A line scan lens

Abstract

The present invention discloses a line-scanning lens, which includes a first fixed lens, a floating focusing lens group, and a second fixed lens arranged in sequence along the optical axis from the object plane to the image plane; the positions of the first fixed lens and the second fixed lens are fixed, and the position of the floating focusing lens group can float along the optical axis. In this way, the first fixed lens and the second fixed lens remain stationary to maintain symmetry, which can weaken the influence of the movement of the floating focusing lens group on aberration and ensure that the image quality at each working distance reaches balance; moreover, the shape coefficient X1 of the first fixed lens and the shape coefficient X2 of the second fixed lens satisfy -2.029 < X2 / X1 < -0.779, ensuring that the shapes of the first fixed lens and the second fixed lens are similar and opposite in direction, canceling the lateral aberration and improving the imaging quality; at the same time, the combined focal power fai 浮动 of the floating focusing lens group and the focal power fai of the line-scanning lens satisfy 1.034 < fai 浮动 / fai < 1.351. In this way, the focal power of the floating focusing lens group is close to that of the entire lens, which is beneficial to ensuring that the focal length of the lens remains constant at different object distances.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of optical devices, and in particular, to a line scan lens. Background Art

[0002] In the field of line scan machine vision of industrial lenses, there is a need for short focal lengths and wide working distances. On the premise of a constant target surface, the shorter the focal length, the larger the field of view angle. When there are requirements for small distortion and wide working distance, the difficulty of aberration correction increases sharply. Therefore, how to design a high-performance line scan lens has become a research difficulty. Summary of the Invention

[0003] The present invention provides a line scan lens, realizing a high-performance line scan lens design scheme with distortion of -1.5% to +1.5% within a working distance range of 200 - 900 mm, a focal length of 40 mm, F4.0, a target surface of Φ60 mm, an illuminance of 60%, and MTF > 0.2 at 100 line pairs / mm.

[0004] Embodiments of the present invention provide a line scan lens, including a first fixed lens, a floating focusing lens group, and a second fixed lens arranged in sequence along the optical axis from the object surface to the image surface; the positions of the first fixed lens and the second fixed lens are fixed, and the position of the floating focusing lens group can float along the optical axis;

[0005] The shape factor X1 of the first fixed lens and the shape factor X2 of the second fixed lens satisfy -2.029 < X2 / X1 < -0.779; the shape factor X1 of the first fixed lens satisfies X1 = (ca1 + cb1) / (ca1 - cb1), and the shape factor X2 of the second fixed lens satisfies X2 = (ca2 + cb2) / (ca2 - cb2); where ca1 represents the curvature of the object side surface of the first fixed lens, cb1 represents the curvature of the image side surface of the first fixed lens, ca2 represents the curvature of the object side surface of the second fixed lens, and cb2 represents the curvature of the image side surface of the second fixed lens;

[0006] The combined optical power fai of the floating focusing lens group 浮动 and the optical power fai of the line scan lens satisfy 1.034 < fai 浮动 / fai < 1.351.

[0007] Optionally, the first fixed lens includes a first lens;

[0008] The floating focusing lens group includes a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged in sequence along the optical axis from the object surface to the image surface;

[0009] The second fixed lens includes a ninth lens.

[0010] Optionally, the line scanning lens further includes a diaphragm, and the diaphragm is disposed in the optical path between the fifth lens and the sixth lens;

[0011] The fourth lens and the fifth lens are adhesively disposed, and the sixth lens and the seventh lens are adhesively disposed.

[0012] Optionally, the combined focal power of the fourth lens and the fifth lens is fai 45 , the combined focal power of the sixth lens and the seventh lens is fai 67 , the focal power of the fourth lens is fai4, the focal power of the fifth lens is fai5, the focal power of the sixth lens is fai6, the focal power of the seventh lens is fai7, the Abbe number of the fourth lens is vd4, the Abbe number of the fifth lens is vd5, the Abbe number of the sixth lens is vd6, and the Abbe number of the seventh lens is vd7;

[0013] Among them, -0.905 < fai 45 / fai 67 < -0.837;

[0014] 0.02 < 1000 * (fai4 / vd4 + fai5 / vd5) < 0.322;

[0015] -1.793 < 1000 * (fai6 / vd6 + fai7 / vd7) < -0.612.

[0016] Optionally, the combined focal power of the second lens and the third lens is fai 23 , the focal power of the second lens is fai2, the focal power of the third lens is fai3, the Abbe number of the second lens is vd2, and the Abbe number of the third lens is vd3;

[0017] Among them, 0.206 < fai 23 / fai < 0.318;

[0018] 0.035 < 1000 * (fai2 / vd2 + fai3 / vd3) < 0.25.

[0019] Optionally, the focal power of the eighth lens is fai8, and the refractive index of the eighth lens is nd8;

[0020] Among them, 1.5 < fai8 / fai < 1.864, and nd8 > 1.9.

[0021] Optionally, the distance that the floating focusing lens group moves from the near object distance to the far object distance is Zmove, the focal length of the line scan lens is f, the clear aperture of the first lens is Dia1, and the total optical length of the line scan lens is TTL;

[0022] Wherein, 0.111 < Zmove / f < 0.131, and 0.335 < Dia1 / TTL < 0.45.

[0023] Optionally, the clear aperture of the aperture stop is adjustable.

[0024] Optionally, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens all include glass spherical lenses.

[0025] Optionally, the line scan lens further includes a flat glass, and the flat glass is disposed in the optical path between the second fixed lens and the image plane.

[0026] The line scan lens provided by the embodiment of the present invention is provided with a floating focusing lens group between the first fixed lens and the second fixed lens. By keeping the first fixed lens and the second fixed lens stationary to maintain symmetry, the influence of the movement process of the floating focusing lens group on the aberration can be weakened, ensuring that the image quality at each working distance reaches balance; moreover, the shape factor X1 of the first fixed lens and the shape factor X2 of the second fixed lens satisfy -2.029 < X2 / X1 < -0.779, ensuring that the shapes of the first fixed lens and the second fixed lens are similar and opposite in direction, canceling out the lateral aberration and improving the imaging quality; at the same time, the combined optical power fai_floating of the floating focusing lens group and the optical power fai of the line scan lens satisfy 1.034 < fai_floating / fai < 1.351. In this way, the optical power of the floating focusing lens group is close to that of the entire lens, and the optical power of other lenses accounts for a relatively small proportion, which is beneficial to ensuring that the focal length of the lens remains constant at different object distances. In this way, a high-performance line scan lens design solution with a distortion of -1.5% to +1.5% within the working distance range of 200 - 900 mm, a focal length of 40 mm, F4.0, a target surface of Φ60 mm, an illuminance of 60%, and an MTF of 100 line pairs / mm > 0.2 is achieved.

[0027] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. 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 creative work.

[0029] Figure 1 1 is a schematic structural diagram of a line scanning lens provided in Embodiment 1 of the present invention at a close object distance of 200 mm;

[0030] Figure 2 1 is a schematic structural diagram of a line scanning lens provided in Embodiment 1 of the present invention at a medium object distance of 400 mm;

[0031] Figure 3 1 is a schematic structural diagram of a line scanning lens provided in Embodiment 1 of the present invention at a far object distance of 900 mm;

[0032] Figure 4 1 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 1 of the present invention at a close object distance of 200 mm;

[0033] Figure 5 1 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 1 of the present invention at a medium object distance of 400 mm;

[0034] Figure 6 1 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 1 of the present invention at a long object distance of 900 mm;

[0035] Figure 7 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by the first embodiment of the present invention;

[0036] Figure 8 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by the first embodiment of the present invention;

[0037] Fig. 9 1 is a schematic structural diagram of a line scanning lens provided by Embodiment 2 of the present invention at a close object distance of 200 mm;

[0038] Fig.10 1 is a schematic structural diagram of a line scanning lens provided in Embodiment 2 of the present invention at a medium object distance of 400 mm;

[0039] Fig.11 1 is a schematic structural diagram of a line scanning lens provided in Embodiment 2 of the present invention at a far object distance of 900 mm;

[0040] Fig.12Schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 2 of the present invention at a close object distance of 200 mm;

[0041] Fig.13 Schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 2 of the present invention at a medium object distance of 400 mm;

[0042] Fig.14 Schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 2 of the present invention at a far object distance of 900 mm;

[0043] Fig.15 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by the second embodiment of the present invention;

[0044] Fig.16 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by the second embodiment of the present invention;

[0045] Fig.17 1 is a schematic structural diagram of a line scanning lens provided by Embodiment 3 of the present invention at a close object distance of 200 mm;

[0046] Fig.18 1 is a schematic structural diagram of a line scanning lens provided in Embodiment 3 of the present invention at a medium object distance of 400 mm;

[0047] Fig.19 1 is a schematic structural diagram of a line scanning lens provided in Embodiment 3 of the present invention at a far object distance of 900 mm;

[0048] Fig. 20 Schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 3 of the present invention at a close object distance of 200 mm;

[0049] Fig.21 1 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 3 of the present invention at a medium object distance of 400 mm;

[0050] Fig. 22 Schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 3 of the present invention at a long object distance of 900 mm;

[0051] Fig.23 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by the third embodiment of the present invention;

[0052] Fig.24 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by the third embodiment of the present invention;

[0053] Fig.251 is a schematic structural diagram of a line scanning lens provided by a fourth embodiment of the present invention at a close object distance of 200 mm;

[0054] Fig.26 1 is a schematic structural diagram of a line scanning lens provided by a fourth embodiment of the present invention at a medium object distance of 400 mm;

[0055] Fig. 27 1 is a schematic structural diagram of a line scanning lens provided by a fourth embodiment of the present invention at a far object distance of 900 mm;

[0056] Fig.28 Schematic diagram of an MTF curve of a line scanning lens provided by a fourth embodiment of the present invention at a close object distance of 200 mm;

[0057] Fig.29 1 is a schematic diagram of an MTF curve of a line scanning lens provided in a fourth embodiment of the present invention at a medium object distance of 400 mm;

[0058] Fig.30 Schematic diagram of an MTF curve of a line scanning lens provided by a fourth embodiment of the present invention at a far object distance of 900 mm;

[0059] Fig.31 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by a fourth embodiment of the present invention;

[0060] Fig.32 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by a fourth embodiment of the present invention;

[0061] Fig.33 1 is a schematic structural diagram of a line scanning lens provided by Embodiment 5 of the present invention at a close object distance of 200 mm;

[0062] Fig.34 1 is a schematic structural diagram of a line scanning lens provided in Embodiment 5 of the present invention at a medium object distance of 400 mm;

[0063] Fig.35 1 is a schematic structural diagram of a line scanning lens provided in Embodiment 5 of the present invention at a far object distance of 900 mm;

[0064] Fig.36 Schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 5 of the present invention at a close object distance of 200 mm;

[0065] Fig.37 1 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 5 of the present invention at a medium object distance of 400 mm;

[0066] Fig.381 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 5 of the present invention at a far object distance of 900 mm;

[0067] Fig.39 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by Embodiment 5 of the present invention;

[0068] Fig.40 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by Embodiment 5 of the present invention;

[0069] Fig.41 1 is a schematic structural diagram of a line scanning lens provided by Embodiment 6 of the present invention at a close object distance of 200 mm;

[0070] Fig.42 1 is a schematic structural diagram of a line scanning lens provided in Embodiment 6 of the present invention at a medium object distance of 400 mm;

[0071] Fig.43 1 is a schematic structural diagram of a line scanning lens provided by Embodiment 6 of the present invention at a far object distance of 900 mm;

[0072] Fig.44 1 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 6 of the present invention at a close object distance of 200 mm;

[0073] Fig.45 1 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 6 of the present invention at a medium object distance of 400 mm;

[0074] Fig.46 1 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 6 of the present invention at a far object distance of 900 mm;

[0075] Fig.47 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by Embodiment 6 of the present invention;

[0076] Fig.48 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by Embodiment 6 of the present invention;

[0077] Fig.49 1 is a schematic structural diagram of a line scanning lens provided by Embodiment 7 of the present invention at a close object distance of 200 mm;

[0078] Fig.50 1 is a schematic structural diagram of a line scanning lens provided by Embodiment 7 of the present invention at a medium object distance of 400 mm;

[0079] Fig.511 is a schematic structural diagram of a line scanning lens provided by Embodiment 7 of the present invention at a far object distance of 900 mm;

[0080] Fig.52 1 is a schematic diagram of an MTF curve of a line scanning lens provided by Embodiment 7 of the present invention at a close object distance of 200 mm;

[0081] Fig.53 1 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 7 of the present invention at a medium object distance of 400 mm;

[0082] Fig.54 1 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 7 of the present invention at a far object distance of 900 mm;

[0083] Fig.55 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by Embodiment 7 of the present invention;

[0084] Fig.56 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by Embodiment 7 of the present invention;

[0085] Fig.57 1 is a schematic structural diagram of a line scanning lens provided by Embodiment 8 of the present invention at a close object distance of 200 mm;

[0086] Fig.58 1 is a schematic structural diagram of a line scanning lens provided in Embodiment 8 of the present invention at a medium object distance of 400 mm;

[0087] Fig.59 1 is a schematic structural diagram of a line scanning lens provided in Embodiment 8 of the present invention at a far object distance of 900 mm;

[0088] Fig.60 1 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 8 of the present invention at a close object distance of 200 mm;

[0089] Fig.61 1 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 8 of the present invention at a medium object distance of 400 mm;

[0090] Fig.62 1 is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 8 of the present invention at a far object distance of 900 mm;

[0091] Fig.63 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by Embodiment 8 of the present invention;

[0092] Fig.64It is a schematic diagram of the optical distortion curve of a line scan lens provided in the eighth embodiment of the present invention at different object distances. Detailed implementation manners

[0093] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0094] Embodiment 1

[0095] Figure 1 It is a schematic diagram of the structure of a line scan lens provided in the first embodiment of the present invention at a near object distance of 200 mm. Figure 2 It is a schematic diagram of the structure of a line scan lens provided in the first embodiment of the present invention at a medium object distance of 400 mm. Figure 3 It is a schematic diagram of the structure of a line scan lens provided in the first embodiment of the present invention at a far object distance of 900 mm. As shown in Figure 1-Figure 3 The line scan lens provided in the embodiment of the present invention includes a first fixed lens S1, a floating focusing lens group S2, and a second fixed lens S3 arranged in sequence from the object plane to the image plane along the optical axis; the positions of the first fixed lens S1 and the second fixed lens S3 are fixed, and the position of the floating focusing lens group S2 can float along the optical axis; the shape coefficient X1 of the first fixed lens S1 and the shape coefficient X2 of the second fixed lens S3 satisfy -2.029 < X2 / X1 < -0.779; the shape coefficient X1 of the first fixed lens S1 satisfies X1 = (ca1 + cb1) / (ca1 - cb1), and the shape coefficient X2 of the second fixed lens S3 satisfies X2 = (ca2 + cb2) / (ca2 - cb2); where ca1 represents the curvature of the object side surface of the first fixed lens, cb1 represents the curvature of the image side surface of the first fixed lens, ca2 represents the curvature of the object side surface of the second fixed lens, and cb2 represents the curvature of the image side surface of the second fixed lens; the combined optical power fai 浮动 of the floating focusing lens group S2 and the optical power fai of the line scan lens satisfy 1.034 < fai 浮动 / fai < 1.351.

[0096] Specifically, the line scanning lens provided by the embodiment of the present invention includes a first fixed lens S1, a second fixed lens S3, and a floating focusing lens group S2 located between the first fixed lens S1 and the second fixed lens S3 along the optical axis direction. Among them, both the first fixed lens S1 and the second fixed lens S3 can be understood as lenses with fixed positions that do not change, and the floating focusing lens group S2 can be understood as a lens group with a changing position. The floating focusing lens group S2 specifically moves between the first fixed lens S1 and the second fixed lens S3, and adjusts the focal length of the line scanning lens by changing the position of the floating focusing lens group S2 to ensure that the line scanning lens can achieve focusing at different object distances and ensure clear imaging at different object distances. Combining Figure 1 , Figure 2 and Figure 3 , it can be clearly understood that as the object distance increases, the distance between the floating focusing lens group S2 and the first fixed lens S1 gradually increases, and the distance between the floating focusing lens group S2 and the second fixed lens S3 gradually decreases to ensure clear imaging at different object distances. Moreover, since the positions of the first fixed lens S1 and the second fixed lens S3 remain unchanged, in the case of different working distances, the change in aberration caused by the forward and backward movement of the floating focusing lens group S2 will be weakened due to the immobility of the first fixed lens S1 and the second fixed lens S3, maintaining symmetry, thus ensuring that the image quality at each working distance reaches balance and guaranteeing the imaging quality.

[0097] Furthermore, the shape system of the lens can be characterized by the curvature of its object side and the curvature of its image side. Specifically, the shape coefficient X1 of the first fixed lens S1 satisfies X1 = (ca1 + cb1) / (ca1 - cb1), and the shape coefficient X2 of the second fixed lens S3 satisfies X2 = (ca2 + cb2) / (ca2 - cb2); where ca1 represents the curvature of the object side of the first fixed lens, and cb1 represents the curvature of the image side of the first fixed lens. And, the position of the second fixed lens S3 is fixed, and the position of the floating focusing lens group S2 can float along the optical axis; the shape coefficient X1 of the first fixed lens S1 and the shape coefficient X2 of the second fixed lens S3 satisfy -2.029 < X2 / X1 < -0.779, that is, the proportional relationship between the shape coefficient X1 of the first fixed lens S1 and the shape coefficient X2 of the second fixed lens S3 is around -1. In this way, it can be ensured that the first fixed lens S1 and the second fixed lens S3 are similar in shape and opposite in direction, so that the lateral aberration of the line scanning lens can be offset from each other, guaranteeing the improvement of the imaging quality.

[0098] Furthermore, the focal length is equal to the difference between the convergence of the image-side beam and the convergence of the object-side beam, and it characterizes the ability of the optical system to deflect light. The larger the absolute value of the focal length, the stronger the ability to bend light, and the smaller the absolute value of the focal length, the weaker the ability to bend light. When the focal length is a positive number, the refraction of light is convergent; when the focal length is a negative number, the refraction of light is divergent. In the line scanning lens provided in the embodiment of the present invention, the combined focal length fai of the floating focus lens group S2 is 1 / 200. 浮动 The focal length fai of the line scan lens meets 1.034 <fai 浮动 / fai<1.351, that is, the combined focal power fai of the floating focus lens group S2 浮动 The ratio between the optical power fai of the line scanning lens is approximately 1, that is, the optical power of the floating focus lens group is close to that of the entire line scanning lens, and the optical power of the first fixed lens S1 and the second fixed lens S3 accounts for a relatively small proportion of the optical power of the entire line scanning lens. This is conducive to maintaining the optical power of the line scanning lens at different object distances, that is, the focal length is constant, and realizing a line scanning lens with a fixed focus function.

[0099] In summary, the line scanning lens provided by the embodiment of the present invention has a floating focus lens group arranged between the first fixed lens and the second fixed lens, and the first fixed lens and the second fixed lens are fixed to maintain symmetry to reduce the influence of the floating focus lens group movement process on the aberration, thereby ensuring that the image quality of each working distance is balanced; and the shape coefficient X1 of the first fixed lens and the shape coefficient X2 of the second fixed lens satisfy -2.029 <X 2 / X1<-0.779, ensuring that the first fixed lens and the second fixed lens are similar in shape and opposite in direction, offsetting the vertical axis aberration and improving the imaging quality; at the same time, the combined focal length fai of the floating focus lens group and the focal length fai of the line scanning lens meet 1.034 <fai 浮动 / fai<1.351, so the optical power of the floating focus lens group is close to that of the entire lens, and the optical power of other lenses accounts for a small proportion, which is conducive to ensuring that the focal length of the lens is constant at different object distances. In this way, a high-performance line scan lens design with a distortion of -1.5% to +1.5% in the working distance range of 200-900mm, a focal length of 40mm, F4.0, a target surface of Φ60mm, an illumination of 60%, and MTF100 line pairs / mm>0.2 is achieved.

[0100] Based on the above embodiments, continue to refer to Figure 1-Figure 3As shown, the line scanning lens provided by the embodiment of the present invention may specifically include nine lenses, wherein the first fixed lens S1 includes a first lens 101; the floating focus lens group S2 includes a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, a sixth lens 106, a seventh lens 107 and an eighth lens 108 arranged in sequence along the optical axis from the object plane to the image plane; and the second fixed lens includes a ninth lens 109. That is, the line scanning lens is realized by arranging nine lenses, and the arrangement of the line scanning lens is simple.

[0101] Further, the first lens 101 , the second lens 102 , the third lens 103 , the fourth lens 104 , the fifth lens 105 , the sixth lens 106 , the seventh lens 107 , the eighth lens 108 and the ninth lens 109 all include glass spherical lenses.

[0102] Specifically, the spherical lens is characterized by having a constant curvature from the center of the lens to the periphery of the lens, ensuring that the lens is set in a simple manner. Furthermore, since the thermal expansion coefficient of the glass lens is small and the stability is good, the first lens 101, the second lens 102, the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 106, the seventh lens 107, the eighth lens 108 and the ninth lens 109 are all glass spherical lenses, so that high and low temperatures can be balanced. When the ambient temperature of the line scanning lens changes greatly, it is beneficial to maintain the focal length of the line scanning lens stable, for example, to ensure that the line scanning lens has stable optical performance at -40°C to 85°C.

[0103] Based on the above embodiments, continue to refer to Figure 1-Figure 3 As shown, the line scanning lens may further include an aperture 110, which is disposed in the optical path between the fifth lens 105 and the sixth lens 106; the fourth lens 104 and the fifth lens 105 are glued together, and the sixth lens 106 and the seventh lens 107 are glued together.

[0104] Specifically, the fourth lens 104 and the fifth lens 105 are glued together to form a glued lens, and the sixth lens 106 and the seventh lens 107 are glued together to form a glued lens, that is, glued lenses are formed in the light paths on both sides of the aperture 110, respectively. The glued lens can be used to minimize or eliminate chromatic aberration. The use of a glued lens in a line scanning lens can improve image quality and reduce the reflection loss of light energy, thereby improving the clarity of lens imaging. In addition, the gluing of the lenses omits the air gap between the two lenses, making the optical system compact as a whole, meeting the requirements of system miniaturization. In addition, the gluing of the lenses will reduce the tolerance sensitivity problems such as tilt / eccentricity generated by the lens unit during the assembly process. Exemplarily, the fourth lens 104 and the fifth lens 105 can be supported by a gasket, or can be glued by glue; the sixth lens 106 and the seventh lens 107 can be supported by a gasket, or can be glued by glue; the embodiment of the present invention does not limit the specific setting method of the glued lens.

[0105] Furthermore, the second lens 102 and the third lens 103 can be glued together or not glued together, that is, independently. When the second lens 102 and the third lens 103 are glued together to form a glued lens, the image quality can be further improved and the reflection loss of light energy can be reduced; when the second lens 102 and the third lens 103 are independently arranged, the second lens 102 and the third lens 103 have a high degree of freedom in arrangement and a relatively simple arrangement method. In the subsequent embodiments, the glued arrangement and the non-glued arrangement of the second lens and the third lens are respectively described.

[0106] Based on the above embodiment, the combined focal power of the fourth lens 104 and the fifth lens 105 is fai 45 The combined focal length of the sixth lens 106 and the seventh lens 107 is fai 67 , the focal power of the fourth lens 104 is fai4, the focal power of the fifth lens 105 is fai5, the focal power of the sixth lens 106 is fai6, the focal power of the seventh lens 107 is fai7, the Abbe constant of the fourth lens 104 is vd4, the Abbe constant of the fifth lens 105 is vd5, the Abbe constant of the sixth lens 106 is vd6, and the Abbe constant of the seventh lens 107 is vd7; wherein, -0.905 <fai 45 / fai 67 <-0.837; 0.02<1000*(fai4 / vd4+fai5 / vd5)<0.322; -1.793<1000*(fai6 / vd6+fai7 / vd7)<-0.612.

[0107] Specifically, the combined focal length of the fourth lens 104 and the fifth lens 105 is 45The combined optical power of the sixth lens 106 and the seventh lens 107 is fai 67 Satisfied -0.905 <fai 45 / fai 67 <-0.837, that is, the focal length of the cemented lenses in the light paths on both sides of the aperture 101 is approximately equal to -1, that is, the focal length of the cemented lenses in the light paths on both sides of the aperture 101 is approximately symmetrical, so that the residual chromatic aberrations can be offset each other and the imaging quality can be improved.

[0108] Moreover, the Abbe constant is an index used to represent the dispersion ability of a transparent medium. Generally speaking, the larger the refractive index of the medium, the more severe the dispersion and the smaller the Abbe constant; conversely, the smaller the refractive index of the medium, the milder the dispersion and the larger the Abbe constant. In the embodiment of the present invention, the focal power fai4 and the Abbe constant vd4 of the fourth lens 104, the focal power fai5 and the Abbe constant vd5 of the fifth lens 105 satisfy 0.02<1000*(fai4 / vd4+fai5 / vd5)<0.322, the focal power fai6 and the Abbe constant vd6 of the sixth lens 106, and the focal power fai7 and the Abbe constant vd7 of the seventh lens 107 satisfy -1.793<1000*(fai6 / vd6+fai7 / vd7)<-0.612. By constraining the chromatic aberration of the cemented lenses in the optical paths on both sides of the aperture 101, the residual chromatic aberration can be further offset to improve the imaging quality.

[0109] Based on the above embodiment, the combined focal length of the second lens 102 and the third lens 103 is fai 23 , the focal power of the second lens 102 is fai2, the focal power of the third lens 103 is fai3, the Abbe constant of the second lens 102 is vd2, and the Abbe constant of the third lens 103 is vd3; wherein,

[0110] 0.206 <fai 23 / fai<0.318;0.035<1000*(fai2 / vd2+fai3 / vd3)<0.25.

[0111] Specifically, the second lens 102 and the third lens 103 are the front two lenses in the floating focus lens group S2. Since the off-axis light height of these two lenses is relatively high, the influence on the aberration is relatively large. By constraining the optical focal length and chromatic aberration of the front lens of the floating focus lens group S2 within the above-mentioned constraint range, the movement of the floating focus lens group can have less influence on the image quality at different working object distances, thereby ensuring the imaging quality of the line scanning lens.

[0112] Based on the above embodiments, the optical power of the eighth lens 108 is fai8, and the refractive index of the eighth lens 108 is nd8; wherein, 1.5 < fai8 / fai < 1.864, and nd8 > 1.9. By limiting the proportion of the optical power of the eighth lens 108 within this range, and at the same time using a high refractive index material for the eighth lens 108, the height of the light rays at the end of the entire line scanning lens can be reduced, so that the number of lenses included in the lens can be reduced and the lens cost can be lowered.

[0113] Based on the above embodiments, the distance that the floating focusing lens group S2 moves from the near object distance to the far object distance is Zmove, the focal length of the line scanning lens is f, the clear aperture of the first lens 101 is Dia1, and the total optical length of the line scanning lens is TTL; wherein, 0.111 < Zmove / f < 0.131, and 0.335 < Dia1 / TTL < 0.45.

[0114] Specifically, it is set that 0.111 < Zmove / f < 0.131 is satisfied between the moving distance Zmove of the floating focusing lens group S2 and the focal length f of the line scanning lens, that is, the moving range of the floating focusing lens group S2 is restricted within this range to ensure that the image quality of the lens at different working distances will not deteriorate significantly, and at the same time, the cutting of light rays will not be caused due to the movement of the floating focusing lens group S2, resulting in a decrease in relative illumination, so as to ensure the imaging quality. Further, 0.335 < Dia1 / TTL < 0.45 is satisfied between the clear aperture Dia1 of the first lens 101 and the total optical length TTL of the line scanning lens, so as to avoid the clear aperture of the lens being too large caused by the over-large moving range of the floating focusing lens group S2, and avoid the increase in cost.

[0115] Based on the above embodiments, the clear aperture of the aperture stop 110 is adjustable, and the aperture size of the lens can be controlled by adjusting the clear aperture of the aperture stop 110 to control the exposure amount.

[0116] Based on the above embodiments, continue to refer to Figure 1-Figure 3 As shown, the line scanning lens provided by the embodiment of the present invention further includes a flat glass 111, and the flat glass 111 is disposed in the optical path between the second fixed lens S3 and the image plane. The flat glass 111 functions to filter out unnecessary spectra or protect the sensor.

[0117] As a feasible implementation manner, the parameters of each lens in the line scanning lens will be described next.

[0118] Table 1 Optical design values of each lens in the line scanning lens

[0119] Surface number radius Thickness(mm) nd vd Semi-diameter (mm) Physical surface unlimited 200.000 S1 85.222 3.082 1.680 58.154 25.118 S2 26.264 14.656 20.494 S3 -57.966 1.315 1.475 59.730 19.741 S4 59.168 0.936 20.073 S5 57.856 6.967 1.807 64.789 20.357 S6 -103.337 5.190 20.305 S7 26.065 13.728 1.789 12.264 16.911 S8(Gluing) 14.078 0.000 10.675 S9 14.078 10.504 1.594 39.088 10.675 S10 -122.769 2.846 8.428 STO unlimited 3.075 5.528 S12 -197.059 3.532 1.535 33.852 7.016 S13(Gluing) -10.820 0.000 7.283 S14 -10.820 4.585 1.722 32.232 7.283 S15 147.344 2.980 10.194 S16 448.735 5.261 1.943 33.934 12.771 S17 -26.615 14.778 13.296 S18 -23.880 9.082 1.736 71.308 14.534 S19 -91.604 17.075 19.166 S20 unlimited 1.000 1.500 60.000 29.333 S21 unlimited 0.700 29.661 Image plane unlimited 0.000 30.033

[0120] In the above Table 1, the surface numbers are numbered according to the order of the surfaces of each lens. "S1" represents the object surface of the first lens, "S2" represents the image surface of the first lens, and so on. "STO" represents the aperture of the lens. The radius represents the degree of curvature of the lens surface. A positive value represents that the surface is bent toward the object side, and a negative value represents that the surface is bent toward the image side. "Infinite" represents that the surface is a plane and the radius of curvature is infinite. The thickness represents the central axial distance from the current surface to the next surface. nd represents the refractive index, which represents the ability of the material between the current surface and the next surface to deflect light. The space represents that the current position is air, and the refractive index is 1. vd represents the Abbe constant, which represents the dispersion characteristics of the material between the current surface and the next surface to light. The space represents that the current position is air.

[0121] Table 2 The distance between the front end of the floating focus lens group and the first fixed lens and the distance between the rear end of the floating focus lens group and the second fixed lens at different object distances

[0122] Close object distance (mm) Middle object distance(mm) Far object distance (mm) Physical surface 200 400 900 S2 14.656 17.752 19.251 S17 14.778 11.682 10.182

[0123] Wherein, S2 represents the distance between the front end of the floating focus lens group and the first fixed lens, and S17 represents the distance between the rear end of the floating focus lens group and the second fixed lens.

[0124] The optical system of this embodiment achieves the following technical indicators:

[0125] Focal length: f=41.6mm;

[0126] Aperture number: F#4.

[0127] Figure 4 A schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 1 of the present invention at a close object distance of 200 mm, Figure 5 : is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 1 of the present invention at a medium object distance of 400 mm. Figure 6 Schematic diagram of the MTF curve of a line scanning lens provided in the first embodiment of the present invention at a far object distance of 900 mm. Figure 4-Figure 6 It can be known that, for the line scanning lens provided by the embodiment of the present invention, at different object distances, 100 line pairs / mm in the optical modulation function curve is greater than 0.2 or close to 0.2, thus realizing the design of a high-performance line scanning lens.

[0128] Figure 7 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by the first embodiment of the present invention, Figure 7 It can be known that the relative illumination of the line scanning mirror provided by the embodiment of the present invention at different object distances is greater than 60%, and a good relative illumination requirement can be achieved.

[0129] Figure 8 It is a schematic diagram of the optical distortion curve of a line-scanning lens provided in the first embodiment of the present invention at different object distances. From Figure 8 it can be known that the distortion of the line-scanning lens provided in the embodiment of the present invention at different object distances is within the range of -1.5% to +1.5%, and the distortion is small.

[0130] In summary, the line-scanning lens provided in the embodiment of the present invention can achieve a high-performance line-scanning lens design solution with a distortion of -1.5% to +1.5% within the working distance range of 200 - 900 mm, a focal length of 40 mm, F4.0, a target surface of Φ60 mm, an illuminance of 60%, and an MTF of >0.2 at 100 line pairs / mm.

[0131] Embodiment 2

[0132] Fig. 9 It is a schematic structural diagram of a line-scanning lens provided in the second embodiment of the present invention at a near object distance of 200 mm. Fig.10 It is a schematic structural diagram of a line-scanning lens provided in the second embodiment of the present invention at a medium object distance of 400 mm. Fig.11 It is a schematic structural diagram of a line-scanning lens provided in the second embodiment of the present invention at a far object distance of 900 mm. As shown in combination with Figure 9-11 the line-scanning lens provided in the second embodiment of the present invention includes a first fixed lens S1, a floating focusing lens group S2, and a second fixed lens S3 arranged in sequence from the object surface to the image surface along the optical axis; the positions of the first fixed lens S1 and the second fixed lens S3 are fixed, and the position of the floating focusing lens group S2 can float along the optical axis; the shape factor X1 of the first fixed lens S1 and the shape factor X2 of the second fixed lens S3 satisfy -2.029 < X2 / X1 < -0.779; the shape factor X1 of the first fixed lens S1 satisfies X1 = (ca1 + cb1) / (ca1 - cb1), and the shape factor X2 of the second fixed lens S3 satisfies X2 = (ca2 + cb2) / (ca2 - cb2); where ca1 represents the curvature of the object side surface of the first fixed lens, cb1 represents the curvature of the image side surface of the first fixed lens, ca2 represents the curvature of the object side surface of the second fixed lens, and cb2 represents the curvature of the image side surface of the second fixed lens; the combined optical power fai 浮动 of the floating focusing lens group S2 and the optical power fai of the line-scanning lens satisfy 1.034 < fai 浮动 / fai < 1.351.

[0133] Among them, the above parameters are the same as those in Embodiment 1 and will not be elaborated here.

[0134] As another feasible implementation manner, the specific parameters in the line-scanning lens will be described below.

[0135] Table 3 Optical design values ​​of each lens in the line scanning lens

[0136] Surface number radius Thickness(mm) nd vd Semi-diameter (mm) Physical surface unlimited 200.000 S1 102.742 1.500 1.630 55.137 24.449 S2 26.421 14.700 20.375 S3 -55.809 1.510 1.471 81.587 19.402 S4 60.794 1.186 19.577 S5 61.757 6.457 1.816 62.308 19.826 S6 -91.903 3.633 19.777 S7 25.975 15.935 1.838 22.677 16.415 S8(Gluing) 14.041 0.000 9.390 S9 14.041 7.154 1.593 71.302 9.390 S10 -140.605 2.457 7.870 STO unlimited 2.744 5.194 S12 -178.721 3.949 1.534 45.534 6.652 S13(Gluing) -10.459 0.000 7.101 S14 -10.459 3.693 1.719 30.056 7.101 S15 147.344 2.608 9.849 S16 411.765 7.213 1.991 29.796 12.373 S17 -27.138 15.100 13.577 S18 -23.880 6.440 1.907 51.016 14.912 S19 -59.540 16.502 18.678 S20 unlimited 1.336 1.500 60.000 29.208 S21 unlimited 0.700 29.651 Image plane unlimited 0.000 30.029

[0137] Table 4 The distance between the front end of the floating focus lens group and the first fixed lens and the distance between the rear end of the floating focus lens group and the second fixed lens at different object distances

[0138] Close object distance (mm) Middle object distance(mm) Far object distance (mm) Physical surface 200 400 900 S2 14.700 17.890 19.200 S17 15.100 12.010 10.600

[0139] In the above table, the meaning of each parameter is the same as that in the first embodiment and will not be repeated here.

[0140] The optical system of this embodiment achieves the following technical indicators:

[0141] Focal length: f=40.08mm;

[0142] Aperture number: F#4.

[0143] Fig.12 A schematic diagram of an MTF curve of a line scanning lens provided in a second embodiment of the present invention at a close object distance of 200 mm. Fig.13 : is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 2 of the present invention at a medium object distance of 400 mm. Fig.14 Schematic diagram of the MTF curve of a line scanning lens provided in the second embodiment of the present invention at a far object distance of 900 mm. Figure 12-14 It can be known that, for the line scanning lens provided by the embodiment of the present invention, at different object distances, 100 line pairs / mm in the optical modulation function curve is greater than 0.2 or close to 0.2, thus realizing the design of a high-performance line scanning lens.

[0144] Fig.15 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by the second embodiment of the present invention, Fig.15 It can be known that the relative illumination of the line scanning mirror provided by the embodiment of the present invention at different object distances is greater than 60%, and a good relative illumination requirement can be achieved.

[0145] Fig.16 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by the second embodiment of the present invention, Fig.16 It can be known that the distortion of the line scanning mirror provided by the embodiment of the present invention at different object distances is within the range of -1.5% to +1.5%, and the distortion is small.

[0146] In summary, the line scan lens provided by the embodiment of the present invention can achieve a high-performance line scan lens design solution with a distortion of -1.5% to +1.5% within a working distance range of 200 - 900 mm, a focal length of 40 mm, F4.0, a target surface of Φ60 mm, an illuminance of 60%, and an MTF of >0.2 at 100 line pairs / mm.

[0147] Embodiment III

[0148] Fig.17 FIG. 7 is a schematic structural diagram of a line scan lens provided by Embodiment III of the present invention at a near object distance of 200 mm. Fig.18 FIG. 8 is a schematic structural diagram of a line scan lens provided by Embodiment III of the present invention at a medium object distance of 400 mm. Fig.19 FIG. 9 is a schematic structural diagram of a line scan lens provided by Embodiment III of the present invention at a far object distance of 900 mm. As shown in Figure 17-Figure 19 FIGS. 7 - 9, the line scan lens provided by Embodiment III of the present invention includes a first fixed lens S1, a floating focusing lens group S2, and a second fixed lens S3 arranged in sequence from the object surface to the image surface along the optical axis; the positions of the first fixed lens S1 and the second fixed lens S3 are fixed, and the position of the floating focusing lens group S2 can float along the optical axis; the shape factor X1 of the first fixed lens S1 and the shape factor X2 of the second fixed lens S3 satisfy -2.029 < X2 / X1 < -0.779; the shape factor X1 of the first fixed lens S1 satisfies X1 = (ca1 + cb1) / (ca1 - cb1), and the shape factor X2 of the second fixed lens S3 satisfies X2 = (ca2 + cb2) / (ca2 - cb2); where ca1 represents the curvature of the object side surface of the first fixed lens, cb1 represents the curvature of the image side surface of the first fixed lens, ca2 represents the curvature of the object side surface of the second fixed lens, and cb2 represents the curvature of the image side surface of the second fixed lens; the combined optical power fai 浮动 of the floating focusing lens group S2 and the optical power fai of the line scan lens satisfy 1.034 < fai 浮动 / fai < 1.351.

[0149] Among them, the above parameters are the same as those in Embodiment I and will not be elaborated here.

[0150] As another feasible implementation manner, the specific parameters in the line scan lens will be described below.

[0151] Table 5 Optical design values of each lens in the line scan lens

[0152] Surface number radius Thickness(mm) nd vd Semi-diameter (mm) Physical surface unlimited 200.000 S1 88.880 1.500 1.629 71.311 20.397 S2 26.315 10.887 17.895 S3 -72.380 1.110 1.470 71.322 16.852 S4 49.792 0.895 16.802 S5 46.316 6.310 1.812 52.308 17.002 S6 -182.243 0.587 16.792 S7 25.457 8.225 1.835 44.213 15.181 S8(Gluing) 14.353 0.000 11.219 S9 14.353 14.557 1.596 63.876 11.219 S10 -128.301 1.293 7.948 STO unlimited 4.046 6.085 S12 -164.157 7.389 1.541 35.948 8.113 S13(Gluing) -11.257 0.000 8.876 S14 -11.257 1.372 1.718 22.518 8.876 S15 147.344 3.721 10.819 S16 553.127 4.637 1.969 28.427 13.443 S17 -27.059 16.518 13.672 S18 -23.880 16.807 1.905 68.336 14.010 S19 -75.356 20.263 20.395 S20 unlimited 1.069 1.500 60.000 29.740 S21 unlimited 0.700 30.015 Image plane unlimited 0.000 30.298

[0153] Table 6 Distances between the front end of the floating focusing lens group and the first fixed lens and between the rear end of the floating focusing lens group and the second fixed lens at different object distances

[0154] Close object distance (mm) Middle object distance(mm) Far object distance (mm) Physical surface 200 400 900 S2 10.887 14.984 16.802 S17 16.518 12.422 10.603

[0155] In the above table, the meaning of each parameter is the same as that in the first embodiment and will not be repeated here.

[0156] The optical system of this embodiment achieves the following technical indicators:

[0157] Focal length: f=49.81mm;

[0158] Aperture number: F#4.

[0159] Fig. 20 A schematic diagram of an MTF curve of a line scanning lens provided in a third embodiment of the present invention at a close object distance of 200 mm. Fig.21 : is a schematic diagram of an MTF curve of a line scanning lens provided in Embodiment 3 of the present invention at a medium object distance of 400 mm. Fig. 22 Schematic diagram of the MTF curve of a line scanning lens provided in the third embodiment of the present invention at a far object distance of 900 mm. Figure 20-Figure 22 It can be known that, for the line scanning lens provided by the embodiment of the present invention, at different object distances, 100 line pairs / mm in the optical modulation function curve is greater than 0.2 or close to 0.2, thus realizing the design of a high-performance line scanning lens.

[0160] Fig.23 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by the third embodiment of the present invention, Fig.23 It can be known that the relative illumination of the line scanning mirror provided by the embodiment of the present invention at different object distances is greater than 60%, and a good relative illumination requirement can be achieved.

[0161] Fig.24 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by the third embodiment of the present invention, Fig.24 It can be known that the distortion of the line scanning mirror provided by the embodiment of the present invention at different object distances is within the range of -1.5% to +1.5%, and the distortion is small.

[0162] In summary, the line scan lens provided in the embodiment of the present invention can achieve a high-performance line scan lens design with a distortion of -1.5% to +1.5% in the working distance range of 200-900mm, a focal length of 40mm, F4.0, a target surface of Φ60mm, an illumination of 60%, and MTF100 line pairs / mm>0.2.

[0163] Embodiment 4

[0164] Fig.25 is a schematic structural diagram of a line scanning lens provided by a fourth embodiment of the present invention at a close object distance of 200 mm. Fig.26It is a schematic structural diagram of a line-scanning lens provided in Embodiment 4 of the present invention at a medium object distance of 400 mm. Fig. 27 It is a schematic structural diagram of a line-scanning lens provided in Embodiment 4 of the present invention at a far object distance of 900 mm. As shown in Figure 25-27 the line-scanning lens provided in Embodiment 4 of the present invention includes a first fixed lens S1, a floating focusing lens group S2, and a second fixed lens S3 arranged in sequence from the object plane to the image plane along the optical axis; the positions of the first fixed lens S1 and the second fixed lens S3 are fixed, and the position of the floating focusing lens group S2 can float along the optical axis; the shape factor X1 of the first fixed lens S1 and the shape factor X2 of the second fixed lens S3 satisfy -2.029 < X2 / X1 < -0.779; the shape factor X1 of the first fixed lens S1 satisfies X1 = (ca1 + cb1) / (ca1 - cb1), and the shape factor X2 of the second fixed lens S3 satisfies X2 = (ca2 + cb2) / (ca2 - cb2); where, ca1 represents the curvature of the object side surface of the first fixed lens, cb1 represents the curvature of the image side surface of the first fixed lens, ca2 represents the curvature of the object side surface of the second fixed lens, and cb2 represents the curvature of the image side surface of the second fixed lens; the combined optical power fai 浮动 of the floating focusing lens group S2 and the optical power fai of the line-scanning lens satisfy 1.034 < fai 浮动 / fai < 1.351.

[0165] Among them, the above parameters are the same as those in Embodiment 1 and will not be elaborated here.

[0166] As another feasible implementation manner, the specific parameters in the line-scanning lens will be described below.

[0167] Table 7 Optical design values of each lens in the line-scanning lens

[0168] Surface number radius Thickness(mm) nd vd Semi-diameter (mm) Physical surface unlimited 200.000 S1 103.873 1.550 1.646 53.358 24.401 S2 26.925 12.523 20.462 S3 -61.426 1.421 1.476 68.635 19.735 S4 54.302 0.845 19.893 S5 60.424 6.481 1.809 58.584 20.005 S6 -97.837 2.939 19.966 S7 26.133 18.174 1.739 25.078 17.074 S8(Gluing) 13.805 0.000 9.423 S9 13.805 7.848 1.594 67.324 9.423 S10 -118.786 2.316 7.662 STO unlimited 2.659 5.140 S12 -146.762 3.823 1.538 44.184 6.494 S13(Gluing) -10.291 0.000 6.945 S14 -10.291 3.804 1.720 29.666 6.945 S15 147.344 2.228 9.732 S16 401.077 8.213 1.986 29.356 11.905 S17 -26.878 15.252 13.491 S18 -23.880 8.080 1.757 44.528 14.863 S19 -82.848 15.401 19.369 S20 unlimited 1.000 1.500 60.000 29.296 S21 unlimited 0.700 29.639 Image plane unlimited 0.000 30.032

[0169] Table 8 Distances between the front end of the floating focusing lens group and the first fixed lens and between the rear end of the floating focusing lens group and the second fixed lens at different object distances

[0170] Close object distance (mm) Middle object distance(mm) Far object distance (mm) Physical surface 200 400 900 S2 12.523 15.860 17.439 S17 15.252 11.915 10.336

[0171] In the above tables, the meanings of each parameter are the same as those in Embodiment 1 and will not be elaborated here.

[0172] The optical system of this embodiment has achieved the following technical indicators:

[0173] Focal length: f = 40.74 mm;

[0174] Aperture number: F#4.

[0175] Fig.28 A schematic diagram of an MTF curve of a line scanning lens provided by a fourth embodiment of the present invention at a close object distance of 200 mm, Fig.29 : is a schematic diagram of an MTF curve of a line scanning lens provided by a fourth embodiment of the present invention at a medium object distance of 400 mm. Fig.30 Schematic diagram of the MTF curve of a line scanning lens provided by the fourth embodiment of the present invention at a far object distance of 900 mm. Figure 28-Figure 30 It can be known that, for the line scanning lens provided by the embodiment of the present invention, at different object distances, 100 line pairs / mm in the optical modulation function curve is greater than 0.2 or close to 0.2, thus realizing the design of a high-performance line scanning lens.

[0176] Fig.31 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by the fourth embodiment of the present invention, Fig.31 It can be known that the relative illumination of the line scanning mirror provided by the embodiment of the present invention at different object distances is greater than 60% or close to greater than 60%, which can achieve good relative illumination requirements.

[0177] Fig.32 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by the fourth embodiment of the present invention, Fig.32 It can be known that the distortion of the line scanning mirror provided by the embodiment of the present invention at different object distances is within the range of -1.5% to +1.5%, and the distortion is small.

[0178] In summary, the line scan lens provided in the embodiment of the present invention can achieve a high-performance line scan lens design with a distortion of -1.5% to +1.5% in the working distance range of 200-900mm, a focal length of 40mm, F4.0, a target surface of Φ60mm, an illumination of 60%, and MTF100 line pairs / mm>0.2.

[0179] Embodiment 5

[0180] Fig.33 is a schematic structural diagram of a line scanning lens provided by Embodiment 5 of the present invention at a close object distance of 200 mm. Fig.34 1 is a schematic diagram of the structure of a line scanning lens provided by Embodiment 5 of the present invention at a medium object distance of 400 mm. Fig.35 is a schematic diagram of the structure of a line scanning lens provided by Embodiment 5 of the present invention at a far object distance of 900 mm, combined with Figure 33-Figure 35As shown in the figure, the line scanning lens provided in the fifth embodiment of the present invention includes a first fixed lens S1, a floating focusing lens group S2, and a second fixed lens S3 whose optical axes are arranged in sequence from the object plane to the image plane; the positions of the first fixed lens S1 and the second fixed lens S3 are fixed, and the position of the floating focusing lens group S2 can float along the optical axis; the shape factor X1 of the first fixed lens S1 and the shape factor X2 of the second fixed lens S3 satisfy -2.029 < X2 / X1 < -0.779; the shape factor X1 of the first fixed lens S1 satisfies X1 = (ca1 + cb1) / (ca1 - cb1), and the shape factor X2 of the second fixed lens S3 satisfies X2 = (ca2 + cb2) / (ca2 - cb2); where ca1 represents the curvature of the object side surface of the first fixed lens, cb1 represents the curvature of the image side surface of the first fixed lens, ca2 represents the curvature of the object side surface of the second fixed lens, and cb2 represents the curvature of the image side surface of the second fixed lens; the combined optical power fai 浮动 of the floating focusing lens group S2 and the optical power fai of the line scanning lens satisfy 1.034 < fai 浮动 / fai < 1.351.

[0181] Among them, the above parameters are the same as those in the first embodiment and will not be elaborated here.

[0182] As another feasible implementation manner, the specific parameters in the line scanning lens will be described below.

[0183] Table 9 Optical design values of each lens in the line scanning lens

[0184] Surface number radius Thickness(mm) nd vd Semi-diameter (mm) Physical surface unlimited 200.000 S1 96.630 1.712 1.670 55.903 24.321 S2 26.828 13.926 20.397 S3 -51.936 1.351 1.468 64.789 19.553 S4 66.238 0.000 19.923 S5 66.238 6.243 1.820 60.299 19.923 S6 -87.181 2.904 19.901 S7 26.007 15.554 1.795 17.968 16.936 S8(Gluing) 14.072 0.000 10.089 S9 14.072 9.235 1.600 57.521 10.089 S10 -149.564 2.688 7.977 STO unlimited 2.794 5.252 S12 -194.331 3.991 1.536 39.561 6.683 S13(Gluing) -10.456 0.000 7.133 S14 -10.456 3.507 1.721 31.070 7.133 S15 147.344 2.272 9.812 S16 435.675 7.557 1.956 30.185 11.967 S17 -26.324 16.261 13.340 S18 -23.880 8.758 1.684 44.905 14.883 S19 -95.003 15.355 19.678 S20 unlimited 1.000 1.500 60.000 29.310 S21 unlimited 0.700 29.650 Image plane unlimited 0.000 30.038

[0185] Table 10 Distances between the front end of the floating focusing lens group and the first fixed lens and between the rear end of the floating focusing lens group and the second fixed lens at different object distances

[0186] Close object distance (mm) Middle object distance(mm) Far object distance (mm) Physical surface 200 400 900 S2 13.926 17.641 19.336 S17 16.261 12.546 10.851

[0187] In the above tables, the meanings of each parameter are the same as those in the first embodiment and will not be elaborated here.

[0188] The optical system of this embodiment has achieved the following technical indicators:

[0189] Focal length: f = 41.45 mm;

[0190] Aperture number: F#4.

[0191] Fig.36 Schematic diagram of the MTF curve of a line scanning lens provided in the fifth embodiment of the present invention at a near object distance of 200 mm, Fig.37 is a schematic diagram of the MTF curve of a line scanning lens provided in the fifth embodiment of the present invention at a medium object distance of 400 mm, Fig.38 Schematic diagram of the MTF curve of a line scanning lens provided in Embodiment 5 of the present invention at a far object distance of 900 mm. Figure 36-Figure 38 It can be known that, for the line scanning lens provided by the embodiment of the present invention, at different object distances, 100 line pairs / mm in the optical modulation function curve is greater than 0.2 or close to 0.2, thus realizing the design of a high-performance line scanning lens.

[0192] Fig.39 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by the fifth embodiment of the present invention, Fig.39 It can be known that the relative illumination of the line scanning mirror provided by the embodiment of the present invention at different object distances is greater than 60%, and a good relative illumination requirement can be achieved.

[0193] Fig.40 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by Embodiment 5 of the present invention, Fig.40 It can be known that the distortion of the line scanning mirror provided by the embodiment of the present invention at different object distances is within the range of -1.5% to +1.5%, and the distortion is small.

[0194] In summary, the line scan lens provided in the embodiment of the present invention can achieve a high-performance line scan lens design with a distortion of -1.5% to +1.5% in the working distance range of 200-900mm, a focal length of 40mm, F4.0, a target surface of Φ60mm, an illumination of 60%, and MTF100 line pairs / mm>0.2.

[0195] Embodiment 6

[0196] Fig.41 1 is a schematic diagram of the structure of a line scanning lens provided by Embodiment 6 of the present invention at a close object distance of 200 mm. Fig.42 1 is a schematic diagram of the structure of a line scanning lens provided by Embodiment 6 of the present invention at a medium object distance of 400 mm. Fig.43 Schematic diagram of the structure of a line scanning lens provided by Embodiment 6 of the present invention at a far object distance of 900 mm, combined with Figure 41-43As shown in the figure, the line scanning lens provided in the sixth embodiment of the present invention includes a first fixed lens S1, a floating focusing lens group S2, and a second fixed lens S3, whose optical axes are arranged in sequence from the object plane to the image plane; the positions of the first fixed lens S1 and the second fixed lens S3 are fixed, and the position of the floating focusing lens group S2 can float along the optical axis; the shape factor X1 of the first fixed lens S1 and the shape factor X2 of the second fixed lens S3 satisfy -2.029 < X2 / X1 < -0.779; the shape factor X1 of the first fixed lens S1 satisfies X1 = (ca1 + cb1) / (ca1 - cb1), and the shape factor X2 of the second fixed lens S3 satisfies X2 = (ca2 + cb2) / (ca2 - cb2); where ca1 represents the curvature of the object side surface of the first fixed lens, cb1 represents the curvature of the image side surface of the first fixed lens, ca2 represents the curvature of the object side surface of the second fixed lens, and cb2 represents the curvature of the image side surface of the second fixed lens; the combined optical power fai of the floating focusing lens group S2 浮动 and the optical power fai of the line scanning lens satisfy 1.034 < fai 浮动 / fai < 1.351.

[0197] Among them, the above parameters are the same as those in the first embodiment and will not be elaborated here.

[0198] As another feasible implementation manner, the specific parameters in the line scanning lens will be described below.

[0199] Table 11 Optical design values of each lens in the line scanning lens

[0200] Surface number radius Thickness(mm) nd vd Semi-diameter (mm) Physical surface unlimited 200.000 S1 100.709 3.454 1.637 75.483 24.783 S2 27.174 13.880 20.199 S3 -60.323 2.113 1.459 75.486 18.986 S4 71.614 0.000 18.907 S5 71.614 9.949 1.827 53.997 18.907 S6 -114.530 2.101 18.530 S7 23.932 8.427 1.847 36.252 15.914 S8(Gluing) 14.450 0.000 11.585 S9 14.450 14.090 1.596 67.332 11.585 S10 -136.727 2.674 8.136 STO unlimited 2.649 5.525 S12 -147.597 7.044 1.535 42.806 6.688 S13(Gluing) -10.658 0.000 7.883 S14 -10.658 2.061 1.723 27.520 7.883 S15 147.344 3.466 10.187 S16 825.909 5.433 1.979 32.968 13.380 S17 -26.533 15.835 13.887 S18 -23.880 8.093 1.704 71.321 15.155 S19 -91.827 16.003 19.641 S20 unlimited 1.000 1.500 60.000 29.341 S21 unlimited 0.700 29.673 Image plane unlimited 0.000 30.049

[0201] Table 12 Distances between the front end of the floating focusing lens group and the first fixed lens and between the rear end of the floating focusing lens group and the second fixed lens at different object distances

[0202] Close object distance (mm) Middle object distance(mm) Far object distance (mm) Physical surface 200 400 900 S2 13.880 17.144 18.715 S17 15.835 12.571 11.000

[0203] In the above table, the meanings of each parameter are the same as those in the first embodiment and will not be elaborated here.

[0204] The optical system of this embodiment has achieved the following technical indicators:

[0205] Focal length: f = 41.24 mm;

[0206] Aperture number: F#4.

[0207] Fig.44 Schematic diagram of the MTF curve of the line scanning lens provided in the sixth embodiment of the present invention at a near object distance of 200 mm, Fig.45 is the schematic diagram of the MTF curve of the line scanning lens provided in the sixth embodiment of the present invention at a medium object distance of 400 mm, Fig.46 Schematic diagram of the MTF curve of a line scanning lens provided in Example 6 of the present invention at a far object distance of 900 mm. Figure 44-Figure 46 It can be known that, for the line scanning lens provided by the embodiment of the present invention, at different object distances, 100 line pairs / mm in the optical modulation function curve is greater than 0.2 or close to 0.2, thus realizing the design of a high-performance line scanning lens.

[0208] Fig.47 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by Embodiment 6 of the present invention, Fig.47 It can be known that the relative illumination of the line scanning mirror provided by the embodiment of the present invention at different object distances is greater than 60% or close to greater than 60%, which can achieve good relative illumination requirements.

[0209] Fig.48 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by Embodiment 6 of the present invention, Fig.48 It can be known that the distortion of the line scanning mirror provided by the embodiment of the present invention at different object distances is within the range of -1.5% to +1.5%, and the distortion is small.

[0210] In summary, the line scan lens provided in the embodiment of the present invention can achieve a high-performance line scan lens design with a distortion of -1.5% to +1.5% in the working distance range of 200-900mm, a focal length of 40mm, F4.0, a target surface of Φ60mm, an illumination of 60%, and MTF100 line pairs / mm>0.2.

[0211] Embodiment 7

[0212] Fig.49 1 is a schematic diagram of the structure of a line scanning lens provided by Embodiment 7 of the present invention at a close object distance of 200 mm. Fig.50 1 is a schematic diagram of the structure of a line scanning lens provided by Embodiment 7 of the present invention at a medium object distance of 400 mm. Fig.51 Schematic diagram of the structure of a line scanning lens provided by Embodiment 7 of the present invention at a far object distance of 900 mm, combined with Figure 49-Figure 51As shown in the figure, the line scanning lens provided in the seventh embodiment of the present invention includes a first fixed lens S1, a floating focusing lens group S2, and a second fixed lens S3 whose optical axes are arranged in sequence from the object plane to the image plane; the positions of the first fixed lens S1 and the second fixed lens S3 are fixed, and the position of the floating focusing lens group S2 can float along the optical axis; the shape factor X1 of the first fixed lens S1 and the shape factor X2 of the second fixed lens S3 satisfy -2.029 < X2 / X1 < -0.779; the shape factor X1 of the first fixed lens S1 satisfies X1 = (ca1 + cb1) / (ca1 - cb1), and the shape factor X2 of the second fixed lens S3 satisfies X2 = (ca2 + cb2) / (ca2 - cb2); where ca1 represents the curvature of the object side surface of the first fixed lens, cb1 represents the curvature of the image side surface of the first fixed lens, ca2 represents the curvature of the object side surface of the second fixed lens, and cb2 represents the curvature of the image side surface of the second fixed lens; the combined optical power fai of the floating focusing lens group S2 浮动 and the optical power fai of the line scanning lens satisfy 1.034 < fai 浮动 / fai < 1.351.

[0213] Among them, the above parameters are the same as those in the first embodiment and will not be elaborated here.

[0214] As another feasible implementation manner, the specific parameters in the line scanning lens will be described below.

[0215] Table 13 Optical design values of each lens in the line scanning lens

[0216] Surface number radius Thickness(mm) nd vd Semi-diameter (mm) Physical surface unlimited 200.000 S1 2335.485 1.500 1.502 68.615 25.504 S2 30.613 11.443 21.464 S3 -60.528 0.602 1.459 62.948 20.844 S4 55.320 0.580 20.983 S5 62.872 6.747 1.816 64.275 20.996 S6 -93.720 6.316 20.965 S7 25.869 15.765 1.789 28.302 16.760 S8(Gluing) 14.189 0.000 9.809 S9 14.189 9.283 1.597 70.366 9.809 S10 -177.430 2.192 7.401 STO unlimited 2.661 5.124 S12 -224.195 3.800 1.543 37.995 6.496 S13(Gluing) -10.147 0.000 6.904 S14 -10.147 2.656 1.720 31.206 6.904 S15 147.344 2.995 9.149 S16 450.149 8.802 1.967 40.784 11.973 S17 -26.484 16.624 13.697 S18 -23.880 9.875 1.914 68.363 15.079 S19 -67.963 12.914 20.346 S20 unlimited 1.000 1.500 60.000 29.301 S21 unlimited 0.700 29.643 Image plane unlimited 0.000 30.034

[0217] Table 14 Distances between the front end of the floating focusing lens group and the first fixed lens and between the rear end of the floating focusing lens group and the second fixed lens at different object distances

[0218] Close object distance (mm) Middle object distance(mm) Far object distance (mm) Physical surface 200 400 900 S2 11.443 14.787 16.402 S17 16.624 13.279 11.664

[0219] In the above table, the meanings of each parameter are the same as those in the first embodiment and will not be elaborated here.

[0220] The optical system of this embodiment has achieved the following technical indicators:

[0221] Focal length: f = 41.72 mm;

[0222] Aperture number: F#4.

[0223] Fig.52 Schematic diagram of the MTF curve of a line scanning lens provided in the seventh embodiment of the present invention at a near object distance of 200 mm, Fig.53 is a schematic diagram of the MTF curve of a line scanning lens provided in the seventh embodiment of the present invention at a medium object distance of 400 mm,Fig.54 Schematic diagram of the MTF curve of a line scanning lens provided by Embodiment 7 of the present invention at a far object distance of 900 mm. Figure 52-Figure 54 It can be known that, for the line scanning lens provided by the embodiment of the present invention, at different object distances, 100 line pairs / mm in the optical modulation function curve is greater than 0.2 or close to 0.2, thus realizing the design of a high-performance line scanning lens.

[0224] Fig.55 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by Embodiment 7 of the present invention, Fig.55 It can be known that the relative illumination of the line scanning mirror provided by the embodiment of the present invention at different object distances is greater than 60% or close to greater than 60%, which can achieve good relative illumination requirements.

[0225] Fig.56 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by Embodiment 7 of the present invention, Fig.56 It can be known that the distortion of the line scanning mirror provided by the embodiment of the present invention at different object distances is within the range of -1.5% to +1.5%, and the distortion is small.

[0226] In summary, the line scan lens provided in the embodiment of the present invention can achieve a high-performance line scan lens design with a distortion of -1.5% to +1.5% in the working distance range of 200-900mm, a focal length of 40mm, F4.0, a target surface of Φ60mm, an illumination of 60%, and MTF100 line pairs / mm>0.2.

[0227] Embodiment 8

[0228] Fig.57 1 is a schematic diagram of the structure of a line scanning lens provided by Embodiment 8 of the present invention at a close object distance of 200 mm. Fig.58 1 is a schematic diagram of the structure of a line scanning lens provided by Embodiment 8 of the present invention at a medium object distance of 400 mm. Fig.59 is a schematic diagram of the structure of a line scanning lens provided by Embodiment 8 of the present invention at a far object distance of 900 mm, combined with Figure 57-Figure 59As shown in the figure, the line scanning lens provided in the eighth embodiment of the present invention includes a first fixed lens S1, a floating focusing lens group S2, and a second fixed lens S3 whose optical axes are arranged in sequence from the object plane to the image plane; the positions of the first fixed lens S1 and the second fixed lens S3 are fixed, and the position of the floating focusing lens group S2 can float along the optical axis; the shape factor X1 of the first fixed lens S1 and the shape factor X2 of the second fixed lens S3 satisfy -2.029 < X2 / X1 < -0.779; the shape factor X1 of the first fixed lens S1 satisfies X1 = (ca1 + cb1) / (ca1 - cb1), and the shape factor X2 of the second fixed lens S3 satisfies X2 = (ca2 + cb2) / (ca2 - cb2); where ca1 represents the curvature of the object side surface of the first fixed lens, cb1 represents the curvature of the image side surface of the first fixed lens, ca2 represents the curvature of the object side surface of the second fixed lens, and cb2 represents the curvature of the image side surface of the second fixed lens; the combined optical power fai of the floating focusing lens group S2 浮动 and the optical power fai of the line scanning lens satisfy 1.034 < fai 浮动 / fai < 1.351.

[0229] Among them, the above parameters are the same as those in the first embodiment and will not be elaborated here.

[0230] As another feasible implementation manner, the specific parameters in the line scanning lens will be described below.

[0231] Table 15 Optical design values of each lens in the line scanning lens

[0232] Surface number radius Thickness(mm) nd vd Semi-diameter (mm) Physical surface unlimited 200.000 S1 74.691 1.483 1.707 71.301 25.240 S2 26.699 15.716 21.147 S3 -54.739 1.588 1.472 59.717 20.206 S4 60.165 1.061 20.482 S5 62.024 6.839 1.812 68.305 20.724 S6 -93.651 4.035 20.686 S7 26.098 14.614 1.810 15.575 17.145 S8(Gluing) 14.023 0.000 10.409 S9 14.023 10.639 1.595 56.738 10.409 S10 -128.175 2.556 7.811 STO unlimited 2.920 5.101 S12 -145.804 4.081 1.535 49.457 6.629 S13(Gluing) -10.436 0.000 7.139 S14 -10.436 4.407 1.720 47.196 7.139 S15 147.344 2.322 10.293 S16 476.908 6.327 1.971 41.283 12.572 S17 -26.426 14.768 13.491 S18 -23.880 6.743 1.672 63.496 15.018 S19 -97.835 15.648 19.174 S20 unlimited 1.000 1.500 60.000 29.276 S21 unlimited 0.700 29.627 Image plane unlimited 0.000 30.030

[0233] Table 16 Distances between the front end of the floating focusing lens group and the first fixed lens and between the rear end of the floating focusing lens group and the second fixed lens at different object distances

[0234] Close object distance (mm) Middle object distance(mm) Far object distance (mm) Physical surface 200 400 900 S2 15.716 18.728 20.213 S17 14.768 11.756 10.271

[0235] In the above tables, the meanings of each parameter are the same as those in the first embodiment and will not be elaborated here.

[0236] The optical system of this embodiment has achieved the following technical indicators:

[0237] Focal length: f = 39.55 mm;

[0238] Aperture number: F#4.

[0239] Fig.60 Schematic diagram of the MTF curve of a line scanning lens provided in the eighth embodiment of the present invention at a near object distance of 200 mm, Fig.61 is a schematic diagram of the MTF curve of a line scanning lens provided in the eighth embodiment of the present invention at a medium object distance of 400 mm, Fig.62 Schematic diagram of the MTF curve of a line scanning lens provided in Embodiment 8 of the present invention at a far object distance of 900 mm. Figure 60-Figure 62 It can be known that, for the line scanning lens provided by the embodiment of the present invention, at different object distances, 100 line pairs / mm in the optical modulation function curve is greater than 0.2 or close to 0.2, thus realizing the design of a high-performance line scanning lens.

[0240] Fig.63 is a schematic diagram of a relative illumination curve of a line scanning lens at different object distances provided by Embodiment 8 of the present invention, Fig.63 It can be known that the relative illumination of the line scanning mirror provided by the embodiment of the present invention at different object distances is greater than 60% or close to greater than 60%, which can achieve good relative illumination requirements.

[0241] Fig.64 is a schematic diagram of an optical distortion curve of a line scanning lens at different object distances provided by Embodiment 8 of the present invention, Fig.64 It can be known that the distortion of the line scanning mirror provided by the embodiment of the present invention at different object distances is within the range of -1.5% to +1.5%, and the distortion is small.

[0242] In summary, the line scan lens provided in the embodiment of the present invention can achieve a high-performance line scan lens design with a distortion of -1.5% to +1.5% in the working distance range of 200-900mm, a focal length of 40mm, F4.0, a target surface of Φ60mm, an illumination of 60%, and MTF100 line pairs / mm>0.2.

[0243] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A line scanning lens, characterized in that: It includes a first fixed lens, a floating focusing lens group, and a second fixed lens arranged in sequence along the optical axis from the object plane to the image plane; the positions of the first fixed lens and the second fixed lens are fixed, and the position of the floating focusing lens group can float along the optical axis; The shape factor X1 of the first fixed lens and the shape factor X2 of the second fixed lens satisfy -2.029 < X2 / X1 < -0.779; the shape factor X1 of the first fixed lens satisfies X1 = (ca1 + cb1) / (ca1 - cb1), and the shape factor X2 of the second fixed lens satisfies X2 = (ca2 + cb2) / (ca2 - cb2); wherein, ca1 represents the curvature of the object side surface of the first fixed lens, cb1 represents the curvature of the image side surface of the first fixed lens, ca2 represents the curvature of the object side surface of the second fixed lens, and cb2 represents the curvature of the image side surface of the second fixed lens; The combined optical power of the floating focus lens group is fai 浮动 The optical power fai of the line scan lens meets 1.034 <fai 浮动 / fai<1.

351.

2. The line scanning lens according to claim 1, characterized in that: The first fixed lens includes a first lens; The floating focusing lens group includes a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged in sequence along the optical axis from the object plane to the image plane; The second fixed lens includes a ninth lens.

3. The line scanning lens according to claim 2, characterized in that: The line scanning lens further includes a diaphragm, and the diaphragm is arranged in the optical path between the fifth lens and the sixth lens; The fourth lens and the fifth lens are adhesively disposed, and the sixth lens and the seventh lens are adhesively disposed.

4. The line scanning lens according to claim 3, characterized in that: The combined focal power of the fourth lens and the fifth lens is fai 45 The combined focal power of the sixth lens and the seventh lens is fai 67 , the focal power of the fourth lens is fai4, the focal power of the fifth lens is fai5, the focal power of the sixth lens is fai6, the focal power of the seventh lens is fai7, the Abbe constant of the fourth lens is vd4, the Abbe constant of the fifth lens is vd5, the Abbe constant of the sixth lens is vd6, and the Abbe constant of the seventh lens is vd7; Among them, -0.905 <fai 45 / fai 67 <-0.837; 0.02 < 1000*(fai4 / vd4 + fai5 / vd5) < 0.322; -1.793 < 1000*(fai6 / vd6 + fai7 / vd7) < -0.

612.

5. The line scanning lens according to claim 2, characterized in that: The combined focal length of the second lens and the third lens is fai 23 , the focal power of the second lens is fai2, the focal power of the third lens is fai3, the Abbe constant of the second lens is vd2, and the Abbe constant of the third lens is vd3; Among them, 0.206 <fai 23 / fai<0.318; 0.035 < 1000*(fai2 / vd2 + fai3 / vd3) < 0.

25.

6. The line scanning lens according to claim 2, characterized in that: The optical power of the eighth lens is fai8, and the refractive index of the eighth lens is nd8; wherein, 1.5 < fai8 / fai < 1.864, and nd8 > 1.

9.

7. The line scanning lens according to claim 2, characterized in that: The moving distance of the floating focusing lens group from the near object distance to the far object distance is Zmove, the focal length of the line scanning lens is f, the clear aperture of the first lens is Dia1, and the total optical length of the line scanning lens is TTL; wherein, 0.111 < Zmove / f < 0.131, and 0.335 < Dia1 / TTL < 0.

45.

8. The line scanning lens according to claim 3, characterized in that: The clear aperture of the diaphragm is adjustable.

9. The line scanning lens according to claim 2, characterized in that: The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens all include glass spherical lenses.

10. The line scanning lens according to claim 1, characterized in that: The line scanning lens further includes a flat glass, and the flat glass is arranged in the optical path between the second fixed lens and the image plane.

Images