A high-resolution industrial lens

Abstract

The present invention belongs to the field of optical imaging technology, and specifically discloses a high-resolution industrial lens, including an optical module, wherein the optical module is provided with a front lens group, an aperture and a rear focusing group in sequence from the object side to the image side; wherein the focal length of the optical module is f, the focal length of the front lens group is fS1, and the combined focal length of the rear focusing group is fS2, which satisfy the relationship: 1.2<|fS1 / f|<2.2; 1<|fS2 / f|<2. The present invention provides a high-resolution industrial lens, which has an image side F number of 2.8 and can match a 1.1” inch camera when the focal length is 12mm. The maximum pixel can reach 23 million pixels, achieving high-quality imaging. At the same time, the present invention adopts a floating focus focusing method, and its clear aperture can be flexibly adjusted, effectively balancing the contradiction between the telecentricity and low distortion of the optical system.

Description

Technical Field

[0001] The invention belongs to the technical field of optical imaging, and in particular relates to a high-resolution industrial lens. Background Art

[0002] Driven by Industry 4.0, industrial lenses are also developing and improving. Optical lenses are being used more and more widely, especially in the field of detection applications, such as: size measurement, pin positioning, PCB board defect detection, floor tile surface texture and color detection, etc., all of which are detected by machine vision. The machine vision system refers to the use of machine vision products (i.e. image acquisition devices, divided into CMOS and CCD) to convert the target to be detected into digital signals, which are then transmitted to a dedicated image processing system (divided into embedded and video card methods). The image processing system sets the detection task according to the requirements of the target to be detected. Then, the equipment action on site is controlled according to the results of the judgment to achieve functions such as positioning, judgment, identification, detection and control. Once the information is seriously lost in the imaging system, it will be very difficult to try to recover it in the subsequent links.

[0003] The ever-increasing demand for detection accuracy and the widespread use of high-resolution cameras have put forward new requirements for the imaging quality and performance of industrial lenses, especially in terms of field of view and resolution. At the same time, the pixel size of camera chips tends to be larger, and high-pixel 1.1″ chips are one of the current mainstream chips.

[0004] However, there are few optical lenses designed for 1.1″ chips in China, and they are insufficient in resolution and lens size, especially in imaging at close distances. Therefore, the research and development of high-pixel, low-distortion optical lenses is more urgent. Summary of the invention

[0005] The purpose of the present invention is to provide a high-resolution industrial lens to meet application requirements in view of the deficiencies of the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A high-resolution industrial lens comprises an optical module, wherein the optical module is provided with a front lens group, an aperture and a rear focusing group in sequence from the object side to the image side; the front lens group comprises a first lens with negative focal power, a second lens with positive focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with positive focal power and a sixth lens with positive focal power; the aperture is arranged between the front lens group and the rear focusing group; the rear focusing group comprises a seventh lens with positive focal power, an eighth lens with negative focal power, a ninth lens with positive focal power, a tenth lens with positive focal power, an eleventh lens with negative focal power and a twelfth lens with positive focal power;

[0008] Among them, the focal length of the optical module is f, the focal length of the front lens group is fS1, and the combined focal length of the rear focusing group is fS2, which satisfies the relationship: 1.2<|fS1 / f|<2.2; 1<|fS2 / f|<2.

[0009] As an improvement of the high-resolution industrial lens described in the present invention, the first lens is a meniscus structure, and the focal length of the first lens is fG1; the second lens is a biconvex structure, and the focal length of the second lens is fG2; the third lens is a meniscus structure, and the focal length of the third lens is fG3; the fourth lens is a biconcave structure, and the focal length of the fourth lens is fG4; the fifth lens is a biconvex structure, and the focal length of the fifth lens is fG5; the sixth lens is a meniscus structure, and the focal length of the sixth lens is fG6; the seventh lens is a biconvex structure, and the focal length of the seventh lens is fG7; the eighth lens is a biconcave structure, and the focal length of the eighth lens is fG8; the ninth lens is a biconvex structure, and the focal length of the ninth lens is fG9; the tenth lens is a meniscus structure, and the focal length of the tenth lens is fG10; the eleventh lens is a meniscus structure, and the focal length of the eleventh lens is fG11; the twelfth lens is a biconvex structure, and the focal length of the twelfth lens is fG12.

[0010] The structures of the first lens, the second lens and the third lens are suitable for use in a large field of view optical system to correct distortion while reducing the size of the optical system.

[0011] As an improvement of the high-resolution industrial lens described in the present invention, the fourth lens and the fifth lens form a first cemented lens, and the focal length of the first cemented lens is fU1; the eighth lens and the ninth lens form a second cemented lens, and the focal length of the second cemented lens is fU2; the tenth lens and the eleventh lens form a third cemented lens, and the focal length of the third cemented lens is fU3.

[0012] As an improvement of the high-resolution industrial lens described in the present invention, the ratios of the focal length fG1 of the first lens, the focal length fG2 of the second lens, the focal length fG3 of the third lens, the focal length fG6 of the sixth lens and the focal length fS1 of the front lens group respectively satisfy the relationship:

[0013] 1.7<|fG1 / fS1|<2.7; 1.4<|fG2 / fS1|<2.4;

[0014] 0.5<|fG3 / fS1|<1.2; 0.8<|fG6 / fS1|<1.8.

[0015] As an improvement of the high-resolution industrial lens described in the present invention, the ratio of the focal length fU1 of the first cemented lens to the focal length fS1 of the front lens group satisfies the relationship: 6.2<|fU1 / fS1|<8.2.

[0016] As an improvement of the high-resolution industrial lens described in the present invention, the ratio of the focal length fU2 of the second cemented lens to the focal length fS2 of the rear focusing group satisfies the relationship: 0.4<|fU2 / fS2|<1.4.

[0017] As an improvement of the high-resolution industrial lens described in the present invention, the ratio of the focal length fU3 of the third cemented lens and the focal length fS2 of the rear focusing group satisfies the relationship: 2<|fU3 / fS2|<3.

[0018] As an improvement of the high-resolution industrial lens described in the present invention, the ratios of the focal length fG7 of the seventh lens and the focal length fG12 of the twelfth lens to the focal length fS2 of the rear focusing group respectively satisfy the relationship:

[0019] 1.35<|fG7 / fS2|<2.35; 0.6<|fG12 / fS2|<1.6.

[0020] As an improvement of the high-resolution industrial lens described in the present invention, the rear focusing group is a floating focusing group, and the rear focusing group is used to ensure good imaging at long distances and short distances.

[0021] As an improvement of the high-resolution industrial lens described in the present invention, the half-image height y' of the optical module and the focal length f of the optical module satisfy the relationship: |y' / f|<0.74.

[0022] The beneficial effects of the present invention are as follows: a high-resolution industrial lens provided by the present invention comprises an optical module, wherein the optical module is provided with a front lens group, an aperture and a rear focusing group in sequence from the object side to the image side; the front lens group comprises a first lens with negative focal power, a second lens with positive focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with positive focal power and a sixth lens with positive focal power; the aperture is arranged between the front lens group and the rear focusing group; the rear focusing group comprises a seventh lens with positive focal power, an eighth lens with negative focal power, a ninth lens with positive focal power, a tenth lens with positive focal power, an eleventh lens with negative focal power and a twelfth lens with positive focal power; wherein the focal length of the optical module is f, the focal length of the front lens group is fS1, and the combined focal length of the rear focusing group is fS2, which satisfies the relationship: 1.2<|fS1 / f|<2.2; 1<|fS2 / f|<2. The present invention provides a high-resolution industrial lens with an image side F number of 2.8. When the focal length is 12 mm, it can match a 1.1" inch camera. The maximum pixel can reach 23 million pixels, achieving high-quality imaging. At the same time, the present invention adopts a floating focus adjustment method, and the light aperture can be flexibly adjusted, effectively balancing the contradiction between the telecentricity and low distortion of the optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of an optical module in an embodiment of the present invention;

[0024] Figure 2 : is the MTF diagram of the optical module in the embodiment of the present invention.

[0025] in:

[0026] S1-optical module;

[0027] S2-aperture;

[0028] S3-rear focusing group;

[0029] G1-first lens; G2-second lens; G3-third lens; G4-fourth lens;

[0030] G5-fifth lens; G6-sixth lens; G7-seventh lens; G8-eighth lens;

[0031] G9-ninth lens; G10-tenth lens; G11-eleventh lens; G12-twelfth lens;

[0032] U1-the first cemented lens; U2-the second cemented lens; U3-the third cemented lens. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the concept, specific structure and technical effects of the present invention in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by technicians in this field without creative work are all within the scope of protection of the present invention. In addition, all the connection relationships mentioned in the text do not refer to the direct connection of components, but refer to the fact that a better connection structure can be formed by adding or reducing connecting accessories according to the specific implementation situation. The various technical features in the invention can be combined interchangeably without conflicting with each other.

[0034] like Figures 1-2 As shown, a high-resolution industrial lens provided by the present invention comprises an optical module, wherein the optical module is provided with a front lens group S1, an aperture S2 and a rear focusing group S3 in sequence from the object side to the image side; the front lens group S1 comprises a first lens G1 with negative focal power, a second lens G2 with positive focal power, a third lens G3 with negative focal power, a fourth lens G4 with negative focal power, a fifth lens G5 with positive focal power and a sixth lens G6 with positive focal power; the aperture S2 is arranged between the front lens group S1 and the rear focusing group S3; the rear focusing group S3 comprises a seventh lens G7 with positive focal power, an eighth lens G8 with negative focal power, a ninth lens G9 with positive focal power, a tenth lens G10 with positive focal power, an eleventh lens G11 with negative focal power and a twelfth lens G12 with positive focal power;

[0035] Among them, the focal length of the optical module is f, the focal length of the front lens group S1 is fS1, and the combined focal length of the rear focusing group S3 is fS2, which satisfies the relationship: 1.2<|fS1 / f|<2.2; 1<|fS2 / f|<2.

[0036] Preferably, the first lens G1 is a meniscus structure, and the focal length of the first lens G1 is fG1; the second lens G2 is a biconvex structure, and the focal length of the second lens G2 is fG2; the third lens G3 is a meniscus structure, and the focal length of the third lens G3 is fG3; the fourth lens G4 is a biconcave structure, and the focal length of the fourth lens G4 is fG4; the fifth lens G5 is a biconvex structure, and the focal length of the fifth lens G5 is fG5; the sixth lens G6 is a meniscus structure, and the focal length of the sixth lens G6 is fG6; the seventh lens G7 is a biconvex structure, and the focal length of the seventh lens G7 is fG7; the eighth lens G8 is a biconcave structure, and the focal length of the eighth lens G8 is fG8; the ninth lens G9 is a biconvex structure, and the focal length of the ninth lens G9 is fG9; the tenth lens G10 is a meniscus structure, and the focal length of the tenth lens G10 is fG10; the eleventh lens G11 is a meniscus structure, and the focal length of the eleventh lens G11 is fG11; the twelfth lens G12 is a biconvex structure, and the focal length of the twelfth lens G12 is fG12.

[0037] The structures of the first lens G1, the second lens G2 and the third lens G3 are suitable for use in a large field of view optical system to correct distortion and reduce the size of the optical system.

[0038] Preferably, the fourth lens G4 and the fifth lens G5 form a first cemented lens U1, and the focal length of the first cemented lens U1 is fU1; the eighth lens G8 and the ninth lens G9 form a second cemented lens U2, and the focal length of the second cemented lens U2 is fU2; the tenth lens G10 and the eleventh lens G11 form a third cemented lens U3, and the focal length of the third cemented lens U3 is fU3.

[0039] Preferably, the ratios of the focal length fG1 of the first lens G1, the focal length fG2 of the second lens G2, the focal length fG3 of the third lens G3, the focal length fG6 of the sixth lens G6 and the focal length fS1 of the front lens group S1 satisfy the relationship:

[0040] 1.7<|fG1 / fS1|<2.7; 1.4<|fG2 / fS1|<2.4;

[0041] 0.5<|fG3 / fS1|<1.2; 0.8<|fG6 / fS1|<1.8.

[0042] Preferably, the ratio of the focal length fU1 of the first cemented lens U1 to the focal length fS1 of the front lens group S1 satisfies the relationship: 6.2<|f U1 / fS1|<8.2.

[0043] Preferably, the ratio of the focal length fU2 of the second cemented lens U2 to the focal length fS2 of the rear focusing group S3 satisfies the relationship: 0.4<|fU2 / fS2|<1.4.

[0044] Preferably, the ratio of the focal length fU3 of the third cemented lens U3 to the focal length fS2 of the rear focusing group S3 satisfies the relationship: 2<|fU3 / fS2|<3.

[0045] Preferably, the ratios of the focal length fG7 of the seventh lens G7 and the focal length fG12 of the twelfth lens G12 to the focal length fS2 of the rear focusing group S3 satisfy the relationship:

[0046] 1.35<|fG7 / fS2|<2.35; 0.6<|fG12 / fS2|<1.6.

[0047] Preferably, the rear focusing group S3 is a floating focusing group, and the rear focusing group S3 is used to ensure good imaging at long distances and short distances.

[0048] Preferably, the half image height y' of the optical module and the focal length f of the optical module satisfy the relationship: |y' / f|<0.74.

[0049] In this embodiment, the optical module data is as follows:

[0050]

[0051]

[0052] In this example, the focal length of the optical module is 12.25 mm, the half image height y'=8.8 mm, the maximum aperture is F=2.8, and the combined focal length f of the front lens group S1 is S1 =20.03mm, the combined focal length of the rear focusing group S3 is f S3 =21.04mm, the focal length of the first lens G1 is f G1 =-48.59mm, the focal length of the second lens G2 is f G2 =41.10mm, the focal length of the third lens G3 is f G3 =-18.90mm, the focal length of the first cemented lens U1 is f U1 =159.06mm, the focal length of the sixth lens G6 is f G6 =28.89mm, the focal length of the seventh lens G7 is f G7 =38.62mm, the focal length of the second cemented lens U2 is f U2 =-18.50mm, the focal length of the third cemented lens U3 U3 =52.46mm, the focal length of the twelfth lens G12 is f G12 =23.23mm;

[0053] The following relationship is satisfied:

[0054] (|y' / f|=0.72)<0.74;

[0055] 1.2<(|f S1 / f|=1.64)<2.2;1<(|f S2 / f|=1.72)<2;

[0056] 1.7<(|f G1 / f S1 |=2.21)<2.7;1.4<(|f G2 / f S1 |=1.87)<2.4;

[0057] 0.5<(|f G3 / f S1 |=0.86)<1.2;6.2<(|f U1 / f S1 |=7.22)<8.2;

[0058] 0.8<(|f G6 / f S1 |=1.31)<1.8;1.35<(|f G7 / f S2 |=1.84)<2.35;

[0059] 0.4<(|f U2 / f S2 |=0.88)<1.4;2<(|f U3 / f S2 |=2.49)<3;

[0060] 0.6<(|f G12 / f S2 |=1.10)<1.6.

[0061] Figure 2 It is the MTF diagram of the optical module of this embodiment.

[0062] The present invention provides a high-resolution industrial lens with an image side F number of 2.8. When the focal length is 12 mm, it can match a 1.1" inch camera. The maximum pixel can reach 23 million pixels, achieving high-quality imaging. At the same time, the present invention adopts a floating focus adjustment method, and the light aperture can be flexibly adjusted, effectively balancing the contradiction between the telecentricity and low distortion of the optical system.

[0063] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs can also change and modify the above embodiment. Therefore, the present invention is not limited to the above specific embodiment, and any obvious improvement, replacement or modification made by those skilled in the art on the basis of the present invention belongs to the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A high-resolution industrial lens, characterized by: The optical module comprises an optical module, wherein the optical module is provided with a front lens group (S1), an aperture (S2) and a rear focusing group (S3) in sequence from the object side to the image side; The front lens group (S1) includes a first lens (G1) with negative power, a second lens (G2) with positive power, a third lens (G3) with negative power, a fourth lens (G4) with negative power, a fifth lens (G5) with positive power, and a sixth lens (G6) with positive power; The aperture (S2) is arranged between the front lens group (S1) and the rear focusing group (S3); The rear focusing group (S3) includes a seventh lens (G7) with positive focal power, an eighth lens (G8) with negative focal power, a ninth lens (G9) with positive focal power, a tenth lens (G10) with positive focal power, an eleventh lens (G11) with negative focal power, and a twelfth lens (G12) with positive focal power; The focal length of the optical module is f, the combined focal length of the front lens group (S1) is fS1, and the combined focal length of the rear focusing group (S3) is fS2, which satisfies the relationship: 1.2<|fS1 / f|<2.2; 1<|fS2 / f|<2; The first lens (G1) is a meniscus structure, and the focal length of the first lens (G1) is fG1; The second lens (G2) is a biconvex structure, and the focal length of the second lens (G2) is fG2; The third lens (G3) is a meniscus structure, and the focal length of the third lens (G3) is fG3; The fourth lens (G4) is a biconcave structure, and the focal length of the fourth lens (G4) is fG4; The fifth lens (G5) is a biconvex structure, and the focal length of the fifth lens (G5) is fG5; The sixth lens (G6) is a meniscus structure, and the focal length of the sixth lens (G6) is fG6; The seventh lens (G7) is a biconvex structure, and the focal length of the seventh lens (G7) is fG7; The eighth lens (G8) is a double concave structure, and the focal length of the eighth lens (G8) is fG8; The ninth lens (G9) is a biconvex structure, and the focal length of the ninth lens (G9) is fG9; The tenth lens (G10) is a meniscus structure, and the focal length of the tenth lens (G10) is fG10; The eleventh lens (G11) is a meniscus structure, and the focal length of the eleventh lens (G11) is fG11; The twelfth lens (G12) is a biconvex structure, and the focal length of the twelfth lens (G12) is fG12; The fourth lens (G4) and the fifth lens (G5) form a first cemented lens (U1), and the focal length of the first cemented lens (U1) is fU1; The eighth lens (G8) and the ninth lens (G9) form a second cemented lens (U2), and the focal length of the second cemented lens (U2) is fU2; The tenth lens (G10) and the eleventh lens (G11) form a third cemented lens (U3), and the focal length of the third cemented lens (U3) is fU3; The ratios of the focal length fG1 of the first lens (G1), the focal length fG2 of the second lens (G2), the focal length fG3 of the third lens (G3), the focal length fG6 of the sixth lens (G6) and the focal length fS1 of the front lens group (S1) satisfy the relationship: 1.7<|fG1 / fS1|<2.7; 1.4<|fG2 / fS1|<2.4; 0.5<|fG3 / fS1|<1.2; 0.8<|fG6 / fS1|<1.8; The ratio of the focal length fU1 of the first cemented lens (U1) to the focal length fS1 of the front lens group (S1) satisfies the relationship: 6.2<|fU1 / fS1|<8.2; The ratio of the focal length fU2 of the second cemented lens (U2) to the focal length fS2 of the rear focusing group (S3) satisfies the relationship: 0.4<|fU2 / fS2|<1.4; The ratio of the focal length fU3 of the third cemented lens (U3) to the focal length fS2 of the rear focusing group (S3) satisfies the relationship: 2<|fU3 / fS2|<3.

2. A high-resolution industrial lens according to claim 1, characterized in that: The ratios of the focal length fG7 of the seventh lens (G7) and the focal length fG12 of the twelfth lens (G12) to the focal length fS2 of the rear focusing group (S3) satisfy the relationship: 1.35<|fG7 / fS2|<2.35; 0.6<|fG12 / fS2|<1.

6.

3. A high-resolution industrial lens according to claim 1, characterized in that: The rear focusing group (S3) is a floating focusing group, and the rear focusing group (S3) is used to ensure good imaging at long distances and short distances.

4. A high-resolution industrial lens according to claim 1, characterized in that: The half image height y' of the optical module and the focal length f of the optical module satisfy the relationship: |y' / f|<0.74.

Images