Surgical microscope continuous magnification system and surgical microscope

Abstract

It is a surgical microscope and a continuous zoom system for a surgical microscope. The continuous zoom system is applied to the surgical microscope. The surgical microscope is provided with a zoom cam (1). The continuous zoom system (2) includes a front fixed lens group (21), a zoom lens group (22), a compensating lens group (23), a first rear fixed lens group (24), and a second rear fixed lens group (25) that are sequentially provided along the principal optical axis. The zoom lens group (22) and the compensating lens group (23) move simultaneously along the principal optical axis between the front fixed lens group (21) and the first rear fixed lens group (24) so as to linearly and continuously change the system focal length value by driving the zoom cam (1). The zoom cam (1) has a first cam curve and a second cam curve, and both the first cam curve and the second cam curve are exponential curves. The zoom lens group (22) moves according to the law of the first cam curve, and the compensating lens group (23) moves according to the law of the second cam curve.

Description

[Technical Field]

[0001] The invention of the present application claims priority based on the Chinese Patent Application No. 202211587619.8 filed with the China National Intellectual Property Administration on December 12, 2022, and incorporates all the contents described in said application into the invention of the present application by reference.

[0002] The present disclosure relates to the fields of optical technology and surgical microscope technology, for example, to a continuous zoom system for a surgical microscope and a surgical microscope applicable to ophthalmic surgery scenarios. [Background Art]

[0003] A continuous zoom system for a surgical microscope is an important part of an optical system for a surgical microscope that implements a continuous zoom function of the surgical microscope system. [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] If the motion law curves of the zoom lens group and the compensation lens group of a continuous zoom system for a surgical microscope are not reasonably designed, it will cause discontinuous zooming of the surgical microscope system, and the discontinuous zooming of the system will further cause field jumping when the field of view on the object plane changes, causing discomfort to the observer; or, if the motion law curves of the zoom lens group and the compensation lens group of a continuous zoom system for a surgical microscope are not reasonably designed, it may increase the difficulty of mechanical design of the surgical microscope, and when the difficulty of mechanical design of the surgical microscope increases, mechanical jamming will occur during zooming of the system due to substandard mechanical design. [Means for Solving the Problem]

[0005] According to the first aspect, the present disclosure provides a surgical microscope continuous magnification system applicable to a surgical microscope, wherein the surgical microscope has a zoom cam, and the continuous magnification system comprises a front fixed lens group, a magnification lens group, a compensating lens group, a first rear fixed lens group, and a second rear fixed lens group, all arranged in order along the principal optical axis. The variable magnification lens group and the compensation lens group are configured to move simultaneously along the principal optical axis between the front fixed lens group and the first rear fixed lens group so as to change the system focal length value linearly and continuously by the drive of the zoom cam. The zoom cam has a first cam curve and a second cam curve, both of which are exponential curves, the variable magnification lens group moves according to the law of the first cam curve, and the compensating lens group moves according to the law of the second cam curve.

[0006] According to the second aspect, the present disclosure provides a surgical microscope comprising a zoom cam having a first cam curve and a second cam curve, and the surgical microscope continuous magnification system according to the first aspect. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram of a surgical microscope continuous magnification system and zoom cam according to an embodiment of the present disclosure. [Figure 2A] This is an optical structure diagram of a continuous magnification system for a surgical microscope according to an embodiment of the present disclosure. [Figure 2B] This is an optical structure diagram of another continuous magnification system for a surgical microscope according to an embodiment of the present disclosure. [Figure 3] This is a schematic diagram of the optical structure in the large field, medium field, and small field of view of the surgical microscope continuous magnification system according to an embodiment of the present disclosure. [Figure 4] This is a diagram of a cam curve according to an embodiment of the present disclosure. [Figure 5] This is a graph showing the change in system focal length according to the embodiment of this disclosure. [Figure 6] This is a grid diagram of distortion in the case of a small field of view according to an embodiment of the present disclosure. [Figure 7] This is a grid diagram of distortion in the case of a large field of view according to an embodiment of the present disclosure. [Figure 8] This diagram shows the resolution in different frequency bands when high-magnification imaging is performed according to the embodiments of this disclosure. [Modes for carrying out the invention]

[0008] The exemplary embodiments of this disclosure will be described in detail below with reference to the attached drawings. The attached drawings omit parts that are not relevant to the description of the exemplary embodiments.

[0009] In this disclosure, terms such as “includes” or “having” mean to indicate the presence of features, components, parts or combinations thereof disclosed herein, and are not intended to exclude the possibility of the presence or addition of one or more other features, components, parts or combinations thereof.

[0010] The embodiments of this disclosure will be described below with reference to the attached drawings.

[0011] Embodiments of this disclosure provide a surgical microscope equipped with an ophthalmic surgical microscope.

[0012] Figure 1 is a schematic diagram of a surgical microscope continuous magnification system and zoom cam according to an embodiment of the present disclosure.

[0013] As shown in Figure 1, the surgical microscope comprises a zoom cam 1 and a surgical microscope continuous magnification system 2.

[0014] The zoom cam 1 has a cylindrical structure and has a first cam curve and a second cam curve. Both the first and second cam curves are exponential curves and are engraved as grooves on the outer wall surface of the cylindrical body of the zoom cam 1.

[0015] The surgical microscope continuous zoom system 2 comprises a front fixed lens group 21, a variable power lens group 22, a compensation lens group 23, a first rear fixed lens group 24, and a second rear fixed lens group 25, which are sequentially arranged from the image side to the object side along the main optical axis.

[0016] When the zoom cam 1 rotates, the variable power lens group 22 and the compensation lens group 23 are driven and simultaneously move along the main optical axis between the front fixed lens group 21 and the first rear fixed lens group 24, so that the system focal length value can be changed linearly and continuously. The variable power lens group 22 moves according to the law of the first cam curve described above, and the compensation lens group 23 moves according to the law of the second cam curve described above. Both the first cam curve and the second cam curve in the zoom cam 1 are obtained through simulation based on the optical structure and optical parameters of the surgical microscope continuous zoom system 2.

[0017] According to an embodiment of the present disclosure, both the first cam curve and the second cam curve are designed as smooth exponential curves, so the difficulty of mechanical design of the zoom cam 1 is reduced. By using the zoom cam 1 having such cam curves, the surgical microscope does not experience mechanical jamming during continuous zooming caused by defects in the mechanical design of the zoom cam 1.

[0018] In this way, only through the cooperation between the zoom cam 1 and the surgical microscope continuous zoom system 2 can continuous focus-free zooming of the surgical microscope system be realized, and further continuous change of the field of view range on the object plane can be realized, which does not cause discomfort to a user (e.g., an ophthalmic surgeon) caused by jump of the field of view on the object plane, reduces the difficulty of mechanical design of the zoom cam 1, and eliminates the mechanical jamming phenomenon caused by defects in the mechanical design of the zoom cam 1.

[0019] The optical structure, optical parameters, and other contents of the surgical microscope continuous zoom system 2 will be described in detail in the following embodiments, and will not be repeatedly described in the present disclosure.

[0020] Embodiments of the present disclosure further provide a continuous zoom system for a surgical microscope. The continuous zoom system for a surgical microscope is applicable to the above-mentioned surgical microscope.

[0021] Figure 2A is an optical structural diagram of a continuous zoom system for a surgical microscope according to an embodiment of the present disclosure.

[0022] As shown in Figure 2A, the continuous zoom system 2 for a surgical microscope is applied to a surgical microscope having a zoom cam 1. The continuous zoom system 2 comprises a front fixed lens group 21, a zooming lens group 22, a compensation lens group 23, a first rear fixed lens group 24, and a second rear fixed lens group 25, which are sequentially arranged along a main optical axis from an image side to an object side.

[0023] The zooming lens group 22 and the compensation lens group 23 can simultaneously move along the main optical axis between the front fixed lens group 21 and the first rear fixed lens group 24 under the drive of the zoom cam 1, so as to linearly and continuously change the focal length value of the system. Illustratively, the zooming lens group 22 and the compensation lens group 23 can simultaneously move in the same direction along the main optical axis under the drive of the zoom cam 1.

[0024] The zoom cam 1 has a first cam curve and a second cam curve, both of which are exponential curves. The zooming lens group 22 moves according to the law of the first cam curve, and the compensation lens group 23 moves according to the law of the second cam curve.

[0025] The zoom cam 1 of the present embodiment is the same as the zoom cam 1 of the above embodiment, and will not be repeatedly described in the present disclosure.

[0026] According to the embodiments of this disclosure, the surface of the object to be observed (e.g., the retinal surface of the human eye) is located at the object-side focal plane of the objective lens, and light rays emitted from the surface of the object to be observed pass through the objective lens and emit a parallel beam. This parallel beam continues to be emitted as a parallel beam even after passing through the continuous magnification system 2, and then the parallel beam is focused at the image-side focal plane of the eyepiece group by an auxiliary lens group (e.g., a beam splitter, a lens group in the microscope tube, and an eyepiece group) located on the image side of the continuous magnification system 2, thereby allowing the observer to observe a microscopic image of the surface of the object to be observed.

[0027] Thus, when a surgical microscope is continuously magnified by the continuous magnification system 2, the focal length value of the surgical microscope system changes linearly and continuously, and therefore the field of view of the object being observed also changes linearly and continuously. In other words, there is no jump in the field of view within the field of view of the object being observed, thus eliminating the discomfort to the observer caused by jumps in the field of view. Furthermore, since both the first cam curve and the second cam curve are provided as smooth exponential curves, the difficulty of the mechanical design of the zoom cam 1 is reduced. By using such a zoom cam 1, the surgical microscope is free from mechanical jams during continuous magnification due to defects in the mechanical design of the zoom cam 1.

[0028] According to embodiments of the present disclosure, as shown in Figures 2A and 2B, the front fixed lens group 21 is a double bonded lens including a first lens 211 and a second lens 212, the first lens 211 and the second lens 212 are arranged sequentially along the principal optical axis from the image side to the object side, and the system focal length value has a positive correlation with the distance from the compensating lens group 23 to the center of the second lens 212 in the front fixed lens group 21.

[0029] According to the embodiments of this disclosure, the system focal length value has a positive correlation with the central distance from the center of the compensating lens group 23 to the center of the second lens 212 in the pre-fixed lens group 21. In this way, it is possible to ensure that the focal length value of the surgical microscope system changes linearly and continuously, and to realize that the field of view of the observed object surface changes linearly and continuously.

[0030] For example, the system focal length value changes with the movement of the variable magnification lens group 22 and the compensating lens group 23, and this can be expressed by the equation f(x) = -92.32x - 326.4, where x is the central distance from the center of the compensating lens group 23 to the center of the second lens 212 of the front fixed lens group 21, and f(x) is the system focal length value. When a surgical microscope system is magnified, the system focal length value f(x) is close to infinity, so a continuous magnification surgical microscope system is also called a continuous focusless magnification surgical microscope system.

[0031] According to the embodiments of this disclosure, the lens surface of the first lens 211 facing the image side is convex, and the lens surface of the first lens 211 facing the object side is also convex. The lens surface of the second lens 212 facing the image side is concave, and the lens surface of the second lens 212 facing the object side is convex.

[0032] According to the embodiments of this disclosure, as shown in Figures 2A and 2B, the variable magnification lens group 22, the compensating lens group 23, and the first post-fixed lens group 24 are all double-bonded lenses, and the second post-fixed lens group 25 is a meniscus single lens.

[0033] According to the embodiments of this disclosure, the surgical microscope continuous magnification system 2 is designed with two post-fixation lens groups, namely, a first post-fixation lens group 24 which is a double-bonded lens, and a second post-fixation lens group 25 which is a meniscus single lens.

[0034] In this way, in addition to the first post-fixed lens group 24, a second post-fixed lens group 25 with a meniscus single-lens structure is also added. By orienting the concave surface of the meniscus single-lens toward the image side and the convex surface toward the object side, the beam emitted from the surgical microscope objective lens can be focused, reducing spherical aberration in the imaging optical path of the microscope. This reduces the numerical aperture (NA) of the continuous magnification system 2 and auxiliary lens groups (e.g., lens groups inside the microscope tube), and furthermore, in order to ensure continuous magnification of the surgical microscope, the overall volume of the surgical microscope and the proportion of the surgical microscope occupied in the surgical space are simultaneously reduced, contributing to the layout of the surgical space and making surgery easier.

[0035] According to embodiments of the present disclosure, as shown in Figure 2B, the variable magnification lens group 22 is a double-bonded lens including a third lens 221 and a fourth lens 222, the compensating lens group 2 is a double-bonded lens including a fifth lens 231 and a sixth lens 232, the first rear-fixed lens group 24 is a double-bonded lens including a seventh lens 241 and an eighth lens 242, the first lenses 211 to the eighth lenses 242 are arranged in order along the principal optical axis from the image side to the object side, the optical glass used for the first lens 211, the third lens 221 and the fifth lens 231 is H-FK61, the optical glass used for the second lens 212 is H-ZBAF20, the optical glass used for the fourth lens 222 is H-LAF3B, the optical glass used for the sixth lens 232 is H-ZF5, the optical glass used for the seventh lens 241 is H-QK3L, and the optical glass used for the eighth lens 242 is H-BAF2.

[0036] According to the embodiments of this disclosure, the first to eighth lenses 242 are all double spherical lenses. The lens surface of the first lens 211 facing the image side is convex, and the lens surface of the first lens 211 facing the object side is also convex. The lens surface of the second lens 212 facing the image side is concave, and the lens surface of the second lens 212 facing the object side is convex. The lens surface of the third lens 221 facing the image side is concave, and the lens surface facing the object side is concave. The lens surface of the fourth lens 222 facing the image side is convex, and the lens surface facing the object side is also concave. The lens surface of the fifth lens 231 facing the image side is concave, and the lens surface facing the object side is also concave. The lens surface of the sixth lens 232 facing the image side is convex, and the lens surface facing the object side is concave. The lens surface of the seventh lens 241, which faces the image side, is convex, and the lens surface facing the object side is also convex. The lens surface of the eighth lens 242, which faces the image side, is concave, and the lens surface facing the object side is convex.

[0037] Thus, by designing the front fixed lens group 21, the variable magnification lens group 22, the compensating lens group 23, and the first rear fixed lens group 24 in the continuous magnification system 2 as double-bonded lenses, reflection loss on both sides of the lens can be eliminated, total internal reflection in the air gap can be prevented, and off-axis image quality and on-axis chromatic aberration can be easily corrected. At the same time, these double-bonded lenses are designed using the above-mentioned optical glass materials, that is, the optical glass materials of these double-bonded lenses all use a combination of high refractive index and low Abbe number, or low refractive index and high Abbe number, thereby achieving the objective of eliminating chromatic aberration and ensuring the imaging quality of the microscope. Furthermore, compared to related technologies, this embodiment improves the effect of eliminating chromatic aberration.

[0038] In other words, according to the embodiments of this disclosure, the front fixed lens group 21, the variable magnification lens group 22, the compensating lens group 23, and the first rear fixed lens group 24 in the continuous variable magnification system 2 employ a double-bonded lens design, and by employing the above-mentioned optical glass material as the optical glass material for these double-bonded lenses, both the elimination of chromatic aberration in the microscope and the improvement of imaging quality are achieved.

[0039] In this way, improving the chromatic aberration reduction effect can increase the resolution of the image, allowing surgeons to obtain clear images with reduced color distortion during surgery, thereby improving safety during the procedure.

[0040] According to the embodiments of this disclosure, the refractive index and Abbe number of the optical glass material are shown in Table 1. [Table 1]

[0041] According to the embodiments of this disclosure, the focal length of the first lens 211 is a positive value, the focal length of the second lens 212 is a negative value, and the third lens 221 The focal length is a negative value, The focal length of the fourth lens 222 is Positive This is the value of the 5th lens 231 The focal length is a negative value, Focal length of lens 232 of the 6th lens is correct The values ​​are such that the focal length of the 7th lens 241 is a positive value, and the focal length of the 8th lens 242 is a negative value.

[0042] According to the embodiments of this disclosure, the focal length of the front fixed lens group 21 is a positive value, the focal lengths of the variable magnification lens group 22 and the compensating lens group 23 are both negative values, and the first rear fixed lens group 24 The focal length is a positive value, The focal length of the second rear fixed lens group 25 is negative This is the value.

[0043] In other words, the fixed front lens group 21 has a positive refractive power and is formed by bonding a first lens 211 with a positive refractive power and a second lens 212 with a negative refractive power. The variable magnification lens group 22 has a negative refractive power and is formed by bonding a third lens 221 with a negative refractive power and Positive The fourth lens 222 with a refractive power is bonded to the compensating lens group 23, which has a negative refractive power and the fifth lens 231 with a negative refractive power. Positive The sixth lens 232, which has a refractive power, is bonded to the first fixed lens group 24, which has a positive refractive power, and is formed by bonding the seventh lens 241, which has a positive refractive power, to the eighth lens 242, which has a negative refractive power. In this way, a continuous magnification system 2 with a "positive-negative-positive" five-lens configuration can be obtained.

[0044] According to embodiments of this disclosure, the focal length of the variable magnification lens group 22 is M times the focal length of the compensating lens group 23, where M is greater than 1, and / or the focal length of the front fixed lens group 21 is N times the focal length of the combination of the first rear fixed lens group 24 and the second rear fixed lens group 25, where N is less than 1. Exemplarily, M may be greater than 1 and less than 2, for example, M=1.2 and N=0.8.

[0045] For illustrative purposes, with reference to Figures 2A and 2B, the radii of curvature and central thickness of different lenses in the continuous magnification system 2 are shown in Table 2. [Table 2]

[0046] As shown in Figure 2A, the lens surfaces in the continuous magnification system 2 are, from left to right, surface 1, surface 2, ..., surface 14.

[0047] For illustrative purposes, as shown in Figure 3, a, b, and c correspond to the optical structures of the surgical microscope continuous magnification system 2 in the large, medium, and small fields of view, respectively. Referring to Figure 3, the change in the air gap between the magnification lens group 22 and the compensating lens group 23 is shown in Table 3. [Table 3]

[0048] As shown in Figure 3, thickness 3 represents the gap between A and B, thickness 6 represents the gap between B and C, and thickness 9 represents the gap between C and D.

[0049] As shown in Figure 3, when the variable magnification lens group 22 and the compensating lens group 23 move simultaneously in the same direction along the principal optical axis, the thicknesses 3, 6, and 9 change simultaneously, thereby realizing the function of continuously changing the field of view and changing the magnification ratio. According to the embodiment of this disclosure, for example, the continuous magnification system 2 can achieve a magnification ratio of 1:6, a field of view change range of 0 to 7.4°, and a pupil diameter change range of 3.4 mm to 18 mm.

[0050] As shown in Figure 4, simulation curves L1 and L2 represent the first and second cam curves of the continuous magnification system 2 for surgical microscope according to this embodiment, respectively. That is, simulation curve L1 represents the motion law curve of the magnification lens group 22, and simulation curve L2 represents the motion law curve of the compensation lens group 23. Therefore, it can be seen that the two cam curves are smooth exponential curves. As shown in Figure 5, simulation curve L3 represents the change curve of the system focal length value of the continuous magnification system 2 according to this embodiment. Since it is a curve that is very close to a straight line, the system focal length value in this embodiment changes almost perfectly linearly. Figure 6 is a grid diagram of distortion in the case of a small field of view according to an embodiment of this disclosure. Figure 7 is a grid diagram of distortion in the case of a large field of view according to an embodiment of this disclosure. As can be seen, this embodiment has small image distortion in the case of a small field of view and large image distortion in the case of a large field of view. Figure 8 is a diagram showing the resolution of different frequency bands in the case of high-magnification imaging according to an embodiment of this disclosure. As can be seen, in this embodiment, when the modulus value of the optical transfer function is 0.2, the resolution of light of different colors can reach 11 lines pair / mm. [Explanation of symbols]

[0051] 1 Zoom cam, 2 Continuous variable magnification system, 21 Front fixed lens group, 22 Variable magnification lens group, 23 Compensating lens group, 24 First rear fixed lens group, 25 Second rear fixed lens group, 211 First lens, 212 Second lens, 221 Third lens, 222 Fourth lens, 231 Fifth lens, 232 Sixth lens, 241 Seventh lens, 242 Eighth lens.

Claims

1. A continuous magnification system for surgical microscopes, applicable to surgical microscopes, The surgical microscope is equipped with a zoom cam (1), and the continuous magnification system (2) comprises a front fixed lens group (21), a magnification lens group (22), a compensating lens group (23), a first rear fixed lens group (24), and a second rear fixed lens group (25), all arranged in order along the principal optical axis. The variable magnification lens group (22) and the compensation lens group (23) are configured to move simultaneously along the principal optical axis between the front fixed lens group (21) and the first rear fixed lens group (24) in such a way that the system focal length value is changed linearly and continuously by the drive of the zoom cam (1). A first cam curve and a second cam curve are engraved on the outer wall of the zoom cam (1), and both the first and second cam curves are exponential curves, the variable magnification lens group (22) moves according to the law of the first cam curve, and the compensating lens group (23) moves according to the law of the second cam curve. The first rear fixed lens group (24) is a double bonded lens, The second rear fixed lens group (25) is a meniscus single lens, the concave surface of the meniscus single lens faces the image side, and the convex surface of the meniscus single lens faces the object side. The focal length of the front fixed lens group (21) is a positive value, the focal lengths of the variable magnification lens group (22) and the compensating lens group (23) are both negative values, the focal length of the first rear fixed lens group (24) is a positive value, and the focal length of the second rear fixed lens group (25) is a negative value. Continuous magnification system for surgical microscopes.

2. The front fixed lens group (21) is a double-bonded lens including a first lens (211) and a second lens (212), the first lens (211) and the second lens (212) are arranged sequentially along the principal optical axis from the image side to the object side, and the system focal length value and the distance from the compensating lens group (23) to the center of the second lens (212) of the front fixed lens group (21) have a positive correlation. The surgical microscope continuous magnification system according to claim 1.

3. The variable magnification lens group (22) and the compensating lens group (23) are both double-bonded lenses. The surgical microscope continuous magnification system according to claim 2.

4. The variable magnification lens group (22) is a double-bonded lens including a third lens (221) and a fourth lens (222), the compensating lens group (23) is a double-bonded lens including a fifth lens (231) and a sixth lens (232), the first rear-fixed lens group (24) is a double-bonded lens including a seventh lens (241) and an eighth lens (242), and the first lens (211) to the eighth lens (242) are arranged in order along the principal optical axis from the image side to the object side, the first lens (211), the third lens The optical glass used in the lens (221) and the fifth lens (231) is H-FK61, the optical glass used in the second lens (212) is H-ZBAF20, the optical glass used in the fourth lens (222) is H-LAF3B, the optical glass used in the sixth lens (232) is H-ZF5, the optical glass used in the seventh lens (241) is H-QK3L, and the optical glass used in the eighth lens (242) is H-BAF2. The surgical microscope continuous magnification system according to claim 3.

5. The first lens (211) to the eighth lens (242) are all double spherical lenses. The surgical microscope continuous magnification system according to claim 4.

6. The focal length of the first lens (211) is a positive value, the focal length of the second lens (212) is a negative value, the focal length of the third lens (221) is a negative value, the focal length of the fourth lens (222) is a positive value, the focal length of the fifth lens (231) is a negative value, the focal length of the sixth lens (232) is a positive value, the focal length of the seventh lens (241) is a positive value, and the focal length of the eighth lens (242) is a negative value. The surgical microscope continuous magnification system according to claim 4.

7. The variable magnification lens group (22) and the compensating lens group (23) move simultaneously in the same direction along the principal optical axis by the drive of the zoom cam (1). The surgical microscope continuous magnification system according to claim 1.

8. The focal length of the variable magnification lens group (22) is M (where M is greater than 1) times the focal length of the compensating lens group (23), and the focal length of the front fixed lens group (21) is N (where N is less than 1) times the focal length of the combination of the first rear fixed lens group (24) and the second rear fixed lens group (25), satisfying at least one of these conditions. The surgical microscope continuous magnification system according to claim 1.

9. A zoom cam (1) having a first cam curve and a second cam curve, A surgical microscope continuous magnification system (2) according to any one of claims 1 to 8, comprising: Surgical microscope.

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