oblique optical microscope

Abstract

The utility model provides a kind of oblique optical microscope.Oblique optical microscope includes: first mirror group and second mirror group are arranged in order from object side to image side with optical axis, and optical axis is arranged with object plane inclination;First mirror group includes first lens group, third lens and second lens group;Second mirror group includes third lens group, eighth lens and fourth lens group;First lens group, second lens group, third lens group and fourth lens group include at least two lenses respectively, and the refractive index of at least two lenses in each lens group is different.Oblique optical microscope of the utility model can realize greater magnification and higher resolution while being inclined to shoot, so as to meet the shooting demand under special circumstances.

Description

Technical Field

[0001] This utility model relates to the field of microscopes, and in particular to an oblique axis optical microscope. Background Technology

[0002] Conventional optical microscopes are used to take pictures perpendicular to the object plane. However, in some fields, optical microscopes cannot take pictures perpendicularly, such as when used in conjunction with scanning electron microscopes or in fields where other operations need to be performed in the vertical direction.

[0003] Currently, some low-magnification, low-resolution visual inspections can utilize a large depth of field to achieve tilted shooting, but in some microscopic fields, the resolution of this solution is far from meeting the requirements. Utility Model Content

[0004] One objective of this invention is to enable optical microscopes to take tilted images.

[0005] A further objective of this invention is to maintain high-resolution imaging even when shooting at an angle.

[0006] Specifically, this utility model provides an oblique-axis optical microscope, comprising: a first lens group and a second lens group arranged coaxially from the object side to the image side, with the optical axis inclined to the object plane; the first lens group includes a first lens group, a third lens, and a second lens group; the second lens group includes a third lens group, an eighth lens, and a fourth lens group; the third lens has a convex surface facing both the object and image sides; the eighth lens has a convex surface facing both the object and image sides; the first, second, third, and fourth lens groups each include at least two lenses, and the at least two lenses in each lens group have different refractive indices; the first lens group has a concave surface facing the object side and a convex surface facing the image side; the second lens group has a concave surface facing the object side and a convex surface facing the image side; the third lens group has a convex surface facing the object side and a concave surface facing the image side; the fourth lens group has a convex surface facing the object side and a concave surface facing the image side.

[0007] Optionally, the first lens group is a cemented doublet lens, including a first lens and a second lens starting from the object side; the first lens is a positive meniscus lens, with a concave surface facing the object side and a convex surface facing the image side; the second lens is a negative meniscus lens, with a concave surface facing the object side and a convex surface facing the image side; the second lens group is a cemented doublet lens, including a fourth lens and a fifth lens starting from the object side; the fourth lens is a biconcave lens, with a concave surface facing both the object and image sides; the fifth lens is a biconvex lens, with a convex surface facing both the object and image sides. The third lens group is a cemented doublet, including the sixth and seventh lenses starting from the object side; the sixth lens is a biconvex lens, with a convex surface facing both the object and image sides; the seventh lens is a biconcave lens, with a concave surface facing both the object and image sides; the fourth lens group is a cemented doublet, including the ninth and tenth lenses starting from the object side; the ninth lens is a meniscus negative lens, with a convex surface facing both the object and image sides; the tenth lens is a meniscus positive lens, with a convex surface facing both the object and image sides.

[0008] Optionally, the first lens is made of H-FK71 material; the second lens is made of H-TF5 material; the third lens is made of H-ZPK5 material; the fourth lens is made of H-ZLAF68C material; the fifth lens is made of H-ZBAF20 material; the sixth lens is made of BAF5 material; the seventh lens is made of H-ZLAF68B material; the eighth lens is made of H-ZPK7 material; the ninth lens is made of TF3 material; and the tenth lens is made of H-FK95N material.

[0009] Optionally, the object-facing surface of the first lens is the first mirror surface, the cemented surface of the first and second lenses is the second mirror surface, and the image-facing surface of the second lens is the third mirror surface; the object-facing surface of the third lens is the fourth mirror surface, and the image-facing surface of the third lens is the fifth mirror surface; the object-facing surface of the fourth lens is the sixth mirror surface, the cemented surface of the fourth and fifth lenses is the seventh mirror surface, and the image-facing surface of the fifth lens is the eighth mirror surface; the object-facing surface of the sixth lens is the ninth mirror surface, the cemented surface of the sixth and seventh lenses is the tenth mirror surface, and the image-facing surface of the seventh lens is the eleventh mirror surface; The object-facing surface of the eighth lens is the twelfth mirror surface, and the image-facing surface of the eighth lens is the thirteenth mirror surface; the object-facing surface of the ninth lens is the fourteenth mirror surface, the cemented surface of the ninth and tenth lenses is the fifteenth mirror surface, and the image-facing surface of the tenth lens is the sixteenth mirror surface; the radii of curvature of the first, second, third, fifth, sixth, eighth, tenth, and thirteenth mirror surfaces are negative; the radii of curvature of the fourth, seventh, ninth, eleventh, twelfth, fourteenth, fifteenth, and sixteenth mirror surfaces are positive.

[0010] Optionally, the radius of curvature of the first mirror is -39.41±0.01mm; the radius of curvature of the second mirror is -8.89±0.01mm; the radius of curvature of the third mirror is -19.38±0.01mm; the radius of curvature of the fourth mirror is 48.07±0.01mm; the radius of curvature of the fifth mirror is -28.14±0.01mm; the radius of curvature of the sixth mirror is -103.34±0.01mm; the radius of curvature of the seventh mirror is 16.13±0.01mm; and the radius of curvature of the eighth mirror is -50.86±0.01mm. The radius of curvature of the ninth mirror is 42.62±0.01mm; the radius of curvature of the tenth mirror is -34.51±0.01mm; the radius of curvature of the eleventh mirror is 142.84±0.01mm; the radius of curvature of the twelfth mirror is 167.78±0.01mm; the radius of curvature of the thirteenth mirror is -50.96±0.01mm; the radius of curvature of the fourteenth mirror is 36.17±0.01mm; the radius of curvature of the fifteenth mirror is 17.82±0.01mm; and the radius of curvature of the sixteenth mirror is 77.63±0.01mm.

[0011] Optionally, the light-transmitting aperture of the first mirror is 8.38 mm; the light-transmitting aperture of the second mirror is 8.87 mm; the light-transmitting aperture of the third mirror is 9.83 mm; the light-transmitting aperture of the fourth mirror is 10.29 mm; the light-transmitting aperture of the fifth mirror is 10.42 mm; the light-transmitting aperture of the sixth mirror is 8.56 mm; the light-transmitting aperture of the seventh mirror is 8.49 mm; the light-transmitting aperture of the eighth mirror is 8.54 mm; and the ninth mirror has a light-transmitting aperture of 8.56 mm. The light-transmitting aperture of the tenth mirror is 9.44 mm; the light-transmitting aperture of the eleventh mirror is 9.34 mm; the light-transmitting aperture of the eleventh mirror is 9.35 mm; the light-transmitting aperture of the twelfth mirror is 10.54 mm; the light-transmitting aperture of the thirteenth mirror is 10.61 mm; the light-transmitting aperture of the fourteenth mirror is 10.46 mm; the light-transmitting aperture of the fifteenth mirror is 10.10 mm; and the light-transmitting aperture of the sixteenth mirror is 9.59 mm.

[0012] Optionally, the mirror distance between the first and second mirrors is 2.94 mm; the mirror distance between the second and third mirrors is 2.2 mm; the mirror distance between the third and fourth mirrors is 1 mm; the mirror distance between the fourth and fifth mirrors is 2.83 mm; the mirror distance between the fifth and sixth mirrors is 14.79 mm; the mirror distance between the sixth and seventh mirrors is 2.18 mm; the mirror distance between the seventh and eighth mirrors is 2.04 mm; and the mirror distance between the eighth and ninth mirrors is... The distance between the ninth and tenth mirrors is 52.85mm; the distance between the tenth and eleventh mirrors is 2.83mm; the distance between the eleventh and twelfth mirrors is 0.86mm; the distance between the eleventh and twelfth mirrors is 18.19mm; the distance between the twelfth and thirteenth mirrors is 4.17mm; the distance between the thirteenth and fourteenth mirrors is 1mm; the distance between the fourteenth and fifteenth mirrors is 1.82mm; and the distance between the fifteenth and sixteenth mirrors is 4.98mm.

[0013] Optionally, it also includes: an aperture stop disposed between the second lens group and the third lens group; the aperture stop has a light-transmitting aperture of 7.22 mm; the mirror distance between the aperture stop and the eighth mirror is 19.95 mm, and the mirror distance between the aperture stop and the ninth mirror is 32.9 mm.

[0014] Alternatively, the relationship between the object distance and image distance in an oblique-axis optical microscope is as follows: in, Indicates the focal length of the first lens group. The focal length of the second lens group is represented by u, the object distance is represented by v, and the image distance is represented by v.

[0015] Optionally, the formula for calculating the angle between the image plane of an oblique-axis optical microscope and the plane perpendicular to the optical axis is: Where θ represents the angle between the image plane and the plane perpendicular to the optical axis. Indicates the focal length of the first lens group. α represents the focal length of the second lens group, u represents the object distance, v represents the image distance, α represents the angle between the optical axis of the lens and the object plane, β represents the system magnification, and FOV represents the field of view.

[0016] The imaging lens of the oblique axis optical microscope of this invention is a double telecentric lens. By setting the specific parameters and structure of each lens, the optical magnification of the oblique axis optical microscope is 2x, the field of view is 2mm in diameter, and the numerical aperture (NA) is 0.12. It can achieve a large magnification and high resolution while shooting at an angle. Furthermore, the image will be stretched along the tilt direction, but the magnification will not change.

[0017] The above and other objects, advantages and features of this utility model will become more apparent to those skilled in the art from the following detailed description of specific embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0018] The following sections will describe some specific embodiments of the present invention in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or components. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic diagram of the optical path and structure of an oblique-axis optical microscope according to an embodiment of the present invention; Figure 2 This is a dot plot of different fields of view of an oblique-axis optical microscope according to an embodiment of the present invention; Figure 3 This is a modulation transfer function curve of a microscope objective lens according to an embodiment of the present invention; and Figure 4 This is a field curvature distortion diagram of a microscope objective lens according to an embodiment of the present invention. Detailed Implementation

[0019] This embodiment provides a tilting optical microscope that can achieve a large magnification and high resolution while taking tilted images. Figure 1 This is a schematic diagram of the optical path and structure of an oblique-axis optical microscope according to an embodiment of the present invention, as shown below. Figure 1 As shown, the oblique-axis optical microscope includes a first mirror group and a second mirror group arranged coaxially from the object side to the image side, with the optical axis tilted relative to the object plane P.

[0020] The first lens group includes a first lens group G1, a third lens L3, and a second lens group G2; the second lens group includes a third lens group G3, an eighth lens L8, and a fourth lens group G4. The first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 each include at least two lenses, and the at least two lenses in each lens group have different refractive indices.

[0021] The third lens L3 is convex when facing the object and convex when facing the image; the eighth lens L8 is convex when facing the object and convex when facing the image; the first lens group G1 is concave when facing the object and convex when facing the image; the second lens group G2 is concave when facing the object and convex when facing the image; the third lens group G3 is convex when facing the object and concave when facing the image; the fourth lens group G4 is convex when facing the object and concave when facing the image.

[0022] In some optional embodiments, the first lens group G1 is a cemented doublet lens, including a first lens L1 and a second lens L2 starting from the object side; the first lens L1 is a meniscus positive lens, with a concave surface facing the object side and a convex surface facing the image side; the second lens L2 is a meniscus negative lens, with a concave surface facing the object side and a convex surface facing the image side. This meniscus-shaped (concave on one side, convex on the other) design of the first lens L1 can accommodate the incident angle of oblique rays, with the concave surface facing the object side guiding the diverging oblique rays to converge towards the center; the convex surface facing the image side smoothly transmits the converged light to the second lens L2. Its positive lens properties (thick at the center and thin at the edges) have the effect of converging light rays, avoiding energy loss caused by excessive divergence of oblique light rays; while the second lens L2 is a meniscus negative lens (concave when facing the object and convex when facing the image). After being cemented with the first lens L1, the negative lens properties (thin at the center and thick at the edges) can counteract the excessive convergence of the first lens L1. At the same time, through the design of "concave surface fitting with convex surface of first lens L1", the light refraction angle is further optimized.

[0023] The second lens group G2 is a cemented doublet, consisting of a fourth lens L4 and a fifth lens L5 starting from the object side. The fourth lens L4 is a biconcave lens, with a concave surface facing both the object and image sides. The fifth lens L5 is a biconvex lens, with a convex surface facing both the object and image sides. The biconcave structure provides strong diverging light and can counteract excessive convergence that might occur with the preceding lens group, especially addressing the refraction deviation of marginal rays (i.e., rays far from the optical axis) in oblique incidence, preventing excessive convergence that could lead to an overly bright image center and dark edges. After cementing the fifth lens L5 with the fourth lens L4, the strong converging effect of the biconvex structure refocuses the diverged light, forming a complementary divergence-convexity combination for precise optical path calibration. Simultaneously, the symmetrical structure of the biconvex lens effectively counteracts field curvature common in oblique-axis imaging (i.e., a sharp image center but blurred edges), ensuring clear imaging of sample details at all locations on the object plane P.

[0024] The third lens group G3 is a cemented doublet, consisting of the sixth lens L6 and the seventh lens L7, starting from the object side. The sixth lens L6 is a biconvex lens, with a convex surface facing both the object and image sides. The seventh lens L7 is a biconcave lens, with a concave surface facing both the object and image sides. As the first lens after the aperture AS, the biconvex structure of the sixth lens L6 efficiently receives the central light rays filtered by the aperture AS, stabilizing the optical path direction through symmetrical converging and laying the foundation for subsequent image-side imaging. After cementing with the sixth lens L6, the diverging effect of the biconcave structure of the seventh lens L7 neutralizes the excessive convergence of the biconvex lens, forming a balanced convergence-divergence combination. This further eliminates spherical aberration caused by long-distance light propagation in the oblique axis optical path (i.e., the appearance of blurred haloes at the image edges). This combination is particularly suitable for scenarios in oblique axis microscopes where the light propagation path is long and the angular deviation accumulates significantly, ensuring optical path stability.

[0025] The fourth lens group G4 is a cemented doublet, consisting of the ninth lens L9 and the tenth lens L10, starting from the object side. The ninth lens L9 is a meniscus negative lens, with a convex surface facing the object side and a concave surface facing the image side. The tenth lens L10 is a meniscus positive lens, also with a convex surface facing the object side and a concave surface facing the image side. The meniscus structure of the ninth lens L9 conforms to the propagation angle of the light path on the image side. The convex surface receives preceding rays and guides them towards the center, while the concave surface, through the diverging effect of the negative lens, adjusts the incident angle of the light, preventing distortion (i.e., image stretching or compression) at the edge of the image plane Q due to excessive incident angles. The tenth lens L10, as a meniscus positive lens, after cementing with the ninth lens L9, uses the converging effect of the positive lens to focus the diverging rays onto the image plane Q. Simultaneously, the design of the convex surface fitting the concave surface of the ninth lens L9 further compensates for the optical path deviation caused by the tilt of the image plane Q in oblique imaging, ensuring consistent sharpness at all points on the image plane Q (i.e., ensuring the flattening of the image plane Q).

[0026] In some preferred embodiments, the specific materials of the first lens L1 to the tenth lens L10 can be referred to Table 1. As shown in Table 1, the first lens L1 can be made of H-FK71 material; the second lens L2 can be made of H-TF5 material; the third lens L3 can be made of H-ZPK5 material; the fourth lens L4 can be made of H-ZLAF68C material; the fifth lens L5 can be made of H-ZBAF20 material; the sixth lens L6 can be made of BAF5 material; the seventh lens L7 can be made of H-ZLAF68B material; the eighth lens L8 can be made of H-ZPK7 material; the ninth lens L9 can be made of TF3 material; and the tenth lens L10 can be made of H-FK95N material.

[0027] Table 1 The first lens L1 (H-FK71) is a low-dispersion optical glass (high Abbe number, usually >60). Its characteristics are that the refraction angle of light of different wavelengths is small, which can reduce the propagation deviation of red, green, blue and other colors of light in oblique light, laying the foundation for subsequent correction. At the same time, H-FK71 has high light transmittance, which can reduce the energy loss of oblique light and avoid the blurring of sample details due to insufficient light.

[0028] The second lens L2 (H-TF5): It is a medium-high dispersion optical glass (Abbe number lower than H-FK71, usually Abbe number <45). It forms a complementary combination of "low dispersion + high dispersion" with H-FK71. After the first lens L1 and the second lens L2 are double bonded, H-TF5 can accurately cancel the trace dispersion left by H-FK71, realize "synchronous propagation of all colors of light in oblique incident light", and avoid the appearance of colored fringes at the edge of the image from the source (the chromatic aberration problem is more prominent in oblique axis imaging, because the dispersion deviation will be amplified when the light is obliquely incident).

[0029] The third lens, L3, is the only standalone lens (non-cemented) in the first lens group. Its function is to "receive the light from the preceding cemented doublet, stabilize the direction of the oblique light path, and avoid introducing additional aberrations." The material chosen focuses on "low distortion and high mechanical stability." The third lens, L3 (H-ZPK5), is a high-refractive-index, low-dispersion glass (refractive index n≈1.6, Abbe number>50), possessing both "light-converging ability" and "low aberration characteristics." The high refractive index allows for smooth light convergence through a smaller surface curvature (e.g., a front surface curvature radius of 48.07mm), avoiding spherical aberration (blurred halo at image edges) caused by excessive curvature. The low dispersion characteristics ensure that oblique light passing through the standalone lens does not reintroduce chromatic aberration, perfectly complementing the correction effect of the preceding cemented doublet. Simultaneously, H-ZPK5 has good thermal stability (low coefficient of linear expansion), preventing lens deformation due to temperature changes during microscope operation and ensuring long-term stability of the oblique axis light path.

[0030] The fourth lens L4 (H-ZLAF68C) is a high-refractive-index, high-dispersion glass. Its double-concave design (both sides are concave) requires a high refractive index to enhance light dispersion, while its high dispersion characteristics can specifically counteract the spherical aberration of the "edge rays" in oblique rays (edge ​​rays have more obvious spherical aberration deviation due to the large incident angle).

[0031] The fifth lens, L5 (H-ZBAF20), is a medium-refractive-index, low-dispersion glass, forming a combination of "high-dispersion dispersion + low-dispersion convergence" with H-ZLAF68C. The converging effect of the biconvex lens type (both surfaces are convex) can refocus the light rays diverged by the fourth lens, L4, while the low-dispersion characteristics further suppress aberration accumulation, ensuring that sample details at the edge of the object plane P (such as the edge of the field of view in oblique axis shooting) can also be clearly transmitted.

[0032] The sixth lens, L6 (BAF5), is a low-dispersion medium-refractive-index glass. The biconvex lens type can efficiently receive parallel light rays from the stop AS. The low dispersion characteristics ensure that no new color deviation is generated when the light transitions from object to image. At the same time, BAF5 has good chemical stability and can withstand local light intensity concentration near the stop AS for a long time (avoiding glass aging that leads to a decrease in light transmittance).

[0033] The seventh lens L7 (H-ZLAF68B) and the fourth lens L4 (H-ZLAF68C) both belong to the ZLAF series (high dispersion characteristics). The divergent effect of the biconcave type can neutralize the convergence of the sixth lens L6, forming a "light path balance in the transition stage" and avoiding the increase in correction pressure on the image receiving end (subsequent lenses) due to excessive light convergence.

[0034] The eighth lens L8 (H-ZPK7) is a high-transmittance, low-dispersion glass. Its biconvex lens design guides light to the final correction group (ninth and tenth lenses) on the image side through precise curvature. Its wide-band light transmission characteristics are particularly suitable for the possible "multi-wavelength illumination" scenarios (such as fluorescence imaging) of oblique axis microscopes, avoiding the loss of details caused by the absorption of specific wavelengths of light by the material.

[0035] The ninth lens L9 (TF3) is a medium-dispersion, medium-refractive-index glass. Its meniscus negative lens type (convex in front and concave in back) surface shape can fit the tilt angle of the image plane Q. By adjusting the angle of light incident on the image plane Q through the divergence effect of the negative lens, it avoids distortion (such as stretching or compression) at the edge of the image plane Q caused by "excessive oblique incidence" of light.

[0036] The tenth lens L10 (H-FK95N) is a low-dispersion, high-transmittance glass. When cemented with the ninth lens L9, its low-dispersion characteristics can eliminate residual chromatic aberration in the final stage, and its high transmittance ensures that weak detail signals (such as the fine texture of the sample edge) can be transmitted to the image plane Q. At the same time, the refractive index of H-FK95N matches that of the ninth lens L9 (TF3), which can reduce the light reflection loss at the cemented surface of the two lenses and further improve the brightness uniformity of the image plane Q.

[0037] Ultimately, this invention forms a complete aberration correction system for oblique-axis imaging by combining four sets of cemented doublet lenses with two separate lenses: from the reception of oblique rays on the object plane P, to the calibration of the optical path and the compensation of aberrations, and then to the precise focusing on the image plane Q, each lens group undertakes a specific correction function, ultimately achieving the goal of transmitting sample details without distortion and with high clarity when shooting on the oblique axis, thus meeting the microscope's requirements for high resolution and stability.

[0038] In some optional embodiments, the object-facing surface of the first lens L1 is the first mirror surface S1, the cemented surface of the first lens L1 and the second lens L2 is the second mirror surface S2, and the image-facing surface of the second lens L2 is the third mirror surface S3; the object-facing surface of the third lens L3 is the fourth mirror surface S4, and the image-facing surface of the third lens L3 is the fifth mirror surface S5; the object-facing surface of the fourth lens L4 is the sixth mirror surface S6, the cemented surface of the fourth lens L4 and the fifth lens L5 is the seventh mirror surface S7, and the image-facing surface of the fifth lens L5 is the eighth mirror surface S8; the sixth The object-facing surface of lens L6 is the ninth mirror surface S9; the cemented surface of the sixth lens L6 and the seventh lens L7 is the tenth mirror surface S10; the image-facing surface of the seventh lens L7 is the eleventh mirror surface S11; the object-facing surface of the eighth lens L8 is the twelfth mirror surface S12; the image-facing surface of the eighth lens L8 is the thirteenth mirror surface S13; the object-facing surface of the ninth lens L9 is the fourteenth mirror surface S14; the cemented surface of the ninth lens L9 and the tenth lens L10 is the fifteenth mirror surface S15; and the image-facing surface of the tenth lens L10 is the sixteenth mirror surface S16. Optionally, the radii of curvature of the first mirror S1, the second mirror S2, the third mirror S3, the fifth mirror S5, the sixth mirror S6, the eighth mirror S8, the tenth mirror S10, and the thirteenth mirror S13 can be negative; the radii of curvature of the fourth mirror S4, the seventh mirror S7, the ninth mirror S9, the eleventh mirror S11, the twelfth mirror S12, the fourteenth mirror S14, the fifteenth mirror S15, and the sixteenth mirror S16 can be positive.

[0039] Preferably, the specific values ​​of the radius of curvature, aperture, and mirror distance between adjacent mirrors for the first mirror S1 to the sixteenth mirror S16 can be found in Table 2. As shown in Table 2: the radius of curvature of the first mirror S1 is -39.41±0.01mm, the aperture is 8.38mm, and the mirror distance between the first mirror S1 and the second mirror S2 is 2.94mm; the radius of curvature of the second mirror S2 is -8.89±0.01mm, the aperture is 8.87mm, and the mirror distance between the second mirror S2 and the third mirror S3 is 2.2mm; the radius of curvature of the third mirror S3 is -19.38±0.01mm, the aperture is 9.83mm, and the mirror distance between the third mirror S3 and the fourth mirror S4 is 1mm. The tolerance of ±0.01mm ensures curvature accuracy and prevents additional aberrations introduced by processing errors. The radius of curvature of the fourth mirror S4 is 48.07±0.01mm, the aperture is 10.29mm, and the mirror distance between the fourth mirror S4 and the fifth mirror S5 is 2.83mm; the radius of curvature of the fifth mirror S5 is -28.14±0.01mm, the aperture is 10.42mm, and the mirror distance between the fifth mirror S5 and the sixth mirror S6 is 14.79mm.

[0040] The radius of curvature of the sixth mirror S6 is -103.34±0.01mm, and the aperture is 8.56mm. The mirror distance between the sixth mirror S6 and the seventh mirror S7 is 2.18mm. The radius of curvature of the seventh mirror S7 is 16.13±0.01mm, and the aperture is 8.49mm. The mirror distance between the seventh mirror S7 and the eighth mirror S8 is 2.04mm. The radius of curvature of the eighth mirror S8 is -50.86±0.01mm, and the aperture is 8.54mm. The mirror distance between the eighth mirror S8 and the ninth mirror S9 is 52.85mm.

[0041] The radius of curvature of the ninth mirror S9 is 42.62±0.01mm, and the aperture is 9.44mm. The mirror distance between the ninth mirror S9 and the tenth mirror S10 is 2.83mm. The radius of curvature of the tenth mirror S10 is -34.51±0.01mm, and the aperture is 9.34mm. The mirror distance between the tenth mirror S10 and the eleventh mirror S11 is 0.86mm. The radius of curvature of the eleventh mirror S11 is 142.84±0.01mm, and the aperture is 9.35mm. The mirror distance between the eleventh mirror S11 and the twelfth mirror S12 is 18.19mm.

[0042] The radius of curvature of the twelfth mirror S12 is 167.78±0.01mm, and the aperture is 10.54mm. The mirror distance between the twelfth mirror S12 and the thirteenth mirror S13 is 4.17mm. The radius of curvature of the thirteenth mirror S13 is -50.96±0.01mm, and the aperture is 10.61mm. The mirror distance between the thirteenth mirror S13 and the fourteenth mirror S14 is 1mm.

[0043] The radius of curvature of the fourteenth mirror S14 is 36.17±0.01mm, and the aperture is 10.46mm. The mirror distance between the fourteenth mirror S14 and the fifteenth mirror S15 is 1.82mm. The radius of curvature of the fifteenth mirror S15 is 17.82±0.01mm, and the aperture is 10.10mm. The mirror distance between the fifteenth mirror S15 and the sixteenth mirror S16 is 4.98mm. The radius of curvature of the sixteenth mirror S16 is 77.63±0.01mm, and the aperture is 9.59mm.

[0044] Table 2 In a preferred embodiment, the oblique-axis optical microscope of this invention is further provided with an aperture stop AS, also known as an aperture diaphragm. The function of the aperture stop AS is to limit the aperture through which the light beam passes, and the aperture stop AS can be positioned between the second lens group G2 and the third lens group G3. The aperture of the aperture stop AS is 7.22 mm; the mirror distance between the aperture stop AS and the eighth mirror S8 is 19.95 mm, and the mirror distance between the aperture stop AS and the ninth mirror S9 is 32.9 mm.

[0045] The imaging lens of the oblique axis optical microscope of this invention is a double telecentric lens. By setting the specific parameters and structure of each lens in Tables 1 and 2 above, the optical magnification of the oblique axis optical microscope can be 2x, the field of view is 2mm in diameter, and the numerical aperture NA is 0.12. It can achieve a large magnification and high resolution while shooting at an angle, and the image will be stretched along the tilt direction, but the magnification will not change.

[0046] In one specific embodiment, such as Figure 1 As shown, the optical axis of the optical lens of this utility model forms a 45° angle with the object plane P. The camera is set at the image plane Q. The intersection of the object plane P and the optical axis of the optical lens is the axial working distance of the optical lens. Taking the embodiment of this utility model with a distance of 25mm as an example, the corresponding image-side axial back intercept is 50.02mm. In non-axial situations, if the object distance changes, the image distance will also change accordingly. The relationship between the object distance and the image distance of the oblique axis optical microscope of this utility model is shown in equation (1): (1) in, Indicates the focal length of the first lens group. The focal length of the second lens group is represented by u, the object distance is represented by v, and the image distance is represented by v.

[0047] In this embodiment, It is 30mm. The object distance is 60 mm, the axial object distance is 30 mm, the axial image distance is 60 mm, and β is 2. Based on this setting, when the object distance u changes uniformly, the image distance v also changes uniformly, and the two have a good linear relationship. When the object plane P is a plane, the corresponding image plane Q is also a plane. The formula for calculating the angle θ between the image plane Q of the oblique axis optical microscope and the plane perpendicular to the optical axis is shown in equation (2): Equation (2) Where θ represents the angle between the image plane Q and the plane perpendicular to the optical axis. Indicates the focal length of the first lens group. The focal length of the second lens group is represented by u, the object distance by v, the image distance by α, the angle between the optical axis of the lens and the object plane P, the system magnification by β, the field of view by FOV, and v- This indicates the degree of change in image distance Δv based on the 60mm baseline of this embodiment. For example, in... Figure 1 In the embodiment shown, when the image distance v becomes 57.171 mm, the corresponding included angle θ can be calculated as 63.435° using equation (2).

[0048] It should be noted that those skilled in the art can adjust the magnification or optical axis tilt angle of the optical lens according to the actual situation. New embodiments resulting from changes in the magnification or optical axis tilt angle of the optical lens are also within the protection scope of this utility model.

[0049] Figure 2 This is a dot plot of different fields of view of an oblique-axis optical microscope according to an embodiment of the present invention. Figure 2 The focusing of light with wavelengths of 0.55, 0.45, and 0.65 nm at the focal point is shown under different object plane fields of view. The object plane field of view of field (1) is 1 mm, the object plane half field of view of field (2) is 0 mm, and the on-axis field of view of field (3) is -1 mm. The test data are as follows: Airy disk radius (diffraction limit) is 5.591 μm, RMS radius (root mean square) of field (1) is 1.516 μm, GEO radius (maximum) is 3.581 μm, RMS radius of field (2) is 1.661 μm, GEO radius is 3.126 μm, and RMS radius of field (3) is 1.516 μm and GEO radius is 3.581 μm.

[0050] The RMS radius, also known as the root mean square spot radius, is an indicator used to describe the size of a light beam. It is the spot radius obtained by taking the square root of the second average of the light intensity distribution. The GEO radius (Geometric Optical Radius) represents the radius of the smallest central circle that contains all light rays. Specifically, the GEO radius is the radius of the smallest central circle that allows all light rays to fall within its range. Figure 2 It can be seen that the focused spots of light of different wavelengths in different fields of view are all within the Airy disk range, indicating that the oblique axis optical microscope of this embodiment has excellent focusing effect, and that the aberration control of the oblique axis optical microscope of this embodiment is good.

[0051] Figure 3 This is a modulation transfer function curve of a microscope objective lens according to an embodiment of the present invention. Figure 3 The ordinate represents the magnitude of the optical transfer function (OTF), and the abscissa represents the spatial frequency, with units of lp / mm. The outermost line is the transfer function curve of the system under diffraction-limited conditions. For example... Figure 3As shown, in this embodiment of the oblique-axis optical microscope, when the object plane field of view is 1mm, 0mm, and -1mm, the transfer function curves of light of different wavelengths in the meridional and sagittal planes show that the on-axis field of view transfer function curve and the off-axis field of view transfer function curve are close to the diffraction limit, indicating that the imaging contrast of the optical system across the entire field of view is very high and the imaging layering is distinct.

[0052] Figure 4 This is a field curvature distortion diagram of a microscope objective lens according to an embodiment of the present invention. Figure 4 The left side of the graph is the field curvature diagram. The vertical axis represents the field of view in the direction of the incident light from the objective lens, and the horizontal axis represents the field curvature value, in millimeters. Figure 4 The right-hand side of the graph shows the distortion plot. The vertical axis represents the image-side field of view during imaging, and the horizontal axis represents the distortion percentage. The data obtained when testing the field curvature plot are as follows: maximum field of view 1.000 mm, sagittal field curvature 0.0647 mm, meridional field curvature 0.0356 mm. The data obtained when testing the distortion plot are as follows: maximum field of view 1.000 mm, maximum distortion 0.0357%. (The text repeats itself here.) Figure 4 As shown, the field curvature values ​​in both the meridional and sagittal planes at each wavelength are below 0.07 mm, resulting in clear imaging across the entire field of view without introducing additional field curvature. The distortion across the entire field of view at each wavelength is within 0.04%, indicating good distortion correction and excellent imaging performance.

[0053] In summary, the oblique-axis optical microscope of this invention, by setting the specific parameters and structure of each lens, can achieve a large magnification and high resolution while taking pictures at an angle, thereby meeting the shooting needs under special circumstances.

[0054] Those skilled in the art should understand that, unless otherwise specified, the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," "clockwise," and "counterclockwise" used to indicate orientation or positional relationships in the embodiments of this utility model are merely for the convenience of describing and understanding the technical solution of this utility model, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0055] The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," etc., may explicitly or implicitly include at least one of that feature, that is, include one or more of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. When a feature "includes or contains" one or more of the features it encompasses, unless otherwise specifically described, this indicates that other features are not excluded and may be further included.

[0056] Unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art should be able to understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0057] Furthermore, in the description of this embodiment, "above" or "below" the second feature can include direct contact between the first and second features, or it can include contact between the first and second features through another feature between them. That is, in the description of this embodiment, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "below" of the second feature can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0058] In the description of this embodiment, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] Therefore, those skilled in the art should recognize that although many exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all such other variations or modifications.

Claims

1. An oblique-axis optical microscope, characterized in that, include: A first mirror group and a second mirror group are arranged coaxially from the object side to the image side, and the optical axis is inclined to the object surface; The first lens group includes a first lens group, a third lens, and a second lens group; The second lens group includes a third lens group, an eighth lens, and a fourth lens group; The third lens has a convex surface facing both the object side and the image side; The eighth lens has a convex surface facing both the object side and the image side; The first lens group, the second lens group, the third lens group, and the fourth lens group each include at least two lenses, and the at least two lenses in each lens group have different refractive indices; The first lens group has a concave surface facing the object and a convex surface facing the image. The second lens group has a concave surface facing the object and a convex surface facing the image; the third lens group has a convex surface facing the object and a concave surface facing the image; the fourth lens group has a convex surface facing the object and a concave surface facing the image.

2. The oblique-axis optical microscope according to claim 1, characterized in that, The first lens group is a cemented doublet lens, including a first lens and a second lens starting from the object side; the first lens is a meniscus positive lens, which is concave when facing the object side and convex when facing the image side; the second lens is a meniscus negative lens, which is concave when facing the object side and convex when facing the image side. The second lens group is a cemented doublet lens, including a fourth lens and a fifth lens starting from the object side; the fourth lens is a biconcave lens, with a concave surface facing the object side and a concave surface facing the image side; the fifth lens is a biconvex lens, with a convex surface facing the object side and a convex surface facing the image side. The third lens group is a cemented doublet lens, including a sixth lens and a seventh lens starting from the object side; the sixth lens is a biconvex lens, with a convex surface facing the object side and a convex surface facing the image side; The seventh lens is a biconcave lens, with a concave surface facing both the object and image sides; The fourth lens group is a cemented doublet lens, including a ninth lens and a tenth lens starting from the object side; the ninth lens is a meniscus negative lens, which is convex when facing the object side and concave when facing the image side; the tenth lens is a meniscus positive lens, which is convex when facing the object side and concave when facing the image side.

3. The oblique-axis optical microscope according to claim 2, characterized in that, The first lens is made of H-FK71 material; The second lens is made of H-TF5 material; The third lens is made of H-ZPK5 material; The fourth lens is made of H-ZLAF68C material; The fifth lens is made of H-ZBAF20 material; The sixth lens is made of BAF5 material; The seventh lens is made of H-ZLAF68B material; The eighth lens is made of H-ZPK7 material; The ninth lens is made of TF3 material; The tenth lens is made of H-FK95N material.

4. The oblique-axis optical microscope according to claim 3, characterized in that, The object-facing surface of the first lens is the first mirror surface, the cemented surface of the first lens and the second lens is the second mirror surface, and the image-facing surface of the second lens is the third mirror surface. The object-facing surface of the third lens is the fourth mirror surface, and the image-facing surface of the third lens is the fifth mirror surface. The object-facing surface of the fourth lens is the sixth mirror surface, the cemented surface of the fourth lens and the fifth lens is the seventh mirror surface, and the image-facing surface of the fifth lens is the eighth mirror surface. The object-facing surface of the sixth lens is the ninth mirror surface, the cemented surface of the sixth lens and the seventh lens is the tenth mirror surface, and the image-facing surface of the seventh lens is the eleventh mirror surface. The object-facing surface of the eighth lens is the twelfth mirror surface, and the image-facing surface of the eighth lens is the thirteenth mirror surface. The object-facing surface of the ninth lens is the fourteenth mirror surface, the cemented surface of the ninth and tenth lenses is the fifteenth mirror surface, and the image-facing surface of the tenth lens is the sixteenth mirror surface. The radii of curvature of the first, second, third, fifth, sixth, eighth, tenth, and thirteenth mirrors are negative; the radii of curvature of the fourth, seventh, ninth, eleventh, twelfth, fourteenth, fifteenth, and sixteenth mirrors are positive.

5. The oblique-axis optical microscope according to claim 4, characterized in that, The radius of curvature of the first mirror is -39.41±0.01mm; The radius of curvature of the second mirror is -8.89±0.01mm; The radius of curvature of the third mirror is -19.38±0.01mm; The radius of curvature of the fourth mirror is 48.07 ± 0.01 mm; The radius of curvature of the fifth mirror is -28.14 ± 0.01 mm; The radius of curvature of the sixth mirror is -103.34 ± 0.01 mm; The radius of curvature of the seventh mirror is 16.13 ± 0.01 mm; The radius of curvature of the eighth mirror is -50.86±0.01mm; The radius of curvature of the ninth mirror is 42.62 ± 0.01 mm; The radius of curvature of the tenth mirror is -34.51 ± 0.01 mm; The radius of curvature of the eleventh mirror is 142.84 ± 0.01 mm; The radius of curvature of the twelfth mirror is 167.78 ± 0.01 mm; The radius of curvature of the thirteenth mirror is -50.96±0.01mm; The radius of curvature of the fourteenth mirror is 36.17 ± 0.01 mm; The radius of curvature of the fifteenth mirror is 17.82 ± 0.01 mm; The radius of curvature of the sixteenth mirror is 77.63±0.01mm.

6. The oblique-axis optical microscope according to claim 5, characterized in that, The aperture of the first mirror is 8.38 mm; The aperture of the second mirror is 8.87 mm; The aperture of the third mirror is 9.83 mm; The aperture of the fourth mirror is 10.29 mm; The aperture of the fifth mirror is 10.42 mm; The aperture of the sixth mirror is 8.56 mm; The aperture of the seventh mirror is 8.49 mm; The aperture of the eighth mirror is 8.54 mm; The aperture of the ninth mirror is 9.44 mm; The aperture of the tenth mirror is 9.34 mm; The aperture of the eleventh mirror is 9.35 mm; The aperture of the twelfth mirror is 10.54 mm; The aperture of the thirteenth mirror is 10.61 mm; The aperture of the fourteenth mirror is 10.46 mm; The aperture of the fifteenth mirror is 10.10 mm; The aperture of the sixteenth mirror is 9.59 mm.

7. The oblique-axis optical microscope according to claim 6, characterized in that, The mirror distance between the first mirror and the second mirror is 2.94 mm; The mirror distance between the second mirror and the third mirror is 2.2 mm; The mirror distance between the third mirror and the fourth mirror is 1mm; The mirror distance between the fourth mirror and the fifth mirror is 2.83 mm; The mirror distance between the fifth mirror and the sixth mirror is 14.79 mm; The mirror distance between the sixth mirror and the seventh mirror is 2.18 mm; The mirror distance between the seventh mirror and the eighth mirror is 2.04 mm; The mirror distance between the eighth mirror and the ninth mirror is 52.85 mm; The mirror distance between the ninth mirror and the tenth mirror is 2.83 mm; The mirror distance between the tenth mirror and the eleventh mirror is 0.86 mm; The mirror distance between the eleventh mirror and the twelfth mirror is 18.19 mm; The mirror distance between the twelfth and thirteenth mirrors is 4.17 mm; The mirror distance between the thirteenth mirror and the fourteenth mirror is 1mm; The mirror distance between the fourteenth mirror and the fifteenth mirror is 1.82 mm; The mirror distance between the fifteenth mirror and the sixteenth mirror is 4.98 mm.

8. The oblique-axis optical microscope according to claim 4, characterized in that, Also includes An aperture stop is disposed between the second lens group and the third lens group; The aperture of the aperture is 7.22 mm; The mirror distance between the aperture and the eighth mirror is 19.95 mm, and the mirror distance between the aperture and the ninth mirror is 32.9 mm.

9. The oblique-axis optical microscope according to claim 1, characterized in that, The relationship between the object distance and image distance of the oblique axis optical microscope is as follows: Among them, the Indicates the focal length of the first lens group, the The focal length of the second lens group is represented by u, the object distance is represented by u, and the image distance is represented by v.

10. The oblique-axis optical microscope according to claim 9, characterized in that, The formula for calculating the angle between the image plane of the oblique-axis optical microscope and the plane perpendicular to the optical axis is as follows: Where θ represents the angle between the image plane and the plane perpendicular to the optical axis, the Indicates the focal length of the first lens group, the The focal length of the second lens group is represented by u, the object distance is represented by v, the image distance is represented by α, the angle between the optical axis of the lens and the object plane is represented by β, the system magnification is represented by β, and the field of view (FOV) is represented by FOV.

Images