A hand-held stack photography telescopic lens structure

Abstract

The utility model discloses a handheld type stack photography telescopic lens structure, through mechanical elasticity and manual or damping control synergic design, realize lightweight macro stack shooting, core includes sliding cylinder, telescopic lens barrel, lens, telescopic spring and adapter ring: sliding cylinder front end is equipped with the limit ring side, rear end inner wall is with internal thread, telescopic lens barrel is covered in the sliding cylinder, and the rear section convex limit cylinder shoulder is limited by the limit ring side when extending, and the card slot accommodation telescopic spring is formed between it and the sliding cylinder, lens is fixed in telescopic lens barrel and constitutes telescopic lens group, and adapter ring is detachably connected sliding cylinder, and is suitable for multiple shooting equipment. Through manual or passive friction resistance offset part spring elasticity, make telescopic lens barrel slowly extend, in this process, telescopic lens barrel uniform velocity displacement along the optical axis, cooperate and get the sequence photo of focal point continuous change of continuous shooting, satisfy the demand of macro stack synthesis, replace the cumbersome equipment required when traditional stack photography, improve portability and operation convenience.

Description

Technical Field

[0001] This utility model relates to the field of photographic equipment technology, specifically to a handheld stackable telescopic lens structure for photography. Background Technology

[0002] The core characteristic of macro photography is its high magnification (usually 1:1 or higher, capable of capturing the compound eyes of insects, the texture of petals, and the details of electronic components). However, this comes with an extremely shallow depth of field (which can be understood as an extremely narrow range of sharpness). For example, when photographing an ant, a single macro photo might only show the ant's head, while its body and legs would be blurred. Similarly, when photographing a small flower, a single image might only show the stamen, while the edges of the petals would be blurred. This problem of "partial sharpness and mostly blurry" cannot be fundamentally solved by adjusting the aperture (even stopping down to the smallest aperture only slightly increases the depth of field and can even lead to a decrease in image quality). The essence of macro stacking is to combine the "sharp parts" of each photo by "overlaying multiple photos with different focal points," ultimately achieving "sharpness across the entire image."

[0003] During shooting, keep the camera and subject in a completely fixed position. Focus manually (or use autofocus on professional equipment), gradually moving the focus from the foreground to the background of the subject, taking a series of photos (usually 5-30 shots, but potentially hundreds for complex scenes). For example, when shooting a coin, the first shot focuses on the edge, the second on the surface texture, the third on the center, and so on, ensuring only a small area is sharp in each shot. Then, use professional software (such as Photoshop or HeliconFocus) to identify the "sharp areas" in each photo, automatically removing blurry parts and stitching all sharp areas together into a complete, fully sharp image. Macro stacking photography consists of two steps: "pre-shooting" and "post-processing." The rigor of the pre-shooting process directly determines the post-processing effect.

[0004] Currently, to ensure that every photo has completely consistent composition and exposure parameters, with only the focus differing, the industry requires external devices for stable movement, such as focus rails and camera tripods. These specialized tools are needed to control the panning of the camera or lens, allowing for more even and stable focus movement. However, these devices are usually large and inconvenient to carry around. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a handheld stacked telescopic lens structure for photography. Through a synergistic design of mechanical elastic energy storage and damping control, it overcomes the limitations of traditional stacked photography technology in terms of portability, ease of operation, stability, and cost.

[0006] Specifically, this utility model is implemented as follows:

[0007] A handheld stackable telescopic lens structure includes: a sliding cylinder with a limiting ring at the front end and an internal thread on the inner wall of the rear end; a telescopic lens tube fitted inside the sliding cylinder, the front part of which can extend and retract from the front end of the sliding cylinder, and the rear part having a protruding limiting shoulder, the front end of which is restricted by the limiting ring when extended; the rear end of the limiting shoulder forms a groove with the telescopic lens tube and the sliding cylinder; a lens installed inside the telescopic lens tube, forming a telescopic lens assembly; a telescopic spring placed inside the sliding cylinder, one end of which is inserted into the groove, and the other end contacting the lens via an adapter ring or the outer ring of the lens; under normal conditions, the telescopic spring can support the telescopic lens tube, causing it to extend out of the sliding cylinder; when the telescopic lens tube is subjected to compressive force, the telescopic spring compresses, and the telescopic lens tube retracts back into the sliding cylinder; the adapter ring or the outer ring of the lens is detachably connected to the end of the sliding cylinder.

[0008] Furthermore, the adapter ring includes a first external thread that matches the internal thread specification of the sliding cylinder, and a second external thread or a second internal thread that matches the internal or external thread of the lens to be installed.

[0009] Furthermore, a retaining ring is provided on the inner wall of the front or rear end of the telescopic lens tube, and an internal thread is provided on the inner wall of the other end, so that the lens can be inserted from the end with the internal thread and then tightened by a clamping ring with an external thread, so that the lens is fixed between the retaining ring and the clamping ring.

[0010] Furthermore, the lens is a cemented doublet positive lens.

[0011] Furthermore, the adapter ring can be combined and installed with the mobile terminal fixture, and the lens is a magnifying lens for the mobile terminal, which can be connected to the mobile phone fixture by threads, so that the telescopic lens assembly can be firmly covered on the camera of the mobile terminal.

[0012] Furthermore, the size and specifications of the limiting shoulder are adapted to the inner diameter of the sliding cylinder, so that when the sliding cylinder and the telescopic lens cylinder move relative to each other, the limiting shoulder is always in contact with the inner wall of the sliding cylinder for guidance and limiting, making the telescopic lens cylinder relatively stable during displacement.

[0013] Furthermore, a damping friction element is installed on the outer shoulder surface of the limiting cylinder shoulder, so that when the sliding cylinder and the telescopic lens cylinder move relative to each other, the damping friction element forms damping friction with the inner wall of the sliding cylinder, so that when the telescopic spring is released from the compressed state, the telescopic lens cylinder can slowly extend out of the sliding cylinder.

[0014] Furthermore, damping friction elements are installed on the outer shoulder surface of the limiting cylinder and the inner wall of the sliding cylinder, so that when the sliding cylinder and the telescopic lens cylinder move relative to each other, the damping friction elements form damping friction with the inner wall of the sliding cylinder, so that when the telescopic spring is released from the compressed state, the telescopic lens cylinder can slowly extend out of the sliding cylinder.

[0015] Furthermore, the damping friction element is a rubber ring or rubber pad made of rubber products. After installation, the damping friction element is in interference contact, and the overall frictional resistance does not exceed the elastic force of the telescopic spring.

[0016] Furthermore, 1-3 annular grooves are formed on the limiting sleeve shoulder to nest a corresponding number of nitrile rubber O-rings, ensuring that the O-rings are higher than the outer wall of sleeve A to form an interference fit; and / or, silicone-based damping grease is pre-applied to the inner wall of the sliding cylinder, so that the surface of the silicone-based damping grease contacts the limiting sleeve shoulder and / or the nitrile rubber O-rings, generating frictional resistance of the interference fit, which is used to offset part of the elastic force of the telescopic spring, so that the telescopic spring slows down the extension speed.

[0017] The working principle of this invention: The core of the handheld stacked photography telescopic lens structure lies in the synergistic effect of mechanical elastic energy storage and damping control to achieve low-cost, lightweight continuous focus shift, thereby replacing the professional focusing rail equipment required for traditional stacked photography. The built-in telescopic spring (normally in a supporting state) constitutes the core power source. When the user manually compresses the telescopic lens barrel, the spring undergoes elastic deformation and stores potential energy; after releasing the pressure, the spring's potential energy is converted into mechanical energy, driving the telescopic lens barrel to extend linearly along the optical axis. This design cleverly utilizes the linear recovery characteristic of the spring, ensuring that the driving force release for each focus shift provides relatively convenient and stable focus shift, allowing for continuous shooting during focus shift. This achieves full focal length coverage of the subject during the required macro stacking process, obtaining several macro photos of the subject with different focal points through continuous shooting. Ultimately, this achieves the pre-stack requirement of "multiple photos differing only in focus, with all other parameters identical," facilitating subsequent software stacking and fusion to obtain a single, deep-field macro photograph with all subjects in sharp focus. There are two ways to release the telescopic spring: manual and automatic. In manual mode, press the edge of the compressed telescopic lens assembly with your finger, being careful not to obstruct the subject. Prepare the shooting time and current focus point. Once confirmed, slowly release your finger, feeling the telescopic lens assembly extend. Gradually release your finger until the telescopic lens assembly is fully extended. During this process, use your other hand to press the shutter button for continuous shooting. The other method uses a damped friction displacement control structure to achieve automatic release of the telescopic lens assembly, eliminating the need for manual release. This invention utilizes the principle that the front lens moves back and forth along the optical axis, changing the image distance between the lens and the sensor, thus changing the focus point position. The movement of the front lens can be relatively stably controlled within the lens barrel, making it more stable and reliable than manual displacement. The photographer only needs to keep their hand relatively stable; the arm does not need to move.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] (1) Breakthrough in lightweight and portability: Traditional stacked photography relies on large peripherals such as focus rails and tripods, resulting in bulky equipment and significantly increased weight. This invention utilizes the linear restoring force of a telescopic spring to achieve focus displacement, eliminating the need for complex stepper motors or lead screw structures, and keeping the overall weight within a very lightweight range. The highly integrated nested structure of the sliding cylinder and telescopic lens barrel allows the length to be compressed to a few centimeters, making it easy to store in a pocket or small camera bag, significantly improving the mobility of outdoor shooting. It can be adapted to various devices such as mobile phones and mirrorless cameras via an adapter ring.

[0020] (2) Simplified operation process and reduced cost: One-handed grip to achieve continuous focus coverage: Users only need to compress the lens barrel with one hand to store energy and trigger continuous shooting with the other hand to complete 5-30 focus sequence shooting within 2-3 seconds; the continuous shooting photos only have different focus, avoiding the displacement deviation that may be caused by traditional manual displacement, thereby improving the success rate of post-stack compositing.

[0021] (3) Modular design: Core components such as telescopic lens barrel and spring can be replaced individually. For example, by replacing the spring with a different elastic coefficient, it can be adapted to different focal length lenses and used as a teleconverter. It not only meets the needs of cameras, mirrorless cameras, and mobile phone clamps, but can also be directly applied to mobile phones for macro photography, significantly extending the playability and practicality of the product. Attached Figure Description

[0022] Figure 1 A stereoscopic view of a handheld stacked telescopic lens structure for photography.

[0023] Figure 2 A cross-sectional view of the structural composition of a handheld stacked telescopic lens structure for photography.

[0024] Figure 3 An exploded view of a handheld stacked telescopic lens structure for photography.

[0025] Figure 4 A comparison of the telescopic states of a handheld stacked photographic telescopic lens structure.

[0026] Figure 5 A schematic diagram of a handheld stacked telescopic lens structure for photography, showing its docking and installation with a lens.

[0027] Figure 6 A stereoscopic view of a handheld stacked photographic telescopic lens structure mounted on a camera;

[0028] Figure 7 A schematic diagram of the press-and-extend state of a handheld stacked telescopic lens structure for photography.

[0029] Figure 8A schematic diagram illustrating the manually released telescopic lens barrel state when taking a photo using a handheld stacked telescopic lens structure;

[0030] Figure 9 A stereoscopic image of a handheld stacked telescopic lens structure mounted on a mobile phone;

[0031] Figure 10 This is a schematic diagram illustrating the state of using a handheld stacked telescopic lens structure combined with a mobile phone macro external lens.

[0032] Figure label:

[0033] 1—Sliding cylinder, 11—Limiting ring edge,

[0034] 2—Telescopic lens barrel, 21—Limiting shoulder, 22—Clamping ring, 23—Pressure ring,

[0035] 3—lens,

[0036] 4—Extension spring,

[0037] 5—Adapter ring, 51—First external thread, 52—Second external thread,

[0038] 6—Outer ring of the lens,

[0039] 7—Mobile terminal fixture;

[0040] 8—External macro lens for mobile phone. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Example

[0042] The handheld stacked photography telescopic lens structure provided in this embodiment is highly compatible with the core needs of macro stacked photography in terms of its "lightweight, portable and simplified operation" characteristics. It is especially suitable for users who have high requirements for equipment portability and flexible shooting scenarios (such as outdoor photography enthusiasts, macro beginners, mobile device photography users, etc.).

[0043] like Figure 1 As shown, this utility model provides a handheld stackable telescopic lens structure, including: a sliding cylinder 1, a telescopic spring 4, and a telescopic lens barrel 2; a lens 3 is installed inside the telescopic lens barrel 2, forming a telescopic lens assembly with the telescopic lens barrel 2; under normal conditions, the telescopic spring 4 can support the telescopic lens barrel 2, causing the telescopic lens barrel 2 to extend out of the sliding cylinder 1; when the telescopic lens barrel 2 is subjected to compressive force, the telescopic spring 4 is compressed, and the telescopic lens barrel 2 retracts back into the telescopic lens barrel 2; an adapter ring 5 is detachably connected to the end of the sliding cylinder 1.

[0044] Depending on whether you are using a mirrorless or DSLR camera, install the macro lens and select an adapter ring 5 that matches the lens specifications. Tighten the adapter ring 5 to the internal thread at the rear end of the sliding cylinder 1 via the first external thread 51, and then connect it to the lens of the shooting device via the second external thread 52. Ensure that the cemented doublet positive lens inside the telescopic lens barrel 2 is secured by the retaining ring 22 and the clamping ring 23 to prevent lens 3 from shifting during shooting and causing image blur. The achromatic properties of the cemented doublet positive lens can reduce chromatic aberration in macro photography and ensure image quality.

[0045] Set the aperture, ISO, and shutter speed in the shooting equipment (manual mode or exposure lock function is recommended). Ensure the starting focus position of the sequence of photos, and lock the exposure information, white balance, and other parameters. Observe visually or on the device screen. At this time, the telescopic lens tube 2 is in the "uncompressed" state (the spring supports the lens tube to extend). At this time, the lens 3 is closest to the subject, and the focus should fall on the "farthest end" of the subject. Then press the telescopic lens tube 2 to retract it. Observe visually or on the device screen. The focus should fall on the "nearest end" of the subject. Then release the telescopic lens tube 2 and observe whether the change in depth of field can cover the entire range of the object. If so, you can prepare to shoot.

[0046] Activate continuous shooting mode on your camera to ensure the number of shots covers the entire focal range from foreground to background. Hold the camera and shutter button with one hand, keeping them stable, and gently push the front edge of the telescopic lens barrel 2 with the other hand (avoiding obstruction of lens 3) to retract the telescopic lens barrel 2 into the sliding barrel 1. At this time, the telescopic spring 4 is compressed until the limiting shoulder 21 approaches the limiting ring edge 11 of the sliding barrel 1, and the lens barrel retracts to its shortest state. At this point, the lens 3 is furthest from the subject, and the focus falls on the "foreground area" of the subject. After confirming focus, press the shutter button to start continuous shooting, while gradually releasing your hand from pushing the telescopic lens barrel 2. The elastic force of the telescopic spring 4 pushes the telescopic lens barrel 2 to slowly extend along the sliding barrel 1. Extend and retract the lens barrel 2 as linearly as possible. During the extension of the lens barrel, the distance between the lens 3 and the subject gradually shortens, and the focus moves continuously from the "foreground" to the "background". After the telescopic lens barrel 2 stops, release the shutter button to obtain a series of photos with "sequential focus shifts and completely consistent composition".

[0047] Importing the burst of photos into professional image stacking software (such as Photoshop or HeliconFocus) allows the software to automatically identify and stitch together the sharp areas of each photo, ultimately producing a fully sharp macro image. Because this lens structure ensures that the photos in the sequence differ only in focus (consistent composition and exposure), the success rate of post-processing is significantly higher than with traditional manual focus shooting.

[0048] Preferably, the adapter ring 5 is not needed in certain situations, such as when the front end specifications of the macro lens barrel and the extended docking lens outer ring 6 interface match the end docking specifications of the sliding tube 1, or when the end of the sliding tube 1 is directly connected to the fixed lens barrel flange of the camera (connection specifications match). Example

[0049] Unlike Embodiment 1, the shooting device is different. In this embodiment, a mobile phone is used instead of a mirrorless camera for shooting. The accessory "Mobile Terminal Clamp 7" is required, which is a mobile phone accessory that can accommodate an external lens. The adapter ring 5 can be combined and installed with the Mobile Terminal Clamp 7. In this embodiment, the lens 3 is a magnifying lens for the mobile terminal. After installation, the mobile phone camera can perform macro photography. This structure is installed on the mobile phone clamp via a threaded connection, so that the telescopic lens assembly is securely covered on the mobile terminal's camera. The remaining operations are the same as in Embodiment 1. Alternatively, it can be used by connecting and installing it on an external macro lens 8 of the mobile phone via the adapter ring 5. Example

[0050] Unlike Embodiment 1, a damping friction element is installed on the outer shoulder surface of the limiting sleeve shoulder 21, so that when the sliding sleeve 1 and the telescopic lens sleeve 2 move relative to each other, the damping friction element forms damping friction with the inner wall of the sliding sleeve 1, so that when the telescopic spring 4 is released from the compressed state, the telescopic lens sleeve 2 can slowly extend out of the sliding sleeve 1.

[0051] The movement of the telescopic lens tube 2 is determined by two forces:

[0052] Driving force: comes from the compressed telescopic spring 4. When the spring is released, it generates an outward elastic force, attempting to quickly push the telescopic mirror tube 2 out of the sliding tube 1.

[0053] Resistance: The friction between the damping friction element and the inner wall of the sliding cylinder 1. The damping friction element on the outer shoulder surface of the limiting cylinder shoulder 21 is in close contact with the inner wall of the sliding cylinder 1. When the lens barrel moves, the contact surface will generate friction force, which is opposite to the direction of the lens barrel extension, thus hindering the rapid movement of the lens barrel.

[0054] The spring force being greater than the damping friction ensures that the lens barrel can eventually extend fully, while the damping friction is sufficient to offset part of the spring force, reducing the acceleration of the lens barrel's movement and resulting in a slow, uniform extension rather than an instantaneous spring-like motion. Typically, the damping friction element is a rubber ring or rubber pad. The rubber ring's diameter is slightly larger than the inner wall diameter of the sliding cylinder 1. After installation, the rubber ring is slightly compressed, tightly fitting against the inner wall to ensure constant contact between the friction surfaces. The coefficient of friction of rubber is much greater than that of metal, generating sufficient resistance with a small contact area. Simultaneously, the elasticity of the rubber buffers minor vibrations, preventing sudden fluctuations in friction. By adjusting the thickness or hardness of the rubber ring, the total friction can be effectively adjusted and controlled, ensuring it is less than the spring force while still sufficient to control the extension time within the "golden range" of 2-3 seconds. Based on this design, manual release is unnecessary as in Example 1, providing greater operational convenience. The damping friction element can be located on the inner wall of the sliding cylinder 1, on the limiting shoulder 21, or both. Example

[0055] Based on Example 3, a complete and detailed design scheme is further provided:

[0056] The interference fit of the nitrile rubber O-ring: 1-3 annular grooves are made on the limiting sleeve shoulder 21 (the part that moves with the telescopic lens tube 2), and the nitrile rubber O-ring is embedded in the groove. The outer diameter of the O-ring is slightly larger than the inner wall diameter of the sliding cylinder 1. After the O-ring is embedded in the annular groove, its outer ring will protrude above the outer wall of the telescopic lens tube 2, forming a "compression contact" with the inner wall of the sliding cylinder 1. That is, the O-ring is slightly compressed and always tightly fits the inner wall of the sliding cylinder 1, ensuring that friction will inevitably occur when the two move relative to each other.

[0057] The significance of the number of O-rings: 1-3 O-rings can adjust the total friction. The more O-rings, the larger the friction surface and the greater the total resistance. This allows for the adaptation of extension springs 4 with different elastic coefficients. When the spring force is different, different resistances need to be matched to control the speed. Silicone-based damping grease (a high-viscosity, semi-solid grease with both lubricating and damping properties) is pre-applied to the inner wall of the sliding cylinder 1. The damping grease directly contacts the outer ring of the O-rings. Its viscous properties increase the coefficient of friction at the contact surface. In this embodiment, a solution using nitrile rubber O-rings alone or a solution using nitrile rubber O-rings in combination with silicone-based damping grease can be selected.

[0058] The extension speed of the telescopic lens barrel 2 is determined by the balance between the driving force of the telescopic spring 4 and the total frictional resistance. The driving force comes from the compressed telescopic spring 4, whose elastic force gradually decreases with the extension stroke (conforming to Hooke's Law), but the overall trend is to push the lens barrel outward rapidly. The total frictional resistance consists of two parts: the squeezing friction between the O-ring and the inner wall of the sliding cylinder 1 (the main resistance) + the viscous friction between the damping grease and the contact surface (the auxiliary resistance). The balance logic is: the design ensures that the total frictional resistance is less than the maximum elastic force of the spring (ensuring that the lens barrel can eventually be fully extended), but the total frictional resistance is large enough (to significantly offset the spring elastic force). This achieves slow extension rather than instantaneous ejection without resistance. This greatly improves the operational feasibility of handheld macro stacking photography.

[0059] The above-described specific examples are for illustrative purposes only and are not intended to limit the scope of this invention. Those skilled in the art to which this invention pertains can make various simple deductions, modifications, or substitutions based on the concept of this invention.

Claims

1. A handheld stacked telescopic lens structure for photography, characterized in that... include: The sliding cylinder (1) has a limiting ring edge (11) at the front end and an internal thread on the inner wall at the rear end; The telescopic lens tube (2) is fitted inside the sliding tube (1). The front part can extend and retract from the front end of the sliding tube (1), and the rear part has a ring of limiting shoulder (21) protruding. When it is extended into place, the front end of the limiting shoulder (21) is restricted by the limiting ring edge (11). The rear end of the limiting shoulder (21) forms a groove between the telescopic lens tube (2) and the sliding tube (1). The lens (3) is installed inside the telescopic lens tube (2) and together with the telescopic lens tube (2) form a telescopic lens group; The telescopic spring (4) is placed inside the sliding cylinder (1), with one end inserted into the slot and the other end contacting the lens via the adapter ring (5) or the lens outer ring (6). Under normal conditions, the telescopic spring (4) can support the telescopic lens tube (2), causing the telescopic lens tube (2) to extend out of the sliding cylinder (1). When the telescopic lens tube (2) is subjected to compressive force, the telescopic spring (4) is compressed, and the telescopic lens tube (2) retracts back into the sliding cylinder (1). The adapter ring (5) or lens outer ring (6) is detachably connected to the end of the sliding cylinder (1).

2. The handheld stacked telescopic lens structure according to claim 1, characterized in that, The adapter ring (5) includes a first external thread (51) that matches the internal thread specification of the sliding cylinder (1), and a second external thread (52) or a second internal thread that matches the internal or external thread of the lens to be installed.

3. The handheld stacked telescopic lens structure according to claim 1, characterized in that, The telescopic lens tube (2) has a retaining ring (22) on the inner wall of the front or rear end and an internal thread on the inner wall of the other end, so that the lens (3) can be inserted from the end with the internal thread and tightened by a clamping ring (23) with an external thread, so that the lens (3) is fixed between the retaining ring (22) and the clamping ring (23).

4. The handheld stacked telescopic lens structure according to claim 3, characterized in that, The lens (3) is a cemented doublet positive lens.

5. The handheld stacked telescopic lens structure according to claim 1, characterized in that, The adapter ring (5) can be combined and installed with the mobile terminal fixture (7). The lens (3) is a magnifying lens for the mobile terminal and can be connected to the mobile phone fixture by threads, so that the telescopic lens assembly can be firmly covered on the camera of the mobile terminal.

6. The handheld stacked telescopic lens structure according to claim 1, characterized in that, The size of the limiting shoulder (21) is adapted to the inner diameter of the sliding cylinder (1), so that when the sliding cylinder (1) and the telescopic mirror cylinder (2) move relative to each other, the limiting shoulder (21) is always in contact with the inner wall of the sliding cylinder (1) for guidance and limiting, so that the telescopic mirror cylinder (2) is relatively stable during displacement.

7. The handheld stacked telescopic lens structure according to claim 1, characterized in that, A damping friction element is installed on the outer shoulder surface of the limiting sleeve (21), so that when the sliding sleeve (1) and the telescopic lens sleeve (2) move relative to each other, the damping friction element forms damping friction with the inner wall of the sliding sleeve (1), so that when the telescopic spring (4) is released from the compressed state, the telescopic lens sleeve (2) can slowly extend out of the sliding sleeve (1).

8. The handheld stacked telescopic lens structure according to claim 1, characterized in that, Damping friction elements are installed on the outer shoulder surface of the limiting sleeve shoulder (21) and the inner wall of the sliding sleeve (1), so that when the sliding sleeve (1) and the telescopic lens sleeve (2) move relative to each other, the damping friction elements form damping friction with the inner wall of the sliding sleeve (1), so that when the telescopic spring (4) is released from the compressed state, the telescopic lens sleeve (2) can slowly extend out of the sliding sleeve (1).

9. The handheld stacked telescopic lens structure according to claim 7 or 8, characterized in that, The damping friction element is a rubber ring or rubber pad made of rubber products. After installation, the damping friction element is in interference contact, and the overall frictional resistance does not exceed the elastic force of the telescopic spring (4).

10. The handheld stacked telescopic lens structure according to claim 9, characterized in that, The limiting sleeve shoulder (21) has 1-3 annular grooves for nesting a corresponding number of nitrile rubber O-rings, ensuring that the O-rings are higher than the outer wall of sleeve A to form an interference fit; and / or, silicone damping grease is pre-applied to the inner wall of the sliding sleeve (1), so that the surface of the silicone damping grease contacts the limiting sleeve shoulder (21) and / or the nitrile rubber O-rings, generating frictional resistance of interference fit, which is used to offset part of the elastic force of the telescopic spring (4), so that the telescopic spring (4) slows down the extension speed.

Images