An optical observation device

Abstract

The application provides an optical observation device, which comprises, in sequence from the object side to the same optical axis, an objective lens system, a relay lens system and a magnifying lens system, and parallel light paths are formed among the objective lens system, the relay lens system and the magnifying lens system; the objective lens system comprises, in sequence from the object side to the same optical axis, a first double cemented lens, a first double convex lens, a first double concave lens and a second double convex lens; the relay lens system comprises at least one relay lens group, and the relay lens group comprises two three-cemented rod lenses which are arranged in optical property symmetry; and the magnifying lens system comprises, in sequence from the object side to the same optical axis, a second double cemented lens, a second double concave lens and a fourth double meniscus lens. According to the application, the difficulty of assembly and adjustment is reduced, the field of view is larger, the vignetting is smaller, the number of lenses is smaller, and the cost performance is higher under the condition that the overall size is unchanged.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical technology, in particular to an optical observation device. BACKGROUND

[0002] An endoscope is a device for checking and treating internal tissues of a human body through a head probe and an optical lens. Its working principle is based on optical imaging and probe technology. By introducing a light source and a lens into a body cavity or tissue, microscopic structures or diseased tissues in the body can be observed. The optical imaging principle of the endoscope is that light from a light source behind the human body enters the human body and is reflected by the inner wall of the endoscope, and finally guided to the observation equipment by an optical fiber. The optical lens of the endoscope focuses the light to form an enlarged image for the doctor to observe. Therefore, the quality of optical imaging directly affects the use effect of the endoscope.

[0003] The optical imaging of the endoscope is mainly realized by the optical system arranged inside the endoscope. The optical system is composed of an objective lens, a relay lens and a magnifying lens arranged in sequence from the front end (the end of the biological tissue) to the rear end. The objective lens is used to collect the initial optical image of the biological tissue, the relay lens is used to transfer the image formed by the objective lens to the rear end of the endoscope, and the magnifying lens is used to further magnify the image transmitted by the relay lens. The existing objective lens, relay lens and magnifying lens each have a separate object image plane. During assembly and adjustment, the alignment of the image of the former and the object of the latter (such as the image plane of the objective lens and the object plane of the relay lens, the image plane of the relay lens and the object plane of the magnifying lens) is required to be very high. In the actual manufacturing process, optical tilt and translation are easily caused, which affects the imaging quality. At the same time, the limited conjugate endoscope needs to optimize the limited distance of the central light path object and image plane, which requires more lenses. Too many lenses will significantly reduce the fault tolerance of the optical system. Any small imperfections (such as shape error, surface defect) of a lens will accumulate in the endoscope, eventually seriously affecting the imaging quality of the endoscope.

[0004] Therefore, it is necessary to improve the existing endoscope to solve the above problems.

[0005] It should be noted that the above introduction to the background art is only for the convenience of clearly and completely describing the technical solutions of the present application, and for the convenience of understanding by those skilled in the art. The above technical solutions cannot be considered as known to those skilled in the art merely because they are described in the background art part of the present application. SUMMARY

[0006] The purpose of the present application is to solve the problem that the existing optical observation devices such as endoscopes are prone to cause optical tilt and translation in the actual manufacturing process, and the fault tolerance is low due to the need for too many lenses for imaging, and thus affect the imaging quality.

[0007] To achieve the above object, the application provides an optical observation device, comprising: an objective lens system, a relay lens system and a magnifying lens system arranged in sequence along an optical axis from an object side, and parallel light paths between the objective lens system, the relay lens system and the magnifying lens system;

[0008] The objective lens system comprises: a first double cemented lens with positive focal power, a first double convex lens with positive focal power, a first double concave lens with negative focal power and a second double convex lens with positive focal power arranged in sequence along an optical axis from an object side.

[0009] The relay lens system comprises: at least one relay lens group, and the relay lens group comprises two three-cemented rod lenses arranged in optical property symmetry.

[0010] The magnifying lens system comprises: a second double cemented lens with positive focal power, a second double concave lens with negative focal power and a fourth double meniscus lens with positive focal power arranged in sequence along an optical axis from an object side.

[0011] As a further improvement of the application, the first double cemented lens comprises: a first lens with positive focal power and a second lens with positive focal power arranged in sequence along an optical axis from an object side, the object side surface of the first lens is a plane or a concave surface, the image side surface of the first lens is a convex surface, the object side surface of the second lens is a concave surface, the image side surface of the second lens is a convex surface, and the image side surface of the first lens and the object side surface of the second lens are cemented to form a first cemented surface.

[0012] As a further improvement of the application,

[0013] The combined focal length F1 of the first double cemented lens and the first double convex lens and the focal length F10 of the objective lens system satisfy ;

[0014] The focal length f2 of the first lens, the Abbe number v2 of the first lens, the focal length f3 of the second lens and the Abbe number v3 of the second lens satisfy ;

[0015] The central thickness d2 of the first lens, the curvature radius r4 corresponding to the first cemented surface and the curvature radius r3 corresponding to the object side surface of the first lens satisfy .

[0016] As a further improvement of the application,

[0017] The focal length f6 of the second double convex lens and the focal length F10 of the objective lens system satisfy ;

[0018] The center thickness d6 of the second lenticular lens, the refractive index n6 of the second lenticular lens, the radius of curvature r10 corresponding to the object side surface of the second lenticular lens, and the radius of curvature r11 corresponding to the image side surface of the second lenticular lens satisfy ;

[0019] The center thickness d5 of the first double concave lens, the refractive index n5 of the first double concave lens, the radius of curvature r8 corresponding to the object side surface of the first double concave lens, and the radius of curvature r9 corresponding to the image side surface of the first double concave lens satisfy ;

[0020] The focal length f4 of the first lenticular lens, the refractive index f4 of the first lenticular lens, the radius of curvature r6 corresponding to the object side surface of the first lenticular lens, and the radius of curvature r7 corresponding to the image side surface of the first lenticular lens satisfy .

[0021] As a further improvement of the present application, the three-cemented rod lens includes a first double-crescent lens with negative optical power, a second double-crescent lens with positive optical power, and a third double-crescent lens with positive optical power, the concave surface of the first double-crescent lens and the convex surface of the second double-crescent lens are cemented to form a second cemented surface, and the concave surface of the second double-crescent lens and the convex surface of the third double-crescent lens are cemented to form a third cemented surface.

[0022] Among them, the two third cemented surfaces respectively formed by the two three-cemented rod lenses in a single relay lens group are located between the two second cemented surfaces.

[0023] As a further improvement of the present application,

[0024] The focal length f7 of the first double-crescent lens and the focal length F2 of the three-cemented rod lens satisfy ;

[0025] The focal length f8 of the second double-crescent lens and the focal length F2 of the three-cemented rod lens satisfy ;

[0026] The focal length f9 of the third double-crescent lens and the focal length F2 of the three-cemented rod lens satisfy ;

[0027] The center thickness h7 of the first double-crescent lens, the center thickness h8 of the second double-crescent lens, the center thickness h9 of the third double-crescent lens, and the focal length F2 of the three-cemented rod lens satisfy ;

[0028] The focal length f7 of the first double-crescent lens, the Abbe number v7 of the first double-crescent lens, the focal length f8 of the second double-crescent lens, the Abbe number v8 of the second double-crescent lens, the focal length f9 of the third double-crescent lens, and the Abbe number v9 of the third double-crescent lens satisfy ;

[0029] The refractive index n7 of the first double-crescent lens and the refractive index n8 of the second double-crescent lens satisfy ;

[0030] The refractive index n8 of the second double-crescent lens and the refractive index n9 of the third double-crescent lens satisfy ;

[0031] The radius of curvature r12 corresponding to the surface of the first double-crescent lens away from the second cemented surface, the radius of curvature r13 corresponding to the second cemented surface, and the central thickness h7 of the first double-crescent lens satisfy ;

[0032] The radius of curvature r13 corresponding to the second cemented surface and the radius of curvature r14 corresponding to the third cemented surface satisfy .

[0033] As a further improvement of the present application,

[0034] The pupil diameter D2 of the relay lens group and the effective clear aperture CA2 of the relay lens group satisfy ;

[0035] The light flux of the relay lens system is greater than or equal to the light flux of the objective lens system;

[0036] The wavelength of the relay lens system is equal to the wavelength of the objective lens system;

[0037] The entrance pupil diameter of the relay lens system is greater than or equal to the exit pupil diameter of the objective lens system;

[0038] The field of view angle of the relay lens system is equal to the field of view angle of the objective lens system.

[0039] As a further improvement of the present application, the second double-cemented lens comprises: a third lens with positive focal power and a fourth lens with positive focal power arranged in sequence along the optical axis from the object side, the object side surface of the third lens is convex, the image side surface of the third lens is concave, the object side surface of the fourth lens is convex, the image side surface of the fourth lens is convex, and the image side surface of the third lens and the object side surface of the fourth lens are cemented to form a fourth cemented surface.

[0040] As a further improvement of the present application,

[0041] The objective lens system further comprises a first plane mirror arranged on the object side of the first double cemented lens;

[0042] The magnifying lens system further comprises a second plane mirror arranged on the image side of the fourth double meniscus lens.

[0043] As a further improvement of the present application, the optical observation device further comprises an image sensor arranged on the image side of the magnifying lens system, and the magnifying lens system further comprises a third plane mirror arranged on the image side of the second plane mirror.

[0044] Compared with the prior art, the present application has the following beneficial effects:

[0045] The optical observation device comprises an objective lens system, a relay lens system and a magnifying lens system arranged in sequence on the object side, and the objective lens system, the relay lens system and the magnifying lens system are parallel light paths. The objective lens system comprises a first double cemented lens with positive focal power, a first double convex lens with focal power, a first double concave lens with negative focal power and a second double convex lens with positive focal power arranged in sequence on the object side. The relay lens system comprises at least one relay lens group, and the relay lens group comprises two three-cemented rod-shaped mirrors arranged in optical symmetry. The magnifying lens system comprises a second double cemented lens with positive focal power, a second double concave lens with negative focal power and a fourth double meniscus lens with positive focal power arranged in sequence on the object side. The optical observation device disclosed in the present application is composed of an objective lens system, a relay lens system and a magnifying lens system, each optical system is designed separately, and each aberration is corrected independently, and the target function is finally realized by combination, thereby being more advantageous in manufacturing process control, and different optical functions can be realized by replacing the optical system under the same optical flux, such as adapting the CMOS camera, different object field of view, etc. Compared with the existing endoscope, the present application has a larger field of view, smaller vignetting and fewer lenses under the condition of the same overall size, and has a higher cost performance. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 The cross-sectional structure of the objective lens system in one embodiment;

[0047] Figure 2 The cross-sectional structure of the objective lens system in another embodiment;

[0048] Figure 3 The cross-sectional structure of the objective lens system in another embodiment;

[0049] Figure 4 The cross-sectional structure of the relay lens system in one embodiment;

[0050] Figure 5 The cross-sectional structure of the relay lens system in another embodiment;

[0051] Figure 6 Cross-sectional structure of a relay lens system in another embodiment;

[0052] Figure 7 Cross-sectional structure of a magnifier lens system in one embodiment;

[0053] Figure 8 Cross-sectional structure of an optical viewing device in one embodiment;

[0054] Figure 9 MTF plot for the objective lens system shown at 0.707 field; Figure 1

[0055] MTF plot for the objective lens system shown at edge field; Figure 10 Figure 1 MTF plot for the objective lens system shown at center field;

[0056] Figure 11 Figure 1 MTF plot for the objective lens system shown at 0.707 field;

[0057] Figure 12 MTF plot for the objective lens system shown at edge field; Figure 2

[0058] MTF plot for the objective lens system shown at center field; Figure 13 Figure 2 MTF plot for the objective lens system shown at 0.707 field;

[0059] Figure 14 Figure 2 MTF plot for the objective lens system shown at edge field;

[0060] Figure 15 MTF plot for the objective lens system shown at center field; Figure 3

[0061] MTF plot for the objective lens system shown at 0.707 field; Figure 16 Figure 3 MTF plot for the objective lens system shown at edge field;

[0062] Figure 17 Figure 3 MTF plot for the objective lens system shown at center field;

[0063] Figure 18 MTF plot for the relay lens system shown at 0.707 field; Figure 4

[0064] MTF plot for the relay lens system shown at edge field; Figure 19 Figure 4 ​​​​​​​MTF plot for the relay mirror system shown at the edge of field of view;

[0065] Figure 20 For Figure 4 MTF plot for the relay mirror system shown at the center of field of view;

[0066] Figure 21 For Figure 5 MTF plot for the relay mirror system shown at 0.707 field of view;

[0067] Figure 22 For Figure 5 MTF plot for the relay mirror system shown at the edge of field of view;

[0068] Figure 23 For Figure 5 MTF plot for the relay mirror system shown at the center of field of view;

[0069] Figure 24 For Figure 6 MTF plot for the relay mirror system shown at 0.707 field of view;

[0070] Figure 25 For Figure 6 MTF plot for the relay mirror system shown at the edge of field of view;

[0071] Figure 26 For Figure 6 MTF plot for the relay mirror system shown at the center of field of view;

[0072] Figure 27 For Figure 7 MTF plot for the magnifier system shown at 0.707 field of view;

[0073] Figure 28 For Figure 7 MTF plot for the magnifier system shown at the edge of field of view;

[0074] Figure 29 For Figure 7 MTF plot for the magnifier system shown at the center of field of view;

[0075] Figure 30 For Figure 8 MTF plot for the optical viewing device shown at 0.707 field of view;

[0076] Figure 31 For Figure 8 MTF plot for the optical viewing device shown at the edge of field of view;

[0077] Figure 32 For Figure 8The MTF curve of the optical observation device shown in the central field of view. DETAILED DESCRIPTION

[0078] The present application will be described in detail below with reference to the embodiments shown in the drawings, but it should be noted that these embodiments are not limiting to the present application, and equivalent transformations or substitutions of function, method, or structure made by those skilled in the art based on these embodiments are within the scope of the present application.

[0079] It should be noted that in the present application, the "object side" refers to the side of the optical observation device (not shown) close to the object plane (not shown), i.e., the side where the light enters the optical observation device; the "image side" refers to the side of the optical observation device (not shown) close to the image plane (not shown), i.e., the side where the light exits the optical observation device.

[0080] Please refer to Figures 1 to 32 As shown, the present application shows a specific embodiment of an optical observation device (not shown). The optical observation device is used for observing an observed object (such as living or excised biological tissue, etc.), for example, an endoscope, which is not specifically limited in the present embodiment.

[0081] Specifically, the optical observation device includes, in order from the object side along the optical axis (i.e., optical axis 40), an objective lens system 10, a relay lens system 20, and a magnifying lens system 30, and the objective lens system 10, the relay lens system 20, and the magnifying lens system 30 are all parallel light paths. The objective lens system 10 includes, in order from the object side along the optical axis, a first doublet lens 102 with positive optical power, a first double convex lens 103 with optical power, a first double concave lens 104 with negative optical power, and a second double convex lens 105 with positive optical power. The relay lens system 20 includes at least one relay lens group 21, and the relay lens group 21 includes two optically symmetrically arranged three-gem rod lenses (not shown). The magnifying lens system 30 includes, in order from the object side along the optical axis, a second doublet lens 301 with positive optical power, a second double concave lens 302 with negative optical power, and a fourth double meniscus lens 303 with positive optical power.

[0082] In the present application, the objective lens system 10 is an infinite conjugate system, the relay lens system 20 is a 1-fold telescope system, and the magnifying lens system 30 is an infinite conjugate system. Any one of the individual systems (i.e., the objective lens system 10, the relay lens system 20, or the magnifying lens system 30) cannot independently form an image, thereby constituting a brand-new optical observation device. The optical paths between the objective lens system 10 and the relay lens system 20 are parallel, and the optical paths between the relay lens system 20 and the magnifying lens system 30 are also parallel. For the digital detection of products, the infinite conjugate system is more suitable for detection than the finite conjugate system, and is more advantageous in the manufacturing process control. Therefore, the optical observation device disclosed in the present application fundamentally eliminates the harsh requirement that the existing endoscope must perform high-precision alignment between the image of the former and the object of the latter. The parallel optical paths have high tolerance for the tilt and translation errors of the optical elements, which significantly reduces the difficulty of assembling and adjusting the entire optical observation device 100, reduces the dependence on precise assembling equipment and processes, greatly improves the production yield and efficiency, and reduces the manufacturing cost.

[0083] In particular, the objective lens system 10 is composed of the aforementioned four lenses (i.e., the first doublet lens 102, the first double convex lens 103, the first double concave lens 104, and the second double convex lens 105), which ensures that the objective lens system 10 has the property of infinite conjugation. The first doublet lens 111 corrects chromatic aberration and controls the numerical aperture; the first double convex lens 103 controls the aperture (i.e., the entrance pupil aperture) and corrects spherical aberration; and the first double concave lens 104 and the second double convex lens 105 ensure the object far field. Thus, compared with the existing finite conjugate objective lens, the objective lens system 10 disclosed in the present application itself and other optical systems (such as the relay lens system 20 and the magnifying lens system 30) used in conjunction with it have low tolerance requirements, which is more conducive to assembly and adjustment. Moreover, the objective lens system 10 has a larger field of view, smaller vignetting, fewer lenses, and higher cost performance. Thus, the problems of poor adaptability, poor stability, and increased cost and volume caused by the large number of lenses in the existing objective lens, which is mostly a finite conjugate system, are solved.

[0084] The relay lens system 20 is mainly composed of three doublet rod lenses. The focal length of the first double crescent lens 201 in the three doublet rod lenses plays a role in aberration compensation and far field control, and the combined focal length of the second double crescent lens 202 and the third double crescent lens 203 plays a role in basic light deflection. Thus, the relay lens system 20 disclosed in the present application itself and other optical systems (such as the objective lens system 10 and the magnifying lens system 30) used in conjunction with it have low tolerance requirements, and can achieve lossless transmission of the pupil under the premise of low tolerance requirements and more conducive to assembly and adjustment, i.e., accurately and accurately transmitting the exit pupil plane of the objective lens system to the magnifying lens system 30 through the relay lens system 20, ensuring high-standard image quality transmission, and having fewer lenses and higher cost performance compared with the prior art.

[0085] The magnifying lens system 30 is composed of the aforementioned three lenses (i.e., the second doublet lens 301, the second double concave lens 302, and the fourth double meniscus lens 303). The second doublet lens 301 and the second double concave lens 302 form a quasi-telephoto system, which is responsible for aberration correction and pupil scaling, and the fourth double meniscus lens 303 undertakes the core optical parameters, so that the tolerance requirement between the magnifying lens system 30 itself and other optical systems (such as the objective lens system 10 and the relay lens system 20) used in conjunction with the magnifying lens system 30 is low, and the imaging quality of the magnifying lens system 30 can be ensured under the premise of fewer lenses.

[0086] It should be noted that the tolerance of the objective lens system 10 itself, the tolerance of the relay lens system 20 itself, and the tolerance of the magnifying lens system 30 itself include the manufacturing tolerance between the lenses and the assembly tolerance between the lenses.

[0087] In summary, the optical observation device disclosed in the present application is composed of the objective lens system 10, the relay lens system 20, and the magnifying lens system 30. Each optical system is designed separately, corrects its own aberration, and finally combines to achieve the target function. Therefore, different optical functions can be achieved by replacing the optical system under the same optical flux, such as adapting the CMOS camera, different object field of view, etc. Compared with the existing endoscope, the present application has a larger field of view, smaller vignetting, fewer lenses, and higher cost performance under the condition of the same overall size.

[0088] In an embodiment, the first doublet lens 102 comprises, sequentially arranged along the same optical axis from the object side, a first lens 106 with positive refractive power and a second lens 107 with positive refractive power. The object side surface of the first lens 106 is a plane (as shown in FIG. 1A) or a concave surface (as shown in FIG. 1B), and the image side surface is a convex surface. The object side surface of the second lens 107 is a concave surface, and the image side surface is a convex surface. The image side surface of the first lens 106 and the object side surface of the second lens 107 are cemented to form a first cemented surface 108. Figure 2 The object side surface of the second lens 107 is a concave surface, and the image side surface is a convex surface. The image side surface of the first lens 106 and the object side surface of the second lens 107 are cemented to form a first cemented surface 108. Figure 1 Figure 3 The object side surface of the second lens 107 is a concave surface, and the image side surface is a convex surface. The image side surface of the first lens 106 and the object side surface of the second lens 107 are cemented to form a first cemented surface 108.

[0089] In an embodiment, the combined focal length F1 of the first lens 106 and the first double convex lens 103 and the focal length F10 of the objective lens system 10 satisfy , thereby ensuring the numerical aperture on the object side. The focal length f2 of the first lens 106, the Abbe number v2 of the first lens 106, the focal length f3 of the second lens 107, and the Abbe number v3 of the second lens 107 satisfy , thereby eliminating chromatic aberration by the first doublet lens 102. The central thickness d2 of the first lens 106, the radius of curvature r4 corresponding to the first cemented surface 108, and the radius of curvature r3 corresponding to the object side surface of the first lens 106 satisfy​ Thus, the first double-glassed lens 102 is easier to process.

[0090] In an embodiment, the focal length f6 of the second double convex lens 105 and the focal length F10 of the objective lens system 10 satisfy Thus, by limiting the focal length of the second double convex lens 105 and the focal length of the objective lens system 10, the imaging quality of the objective lens system 10 is ensured. The central thickness d6 of the second double convex lens 105, the refractive index n6 of the second double convex lens 105, the radius of curvature r10 corresponding to the object side surface of the second double convex lens 105, and the radius of curvature r11 corresponding to the image side surface of the second double convex lens 105 satisfy ; the central thickness d5 of the first double concave lens 104, the refractive index n5 of the first double concave lens 104, the radius of curvature r8 corresponding to the object side surface of the first double concave lens 104, and the radius of curvature r9 corresponding to the image side surface of the first double concave lens 104 satisfy Thus, the object side telecentricity is ensured by the first double concave lens 104 and the second double convex lens 105. The focal length f4 of the first double convex lens 103, the refractive index f4 of the first double convex lens 103, the radius of curvature r6 corresponding to the object side surface of the first double convex lens 103, and the radius of curvature r7 corresponding to the image side surface of the first double convex lens 103 satisfy Thus, the aperture of the objective lens system 10 is controlled by the first double convex lens 103, and the spherical aberration is corrected.

[0091] In an embodiment, the three-glassed rod lens includes a first double-crescent lens 201 with negative optical power, a second double-crescent lens 202 with positive optical angle, and a third double-crescent lens 203 with positive optical power. The concave surface of the first double-crescent lens 201 and the convex surface of the second double-crescent lens 202 are glassed to form a second glassed surface 204, and the concave surface of the second double-crescent lens 202 and the convex surface of the third double-crescent lens 203 are glassed to form a third glassed surface 205. Among them, the two third glassed surfaces 205 formed by the two three-glassed rod lenses in the single relay lens group 21 are located between the two second glassed surfaces 204.

[0092] More specifically, the relay lens group 21 includes two three-glassed rod lenses arranged in optical symmetry, i.e., a three-glassed rod lens on the object side and a three-glassed rod lens on the image side (in other words, in a symmetrical manner with respect to the optical axis). Figures 4 to 6The three-cemented rod lenses on the left and the three-cemented rod lenses on the right are symmetrically arranged with respect to the intermediate image 206, and the optical properties of the two three-cemented rod lenses are symmetrically arranged with respect to the intermediate image 206. The three-cemented rod lenses on the object side include, in order from the object side along the optical axis, a first double crescent lens 201, a second double crescent lens 202, and a third double crescent lens 203; the three-cemented rod lenses on the image side include, in order from the object side along the optical axis, the third double crescent lens 203, the second double crescent lens 202, and the first double crescent lens 201, thereby forming the relay lens group 21.

[0093] It should be noted that, in the three-cemented rod lenses on the object side, the object side surface of the first double crescent lens 201 is convex, and the image side surface is concave; the object side surface of the second double crescent lens 202 is convex, and the image side surface is concave; the object side surface of the third double crescent lens 203 is convex, and the image side surface is concave. In the three-cemented rod lenses on the image side, the object side surface of the third double crescent lens 203 is concave, and the image side surface is convex; the object side surface of the second double crescent lens 202 is concave, and the image side surface is convex; the object side surface of the first double crescent lens 201 is concave, and the image side surface is convex. In this way, the three-cemented rod lenses on the object side and the three-cemented rod lenses on the image side are symmetrically arranged with respect to the intermediate image 206 in terms of optical properties.

[0094] In this application, the three-cemented rod lenses on the object side in the relay lens group 21 have a lens structure in which the focal powers from the object side are negative, positive, and positive in order, and the three-cemented rod lenses on the image side have a lens structure in which the focal powers from the object side are positive, positive, and negative in order. The focal length of the first double crescent lens 201 in the three-cemented rod lenses plays a role in aberration compensation and telecentricity control, and the combined focal length of the second double crescent lens 202 and the third double crescent lens 203 plays a role in basic light deflection. In this way, the relay lens system 20 can ensure the lossless transmission of the pupil under the premise of low tolerance requirements and better adjustment.

[0095] As for the specific number of the relay lens group 21 in the relay lens system 20, the relay lens system 20 includes at least one relay lens group 21, that is, one, two, or more relay lens groups 21. If multiple relay lens groups 21 are included, the multiple relay lens groups 21 are arranged in order along the optical axis. This embodiment does not make more specific limitations on the number of relay lens groups 21, and one relay lens group 21 is exemplarily described in the following embodiments, but this cannot limit the protection scope of this application.

[0096] In one embodiment, the focal length f7 of the first double crescent lens 201 and the focal length F2 of the three-cemented rod lenses satisfy ; the focal length f8 of the second double crescent lens 202 and the focal length F2 of the three-cemented rod lenses satisfy ; focal length f9 of the third double crescent lens 203 and focal length F2 of the three-hybrid rod lens satisfy . Thus, by limiting the focal length of the single lens and the overall focal length of the three-hybrid rod lens, the high standard image quality transmission of the relay lens group 21 is further ensured.

[0097] In an embodiment, the central thickness h7 of the first double crescent lens 201, the central thickness h8 of the second double crescent lens 202, the central thickness h9 of the third double crescent lens 203, and the focal length F2 of the three-hybrid rod lens satisfy By limiting the overall length and focal length of the three-hybrid rod lens, the stability of the three-hybrid rod lens is ensured, and the overall relay lens group 21 structure is more compact, the parameters are stable, and the production is facilitated.

[0098] In an embodiment, the focal length f7 of the first double crescent lens 201, the Abbe number v7 of the lens material, the focal length f8 of the second double crescent lens 202, the Abbe number v8 of the lens material, the focal length f9 of the third double crescent lens 203, and the Abbe number v9 of the lens material satisfy By limiting the material and focal length of the three double crescent lenses, chromatic aberration is eliminated.

[0099] In an embodiment, by limiting the material of the three double crescent lenses (i.e., the first double crescent lens 201, the second double crescent lens 202, and the third double crescent lens 203), the refractive index n7 of the first double crescent lens 201 and the refractive index n8 of the second double crescent lens 202 satisfy Thus, the high-order spherical aberration and coma are controlled, and the curvature radius of the second cemented surface 204 is not too small to be difficult to process; the refractive index n8 of the second double crescent lens 202 and the refractive index n9 of the third double crescent lens 203 satisfy Thus, the chromatic aberration is corrected, and the correction of the flat image field is facilitated.

[0100] In an embodiment, the surface of the first double crescent lens 201 away from the second cemented surface 204 corresponds to the curvature radius r12, the second cemented surface 204 corresponds to the curvature radius r13, and the central thickness h7 of the first double crescent lens 201 satisfy Thus, the first double crescent lens 201 is facilitated to be processed.

[0101] In an embodiment, the second cemented surface 204 corresponds to the curvature radius r13, and the third cemented surface 205 corresponds to the curvature radius r14 satisfy Thus, by controlling the shape of the three-hybrid rod lens, the three-hybrid rod lens is easy to process, and the manufacturing cost and difficulty are reduced.

[0102] In an embodiment, the pupil diameter D2 of the relay lens group 21 and the effective clear aperture CA2 of the relay lens group 21 satisfy Thus, all the light rays of all the fields of view can pass through the relay lens group 21, realizing uniform illumination of the full field of view without vignetting, and reserving a safety margin for the processing and assembly errors of the lenses in the relay lens group 21 to ensure that the optical performance requirements can be stably met under actual manufacturing conditions.

[0103] In an embodiment, the light flux of the relay lens system 20 is greater than or equal to the light flux of the objective lens system 10, the wavelength of the relay lens system 20 is equal to the wavelength of the objective lens system 10, the entrance pupil diameter of the relay lens system 20 is greater than or equal to the exit pupil diameter of the objective lens system 10, and the field of view angle of the relay lens system 20 is equal to the field of view angle of the objective lens system 10, so as to transfer the optical information of the object to be measured captured by the objective lens system 10 to the rear end of the optical observation device, realizing lossless connection between the exit pupil of the objective lens system 10 and the entrance pupil of the relay lens system 20, and ensuring efficient and non-vignetting transmission of the light flux.

[0104] In an embodiment, the second doublet lens 301 comprises, in order from the object side, a third lens 304 having a positive focal power and a fourth lens 305 having a positive focal power. The object side surface of the third lens 304 is a convex surface, and the image side surface thereof is a concave surface. The object side surface of the fourth lens 305 is a convex surface, and the image side surface thereof is a convex surface. The image side surface of the third lens 304 and the object side surface of the fourth lens 305 are cemented to form a fourth cemented surface 306.

[0105] In an embodiment, the objective lens system 10 further comprises a first plane mirror 101 arranged on the object side of the first doublet lens 102 coaxially with the optical axis, for spherical aberration compensation. The addition of the first plane mirror 101 based on the aforementioned four lenses further ensures that the number of lenses is small and the imaging quality is good.

[0106] In an embodiment, the magnifying lens system 30 further comprises a second plane mirror 307 arranged on the image side of the fourth doublet lens 303 coaxially with the optical axis, as a dustproof protective mirror of the magnifying lens system 30, to prevent dust and other impurities from entering the interior of the optical observation device.

[0107] In an embodiment, the optical observation device further comprises an image sensor (not shown) arranged on the image side of the magnifying lens system 30 coaxially with the optical axis. The image sensor may, for example, be a CMOS camera. The magnifying lens system 30 comprises a third plane mirror 308 arranged on the image side of the second plane mirror 307, as a front protective mirror of the image sensor, to protect the image sensor.

[0108] The following describes a numerical embodiment of the objective lens system 10 of the present application.

[0109] [Example 1]

[0110] like Figure 1 As shown, the objective lens system 10a is formed by arranging a first plane mirror 101a, a first cemented doublet lens 102a with positive optical power (including a first lens 106a with positive optical power and a second lens 107a with negative optical power), a first biconvex lens 103a, a first biconcave lens 104a, and a second biconvex lens 105a along the same optical axis 40a from the object side. The object-side surface of the first lens 106a is concave and the image-side surface is convex, and the object-side surface of the second lens 107a is concave and the image-side surface is convex. The image-side surface of the first lens 106a and the object-side surface of the second lens 107a are cemented together to form a first cemented surface 108a.

[0111] Table 1 shows the basic parameters of the surfaces contained in the objective system 10a of Example 1, including serial number, radius of curvature, center thickness, refractive index, and Abbe number.

[0112] In the basic parameter table, number 1 corresponds to the exit pupil surface (not shown), numbers 2 to 10 correspond to the surfaces closest to the image side to the object side of the second biconvex lens 105a, the first biconcave lens 104a, the first biconvex lens 103a, and the first cemented doublet lens 102a, respectively, and number 12 corresponds to the object surface (not shown). Since the image-side surface and object-side surface of the first plane mirror 101a are the same, only number 11 corresponding to the first plane mirror 101a is shown.

[0113] The "Radius of Curvature" column indicates the radius of curvature corresponding to the surface with the current serial number. The sign of the radius of curvature is positive if the surface bulges towards the image side and negative if it bulges towards the object side.

[0114] The "Center Thickness" column indicates the distance between the center positions of the current and next numbered surfaces. Serial number 11 indicates the center thickness of the first plane mirror 101a.

[0115] The refractive index column indicates the refractive index of each lens under light with a wavelength of 587nm, and it is filled in at the corresponding serial number on the image-side surface of that lens. Serial number 11 indicates the refractive index of the first plane mirror 101a.

[0116] The Abbe number column indicates the Abbe number corresponding to the material of each lens, and it is filled in the serial number corresponding to the image side surface of that lens. Serial number 11 indicates the Abbe number corresponding to the material of the first plane mirror 101a.

[0117] The focal length of the objective lens system 10a shown in Embodiment 1 is 5 (unit, millimeter, mm), the wavelength is 0.43-0.66 (unit, micrometer, pm), the half field of view is 4.3 (unit, degree, °), and the entrance pupil diameter is 3.2 (unit, millimeter, mm). The length unit of the numerical values of Table 1 is "millimeter" (abbreviation "mm"), but it is only one column, which can be enlarged or reduced in proportion, so other appropriate units can also be used. At the same time, the values shown in Table 1 are rounded off to the specified number of digits.

[0118]

[0119] The calculated values of the objective lens system 10a shown in Embodiment 1 are shown in Table 2.

[0120]

[0121] Reference is made to Figures 9 to 11 The MTF curve graphs of Embodiment 1 at 0.707 field of view, at edge field of view, and at center field of view are shown respectively, and Figures 9 to 11 The ideal case MTF curve is also shown for comparison. In Figures 9 to 11 The black solid line (Diff. Limit-Tangential) and the black dashed line (Diff. Limit-Sagittal) in the figure respectively refer to the MTF curves of the objective lens system 10a in the tangential direction and the sagittal direction under the ideal case, and the MTF curves in the tangential direction and the sagittal direction under the ideal case coincide, so Figures 9 to 11 The black solid line and the black dashed line contained in the figure respectively coincide with each other, and only the black solid line is shown. The green solid line (3.1113 (deg) - Tangential) and the green dashed line 3.1113 (deg) - Sagittal) respectively refer to the MTF curves of the objective lens system 10a in the tangential direction and the sagittal direction under 0.707 field of view; the red solid line (4.3000 (deg) - Tangential) and the red dashed line (4.3000 (deg) - Sagittal) respectively refer to the MTF curves of the objective lens system 10a in the tangential direction and the sagittal direction under edge field of view; the blue solid line (0.0000 (deg) - Tangential) and the blue dashed line (0.0000 (deg) - Sagittal) respectively refer to the MTF curves of the objective lens system 10a in the tangential direction and the sagittal direction under center field of view, since the blue solid line and the blue dashed line overlap, only the blue solid line can be shown.

[0122] The above-described illustration method, symbols, meanings, and description method of various data of the objective lens system 10a of Embodiment 1 are also applicable to the objective lens system 10b and the objective lens system 10c of Embodiment 2 and Embodiment 3 below unless otherwise specified, so the repeated description is omitted below.

[0123] [Example 2]

[0124] As Figure 2 shown, the objective lens system 10b is formed by arranging a first plane mirror 101b, a first doublet lens 102b with positive optical power (including a first lens 106b with positive optical power and a second lens 107b with negative optical power), a first biconvex lens 103b, a first biconcave lens 104b, and a second biconvex lens 105b coaxially on the optical axis 40b in sequence from the object side. The object-side surface of the first lens 106b is a plane, and the image-side surface is convex. The object-side surface of the second lens 107b is concave, and the image-side surface is convex. The image-side surface of the first lens 106b and the object-side surface of the second lens 107b are cemented to form a first cemented surface 108b.

[0125] Table 3 shows the basic parameter table of the surfaces included in the objective lens system 10b of Example 2, which includes the serial number, radius of curvature, central thickness, refractive index, and Abbe number.

[0126] The focal length of the objective lens system 10b shown in Example 2 is 5 mm, the wavelength is 0.43 - 0.66 μm, the semi-field of view is 4.3 degrees, and the entrance pupil diameter is 3.2 mm.

[0127]

[0128] Table 4 shows the calculated values of the objective lens system 10b shown in Example 2.

[0129]

[0130] Refer Figures 12 to 14 to the MTF curve graphs of Example 2 shown respectively at 0.707 field of view, edge field of view, and central field of view, and Figures 12 to 14 also shows the MTF curve under ideal conditions for comparison. In Figures 12 to 14 it, the solid black line (Diff. Limit - Tangential) and the dashed black line (Diff. Limit - Sagittal) respectively refer to the MTF curves of the objective lens system 10b in the meridional direction and sagittal direction under ideal conditions, and the MTF curves in the meridional direction and sagittal direction coincide under ideal conditions. Therefore, Figures 12 to 14The black solid line and the black dashed line contained respectively therein coincide with each other, and only the black solid line can be shown. The green solid line (3.1113 (deg)-Tangential) and the green dashed line (3.1113 (deg)-Sagittal) respectively refer to the MTF curves of the objective lens system 10b in the meridional direction and the sagittal direction at a 0.707 field of view; the red solid line (4.3000 (deg)-Tangential) and the red dashed line (4.3000 (deg)-Sagittal) respectively refer to the MTF curves of the objective lens system 10b in the meridional direction and the sagittal direction at the edge field of view; the blue solid line (0.0000 (deg)-Tangential) and the blue dashed line (0.0000 (deg)-Sagittal) respectively refer to the MTF curves of the objective lens system 10b in the meridional direction and the sagittal direction at the central field of view. Since the blue solid line and the blue dashed line overlap, only the blue solid line can be shown.

[0131] [Embodiment 3]

[0132] As Figure 3 shown, the objective lens system 10c is formed by sequentially arranging a first plane mirror 101c, a first doublet lens 102c with a positive optical power (including a first lens 106c with a positive optical power and a second lens 107c with a negative optical power), a first biconvex lens 103c, a first biconcave lens 104c, and a second biconvex lens 105c on the same optical axis 40c from the object side. The object-side surface of the first lens 106c is concave and the image-side surface is convex. The object-side surface of the second lens 107c is concave and the image-side surface is convex. Moreover, the image-side surface of the first lens 106c and the object-side surface of the second lens 107c are cemented to form a first cemented surface 108c.

[0133] Table 5 shows the basic parameter table of the surfaces included in the objective lens system 10c of Embodiment 3, which includes the serial number, radius of curvature, central thickness, refractive index, and Abbe number.

[0134] The focal length of the objective lens system 10c shown in Embodiment 3 is 5 mm, the wavelength is 0.43 - 0.66 μm, the semi-field of view is 4.3 degrees, and the entrance pupil diameter is 3.2 mm.

[0135] <0​​​​​​​​The ideal case MTF curve is also shown for comparison. Figures 15 to 17 In the ideal case, the black solid line (Diff. Limit-Tangential) and the black dashed line (Diff. Limit-Sagittal) represent the MTF curves of the objective lens system 10c in the tangential direction and the sagittal direction, respectively, and the MTF curves in the tangential direction and the sagittal direction coincide in the ideal case, thus, Figures 15 to 17 In the ideal case, the black solid line and the black dashed line included in the ideal case coincide with each other, and only the black solid line can be shown. The green solid line (3.0406 (deg)-Tangential) and the green dashed line (3.0406 (deg)-Sagittal) represent the MTF curves of the objective lens system 10c in the tangential direction and the sagittal direction, respectively, at 0.707 field of view; the red solid line (4.3000 (deg)-Tangential) and the red dashed line (4.3000 (deg)-Sagittal) represent the MTF curves of the objective lens system 10c in the tangential direction and the sagittal direction, respectively, at the edge field of view; the blue solid line (0.0000 (deg)-Tangential) and the blue dashed line (0.0000 (deg)-Sagittal) represent the MTF curves of the objective lens system 10c in the tangential direction and the sagittal direction, respectively, at the center field of view, and since the blue solid line and the blue dashed line overlap, only the blue solid line can be shown.

[0139] It should be noted that, in the ideal case, the MTF curves in the tangential direction and the sagittal direction coincide to achieve the best imaging effect and the lower the distortion rate, the closer the ordinate corresponding to the same abscissa in the actual test case, the closer the MTF curves in the tangential direction and the sagittal direction are; at the same time, from the actual imaging angle, the closer the ordinate corresponding to the same abscissa in the test case and the ordinate corresponding to the same abscissa in the ideal case, the better the imaging efficiency, the closer the image to the real image, and the lower the distortion rate of the image. Based on this, Figures 9 to 17 It can be known that the objective lens system 10 disclosed in the present application not only has the attribute of infinite conjugate to improve the adaptability in practical application, but also has good imaging effect under the condition of fewer lenses.

[0140] The following describes a numerical embodiment of the relay lens system 20 of the present application.

[0141] [Embodiment 4]

[0142] As Figure 4As shown, the first double-crescent lens 201a, the second double-crescent lens 202a and the third double-crescent lens 203a are glued in order from the object side to form a three-glued rod lens on the object side, the third double-crescent lens 203a, the second double-crescent lens 202a and the first double-crescent lens 201a are glued in order from the object side to form a three-glued rod lens on the image side, thereby constituting the relay lens group 21a. Meanwhile, the concave surface of the first double-crescent lens 201a and the convex surface of the second double-crescent lens 202a are glued to form the second glued surface 204a, and the concave surface of the second double-crescent lens 202a and the convex surface of the third double-crescent lens 203a are glued to form the third glued surface 205a.

[0143] The basic parameter table of the relay lens system 20a of Example 4 shown in Table 7 includes the serial number, the radius of curvature, the central thickness, the refractive index and the Abbe number, and contains the entrance pupil surface (not shown) and the intermediate image 206a.

[0144] The serial number 1 in the serial number column of the basic parameter table corresponds to the entrance pupil surface, the serial numbers 2 to 5 correspond to the surface closest to the object side to the surface closest to the image side of the three-glued rod lens on the object side in order, the serial number 6 corresponds to the intermediate image 206a, and the serial numbers 7 to 10 correspond to the surface closest to the object side to the surface closest to the image side of the three-glued rod lens on the image side in order.

[0145] The radius of curvature column indicates the radius of curvature corresponding to the surface of the current serial number, and the sign of the radius of curvature is positive when the surface forms a convex shape to the object side, and negative when it forms a convex shape to the image side.

[0146] The central thickness column indicates the separation distance formed at the central position between the surface of the current serial number and the surface of the next serial number.

[0147] The refractive index column indicates the refractive index of each lens under light with a wavelength of 546 nm, and is filled in at the serial number corresponding to the object side surface of the lens.

[0148] The Abbe number column indicates the Abbe number corresponding to the material of each lens, and is filled in at the serial number corresponding to the object side surface of the lens.

[0149] The focal length of the relay lens system 20a shown in Example 4 is 20.25 (unit, millimeter, mm), the entrance pupil diameter is 3.20 (unit, millimeter, mm), the effective clear aperture is 3.2 (unit, millimeter, mm), and the half field angle is 4.3 (unit, degree, °). "Millimeter" (abbreviation "mm") is used as the length unit of the values in Table 1, but it is only a column, which can be scaled up or scaled down for use, so other appropriate units can also be used. Meanwhile, the values in Table 7 are shown after rounding off to a specified number of digits.

[0150]

[0151] The calculated values of the relay mirror system 20a shown in Example 4 are shown in Table 8.

[0152] <​​​​​​​​​​​​​​​​​​​​As shown, a triple cemented rod lens on the object side is formed by sequentially cementing the first double meniscus lens 201b, the second double meniscus lens 202b, and the third double meniscus lens 203b coaxially with the optical axis 40e starting from the object side. A triple cemented rod lens on the image side is formed by sequentially cementing the third double meniscus lens 203b, the second double meniscus lens 202b, and the first double meniscus lens 201b coaxially with the optical axis 40e starting from the object side, thus constituting the relay lens group 21b. At the same time, the concave surface of the first double meniscus lens 201b and the convex surface of the second double meniscus lens 202b in the relay lens group 21b are cemented to form the second cemented surface 204b, and the concave surface of the second double meniscus lens 202b and the convex surface of the third double meniscus lens 203b are cemented to form the third cemented surface 205b. [[ID=**1**]] [[ID=**2**]]

[0157] [[ID=**3**]]Table 9 shows the basic parameter table of the relay lens system 20b in Example 5, including the surfaces contained, the entrance pupil surface (not shown), and the intermediate image 206b, which includes the serial number, radius of curvature, central thickness, refractive index, and Abbe number. [[ID=**4**]] [[ID=**5**]]

[0158] [[ID=**6**]]The focal length of the relay lens system 20b shown in Example 5 is 19.6 (unit: millimeter, mm), the entrance pupil diameter is 3.2 (unit: millimeter, mm), the effective clear aperture is 3.2 (unit: millimeter, mm), and the half field angle is 4.3 (unit: degree, °). [[ID=**7**]] [[ID=**8**]]

[0159] [[ID=**9**]] [[ID=**10**]] [[ID=**11**]]

[0160] [[ID=**12**]]Table 10 shows the calculated values of the relay lens system 20b shown in Example 5. [[ID=**<13>**]] [[ID=**<14>**]]

[0161] [[ID=**<15>**]] [[ID=**<16>**]] [[ID=**<17>**]]<00,00455>[[ID=**<18>**]]See [[ID=**<19>**]] Figures 21 to 23 [[ID=**<20>**]]The MTF curves of Example 5 shown respectively at 0.707 field, edge field, and central field, and [[ID=**<21>**]] Figures 21 to 23 [[ID=**<22>**]]also shows the MTF curve under ideal conditions for comparison. In [[ID=**<23>**]] Figures 21 to 23 [[ID=**<24>**]]it, the solid black line (Diff. Limit - Tangential) and the dashed black line (Diff. Limit - Sagittal) respectively refer to the MTF curves of the relay lens system 20b in the meridional direction and the sagittal direction under ideal conditions, and the MTF curves in the meridional direction and the sagittal direction coincide under ideal conditions. Therefore, [[ID=**<25>**]] Figures 21 to 23The black solid lines and black dashed lines in the diagram overlap, and only the black solid lines are shown. The green solid line (3.0406 (deg) - Tangential) and the green dashed line (3.0406 (deg) - Sagittal) refer to the MTF curves of the relay system 20b in the meridional and sagittal directions under a 0.707 field of view, respectively; the red solid line (4.3000 (deg) - Tangential) and the red dashed line (4.3000 (deg) - Sagittal) refer to the MTF curves of the relay system 20b in the meridional and sagittal directions under a peripheral field of view, respectively; the blue solid line (0.0000 (deg) - Tangential) and the blue dashed line (0.0000 (deg) - Sagittal) refer to the MTF curves of the relay system 20b in the meridional and sagittal directions under a central field of view, respectively. Since the blue solid lines and blue dashed lines overlap, only the blue solid lines are shown.

[0163] [Example 6]

[0164] like Figure 6 As shown, a triplet rod-shaped lens is formed on the object side by cementing the first double meniscus lens 201c, the second double meniscus lens 202c, and the third double meniscus lens 203c together with the optical axis 40f from the object side. A triplet rod-shaped lens is also formed on the image side by cementing the third double meniscus lens 203c, the second double meniscus lens 202c, and the first double meniscus lens 201c together with the optical axis 40f from the object side, thus forming a triplet rod-shaped lens assembly 21c. Simultaneously, the concave surface of the first double meniscus lens 201c and the convex surface of the second double meniscus lens 202c are cemented together to form a second cemented surface 204c, and the concave surface of the second double meniscus lens 202c and the convex surface of the third double meniscus lens 203c are cemented together to form a third cemented surface 205c.

[0165] Table 11 shows the basic parameters of the surfaces included in the relay mirror system 20c of Embodiment 6, including the incident pupil surface (not shown) and the intermediate image 206c, which include serial numbers, radii of curvature, central thickness, refractive index, and Abbe number.

[0166] The relay lens system 20c shown in Example 6 has a focal length of 18.44 mm, an entrance pupil diameter of 3.2 mm, an effective aperture of 3.2 mm, and a half field of view of 4.3 degrees.

[0167]

[0168] Table 12 shows the calculated values ​​for the relay mirror system 20c shown in Example 6.

[0169]

[0170] Reference Figures 24 to 26 The MTF curves of Example 6 shown respectively under a 0.707 field of view, at the edge field of view, and at the central field of view, and Figures 24 to 26 also shows the MTF curve under ideal conditions for comparison. In Figures 24 to 26 it, the solid black line (Diff. Limit - Tangential) and the dashed black line (Diff. Limit - Sagittal) respectively refer to the MTF curves of the relay mirror system 20c in the meridional direction and the sagittal direction under ideal conditions, and the MTF curves in the meridional direction and the sagittal direction coincide under ideal conditions. Therefore, Figures 24 to 26 the solid black line and the dashed black line included respectively in it coincide with each other and only the solid black line can be shown. The solid green line (3.0406 (deg) - Tangential) and the dashed green line (3.0406 (deg) - Sagittal) respectively refer to the MTF curves of the relay mirror system 20c in the meridional direction and the sagittal direction under a 0.707 field of view; the solid red line (4.3000 (deg) - Tangential) and the dashed red line (4.3000 (deg) - Sagittal) respectively refer to the MTF curves of the relay mirror system 20c in the meridional direction and the sagittal direction at the edge field of view; the solid blue line (0.0000 (deg) - Tangential) and the dashed blue line (0.0000 (deg) - Sagittal) respectively refer to the MTF curves of the relay mirror system 20c in the meridional direction and the sagittal direction at the central field of view. Since the solid blue line and the dashed blue line overlap, only the solid blue line can be shown.

[0171] In summary, it can be seen that under ideal conditions, the coincidence of the MTF curves in the meridional direction and the sagittal direction can achieve the best imaging effect and the lower the distortion rate. In the actual test situation, the closer the ordinates corresponding to the same abscissa are, the closer the MTF curves in the meridional direction and the sagittal direction are approximated; at the same time, from the perspective of actual imaging, the closer the ordinates corresponding to the same abscissa in the test situation and the ordinates corresponding to the same abscissa under ideal conditions are, the better the imaging efficiency, the more the image tends to be real, and the lower the distortion rate of the image. Based on this, from Figures 18 to 26 it can be seen that the relay mirror system 20 disclosed in the present application can achieve lossless transmission of the pupil on the premise of low tolerance requirements and being more conducive to alignment and adjustment.

[0172] The following describes the numerical examples of the magnifying glass system 30 of the present application.

[0173] [Example 7]

[0174] As Figure 7As shown, the magnifying lens system 30 is formed by arranging the second double cemented lens 301 with positive focal power (including the third lens 304 with positive focal power and the fourth lens 305 with positive focal power), the second double concave lens 302 with negative focal power, and the fourth double meniscus lens 303 with positive focal power, the second plane mirror 307, and the third plane mirror 308 in sequence from the object side to the image side along the optical axis 40g. The object side surface of the third lens 304 is a convex surface, and the image side surface thereof is a concave surface. The object side surface of the fourth lens 305 is a convex surface, and the image side surface thereof is a convex surface. The image side surface of the third lens 304 and the object side surface of the fourth lens 305 are cemented to form the fourth cemented surface 306.

[0175] The basic parameter table of the surfaces included in the magnifying lens system 30 of Example 7 and containing the entrance pupil surface (not shown) and the image surface (not shown) is shown in Table 13, which contains the serial number, the radius of curvature, the central thickness, the refractive index, and the Abbe number.

[0176] In the serial number column of the basic parameter table, serial number 1 corresponds to the entrance pupil surface, serial numbers 2 to 8 correspond to the surfaces of the second double cemented lens 301, the second double concave lens 302, and the fourth double meniscus lens 303 from the surface closest to the object side to the surface closest to the image side in sequence, and serial number 12 corresponds to the image surface. Since the object side surface and the image side surface of the second plane mirror 307 are the same, only serial number 9 is shown to correspond to the second plane mirror 307. Similarly, only serial number 10 is shown to correspond to the third plane mirror 308.

[0177] The radius of curvature column indicates the radius of curvature corresponding to the surface of the current serial number, and the sign of the radius of curvature is positive when the surface forms a convex shape towards the object side, and negative when the surface forms a convex shape towards the image side.

[0178] The central thickness column indicates the separation distance formed by the central position between the surface of the current serial number and the surface of the next serial number. Serial number 9 indicates the central thickness of the second plane mirror 307, and serial number 10 indicates the central thickness of the third plane mirror 308.

[0179] The refractive index column indicates the refractive index of each lens under light with a wavelength of 546 nm, and is filled in at the serial number corresponding to the image side surface of the lens. Serial number 9 indicates the refractive index of the second plane mirror 307, and serial number 10 indicates the refractive index of the third plane mirror 308.

[0180] The Abbe number column indicates the Abbe number corresponding to the material of each lens, and is filled in at the serial number corresponding to the object side surface of the lens. Serial number 9 indicates the Abbe number corresponding to the material of the second plane mirror 307, and serial number 10 indicates the Abbe number corresponding to the material of the third plane mirror 308.

[0181] The magnifying lens system 30 shown in Embodiment 7 has a focal length of 58.51 (unit, millimeter, mm), a wavelength of 0.43-0.66 (unit, micrometer, pm), and a half field of view of 4.3 (unit, degree, °). The "millimeter" (abbreviation "mm") is used as the unit of length for the values in Table 13, but it is only one column, which can be scaled up or scaled down, so other appropriate units can also be used. Meanwhile, the values shown in Table 13 are rounded to a specified number of digits.

[0182]

[0183] Referring to Figures 27 to 29 The MTF curves of Embodiment 7 at 0.707 field of view, edge field of view, and center field of view are shown respectively, and Figures 27 to 29 The ideal MTF curves are also shown for comparison. In Figures 27 to 29 The black solid line (Diff. Limit-Tangential) and the black dashed line (Diff. Limit-Sagittal) in the ideal case respectively represent the MTF curves of the relay lens system 20c in the tangential direction and the sagittal direction, and the MTF curves in the tangential direction and the sagittal direction coincide, so Figures 27 to 29 The black solid line and the black dashed line included in the ideal case coincide with each other, and only the black solid line can be shown. The green solid line (3.1113 (deg)-Tangential) and the green dashed line (3.1113 (deg)-Sagittal) respectively represent the MTF curves of the relay lens system 20c in the tangential direction and the sagittal direction at 0.707 field of view; the red solid line (4.4000 (deg)-Tangential) and the red dashed line (4.4000 (deg)-Sagittal) respectively represent the MTF curves of the relay lens system 20c in the tangential direction and the sagittal direction at edge field of view; the blue solid line (0.0000 (deg)-Tangential) and the blue dashed line (0.0000 (deg)-Sagittal) respectively represent the MTF curves of the relay lens system 20c in the tangential direction and the sagittal direction at center field of view, and since the blue solid line and the blue dashed line overlap, only the blue solid line can be shown.

[0184] In summary, in the ideal case, the MTF curves in the tangential direction and the sagittal direction coincide to achieve the best imaging effect, and the lower the distortion rate, in the actual test case, the closer the corresponding vertical coordinates of the same horizontal coordinates, the closer the MTF curves in the tangential direction and the sagittal direction; at the same time, from the actual imaging angle, the closer the corresponding vertical coordinates of the same horizontal coordinates in the test case and the corresponding vertical coordinates of the same horizontal coordinates in the ideal case, the better the imaging efficiency, the closer the image to the real image, and the lower the distortion rate of the image. Based on this, Figures 27 to 29It is understood that the magnifying glass system 30 disclosed in this application not only has infinite conjugation properties to improve adaptability in practical applications, but also has good imaging effect even with a small number of lenses.

[0185] More specifically, participants Figure 8 As shown, to more clearly demonstrate that this application has better imaging performance, the objective lens system 10a of Embodiment 1, the relay lens system 20c of Embodiment 4, and the magnifying lens system 30 of Embodiment 7 are combined and sequentially arranged along the optical axis 40 from the object side to form an optical observation device 100, which is described as Embodiment 8. (See reference...) Figures 30 to 32 The figures show the MTF curves of Example 8 under a 0.707 field of view, an edge field of view, and a center field of view, respectively. Figures 30 to 32 The ideal MTF curve is also shown for comparison. Figures 30 to 32 In the diagram, the solid black line (Diff. Limit-Tangential) and the dashed black line (Diff. Limit-Sagittal) represent the MTF curves of the optical observation device 100 under ideal conditions in the meridional and sagittal directions, respectively. Furthermore, under ideal conditions, the MTF curves in the meridional and sagittal directions coincide. Figures 30 to 32 The black solid lines and black dashed lines in the diagram overlap, and only the black solid lines are shown. The green solid line (0.2652 deg - Tangential) and the green dashed line (0.2652 deg - Sagittal) refer to the MTF curves of the optical observation device 100 in the meridional and sagittal directions under a 0.707 field of view, respectively; the red solid line (0.3750 deg - Tangential) and the red dashed line (0.3750 deg - Sagittal) refer to the MTF curves of the optical observation device 100 in the meridional and sagittal directions under the peripheral field of view, respectively; the blue solid line (0.0000 deg - Tangential) and the blue dashed line (0.0000 deg - Sagittal) refer to the MTF curves of the optical observation device 100 in the meridional and sagittal directions under the central field of view, respectively. Since the blue solid lines and blue dashed lines overlap, only the blue solid lines are shown. Based on this, Figures 30 to 32 It is understood that the optical observation device 100 disclosed in this application can ensure imaging quality under the premise of low tolerance requirements and easier assembly and adjustment, and with the overall size unchanged, it has a larger field of view, less vignetting, fewer lenses, and higher cost performance.

[0186] The detailed descriptions listed above are merely specific descriptions of feasible implementation methods of this application and are not intended to limit the scope of protection of this application. All equivalent implementation methods or modifications made without departing from the spirit of the art of this application should be included within the scope of protection of this application.

[0187] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes only one independent technical solution, and the specification is described in this way only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. An optical observation device, characterized in that, include: The objective lens system, the relay lens system, and the magnifying lens system are arranged sequentially along the optical axis from the object side, and all three systems are parallel optical paths. The objective lens system includes: a first cemented doublet with positive optical power, a first biconvex lens with positive optical power, a first biconcave lens with negative optical power, and a second biconvex lens with positive optical power, arranged sequentially along the optical axis from the object side. The relay mirror system includes: at least one relay mirror group, wherein the relay mirror group includes two cemented rod mirrors arranged symmetrically with optical properties; The magnifying lens system includes: a second cemented doublet lens with positive optical power, a second biconcave lens with negative optical power, and a fourth bimens lens with positive optical power, arranged sequentially along the optical axis from the object side.

2. The optical observation device according to claim 1, characterized in that, The first cemented doublet lens includes a first lens with positive optical power and a second lens with positive optical power arranged sequentially along the optical axis from the object side. The object side surface of the first lens is a plane or concave surface and the image side surface is a convex surface. The object side surface of the second lens is a concave surface and the image side surface is a convex surface. The image side surface of the first lens and the object side surface of the second lens are cemented together to form a first cemented surface.

3. The optical observation device according to claim 2, characterized in that, The combined focal length F1 of the first cemented doublet lens and the first biconvex lens, and the focal length F10 of the objective lens system satisfy the following conditions: ; The focal length f2 of the first lens, the Abbe number v2 of the first lens, the focal length f3 of the second lens, and the Abbe number v3 of the second lens satisfy the following conditions: ; The center thickness d2 of the first lens, the radius of curvature r4 corresponding to the first cemented surface, and the radius of curvature r3 corresponding to the object-side surface of the first lens satisfy the following conditions: .

4. The optical observation device according to claim 1, characterized in that, The focal length f6 of the second biconvex lens and the focal length F10 of the objective lens system satisfy the following conditions: ; The center thickness d6 of the second biconvex lens, the refractive index n6 of the second biconvex lens, the radius of curvature r10 of the object-side surface of the second biconvex lens, and the radius of curvature r11 of the image-side surface of the second biconvex lens satisfy the following conditions: ; The center thickness d5 of the first biconcave lens, the refractive index n5 of the first biconcave lens, the radius of curvature r8 corresponding to the object-side surface of the first biconcave lens, and the radius of curvature r9 corresponding to the image-side surface of the first biconcave lens satisfy the following conditions: ; The focal length f4, refractive index f4, radius of curvature r6 of the object-side surface of the first biconvex lens, and radius of curvature r7 of the image-side surface of the first biconvex lens satisfy the following conditions: .

5. The optical observation device according to claim 1, characterized in that, The triple-cemented rod lens includes: a first double meniscus lens with negative optical power, a second double meniscus lens with positive optical power, and a third double meniscus lens with positive optical power. The concave surface of the first double meniscus lens and the convex surface of the second double meniscus lens are cemented together to form a second cemented surface, and the concave surface of the second double meniscus lens and the convex surface of the third double meniscus lens are cemented together to form a third cemented surface. In this single relay lens group, the two third cemented surfaces formed by the two triple-cemented rod-shaped lenses are located between the two second cemented surfaces.

6. The optical observation device according to claim 5, characterized in that, The focal length f7 of the first double meniscus lens and the focal length F2 of the cemented rod lens satisfy the following conditions: ; The focal length f8 of the second double meniscus lens and the focal length F2 of the cemented rod lens satisfy the following conditions: ; The focal length f9 of the third double meniscus lens and the focal length F2 of the cemented rod lens satisfy the following conditions: ; The center thickness h7 of the first double meniscus lens, the center thickness h8 of the second double meniscus lens, the center thickness h9 of the third double meniscus lens, and the focal length F2 of the cemented trilateration rod lens satisfy the following conditions: ; The focal length f7 of the first double meniscus lens, the Abbe number v7 of the first double meniscus lens, the focal length f8 of the second double meniscus lens, the Abbe number v8 of the second double meniscus lens, the focal length f9 of the third double meniscus lens, and the Abbe number v9 of the third double meniscus lens satisfy the following conditions: ; The refractive index n7 of the first double meniscus lens and the refractive index n8 of the second double meniscus lens satisfy the following conditions: ; The refractive index n8 of the second bimenstrual lens and the refractive index n9 of the third bimenstrual lens satisfy the following conditions: ; The radius of curvature r12 of the surface of the first double meniscus lens away from the second cemented surface, the radius of curvature r13 of the second cemented surface, and the center thickness h7 of the first double meniscus lens satisfy the following conditions: ; The radius of curvature r13 corresponding to the second glued surface and the radius of curvature r14 corresponding to the third glued surface satisfy the following conditions: .

7. The optical observation device according to claim 5, characterized in that, The pupil diameter D2 and the effective aperture CA2 of the relay lens group satisfy the following conditions: ; The light flux of the relay lens system is greater than or equal to the light flux of the objective lens system; The wavelength of the relay mirror system is equal to the wavelength of the objective mirror system; The entrance pupil diameter of the relay lens system is greater than or equal to the exit pupil diameter of the objective lens system; The field of view of the relay lens system is equal to the field of view of the objective lens system.

8. The optical observation device according to claim 1, characterized in that, The second cemented doublet lens includes a third lens with positive optical power and a fourth lens with positive optical power arranged sequentially along the optical axis from the object side. The object-side surface of the third lens is convex and the image-side surface is concave. The object-side surface of the fourth lens is convex and the image-side surface is convex. The image-side surface of the third lens and the object-side surface of the fourth lens are cemented together to form a fourth cemented surface.

9. The optical observation device according to claim 1, characterized in that, The objective lens system further includes: a first plane mirror disposed on the object side of the first cemented doublet lens along the optical axis; The magnifying glass system further includes a second plane mirror that is coaxially positioned on the image side of the fourth double meniscus lens.

10. The optical observation device according to claim 9, characterized in that, The optical observation device further includes an image sensor coaxially disposed on the image side of the magnifying glass system, and the magnifying glass system further includes a third plane mirror disposed on the image side of the second plane.

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