Optical system and microscope

Abstract

The embodiment of the invention provides an optical system and a microscope. The optical system comprises a microscope objective and a tube lens which are sequentially arranged along the optical axis from the object space to the image space. The microscope objective comprises a first lens group, a second lens group, a diaphragm and a third lens group which are sequentially arranged along the direction of an optical axis. The first lens group has positive focal power and is at least used for correcting spherical aberration, astigmatism and axial chromatic aberration. The first lens group comprises a first bonding lens, a third lens and a second bonding lens. The second lens group has positive refractive power and is at least used for correcting coma and distortion. The second lens group comprises a sixth lens and a third balsaming lens. The third lens group has positive focal power and is at least used for correcting field curvature and vertical axis chromatic aberration. The third lens group comprises a fourth balsaming lens, a thirteenth lens, a fourteenth lens and a fifteenth lens. The tube lens has positive focal power. The tube lens comprises a fifth balsaming lens, a sixth balsaming lens and a twenty-first lens which are sequentially arranged in the optical axis direction.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of optical imaging technologies, and in particular, to an optical system and a microscope. Background Art

[0002] With the applications in scenarios such as defect diversity of compound semiconductor quantity detection and fluorescence detection in life sciences, product type complexity, weak light emission, and high detection efficiency, higher requirements are put forward for the microscopic imaging optical system. To meet these application requirements of the optical system, the optical system needs to have a large field of view. A large field of view can significantly increase the imaging field of view of the optical system. For a sample with a fixed area, a larger imaging range means more light flux and fewer detection times, thereby improving the overall detection efficiency. Summary of the Invention

[0003] In a first aspect of the present disclosure, an optical system is provided. The optical system includes: a microscopic objective lens and a tube lens arranged in sequence along the optical axis from the object side to the image side, where the microscopic objective lens includes a first lens group, a second lens group, a diaphragm, and a third lens group arranged in sequence along the optical axis direction; the first lens group has a positive optical power and is at least used to correct spherical aberration, astigmatism, and axial chromatic aberration. The first lens group includes a first cemented lens, a third lens, and a second cemented lens. The first cemented lens includes a first lens and a second lens cemented to each other, and the second cemented lens includes a fourth lens and a fifth lens cemented to each other; the second lens group has a positive optical power and is at least used to correct coma and distortion. The second lens group includes a sixth lens and a third cemented lens. The third cemented lens includes a seventh lens, an eighth lens, and a ninth lens cemented in sequence; the third lens group has a positive optical power and is at least used to correct field curvature and lateral chromatic aberration. The third lens group includes a fourth cemented lens, a thirteenth lens, a fourteenth lens, and a fifteenth lens. The fourth cemented lens includes a tenth lens, an eleventh lens, and a twelfth lens cemented in sequence; the diaphragm is arranged between the third cemented lens and the fourth cemented lens to correct chromatic aberration by placing the third cemented lens and the fourth cemented lens on both sides of the diaphragm; the tube lens has a positive optical power. The tube lens includes a fifth cemented lens, a sixth cemented lens, and a twenty-first lens arranged in sequence along the optical axis direction. The fifth cemented lens includes a sixteenth lens and a seventeenth lens cemented to each other, and the sixth cemented lens includes an eighteenth lens, a nineteenth lens, and a twentieth lens cemented in sequence.

[0004] In some embodiments, the microscopic objective lens is an infinity conjugate objective lens, at least used to image an object on the object side to infinity, and the tube lens is an infinity focusing lens, at least used to image an object at infinity to a detector on the image side.

[0005] In some embodiments, the focal length of the tube lens is 200 mm.

[0006] In some embodiments, the focal lengths of the first lens group, the second lens group, and the third lens group satisfy: 1.0 < |f1 / f| < 2.0, 1.5 < |f2 / f| < 2.5, 7.0 < |f3 / f| < 8.0, where f is the total focal length of the microscope objective, f1 is the focal length of the first lens group, f2 is the focal length of the second lens group, and f3 is the focal length of the third lens group.

[0007] In some embodiments, the object side of the first lens is concave, and the image side of the first lens is concave; the object side of the second lens is convex, and the image side of the second lens is convex; the object side of the third lens is convex, and the image side of the third lens is convex; the object side of the fourth lens is concave, and the image side of the fourth lens is concave; the object side of the fifth lens is convex, and the image side of the fifth lens is flat; the object side of the sixth lens is concave, and the image side of the sixth lens is convex; the object side of the seventh lens is convex, and the image side of the seventh lens is convex; the object side of the eighth lens is concave, and the image side of the eighth lens is concave; the object side of the ninth lens is convex, and the image side of the ninth lens is convex; the object side of the tenth lens is convex, and the image side of the tenth lens is concave; the object side of the eleventh lens is convex, and the image side of the eleventh lens is convex; the object side of the twelfth lens is concave, and the image side of the twelfth lens is concave; the object side of the thirteenth lens is concave, and the image side of the thirteenth lens is convex; the object side of the fourteenth lens is concave, and the image side of the fourteenth lens is convex; the object side of the fifteenth lens is convex, and the image side of the fifteenth lens is convex.

[0008] In some embodiments, the first lens has a negative optical power, and its focal length is in the range of -410 mm to -400 mm; the second lens has a positive optical power, and its focal length is in the range of 20 mm to 30 mm; the third lens has a positive optical power, and its focal length is in the range of 40 mm to 50 mm; the fourth lens has a negative optical power, and its focal length is in the range of -40 mm to -30 mm; the fifth lens has a positive optical power, and its focal length is in the range of 160 mm to 170 mm; the sixth lens has a positive optical power, and its focal length is in the range of 40 mm to 50 mm; the seventh lens has a positive optical power, and its focal length is in the range of 110 mm to 120 mm; the eighth lens has a negative optical power, and its focal length is in the range of -55 mm to -45 mm; the ninth lens has a negative optical power, and its focal length is in the range of -120 mm to -110 mm; the tenth lens has a positive optical power, and its focal length is in the range of 20 mm to 30 mm; the eleventh lens has a negative optical power, and its focal length is in the range of -20 mm to -10 mm; the twelfth lens has a negative optical power, and its focal length is in the range of -25 mm to -15 mm; the thirteenth lens has a negative optical power, and its focal length is in the range of -20 mm to -10 mm; the fourteenth lens has a positive optical power, and its focal length is in the range of 55 mm to 65 mm; the fifteenth lens has a positive optical power, and its focal length is in the range of 110 mm to 120 mm.

[0009] In some embodiments, the focal lengths of the first lens group, the second lens group, and the third lens group satisfy: 0.5 < |f1 / f| < 1.5, 1.3 < |f2 / f| < 2.3, 1.0 < |f3 / f| < 2.0, where f is the total focal length of the microscope objective, f1 is the focal length of the first lens group, f2 is the focal length of the second lens group, and f3 is the focal length of the third lens group.

[0010] In some embodiments, the object side of the first lens is concave, and the image side of the first lens is concave; the object side of the second lens is convex, and the image side of the second lens is convex; the object side of the third lens is convex, and the image side of the third lens is convex; the object side of the fourth lens is concave, and the image side of the fourth lens is concave; the object side of the fifth lens is convex, and the image side of the fifth lens is flat; the object side of the sixth lens is flat, and the image side of the sixth lens is convex; the object side of the seventh lens is convex, and the image side of the seventh lens is convex; the object side of the eighth lens is concave, and the image side of the eighth lens is concave; the object side of the ninth lens is convex, and the image side of the ninth lens is convex; the object side of the tenth lens is convex, and the image side of the tenth lens is concave; the object side of the eleventh lens is convex, and the image side of the eleventh lens is convex; the object side of the twelfth lens is concave, and the image side of the twelfth lens is flat; the object side of the thirteenth lens is concave, and the image side of the thirteenth lens is convex; the object side of the fourteenth lens is concave, and the image side of the fourteenth lens is convex; the object side of the fifteenth lens is convex, and the image side of the fifteenth lens is convex.

[0011] In some embodiments, the first lens has a negative optical power, and its focal length ranges from -60 mm to -50 mm; the second lens has a positive optical power, and its focal length ranges from 20 mm to 30 mm; the third lens has a positive optical power, and its focal length ranges from 30 mm to 40 mm; the fourth lens has a negative optical power, and its focal length ranges from -30 mm to -20 mm; the fifth lens has a positive optical power, and its focal length ranges from 300 mm to 310 mm; the sixth lens has a positive optical power, and its focal length ranges from 45 mm to 55 mm; the seventh lens has a positive optical power, and its focal length ranges from 190 mm to 200 mm; the eighth lens has a negative optical power, and its focal length ranges from -70 mm to -60 mm; the ninth lens has a negative optical power, and its focal length ranges from -85 mm to -75 mm; the tenth lens has a positive optical power, and its focal length ranges from 20 mm to 30 mm; the eleventh lens has a negative optical power, and its focal length ranges from -20 mm to -10 mm; the twelfth lens has a negative optical power, and its focal length ranges from -45 mm to -35 mm; the thirteenth lens has a negative optical power, and its focal length ranges from -20 mm to -10 mm; the fourteenth lens has a positive optical power, and its focal length ranges from 45 mm to 55 mm; the fifteenth lens has a positive optical power, and its focal length ranges from 105 mm to 115 mm.

[0012] In some embodiments, the focal lengths of the first lens group, the second lens group, and the third lens group satisfy: 0.9 < |f1 / f| < 1.9, 5.5 < |f2 / f| < 6.5, 18.0 < |f3 / f| < 19.0, where f is the total focal length of the microscope objective, f1 is the focal length of the first lens group, f2 is the focal length of the second lens group, and f3 is the focal length of the third lens group.

[0013] In some embodiments, the object side of the first lens is concave, and the image side of the first lens is convex; the object side of the second lens is concave, and the image side of the second lens is convex; the object side of the third lens is convex, and the image side of the third lens is concave; the object side of the fourth lens is convex, and the image side of the fourth lens is concave; the object side of the fifth lens is convex, and the image side of the fifth lens is concave; the object side of the sixth lens is concave, and the image side of the sixth lens is convex; the object side of the seventh lens is convex, and the image side of the seventh lens is convex; the object side of the eighth lens is concave, and the image side of the eighth lens is concave; the object side of the ninth lens is convex, and the image side of the ninth lens is convex; the object side of the tenth lens is convex, and the image side of the tenth lens is concave; the object side of the eleventh lens is convex, and the image side of the eleventh lens is convex; the object side of the twelfth lens is concave, and the image side of the twelfth lens is concave; the object side of the thirteenth lens is concave, and the image side of the thirteenth lens is convex; the object side of the fourteenth lens is concave, and the image side of the fourteenth lens is convex; the object side of the fifteenth lens is convex, and the image side of the fifteenth lens is convex.

[0014] In some embodiments, the first lens has a negative optical power, and its focal length ranges from -40 mm to -30 mm; the second lens has a positive optical power, and its focal length ranges from 10 mm to 20 mm; the third lens has a positive optical power, and its focal length ranges from 30 mm to 40 mm; the fourth lens has a positive optical power, and its focal length ranges from 30 mm to 40 mm; the fifth lens has a negative optical power, and its focal length ranges from -50 mm to -40 mm; the sixth lens has a positive optical power, and its focal length ranges from 60 mm to 70 mm; the seventh lens has a positive optical power, and its focal length ranges from 100 mm to 110 mm; the eighth lens has a negative optical power, and its focal length ranges from -45 mm to -35 mm; the ninth lens has a negative optical power, and its focal length ranges from -120 mm to -110 mm; the tenth lens has a positive optical power, and its focal length ranges from 10 mm to 20 mm; the eleventh lens has a negative optical power, and its focal length ranges from -15 mm to -5 mm; the twelfth lens has a negative optical power, and its focal length ranges from -15 mm to -5 mm; the thirteenth lens has a negative optical power, and its focal length ranges from -15 mm to -5 mm; the fourteenth lens has a positive optical power, and its focal length ranges from 55 mm to 65 mm; the fifteenth lens has a positive optical power, and its focal length ranges from 90 mm to 100 mm.

[0015] In some embodiments, the object side of the sixteenth lens is convex, and the image side of the sixteenth lens is convex; the object side of the seventeenth lens is concave, and the image side of the seventeenth lens is convex; the object side of the eighteenth lens is convex, and the image side of the eighteenth lens is concave; the object side of the nineteenth lens is convex, and the image side of the nineteenth lens is concave; the object side of the twentieth lens is convex, and the image side of the twentieth lens is flat; the object side of the twenty-first lens is flat, and the image side of the twenty-first lens is concave.

[0016] In some embodiments, the sixteenth lens has a negative optical power, and its focal length ranges from -310 mm to -300 mm; the seventeenth lens has a positive optical power, and its focal length ranges from 350 mm to 360 mm; the eighteenth lens has a positive optical power, and its focal length ranges from 80 mm to 90 mm; the nineteenth lens has a positive optical power, and its focal length ranges from 1340 mm to 1350 mm; the twentieth lens has a positive optical power, and its focal length ranges from 5790 mm to 5800 mm; the twenty-first lens has a negative optical power, and its focal length ranges from -70 mm to -60 mm.

[0017] In some embodiments, the diameter of the aperture includes one of 12 mm and 8 mm.

[0018] In some embodiments, the operating wavelength band of the optical system includes 400 nm - 700 nm.

[0019] In some embodiments, the distance between the object side surface of the first lens and the object is in the range of 7.0 mm to 13.0 mm.

[0020] In some embodiments, the front entrance pupil distance of the tube lens is in the range of 100.0 mm to 210.0 mm, and the rear working distance of the tube lens is in the range of 150.0 mm to 151.0 mm.

[0021] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens, the tenth lens, the eleventh lens, the twelfth lens, the thirteenth lens, the fourteenth lens, the fifteenth lens, the sixteenth lens, the seventeenth lens, the eighteenth lens, the nineteenth lens, the twentieth lens, and the twenty - first lens are standard spherical lenses.

[0022] In a second aspect of the present disclosure, a microscope is provided. The microscope includes the optical system of the first aspect of the present disclosure.

[0023] In some embodiments, the microscope further includes a first optical element disposed between the microscopic objective lens and the tube lens, and / or a second optical element disposed between the tube lens and the image - side detector.

[0024] In some embodiments, the first optical element includes at least one of a dichroic mirror, a filter, and a prism, and the second optical element includes at least one of a beam splitter and a filter.

[0025] In an embodiment of the present disclosure, the optical system includes a microscope objective lens and a tube lens arranged in sequence along the optical axis from the object side to the image side. The microscope objective lens includes a first lens group, a second lens group, a diaphragm, and a third lens group arranged in sequence along the optical axis direction. The first lens group has a positive optical power and is at least used to correct spherical aberration, astigmatism, and axial chromatic aberration. The first lens group includes a first cemented lens, a third lens, and a second cemented lens. The first cemented lens includes a first lens and a second lens cemented to each other. The second cemented lens includes a fourth lens and a fifth lens cemented to each other. The second lens group has a positive optical power and is at least used to correct coma and distortion. The second lens group includes a sixth lens and a third cemented lens. The third cemented lens includes a seventh lens, an eighth lens, and a ninth lens cemented in sequence. The third lens group has a positive optical power and is at least used to correct field curvature and lateral chromatic aberration. The third lens group includes a fourth cemented lens, a thirteenth lens, a fourteenth lens, and a fifteenth lens. The fourth cemented lens includes a tenth lens, an eleventh lens, and a twelfth lens cemented in sequence. The diaphragm is arranged between the third cemented lens and the fourth cemented lens, and chromatic aberration can be corrected by placing the diaphragm on both sides of the diaphragm via the third cemented lens and the fourth cemented lens. The tube lens has a positive optical power. The tube lens includes a fifth cemented lens, a sixth cemented lens, and a twenty-first lens arranged in sequence along the optical axis direction. The fifth cemented lens includes a sixteenth lens and a seventeenth lens cemented to each other. The sixth cemented lens includes an eighteenth lens, a nineteenth lens, and a twentieth lens cemented in sequence.

[0026] With this arrangement, the microscope objective lens of the optical system includes three lens groups with positive optical power. The first lens group can correct spherical aberration, astigmatism, and axial chromatic aberration, the second lens group can optimize coma and distortion, the third lens group can correct field curvature and lateral chromatic aberration, and multiple cemented lenses can effectively reduce chromatic aberration and spherical aberration. The tube lens has a positive optical power and includes two cemented lenses and a single lens, which can further improve the imaging quality. Through the collaborative correction of multiple lens groups, the field of view range can be expanded while maintaining high resolution and imaging clarity. A larger field number can reduce the number of scans, thereby improving the detection efficiency.

[0027] It should be understood that the content described in this part is not intended to limit the key features or important features of the embodiments of the present disclosure, nor is it used to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Combined with the drawings and referring to the following detailed description, the above and other features, advantages, and aspects of the embodiments of the present disclosure will become more obvious. In the drawings, the same or similar reference numerals represent the same or similar elements, where: Figure 1 The schematic diagram of the optical structure of a microscope objective lens with a focal length of 20 mm according to an embodiment of the present disclosure is shown; Figure 2 Shows the reverse design modulation transfer function curve graph of a 20mm focal length microscopic objective lens according to an embodiment of the present disclosure; Figure 3 Shows the reverse design field curvature and distortion graph of a 20mm focal length microscopic objective lens according to an embodiment of the present disclosure; Figure 4 Shows the reverse design 0.707 pupil chromatic focal shift graph of a 20mm focal length microscopic objective lens according to an embodiment of the present disclosure; Figure 5 Shows the optical structure schematic diagram of a 200mm focal length tube lens according to an embodiment of the present disclosure; Figure 6 Shows the modulation transfer function curve graph of a 200mm focal length tube lens according to an embodiment of the present disclosure; Figure 7 Shows the field curvature and distortion graph of a 200mm focal length tube lens according to an embodiment of the present disclosure; Figure 8 Shows the optical structure schematic diagram of a microscopic imaging optical system with a magnification of 10x formed by combining a 20mm focal length microscopic objective lens and a 200mm focal length tube lens according to an embodiment of the present disclosure; Figure 9 Shows the modulation transfer function curve graph of a microscopic imaging optical system with a magnification of 10x formed by combining a 20mm focal length microscopic objective lens and a 200mm focal length tube lens according to an embodiment of the present disclosure; Figure 10 Shows the optical structure schematic diagram of a 40mm focal length microscopic objective lens according to an embodiment of the present disclosure; Figure 11 Shows the reverse design modulation transfer function curve graph of a 40mm focal length microscopic objective lens according to an embodiment of the present disclosure; Figure 12 Shows the reverse design field curvature and distortion graph of a 40mm focal length microscopic objective lens according to an embodiment of the present disclosure; Figure 13 Shows the reverse design 0.707 pupil chromatic focal shift graph of a 40mm focal length microscopic objective lens according to an embodiment of the present disclosure; Figure 14 Shows the optical structure schematic diagram of a microscopic imaging optical system with a magnification of 5x formed by combining a 40mm focal length microscopic objective lens and a 200mm focal length tube lens according to an embodiment of the present disclosure; Figure 15 Shows the modulation transfer function curve graph of a microscopic imaging optical system with a magnification of 5x formed by combining a 40mm focal length microscopic objective lens and a 200mm focal length tube lens according to an embodiment of the present disclosure; Figure 16 Shows the optical structure schematic diagram of a 10mm focal length microscopic objective lens according to an embodiment of the present disclosure; Figure 17 Shows the reverse design modulation transfer function curve graph of the 10mm focal length microscopic objective lens of the embodiments of the present disclosure; Figure 18 Shows the reverse design field curvature and distortion graph of the 10mm focal length microscopic objective lens of the embodiments of the present disclosure; Figure 19 Shows the reverse design 0.707 pupil chromatic focal shift graph of the 10mm focal length microscopic objective lens of the embodiments of the present disclosure; Figure 20 Shows the schematic optical structure diagram of the microscopic imaging optical system with a magnification of 20x formed by combining the 10mm focal length microscopic objective lens of the embodiments of the present disclosure and a tube lens with a focal length of 200mm; and Figure 21 Shows the modulation transfer function curve graph of the microscopic imaging optical system with a magnification of 20x formed by combining the 10mm focal length microscopic objective lens of the embodiments of the present disclosure and a tube lens with a focal length of 200mm.

[0029] Explanation of reference numerals: Obj, microscopic objective lens; TL, tube lens; STOP, aperture; G1, the first lens group; G2, the second lens group; G3, the third lens group; B1, the first cemented lens; B2, the second cemented lens; B3, the third cemented lens; B4, the fourth cemented lens; B5, the fifth cemented lens; B6, the sixth cemented lens; L1, the first lens; L2, the second lens; L3, the third lens; L4, the fourth lens; L5, the fifth lens; L6, the sixth lens; L7, the seventh lens; L8, the eighth lens; L9, the ninth lens; L10, the tenth lens; L11, the eleventh lens; L12, the twelfth lens; L13, the thirteenth lens; L14, the fourteenth lens; L15, the fifteenth lens; L16, the sixteenth lens; L17, the seventeenth lens; L18, the eighteenth lens; L19, the nineteenth lens; L20, the twentieth lens; L21, the twenty - first lens. Detailed implementation manners

[0030] Hereinafter, the preferred embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the preferred embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0031] As used herein, the term "comprising" and its variations denote open-ended inclusion, i.e., "including but not limited to". Unless otherwise specified, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc. may refer to different or the same objects.

[0032] In a conventional infinity conjugate microscopic imaging optical system, the field number is generally low, unable to meet the requirements of current semiconductor applications, thus limiting the efficiency of semiconductor quantity detection.

[0033] Embodiments of the present disclosure provide an optical system and a microscope. The optical system includes a microscopic objective lens and a tube lens arranged in sequence along the optical axis from the object side to the image side. The microscopic objective lens includes a first lens group, a second lens group, a diaphragm, and a third lens group arranged in sequence along the optical axis direction. The first lens group has a positive optical power and is at least used to correct spherical aberration, astigmatism, and axial chromatic aberration. The first lens group includes a first cemented lens, a third lens, and a second cemented lens. The first cemented lens includes a first lens and a second lens cemented to each other. The second cemented lens includes a fourth lens and a fifth lens cemented to each other. The second lens group has a positive optical power and is at least used to correct coma and distortion. The second lens group includes a sixth lens and a third cemented lens. The third cemented lens includes a seventh lens, an eighth lens, and a ninth lens cemented in sequence. The third lens group has a positive optical power and is at least used to correct field curvature and lateral chromatic aberration. The third lens group includes a fourth cemented lens, a thirteenth lens, a fourteenth lens, and a fifteenth lens. The fourth cemented lens includes a tenth lens, an eleventh lens, and a twelfth lens cemented in sequence. The diaphragm is arranged between the third cemented lens and the fourth cemented lens, and chromatic aberration can be corrected by placing it on both sides of the diaphragm via the third cemented lens and the fourth cemented lens. The tube lens has a positive optical power. The tube lens has a positive optical power. The tube lens includes a fifth cemented lens, a sixth cemented lens, and a twenty-first lens arranged in sequence along the optical axis direction. The fifth cemented lens includes a sixteenth lens and a seventeenth lens cemented to each other. The sixth cemented lens includes an eighteenth lens, a nineteenth lens, and a twentieth lens cemented in sequence.

[0034] With this arrangement, the microscope objective of the optical system comprises three positive refractive power lens groups. The first lens group can correct spherical aberration, astigmatism, and axial chromatic aberration. The second lens group can optimize coma and distortion. The third lens group can correct field curvature and lateral chromatic aberration. Multiple cemented lenses can effectively reduce chromatic aberration and spherical aberration. The tube lens has positive refractive power and comprises two cemented lenses and a singlet lens, which can further improve the imaging quality. Through the collaborative correction of multiple lens groups, the field of view can be expanded while maintaining high resolution and imaging clarity. A larger field number can reduce the number of scans, thereby improving the detection efficiency. The principles of the present disclosure will be described in detail below in conjunction with Figures 1 to 21 to describe the principles of the present disclosure in detail.

[0035] As Figures 1 to 8 shown, the optical system includes a microscope objective Obj and a tube lens TL arranged in sequence along the optical axis from the object side to the image side. The microscope objective Obj can focus the light of the object and preliminarily correct various aberrations, while the tube lens TL can optimize the optical path and finally form a high-quality image. The optical system can be applied to microscopic detection scenarios with high resolution and a large field of view, such as biomedical research, material analysis, and semiconductor detection.

[0036] As Figure 1 shown, the microscope objective Obj is composed of a first lens group G1, a second lens group G2, and a third lens group G3 arranged in sequence along the optical axis. Each lens group undertakes specific aberration correction tasks and can effectively control various optical aberrations in a complex imaging environment, thereby achieving imaging with high resolution and a large field of view.

[0037] As Figure 1 shown, the first lens group G1 is located at the front end of the microscope objective Obj and has positive refractive power. The first lens group G1 can correct spherical aberration, astigmatism, and axial chromatic aberration. The first lens group G1 includes a first cemented lens B1, a third lens L3, and a second cemented lens B2. The first cemented lens B1 is formed by cementing a first lens L1 and a second lens L2, and the second cemented lens B2 is formed by cementing a fourth lens L4 and a fifth lens L5. By tightly combining lenses with different refractive indices and dispersion characteristics, axial chromatic aberration can be reduced while optimizing spherical aberration and astigmatism. The third lens L3, as a singlet lens, can assist in adjusting the convergence of the optical path, thereby providing appropriate optical conditions for the subsequent lens groups. The first lens group G1 can ensure that the light has small initial aberrations when entering the subsequent lens groups.

[0038] As Figure 1As shown, the second lens group G2 also has a positive optical power and can correct coma and distortion. The second lens group G2 includes the sixth lens L6 and the third cemented lens B3. The third cemented lens B3 is formed by sequentially cementing the seventh lens L7, the eighth lens L8, and the ninth lens L9. Coma appears as an asymmetric light spot and can cause trailing when imaging a point light source, while distortion can cause geometric distortion of the image edge and affect the imaging quality at the edge of the field of view. Through the combination of the single lens of the sixth lens L6 and the third cemented lens B3, the second lens group G2 can control the propagation path of light at different field angles, thereby effectively suppressing coma and distortion. The second lens group G2 can ensure that the imaging quality at the center of the field of view can be extended to the edge region, providing support for large-field imaging.

[0039] As Figure 1 shown, the third lens group G3 is located at the end of the microscope objective Obj and has a positive optical power. The third lens group G3 can be used to correct field curvature and lateral chromatic aberration. The third lens group G3 includes the fourth cemented lens B4, the thirteenth lens L13, the fourteenth lens L14, and the fifteenth lens L15. The fourth cemented lens B4 is formed by sequentially cementing the tenth lens L10, the eleventh lens L11, and the twelfth lens L12. Field curvature can cause the image plane to deviate from the ideal plane and affect the clarity of the entire field of view, while lateral chromatic aberration appears as the lateral separation of light rays of different wavelengths at the edge of the field of view. Through the combination of multiple lenses, the fourth cemented lens B4 can further reduce chromatic aberration. At the same time, in cooperation with the subsequent single lenses (the thirteenth lens L13 to the fifteenth lens L15), it adjusts the focusing characteristics of light rays to correct field curvature and ensure the planarity of the entire field of view. In this way, the third lens group G3 can enable the optical system to maintain uniform imaging quality within a relatively large field of view.

[0040] In some embodiments, as Figure 1 , Figure 10 and Figure 16 shown, the optical system further includes a stop STOP disposed between the third cemented lens B3 and the fourth cemented lens B4. In this way, chromatic aberration can be corrected by placing the third cemented lens and the fourth cemented lens on both sides of the stop.

[0041] As Figure 5As shown, the tube lens TL is located behind the microscope objective Obj and has a positive optical power. The tube lens TL can further magnify the intermediate image formed by the microscope objective Obj and finally project it onto the imaging plane. The tube lens TL includes a fifth cemented lens B5, a sixth cemented lens B6, and a twenty-first lens L21. The fifth cemented lens B5 is formed by cementing a sixteenth lens L16 and a seventeenth lens L17. The sixth cemented lens B6 is formed by sequentially cementing an eighteenth lens L18, a nineteenth lens L19, and a twentieth lens L20. Cemented lenses can further reduce chromatic aberration. The twenty-first lens L21, as a single lens, can adjust the convergence of the optical path to ensure the clarity and contrast of the final image. The tube lens TL and the microscope objective Obj work together to optimize the propagation path of light, thereby improving the imaging quality in the marginal area under a large field of view.

[0042] In this way, the microscope objective Obj of the optical system includes three positive optical power lens groups, and each group is optimized for specific aberrations. The first lens group G1 corrects spherical aberration, astigmatism, and axial chromatic aberration through the first cemented lens B1, the third lens L3, and the second cemented lens B2, providing a high-quality optical basis for the subsequent optical path. The second lens group G2 can optimize coma and distortion through the sixth lens L6 and the third cemented lens B3 to ensure the accurate geometry at the edge of the field of view. The third lens group G3 corrects field curvature and lateral chromatic aberration through the fourth cemented lens B4 and a single lens, maintaining the planarity and color consistency of the entire field of view. Multiple groups of cemented lenses can reduce chromatic aberration and aberration, thereby improving the clarity and resolution of the image.

[0043] Secondly, the tube lens TL has a positive optical power. Through the combination of the fifth cemented lens B5, the sixth cemented lens B6, and the twenty-first lens L21, the imaging quality can be improved. Cemented lenses can suppress chromatic aberration, and single lenses can optimize the convergence of the optical path to ensure high contrast and sharpness of the image. The synergistic effect of the microscope objective Obj and the tube lens TL, through the precise correction of multiple lens groups, can significantly expand the field of view range of the system while maintaining high resolution and imaging clarity.

[0044] In addition, through the transmission of the light field, the microscopic imaging optical system images the sample on the object side onto the sensor on the image side at an appropriate magnification, and can provide a long working distance of the microscope objective Obj, the entrance pupil distance and the back working distance of the tube lens TL, enabling the microscopic imaging optical system to have a large operating space to add various other optical components required for each application scenario, such as oblique illumination, coaxial illumination, autofocus module, filter, dichroic mirror, beam splitter, mirror, prism, etc. to meet the microscopic imaging requirements of the application scenario.

[0045] Finally, the optical system can provide a large field of view imaging field of 45 mm, thereby reducing the number of image acquisitions for quantity detection and improving the quantity detection efficiency.

[0046] As an example, the microscopic imaging optical system of the present disclosure can provide at least microscopic objective lens focal lengths of 10 mm, 20 mm, 40 mm, and a parfocal distance of 95 mm for the microscopic objective lens.

[0047] In some embodiments, the focal length of the tube lens TL is 200 mm.

[0048] In some embodiments, where the microscopic objective lens Obj is an infinity conjugate objective lens, at least for imaging an object on the object side to infinity, and the tube lens TL is an infinity focusing lens, at least for imaging an object at infinity onto a detector on the image side. With this arrangement, microscopic objective lenses Obj with different focal lengths combined with a tube lens TL with a focal length of 200 mm can form microscopic imaging optical systems with different magnification factors.

[0049] As an example, as Figures 1 to 4 shown, the total focal length f of the microscopic objective lens Obj is 20 mm. Here, the focal lengths of the first lens group G1, the second lens group G2, and the third lens group G3 satisfy: 1.0 < |f1 / f| < 2.0, 1.5 < |f2 / f| < 2.5, 7.0 < |f3 / f| < 8.0, where f1 is the focal length of the first lens group G1, f2 is the focal length of the second lens group G2, and f3 is the focal length of the third lens group G3.

[0050] In some embodiments, the object side of the first lens L1 is concave, and the image side of the first lens L1 is concave. The object side of the second lens L2 is convex, and the image side of the second lens L2 is convex. The object side of the third lens L3 is convex, and the image side of the third lens L3 is convex. The object side of the fourth lens L4 is concave, and the image side of the fourth lens L4 is concave. The object side of the fifth lens L5 is convex, and the image side of the fifth lens L5 is flat. The object side of the sixth lens L6 is concave, and the image side of the sixth lens L6 is convex. The object side of the seventh lens L7 is convex, and the image side of the seventh lens L7 is convex. The object side of the eighth lens L8 is concave, and the image side of the eighth lens L8 is concave. The object side of the ninth lens L9 is convex, and the image side of the ninth lens L9 is convex. The object side of the tenth lens L10 is convex, and the image side of the tenth lens L10 is concave. The object side of the eleventh lens L11 is convex, and the image side of the eleventh lens L11 is convex. The object side of the twelfth lens L12 is concave, and the image side of the twelfth lens L12 is concave. The object side of the thirteenth lens L13 is concave, and the image side of the thirteenth lens L13 is convex. The object side of the fourteenth lens L14 is concave, and the image side of the fourteenth lens L14 is convex. The object side of the fifteenth lens L15 is convex, and the image side of the fifteenth lens L15 is convex.

[0051] With this arrangement, the approximately planar object side and the concave image side of the first lens L1 contribute to initial light collection and reduce spherical aberration. The convex shapes of the second lens L2 and the third lens L3 can enhance light convergence and optimize axial chromatic aberration and astigmatism. The convex-concave combination of the fourth lens L4 and the fifth lens L5 effectively corrects chromatic aberration, and the planar image side of the fifth lens L5 can stabilize the optical path. The convex-concave shape of the sixth lens L6 helps correct coma. The convex-convex-concave combination of the seventh lens L7 to the ninth lens L9 can optimize coma and distortion, and the concave side of the eighth lens L8 can balance aberrations. The convex-concave shapes of the tenth lens L10 to the twelfth lens L12 can correct field curvature. The convex-concave shapes of the thirteenth lens L13 to the fourteenth lens L14 can improve lateral chromatic aberration. The convex side and the approximately planar image side of the fifteenth lens L15 can ensure field uniformity.

[0052] In some embodiments, the first lens L1 has a negative optical power, and the focal length ranges from -410 mm to -400 mm. The second lens L2 has a positive optical power, and the focal length ranges from 20 mm to 30 mm. The third lens L3 has a positive optical power, and the focal length ranges from 40 mm to 50 mm. The fourth lens L4 has a negative optical power, and the focal length ranges from -40 mm to -30 mm. The fifth lens L5 has a positive optical power, and the focal length ranges from 160 mm to 170 mm. The sixth lens L6 has a positive optical power, and the focal length ranges from 40 mm to 50 mm. The seventh lens L7 has a positive optical power, and the focal length ranges from 110 mm to 120 mm. The eighth lens L8 has a negative optical power, and the focal length ranges from -55 mm to -45 mm. The ninth lens L9 has a negative optical power, and the focal length ranges from -120 mm to -110 mm. The tenth lens L10 has a positive optical power, and the focal length ranges from 20 mm to 30 mm. The eleventh lens L11 has a negative optical power, and the focal length ranges from -20 mm to -10 mm. The twelfth lens L12 has a negative optical power, and the focal length ranges from -25 mm to -15 mm. The thirteenth lens L13 has a negative optical power, and the focal length ranges from -20 mm to -10 mm. The fourteenth lens L14 has a positive optical power, and the focal length ranges from 55 mm to 65 mm. The fifteenth lens L15 has a positive optical power, and the focal length ranges from 110 mm to 120 mm.

[0053] As an example, as Figures 10 to 15 shown, the total focal length f of the microscope objective Obj is 40 mm. Here, the focal lengths of the first lens group G1, the second lens group G2, and the third lens group G3 satisfy: 0.5 < |f1 / f| < 1.5, 1.3 < |f2 / f| < 2.3, 1.0 < |f3 / f| < 2.0, Among them, f1 is the focal length of the first lens group G1, f2 is the focal length of the second lens group G2, and f3 is the focal length of the third lens group G3.

[0054] In some embodiments, the object side of the first lens L1 is concave, and the image side of the first lens L1 is concave. The object side of the second lens L2 is convex, and the image side of the second lens L2 is convex. The object side of the third lens L3 is convex, and the image side of the third lens L3 is convex. The object side of the fourth lens L4 is concave, and the image side of the fourth lens L4 is concave. The object side of the fifth lens L5 is convex, and the image side of the fifth lens L5 is flat. The object side of the sixth lens L6 is flat, and the image side of the sixth lens L6 is convex. The object side of the seventh lens L7 is convex, and the image side of the seventh lens L7 is convex. The object side of the eighth lens L8 is concave, and the image side of the eighth lens L8 is concave. The object side of the ninth lens L9 is convex, and the image side of the ninth lens L9 is convex. The object side of the tenth lens L10 is convex, and the image side of the tenth lens L10 is concave. The object side of the eleventh lens L11 is convex, and the image side of the eleventh lens L11 is convex. The object side of the twelfth lens L12 is concave, and the image side of the twelfth lens L12 is flat. The object side of the thirteenth lens L13 is concave, and the image side of the thirteenth lens L13 is convex. The object side of the fourteenth lens L14 is concave, and the image side of the fourteenth lens L14 is convex. The object side of the fifteenth lens L15 is convex, and the image side of the fifteenth lens L15 is convex.

[0055] In some embodiments, the first lens L1 has a negative optical power, and its focal length ranges from -60 mm to -50 mm. The second lens L2 has a positive optical power, and its focal length ranges from 20 mm to 30 mm. The third lens L3 has a positive optical power, and its focal length ranges from 30 mm to 40 mm. The fourth lens L4 has a negative optical power, and its focal length ranges from -30 mm to -20 mm. The fifth lens L5 has a positive optical power, and its focal length ranges from 300 mm to 310 mm. The sixth lens L6 has a positive optical power, and its focal length ranges from 45 mm to 55 mm. The seventh lens L7 has a positive optical power, and its focal length ranges from 190 mm to 200 mm. The eighth lens L8 has a negative optical power, and its focal length ranges from -70 mm to -60 mm. The ninth lens L9 has a negative optical power, and its focal length ranges from -85 mm to -75 mm. The tenth lens L10 has a positive optical power, and its focal length ranges from 20 mm to 30 mm. The eleventh lens L11 has a negative optical power, and its focal length ranges from -20 mm to -10 mm. The twelfth lens L12 has a negative optical power, and its focal length ranges from -45 mm to -35 mm. The thirteenth lens L13 has a negative optical power, and its focal length ranges from -20 mm to -10 mm. The fourteenth lens L14 has a positive optical power, and its focal length ranges from 45 mm to 55 mm. The fifteenth lens L15 has a positive optical power, and its focal length ranges from 105 mm to 115 mm.

[0056] As an example, as Figures 16 to 21 shown, the total focal length f of the microscope objective Obj is 10 mm. Here, the focal lengths of the first lens group G1, the second lens group G2, and the third lens group G3 satisfy: 0.9 < |f1 / f| < 1.9, 5.5 < |f2 / f| < 6.5, 18.0 < |f3 / f| < 19.0, where f1 is the focal length of the first lens group G1, f2 is the focal length of the second lens group G2, and f3 is the focal length of the third lens group G3.

[0057] In some embodiments, the object side of the first lens L1 is concave, and the image side of the first lens L1 is convex. The object side of the second lens L2 is concave, and the image side of the second lens L2 is convex. The object side of the third lens L3 is convex, and the image side of the third lens L3 is concave. The object side of the fourth lens L4 is convex, and the image side of the fourth lens L4 is concave. The object side of the fifth lens L5 is convex, and the image side of the fifth lens L5 is concave. The object side of the sixth lens L6 is concave, and the image side of the sixth lens L6 is convex. The object side of the seventh lens L7 is convex, and the image side of the seventh lens L7 is convex. The object side of the eighth lens L8 is concave, and the image side of the eighth lens L8 is concave. The object side of the ninth lens L9 is convex, and the image side of the ninth lens L9 is convex. The object side of the tenth lens L10 is convex, and the image side of the tenth lens L10 is concave. The object side of the eleventh lens L11 is convex, and the image side of the eleventh lens L11 is convex. The object side of the twelfth lens L12 is concave, and the image side of the twelfth lens L12 is concave. The object side of the thirteenth lens L13 is concave, and the image side of the thirteenth lens L13 is convex. The object side of the fourteenth lens L14 is concave, and the image side of the fourteenth lens L14 is convex. The object side of the fifteenth lens L15 is convex, and the image side of the fifteenth lens L15 is convex.

[0058] In some embodiments, the first lens L1 has a negative optical power, and its focal length ranges from -40 mm to -30 mm. The second lens L2 has a positive optical power, and its focal length ranges from 10 mm to 20 mm. The third lens L3 has a positive optical power, and its focal length ranges from 30 mm to 40 mm. The fourth lens L4 has a positive optical power, and its focal length ranges from 30 mm to 40 mm. The fifth lens L5 has a negative optical power, and its focal length ranges from -50 mm to -40 mm. The sixth lens L6 has a positive optical power, and its focal length ranges from 60 mm to 70 mm. The seventh lens L7 has a positive optical power, and its focal length ranges from 100 mm to 110 mm. The eighth lens L8 has a negative optical power, and its focal length ranges from -45 mm to -35 mm. The ninth lens L9 has a negative optical power, and its focal length ranges from -120 mm to -110 mm. The tenth lens L10 has a positive optical power, and its focal length ranges from 10 mm to 20 mm. The eleventh lens L11 has a negative optical power, and its focal length ranges from -15 mm to -5 mm. The twelfth lens L12 has a negative optical power, and its focal length ranges from -15 mm to -5 mm. The thirteenth lens L13 has a negative optical power, and its focal length ranges from -15 mm to -5 mm. The fourteenth lens L14 has a positive optical power, and its focal length ranges from 55 mm to 65 mm. The fifteenth lens L15 has a positive optical power, and its focal length ranges from 90 mm to 100 mm.

[0059] In some embodiments, such as Figures 5 to 9As shown, the object side of the sixteenth lens L16 is convex, and the image side of the sixteenth lens L16 is convex. The object side of the seventeenth lens L17 is concave, and the image side of the seventeenth lens L17 is convex. The object side of the eighteenth lens L18 is convex, and the image side of the eighteenth lens L18 is concave. The object side of the nineteenth lens L19 is convex, and the image side of the nineteenth lens L19 is concave. The object side of the twentieth lens L20 is convex, and the image side of the twentieth lens L20 is flat. The object side of the twenty-first lens L21 is flat, and the image side of the twenty-first lens L21 is concave.

[0060] In some embodiments, the sixteenth lens L16 has a negative optical power, and the focal length is in the range of -310 mm to -300 mm. The seventeenth lens L17 has a positive optical power, and the focal length is in the range of 350 mm to 360 mm. The eighteenth lens L18 has a positive optical power, and the focal length is in the range of 80 mm to 90 mm. The nineteenth lens L19 has a positive optical power, and the focal length is in the range of 1340 mm to 1350 mm. The twentieth lens L20 has a positive optical power, and the focal length is in the range of 5790 mm to 5800 mm. The twenty-first lens L21 has a negative optical power, and the focal length is in the range of -70 mm to -60 mm.

[0061] In some embodiments, the diameter D of the aperture STOP of the microscopic objective lens Obj is associated with the numerical aperture NA of the microscopic objective lens Obj, NA = D / (2*f), where f is the focal length of the microscopic objective lens Obj. Different diameters D of the aperture STOP and different focal lengths f of the microscopic objective lens Obj can determine the size of the numerical aperture NA of the microscopic objective lens Obj.

[0062] When f is 20 mm, the diameter D of the aperture STOP is 12 mm, and the numerical aperture NA of the microscopic objective lens Obj is 0.3.

[0063] When f is 40 mm, the diameter D of the aperture STOP is 12 mm, and the numerical aperture NA of the microscopic objective lens Obj is 0.15.

[0064] When f is 10 mm, the diameter D of the aperture STOP is 8 mm, and the numerical aperture NA of the microscopic objective lens Obj is 0.4.

[0065] In some embodiments, the working wavelength band of the optical system includes 400 nm - 700 nm. In this way, the wide wavelength band can support multi-color imaging, can be used for the simultaneous excitation and detection of multiple fluorescent dyes in a fluorescence microscope, and improve the diversity of biological sample analysis. Secondly, the visible wavelength band matches the human eye vision, and the imaging result is intuitive, which is convenient for direct observation or recording.

[0066] In some embodiments, the magnification M of the optical system = the focal length of the tube lens TL / the total focal length of the microscope objective Obj. The focal length of the tube lens TL is 200 mm, and the focal length of the microscope objective Obj can be at least 20 mm, 40 mm, and 10 mm. Therefore, the optical system can have different magnifications, such as 10x, 5x, and 20x.

[0067] In some embodiments, the distance between the object side of the first lens L1 and the object is in the range of 7.0 mm to 13.0 mm. In this way, the long working distance of the microscope objective can provide sufficient space for convenient operation and observation of thick samples.

[0068] In some embodiments, the front entrance pupil distance of the tube lens TL is in the range of 100.0 mm to 210.0 mm, and the rear working distance of the tube lens TL is in the range of 150.0 mm to 151.0 mm. In this way, a large front entrance pupil distance can facilitate adding other optical elements, such as dichroic mirrors, filters, prisms, etc., in the parallel light section between the microscope objective Obj and the tube lens TL according to actual usage requirements. A large rear working distance can facilitate adding required optical elements, such as beam splitters and filters, etc., between the tube lens TL and the image-side detector according to actual usage requirements.

[0069] In some embodiments, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, the ninth lens L9, the tenth lens L10, the eleventh lens L11, the twelfth lens L12, the thirteenth lens L13, the fourteenth lens L14, the fifteenth lens L15, the sixteenth lens L16, the seventeenth lens L17, the eighteenth lens L18, the nineteenth lens L19, the twentieth lens L20, and the twenty-first lens L21 are standard spherical lenses. In this way, the manufacturing process of the standard spherical lenses is mature, which can ensure high quality and consistency, and can reduce the manufacturing cost. In addition, the spherical lenses can provide excellent light converging ability, maintain high resolution and contrast, and ensure image clarity and detail performance. Through the combination of spherical lenses and material selection, aberration problems such as chromatic aberration and spherical aberration can be effectively corrected, thereby improving the imaging quality.

[0070] The present disclosure also provides a microscope. The microscope includes the optical system of any one of the above.

[0071] In some embodiments, the microscope further includes a first optical element disposed between the microscope objective Obj and the tube lens TL.

[0072] As an example, the first optical element may include a dichroic mirror. A dichroic mirror is a special optical element that can selectively reflect or transmit light according to wavelength. Its main function is to separate the excitation light and the emission light in applications such as fluorescence microscopes. For example, in fluorescence imaging, the dichroic mirror allows short-wavelength excitation light to pass through to illuminate the sample, while reflecting the long-wavelength fluorescence signal to the tube lens TL and the detector. This separation improves the imaging contrast, reduces the interference of background light, thereby enhancing the detection accuracy of the fluorescence signal, and is applicable to scenarios such as cell imaging in biomedical research.

[0073] As another example, the first optical element may include a filter. The function of a filter is to selectively transmit light of a specific wavelength and block light of other wavelengths. In microscopic imaging, filters are often used to enhance the contrast and purity of the image. For example, in a fluorescence microscope, a band-pass filter can only allow the fluorescence wavelength emitted by the sample to pass through, filtering out the excitation light or other stray light, thereby improving the clarity of the signal. In addition, filters can also be used in multispectral imaging to separate light of different bands, and are applicable to material analysis or multicolor labeling research of biological samples.

[0074] As another example, the first optical element may include a prism. The main function of a prism is to change the direction of the light path or disperse light. For example, in a stereomicroscope or a polarization microscope, a prism can be used to adjust the light path to achieve observation at a specific angle, or divide the light beam into multiple paths to support multi-view imaging. In addition, a dispersive prism can separate light of different wavelengths and is applicable to spectral analysis or multi-color imaging systems. The addition of a prism enhances the flexibility of the system, enabling it to adapt to complex optical configurations such as polarization detection or multi-path microscopic imaging.

[0075] In some embodiments, the microscope further includes a second optical element disposed between the tube lens TL and the image-side detector.

[0076] As an example, the second optical element may include a beam splitter. The function of a beam splitter is to divide the incident light beam into two or more beams according to a certain ratio or characteristic. For example, in a microscopic imaging system, a beam splitter can divide the light beam into two, one path is directed to the main detector (such as a CCD camera) for imaging, and the other path is directed to an auxiliary detector (such as a spectrometer) for spectral analysis. This configuration supports simultaneous imaging and spectral measurement and is widely used in multimodal microscopes. In addition, beam splitters can also be used for dual-channel imaging, enhancing the versatility of the system and improving the detection efficiency.

[0077] As another example, the second optical element may include a filter. The function of the filter is to selectively transmit light of a specific wavelength and block light of other wavelengths. In microscopic imaging, filters are commonly used to enhance the contrast and purity of images. For example, in a fluorescence microscope, a bandpass filter allows only the fluorescence wavelength emitted by the sample to pass through, filtering out the excitation light or other stray light, thereby improving the clarity of the signal. In addition, filters can also be used in multispectral imaging to separate light of different bands, which is suitable for material analysis or multicolor labeling studies of biological samples.

[0078] The following uses the optical parameter values shown in Tables 1 to 3 and Figures 1 to 21 the optical structure and experimental data to describe the optical system of the present disclosure in detail, where Figures 1 to 9 shows the optical structure and test data of the optical system of the first embodiment using the optical parameter values shown in Table 1, Figures 10 to 15 shows the optical structure and test data of the optical system of the second embodiment using the optical parameter values shown in Table 2, Figures 16 to 21 shows the optical structure and test data of the optical system of the third embodiment using the optical parameter values shown in Table 3. First, in combination with the optical parameter values shown in Table 1 and Figures 1 to 9 to describe in detail the principle of the optical system of the first embodiment of the present disclosure.

[0079] Table 1 is the optical parameters of a microscopic imaging optical system with a magnification of 10 times.

[0080] Table 1

[0081] In the first embodiment of the present disclosure, the lenses of the microscopic objective lens and the tube lens adopt the optical parameter values shown in Table 1. The focal length of the microscopic objective lens is 20 mm, the numerical aperture is 0.3, the parfocal distance is 95 mm, and the working distance is 10.00 mm. The focal length of the tube lens is 200 mm, the numerical aperture is 0.0325, the front entrance pupil distance is 100 mm to 210 mm, and the rear working distance is 150.67 mm. The magnification of the microscopic imaging optical system is 10 times, the working wavelength range is 400 nm to 700 nm, the field number is 45 mm, and the total length is 382.490 mm.

[0082] As Figure 2 shown, the modulation transfer function of the microscopic objective lens with a focal length of 20 mm is close to the diffraction limit, and the modulus value is greater than 0.4 at 500 lp / mm, indicating excellent imaging quality.

[0083] As Figure 3As shown, the sagittal field curvature of the microscopic objective lens with a focal length of 20 mm is 6.8 μm, and the meridional field curvature is 5.7 μm, which is much smaller than the focal depth of 6.531 μm. It is a flat-field microscopic objective lens, and the field curvature is effectively corrected. The distortion is 0.25%, and the distortion amount is small, so the distortion is effectively corrected.

[0084] As Figure 4 shown, the maximum focal shift change of the 0.707 pupil of the microscopic objective lens with a focal length of 20 mm is 0.5 μm, which is much smaller than 1 / 4 of the focal depth of 1.633 μm, and the microscopic objective lens can achieve perfect imaging.

[0085] As Figure 6 shown, in the modulation transfer function curve graph of the tube lens with a focal length of 200 mm, it is close to the diffraction limit.

[0086] As Figure 7 shown, the sagittal field curvature of the tube lens with a focal length of 200 mm is 284.5 μm, and the meridional field curvature is 3.08 μm, which is less than the focal depth of 556.20 μm, and the field curvature is effectively corrected. The distortion is 0.33%, and the distortion amount is small, so the distortion is effectively corrected.

[0087] As Figure 9 shown, it can be seen from the modulation transfer function curve graph of the microscopic imaging optical system with a magnification of 10 times that it is close to the diffraction limit.

[0088] Next, in combination with the optical parameter values shown in Table 2 and Figures 10 to 15 to describe in detail the principle of the optical system of the second embodiment of the present disclosure. The tube lens of the optical system of the second embodiment has the same focal length as the tube lens of the first embodiment described in combination with Figures 1 to 9 description. In the following text, an optical system composed of a microscopic objective lens with a focal length of 40 mm and a tube lens with a focal length of 200 mm will be mainly described, and the same parts will not be described again.

[0089] Table 2 shows the optical parameters of the microscopic imaging optical system with a magnification of 5 times.

[0090] Table 2

[0091] In the second embodiment of the present disclosure, the lenses of the microscopic objective lens and the tube lens adopt the optical parameter values shown in Table 2. The focal length of the microscopic objective lens is 40 mm, the numerical aperture is 0.15, the parfocal distance is 95 mm, and the working distance is 11.22 mm. The focal length of the tube lens is 200 mm, the numerical aperture is 0.0325, the front entrance pupil distance is 100 mm to 210 mm, and the rear working distance is 150.67 mm. The magnification of the microscopic imaging optical system is 5 times, the working wavelength range is 400 nm to 700 nm, the field number is 45 mm, and the total length is 381.271 mm.

[0092] As Figure 11 shown, the modulation transfer function of the microscopic objective lens with a focal length of 40 mm is close to the diffraction limit, and the modulus value is greater than 0.47 at 220 lp / mm, indicating excellent imaging quality.

[0093] As Figure 12 shown, the sagittal field curvature of the microscopic objective lens with a focal length of 40 mm is 12.2 um, and the meridional field curvature is 7.4 um, which is much smaller than the depth of focus of 26.116 um. It is a flat-field microscopic objective lens, and the field curvature is effectively corrected. The distortion is 0.40%, and the amount of distortion is small, so the distortion is effectively corrected.

[0094] As Figure 13 shown, the maximum focal shift variation of the 0.707 pupil of the microscopic objective lens with a focal length of 40 mm is 2.64 um, which is much smaller than 1 / 4 of the depth of focus of 6.529 um, indicating that the microscopic objective lens can achieve perfect imaging.

[0095] As Figure 15 shown, it can be seen from the modulation transfer function curve of the microscopic imaging optical system with a magnification of 5 times that it is close to the diffraction limit.

[0096] Next, in combination with the optical parameter values shown in Table 3 and Figures 16 to 21 to describe in detail the principle of the optical system of the third embodiment of the present disclosure. The tube lens of the optical system of the third embodiment has the same focal length as the tube lens of the first embodiment described in combination with Figures 1 to 9 In the following, an optical system composed of a microscopic objective lens with a focal length of 10 mm and a tube lens with a focal length of 200 mm will be mainly described, and the same parts will not be described again.

[0097] Table 3 shows the optical parameters of the microscopic imaging optical system with a magnification of 20 times.

[0098] Table 3

[0099] In the third embodiment of the present disclosure, the lenses of the microscopic objective lens and the tube lens adopt the optical parameter values shown in Table 3. The magnification of the microscopic imaging optical system is 20 times, the working wavelength band is from 400 nm to 700 nm, the field number is 45 mm, and the total length is 384.507 mm. The focal length of the microscopic objective lens is 10 mm, the numerical aperture is 0.4, the parfocal distance is 95 mm, and the working distance is 7.984 mm. The focal length of the tube lens is 200 mm, the numerical aperture is 0.0325, the front entrance pupil distance is from 100 mm to 210 mm, and the rear working distance is 150.67 mm.

[0100] As Figure 17 shown, the modulation transfer function of the microscopic objective lens with a focal length of 10 mm is close to the diffraction limit, and the modulus value is greater than 0.29 at 800 lp / mm, and the imaging quality is excellent.

[0101] As Figure 18 shown, the sagittal field curvature of the microscopic objective lens with a focal length of 10 mm is 1.1 um, and the meridional field curvature is 1.0 um, which is much smaller than the depth of focus of 3.696 um. It is a flat-field microscopic objective lens, and the field curvature is effectively corrected. The distortion is 0.40%, and the distortion amount is small, and the distortion is effectively corrected.

[0102] As Figure 19 shown, the maximum focal shift change amount of the 0.707 pupil of the microscopic objective lens with a focal length of 10 mm is 0.8251 um, which is less than 1 / 4 of the depth of focus of 0.924 um, and the microscopic objective lens can achieve perfect imaging.

[0103] As Figure 21 shown, it can be seen that it is close to the diffraction limit in the modulation transfer function curve graph of the microscopic imaging optical system with a magnification of 20 times.

[0104] It can be seen from this that the embodiment of the present disclosure can provide a large-field microscopic imaging optical system, and there are at least 3 different focal lengths for the microscopic objective lens, namely 20 mm, 40 mm, and 10 mm. The tube lens matched with it has a focal length of 200 mm. Therefore, there are 3 combinations of microscopic objective lenses and 1 tube lens to form 3 different magnifications of microscopic imaging optical systems, namely 10 times, 5 times, and 20 times. The microscopic imaging optical system has a long working distance greater than 8.00 mm, a numerical aperture of 0.15 / 0.3 / 0.4, a field number of 45 mm, and a visible light wavelength band of 400 nm to 700 nm. While improving the detection efficiency of the optical system, it can also achieve flat-field apochromatic perfect imaging.

[0105] The embodiments of the present disclosure have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, the practical application, or the improvement of technologies in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. An optical system, characterized in that, Comprising: A microscope objective lens (Obj) and a tube lens (TL) arranged in sequence along the optical axis from the object side to the image side, wherein the microscope objective lens (Obj) includes a first lens group (G1), a second lens group (G2), a stop (STOP), and a third lens group (G3) arranged in sequence along the optical axis direction; The first lens group (G1) has a positive optical power and is at least used to correct spherical aberration, astigmatism, and axial chromatic aberration. The first lens group (G1) includes a first cemented lens (B1), a third lens (L3), and a second cemented lens (B2). The first cemented lens (B1) includes a first lens (L1) and a second lens (L2) cemented to each other. The second cemented lens (B2) includes a fourth lens (L4) and a fifth lens (L5) cemented to each other; The second lens group (G2) has a positive optical power and is at least used to correct coma and distortion. The second lens group (G2) includes a sixth lens (L6) and a third cemented lens (B3). The third cemented lens (B3) includes a seventh lens (L7), an eighth lens (L8), and a ninth lens (L9) cemented in sequence; The third lens group (G3) has a positive optical power and is at least used to correct field curvature and lateral chromatic aberration. The third lens group (G3) includes a fourth cemented lens (B4), a thirteenth lens (L13), a fourteenth lens (L14), and a fifteenth lens (L15). The fourth cemented lens (B4) includes a tenth lens (L10), an eleventh lens (L11), and a twelfth lens (L12) cemented in sequence; The stop (STOP) is arranged between the third cemented lens (B3) and the fourth cemented lens (B4) to correct chromatic aberration by placing the stop (STOP) on both sides of the stop (STOP) via the third cemented lens (B3) and the fourth cemented lens (B4); The tube lens (TL) has a positive optical power. The tube lens (TL) includes a fifth cemented lens (B5), a sixth cemented lens (B6), and a twenty-first lens (L21) arranged in sequence along the optical axis direction. The fifth cemented lens (B5) includes a sixteenth lens (L16) and a seventeenth lens (L17) cemented to each other. The sixth cemented lens (B6) includes an eighteenth lens (L18), a nineteenth lens (L19), and a twentieth lens (L20) cemented in sequence.

2. The optical system according to claim 1, wherein the microscope objective lens (Obj) is an infinity conjugate objective lens, at least used to image an object on the object side to infinity, and the tube lens (TL) is an infinity focusing lens, at least used to image an object at infinity to a detector on the image side.

3. The optical system according to claim 2, wherein the focal length of the tube lens (TL) is 200 mm.

4. The optical system according to claim 2, wherein the focal lengths of the first lens group (G1), the second lens group (G2), and the third lens group (G3) satisfy: 1.0 < |f1 / f| < 2.0, 1.5 < |f2 / f| < 2.5, 7.0 < |f3 / f| < 8.0, Among them, f is the total focal length of the microscope objective lens (Obj), f1 is the focal length of the first lens group (G1), f2 is the focal length of the second lens group (G2), and f3 is the focal length of the third lens group (G3).

5. The optical system according to claim 4, wherein the object side of the first lens (L1) is concave and the image side of the first lens (L1) is concave; the object side of the second lens (L2) is convex and the image side of the second lens (L2) is convex; the object side of the third lens (L3) is convex and the image side of the third lens (L3) is convex; the object side of the fourth lens (L4) is concave and the image side of the fourth lens (L4) is concave; the object side of the fifth lens (L5) is convex and the image side of the fifth lens (L5) is flat; the object side of the sixth lens (L6) is concave and the image side of the sixth lens (L6) is convex; the object side of the seventh lens (L7) is convex and the image side of the seventh lens (L7) is convex; the object side of the eighth lens (L8) is concave and the image side of the eighth lens (L8) is concave; the object side of the ninth lens (L9) is convex and the image side of the ninth lens (L9) is convex; the object side of the tenth lens (L10) is convex and the image side of the tenth lens (L10) is concave; the object side of the eleventh lens (L11) is convex and the image side of the eleventh lens (L11) is convex; the object side of the twelfth lens (L12) is concave and the image side of the twelfth lens (L12) is concave; the object side of the thirteenth lens (L13) is concave and the image side of the thirteenth lens (L13) is convex; the object side of the fourteenth lens (L14) is concave and the image side of the fourteenth lens (L14) is convex; the object side of the fifteenth lens (L15) is convex and the image side of the fifteenth lens (L15) is convex.

6. The optical system according to claim 4, wherein the first lens (L1) has a negative optical power and the focal length is in the range of -410 mm to -400 mm; the second lens (L2) has a positive optical power and the focal length is in the range of 20 mm to 30 mm; the third lens (L3) has a positive optical power and the focal length is in the range of 40 mm to 50 mm; the fourth lens (L4) has a negative optical power and the focal length is in the range of -40 mm to -30 mm; the fifth lens (L5) has a positive optical power and the focal length is in the range of 160 mm to 170 mm; the sixth lens (L6) has a positive optical power and the focal length is in the range of 40 mm to 50 mm; the seventh lens (L7) has a positive optical power and the focal length is in the range of 110 mm to 120 mm; the eighth lens (L8) has a negative optical power and the focal length is in the range of -55 mm to -45 mm; The ninth lens (L9) has a negative optical power, and its focal length ranges from -120 mm to -110 mm; The tenth lens (L10) has a positive optical power, and its focal length ranges from 20 mm to 30 mm; The eleventh lens (L11) has a negative optical power, and its focal length ranges from -20 mm to -10 mm; The twelfth lens (L12) has a negative optical power, and its focal length ranges from -25 mm to -15 mm; The thirteenth lens (L13) has a negative optical power, and its focal length ranges from -20 mm to -10 mm; The fourteenth lens (L14) has a positive optical power, and its focal length ranges from 55 mm to 65 mm; The fifteenth lens (L15) has a positive optical power, and its focal length ranges from 110 mm to 120 mm.

7. The optical system according to claim 2, wherein the focal lengths of the first lens group (G1), the second lens group (G2), and the third lens group (G3) satisfy: 0.5 < |f1 / f| < 1.5, 1.3 < |f2 / f| < 2.3, 1.0 < |f3 / f| < 2.0, Among them, where f is the total focal length of the microscope objective (Obj), f1 is the focal length of the first lens group (G1), f2 is the focal length of the second lens group (G2), and f3 is the focal length of the third lens group (G3).

8. The optical system according to claim 7, wherein the object side of the first lens (L1) is concave, and the image side of the first lens (L1) is concave; The object side of the second lens (L2) is convex, and the image side of the second lens (L2) is convex; The object side of the third lens (L3) is convex, and the image side of the third lens (L3) is convex; The object side of the fourth lens (L4) is concave, and the image side of the fourth lens (L4) is concave; The object side of the fifth lens (L5) is convex, and the image side of the fifth lens (L5) is flat; The object side of the sixth lens (L6) is flat, and the image side of the sixth lens (L6) is convex; The object side of the seventh lens (L7) is convex, and the image side of the seventh lens (L7) is convex; The object side of the eighth lens (L8) is concave, and the image side of the eighth lens (L8) is concave; The object side of the ninth lens (L9) is convex, and the image side of the ninth lens (L9) is convex; The object side of the tenth lens (L10) is convex, and the image side of the tenth lens (L10) is concave; The object side of the eleventh lens (L11) is convex, and the image side of the eleventh lens (L11) is convex; The object side of the twelfth lens (L12) is concave, and the image side of the twelfth lens (L12) is flat; The object side of the thirteenth lens (L13) is concave, and the image side of the thirteenth lens (L13) is convex; The object side of the fourteenth lens (L14) is concave, and the image side of the fourteenth lens (L14) is convex; The object side of the fifteenth lens (L15) is convex, and the image side of the fifteenth lens (L15) is convex.

9. The optical system according to claim 7, wherein the first lens (L1) has a negative optical power, and the focal length ranges from -60 mm to -50 mm; the second lens (L2) has a positive optical power, and the focal length ranges from 20 mm to 30 mm; the third lens (L3) has a positive optical power, and the focal length ranges from 30 mm to 40 mm; the fourth lens (L4) has a negative optical power, and the focal length ranges from -30 mm to -20 mm; the fifth lens (L5) has a positive optical power, and the focal length ranges from 300 mm to 310 mm; the sixth lens (L6) has a positive optical power, and the focal length ranges from 45 mm to 55 mm; the seventh lens (L7) has a positive optical power, and the focal length ranges from 190 mm to 200 mm; the eighth lens (L8) has a negative optical power, and the focal length ranges from -70 mm to -60 mm; the ninth lens (L9) has a negative optical power, and the focal length ranges from -85 mm to -75 mm; the tenth lens (L10) has a positive optical power, and the focal length ranges from 20 mm to 30 mm; the eleventh lens (L11) has a negative optical power, and the focal length ranges from -20 mm to -10 mm; the twelfth lens (L12) has a negative optical power, and the focal length ranges from -45 mm to -35 mm; the thirteenth lens (L13) has a negative optical power, and the focal length ranges from -20 mm to -10 mm; the fourteenth lens (L14) has a positive optical power, and the focal length ranges from 45 mm to 55 mm; the fifteenth lens (L15) has a positive optical power, and the focal length ranges from 105 mm to 115 mm.

10. The optical system according to claim 2, wherein the focal lengths of the first lens group (G1), the second lens group (G2), and the third lens group (G3) satisfy: 0.9 < |f1 / f| < 1.9, 5.5 < |f2 / f| < 6.5, 18.0 < |f3 / f| < 19.0, Among them, where f is the total focal length of the microscope objective (Obj), f1 is the focal length of the first lens group (G1), f2 is the focal length of the second lens group (G2), and f3 is the focal length of the third lens group (G3).

11. The optical system according to claim 10, wherein the object side of the first lens (L1) is concave, and the image side of the first lens (L1) is convex; the object side of the second lens (L2) is concave, and the image side of the second lens (L2) is convex; the object side of the third lens (L3) is convex, and the image side of the third lens (L3) is concave; the object side of the fourth lens (L4) is convex, and the image side of the fourth lens (L4) is concave; the object side of the fifth lens (L5) is convex, and the image side of the fifth lens (L5) is concave; the object side of the sixth lens (L6) is concave, and the image side of the sixth lens (L6) is convex; the object side of the seventh lens (L7) is convex, and the image side of the seventh lens (L7) is convex; The object side of the eighth lens (L8) is concave, and the image side of the eighth lens (L8) is concave; The object side of the ninth lens (L9) is convex, and the image side of the ninth lens (L9) is convex; The object side of the tenth lens (L10) is convex, and the image side of the tenth lens (L10) is concave; The object side of the eleventh lens (L11) is convex, and the image side of the eleventh lens (L11) is convex; The object side of the twelfth lens (L12) is concave, and the image side of the twelfth lens (L12) is concave; The object side of the thirteenth lens (L13) is concave, and the image side of the thirteenth lens (L13) is convex; The object side of the fourteenth lens (L14) is concave, and the image side of the fourteenth lens (L14) is convex; The object side of the fifteenth lens (L15) is convex, and the image side of the fifteenth lens (L15) is convex.

12. The optical system according to claim 10, wherein the first lens (L1) has a negative optical power, and the focal length is in the range of -40 mm to -30 mm; The second lens (L2) has a positive optical power, and the focal length is in the range of 10 mm to 20 mm; The third lens (L3) has a positive optical power, and the focal length is in the range of 30 mm to 40 mm; The fourth lens (L4) has a positive optical power, and the focal length is in the range of 30 mm to 40 mm; The fifth lens (L5) has a negative optical power, and the focal length is in the range of -50 mm to -40 mm; The sixth lens (L6) has a positive optical power, and the focal length is in the range of 60 mm to 70 mm; The seventh lens (L7) has a positive optical power, and the focal length is in the range of 100 mm to 110 mm; The eighth lens (L8) has a negative optical power, and the focal length is in the range of -45 mm to -35 mm; The ninth lens (L9) has a negative optical power, and the focal length is in the range of -120 mm to -110 mm; The tenth lens (L10) has a positive optical power, and the focal length is in the range of 10 mm to 20 mm; The eleventh lens (L11) has a negative optical power, and the focal length is in the range of -15 mm to -5 mm; The twelfth lens (L12) has a negative optical power, and the focal length is in the range of -15 mm to -5 mm; The thirteenth lens (L13) has a negative optical power, and the focal length is in the range of -15 mm to -5 mm; The fourteenth lens (L14) has a positive optical power, and the focal length is in the range of 55 mm to 65 mm; The fifteenth lens (L15) has a positive optical power, and the focal length is in the range of 90 mm to 100 mm.

13. The optical system according to claim 3, wherein the object side of the sixteenth lens (L16) is convex, and the image side of the sixteenth lens (L16) is convex; The object side of the seventeenth lens (L17) is concave, and the image side of the seventeenth lens (L17) is convex; The object side of the eighteenth lens (L18) is convex, and the image side of the eighteenth lens (L18) is concave; The object side of the nineteenth lens (L19) is convex, and the image side of the nineteenth lens (L19) is concave; The object side of the twentieth lens (L20) is convex, and the image side of the twentieth lens (L20) is flat; The object side of the twenty - first lens (L21) is flat, and the image side of the twenty - first lens (L21) is concave.

14. The optical system according to claim 13, wherein the sixteenth lens (L16) has a negative focal power, and the focal length is in the range of - 310 mm to - 300 mm; The seventeenth lens (L17) has a positive focal power, and the focal length is in the range of 350 mm to 360 mm; The eighteenth lens (L18) has a positive focal power, and the focal length is in the range of 80 mm to 90 mm; The nineteenth lens (L19) has a positive focal power, and the focal length is in the range of 1340 mm to 1350 mm; The twentieth lens (L20) has a positive focal power, and the focal length is in the range of 5790 mm to 5800 mm; The twenty - first lens (L21) has a negative focal power, and the focal length is in the range of - 70 mm to - 60 mm.

15. The optical system according to claim 1, wherein the diameter of the aperture (STOP) includes one of 12 mm and 8 mm.

16. The optical system according to claim 1, wherein the working wavelength band of the optical system includes 400 nm - 700 nm.

17. The optical system according to claim 1, wherein the distance between the object side surface of the first lens (L1) and the object is in the range of 7.0 mm to 13.0 mm.

18. The optical system according to claim 1, wherein the front entrance pupil distance of the tube lens (TL) is in the range of 100.0 mm to 210.0 mm, and the rear working distance of the tube lens (TL) is in the range of 150.0 mm to 151.0 mm.

19. The optical system according to claim 1, wherein the first lens (L1), the second lens (L2), the third lens (L3), the fourth lens (L4), the fifth lens (L5), the sixth lens (L6), the seventh lens (L7), the eighth lens (L8), the ninth lens (L9), the tenth lens (L10), the eleventh lens (L11), the twelfth lens (L12), the thirteenth lens (L13), the fourteenth lens (L14), the fifteenth lens (L15), the sixteenth lens (L16), the seventeenth lens (L17), the eighteenth lens (L18), the nineteenth lens (L19), the twentieth lens (L20) and the twenty - first lens (L21) are standard spherical lenses.

20. A microscope, characterized in that, Comprising: The optical system according to any one of claims 1 to 19.

21. The microscope according to claim 20 further includes a first optical element disposed between the microscope objective lens (Obj) and the tube lens (TL), and / or a second optical element disposed between the tube lens (TL) and the image-side detector.

22. The microscope according to claim 21, wherein the first optical element includes at least one of a dichroic mirror, a filter, and a prism, and the second optical element includes at least one of a beam splitter and a filter.

Images