A large-aperture large-relative-illumination scanning lens

Abstract

The application provides a large-aperture large-relative-illumination scanning lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens and a photosensitive chip arranged in sequence along an optical axis from an object plane to an image plane, wherein the first lens to the tenth lens are all glass lenses, focal lengths of the first lens to the tenth lens are negative, negative, positive, positive, negative, positive, negative, positive, positive and positive in sequence, the first lens, the second lens and the third lens form a fixed group, and the fourth lens to the tenth lens form a focusing group, wherein the floating focusing mode is adopted to optimize distortion and magnification, and small distortion and wide magnification are achieved; through relative movement of the focusing group, clear focusing of a working distance of 150mm-600mm is realized, and the application requirements of wide measurement range, large aperture and low distortion can be met, and the light aperture can also be flexibly adjusted.

Description

Technical Field

[0001] This invention relates to the field of scanning lens technology, and specifically to a scanning lens with a large aperture and high relative illumination. Background Technology

[0002] With the rapid development of society and the economy, the demand for machine vision is increasing daily, especially in many industries such as electronics manufacturing, LCD screen defect detection, mobile phone touch screen circuit and size measurement, and food packaging. Line scan machine vision lenses have been widely used to improve production efficiency and yield. The requirements for the optical performance and measurement range of line scan machine vision lenses are also becoming increasingly stringent.

[0003] However, existing line scan machine vision lenses in China generally suffer from narrow measurement range, large distortion, and insufficient light transmission. Summary of the Invention

[0004] In view of this, the present invention provides a scanning lens with a large aperture and high relative illumination, which can meet the application requirements of wide measurement range, large aperture and low distortion, and its light transmission aperture can also be flexibly adjusted.

[0005] To achieve the above objectives, the present invention provides a large-aperture, high-relative-illuminance scanning lens, employing the following technical solution:

[0006] A large-aperture, high-relative-illuminance scanning lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, and a photosensitive chip arranged sequentially along the optical axis from the object plane to the image plane. The first to tenth lenses are all glass lenses, and the focal lengths of the first to tenth lenses are negative, negative, positive, positive, negative, positive, negative, positive, positive, positive, and positive, respectively. The first, second, and third lenses form a fixed group, and the fourth to tenth lenses form a focusing group.

[0007] This invention features ten lenses arranged sequentially, with the first, second, and third lenses forming a fixed group, and the fourth to tenth lenses forming a focusing group. By employing a floating focusing method, distortion and magnification are optimized, achieving both low distortion and wide magnification. Through the relative movement of the focusing group, clear focusing is achieved at working distances of 150mm-600mm, meeting the application requirements of a wide measurement range, large aperture, and low distortion. At the same time, its light-transmitting aperture can also be flexibly adjusted.

[0008] Furthermore, a variable aperture is provided between the sixth lens and the seventh lens.

[0009] The variable aperture set by the above technical solution limits the beam.

[0010] Furthermore, the first lens, the second lens, the fourth lens, the fifth lens, and the seventh lens are all negative meniscus lenses; the third lens and the tenth lens are both biconvex lenses; and the sixth lens, the eighth lens, and the ninth lens are all positive meniscus lenses.

[0011] The above technical solutions improve the imaging resolution of the scanning lens, reduce the imaging distortion rate, and meet the magnification requirements of different working distances.

[0012] Furthermore, the fifth and sixth lenses are bonded together to form a first cemented lens using photosensitive adhesive, and the seventh and eighth lenses are bonded together to form a second cemented lens using photosensitive adhesive.

[0013] Through the above technical solution, the relationship between 10 lenses in 8 groups is optimized and adjusted, and the relative illumination is greatly improved, reaching more than 70% at the optimal working distance.

[0014] Furthermore, the center thicknesses of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens, ninth lens, and tenth lens are 9mm, 6mm, 10.5mm, 7.65mm, 0.7mm, 4mm, 1.2mm, 3.6mm, 3.5mm, and 3.9mm, respectively.

[0015] Furthermore, the distances between the first lens and the second lens, the second lens and the third lens, the third lens and the fourth lens, the fourth lens and the fifth lens, the sixth lens and the seventh lens, the eighth lens and the ninth lens, and the ninth lens and the tenth lens are 5.9 mm, 20.3 mm, 3.6 mm, 1.07 mm, 8.8 mm, 12 mm, and 12 mm, respectively.

[0016] Furthermore, the radii of curvature on the object side of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens, ninth lens and tenth lens are 51.2mm, 82.7mm, 40mm, 15.4mm, 27.6mm, 8.3mm, -9.5mm, -31mm, -88.8mm and 83.5mm, respectively.

[0017] Furthermore, the radii of curvature on the image plane side of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens, ninth lens, and tenth lens are 25.6 mm, 26.9 mm, -70.5 mm, 14 mm, 8.3 mm, 612 mm, -31 mm, -14.6 mm, -31.4 mm, and -390 mm, respectively.

[0018] Furthermore, the refractive indices of the first lens, second lens, third lens, fourth lens, fifth lens, sixth lens, seventh lens, eighth lens, ninth lens, and tenth lens are 1.75, 11.5, 1.6, 2.0, 1.8, 1.6, 1.65, 1.77, 1.73, and 1.73, respectively.

[0019] By using the above technical solution, the center thickness, refractive index, radius of curvature of each lens and the spacing between two adjacent lenses are specifically defined, thus realizing an optical system for a large-aperture, low-distortion fixed-focus linear scanning machine vision lens with a focal length of 25mm. The image-side F number is 2.4, the maximum imaging plane position resolution can reach 75lp / mm, and the maximum optical distortion across the entire field of view is less than 0.3%.

[0020] The above-described technical solution of the present invention has at least the following beneficial effects:

[0021] 1. This invention sequentially sets up ten lenses, with the first, second, and third lenses forming a fixed group, and the fourth to tenth lenses forming a focusing group. By adopting a floating focusing method, distortion and magnification are optimized, achieving both low distortion and wide magnification. Through the relative movement of the focusing group, clear focusing is achieved at a working distance of 150mm-600mm, which can meet the application requirements of wide measurement range, large aperture, and low distortion. At the same time, its light transmission aperture can also be flexibly adjusted.

[0022] 2. The fifth and sixth lenses are combined with photosensitive adhesive to form the first cemented lens, and the seventh and eighth lenses are combined with photosensitive adhesive to form the second cemented lens. By optimizing and adjusting the relationship of the 10 lenses in total (8 groups), the relative illumination is greatly improved, reaching more than 70% at the optimal working distance.

[0023] 3. The first, second, fourth, fifth, and seventh lenses are all negative meniscus lenses; the third and tenth lenses are both biconvex lenses; the sixth, eighth, and ninth lenses are all positive meniscus lenses; by combining lenses of different materials and adjusting the relative positions of the lens groups, the imaging resolution of the scanning lens is improved, the imaging distortion rate is reduced, and the magnification requirements for different working distances are met.

[0024] 4. This invention realizes the optical system of a large aperture, low distortion fixed-focus linear scanning machine vision lens with a focal length of 25mm, an image-side F number of 2.4, a maximum imaging plane position resolution of 75lp / mm, and a maximum optical distortion of less than 0.3% across the entire field of view. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the large aperture, high relative illumination scanning lens of the present invention;

[0026] Figure 2This is the MTF curve of the large aperture and high relative illumination scanning lens of the present invention;

[0027] Figure 3 This is an optical distortion curve of the large aperture, high relative illumination scanning lens of the present invention;

[0028] Figure 4 This is a relative illumination curve of the large aperture, high relative illumination scanning lens of the present invention.

[0029] In the picture:

[0030] 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens;

[0031] U1, First cemented lens; 5, Fifth lens; 6, Sixth lens;

[0032] U2, Second Cemented Lens; 7, Seventh Lens; 8, Eighth Lens;

[0033] 9. Ninth lens; 10. Tenth lens; 11. Photosensitive chip. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will be described in conjunction with the accompanying drawings of the embodiments of the present invention. Figure 1-4 The technical solutions of the embodiments of the present invention will be clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0035] like Figure 1 As shown, a large-aperture, high-relative-illuminance scanning lens includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10, and a photosensitive chip 11, arranged sequentially along the optical axis from the object plane to the image plane. The first to tenth lenses 10 are all glass lenses, and their focal lengths are negative, negative, positive, positive, positive, negative, positive, positive, positive, and positive, respectively. The first lens 1, the second lens 2, and the third lens 3 form a fixed group, while the fourth to tenth lenses 10 form a focusing group.

[0036] This invention optimizes distortion and magnification by employing a floating focusing method, achieving both low distortion and wide magnification. Through the relative movement of the focusing group, it achieves clear focusing at a working distance of 150mm-600mm, meeting the application requirements of a wide measurement range, large aperture, and low distortion. At the same time, its light-transmitting aperture can also be flexibly adjusted.

[0037] According to one embodiment of the present invention, the fifth lens and the sixth lens 6 are combined with photosensitive adhesive to form a first cemented lens U1, and the seventh lens 7 and the eighth lens 8 are combined with photosensitive adhesive to form a second cemented lens U2.

[0038] By combining and optimizing the relationship between 10 lenses in 8 groups, the relative illumination is greatly improved, reaching over 70% at the optimal working distance.

[0039] Lens 1, 2, 4, 5, and 7 are all negative meniscus lenses; Lens 3 and 10 are both biconvex lenses; Lens 6, 8, and 9 are all positive meniscus lenses.

[0040] By combining lenses of different materials and adjusting the relative positions of lens groups, the imaging resolution of the scanning lens is improved, the imaging distortion rate is reduced, and the magnification requirements for different working distances are met. Through this structure, an optical system for a large-aperture, low-distortion fixed-focus linear scanning machine vision lens with a focal length of 25mm is achieved. The image-side F-number is 24, the maximum imaging surface resolution reaches 75 lp / mm, and the maximum optical distortion across the entire field of view is less than 0.3%.

[0041] A variable aperture is arranged between the sixth lens 6 and the seventh lens 7 to limit the beam.

[0042] In one embodiment of the present invention, as shown in Table 1:

[0043] The center thicknesses of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, the ninth lens 9, and the tenth lens 10 are 9mm, 6mm, 10.5mm, 7.65mm, 0.7mm, 4mm, 1.2mm, 3.6mm, 3.5mm, and 3.9mm, respectively.

[0044] The distances between the first lens 1 and the second lens 2, the second lens 2 and the third lens 3, the third lens 3 and the fourth lens 4, the fourth lens 4 and the fifth lens 5, the sixth lens 6 and the seventh lens 7, the eighth lens 8 and the ninth lens 9, and the ninth lens 9 and the tenth lens 10 are 5.9mm, 20.3mm, 3.6mm, 1.07mm, 8.8mm, 12mm, and 12mm, respectively.

[0045] The radii of curvature on the object plane of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, the ninth lens 9, and the tenth lens 10 are 51.2 mm, 82.7 mm, 40 mm, 15.4 mm, 27.6 mm, 8.3 mm, -9.5 mm, -31 mm, -88.8 mm, and 83.5 mm, respectively.

[0046] The radii of curvature on the image plane side of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, the fifth lens 5, the sixth lens 6, the seventh lens 7, the eighth lens 8, the ninth lens 9, and the tenth lens 10 are 25.6 mm, 26.9 mm, -70.5 mm, 14 mm, 8.3 mm, 612 mm, -31 mm, -14.6 mm, -31.4 mm, and -390 mm, respectively.

[0047] The first lens 1 is a high-refractive-index lens with Nd=1.75;

[0048] The second lens 2 is a high-dispersion lens with Nd=1.50 and Vd=81.6;

[0049] The third lens 3 is a high-dispersion lens with Nd=1.60 and Vd=65.5;

[0050] The fourth lens is a low-dispersion lens with Nd=2.0 and Vd=25.4;

[0051] The fifth lens is a low-dispersion lens with Nd=1.8 and Vd=25.4;

[0052] The sixth lens is a high-dispersion lens with Nd=1.6 and Vd=68.3;

[0053] The seventh lens is a low-dispersion lens with Nd=1.65 and Vd=33.8;

[0054] The eighth lens is a high-refractive-index, low-dispersion lens with Nd=1.77 and Vd=49.6.

[0055] The ninth lens is a high-refractive-index, low-dispersion lens with Nd=1.73 and Vd=54.7.

[0056] The tenth lens is a high-refractive-index, low-dispersion lens with Nd=1.73 and Vd=54.7.

[0057] Table 1

[0058]

[0059] In Table 1, surface numbers 1 and 2 represent the first and second surfaces of the first lens 1, respectively.

[0060] Surface numbers 3 and 4 represent the first and second surfaces of the second lens 2, respectively;

[0061] Surface numbers 5 and 6 represent the first and second surfaces of the third lens 3, respectively;

[0062] Surface numbers 7 and 8 represent the first and second surfaces of the fourth lens 4, respectively;

[0063] The surface numbers 9, 10, and 11 represent the first, third, and second surfaces of the fifth lens 5 and the sixth lens 6, respectively.

[0064] Face numbers 12, 13, and 14 represent the first, third, and second faces of the seventh lens and the eighth lens 8, respectively.

[0065] Surface numbers 15 and 16 represent the first and second surfaces of the ninth lens 9, respectively;

[0066] Surface numbers 17 and 18 represent the first and second surfaces of the tenth lens 10, respectively;

[0067] The first surface refers to the side facing the object plane, the second surface refers to the side facing the image plane, and the third surface is the side shared by both lenses.

[0068] Based on the above technical solutions, the following conclusions are drawn. Figure 2 , Figure 3 and Figure 4 .

[0069] Depend on Figure 2 It can be seen that the maximum imaging surface position resolution of the present invention can reach 75 lp / mm;

[0070] Depend on Figure 3 It can be seen that the maximum optical distortion of the present invention across the entire field of view is less than 0.3%;

[0071] Depend on Figure 4 It can be seen that the relative illumination of the present invention can reach 70%.

[0072] In the description of this invention, it should be understood that 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0073] In this invention, unless otherwise explicitly specified and limited, the first feature being "above" or "below", "left" or "right" of the second feature may be in direct contact with the first feature, or indirect contact between the first and second features through an intermediate medium.

[0074] While various embodiments of the invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in the practice of the invention. The appended claims are intended to define the scope of the invention and therefore cover any modular compositions, equivalents, or alternatives within the scope of these claims.

Claims

1. A large-aperture, high-relative-illuminance scanning lens, characterized in that: The system includes a first lens (1), a second lens (2), a third lens (3), a fourth lens (4), a fifth lens (5), a sixth lens (6), a seventh lens (7), an eighth lens (8), a ninth lens (9), a tenth lens (10), and a photosensitive chip (11) arranged sequentially from the object plane to the image plane along the optical axis. The first lens (1) to the tenth lens (10) are all glass lenses. The focal lengths of the first lens (1) to the tenth lens (10) are negative, negative, positive, positive, negative, positive, negative, positive, positive, positive, positive, positive, and positive, respectively. The first lens (1), the second lens (2), and the third lens (3) form a fixed group, and the fourth lens (4) to the tenth lens (10) form a focusing group. The center thicknesses of the first lens (1), the second lens (2), the third lens (3), the fourth lens (4), the fifth lens (5), the sixth lens (6), the seventh lens (7), the eighth lens (8), the ninth lens (9), and the tenth lens (10) are 9mm, 6mm, 10.5mm, 7.65mm, 0.7mm, 4mm, 1.2mm, 3.6mm, 3.5mm, and 3.9mm, respectively. The distances between the first lens (1) and the second lens (2), the second lens (2) and the third lens (3), the third lens (3) and the fourth lens (4), the fourth lens (4) and the fifth lens (5), the sixth lens (6) and the seventh lens (7), the eighth lens (8) and the ninth lens (9), and the ninth lens (9) and the tenth lens (10) are 5.9 mm, 20.3 mm, 3.6 mm, 1.07 mm, 8.8 mm, 12 mm, and 12 mm, respectively.

2. The large aperture, high relative illumination scanning lens according to claim 1, characterized in that: A variable aperture is provided between the sixth lens (6) and the seventh lens (7).

3. The large aperture, high relative illumination scanning lens according to claim 1, characterized in that: The first lens (1), the second lens (2), the fourth lens (4), the fifth lens (5) and the seventh lens (7) are all negative meniscus lenses; the third lens (3) and the tenth lens (10) are both biconvex lenses; the sixth lens (6), the eighth lens (8) and the ninth lens (9) are all positive meniscus lenses.

4. The large aperture, high relative illumination scanning lens according to claim 1, characterized in that: The fifth lens (5) and the sixth lens (6) are combined to form a first cemented lens (U1) using photosensitive adhesive, and the seventh lens (7) and the eighth lens (8) are combined to form a second cemented lens (U2) using photosensitive adhesive.

5. The large aperture, high relative illumination scanning lens according to claim 1, characterized in that: The radii of curvature on the object side of the first lens (1), the second lens (2), the third lens (3), the fourth lens (4), the fifth lens (5), the sixth lens (6), the seventh lens (7), the eighth lens (8), the ninth lens (9), and the tenth lens (10) are 51.2 mm, 82.7 mm, 40 mm, 15.4 mm, 27.6 mm, 8.3 mm, -9.5 mm, -31 mm, -88.8 mm, and 83.5 mm, respectively.

6. The large aperture, high relative illumination scanning lens according to claim 1, characterized in that: The radii of curvature on the image plane side of the first lens (1), the second lens (2), the third lens (3), the fourth lens (4), the fifth lens (5), the sixth lens (6), the seventh lens (7), the eighth lens (8), the ninth lens (9), and the tenth lens (10) are 25.6 mm, 26.9 mm, -70.5 mm, 14 mm, 8.3 mm, 612 mm, -31 mm, -14.6 mm, -31.4 mm, and -390 mm, respectively.

7. The large aperture, high relative illumination scanning lens according to claim 1, characterized in that: The refractive indices of the first lens (1), the second lens (2), the third lens (3), the fourth lens (4), the fifth lens (5), the sixth lens (6), the seventh lens (7), the eighth lens (8), the ninth lens (9), and the tenth lens (10) are 1.75, 1.5, 1.6, 2.0, 1.8, 1.6, 1.65, 1.77, 1.73, and 1.73, respectively.

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