A continuously variable scale magnifier

Abstract

The present application relates to zoom lens technical field, provide a kind of scale magnifying glass of continuous zoom, including lens barrel and optical system being arranged in its inside, optical system includes objective lens group, zoom lens group and eyepiece group being sequentially arranged along the direction of light incidence;Lens barrel includes objective lens barrel, eyepiece barrel, focusing sleeve and zoom sleeve, objective lens group is fixedly arranged in the inside of objective lens barrel, eyepiece group is fixedly arranged in the inside of eyepiece barrel, zoom lens group is fixedly arranged on zoom lens frame, zoom lens frame is arranged in the inside of focusing sleeve, focusing sleeve is connected with objective lens barrel by thread, zoom sleeve is rotationally arranged between focusing sleeve and eyepiece barrel;Zoom sleeve is connected with zoom nut by thread in the inside, zoom nut is connected with zoom lens frame by several connecting screws, and the side wall of focusing sleeve is provided with strip-shaped sliding hole matched with connecting screw one by one.The present application discards the necessary optical compensation lens group and complex cam linkage mechanism in traditional zoom lens, and through independent focusing structure, it is ensured that accurate focusing can be achieved under each magnification in full zoom interval.

Description

Technical Field

[0001] This invention relates to the field of zoom lens technology, and more specifically, to a scale magnifying lens with continuous zoom. Background Technology

[0002] Continuous zoom lenses are widely used in the field of optical imaging, especially in scenarios such as surveillance, forest fire prevention, and reconnaissance. They can achieve clear imaging of targets at different distances and provide flexible field-of-view switching capabilities. Traditional continuous zoom lenses typically use a cam-slot structure to drive the zoom group and compensation group in conjunction to achieve high magnification zoom. For example, Chinese patent publication number "CN110174754A" discloses a high-magnification continuous zoom lens, which uses a zoom cam in conjunction with a compensation slide. The cam slot drives the negative lens B and the positive lens C to move, completing the zoom process, and an independent focusing cam drives the rear positive lens F for focusing. This type of solution has certain advantages in achieving high zoom ratios (such as 10x and above).

[0003] However, in low-magnification continuous zoom applications (such as zoom ratios less than 5x), the traditional cam-plus-compensation group structure is quite complex. Low-magnification zooms have lower requirements for zoom travel and non-linear compensation; using complex cam curves and compensation lens groups would only increase the system's size, weight, and assembly difficulty. Furthermore, existing low-magnification zoom lenses still have shortcomings in image quality and consistency of sharpness across all magnifications, making it difficult to balance structural simplification with imaging performance. Summary of the Invention

[0004] The purpose of this invention is to provide a continuously variable magnifying scale magnifier to overcome the aforementioned deficiencies of the prior art.

[0005] This invention is achieved through the following technical solution: A continuously zoom scale magnifying glass includes a lens barrel and an optical system disposed therein. The optical system includes an objective lens group, a zoom lens group and an eyepiece group arranged sequentially along the incident direction of light. The microscope tube includes an objective lens tube, an eyepiece tube, a focusing sleeve, and a zoom sleeve. The objective lens group is fixed inside the objective lens tube, the eyepiece group is fixed inside the eyepiece tube, the zoom lens group is fixed on the zoom lens frame, the zoom lens frame is located inside the focusing sleeve, the focusing sleeve is connected to the objective lens tube by a thread, and the zoom sleeve is rotatably positioned between the focusing sleeve and the eyepiece tube. The zoom sleeve has a zoom nut connected by threads inside. The zoom nut is connected to the zoom lens frame by several connecting screws. The side wall of the focusing sleeve has strip-shaped sliding holes that mate with the connecting screws one by one.

[0006] Furthermore, the thread between the focusing sleeve and the objective lens barrel is defined as a focusing thread, and the thread between the zoom sleeve and the zoom nut is defined as a zoom thread; both the focusing thread and the zoom thread are multi-start threads, and the lead of the focusing thread is less than the lead of the zoom thread.

[0007] Furthermore, the axial movement range of the focusing sleeve is 2-4 mm.

[0008] Furthermore, the side wall of the focusing sleeve is connected to a limiting screw, and the objective lens barrel is provided with a limiting step to block the limiting screw.

[0009] Furthermore, the connecting screw is fitted with a screw washer that mates with the strip-shaped sliding hole.

[0010] Furthermore, the objective lens group includes a front cemented lens group, a middle biconvex positive lens, and a rear cemented lens group arranged sequentially along the incident direction of light. Both the front cemented lens group and the rear cemented lens group are positive optical powers and are each cemented together by a positive lens and a negative lens.

[0011] Furthermore, the zoom lens assembly includes a front concave negative lens and a rear concave negative lens arranged sequentially along the incident direction of light, with their concave surfaces facing each other.

[0012] Furthermore, both the front concave negative lens and the rear concave negative lens are aspherical optical lenses.

[0013] Furthermore, the eyepiece assembly is composed of a positive lens and a negative lens cemented together, and has a positive optical power.

[0014] Furthermore, the optical system also includes a reticle located at the front end of the objective lens group.

[0015] Furthermore, the reticle is equipped with a scale.

[0016] The technical solution of the present invention has at least the following advantages and beneficial effects: In the present invention, when the zoom sleeve is rotated, the zoom nut drives the zoom lens frame to move axially relative to the focusing sleeve, thereby changing the air gap between the zoom lens group and the objective lens group, as well as between the zoom lens group and the eyepiece group, thereby continuously changing the equivalent focal length of the system to complete the zoom; at the same time, by rotating the focusing sleeve to make it axially displace the zoom sleeve and the zoom lens group as a whole, the slight image plane drift generated during the zoom process can be compensated, and this compensation function is completely realized by an independent threaded transmission structure, without the need to set any independent optical compensation lens group.

[0017] As can be seen, the zoom and magnification functions in this invention are independent of each other. The zoom function is responsible for switching magnification, while the magnification function is responsible for focus compensation. The two work together to achieve continuous stepless zoom. This not only eliminates the optical compensation lens group and complex cam linkage mechanism required in traditional zoom lenses, but also maintains image plane stability throughout the entire zoom range through an independent focusing structure, ensuring accurate focus at all magnifications. This balances structural simplification and imaging performance. Attached Figure Description

[0018] Figure 1 A cross-sectional view of a continuously variable magnifying scale magnifier provided by the present invention; Figure 2 This is an enlarged structural schematic diagram of the focusing nut; Figure 3 for Figure 1 Enlarged view of point A in the image; Figure 4 This is an enlarged schematic diagram of the focusing sleeve. Figure 5 This is an enlarged schematic diagram of the connection structure of the focusing sleeve, zoom nut, and zoom lens frame. Reference numerals: 1-Objective lens group, 101-Front cemented lens group, 102-Intermediate biconvex positive lens, 103-Rear cemented lens group, 2-Zoom lens group, 3-Eyepiece group, 4-Objective lens tube, 401-Transparent cover, 402-Metal outer frame, 403-Focusing nut, 4031-Limiting step, 5-Eyepiece tube, 6-Zoom lens frame, 7-Focusing sleeve, 701-Strip-shaped sliding hole, 8-Zoom sleeve, 9-Zoom nut, 10-Connecting screw, 11-Screw washer, 12-Limiting screw, 13-Reticle. Detailed Implementation

[0019] refer to Figure 1 A continuously variable magnifying scale lens includes a lens barrel and an optical system disposed therein, the optical system comprising components along the direction of light incidence (i.e., Figure 1 The objective lens group 1, zoom lens group 2, and eyepiece group 3 are arranged sequentially from left to right in the center; the lens tube includes objective lens tube 4, eyepiece tube 5, focusing sleeve 7, and zoom sleeve 8.

[0020] Objective lens group 1 is fixed inside objective lens tube 4, eyepiece group 3 is fixed inside eyepiece tube 5, zoom lens group 2 is fixed on zoom lens frame 6, zoom lens frame 6 is located inside focusing sleeve 7, focusing sleeve 7 is threaded to objective lens tube 4, and zoom sleeve 8 is rotatably positioned between focusing sleeve 7 and eyepiece tube 5. It should be understood that zoom sleeve 8 can only rotate and cannot move axially relative to focusing sleeve 7. (Reference) Figures 2-5The zoom sleeve 8 has a zoom nut 9 connected internally via threads. The zoom nut 9 is connected to the zoom lens frame 6 by several connecting screws 10. The side wall of the focusing sleeve 7 has a strip-shaped sliding hole 701 that mates with each of the connecting screws 10. The strip-shaped sliding hole 701, in conjunction with the connecting screws 10, restricts the rotational freedom of the zoom lens frame 6 and the zoom nut 9. Simultaneously, the strip-shaped sliding hole 701 provides guidance for the axial movement of the zoom lens assembly 2, the zoom lens frame 6, and the zoom nut 9 as a whole. Alternatively, in this embodiment, a screw washer 11 is fitted onto the connecting screw 10. The screw washer 11 mates with the strip-shaped sliding hole 701, allowing for replacement of the screw washer 11 after wear.

[0021] In practical applications, when the zoom sleeve 8 is rotated, the zoom nut 9 drives the zoom lens frame 6 to move axially relative to the focusing sleeve 7, thereby changing the air gap between the zoom lens group 2 and the objective lens group 1, as well as between the zoom lens group 2 and the eyepiece group 3, thus continuously changing the equivalent focal length of the system to complete the zoom. Simultaneously, by rotating the focusing sleeve 7 to make it axially displace along with the zoom sleeve 8 and the zoom lens group 2, the slight image plane drift generated during zooming can be compensated. This compensation function is entirely achieved by an independent threaded transmission structure, without the need for any independent optical compensation lens group. Therefore, in this invention, the zoom and magnification functions are independent. The zoom function handles magnification switching, while the focusing function handles focus compensation. Their synergistic effect achieves continuous stepless zoom while eliminating the necessary optical compensation lens group and complex cam linkage mechanism of traditional zoom lenses. Furthermore, the independent focusing structure maintains image plane stability throughout the entire zoom range, ensuring accurate focusing at all magnifications, thus balancing structural simplification and imaging performance.

[0022] For ease of description, the thread between the focusing sleeve 7 and the objective lens barrel 4 is defined as the focusing thread, and the thread between the zoom sleeve 8 and the zoom nut 9 is defined as the zoom thread. In a preferred embodiment, both the focusing thread and the zoom thread are multi-start threads, and the lead of the focusing thread is less than that of the zoom thread. In practical applications, the zoom thread uses a large-lead multi-start thread, requiring only a small rotation of the zoom sleeve 8 for the zoom thread to drive the zoom nut 9 and produce a significant axial displacement of the zoom lens assembly 2. The focusing thread uses a precision fine-pitch multi-start thread. After zooming, the optical system experiences a very slight image plane shift. Rotating the focusing sleeve 7 causes the focusing sleeve 7, zoom sleeve 8, and zoom lens assembly 2 to move slightly axially along the optical axis, precisely compensating for the image plane drift caused by zooming and completing the focusing action. This mechanical fine-tuning structure can completely replace the optical compensation group of a traditional zoom lens, achieving precise focusing across the entire magnification range through mechanical structure. Furthermore, the axial movement range (i.e., stroke) of the focusing sleeve 7 is 2-4 mm, relying on short-stroke fine adjustment. In this embodiment, the stroke of the focusing sleeve 7 is preferably 3 mm (other strokes, such as 2 mm or 4 mm, can of course be selected in other embodiments).

[0023] To ensure the range of motion of the focusing sleeve 7, in this embodiment, a limiting screw 12 is connected to the side wall of the focusing sleeve 7, and a limiting step 4031 is provided on the outer wall of the objective lens barrel 4 to block the limiting screw 12. Based on this, it should be understood that... Figure 1 The indicated orientation is for reference. When the limiting screw 12 abuts against the limiting step 4031, it is the limit position for the focusing sleeve 7 to move to the right; when the end face of the focusing sleeve 7 abuts against the objective lens tube 4, it is the limit position for the focusing sleeve 7 to move to the left.

[0024] Refer again Figure 1 In this embodiment, the objective lens barrel 4 includes a transparent cover 401, a metal frame 402, and a focusing nut 403, which are sequentially fixed along the light incident direction. It is easy to understand that, based on this, the focusing sleeve 7 is threadedly connected to the focusing nut 403, and the aforementioned limiting step 4031 is provided on the focusing nut 403. The objective lens group 1 is mounted on the objective lens frame, which is fixedly connected to the focusing nut 403. As a preferred embodiment, the objective lens group 1 in this embodiment includes a front cemented lens group 101, a middle biconvex positive lens 102, and a rear cemented lens group 103, which are sequentially arranged along the light incident direction. Both the front cemented lens group 101 and the rear cemented lens group 103 are positive power cemented achromatic doublets, each composed of a positive lens and a negative lens cemented together. It is worth noting that the objective lens group 1 structure composed of three compound lenses can significantly reduce the basic optical residual error, resulting in a smaller image plane drift during zooming, providing a rigid optical condition for eliminating the compensation group.

[0025] The zoom lens group 2 includes a front concave negative lens and a rear concave negative lens arranged sequentially along the incident light direction. Both lenses are aspherical optical lenses, and they are arranged with their concave surfaces facing each other. It is worth noting that the optical characteristics of aspherical lenses can effectively correct distortion, field curvature, and higher-order spherical aberrations, significantly improving edge blurring and distortion during zooming, and ensuring a flat and clear image at both high and low magnification.

[0026] Eyepiece group 3 also employs a cemented doublet structure, formed by cementing a positive lens and a negative lens together, providing overall positive optical power. Eyepiece group 3 is used to ultimately correct residual astigmatism and chromatic aberration in the system, optimize exit pupil imaging quality, and ensure comfortable viewing for the human eye with a clear and sharp image.

[0027] In this embodiment, a reticle 13 is also provided at the front end of the optical system. In practical applications, a high-precision scale (not shown) is provided on the reticle 13 to facilitate direct size comparison and micro-measurement while magnifying observation.

[0028] In some embodiments, a plurality of LED lights can be arranged along the circumferential direction at the front end of the reticle 13 to provide uniform illumination to the observation working surface, solving the problem of unclear observation in low light environments, small gaps, and shadow areas, and adapting to the inspection of precision and small objects. Furthermore, a built-in rechargeable battery module can be adaptively equipped, with a charging interface reserved on the outside of the telescope barrel.

[0029] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A continuously variable magnifying scale magnifying glass, comprising a lens barrel and an optical system disposed therein, characterized in that, The optical system includes an objective lens group, a zoom lens group, and an eyepiece group arranged sequentially along the incident direction of light. The microscope tube includes an objective lens tube, an eyepiece tube, a focusing sleeve, and a zoom sleeve. The objective lens group is fixed inside the objective lens tube, the eyepiece group is fixed inside the eyepiece tube, the zoom lens group is fixed on the zoom lens frame, the zoom lens frame is located inside the focusing sleeve, the focusing sleeve is connected to the objective lens tube by a thread, and the zoom sleeve is rotatably positioned between the focusing sleeve and the eyepiece tube. The zoom sleeve has a zoom nut connected by threads inside. The zoom nut is connected to the zoom lens frame by several connecting screws. The side wall of the focusing sleeve has strip-shaped sliding holes that mate with the connecting screws one by one.

2. The continuously variable magnifying scale magnifying glass according to claim 1, characterized in that, The thread between the focusing sleeve and the objective lens barrel is defined as the focusing thread, and the thread between the zoom sleeve and the zoom nut is defined as the zoom thread; both the focusing thread and the zoom thread are multi-start threads, and the lead of the focusing thread is less than the lead of the zoom thread.

3. The continuously variable magnifying scale magnifying glass according to claim 2, characterized in that, The side wall of the focusing sleeve is connected to a limiting screw, and the objective lens barrel is provided with a limiting step to block the limiting screw.

4. The continuously variable magnifying scale magnifying glass according to claim 1, characterized in that, The connecting screw is fitted with a screw washer that mates with the strip-shaped sliding hole.

5. The continuously variable magnifying scale magnifying glass according to claim 1, characterized in that, The objective lens group includes a front cemented lens group, a middle biconvex positive lens, and a rear cemented lens group arranged sequentially along the incident direction of light. Both the front cemented lens group and the rear cemented lens group are positive optical powers and are each cemented together by a positive lens and a negative lens.

6. The continuously variable magnifying scale magnifying glass according to claim 1, characterized in that, The zoom lens assembly includes a front concave negative lens and a rear concave negative lens arranged sequentially along the incident direction of light, with their concave surfaces facing each other.

7. The continuously variable magnifying scale magnifying glass according to claim 6, characterized in that, Both the front concave negative lens and the rear concave negative lens are aspherical optical lenses.

8. The continuously variable magnifying scale magnifying glass according to claim 1, characterized in that, The eyepiece assembly is made of a positive lens and a negative lens cemented together, and has a positive optical power.

9. The continuously variable magnifying scale magnifying glass according to any one of claims 1-8, characterized in that, The optical system also includes a reticle located at the front end of the objective lens group.

10. The continuously zoom scale magnifying glass according to claim 9, characterized in that, The reticle is equipped with a scale.

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