Dual-band confocal-plane optical system

Abstract

The invention discloses a dual-band confocal-plane optical system which comprises an infrared optical system and a visible light optical system, the infrared optical system and the visible light optical system are designed in a common-aperture and common-focal-plane mode in a nested fusion mode, and specifically, holes are formed in the centers of a first infrared lens and a second infrared lens of the infrared optical system; the hole diameter corresponding to the hole is greater than the diameter corresponding to each visible light lens; the first visible light lens, the second visible light lens and the third visible light lens are inserted into the holes of the first infrared lens and the second infrared lens; the common-path lens, the detector assembly and the visible light lenses are located on the same horizontal line, and the common-path lens is used for sharing the infrared optical system and the visible light optical system and converging light paths to the detector focal plane of the detector assembly. By applying the system, the coaxial precision of the system can be improved through the common aperture design; in addition, manufacturing cost is low, machining and assembling manufacturability is good, and batch production is facilitated.

Description

Technical Field

[0001] The present application relates to the field of multi-band optical technology, and in particular to a dual-band confocal optical system. Background Art

[0002] In recent years, with the continuous development of technology, users' requirements for low-cost, miniaturized, multi-band optoelectronic observation equipment in application fields such as handheld observation and security monitoring are also increasing.

[0003] The detection capabilities of traditional single-band optoelectronic observation equipment have gradually become insufficient. Although multi-band optoelectronic observation equipment has obvious advantages in information acquisition, its cost, volume and weight have also increased significantly compared to single-band equipment.

[0004] In view of this, how to provide a new dual-band confocal optical system that balances the stability dimension, accuracy and effective carrying space of the current system has become a technical problem that urgently needs to be solved. Summary of the invention

[0005] The embodiment of the present application provides a dual-band confocal optical system for solving the contradiction between the stability dimension, accuracy and effective carrying space of the current system.

[0006] In a first aspect of an embodiment of the present application, a dual-band confocal plane optical system is provided, the dual-band confocal plane optical system comprising an infrared optical system and a visible light optical system, the infrared optical system and the visible light optical system are designed with a common aperture and a confocal plane by means of nested fusion, wherein:

[0007] The infrared optical system is provided with a first infrared lens, a second infrared lens, a common light path lens and a detector assembly in sequence along the incident direction of the light from left to right, wherein the first infrared lens and the second infrared lens are provided with holes at their centers, and the hole diameters corresponding to the holes are larger than the diameters corresponding to the visible light lenses;

[0008] The visible light optical system is arranged in sequence along the incident direction of the light from left to right, including a first visible light lens, a second visible light lens, a visible light aperture, a third visible light lens, a common light path lens, and a detector assembly, wherein the first visible light lens, the second visible light lens, and the third visible light lens are inserted into the openings of the first infrared lens and the second infrared lens; the common light path lens and the detector assembly are on the same horizontal line as each visible light lens, and the common light path lens is used to share the infrared optical system and the visible light optical system to converge the light path onto the detector focal plane of the detector assembly.

[0009] Optionally, a visible light stop is further provided between the second visible light lens and the third visible light lens, for maintaining the structure of the visible light optical system as a double Gaussian structure.

[0010] Optionally, the first infrared lens and the second infrared lens are plano-convex, bi-convex or meniscus lenses with positive optical power, wherein the focal length f1' of the first infrared lens satisfies: 5mm≤focal length f1'≤500mm; the focal length f2' of the second infrared lens satisfies: 5mm≤focal length f2'≤500mm.

[0011] Optionally, the common light path lens is a plano-concave, bi-concave or negative meniscus lens with negative optical power, wherein the focal length f3' of the common light path lens satisfies: -1000mm≤focal length f3'≤-5mm.

[0012] Optionally, the first visible light lens and the third visible light lens are plano-convex, bi-convex, positive meniscus lenses or cemented lenses with positive optical power, wherein the focal length f4' of the first visible light lens satisfies: 5mm≤focal length f4'≤500mm; the focal length f7' of the third visible light lens satisfies: 5mm≤focal length f7'≤500mm.

[0013] Optionally, the second visible light lens is a plano-concave, bi-concave, negative meniscus lens or cemented lens with negative optical power, wherein the focal length f5' of the second visible light lens satisfies: -500mm≤focal length f5'≤-5mm.

[0014] Optionally, F#1 of the infrared optical system satisfies: 0.8≤F#1≤2;

[0015] The system focal length f of the infrared optical system I ' R Satisfy: 5mm≤system focal length f I ' R ≤200mm;

[0016] The total system length L1 of the infrared optical system satisfies: 4 mm ≤ total system length L1 ≤ 400 mm.

[0017] Optionally, F#2 of the visible light optical system satisfies: 0.8≤F#2≤10;

[0018] The system focal length f' of the infrared optical system VIS Satisfy: 5mm≤system focal length f' VIS ≤200mm;

[0019] The total system length L2 of the infrared optical system satisfies: 4 mm ≤ total system length L2 ≤ 400 mm.

[0020] The present application provides a dual-band confocal plane optical system, which includes an infrared optical system and a visible light optical system. The infrared optical system and the visible light optical system are designed with a common aperture and a common focal plane by means of nested fusion, wherein the infrared optical system is sequentially arranged along the incident direction of light from left to right as a first infrared lens, a second infrared lens, a common light path lens and a detector assembly, wherein the first infrared lens and the second infrared lens are provided with holes at their centers, and the hole diameters corresponding to the holes are larger than the diameters corresponding to the visible light lenses; the visible light optical system is sequentially arranged along the incident direction of light from left to right as a first visible light lens, a second visible light lens, a visible light stop, a third visible light lens, a common light path lens and a detector assembly, wherein the first visible light lens, the second visible light lens and the third visible light lens are inserted into the openings of the first infrared lens and the second infrared lens; the common light path lens and the detector assembly are on the same horizontal line as the visible light lenses, and the common light path lens is used to share the infrared optical system and the visible light optical system and converge the light path onto the detector focal plane of the detector assembly.

[0021] The dual-band confocal optical system provided by the embodiment of the present application has the following beneficial effects:

[0022] 1. The optical system of the present invention uses conventional lenses and conventional materials to realize dual-band confocal surface design, which has the advantages of low manufacturing cost, good processing and assembly processability, and is suitable for mass production;

[0023] 2. The optical system of the present invention realizes dual-band confocal surface design by nesting, and realizes two lens designs within the volume envelope of one lens, which has the advantages of small size and light weight;

[0024] 3. The optical system of the present invention can achieve the application effect of two lenses plus two detectors by using one lens plus one detector, and can subsequently replace the existing optical system in the fields of gun sights, handheld observation equipment, etc.;

[0025] 4. The optical system of the present invention has the advantages of high reliability and good environmental adaptability;

[0026] 5. The optical system of the present invention is designed with a common aperture, which is beneficial to improving the coaxial accuracy of the system.

[0027] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, which can be implemented in accordance with the contents of the specification, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0029] Figure 1 A schematic diagram of an optical path diagram of a dual-band confocal optical system provided in an embodiment of the present application;

[0030] Figure 2 A schematic diagram of an optical path diagram of an infrared optical system of a dual-band confocal optical system provided in an embodiment of the present application;

[0031] Figure 3 A schematic diagram of a normal temperature optical transfer function MTF curve of an infrared optical system of a dual-band confocal optical system provided in an embodiment of the present application;

[0032] Figure 4 A schematic diagram of distortion and field curvature curves of an infrared optical system of a dual-band confocal optical system provided in an embodiment of the present application;

[0033] Figure 5 A schematic diagram of an optical path diagram of an infrared optical system and a visible light optical system of a dual-band confocal optical system provided in an embodiment of the present application;

[0034] Figure 6 A schematic diagram of a normal temperature optical transfer function MTF curve of an infrared optical system and a visible light optical system of a dual-band confocal optical system provided in an embodiment of the present application;

[0035] Figure 7 A schematic diagram of distortion and field curvature curves of an infrared optical system and a visible light optical system of a dual-band confocal optical system provided in an embodiment of the present application;

[0036] Among them, there are infrared lens-1, infrared lens-2, visible light lens-4, visible light lens-5, visible light aperture-6, visible light lens-7, common light path lens-3 and detector assembly-8. DETAILED DESCRIPTION

[0037] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0038] In order to solve the current problems, the development of miniaturized, low-cost multi-band confocal optical systems is an important research direction. Multi-band confocal optical systems can not only meet the user's low-cost miniaturized, multi-band application needs, but also take into account the advantages of small size and light weight of single-band optical systems, and will definitely become one of the important trends in subsequent development.

[0039] The purpose of this application is to provide a dual-band confocal plane optical system and a design method. In view of the wide application prospects of the dual-band confocal plane optical system in the fields of handheld observation, security monitoring and gun sights, it is necessary to invent a dual-band confocal plane optical system with a simple and compact structure, low cost, high performance, high strength and high environmental adaptability to replace traditional single-band and multi-band optoelectronic observation equipment and enhance its market competitiveness.

[0040] See also Figure 1 , Figure 1 A schematic diagram of an optical path diagram of a dual-band confocal plane optical system provided in an embodiment of the present application.

[0041] like Figure 1 As shown, the dual-band confocal plane optical system includes an infrared optical system and a visible light optical system. The infrared optical system and the visible light optical system are designed with a common aperture and confocal plane by means of nested fusion.

[0042] Among them, the infrared optical system is arranged in sequence along the incident direction of the light from left to right, including a first infrared lens, a second infrared lens, a common light path lens and a detector assembly, wherein holes are provided in the centers of the first infrared lens and the second infrared lens, and the hole diameters corresponding to the holes are larger than the diameters corresponding to the visible light lenses, thereby ensuring that the visible light lenses can be inserted.

[0043] The visible light optical system is arranged in sequence along the incident direction of the light from left to right, including a first visible light lens, a second visible light lens, a visible light aperture, a third visible light lens, a common light path lens, and a detector assembly, wherein the first visible light lens, the second visible light lens, and the third visible light lens are inserted into the openings of the first infrared lens and the second infrared lens; the common light path lens and the detector assembly are on the same horizontal line as each visible light lens, and the common light path lens is used to share the infrared optical system and the visible light optical system to converge the light path onto the detector focal plane of the detector assembly.

[0044] In the embodiment of the present application, a visible light stop is further provided between the second visible light lens and the third visible light lens, for maintaining the structure of the visible light optical system as a double Gaussian structure.

[0045] In an embodiment of the present application, the first infrared lens and the second infrared lens are plano-convex, bi-convex or meniscus lenses with positive optical power, wherein the focal length f1' of the first infrared lens satisfies: 5mm≤focal length f1'≤500mm; the focal length f2' of the second infrared lens satisfies: 5mm≤focal length f2'≤500mm.

[0046] It should be noted that the materials of the first infrared lens and the second infrared lens may be germanium, chalcogenide glass, zinc selenide and zinc sulfide, and the surface shape may be spherical or even-aspherical.

[0047] In the embodiment of the present application, the common light path lens is a plano-concave, bi-concave or negative meniscus lens with negative optical power, wherein the focal length f3' of the common light path lens satisfies: -1000mm≤focal length f3'≤-5mm.

[0048] It should be noted that the material of the common light path lens can be multi-spectrum zinc sulfide, zinc selenide or other wide-spectrum transmission materials, and the surface shape can be spherical or even-aspherical.

[0049] In the embodiment of the present application, the first visible light lens and the third visible light lens are plano-convex, bi-convex, positive meniscus lenses or cemented lenses with positive optical power, wherein the focal length f4' of the first visible light lens satisfies: 5mm≤focal length f4'≤500mm; the focal length f7' of the third visible light lens satisfies: 5mm≤focal length f7'≤500mm.

[0050] It should be noted that the surface shapes of the first visible light lens and the third visible light lens may be spherical surfaces or even-order aspherical surfaces.

[0051] In the embodiment of the present application, the second visible light lens is a plano-concave, bi-concave, negative meniscus lens or cemented lens with negative optical power, wherein the focal length f5' of the second visible light lens satisfies: -500mm≤focal length f5'≤-5mm.

[0052] It should be noted that the surface of the second visible light lens may be a spherical surface or an even-order aspherical surface.

[0053] In the embodiment of the present application, F#1 of the infrared optical system satisfies: 0.8≤F#1≤2;

[0054] The system focal length f of the infrared optical system I ' R Satisfy: 5mm≤system focal length f I ' R ≤200mm;

[0055] The total system length L1 of the infrared optical system satisfies: 4 mm ≤ total system length L1 ≤ 400 mm.

[0056] In the embodiment of the present application, F#2 of the visible light optical system satisfies: 0.8≤F#2≤10;

[0057] The system focal length f' of the infrared optical system VIS Satisfy: 5mm≤system focal length f' VIS ≤200mm;

[0058] The total system length L2 of the infrared optical system satisfies: 4 mm ≤ total system length L2 ≤ 400 mm.

[0059] according to Figure 1 The optical path diagram of the system is shown in Example 1, wherein the focal length of the infrared optical system is 60 mm, the F number is 1.1, the field of view is ±12.4°, the total length of the optical system is 90 mm, and the design wavelength is 8-12 μm. Figure 2 As shown, Figure 2 A schematic diagram of an optical path diagram of an infrared optical system of a dual-band confocal plane optical system provided in an embodiment of the present application.

[0060] The specific parameters are shown in Table 1.

[0061] Table 1

[0062] Surface serial number Face type Radius of curvature Center thickness Material S1 Aspheric 94.03 4.50 Ge S2 Aspheric 121.3 3.9 S3(Aperture) flat infinity 33 S4 Aspheric -115.55 5 IG4 S5 Spherical -79.676 30.03 S6 Aspheric 53.44 4 ZNS S7 Aspheric 46.88 9 Image plane Spherical infinity 0

[0063] Rotationally symmetric even-order aspheric surfaces satisfy the following equations:

[0064]

[0065] In the above formula, Z is the vector height from the vertex of the aspheric surface when the aspheric surface is at a height of Y along the optical axis, R is the paraxial curvature radius of the lens, K is the cone coefficient, and A, B, C, and D are high-order aspheric coefficients.

[0066] Table 2 shows the aspheric parameters of this embodiment.

[0067] Table 2

[0068] K A B C D S1 0 -2.91505E-7 -8.35128E-11 -8.05268E-14 0 S2 0 -1.13218E-7 -4.42535E-11 8.2754E-13 0 S4 0 -3.3907E-7 2.17185E-10 -4.52822E-14 0 S6 0 5.819945E-6 -2.50053E-8 -8.0702E-11 0 S7 0 1.30571E-5 -4.00297E-8 -1.21107E-10 0

[0069] The MTF curve of the optical system of this embodiment 1 is as follows Figure 3 As shown, Figure 3 A schematic diagram of the room temperature optical transfer function MTF curve of an infrared optical system of a dual-band confocal optical system provided in an embodiment of the present application. Distortion and spherical aberration curves are shown in FIG. Figure 4 As shown, Figure 4 A schematic diagram of distortion and field curvature curves of an infrared optical system of a dual-band confocal optical system provided in an embodiment of the present application.

[0070] according to Figure 1 The optical path diagram of the system is shown in Example 1, wherein the focal length of the visible light optical system is 60 mm, the F number is 6, the field of view is ±12.4°, the total length of the optical system is 90 mm, and the design wavelength is 486 nm-656 nm. Figure 5 As shown, Figure 5 A schematic diagram of an optical path diagram of an infrared optical system and a visible light optical system of a dual-band confocal optical system provided in an embodiment of the present application.

[0071] The specific parameters are shown in Table 3.

[0072] Table 3

[0073] Surface serial number Face type Radius of curvature Center thickness Material S1 Spherical 23.93 3.5 HZF52 S2 Spherical 76.54 1.61 S3 Spherical 23.93 3.9 HBAK3 S4 Spherical -74.84 2 HZF52 S5 Spherical 11.2 16.8 S6 Spherical -172.6 4 HBAK4 S7 Spherical -17.5 44.66 S8 Aspheric 53.44 4 ZNS S9 Aspheric 46.88 9 Image plane Spherical infinity 0

[0074] Rotationally symmetric even-order aspheric surfaces satisfy the following equations:

[0075]

[0076] In the above formula, Z is the vector height from the vertex of the aspheric surface when the aspheric surface is at a height of Y along the optical axis, R is the paraxial curvature radius of the lens, K is the cone coefficient, and A, B, C, and D are high-order aspheric coefficients.

[0077] Table 4 shows the aspheric parameters of this embodiment.

[0078] Table 4

[0079] K A B C D S6 0 5.819945E-6 -2.50053E-8 -8.0702E-11 0 S7 0 1.30571E-5 -4.00297E-8 -1.21107E-10 0

[0080] The MTF curve of the optical system of this embodiment 1 is as follows Figure 6 As shown, Figure 6 This is a schematic diagram of the room temperature optical transfer function MTF curve of the infrared optical system and the visible light optical system of a dual-band confocal optical system provided in an embodiment of the present application. Figure 7 As shown, Figure 7 A schematic diagram of distortion and field curvature curves of an infrared optical system and a visible light optical system of a dual-band confocal optical system provided in an embodiment of the present application.

[0081] The dual-band confocal optical system provided by the embodiment of the present application has the following beneficial effects:

[0082] 1. The optical system of the present invention uses conventional lenses and conventional materials to realize dual-band confocal surface design, which has the advantages of low manufacturing cost, good processing and assembly processability, and is suitable for mass production;

[0083] 2. The optical system of the present invention realizes dual-band confocal surface design by nesting, and realizes two lens designs within the volume envelope of one lens, which has the advantages of small size and light weight;

[0084] 3. The optical system of the present invention can achieve the application effect of two lenses plus two detectors by using one lens plus one detector, and can subsequently replace the existing optical system in the fields of gun sights, handheld observation equipment, etc.;

[0085] 4. The optical system of the present invention has the advantages of high reliability and good environmental adaptability;

[0086] 5. The optical system of the present invention is designed with a common aperture, which is beneficial to improving the coaxial accuracy of the system.

[0087] It should be noted that the above is a description of a specific embodiment of the present specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the embodiments of the present specification.

[0088] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0089] The preferred embodiments of this specification disclosed above are only used to help explain this specification. The optional embodiments do not describe all the details in detail, nor do they limit the invention to only the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of the embodiments of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the embodiments of this specification, so that technicians in the relevant technical field can well understand and use this specification. This specification is only limited by the claims and their full scope and equivalents.

Claims

1. A dual-band confocal optical system, characterized in that: The dual-band confocal optical system includes an infrared optical system and a visible light optical system. The infrared optical system and the visible light optical system are designed with a common aperture and a confocal surface by means of nested fusion, wherein: The infrared optical system is provided with a first infrared lens, a second infrared lens, a common light path lens and a detector assembly in sequence along the incident direction of the light from left to right, wherein the first infrared lens and the second infrared lens are provided with holes at their centers, and the hole diameters corresponding to the holes are larger than the diameters corresponding to the visible light lenses; The visible light optical system is arranged in sequence along the incident direction of the light from left to right, including a first visible light lens, a second visible light lens, a visible light aperture, a third visible light lens, a common light path lens, and a detector assembly, wherein the first visible light lens, the second visible light lens, and the third visible light lens are inserted into the openings of the first infrared lens and the second infrared lens; the common light path lens and the detector assembly are on the same horizontal line as each visible light lens, and the common light path lens is used to share the infrared optical system and the visible light optical system to converge the light path onto the detector focal plane of the detector assembly.

2. A dual-band confocal optical system according to claim 1, characterized in that: A visible light stop is further provided between the second visible light lens and the third visible light lens, for maintaining the structure of the visible light optical system as a double Gaussian structure.

3. A dual-band confocal optical system according to claim 1, characterized in that: The first infrared lens and the second infrared lens are plano-convex, biconvex or meniscus lenses with positive optical power, wherein the focal length f1' of the first infrared lens satisfies: 5mm≤focal length f1'≤500mm; the focal length f2' of the second infrared lens satisfies: 5mm≤focal length f2'≤500mm.

4. The dual-band confocal optical system according to claim 1, characterized in that: The common light path lens is a plano-concave, bi-concave or negative meniscus lens with negative optical power, wherein the focal length f3' of the common light path lens satisfies: -1000mm≤focal length f3'≤-5mm.

5. The dual-band confocal optical system according to claim 1, characterized in that: The first visible light lens and the third visible light lens are plano-convex, biconvex, positive meniscus lenses or cemented lenses with positive optical power, wherein the focal length f4' of the first visible light lens satisfies: 5mm≤focal length f4'≤500mm; the focal length f7' of the third visible light lens satisfies: 5mm≤focal length f7'≤500mm.

6. The dual-band confocal optical system according to claim 1, characterized in that: The second visible light lens is a plano-concave, bi-concave, negative meniscus lens or cemented lens with negative optical power, wherein the focal length f5' of the second visible light lens satisfies: -500mm≤focal length f5'≤-5mm.

7. The dual-band confocal optical system according to claim 1, characterized in that: F#1 of the infrared optical system satisfies: 0.8≤F#1≤2; The system focal length f of the infrared optical system I ' R Satisfy: 5mm≤system focal length f I ' R ≤200mm; The total system length L1 of the infrared optical system satisfies: 4 mm ≤ total system length L1 ≤ 400 mm.

8. The dual-band confocal optical system according to claim 1, characterized in that: F#2 of the visible light optical system satisfies: 0.8≤F#2≤10; The system focal length f' of the infrared optical system VIS Satisfy: 5mm≤system focal length f' VIS ≤200mm; The total system length L2 of the infrared optical system satisfies: 4mm≤total system length L2≤400mm.

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