Surgical microscope continuous zoom 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] This invention claims priority based on Chinese Patent Application No. 202211587619.8 filed with the Chinese Patent Office on December 12, 2022, and incorporates all the descriptions set forth in that application into this invention.

[0002] This disclosure relates to the fields of optical technology and surgical microscope technology, and relates to, for example, a surgical microscope continuous zoom system and a surgical microscope applicable to an ophthalmic surgery scenario.

Background Art

[0003] A surgical microscope continuous zoom system is an important part of a surgical microscope optical system that provides the continuous zoom function of a surgical microscope system.

Summary of the Invention

Problems to be Solved by the Invention

[0004] If the movement law curves of the zoom lens group and the compensation lens group of a surgical microscope continuous zoom system are not reasonably designed, it will cause discontinuous zoom of the surgical microscope system. The discontinuous zoom of the system will further cause jumps in the field of view when the field of view of the object plane changes, giving discomfort to the observer. Or, if the movement law curves of the zoom lens group and the compensation lens group of a surgical microscope continuous zoom system are not reasonably designed, it may increase the difficulty of the mechanical design of the surgical microscope. When the difficulty of the mechanical design of the surgical microscope increases, due to substandard mechanical design, mechanical jamming phenomena will occur during the zooming of the system.

Means for Solving the Problems

[0005] According to the first aspect, the present disclosure provides a surgical microscope continuous zoom system applied to a surgical microscope. The surgical microscope has a zoom cam. The continuous zoom system includes a front fixed lens group, a zoom lens group, a compensation lens group, a first rear fixed lens group, and a second rear fixed lens group provided in sequence along the principal optical axis. The zoom 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 linearly and continuously change the system focal length value by driving the zoom cam. The zoom cam has a first cam curve and a second cam curve. Both the first cam curve and the second cam curve are exponential curves. The zoom lens group moves according to the law of the first cam curve, and the compensation 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 including a zoom cam having a first cam curve and a second cam curve, and the surgical microscope continuous zoom system according to the first aspect above.

Brief Description of the Drawings

[0007]

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Figure 2B

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DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Parts not related to the description of the exemplary embodiments are omitted from the accompanying drawings.

[0009] In the present disclosure, for example, terms such as "comprising" or "having" are meant to indicate the presence of the features, members, parts, or combinations thereof disclosed herein, and are not intended to exclude the presence or possibility of addition of one or more other features, members, parts, or combinations thereof.

[0010] Hereinafter, the present disclosure will be described in combination with embodiments with reference to the accompanying drawings.

[0011] An embodiment of the present disclosure provides an operating microscope including an ophthalmic surgical microscope.

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

[0013] As shown in FIG. 1, the operating microscope includes a zoom cam 1 and an operating microscope continuous zoom system 2.

[0014] The zoom cam 1 has a cylindrical structure, and the zoom cam 1 has a first cam curve and a second cam curve. Both the first cam curve and the second cam curve 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 includes a front fixed lens group 21, a zoom 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 provided in order from the image side to the object side along the principal optical axis.

[0016] When the zoom cam 1 rotates, the zoom lens group 22 and the compensation lens group 23 are driven to move simultaneously along the principal 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 linearly and continuously changed. The zoom 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. The first cam curve and the second cam curve in the zoom cam 1 are both obtained by simulation based on the optical structure and optical parameters of the surgical microscope continuous zoom system 2.

[0017] According to the embodiments of the present disclosure, since both the first cam curve and the second cam curve are designed as smooth exponential curves, the difficulty of the mechanical design of the zoom cam 1 is reduced. By using the zoom cam 1 having such a cam curve, the surgical microscope does not cause the phenomenon of mechanical jamming during continuous zooming due to defects in the mechanical design of the zoom cam 1.

[0018] In this way, only by the cooperation between the zoom cam 1 and the surgical microscope continuous zoom system 2, continuous focus-free zooming of the surgical microscope system can be realized, and furthermore, continuous change of the field of view range of the object plane can be realized, without giving the user (for example, an ophthalmic surgeon) the discomfort caused by the jump of the field of view of the object plane, reducing the difficulty of the mechanical design of the zoom cam 1, and eliminating the phenomenon of mechanical jamming due to defects in the mechanical design of the zoom cam 1.

[0019] The optical structure and optical parameters 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-described surgical microscope.

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

[0022] As shown in FIG. 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 includes a front fixed lens group 21, a zoom 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 provided along the principal axis from the image side to the object side.

[0023] The zoom lens group 22 and the compensation lens group 23 can move simultaneously along the principal 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. Exemplarily, the zoom lens group 22 and the compensation lens group 23 can move simultaneously in the same direction along the principal axis by driving the zoom cam 1.

[0024] The zoom cam 1 has a first cam curve and a second cam curve. 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 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 described repeatedly in the present disclosure.

[0026] According to an embodiment of the present disclosure, the surface of the object to be observed (for example, the retina surface of a human eye) is located on the object-side focal plane of the objective lens, and the light rays emitted from the surface of the object to be observed pass through the objective lens and then emit a parallel beam. After passing through the continuous zoom system 2, the parallel beam is also emitted as a parallel beam. Then, the parallel beam is converged by an auxiliary lens group (for example, a beam splitter, a lens group in the lens barrel, an eyepiece lens group, etc.) disposed on the image side of the continuous zoom system 2 to the focal plane on the image side of the eyepiece lens group. Thereby, the observer can observe the microscopic image of the surface of the object to be observed.

[0027] In this way, when the surgical microscope is continuously zoomed by the continuous zoom system 2, since the focal length value of the surgical microscope system changes linearly and continuously, the field of view of the surface of the object to be observed also changes linearly and continuously, that is, there is no jump in the field of view within the field of view range of the surface of the object to be observed. Therefore, the discomfort of the observer due to the jump in the field of view can be eliminated. Further, 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 does not cause a mechanical jam phenomenon during continuous zooming due to a defect in the mechanical design of the zoom cam 1.

[0028] According to an embodiment of the present disclosure, as shown in FIGS. 2A and 2B, the front fixed lens group 21 is a double cemented lens including a first lens 211 and a second lens 212. The first lens 211 and the second lens 212 are sequentially provided along the principal axis from the image side to the object side, and the system focal length value has a positive correlation with the distance from the compensation lens group 23 to the center of the second lens 212 in the front fixed lens group 21.

[0029] According to an embodiment of the present disclosure, the system focal length value has a positive correlation with the center distance from the center of the compensation lens group 23 to the center of the second lens 212 in the front fixed lens group 21. In this way, it can be ensured that the focal length value of the surgical microscope system changes linearly and continuously, and it can be realized that the field of view range of the surface of the object to be observed changes linearly and continuously.

[0030] Exemplarily, the formula according to which the system focal length value changes with the movement of the zoom lens group 22 and the compensation lens group 23 can be expressed as f(x) = -92.32x - 326.4. Here, x represents the center distance from the center of the compensation lens group 23 to the center of the second lens 212 of the front fixed lens group 21, and f(x) represents the system focal length value. When the surgical microscope system zooms, since the system focal length value f(x) is close to infinity, the surgical microscope continuous zoom system is also called a continuous focus-free zoom system of the surgical microscope.

[0031] According to an embodiment of the present 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 an embodiment of the present disclosure, as shown in FIGS. 2A and 2B, the zoom lens group 22, the compensation lens group 23, and the first rear fixed lens group 24 are all double-adhesive lenses, and the second rear fixed lens group 25 is a meniscus single lens.

[0033] According to an embodiment of the present disclosure, the surgical microscope continuous zoom system 2 is designed with two rear fixed lens groups, namely, the first rear fixed lens group 24 which is a double-adhesive lens, and the second rear fixed lens group 25 which is a meniscus single lens.

[0034] In this way, in addition to the first rear fixed lens group 24, a second rear fixed lens group 25 with a meniscus single lens structure is also added. By turning the concave surface of the meniscus single lens toward the image side and the convex surface toward the object side, the beam radiated from the surgical microscope objective lens can be converged, and the spherical aberration of the imaging optical path of the microscope can be reduced. The numerical aperture (NA) of the continuous zoom system 2 and the auxiliary lens group (for example, the lens group in the lens barrel, etc.) can be reduced. Furthermore, in order to ensure the continuous zoom of the surgical microscope, by simultaneously reducing the volume of the entire surgical microscope and the proportion of the surgical microscope occupying the surgical space, it contributes to the layout of the surgical space and makes the surgery easier.

[0035] According to an embodiment of the present disclosure, as shown in FIG. 2B, the zoom lens group 22 is a double adhesive lens including a third lens 221 and a fourth lens 222, the compensation lens group 2 is a double adhesive lens including a fifth lens 231 and a sixth lens 232, the first rear fixed lens group 24 is a double adhesive lens including a seventh lens 241 and an eighth lens 242, and the first lens 211 to the eighth lens 242 are sequentially provided 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 all 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 the present disclosure, the first lens 211 to the eighth lens 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 facing the image side is convex, and the lens surface facing the object side is also convex. The lens surface of the eighth lens 242 facing the image side is concave, and the lens surface facing the object side is convex.

[0037] In this way, by designing the front fixed lens group 21, the zoom lens group 22, the compensation lens group 23, and the first rear fixed lens group 24 in the continuous zoom system 2 as double adhesive lenses, it is possible to eliminate the reflection loss on both surfaces of the lens, prevent total reflection in the air gap, and easily correct the off-axis image quality and the axial chromatic aberration. At the same time, these double adhesive lenses are designed using the above optical glass materials, that is, the optical glass materials of these double adhesive lenses all use a combination of high refractive index and low Abbe number, or low refractive index and high Abbe number to achieve the purpose of removing chromatic aberration and ensuring the imaging quality of the microscope. Also, compared with the related art, this embodiment improves the effect of removing chromatic aberration.

[0038] That is, according to the embodiments of the present disclosure, the front fixed lens group 21, the zoom lens group 22, the compensation lens group 23, and the first rear fixed lens group 24 in the continuous zoom system 2 adopt the design of double adhesive lenses, and as the optical glass materials of these double adhesive lenses, the above-mentioned optical glass materials are adopted to achieve both the removal of chromatic aberration of the microscope and the improvement of imaging quality.

[0039] In this way, by improving the effect of removing chromatic aberration, the imaging resolution can be increased, enabling the doctor to obtain clear images with suppressed color distortion during the operation, thereby improving the safety during the operation.

[0040] According to an embodiment of the present disclosure, the refractive index and Abbe number of the above optical glass material are shown in Table 1.

Table 1

[0041] According to an embodiment of the present 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, the focal lengths of the third lens 221 and the fourth lens 222 are both negative values, the focal lengths of the fifth lens 231 and the sixth lens 232 are both negative values, 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.

[0042] According to an embodiment of the present 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 compensation lens group 23 are both negative values, and the focal lengths of the first rear fixed lens group 24 and the second rear fixed lens group 25 are both positive values.

[0043] That is, the front fixed lens group 21 has a positive refractive power and is formed by adhering the first lens 211 with positive refractive power and the second lens 212 with negative refractive power. The variable magnification lens group 22 has a negative refractive power and is formed by adhering the third lens 221 with negative refractive power and the fourth lens 222 with negative refractive power. The compensation lens group 23 has a negative refractive power and is formed by adhering the fifth lens 231 with negative refractive power and the sixth lens 232 with negative refractive power. The first rear fixed lens group 24 has a positive refractive power and is formed by adhering the seventh lens 241 with positive refractive power and the eighth lens 242 with negative refractive power. In this way, a continuous zoom system 2 with a five-piece configuration of "positive-negative-positive" can be obtained.

[0044] According to an embodiment of the present disclosure, the focal length of the zoom lens group 22 is M times the focal length of the compensation 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 a value greater than 1 and less than 2. For example, M = 1.2 and N = 0.8.

[0045] Exemplarily, referring to FIGS. 2A and 2B, the radii of curvature and the central thicknesses of the different lenses of the continuous zoom system 2 are shown in Table 2.

Table 2

[0046] As shown in FIG. 2A, the lens surfaces in the continuous zoom system 2 are, in order from left to right, surface 1, surface 2, ··· surface 14.

[0047] Exemplarily, as shown in FIG. 3, a, b, and c respectively show the optical structures in the large, medium, and small fields of view of the surgical microscope continuous zoom system 2 of the present embodiment. Referring to FIG. 3, the changes in the air gap between the zoom lens group 22 and the compensation lens group 23 are shown in Table 3.

Table 3

[0048] As shown in FIG. 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 FIG. 3, when the zoom lens group 22 and the compensation lens group 23 move simultaneously in the same direction along the principal optical axis, thickness 3, thickness 6, and thickness 9 change simultaneously, thereby realizing the function of continuously changing the field of view range and changing the zoom ratio. According to an embodiment of the present disclosure, for example, the continuous zoom system 2 can reach a zoom 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 FIG. 4, the simulation curve L1 and the simulation curve L2 respectively represent the first cam curve and the second cam curve of the surgical microscope continuous zoom system 2 according to the present embodiment. That is, the simulation curve L1 represents the movement law curve of the zoom lens group 22, and the simulation curve L2 represents the movement 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 FIG. 5, the simulation curve L3 represents the change curve of the system focal length value of the continuous zoom system 2 according to the present embodiment. Since it is a curve extremely close to a straight line, the system focal length value in the present embodiment changes almost completely linearly. FIG. 6 is a grid diagram of distortion in the case of a small field of view according to an embodiment of the present disclosure. FIG. 7 is a grid diagram of distortion in the case of a large field of view according to an embodiment of the present disclosure. As can be seen, in the present embodiment, the imaging distortion in the case of a small field of view is small, and the imaging distortion in the case of a large field of view is large. FIG. 8 is a diagram showing the resolution situation of different frequency bands in the case of high-magnification imaging according to an embodiment of the present disclosure. As can be seen, in this embodiment, when the optical transfer function modulus value is 0.2, the resolution of light of different colors can reach 11 line pairs / mm.

Explanation of Signs

[0051] 1 Zoom cam, 2 Continuous zoom system, 21 Front fixed lens group, 22 Zoom lens group, 23 Compensation 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 surgical microscope continuous zoom system applied to a surgical microscope, wherein the surgical microscope is provided with a zoom cam (1), and the continuous zoom system (2) includes a front fixed lens group (21), a zoom lens group (22), a compensation lens group (23), a first rear fixed lens group (24), and a second rear fixed lens group (25) provided in order along the principal optical axis, the zoom 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) 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, 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 compensation lens group (23) moves according to the law of the second cam curve A surgical microscope continuous zoom system.

2. The front fixed lens group (21) is a double-adhesive lens including a first lens (211) and a second lens (212), the first lens (211) and the second lens (212) are provided in order along the principal optical axis from the image side to the object side, and there is a positive correlation between the system focal length value and the distance from the compensation lens group (23) to the center of the second lens (212) of the front fixed lens group (21). The surgical microscope continuous zoom system according to Claim 1.

3. The zoom lens group (22), the compensation lens group (23), and the first rear fixed lens group (24) are all double-adhesive lenses, and the second rear fixed lens group (25) is a meniscus single lens. The surgical microscope continuous zoom system according to Claim 2.

4. The zoom lens group (22) is a double cemented lens including a third lens (221) and a fourth lens (222), the compensating lens group (23) is a double cemented lens including a fifth lens (231) and a sixth lens (232), the first rear fixed lens group (24) is a double cemented lens including a seventh lens (241) and an eighth lens (242), the first lens (211) to the eighth lens (242) are provided 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 all 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 The surgical microscope continuous zoom system according to claim 3

5. Each of the first lens (211) to the eighth lens (242) is a double spherical lens The surgical microscope continuous zoom 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 lengths of the third lens (221) and the fourth lens (222) are both negative values, the focal lengths of the fifth lens (231) and the sixth lens (232) are also both negative values, 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 zoom system according to claim 4

7. The focal length of the front fixed lens group (21) is a positive value, the focal lengths of the zoom lens group (22) and the compensating lens group (23) are both negative values, and the focal lengths of the first rear fixed lens group (24) and the second rear fixed lens group (25) are both positive values The surgical microscope continuous zoom system according to claim 1

8. The zoom 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 zoom system according to claim 1

9. The focal length of the variable magnification lens group (22) is M (M > 1) times the focal length of the compensating lens group (23), and / or the focal length of the front fixed lens group (21) is N (N < 1) times the combined focal length of the first rear fixed lens group (24) and the second rear fixed lens group (25), satisfying at least one of the above conditions. The surgical microscope continuous zoom system according to claim 1.

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

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