Imaging Lenses

Abstract

The present invention relates to an imaging lens, comprising a first lens (L1), a second lens (L2), a third lens (L3), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), a stop (STOP), a seventh lens (L7), an eighth lens (L8), a ninth lens (L9), a tenth lens (L10), an eleventh lens (L11), and a twelfth lens (L12) arranged in sequence from the object side to the image side along an optical axis, wherein the optical focal lengths of the first lens (L1), the second lens (L2), the fourth lens (L4), the sixth lens (L6), the eighth lens (L8), and the eleventh lens (L11) are negative, and the optical focal lengths of the remaining lenses are positive. The imaging lens of the present invention can realize the confocality of the visible spectrum and the infrared spectrum, and no additional light supplement equipment is required when working at night. At the same time, it has the superior performance of a large aperture and a large target surface, and can obtain high-definition imaging pictures for both the visible spectrum and the infrared spectrum; and has an automatic temperature compensation function.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and in particular to an imaging lens suitable for intelligent traffic monitoring. Background Art

[0002] Intelligent traffic monitoring lenses are high-end optical devices for application scenarios and are crucial to the establishment of traffic safety systems. Most existing intelligent traffic monitoring lenses can only image the visible spectrum, and at night they need to be equipped with fill-in lighting equipment to work. Moreover, such fill-in lighting equipment has strong light, which can easily cause dizziness in the driver's eyes. Summary of the invention

[0003] The object of the present invention is to solve the above-mentioned problem and provide an imaging lens.

[0004] To achieve the above-mentioned object of the invention, the present invention provides an imaging lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, an aperture, a seventh lens, an eighth lens, a ninth lens, a tenth lens, an eleventh lens, and a twelfth lens arranged in sequence from the object side to the image side along the optical axis, wherein the optical power of the first lens, the second lens, the fourth lens, the sixth lens, the eighth lens, and the eleventh lens is negative, and the optical power of the remaining lenses is positive.

[0005] According to one aspect of the present invention, the fifth lens is biconvex, the sixth lens is biconcave, the seventh lens is biconvex, the eighth lens is biconcave, and the ninth lens is biconvex.

[0006] According to one aspect of the present invention, the first lens is a convexo-convex type, the second lens is a concave-convex type, the third lens is a biconvex type, the fourth lens is a biconcave type, the tenth lens is a biconvex type, the eleventh lens is a biconcave type, and the twelfth lens is a biconvex type.

[0007] According to one aspect of the present invention, at least three cemented lens groups are included.

[0008] According to one aspect of the present invention, the third lens and the fourth lens form a doublet lens group or are independent of each other;

[0009] The fifth lens and the sixth lens form a doublet lens group;

[0010] The seventh lens, the eighth lens and the ninth lens form a triplet lens group;

[0011] The tenth lens and the eleventh lens form a doublet lens group, or the eleventh lens and the twelfth lens form a doublet lens group, or the tenth lens, the eleventh lens and the twelfth lens form a triplet lens group.

[0012] According to one aspect of the present invention, the half image height IH and the effective focal length EFL of the imaging lens satisfy the following relationship:

[0013] 0.30≤IH / EFL≤0.45.

[0014] According to one aspect of the present invention, the refractive index Nd5 and the Abbe number Vd5 of the fifth lens satisfy the following relationship:

[0015] 1.85≤Nd5≤1.95;

[0016] 30.00≤Vd5≤40.00.

[0017] According to one aspect of the present invention, the refractive index Nd6 and the Abbe number Vd6 of the sixth lens satisfy the following relationship:

[0018] 1.60≤Nd6≤1.65;

[0019] 35.00≤Vd6≤39.00.

[0020] According to one aspect of the present invention, the refractive index Nd7 and the Abbe number Vd7 of the seventh lens satisfy the following relationship:

[0021] 1.45≤Nd7≤1.65;

[0022] 60.00≤Vd7≤82.00.

[0023] According to one aspect of the present invention, the refractive index Nd8 and the Abbe number Vd8 of the eighth lens satisfy the following relationship:

[0024] 1.60≤Nd8≤1.70;

[0025] 30.00≤Vd8≤35.00.

[0026] According to one aspect of the present invention, the refractive index Nd9 and the Abbe number Vd9 of the ninth lens satisfy the following relationship:

[0027] 1.45≤Nd9≤1.65;

[0028] 60.00≤Vd9≤85.00.

[0029] According to one aspect of the present invention, the refractive index Nd10 and the Abbe number Vd10 of the tenth lens satisfy the following relationship:

[0030] 1.75≤Nd10≤1.85;

[0031] 20.00≤Vd10≤26.00.

[0032] According to one aspect of the present invention, the refractive index Nd11 and the Abbe number Vd11 of the eleventh lens satisfy the following relationship:

[0033] 1.65≤Nd11≤1.75;

[0034] 25.00≤Vd11≤35.00.

[0035] According to one aspect of the present invention, the refractive index Nd12 and the Abbe number Vd12 of the twelfth lens satisfy the following relationship:

[0036] 1.70≤Nd12≤1.80;

[0037] 45.00≤Vd12≤50.00.

[0038] According to one aspect of the present invention, the axial distance BFL from the image side surface of the twelfth lens to the image plane and the axial distance TTL from the object side surface of the first lens to the image plane satisfy the following relationship:

[0039] 2.50≤(TTL-1.25*BFL) / BFL≤3.00.

[0040] According to the concept of the present invention, by using different glass material lenses and matching designs, the visible spectrum and infrared spectrum can be confocal, and no additional light supplement equipment is required when working at night. At the same time, it has the superior performance of large aperture (Fno≤1.6) and large target surface (half-image height φ≥8.75mm), and can obtain high-definition imaging pictures for both visible spectrum and infrared spectrum; and it has automatic temperature compensation function (no out-of-focus within -40℃~+85℃).

[0041] According to the present invention, by properly disposing positive power lenses and negative power lenses at different positions, the imaging lens can receive incident light of a certain angle and ensure that the light has a sufficient image height when it reaches the image plane. In addition, it can avoid large-angle refraction of the incident light when it passes through each optical surface, making the light trend smooth, which is conducive to correcting aberrations and reducing the system tolerance sensitivity.

[0042] According to one solution of the present invention, by designing the concave and convex properties of each lens, the direction of curvature of each optical surface and the shape of the lens can be ensured to meet certain field of view angle and image height requirements. In addition, optical distortion can be effectively controlled to achieve low-distortion imaging effects. The light trend can also be smoothed, which is conducive to correcting aberrations and reducing system tolerance sensitivity.

[0043] According to one solution of the present invention, by making certain lenses in the imaging lens form double-cemented and triple-cemented lens groups, it is beneficial to correct the chromatic aberration of the visible spectrum of the lens, ensure the imaging quality, and improve the resolution performance; achieve visible light and infrared light confocality to ensure that the resolution requirements of visible light and infrared light can be taken into account at the same time; it is also beneficial to reduce tolerance sensitivity and improve production yield.

[0044] According to one solution of the present invention, the half image height IH and the effective focal length EFL of the imaging lens satisfy the following relationship: 0.30≤IH / EFL≤0.45. In this way, the lens system can be guaranteed to meet the performance advantages of a large target surface and can be used with various types of chips. The distortion of the optical system can also be effectively controlled to achieve a low-distortion imaging effect.

[0045] According to one solution of the present invention, the refractive index Nd5 and the Abbe number Vd5 of the fifth lens satisfy the following relationship: 1.85≤Nd5≤1.95; 30.00≤Vd5≤40.00. When the refractive index and the Abbe number of the material used for the fifth lens satisfy the above relationship, it is beneficial to correct the aberration of the large aperture and large target surface lens and ensure the resolution performance.

[0046] According to one solution of the present invention, the refractive index Nd6 and the Abbe number Vd6 of the sixth lens satisfy the following relationship: 1.60≤Nd6≤1.65; 35.00≤Vd6≤39.00. When the refractive index and the Abbe number of the material used for the sixth lens satisfy the above relationship, it is beneficial to correct the aberration of the large aperture and large target surface lens and ensure the resolution performance.

[0047] According to one solution of the present invention, the refractive index Nd7 and the Abbe number Vd7 of the seventh lens satisfy the following relationship: 1.45≤Nd7≤1.65; 60.00≤Vd7≤82.00. When the refractive index and the Abbe number of the material used for the seventh lens satisfy the above relationship, it is beneficial to correct the chromatic aberration of the large aperture and large target surface lens and ensure the resolution performance. It can maintain the stability of the effective focal length of the lens in different temperature environments, realize the automatic temperature compensation function, and ensure the imaging quality in different temperature environments.

[0048] According to one solution of the present invention, the refractive index Nd8 and the Abbe number Vd8 of the eighth lens satisfy the following relationship: 1.60≤Nd8≤1.70; 30.00≤Vd8≤35.00. When the refractive index and the Abbe number of the material used in the eighth lens satisfy the above relationship, it is beneficial to correct the chromatic aberration of the large aperture and large target surface lens and ensure the resolution performance.

[0049] According to one solution of the present invention, the refractive index Nd9 and the Abbe number Vd9 of the ninth lens satisfy the following relationship: 1.45≤Nd9≤1.65; 60.00≤Vd9≤85.00. When the refractive index and the Abbe number of the material used in the ninth lens satisfy the above relationship, it is beneficial to correct the chromatic aberration of the large aperture and large target surface lens and ensure the resolution performance. It can maintain the stability of the effective focal length of the lens in different temperature environments, realize the automatic temperature compensation function, and ensure the imaging quality in different temperature environments.

[0050] According to one solution of the present invention, the refractive index Nd10 and the Abbe number Vd10 of the tenth lens satisfy the following relationship: 1.75≤Nd10≤1.85; 20.00≤Vd10≤26.00. When the refractive index and the Abbe number of the material used in the tenth lens satisfy the above relationship, it is beneficial to correct the chromatic aberration of the large aperture and large target surface lens and ensure the resolution performance. It can achieve confocality of visible light and infrared light, ensuring that the resolution requirements of visible light and infrared light can be taken into account at the same time.

[0051] According to one solution of the present invention, the refractive index Nd11 and the Abbe number Vd11 of the eleventh lens satisfy the following relationship: 1.65≤Nd11≤1.75; 25.00≤Vd11≤35.00. When the refractive index and the Abbe number of the material used in the eleventh lens satisfy the above relationship, it is beneficial to correct the chromatic aberration of the large aperture and large target surface lens and ensure the resolution performance. It can achieve confocality of visible light and infrared light, ensuring that the resolution requirements of visible light and infrared light can be taken into account at the same time.

[0052] According to one solution of the present invention, the refractive index Nd12 and the Abbe number Vd12 of the twelfth lens satisfy the following relationship: 1.70≤Nd12≤1.80; 45.00≤Vd12≤50.00. When the refractive index and the Abbe number of the material used for the twelfth lens satisfy the above relationship, it is beneficial to correct the chromatic aberration of the large aperture and large target surface lens and ensure the resolution performance.

[0053] According to one solution of the present invention, the axial distance BFL from the image side of the twelfth lens to the image plane (target plane) and the axial distance TTL from the object side of the first lens to the image plane satisfy the following relationship: 2.50≤(TTL-1.25*BFL) / BFL≤3.00. On the premise of ensuring the total length of the optical system, there is sufficient space from the image side of the twelfth lens to the target plane to meet the flange distance requirements; there is enough space to place the filter element to effectively filter out the influence of the non-imaging spectrum, ensuring that high-resolution visible light and infrared light imaging quality can be obtained respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A schematic diagram showing the structure of an imaging lens according to a first embodiment of the present invention;

[0055] Figure 2 A diagram schematically showing a visible light MTF performance diagram of an imaging lens according to a first embodiment of the present invention;

[0056] Figure 3 Schematically showing an infrared light Through-Focus-MTF performance diagram of an imaging lens according to a first embodiment of the present invention;

[0057] Figure 4 Schematically showing a -40°C Through-Focus-MTF performance diagram of an imaging lens according to a first embodiment of the present invention;

[0058] Figure 5 Schematically showing a +85°C Through-Focus-MTF performance diagram of an imaging lens according to a first embodiment of the present invention;

[0059] Figure 6 A schematic diagram showing the structure of an imaging lens according to a second embodiment of the present invention;

[0060] Figure 7 A diagram schematically showing a visible light MTF performance diagram of an imaging lens according to a second embodiment of the present invention;

[0061] Figure 8 Schematically showing an infrared light Through-Focus-MTF performance diagram of an imaging lens according to a second embodiment of the present invention;

[0062] Fig. 9 Schematically showing a -40°C Through-Focus-MTF performance diagram of an imaging lens according to a second embodiment of the present invention;

[0063] Fig.10 Schematically showing a +85°C Through-Focus-MTF performance diagram of an imaging lens according to a second embodiment of the present invention;

[0064] Fig.11 A schematic diagram showing the structure of an imaging lens according to a third embodiment of the present invention;

[0065] Fig.12 A diagram schematically showing a visible light MTF performance diagram of an imaging lens according to a third embodiment of the present invention;

[0066] Fig.13 Schematically showing an infrared light Through-Focus-MTF performance diagram of an imaging lens according to a third embodiment of the present invention;

[0067] Fig.14Schematically showing a -40°C Through-Focus-MTF performance diagram of an imaging lens according to a third embodiment of the present invention;

[0068] Fig.15 Schematically showing a +85°C Through-Focus-MTF performance diagram of an imaging lens according to a third embodiment of the present invention;

[0069] Fig.16 A schematic diagram showing the structure of an imaging lens according to a fourth embodiment of the present invention;

[0070] Fig.17 A diagram schematically showing a visible light MTF performance diagram of an imaging lens according to a fourth embodiment of the present invention;

[0071] Fig.18 Schematically showing an infrared light Through-Focus-MTF performance diagram of an imaging lens according to a fourth embodiment of the present invention;

[0072] Fig.19 Schematically showing a -40°C Through-Focus-MTF performance diagram of an imaging lens according to a fourth embodiment of the present invention;

[0073] Fig. 20 The +85°C Through-Focus-MTF performance diagram of the imaging lens according to the fourth embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0074] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0075] When describing the embodiments of the present invention, the orientation or positional relationship expressed by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or positional relationship shown in the relevant drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0076] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments cannot be described one by one here, but the embodiments of the present invention are not therefore limited to the following embodiments.

[0077] See also Figure 1 The imaging lens of the present invention comprises a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, an aperture STOP, a seventh lens L7, an eighth lens L8, a ninth lens L9, a tenth lens L10, an eleventh lens L11, and a twelfth lens L12, which are arranged in sequence from the object side to the image side along the optical axis. The optical focal lengths of the first lens L1, the second lens L2, the fourth lens L4, the sixth lens L6, the eighth lens L8, and the eleventh lens L11 are negative, and the optical focal lengths of the remaining lenses are positive. In this way, the present invention reasonably configures positive optical focal length lenses and negative optical focal length lenses at different positions, which can receive incident light of a certain angle and ensure that the light has a sufficient image height when it reaches the image plane. In addition, it can avoid large-angle refraction of the incident light when passing through each optical surface, so that the light trend is smooth, which is conducive to correcting aberrations and reducing the system tolerance sensitivity.

[0078] In the present invention, the first lens L1 is a convexo-concave type, the second lens L2 is a concave-convex type, the third lens L3 is a biconvex type, the fourth lens L4 is a biconcave type, the fifth lens L5 is a biconvex type, the sixth lens L6 is a biconcave type, the seventh lens L7 is a biconvex type, the eighth lens L8 is a biconcave type, the ninth lens L9 is a biconvex type, the tenth lens L10 is a biconvex type, the eleventh lens L11 is a biconcave type, and the twelfth lens L12 is a biconvex type. In this way, the direction of curvature of each optical surface of the lens at different specific positions and the shape presented by the lens ensure that the lens can meet certain field of view angles and image height requirements; effectively control optical distortion and achieve low distortion imaging effects; can make the light trend smooth, which is conducive to correcting aberrations and reducing system tolerance sensitivity.

[0079] In the present invention, the imaging lens comprises at least three cemented lens groups. Specifically, the third lens L3 and the fourth lens L4 form a double cemented lens group or are independent of each other. The fifth lens L5 and the sixth lens L6 form a double cemented lens group. The seventh lens L7, the eighth lens L8 and the ninth lens L9 form a triple cemented lens group. The tenth lens L10 and the eleventh lens L11 form a double cemented lens group; or, the eleventh lens L11 and the twelfth lens L12 form a double cemented lens group; or, the tenth lens L10, the eleventh lens L11 and the twelfth lens L12 form a triple cemented lens group. As designed above, in the entire imaging lens, by reasonably designing double cemented or triple cemented lenses, it is beneficial to correct the chromatic aberration of the visible spectrum of the lens, ensure the imaging quality, and improve the resolution performance; achieve the confocal of visible light and infrared light, and ensure that the resolution requirements of visible light and infrared light can be taken into account at the same time; it is also beneficial to reduce the tolerance sensitivity and improve the production yield.

[0080] In the present invention, the half image height IH and the effective focal length EFL of the imaging lens satisfy the following relationship: 0.30≤IH / EFL≤0.45. In this way, the lens system can be guaranteed to meet the performance advantages of a large target surface and can be used with chips of various models. The distortion of the optical system can be effectively controlled to achieve a low-distortion imaging effect.

[0081] The refractive index Nd5 and the Abbe number Vd5 of the fifth lens L5 satisfy the following relationship: 1.85≤Nd5≤1.95; 30.00≤Vd5≤40.00. The refractive index Nd6 and the Abbe number Vd6 of the sixth lens L6 satisfy the following relationship: 1.60≤Nd6≤1.65; 35.00≤Vd6≤39.00. The refractive index Nd7 and the Abbe number Vd7 of the seventh lens L7 satisfy the following relationship: 1.45≤Nd7≤1.65; 60.00≤Vd7≤82.00. The refractive index Nd8 and the Abbe number Vd8 of the eighth lens L8 satisfy the following relationship: 1.60≤Nd8≤1.70; 30.00≤Vd8≤35.00. The refractive index Nd9 and the Abbe number Vd9 of the ninth lens L9 satisfy the following relationship: 1.45≤Nd9≤1.65; 60.00≤Vd9≤85.00. The refractive index Nd10 and the Abbe number Vd10 of the tenth lens L10 satisfy the following relationship: 1.75≤Nd10≤1.85; 20.00≤Vd10≤26.00. The refractive index Nd11 and the Abbe number Vd11 of the eleventh lens L11 satisfy the following relationship: 1.65≤Nd11≤1.75; 25.00≤Vd11≤35.00. The refractive index Nd12 and the Abbe number Vd12 of the twelfth lens L12 satisfy the following relationship: 1.70≤Nd12≤1.80; 45.00≤Vd12≤50.00.

[0082] When each lens satisfies the above relationship, it is beneficial to correct the chromatic aberration of the large aperture and large target surface lens and ensure the resolution performance. Among them, the seventh lens L7 and the ninth lens L9 satisfy the above relationship and can also maintain the stability of the effective focal length of the lens in different temperature environments, realize the automatic temperature compensation function, and ensure the imaging quality in different temperature environments. The tenth lens L10 and the eleventh lens L11 satisfy the above relationship and can also achieve visible light and infrared light confocality, ensuring that the resolution requirements of visible light and infrared light can be taken into account at the same time.

[0083] In the present invention, the axial distance BFL from the image side surface (second optical surface) of the twelfth lens L12 to the image plane (target surface) and the axial distance TTL from the object side surface (first optical surface) of the first lens L1 to the image plane satisfy the following relationship: 2.50≤(TTL-1.25*BFL) / BFL≤3.00. In this way, under the premise of ensuring the total length of the optical system, there is sufficient space from the image side surface of the twelfth lens L12 to the target surface to meet the flange distance requirements; there is enough space to place the filter element A to effectively filter out the influence of the non-imaging spectrum, ensuring that high-resolution visible light and infrared light imaging quality can be obtained respectively.

[0084] Four sets of implementations are given below to specifically illustrate the optical system of the present invention based on the above-mentioned configuration of the present invention. In the following implementations, S1, S2, ..., SN are used to represent the surfaces of each lens, wherein the cemented surface of the cemented lens group is recorded as one surface, and the stop is recorded as STOP. The parameter settings of each implementation meet the following Table 1:

[0085]

[0086]

[0087] Table 1

[0088] The first implementation method:

[0089] See also Figure 1 In this embodiment, the fifth lens L5 and the sixth lens L6 form a doublet lens group, the seventh lens L7, the eighth lens L8 and the ninth lens L9 form a triplet lens group, and the tenth lens L10 and the eleventh lens L11 form a doublet lens group. The half image height IH of the imaging lens is 10.89 mm, and the aperture value FNo is 1.60. The parameters of each lens are shown in Table 2 below:

[0090] Surface number Surface type Radius of curvature thickness Refractive Index Abbe number S1 Spherical 43.60 1.00 1.49 70.4 S2 Spherical 15.67 6.69 S3 Spherical -21.58 5.00 1.73 54.7 S4 Spherical -27.25 0.10 S5 Spherical 29.95 3.74 1.83 42.7 S6 Spherical -134.84 3.02 S7 Spherical -54.88 1.00 1.49 70.4 S8 Spherical 20.58 7.17 S9 Spherical 22.28 5.56 1.88 39.2 S10 Spherical -32.37 0.80 1.60 38.0 S11 Spherical 13.81 5.15 S12(STOP) Spherical Infinity 2.25 S13 Spherical 57.24 6.35 1.62 63.4 S14 Spherical -10.23 0.80 1.64 33.8 S15 Spherical 14.59 5.46 1.49 81.6 S16 Spherical -58.80 2.62 S17 Spherical 78.09 5.37 1.85 23.8 S18 Spherical -13.29 0.80 1.69 31.2 S19 Spherical 26.48 1.07 S20 Spherical 26.79 7.22 1.79 47.5 S21 Spherical -81.80 6.75 S22 Spherical Infinity 1.60 1.52 64.2 S23 Spherical Infinity 14.27 S24 (image plane) Spherical Infinity

[0091] Table 2

[0092] After combination Figures 2 to 5 It can be seen that the imaging lens of this embodiment can achieve confocality of the visible spectrum and the infrared spectrum by using different glass material lenses and designs, and no additional light supplement equipment is required when working at night. At the same time, it has the superior performance of large aperture (Fno≤1.6) and large target surface (half-image height φ≥8.75mm), and can obtain high-definition imaging pictures for both visible spectrum and infrared spectrum; and has automatic temperature compensation function (no out-of-focus within -40℃~+85℃).

[0093] The second implementation method:

[0094] See also Figure 6In this embodiment, the third lens L3 and the fourth lens L4 form a doublet group, the fifth lens L5 and the sixth lens L6 form a doublet group, the seventh lens L7, the eighth lens L8 and the ninth lens L9 form a triplet group, and the tenth lens L10 and the eleventh lens L11 form a doublet group. The half image height IH of the imaging lens is 10.18 mm, and the aperture value FNo is 1.58. The parameters of each lens are shown in Table 3 below:

[0095] Surface number Surface type Radius of curvature thickness Refractive Index Abbe number S1 Spherical 40.50 1.23 1.49 70.4 S2 Spherical 14.73 7.18 S3 Spherical -21.34 3.50 1.73 54.7 S4 Spherical -26.74 0.10 S5 Spherical 32.10 3.22 1.83 42.7 S6 Spherical -121.10 2.48 1.49 70.4 S7 Spherical 20.07 9.58 S8 Spherical 21.99 7.22 1.89 37.1 S9 Spherical -33.94 0.80 1.61 37.0 S10 Spherical 13.72 5.29 S11(STOP) Spherical Infinity 3.44 S12 Spherical 58.33 5.91 1.60 65.5 S13 Spherical -10.08 0.80 1.66 33.1 S14 Spherical 14.89 5.89 1.59 67.3 S15 Spherical -63.86 3.00 S16 Spherical 69.56 4.85 1.82 22.7 S17 Spherical -13.81 0.80 1.70 30.1 S18 Spherical 26.39 1.16 S19 Spherical 28.69 3.12 1.77 49.6 S20 Spherical -84.90 7.56 S21 Spherical Infinity 1.60 1.52 64.2 S22 Spherical Infinity 15.05 S23 Spherical Infinity

[0096] Table 3

[0097] After combination Figures 7 to 10 It can be seen that the imaging lens of this embodiment can achieve confocality of the visible spectrum and the infrared spectrum by using different glass material lenses and designs, and no additional light supplement equipment is required when working at night. At the same time, it has the superior performance of large aperture (Fno≤1.6) and large target surface (half-image height φ≥8.75mm), and can obtain high-definition imaging pictures for both visible spectrum and infrared spectrum; and has automatic temperature compensation function (no out-of-focus within -40℃~+85℃).

[0098] The third implementation method:

[0099] See also Fig.11 In this embodiment, the fifth lens L5 and the sixth lens L6 form a doublet lens group, the seventh lens L7, the eighth lens L8 and the ninth lens L9 form a triplet lens group, and the tenth lens L10, the eleventh lens L11 and the twelfth lens L12 form a triplet lens group. The half image height IH of the imaging lens is 9.47 mm, and the aperture value FNo is 1.56. The parameters of each lens are shown in Table 4 below:

[0100] Surface number Surface type Radius of curvature thickness Refractive Index Abbe number S1 Spherical 35.20 2.50 1.49 70.4 S2 Spherical 14.68 6.76 S3 Spherical -23.80 5.00 1.73 54.7 S4 Spherical -29.79 0.10 S5 Spherical 29.59 3.86 1.87 40.7 S6 Spherical -122.74 1.35 S7 Spherical -58.14 0.80 1.49 70.4 S8 Spherical 18.92 7.79 S9 Spherical 21.46 5.56 1.90 31.4 S10 Spherical -29.77 0.80 1.62 36.4 S11 Spherical 13.35 5.28 S12(STOP) Spherical Infinity 2.25 S13 Spherical 146.00 5.83 1.59 67.3 S14 Spherical -9.54 0.80 1.67 32.2 S15 Spherical 15.16 5.19 1.60 65.5 S16 Spherical -51.02 2.93 S17 Spherical 90.07 5.44 1.81 25.5 S18 Spherical -12.50 0.80 1.72 29.5 S19 Spherical 39.74 7.20 1.76 47.7 S20 Spherical -54.73 7.39 S21 Spherical Infinity 1.60 1.52 64.2 S22 Spherical Infinity 15.3 S23 Spherical Infinity

[0101] Table 4

[0102] After combination Figures 12 to 15 It can be seen that the imaging lens of this embodiment can achieve confocality of the visible spectrum and the infrared spectrum by using different glass material lenses and designs, and no additional light supplement equipment is required when working at night. At the same time, it has the superior performance of large aperture (Fno≤1.6) and large target surface (half-image height φ≥8.75mm), and can obtain high-definition imaging pictures for both visible spectrum and infrared spectrum; and has automatic temperature compensation function (no out-of-focus within -40℃~+85℃).

[0103] The fourth implementation method:

[0104] See also Fig.16In this embodiment, the fifth lens L5 and the sixth lens L6 form a doublet lens group, the seventh lens L7, the eighth lens L8 and the ninth lens L9 form a triplet lens group, and the eleventh lens L11 and the twelfth lens L12 form a doublet lens group. The half image height IH of the imaging lens is 8.75 mm, and the aperture value FNo is 1.54. The parameters of each lens are shown in Table 5 below:

[0105]

[0106]

[0107] Table 5

[0108] After combination Figures 17 to 20 It can be seen that the imaging lens of this embodiment can achieve confocality of the visible spectrum and the infrared spectrum by using different glass material lenses and designs, and no additional light supplement equipment is required when working at night. At the same time, it has the superior performance of large aperture (Fno≤1.6) and large target surface (half-image height φ≥8.75mm), and can obtain high-definition imaging pictures for both visible spectrum and infrared spectrum; and has automatic temperature compensation function (no out-of-focus within -40℃~+85℃).

[0109] The above is only one solution of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An imaging lens, comprising a first lens (L1), a second lens (L2), a third lens (L3), a fourth lens (L4), a fifth lens (L5), a sixth lens (L6), a stop (STOP), a seventh lens (L7), an eighth lens (L8), a ninth lens (L9), a tenth lens (L10), an eleventh lens (L11), and a twelfth lens (L12) arranged in sequence from the object side to the image side along the optical axis, characterized in that: The optical power of the first lens (L1), the second lens (L2), the fourth lens (L4), the sixth lens (L6), the eighth lens (L8) and the eleventh lens (L11) is negative, and the optical power of the remaining lenses is positive.

2. The imaging lens according to claim 1, characterized in that: The fifth lens (L5) is biconvex, the sixth lens (L6) is biconcave, the seventh lens (L7) is biconvex, the eighth lens (L8) is biconcave, and the ninth lens (L9) is biconvex.

3. The imaging lens according to claim 1, wherein: The first lens (L1) is a convex-concave type, the second lens (L2) is a concave-convex type, the third lens (L3) is a biconvex type, the fourth lens (L4) is a biconcave type, the tenth lens (L10) is a biconvex type, the eleventh lens (L11) is a biconcave type, and the twelfth lens (L12) is a biconvex type.

4. The imaging lens according to claim 1, wherein: Contains at least three cemented lens groups.

5. The imaging lens according to claim 4, characterized in that: The third lens (L3) and the fourth lens (L4) form a doublet lens group or are independent of each other; The tenth lens (L10) and the eleventh lens (L11) form a doublet lens group, or the eleventh lens (L11) and the twelfth lens (L12) form a doublet lens group, or the tenth lens (L10), the eleventh lens (L11) and the twelfth lens (L12) form a triplet lens group.

6. The imaging lens according to claim 4, characterized in that: The fifth lens (L5) and the sixth lens (L6) form a doublet lens group; The seventh lens (L7), the eighth lens (L8) and the ninth lens (L9) form a triplet lens group.

7. The imaging lens according to any one of claims 1 to 6, characterized in that: The half image height IH and the effective focal length EFL of the imaging lens satisfy the following relationship: 0.30≤IH / EFL≤0.

45.

8. The imaging lens according to any one of claims 1 to 6, characterized in that: The refractive index Nd5 and the Abbe number Vd5 of the fifth lens (L5) satisfy the following relationship: 1.85≤Nd5≤1.95; 30.00≤Vd5≤40.

00.

9. The imaging lens according to any one of claims 1 to 6, characterized in that: The refractive index Nd6 and the Abbe number Vd6 of the sixth lens (L6) satisfy the following relationship: 1.60≤Nd6≤1.65; 35.00≤Vd6≤39.

00.

10. The imaging lens according to any one of claims 1 to 6, characterized in that: The refractive index Nd7 and the Abbe number Vd7 of the seventh lens (L7) satisfy the following relationship: 1.45≤Nd7≤1.65; 60.00≤Vd7≤82.

00.

11. The imaging lens according to any one of claims 1 to 6, characterized in that: The refractive index Nd8 and the Abbe number Vd8 of the eighth lens (L8) satisfy the following relationship: 1.60≤Nd8≤1.70; 30.00≤Vd8≤35.

00.

12. The imaging lens according to any one of claims 1 to 6, characterized in that: The refractive index Nd9 and the Abbe number Vd9 of the ninth lens (L9) satisfy the following relationship: 1.45≤Nd9≤1.65; 60.00≤Vd9≤85.

00.

13. The imaging lens according to any one of claims 1 to 6, characterized in that: The refractive index Nd10 and the Abbe number Vd10 of the tenth lens (L10) satisfy the following relationship: 1.75≤Nd10≤1.85; 20.00≤Vd10≤26.

00.

14. The imaging lens according to any one of claims 1 to 6, characterized in that: The refractive index Nd11 and the Abbe number Vd11 of the eleventh lens (L11) satisfy the following relationship: 1.65≤Nd11≤1.75; 25.00≤Vd11≤35.

00.

15. The imaging lens according to any one of claims 1 to 6, characterized in that: The refractive index Nd12 and the Abbe number Vd12 of the twelfth lens (L12) satisfy the following relationship: 1.70≤Nd12≤1.80; 45.00≤Vd12≤50.

00.

16. The imaging lens according to any one of claims 1 to 6, characterized in that: The axial distance BFL from the image side surface of the twelfth lens (L12) to the image plane and the axial distance TTL from the object side surface of the first lens (L1) to the image plane satisfy the following relationship: 2.50≤(TTL-1.25*BFL) / BFL≤3.00.

Images