16K line-scan digital camera, double telecentric line scanning lens and optical system of double telecentric line scanning lens

Abstract

The invention relates to the technical field of machine vision lenses, and discloses a 16K linear array camera, a double telecentric line scanning lens and an optical system thereof. The optical system comprises a front group S1, a diaphragm T and a rear group S2 which are sequentially arranged from an object side to an image side. The front group S1 comprises a first lens G1 with positive focal power, a second lens G2 with positive focal power, a third lens G3 with positive focal power and a fourth lens G4 with negative focal power; and the rear group S2 comprises a fifth lens G5 with negative focal power, a sixth lens G6 with positive focal power, a seventh lens G7 with positive focal power and an eighth lens G8 with positive focal power. The optical system provided by the invention can support a 16K and 5 [mu] m large-target-surface linear array camera and has the characteristic of low distortion, and the resolution of the maximum imaging surface can reach 100lp / mm and above.

Description

Technical Field

[0001] The present invention relates to the technical field of machine vision lenses, and in particular to a 16K linear array camera, a double telecentric line scanning lens and an optical system thereof. Background Art

[0002] Machine vision is a rapidly developing branch of artificial intelligence. Simply put, machine vision is to use machines to replace human eyes for measurement and judgment. The machine vision system refers to the use of image capture devices to convert the captured target into image signals, which are transmitted to a dedicated image processing system and converted into digital signals based on pixel distribution, brightness, color and other information; the image system is used to perform various operations on these signals to extract the characteristics of the target, and then control the operation of the equipment on site based on the results of the judgment.

[0003] The lens is one of the core components in the machine vision inspection system. Line scan lenses have the characteristics of large target size and high precision, and are widely used in the field of scanning measurement, such as packaging printing, smart logistics, automobile manufacturing, new energy and other product measurement and defect detection. However, as the object distance changes, the line scan lens will have problems such as different magnifications and parallax. In addition, since the light angles entering the lens are different for objects at different positions, the line scan lens cannot well restore the details of the faults and gaps of non-flat objects.

[0004] Therefore, traditional line scan lenses no longer meet the application requirements of the industry, and it is necessary to further improve the existing line scan lenses to meet the needs of detection.

[0005] The above information is presented as background information only to assist with understanding the present disclosure and no determination or admission is made as to whether any of the above may be used as prior art with respect to the present disclosure. Summary of the invention

[0006] The object of the present invention is to provide a 16K linear array camera, a dual telecentric line scanning lens and an optical system thereof, so as to solve or at least partially solve the technical problems existing in the prior art.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides an optical system of a low-distortion anti-vibration lens, comprising a front group S1, a stop T, and a rear group S2 arranged in sequence from the object side to the image side;

[0009] The front group S1 includes a first lens G1 having positive refractive power, a second lens G2 having positive refractive power, a third lens G3 having positive refractive power, and a fourth lens G4 having negative refractive power;

[0010] The rear group S2 includes a fifth lens G5 having negative power, a sixth lens G6 having positive power, a seventh lens G7 having positive power, and an eighth lens G8 having positive power;

[0011] The combined focal length of the front group S1 is f S1 , the combined focal length of the rear group S2 is f S2 , f S1 、f S2 Satisfies the relationship: 0.7<|f S1 / f S2 |<1.3; the half-image height y' and f of the optical system S2 Satisfies the relationship: 0.2<|y' / f S2 |<0.5.

[0012] Optionally, the third lens G3 and the fourth lens G4 form a cemented lens U1, and the focal length of the cemented lens U1 is f U1 , f U1 With f S1 Satisfies the relationship: 0.3<|f U1 / f S1 |<1.3;

[0013] The fifth lens G5 and the sixth lens G6 form a cemented lens U2, and the focal length of the cemented lens U2 is f U2 , f U2 With f S2 Satisfies the relationship: 0.9<|f U2 / f S2 |<1.9.

[0014] Optionally, the refractive index of the first lens G1 is n1, the Abbe number is v1, and n1 and v1 respectively satisfy the relationship: 1.85 <n1<2.2,20<v1<30;

[0015] The refractive index of the second lens G2 is n2, and the Abbe number is v2. n2 and v2 respectively satisfy the relationship: 1.55 <n2<1.65,55<v2<70。

[0016] Optionally, the refractive index of the seventh lens G7 is n7, the Abbe number is v7, and n7 and v7 respectively satisfy the relationship: 1.48 <n7<1.65,60<v7<82;

[0017] The refractive index of the eighth lens G8 is n8, and the Abbe number is v8. n8 and v8 respectively satisfy the relationship: 1.80 <n8<2.2,18<v8<30。

[0018] Optionally, the first lens G1 is a biconvex lens, and the second lens G2, the third lens G3 and the third lens G4 are meniscus lenses.

[0019] Optionally, the fifth lens G5 is a biconcave lens, the sixth lens G6 and the eighth lens G8 are biconvex lenses, and the seventh lens G7 is a meniscus lens.

[0020] Optionally, the first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8 and the ninth lens G9 are all spherical lenses, and the optical axes of all the spherical lenses coincide.

[0021] Optionally, the aperture of the aperture T is a circular hole, and the center of the circular hole is on the optical axis of the spherical lens.

[0022] In a second aspect, the present invention provides a double telecentric line scanning lens, including an optical system of the double telecentric line scanning lens as described above.

[0023] In a third aspect, the present invention provides a 16K line array camera equipped with a double telecentric line scanning lens, wherein the double telecentric line scanning lens adopts a double telecentric line scanning lens as described above.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The optical system of a double-telecentric line scanning lens provided by the present invention is a double-telecentric structure, which can improve the shortcomings of ordinary line scanning lenses such as parallax and lack of imaging details; the optical system can support 16K, 5μm large-target linear array cameras, and has the characteristics of low distortion, and the resolution of the maximum imaging surface can reach 100lp / mm and above; and the optical system has a magnification of more than 0.7 times, can detect tiny objects, and can also be used in application scenarios with high requirements on accuracy and field of view.

[0026] The present invention has other features and advantages, which will be apparent from or will be described in detail in the accompanying drawings and the following detailed description incorporated herein, which together serve to explain the specific principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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.

[0028] Figure 1 It is a schematic diagram of the optical path structure of an optical system of a double telecentric line scanning lens provided in Embodiment 1 of the present invention.

[0029] Figure 2 This is an MTF curve diagram of an optical system of a double telecentric line scanning lens provided in Embodiment 1 of the present invention.

[0030] Figure 3 This is an optical distortion curve diagram of an optical system of a double telecentric line scanning lens provided in Embodiment 1 of the present invention.

[0031] Figure 4 It is a schematic diagram of the optical path structure of an optical system of a double telecentric line scanning lens provided in Embodiment 2 of the present invention.

[0032] Figure 5 This is an MTF curve diagram of an optical system of a double telecentric line scanning lens provided in Embodiment 2 of the present invention.

[0033] Figure 6 This is an optical distortion curve diagram of an optical system of a double telecentric line scanning lens provided in the second embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to explain in detail the possible application scenarios, technical principles, specific schemes that can be implemented, and the purposes and effects that can be achieved, the following is a detailed description of the specific embodiments listed in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0035] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0036] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0037] In the description of this application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that three relationships may exist, for example, A and / or B, which means: A exists, B exists, and A and B exist at the same time. In addition, the character " / " in this article generally indicates that the objects before and after are in an "or" logical relationship.

[0038] In the present application, terms such as “first” and “second” are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship of quantity, priority or sequence between these entities or operations.

[0039] Without further limitations, in this application, the words "include", "comprises", "has" or other similar expressions used in the sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product including the elements, so that the process, method or product including a series of elements may include not only those limited elements, but also other elements not explicitly listed, or also include elements inherent to such process, method or product.

[0040] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than", "less than", "exceed" and the like are understood to exclude the number itself; expressions such as "above", "below", "within" and the like are understood to include the number itself. In addition, in the description of the embodiments of this application, "multiple" means more than two (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups", "multiple times", etc., unless otherwise clearly and specifically limited.

[0041] In the description of the embodiments of the present application, space-related expressions used, such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or position relationship based on the orientation or position relationship shown in the specific embodiments or drawings, and are only for the convenience of describing the specific embodiments of the present application or facilitating the reader's understanding, and do not indicate or imply that the referred device or component must have a specific position, a specific orientation, or be constructed or operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0042] Unless otherwise expressly specified or limited, in the description of the embodiments of the present application, the terms such as "install", "connect", "connect", "fix", "set", etc. used should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integrated setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For technicians in the technical field to which the present application belongs, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0043] Embodiment 1:

[0044] See also Figure 1 , Figure 1 The diagram is a schematic diagram of the optical path structure of an optical system of a double telecentric line scanning lens provided in an embodiment of the present invention.

[0045] like Figure 1 As shown, the optical system includes:

[0046] It includes a front group S1, a stop T and a rear group S2 which are arranged in sequence from the object side to the image side;

[0047] Specifically, the front group S1 includes a first lens G1 having positive power, a second lens G2 having positive power, a third lens G3 having positive power, and a fourth lens G4 having negative power;

[0048] The rear group S2 includes a fifth lens G5 having negative power, a sixth lens G6 having positive power, a seventh lens G7 having positive power, and an eighth lens G8 having positive power;

[0049] The combined focal length of the front group S1 is f S1 , the combined focal length of the rear group S2 is f S2 , f S1 、f S2 Satisfies the relationship: 0.7<|f S1 / f S2 |<1.3; the half-image height y' and f of the optical system S2 Satisfies the relationship: 0.2<|y' / f S2 |<0.5.

[0050] In this embodiment, the lens structure of the front group S1 and the rear group S2 is relatively symmetrical, which is conducive to the correction of vertical axis aberrations such as distortion and coma; the aperture T is arranged between the fourth lens G4 and the fifth lens G5 to form a double telecentric structure, and the aperture of the aperture T is a circular hole.

[0051] Furthermore, the third lens G3 and the fourth lens G4 form a cemented lens U1, and the focal length of the cemented lens U1 is f U1 , f U1 With f S1 Satisfies the relationship: 0.3<|f U1 / f S1 |<1.3;

[0052] The fifth lens G5 and the sixth lens G6 form a cemented lens U2, and the focal length of the cemented lens U2 is f U2 , f U2 With f S2 Satisfies the relationship: 0.9<|f U2 / f S2|<1.9。

[0053] The cemented lens U1 and the cemented lens U2 can correct chromatic aberration and field curvature, and the cemented surface of the cemented lens U2 can correct astigmatism.

[0054] Furthermore, the refractive index of the first lens G1 is n1, and the Abbe number is v1. n1 and v1 respectively satisfy the relational expressions: 1.85 < n1 < 2.2, 20 < v1 < 30; it can be understood that using a high refractive index material can reduce the curvature of the lens, thereby reducing higher-order aberrations and lowering the tolerance sensitivity;

[0055] The refractive index of the second lens G2 is n2, and the Abbe number is v2. n2 and v2 respectively satisfy the relational expressions: 1.55 < n2 < 1.65, 55 < v2 < 70.

[0056] As Figure 1 shown, in this embodiment, a relatively large interval is maintained between the first lens G1 and the second lens G2. The first lens G1 is made of a material with a low Abbe number and high dispersion, so that light rays with different wavelengths and different fields of view form different height differences on the cemented lens U1, which is beneficial to correcting chromatic aberration and spherical aberration of the optical system and improving the imaging performance of the lens optical system.

[0057] Furthermore, the refractive index of the seventh lens G7 is n7, and the Abbe number is v7. n7 and v7 respectively satisfy the relational expressions: 1.48 < n7 < 1.65, 60 < v7 < 82; by satisfying the above relational expressions, the formation of chromatic aberration can be reduced, and spherical aberration and coma can be better balanced;

[0058] The refractive index of the eighth lens G8 is n8, and the Abbe number is v8. n8 and v8 respectively satisfy the relational expressions: 1.80 < n8 < 2.2, 18 < v8 < 30. Using a high refractive index material can reduce the curvature of the lens, thereby reducing higher-order aberrations and lowering the tolerance sensitivity.

[0059] Specifically, in this embodiment, the first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, and the ninth lens G9 are all spherical lenses, and the optical axes of all spherical lenses coincide; the center of the circular hole of the aperture stop T is on the above-mentioned optical axis. It can be understood that the aperture value of the aperture stop T needs to be adjusted correspondingly according to the specific application scenario.

[0060] More specifically, the first lens G1 is a biconvex lens, the second lens G2, the third lens G3, and the third lens G4 are meniscus lenses. The fifth lens G5 is a biconcave lens, the sixth lens G6 and the eighth lens G8 are biconvex lenses, and the seventh lens G7 is a meniscus lens.

[0061] Furthermore, in order to verify the performance of the above optical system, a specific application case is given below for illustration:

[0062] In this application case, the relevant data of the optical system are shown in Table 1:

[0063] Table 1

[0064] surface Radius(mm) Thickness(mm) Refractive Index Abbe number G1 front surface 359.7 20 2.0 25 G1 rear surface -1023.7 121.6 G2 front surface 56.5 15.3 1.60 65 G2 rear surface 176.6 3.2 G3 front surface 46.1 16.9 1.50 - G3, G4 glued surface 499.2 9.7 1.75 - G4 rear surface 25.7 28.4 Aperture T ∞ 15.1 G5 front surface -35.5 4.0 1.70 - G5, G6 bonding surface 259.2 8.5 1.50 - G6 rear surface -37.5 26.9 G7 front surface -148.8 16.2 1.50 65 G7 rear surface -56.9 90.0 G8 front surface 558.1 18.0 2.0 25 G8 rear surface -340.4 157.0 Image plane /

[0065] It should be noted that in Table 1, the “front surface” corresponds to Figure 1 The left side surface of the lens or lens group corresponds to the "back surface" Figure 1 The corresponding lens or lens group on the right side surface; or can be understood as: the object side is Figure 1 On the left, the image side (or image plane) is Figure 1 On the right side, the surface close to the object side is the "front surface", and the surface close to the image side is the "back surface".

[0066] In this application case, the optical system is a double telecentric structure with a working distance of 216mm, a magnification of 0.8 times, and a half-image height y'=41mm, that is, the maximum imaging surface reaches Φ82mm, which can support 16K, 5-micron linear array cameras; the combined focal length of the front group S1 is f S1 =153mm; the combined focal length of the rear group S2 is f S2 =122mm; focal length f of cemented lens U1 U1 =-79mm; focal length f of cemented lens U2 U2 =-195mm.

[0067] Substituting the above values ​​into each relational expression, we obtain:

[0068] |f S1 / f S2 |=1.254,|y' / f S2 |=0.336,|f U1 / f S1 |=0.516,|f U2 / f S2 |=1.598.

[0069] Therefore, the relevant relationship of this embodiment is satisfied, namely:

[0070] 0.7<|f S1 / f S2 |<1.3, 0.2<|y' / f S2 |<0.5, 0.3<|f U1 / f S1 |<1.3, 0.9<|f U2 / f S2|<1.9.

[0071] Please continue to refer to Figure 2 and Figure 3 , Figure 2 is an MTF curve diagram of an optical system of a double telecentric line scanning lens provided by an embodiment of the present invention, Figure 3 is an optical distortion curve diagram of an optical system of a double telecentric line scanning lens provided by an embodiment of the present invention;

[0072] like Figure 2 As shown in the figure, according to experimental verification, MTF30 reaches 100lp / mm, which can achieve uniform imaging in the entire field of view of the optical system. Figure 2 As shown, the distortion of the optical system is less than 0.02%.

[0073] The optical system of a double-telecentric line scanning lens provided in this embodiment can improve the shortcomings of ordinary line scanning lenses such as parallax and lack of imaging details; the optical system can support 16K, 5μm large-target linear array cameras, and has the characteristics of low distortion. The resolution of the maximum imaging surface can reach 100lp / mm and above; and the optical system has a magnification of more than 0.7 times, can detect tiny objects, and can also be used in application scenarios with high requirements for accuracy and field of view.

[0074] Embodiment 2:

[0075] It includes a front group S1, a stop T and a rear group S2 which are arranged in sequence from the object side to the image side;

[0076] Specifically, the front group S1 includes a first lens G1 having positive power, a second lens G2 having positive power, a third lens G3 having positive power, and a fourth lens G4 having negative power;

[0077] The rear group S2 includes a fifth lens G5 having negative power, a sixth lens G6 having positive power, a seventh lens G7 having positive power, and an eighth lens G8 having positive power;

[0078] The combined focal length of the front group S1 is f S1 , the combined focal length of the rear group S2 is f S2 , f S1 、f S2 Satisfies the relationship: 0.7<|f S1 / f S2 |<1.3; the half-image height y' and f of the optical system S2 Satisfies the relationship: 0.2<|y' / f S2 |<0.5.

[0079] In this embodiment, the lenses of the front group S1 and the lenses of the rear group S2 are relatively symmetric in structure, which is beneficial to the correction of lateral aberrations such as distortion and coma. The aperture stop T is arranged between the fourth lens G4 and the fifth lens G5 to form a double telecentric structure, and the aperture of the aperture stop T is a circular hole.

[0080] Further, the third lens G3 and the fourth lens G4 form a cemented lens U1, and the focal length of the cemented lens U1 is f U1 , f U1 and f S1 satisfy the relational expression: 0.3 < |f U1 / f S1 | < 1.3;

[0081] The fifth lens G5 and the sixth lens G6 form a cemented lens U2, and the focal length of the cemented lens U2 is f U2 , f U2 and f S2 satisfy the relational expression: 0.9 < |f U2 / f S2 | < 1.9.

[0082] The cemented lens U1 and the cemented lens U2 can correct chromatic aberration and field curvature, and the cemented surface of the cemented lens U2 can correct astigmatism.

[0083] Further, the refractive index of the first lens G1 is n1, and the Abbe number is v1. n1 and v1 respectively satisfy the relational expressions: 1.85 < n1 < 2.2, 20 < v1 < 30. It can be understood that using a high refractive index material can reduce the curvature of the lens, thereby reducing higher-order aberrations and reducing the tolerance sensitivity;

[0084] The refractive index of the second lens G2 is n2, and the Abbe number is v2. n2 and v2 respectively satisfy the relational expressions: 1.55 < n2 < 1.65, 55 < v2 < 70.

[0085] As Figure 1 shown, in this embodiment, the first lens G1 and the second lens G2 maintain a large interval. The first lens G1 selects a low Abbe number and high-dispersion material, so that light rays with different wavelengths and different fields of view form different height differences on the cemented lens U1, which is beneficial to correcting the chromatic aberration and spherical aberration of the optical system and improving the imaging performance of the lens optical system.

[0086] Further, the refractive index of the seventh lens G7 is n7, and the Abbe number is v7. n7 and v7 respectively satisfy the relational expressions: 1.48 < n7 < 1.65, 60 < v7 < 82; by satisfying the above relational expressions, the formation of chromatic aberration can be reduced, and the spherical aberration and coma can be better balanced;

[0087] The refractive index of the eighth lens G8 is n8, and the Abbe number is v8. n8 and v8 respectively satisfy the relational expressions: 1.80 < n8 < 2.2, 18 < v8 < 30. Using a high refractive index material can reduce the curvature of the lens, thereby reducing higher-order aberrations and lowering the tolerance sensitivity.

[0088] Specifically, in this embodiment, the first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8, and the ninth lens G9 are all spherical lenses, and the optical axes of all spherical lenses coincide; the center of the circular hole of the aperture stop T is on the above-mentioned optical axis. It can be understood that the aperture value of the aperture stop T needs to be adjusted correspondingly according to the specific application scenario.

[0089] More specifically, the first lens G1 is a biconvex lens, and the second lens G2, the third lens G3, and the third lens G4 are meniscus lenses. The fifth lens G5 is a biconcave lens, the sixth lens G6 and the eighth lens G8 are biconvex lenses, and the seventh lens G7 is a meniscus lens.

[0090] Furthermore, to verify the performance of the above light ray system, the following specific application cases are given for illustration:

[0091] In this application case, the relevant data of the optical system are specifically shown in Table 2 as follows:

[0092] Table 2

[0093] surface Radius(mm) Thickness(mm) Refractive Index Abbe number G1 front surface 581.0 17.7 1.85 25 G1 rear surface -331.8 7.2 G2 front surface 142.2 16.0 1.60 65 G2 rear surface 415.4 58.3 G3 front surface 40.1 20.1 1.50 - G3, G4 glued surface 200.2 11.1 1.75 - G4 rear surface 26.8 28.2 Aperture T ∞ 20.9 G5 front surface -35.6 4.0 1.69 - G5, G6 bonding surface 425.1 9.2 1.50 - G6 rear surface -43.2 15.0 G7 front surface -146.9 9.6 1.60 65 G7 rear surface -52.7 124.6 G8 front surface 412.4 18.0 1.85 25 G8 rear surface -370.7 177.6 Image plane /

[0094] It should be noted that in Table 1, the "front surface" corresponds to Figure 4 the left surface of the corresponding lens or lens group, and the "rear surface" corresponds to Figure 4 the right surface of the corresponding lens or lens group; or it can be understood that: the object side is on the Figure 4 left side, and the image side (or image plane) is on the Figure 1 right side. The surface closer to the object side is the "front surface", and the surface closer to the image side is the "rear surface".

[0095] In this application case, the optical system is a double telecentric structure, its working distance is 199 mm, the magnification reaches 1 times, the semi-image height y' = 41 mm, that is, the maximum imaging surface reaches Φ82 mm; among them, the combined focal length of the front group S1 is f S1 = 138 mm; the combined focal length of the rear group S2 is f S2 = 135 mm; the focal length of the cemented lens group U1 is f U1 = -159 mm; the focal length of the cemented lens group U2 is f U2 = -155 mm.

[0096] Substituting the above values ​​into each relational expression, we obtain:

[0097] |f S1 / f S2 |=1.022,|y' / f S2 |=0.304,|f U1 / f S1 |=1.123,|f U2 / f S2 |=1.148.

[0098] Therefore, the relevant relationship of this embodiment is satisfied, namely:

[0099] 0.7<|f S1 / f S2 |<1.3, 0.2<|y' / f S2 |<0.5, 0.3<|f U1 / f S1 |<1.3, 0.9<|f U2 / f S2 |<1.9.

[0100] Please continue to refer to Figure 5 and Figure 6 , Figure 5 is an MTF curve diagram of an optical system of a double telecentric line scanning lens provided in the second embodiment of the present invention, Figure 6 is an optical distortion curve diagram of an optical system of a double telecentric line scanning lens provided in the second embodiment of the present invention;

[0101] like Figure 5 As shown in the figure, according to experimental verification, MTF30 reaches 100lp / mm, which can achieve uniform imaging in the entire field of view of the optical system and support 16K and 5-micron linear array cameras. Figure 6 As shown, the distortion of the optical system is less than 0.02%.

[0102] The optical system of a double-telecentric line scanning lens provided in this embodiment can improve the shortcomings of ordinary line scanning lenses such as parallax and lack of imaging details; the optical system can support 16K, 5μm large-target linear array cameras, and has the characteristics of low distortion. The resolution of the maximum imaging surface can reach 100lp / mm and above; and the optical system has a magnification of more than 0.7 times, can detect tiny objects, and can also be used in application scenarios with high requirements for accuracy and field of view.

[0103] Embodiment three:

[0104] This embodiment provides a double telecentric line scanning lens, including an optical system of the double telecentric line scanning lens as described in the first or second embodiment.

[0105] Since the optical system has been described in detail in the above embodiments, it will not be described in detail in this embodiment.

[0106] In addition, based on the above technical ideas, this embodiment also provides a 16K line array camera equipped with a double telecentric line scanning lens, and the double telecentric line scanning lens adopts a double telecentric line scanning lens described above.

[0107] In summary, this embodiment realizes a 16K line array camera and its dual telecentric line scan lens, the resolution of the maximum imaging surface can reach 100lp / mm or above, and has a magnification of more than 0.7 times, which can detect tiny objects and is also suitable for application scenarios with high requirements on precision and field of view.

[0108] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical system of a double telecentric line scanning lens, characterized in that: It includes a front group S1, a stop T and a rear group S2 which are arranged in sequence from the object side to the image side; The front group S1 includes a first lens G1 having positive refractive power, a second lens G2 having positive refractive power, a third lens G3 having positive refractive power, and a fourth lens G4 having negative refractive power; The rear group S2 includes a fifth lens G5 having negative power, a sixth lens G6 having positive power, a seventh lens G7 having positive power, and an eighth lens G8 having positive power; The combined focal length of the front group S1 is f S1 , the combined focal length of the rear group S2 is f S2 , f S1 、f S2 Satisfies the relationship: 0.7<|f S1 / f S2 |<1.3; the half-image height y' and f of the optical system S2 Satisfies the relationship: 0.2<|y' / f S2 |<0.

5.

2. The optical system of a double telecentric line scanning lens according to claim 1, characterized in that: The third lens G3 and the fourth lens G4 form a cemented lens U1, and the focal length of the cemented lens U1 is f U1 , f U1 With f S1 Satisfies the relationship: 0.3<|f U1 / f S1 |<1.3; The fifth lens G5 and the sixth lens G6 form a cemented lens U2, and the focal length of the cemented lens U2 is f U2 , f U2 With f S2 Satisfies the relationship: 0.9<|f U2 / f S2 |<1.

9.

3. The optical system of a double telecentric line scanning lens according to claim 2, characterized in that: The refractive index of the first lens G1 is n1, and the Abbe number is v1. n1 and v1 respectively satisfy the relationship: 1.85 <n1<2.2,20<v1<30; The refractive index of the second lens G2 is n2, and the Abbe number is v2. n2 and v2 respectively satisfy the relationship: 1.55 <n2<1.65,55<v2<70。 4. The optical system of a double telecentric line scanning lens according to claim 2, characterized in that: The refractive index of the seventh lens G7 is n7, and the Abbe number is v7. n7 and v7 respectively satisfy the relationship: 1.48 <n7<1.65,60<v7<82; The refractive index of the eighth lens G8 is n8, and the Abbe number is v8. n8 and v8 respectively satisfy the relationship: 1.80 <n8<2.2,18<v8<30。 5. The optical system of a double telecentric line scanning lens according to claim 3, characterized in that: The first lens G1 is a biconvex lens, and the second lens G2, the third lens G3 and the third lens G4 are meniscus lenses.

6. The optical system of a double telecentric line scanning lens according to claim 4, characterized in that: The fifth lens G5 is a biconcave lens, the sixth lens G6 and the eighth lens G8 are biconvex lenses, and the seventh lens G7 is a meniscus lens.

7. The optical system of a double telecentric line scanning lens according to claim 1, characterized in that: The first lens G1, the second lens G2, the third lens G3, the fourth lens G4, the fifth lens G5, the sixth lens G6, the seventh lens G7, the eighth lens G8 and the ninth lens G9 are all spherical lenses, and the optical axes of all the spherical lenses coincide.

8. The optical system of a double telecentric line scanning lens according to claim 7, characterized in that: The aperture of the aperture T is a circular hole, and the center of the circular hole is on the optical axis of the spherical lens.

9. A dual telecentric line scanning lens, characterized in that: An optical system comprising a double telecentric line scanning lens as described in any one of claims 1-8.

10. A 16K line array camera equipped with a dual telecentric line scan lens, characterized in that: The double telecentric line scanning lens adopts the double telecentric line scanning lens described in claim 9.

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