Periscopic sighting device based on compound prism and design method thereof

Abstract

This application discloses a periscope-style aiming device based on a compound prism and its design method, relating to the field of optical observation and aiming system technology, to solve the problems of large size, long zoom time, and apochromatic design failure of liquid lenses in zoom devices. The device includes a protective window, a head mirror, a common objective lens group, a compound prism, a laser component, a visible light observation component, and a near-infrared television observation component; the compound prism achieves three-band beam splitting; the visible light observation component and the near-infrared television observation component each include a liquid lens with variable curvature. The design method includes determining the aberration characteristics of the liquid lens, selecting fixed optical elements at the front and rear, actively generating aberrations with opposite signs to those of the liquid lens to achieve dynamic balance, and using a multi-configuration optimization algorithm to dynamically compensate for aberrations. It achieves 100ms fast zoom and apochromatic aberration across the entire zoom range and a wide spectral band.

Description

Technical Field

[0001] This invention relates to the field of optical aiming systems, specifically to a periscope aiming device based on a composite prism and its design method. Background Technology

[0002] Currently, periscope aiming systems are widely used in vehicle-mounted observation and aiming applications due to their advantages such as good concealment and operational safety. Traditional direct-fire telescope systems require operators to move the telescope up, down, left, and right to observe the surrounding environment, resulting in problems such as inconsistent human-machine interface and high operational difficulty. To solve these problems, existing technologies have introduced compound prisms to achieve fully automatic periscope aiming systems, allowing operators to achieve real-time observation and aiming at targets and the surrounding environment without moving.

[0003] However, existing fully automatic periscope aiming systems, after introducing compound prisms, suffer from the following problems because traditional optical zoom systems require complex mechanical structures and motors to control the displacement of solid lenses in order to change magnification and focal length:

[0004] First, the zoom mechanism includes complex mechanical moving components such as guide rails, motors, and gear transmission mechanisms, resulting in a large size and heavy weight, which is not conducive to miniaturization and lightweight design. Second, the movement of the solid lens requires motor drive, resulting in high power consumption and affecting battery life. Third, the response speed of the mechanically moving lens group is limited, and the zoom time is long, usually about 2 seconds, which affects the efficiency of rapid target acquisition and tracking. In addition, when realizing multiple functions such as laser reception, visible light observation and aiming, and near-infrared television observation and aiming in existing technologies, multiple independent optical systems are often required. The lack of efficient spectral splitting structures leads to low system integration and poor optical axis consistency.

[0005] Therefore, how to achieve rapid magnification, miniaturization, and low power consumption while maintaining the multi-functional integrated advantages of periscope aiming systems is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a periscope-style aiming device based on a compound prism and its design method, so as to solve the following technical problems existing in the prior art:

[0007] (1) Existing periscope aiming systems use mechanical structures to control the displacement of solid lenses to achieve magnification, resulting in the magnification device containing complex mechanical moving components such as guide rails, motors, and gear transmission mechanisms. The device is large in size and heavy in weight, which is not conducive to miniaturization and lightweight design.

[0008] (2) Lens movement requires motor drive, which consumes a lot of power and affects the battery life; mechanically moving lens group has limited response speed and long magnification time, usually about 2 seconds, which affects the efficiency of fast target acquisition and tracking.

[0009] (3) In the existing technology, when realizing the integration of multiple functions such as laser reception, visible light observation and near-infrared television observation, multiple independent optical systems are often required. The lack of efficient spectral splitting structure leads to low system integration and poor optical axis consistency.

[0010] (4) When designing the optical system of a liquid lens zoom system, the traditional apochromatic design method fails due to the single and fixed liquid lens material, the dynamic change of the interface curvature, and the simplification of the system structure, which reduces the degree of freedom. It is difficult to achieve clear imaging throughout the zoom range.

[0011] To achieve the above objectives, this invention first provides a periscope aiming device based on a composite prism. Employing a shared composite prism optical structure, it realizes a multi-functional periscope-style universal aiming optical system integrating visible light observation, near-infrared television observation, and laser reception. This system is low-cost, highly integrated, and can be mounted on various vehicle platforms for use in the fields of aiming optical systems and periscope aiming technology. Furthermore, this invention introduces a liquid lens into the composite prism-based periscope aiming device, employing an achromatic design between the liquid and solid lenses to achieve multi-channel zoom periscope observation without moving components. This allows for greater improvements in the optomechanical system in terms of no mechanical movement, lightweight design, and low power consumption, while simultaneously increasing the zoom time from 2 seconds to 100ms, thereby improving the detection and recognition efficiency of the periscope aiming device. Finally, it proposes corresponding design methods to address the problems in optical system design caused by the introduction of liquid lenses.

[0012] The present invention adopts the following technical solution;

[0013] This invention provides a periscope aiming device based on a compound prism, including a protective window, a head mirror, and a common objective lens group, and also includes;

[0014] A composite prism is located on the transmission optical path of the common objective lens group. The composite prism includes a first beam-splitting surface and a second beam-splitting surface. The first beam-splitting surface reflects a first wavelength band and transmits a second wavelength band and a third wavelength band. The second beam-splitting surface reflects the second wavelength band and transmits the third wavelength band.

[0015] A laser assembly, located on the reflected light path of the first beam-splitting surface, includes a laser detector;

[0016] A visible light observation and aiming assembly, located on the reflected light path of the second beam splitter, the visible light observation and aiming assembly comprising a first liquid lens, a reticle, and an eyepiece group;

[0017] A near-infrared television viewing and aiming assembly, wherein the near-infrared television viewing and aiming assembly is located in the transmission light path of the second beam splitter, and the near-infrared television viewing and aiming assembly includes a second liquid lens, a television cemented lens, and a near-infrared imaging device;

[0018] The curvatures of the first liquid lens and the second liquid lens are variable;

[0019] The protective window forms a preset angle with the incident optical axis;

[0020] The reflective surface of the head mirror forms a 45° angle with the incident optical axis, and the head mirror can rotate relative to the incident optical axis.

[0021] The shared objective lens group includes at least one cemented lens.

[0022] By employing a rotatable head-mounted reflector, a 90° optical path deflection and target search function are achieved, allowing operators to perform periscope-style observation and aiming without moving. The two-stage beam-splitting structure of the composite prism separates the laser band from the observation band on the first beam-splitting surface, and the visible light band from the near-infrared band on the second beam-splitting surface, integrating laser reception, visible light observation and aiming, and near-infrared television observation and aiming into one integrated system. By introducing a variable-curvature liquid lens to replace the traditional mechanically moving lens assembly, complex mechanical moving components such as guide rails, motors, and gear transmission mechanisms are eliminated, achieving miniaturization and weight reduction of the device.

[0023] Furthermore, the first liquid lens is cascaded with the common objective lens group and the eyepiece group, and the second liquid lens is cascaded with the common objective lens group and the television cemented lens. Through the cascaded design of the liquid lens with the eyepiece group and the liquid lens with the television cemented lens, a continuous zoom function of 1x to 4x is achieved. Simultaneously, through the matching design of materials and optical power, the apochromatic design challenge caused by the single material of the liquid lens is solved.

[0024] Preferably, the first band is a 1.064μm laser band, the second band is a 450nm~650nm visible light band, and the third band is a 700nm~900nm near-infrared band. This band division method can meet the comprehensive needs of military reconnaissance, vehicle-mounted observation and targeting, and other fields for laser ranging, visible light visual observation, and near-infrared night vision imaging.

[0025] Specifically, the first beam-splitting surface is coated with a beam-splitting film that reflects 1.064 μm laser light and transmits 450 nm–650 nm visible light and 700 nm–900 nm near-infrared light. The second beam-splitting surface is coated with a beam-splitting film that reflects 450 nm–650 nm visible light and transmits 700 nm–900 nm near-infrared light. By coating specific spectral beam-splitting films on the beam-splitting surfaces, precise separation and guidance of light rays in different wavelengths are achieved.

[0026] Furthermore, the head-mounted reflector has an azimuth rotation range of -4° to +4° and a pitch rotation range of -7° to +18°. This rotation range can cover the needs of conventional observation and aiming scenarios, enabling real-time scanning of the target and its surrounding environment.

[0027] Preferably, the angle between the protective window and the incident optical axis is 3° to 7°. The tilted design of the protective window effectively reduces interference from reflected light on imaging. Furthermore, the protective window is secured around its perimeter with sealing strips and silicone rubber adhesive, achieving a sealed and waterproof function inside the device.

[0028] Furthermore, the composite prism is composed of a first cubic prism, a roof pentaprism, a right-angle prism, and a second cubic prism. The cemented surface of the first cubic prism serves as the first beam-splitting surface, and the hypotenuse of the roof pentaprism serves as the second beam-splitting surface. This prism combination not only achieves spectral splitting but also enables image inversion (up, down, left, and right) through the roof structure of the roof pentaprism, resulting in an upright image. Simultaneously, it folds the light path, achieving a compact periscope-like structure.

[0029] Furthermore, the shared objective lens group also includes a single lens, which is made of anomalous dispersion glass. The single lens is used to correct field curvature and distortion in the system, thereby improving image quality.

[0030] Preferably, the positive lens of the cemented lens in the shared objective lens group is made of high Abbe number crown glass, and the negative lens is made of lanthanum flint glass. This material combination achieves effective chromatic aberration correction for the center wavelength of visible light.

[0031] Furthermore, both the first and second liquid lenses comprise two incompatible liquids, electrodes, and a dielectric layer. The interface curvature of the two incompatible liquids is altered by applying a voltage across the electrodes. The working principle of the liquid lens utilizes the electrowetting effect; by applying voltage, the interfacial tension between the conductive liquid and the hydrophobic dielectric layer is changed, thereby altering the contact angle and interface shape, achieving continuous adjustment of the focal length.

[0032] Preferably, the first liquid lens has an aperture of 8mm to 12mm and a curvature range of 15mm to 160mm. The second liquid lens has an aperture of 6mm to 10mm and a curvature range of 30mm to 130mm. This size and curvature range design can meet the requirements of 1x to 4x continuous zoom while ensuring image quality.

[0033] The present invention also provides a design method for a periscope aiming device based on a composite prism, comprising the following steps;

[0034] S1; Determine the aberration characteristics of the liquid lens under different curvatures. By simulating the aberration characteristics of the liquid lens under different voltages (i.e., different focal lengths), especially the chromatic aberration characteristics, a data foundation is provided for subsequent aberration compensation design.

[0035] S2; Select the optical elements for the front and rear fixed groups, wherein the front fixed group is located in front of the liquid lens and the rear fixed group is located behind the liquid lens. By rationally selecting the optical element materials and structures of the front and rear fixed groups, conditions are created for achieving dynamic aberration balance.

[0036] S3; Throughout the zoom range, the front fixed group and the rear fixed group actively generate aberrations with opposite signs to those of the liquid lens, achieving dynamic aberration balance. This is the core technical approach of the present invention, abandoning the traditional approach of relying on the liquid lens itself for aberration correction, and shifting the design focus from materials to global aberration matching and compensation.

[0037] S4; Employing a global optimization algorithm to cover aberrations across all zoom configurations, dynamically compensating for the inherent and dynamic aberrations of the liquid lens. Through a multi-configuration, wide-band global optimization algorithm, apochromatic aberration is achieved throughout the entire zoom range.

[0038] Furthermore, in step S2, for the visible light band, the front fixing group uses an apochromatic cemented lens and an anomalous dispersion glass single lens, while the rear fixing group uses a double cemented lens and a single lens. This material combination achieves effective chromatic aberration correction for the center band of visible light.

[0039] Furthermore, in step S2, for the near-infrared band, the rear fixing assembly employs a cemented lens composed of a calcium fluoride crystal positive lens and a fused silica negative lens. This material combination achieves effective chromatic aberration correction for the near-infrared spectrum.

[0040] Furthermore, in step S4, the global optimization algorithm covers at least three configurations within the 1x to 4x zoom range. By covering multiple typical configurations (such as 1x, 2x, and 4x), image quality balance is achieved throughout the entire zoom range.

[0041] Preferably, the positive lens of the apochromatic cemented mirror is H-FK95, the negative lens is H-LaF62, and the aberrant dispersion glass single lens is H-FK61. This specific combination of material grades has been optimized to achieve the best chromatic aberration correction effect.

[0042] Preferably, the double-cemented eyepiece comprises a first cemented eyepiece and a second cemented eyepiece, wherein the first cemented eyepiece is composed of H-ZF88 and H-FK61, and the second cemented eyepiece is composed of H-K9L and H-ZF3. This combination of materials in the eyepiece assembly enables good chromatic aberration correction and image quality.

[0043] Preferably, the calcium fluoride crystal has a refractive index of 1.43 and an Abbe number of 95, while the fused silica has a refractive index of 1.46 and an Abbe number of 68. This combination of optical parameters enables effective chromatic aberration correction in the near-infrared band.

[0044] Beneficial effects

[0045] The present invention has the following beneficial effects;

[0046] (1) By adopting head-reflecting mirror search technology, a periscope-style observation system with multiple functions including visible light observation, near-infrared television observation and laser reception can be achieved without personnel movement, and human-machine operation is coordinated; the operator and the protective window are not on the same horizontal plane, which is conducive to concealment and high security;

[0047] (2) By adopting the optical structure of a shared composite prism, spectral splitting of three bands is achieved. There are no moving parts in the system, the optical axis is stable and accurate, the structure is compact and the cost is low.

[0048] (3) By introducing liquid lenses into the visible light observation component and the near-infrared television observation component respectively, a 100ms fast zoom without zoom movement component is achieved, which is 20 times faster than the 2-second zoom time of traditional mechanical zoom. This achieves miniaturization, low power consumption and high detection and recognition efficiency of the periscope observation device. The liquid lens driving voltage only requires a few volts, which is more than 90% lower than the power consumption of motor drive.

[0049] (4) The design method of the periscope aiming device based on the composite prism provided by this invention solves the problem of apochromatic design failure caused by the single and fixed material of the liquid lens and the dynamic change of the interface curvature. This design method abandons the traditional approach of relying on the liquid lens itself for aberration correction, and adopts the design concept of "global aberration matching and compensation". By actively generating aberrations with opposite signs to the liquid lens through the front and rear fixed groups, combined with multi-configuration optimization algorithms, apochromatic aberration is achieved in the entire 1 to 4x zoom range and wide band, dynamically compensating for the inherent and dynamic aberrations of the liquid lens, and ensuring clear imaging;

[0050] (5) This design method is universal and can be applied to the design of other liquid lens optical systems, providing an effective design means for the application of liquid lenses in zoom optical systems.

[0051] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0052] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0053] Figure 1 This is a schematic diagram of the optical system structure of a periscope aiming device based on a compound prism.

[0054] Figure 2 This is a schematic diagram of the structure of a compound prism.

[0055] Figure 3 This is a schematic diagram of the eyepiece assembly.

[0056] Figure 4 This is a schematic diagram of the cross-sectional structure of a liquid lens.

[0057] In the diagram: 1-Protective window, 2-Head reflector, 3-Common objective lens group, 4-Compound prism, 5-Laser cemented lens, 6-Laser filter, 7-Laser detector, 8-First liquid lens, 9-Reticle, 10-Eyepiece group, 11-Second liquid lens, 12-TV cemented lens, 13-Near-infrared camera, 14-First cubic prism, 15-Roof pentaprism, 16-Right-angle prism, 17-Second cubic prism, 18-Eyepiece A, 19-Eyepiece B, 20-Eyepiece C, 21-Eyepiece D, 22-Eyepiece E, 23-Cemented surface of cubic prism 14, 24-Hyperbend of roof pentaprism 15, 25-Cemented surface of cubic prism 17, 26-Insulating liquid, 27-Conductive liquid, 28-Hydrophobic dielectric layer, 29-Electrode, 30-Glass cover. Detailed Implementation

[0058] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0059] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0060] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0061] Example 1

[0062] This embodiment provides a periscope aiming device based on a composite prism, see [link to previous document]. Figure 1 As shown, it includes a protective window 1, a head reflector 2, a common objective lens group 3, a compound prism 4, a laser assembly, a visible light observation assembly, and a near-infrared television observation assembly.

[0063] The protective window 1 is located at the front of the device to protect the internal optical system from external environmental influences. The protective window 1 forms a preset angle with the incident optical axis and is secured around its perimeter with sealing strips and silicone rubber adhesive, achieving a sealed and waterproof function for the device's interior. A broadband anti-reflective coating is deposited on the surface of the protective window 1 to reduce light reflection loss.

[0064] The head-mounted reflector 2 is positioned behind the protective window 1, with its reflective surface forming a 45° angle with the incident optical axis. Incident light emitted from the target is transmitted through the protective window 1 and then strikes the reflective surface of the head-mounted reflector 2. After reflection, the light path direction is altered, achieving a 90° deflection. The head-mounted reflector 2 can rotate relative to the incident optical axis, enabling target search and tracking. A broadband reflective coating is deposited on the reflective surface of the head-mounted reflector 2 to improve reflection efficiency.

[0065] The common objective lens group 3 is positioned in the reflected light path of the head mirror 2 to receive the light reflected by the head mirror 2. The common objective lens group 3 consists of a cemented lens and a single lens. The cemented lens, formed by cementing a positive and a negative lens, is used to correct chromatic aberration. The single lens is positioned after the cemented lens and is used to correct field curvature and distortion in the system. The common objective lens group 3 uses a high Abbe number achromatic material, and the entrance pupil of the optical system is located on the first objective lens frame of the common objective lens group 3.

[0066] The compound prism 4 is positioned in the transmission path of the shared objective lens group 3, see [reference]. Figure 2 As shown, the composite prism 4 is composed of a first cubic prism 14, a roof pentaprism 15, a right-angle prism 16, and a second cubic prism 17. The first cubic prism 14 and the roof pentaprism 15 are connected by a glued surface, with the glued surface 23 of the first cubic prism 14 serving as the first beam-splitting surface. The inclined side 24 of the roof pentaprism 15 serves as the second beam-splitting surface. The right-angle prism 16 is positioned after the roof pentaprism 15 and is used to transmit near-infrared light.

[0067] The laser assembly includes a laser bonding mirror 5, a laser filter 6, and a laser detector 7. The laser assembly is positioned on the reflected light path of the first beam splitter and is used to receive light in the laser band. After the target light passes through the protective window 1 and the head reflector 2 into the common objective lens group 3, it is reflected by the bonding surface 23 of the first cubic prism 14 in the compound prism 4, resulting in light in the first band. The reflected light then passes sequentially through the laser bonding mirror 5 and the laser filter 6 before being received by the laser detector 7.

[0068] The visible light aiming assembly includes a first liquid lens 8, a reticle 9, and an eyepiece group 10. The visible light aiming assembly is positioned on the reflected light path of the second beam splitter and is used to enable human eye observation of the target. After the target light passes through the protective window 1 and the head mirror 2, it enters the common objective lens group 3. The cemented surface 23 of the first cubic prism 14 in the compound prism 4 transmits light in the second and third wavelength bands. The transmitted light then enters the roof pentaprism 15, where the hypotenuse 24 reflects the second wavelength band light. The reflected light passes through the first liquid lens 8 and forms an image on the reticle 9. The human eye observes the image on the reticle 9 through the eyepiece group 10.

[0069] The near-infrared television viewing assembly includes a second liquid lens 11, a television cemented lens 12, and a near-infrared imaging device 13. The near-infrared television viewing assembly is positioned on the transmission light path of the second beam splitter to achieve near-infrared imaging. Target light enters the common objective lens group 3 through the protective window 1 and head reflector 2. The cemented surface 23 of the first cubic prism 14 in the compound prism 4 transmits light in the second and third wavelength bands. The transmitted light then enters the roof pentaprism 15, where the hypotenuse 24 transmits the third wavelength band light. After passing through the right-angle prism 16, the transmitted light is converged by the second liquid lens 11 and the television cemented lens 12, and is received by the near-infrared imaging device 13.

[0070] The curvature of the first liquid lens 8 and the second liquid lens 11 is variable, achieving zoom functionality by changing the curvature. The first liquid lens 8 is cascaded with the common objective lens group 3 and the eyepiece group 10 to form a visible light continuous zoom objective lens. The curvature of the first liquid lens 8 is controlled by a drive circuit, and its combination with the common objective lens group 3 and the eyepiece group 10 achieves the zoom effect. The second liquid lens 11 is cascaded with the common objective lens group 3 and the television cemented lens 12 to form a near-infrared continuous zoom objective lens. The curvature of the second liquid lens 11 is controlled by a drive circuit, and its combination with the common objective lens group 3 and the television cemented lens 12 achieves the zoom effect.

[0071] The head-mounted reflector 2 can perform azimuth and elevation scans, and its rotation enables real-time searching of the target and its surrounding environment. Operators can perform periscope-style observation and aiming without moving, ensuring smooth human-machine operation. The operator and the protective window 1 are not on the same horizontal plane, facilitating concealment and enhancing security.

[0072] Example 2

[0073] The difference from Embodiment 1 is that this embodiment provides a detailed description of the specific structure of the visible light observation component.

[0074] The shared objective group 3 consists of a cemented lens and a single lens. The cemented lens is made by cementing a positive lens and a negative lens together. The positive lens is made of high Abbe number crown glass, and the negative lens is made of lanthanum flint glass. This combination is designed to correct chromatic aberration in the center band of visible light. The single lens is made of aberrant dispersion glass and is positioned after the cemented lens. It is designed to match the reticle 9 and is used to correct field curvature and distortion in the system.

[0075] First liquid lens 8 (see also) Figure 4 As shown, the first liquid lens 8 is a glass cylinder structure, composed of an insulating liquid 26, a conductive liquid 27, a hydrophobic dielectric layer 28, an electrode 29, and a glass cover plate 30. The transparent electrode 29 and the hydrophobic dielectric layer 28 are sequentially deposited on the inner wall of the glass cylinder. The insulating liquid 26 and the conductive liquid 27 fill the interior of the glass cylinder; these two liquids are incompatible. The conductive liquid 27 and the electrode 29 form a capacitor. By applying a voltage across the electrode 29, the interfacial tension between the conductive liquid 27 and the hydrophobic dielectric layer 28 is changed, thereby altering the contact angle between them and achieving a change in the shape of the interface between the two liquids. This enables the first liquid lens 8 to perform a zoom function.

[0076] The reticle 9 is made of high-gloss flat glass, with etched aiming lines on its reticle surface to provide aiming reference. The reticle 9 is positioned between the first liquid lens 8 and the eyepiece group 10, and the first liquid lens 8 images light onto the reticle 9.

[0077] See eyepiece group 10. Figure 3 As shown, eyepiece group 10 includes eyepieces A18, B19, C20, D21, and E22. Eyepiece A18 is a left-convex-right-concave lens, and eyepiece B19 is a biconvex lens. Eyepieces A18 and B19 are coaxially cemented together to form a first cemented lens. Eyepiece C20 is a biconvex lens, and eyepiece D21 is a left-concave-right-convex lens. Eyepieces C20 and D21 are coaxially cemented together to form a second cemented lens. Eyepiece E22 is a biconvex lens and is positioned after eyepiece D21. Eyepieces A18, B19, C20, D21, and E22 are located on the same optical axis.

[0078] The first liquid lens 8 is cascaded with the common objective lens group 3 and the eyepiece group 10 to form a visible light continuous zoom objective lens. The curvature of the first liquid lens 8 is controlled by a drive circuit, achieving the zoom effect in combination with the common objective lens group 3 and the eyepiece group 10. Through matching optical glass materials, curvature, and thickness, the common objective lens group 3, the first liquid lens 8, and the eyepiece group 10 employ a multi-configuration, wide-band global optimization algorithm to dynamically compensate for the inherent and dynamic aberrations of the first liquid lens 8, achieving wide-band apochromatic aberration and clear imaging throughout the entire zoom range.

[0079] Example 3

[0080] The difference from Embodiment 1 is that this embodiment provides a detailed description of the specific structure of the near-infrared television viewing component.

[0081] The structure of the second liquid lens 11 is the same as that of the first liquid lens 8. See [link / reference] Figure 4 As shown, the second liquid lens 11 is a glass cylinder structure, composed of an insulating liquid 26, a conductive liquid 27, a hydrophobic dielectric layer 28, an electrode 29, and a glass cover plate 30. The transparent electrode 29 and the hydrophobic dielectric layer 28 are sequentially deposited on the inner wall of the glass cylinder. The insulating liquid 26 and the conductive liquid 27 fill the interior of the glass cylinder; these two liquids are incompatible. By applying a voltage across the electrode 29 to change the interface shape between the two liquids, the zoom function of the second liquid lens 11 is achieved.

[0082] The television cemented lens 12 is composed of a positive lens and a negative lens cemented together. The positive lens is made of calcium fluoride crystal material, and the negative lens is made of fused silica. This combination is designed to correct chromatic aberration in the near-infrared spectrum. The television cemented lens 12 is positioned between the second liquid lens 11 and the near-infrared imaging device 13 to focus light onto the near-infrared imaging device 13.

[0083] The near-infrared imaging device 13 is a near-infrared camera used to receive light in the near-infrared band and perform imaging.

[0084] The second liquid lens 11 is cascaded with the common objective lens group 3 and the television cemented lens 12 to form a near-infrared continuous zoom objective lens. The curvature of the second liquid lens 11 is controlled by a drive circuit, achieving the zoom effect in combination with the common objective lens group 3 and the television cemented lens 12. Through matching optical glass materials, curvature, and thickness, the common objective lens group 3, the second liquid lens 11, and the television cemented lens 12 rationally allocate optical power, actively generating aberrations of opposite sign to those of the second liquid lens 11 throughout the zoom range and near-infrared operating band. This achieves dynamic balance in the optical system, resulting in clear imaging.

[0085] Example 4

[0086] The difference from Example 1 is that this example provides a detailed description of the specific structure of the composite prism 4.

[0087] See compound prism 4 Figure 2 As shown, it is composed of a first cubic prism 14, a ridge pentagonal prism 15, a right-angle prism 16, and a second cubic prism 17.

[0088] The first cubic prism 14 is cubic in shape. Its glued surface 23 serves as the first beam-splitting surface. The glued surface 23 is coated with a semi-reflective, semi-transparent spectral splitting film for broadband spectral splitting. The glued surface 23 reflects light in the first wavelength band and transmits light in the second and third wavelength bands. The first cubic prism 14 is connected to the roof pentagonal prism 15 via the glued surface 23.

[0089] The ridge pentaprism 15 is shaped like a pentaprism with a ridge structure at the top. The inclined side 24 of the ridge pentaprism 15 serves as the second beam-splitting surface, coated with a semi-reflective, semi-transparent spectral splitting film for wide-band spectral splitting. The inclined side 24 reflects light in the second band and transmits light in the third band. The bottom surface of the ridge pentaprism 15 is glued to the adhesive surface 23 of the first cubic prism 14, and the incident and exit surfaces of the ridge pentaprism 15 are on the same plane. The ridge structure of the ridge pentaprism 15 is used to achieve image inversion (vertical, horizontal, and vertical), resulting in an upright image.

[0090] The right-angle prism 16 is a right-angled triangle and is positioned behind the pentagonal prism 15 on the roof ridge to transmit light in the third band.

[0091] The compound prism 4, through the combination of four prisms, achieves optical path folding, image inversion, and three-band beam splitting. The cemented surface 23 of the cubic prism 14 achieves the first-order beam splitting, separating the first band from the second and third bands. The inclined side 24 of the roof pentaprism 15 achieves the second-order beam splitting, separating the second band from the third band. The compound prism 4 has no moving parts, high optical axis stability, and a compact structure.

[0092] Example 5

[0093] This embodiment provides a detailed explanation of the application of the design method for a periscope aiming device based on a composite prism.

[0094] As is well known, optical zoom systems need to achieve apochromatic aberration throughout the zoom range during design. Traditional optical zoom systems control the displacement of solid lenses through complex mechanical structures to change magnification and focal length; that is, they change the focal length by physically moving the lens group. Therefore, the core of their design is "materials" and "structure." Utilizing the dispersion characteristics of different optical glasses, apochromatic cemented lenses are formed by cementing low-dispersion crown glass and high-dispersion flint glass lenses, splitting a single lens with high optical power into two or more separate lenses. By systematically designing the optical power, shape, and materials of each lens group, positive and negative optical power are distributed to different lens groups. Each lens group produces a specific amount of chromatic aberration, allowing the chromatic aberration produced by the previous group to be precisely compensated by the subsequent group, ultimately achieving apochromatic aberration throughout the zoom range.

[0095] However, after replacing the traditional zoom lens with a liquid lens in this invention, the following problems arise when designing the optical zoom system:

[0096] (1) The materials are simple and fixed.

[0097] At its core, a liquid lens consists of one or more fixed transparent windows and two liquids with different but constant refractive indices, typically oil and water-based solutions. The design cannot select or change the liquid materials, thus losing the most important method in traditional design—the ability to correct chromatic aberration by choosing combinations of various glass materials. Furthermore, the Abbe number and partial dispersion of the liquid are fixed and often undesirable (e.g., water has an Abbe number of approximately 55, and various oils have lower Abbe numbers), and it is difficult to find liquid combinations with anomalous partial dispersion, such as calcium fluoride. This results in a very severe inherent second-order spectrum in the system, which is difficult to eliminate using traditional methods.

[0098] (2) Dynamic changes in interface curvature

[0099] Liquid lenses achieve zoom and magnification by changing the curvature of the liquid-liquid interface. The dynamically changing surface produces aberrations that vary with the focal length. In traditional designs, aberrations can be corrected for each fixed zoom position by finely adjusting the lens shape and spacing. However, in liquid lenses, the interface shape changes continuously, rendering the traditional "fixed-point optimization" method ineffective. It is necessary to seek image quality balance across the entire focal length range, increasing the design complexity.

[0100] (3) The reduction of degrees of freedom brought about by the simplification of system structure

[0101] Replacing mechanically moving lens groups with liquid lenses allows for system miniaturization and faster operation, but reduces available physical degrees of freedom (such as changes in distance between lens groups). Traditional zoom systems rely on lens movement to maintain image plane stability and image quality during zooming, but in liquid lens zoom optics, the compensation mechanism disappears, and all aberration correction pressure is concentrated on the remaining fixed lens groups.

[0102] It is evident that the introduction of liquid lenses has led to two major challenges: "fixed and single available materials" and "dynamic changes in the interface," rendering traditional apochromatic design methods that rely on complex glass materials and static structural optimization almost ineffective.

[0103] To address the aforementioned shortcomings, the present invention employs the following design methods in its optical design:

[0104] Step S1: Determine the aberration characteristics of the liquid lens under different curvatures. For the first liquid lens 8, simulate its aberration characteristics in the visible light band, including axial chromatic aberration, magnification chromatic aberration, spherical aberration, coma, field curvature, and distortion, as its curvature changes. For the second liquid lens 11, simulate its aberration characteristics in the near-infrared band, including axial chromatic aberration, magnification chromatic aberration, spherical aberration, coma, field curvature, and distortion, as its curvature changes. Accurate simulation of the aberration characteristics of the liquid lens under different voltages provides a data foundation for subsequent aberration compensation design.

[0105] Step S2: Select the optical elements for the front and rear fixed groups. For the visible light band, the front fixed group is a common objective lens group 3, employing an apochromatic cemented lens and an anomalous dispersion glass single lens. The apochromatic cemented lens is composed of a positive lens and a negative lens cemented together; the positive lens is made of high Abbe number crown glass, and the negative lens is made of lanthanum flint glass. The single lens is made of anomalous dispersion glass. The rear fixed group is eyepiece group 10, employing a cemented doublet and a single lens. The cemented doublet includes a first cemented lens and a second cemented lens; the first cemented lens consists of eyepieces A18 and B19, and the second cemented lens consists of eyepieces C20 and D21. The single lens is eyepiece E22.

[0106] For the near-infrared band, the front fixed group is a shared objective lens group 3, with the same structure as above. The rear fixed group is a television cemented lens 12, which is a cemented lens composed of a calcium fluoride crystal positive lens and a fused silica negative lens.

[0107] Step S3: Actively generate aberrations of opposite sign to those of the liquid lens throughout the zoom range. For the visible light band, by adjusting the radius of curvature, center thickness, and material combination of the common objective lens group 3 and the eyepiece group 10, axial chromatic aberration and magnification chromatic aberration of opposite sign to those of the first liquid lens 8 are generated under multiple typical configurations. For the near-infrared band, by adjusting the optical power distribution of the common objective lens group 3 and the television cemented lens 12, axial chromatic aberration and magnification chromatic aberration of opposite sign to those of the second liquid lens 11 are generated under multiple typical configurations. By actively generating aberrations of opposite sign through the front and rear fixed groups, dynamic balance of aberrations is achieved.

[0108] Step S4: Dynamically compensate for aberrations using a multi-configuration optimization algorithm. An optimization function is set to cover multiple typical configurations, each containing multiple wavelengths. For the visible light band, multiple wavelengths are covered. For the near-infrared band, multiple wavelengths are covered. Optimization targets include imaging quality indicators such as axial chromatic aberration, magnification chromatic aberration, and modulation transfer function. Optimization variables include the radius of curvature and center thickness of the shared objective lens group 3, the radius of curvature and center thickness of the eyepiece group 10, and the radius of curvature and center thickness of the television cemented lens 12. Through the multi-configuration optimization algorithm, apochromatic aberration is achieved throughout the zoom range, dynamically compensating for the inherent and dynamic aberrations of the liquid lens to ensure clear imaging.

[0109] The periscope aiming device based on a composite prism proposed in this invention was finally obtained through the above design method.

[0110] In embodiments of the present invention, the solid lens of the visible light viewing assembly and the near-infrared television viewing assembly includes a common objective lens group 3, a reticle 9, an eyepiece group 10, and a television cemented lens 12, wherein the radius of curvature r, center thickness d, refractive index N, and Abbe number V of each surface satisfy the following table:

[0111]

[0112] The periscope aiming device design method based on a compound prism provided in this embodiment solves the problem of apochromatic design failure caused by the single and fixed material of the liquid lens and the dynamic change of the interface curvature. This design method abandons the traditional approach of relying on the liquid lens itself for aberration correction, and adopts the design concept of "global aberration matching and compensation". By actively generating aberrations with opposite signs to those of the liquid lens through front and rear fixed groups, and combining multi-configuration optimization algorithms, apochromatic aberration is achieved throughout the zoom range and wide band, dynamically compensating for the inherent and dynamic aberrations of the liquid lens, and ensuring clear imaging.

[0113] This invention utilizes a head-mounted reflector 2 search technology to achieve a multi-functional periscope-style observation and targeting system integrating visible light observation, near-infrared television observation, and laser reception without requiring personnel movement. By employing a shared composite prism 4 optical structure, it achieves spectral splitting across three wavelengths. The system has no moving parts, boasts high optical axis stability and precision, and features a compact structure and low cost. Furthermore, by introducing liquid lenses into the visible light and near-infrared television observation components, it enables rapid magnification without the need for moving zoom components, achieving miniaturization, low power consumption, and high detection and recognition efficiency in the periscope-style observation and targeting device.

[0114] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

[0115] The composite prism includes a first beam-splitting surface and a second beam-splitting surface. The first beam-splitting surface reflects laser light and transmits visible and near-infrared light, while the second beam-splitting surface reflects visible light and transmits near-infrared light. The visible light observation and aiming components and the near-infrared television observation and aiming components each include a liquid lens with variable curvature. By replacing the mechanically moving lens group with a liquid lens, a 100ms rapid zoom is achieved, which is 20 times faster than the traditional 2-second zoom time, resulting in miniaturization, low power consumption, and high detection and recognition efficiency.

[0116] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A periscope-style aiming device based on a compound prism, comprising a protective window, a head mirror, and a common objective lens group, characterized in that, Also includes: A composite prism, located in the transmission light path of the shared objective lens group, the composite prism comprising a first beam-splitting surface and a second beam-splitting surface; The first beam-splitting surface reflects the first waveband and transmits the second and third wavebands. The second beam-splitting surface reflects the second waveband and transmits the third waveband; A laser assembly, located on the reflected light path of the first beam-splitting surface, includes a laser detector; A visible light observation and aiming assembly, located on the reflected light path of the second beam splitter, the visible light observation and aiming assembly comprising a first liquid lens, a reticle, and an eyepiece group; A near-infrared television viewing and aiming assembly, wherein the near-infrared television viewing and aiming assembly is located in the transmission light path of the second beam splitter, and the near-infrared television viewing and aiming assembly includes a second liquid lens, a television cemented lens, and a near-infrared imaging device; The curvatures of the first liquid lens and the second liquid lens are variable; The protective window forms a preset angle with the incident optical axis; The reflective surface of the head mirror forms a 45° angle with the incident optical axis, and the head mirror can rotate relative to the incident optical axis. The shared objective lens group includes at least one cemented lens.

2. The periscope aiming device based on a composite prism according to claim 1, characterized in that, The first liquid lens is cascaded with the common objective lens group and the eyepiece group, and the second liquid lens is cascaded with the common objective lens group and the television cemented lens.

3. The periscope aiming device based on a composite prism according to claim 2, characterized in that, The first band is the 1.064μm laser band, the second band is the 450nm~650nm visible light band, and the third band is the 700nm~900nm near-infrared band; the first beam-splitting surface is coated with a beam-splitting film that reflects the 1.064μm laser band and transmits the 450nm~650nm visible light band and the 700nm~900nm near-infrared band; the second beam-splitting surface is coated with a beam-splitting film that reflects the 450nm~650nm visible light band and transmits the 700nm~900nm near-infrared band.

4. The periscope aiming device based on a composite prism according to claim 2, characterized in that, The azimuth rotation range of the head reflector is -4° to +4°, and the pitch rotation range is -7° to +18°; the angle between the protective window and the incident optical axis is 3° to 7°.

5. The periscope aiming device based on a composite prism according to claim 1, characterized in that, The composite prism is composed of a cubic prism, a ridge pentagonal prism, and a right-angle prism; the glued surface of the cubic prism serves as the first beam-splitting surface, and the hypotenuse of the ridge pentagonal prism serves as the second beam-splitting surface.

6. The periscope aiming device based on a composite prism according to claim 1, characterized in that, The shared objective lens group also includes a single lens, which is made of anomalous dispersion glass; the positive lens of the cemented lens of the shared objective lens group is made of high Abbe number crown glass, and the negative lens is made of lanthanum flint glass.

7. The periscope aiming device based on a composite prism according to claim 1, characterized in that, Both the first liquid lens and the second liquid lens include two incompatible liquids, electrodes, and a dielectric layer. The interface curvature of the two incompatible liquids is changed by applying a voltage across the electrodes. The first liquid lens has an aperture of 8mm to 12mm and a curvature range of 15mm to 160mm. The second liquid lens has an aperture of 6mm to 10mm and a curvature range of 30mm to 130mm.

8. A design method for a periscope-style aiming device based on a compound prism, characterized in that, Includes the following steps: S1: Determine the aberration characteristics of the liquid lens under different curvatures; S2: Select optical elements for the front fixation group and the rear fixation group, wherein the front fixation group is located in front of the liquid lens and the rear fixation group is located behind the liquid lens; S3: Throughout the zoom range, the front fixed group and the rear fixed group actively generate aberrations with opposite signs to those of the liquid lens to achieve dynamic aberration balance. S4: Employs a multi-configuration optimization algorithm to cover aberrations under all zoom configurations and dynamically compensates for the inherent and dynamic aberrations of the liquid lens.

9. The design method of the periscope aiming device based on a compound prism according to claim 8, characterized in that, In step S2, for the visible light band, the front fixing group uses an apochromatic cemented lens and an anomalous dispersion glass single lens, and the rear fixing group uses a double cemented lens and a single lens; for the near-infrared band, the rear fixing group uses a cemented lens composed of a calcium fluoride crystal positive lens and a fused silica negative lens.

10. The design method of the periscope aiming device based on a compound prism according to claim 9, characterized in that, The positive lens of the apochromatic cemented mirror is H-FK95, the negative lens is H-LaF62, and the single lens of the anomalous dispersion glass is H-FK61; the double cemented mirror includes a first cemented mirror and a second cemented mirror, the first cemented mirror is composed of H-ZF88 and H-FK61, and the second cemented mirror is composed of H-K9L and H-ZF3; the calcium fluoride crystal has a refractive index of 1.43 and an Abbe number of 95, and the fused silica has a refractive index of 1.46 and an Abbe number of 68.

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