Image plane consistency adjusting method of continuous zoom lens

Abstract

The invention provides an image plane consistency adjustment method for a continuous zoom lens, which is used for solving the technical problem of low installation and adjustment efficiency caused by large limitation, lack of theoretical guidance, large blindness and tedious operation in the existing image plane consistency adjustment method for a continuous zoom system. According to the image plane consistency adjustment method for the continuous zoom lens, optical design theory analysis is used as guidance of the adjustment process, and the normalized image plane out-of-focus sensitivity of the short focus and the long focus of each zoom component in the continuous zoom lens is analyzed; according to the continuous zoom lens, the zoom component needing to be adjusted is found and the axial movement amount and the movement direction of the zoom component are determined according to the amplification factor relation between the image plane defocusing amount of the zoom component sensitive in defocusing and the movement amount of the zoom component, so that image plane consistency adjustment is completed, adjustment is efficient and convenient, the imaging quality of the continuous zoom lens is effectively guaranteed, and the continuous zoom lens is suitable for large-scale popularization and application. The method can be widely applied to image plane consistency adjustment of various zoom lenses.

Description

Technical Field

[0001] The present invention relates to a calibration method for a zoom lens, and more particularly to a method for calibrating the image plane consistency of a continuous zoom lens. Background Art

[0002] At present, continuous zoom lenses have been widely used in the fields of security, surveillance, sky network, transportation, work safety, and forest fire prevention. A continuous zoom lens includes different zoom components. Since there are both moving components, such as a variable magnification group and a compensating group, and fixed components, such as a front fixed group, an intermediate fixed group, and a rear fixed group, in the zoom components, the overall assembly and adjustment are relatively complex, and fast and high-quality assembly and adjustment have always been important factors restricting the application of continuous zoom lenses.

[0003] At present, two main calibration contents are involved in the assembly process of a continuous zoom lens: 1. Calibration of the imaging quality of the continuous zoom lens. The calibration of the continuous zoom lens should ensure the system imaging quality at the image plane at each focal length position. For example, the system wave aberration or the optical transfer function MTF at the image plane at each focal length position should meet the requirements; 2. Calibration of the image plane consistency of the continuous zoom lens. Since the focal length of the continuous zoom lens continuously changes throughout the zooming process, after the overall assembly is completed, the image plane consistency throughout the zooming process should be ensured, that is, the imaging should be consistently clear throughout the zooming process. However, in the calibration of the imaging quality of the continuous zoom lens, it is mainly to control the assembly errors such as the eccentricity and tilt of the internal optical lenses of each zoom component. During the assembly process, only whether the imaging quality at the image plane corresponding to each focal length position meets the requirements is considered separately, and the imaging quality throughout the zooming process is not considered. Moreover, during the test, the system wave aberration or the optical transfer function MTF is also tested at the image plane corresponding to each focal length position. However, during the initial assembly process of the continuous zoom lens, due to the accumulation of assembly errors (such as zoom component intervals and cam curve errors), the image planes corresponding to each focal length position are not unique. Even if the imaging quality at the image plane corresponding to each focal length position meets the requirements, since there can only be a common image plane at each focal length position of the final continuous zoom lens to place the image detector, if the image plane consistency is not calibrated, the imaging cannot be consistently clear throughout the zooming process. Therefore, the calibration of the image plane consistency of the continuous zoom lens is an urgent problem to be solved.

[0004] At present, the alignment of continuous zoom lenses mostly only focuses on the calibration of their imaging quality. For example, Zhao Yue et al. published "Alignment of Zoom Optical Systems Based on Aberration Feature Analysis" in the 2nd issue of the 41st volume of "Applied Optics", which mentioned a coaxial alignment method of a zoom system based on aberration characteristic analysis, mainly introducing the calibration of the imaging quality of the zoom lens, but did not introduce the calibration of the image plane consistency of the zoom lens. Chinese Patent Publication No. CN 111650711A discloses a method for aligning a continuous zoom system, which realizes the calibration of the image plane consistency of the continuous zoom system. It achieves the image plane consistency throughout the zoom process by repeatedly adjusting the axial positions of the focusing group and the image detector. However, this calibration method has obvious limitations. It is only applicable to continuous zoom lenses with the front fixed group as the focusing group and no other fixed components between the moving components, and is not universal for other zoom structural forms with fixed components between the moving components. In addition, this method lacks theoretical guidance and has great blindness. It is necessary to repeatedly try to adjust the positions of the focusing group and the imaging detector, and the operation is cumbersome, resulting in low alignment efficiency. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problems of the existing calibration method for the image plane consistency of continuous zoom systems, which has large limitations, lacks theoretical guidance, has great blindness, and is cumbersome in operation, thereby resulting in low alignment efficiency, and to provide a calibration method for the image plane consistency of continuous zoom lenses.

[0006] To achieve the above purpose, the technical solution provided by the present invention is as follows: A calibration method for the image plane consistency of a continuous zoom lens, characterized in that it includes the following steps: Step 1, adjust the distances between the zoom components of the continuous zoom lens to meet the design requirements; Step 2, analyze the image plane defocus amount caused when each zoom component of the continuous zoom lens independently changes a certain same moving amount at the short focal position and the long focal position respectively, and the magnification ratio between the image plane defocus amount and the moving amount of the zoom component, to obtain the normalized image plane defocus sensitivity of each zoom component at short focus and long focus; according to the normalized image plane defocus sensitivity of each zoom component at short focus and long focus, take the zoom component that is sensitive to the long focal plane defocus and has the largest difference in sensitivity between the long focal plane defocus and the short focal plane defocus as the most sensitive component at long focus; Step 3, image plane consistency test; Step 3.1, build an image plane consistency test device; the image plane consistency test device includes a collimator, a resolution target plate placed at the focal plane position of the collimator, and a reading microscope coaxially placed behind the collimator; during the test, the continuous zoom lens is coaxially placed between the collimator and the reading microscope; Step 3.2: Move the continuous zoom lens to the short focal length position, and then adjust the axial position of the reading microscope until the image of the resolution test chart is the clearest. Step 3.3: Move the continuous zoom lens to the long focal length position, and observe through the reading microscope whether the imaging clarity of the resolution test chart at the long focal length position meets the preset requirements. If so, the image plane consistency meets the preset requirements, and the image plane consistency adjustment is completed; otherwise, adjust the axial position of the reading microscope until the imaging clarity of the resolution test chart at the long focal length position meets the preset requirements, record the axial movement amount and movement direction of the reading microscope, and execute Step 4. Step 4: Image plane consistency adjustment. Step 4.1: According to the axial movement amount and movement direction of the reading microscope recorded in Step 3.3, combined with the magnification ratio between the image plane defocus amount corresponding to the most sensitive component at the long focal length and the movement amount of the zoom component in Step 2, calculate the axial movement amount of the most sensitive component at the long focal length, and determine the movement direction. Step 4.2: According to the axial movement amount and movement direction of the most sensitive component at the long focal length, adjust the axial position of the most sensitive component at the long focal length, and return to Step 3.2 for cyclic adjustment until the imaging clarity of the resolution test chart at the long focal length position observed by the reading microscope meets the preset requirements when the continuous zoom lens is moved to the long focal length position in Step 3.3, and the image plane consistency adjustment is completed.

[0007] Further, before Step 1, there is also Step A: Adjust the distance between the center point of the pin on the barrel of each moving component in the continuous zoom lens and the axial vertex of the first lens in the corresponding moving component barrel to within a preset range.

[0008] Further, in Step A, the distance tolerance between the center point of the pin on the barrel of each moving component in the continuous zoom lens and the axial vertex of the first lens in the corresponding moving component barrel is less than or equal to 0.05 mm.

[0009] Further, Step 1 is specifically: The intervals between adjacent fixed components and the intervals between adjacent moving components and fixed components are adjusted according to the optical system design tolerance requirements, and the intervals between adjacent moving components are constrained according to the cam curve.

[0010] Further, in Step 2, using optical design software CODE V or ZEMAX, analyze the image plane defocus amount caused when each zoom component in the continuous zoom lens independently changes by the same movement amount at the short focal length position and the long focal length position, as well as the magnification ratio between the image plane defocus amount and the movement amount of the zoom component.

[0011] Further, in Step 2, the movement amount is taken as a positive value or a negative value; the movement amount is ±0.05 mm or ±0.1 mm.

[0012] Further, in step 3.1, the focal length of the collimator is greater than three times the telephoto focal length of the continuous zoom lens; the numerical aperture of the reading microscope is greater than the maximum numerical aperture of the continuous zoom lens.

[0013] The beneficial effects of the present invention compared with the prior art are as follows: 1. A method for adjusting the image plane consistency of a continuous zoom lens provided by the present invention uses optical design theory analysis as a guide for the alignment process. By analyzing the normalized image plane defocus sensitivity of each zoom component in the continuous zoom lens at short focus and telephoto, and combining the magnification relationship between the image plane defocus amount of the zoom component with high defocus sensitivity and the movement amount of the zoom component, the zoom component to be adjusted is found and the axial movement amount and movement direction of the zoom component are determined, avoiding the technical problems of the existing method for adjusting the image plane consistency of continuous zoom lenses, such as lack of theoretical guidance, great blindness in operation, and low assembly efficiency of zoom lenses caused by cumbersome operation. It can be widely applied to the adjustment of the image plane consistency of various continuous zoom lenses.

[0014] 2. A method for adjusting the image plane consistency of a continuous zoom lens provided by the present invention essentially studies the factors affecting the image plane consistency in the continuous zoom lens, provides guidance for alignment, avoids repeated disassembly and assembly without a clear purpose during lens assembly, not only ensures the final imaging quality of the zoom lens, but also saves assembly time, which is of great significance for improving the assembly efficiency of continuous zoom lenses and has the characteristics of simple operation, high efficiency, and practicality.

[0015] 3. The method for adjusting the image plane consistency of the continuous zoom lens provided by the present invention is not limited by the structure of the continuous zoom lens and is applicable to both continuous zoom lenses without other fixed components between moving components and continuous zoom lenses including fixed components, improving the versatility and universality of the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic flow chart of an embodiment of a method for adjusting the image plane consistency of a continuous zoom lens of the present invention; Figure 2 It is an optical path diagram of the continuous zoom lens in the embodiment of the present invention; Figure 3 It is a schematic structural diagram of the image plane consistency test device in the embodiment of the present invention; Figure 4 It is a normalized image plane defocus sensitivity diagram of each zoom component in the continuous zoom lens at short focus and telephoto in the embodiment of the present invention.

[0017] The specific reference numerals are as follows: 1 - Collimator; 2 - Resolution test chart; 3 - Continuous zoom lens; 4 - Reading microscope; 5 - Human eye observation point; 6 - Front fixed group, 7 - Zooming group, 8 - Intermediate fixed group, 9 - Compensation group, 10 - Rear fixed group. Detailed implementation mode

[0018] To make the advantages and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] A method for adjusting the image plane consistency of a continuous zoom lens, as Figure 1 shown, specifically includes the following steps: Step 1, adjustment of the interval between each moving component in the continuous zoom lens 3 and the corresponding pin.

[0020] As Figure 2 shown, in this embodiment, the continuous zoom lens 3 includes a front fixed group 6, a zooming group 7, an intermediate fixed group 8, a compensation group 9 and a rear fixed group 10. The focal length change range of the continuous zoom lens 3 is 15 mm to 300 mm, the working wavelength is 450 nm to 650 nm, and the F-number change range is F4.5 to F5.5.

[0021] Each zoom component in the continuous zoom lens 3 is installed in its respective lens barrel. For the moving components, pins are installed on the outer side of the lens barrel, and the pins are motion-constrained through the cam curve grooves in the cam barrel, so as to achieve the motion law required for zooming. In the assembly of each moving component, control the interval distance between the center point of the pin on the lens barrel of each moving component and the axial vertex of the first lens in the lens barrel of the corresponding moving component (along the optical axis direction). According to experience, the tolerance of this interval distance is generally controlled within 0.05 mm.

[0022] Step 2, adjustment of the interval between each zoom component in the continuous zoom lens 3.

[0023] In the assembly of the continuous zoom lens 3, it is necessary to adjust the distance between each zoom component. Among them, the intervals between adjacent two fixed components and the intervals between adjacent moving components and fixed components all meet the requirements of the optical system design tolerance, and the interval between adjacent two moving components is constrained according to the cam curve.

[0024] In this embodiment, the total length of the continuous zoom lens 3 is based on the telephoto position. The total length of the continuous zoom lens 3 at the telephoto position needs to be consistent with the design value. At the short focal position, the total length of the continuous zoom lens 3 is allowed to have a certain deviation from the design value, generally controlled within a total length deviation ≤ 0.2 mm.

[0025] Step 3, analysis of the normalized image plane defocus sensitivity of each zoom component at short focus and long focus.

[0026] When the image plane consistency does not meet the requirements, it is necessary to perform image plane defocus sensitivity analysis. In the optical design software CODE V or ZEMAX, when analyzing the continuous zoom lens 3, when the axial positions of each zoom component independently change by the same certain amount at the short focal length position and the long focal length position respectively, the resulting image plane defocus amount and the magnification between the image plane defocus amount and the movement amount of the zoom component are obtained, and then the normalized image plane defocus sensitivities of each zoom component at the short focal length and the long focal length are obtained.

[0027] When analyzing the image plane defocus amount caused by the axial positions of each zoom component of the continuous zoom lens 3 independently changing by the same certain amount at the short focal length position and the long focal length position respectively, the movement amount can be either positive or negative. Generally, a small amount, such as ±0.05 mm, ±0.1 mm, etc., is taken for analysis to maintain the relative stability of the magnification between the image plane defocus amount and the movement amount of the zoom component. In addition, when analyzing the normalized image plane defocus sensitivities of each zoom component at the short focal length and the long focal length in the present invention, mainly the axial positions of each zoom component in the continuous zoom lens 3 are moved, such as the front fixed group 6, the variable magnification group 7, the intermediate fixed group 8, the compensation group 9, and the rear fixed group 10, etc., and the lenses inside each zoom component are not adjusted.

[0028] In this embodiment, each zoom component of the continuous zoom lens 3 is moved by 0.1 mm, and the normalized image plane defocus sensitivities at the short focal length and the long focal length are shown in Table 1.

[0029] Table 1 Image plane defocus sensitivities of each zoom component

[0030] According to the normalized image plane defocus sensitivities at the short focal length and the long focal length in Table 1, a graph is drawn to form the normalized image plane defocus sensitivity graph of each zoom component as shown in Figure 4 By this graph, the normalized image plane defocus sensitivity conditions of each zoom component at the short focal length and the long focal length can be observed. It can be known from Table 1 and Figure 4 that in this embodiment, the front fixed group 6 is the most sensitive to the long focal length image plane defocus and extremely insensitive to the short focal length image plane defocus. The variable magnification group 7 is the second most sensitive to the long focal length image plane defocus and has a lower sensitivity to the short focal length image plane defocus. The intermediate fixed group 8, the compensation group 9, and the rear fixed group 10 have relatively the same sensitivities to both the long focal length image plane defocus and the short focal length image plane defocus of the continuous zoom lens 3.

[0031] Table 2 shows the axial magnifications between the image plane defocus amounts and their movement amounts of each zoom component at the short focal length and the long focal length. + indicates that the image plane defocus direction is the same as the movement direction of each zoom component, and – indicates that the image plane defocus direction is opposite to the movement direction of each zoom component.

[0032] Table 2 Axial magnifications between the image plane defocus amounts and their movement amounts of each zoom component

[0033] As can be seen from Table 2, the telephoto axial magnification of the front fixed group 6 in the continuous zoom lens 3 is much higher than the short - focal axial magnification. That is to say, when the continuous zoom lens 3 is in the telephoto position, the defocus of the short - focal image plane caused by adjusting the position of the front fixed group 6 can be basically ignored.

[0034] Therefore, in this embodiment, the zoom element that is sensitive to the telephoto image - plane defocus and has the largest difference in sensitivity between the telephoto image - plane defocus and the short - focal image - plane defocus is the front fixed group 6, that is, the front fixed group 6 is the most sensitive element for telephoto.

[0035] Step 4, image - plane consistency test.

[0036] Step 4.1, The image - plane consistency test of the continuous zoom lens 3 needs to be realized with the help of Figure 3 the image - plane consistency test device as shown. The image - plane consistency test device mainly consists of a collimator 1, a resolution test chart 2 and a reading microscope 4; the resolution test chart 2 is placed at the focal plane position of the collimator 1, and the reading microscope 4 is coaxially placed behind the collimator 1. During the test, the continuous zoom lens 3 is coaxially placed between the collimator 1 and the reading microscope 4. The continuous zoom lens 3 is used to image the resolution test chart 2 at the focal plane position of the collimator 1. The operator observes the imaging situation of the resolution test chart 2 during the entire zoom process from short - focal to telephoto through the reading microscope 4 at the position of the human - eye observation point 5 and analyzes it.

[0037] Among them, the focal length of the collimator 1 is generally selected to be about more than 3 times the telephoto focal length of the continuous zoom lens 3. For example, if the telephoto focal length of the continuous zoom lens 3 is 300 mm, the focal length of the collimator 1 is selected as 900 mm.

[0038] Step 4.2, Move the continuous zoom lens 3 to the short - focal position. At this time, adjust the axial position of the reading microscope 4 until the imaging of the resolution test chart 2 is the clearest.

[0039] Step 4.3, Rotate the zoom cam of the continuous zoom lens 3 to move the continuous zoom lens 3 to the telephoto position. Observe whether the imaging clarity of the resolution test chart 2 at the telephoto position meets the preset requirements through the reading microscope 4. If so, it proves that the image - plane consistency meets the preset requirements and the image - plane consistency adjustment is completed; otherwise, it proves that the image - plane consistency does not meet the preset requirements. Adjust the axial position of the reading microscope 4 until the imaging clarity of the resolution test chart 2 at the telephoto position meets the preset requirements. At this time, record the axial movement amount and movement direction of the reading microscope 4 at the telephoto position, and then execute Step 5.

[0040] It should be noted that the numerical aperture of the reading microscope 4 should be greater than the maximum numerical aperture of the continuous zoom lens 3, that is, greater than F4.5.

[0041] Step 5, Image plane consistency calibration.

[0042] Step 5.1, According to the axial movement amount and movement direction of the reading microscope 4 recorded in Step 4.3, and combining with the magnification factor between the image plane defocus amount corresponding to the long focal length most sensitive component and the movement amount of the zoom component in Step 2, calculate the axial movement amount of the long focal length most sensitive component and determine the movement direction.

[0043] The axial movement amount of the long focal length most sensitive component is the ratio of the axial movement amount of the reading microscope 4 to the magnification factor. The movement direction is determined according to the positive or negative sign of the magnification factor. When the magnification factor is positive, the movement direction of the long focal length most sensitive component is opposite to the movement direction of the reading microscope 4 in Step 4.3. When the magnification factor is negative, the two movement directions are the same.

[0044] Step 5.2, According to the axial movement amount and movement direction of the long focal length most sensitive component, adjust the axial position of the long focal length most sensitive component, and then return to Step 4.2 for cyclic adjustment until the imaging clarity of the resolution test chart 2 at the long focal position observed by the reading microscope 4 meets the preset requirements when the continuous zoom lens 3 moves to the long focal position in Step 4.3, thus completing the image plane consistency calibration.

[0045] To take into account all possible situations that may not have been considered yet, when the adjusted zoom component is sensitive to the short focal length but not sensitive to the long focal length, in Step 4.2, the continuous zoom lens 3 can also be moved to the long focal position, and the axial position of the reading microscope 4 is adjusted until the imaging of the resolution test chart 2 is the clearest. Correspondingly, in Step 4.3, the axial position of the reading microscope 4 needs to be adjusted until the imaging clarity of the resolution test chart 2 at the short focal position meets the preset requirements, that is, at this time, record the axial movement amount and movement direction of the reading microscope 4 at the short focal position, and at the same time, it is also necessary to find the short focal length most sensitive component.

[0046] It should be noted that the present invention mainly solves the rapid calibration of the image plane consistency of the continuous zoom lens. Before the image plane consistency calibration, the imaging quality calibration of the continuous zoom lens has been completed, that is, the system wave aberration or the optical transfer function MTF at the image plane of each focal length position has met the requirements, and the imaging quality calibration of the continuous zoom lens is prior art and does not belong to the content involved in the present invention.

[0047] As described above, it is only used to illustrate the technical solution of the present invention, rather than to limit it. For those of ordinary professional skills in the art, the specific technical solution recorded in the above embodiments can be modified, or some of the technical features can be equivalently replaced, and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution protected by the present invention.

Claims

1. A method for adjusting image plane consistency of a continuous zoom lens, characterized in that: The following steps are involved: Step 1, adjusting the distance between each zoom component of the continuous zoom lens (3) to meet the design requirements; Step 2, analyzing the image plane defocus amount and the magnification ratio between the image plane defocus amount and the zoom component movement amount caused when the axial position of each zoom component of the continuous zoom lens (3) changes independently by a certain same movement amount at the short focus position and the long focus position, respectively, to obtain the normalized image plane defocus sensitivity of each zoom component at the short focus and the long focus; according to the normalized image plane defocus sensitivity of each zoom component at the short focus and the long focus, the zoom component that is sensitive to the long focus image plane defocus and has the largest difference in the long focus image plane defocus sensitivity and the short focus image plane defocus sensitivity is taken as the most sensitive component at the long focus; Step 3: image plane consistency test; Step 3.1, constructing an image plane consistency test device; the image plane consistency test device comprises a collimator (1), a resolution plate (2) placed at the focal plane position of the collimator (1), and a reading microscope (4) coaxially placed behind the collimator (1); during the test, the continuous zoom lens (3) is coaxially placed between the collimator (1) and the reading microscope (4); Step 3.2, move the continuous zoom lens (3) to the short focal position, and then adjust the axial position of the reading microscope (4) until the image of the discrimination plate (2) is clearest; Step 3.3, move the continuous zoom lens (3) to the telephoto position, and observe through the reading microscope (4) whether the image clarity of the discrimination plate (2) at the telephoto position meets the preset requirements. If so, the image plane consistency meets the preset requirements, and the image plane consistency adjustment is completed; otherwise, adjust the axial position of the reading microscope (4) until the image clarity of the discrimination plate (2) at the telephoto position meets the preset requirements, record the axial movement amount and movement direction of the reading microscope (4), and execute step 4; Step 4: image plane consistency adjustment; Step 4.1, based on the axial movement amount and movement direction of the reading microscope (4) recorded in step 3.3, combined with the magnification ratio between the image plane defocus amount corresponding to the most sensitive component of the telephoto lens and the movement amount of the zoom component in step 2, calculate the axial movement amount of the most sensitive component of the telephoto lens, and determine the movement direction; Step 4.2, according to the axial movement amount and movement direction of the most telephoto sensitive component, adjust the axial position of the most telephoto sensitive component, return to step 3.2 for cyclic adjustment, until the image clarity of the discrimination plate (2) at the telephoto position observed by the reading microscope (4) meets the preset requirements when the continuous zoom lens (3) moves to the telephoto position in step 3.3, and the image plane consistency adjustment is completed.

2. The method for adjusting image plane consistency of a continuous zoom lens according to claim 1, characterized in that: Step 1 also includes step A before: The distance between the center point of the pin on each moving component lens barrel in the continuous zoom lens (3) and the axial vertex of the first lens in the corresponding moving component lens barrel is adjusted to within a preset range.

3. The method for adjusting image plane consistency of a continuous zoom lens according to claim 2, characterized in that: In step A, the distance tolerance between the center point of the pin on each moving component barrel in the continuous zoom lens (3) and the axial vertex of the first lens in the corresponding moving component barrel is less than or equal to 0.05 mm.

4. The method for adjusting image plane consistency of a continuous zoom lens according to any one of claims 1 to 3, characterized in that: Step 1 is as follows: The interval between two adjacent fixed components and the interval between adjacent moving components and the fixed component are adjusted according to the design tolerance requirements of the optical system, and the interval between two adjacent moving components is constrained according to the cam curve.

5. The method for adjusting image plane consistency of a continuous zoom lens according to claim 4, characterized in that: In step 2, optical design software CODE V or ZEMAX is used to analyze the image plane defocus amount and the magnification ratio between the image plane defocus amount and the zoom component movement amount caused when the axial position of each zoom component of the continuous zoom lens (3) is independently changed by the same movement amount at the short focal position and the long focal position.

6. The method for adjusting image plane consistency of a continuous zoom lens according to claim 5, characterized in that: In step 2, the movement amount is a positive value or a negative value; the movement amount is ±0.05mm or ±0.1mm.

7. The method for adjusting image plane consistency of a continuous zoom lens according to claim 1, characterized in that: In step 3.1, the focal length of the collimator (1) is greater than 3 times the telephoto focal length of the continuous zoom lens (3); and the numerical aperture of the reading microscope (4) is greater than the maximum numerical aperture of the continuous zoom lens (3).

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