A portable dovetail connected optical filter for spectral imaging

Abstract

This utility model belongs to the field of spectral filters and provides a portable optical filter with a mortise and tenon structure connection for spectral imaging. It includes a lens, the lens comprising a filter with a positioning surface on its annular edge. The positioning surface can be configured as an arc-shaped convex or concave surface. A protective ring is fitted around the outer side of the positioning surface. The protective ring includes a flexible washer disposed on the outer side of the filter. The inner annular surface of the flexible washer fits against the positioning surface, and a positioning ring is fitted around the outer side of the flexible washer. This utility model achieves integrated molding of the lens and protective ring, simplifying the processing technology and reducing costs. The protective ring also provides shock absorption to extend the lens's service life. Simultaneously, the mortise and tenon structure connects the positioning post and positioning hole, thereby compressing the flexible washer to tightly wrap the lens. This not only ensures stable and reliable installation but also improves sealing and prevents dust intrusion. It has the advantages of simple processing, low production cost, and long service life.

Description

Technical Field

[0001] This invention belongs to the field of spectral filters, specifically a portable optical filter with a tenon-and-mortise structure for spectral imaging. Background Technology

[0002] Hyperspectral imaging technology can acquire spectral information of a target object across multiple consecutive narrow bands, and has wide applications in many fields such as geological exploration, environmental monitoring, and agricultural remote sensing. In this technology, optical filters are responsible for accurately selecting light within a specific wavelength range from a complex mixed spectrum, and their performance directly determines the accuracy and reliability of the imaging system in acquiring the target's spectral information.

[0003] Traditional optical filters often employ a design with annular grooves carved into the edges to allow direct engagement with the lens's inner wall. For example, Chinese Patent CN214311037U discloses a portable mortise and tenon joint optical filter for spectral imaging. This filter, through the combined action of a front limiting ring, a rear limiting ring, and two semi-circular retaining rings, provides protection for the lens, effectively preventing edge wear caused by direct engagement between the lens and the filter, and reducing the damage rate.

[0004] However, in the manufacturing process, forming a precise annular groove structure for optical filters requires multiple complex machining steps, such as precision milling and engraving. This not only demands extremely high precision from the machining equipment but also significantly increases manufacturing costs. Furthermore, in actual use, the annular groove structure disrupts the continuity of the filter's edges. When subjected to vibration or impact, the cross-sectional dimensions at the annular groove undergo abrupt changes. This geometric discontinuity makes the annular groove a stress concentration point, easily damaging the filter and severely affecting the accuracy and stability of hyperspectral imaging. Utility Model Content

[0005] To address the aforementioned technical problems, this invention provides a portable mortise and tenon joint optical filter for spectral imaging, which solves the problems of complex processing and high cost associated with the annular groove structure of traditional optical filters.

[0006] A portable mortise and tenon joint optical filter for spectral imaging includes a lens, the lens including a filter with a positioning surface on its annular edge, a protective ring sleeved on the outer side of the positioning surface, the protective ring including a flexible washer disposed on the outer side of the filter, a positioning ring sleeved on the outer side of the flexible washer, and the positioning ring and the flexible washer being connected by a mortise and tenon joint.

[0007] Preferably, the positioning surface can be set as an arc-shaped convex or concave surface, and the inner ring surface of the flexible washer is in contact with the positioning surface.

[0008] Preferably, the flexible washer is provided with a plurality of positioning holes, which extend from the middle position to both sides along its axial direction, and the diameter of the holes gradually increases.

[0009] Preferably, the positioning ring includes two connecting rings disposed on the outside of the flexible washer, and the inner side of the connecting ring is provided with a plurality of positioning pins that cooperate with the positioning holes.

[0010] Preferably, the tenon and mortise structure includes a groove provided on the positioning ring, and a snap ring adapted to the groove is provided on the inner wall of the positioning hole, wherein the groove and the snap ring are interference fit.

[0011] Preferably, each of the outer ring surfaces of the connecting ring is provided with a stepped groove, and two stepped grooves are combined to form a slot.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. This utility model, through the combined use of lens and protective ring, compared with traditional filter sheets with annular grooves, can be integrally molded by mold, which simplifies the processing technology and processing cost, reduces the impact of stress on the filter sheet, and the protective ring can provide shock absorption and buffer protection for the lens, extending the service life of the lens.

[0014] 2. This utility model achieves a quick and secure connection between the protective ring and the positioning ring through a mortise and tenon structure (groove and snap ring). The flexible gasket is squeezed by the cooperation of the positioning post and the positioning hole, so that it tightly wraps the lens. This not only makes the installation stable and reliable, but also helps to improve the sealing performance and prevent dust from entering. Attached Figure Description

[0015] Figure 1 This is a first-view perspective three-dimensional structural diagram of the present invention;

[0016] Figure 2 This is a second-view perspective three-dimensional structural diagram of the present invention;

[0017] Figure 3 This is a schematic diagram of the third-view three-dimensional structure of this utility model.

[0018] In the picture:

[0019] 1. Lens; 101. Filter; 102. Positioning surface; 2. Protective ring; 201. Flexible washer; 202. Positioning hole; 203. Snap-fit ​​ring; 3. Positioning ring; 301. Connecting ring; 302. Positioning post; 303. Groove; 4. Slot. Detailed Implementation

[0020] The embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of this utility model.

[0021] As attached Figure 1 To be continued Figure 3 As shown:

[0022] This invention provides a portable optical filter with a mortise and tenon joint connection for spectral imaging, mainly composed of a lens 1, a protective ring 2, and a positioning ring 3. The lens 1 includes a filter 101, which is made of an optical material with high transmittance for specific wavelengths of light and high absorption for other wavelengths, according to the specific requirements of hyperspectral imaging. For example, in hyperspectral imaging in geological exploration, to accurately identify different minerals, the filter 101 uses a material with good transmittance for the characteristic spectral bands of common minerals. For instance, for the characteristic absorption peak of iron oxides in the near-infrared band of 800-1000nm, a filter material with transmittance greater than 90% in this band and less than 10% in other bands is selected, ensuring that only the characteristic spectrum related to the target mineral can pass through the filter, providing a basis for subsequent accurate spectral analysis. The filter 101 can be manufactured using precision molds through processes such as injection molding, die casting, or hot pressing, depending on the material. The annular edge of the filter 101 is provided with a positioning surface 102. The positioning surface 102 can be set as an arc-shaped convex or concave surface. The height of the positioning surface 102 is 0.05~0.2mm. The convex or concave surface avoids any perceptible impact on the optical performance. It provides a precise positioning reference for the subsequent installation of the protective ring 2, so that the protective ring 2 can fit tightly against the outer side of the filter 101, effectively enhancing the stability of the overall structure of the lens 1.

[0023] As attached Figure 2 To be continued Figure 3 As shown: The protective ring 2 is installed on the outer side of the positioning surface 102 of the lens 1, and is mainly composed of a flexible washer 201. The flexible washer 201 has several positioning holes 202, which extend from the center to both sides along its axial direction, with the hole diameter gradually increasing. The flexible washer 201 is made of materials with good elasticity and wear resistance, such as rubber or silicone, and is manufactured by injection molding, injecting the material into a mold with the shape of the positioning holes 202. The inner ring surface of the flexible washer 201 is tightly fitted to the positioning surface 102. This fitting structure plays an important role in the use of the optical filter. When the imaging equipment is subjected to vibration or impact during transportation or use, the flexible washer 201 can absorb vibration energy through its own elastic deformation, playing a shock-absorbing and buffering role, effectively reducing the impact on the filter 101, thereby protecting the filter 101 and extending its service life.

[0024] As attached Figure 2 To be continued Figure 3 As shown: The positioning ring 3 is installed on the outside of the protective ring 2 and consists of two connecting rings 301 located on the outside of the flexible washer 201. Several positioning posts 302 are provided on the inner side of the connecting ring 301 to cooperate with the positioning holes 202. Stepped grooves are provided on the outer ring surface of the connecting ring 301, and two stepped grooves combine to form a locking groove 4. The locking groove 4 can be used to directly engage with the inner wall of the lens in the imaging system, further enhancing the stability of the optical filter in the imaging system. The connecting ring 301 is made of plastic material and is manufactured using an integral molding technology, resulting in a connecting ring 301 with positioning posts 302 and stepped grooves. The tenon and mortise structure includes an annular groove 303 on the outer wall of the positioning post 302 and a locking ring 203 on the inner wall of the positioning hole 202 that matches the groove 303. During installation, pressure is applied to press the positioning post 302 into the positioning hole 202. The elastic deformation of the flexible washer 201 causes the locking ring 203 to engage with the groove 303, achieving an interference fit and thus firmly connecting the positioning ring 3 to the protective ring 2. The positioning hole 202 works in conjunction with the positioning post 302 on the positioning ring 3. During installation, as the positioning post 302 gradually enters the positioning hole 202, it compresses the flexible washer 201, making it fit more tightly against the side of the filter 101. This further enhances the stability of the lens 1 installation and ensures that the optical filter maintains a stable working state in the imaging system.

[0025] Working Principle: Taking agricultural pest and disease monitoring as an example, hyperspectral imaging technology can be used to detect crop pests and diseases early, allowing for timely control measures and reducing economic losses. When using a hyperspectral imaging device equipped with this optical filter to monitor farmland, the imaging device collects the light signals reflected from the surface of crops. This light contains rich spectral information. The filter 101 of the optical filter selects light within a specific wavelength range based on the spectral characteristics of pests and diseases in different wavelength bands. For example, when crops are infested by aphids, aphids have unique spectral reflection characteristics in the near-infrared band (950-1050nm). The filter 101 uses a material with high transmittance in this band, allowing this portion of the light carrying pest and disease information to pass through smoothly, while effectively blocking light in other wavelength bands. The light filtered by the filter enters the imaging detector, is converted into an electrical signal, and then analyzed by the data processing system to generate a hyperspectral image of the crop. By analyzing the spectral data in the image, it is possible to accurately determine whether crops are infested by pests and diseases, the type of pests and diseases, and the degree of infestation. During actual monitoring, the protective ring 2 of this optical filter and the portable lens case played a crucial role. The protective ring 2 effectively buffers vibrations generated during equipment transportation and field operations, protecting the filter from damage. When carrying the device, it is placed in the matching lens case, which is made of high-strength, lightweight composite material with a high-density sponge padding layer inside. The sponge padding layer has grooves that fit the device, effectively cushioning external impacts and preventing scratches on the lens 1. An external locking mechanism facilitates carrying and storage.

[0026] When installing the optical filter, first, place the protective ring 2 onto the lens 1, ensuring that the flexible washer 201 fits tightly against the positioning surface 102. Then, place the two connecting rings 301 on either side of the flexible washer 201, aligning the positioning pins 302 on the inner side of the connecting rings 301 with the positioning holes 202 on the flexible washer 201. Since the positioning holes 202 extend axially from the center to both sides with gradually increasing diameter, when the two connecting rings 301 are pushed closer, the positioning pins 302 gradually enter the positioning holes 202 and compress the flexible washer 201. Simultaneously, the grooves 303 on the positioning pins 302 and the locking rings 203 on the inner wall of the positioning holes 202 achieve an interference fit through a tenon and mortise structure, making the flexible washer 201 fit more tightly against the side of the filter 101, thereby improving the installation stability of the lens 1. Finally, fix the positioning ring 3 to the mounting position of the imaging system, completing the installation of the optical filter. Meanwhile, the slot 4 formed by the stepped groove combination on the outer ring surface of the connecting ring 301 is engaged and fixed with the lens in the imaging system, further enhancing the stability of the optical filter in the imaging system.

[0027] The embodiments of this utility model are given for the purpose of illustration and description. Although embodiments of this utility model have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the utility model. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this utility model.

Claims

1. A portable mortise and tenon joint optical filter for spectral imaging, characterized in that: The lens (1) includes a filter (101) with a positioning surface (102) on its annular edge. A protective ring (2) is sleeved on the outside of the positioning surface (102). The protective ring (2) includes a flexible gasket (201) disposed on the outside of the filter (101). A positioning ring (3) is sleeved on the outside of the flexible gasket (201). The positioning ring (3) and the flexible gasket (201) are connected by a tenon and mortise structure.

2. The portable mortise and tenon joint optical filter for spectral imaging as described in claim 1, characterized in that: The positioning surface (102) can be set as an arc-shaped convex or concave surface, and the inner ring surface of the flexible washer (201) is in contact with the positioning surface (102).

3. The portable mortise and tenon joint optical filter for spectral imaging as described in claim 1, characterized in that: The flexible washer (201) is provided with a plurality of positioning holes (202), which extend from the middle position to both sides along their axial direction, and the diameter of the holes gradually increases.

4. The portable mortise and tenon joint optical filter for spectral imaging as described in claim 3, characterized in that: The positioning ring (3) includes two connecting rings (301) disposed on the outside of the flexible washer (201), and the inner side of the connecting ring (301) is provided with a plurality of positioning pins (302) that cooperate with the positioning hole (202).

5. The portable mortise and tenon joint optical filter for spectral imaging as described in claim 4, characterized in that: The tenon and mortise structure includes a groove (303) provided on the positioning ring (3), and a snap ring (203) adapted to the groove (303) is provided on the inner wall of the positioning hole. The groove (303) and the snap ring (203) are interference fit.

6. The portable mortise and tenon joint optical filter for spectral imaging as described in claim 5, characterized in that: Each of the outer ring surfaces of the connecting ring (301) is provided with stepped grooves, and two stepped grooves are combined to form a slot (4).

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