High-resolution low-distortion industrial lens and optical system thereof

Abstract

The application relates to the field of optical imaging technology and discloses a high-resolution low-distortion industrial lens and an optical system thereof. The optical system comprises a front group T1 with positive optical power, a diaphragm A0 and a rear group T2 with positive optical power; the front group T1 comprises a first lens group S1 with negative optical power, a second lens group S2 with positive optical power and a third lens group S3 with positive optical power; the distance between the vertex of the rear surface of the first lens group S1 and the vertex of the front surface of the third lens group S3 is D S , the focal length f of the optical system and D S satisfy the relationship: |D S / f|>0.90. The application adopts a floating focusing mode, realizes the optical system of the industrial lens with a focal length of 16 mm, the highest resolution can reach 185 lp / mm, can match a 2.7-micron pixel chip, when corresponding to the maximum chip size, the pixels can reach 24 million, and the maximum optical distortion of the full field of view is less than 0.45%.

Description

Technical Field

[0001] This invention relates to the field of optical imaging technology, and in particular to a high-resolution, low-distortion industrial lens and its optical system. Background Technology

[0002] With the upgrading and increasing automation of China's manufacturing industry, the demand for high-resolution, low-distortion industrial lenses is constantly increasing. Industrial lenses are widely used in automotive manufacturing, electronics manufacturing, and machinery manufacturing for dimensional measurement, appearance inspection, and defect detection of parts. For example, in the production of automotive parts, high-resolution, low-distortion industrial lenses can accurately detect the dimensions and surface defects of components such as engine blocks and crankshafts, ensuring product quality.

[0003] In recent years, image sensor technologies such as CMOS (Complementary Metal Oxide Semiconductor) and CCD (charge-coupled device) have made continuous progress, with pixel count and resolution constantly improving, leading to the increasing popularity of large-format image sensors. To fully leverage the performance advantages of large-format image sensors, matching large-format industrial lenses are needed to achieve optimal imaging results. The combination of large-format industrial lenses and high-pixel image sensors can meet the demands for wide field-of-view, high-resolution imaging, driving the development of industrial lenses towards larger formats.

[0004] Large-aperture lenses require more complex design and manufacturing processes, necessitating the use of higher-quality optical materials and more precise processing equipment. This results in higher manufacturing costs and a relatively expensive price, increasing the overall cost of the system. Furthermore, due to the lens's large imaging area and complex optical structure, completely eliminating distortion remains challenging, especially at the edges of the field of view, where distortion may occur, affecting the accuracy and stability of the image. For this field, existing lens designs can no longer meet new industry demands; therefore, the development of high-resolution, low-distortion industrial lenses is even more urgent.

[0005] The above information is provided as background information only to aid in understanding this disclosure and does not constitute an assertion or admission that any of the above content can be used as prior art relative to this disclosure. Summary of the Invention

[0006] The purpose of this invention is to provide a high-resolution, low-distortion industrial lens and its optical system to solve or at least partially solve the technical problems existing in the prior art.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides an optical system for a high-resolution, low-distortion industrial lens, comprising a front group T1 with positive optical power, an aperture A0, and a rear group T2 with positive optical power arranged sequentially from the object side to the image side.

[0009] The focal length f of the optical system, and the focal length of the front group T1 is f. T1 The focal length of the rear group T2 is f. T2 ;f and f T1 The relation is satisfied: 0.95 < |f T1 / f|<1.60; f and f T2 Satisfies the relation: 1.40 < |f T2 / f|<2.10;

[0010] The front group T1 includes a first lens group S1 with negative optical power, a second lens group S2 with positive optical power, and a third lens group S3 with positive optical power, arranged sequentially from the object side to the image side; the distance between the vertex of the rear surface of the first lens group S1 and the vertex of the front surface of the third lens group S3 is D. S f and D S Satisfying the relation: |D S / f|>0.90;

[0011] The relative positions of the first lens group S1, the third lens group S3, and the rear lens group T2 with the image plane remain unchanged. The second lens group S2 can be driven to move along the optical axis of the optical system within the focusing area between the rear surface of the first lens group S1 and the front surface of the third lens group S3.

[0012] Optionally, the first lens group S1 includes a first lens G1 with positive optical power, a second lens G2 with negative optical power, a third lens G3 with negative optical power, and a fourth lens G4 with negative optical power.

[0013] The second lens group S2 includes a fifth lens G5 with negative optical power, a sixth lens G6 with positive optical power, and a seventh lens G7 with positive optical power, wherein the fifth lens G5 and the sixth lens G6 are cemented together to form a first cemented lens group U1 with positive optical power.

[0014] The third lens group S3 includes an eighth lens G8 with positive optical power;

[0015] D S It is the distance between the rear surface of the fourth lens G4 and the front surface of the eighth lens G8.

[0016] Optionally, the focal length of the first lens group S1 is f. S1 The focal length of the second lens group S2 is f. S2 The focal length of the third lens group S3 is f. S3 ;

[0017] f S1 The ratio of f to f satisfies the following relationship: 0.55 < |f| S1 / f|<1.00;

[0018] f S2 The ratio of f to f satisfies the following relationship: 1.00 < |f| S2 / f|<1.45;

[0019] f S3 The ratio of f to f satisfies the following relationship: 2.50 < |f S3 / f|<6.00.

[0020] Optionally, the focal length of the first lens G1 is f. G1 f G1 The relationship between f and f is: 2.40 < |f G1 / f|<3.20;

[0021] The focal length of the second lens G2 is f G2 f G2 The relationship between f and f is: 1.20 < |f G2 / f|<1.80;

[0022] The focal length of the third lens G3 is f G3 f G3 The relationship between f and f is: 0.90 < |f G3 / f|<1.50;

[0023] The focal length of the fourth lens G4 is f G4 f G4 The relationship between f and f is: 5.00 < |f G4 / f|<6.00;

[0024] The focal length of the first cemented lens group is f. U1 f U1 The relationship between f and f is: 2.70 < |f U1 / f|<3.20;

[0025] The focal length of the seventh lens G7 is f G7 f G7 The relationship between f and f is: 1.40 < |f G7 / f|<2.00;

[0026] The focal length of the eighth lens G8 is f G8 f G8 The relationship between f and f is: 4.00 < |f G8 / f|<5.00.

[0027] Optionally, in the first lens group S1, the first lens G1 and the second lens G2 are both meniscus lenses, and the third lens G3 and the fourth lens G4 are both biconcave lenses.

[0028] In the second lens group S2, the fifth lens G5 is a meniscus lens, and the sixth lens G6 and the seventh lens G7 are both biconvex lenses.

[0029] The eighth lens, G8, is a biconvex lens.

[0030] Optionally, the rear group T2 includes a ninth lens G9 with negative optical power, a tenth lens G10 with positive optical power, an eleventh lens G11 with positive optical power, and a twelfth lens G12 with positive optical power arranged sequentially from the object side to the image side, wherein the ninth lens G9 and the tenth lens G10 are cemented together to form a second cemented lens group U2 with negative optical power.

[0031] The focal length of the second cemented lens group is f. U2 f U2 The relationship between f and f is: 1.00 < |f U2 / f|<1.80;

[0032] The focal length of the eleventh lens G11 is f. G11 f G11 The relationship between f and f is: 1.20 < |f G11 / f|<1.80;

[0033] The focal length of the twelfth lens G12 is f. G12 f G12 The relationship between f and f is: 3.00 < |f G12 / f|<3.80.

[0034] Optionally, the ninth lens G9 is a biconcave lens, the tenth lens G10 and the eleventh lens G11 are both biconvex lenses, and the twelfth lens G12 is a meniscus lens.

[0035] Optionally, the first lens G1, the second lens G2, the third lens G13, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, the ninth lens G9, the tenth lens G10, the eleventh lens G11, and the twelfth lens G12 are all glass spherical lenses.

[0036] Optionally, the optical axes of the first lens G1, the second lens G2, the third lens G13, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, the ninth lens G9, the tenth lens G10, the eleventh lens G11, and the twelfth lens G12 all coincide with the optical axis of the optical system.

[0037] The aperture of stop A0 is a circular aperture, and the center of the circular aperture is on the optical axis of the optical system; the adjustment range of the aperture of stop A0 is F2.8 to F16.

[0038] Secondly, the present invention provides a high-resolution, low-distortion industrial lens, including a focusing structure and an optical system for a high-resolution, low-distortion industrial lens as described above.

[0039] The focusing structure is used to drive the second lens group S2 to move along the optical axis of the optical system within the focusing area between the rear surface of the first lens group S1 and the front surface of the third lens group S3.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] Through the structural design of the aforementioned optical system, this invention employs a floating focusing method to achieve an optical system for an industrial lens with a focal length of 16mm. The maximum resolution can reach 185lp / mm, and it can be matched with a 2.7-micron pixel chip. When the chip size is at its maximum, the pixel count can reach 24 million pixels, and the maximum optical distortion across the entire field of view is less than 0.45%.

[0042] The present invention has other features and advantages, which will be apparent from or will be set forth in detail in the accompanying drawings and the following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the optical system of a high-resolution, low-distortion industrial lens provided in Embodiment 1 of the present invention.

[0045] Figure 2 This is an optical distortion curve diagram of an optical system for a high-resolution, low-distortion industrial lens provided in Embodiment 1 of the present invention. Detailed Implementation

[0046] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0047] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0048] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0049] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0050] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0051] Unless otherwise specified, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0052] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0053] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0054] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0055] Example 1:

[0056] Please see Figure 1 , Figure 1 This is a schematic diagram of the optical system of a high-resolution, low-distortion industrial lens provided in Embodiment 1 of the present invention.

[0057] like Figure 1 As shown, the optical system includes:

[0058] The present invention provides an optical system for a high-resolution, low-distortion industrial lens, comprising a front group T1 with positive optical power, an aperture A0, and a rear group T2 with positive optical power arranged sequentially from the object side to the image side.

[0059] The focal length f of the optical system, and the focal length of the front group T1 is f. T1 The focal length of the rear group T2 is f.T2 ;f and f T1 The relation is satisfied: 0.95 < |f T1 / f|<1.60; f and f T2 Satisfies the relation: 1.40 < |f T2 / f|<2.10;

[0060] The front group T1 includes a first lens group S1 with negative optical power, a second lens group S2 with positive optical power, and a third lens group S3 with positive optical power, arranged sequentially from the object side to the image side; the distance between the vertex of the rear surface of the first lens group S1 and the vertex of the front surface of the third lens group S3 is D. S f and D S Satisfying the relation: |D S / f|>0.90;

[0061] The relative positions of the first lens group S1, the third lens group S3, and the rear lens group T2 with the image plane remain unchanged. The second lens group S2 can be driven to move along the optical axis of the optical system within the focusing area between the rear surface of the first lens group S1 and the front surface of the third lens group S3.

[0062] Optionally, the first lens group S1 includes a first lens G1 with positive optical power, a second lens G2 with negative optical power, a third lens G3 with negative optical power, and a fourth lens G4 with negative optical power.

[0063] The second lens group S2 includes a fifth lens G5 with negative optical power, a sixth lens G6 with positive optical power, and a seventh lens G7 with positive optical power, wherein the fifth lens G5 and the sixth lens G6 are cemented together to form a first cemented lens group U1 with positive optical power.

[0064] The third lens group S3 includes an eighth lens G8 with positive optical power;

[0065] D S It is the distance between the rear surface of the fourth lens G4 and the front surface of the eighth lens G8.

[0066] Furthermore, the focal length of the first lens group S1 is f. S1 The focal length of the second lens group S2 is f. S2 The focal length of the third lens group S3 is f. S3 ;

[0067] f S1 The ratio of f to f satisfies the following relationship: 0.55 < |f| S1 / f|<1.00;

[0068] f S2 The ratio of f to f satisfies the following relationship: 1.00 < |f| S2 / f|<1.45;

[0069] f S3 The ratio of f to f satisfies the following relationship: 2.50 < |f S3 / f|<6.00.

[0070] Wherein, the focal length of the first lens G1 is f G1 f G1 The relationship between f and f is: 2.40 < |f G1 / f|<3.20;

[0071] The focal length of the second lens G2 is f G2 f G2 The relationship between f and f is: 1.20 < |f G2 / f|<1.80;

[0072] The focal length of the third lens G3 is f G3 f G3 The relationship between f and f is: 0.90 < |f G3 / f|<1.50;

[0073] The focal length of the fourth lens G4 is f G4 f G4 The relationship between f and f is: 5.00 < |f G4 / f|<6.00;

[0074] The focal length of the first cemented lens group is f. U1 f U1 The relationship between f and f is: 2.70 < |f U1 / f|<3.20;

[0075] The focal length of the seventh lens G7 is f G7 f G7 The relationship between f and f is: 1.40 < |f G7 / f|<2.00;

[0076] The focal length of the eighth lens G8 is f G8 f G8 The relationship between f and f is: 4.00 < |f G8 / f|<5.00.

[0077] In this embodiment, in the first lens group S1, the first lens G1 and the second lens G2 are both meniscus lenses, and the third lens G3 and the fourth lens G4 are both biconcave lenses.

[0078] In the second lens group S2, the fifth lens G5 is a meniscus lens, and the sixth lens G6 and the seventh lens G7 are both biconvex lenses.

[0079] The eighth lens, G8, is a biconvex lens.

[0080] Furthermore, the rear group T2 includes a ninth lens G9 with negative optical power, a tenth lens G10 with positive optical power, an eleventh lens G11 with positive optical power, and a twelfth lens G12 with positive optical power arranged sequentially from the object side to the image side. The ninth lens G9 and the tenth lens G10 are cemented together to form a second cemented lens group U2 with negative optical power.

[0081] The focal length of the second cemented lens group is f. U2 f U2 The relationship between f and f is: 1.00 < |f U2 / f|<1.80;

[0082] The focal length of the eleventh lens G11 is f. G11 f G11 The relationship between f and f is: 1.20 < |f G11 / f|<1.80;

[0083] The focal length of the twelfth lens G12 is f. G12 f G12 The relationship between f and f is: 3.00 < |f G12 / f|<3.80.

[0084] In this embodiment, the ninth lens G9 is a biconcave lens, the tenth lens G10 and the eleventh lens G11 are both biconvex lenses, and the twelfth lens G12 is a meniscus lens.

[0085] Specifically, the first lens G1, the second lens G2, the third lens G13, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, the ninth lens G9, the tenth lens G10, the eleventh lens G11, and the twelfth lens G12 are all glass spherical lenses.

[0086] Furthermore, the optical axes of the first lens G1, the second lens G2, the third lens G13, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, the ninth lens G9, the tenth lens G10, the eleventh lens G11, and the twelfth lens G12 all coincide with the optical axis of the optical system.

[0087] The aperture of stop A0 is a circular aperture, with its center on the optical axis of the optical system; the aperture adjustment range of stop A0 is F2.8 to F16. It is understood that the aperture value of stop T needs to be adjusted according to the specific application scenario.

[0088] To verify whether the optical system described above meets the design objectives, the following are specific application examples based on the above settings in this embodiment:

[0089] In this application example, the lens data of the optical system are shown in Table 1 below:

[0090] Table 1

[0091]

[0092]

[0093] It should be noted that in Table 1, "front surface" corresponds to... Figure 1 The left surface of the lens or lens group corresponds to the middle surface, while the rear surface corresponds to the left surface. Figure 1 The right side surface of the corresponding lens or lens group; or it can be understood as: the object surface in Figure 1 On the left, the image plane (or image surface) is... Figure 1 On the right side, the surface closer to the object is called the "front surface", and the surface closer to the image is called the "back surface".

[0094] In this example, the focal length f of the optical system is 16mm, the maximum aperture is F# = 2.8, and the focal length f of the front group T1 is... T1 =21.87mm, focal length f of rear element T2 T2 =28.05mm, optical back intercept BFL =16.80mm, half image height y' =9.6mm, focal length f of the first lens group S1 S1 = -13.26mm, the focal length f of the second lens group S2 S2 =17.77mm, the focal length f of the third lens group S3 S3 =71.92mm, the focal length f of the first lens G1 G1 = 45.86mm, the focal length f of the second lens G2 G2 = -24.45mm, the focal length f of the third lens G3 G3 = -19.81mm, the focal length f of the fourth lens G4 G4 = -86.76mm, focal length f of the first cemented lens group U1 = 47.38mm, the focal length f of the seventh lens G7 G7 =27.78mm, the focal length f of the eighth lens G8 G8 =71.92mm, focal length f of the second cemented lens group U2 = -22.00mm, the focal length f of the eleventh lens G11 G11 =24.22mm, the focal length f of the twelfth lens G12 G12 =54.48mm.

[0095] Various relational expressions:

[0096] |f T1 / f|=1.37;|fT2 / f|=1.75; |L / f|=4.20; |BFL / f|=1.05;

[0097] |y' / f|=0.60;|f S1 / f|=0.83;|f S2 / f|=1.11;|f S3 / f|=4.50;

[0098] |f G1 / f|=2.87;|f G2 / f|=1.53;|f G3 / f|=1.24;|f G4 / f|=5.42;

[0099] |f U1 / f|=2.96;|f G7 / f|=1.74;|f G8 / f|=4.50;|f U2 / f|=1.38;

[0100] |f G11 / f|=1.51;|f G12 / f|=3.41;|D S / f|=1.45.

[0101] Satisfying the relation:

[0102] 0.95<|f T1 / f|<1.60; 1.40<|f T2 / f|<2.10;|L / f|>3.00;

[0103] |BFL / f|<1.60; |y' / f|<0.85; 0.55<|f S1 / f|<1.00;

[0104] 1.00 < |f S2 / f| < 1.45; 2.50 < |f S3 / f|<6.00;

[0105] 2.40 < |f G1 / f| < 3.20; 1.20 < |f G2 / f|<1.80;

[0106] 0.90 < |f G3 / f| < 1.50; 5.00 < |f G4 / f|<6.00;

[0107] 2.70 < |f U1 / f| < 3.20; 1.40 < |f G7 / f|<2.00;

[0108] 4.00 < |f G8 / f| < 5.00; 1.00 < |f U2 / f|<1.80;

[0109] 1.20 < |f G11 / f| < 1.80; 3.00 < |f G12 / f|<3.80;|D S / f|>0.90.

[0110] Please refer to Figure 2 , Figure 2 The optical distortion curve of the optical system designed based on the above parameters is shown in the figure below. Figure 2 As shown, the maximum optical distortion of this optical system is less than 0.45% across the entire field of view;

[0111] Through the above structure, this embodiment realizes the optical system of a low-distortion, wide-field macro lens with a focal length of 16mm, an image-side F-number of 2.8, and a maximum imaging plane of [missing information]. The maximum resolution can reach 185 lp / mm, which can be matched with a 2.7 micrometer pixel chip. When the chip size is the largest, the pixel count can reach 24 million pixels, and the maximum optical distortion across the entire field of view is less than 0.45%. In addition, the optical system adopts a floating focusing method, and its aperture can be flexibly adjusted.

[0112] Example 2:

[0113] This embodiment provides a high-resolution, low-distortion industrial lens, including a focusing structure and an optical system for a high-resolution, low-distortion industrial lens as described in Embodiment 1.

[0114] The focusing structure is used to drive the second lens group S2 to move along the optical axis of the optical system within the focusing area between the rear surface of the first lens group S1 and the front surface of the third lens group S3.

[0115] Specifically, such as Figure 1 As shown, the optical system includes a front group T1 with positive optical power, an aperture A0, and a rear group T2 with positive optical power arranged sequentially from the object side to the image side.

[0116] The focal length f of the optical system, and the focal length of the front group T1 is f. T1 The focal length of the rear group T2 is f. T2 ;f and f T1 The relation is satisfied: 0.95 < |f T1 / f|<1.60; f and f T2 Satisfies the relation: 1.40 < |fT2 / f|<2.10;

[0117] The front group T1 includes a first lens group S1 with negative optical power, a second lens group S2 with positive optical power, and a third lens group S3 with positive optical power, arranged sequentially from the object side to the image side; the distance between the vertex of the rear surface of the first lens group S1 and the vertex of the front surface of the third lens group S3 is D. S f and D S Satisfying the relation: |D S / f|>0.90;

[0118] The relative positions of the first lens group S1, the third lens group S3, and the rear lens group T2 with the image plane remain unchanged. The second lens group S2 can be driven to move along the optical axis of the optical system within the focusing area between the rear surface of the first lens group S1 and the front surface of the third lens group S3.

[0119] Optionally, the first lens group S1 includes a first lens G1 with positive optical power, a second lens G2 with negative optical power, a third lens G3 with negative optical power, and a fourth lens G4 with negative optical power.

[0120] The second lens group S2 includes a fifth lens G5 with negative optical power, a sixth lens G6 with positive optical power, and a seventh lens G7 with positive optical power, wherein the fifth lens G5 and the sixth lens G6 are cemented together to form a first cemented lens group U1 with positive optical power.

[0121] The third lens group S3 includes an eighth lens G8 with positive optical power;

[0122] D S It is the distance between the rear surface of the fourth lens G4 and the front surface of the eighth lens G8.

[0123] Furthermore, the focal length of the first lens group S1 is f. S1 The focal length of the second lens group S2 is f. S2 The focal length of the third lens group S3 is f. S3 ;

[0124] f S1 The ratio of f to f satisfies the following relationship: 0.55 < |f| S1 / f|<1.00;

[0125] f S2 The ratio of f to f satisfies the following relationship: 1.00 < |f| S2 / f|<1.45;

[0126] f S3 The ratio of f to f satisfies the following relationship: 2.50 < |f S3 / f|<6.00.

[0127] Specifically, the focal length of the first lens G1 is f. G1 f G1 The relationship between f and f is: 2.40 < |f G1 / f|<3.20;

[0128] The focal length of the second lens G2 is f G2 f G2 The relationship between f and f is: 1.20 < |f G2 / f|<1.80;

[0129] The focal length of the third lens G3 is f G3 f G3 The relationship between f and f is: 0.90 < |f G3 / f|<1.50;

[0130] The focal length of the fourth lens G4 is f G4 f G4 The relationship between f and f is: 5.00 < |f G4 / f|<6.00;

[0131] The focal length of the first cemented lens group is f. U1 f U1 The relationship between f and f is: 2.70 < |f U1 / f|<3.20;

[0132] The focal length of the seventh lens G7 is f G7 f G7 The relationship between f and f is: 1.40 < |f G7 / f|<2.00;

[0133] The focal length of the eighth lens G8 is f G8 f G8 The relationship between f and f is: 4.00 < |f G8 / f|<5.00.

[0134] In this embodiment, in the first lens group S1, the first lens G1 and the second lens G2 are both meniscus lenses, and the third lens G3 and the fourth lens G4 are both biconcave lenses.

[0135] In the second lens group S2, the fifth lens G5 is a meniscus lens, and the sixth lens G6 and the seventh lens G7 are both biconvex lenses.

[0136] The eighth lens, G8, is a biconvex lens.

[0137] Furthermore, the rear group T2 includes a ninth lens G9 with negative optical power, a tenth lens G10 with positive optical power, an eleventh lens G11 with positive optical power, and a twelfth lens G12 with positive optical power arranged sequentially from the object side to the image side. The ninth lens G9 and the tenth lens G10 are cemented together to form a second cemented lens group U2 with negative optical power.

[0138] The focal length of the second cemented lens group is f. U2 f U2 The relationship between f and f is: 1.00 < |f U2 / f|<1.80;

[0139] The focal length of the eleventh lens G11 is f. G11 f G11 The relationship between f and f is: 1.20 < |f G11 / f|<1.80;

[0140] The focal length of the twelfth lens G12 is f. G12 f G12 The relationship between f and f is: 3.00 < |f G12 / f|<3.80.

[0141] In this embodiment, the ninth lens G9 is a biconcave lens, the tenth lens G10 and the eleventh lens G11 are both biconvex lenses, and the twelfth lens G12 is a meniscus lens.

[0142] Specifically, the first lens G1, the second lens G2, the third lens G13, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, the ninth lens G9, the tenth lens G10, the eleventh lens G11, and the twelfth lens G12 are all glass spherical lenses.

[0143] Furthermore, the optical axes of the first lens G1, the second lens G2, the third lens G13, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, the ninth lens G9, the tenth lens G10, the eleventh lens G11, and the twelfth lens G12 all coincide with the optical axis of the optical system.

[0144] The aperture of stop A0 is a circular aperture, with its center on the optical axis of the optical system; the aperture adjustment range of stop A0 is F2.8 to F16. It is understood that the aperture value of stop T needs to be adjusted according to the specific application scenario.

[0145] In summary, the embodiments of the present invention realize a high-resolution, low-distortion industrial lens with a focal length of 16mm, which has both high resolution and low distortion, and can meet new industry requirements.

[0146] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical system of a high-resolution low-distortion industrial lens, characterized by, The front group T1 with positive focal length, the diaphragm A0 and the rear group T2 with positive focal length are sequentially arranged from the object side to the image side; focal length f of the optical system, the focal length of the front group T1 being f T1 , the focal length of the rear group T2 being f T2 ; f and f T1 satisfy the relationship: 0.95 < |f T1 / f | < 1.60; f and f T2 satisfy the relationship: 1.40 < |f T2 / f | < 2.10; The front group T1 is composed of a first lens group S1 having negative focal power, a second lens group S2 having positive focal power, and a third lens group S3 having positive focal power, which are arranged in order from the object side to the image side; the distance between the vertex of the rear surface of the first lens group S1 and the vertex of the front surface of the third lens group S3 is D S , f and D S satisfy the relation: |D S / f| > 0.

90. The first lens group S1 is composed of a first lens G1 with positive focal length, a second lens G2 with negative focal length, a third lens G3 with negative focal length and a fourth lens G4 with negative focal length; The second lens group S2 is composed of a fifth lens G5 with negative focal length, a sixth lens G6 with positive focal length and a seventh lens G7 with positive focal length; The third lens group S3 is composed of an eighth lens G8 with positive focal length; The rear group T2 is composed of a ninth lens G9 with negative focal length, a tenth lens G10 with positive focal length, an eleventh lens G11 with positive focal length and a twelfth lens G12 with positive focal length, sequentially arranged from the object side to the image side; The first lens group S1, the third lens group S3 and the rear group T2 all keep the relative position with the image plane unchanged, and the second lens group S2 can be driven to move along the optical axis of the optical system in the focusing region between the rear surface of the first lens group S1 and the front surface of the third lens group S3.

2. The optical system of a high-resolution low-distortion industrial lens according to claim 1, wherein, The fifth lens G5 and the sixth lens G6 are cemented into a first cemented lens group U1 with positive focal length; D S G8 is the distance between the rear surface of the fourth lens G4 and the front surface of the eighth lens G8.

3. The optical system of a high-resolution low-distortion industrial lens according to claim 2, characterized in that, The focal length of the first lens group S1 is f S1 , the focal length of the second lens group S2 is f S2 , and the focal length of the third lens group S3 is f S3 . f S1 The ratio of f to f satisfies the relationship: 0.55 < |f S1 / f| < 1.00; f S2 The ratio of f to f satisfies the relationship: 1.00 < |f S2 / f| < 1.45; f S3 The ratio of f to f satisfies the relationship: 2.50 < |f S3 / f| < 6.

00.

4. The optical system of a high-resolution low-distortion industrial lens according to claim 3, wherein The focal length of the first lens G1 is f G1 , f G1 and f satisfy the relationship: 2.40 < |f G1 / f| < 3.

20. The focal length of the second lens G2 is f G2 , f G2 and f satisfy the relationship: 1.20 < |f G2 / f| < 1.

80. The focal length of the third lens G3 is f G3 , f G3 and f satisfy the relationship: 0.90 < |f G3 / f| < 1.

50. The focal length of the fourth lens G4 is f G4 , f G4 and f satisfy the relationship: 5.00 < |f G4 / f| < 6.

00. The focal length of the first cemented lens group is f U1 , f U1 and f satisfy the relationship: 2.70 < |f U1 / f| < 3.

20. The focal length of the seventh lens G7 is f G7 , f G7 and f satisfy the relationship: 1.40 < |f G7 / f| < 2.

00. The focal length of the eighth lens G8 is f G8 , f G8 and f satisfy the relationship: 4.00 < |f G8 / f| < 5.

00.

5. The optical system of a high resolution low distortion industrial lens according to claim 4, wherein, In the first lens group S1, the first lens G1 and the second lens G2 are both meniscus lenses, and the third lens G3 and the fourth lens G4 are both double-concave lenses; In the second lens group S2, the fifth lens G5 is a meniscus lens, and the sixth lens G6 and the seventh lens G7 are both double-convex lenses; The eighth lens G8 is a double-convex lens.

6. The optical system of a high resolution low distortion industrial lens according to claim 3, wherein, The ninth lens G9 and the tenth lens G10 are cemented into a second cemented lens group U2 with negative focal length; The focal length of the second cemented lens group is f U2 , f U2 and f satisfy the relationship: 1.00 < |f U2 / f| < 1.

80. The focal length of the eleventh lens G11 is f G11 , f G11 and f satisfy the relationship: 1.20 < |f G11 / f| < 1.

80. The focal length of the twelfth lens G12 is f G12 , f G12 and f satisfy the relationship: 3.00 < |f G12 / f| < 3.

80.

7. The optical system of a high resolution low distortion industrial lens according to claim 6, wherein, The ninth lens G9 is a double-concave lens, the tenth lens G10 and the eleventh lens G11 are both double-convex lenses, and the twelfth lens G12 is a meniscus lens.

8. The optical system of a high-resolution low-distortion industrial lens according to claim 7, characterized in that, The first lens G1, the second lens G2, the third lens G13, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, the ninth lens G9, the tenth lens G10, the eleventh lens G11 and the twelfth lens G12 are all glass spherical lenses.

9. The optical system of a high resolution low distortion industrial lens according to claim 8, wherein, The optical axes of the first lens G1, the second lens G2, the third lens G13, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, the ninth lens G9, the tenth lens G10, the eleventh lens G11 and the twelfth lens G12 all coincide with the optical axis of the optical system; The aperture of the diaphragm A0 is a circular hole, and the center of the circular hole is on the optical axis of the optical system; the adjustment range of the aperture of the diaphragm A0 is F2.8-F16.

10. A high resolution, low distortion industrial lens characterized by, An optical system comprising a focusing structure and a high-resolution low-distortion industrial lens according to any one of claims 1-9; The focusing structure is used to drive the second lens group S2 to move along the optical axis of the optical system in the focusing region between the rear surface of the first lens group S1 and the front surface of the third lens group S3.

Images