TWI589926B - Three-piece infrared single wavelength lens assembly - Google Patents

Description

Three-piece infrared single-wavelength lens set

The present invention relates to a lens group, and more particularly to a miniaturized three-piece infrared single-wavelength lens set for use in electronic products.

Nowadays, digital imaging technology is constantly innovating and changing. Especially in digital cameras such as digital cameras and mobile phones, miniaturization is being developed. Photosensitive components such as CCD or CMOS are also required to be more miniaturized. In addition to the application of infrared focusing lenses, In the field of photography, in recent years, it has also been widely used in the field of infrared receiving and sensing of game machines, and in order to make the range of the user of the game machine wider, the lens group that receives the infrared wavelength is mostly in the angle of drawing. The wide-angle lens group is the mainstream.

Among them, the applicant has previously proposed a number of lens sets for infrared wavelength reception. However, the current game machine is mainly a 3D game with more stereo, real and realistic feeling. Therefore, the current lens group of the applicant or the applicant is The 2D plane game detection is so demanding that it cannot satisfy the depth sensing effect of the 3D game.

Furthermore, the infrared receiving and sensing lens sets for game machines are made of plastic lenses for the pursuit of low cost. The poor light transmittance of the materials is one of the key factors affecting the depth detection accuracy of the game machine. Secondly, the plastic lenses are easy to be used. The ambient temperature is too hot or too cold, so that the focal length of the lens group changes and the focus cannot be detected accurately. As mentioned above, the lens group that receives the infrared wavelength is unable to meet the two technical problems of accurate sensing of the depth of the 3D game.

In view of this, how to provide an accurate depth-distance detection, reception, and prevention of the focal length change of the lens group affects the depth detection effect, and the lens group that is the infrared wavelength receiving is currently eager to overcome the technical bottleneck.

It is an object of the present invention to provide a three-piece infrared single-wavelength lens set, and more particularly to a three-piece infrared single-wavelength lens set having a better image sensing function.

In order to achieve the foregoing objective, a three-piece infrared single-wavelength lens group according to the present invention includes, in order from the object side to the image side, an aperture; a first lens having a positive refractive power and an object side thereof The surface near-optical axis is convex, and the image side surface is convex at the near-optical axis, and at least one surface of the object-side surface and the image-side surface is aspherical; a second lens has a positive refractive power, and the object side surface is low-beam The axis is a concave surface, and the image side surface is convex at the near optical axis, and at least one surface of the object side surface and the image side surface is aspherical; a third lens has a positive refractive power, and the object side surface is at the near optical axis. a convex surface having a concave surface at a near-optical axis of the image side surface, and at least one surface of the object side surface and the image side surface is aspherical;

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 condition is satisfied: 0.5 < f1/f23 < 1.0. Thereby, the three-chip infrared single-wavelength lens group can significantly improve the resolution of the image while obtaining a wide angle of view (angle of view).

Preferably, the focal length of the first lens is f1, the focal length of the second lens is f2, and the following condition is satisfied: 0.05 < f1/f2 < 0.45. Thereby, the refractive power arrangement of the first lens and the second lens is suitable, which is advantageous for obtaining a wide angle of view (angle of view) and reducing excessive increase of system aberration.

Preferably, the focal length of the second lens is f2, the focal length of the third lens is f3, and the following condition is satisfied: 0.5 < f2 / f3 < 2.6. Thereby, the arrangement of the refractive power of the second lens and the third lens is balanced, which contributes to the correction of the aberration and the reduction of the sensitivity.

Preferably, the focal length of the first lens is f1, the focal length of the third lens is f3, and the following condition is satisfied: 0.05 < f1/f3 < 0.7. Thereby, the positive refractive power of the first lens is effectively distributed, and the sensitivity of the three-piece infrared single-wavelength lens group is reduced.

Preferably, the combined focal length of the first lens and the second lens is f12, the focal length of the third lens is f3, and the following condition is satisfied: 0.1 < f12/f3 < 0.65. Thereby, the three-chip infrared single-wavelength lens group can significantly improve the resolution of the image while obtaining a wide angle of view (angle of view).

Preferably, the image side surface has a radius of curvature R2, and the second lens has an object side surface radius of curvature R3 and satisfies the following condition: 25 < R2/R3 < 270. Thereby, the spherical aberration and astigmatism of the three-piece infrared single-wavelength lens group are effectively reduced.

Preferably, the maximum field of view of the three-piece infrared single-wavelength lens set is FOV and satisfies the following condition: 45 < FOV < 75. Thereby, the three-piece infrared single-wavelength lens group can have a suitable larger angle of view.

Preferably, the thickness of the first lens on the optical axis is CT1, and the distance between the first lens and the second lens on the optical axis is T12, and the following condition is satisfied: 1.4 < CT1/T12 < 2.4. Thereby, the assembly of the lens group is facilitated to improve the production yield.

Preferably, the distance between the first lens and the second lens on the optical axis is T12, the thickness of the second lens on the optical axis is CT2, and the following condition is satisfied: 0.5 < T12/CT2 < 1.4. Thereby, the moldability and homogeneity of the lens are contributed, and the assembly yield is increased.

Preferably, the distance between the first lens and the second lens on the optical axis is T12, and the distance between the second lens and the third lens on the optical axis is T23, and the following conditions are met: 5.4 < T12/T23 < 9.0. Thereby, the separation distance of the lens is suitable, which helps the lens assembly to increase the yield of the finished product.

Preferably, the first lens has a dispersion coefficient of V1, the second lens has a dispersion coefficient of V2, and satisfies the following condition: 30 < V1-V2<42. Thereby, the chromatic aberration of the three-piece infrared single-wavelength lens group is effectively reduced.

Preferably, the first lens has a dispersion coefficient of V1, and the third lens has a dispersion coefficient of V3 and satisfies the following condition: 30 < V1 - V3 < 42. Thereby, the chromatic aberration of the three-piece infrared single-wavelength lens group can be effectively corrected, and the imaging quality is improved.

Preferably, the three-chip infrared single-wavelength lens group has an aperture value of Fno and satisfies the following condition: 1.2 < Fno < 1.8. Thereby, the aperture size of the three-piece infrared single-wavelength lens group can be appropriately adjusted, so that the three-piece infrared single-wavelength lens group has a large aperture characteristic.

With regard to the techniques, means and other effects of the present invention in order to achieve the above objects, four preferred embodiments are described in detail with reference to the drawings.

<First Embodiment>

1A and FIG. 1B, FIG. 1A is a schematic diagram of a three-chip infrared single-wavelength lens group according to a first embodiment of the present invention, and FIG. 1B is a three-chip infrared of the first embodiment from left to right. Spherical aberration, astigmatism, and distortion curves for a single-wavelength lens set. As shown in FIG. 1A, the three-chip infrared single-wavelength lens assembly 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 infrared filter filter element 170 and the imaging surface 180, wherein the three-piece infrared single-wavelength lens group has three refractive lenses. The aperture 100 is disposed between the image side surface 112 of the first lens 110 and the subject.

The first lens 110 has a positive refractive power and is made of a plastic material. The object side surface 111 is convex at the near optical axis 190, and the image side surface 112 is convex at the near optical axis 190, and the object side surface 111 and the image side are Surface 112 is aspherical.

The second lens 120 has a positive refractive power and is made of a plastic material. The object side surface 121 is a concave surface at the near optical axis 190, and the image side surface 122 is convex at the near optical axis 190, and the object side surface 121 and the image side are Surface 122 is aspherical.

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

The infrared filter element 170 is made of glass and disposed between the third lens 130 and the imaging surface 180 without affecting the focal length of the three-piece infrared single-wavelength lens group.

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

<TABLE border="1" borderColor="#000000" width="_0002"><TBODY><tr><td width="127" height="2"></td></tr><tr>< Td></td><td><img wi="485" he="48" file="02_image001.jpg" img-format="jpg"></img></td></tr></ TBODY></TABLE>

Where z is the position value with reference to the surface apex at a position of height h in the direction of the optical axis 190; c is the curvature of the lens surface near 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 near the optical axis 190, h is the vertical distance of the lens surface from the optical axis 190, k is a conic constant, and A, B, C, D, E, G, ... are High order aspheric coefficient.

In the three-piece infrared single-wavelength lens group of the first embodiment, the focal length of the three-piece infrared single-wavelength lens group is f, and the aperture value (f-number) of the three-piece infrared single-wavelength lens group is Fno, three-piece The maximum field of view (arrow angle) in the infrared single-wavelength lens set is FOV, and its values are as follows: f = 1.192 (mm); Fno = 1.4; and FOV = 60 (degrees).

In the three-piece infrared single-wavelength lens group 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 satisfied: f1/f23 = 0.64636.

In the three-piece infrared single-wavelength lens group of the first embodiment, the focal length of the first lens 110 is f1, the focal length of the second lens 120 is f2, and the following condition is satisfied: f1/f2 = 0.22985.

In the three-piece infrared single-wavelength lens group of the first embodiment, the focal length of the second lens 120 is f2, the focal length of the third lens 130 is f3, and the following condition is satisfied: f2/f3 = 1.39174.

In the three-piece infrared single-wavelength lens group of the first embodiment, the focal length of the first lens 110 is f1, the focal length of the third lens 130 is f3, and the following condition is satisfied: f1/f3 = 0.31990.

In the three-piece red single-wavelength lens group of the first embodiment, the composite focal length of the first lens 110 and the second lens 120 is f12, and the focal length of the third lens 130 is f3, and the following conditions are satisfied: f12/f3 = 0.32798.

In the three-piece infrared single-wavelength lens set of the first embodiment, the image side surface 112 of the first lens 110 has a radius of curvature R2, and the object side surface 121 of the second lens 120 has a radius of curvature of R3, and satisfies the following conditions: R2/R3 = 261.90368.

In the three-piece infrared single-wavelength lens group of the first embodiment, the thickness of the first lens 110 on the optical axis 190 is CT1, and the distance between the first lens 110 and the second lens 120 on the optical axis 190 is T12. And meet the following conditions: CT1/T12 = 1.85473.

In the three-piece infrared single-wavelength lens group of the first embodiment, the distance between the first lens 110 and the second lens 120 on the optical axis 190 is T12, and the thickness of the second lens 120 on the optical axis 190 is CT2. And meet the following conditions: T12/CT2 = 0.97384.

In the three-piece infrared single-wavelength lens group of the first embodiment, the distance between the first lens 110 and the second lens 120 on the optical axis 190 is T12, and the second lens 120 and the third lens 130 are on the optical axis 190. The upper separation distance is T23 and the following conditions are met: T12/T23 = 7.159.

In the three-piece infrared single-wavelength lens group of the first embodiment, the first lens 110 has a dispersion coefficient of V1, and the second lens 120 has a dispersion coefficient of V2 and satisfies the following conditions: V1-V2 = 34.5.

In the three-piece infrared single-wavelength lens group of the first embodiment, the first lens 110 has a dispersion coefficient of V1, and the third lens 130 has a dispersion coefficient of V3 and satisfies the following conditions: V1-V3 = 34.5.

Refer to Table 1 and Table 2 below for reference.

<TABLE border="1" borderColor="#000000" width="_0003"><TBODY><tr><td><b>Table 1</b></td></tr><tr><td > First Embodiment </td></tr><tr><td><u>f(uu><u>focal length)=1.192 mm (mm), Fno (aperture value) = 1.4, FOV (painting angle) = 60 deg. (degrees)</u></td></tr><tr><td> surface </td><td> </td><td> radius of curvature</td> <td> Thickness </td><td> Material </td><td> Refractive Index </td><td> Dispersion Coefficient </td><td> Focal Length </td></tr><tr>< Td> 0 </td><td> Subject </td><td> Unlimited</td><td> 500.000 </td><td> </td><td> </td><td> </td><td> </td></tr><tr><td> 1 </td><td> </td><td> infinity</td><td> 0.002 </td>< Td> </td><td> </td><td> </td><td> </td></tr><tr><td> 2 </td><td> aperture</td> <td> Unlimited</td><td> -0.002 </td><td> </td><td> </td><td> </td><td> </td></tr>< Tr><td> 3 </td><td> first lens</td><td> 0.866 </td><td> (ASP) </td><td> 0.398 </td><td> plastic </td><td> 1.544 </td><td> 56.000 </td><td> 1.610 </td></tr><tr><td> 4 </td><td> </td> <td> -107.896 </td><td> (ASP) </td><td> 0.215 </td>< Td> </td><td> </td><td> </td><td> </td></tr><tr><td> 5 </td><td> second lens</ Td><td> -0.412 </td><td> (ASP) </td><td> 0.221 </td><td> Plastic</td><td> 1.651 </td><td> 21.500 < /td><td> 7.005 </td></tr><tr><td> 6 </td><td> </td><td> -0.454 </td><td> (ASP) </ Td><td> 0.030 </td><td> </td><td> </td><td> </td><td> </td></tr><tr><td> 7 < /td><td> Third lens</td><td> 0.658 </td><td> (ASP) </td><td> 0.256 </td><td> Plastic </td><td> 1.651 </td><td> 21.500 </td><td> 5.034 </td></tr><tr><td> 8 </td><td> </td><td> 0.707 </td ><td> (ASP) </td><td> 0.379 </td><td> </td><td> </td><td> </td><td> </td></tr ><tr><td> 9 </td><td> Infrared Filter Filter </td><td> Unlimited</td><td> 0.210 </td><td> Glass</td>< Td> 1.517 </td><td> 64.167 </td><td> - </td></tr><tr><td> 10 </td><td> </td><td> infinity< /td><td> 0.131 </td><td> </td><td> </td><td> </td><td> </td></tr><tr><td> 11 </td><td> imaging surface </td><td> infinity</td><td> 0.000 </td><td> </ Td><td> </td><td> </td><td> </td></tr></TBODY></TABLE>

<TABLE border="1" borderColor="#000000" width="_0004"><TBODY><tr><td><b>Table 2</b></td></tr><tr><td > aspherical coefficient </td></tr><tr><td> plane</td><td> 3 </td><td> 4 </td><td> 5 </td></tr ><tr><td> K: </td><td> 1.6561E-01 </td><td> 9.0001E+01 </td><td> -5.0677E-01 </td></tr ><tr><td> A: </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td></tr> <tr><td> B: </td><td> -1.7783E-01 </td><td> -3.8297E-01 </td><td> 2.8597E+00 </td></tr ><tr><td> C: </td><td> 2.2848E+00 </td><td> 7.7170E+00 </td><td> -5.9554E+00 </td></tr ><tr><td> D: </td><td> -5.8170E+01 </td><td> -1.3481E+02 </td><td> -6.6323E+01 </td>< /tr><tr><td> E: </td><td> 5.3783E+02 </td><td> 1.0727E+03 </td><td> 1.1671E+03 </td></ Tr><tr><td> F: </td><td> -2.3081E+03 </td><td> -3.8622E+03 </td><td> -4.7624E+03 </td> </tr><tr><td> G </td><td> 3.4798E+03 </td><td> 4.9505E+03 </td><td> 6.3678E+03 </td></ Tr><tr><td> H </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td></tr> <tr><td> Plane</td><td> 6 </td><td> 7 </td><td> 8 </td></tr><tr><td> K: </td><td> -1.5487E+00 </td><td> -1.1929E+01 </ Td><td> -6.9879E+00 </td></tr><tr><td> A: </td><td> 0.0000E+00 </td><td> 0.0000E+00 </ Td><td> 0.0000E+00 </td></tr><tr><td> B: </td><td> -4.3135E-01 </td><td> 2.0091E+00 </ Td><td> -5.2294E-01 </td></tr><tr><td> C: </td><td> 5.6008E+00 </td><td> -2.1131E+01 < /td><td> 1.5078E+00 </td></tr><tr><td> D: </td><td> -5.8963E+01 </td><td> 1.1419E+02 < /td><td> -1.1792E+01 </td></tr><tr><td> E: </td><td> 3.4446E+02 </td><td> -3.9602E+02 </td><td> 3.2929E+01 </td></tr><tr><td> F: </td><td> -7.4388E+02 </td><td> 7.4075E+02 </td><td> -5.7999E+01 </td></tr><tr><td> G </td><td> 5.0956E+02 </td><td> -6.2921E+02 </td><td> 4.4847E+01 </td></tr><tr><td> H </td><td> 0.0000E+00 </td><td> 0.0000E+00 </ Td><td> 0.0000E+00 </td></tr></TBODY></TABLE>

Table 1 is the detailed structural data of the first embodiment of Fig. 1A, in which the unit of curvature radius, thickness and focal length is mm, and the surfaces 0-11 sequentially represent the surface from the object side to the image side. Table 2 is the aspherical surface data in the first embodiment, wherein the cone surface coefficients in the a-spherical curve equation of k, A, B, C, D, E, F, G, H, ... are high-order aspherical coefficients. In addition, the table of the following embodiments corresponds to the schematic diagram and the aberration diagram of each embodiment, and the definition of the data in the table is the same as the definitions of Table 1 and Table 2 of the first embodiment, and details are not described herein.

<Second embodiment>

2A and 2B, wherein FIG. 2A is a schematic diagram of a three-chip infrared single-wavelength lens group according to a second embodiment of the present invention, and FIG. 2B is a three-chip infrared of the second embodiment from left to right. Spherical aberration, astigmatism, and distortion curves for a single-wavelength lens set. As can be seen from FIG. 2A, the three-piece infrared single-wavelength lens assembly includes an aperture 200 and an optical group. The optical group includes a first lens 210, a second lens 220, and a third lens 230 from the object side to the image side. The infrared filter filter element 270 and the imaging surface 280, wherein the three-piece infrared single-wavelength lens group has three refractive lenses. The aperture 200 is disposed between the image side surface 212 of the first lens 210 and the object.

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

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

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

The infrared filter element 270 is made of glass and disposed between the third lens 230 and the imaging surface 280 without affecting the focal length of the three-piece infrared single-wavelength lens group.

Refer to Table 3 and Table 4 below.

<TABLE border="1" borderColor="#000000" width="_0005"><TBODY><tr><td><b>Table 3</b></td></tr><tr><td > Second Embodiment </td></tr><tr><td><u>f(</u><u>focal length)=1.264 mm (mm), Fno (aperture value) = 1.4, FOV (painting angle) = 55 deg. (degrees)</u></td></tr><tr><td> surface </td><td> </td><td> radius of curvature</td> <td> Thickness </td><td> Material </td><td> Refractive Index </td><td> Dispersion Coefficient </td><td> Focal Length </td></tr><tr>< Td> 0 </td><td> Subject </td><td> Unlimited</td><td> 500.000 </td><td> </td><td> </td><td> </td><td> </td></tr><tr><td> 1 </td><td> </td><td> infinity</td><td> 0.003 </td>< Td> </td><td> </td><td> </td><td> </td></tr><tr><td> 2 </td><td> aperture</td> <td> Unlimited</td><td> -0.003 </td><td> </td><td> </td><td> </td><td> </td></tr>< Tr><td> 3 </td><td> first lens</td><td> 0.956 </td><td> (ASP) </td><td> 0.479 </td><td> plastic </td><td> 1.544 </td><td> 56.000 </td><td> 1.760 </td></tr><tr><td> 4 </td><td> </td> <td> -56.134 </td><td> (ASP) </td><td> 0.258 </td><t d> </td><td> </td><td> </td><td> </td></tr><tr><td> 5 </td><td> second lens </ Td><td> -0.453 </td><td> (ASP) </td><td> 0.221 </td><td> Plastic </td><td> 1.651 </td><td> 21.500 < /td><td> 9.111 </td></tr><tr><td> 6 </td><td> </td><td> -0.499 </td><td> (ASP) </ Td><td> 0.030 </td><td> </td><td> </td><td> </td><td> </td></tr><tr><td> 7 < /td><td> Third lens</td><td> 0.669 </td><td> (ASP) </td><td> 0.274 </td><td> Plastic </td><td> 1.651 </td><td> 21.500 </td><td> 4.227 </td></tr><tr><td> 8 </td><td> </td><td> 0.752 </td ><td> (ASP) </td><td> 0.367 </td><td> </td><td> </td><td> </td><td> </td></tr ><tr><td> 9 </td><td> Infrared Filter Filter </td><td> Unlimited</td><td> 0.210 </td><td> Glass</td>< Td> 1.517 </td><td> 64.167 </td><td> - </td></tr><tr><td> 10 </td><td> </td><td> infinity< /td><td> 0.144 </td><td> </td><td> </td><td> </td><td> </td></tr><tr><td> 11 </td><td> imaging surface </td><td> infinity</td><td> 0.000 </td><td> </t d><td> </td><td> </td><td> </td></tr></TBODY></TABLE>

<TABLE border="1" borderColor="#000000" width="_0006"><TBODY><tr><td><b>Table 4</b></td></tr><tr><td > aspherical coefficient </td></tr><tr><td> plane</td><td> 3 </td><td> 4 </td><td> 5 </td></tr ><tr><td> K: </td><td> 1.4591E-01 </td><td> 8.6453E+03 </td><td> -5.0418E-01 </td></tr ><tr><td> A: </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td></tr> <tr><td> B: </td><td> -1.4983E-01 </td><td> -2.5141E-01 </td><td> 2.1650E+00 </td></tr ><tr><td> C: </td><td> 1.4038E+00 </td><td> 4.8007E+00 </td><td> -3.7831E+00 </td></tr ><tr><td> D: </td><td> -2.9628E+01 </td><td> -6.9229E+01 </td><td> -3.4353E+01 </td>< /tr><tr><td> E: </td><td> 2.2943E+02 </td><td> 4.5491E+02 </td><td> 4.9418E+02 </td></ Tr><tr><td> F: </td><td> -8.0646E+02 </td><td> -1.3541E+03 </td><td> -1.6700E+03 </td> </tr><tr><td> G </td><td> 1.0122E+03 </td><td> 1.4330E+03 </td><td> 1.8433E+03 </td></ Tr><tr><td> H </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td></tr> <tr><td> Plane</td><td> 6 </td><td> 7 </td><td> 8 </td></tr><tr><td> K: </td><td> -1.4998E+00 </td><td> -1.0282E+01 < /td><td> -5.4983E+00 </td></tr><tr><td> A: </td><td> 0.0000E+00 </td><td> 0.0000E+00 < /td><td> 0.0000E+00 </td></tr><tr><td> B: </td><td> -3.2878E-01 </td><td> 1.8526E+00 < /td><td> -8.3680E-02 </td></tr><tr><td> C: </td><td> 3.5347E+00 </td><td> -1.3143E+01 </td><td> 1.1134E+00 </td></tr><tr><td> D: </td><td> -3.0133E+01 </td><td> 5.8273E+01 </td><td> -6.4602E+00 </td></tr><tr><td> E: </td><td> 1.4609E+02 </td><td> -1.6768E+ 02 </td><td> 1.3145E+01 </td></tr><tr><td> F: </td><td> -2.6120E+02 </td><td> 2.6112E+ 02 </td><td> -2.0481E+01 </td></tr><tr><td> G </td><td> 1.4485E+02 </td><td> -1.7938E+ 02 </td><td> 1.5542E+01 </td></tr><tr><td> H </td><td> 0.0000E+00 </td><td> 0.0000E+00 < /td><td> 0.0000E+00 </td></tr></TBODY></TABLE>

In the second embodiment, the aspherical curve equation represents the form 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 are not described herein.

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

<TABLE border="1" borderColor="#000000" width="_0007"><TBODY><tr><td> Second Embodiment</td></tr><tr><td> f </td ><td> 1.264 </td><td> f12/f3 </td><td> 0.43356 </td></tr><tr><td> Fno </td><td> 1.4 </td> <td> R2/R3 </td><td> 123.96486 </td></tr><tr><td> FOV </td><td> 55 </td><td> CT1/T12 </td ><td> 1.85478 </td></tr><tr><td> f1/f2 </td><td> 0.19314 </td><td> T12/CT2 </td><td> 1.16877 </ Td></tr><tr><td> f2/f3 </td><td> 2.15539 </td><td> T12/T23 </td><td> 8.60333 </td></tr>< Tr><td> f1/f3 </td><td> 0.41629 </td><td> V1-V2 </td><td> 34.5 </td></tr><tr><td> f1/ F23 </td><td> 0.71360 </td><td> V1-V3 </td><td> 34.5 </td></tr></TBODY></TABLE>

<Third embodiment>

Please refer to FIG. 3A and FIG. 3B , wherein FIG. 3A is a schematic diagram of a three-chip infrared single-wavelength lens group according to a third embodiment of the present invention, and FIG. 3B is a three-chip infrared of the third embodiment from left to right. Spherical aberration, astigmatism, and distortion curves for a single-wavelength lens set. As shown in FIG. 3A, the three-chip infrared single-wavelength lens assembly includes an aperture 300 and an optical group. The optical group sequentially includes a first lens 310, a second lens 320, and a third lens 330 from the object side to the image side. The infrared filter filter element 370 and the imaging surface 380, wherein the lens of the three-piece infrared single-wavelength lens group has a refractive power of three. The aperture 300 is disposed between the image side surface 312 of the first lens 310 and the subject.

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

The second lens 320 has a positive refractive power and is made of a plastic material. The object side surface 321 is concave at the near optical axis 390, and the image side surface 322 is convex at the near optical axis 390, and the object side surface 321 and the image side are Surfaces 322 are all aspherical.

The third lens 330 has a positive refractive power and is made of a plastic material. The object side surface 331 is convex at the near optical axis 390, and the image side surface 332 is concave at the near optical axis 390, and the object side surface 331 and the image side are Surface 332 is aspherical.

The infrared filter element 370 is made of glass and disposed between the third lens 330 and the imaging surface 380 without affecting the focal length of the three-piece infrared single-wavelength lens group.

Refer to Table 5 and Table 6 below for reference.

<TABLE border="1" borderColor="#000000" width="_0008"><TBODY><tr><td><b>Table 5</b></td></tr><tr><td > Third Embodiment </td></tr><tr><td><u>f(</u><u>focal length)=1.076 mm (mm), Fno (aperture value) = 1.6, FOV (painting angle) = 65 deg. (degrees)</u></td></tr><tr><td> surface </td><td> </td><td> radius of curvature</td> <td> Thickness </td><td> Material </td><td> Refractive Index </td><td> Dispersion Coefficient </td><td> Focal Length </td></tr><tr>< Td> 0 </td><td> Subject </td><td> Unlimited</td><td> 500.000 </td><td> </td><td> </td><td> </td><td> </td></tr><tr><td> 1 </td><td> </td><td> infinity</td><td> -0.054 </td> <td> </td><td> </td><td> </td><td> </td></tr><tr><td> 2 </td><td> aperture</td ><td> Unlimited</td><td> 0.054 </td><td> </td><td> </td><td> </td><td> </td></tr>< Tr><td> 3 </td><td> first lens</td><td> 0.876 </td><td> (ASP) </td><td> 0.358 </td><td> plastic </td><td> 1.544 </td><td> 56.000 </td><td> 1.602 </td></tr><tr><td> 4 </td><td> </td> <td> -37.188 </td><td> (ASP) </td><td> 0.211 </td><t d> </td><td> </td><td> </td><td> </td></tr><tr><td> 5 </td><td> second lens </ Td><td> -0.412 </td><td> (ASP) </td><td> 0.213 </td><td> Plastic </td><td> 1.651 </td><td> 21.500 < /td><td> 7.268 </td></tr><tr><td> 6 </td><td> </td><td> -0.453 </td><td> (ASP) </ Td><td> 0.030 </td><td> </td><td> </td><td> </td><td> </td></tr><tr><td> 7 < /td><td> Third lens</td><td> 0.626 </td><td> (ASP) </td><td> 0.254 </td><td> Plastic </td><td> 1.651 </td><td> 21.500 </td><td> 3.216 </td></tr><tr><td> 8 </td><td> </td><td> 0.764 </td ><td> (ASP) </td><td> 0.333 </td><td> </td><td> </td><td> </td><td> </td></tr ><tr><td> 9 </td><td> Infrared Filter Filter </td><td> Unlimited</td><td> 0.210 </td><td> Glass</td>< Td> 1.517 </td><td> 64.167 </td><td> - </td></tr><tr><td> 10 </td><td> </td><td> infinity< /td><td> 0.131 </td><td> </td><td> </td><td> </td><td> </td></tr><tr><td> 11 </td><td> imaging surface </td><td> infinity</td><td> 0.000 </td><td> </t d><td> </td><td> </td><td> </td></tr></TBODY></TABLE>

<TABLE border="1" borderColor="#000000" width="_0009"><TBODY><tr><td><b>Table 6</b></td></tr><tr><td > aspherical coefficient </td></tr><tr><td> plane</td><td> 3 </td><td> 4 </td><td> 5 </td></tr ><tr><td> K: </td><td> 1.1143E-01 </td><td> 4.5584E+03 </td><td> -5.0524E-01 </td></tr ><tr><td> A: </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td></tr> <tr><td> B: </td><td> -2.6472E-01 </td><td> -4.3381E-01 </td><td> 3.0370E+00 </td></tr ><tr><td> C: </td><td> 2.4231E+00 </td><td> 1.0284E+01 </td><td> -1.0318E+01 </td></tr ><tr><td> D: </td><td> -3.2150E+01 </td><td> -1.4021E+02 </td><td> -1.4086E+01 </td>< /tr><tr><td> E: </td><td> 1.7801E+02 </td><td> 9.7852E+02 </td><td> 8.8790E+02 </td></ Tr><tr><td> F: </td><td> -6.4089E+02 </td><td> -3.3473E+03 </td><td> -4.0655E+03 </td> </tr><tr><td> G </td><td> 8.4568E+02 </td><td> 4.1659E+03 </td><td> 5.7099E+03 </td></ Tr><tr><td> H </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td></tr> <tr><td> Plane</td><td> 6 </td><td> 7 </td><td> 8 </td></tr><tr><td> K: </td><td> -1.4714E+00 </td><td> -1.2397E+01 </ Td><td> -6.4401E+00 </td></tr><tr><td> A: </td><td> 0.0000E+00 </td><td> 0.0000E+00 </ Td><td> 0.0000E+00 </td></tr><tr><td> B: </td><td> -4.9828E-01 </td><td> 2.6913E+00 </ Td><td> -4.5859E-01 </td></tr><tr><td> C: </td><td> 6.5987E+00 </td><td> -2.3621E+01 < /td><td> 5.1313E+00 </td></tr><tr><td> D: </td><td> -7.6651E+01 </td><td> 1.2891E+02 < /td><td> -3.6777E+01 </td></tr><tr><td> E: </td><td> 4.6447E+02 </td><td> -4.6825E+02 </td><td> 1.1797E+02 </td></tr><tr><td> F: </td><td> -1.0766E+03 </td><td> 9.5965E+02 </td><td> -1.9549E+02 </td></tr><tr><td> G </td><td> 8.5055E+02 </td><td> -8.6698E+02 </td><td> 1.2566E+02 </td></tr><tr><td> H </td><td> 0.0000E+00 </td><td> 0.0000E+00 </ Td><td> 0.0000E+00 </td></tr></TBODY></TABLE>

In the third embodiment, the aspherical curve equation represents the form 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 are not described herein.

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

<TABLE border="1" borderColor="#000000" width="_0010"><TBODY><tr><td> Third Embodiment</td></tr><tr><td> f </td ><td> 1.076 </td><td> f12/f3 </td><td> 0.50896 </td></tr><tr><td> Fno </td><td> 1.6 </td> <td> R2/R3 </td><td> 90.34390 </td></tr><tr><td> FOV </td><td> 65 </td><td> CT1/T12 </td ><td> 1.69914 </td></tr><tr><td> f1/f2 </td><td> 0.22035 </td><td> T12/CT2 </td><td> 0.98882 </ Td></tr><tr><td> f2/f3 </td><td> 2.26020 </td><td> T12/T23 </td><td> 7.01767 </td></tr>< Tr><td> f1/f3 </td><td> 0.49804 </td><td> V1-V2 </td><td> 34.5 </td></tr><tr><td> f1/ F23 </td><td> 0.84401 </td><td> V1-V3 </td><td> 34.5 </td></tr></TBODY></TABLE>

<Fourth embodiment>

Please refer to FIG. 4A and FIG. 4B , wherein FIG. 4A is a schematic diagram of a three-chip infrared single-wavelength lens group according to a fourth embodiment of the present invention, and FIG. 4B is a three-chip infrared of the fourth embodiment from left to right. Spherical aberration, astigmatism, and distortion curves for a single-wavelength lens set. As shown in FIG. 4A, the three-chip infrared single-wavelength lens assembly 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 infrared filter filter element 470 and the imaging surface 480, wherein the lens of the three-piece infrared single-wavelength lens group has a refractive power of three. The aperture 400 is disposed between the image side surface 412 of the first lens 410 and the object.

The first lens 410 has a positive refractive power and is made of a plastic material. The object side surface 411 is convex at the near optical axis 490, and the image side surface 412 is convex at the near optical axis 490, and the object side surface 411 and the image side are Surface 412 is aspherical.

The second lens 420 has a positive refractive power and is made of a plastic material. The object side surface 421 is concave at the near optical axis 490, and the image side surface 422 is convex at the near optical axis 490, and the object side surface 421 and the image side are Surface 422 is aspherical.

The third lens 430 has a positive refractive power and is made of a plastic material. The object side surface 431 is convex at the near optical axis 490, and the image side surface 432 is concave at the near optical axis 490, and the object side surface 431 and the image side are Surface 432 is aspherical.

The infrared filter element 470 is made of glass and disposed between the third lens 430 and the imaging surface 480 without affecting the focal length of the three-piece infrared single-wavelength lens group.

Refer to Table 7 and Table 8 below for reference.

<TABLE border="1" borderColor="#000000" width="_0011"><TBODY><tr><td><b>Table 7</b></td></tr><tr><td > Fourth Embodiment </td></tr><tr><td><u>f(</u><u>focal length)=1.11 mm (mm), Fno (aperture value) = 1.4, FOV (painting angle) = 64 deg. (degrees)</u></td></tr><tr><td> surface </td><td> </td><td> radius of curvature</td> <td> Thickness </td><td> Material </td><td> Refractive Index </td><td> Dispersion Coefficient </td><td> Focal Length </td></tr><tr>< Td> 0 </td><td> Subject </td><td> Unlimited</td><td> 500.000 </td><td> </td><td> </td><td> </td><td> </td></tr><tr><td> 1 </td><td> </td><td> infinity</td><td> 0.000 </td>< Td> </td><td> </td><td> </td><td> </td></tr><tr><td> 2 </td><td> aperture</td> <td> Unlimited</td><td> 0.000 </td><td> </td><td> </td><td> </td><td> </td></tr><tr ><td> 3 </td><td> First lens</td><td> 0.848 </td><td> (ASP) </td><td> 0.364 </td><td> Plastic< /td><td> 1.544 </td><td> 56.000 </td><td> 1.508 </td></tr><tr><td> 4 </td><td> </td>< Td> -13.555 </td><td> (ASP) </td><td> 0.173 </td><td> </td><td> </td><td> </td><td> </td></tr><tr><td> 5 </td><td> second lens</td> <td> -0.416 </td><td> (ASP) </td><td> 0.234 </td><td> Plastic</td><td> 1.635 </td><td> 23.900 </td ><td> 5.081 </td></tr><tr><td> 6 </td><td> </td><td> -0.445 </td><td> (ASP) </td> <td> 0.030 </td><td> </td><td> </td><td> </td><td> </td></tr><tr><td> 7 </td ><td> Third lens</td><td> 0.612 </td><td> (ASP) </td><td> 0.236 </td><td> Plastic </td><td> 1.635 < /td><td> 23.900 </td><td> 6.070 </td></tr><tr><td> 8 </td><td> </td><td> 0.625 </td>< Td> (ASP) </td><td> 0.358 </td><td> </td><td> </td><td> </td><td> </td></tr>< Tr><td> 9 </td><td> Infrared Filter Filter </td><td> Unlimited</td><td> 0.210 </td><td> Glass </td><td> 1.517 </td><td> 64.167 </td><td> - </td></tr><tr><td> 10 </td><td> </td><td> Unlimited</td ><td> 0.131 </td><td> </td><td> </td><td> </td><td> </td></tr><tr><td> 11 </ Td><td> imaging surface</td><td> infinity</td><td> 0.000 </td><td> </td> <td> </td><td> </td><td> </td></tr></TBODY></TABLE>

<TABLE border="1" borderColor="#000000" width="_0012"><TBODY><tr><td><b>Table 8</b></td></tr><tr><td > aspherical coefficient </td></tr><tr><td> plane</td><td> 3 </td><td> 4 </td><td> 5 </td></tr ><tr><td> K: </td><td> -6.8165E-02 </td><td> -6.6204E+01 </td><td> -5.5086E-01 </td>< /tr><tr><td> A: </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td></ Tr><tr><td> B: </td><td> -9.2855E-02 </td><td> -3.9781E-01 </td><td> 2.8075E+00 </td>< /tr><tr><td> C: </td><td> -1.7300E+00 </td><td> -9.5082E-01 </td><td> -1.4380E+01 </td ></tr><tr><td> D: </td><td> -1.1434E+01 </td><td> 7.3878E+00 </td><td> 1.3482E+02 </td ></tr><tr><td> E: </td><td> 3.1050E+02 </td><td> 2.2340E+00 </td><td> -3.5346E+02 </td ></tr><tr><td> F: </td><td> -2.3349E+03 </td><td> -1.6160E+02 </td><td> 3.2516E+02 </ Td></tr><tr><td> G </td><td> 5.0324E+03 </td><td> 3.4273E+02 </td><td> -1.3212E+01 </td ></tr><tr><td> H </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td>< /tr><tr><td> Plane</td><td> 6 </td><td > 7 </td><td> 8 </td></tr><tr><td> K: </td><td> -1.6842E+00 </td><td> -1.0036E+01 </td><td> -6.3872E+00 </td></tr><tr><td> A: </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td><td> 0.0000E+00 </td></tr><tr><td> B: </td><td> -4.2370E-01 </td><td> 2.1256E+00 </td><td> -2.1000E-01 </td></tr><tr><td> C: </td><td> 2.6819E+00 </td><td> -2.0101E+ 01 </td><td> 5.4441E-01 </td></tr><tr><td> D: </td><td> 8.1475E+00 </td><td> 1.1789E+02 </td><td> -5.4072E+00 </td></tr><tr><td> E: </td><td> -8.0008E+01 </td><td> -4.9289E +02 </td><td> -5.1579E+00 </td></tr><tr><td> F: </td><td> 4.9479E+02 </td><td> 1.1501E +03 </td><td> 3.0434E+01 </td></tr><tr><td> G </td><td> -8.8479E+02 </td><td> -1.2123E +03 </td><td> -2.9698E+01 </td></tr><tr><td> H </td><td> 0.0000E+00 </td><td> 0.0000E+ 00 </td><td> 0.0000E+00 </td></tr></TBODY></TABLE>

In the fourth embodiment, the aspherical curve equation represents the form 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 are not described herein.

The following data can be derived from Table 7 and Table 8:

<TABLE border="1" borderColor="#000000" width="_0013"><TBODY><tr><td> Fourth Embodiment</td></tr><tr><td> f </td ><td> 1.11 </td><td> f12/f3 </td><td> 0.24379 </td></tr><tr><td> Fno </td><td> 1.4 </td> <td> R2/R3 </td><td> 32.60571 </td></tr><tr><td> FOV </td><td> 64 </td><td> CT1/T12 </td ><td> 2.10076 </td></tr><tr><td> f1/f2 </td><td> 0.29673 </td><td> T12/CT2 </td><td> 0.74124 </ Td></tr><tr><td> f2/f3 </td><td> 0.83702 </td><td> T12/T23 </td><td> 5.77300 </td></tr>< Tr><td> f1/f3 </td><td> 0.24837 </td><td> V1-V2 </td><td> 32.1 </td></tr><tr><td> f1/ F23 </td><td> 0.63936 </td><td> V1-V3 </td><td> 32.1 </td></tr></TBODY></TABLE>

The three-piece infrared single-wavelength lens set provided by the invention can be made of plastic or glass. When the lens material is plastic, the production cost can be effectively reduced. When the lens material is glass, a three-chip infrared single can be added. The degree of freedom in the configuration of the refractive power of the wavelength lens set. In addition, the object side surface and the image side surface of the lens in the three-piece infrared single-wavelength lens group may be aspherical, and the aspherical surface can be easily formed into a shape other than the spherical surface, and more control variables are obtained to reduce the aberration, and further The number of lenses used is reduced, so that the overall length of the three-piece infrared single wavelength lens set of the present invention can be effectively reduced.

In the three-piece infrared single-wavelength lens set provided by the present invention, in the case of a lens having a refractive power, if the lens surface is convex and the convex position is not defined, it indicates that the lens surface is convex at the low beam axis. If the lens surface is concave and the concave position is not defined, it indicates that the lens surface is concave at the low beam axis.

The three-piece infrared single-wavelength lens set provided by the invention is more suitable for the optical system of moving focus, and has the characteristics of excellent aberration correction and good imaging quality, and can be applied to 3D (3D) image capture in various aspects. In electronic imaging systems such as digital cameras, mobile devices, digital tablets or car photography.

In the above, the above embodiments and drawings are only the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, that is, the equivalent changes and modifications made by the scope of the present invention are all It should be within the scope of the patent of the present invention.

100, 200, 300, 400: apertures 110, 210, 310, 410: first lenses 111, 211, 311, 411: object side surfaces 112, 212, 312, 412: image side surfaces 120, 220, 320, 420: Second lenses 121, 221, 321, 421: object side surfaces 122, 222, 322, 422: image side surfaces 130, 230, 330, 430: third lenses 131, 231, 331, 431: object side surfaces 132, 232 , 332, 432: image side surface 170, 270, 370, 470: infrared filter element 180, 280, 380, 480: imaging surface 190, 290, 390, 490: optical axis f: three-chip infrared single wavelength Focal length of the lens group Fno: aperture value of the three-piece infrared single-wavelength lens group FOV: maximum angle of view f1 in the three-piece infrared single-wavelength lens group: focal length f2 of the first lens: focal length f3 of the second lens: third The focal length f12 of the lens: the combined focal length f23 of the first lens and the second lens: the combined focal length R2 of the second lens and the third lens: the radius of curvature of the image side surface of the first lens R3: the radius of curvature of the object side surface of the second lens V1 : dispersion coefficient V2 of the first lens: dispersion coefficient V3 of the second lens: dispersion of the third lens The number CT1: the thickness of the first lens on the optical axis CT2: the thickness T12 of the second lens on the optical axis: the distance between the first lens and the second lens on the optical axis T23: the second lens and the third lens are in the light Spacing distance on the shaft

1A is a schematic view of a three-piece infrared single-wavelength lens group according to a first embodiment of the present invention. 1B is a spherical aberration, astigmatism, and distortion curve of the three-piece infrared single-wavelength lens group of the first embodiment, from left to right. 2A is a schematic illustration of a three-piece infrared single wavelength lens set in accordance with a second embodiment of the present invention. 2B is a spherical aberration, astigmatism, and distortion curve of the three-piece infrared single-wavelength lens group of the second embodiment, from left to right. 3A is a schematic illustration of a three-piece infrared single wavelength lens assembly in accordance with a third embodiment of the present invention. 3B is a spherical aberration, astigmatism, and distortion curve of the three-piece infrared single-wavelength lens group of the third embodiment, from left to right. 4A is a schematic view of a three-piece infrared single-wavelength lens set according to a fourth embodiment of the present invention. 4B is a spherical aberration, astigmatism, and distortion curve of the three-piece infrared single-wavelength lens group of the fourth 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 170: Infrared filtering filter element 180: imaging surface 190: optical axis

Claims (12)

A three-piece infrared single-wavelength lens group comprising: an aperture from the object side to the image side; a first lens having a positive refractive power, a convex surface of the object side surface near the optical axis, and a side surface low beam The shaft is convex, and at least one surface of the object side surface and the image side surface is aspherical; a second lens has a positive refractive power, and the object side surface is concave at the near optical axis, and the image side surface is near the optical axis a convex surface, wherein at least one surface of the object side surface and the image side surface is aspherical; a third lens having a positive refractive power, the object side surface being convex at a near optical axis, and the image side surface having a concave surface at a near optical axis, At least one surface of the object side surface and the image side surface is aspherical; 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 focal length of the third lens is f3, and the following Conditions: 0.5 < f1/f23 < 1.0; 0.05 < f1/f3 < 0.7. The three-piece infrared single-wavelength lens set according to claim 1, wherein the focal length of the first lens is f1, the focal length of the second lens is f2, and the following condition is satisfied: 0.05 < f1/f2 < 0.45. The three-piece infrared single-wavelength lens set according to claim 1, wherein the second lens has a focal length of f2, the third lens has a focal length of f3, and satisfies the following condition: 0.5 < f2 / f3 < 2.6. The three-piece infrared single-wavelength lens set according to claim 1, wherein the first lens and the second lens have a combined focal length of f12, the third lens has a focal length of f3, and satisfies the following condition: 0.1<f12/f3< 0.65. The three-piece infrared single-wavelength lens set according to claim 1, wherein an image side surface curvature radius of the first lens is R2, and an object side surface curvature radius of the second lens is R3, and the following condition is satisfied: 25< R2/R3<270. The three-piece infrared single-wavelength lens set according to claim 1, wherein the three-piece infrared single-wavelength lens group has a maximum angle of view of FOV and satisfies the following condition: 45 < FOV < 75. The three-chip infrared single-wavelength lens set according to claim 1, wherein the thickness of the first lens on the optical axis is CT1, and the distance between the first lens and the second lens on the optical axis is T12, and satisfies The following conditions are: 1.4 < CT1/T12 < 2.4. The three-chip infrared single-wavelength lens set according to claim 1, wherein a distance between the first lens and the second lens on the optical axis is T12, and a thickness of the second lens on the optical axis is CT2, and satisfies The following conditions are: 0.5 < T12 / CT2 < 1.4. The three-piece infrared single-wavelength lens set according to claim 1, wherein a distance between the first lens and the second lens on the optical axis is T12, and a distance between the second lens and the third lens on the optical axis It is T23 and satisfies the following conditions: 5.4 < T12 / T23 < 9.0. The three-piece infrared single-wavelength lens set according to claim 1, wherein the first lens has a dispersion coefficient of V1, the second lens has a dispersion coefficient of V2, and satisfies the following condition: 30 < V1 - V2 < 42. The three-piece infrared single-wavelength lens set according to claim 1, wherein the first lens has a dispersion coefficient of V1, the third lens has a dispersion coefficient of V3, and satisfies the following condition: 30 < V1 - V3 < 42. The three-piece infrared single-wavelength lens set according to claim 1, wherein the three-chip infrared single-wavelength lens group has an aperture value of Fno and satisfies the following condition: 1.2 < Fno < 1.8.