Glass lens and liquid lens mixed large-depth-of-field double telecentric lens

Abstract

The invention relates to the technical field of optical systems, in particular to a glass lens and liquid lens mixed large-depth-of-field double telecentric lens. Comprising a glass lens group, a liquid lens and a lens diaphragm, the glass lens group comprises 12 groups of single lenses and 3 groups of doublet lenses, and two ends of the lens diaphragm are respectively provided with a lens object plane and a lens image plane. The glass lens and liquid lens mixed large-field-depth double-telecentric lens integrated with large field depth, high telecentricity and low distortion is successfully realized, the telecentricity of the lens is less than 0.01 degree, the distortion is less than 0.5%, and the field depth is more than 20 times that of a traditional double-telecentric lens.

Description

Technical Field

[0001] The invention relates to the technical field of optical systems, and in particular to a glass lens, a liquid lens, a large depth of field, and a double telecentric lens. Background Art

[0002] When the online inspection system detects whether the size of the processed workpiece meets the standard, it has extremely high requirements on the performance of the lens. Telecentric optical lenses are widely used in the field of precision measurement due to their unique optical advantages such as high telecentricity and low distortion.

[0003] However, although the traditional bi-telecentric lens has the advantages of high telecentricity and low distortion, its depth of field is limited and it is difficult to adapt to complex and changing inspection environments. Especially when precise measurement of workpieces at different distances is required, the limitations of the traditional bi-telecentric lens are particularly prominent. Summary of the invention

[0004] The purpose of the present invention is to provide a glass lens, liquid lens hybrid large depth of field bi-telecentric lens, aiming to solve the technical problem that the traditional bi-telecentric lens in the prior art has the advantages of high telecentricity and low distortion, but has a limited depth of field and is difficult to adapt to complex and changeable detection environments, especially when precise measurement of workpieces at different distances is required, the limitations of the traditional bi-telecentric lens are particularly prominent.

[0005] To achieve the above-mentioned purpose, the present invention adopts a glass lens, liquid lens hybrid large depth of field double telecentric lens, including a glass lens group, a liquid lens and a lens aperture, the glass lens group includes 12 groups of single lenses and 3 groups of double-cemented lenses, wherein 8 groups of the single lenses are arranged at one end of a corresponding group of the double-cemented lenses, and the other 4 groups of the single lenses are arranged at the other end of the corresponding group of the double-cemented lenses, wherein 1 group of the double-cemented lenses is located on the left side of the liquid lens, and 2 groups of the double-cemented lenses are located on the right side of the liquid lens, the liquid lens is arranged next to the lens aperture, and the two ends of the lens aperture are respectively provided with a lens object plane and a lens image plane.

[0006] Among them, the front and rear surface curvature radii of the single lenses in 8 groups are both >0 and are bent toward the liquid lens, the front and rear surface curvature radii of the single lenses in 2 groups are both <0 and are bent toward the liquid lens, the rear surface curvature radius of the single lenses in 1 group is >0 and is bent away from the liquid lens, and the single lenses in 1 group are one of a biconvex and plano-convex structure, with a front surface curvature radius >0 and a rear surface curvature radius <0.

[0007] The liquid lens is driven by one of electrowetting and piezoelectric drive, with a response time of ≤10ms and a curvature adjustment accuracy of ±0.0001.

[0008] The aperture of the lens diaphragm is adjustable within a range of F / #=8 to 12, and can be adapted to imaging requirements under different lighting conditions.

[0009] The optical parameters of the lens aperture are telecentricity <0.01°, distortion <0.5%, and depth of field ≥10 mm.

[0010] Wherein, the distance between the lens object plane and the lens image plane is 100-200 mm.

[0011] The liquid lens dynamically adjusts the depth of field of the lens by adjusting the radius of curvature of the film.

[0012] The present invention discloses a glass lens and liquid lens hybrid large depth of field double telecentric lens, comprising a glass lens group, a liquid lens and a lens aperture, wherein the glass lens group comprises 12 groups of single lenses and 3 groups of double glued lenses, and the curvature radius and thickness of the 12 groups of single lenses and the 3 groups of double glued lenses all meet the preset optical path matching conditions, wherein 8 groups of single lenses are arranged at one end of a corresponding group of double glued lenses, and the other 4 groups of single lenses are arranged at the other end of a corresponding group of double glued lenses, wherein 1 group of double glued lenses is located on the left side of the liquid lens, and 2 groups of double glued lenses are located on the right side of the liquid lens, the liquid lens is arranged next to the lens aperture, and the two ends of the lens aperture are respectively provided with A lens object plane and a lens image plane are arranged, and by integrating the advantages of high telecentricity and low distortion of a double telecentric lens and the advantages of variable curvature and adjustable depth of field of a liquid lens, a glass lens and a liquid lens hybrid large depth of field double telecentric lens with large depth of field, high telecentricity and low distortion is successfully realized. The lens telecentricity is less than 0.01 degrees, the distortion is less than 0.5%, and the depth of field is more than 20 times that of a traditional double telecentric lens. In this way, the technical problem that although the traditional double telecentric lens has the advantages of high telecentricity and low distortion, its depth of field is limited and it is difficult to adapt to complex and changeable detection environments, especially when precise measurement of workpieces at different distances is required, the limitations of the traditional double telecentric lens are particularly prominent is effectively solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is a structural schematic diagram of a glass lens, a liquid lens, a large depth of field double telecentric lens mixed with the present invention.

[0015] Figure 2It is a structural schematic diagram of the lens in the first embodiment of the glass lens and liquid lens hybrid large depth of field double telecentric lens of the present invention.

[0016] Figure 3 This is a trend diagram of lens distortion in Example 1 of the glass lens, liquid lens hybrid large depth of field double telecentric lens of the present invention.

[0017] Figure 4 It is a schematic diagram of the structure of the lens in the second embodiment of the glass lens and liquid lens hybrid large depth of field double telecentric lens of the present invention.

[0018] Figure 5 This is a trend diagram of lens distortion in the second embodiment of the glass lens, liquid lens hybrid large depth of field double telecentric lens of the present invention.

[0019] Figure 6 It is a structural schematic diagram of the lens in the third embodiment of the glass lens, liquid lens hybrid large depth of field double telecentric lens of the present invention.

[0020] Figure 7 This is a trend diagram of lens distortion in Example 3 of the glass lens, liquid lens hybrid large depth of field double telecentric lens of the present invention.

[0021] Figure 8 It is a schematic diagram of the telecentricity of the lens in the first embodiment of the glass lens and liquid lens hybrid large depth of field double telecentric lens of the present invention.

[0022] Fig. 9 It is a schematic diagram of the telecentricity of the lens in the second embodiment of the glass lens and liquid lens hybrid large depth of field double telecentric lens of the present invention.

[0023] Fig.10 It is a schematic diagram of the telecentricity of the lens in the third embodiment of the glass lens and liquid lens hybrid large depth of field double telecentric lens of the present invention.

[0024] 1-first group of single lens, 2-second group of single lens, 3-third group of single lens, 4-fourth group of single lens, 5-fifth group of single lens, 6-sixth group of single lens, 7-seventh group of single lens, 8-eighth group of single lens, 9ninth group of single lens, 10-tenth group of single lens, 11-eleventh group of single lens, 12-twelfth group of single lens, 13-first group of double cemented lens, 14-second group of double cemented lens, 15-third group of double cemented lens, 16-liquid lens, 17-lens aperture, 18-lens object plane, 19-lens image plane. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0026] See also Figures 1 to 10 The present invention provides a glass lens, liquid lens hybrid large depth of field double telecentric lens, including a glass lens group, a liquid lens and a lens aperture, the glass lens group includes 12 groups of single lenses and 3 groups of double glued lenses, wherein 8 groups of the single lenses are arranged at one end of a corresponding group of the double glued lenses, and the other 4 groups of the single lenses are arranged at the other end of the corresponding group of the double glued lenses, wherein 1 group of the double glued lenses is located on the left side of the liquid lens, and 2 groups of the double glued lenses are located on the right side of the liquid lens, the liquid lens is arranged next to the lens aperture, and the two ends of the lens aperture are respectively provided with a lens object plane and a lens image plane.

[0027] In this embodiment, by integrating the advantages of high telecentricity and low distortion of a double telecentric lens and the advantages of variable curvature and adjustable depth of field of a liquid lens, a glass lens and a liquid lens hybrid with a large depth of field that integrates large depth of field, high telecentricity and low distortion are successfully realized. The telecentricity of the lens is less than 0.01 degrees, the distortion is less than 0.5%, and the depth of field is more than 20 times that of a traditional double telecentric lens. In addition, the curvature radius and thickness of the 12 groups of single lenses and the 3 groups of double-cemented lenses all meet the preset optical path matching conditions. In this way, the technical problem that the traditional double telecentric lens has the advantages of high telecentricity and low distortion, but has a limited depth of field and is difficult to adapt to complex and changeable detection environments, especially when precise measurement of workpieces at different distances is required, the limitations of the traditional double telecentric lens are particularly prominent is effectively solved.

[0028] Furthermore, the front and rear surface curvature radii of the single lenses in 8 groups are both >0 and are bent toward the liquid lens, the front and rear surface curvature radii of the single lenses in 2 groups are both <0 and are bent toward the liquid lens, the rear surface curvature radius of the single lenses in 1 group is >0 and is bent away from the liquid lens, and the single lenses in 1 group are one of a biconvex and plano-convex structure, with a front surface curvature radius >0 and a rear surface curvature radius <0.

[0029] In this embodiment, the optical path is further optimized and the clarity and contrast of the imaging are improved by designing a specific curvature radius direction; at the same time, the single lens is one of a double convex and plano-convex structure, which provides more design possibilities and helps to meet the imaging requirements in different scenarios.

[0030] Furthermore, the driving mode of the liquid lens is one of electrowetting and piezoelectric driving, the response time is ≤10ms, and the curvature adjustment accuracy reaches ±0.0001.

[0031] In this embodiment, the short response time of this design ensures that the lens can quickly adjust the depth of field to meet the real-time imaging requirements; at the same time, the high curvature adjustment accuracy enables the lens to accurately control the depth of field and improve the accuracy and stability of imaging.

[0032] Furthermore, the aperture of the lens diaphragm is adjustable within a range of F / #=8 to 12, and can be adapted to imaging requirements under different lighting conditions.

[0033] In this embodiment, the aperture adjustability of the lens diaphragm enables the lens to adapt to imaging requirements under different lighting conditions, thereby improving the versatility and flexibility of the lens; at the same time, adjusting the aperture can further optimize the imaging quality and meet the imaging requirements in specific application scenarios.

[0034] Furthermore, the optical parameters of the lens aperture are telecentricity <0.01°, distortion <0.5%, and depth of field ≥10 mm.

[0035] In this embodiment, the uniformity and consistency of imaging are ensured by low telecentricity, avoiding image distortion caused by changes in viewing angle; low distortion improves the accuracy of imaging, making the lens suitable for application scenarios with high requirements on image quality; and the large depth of field enables the lens to maintain clear imaging over a wider range, enhancing the practicality and applicability of the lens.

[0036] Furthermore, the distance between the lens object plane and the lens image plane is 100-200 mm.

[0037] In this implementation, by specifying the distance range between the lens object plane and the lens image plane, the imaging quality of the lens within the working distance is ensured, thereby improving the practicality and stability of the lens.

[0038] Furthermore, the liquid lens dynamically adjusts the depth of field of the lens by adjusting the radius of curvature of the film.

[0039] In the present invention, three embodiments are also provided;

[0040] Embodiment 1:

[0041] The present embodiment is designed with F / #=10, image NA=0.05, image height 82mm, lens magnification 0.3 times, glass lens, liquid lens mixed with large depth of field double telecentric lens. Under this parameter, the depth of field of the traditional lens is 2.5mm. The curvature variation range of the liquid lens in the present embodiment is -0.0007 to 0.0007, and the depth of field can reach 60mm, which is 24 times the depth of field of the traditional lens.

[0042]

[0043]

[0044] This table shows the lens parameters in Example 1, where Figure 8 The depth of field of the first embodiment is 60 mm, the telecentricity of the inner lens is < 0.007 degrees, and Figure 3 The depth of field of Example 1 is 60mm, and the internal lens distortion is <0.5%

[0045] Embodiment 2:

[0046] The present embodiment is designed with F / #=10, image NA=0.05, image height 82mm, lens magnification 0.5 times, glass lens, liquid lens mixed with large depth of field double telecentric lens. Under this parameter, the depth of field of the traditional lens is 0.88mm. The curvature variation range of the liquid lens in the present embodiment is -0.0008 to 0.0008, and the depth of field can reach 40mm, which is 45 times the depth of field of the traditional lens.

[0047]

[0048]

[0049] This table shows the lens parameters in Example 2, where Fig. 9 The depth of field of the second embodiment is 40 mm, the telecentricity of the inner lens is <0.008 degrees, and Figure 5 The depth of field of the second embodiment is 40 mm, and the internal lens distortion is less than 0.5%.

[0050] Embodiment three:

[0051] The design of this embodiment is F / #=10, image NA=0.05, image height 82mm, lens magnification 1x glass lens, liquid lens mixed large depth of field double telecentric lens, under this parameter, the depth of field of the traditional lens is 0.22mm, the curvature of the liquid lens in this embodiment varies from -0.0006 to 0.0006, and the depth of field can reach 10mm, which is 45 times the depth of field of the traditional lens.

[0052]

[0053] This table shows the lens parameters in Example 3, where Fig.10 The depth of field of the third embodiment is 10 mm, the telecentricity of the inner lens is <0.009 degrees, and Figure 7 The depth of field of the third embodiment is 40 mm, and the internal lens distortion is less than 0.5%.

[0054] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A glass lens, liquid lens hybrid large depth of field double telecentric lens, characterized in that: It comprises a glass lens group, a liquid lens and a lens aperture, wherein the glass lens group comprises 12 groups of single lenses and 3 groups of double-cemented lenses, wherein 8 groups of the single lenses are arranged at one end of a corresponding group of the double-cemented lenses, and the other 4 groups of the single lenses are arranged at the other end of a corresponding group of the double-cemented lenses, wherein 1 group of the double-cemented lenses is located on the left side of the liquid lens, and 2 groups of the double-cemented lenses are located on the right side of the liquid lens, the liquid lens is arranged beside the lens aperture, and a lens object plane and a lens image plane are respectively arranged at both ends of the lens aperture.

2. The glass lens and liquid lens hybrid large depth of field bi-telecentric lens as claimed in claim 1, characterized in that: Among them, the front and rear surface curvature radii of the single lenses in 8 groups are both >0 and are bent toward the liquid lens, the front and rear surface curvature radii of the single lenses in 2 groups are both <0 and are bent toward the liquid lens, the rear surface curvature radius of the single lenses in 1 group is >0 and is bent away from the liquid lens, and the single lenses in 1 group are one of a biconvex and plano-convex structure, with a front surface curvature radius >0 and a rear surface curvature radius <0.

3. The glass lens and liquid lens hybrid large depth of field bi-telecentric lens as claimed in claim 2, characterized in that: The driving mode of the liquid lens is one of electrowetting and piezoelectric driving, the response time is ≤10ms, and the curvature adjustment accuracy reaches ±0.0001.

4. The glass lens and liquid lens hybrid large depth of field bi-telecentric lens as claimed in claim 3, characterized in that: The aperture of the lens diaphragm is adjustable within a range of F / #=8 to 12, and can be adapted to imaging requirements under different lighting conditions.

5. The glass lens and liquid lens hybrid large depth of field bi-telecentric lens as claimed in claim 4, characterized in that: The optical parameters of the lens aperture are telecentricity <0.01°, distortion <0.5%, and depth of field ≥10 mm.

6. The glass lens and liquid lens hybrid large depth of field bi-telecentric lens as claimed in claim 5, characterized in that: The distance between the lens object plane and the lens image plane is 100-200 mm.

7. The glass lens and liquid lens hybrid large depth of field bi-telecentric lens as claimed in claim 6, characterized in that: The liquid lens dynamically adjusts the depth of field of the lens by adjusting the curvature radius of the film.

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