Optical module with three lens groups

Abstract

The utility model discloses an optical module with three lens groups, which comprises a first lens group, a movable second lens group and a movable third lens group, the first lens group, the second lens group and the third lens group are arranged on one side of an imaging end face from far to near, and the intersection point of incident light is focused on the imaging end face; in the zooming adjustment, the second lens group is moved to realize zooming, and meanwhile, the third lens group is slightly moved to realize focusing compensation, and the focal length deviation of the light focused on the imaging end surface is dynamically adjusted; the long focal length of the optical module is ft, the short focal length of the optical module is fw, the total length of the optical module is TTL, and the back focal length of the optical module is B. The relation among the long focal length, the short focal length, the total length and the back focal length of the optical module meets the following conditions: (1) 2.8 lt; f < t > / f < w >; 3.5); (2) 2.5 ftt; tlt; 2.8 ft; (3) 3fw / 4lt; blt; ft / 3; (4) TTL / ftlt is carried out; 2.8); (5) 0.7 lt; b / fwlt; and 0.8.

Description

Technical Field

[0001] The utility model relates to the technical field of optical lenses, and more specifically to an optical module of three lens groups. Background Art

[0002] Light transmission system refers to the general term for equipment or devices that provide a light channel between the light source and the subject during photography. In photography, the light transmission system mainly includes lens, aperture, shutter, reflector, condenser and other parts. Its main function is to control the way and amount of light entering, thereby affecting the exposure and image quality of the photo.

[0003] Among them, the lens used in the light transmission system includes an optical module. In the prior art, such as the optical module of patent document 202010156658.7, the optical module includes a first lens group for focusing, and a second lens group and a third lens group for zoom adjustment. The dual-lens group linkage of the second lens group and the third lens group can dynamically compensate for the focus deviation of the imaging light beam caused by the change of focal length during the zoom adjustment period, so that the zoom adjustment can be performed without the need for the first lens group to refocus through adaptive movement. Moreover, the full zoom adjustment process between the wide-angle mode and the telephoto mode of the optical module can avoid the diffuse focusing of the imaging light beam on the imaging target surface, so as to achieve clear focus throughout the zoom process.

[0004] However, this optical module is the same as other existing optical modules, and the lenses it uses include aspherical lenses, a large number of lenses, or the use of double lenses, which results in a higher cost for the optical module. In addition, for high-power light transmission systems, due to the higher energy of the light beam, the lens needs to withstand higher temperatures and stronger beam pressures. If double lenses are used, temperature changes, uneven stress distribution and other factors may cause lens deformation, displacement and other problems, affecting the stability of the light beam and optical performance. Summary of the invention

[0005] In order to overcome the shortcomings of the existing optical modules, such as high cost and unsuitability for application in high-power light transmission systems, the utility model provides an optical module with three lens groups.

[0006] The technical solution of the utility model is as follows:

[0007] An optical module with three lens groups, comprising a first lens group, a movable second lens group and a movable third lens group, wherein the first lens group, the second lens group and the third lens group are arranged on one side of an imaging end surface from far to near, and the intersection of incident light rays is focused on the imaging end surface;

[0008] In zoom adjustment, the second lens group is moved to achieve zoom, and the third lens group is slightly moved to achieve focus compensation, dynamically adjusting the focal length deviation of the light focused on the imaging end surface;

[0009] The telephoto of the optical module is ft, the short focal length is fw, the total length of the optical module is TTL, and the back focal length is B. The relationship between the telephoto, short focal length, total length, and back focal length of the optical module satisfies:

[0010] (1)2.8 <ft / fw<3.5;

[0011] (2) 2.5ft <T<2.8ft;

[0012] (3)3fw / 4 <B<ft / 3;

[0013] (4) TTL / ft<2.8;

[0014] (5)0.7

[0015] The first lens group can be fixed or moved during focusing.

[0016] The above-mentioned three-lens group optical module uses 11 spherical lenses in total, and the first lens group includes two lenses with positive focal length.

[0017] In the above-mentioned three-lens group optical module, the focal length of the optical assembly formed by the first lens group is the first lens group focal length GFL1, and the first lens group focal length GFL1 is a positive focal length; the focal length of the optical assembly formed by the second lens group is the second lens group focal length GFL2, and the second lens group focal length GFL2 is a negative focal length; the focal length of the optical assembly formed by the third lens group is the third lens group focal length GFL3, and the third lens group focal length GFL3 is a positive focal length.

[0018] Furthermore, the first lens group includes a first lens and a second lens, the relationship between the focal length SFL1 of the first lens and the focal length GFL1 of the first lens group satisfies: SFL1 / GFL1=1.8~2.2, and the relationship between the focal length SFL2 of the second lens and the focal length GFL1 of the first lens group satisfies: SFL2 / GFL1=1.6~2.0.

[0019] Furthermore, the second lens group includes a third lens, a fourth lens and a fifth lens, and the relationship between the focal length SFL3 of the third lens and the focal length GFL2 of the second lens group satisfies: SFL3 / GFL2=1.2~1.6, the relationship between the focal length SFL4 of the fourth lens and the focal length GFL2 of the second lens group satisfies: SFL4 / GFL2=1.6~2.0, and the relationship between the focal length SFL5 of the fifth lens and the focal length GFL2 of the second lens group satisfies: SFL5 / GFL2=-3.3~-3.7.

[0020] ​Further, the third lens group includes a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens and an eleventh lens, the relationship between the focal length SFL6 of the sixth lens and the focal length GFL3 of the third lens group satisfies: SFL6 / GFL3=1.7-2.1, the relationship between the focal length SFL7 of the seventh lens and the focal length GFL3 of the third lens group satisfies: SFL7 / GFL3=1.2-1.4, the relationship between the focal length SFL8 of the eighth lens and the focal length GFL3 of the third lens group satisfies: SF L8 / GFL3=-0.55~-0.75, the relationship between the focal length SFL9 of the ninth lens and the focal length GFL3 of the third lens group satisfies: SFL9 / GFL3=0.9~1.1, the relationship between the focal length SFL10 of the tenth lens and the focal length GFL3 of the third lens group satisfies: SFL10 / GFL3=1.1~1.4, the relationship between the focal length SFL11 of the eleventh lens and the focal length GFL3 of the third lens group satisfies: SFL11 / GFL3=-1.9~-2.3.

[0021] Furthermore, the relationship between the focal length GFL1 of the first lens group and the telephoto ft of the optical module satisfies: GFL1 / ft=1.8~2.2, the relationship between the focal length GFL2 of the second lens group and the telephoto ft of the optical module satisfies: GFL2 / ft=-0.4~-0.8, and the relationship between the focal length GFL3 of the third lens group and the telephoto ft of the optical module satisfies: GFL3 / ft=0.4~0.8.

[0022] The above-mentioned optical module with three lens groups has a field angle range of a to b, wherein the value range of a is 11 to 15 degrees, and the value range of b is 33 to 45 degrees.

[0023] In the above-mentioned optical module with three lens groups, the refractive index of all lenses of the optical module satisfies: 1.49<nd<1.75, wherein nd is the refractive index of the lens.

[0024] In the above-mentioned three-lens group optical module, the first lens group includes a first lens and a second lens, and both the first lens and the second lens are spherical lenses with positive focal lengths.

[0025] In the above-mentioned three-lens-group optical module, the first lens group includes a first lens and a second lens, the second lens group includes a third lens, a fourth lens and a fifth lens, the third lens group includes a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens and an eleventh lens, and the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens and the eleventh lens are all spherical lenses.

[0026] The above-mentioned three-lens group optical module further includes an aperture, which is arranged on a side of the third lens group away from the imaging end surface.

[0027] The above-mentioned three-lens group optical module also includes a filter, which is arranged between the third lens group and the imaging end face, or the last mirror surface of the third lens group is a plane, and the filter is attached to the last mirror surface of the third lens group.

[0028] The utility model according to the above scheme has the beneficial effect that the utility model uses 11 spherical lenses to form a zoom optical module, and uses two positive lenses in the first lens group to replace the existing three lenses, the combination of doublet lenses and positive lenses, while ensuring the imaging quality and being facilitating the application in high-power light transmission systems, while reducing costs, and by limiting the refractive index of the lens to below 1.75 through the relationship between long focus, short focus, total length and back focus, further reducing costs.

[0029] 1. The present invention uses only 11 lenses without double lenses. The absence of double lenses can ensure that the optical module of the present invention can be used in high-power light-transmitting systems (such as projectors, lighting systems, etc.), and when achieving the same effect, the number of lenses used is reduced, effectively reducing costs.

[0030] 2. The optical module of the utility model maintains an F number of 1.1-1.2 in the full zoom range, ensuring the light throughput of the system within the zoom range, so that the photos taken are clear and bright. In low-light environments, the zoom lens can also provide excellent performance, maintaining high clarity and low noise levels.

[0031] 3. The optical module of the utility model has a distortion value of less than 3% within the full zoom range, which can provide more accurate images, reduce the complexity and workload of post-processing, and allow photographers to adjust the focal length as needed during shooting without worrying about image distortion, providing photographers with greater creative freedom and flexibility.

[0032] 4. The lenses used in the present invention are all spherical lenses. Compared with aspherical lenses, the present invention has lower cost, is easier to manufacture and process, and the curvature of spherical lenses is fixed, so it can better control the aberration of the optical system. Through the arrangement, curvature, focal length relationship and other design schemes of the spherical lenses in the present invention, the aberration can be effectively corrected, the imaging quality of the optical system can be improved, and the use of double lenses can be avoided to meet the needs of high-power light transmission systems. In addition, compared with aspherical lenses, spherical lenses can reduce the thickness and weight of optical modules. On the one hand, for light transmission systems such as video and photographic equipment that need to be worn or handheld for a long time, it can effectively reduce the weight of the product and improve the user experience. On the other hand, the small thickness of the lens is conducive to improving the thermal stability and optical performance of the optical module. The former avoids the lens from absorbing more heat, causing the lens itself to be affected by thermal stress. Long-term use may affect the stability and optical performance of the lens, making the optical module of the present invention conducive to application in high-power light transmission systems. The latter can effectively avoid the generation of chromatic aberration or the reduction of imaging quality in some cases, and ensure the imaging quality.

[0033] 5. The first lens group of the utility model adopts two spherical lenses with positive focal length. Compared with other designs that adopt three lenses (two positive lenses and one negative lens) or two lenses (one positive lens and one negative lens, or one doublet lens and one positive lens), the design of directly using two positive lenses can better maintain the parallelism of light after passing through the first lens group, which helps to improve the overall performance of the optical module, especially when dealing with high-power light transmission systems, it can better control the direction and focusing effect of light, so that the optical module can ensure the imaging quality without the presence of doublet lenses, avoid the generation of chromatic aberration problems, and is more suitable for application in high-power light transmission systems.

[0034] The first lens group is a light-transmitting first lens group. The design of only having positive focal length lenses also helps to improve the transmittance of light, reduce light loss, and improve the overall light utilization rate, which is especially important for application scenarios that require high brightness and high contrast.

[0035] In addition, the two positive focal length lenses used in the utility model can be adjusted independently, and more precise and flexible light control can be achieved in zoom adjustment, which not only simplifies the adjustment process of the optical module, but also improves the adjustability and adaptability of the optical module.

[0036] 6. While utilizing 11 spherical lenses to ensure imaging quality and reduce costs, the utility model limits the refractive index of all lenses to less than 1.75 by numerically limiting the relationship between long focus, short focus, total length, and back focus, thereby further reducing the cost of the lenses. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 It is a schematic diagram of the light path effect of the optical module of the utility model.

[0039] Figure 2 Schematic diagram of the optical path effect when the optical module is in telephoto mode.

[0040] Figure 3 It is a schematic diagram of the optical path effect when the optical module is in the first zoom adjustment process.

[0041] Figure 4 It is a schematic diagram of the optical path effect when the optical module is in the second zoom adjustment process.

[0042] Figure 5 Schematic diagram of the optical path effect when the optical module is in the third zoom adjustment process.

[0043] Figure 6 Schematic diagram of the optical path effect when the optical module is in wide-angle mode.

[0044] Among them, the reference numerals in the figure are:

[0045] 100. first lens group; 200. second lens group; 300. third lens group; 400 aperture; 500; imaging end surface;

[0046] 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; 6. Sixth lens; 7. Seventh lens; 8. Eighth lens; 9. Ninth lens; 10. Tenth lens; 11. Eleventh lens. DETAILED DESCRIPTION

[0047] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0048] An optical module with three lens groups, such as Figure 1-Figure 6 As shown, it includes a first lens group, a movable second lens group and a movable third lens group, the first lens group, the second lens group and the third lens group are arranged on one side of the imaging end surface from far to near, and the intersection of the incident light rays is focused on the imaging end surface;

[0049] In zoom adjustment, the second lens group is moved to achieve zoom, and the third lens group is slightly moved to achieve focus compensation, dynamically adjusting the focal length deviation of the light focused on the imaging end surface;

[0050] The telephoto of the optical module is ft, the short focal length is fw, the total length of the optical module is TTL, and the back focal length is B. The relationship between the telephoto, short focal length, total length, and back focal length of the optical module satisfies:

[0051] (1)2.8 <ft / fw<3.5;

[0052] (2) 2.5ft <T<2.8ft;

[0053] (3)3fw / 4 <B<ft / 3;

[0054] (4) TTL / ft<2.8;

[0055] (5)0.7

[0056] The optical module uses a total of 11 spherical lenses and three lens groups. The focal length GFL1 of the first lens group is positive, the focal length GFL2 of the second lens group is negative, and the focal length GFL3 of the third lens group is positive. The first lens group includes two lenses with positive focal lengths, the first lens group includes the first lens and the second lens, the second lens group includes the third lens, the fourth lens and the fifth lens, the third lens group includes the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens and the eleventh lens, and the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens and the eleventh lens are all spherical lenses.

[0057] The following embodiment is a preferred solution for matching glasses of an optical module. The optical module of this embodiment is as follows: Figure 1 As shown, the optical module is in the zoom adjustment process. In this embodiment, the optical module includes a first lens group 100, a second lens group 200 and a third lens group 300.

[0058] In this embodiment, the first lens group 100 includes a first lens 1 and a second lens 2, the second lens group 200 includes a third lens 3, a fourth lens 4 and a fifth lens 5, the third lens group 300 includes a sixth lens 6, a seventh lens 7, an eighth lens 8, a ninth lens 9, a tenth lens 10 and an eleventh lens 11, and the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens and the eleventh lens are all spherical lenses.

[0059] ​In this embodiment, the long focus of the optical module is 100.00 mm, the short focus of the optical module is 33.00 mm, and the focal length of the middle position of the optical module is 58.00 mm. In other embodiments, when the long focus is scaled to other data, the other data is scaled accordingly.

[0060] The first lens is a spherical lens with a refractive index of 1.49, the curvature radius of the first mirror surface of the first lens is 194.45 mm, the second mirror surface of the first lens is a plane, the aperture of the first mirror surface of the first lens is 57 mm, the aperture of the second mirror surface of the first lens is 57 mm, the thickness of the first lens is 11.03 mm, the field angle of the first lens is 70.40 degrees, and the focal length of the first lens is 400.00.

[0061] The distance between the first lens and the second lens is 1.65 mm.

[0062] The second lens is a spherical lens with a refractive index of 1.49, the curvature radius of the first mirror surface of the second lens is 112.44 mm, the curvature radius of the second mirror surface of the second lens is 274.17 mm, the aperture of the first mirror surface of the second lens is 54 mm, the aperture of the second mirror surface of the second lens is 54 mm, the thickness of the second lens is 10.86 mm, the field angle of the second lens is 70.40 degrees, and the focal length of the second lens is 380.00 mm.

[0063] The distance between the first lens group and the second lens group is 36.74 mm.

[0064] When the optical module is in the wide-angle mode, the distance between the first lens group and the second lens group is 1.65 mm.

[0065] When the optical module is in telephoto mode, the distance between the first lens group and the second lens group is 75.00 mm.

[0066] The focal length of the first lens group is 200.00 mm.

[0067] The third lens is a spherical lens with a refractive index of 1.64. The radius of curvature of the first mirror surface of the third lens is 176.28 mm, the radius of curvature of the second mirror surface of the third lens is 41.26 mm, the aperture of the first mirror surface of the third lens is 33 mm, the aperture of the second mirror surface of the third lens is 29 mm, the thickness of the third lens is 2.47 mm, the field angle of the third lens is 55.40 degrees, and the focal length of the third lens is -85.00 mm.

[0068] The distance between the third lens and the fourth lens is 21.93 mm.

[0069] The fourth lens is a spherical lens with a refractive index of 1.62, the curvature radius of the first mirror surface of the fourth lens is -117.40 mm, the curvature radius of the second mirror surface of the fourth lens is 168.14 mm, the aperture of the first mirror surface of the fourth lens is 27 mm, the aperture of the second mirror surface of the fourth lens is 27 mm, the thickness of the fourth lens is 2.57 mm, the field angle of the fourth lens is 58.10 degrees, and the focal length of the fourth lens is -110.00 mm.

[0070] The distance between the fourth lens and the fifth lens is 6.25 mm.

[0071] The fifth lens is a spherical lens with a refractive index of 1.64, the curvature radius of the first mirror surface of the fifth lens is 88.64 mm, the curvature radius of the second mirror surface of the fifth lens is 253.69 mm, the aperture of the first mirror surface of the fifth lens is 30 mm, the aperture of the second mirror surface of the fifth lens is 30 mm, the thickness of the fifth lens is 7.16 mm, the field angle of the fifth lens is 55.40 degrees, and the focal length of the fifth lens is 210.00 mm.

[0072] The focal length of the second lens group is -60.00 mm.

[0073] The distance between the second lens group and the third lens group is 43.16 mm.

[0074] When the optical module is in the wide-angle mode, the distance between the second lens group and the third lens group is 80.98 mm.

[0075] When the optical module is in telephoto mode, the distance between the second lens group and the third lens group is 5.43 mm.

[0076] The sixth lens is a spherical lens with a refractive index of 1.64, the curvature radius of the first mirror surface of the sixth lens is 156.56 mm, the curvature radius of the second mirror surface of the sixth lens is -139.57 mm, the aperture of the first mirror surface of the sixth lens is 30 mm, the aperture of the second mirror surface of the sixth lens is 30 mm, the thickness of the sixth lens is 8.29 mm, the field angle of the sixth lens is 55.40 degrees, and the focal length of the sixth lens is 115.00 mm.

[0077] The distance between the sixth lens and the seventh lens is 1.65 mm.

[0078] The seventh lens is a spherical lens with a refractive index of 1.62. The curvature radius of the first mirror surface of the seventh lens is 49.63 mm, the curvature radius of the second mirror surface of the seventh lens is -3020.03 mm, the aperture of the first mirror surface of the seventh lens is 30 mm, the aperture of the second mirror surface of the seventh lens is 30 mm, the thickness of the seventh lens is 12.57 mm, the field angle of the seventh lens is 60.30 degrees, and the focal length of the seventh lens is 80.00 mm.

[0079] The distance between the seventh lens and the eighth lens is 8.03 mm.

[0080] The eighth lens is a spherical lens with a refractive index of 1.73. The radius of curvature of the first mirror surface of the eighth lens is -72.97 mm, the radius of curvature of the second mirror surface of the eighth lens is 52.55 mm, the aperture of the first mirror surface of the eighth lens is 28 mm, the aperture of the second mirror surface of the eighth lens is 28 mm, the thickness of the eighth lens is 2.73 mm, the field angle of the eighth lens is 23.80 degrees, and the focal length of the eighth lens is -40.00 mm.

[0081] The distance between the eighth lens and the ninth lens is 17.00 mm.

[0082] The ninth lens is a spherical lens with a refractive index of 1.64, the curvature radius of the first mirror surface of the ninth lens is 137.19 mm, the curvature radius of the second mirror surface of the ninth lens is -53.61 mm, the aperture of the first mirror surface of the ninth lens is 36 mm, the aperture of the second mirror surface of the ninth lens is 36 mm, the thickness of the ninth lens is 21.61 mm, the field angle of the ninth lens is 55.40 degrees, and the focal length of the ninth lens is 64.00 mm.

[0083] The distance between the ninth lens and the tenth lens is 1.65 mm.

[0084] The tenth lens is a spherical lens with a refractive index of 1.64, the curvature radius of the first mirror surface of the tenth lens is 52.12 mm, the second mirror surface of the tenth lens is a plane, the aperture of the first mirror surface of the tenth lens is 30 mm, the aperture of the second mirror surface of the tenth lens is 30 mm, the thickness of the tenth lens is 11.52 mm, the field angle of the tenth lens is 55.40 degrees, and the focal length of the tenth lens is 82.00 mm.

[0085] The distance between the tenth lens and the eleventh lens is 6.72 mm.

[0086] The eleventh lens is a spherical lens with a refractive index of 1.72, the curvature radius of the first mirror surface of the eleventh lens is -82.65 mm, the second mirror surface of the eleventh lens is a plane, the aperture of the first mirror surface of the eleventh lens is 26 mm, the aperture of the second mirror surface of the eleventh lens is 23 mm, the thickness of the eleventh lens is 2.47 mm, the field angle of the eleventh lens is 29.50 degrees, and the focal length of the eleventh lens is -115.00 mm.

[0087] The focal length of the third lens group is 60.00 mm.

[0088] The distance between the third lens group and the imaging end surface, i.e., the back focus, is 28.13 mm.

[0089] When the optical module is in the wide-angle mode, the distance between the third lens group and the imaging end surface is 25.40 mm, that is, the back focus is 25.40 mm.

[0090] When the optical module is in telephoto mode, the distance between the third lens group and the imaging end surface, that is, the back focus, is 27.59 mm.

[0091] In this embodiment, the total length from the first mirror surface to the imaging end surface of the first lens is 270.00 mm.

[0092] In this embodiment, the diameter of the imaging end surface 500 is 13 mm.

[0093] In this embodiment, the viewing angle range of the optical module is a to b, wherein the value range of a is 11 to 15 degrees, and the value range of b is 33 to 45 degrees.

[0094] The optical module further includes an aperture 400, which is disposed on a side of the third lens group away from the imaging end surface. In other implementations, the distance between the aperture and the first mirror surface of the sixth lens of the third lens group is 1.65 mm.

[0095] The optical module also includes a filter, which is arranged between the third lens group and the imaging end face, or the last mirror surface of the third lens group is a plane, and the filter is attached to the last mirror surface of the third lens group.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An optical module with three lens groups, characterized in that: It comprises a first lens group, a movable second lens group and a movable third lens group, wherein the first lens group, the second lens group and the third lens group are arranged on one side of the imaging end surface from far to near, and the intersection of the incident light rays is focused on the imaging end surface; The optical module uses a total of 11 spherical lenses, and the first lens group includes two lenses with positive focal length; The telephoto of the optical module is ft, the short focal length is fw, the total length of the optical module is TTL, and the back focal length is B. The relationship between the telephoto, short focal length, total length, and back focal length of the optical module satisfies: (1)2.8 <ft / fw<3.5; (2) 2.5ft <T<2.8ft; (3)3fw / 4 <B<ft / 3; (4) TTL / ft<2.8; (5)0.7 The first lens group includes a first lens and a second lens, the second lens group includes a third lens, a fourth lens and a fifth lens, the third lens group includes a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens and an eleventh lens, and the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens and the eleventh lens are all spherical lenses.

2. An optical module with three lens groups according to claim 1, characterized in that: The focal length of the optical assembly formed by the first lens group is the first lens group focal length GFL1, which is a positive focal length. The focal length of the optical assembly formed by the second lens group is the second lens group focal length GFL2, which is a negative focal length. The focal length of the optical assembly formed by the third lens group is the third lens group focal length GFL3, which is a positive focal length.

3. The optical module of three lens groups according to claim 1, characterized in that: The first lens group includes a first lens and a second lens. The relationship between the focal length SFL1 of the first lens and the focal length GFL1 of the first lens group satisfies:

4. The optical module of three lens groups according to claim 3, characterized in that: SFL1 / GFL1=1.8-2.2, and the relationship between the focal length SFL2 of the second lens group and the focal length GFL1 of the first lens group satisfies: SFL2 / GFL1=1.6-2.

0. The second lens group includes a third lens, a fourth lens and a fifth lens. The relationship between the focal length SFL3 of the third lens and the focal length GFL2 of the second lens group satisfies: SFL3 / GFL2=1.2-1.

6. The relationship between the focal length SFL4 of the fourth lens and the focal length GFL2 of the second lens group satisfies: SFL4 / GFL2=1.6-2.

0. The relationship between the focal length SFL5 of the fifth lens and the focal length GFL2 of the second lens group satisfies:

5. The three-lens optical module according to claim 3, characterized in that: SFL5 / GFL2=-3.3~-3.

7. ​ 6. The three-lens optical module according to claim 3, characterized in that: The third lens group includes a sixth lens, a seventh lens, an eighth lens, a ninth lens, a tenth lens and an eleventh lens. The relationship between the focal length SFL6 of the sixth lens and the focal length GFL3 of the third lens group satisfies: SFL6 / GFL3=1.7~2.

1. The relationship between the focal length SFL7 of the seventh lens and the focal length GFL3 of the third lens group satisfies: SFL7 / GFL3=1.2~1.

4. The relationship between the focal length SFL8 of the eighth lens and the focal length GFL3 of the third lens group satisfies: SFL8 / GFL3=-0.55~-0.

75. The relationship between the focal length SFL9 of the ninth lens and the focal length GFL3 of the third lens group satisfies: SFL9 / GFL3=0.9~1.

1. The relationship between the focal length SFL10 of the tenth lens and the focal length GFL3 of the third lens group satisfies: SFL10 / GFL3=1.1~1.

4. The relationship between the focal length SFL11 of the eleventh lens and the focal length GFL3 of the third lens group satisfies: SFL11 / GFL3=-1.9~-2.

3.

7. The optical module of three lens groups according to claim 3, characterized in that: The relationship between the focal length GFL1 of the first lens group and the telephoto ft of the optical module satisfies: GFL1 / ft=1.8~2.2, the relationship between the focal length GFL2 of the second lens group and the telephoto ft of the optical module satisfies: GFL2 / ft=-0.4~-0.8, and the relationship between the focal length GFL3 of the third lens group and the telephoto ft of the optical module satisfies: GFL3 / ft=0.4~0.

8.

8. The optical module of three lens groups according to claim 1, characterized in that: The field of view angle range of the optical module is a to b, wherein the value range of a is 11 to 15 degrees, and the value range of b is 33 to 45 degrees.

9. The three-lens optical module according to claim 1, characterized in that: It also includes an aperture, which is arranged on a side of the third lens group away from the imaging end surface.

10. The three-lens optical module according to claim 1, characterized in that: It also includes a filter, which is arranged between the third lens group and the imaging end face, or the last mirror surface of the third lens group is a plane, and the filter is attached to the last mirror surface of the third lens group.

Images