TW202040203A - Four-piece dual waveband optical lens system - Google Patents

Abstract

A four-piece dual waveband optical lens system includes, in order from the object side to the image side: a stop; a first lens element with a positive refractive power having an object-side surface being convex near an optical axis and an image-side surface being convex near the optical axis; a second lens element with a negative refractive power having an object-side surface being concave near the optical axis and an image-side surface being convex near the optical axis; a third lens element with a positive refractive power having an object-side surface being concave near the optical axis and an image-side surface being convex near the optical axis; a fourth lens element with a negative refractive power having an object-side surface being convex near the optical axis and an image-side surface being concave near the optical axis. Such a system has a short length and good performance without re-focusing when used in both visible and infrared wavebands.

Description

Four-piece dual-band imaging lens group

The present invention is related to a four-piece dual-band imaging lens set, in particular to a miniaturized four-piece dual-band imaging lens set applied to electronic products.

With the development of high-standard mobile devices such as smartphones and tablets, high-quality small camera lenses have become standard equipment. With the popularity of the Internet community, more and more people like to take photos or take selfies with others Sharing, such as game consoles, driving recorders, security camera lenses, etc., have an increasing demand for shooting angles, so the requirements for lens shooting angles and image quality are becoming more and more stringent.

In addition, the existing visible light and infrared dual-band zoom systems are mostly composed of two separate systems, which are not only large in size, but also complex in overall structure. In addition, when the external environment changes, such as the target is blocked, camouflaged, interfered by smoke, day and night, and the light path and band are switched, the target needs to be searched again to observe the target, that is, under the dual-band use of visible light and infrared , The focus must be re-adjusted to make the lens better.

The purpose of the present invention is to provide a four-piece dual-band imaging lens set, especially a four-piece dual-band imaging lens set with a short lens length and used in both visible and infrared dual-band without refocusing. One-piece dual-band imaging lens group.

In order to achieve the foregoing objective, a four-piece dual-band imaging lens set according to the present invention includes an aperture and an optical group composed of four lenses, from the object side to the image side, in order: the aperture; The first lens has a positive refractive power. The object side surface of the first lens is convex near the optical axis, the image side surface of the first lens is convex near the optical axis, and the object side surface of the first lens is opposite to the image side. At least one surface of the surface is aspherical; a second lens with negative refractive power, the object side surface of the second lens is concave near the optical axis, and the image side surface of the second lens is convex near the optical axis. At least one of the object side surface and the image side surface of the two lenses is aspherical; a third lens has positive refractive power, the object side surface of the third lens is concave near the optical axis, and the image side surface of the third lens The near optical axis is convex, and at least one of the object side surface and the image side surface of the third lens is aspherical; and a fourth lens has negative refractive power, and the object side surface of the fourth lens is at the near optical axis Convex surface, the image side surface of the fourth lens is concave near the optical axis, and at least one of the object side surface and the image side surface of the fourth lens is aspherical.

Preferably, the focal length of the first lens is f1 and the focal length of the second lens is f2, and the following conditions are satisfied: -0.8 <f1/f2 <-0.4. In this way, the refractive power configuration of the first lens and the second lens is more appropriate, and the excessive increase in system aberration is reduced.

Preferably, the focal length of the second lens is f2 and the focal length of the third lens is f3, and the following conditions are satisfied: -1.6 <f2/f3 <-0.9. In this way, the peripheral resolution and illuminance of the system can be improved.

Preferably, the focal length of the third lens is f3, and the focal length of the fourth lens is f4, and the following conditions are satisfied: -0.8 <f3/f4 <-0.3. In this way, the refractive power configuration of the system can be effectively balanced, and the sensitivity can be reduced to improve the manufacturing yield.

Preferably, the focal length of the first lens is f1 and the focal length of the third lens is f3, and the following conditions are met: 0.6 <f1/f3 <1.0. Thereby, the positive refractive power of the first lens is effectively distributed, and the sensitivity of the four-piece dual-band imaging lens group is reduced.

Preferably, the focal length of the second lens is f2, and the focal length of the fourth lens is f4, and the following conditions are satisfied: 0.3 <f2/f4 <1.2. In this way, the distribution of the positive refractive power of the system is more appropriate, which is beneficial to correct the aberration of the system and improve the imaging quality of the system.

Preferably, the focal length of the first lens is f1, and the combined focal length of the second lens and the third lens is f23, and the following conditions are satisfied: 0.1 <f1/f23 <0.7. In this way, the resolution capability of the four-piece dual-band imaging lens set is improved.

Preferably, the combined focal length of the second lens and the third lens is f23, and the focal length of the fourth lens is f4, and the following conditions are satisfied: -1.6 <f23/f4 <-0.9. This can effectively correct the curvature of the field.

Preferably, the composite focal length of the first lens and the second lens is f12, and the composite focal length of the third lens and the fourth lens is f34, and the following conditions are satisfied: 0.7<f12/f34<1.5. This can effectively correct the curvature of the field.

Preferably, the overall focal length of the four-piece dual-band imaging lens set is f, and the distance from the object side surface of the first lens to the imaging surface on the optical axis is TL, and the following conditions are met: 0.5 <f/TL <0.8. In this way, it is advantageous to maintain the miniaturization of the four-piece dual-band imaging lens set for mounting on thin and light electronic products.

Preferably, the radius of curvature of the object side surface of the first lens is R1, and the radius of curvature of the image side surface of the first lens is R2, and the following conditions are satisfied: -2.1 <R1/R2 <-0.4. In this way, the first lens can have a proper surface shape to reduce astigmatism.

Preferably, the radius of curvature of the object side surface of the third lens is R5, and the radius of curvature of the image side surface of the third lens is R6, and the following conditions are satisfied: 4<R5/R6<14. In this way, sufficient freedom of the peripheral shape of the third lens is provided to correct the off-axis aberration and maintain the relative contrast at the periphery of the imaging surface.

Preferably, the radius of curvature of the object side surface of the fourth lens is R7, and the radius of curvature of the image side surface of the fourth lens is R8, and the following conditions are satisfied: 1.3 <R7/R8 <2.1. In this way, sufficient freedom of the peripheral shape of the fourth lens is provided to correct the off-axis aberration and increase the area of the imaging surface.

Preferably, the thickness of the second lens on the optical axis is CT2, and the thickness of the first lens on the optical axis is CT1, and the following condition is satisfied: 0.3 <CT2/CT1 <0.7. Thereby, the thickness of the first lens and the second lens is not too large or too small, which facilitates the assembly configuration of the lenses.

Regarding the technologies, means and other effects used by the present invention to achieve the above-mentioned objects, seven preferred and feasible embodiments are described in detail in conjunction with the drawings as follows.

<First embodiment>

Please refer to Figures 1A and 1B, where Figure 1A shows a schematic diagram of a four-piece dual-band imaging lens set according to a first embodiment of the present invention, and Figure 1B shows the four-piece dual-band imaging lens set in the first embodiment from left to right. Curve of field curvature and distortion of the band imaging lens group. It can be seen from FIG. 1A that the four-piece dual-band imaging lens group includes an aperture 100 and an optical group. The optical group includes a first lens 110, a second lens 120, and a third lens 130 from the object side to the image side. The fourth lens 140, the infrared filter element 170, and the imaging surface 180, wherein there are four lenses with refractive power in the four-piece dual-band imaging lens group. The aperture 100 is arranged in front of the first lens 110.

The first lens 110 has positive refractive power and is made of plastic. Its object side surface 111 is convex near the optical axis 190, and its image side surface 112 is convex near the optical axis 190, and the object side surface 111 and the image side The surfaces 112 are all aspherical.

The second lens 120 has a negative refractive power and is made of plastic. Its object-side surface 121 is concave near the optical axis 190, and its image-side surface 122 is convex near the optical axis 190, and the object-side surface 121 and the image side are convex. The surfaces 122 are all aspherical.

The third lens 130 has a positive refractive power and is made of plastic. Its object side surface 131 is concave near the optical axis 190, and its image side surface 132 is convex near the optical axis 190, and the object side surface 131 and the image side The surfaces 132 are all aspherical.

The fourth lens 140 has a negative refractive power and is made of plastic. Its object side surface 141 is convex near the optical axis 190, and its image side surface 142 is concave near the optical axis 190. The object side surface 141 and the image side The surface 142 is aspherical, and the object side surface 141 and the image side surface 142 both have at least one inflection point away from the optical axis 190.

The infrared ray filter element 170 is made of glass, which is arranged between the fourth lens 140 and the imaging surface 180 and does not affect the focal length of the four-piece dual-band imaging lens group.

上述各透鏡的非球面的曲線方程式表示如下：

The curve equations of the aspheric surfaces of the above lenses are expressed as follows:

Where z is the position value referenced by the apex of the surface at a height h along the optical axis 190; c is the curvature of the lens surface close to the optical axis 190, and is the reciprocal of the radius of curvature (R) (c=1/R) , R is the radius of curvature of the lens surface close to the optical axis 190, h is the vertical distance from the lens surface to the optical axis 190, k is the conic constant, and A, B, C, D, E, F, ... are Higher-order aspheric coefficients.

In the four-piece dual-band imaging lens group of the first embodiment, the focal length of the four-piece dual-band imaging lens group is f, and the f-number of the four-piece dual-band imaging lens group is Fno. The maximum field of view (angle of view) in the dual-band imaging lens group is FOV, and its values are as follows: f=1.04 (mm); Fno= 2.07; and FOV= 75.69 (degrees).

In the four-piece dual-band imaging lens set of the first embodiment, the focal length of the first lens 110 is f1, and the focal length of the second lens 120 is f2, and the following conditions are satisfied: f1/f2 = -0.620.

In the four-piece dual-band imaging lens set of the first embodiment, the focal length of the second lens 120 is f2, and the focal length of the third lens 130 is f3, and the following conditions are satisfied: f2/f3 = -1.324.

In the four-piece dual-band imaging lens set of the first embodiment, the focal length of the third lens 130 is f3, and the focal length of the fourth lens 140 is f4, and the following conditions are satisfied: f3/f4 = -0.675.

In the four-piece dual-band imaging lens set of the first embodiment, the focal length of the first lens 110 is f1, and the focal length of the third lens 130 is f3, and the following conditions are satisfied: f1/f3=0.822.

In the four-piece dual-band imaging lens set of the first embodiment, the focal length of the second lens 120 is f2, and the focal length of the fourth lens 140 is f4, and the following conditions are satisfied: f2/f4=0.894.

In the four-piece dual-band imaging lens set of the first embodiment, the focal length of the first lens 110 is f1, and the combined focal length of the second lens 120 and the third lens 130 is f23, and the following conditions are met: f1/f23 = 0.458.

In the four-piece dual-band imaging lens set of the first embodiment, the combined focal length of the second lens 120 and the third lens 130 is f23, and the focal length of the fourth lens 140 is f4, and the following conditions are met: f23/f4 = -1.210.

In the four-piece dual-band imaging lens set of the first embodiment, the composite focal length of the first lens 110 and the second lens 120 is f12, and the composite focal length of the third lens 130 and the fourth lens 140 is f34, and meets the following requirements Conditions: f12/f34 = 0.962.

In the four-piece dual-band imaging lens group of the first embodiment, the overall focal length of the four-piece dual-band imaging lens group is f, and the distance between the object side surface 111 of the first lens 110 and the imaging surface 180 on the optical axis 190 The distance is TL and meets the following conditions: f/TL = 0.679.

In the four-piece dual-band imaging lens set of the first embodiment, the radius of curvature of the object side surface 111 of the first lens 110 is R1, and the radius of curvature of the image side surface 112 of the first lens 110 is R2, and the following conditions are met: R1/R2 = -0.857.

In the four-piece dual-band imaging lens set of the first embodiment, the curvature radius of the object side surface 131 of the third lens 130 is R5, and the curvature radius of the image side surface 132 of the third lens 130 is R6, and meets the following conditions: R5/R6 = 11.106.

In the four-piece dual-band imaging lens set of the first embodiment, the radius of curvature of the object side surface 141 of the fourth lens 140 is R7, and the radius of curvature of the image side surface 142 of the fourth lens 140 is R8, and meets the following conditions: R7/R8 = 1.834.

In the four-piece dual-band imaging lens set of the first embodiment, the thickness of the second lens 120 on the optical axis 190 is CT2, and the thickness of the first lens 110 on the optical axis 190 is CT1, and the following conditions are met: CT2/CT1 = 0.545.

Refer to Table 1 and Table 2 below for cooperation.

Table 1 First embodiment f (focal length) = 1.04 mm (mm), Fno (aperture value) = 2.07, FOV (angle of view) = 75.69 deg. (degrees) surface To Radius of curvature thickness Material Refractive index Dispersion coefficient focal length 0 Subject unlimited unlimited To To To To 1 aperture unlimited 0.014 To To To To 2 First lens 0.787 (ASP) 0.294 plastic 1.54 56 0.827 3 To -0.919 (ASP) 0.100 To To To To 4 Second lens -0.307 (ASP) 0.160 plastic 1.64 22.46 -1.333 5 To -0.575 (ASP) 0.020 To To To To 6 Third lens -5.621 (ASP) 0.176 plastic 1.54 56 1.007 7 To -0.506 (ASP) 0.021 To To To To 8 Fourth lens 0.643 (ASP) 0.150 plastic 1.64 22.46 -1.492 9 To 0.351 (ASP) 0.357 To To To To 10 Infrared filter Filter unlimited 0.145 glass 1.52 64.2 To 11 To unlimited 0.100 To To To To 12 Imaging surface unlimited - To To To To

Table 2 Aspheric coefficient flat 2 3 4 5 K: -1.4879E+01 4.0589E+00 -6.2519E-01 -5.1561E-02 A: 2.0739E+00 -4.7131E+00 -4.0068E+00 -4.5455E+00 B: -3.3903E+01 3.6635E+01 1.4180E+02 1.1598E+02 C: 3.7044E+02 -1.0407E+03 -1.6709E+03 -1.2881E+03 D: -9.0872E+03 1.3786E+04 1.6003E+04 8.8162E+03 E: 7.0957E+04 -8.5787E+04 -7.7506E+04 -3.2984E+04 F -3.8602E+05 2.1159E+05 1.9370E+05 5.7657E+04 G 6.0892E+05 -3.2749E+04 -2.1507E+05 1.1620E+04 flat 6 7 8 9 K: 5.3334E+01 -9.0676E+00 -1.1310E+01 -4.8111E+00 A: 2.5962E+00 5.3604E+00 -1.5170E-02 -3.9882E+00 B: -1.6608E+01 -8.0288E+01 -7.5712E+01 1.6202E+01 C: 1.3708E+02 8.3745E+02 8.6550E+02 -4.1440E+01 D: -4.6919E+03 -5.0435E+03 -4.7892E+03 3.2570E+01 E: 5.2351E+04 1.4232E+04 1.3252E+04 7.1844E+01 F -2.6923E+05 -4.2973E+03 -1.2707E+04 -1.3690E+02 G 5.4470E+05 -3.9531E+04 -8.1295E+03 -2.4380E+01

Table 1 shows the detailed structure data of the first embodiment in FIG. 1A, in which the unit of the radius of curvature, the thickness and the focal length are mm, and the surface 0-12 indicates the surface from the object side to the image side in sequence. Table 2 is the aspheric surface data in the first embodiment, where k represents the cone coefficient in the aspheric curve equation, and A, B, C, D, E, F, G... are high-order aspheric surface coefficients. In addition, the following example tables correspond to the schematic diagrams and field curvature and distortion tolerance curves of the respective examples. The definitions of the data in the tables are the same as those in Table 1 and Table 2 of the first embodiment. Add more details.

<Second embodiment>

Please refer to FIGS. 2A and 2B, in which FIG. 2A shows a schematic diagram of a four-piece dual-band imaging lens set according to a second embodiment of the present invention, and FIG. Curve of field curvature and distortion of the band imaging lens group. It can be seen from FIG. 2A that the four-piece dual-band imaging lens group includes an aperture 200 and an optical group, which sequentially includes a first lens 210, a second lens 220, a third lens 230, and an optical group from the object side to the image side. The fourth lens 240, the infrared filter element 270, and the imaging surface 280, wherein the four-piece dual-band imaging lens group has four lenses with refractive power. The aperture 200 is arranged in front of the first lens 210.

The first lens 210 has a positive refractive power and is made of plastic. Its object side surface 211 is convex near the optical axis 290, and its image side surface 212 is convex near the optical axis 290, and the object side surface 211 and the image side are convex. The surfaces 212 are all aspherical.

The second lens 220 has a negative refractive power and is made of plastic material. Its object side surface 221 is concave near the optical axis 290, and its image side surface 222 is convex near the optical axis 290, and the object side surface 221 and the image side The surfaces 222 are all aspherical.

The third lens 230 has a positive refractive power and is made of plastic. Its object side surface 231 is concave near the optical axis 290, and its image side surface 232 is convex near the optical axis 290, and the object side surface 231 and the image side The surfaces 232 are all aspherical.

The fourth lens 240 has a negative refractive power and is made of plastic. Its object side surface 241 is convex near the optical axis 290, and its image side surface 242 is concave near the optical axis 290, and the object side surface 241 and the image side The surface 242 is aspherical, and the object side surface 241 and the image side surface 242 both have at least one inflection point away from the optical axis 290.

The infrared filter element 270 is made of glass, which is arranged between the fourth lens 240 and the imaging surface 280 and does not affect the focal length of the four-piece dual-band imaging lens group.

Refer to Table 3 and Table 4 below for cooperation.

table 3 Second embodiment f (focal length) = 1.18 mm (mm), Fno (aperture value) = 2.07, FOV (angle of view) = 71.44 deg. (degrees) surface To Radius of curvature thickness Material Refractive index Dispersion coefficient focal length 0 Subject unlimited unlimited To To To To 1 aperture unlimited -0.006 To To To To 2 First lens 1.008 (ASP) 0.305 plastic 1.54 56 0.932 3 To -0.916 (ASP) 0.121 To To To To 4 Second lens -0.345 (ASP) 0.155 plastic 1.64 22.46 -1.580 5 To -0.614 (ASP) 0.030 To To To To 6 Third lens -3.996 (ASP) 0.199 plastic 1.54 56 1.087 7 To -0.526 (ASP) 0.028 To To To To 8 Fourth lens 0.720 (ASP) 0.155 plastic 1.64 22.46 -1.477 9 To 0.376 (ASP) 0.362 To To To To 10 Infrared filter Filter unlimited 0.210 glass 1.52 64.2 To 11 To unlimited 0.127 To To To To 12 Imaging surface unlimited - To To To To

Table 4 Aspheric coefficient flat 2 3 4 5 K: -2.1027E+01 2.7762E+00 -6.2733E-01 1.3085E-01 A: 1.2981E+00 -3.2661E+00 -3.2723E+00 -4.1811E+00 B: -2.8632E+01 3.1504E+01 1.0508E+02 8.9194E+01 C: 2.7393E+02 -7.4745E+02 -1.2242E+03 -9.0750E+02 D: -5.2229E+03 8.5224E+03 9.8226E+03 5.5397E+03 E: 4.3651E+04 -4.9381E+04 -4.6111E+04 -1.9120E+04 F -2.0401E+05 1.0929E+05 9.6282E+04 2.7411E+04 G 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 flat 6 7 8 9 K: 8.2408E+01 -9.6359E+00 -9.3563E+00 -4.6010E+00 A: 2.0800E+00 4.1197E+00 -1.7106E-01 -3.4598E+00 B: -1.1654E+01 -6.3048E+01 -6.0610E+01 1.1981E+01 C: 1.0495E+02 5.8384E+02 6.0210E+02 -2.9286E+01 D: -2.9093E+03 -3.2073E+03 -3.0614E+03 2.1350E+01 E: 3.0098E+04 8.1579E+03 7.4214E+03 4.3158E+01 F -1.3987E+05 -2.0410E+03 -6.5485E+03 -6.8022E+01 G 2.4876E+05 -1.5524E+04 0.0000E+00 0.0000E+00

In the second embodiment, the curve equation of the aspheric surface is expressed as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and will not be repeated here.

With Table 3 and Table 4, the following data can be calculated:

Second embodiment f[mm] 1.18 f1/f23 0.514 Fno 2.07 f23/f4 -1.227 FOV[deg.] 71.44 f12/f34 0.823 f1/f2 -0.590 f/TL 0.696 f2/f3 -1.454 R1/R2 -1.100 f3/f4 -0.736 R5/R6 7.604 f1/f3 0.857 R7/R8 1.916 f2/f4 1.070 CT2/CT1 0.509

<The third embodiment>

Please refer to FIGS. 3A and 3B, in which FIG. 3A shows a schematic diagram of a four-piece dual-band imaging lens set according to a third embodiment of the present invention. Curve of field curvature and distortion of the band imaging lens group. It can be seen from FIG. 3A that the four-piece dual-band imaging lens group includes an aperture 300 and an optical group. The optical group includes a first lens 310, a second lens 320, a third lens 330, and an optical group from the object side to the image side. The fourth lens 340, the infrared filter element 370, and the imaging surface 380, wherein there are four lenses with refractive power in the four-piece dual-band imaging lens group. The aperture 300 is arranged in front of the first lens 310.

The first lens 310 has a positive refractive power and is made of plastic. Its object side surface 311 is convex near the optical axis 390, and its image side surface 312 is convex near the optical axis 390. The object side surface 311 and the image side are convex. The surfaces 312 are all aspherical.

The second lens 320 has a negative refractive power and is made of plastic. Its object side surface 321 is concave near the optical axis 390, and its image side surface 322 is convex near the optical axis 390. The object side surface 321 and the image side The surfaces 322 are all aspherical.

The third lens 330 has positive refractive power and is made of plastic. Its object side surface 331 is concave near the optical axis 390, and its image side surface 332 is convex near the optical axis 390. The object side surface 331 and the image side The surfaces 332 are all aspherical.

The fourth lens 340 has a negative refractive power and is made of plastic. Its object side surface 341 is convex near the optical axis 390, and its image side surface 342 is concave near the optical axis 390. The object side surface 341 and the image side The surface 342 is aspherical, and the object side surface 341 and the image side surface 342 both have at least one inflection point away from the optical axis 390.

The infrared ray filter element 370 is made of glass, which is arranged between the fourth lens 340 and the imaging surface 380 and does not affect the focal length of the four-piece dual-band imaging lens group.

Refer to Table 5 and Table 6 below for cooperation.

table 5 The third embodiment f (focal length) = 1.09 mm (mm), Fno (aperture value) = 2.07, FOV (angle of view) = 74.99 deg. (degrees) surface To Radius of curvature thickness Material Refractive index Dispersion coefficient focal length 0 Subject unlimited unlimited To To To To 1 aperture unlimited -0.012 To To To To 2 First lens 1.002 (ASP) 0.285 plastic 1.54 56 0.925 3 To -0.916 (ASP) 0.120 To To To To 4 Second lens -0.330 (ASP) 0.160 plastic 1.64 22.46 -1.673 5 To -0.564 (ASP) 0.020 To To To To 6 Third lens -4.014 (ASP) 0.198 plastic 1.54 56 1.071 7 To -0.519 (ASP) 0.020 To To To To 8 Fourth lens 0.627 (ASP) 0.149 plastic 1.64 22.46 -1.563 9 To 0.351 (ASP) 0.349 To To To To 10 Infrared filter Filter unlimited 0.210 glass 1.52 64.2 To 11 To unlimited 0.118 To To To To 12 Imaging surface unlimited - To To To To

Table 6 Aspheric coefficient flat 2 3 4 5 K: -2.0867E+01 3.0678E+00 -6.2845E-01 1.5157E-01 A: 1.2474E+00 -3.3947E+00 -3.2572E+00 -4.2147E+00 B: -3.0047E+01 3.1269E+01 1.0486E+02 8.9127E+01 C: 2.5652E+02 -7.4639E+02 -1.2242E+03 -9.0720E+02 D: -5.3752E+03 8.5215E+03 9.8442E+03 5.5382E+03 E: 4.2924E+04 -4.9525E+04 -4.5994E+04 -1.9168E+04 F -1.9262E+05 1.0994E+05 9.4407E+04 2.7384E+04 G 4.0648E+05 4.5272E+04 -2.3993E+04 -6.5399E+02 flat 6 7 8 9 K: 8.4833E+01 -8.6378E+00 -1.0091E+01 -4.5639E+00 A: 2.1286E+00 4.1029E+00 -2.2307E-01 -3.4773E+00 B: -1.1597E+01 -6.2885E+01 -6.0676E+01 1.1929E+01 C: 1.0508E+02 5.8619E+02 6.0182E+02 -2.9418E+01 D: -2.9062E+03 -3.2034E+03 -3.0641E+03 2.1152E+01 E: 3.0133E+04 8.1821E+03 7.4042E+03 4.6899E+01 F -1.3952E+05 -1.8397E+03 -6.6274E+03 -7.7023E+01 G 2.5149E+05 -1.4922E+04 1.0199E+02 -8.9583E+00

In the third embodiment, the curve equation of the aspheric surface is expressed as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and will not be repeated here.

With Table 5 and Table 6, the following data can be calculated:

The third embodiment f[mm] 1.09 f1/f23 0.561 Fno 2.07 f23/f4 -1.056 FOV[deg.] 74.99 f12/f34 0.902 f1/f2 -0.553 f/TL 0.672 f2/f3 -1.563 R1/R2 -1.094 f3/f4 -0.685 R5/R6 7.732 f1/f3 0.864 R7/R8 1.788 f2/f4 1.071 CT2/CT1 0.562

<Fourth embodiment>

Please refer to FIGS. 4A and 4B, where FIG. 4A shows a schematic diagram of a four-piece dual-band imaging lens set according to a fourth embodiment of the present invention, and FIG. 4B shows the four-piece dual-band imaging lens group in the fourth embodiment in order from left to right. Curve of field curvature and distortion of the band imaging lens group. It can be seen from FIG. 4A that the four-piece dual-band imaging lens group includes an aperture 400 and an optical group. The optical group includes a first lens 410, a second lens 420, and a third lens 430 from the object side to the image side. The fourth lens 440, the infrared filter element 470, and the imaging surface 480, wherein there are four lenses with refractive power in the four-piece dual-band imaging lens group. The aperture 400 is arranged in front of the first lens 410.

The first lens 410 has positive refractive power and is made of plastic. Its object side surface 411 is convex near the optical axis 490, and its image side surface 412 is convex near the optical axis 490. The object side surface 411 and the image side are convex. The surfaces 412 are all aspherical.

The second lens 420 has a negative refractive power and is made of plastic. Its object-side surface 421 is concave near the optical axis 490, and its image-side surface 422 is convex near the optical axis 490, and the object-side surface 421 and the image side are convex. The surfaces 422 are all aspherical.

The third lens 430 has positive refractive power and is made of plastic. Its object-side surface 431 is concave near the optical axis 490, and its image-side surface 432 is convex near the optical axis 490. The object-side surface 431 and the image side are convex. The surfaces 432 are all aspherical.

The fourth lens 440 has a negative refractive power and is made of plastic. Its object-side surface 441 is convex near the optical axis 490, and its image-side surface 442 is concave near the optical axis 490. The object-side surface 441 and the image side The surface 442 is aspherical, and the object side surface 441 and the image side surface 442 both have at least one inflection point away from the optical axis 490.

The infrared filter element 470 is made of glass, which is arranged between the fourth lens 440 and the imaging surface 480 and does not affect the focal length of the four-piece dual-band imaging lens group.

Refer to Table 7 and Table 8 below for cooperation.

Table 7 Fourth embodiment f (focal length) = 1.04 mm (mm), Fno (aperture value) = 2.07, FOV (angle of view) = 76.14 deg. (degrees) surface To Radius of curvature thickness Material Refractive index Dispersion coefficient focal length 0 Subject unlimited unlimited To To To To 1 aperture unlimited -0.015 To To To To 2 First lens 0.654 (ASP) 0.321 plastic 1.54 56 0.846 3 To -1.299 (ASP) 0.080 To To To To 4 Second lens -0.296 (ASP) 0.138 plastic 1.64 22.46 -1.217 5 To -0.563 (ASP) 0.020 To To To To 6 Third lens -2.616 (ASP) 0.160 plastic 1.54 56 1.263 7 To -0.557 (ASP) 0.020 To To To To 8 Fourth lens 0.523 (ASP) 0.150 plastic 1.64 22.46 -3.260 9 To 0.372 (ASP) 0.383 To To To To 10 Infrared filter Filter unlimited 0.145 glass 1.52 64.2 To 11 To unlimited 0.100 To To To To 12 Imaging surface unlimited - To To To To

Table 8 Aspheric coefficient flat 2 3 4 5 K: -1.0255E+01 7.3889E+00 -5.9214E-01 -1.1041E-01 A: 3.3108E+00 -5.1378E+00 -4.1384E+00 -4.7337E+00 B: -2.6152E+01 1.7969E+01 1.3341E+02 1.1921E+02 C: 3.5287E+02 -1.1454E+03 -1.7624E+03 -1.2998E+03 D: -8.9066E+03 1.3667E+04 1.5536E+04 8.6641E+03 E: 7.9421E+04 -8.2495E+04 -7.7439E+04 -3.3753E+04 F -3.1714E+05 2.5927E+05 2.3293E+05 5.2237E+04 G -1.0449E+06 2.0489E+05 2.7521E+05 7.7114E+03 flat 6 7 8 9 K: 4.8190E+01 -3.2152E+00 -1.3414E+01 -4.9119E+00 A: 2.8157E+00 5.7483E+00 2.0824E-01 -4.1102E+00 B: -2.6086E+01 -7.8456E+01 -7.4728E+01 1.6484E+01 C: 1.5241E+02 8.3278E+02 8.7057E+02 -3.9907E+01 D: -4.5109E+03 -5.0816E+03 -4.7886E+03 3.3662E+01 E: 5.0996E+04 1.4085E+04 1.3223E+04 6.7877E+01 F -2.9107E+05 -4.7591E+03 -1.2874E+04 -1.5392E+02 G 4.7105E+05 -3.4571E+04 -8.5541E+03 -7.0895E+01

In the fourth embodiment, the aspherical curve equation is expressed as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and will not be repeated here.

In conjunction with Table 7 and Table 8, the following data can be calculated:

Fourth embodiment f[mm] 1.04 f1/f23 0.179 Fno 2.07 f23/f4 -1.452 FOV[deg.] 76.14 f12/f34 1.306 f1/f2 -0.695 f/TL 0.684 f2/f3 -0.963 R1/R2 -0.503 f3/f4 -0.387 R5/R6 4.694 f1/f3 0.670 R7/R8 1.406 f2/f4 0.373 CT2/CT1 0.431

<Fifth Embodiment>

Please refer to FIG. 5A and FIG. 5B, where FIG. 5A shows a schematic diagram of a four-piece dual-band imaging lens set according to a fifth embodiment of the present invention, and FIG. 5B shows the four-piece dual-band imaging lens group in the fifth embodiment in order from left to right. Curve of field curvature and distortion of the band imaging lens group. It can be seen from FIG. 5A that the four-piece dual-band imaging lens group includes an aperture 500 and an optical group, which sequentially includes a first lens 510, a second lens 520, a third lens 530, and an optical group from the object side to the image side. The fourth lens 540, the infrared filter element 570, and the imaging surface 580, wherein there are four lenses with refractive power in the four-piece dual-band imaging lens group. The aperture 500 is arranged in front of the first lens 510.

The first lens 510 has positive refractive power and is made of plastic material. Its object side surface 511 is convex near the optical axis 590, and its image side surface 512 is convex near the optical axis 590. The object side surface 511 and the image side are convex. The surfaces 512 are all aspherical.

The second lens 520 has negative refractive power and is made of plastic. Its object-side surface 521 is concave near the optical axis 590, and its image-side surface 522 is convex near the optical axis 590, and the object-side surface 521 and the image side are convex. The surfaces 522 are all aspherical.

The third lens 530 has positive refractive power and is made of plastic. Its object-side surface 531 is concave near the optical axis 590, and its image-side surface 532 is convex near the optical axis 590, and the object-side surface 531 and the image side are convex. The surfaces 532 are all aspherical.

The fourth lens 540 has a negative refractive power and is made of plastic. Its object side surface 541 is convex near the optical axis 590, and its image side surface 542 is concave near the optical axis 590. The object side surface 541 and the image side The surface 542 is aspherical, and both the object side surface 541 and the image side surface 542 have at least one inflection point away from the optical axis 590.

The infrared ray filter element 570 is made of glass, which is arranged between the fourth lens 540 and the imaging surface 580 and does not affect the focal length of the four-piece dual-band imaging lens group.

Refer to Table 9 and Table 10 below for cooperation.

Table 9 Fifth embodiment f (focal length) = 1.05 mm (mm), Fno (aperture value) = 2.08, FOV (angle of view) = 75.74 deg. (degrees) surface To Radius of curvature thickness Material Refractive index Dispersion coefficient focal length 0 Subject unlimited unlimited To To To To 1 aperture unlimited 0.012 To To To To 2 First lens 0.784 (ASP) 0.293 plastic 1.54 56 0.824 3 To -0.914 (ASP) 0.099 To To To To 4 Second lens -0.302 (ASP) 0.161 plastic 1.64 22.46 -1.352 5 To -0.559 (ASP) 0.020 To To To To 6 Third lens -6.837 (ASP) 0.178 plastic 1.54 56 1.038 7 To -0.528 (ASP) 0.021 To To To To 8 Fourth lens 0.685 (ASP) 0.157 plastic 1.54 56 -1.577 9 To 0.351 (ASP) 0.351 To To To To 10 Infrared filter Filter unlimited 0.145 glass 1.52 64.2 To 11 To unlimited 0.100 To To To To 12 Imaging surface unlimited - To To To To

Table 10 Aspheric coefficient flat 2 3 4 5 K: -1.4586E+01 4.1748E+00 -6.2391E-01 -7.9467E-02 A: 2.1283E+00 -4.6581E+00 -4.0508E+00 -4.5178E+00 B: -3.3566E+01 3.5925E+01 1.4245E+02 1.1617E+02 C: 3.6495E+02 -1.0411E+03 -1.6630E+03 -1.2863E+03 D: -9.1784E+03 1.3833E+04 1.6096E+04 8.8316E+03 E: 7.0879E+04 -8.5167E+04 -7.6586E+04 -3.2896E+04 F -3.6678E+05 2.1735E+05 1.9798E+05 5.7773E+04 G 9.3584E+05 3.6528E+03 -3.1493E+05 3.2933E+03 flat 6 7 8 9 K: 1.0193E+02 -8.7380E+00 -1.4669E+01 -4.8111E+00 A: 2.4936E+00 5.3854E+00 -1.5761E-01 -3.9882E+00 B: -1.6534E+01 -8.0347E+01 -7.5482E+01 1.6202E+01 C: 1.3919E+02 8.3660E+02 8.6690E+02 -4.1440E+01 D: -4.6800E+03 -5.0456E+03 -4.7867E+03 3.2570E+01 E: 5.2398E+04 1.4236E+04 1.3250E+04 7.1844E+01 F -2.6923E+05 -4.2064E+03 -1.2816E+04 -1.3690E+02 G 5.4162E+05 -3.9243E+04 -8.1541E+03 -2.4380E+01

In the fifth embodiment, the aspherical curve equation is expressed as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and will not be repeated here.

In conjunction with Table 9 and Table 10, the following data can be calculated:

Fifth embodiment f[mm] 1.05 f1/f23 0.435 Fno 2.08 f23/f4 -1.202 FOV[deg.] 75.74 f12/f34 0.932 f1/f2 -0.609 f/TL 0.680 f2/f3 -1.302 R1/R2 -0.858 f3/f4 -0.658 R5/R6 12.949 f1/f3 0.793 R7/R8 1.953 f2/f4 0.857 CT2/CT1 0.550

<Sixth Embodiment>

Please refer to FIGS. 6A and 6B, where FIG. 6A shows a schematic diagram of a four-piece dual-band imaging lens set according to a sixth embodiment of the present invention, and FIG. Curve of field curvature and distortion of the band imaging lens group. It can be seen from FIG. 6A that the four-piece dual-band imaging lens group includes an aperture 600 and an optical group, which includes a first lens 610, a second lens 620, a third lens 630, and an optical group from the object side to the image side. The fourth lens 640, the infrared filter element 670, and the imaging surface 680, wherein the four-piece dual-band imaging lens group has four lenses with refractive power. The aperture 600 is arranged in front of the first lens 610.

The first lens 610 has positive refractive power and is made of plastic. Its object-side surface 611 is convex near the optical axis 690, and its image-side surface 612 is convex near the optical axis 690, and the object-side surface 611 and the image side are convex. The surfaces 612 are all aspherical.

The second lens 620 has negative refractive power and is made of plastic. Its object side surface 621 is concave near the optical axis 690, and its image side surface 622 is convex near the optical axis 690, and the object side surface 621 and the image side The surfaces 622 are all aspherical.

The third lens 630 has positive refractive power and is made of plastic. Its object side surface 631 is concave near the optical axis 690, and its image side surface 632 is convex near the optical axis 690. The object side surface 631 and the image side The surfaces 632 are all aspherical.

The fourth lens 640 has a negative refractive power and is made of plastic. Its object-side surface 641 is convex near the optical axis 690, and its image-side surface 642 is concave near the optical axis 690, and the object-side surface 641 and the image side The surface 642 is aspherical, and the object side surface 641 and the image side surface 642 both have at least one inflection point away from the optical axis 690.

The infrared filter element 670 is made of glass, which is arranged between the fourth lens 640 and the imaging surface 680 and does not affect the focal length of the four-piece dual-band imaging lens group.

Refer to Table 11 and Table 12 below for cooperation.

Table 11 Sixth embodiment f (focal length) = 1.06 mm (mm), Fno (aperture value) = 2.05, FOV (angle of view) = 75.82 deg. (degrees) surface To Radius of curvature thickness Material Refractive index Dispersion coefficient focal length 0 Subject unlimited unlimited To To To To 1 aperture unlimited 0.012 To To To To 2 First lens 0.784 (ASP) 0.293 plastic 1.54 56 0.840 3 To -0.914 (ASP) 0.099 To To To To 4 Second lens -0.302 (ASP) 0.161 plastic 1.64 22.46 -1.425 5 To -0.559 (ASP) 0.020 To To To To 6 Third lens -6.837 (ASP) 0.178 plastic 1.54 56 0.980 7 To -0.528 (ASP) 0.021 To To To To 8 Fourth lens 0.685 (ASP) 0.157 plastic 1.54 56 -1.332 9 To 0.351 (ASP) 0.351 To To To To 10 Infrared filter Filter unlimited 0.145 glass 1.52 64.2 To 11 To unlimited 0.100 To To To To 12 Imaging surface unlimited - To To To To

Table 12 Aspheric coefficient flat 2 3 4 5 K: -2.1027E+01 2.7762E+00 -6.2733E-01 1.3085E-01 A: 1.7685E+00 -4.4497E+00 -4.4582E+00 -5.6963E+00 B: -4.7939E+01 5.2748E+01 1.7594E+02 1.4934E+02 C: 5.6366E+02 -1.5380E+03 -2.5190E+03 -1.8673E+03 D: -1.3208E+04 2.1551E+04 2.4839E+04 1.4009E+04 E: 1.3566E+05 -1.5346E+05 -1.4330E+05 -5.9421E+04 F -7.7917E+05 4.1741E+05 3.6773E+05 1.0469E+05 G 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 flat 6 7 8 9 K: 8.2408E+01 -9.6359E+00 -9.3563E+00 -4.6010E+00 A: 2.8339E+00 5.6127E+00 -2.3306E-01 -4.7137E+00 B: -1.9512E+01 -1.0556E+02 -1.0148E+02 2.0060E+01 C: 2.1596E+02 1.2013E+03 1.2389E+03 -6.0262E+01 D: -7.3570E+03 -8.1107E+03 -7.7417E+03 5.3991E+01 E: 9.3537E+04 2.5353E+04 2.3064E+04 1.3412E+02 F -5.3422E+05 -7.7953E+03 -2.5011E+04 -2.5980E+02 G 1.1676E+06 -7.2864E+04 0.0000E+00 0.0000E+00

In the sixth embodiment, the curve equation of the aspheric surface is expressed as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and will not be repeated here.

With Table 11 and Table 12, the following data can be calculated:

Sixth embodiment f[mm] 1.06 f1/f23 0.514 Fno 2.05 f23/f4 -1.227 FOV[deg.] 75.82 f12/f34 0.823 f1/f2 -0.590 f/TL 0.694 f2/f3 -1.454 R1/R2 -1.100 f3/f4 -0.736 R5/R6 7.604 f1/f3 0.857 R7/R8 1.916 f2/f4 1.070 CT2/CT1 0.509

<Seventh embodiment>

Please refer to FIGS. 7A and 7B, where FIG. 7A shows a schematic diagram of a four-piece dual-band imaging lens set according to a seventh embodiment of the present invention, and FIG. 7B shows the four-piece dual-band imaging lens group in the seventh embodiment from left to right. Curve of field curvature and distortion of the band imaging lens group. It can be seen from FIG. 7A that the four-piece dual-band imaging lens group includes an aperture 700 and an optical group. The optical group includes a first lens 710, a second lens 720, a third lens 730, and an optical group from the object side to the image side. The fourth lens 740, the infrared filter element 770, and the imaging surface 780, wherein the four lenses with refractive power in the four-piece dual-band imaging lens group are four. The aperture 700 is arranged in front of the first lens 710.

The first lens 710 has positive refractive power and is made of plastic. Its object-side surface 711 is convex near the optical axis 790, and its image-side surface 712 is convex near the optical axis 790. The object-side surface 711 and the image side are convex. The surfaces 712 are all aspherical.

The second lens 720 has negative refractive power and is made of plastic. Its object-side surface 721 is concave near the optical axis 790, and its image-side surface 722 is convex near the optical axis 790, and the object-side surface 721 and the image side are convex. The surfaces 722 are all aspherical.

The third lens 730 has positive refractive power and is made of plastic. Its object side surface 731 is concave near the optical axis 790, and its image side surface 732 is convex near the optical axis 790. The object side surface 731 and the image side The surfaces 732 are all aspherical.

The fourth lens 740 has a negative refractive power and is made of plastic. Its object side surface 741 is convex near the optical axis 790, and its image side surface 742 is concave near the optical axis 790, and the object side surface 741 and the image side The surface 742 is aspherical, and the object side surface 741 and the image side surface 742 both have at least one inflection point away from the optical axis 790.

The infrared ray filter element 770 is made of glass, which is arranged between the fourth lens 740 and the imaging surface 780 and does not affect the focal length of the four-piece dual-band imaging lens group.

Refer to Table 13 and Table 14 below for cooperation.

Table 13 Seventh embodiment f (focal length) = 1.07 mm (mm), Fno (aperture value) = 2.08, FOV (angle of view) = 86.31 deg. (degrees) surface To Radius of curvature thickness Material Refractive index Dispersion coefficient focal length 0 Subject unlimited unlimited To To To To 1 aperture unlimited -0.003 To To To To 2 First lens 1.308 (ASP) 0.358 plastic 1.54 56 0.859 3 To -0.660 (ASP) 0.126 To To To To 4 Second lens -0.299 (ASP) 0.173 plastic 1.66 20.37 -1.262 5 To -0.571 (ASP) 0.027 To To To To 6 Third lens -3.003 (ASP) 0.264 plastic 1.54 56 1.110 7 To -0.520 (ASP) 0.027 To To To To 8 Fourth lens 0.592 (ASP) 0.178 plastic 1.66 20.37 -2.098 9 To 0.366 (ASP) 0.355 To To To To 10 Infrared filter Filter unlimited 0.210 glass 1.52 64.2 To 11 To unlimited 0.100 To To To To 12 Imaging surface unlimited - To To To To

Table 14 Aspheric coefficient flat 2 3 4 5 K: -4.1607E+01 1.0694E+00 -6.0472E-01 6.7461E-03 A: -5.9333E-01 -8.4090E-01 -2.8862E+00 -1.9794E+00 B: 8.8565E+01 -5.7592E+01 4.7909E+01 2.6770E+01 C: -3.7276E+03 1.3826E+03 5.8531E+02 -4.6763E+01 D: 6.8396E+04 -1.7025E+04 -1.4020E+04 -5.5032E+02 E: -6.5409E+05 9.9661E+04 1.0317E+05 3.0796E+03 F 2.5169E+06 -2.1192E+05 -2.4750E+05 -4.1072E+03 G 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 flat 6 7 8 9 K: -3.3766E+02 -7.5351E+00 -4.7683E+00 -5.1773E+00 A: 1.9909E+00 2.0931E+00 -6.6579E-01 -2.2410E-01 B: -1.5468E+01 -1.2634E+01 -4.4990E+00 -4.8883E+00 C: 4.1606E+01 9.2746E+00 -1.8673E+00 1.8897E+01 D: 4.4807E+01 1.9541E+02 7.8209E+01 -3.4300E+01 E: -6.3333E+02 -6.9395E+02 -2.0536E+02 3.0355E+01 F 1.1767E+03 7.3969E+02 1.6258E+02 -1.0842E+01 G 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

In the seventh embodiment, the curve equation of the aspheric surface is expressed as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and will not be repeated here.

With Table 13 and Table 14, the following data can be calculated:

Seventh embodiment f[mm] 1.07 f1/f23 0.411 Fno 2.08 f23/f4 -0.997 FOV[deg.] 86.31 f12/f34 1.407 f1/f2 -0.681 f/TL 0.590 f2/f3 -1.137 R1/R2 -1.980 f3/f4 -0.529 R5/R6 5.776 f1/f3 0.774 R7/R8 1.618 f2/f4 0.602 CT2/CT1 0.482

The four-piece dual-band imaging lens set provided by the present invention can be made of plastic or glass. When the lens is made of plastic, the production cost can be effectively reduced. When the lens is made of glass, four-piece dual-band can be added The degree of freedom in the configuration of the refractive power of the imaging lens group. In addition, the object side surface and the image side surface of the lens in the four-element dual-band imaging lens group can be aspherical, and the aspherical surface can be easily made into a shape other than a spherical surface to obtain more control variables to reduce aberrations, and then The number of lenses used is reduced, so the total length of the four-piece dual-band imaging lens set of the present invention can be effectively reduced.

In the four-piece dual-band imaging lens set provided by the present invention, for a lens with refractive power, if the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at the near optical axis ; If the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at the near optical axis.

The four-piece dual-band imaging lens set provided by the present invention can be applied to a mobile focusing optical system according to requirements, and has the characteristics of excellent aberration correction and good imaging quality, and can be applied to 3D (three-dimensional) image capture in many ways , Digital cameras, mobile devices, digital tablets or car photography and other electronic imaging systems.

100, 200, 300, 400, 500, 600, 700: aperture 110, 210, 310, 410, 510, 610, 710: first lens 111, 211, 311, 411, 511, 611, 711: Object side surface 112, 212, 312, 412, 512, 612, 712: image side surface 120, 220, 320, 420, 520, 620, 720: second lens 121, 221, 321, 421, 521, 621, 721: Object side surface 122, 222, 322, 422, 522, 622, 722: image side surface 130, 230, 330, 430, 530, 630, 730: third lens 131, 231, 331, 431, 531, 631, 731: Object side surface 132, 232, 332, 432, 532, 632, 732: image side surface 140, 240, 340, 440, 540, 640, 740: fourth lens 141, 241, 341, 441, 541, 641, 741: Object side surface 142, 242, 342, 442, 542, 642, 742: image side surface 160, 260, 360, 470, 570, 670, 770: infrared filter element 180, 280, 380, 480, 580, 680, 780: imaging surface 190, 290, 390, 490, 590, 690, 790: optical axis f: The focal length of the four-piece dual-band imaging lens group Fno: The aperture value of the four-piece dual-band imaging lens group FOV: The largest field of view in the four-piece dual-band imaging lens group f1: focal length of the first lens f2: the focal length of the second lens f3: focal length of the third lens f4: focal length of the fourth lens f12: The combined focal length of the first lens and the second lens f23: The combined focal length of the second lens and the third lens f34: The combined focal length of the third lens and the fourth lens R1: The radius of curvature of the object side surface of the first lens R2: The radius of curvature of the image side surface of the first lens R5: The radius of curvature of the object side surface of the third lens R6: The radius of curvature of the image side surface of the third lens R7: The radius of curvature of the object side surface of the fourth lens R8: The radius of curvature of the image side surface of the fourth lens CT1: The thickness of the first lens on the optical axis CT2: The thickness of the second lens on the optical axis TL: The distance from the object side surface of the first lens to the imaging surface on the optical axis

1A is a schematic diagram of a four-piece dual-band imaging lens set according to the first embodiment of the present invention. FIG. 1B is a graph showing the curvature of field and distortion of the four-piece dual-band imaging lens set in the first embodiment from left to right. 2A is a schematic diagram of a four-piece dual-band imaging lens set according to the second embodiment of the present invention. Fig. 2B is a graph showing the curvature of field and distortion of the four-piece dual-band imaging lens set in the second embodiment from left to right. 3A is a schematic diagram of a four-piece dual-band imaging lens set according to the third embodiment of the present invention. Fig. 3B is a graph showing the curvature of field and the distortion of the four-piece dual-band imaging lens set in the third embodiment from left to right. 4A is a schematic diagram of a four-piece dual-band imaging lens set according to a fourth embodiment of the present invention. FIG. 4B is a graph showing the curvature of field and the distortion of the four-piece dual-band imaging lens set in the fourth embodiment from left to right. 5A is a schematic diagram of a four-piece dual-band imaging lens set according to a fifth embodiment of the present invention. Fig. 5B is a graph showing the curvature of field and the distortion of the four-piece dual-band imaging lens set in the fifth embodiment from left to right. 6A is a schematic diagram of a four-piece dual-band imaging lens set according to a sixth embodiment of the present invention. Fig. 6B is a graph showing curvature of field and distortion of the four-piece dual-band imaging lens set in the sixth embodiment from left to right. Fig. 7A is a schematic diagram of a four-piece dual-band imaging lens set according to a seventh embodiment of the present invention. Fig. 7B is a graph showing the curvature of field and the distortion of the four-piece dual-band imaging lens set in the seventh embodiment from left to right.

100: aperture

110: first lens

111: Object side surface

112: Image side surface

120: second lens

121: Object side surface

122: image side surface

130: third lens

131: Object side surface

132: Image side surface

140: fourth lens

141: Object side surface

142: Image side surface

170: Infrared filter element

180: imaging surface

190: optical axis

Claims (14)

A four-piece dual-band imaging lens group, including an aperture and an optical group consisting of four lenses, from the object side to the image side in order: The aperture A first lens with positive refractive power, the object side surface of the first lens is convex near the optical axis, the image side surface of the first lens is convex near the optical axis, and the object side surface of the first lens is At least one surface of the side surface is aspherical; A second lens with negative refractive power, the object side surface of the second lens is concave near the optical axis, the image side surface of the second lens is convex near the optical axis, and the object side surface of the second lens is At least one surface of the side surface is aspherical; A third lens with positive refractive power, the object side surface of the third lens is concave near the optical axis, the image side surface of the third lens is convex near the optical axis, and the object side surface of the second lens is At least one of the side surfaces is aspherical; and A fourth lens with negative refractive power. The object side surface of the fourth lens is convex near the optical axis, and the image side surface of the fourth lens is concave near the optical axis. At least one surface of the side surface is aspherical. The four-piece dual-band imaging lens set according to claim 1, wherein the focal length of the first lens is f1 and the focal length of the second lens is f2, and the following conditions are met: -0.8 <f1/f2 <-0.4. The four-piece dual-band imaging lens set according to claim 1, wherein the focal length of the second lens is f2, and the focal length of the third lens is f3, and the following conditions are met: -1.6 <f2/f3 <-0.9. The four-piece dual-band imaging lens group according to claim 1, wherein the focal length of the third lens is f3 and the focal length of the fourth lens is f4, and the following conditions are met: -0.8 <f3/f4 <-0.3. The four-piece dual-band imaging lens set according to claim 1, wherein the focal length of the first lens is f1, and the focal length of the third lens is f3, and the following conditions are met: 0.6 <f1/f3 <1.0. The four-piece dual-band imaging lens group according to claim 1, wherein the focal length of the second lens is f2, and the focal length of the fourth lens is f4, and the following conditions are satisfied: 0.3 <f2/f4 <1.2. The four-piece dual-band imaging lens set according to claim 1, wherein the focal length of the first lens is f1, the combined focal length of the second lens and the third lens is f23, and the following conditions are met: 0.1 <f1/f23 <0.7. The four-piece dual-band imaging lens set according to claim 1, wherein the combined focal length of the second lens and the third lens is f23, the focal length of the fourth lens is f4, and the following conditions are met: -1.6 <f23/ f4 <-0.9. The four-piece dual-band imaging lens set according to claim 1, wherein the composite focal length of the first lens and the second lens is f12, and the composite focal length of the third lens and the fourth lens is f34, and the following conditions are met: 0.7 <f12/f34 <1.5. The four-piece dual-band imaging lens group according to claim 1, wherein the overall focal length of the four-piece dual-band imaging lens group is f, and the distance from the object side surface of the first lens to the imaging surface on the optical axis is TL, and meet the following conditions: 0.5 <f/TL <0.8. The four-piece dual-band imaging lens set according to claim 1, wherein the radius of curvature of the object side surface of the first lens is R1, and the radius of curvature of the image side surface of the first lens is R2, and the following conditions are met: -2.1 <R1/R2 <-0.4. The four-piece dual-band imaging lens set according to claim 1, wherein the radius of curvature of the object side surface of the third lens is R5, and the radius of curvature of the image side surface of the third lens is R6, and the following conditions are met: 4 < R5/R6 ＜14. The four-piece dual-band imaging lens set according to claim 1, wherein the radius of curvature of the fourth lens object side surface is R7, and the curvature radius of the fourth lens image side surface is R8, and the following conditions are met: 1.3 < R7/R8 <2.1. The four-piece dual-band imaging lens set according to claim 1, wherein the thickness of the second lens on the optical axis is CT2, and the thickness of the first lens on the optical axis is CT1, and the following conditions are met: 0.3 < CT2/CT1 <0.7.

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