Large aperture low distortion fixed focal length line scan lens

Abstract

The present application relates to a kind of big aperture low distortion fixed focus line sweep lens, first lens, second lens, third lens, fourth lens, fifth lens, diaphragm, sixth lens, seventh lens, eighth lens, ninth lens, tenth lens and eleventh lens are sequentially arranged from object side to image side direction and are made of, second lens and third lens, fourth lens and fifth lens, sixth lens and seventh lens, eighth lens and ninth lens respectively form closely double cemented lens, and each other lens is single lens.The present application overcomes the shortcomings of small aperture, long total length and other defects of existing line sweep lens, adopts eleven lenses cooperation, by optimizing the refractive power, shape, air gap, center thickness, radius of curvature of each lens, with the advantages of large aperture, short total length and low distortion.

Description

Technical Field

[0001] This invention relates to a large-aperture, low-distortion fixed-focus line scan lens, which is applied in the field of fixed-focus line scan lens manufacturing. Background Technology

[0002] Traditional imaging systems mostly use area scan cameras, whose sensors are typically rectangular, consisting of a matrix of numerous (usually tens of thousands) photosensitive units. In wide-format applications, using area scan cameras requires stitching together multiple images generated by the photosensitive units of multiple cameras, which is difficult and costly. Line scan cameras, on the other hand, are elongated, with sensors composed of multiple photosensitive elements arranged in a row. They are less expensive than area scan cameras and provide higher-quality inspection services. Therefore, line scan cameras are widely used in various industrial inspection and service sectors, such as textile inspection and QR code and barcode scanning. Existing line scan lenses, such as CN201920918860.1, suffer from drawbacks such as a small aperture (F5.6) and a long overall length (103.3mm). Therefore, providing a large-aperture, low-distortion fixed-focus line scan lens with a large aperture, short overall length, and low distortion has become a pressing need. Summary of the Invention

[0003] To overcome the shortcomings of existing line scan lenses, such as small aperture and long overall length, this invention provides a large aperture, low distortion fixed-focus line scan lens, which uses eleven lenses in combination. By optimizing and limiting the optical power, shape, air gap, center thickness, and radius of curvature of each lens, it has the advantages of large aperture, short overall length, and low distortion.

[0004] The technical solution of the present invention is as follows:

[0005] A large-aperture, low-distortion fixed-focus line-scan lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, an aperture stop, a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens, and an eleventh lens arranged sequentially from the object side to the image side.

[0006] The second and third lenses, the fourth and fifth lenses, the sixth and seventh lenses, the eighth and ninth lenses form closely spaced cemented doublets, and all other lenses are single lenses.

[0007] The first lens is a negative power lens, with a convex first surface and a concave second surface.

[0008] The second lens is a negative power lens, with the first surface being convex and the second surface being concave.

[0009] The third lens is a positive power lens, and the second surface is a convex surface.

[0010] The fourth lens is a negative power lens, with both the first and second surfaces being concave.

[0011] The fifth lens is a positive power lens, and the second surface is a convex surface.

[0012] The sixth lens is a positive power lens, with both the first and second surfaces being convex.

[0013] The seventh lens is a negative power lens, and the second surface is a convex surface.

[0014] The eighth lens is a positive power lens, with both its first and second surfaces being convex.

[0015] The ninth lens is a negative power lens, and the second surface is concave.

[0016] The tenth lens is a negative power lens, with a concave first surface and a convex second surface.

[0017] The eleventh lens is a positive power lens, with a concave first surface and a convex second surface;

[0018] The air gap between the first lens and the second lens is 1.3-3.8 mm.

[0019] The air gap between the third and fourth lenses is 1-1.7mm.

[0020] The air gap between the fifth lens and the aperture stop is 0.1-2.1 mm.

[0021] The air gap between the aperture stop and the sixth lens is 3.3-5.6 mm.

[0022] The air gap between the seventh and eighth lenses is 0.1 mm.

[0023] The air gap between the ninth and tenth lenses is 16.3-17.9 mm.

[0024] The air gap between the tenth and eleventh lenses is 0.1 mm.

[0025] The center thickness of the first lens is 1.471-1.545 mm.

[0026] The center thickness of the second lens is 1.5-1.947 mm.

[0027] The center thickness of the third lens is 5.7-8mm.

[0028] The center thickness of the fourth lens is 1.8-3.3 mm.

[0029] The center thickness of the fifth lens is 4.2-5.1 mm.

[0030] The center thickness of the sixth lens is 2.1-7.3 mm.

[0031] The center thickness of the seventh lens is 1.5-8.5mm.

[0032] The center thickness of the eighth lens is 8.2-8.5 mm.

[0033] The center thickness of the ninth lens is 1.5-2.4 mm.

[0034] The center thickness of the tenth lens is 1.1-3.7 mm.

[0035] The center thickness of the eleventh lens is 9.357 mm;

[0036] The radius of curvature of the first surface of the first lens is 51.1–62.5 mm, and the radius of curvature of the second surface is 16–17.1 mm.

[0037] The radius of curvature of the first surface of the second lens is 23.2–26.3 mm, and the radius of curvature of the second surface is 10.4–11.8 mm. The radius of curvature of the second surface of the third lens is -365.35–-∞ mm.

[0038] The radius of curvature of the first surface of the fourth lens is -31.8 to -35.1 mm, and the radius of curvature of the second surface is 11.5 to 12.1 mm. The radius of curvature of the second surface of the fifth lens is -35 to -35.3 mm. The radius of curvature of the first surface of the sixth lens is 94.2 to 115.5 mm, and the radius of curvature of the second surface is -12.8 to -42.4 mm. The radius of curvature of the second surface of the seventh lens is -17.7 to -19.9 mm.

[0039] The radius of curvature of the first surface of the eighth lens is 21–22.2 mm, and the radius of curvature of the second surface is -21.6–-27.4 mm.

[0040] The radius of curvature of the second surface of the ninth lens is 16.6–18.6 mm.

[0041] The radius of curvature of the first surface of the tenth lens is -13.7 to -15 mm, and the radius of curvature of the second surface is -33.6 to -47.3 mm. The radius of curvature of the first surface of the eleventh lens is -279.7 to -∞ mm, and the radius of curvature of the second surface is -37.2 to -40.8 mm.

[0042] This application's large-aperture, low-distortion fixed-focus line scan lens employs eleven lenses. By optimizing and limiting the optical power, shape, air gap, center thickness, and radius of curvature of each lens, it achieves the advantages of a large aperture, short overall length, and low distortion. This large-aperture, low-distortion fixed-focus line scan lens features a large aperture, large target surface, short overall length, and low distortion; and its characteristics satisfy the following parameters: focal length: 40±10% mm, F-number: 3.8±5% mm (currently, commercially available line scan lenses generally have an F-number of 5.6), total optical length: <86.3 mm, FOV: 70°, image height: 0~60±6 mm.

[0043] The first lens has a half-diameter of 11.9-12.9 mm on its first surface and a half-diameter of 10.365-10.676 mm on its second surface.

[0044] The semi-diameter of the first surface of the second lens is 10.1-10.4 mm, and the semi-diameter of the second surface is 8.6-9.1 mm.

[0045] The semi-diameter of the second surface of the third lens is 8-8.5 mm.

[0046] The fourth lens has a half-diameter of 7.5-8.4 mm on its first surface and a half-diameter of 6.8-7.8 mm on its second surface.

[0047] The half-diameter of the second surface of the fifth lens is 6.6-7.7 mm.

[0048] The sixth lens has a half-diameter of 8.2-9.6 mm on its first surface and a half-diameter of 8.5-10.2 mm on its second surface.

[0049] The semi-diameter of the second surface of the seventh lens is 10.1-11.1 mm.

[0050] The eighth lens has a half-diameter of 10.7-11.9 mm on its first surface and a half-diameter of 11.427-11.770 mm on its second surface.

[0051] The semi-diameter of the second surface of the ninth lens is 9.6-10.5 mm.

[0052] The tenth lens has a half-diameter of 12.6-13.2 mm on its first surface and a half-diameter of 16.5-20 mm on its second surface.

[0053] The half-diameter of the first surface of the eleventh lens is 22.5-25.6 mm, and the half-diameter of the second surface is 23.4-26.2 mm.

[0054] The optimized semi-diameter of each lens surface can better match the size of existing chips on the market, and does not block light for imaging.

[0055] The glass material of the first lens has the following properties: 1.667 ≤ n ≤ 1.671, 47.2 ≤ Vd ≤ 48.4.

[0056] The glass material of the second lens has the following properties: 1.923 ≤ n ≤ 1.95, 17.9 ≤ Vd ≤ 18.9.

[0057] The glass material of the third lens has the following properties: 1.755≤n≤1.77, 26.6≤Vd≤29.7.

[0058] The glass material of the fourth lens: 2.0≤n≤2.003, 25.5≤Vd≤29.1.

[0059] The glass material of the fifth lens: 1.921≤n≤1.946, 18≤Vd≤24.0.

[0060] The glass material of the sixth lens: 1.593≤n≤1.603, 60.5≤Vd≤68.6.

[0061] The glass material of the seventh lens: 1.613≤n≤1.62, 53.9≤Vd≤60.4.

[0062] The glass material of the eighth lens: 1.593≤n≤1.603, 60.5≤Vd≤68.6.

[0063] The glass material of the ninth lens: 1.70≤n≤1.728, 28.3≤Vd≤30.0,

[0064] The glass material of the tenth lens: 1.80≤n≤1.805, 25.5≤Vd≤35.0.

[0065] The glass material of the eleventh lens has the following properties: 1.921 ≤ n ≤ 1.946, 18.0 ≤ Vd ≤ 24.0.

[0066] Where n is the refractive index and Vd is the Abbe coefficient.

[0067] Lenses with superior materials, refractive indices, and Abbe coefficients exhibit better light transmittance, refractive effect, and hardness.

[0068] The large-aperture, low-distortion fixed-focus linear scanning lens is positioned in front of the detector, and a protective glass, which is a planar lens, is provided between the detector and the large-aperture, low-distortion fixed-focus linear scanning lens.

[0069] The protective glass protects the detector.

[0070] The protective glass is made of glass material, n = 1.52, Vd = 64.2; where n is the refractive index and Vd is the Abbe coefficient.

[0071] Protective glass with superior materials, refractive index, and Abbe coefficient has excellent mechanical properties and very low levels of bubbles and impurities, as well as good scratch resistance and chemical stability.

[0072] Compared with the prior art, this invention application has the following advantages:

[0073] 1) The large aperture, low distortion fixed focal length linear scanning lens of this application uses eleven lenses in combination. By optimizing and limiting the optical power, shape, air gap, center thickness and radius of curvature of each lens, it has the advantages of large aperture, short total length and low distortion.

[0074] 2) The protective glass protects the detector. Attached Figure Description

[0075] Figure 1 This is a structural diagram of the optical system of the large aperture, low distortion, fixed focal length linear scanning lens described in this invention;

[0076] Figure 2 This is the MTF diagram of Embodiment 1 of the large aperture, low distortion fixed focal length linear scanning lens described in this invention;

[0077] Figure 3 This is a dot diagram of Embodiment 1 of the large aperture, low distortion fixed-focus linear scanning lens of the present invention;

[0078] Figure 4 This is the field curvature / distortion diagram of Embodiment 1 of the large aperture low distortion fixed focal length line scan lens of the present invention;

[0079] Figure 5 This is the illumination diagram of Embodiment 1 of the large aperture, low distortion, fixed focal length linear scanning lens of the present invention;

[0080] Figure 6 This is the MTF diagram of Embodiment 2 of the large aperture, low distortion fixed focal length linear scanning lens described in this invention;

[0081] Figure 7 This is a dot diagram of Embodiment 2 of the large aperture, low distortion fixed focal length linear scanning lens described in this invention;

[0082] Figure 8 This is the field curvature / distortion diagram of Embodiment 2 of the large aperture low distortion fixed focal length line scan lens of the present invention;

[0083] Figure 9 This is the illumination diagram of Embodiment 2 of the large aperture, low distortion fixed-focus linear scanning lens of the present invention;

[0084] Figure 10 This is the MTF diagram of embodiment 3 of the large aperture, low distortion fixed focal length linear scanning lens described in this invention;

[0085] Figure 11This is a dot diagram of embodiment 3 of the large aperture, low distortion fixed focal length linear scanning lens described in this invention;

[0086] Figure 12 This is the field curvature / distortion diagram of Embodiment 3 of the large aperture low distortion fixed focal length line scan lens of the present invention;

[0087] Figure 13 This is the illumination diagram of Embodiment 3 of the large aperture, low distortion, fixed focal length linear scanning lens described in this invention;

[0088] Figure 14 This is the MTF diagram of embodiment 4 of the large aperture, low distortion fixed focal length linear scanning lens described in this invention;

[0089] Figure 15 This is a dot diagram of embodiment 4 of the large aperture, low distortion fixed focal length linear scanning lens described in this invention;

[0090] Figure 16 This is the field curvature / distortion diagram of Embodiment 4 of the large aperture low distortion fixed focal length line scan lens of the present invention;

[0091] Figure 17 This is the illumination diagram of embodiment 4 of the large aperture, low distortion, fixed focal length linear scanning lens described in this invention;

[0092] Figure 18 This is the MTF diagram of embodiment 5 of the large aperture, low distortion fixed focal length linear scanning lens described in this invention;

[0093] Figure 19 This is a dot diagram of embodiment 5 of the large aperture, low distortion fixed focal length linear scanning lens described in this invention;

[0094] Figure 20 This is the field curvature / distortion diagram of Embodiment 5 of the large aperture low distortion fixed focal length line scan lens of the present invention;

[0095] Figure 21 This is the illumination diagram of embodiment 5 of the large aperture, low distortion fixed-focus linear scan lens described in this invention.

[0096] Label Explanation:

[0097] 1. First lens, 2. Second lens, 3. Third lens, 4. Fourth lens, 5. Fifth lens, 6. Sixth lens, 7. Seventh lens, 8. Eighth lens, 9. Ninth lens, 10. Tenth lens, 11. Eleventh lens, 12. Protective glass, 13. Aperture, 14. Detector. Detailed Implementation

[0098] The following is in conjunction with the instruction manual appendix. Figure 1-21 The technical solution of the present invention will be described in detail below.

[0099] Example 1

[0100] like Figure 1-5 As shown, the large-aperture, low-distortion fixed-focus linear scanning lens of the present invention comprises a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, an aperture stop 13, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10, and an eleventh lens 11 arranged sequentially from the object side to the image side.

[0101] The second lens 2 and the third lens 3, the fourth lens 4 and the fifth lens 5, the sixth lens 6 and the seventh lens 7, the eighth lens 8 and the ninth lens 9 respectively form a closely spaced cemented doublet lens, and all other lenses are single lenses.

[0102] The first lens 1 is a negative power lens, with a convex first surface and a concave second surface.

[0103] The second lens 2 is a negative power lens, with a convex first surface and a concave second surface.

[0104] The third lens 3 is a positive power lens, and the second surface is a convex surface.

[0105] The fourth lens 4 is a negative power lens, with both its first and second surfaces being concave.

[0106] The fifth lens 5 is a positive power lens, and the second surface is a convex surface.

[0107] The sixth lens, 6, is a positive power lens; its first surface is convex, and its second surface is also convex.

[0108] The seventh lens 7 is a negative power lens, and the second surface is a convex surface.

[0109] The eighth lens 8 is a positive power lens, with both its first and second surfaces being convex.

[0110] The ninth lens 9 is a negative power lens, and its second surface is concave.

[0111] The tenth lens 10 is a negative power lens, with a concave first surface and a convex second surface.

[0112] The eleventh lens 11 is a positive power lens, with a concave first surface and a convex second surface;

[0113] The air gap between the first lens 1 and the second lens 2 is 1.760 mm.

[0114] The air gap between the third lens 3 and the fourth lens 4 is 1.617 mm.

[0115] The air gap between the fifth lens 5 and the aperture stop 13 is 0.1 mm.

[0116] The air gap between aperture 13 and the sixth lens 6 is 5.6 mm.

[0117] The air gap between the seventh lens 7 and the eighth lens 8 is 0.1 mm.

[0118] The air gap between the ninth lens 9 and the tenth lens 10 is 17.821 mm.

[0119] The air gap between the tenth lens 10 and the eleventh lens 11 is 0.1 mm;

[0120] The air gap between the eleventh lens 11 and the protective glass 12 is 8.463 mm.

[0121] The air gap between the protective glass 12 and the detector is 0.838 mm.

[0122] The center thickness of the first lens 1 is 1.5mm.

[0123] The center thickness of the second lens 2 is 1.5mm.

[0124] The center thickness of the third lens 3 is 7.908 mm.

[0125] The center thickness of the fourth lens 4 is 3.3 mm.

[0126] The center thickness of the fifth lens 5 is 4.366 mm.

[0127] The center thickness of the sixth lens 6 is 7.215 mm.

[0128] The center thickness of the seventh lens 7 is 1.5mm.

[0129] The center thickness of the eighth lens 8 is 8.257 mm.

[0130] The center thickness of the ninth lens 9 is 1.5mm.

[0131] The center thickness of the tenth lens 10 is 1.5mm.

[0132] The center thickness of the eleventh lens 11 is 9.357 mm;

[0133] The thickness of the protective glass 12 is 2mm;

[0134] The glass material of the first lens 1: n = 1.67, Vd = 47.2.

[0135] The glass material of the second lens 2: n = 1.946, Vd = 17.9.

[0136] The glass material of the third lens 3: n = 1.762, Vd = 26.6.

[0137] The glass material of the fourth lens 4: n = 2.0, Vd = 25.5.

[0138] The glass material of the fifth lens 5: n = 1.923, Vd = 20.9.

[0139] The glass material of the sixth lens 6: n = 1.593, Vd = 68.6.

[0140] The glass material of the seventh lens 7: n = 1.617, Vd = 53.9.

[0141] The glass material of the eighth lens (8) has the following properties: n = 1.593, Vd = 68.6.

[0142] The glass material of the ninth lens 9: n = 1.717, Vd = 29.5.

[0143] The glass material of the tenth lens 10: n = 1.801, Vd = 35.0.

[0144] The glass material of the eleventh lens 11: n = 1.923, Vd = 20.9;

[0145] Where n is the refractive index and Vd is the Abbe coefficient.

[0146] Table 1 Optical structure parameters of Example 1

[0147]

[0148]

[0149] The large aperture, low distortion fixed-focus linear scanning lens is located in front of the detector 14. A protective glass 12, which is a planar lens, is provided between the detector 14 and the large aperture, low distortion fixed-focus linear scanning lens.

[0150] The protective glass 12 is made of glass material, n = 1.52, Vd = 64.2; where n is the refractive index and Vd is the Abbe coefficient.

[0151] Example 1: The large-aperture, low-distortion fixed-focus line scan lens meets the following parameters:

[0152] Focal length: 40mm, F number: 3.8, total optical length: 86.3mm, FOV: 70°, image height: 60mm, distortion <0.27%, MTF across the entire field of view meets 80lp / mm>0.3.

[0153] Example 2

[0154] like Figure 1 ,6 As shown in Figure 9, the large-aperture, low-distortion fixed-focus linear scanning lens of the present invention comprises a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, an aperture stop 13, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10, and an eleventh lens 11 arranged sequentially from the object side to the image side.

[0155] The second lens 2 and the third lens 3, the fourth lens 4 and the fifth lens 5, the sixth lens 6 and the seventh lens 7, the eighth lens 8 and the ninth lens 9 respectively form a closely spaced cemented doublet lens, and all other lenses are single lenses.

[0156] The first lens 1 is a negative power lens, with a convex first surface and a concave second surface.

[0157] The second lens 2 is a negative power lens, with a convex first surface and a concave second surface.

[0158] The third lens 3 is a positive power lens, and the second surface is a convex surface.

[0159] The fourth lens 4 is a negative power lens, with both its first and second surfaces being concave.

[0160] The fifth lens 5 is a positive power lens, and the second surface is a convex surface.

[0161] The sixth lens, 6, is a positive power lens; its first surface is convex, and its second surface is also convex.

[0162] The seventh lens 7 is a negative power lens, and the second surface is a convex surface.

[0163] The eighth lens 8 is a positive power lens, with both its first and second surfaces being convex.

[0164] The ninth lens 9 is a negative power lens, and its second surface is concave.

[0165] The tenth lens, 10, is a negative power lens, with a concave first surface and a convex second surface.

[0166] The eleventh lens 11 is a positive power lens, with a concave first surface and a convex second surface; the air gap between the first lens 1 and the second lens 2 is 3.769 mm.

[0167] The air gap between the third lens 3 and the fourth lens 4 is 1.303 mm.

[0168] The air gap between the fifth lens 5 and the aperture stop 13 is 2.068 mm.

[0169] The air gap between aperture 13 and the sixth lens 6 is 3.946 mm.

[0170] The air gap between the seventh lens 7 and the eighth lens 8 is 0.1 mm.

[0171] The air gap between the ninth lens 9 and the tenth lens 10 is 16.36 mm.

[0172] The air gap between the tenth lens 10 and the eleventh lens 11 is 0.1 mm;

[0173] The air gap between the eleventh lens 11 and the protective glass 12 is 7.250 mm.

[0174] The air gap between the protective glass 12 and the detector is 0.185 mm.

[0175] The center thickness of the first lens 1 is 1.5mm.

[0176] The center thickness of the second lens 2 is 1.947 mm.

[0177] The center thickness of the third lens 3 is 5.719 mm.

[0178] The center thickness of the fourth lens 4 is 1.801 mm.

[0179] The center thickness of the fifth lens 5 is 5.047 mm.

[0180] The center thickness of the sixth lens 6 is 3.782 mm.

[0181] The center thickness of the seventh lens 7 is 3.707 mm.

[0182] The center thickness of the eighth lens 8 is 8.477 mm.

[0183] The center thickness of the ninth lens 9 is 2.392 mm.

[0184] The center thickness of the tenth lens 10 is 1.137 mm.

[0185] The center thickness of the eleventh lens 11 is 9.357 mm;

[0186] The thickness of the protective glass 12 is 2mm;

[0187] The glass material of the first lens 1: n = 1.671, Vd = 47.3.

[0188] The glass material of the second lens 2: n = 1.923, Vd = 18.9.

[0189] The glass material of the third lens 3: n = 1.755, Vd = 27.5.

[0190] The glass material of the fourth lens 4: n = 2.001, Vd = 29.1.

[0191] The glass material of the fifth lens 5: n = 1.921, Vd = 24.0.

[0192] The glass material of the sixth lens 6: n = 1.603, Vd = 65.5.

[0193] The glass material of the seventh lens 7: n = 1.613, Vd = 60.4.

[0194] The glass material of the eighth lens (8) is: n = 1.603, Vd = 65.5.

[0195] The glass material of the ninth lens 9: n = 1.728, Vd = 28.3.

[0196] The glass material of the tenth lens 10: n = 1.80, Vd = 29.8.

[0197] The glass material of the eleventh lens (11) is: n = 1.921, Vd = 24.0.

[0198] Where n is the refractive index and Vd is the Abbe coefficient.

[0199] Table 2 Optical structure parameters of Example 2

[0200]

[0201] The large aperture, low distortion fixed-focus linear scanning lens is located in front of the detector 14. A protective glass 12, which is a planar lens, is provided between the detector 14 and the large aperture, low distortion fixed-focus linear scanning lens.

[0202] The protective glass 12 is made of glass material, n = 1.52, Vd = 64.2; where n is the refractive index and Vd is the Abbe coefficient.

[0203] Example 2: The large-aperture, low-distortion fixed-focus line scan lens meets the following parameters:

[0204] Focal length: 37.38mm, F number: 3.8, total optical length: 81.95mm, FOV: 70°, image height: 56mm, distortion <0.6%, MTF across the entire field of view meets 80lp / mm>0.3.

[0205] Example 3

[0206] like Figure 1 , 10As shown in Figure 13, the large-aperture, low-distortion fixed-focus linear scanning lens of the present invention comprises a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, an aperture stop 13, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10, and an eleventh lens 11 arranged sequentially from the object side to the image side.

[0207] The second lens 2 and the third lens 3, the fourth lens 4 and the fifth lens 5, the sixth lens 6 and the seventh lens 7, the eighth lens 8 and the ninth lens 9 respectively form a closely spaced cemented doublet lens, and all other lenses are single lenses.

[0208] The first lens 1 is a negative power lens, with a convex first surface and a concave second surface.

[0209] The second lens 2 is a negative power lens, with a convex first surface and a concave second surface.

[0210] The third lens 3 is a positive power lens, and the second surface is a convex surface.

[0211] The fourth lens 4 is a negative power lens, with both its first and second surfaces being concave.

[0212] The fifth lens 5 is a positive power lens, and the second surface is a convex surface.

[0213] The sixth lens, 6, is a positive power lens; its first surface is convex, and its second surface is also convex.

[0214] The seventh lens 7 is a negative power lens, and the second surface is a convex surface.

[0215] The eighth lens 8 is a positive power lens, with both its first and second surfaces being convex.

[0216] The ninth lens 9 is a negative power lens, and its second surface is concave.

[0217] The tenth lens 10 is a negative power lens, with a concave first surface and a convex second surface.

[0218] The eleventh lens 11 is a positive power lens, with a concave first surface and a convex second surface;

[0219] The air gap between the first lens 1 and the second lens 2 is 1.330 mm.

[0220] The air gap between the third lens 3 and the fourth lens 4 is 1.040 mm.

[0221] The air gap between the fifth lens 5 and the aperture stop 13 is 2.087 mm.

[0222] The air gap between aperture 13 and the sixth lens 6 is 3.371 mm.

[0223] The air gap between the seventh lens 7 and the eighth lens 8 is 0.1 mm.

[0224] The air gap between the ninth lens 9 and the tenth lens 10 is 17.231 mm.

[0225] The air gap between the tenth lens 10 and the eleventh lens 11 is 0.1 mm;

[0226] The air gap between the eleventh lens 11 and the protective glass 12 is 8.857 mm.

[0227] The air gap between the protective glass 12 and the detector is 1.245 mm.

[0228] The center thickness of the first lens 1 is 1.471 mm.

[0229] The center thickness of the second lens 2 is 1.5mm.

[0230] The center thickness of the third lens 3 is 5.951 mm.

[0231] The center thickness of the fourth lens 4 is 2.276 mm.

[0232] The center thickness of the fifth lens 5 is 4.263 mm.

[0233] The center thickness of the sixth lens 6 is 2.177 mm.

[0234] The center thickness of the seventh lens 7 is 8.472 mm.

[0235] The center thickness of the eighth lens 8 is 8.274 mm.

[0236] The center thickness of the ninth lens 9 is 1.566 mm.

[0237] The center thickness of the tenth lens 10 is 3.691 mm.

[0238] The center thickness of the eleventh lens 11 is 9.357 mm;

[0239] The thickness of the protective glass 12 is 2mm;

[0240] The glass material of the first lens 1: n = 1.667, Vd = 48.4.

[0241] The glass material of the second lens 2: n = 1.95, Vd = 18.0.

[0242] The glass material of the third lens 3: n = 1.77, Vd = 29.7.

[0243] The glass material of the fourth lens 4: n = 2.003, Vd = 28.3.

[0244] The glass material of the fifth lens 5: n = 1.946, Vd = 18.0.

[0245] The glass material of the sixth lens 6: n = 1.594, Vd = 60.5.

[0246] The glass material of the seventh lens 7: n = 1.62, Vd = 60.3.

[0247] The glass material of the eighth lens (8) is: n = 1.594, Vd = 60.5.

[0248] The glass material of the ninth lens 9: n = 1.70, Vd = 30.0.

[0249] The glass material of the tenth lens 10: n = 1.805, Vd = 25.5.

[0250] The glass material of the eleventh lens (11) is: n = 1.946, Vd = 18.0.

[0251] Where n is the refractive index and Vd is the Abbe coefficient.

[0252] Table 3 Optical structure parameters of Example 3

[0253]

[0254]

[0255] The large aperture, low distortion fixed-focus linear scanning lens is located in front of the detector 14. A protective glass 12, which is a planar lens, is provided between the detector 14 and the large aperture, low distortion fixed-focus linear scanning lens.

[0256] The protective glass 12 is made of glass material, n = 1.52, Vd = 64.2; where n is the refractive index and Vd is the Abbe coefficient.

[0257] Example 3: The large-aperture, low-distortion fixed-focus line scan lens meets the following parameters:

[0258] Focal length: 44mm, F number: 3.8, total optical length: 86.3mm, FOV: 70°, image height: 66mm, distortion <-0.5%, MTF across the entire field of view meets 80lp / mm>0.35.

[0259] Example 4

[0260] like Figure 1 ,14 As shown in Figure 17, the large-aperture, low-distortion fixed-focus linear scanning lens of the present invention comprises a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, an aperture stop 13, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10, and an eleventh lens 11 arranged sequentially from the object side to the image side.

[0261] The second lens 2 and the third lens 3, the fourth lens 4 and the fifth lens 5, the sixth lens 6 and the seventh lens 7, the eighth lens 8 and the ninth lens 9 respectively form a closely spaced cemented doublet lens, and all other lenses are single lenses.

[0262] The first lens 1 is a negative power lens, with a convex first surface and a concave second surface.

[0263] The second lens 2 is a negative power lens, with a convex first surface and a concave second surface.

[0264] The third lens 3 is a positive power lens, and the second surface is a convex surface.

[0265] The fourth lens 4 is a negative power lens, with both its first and second surfaces being concave.

[0266] The fifth lens 5 is a positive power lens, and the second surface is a convex surface.

[0267] The sixth lens, 6, is a positive power lens; its first surface is convex, and its second surface is also convex.

[0268] The seventh lens 7 is a negative power lens, and the second surface is a convex surface.

[0269] The eighth lens 8 is a positive power lens, with both its first and second surfaces being convex.

[0270] The ninth lens 9 is a negative power lens, and its second surface is concave.

[0271] The tenth lens 10 is a negative power lens, with a concave first surface and a convex second surface.

[0272] The eleventh lens 11 is a positive power lens, with a concave first surface and a convex second surface;

[0273] The air gap between the first lens 1 and the second lens 2 is 1.810 mm.

[0274] The air gap between the third lens 3 and the fourth lens 4 is 1.663 mm.

[0275] The air gap between the fifth lens 5 and the aperture stop 13 is 0.103 mm.

[0276] The air gap between aperture 13 and the sixth lens 6 is 5.759 mm.

[0277] The air gap between the seventh lens 7 and the eighth lens 8 is 0.103 mm.

[0278] The air gap between the ninth lens 9 and the tenth lens 10 is 18.328 mm.

[0279] The air gap between the tenth lens 10 and the eleventh lens 11 is 0.103 mm;

[0280] The air gap between the eleventh lens 11 and the protective glass 12 is 8.703 mm.

[0281] The air gap between the protective glass 12 and the detector is 0.862 mm.

[0282] The center thickness of the first lens 1 is 1.543 mm.

[0283] The center thickness of the second lens 2 is 1.543 mm.

[0284] The center thickness of the third lens 3 is 8.133 mm.

[0285] The center thickness of the fourth lens 4 is 3.393 mm.

[0286] The center thickness of the fifth lens 5 is 4.490 mm.

[0287] The center thickness of the sixth lens 6 is 7.420 mm.

[0288] The center thickness of the seventh lens 7 is 1.543 mm.

[0289] The center thickness of the eighth lens 8 is 8.491 mm.

[0290] The center thickness of the ninth lens 9 is 1.543 mm.

[0291] The center thickness of the tenth lens 10 is 1.543 mm.

[0292] The center thickness of the eleventh lens 11 is 9.622 mm;

[0293] The thickness of the protective glass 12 is 2mm;

[0294] The glass material of the first lens 1: n = 1.67, Vd = 47.2.

[0295] The glass material of the second lens 2: n = 1.946, Vd = 17.9.

[0296] The glass material of the third lens 3: n = 1.762, Vd = 26.6.

[0297] The glass material of the fourth lens 4: n = 2.0, Vd = 25.5.

[0298] The glass material of the fifth lens 5: n = 1.923, Vd = 20.9.

[0299] The glass material of the sixth lens 6: n = 1.593, Vd = 68.6.

[0300] The glass material of the seventh lens 7: n = 1.617, Vd = 53.9.

[0301] The glass material of the eighth lens (8) has the following properties: n = 1.593, Vd = 68.6.

[0302] The glass material of the ninth lens 9: n = 1.717, Vd = 29.5.

[0303] The glass material of the tenth lens 10: n = 1.801, Vd = 35.0.

[0304] The glass material of the eleventh lens (11) is: n = 1.923, Vd = 20.9.

[0305] Where n is the refractive index and Vd is the Abbe coefficient.

[0306] Table 4 Optical structure parameters of Example 4

[0307]

[0308] The large aperture, low distortion fixed-focus linear scanning lens is located in front of the detector 14. A protective glass 12, which is a planar lens, is provided between the detector 14 and the large aperture, low distortion fixed-focus linear scanning lens.

[0309] The protective glass 12 is made of glass material, n = 1.52, Vd = 64.2; where n is the refractive index and Vd is the Abbe coefficient.

[0310] Example 4: The large-aperture, low-distortion fixed-focus line-scan lens meets the following parameters:

[0311] Focal length: 41.138mm, F number: 4.09, total optical length: 88.752mm, FOV: 70.112°, image height: 30.85mm, distortion <-0.5%, MTF across the entire field of view meets 80lp / mm>0.3.

[0312] Example 5

[0313] like Figure 1 , 18As shown in Figure 21, the large-aperture, low-distortion fixed-focus linear scanning lens of the present invention comprises a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5, an aperture stop 13, a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10, and an eleventh lens 11 arranged sequentially from the object side to the image side.

[0314] The second lens 2 and the third lens 3, the fourth lens 4 and the fifth lens 5, the sixth lens 6 and the seventh lens 7, the eighth lens 8 and the ninth lens 9 respectively form a closely spaced cemented doublet lens, and all other lenses are single lenses.

[0315] The first lens 1 is a negative power lens, with a convex first surface and a concave second surface.

[0316] The second lens 2 is a negative power lens, with a convex first surface and a concave second surface.

[0317] The third lens 3 is a positive power lens, and the second surface is a convex surface.

[0318] The fourth lens 4 is a negative power lens, with both its first and second surfaces being concave.

[0319] The fifth lens 5 is a positive power lens, and the second surface is a convex surface.

[0320] The sixth lens, 6, is a positive power lens; its first surface is convex, and its second surface is also convex.

[0321] The seventh lens 7 is a negative power lens, and the second surface is a convex surface.

[0322] The eighth lens 8 is a positive power lens, with both its first and second surfaces being convex.

[0323] The ninth lens 9 is a negative power lens, and its second surface is concave.

[0324] The tenth lens 10 is a negative power lens, with a concave first surface and a convex second surface.

[0325] The eleventh lens 11 is a positive power lens, with a concave first surface and a convex second surface;

[0326] The air gap between the first lens 1 and the second lens 2 is 1.813 mm.

[0327] The air gap between the third lens 3 and the fourth lens 4 is 1.665 mm.

[0328] The air gap between the fifth lens 5 and the aperture stop 13 is 0.103 mm.

[0329] The air gap between aperture 13 and the sixth lens 6 is 5.768 mm.

[0330] The air gap between the seventh lens 7 and the eighth lens 8 is 0.103 mm.

[0331] The air gap between the ninth lens 9 and the tenth lens 10 is 18.356 mm.

[0332] The air gap between the tenth lens 10 and the eleventh lens 11 is 0.103 mm;

[0333] The air gap between the eleventh lens 11 and the protective glass 12 is 8.716 mm.

[0334] The air gap between the protective glass 12 and the detector is 0.863 mm.

[0335] The center thickness of the first lens 1 is 1.545 mm.

[0336] The center thickness of the second lens 2 is 1.545 mm.

[0337] The center thickness of the third lens 3 is 8.145 mm.

[0338] The center thickness of the fourth lens 4 is 3.399 mm.

[0339] The center thickness of the fifth lens 5 is 4.497 mm.

[0340] The center thickness of the sixth lens 6 is 7.432 mm.

[0341] The center thickness of the seventh lens 7 is 1.545 mm.

[0342] The center thickness of the eighth lens 8 is 8.505 mm.

[0343] The center thickness of the ninth lens 9 is 1.545 mm.

[0344] The center thickness of the tenth lens 10 is 1.545 mm.

[0345] The center thickness of the eleventh lens 11 is 9.637 mm;

[0346] The thickness of the protective glass 12 is 2mm;

[0347] The glass material of the first lens 1: n = 1.671, Vd = 47.3.

[0348] The glass material of the second lens 2: n = 1.923, Vd = 18.9.

[0349] The glass material of the third lens 3: n = 1.755, Vd = 27.5.

[0350] The glass material of the fourth lens 4: n = 2.001, Vd = 29.1.

[0351] The glass material of the fifth lens 5: n = 1.921, Vd = 24.0.

[0352] The glass material of the sixth lens 6: n = 1.603, Vd = 65.5.

[0353] The glass material of the seventh lens 7: n = 1.613, Vd = 60.4.

[0354] The glass material of the eighth lens (8) is: n = 1.603, Vd = 65.5.

[0355] The glass material of the ninth lens 9: n = 1.728, Vd = 28.3.

[0356] The glass material of the tenth lens 10: n = 1.80, Vd = 29.8.

[0357] The glass material of the eleventh lens 11 is: n = 1.921, Vd = 24.0, where n is the refractive index and Vd is the Abbe coefficient.

[0358] Table 5 Optical structure parameters of Example 5

[0359]

[0360] The large aperture, low distortion fixed-focus linear scanning lens is located in front of the detector 14. A protective glass 12, which is a planar lens, is provided between the detector 14 and the large aperture, low distortion fixed-focus linear scanning lens.

[0361] The protective glass 12 is made of glass material, n = 1.52, Vd = 64.2; where n is the refractive index and Vd is the Abbe coefficient.

[0362] Example 5: The large-aperture, low-distortion fixed-focus line-scan lens meets the following parameters:

[0363] Focal length: 41.2mm, F number: 4.09, total optical length: 88.89mm, FOV: 70.112°, image height: 30.9mm, distortion <-0.5%, MTF across the entire field of view meets 80lp / mm>0.3.

[0364] The large-aperture, low-distortion fixed-focus line scan lens described in this invention is not limited to the above embodiments. Any improvements or substitutions based on the principles of this invention should be within the protection scope of this invention.

Claims

1. A large-aperture, low-distortion fixed-focus linear scanning lens, characterized in that it comprises a first lens (1), a second lens (2), a third lens (3), a fourth lens (4), a fifth lens (5), an aperture stop (13), a sixth lens (6), a seventh lens (7), an eighth lens (8), a ninth lens (9), a tenth lens (10), and an eleventh lens (11) arranged sequentially from the object side to the image side. The second lens (2) and the third lens (3), the fourth lens (4) and the fifth lens (5), the sixth lens (6) and the seventh lens (7), the eighth lens (8) and the ninth lens (9) respectively form closely spaced cemented doublets, and all other lenses are single lenses; The first lens (1) is a negative power lens, with a convex first surface and a concave second surface. The second lens (2) is a negative power lens, with a convex first surface and a concave second surface. The third lens (3) is a positive power lens, and the second surface is a convex surface. The fourth lens (4) is a negative power lens, with the first surface being concave and the second surface being concave. The fifth lens (5) is a positive power lens, and the second surface is a convex surface. The sixth lens (6) is a positive power lens, with both the first and second surfaces being convex. The seventh lens (7) is a negative power lens, and the second surface is a convex surface. The eighth lens (8) is a positive power lens, with both its first and second surfaces being convex. The ninth lens (9) is a negative power lens, and the second surface is concave. The tenth lens (10) is a negative power lens, with a concave first surface and a convex second surface. The eleventh lens (11) is a positive power lens, with the first surface being concave and the second surface being convex. The air gap between the first lens (1) and the second lens (2) is 1.330-3.769 mm. The air gap between the third lens (3) and the fourth lens (4) is 1.040-1.617 mm. The air gap between the fifth lens (5) and the aperture stop (13) is 0.1-2.087 mm. The air gap between the aperture stop (13) and the sixth lens (6) is 3.371-5.6 mm. The air gap between the seventh lens (7) and the eighth lens (8) is 0.1 mm. The air gap between the ninth lens (9) and the tenth lens (10) is 16.36-17.821 mm. The air gap between the tenth lens (10) and the eleventh lens (11) is 0.1 mm; The center thickness of the first lens (1) is: 1.471-1.545mm, The center thickness of the second lens (2) is: 1.5-1.947mm, The center thickness of the third lens (3) is: 5.719-7.908mm, The center thickness of the fourth lens (4) is 1.801-3.3 mm. The center thickness of the fifth lens (5) is: 4.263-5.047mm, The center thickness of the sixth lens (6) is 2.177-7.215 mm. The center thickness of the seventh lens (7) is 1.5-8.472 mm. The center thickness of the eighth lens (8) is: 8.257-8.477mm, The center thickness of the ninth lens (9) is 1.5-2.392 mm. The center thickness of the tenth lens (10) is 1.137-3.691 mm. The center thickness of the eleventh lens (11) is 9.357 mm; The radius of curvature of the first surface of the first lens (1) is 51.155~62.413 mm, and the radius of curvature of the second surface is 16.093~17.072 mm. The radius of curvature of the first surface of the second lens (2) is 23.287~26.235mm, and the radius of curvature of the second surface is 10.451~11.719mm. The radius of curvature of the second surface of the third lens (3) is -365.735~ -2306.199 mm. The radius of curvature of the first surface of the fourth lens (4) is -31.826~-35.083mm, and the radius of curvature of the second surface is 11.503~12.074mm. The radius of curvature of the second surface of the fifth lens (5) is -35.083~-35.224 mm. The radius of curvature of the first surface of the sixth lens (6) is 94.240~115.450 mm, and the radius of curvature of the second surface is -12.873~ -42.354 mm. The radius of curvature of the second surface of the seventh lens (7) is -19.370~-19.883mm. The radius of curvature of the first surface of the eighth lens (8) is 21.052~22.189 mm, and the radius of curvature of the second surface is -21.659~-27.326 mm. The radius of curvature of the second surface of the ninth lens (9) is 16.689~18.578 mm. The radius of curvature of the first surface of the tenth lens (10) is -13.757 to -14.945 mm, and the radius of curvature of the second surface is -33.642 to -47.213 mm. The radius of curvature of the first surface of the eleventh lens (11) is -279.771~ -584.052mm, and the radius of curvature of the second surface is -37.258~ -40.774mm. The aperture of this large-aperture, low-distortion fixed-focus linear scan lens is 3.8 ± 5% mm.

2. The large-aperture, low-distortion fixed-focus linear scanning lens according to claim 1, characterized in that: The first lens (1) has a half-diameter of 11.909-12.867 mm on its first surface and a half-diameter of 10.365-10.676 mm on its second surface. The second lens (2) has a half-diameter of 10.127-10.337 mm on its first surface and a half-diameter of 8.636-9.055 mm on its second surface. The semi-diameter of the second surface of the third lens (3) is 8.074-8.487 mm. The fourth lens (4) has a half-diameter of 7.576-8.325 mm on its first surface and a half-diameter of 6.835-7.738 mm on its second surface. The half-diameter of the second surface of the fifth lens (5) is 6.660-7.656 mm. The sixth lens (6) has a half-diameter of 8.291-9.595 mm on its first surface and a half-diameter of 8.58-10.127 mm on its second surface. The semi-diameter of the second surface of the seventh lens (7) is 10.168-11.069 mm. The eighth lens (8) has a half-diameter of 10.752-11.813 mm on its first surface and a half-diameter of 11.427-11.770 mm on its second surface. The semi-diameter of the second surface of the ninth lens (9) is 9.665-10.454 mm. The tenth lens (10) has a half-diameter of 12.665-13.196 mm on its first surface and a half-diameter of 16.597-19.908 mm on its second surface. The first surface of the eleventh lens (11) has a half-diameter of 22.563-25.538 mm and the second surface has a half-diameter of 23.431-26.101 mm.

3. The large-aperture, low-distortion fixed-focus linear scanning lens according to claim 1, characterized in that: The glass material of the first lens (1) is: 1.667≤n≤1.671, 47.2≤Vd≤48.

4. The glass material of the second lens (2) is: 1.923≤n≤1.95, 17.9≤Vd≤18.

9. The glass material of the third lens (3) is: 1.755≤n≤1.77, 26.6≤Vd≤29.

7. The glass material of the fourth lens (4) is: 2.0≤n≤2.003, 25.5≤Vd≤29.

1. The glass material of the fifth lens (5) is: 1.921≤n≤1.946, 18≤Vd≤24.

0. The glass material of the sixth lens (6) is: 1.593≤n≤1.603, 60.5≤Vd≤68.

6. The glass material of the seventh lens (7) is: 1.613≤n≤1.62, 53.9≤Vd≤60.

4. The glass material of the eighth lens (8) is: 1.593≤n≤1.603, 60.5≤Vd≤68.

6. The glass material of the ninth lens (9) is: 1.70≤n≤1.728, 28.3≤Vd≤30.

0. The glass material of the tenth lens (10) is: 1.80≤n≤1.805, 25.5≤Vd≤35.

0. The glass material of the eleventh lens (11) is: 1.921≤n≤1.946, 18.0≤Vd≤24.

0. Where n is the refractive index and Vd is the Abbe coefficient.

4. The large-aperture, low-distortion fixed-focus linear scanning lens according to claim 1, characterized in that: The large aperture low distortion fixed focal length linear scanning lens is located in front of the detector (14). A protective glass (12) is provided between the detector (14) and the large aperture low distortion fixed focal length linear scanning lens. The protective glass (12) is a plane lens.

5. The large-aperture, low-distortion fixed-focus linear scanning lens according to claim 4, characterized in that: The protective glass (12) is a glass material with n=1.52 and Vd=64.2; where n is the refractive index and Vd is the Abbe coefficient.

Images