface of the second lens 202 is spherical, with a radius ranging from 120mm to 125mm; the back surface of the second lens 202 is spherical, with a radius ranging from -45mm to -55mm. The front surface of the third lens 203 is aspherical, and the aspheric equation for the front surface is: R=15mm to 17mm, K=0, A=0, B=-2.5e-6 to -3.1e-6, C=-1.8e-8 to -2.2e-8, D=8.0e-11 to -8.5e-11; the back surface of the third lens 203 is spherical, with a radius ranging from -15mm to -20mm. The front surface of the fourth lens 204 is aspherical, and the aspheric equation for the front surface is: R = -8mm to -10mm, K = 0, A = 0, B = -2.5e-4 to -3.0e-4, C = -6.5e-7 to -7.2e-7, and D = -1.6e-7 to -2.0e-7. The back surface of the fourth lens 204 is spherical, and the back surface radius ranges from 11mm to 15mm. The front surface of the fifth lens 205 is aspherical, and the aspheric equation for the front surface is: R = 85mm to 90mm, K = 0, A = 0, B = 5.1e-6 to 5.2e-6, C = -2.5e-8 to -3.0e-8, and D = 1.8e-11 to 2.1e-11. The back surface of the fifth lens 205 is spherical, and the back surface radius ranges from 75mm to 80mm. It should be noted that in the above aspheric equation, C0=1 / R.

[0043] In this embodiment, the distance L1 between the first optical wedge pair 101 and the second optical wedge pair 102 ranges from 7.5 mm to 8.5 mm; the distance L2 between the second optical wedge pair 102 and the third optical wedge pair 103 ranges from 7.5 mm to 8.5 mm; the distance L3 between the third optical wedge pair 103 and the first lens 201 ranges from 4.5 mm to 7.5 mm; the distance L4 between the first lens 201 and the second lens 202 ranges from 4.0 mm to 5.0 mm; the distance L5 between the second lens 202 and the third lens 203 ranges from 52.0 mm to 60.0 mm; the distance L6 between the third lens 203 and the fourth lens 204 ranges from 15.0 mm to 20.0 mm; and the distance L7 between the fourth lens 204 and the fifth lens 205 ranges from 8.0 mm to 10.0 mm.

[0044] During installation, high-precision machine tools are used to ensure that the concentricity tolerance of each lens mounting surface is less than 0.02 and the axial tolerance is less than ±0.03. During the design process, adjustment and bevel spacers are installed between lenses to ensure further adjustment during lens assembly. After adjustment, the lens is tightened with a pressure ring and thread glue.

[0045] It should be noted that image clarity is adjusted by adjusting the thickness of the trimmed gasket between the optical lens and the camera housing. After adjustment, the camera is dried and sealed with silicone rubber to ensure the optical system's tightness, ensuring normal operation even in humid environments and low pressure. The outer surface of the optical window is coated with a three-proof coating to resist moisture, fog, and mildew. A sealing ring filled with GD414 silicone rubber is used between the optical window and metal structural components. All interfaces are sealed with GD414 silicone rubber. These measures effectively protect against water, moisture, and salt spray, ensuring normal operation even in humid environments.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An optical system based on a multi-wedge, characterized in that: It includes an optical wedge group (1) and an infrared lens group (2), wherein: The optical wedge group (1) comprises a first optical wedge pair (101), a second optical wedge pair (102), and a third optical wedge pair (103); the first optical wedge pair (101), the second optical wedge pair (102), and the third optical wedge pair (103) are sequentially installed in the optical wedge lens barrel (3) from the outside to the inside; The infrared lens assembly (2) comprises a first lens (201), a second lens (202), a third lens (203), a fourth lens (204) and a fifth lens (205), wherein the first lens (201), the second lens (202), the third lens (203), the fourth lens (204) and the fifth lens (205) are sequentially mounted in the infrared lens barrel (4) from the inside out; The optical wedge lens barrel (3) and the infrared lens barrel (4) are detachably connected via bolts or screws. Three sets of rotation drive devices (5) are provided on the outside of the optical wedge lens barrel (3). The rotation drive devices (5) are used to drive the first optical wedge pair (101), the second optical wedge pair (102), and the third optical wedge pair (103) to rotate independently and accurately. The first optical wedge pair (101), the second optical wedge pair (102), and the third optical wedge pair (103) are respectively composed of two optical wedges: a first optical wedge (104) and a second optical wedge (105), wherein: The wedge angle of the first optical wedge (104) ranges from 7° to 9°, the effective optical aperture of the outer surface of the first optical wedge (104) ranges from 76 mm to 80 mm, and the effective optical aperture of the inner surface of the first optical wedge (104) ranges from 73 mm to 76 mm; The wedge angle of the second optical wedge (105) ranges from 2° to 4°, the effective optical aperture of the outer surface of the second optical wedge (105) ranges from 73 mm to 76 mm, and the effective optical aperture of the inner surface of the second optical wedge (105) ranges from 72 mm to 75 mm; The first optical wedge (104) and the second optical wedge (105) are spaced 0.5 mm to 2.5 mm apart; The front surface of the first lens (201) is a spherical surface, and the radius of the front surface ranges from 45 mm to 52 mm; the rear surface of the first lens (201) is a spherical surface, and the radius of the rear surface ranges from -95 mm to -105 mm.

2. The multi-wedge optical system according to claim 1, wherein: The front surface of the second lens (202) is a spherical surface, and the radius of the front surface ranges from 120 mm to 125 mm; the rear surface of the second lens (202) is a spherical surface, and the radius of the rear surface ranges from -45 mm to -55 mm.

3. The multi-wedge optical system according to claim 1, wherein: The front surface of the third lens (203) is an aspheric surface, and the aspheric surface equation of the front surface is: R=15mm to 17mm, K=0, A=0, B=-2.5e-6 to -3.1e-6, C=-1.8e-8 to -2.2e-8, D=8.0e-11 to -8.5e-11; the back surface of the third lens (203) is a spherical surface, and the radius range of the back surface is -15mm to -20mm.

4. The multi-wedge optical system according to claim 1, wherein: The front surface of the fourth lens (204) is an aspheric surface, and the aspheric surface equation of the front surface is: R=-8mm to -10mm, K=0, A=0, B=-2.5e-4 to -3.0e-4, C=-6.5e-7 to -7.2e-7, D=-1.6e-7 to -2.0e-7; the back surface of the fourth lens (204) is a spherical surface, and the radius range of the back surface is 11mm to 15mm.

5. The multi-wedge based optical system according to claim 1, wherein: The front surface of the fifth lens (205) is an aspheric surface, and the aspheric surface equation of the front surface is: R=85mm to 90mm, K=0, A=0, B=5.1e-6 to 5.2e-6, C=-2.5e-8 to -3.0e-8, D=1.8e-11 to 2.1e-11; the back surface of the fifth lens (205) is a spherical surface, and the radius range of the back surface is 75mm to 80mm.

6. The multi-wedge optical system according to claim 1, wherein: The distance (L1) between the first optical wedge pair (101) and the second optical wedge pair (102) ranges from 7.5 mm to 8.5 mm; The distance (L2) between the second optical wedge pair (102) and the third optical wedge pair (103) ranges from 7.5 mm to 8.5 mm; The distance (L3) between the third optical wedge pair (103) and the first lens (201) ranges from 4.5 mm to 7.5 mm; The distance (L4) between the first lens (201) and the second lens (202) ranges from 4.0 mm to 5.0 mm; The distance (L5) between the second lens (202) and the third lens (203) ranges from 52.0 mm to 60.0 mm; The distance (L6) between the third lens (203) and the fourth lens (204) ranges from 15.0 mm to 20.0 mm; The distance (L7) between the fourth lens (204) and the fifth lens (205) ranges from 8.0 mm to 10.0 mm.

7. The multi-wedge based optical system according to claim 1, wherein: The rotary drive device (5) comprises a motor, a reducer, a gear, a gear ring and an encoder, wherein: The motor is detachably mounted on the outer wall of the optical wedge lens barrel (3) through a housing, the output shaft of the motor is connected to the input shaft of the reducer, and the output shaft of the reducer is sheathed with a gear; A transmission opening is provided near the gear on the optical wedge lens barrel (3); the outer end of the gear can pass through the transmission opening, penetrate into the interior of the optical wedge lens barrel (3), and cooperate with the gear ring mounted on the optical wedge pair for transmission; The encoder is installed on the motor and is used to detect the position of the motor.

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