Optical imaging lens group, coupler and endoscope

Abstract

The invention relates to an optical imaging lens group, a coupler and an endoscope. The optical imaging lens group comprises a front fixed group and a zoom group which are arranged along the direction of an optical axis; the front fixing group comprises a meniscus lens group, the meniscus lens group comprises a first meniscus lens, a second meniscus lens and a third meniscus lens, or the front fixing group comprises the third meniscus lens and a first doublet lens; the zoom group comprises a first positive lens and a second doublet lens; and the zoom group is used for changing the focal length of the optical imaging lens group under the condition of moving along the optical axis direction. The optical imaging lens group is beneficial to imaging.

Description

Technical Field

[0001] The present application relates to the technical field of endoscopes, and in particular to an optical imaging lens assembly, a coupler and an endoscope. Background Art

[0002] An endoscope is a commonly used medical device that is mainly used to observe lesions in the patient's body and provide images for clinical surgery and diagnosis.

[0003] The coupler is an important component in the endoscope. It is responsible for connecting the endoscope eyepiece and the detector, thereby transmitting the light signal detected by the endoscope eyepiece to the detector, and the detector forms an image based on the light signal output by the coupler. The optical imaging lens group is an important component of the coupler. Therefore, the design of the optical imaging lens group determines the imaging quality of the endoscope to a certain extent.

[0004] Therefore, how to design an optical imaging lens assembly that is conducive to imaging is a key research topic for people in this field. Summary of the invention

[0005] Based on this, it is necessary to provide an optical imaging lens set, a coupler and an endoscope that can facilitate imaging in order to solve the above-mentioned technical problems.

[0006] In a first aspect, the present application provides an optical imaging lens assembly. The optical imaging lens assembly includes a front fixed group and a variable magnification group arranged along an optical axis;

[0007] The front fixed group includes a meniscus lens group, which includes a first meniscus lens, a second meniscus lens and a third meniscus lens, or the front fixed group includes the third meniscus lens and a first double cemented lens;

[0008] The zoom group includes a first positive lens and a second double cemented lens;

[0009] The zoom group is used to change the focal length of the optical imaging lens group while moving along the optical axis.

[0010] In one embodiment, the optical imaging lens assembly further includes a compensation group, and the variable magnification group is disposed between the front fixed group and the compensation group;

[0011] The compensation group includes a third doublet lens;

[0012] The compensation group is used to work in conjunction with the zoom group to change the focal length of the optical imaging lens group.

[0013] In one embodiment, the optical imaging lens assembly further includes a rear fixing group, and the compensation group is disposed between the zoom group and the rear fixing group;

[0014] The rear fixed group includes a fourth doublet lens.

[0015] In one embodiment, the second meniscus lens is disposed between the first meniscus lens and the third meniscus lens;

[0016] The first meniscus lens comprises a convex meniscus lens with positive optical power; the second meniscus lens and the third meniscus lens respectively comprise concave meniscus lenses with negative optical power.

[0017] In one embodiment, the first positive lens comprises a biconvex lens with positive optical power; and the second doublet lens is disposed between the third meniscus lens and the first positive lens.

[0018] In one embodiment, the second doublet lens includes a biconvex lens with positive power and a concave meniscus lens with negative power;

[0019] The biconvex lens in the second double cemented lens is close to the third meniscus lens, and the concave meniscus lens in the second double cemented lens is far away from the third meniscus lens.

[0020] In one embodiment, the third doublet lens includes a biconvex lens with positive power and a biconcave lens with negative power;

[0021] The biconvex lens in the third double cemented lens is close to the first positive lens, and the biconcave lens in the third double cemented lens is far away from the first positive lens.

[0022] In one embodiment, the fourth doublet lens includes a biconvex lens with positive power and a biconcave lens with negative power;

[0023] The biconvex lens in the fourth double-cemented lens is close to the third double-cemented lens, and the biconcave lens in the fourth double-cemented lens is far away from the third double-cemented lens.

[0024] In one embodiment, the front fixed focal length f1 satisfies -50 mm ≤ f1 ≤ -30 mm;

[0025] The focal length f2 of the zoom group satisfies 10 mm ≤ f2 ≤ 30 mm;

[0026] The focal length f3 of the compensation group satisfies -40 mm ≤ f3 ≤ -20 mm;

[0027] The focal length f4 of the rear fixed group satisfies 50 mm ≤ f4 ≤ 70 mm.

[0028] In one embodiment, -0.6 <f2 / f1<-0.3,0.6<f3 / f1<0.9,-1.7<f4 / f1<-1.4。

[0029] In one embodiment, the optical imaging lens assembly further includes a beam splitter lens, and the beam splitter lens includes a prism or a dichroic mirror;

[0030] The fourth double-cemented lens is disposed between the third double-cemented lens and the beam splitter lens.

[0031] In one embodiment, the optical imaging lens assembly further includes at least one protective sheet among a first protective sheet, a second protective sheet, a third protective sheet, and a fourth protective sheet;

[0032] The first meniscus lens is disposed between the first protective sheet and the second meniscus lens;

[0033] The second protection sheet is arranged between the fourth cemented lens and the beam splitting lens;

[0034] The third protection sheet is arranged between the second protection sheet and the light splitting lens;

[0035] The beam splitter prism is arranged between the third protection sheet and the fourth protection sheet.

[0036] In one embodiment, the optical imaging lens assembly further includes an aperture surface, which coincides with a front surface of the first protective sheet, and the front surface is a surface away from the first meniscus lens.

[0037] In a second aspect, the present application provides a coupler, which includes a detector and any one of the above-mentioned optical imaging lens groups.

[0038] In a third aspect, the present application provides an endoscope comprising the above-mentioned coupler.

[0039] The above-mentioned optical imaging lens group, coupler and endoscope, the optical imaging lens group includes a front fixed group and a zoom group arranged along the optical axis, and the zoom group is used to change the focal length of the optical imaging lens group when moving along the optical axis. Since the front fixed group can be a meniscus lens group including a first meniscus lens, a second meniscus lens 1012 and a third meniscus lens, and can also include a third meniscus lens and a first double-cemented lens, the front fixed group can correct field curvature and chromatic aberration and play a role in limiting the aperture. Furthermore, since the zoom group includes a first positive lens and a second double-cemented lens, the first positive lens can be used to eliminate astigmatism and field curvature, and the second double-cemented lens can be used to reduce chromatic aberration and spherical aberration, which is beneficial to the imaging of the optical imaging lens group to improve the imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic diagram of the structure of an optical imaging lens assembly in an embodiment of the present application;

[0041] Figure 2 This is a schematic structural diagram of another optical imaging lens assembly in an embodiment of the present application;

[0042] Figure 3 This is a schematic structural diagram of another optical imaging lens assembly in an embodiment of the present application;

[0043] Figure 4 This is a schematic structural diagram of another optical imaging lens assembly in an embodiment of the present application;

[0044] Figure 5 This is a schematic structural diagram of a front fixing group in an embodiment of the present application;

[0045] Figure 6 This is a schematic diagram of the structure of a zoom group in an embodiment of the present application;

[0046] Figure 7 This is a schematic diagram of the structure of a compensation group in an embodiment of the present application;

[0047] Figure 8 This is a schematic structural diagram of a rear fixing group in an embodiment of the present application;

[0048] Fig. 9 This is a schematic structural diagram of another optical imaging lens assembly in an embodiment of the present application;

[0049] Fig.10 This is a schematic structural diagram of another optical imaging lens assembly in an embodiment of the present application;

[0050] Fig.11 This is a schematic diagram of the structure of a coupler in an embodiment of the present application;

[0051] Fig.12 This is a schematic diagram of the structure of an endoscope in an embodiment of the present application;

[0052] Fig.13 This is an MTF curve diagram in an embodiment of the present application;

[0053] Fig.14 A schematic diagram of field curvature and distortion in an embodiment of the present application;

[0054] Fig.15 This is another MTF curve diagram in the embodiment of the present application;

[0055] Fig.16 A schematic diagram of another field curvature and distortion in an embodiment of the present application;

[0056] Fig.17 This is another MTF curve diagram in the embodiment of the present application;

[0057] Fig.18 This is a schematic diagram of another field curvature and distortion in an embodiment of the present application.

[0058] Description of reference numerals:

[0059] 100-optical imaging lens group, 101-front fixed group, 1011-first meniscus lens, 1012-second meniscus lens, 1013-third meniscus lens, 102-zooming group, 1021-second double-cemented lens, 1022-first positive lens, 201-first double-cemented lens, 301-compensation group, 302-third double-cemented lens, 401-rear fixed group, 402-fourth double-cemented lens, 601-double convex lens, 602-meniscus concave lens, 701-double convex lens, 702-double concave lens, 801-double convex lens, 802-double concave lens, 901-beam splitter lens, 1001-first protective plate, 1002-second protective plate, 1003-third protective plate, 1004-fourth protective plate, 1100-coupler, 1101-detector, 1200-endoscope. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application 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 application and are not used to limit the present application.

[0061] Figure 1 FIG. 1 is a schematic diagram of the structure of an optical imaging lens assembly according to an embodiment of the present application. Figure 1 As shown, the optical imaging lens assembly 100 includes a front fixed group 101 and a zoom group 102 arranged along the optical axis direction. The optical axis direction can be understood as the propagation direction of light. Figure 1 For example, light enters the optical imaging lens group from left to right, that is, light enters from the front fixed group 101 to the zoom group 102 .

[0062] The zoom group 102 is used to change the focal length of the optical imaging lens group 100 while moving along the optical axis. In other words, by moving the zoom group 102 and changing the distance between the zoom group 102 and the front fixed group 101, the zoom optical imaging lens group 100 can be realized. That is, the zoom group 102 can change the magnification of the optical imaging lens group 100 during the movement, and the magnification is positively correlated with the distance between the zoom group 102 and the front fixed group 101.

[0063] by Figure 1 For example, the front fixed group 101 may include a meniscus lens group, and the meniscus lens group includes a first meniscus lens 1011, a second meniscus lens 1012, and a third meniscus lens 1013. The zoom group 102 includes a first positive lens 1022 and a second doublet lens 1021.

[0064] Figure 2 FIG. 1 is a schematic diagram of the structure of another optical imaging lens assembly in an embodiment of the present application. Figure 2For example, the front fixed group 101 may include a third meniscus lens 1013 and a first doublet lens 201 ; the zoom group 102 includes a first positive lens 1022 and a second doublet lens 1021 .

[0065] It is understandable that in Figure 1 On the basis of Figure 2 The optical imaging lens assembly 100 shown replaces the first meniscus lens 1011 and the second meniscus lens 1012 with a second doublet lens 1021 .

[0066] It should be noted that Figure 1 Take the example of sequentially arranging the first meniscus lens 1011, the second meniscus lens 1012 and the third meniscus lens 1013 along the optical axis in the front fixed group 101, and sequentially arranging the first positive lens 1022 and the second doublet lens 1021 along the optical axis in the zoom group 102.

[0067] Figure 2 For example, the first doublet lens 201 and the third meniscus lens 1013 are sequentially arranged along the optical axis in the front fixed group 101, and the first positive lens 1022 and the second doublet lens 1021 are sequentially arranged along the optical axis in the zoom group 102.

[0068] In some embodiments, the optical imaging lens group 100 may also firstly set a second meniscus lens 1012 along the optical axis in the front fixed group 101, and then sequentially set a first meniscus lens 1011 and a third meniscus lens 1013; and firstly set a second double cemented lens 1021 along the optical axis in the zoom group 102, and then set a first positive lens 1022, which is not limited in this embodiment.

[0069] The first meniscus lens 1011, the second meniscus lens 1012 and the third meniscus lens 1013 are single lenses with positive or negative optical power, respectively.

[0070] The first meniscus lens 1011 and the second meniscus lens 1012 can correct field curvature and chromatic aberration, and the third meniscus lens 1013 can correct astigmatism.

[0071] Similarly, the first double cemented lens 201 is used to replace the first meniscus lens 1011 and the second meniscus lens 1012, so it can also correct field curvature and chromatic aberration.

[0072] The first positive lens 1022 is a lens with positive optical power, which can improve the light bending ability and reduce the diameter of the lens due to its positive optical power. In addition, the first positive lens 1022 can be used to eliminate astigmatism and field curvature.

[0073] The second double-cemented lens 1021 can be composed of a positive lens with positive optical power and a negative lens with negative optical power. The positive lens produces negative spherical aberration and the negative lens produces positive spherical aberration. Therefore, the second double-cemented lens 1021 can correct paraxial spherical aberration, chromatic aberration, and can also correct the secondary spectrum.

[0074] The optical imaging lens group 100 provided in this embodiment includes a front fixed group 101 and a zoom group 102 arranged along the optical axis direction, and the zoom group 102 is used to change the focal length of the optical imaging lens group 100 when moving along the optical axis direction. Since the front fixed group 101 can be a meniscus lens group including a first meniscus lens 1011, a second meniscus lens 1012 and a third meniscus lens 1013, or can also include the third meniscus lens 1013 and a first double-cemented lens 201, the front fixed group 101 can correct field curvature and chromatic aberration and play a role in limiting the aperture. Further, since the zoom group 102 includes a first positive lens 1022 and a second double-cemented lens 1021, the first positive lens 1022 can be used to eliminate astigmatism and field curvature, and the second double-cemented lens 1021 can be used to reduce chromatic aberration and spherical aberration, thereby facilitating the imaging of the optical imaging lens group 100 to improve the imaging quality.

[0075] Figure 3 FIG. 1 is a schematic diagram of the structure of another optical imaging lens assembly in an embodiment of the present application. Figure 3 As shown, in one embodiment, optionally, the optical imaging lens group 100 further includes a compensation group 301, and the zoom group 102 is disposed between the front fixed group 101 and the compensation group 301, that is, the front fixed group 101, the zoom group 102 and the compensation group 301 are arranged in sequence along the optical axis direction.

[0076] The compensation group 301 includes a third doublet lens 302. Similarly, the third doublet lens 302 can also be composed of a positive lens with positive power and a negative lens with negative power, so as to correct paraxial spherical aberration, chromatic aberration, and play a role in correcting the secondary spectrum.

[0077] Furthermore, the compensation group 301 can be linked with the zoom group 102 to change the focal length of the optical imaging lens group 100 .

[0078] In the process of the zoom group 102 moving to change the focal length of the optical imaging lens group 100, the image plane position will change. Therefore, in this embodiment, a compensation group 301 can be set to compensate for the image plane movement caused by the movement of the zoom group 102 by moving the compensation group 301, so as to keep the image plane position fixed in the entire zooming process and keep the image clear.

[0079] The optical imaging lens assembly 100 of this embodiment further includes a compensation group 301. Since the compensation group 301 includes three doublets of cemented lenses 302, the compensation group 301 can further reduce chromatic aberration and spherical aberration by using the third doublet of cemented lenses 302. Furthermore, since the compensation group 301 can be linked with the zoom group 102 to change the focal length of the optical imaging lens assembly 100, the zoom accuracy of the optical imaging lens assembly 100 is improved to improve the imaging effect.

[0080] Figure 4 1 is a schematic diagram of the structure of another optical imaging lens assembly in an embodiment of the present application. In one embodiment, optionally, the optical imaging lens assembly 100 further includes a rear fixed group 401, and the compensation group 301 is disposed between the zoom group 102 and the rear fixed group 401. That is, the front fixed group 101, the zoom group 102, the compensation group 301, and the rear fixed group 401 are sequentially arranged along the optical axis direction.

[0081] The rear fixed group 401 includes a fourth doublet lens 402. The fourth doublet lens 402 may also be composed of a positive lens with positive power and a negative lens with negative power, so as to correct the paraxial spherical aberration and chromatic aberration, and play a role in correcting the secondary spectrum.

[0082] In actual use, due to problems with processing and assembly accuracy, inaccurate focus may occur during zooming. Therefore, in one embodiment, the rear fixing group 401 may optionally move within a small range to provide a focusing function. In this way, not only can the effect of stepless zooming be achieved, but also inaccurate focus caused by processing and assembly errors can be compensated to ensure clear imaging on the detector.

[0083] Since the optical imaging lens assembly 100 of this embodiment further includes the rear fixed group 401, and the rear fixed group 401 is implemented by the fourth doublet lens 402, the rear fixed group 301 can reduce chromatic aberration and spherical aberration and improve zoom accuracy.

[0084] Figure 5 Schematic diagram of the structure of a front fixing group in an embodiment of the present application, such as Figure 5 As shown, in one embodiment, optionally, the second meniscus lens 1012 is disposed between the first meniscus lens 1011 and the third meniscus lens 1013 .

[0085] The first meniscus lens 1011 includes a convex meniscus lens with positive optical power; the second meniscus lens 1012 and the third meniscus lens 1013 include concave meniscus lenses with negative optical power respectively.

[0086] That is to say, in this embodiment, a convex meniscus lens with positive optical power and two concave meniscus lenses with negative optical power are sequentially arranged in the front fixing group 101 along the optical axis direction.

[0087] In this embodiment, since the front fixed group 101 includes a meniscus convex lens with positive optical power and two meniscus concave lenses with negative optical power, the front fixed group 101 can correct field curvature, chromatic aberration and astigmatism at the very beginning of the optical imaging lens group 100.

[0088] Figure 6 Schematic diagram of the structure of a zoom group in the embodiment of the present application. Figure 6 As shown, in one embodiment, optionally, the first positive lens 1022 includes a biconvex lens with positive optical power; the second doublet lens 1021 is disposed between the third meniscus lens 1013 and the first positive lens 1022 .

[0089] Please continue to refer to Figure 6 In one embodiment, optionally, the second double cemented lens 1021 includes a double convex lens 601 with positive optical power and a concave meniscus lens 602 with negative optical power. The double convex lens 601 in the second double cemented lens 1021 is close to the third meniscus lens 1013, and the concave meniscus lens 602 in the second double cemented lens 1021 is far away from the third meniscus lens 1013.

[0090] That is to say, the second doublet lens 1021 composed of the double convex lens 601 and the meniscus concave lens 602 and the first positive lens 1022 can be arranged in sequence along the optical axis in the zoom group 102. The first positive lens 1022 is realized by a double convex lens with positive optical power. In this way, the zoom group 102 can use the second doublet lens 1021 to correct the paraxial spherical aberration and chromatic aberration, and use the first positive lens 1022 to provide positive optical power, thereby improving the light bending ability and reducing the diameter of the lens.

[0091] Figure 7 Schematic diagram of the structure of a compensation group in the embodiment of the present application. Figure 7 As shown, in one embodiment, optionally, the third double-cemented lens 302 includes a double-convex lens 701 with positive optical power and a double-concave lens 702 with negative optical power. The double-convex lens 701 in the third double-cemented lens 302 is close to the first positive lens 1022, and the double-concave lens 702 in the third double-cemented lens 302 is far away from the first positive lens 1022. In this way, the third double-cemented lens 302 can correct field curvature and chromatic aberration through the double-convex lens 701 and the double-concave lens 702.

[0092] Figure 8 Schematic diagram of the structure of a rear fixing group in the embodiment of the present application. Figure 8As shown, in one embodiment, optionally, the fourth double-cemented lens 402 includes a double-convex lens 801 with positive optical power and a double-concave lens 802 with negative optical power. The double-convex lens 801 in the fourth double-cemented lens 402 is close to the third double-cemented lens 302, and the double-concave lens 802 in the fourth double-cemented lens 402 is far away from the third double-cemented lens 302. In this way, the fourth double-cemented lens 402 can correct field curvature and chromatic aberration through the double-convex lens 801 and the double-concave lens 802.

[0093] In one embodiment, optionally, the front fixed focal length f1 satisfies -50 mm ≤ f1 ≤ -30 mm; the focal length f2 of the zoom group 102 satisfies 10 mm ≤ f2 ≤ 30 mm; the focal length f3 of the compensation group 301 satisfies -40 mm ≤ f3 ≤ -20 mm; and the focal length f4 of the rear fixed group 401 satisfies 50 mm ≤ f4 ≤ 70 mm.

[0094] In one embodiment, optionally, -0.6 <f2 / f1<-0.3,0.6<f3 / f1<0.9,-1.7<f4 / f1<-1.4。

[0095] Since the focal lengths of the front fixed group 101, the zoom group 102, the compensation group 301 and the rear fixed group 401 in the optical imaging lens assembly 100 can meet the above requirements, the parameters between the components in the optical imaging lens assembly 100 can be limited, that is, the parameters between the front fixed group 101, the zoom group 102, the compensation group 301 and the rear fixed group 401 are limited. In addition, a connection is established between every two components, so the combination of every two components will also contribute to the aberration correction, so the optical imaging lens assembly 100 of this embodiment is more conducive to imaging.

[0096] Fig. 9 FIG. 1 is a schematic diagram of the structure of another optical imaging lens assembly in an embodiment of the present application. Fig. 9 As shown, in one embodiment, optionally, the optical imaging lens assembly 100 further includes a beam splitter lens 901. The fourth doublet lens 402 is disposed between the third doublet lens 302 and the beam splitter lens 901.

[0097] The beam splitter lens 901 is used to separate light beams of different wavelength bands, for example, to distinguish between visible light and infrared light. The beam splitter lens 901 includes a prism or a dichroic mirror.

[0098] In this embodiment, since the beam splitter lens 801 is provided, the optical imaging lens assembly 100 can be used in multiple bands. Furthermore, since the prism or the dichroic mirror is a parallel flat plate, the influence on the aberration is small, which is beneficial to imaging.

[0099] Fig.10 FIG. 1 is a schematic diagram of the structure of another optical imaging lens assembly in an embodiment of the present application. Fig.10As shown, in one embodiment, optionally, the optical imaging lens assembly 100 further includes at least one protective sheet among a first protective sheet 1001 , a second protective sheet 1002 , a third protective sheet 1003 and a fourth protective sheet 1004 .

[0100] Among them, the first meniscus lens 1011 is arranged between the first protective sheet 1001 and the second meniscus lens 1012, the second protective sheet 1002 is arranged between the fourth cemented lens and the spectrometer lens 901, the third protective sheet 1003 is arranged between the second protective sheet 1002 and the spectrometer lens 901, and the spectrometer prism is arranged between the third protective sheet 1003 and the fourth protective sheet 1004.

[0101] Since at least one protective sheet is provided in the optical imaging lens assembly 100 , the stability of the optical imaging lens assembly 100 is improved.

[0102] like Fig.10 (a)~ Fig.10 As shown in (c), the front fixed group 101 includes a first meniscus lens 1011, a second meniscus lens 1012 and a third meniscus lens 1013, the zoom group 102 includes a second double-cemented lens 1021 and a first positive lens 1022, the compensation group 301 includes a third double-cemented lens 302, and the rear fixed group 401 includes a fourth double-cemented lens 402. In this way, the front fixed lens group 101 and the rear fixed group 401 can remain stationary, and the zoom group 102 and the compensation group 301 in the dotted box are linked along the optical axis to achieve a zoom effect.

[0103] In one embodiment, the optical imaging lens assembly 100 may further include an aperture surface, which coincides with the front surface of the first protective sheet 1001, and the front surface is a surface away from the first meniscus lens 1011. Since a spherical mirror is used in the optical imaging lens assembly 100, and the entrance pupil is located on the first surface, it is beneficial for the optical imaging lens assembly 100 and the endoscope optical system to match the exit pupil with the entrance pupil of the adapter.

[0104] Fig.11 is a schematic diagram of the structure of a coupler in an embodiment of the present application, such as Fig.11 As shown, in one embodiment, a coupler 1100 is further provided. The coupler 1100 includes any of the above optical imaging lens assembly 100 and a detector 1101. It can be understood that the detector 1101 is arranged behind the optical imaging lens assembly 100 along the optical axis direction.

[0105] by Fig.11For example, the light passes through the first protective film 1001, the first meniscus lens 1011, the second meniscus lens 1012, the third meniscus lens 1013, the second double-cemented lens 1021 composed of the double convex lens 601 and the concave meniscus lens 602, the first positive lens 1022, the third double-cemented lens 302 composed of the double convex lens 701 and the double concave lens 702, the fourth double-cemented lens 402 composed of the double convex lens 801 and the double concave lens 802, the second protective film 1002, the third protective film 1003, and the beam splitter lens 1004, and finally performs high-resolution imaging on the target surface of the detector 1101. It can be understood that, with Fig.10 The principle is the same. Fig.11 The coupler 1100 shown is a zoom coupler.

[0106] Fig.12 Schematic diagram of the structure of an endoscope in an embodiment of the present application, such as Fig.12 As shown, in one embodiment, an endoscope 1200 is also provided, and the endoscope 1200 includes the above-mentioned coupler 1100.

[0107] In some embodiments, the endoscope 1200 may further include at least one of a light source component, an image processing component, a control mechanism, and a display component.

[0108] In this way, the optical imaging lens group 100 can be applied to the zoom optical system of a medical rigid tube endoscope to complete medical endoscope detection, and by utilizing the linkage of the magnification group 102 and the compensation group 301, the focal length can be adaptively adjusted according to the distance of the endoscope from the biological tissue, so as to magnify and reduce, and zoom in and out, the lesion area of ​​the biological tissue.

[0109] For example, in one embodiment, the optical imaging lens assembly 100 is used to achieve a zoom effect of 16 mm to 32 mm, and a detector 1001 with a 4K resolution of 1 / 1.8 inches is used as an example.

[0110] Since the pixel size of a 4K resolution detector is 2 microns, the corresponding Nyquist frequency is calculated to be 250lp / mm (line pairs / millimeter), so the MTF (Modulation Transfer Function) at this resolution needs to satisfy >0.1.

[0111] Fig.13 This is an MTF curve diagram in the embodiment of the present application. Fig.13 FIG. 1 shows the MTF curve corresponding to the focal length of the optical imaging group 100 of 16 mm. Fig.13 As shown, Fig.13The Meridian and Sagittal MTF curves corresponding to the center field of view, 2.55° (0.3 field of view), 4.25° (0.5 field of view), 6° (0.707 field of view), 6.8° (0.8 field of view), 8.5° (1 field of view) and diffraction limit are provided. It can be seen that the MTF value of the full field of view at 250lp / mm is greater than 0.1, which meets the resolution requirements of the CMOS (Complementary Metal Oxide Semiconductor) chip, that is, the detector.

[0112] Fig.14 is a schematic diagram of field curvature and distortion in an embodiment of the present application, Fig.14 The field curvature and distortion corresponding to each wavelength of light when the focal length of the optical imaging assembly 100 is 16 mm are shown. Fig.14 As shown, the distortion is less than 3% at full field of view.

[0113] Fig.15 This is another MTF curve diagram in the embodiment of the present application. Fig.15 FIG. 1 shows the MTF curve corresponding to the focal length of the optical imaging group 100 at 24 mm. Fig.15 As shown, Figure 5 The Meridian and Sagittal MTF curves corresponding to the center field of view, 2.55° (0.3 field of view), 4.25° (0.5 field of view), 6° (0.707 field of view), 6.8° (0.8 field of view), 8.5° (1 field of view) and diffraction limit are provided. When the focal length is 24mm, the MTF of the full field of view at 200lp / mm can be greater than 0.1.

[0114] Fig.16 is a schematic diagram of another field curvature and distortion in an embodiment of the present application, Fig.16 The field curvature and distortion corresponding to each wavelength of light when the focal length of the optical imaging assembly 100 is 24 mm are shown. Fig.16 As shown, the distortion at full field of view is also less than 3%.

[0115] Fig.17 This is another MTF curve diagram in the embodiment of the present application. Fig.17 The MTF curve corresponding to the focal length of the optical imaging group 100 is shown in FIG. 1 . The image height of the 8.5° field of view under the telephoto condition exceeds the height of the imaging part of the chip, so the actual field of view angle is less than 8.5°. Fig.17 As shown, Fig.17 The meridional and sagittal MTF curves corresponding to the center field of view, 2.55°, 4.25°, 6°, 6.8°, 8.1° and the diffraction limit are provided. When the focal length is 32mm, the MTF of the entire field of view at 150lp / mm can be greater than 0.1.

[0116] Fig.18 is a schematic diagram of another field curvature and distortion in an embodiment of the present application, Fig.18 The figure shows the field curvature and distortion corresponding to each wavelength of light when the focal length of the optical imaging group 100 is 32 mm. It can be found that the distortion at the full field of view is still less than 3.5%.

[0117] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0118] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An optical imaging lens assembly, characterized in that: The optical imaging lens group includes a front fixed group and a variable magnification group arranged along the optical axis direction; The front fixed group includes a meniscus lens group, the meniscus lens group includes a first meniscus lens, a second meniscus lens and a third meniscus lens, or the front fixed group includes the third meniscus lens and a first double cemented lens; The zoom group includes a first positive lens and a second doublet lens; The variable magnification group is used to change the focal length of the optical imaging lens group while moving along the optical axis direction.

2. The optical imaging lens assembly according to claim 1, characterized in that: The optical imaging lens assembly further includes a compensation group, and the variable magnification group is arranged between the front fixed group and the compensation group; The compensation group includes a third doublet lens; The compensation group is used to work in conjunction with the zoom group to change the focal length of the optical imaging lens group.

3. The optical imaging lens assembly according to claim 2, characterized in that: The optical imaging lens assembly further includes a rear fixing group, and the compensation group is arranged between the variable magnification group and the rear fixing group; The rear fixed group includes a fourth doublet lens.

4. The optical imaging lens assembly according to any one of claims 1 to 3, characterized in that: The second meniscus lens is disposed between the first meniscus lens and the third meniscus lens; The first meniscus lens comprises a convex meniscus lens with positive optical power; the second meniscus lens and the third meniscus lens respectively comprise concave meniscus lenses with negative optical power.

5. The optical imaging lens assembly according to any one of claims 1 to 3, characterized in that: The first positive lens comprises a biconvex lens with positive optical power; the second double cemented lens is arranged between the third meniscus lens and the first positive lens.

6. The optical imaging lens assembly according to claim 5, characterized in that: The second double cemented lens comprises a biconvex lens with positive optical power and a concave meniscus lens with negative optical power; The double convex lens in the second double cemented lens is close to the third meniscus lens, and the concave meniscus lens in the second double cemented lens is far away from the third meniscus lens.

7. The optical imaging lens assembly according to claim 2 or 3, characterized in that: The third double cemented lens comprises a biconvex lens with positive power and a biconcave lens with negative power; The biconvex lens in the third double-cemented lens is close to the first positive lens, and the biconcave lens in the third double-cemented lens is far away from the first positive lens.

8. The optical imaging lens assembly according to claim 3, characterized in that: The fourth double cemented lens includes a biconvex lens with positive power and a biconcave lens with negative power; The biconvex lens in the fourth double-cemented lens is close to the third double-cemented lens, and the biconcave lens in the fourth double-cemented lens is far away from the third double-cemented lens.

9. The optical imaging lens assembly according to claim 3, characterized in that: The front fixed focal length f1 satisfies -50 mm ≤ f1 ≤ -30 mm; The focal length f2 of the zoom group satisfies 10 mm ≤ f2 ≤ 30 mm; The focal length f3 of the compensation group satisfies -40 mm ≤ f3 ≤ -20 mm; The focal length f4 of the rear fixed group satisfies 50 mm≤f4≤70 mm.

10. The optical imaging lens assembly according to claim 9, characterized in that: -0.6 <f2 / f1<-0.3,0.6<f3 / f1<0.9,-1.7<f4 / f1<-1.4。 11. The optical imaging lens assembly according to claim 3, characterized in that: The optical imaging lens assembly further includes a beam splitter lens, and the beam splitter lens includes a prism or a dichroic mirror; The fourth double-cemented lens is disposed between the third double-cemented lens and the beam splitter lens.

12. The optical imaging lens assembly according to claim 11, characterized in that: The optical imaging lens assembly further includes at least one protective sheet among a first protective sheet, a second protective sheet, a third protective sheet and a fourth protective sheet; The first meniscus lens is disposed between the first protective sheet and the second meniscus lens; The second protective sheet is disposed between the fourth cemented lens and the beam splitter lens; The third protective sheet is disposed between the second protective sheet and the light splitting lens; The beam splitter prism is disposed between the third protection sheet and the fourth protection sheet.

13. The optical imaging lens assembly according to any one of claims 1 to 3, characterized in that: The optical imaging lens assembly also includes an aperture surface, which coincides with the front surface of the first protective sheet, and the front surface is a surface away from the first meniscus lens.

14. A coupler, characterized in that: The coupler comprises a detector and an optical imaging lens assembly as described in any one of claims 1-13.

15. An endoscope, characterized in that: The endoscope includes the coupler of claim 14.

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