A zoom lens aperture automatic adjusting mechanism based on cam curve

Abstract

This invention relates to the field of optical lens technology and provides an automatic aperture adjustment mechanism for zoom lenses based on a cam curve. The mechanism includes a base and an aperture adjustment module. The aperture adjustment module includes a drive component, a transmission ring, and blades. The drive component controls the rotation of the transmission ring. A linear guide rail is provided on the surface of the transmission ring. The blades slide against the base and the transmission ring. A movable pin is fixedly connected to the surface of the blades. The movable pin slides within a cam groove and the linear guide rail. A groove structure and a flange structure are respectively provided on both sides of the blades. The groove structure and the flange structure are located near the transmission ring and near the base, respectively. A protrusion structure is provided at the end of the flange structure near the center of the transmission ring. The groove structure and flange structure of two adjacent sets of blades slide against each other. The protrusion structure and the groove structure slide in contact perpendicular to the side of the blade. This mechanism features high precision in blade coordinated movement and ease of maintenance.

Description

Technical Field

[0001] This invention relates to the field of optical lens technology, specifically to an automatic aperture adjustment mechanism for zoom lenses based on a cam curve. Background Technology

[0002] The core principle of automatic aperture adjustment in zoom lenses based on cam curves is to utilize the trajectory constraints of the cam profile and the force conversion of the transmission mechanism to transform the rotational motion of the drive module into the radial synchronous opening and closing of the aperture blades, achieving precise control of the amount of light entering the lens. A cam is a component with a specific profile curve (such as a circular cam or an irregularly shaped cam), and its profile curve is designed according to the correspondence between aperture opening and blade displacement (e.g., a linear curve for stepless adjustment, and a stepped curve for step adjustment). In zoom lenses, the cam is usually integrated into the zoom barrel or a separate drive ring.

[0003] There are two main structures for existing aperture blades, both of which have the following drawbacks:

[0004] Overlapping blades, where adjacent blades only adhere to each other on their surfaces, are prone to misalignment, jamming, and uneven gaps after long-term use due to wear of the sliding grooves and loosening of the movable pins. This results in large deviations in the roundness of the light aperture and distortion of the out-of-focus image. Furthermore, uneven stress on the blades can easily lead to unilateral tilting, which exacerbates wear.

[0005] The blades are aligned without overlap, and light blocking is achieved only by aligning the edges. Although this avoids jamming, it is prone to light leakage due to processing errors and assembly gaps, especially in small aperture mode, which can lead to glare and reduced contrast in the image.

[0006] When adding lubricating oil to the blades, the lens housing needs to be disassembled, which can easily damage the optical components. Summary of the Invention

[0007] The purpose of this invention is to provide an automatic aperture adjustment mechanism for zoom lenses based on a cam curve, which aims to solve the problems existing in the current aperture blades.

[0008] To achieve the above objectives, the present invention provides the following technical solution: an automatic aperture adjustment mechanism for a zoom lens based on a cam curve, comprising a base, wherein a cam groove is provided on the inner side of the base, the cam groove having a regular hexagonal outline, and further comprising:

[0009] An aperture adjustment module includes a driving component, a transmission ring, and blades. The driving component controls the rotation of the transmission ring. A linear guide rail is provided on the surface of the transmission ring. The blades slide against the base and the transmission ring. A movable pin is fixedly connected to the surface of the blades. The movable pin is slidably disposed in the cam groove and the linear guide rail.

[0010] The blade is provided with a groove structure and a flange structure on both sides. The groove structure and the flange structure are located on the side closer to the transmission ring and the side closer to the base, respectively. The flange structure is provided with a protrusion structure at the end closer to the center of the transmission ring. The groove structure and the flange structure of two adjacent sets of blades slide in contact. The protrusion structure and the groove structure slide in contact on the side perpendicular to the blade.

[0011] As a further embodiment of the present invention, both the base and the transmission ring are provided with annular grooves. The annular grooves are filled with lubricant and flexible sealing rings. The flexible sealing rings protrude from one side of the base and the transmission ring surfaces and can slide in contact with the blades. One end of the flexible sealing ring near the annular groove is provided with an incline groove, and the other end of the flexible sealing ring is provided with several through holes. The lubricant is filled in the incline groove.

[0012] As a further embodiment of the present invention, a limiting shell is also included. The base and the limiting shell are respectively provided with BOSS post one and BOSS post two. The limiting shell is fixedly connected to BOSS post one. The radial side of the transmission ring is in sliding contact with BOSS post one. The limiting shell is provided with a fixing ring. The axial side of the transmission ring is in sliding contact with the fixing ring.

[0013] As a further embodiment of the present invention, a plurality of fixing pins are fixedly provided on the side of the transmission ring near the limiting shell, a gear ring is provided on the outer side of the transmission ring, the gear ring is connected to the driving component for transmission, and the driving component is fixedly connected to the limiting shell.

[0014] As a further embodiment of the present invention, it also includes an adjusting ring, wherein a threaded ring is provided on the radial side of the adjusting ring, the threaded ring is threadedly connected to the limiting shell, and the fixing pin is in contact with the axial side of the threaded ring.

[0015] As a further embodiment of the present invention, the surfaces of the limiting shell and the adjusting ring are respectively provided with an arc-shaped guide rail one and an arc-shaped guide rail two, the fixing pin passes through the arc-shaped guide rail one, and the BOSS post two passes through the arc-shaped guide rail two.

[0016] As a further embodiment of the present invention, a top cover is also included, wherein the adjusting ring is disposed between the limiting shell and the top cover, and the top cover is fixedly connected to the BOSS column.

[0017] As a further embodiment of the present invention, rigid sealing rings are provided on both sides of the adjusting ring, and sealing grooves are provided on the surfaces of the base and the top cover, with the rigid sealing rings slidably disposed within the sealing grooves.

[0018] As a further embodiment of the present invention, the compression of the flexible sealing ring is no more than 3.5 mm, and the maximum rotation angle of the adjusting ring is 60 degrees.

[0019] The beneficial effects of this invention are:

[0020] (1) The present invention improves the accuracy of blade coordinated movement by integrating the groove, flange and protrusion structure into a blade structure. It also has the advantage of strong light blocking of overlapping blades. At the same time, it solves the problem of light leakage caused by long-term wear of docking blades and the problems of asynchronous movement, offset and jamming caused by long-term wear of overlapping blades.

[0021] (2) The adjusting ring of the present invention is connected to the transmission ring by a fixed pin. When the adjusting ring is rotated, the fixed pin drives the transmission ring to move axially by a preset distance, thereby compressing the flexible sealing ring and ensuring the extrusion of lubricant. After the adjusting ring is reset, the transmission ring returns to its original position, without affecting the normal aperture adjustment, so as to achieve uniform application of lubricating oil on the blade surface. Lubrication can be replenished without disassembly, and it has the characteristics of easy maintenance. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0023] Figure 1 This is an exploded view of the present invention;

[0024] Figure 2 This is a perspective view of the present invention;

[0025] Figure 3 This is a perspective view of the blade of the present invention;

[0026] Figure 4 This is a cross-sectional view of the blade of the present invention;

[0027] Figure 5 This is a first plan view of the aperture adjustment module of the present invention;

[0028] Figure 6 This is a second plan view of the aperture adjustment module of the present invention;

[0029] Figure 7 This is an exploded view of the base and flexible sealing ring of the present invention;

[0030] Figure 8 This is an exploded view of the transmission ring and flexible sealing ring of the present invention;

[0031] Figure 9 This is a perspective view of the limiting shell of the present invention;

[0032] Figure 10 This is a perspective view of the adjusting ring of the present invention;

[0033] Figure 11 This is a first sectional view of the present invention;

[0034] Figure 12 For the present invention Figure 11 A magnified view of a portion of point a.

[0035] Figure 13 This is a second cross-sectional view of the present invention.

[0036] Explanation of the labels in the diagram:

[0037] 100. Base; 110. Cam groove; 120. BOSS post one; 200. Aperture adjustment module; 210. Drive component; 220. Transmission ring; 221. Linear guide rail; 222. Fixing pin; 230. Blade; 231. Movable pin; 232. Slotted structure; 233. Flanged structure; 2331. Raised structure; 240. Gear ring; 300. Sealing groove; 400. Limiting shell; 410. Fixing ring; 420. Arc guide rail one; 430. BOSS post two; 500. Adjusting ring; 510. Threaded ring; 520. Arc guide rail two; 530. Rigid sealing ring; 600. Top cover; 700. Annular groove; 800. Flexible sealing ring; 810. Through hole; 820. C-shaped groove. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0039] Please see Figures 1 to 13 In one embodiment of the present invention, a zoom lens aperture automatic adjustment mechanism based on a cam curve includes a base 100, wherein a cam groove 110 is provided on the inner side of the base 100, the cam groove 110 having a regular hexagonal outline, and further includes:

[0040] An aperture adjustment module 200 includes a drive component 210, a transmission ring 220, and a blade 230. The drive component 210 controls the rotation of the transmission ring 220. A linear guide rail 221 is provided on the surface of the transmission ring 220. The blade 230 is slidably attached between the base 100 and the transmission ring 220. A movable pin 231 is fixedly connected to the surface of the blade 230. The movable pin 231 is slidably disposed in the cam groove 110 and the linear guide rail 221.

[0041] The blade 230 is provided with a groove structure 232 and a flange structure 233 on both sides. The groove structure 232 and the flange structure 233 are located on the side near the transmission ring 220 and the side near the base 100, respectively. The flange structure 233 is provided with a protrusion structure 2331 at the end near the center of the transmission ring 220. The groove structure 232 and the flange structure 233 of two adjacent sets of blades 230 slide in contact. The protrusion structure 2331 slides in contact with the groove structure 232 on the side perpendicular to the blade 230.

[0042] Please see Figures 3 to 6 Furthermore, it also includes a limiting shell 400. The base 100 and the limiting shell 400 are respectively provided with BOSS post 120 and BOSS post 230. The limiting shell 400 is fixedly connected to BOSS post 120. The radial side of the transmission ring 220 is in sliding contact with BOSS post 120. The limiting shell 400 is provided with a fixing ring 410. The axial side of the transmission ring 220 is in sliding contact with the fixing ring 410.

[0043] Please see Figures 5 to 6 Furthermore, a plurality of fixing pins 222 are fixedly provided on the side of the transmission ring 220 near the limiting shell 400, and a gear ring 240 is provided on the outer side of the transmission ring 220. The gear ring 240 is connected to the driving member 210 in a transmission connection, and the driving member 210 is fixedly connected to the limiting shell 400.

[0044] In this embodiment of the invention, the driving component 210 controls the transmission ring 220 and the blade 230 to rotate along the trajectory of the cam groove 110 via the gear ring 240. Simultaneously, the blade 230 moves radially along the linear guide rail 221 via the movable pin 231 to achieve aperture size adjustment. Unlike the overlapping and mating blades 230 in the prior art, this invention uses a groove structure 232 and a flange structure 233 that overlap or fit together within the plane of the blade 230, similar to the overlapping blades 230 in the prior art. This provides better light-blocking effect. The protruding structure 2331 at the end of the flange structure 233 slides against the side of the groove structure 232 perpendicular to the blade 230, ensuring that even if one of them... When the movable pin 231 or its corresponding linear guide 221 in the blade group 230 becomes out of sync due to long-term wear, it can still provide driving force or tangential force through the cooperation of the protrusion structure 2331 and the surface. The cooperation of the protrusion structure 2331 and the surface can concentrate the pressure between the two adjacent blade groups 230 at the end away from the movable pin 231, which can ensure the consistency of torque and improve the accuracy of the coordinated movement of the blades 230. It not only has the advantage of strong light blocking of the overlapping blades 230 in the prior art, but also solves the light leakage problem of the docking blades 230 due to long-term wear, as well as the problems of asynchronous movement, offset and jamming of the overlapping blades 230 due to long-term wear.

[0045] Please see Figures 7 to 13 In another embodiment of the present invention, both the base 100 and the transmission ring 220 are provided with annular grooves 700. The annular grooves 700 are filled with lubricant and flexible sealing rings 800. The flexible sealing ring 800 protrudes from one side of the surface of the base 100 and the transmission ring 220 and can slide in contact with the blade 230. One end of the flexible sealing ring 800 near the annular groove 700 is provided with a chamfered groove 820, and the other end of the flexible sealing ring 800 is provided with a plurality of through holes 810. The lubricant is filled in the chamfered groove 820.

[0046] In this embodiment of the invention, the flexible sealing ring 800 is made of wear-resistant silicone, and the lubricant is a high-viscosity lubricant, such as grease. The sealing ring protrudes from the surface and slides in contact with the blade 230, thus providing both sealing and lubrication. The through hole 810 design of the flexible sealing ring 800 ensures that the lubricant is squeezed out and prevents dust from entering the groove 820.

[0047] Please see Figures 10 to 13 In another embodiment of the present invention, an adjusting ring 500 is further included, wherein a threaded ring 510 is provided on the radial side of the adjusting ring 500, the threaded ring 510 is threadedly connected to the limiting shell 400, and the fixing pin 222 contacts the axial side of the threaded ring 510.

[0048] Please see Figures 3 to 6 Furthermore, the surfaces of the limiting shell 400 and the adjusting ring 500 are respectively provided with an arc-shaped guide rail 420 and an arc-shaped guide rail 520, the fixing pin 222 passes through the arc-shaped guide rail 420, and the BOSS post 430 passes through the arc-shaped guide rail 520.

[0049] Please see Figure 1 , Figure 2 and Figure 11 Furthermore, it also includes a top cover 600, the adjusting ring 500 is disposed between the limiting shell 400 and the top cover 600, the top cover 600 is fixedly connected to the BOSS column 430, rigid sealing rings 530 are provided on both sides of the adjusting ring 500, and sealing grooves 300 are provided on the surfaces of the base 100 and the top cover 600, and the rigid sealing rings 530 are slidably disposed in the sealing grooves 300.

[0050] In this embodiment of the invention, the base 100 or top cover 600 is provided with scales (0°, 20°, 40° and 60°). The BOSS column 2 passes through the arc-shaped guide rail 2 520, limiting the rotation angle of the adjusting ring 500 (maximum 60 degrees) to avoid over-adjustment and damage to the sealing ring. When the adjusting ring 500 is rotated to the corresponding scale position, the transmission ring 220 can be driven to move axially a preset distance through the fixing pin 222, thereby compressing the flexible sealing ring 800. The compression of the flexible sealing ring 800 is no more than 3.5mm, which ensures both the fit with the blade 230 and avoids excessive friction. Since the outer surface of the flexible sealing ring 800 is coated with lubricating oil, and the incised groove 820 on its back side is filled with lubricating oil (the lubricating oil is similar to solid or high-viscosity butter and cannot flow directly from the through hole 810), when the two sides of the blade 230 slide in contact with the outer surface of the flexible sealing ring 800, the blade 230 can be lubricated. Since the lubricating oil needs to be reapplied after long-term use, To solve the problem of needing to disassemble the outer casing for applying lubricating oil, this invention only requires rotating the adjusting ring 500 according to the scale indication on the top cover 600 or the base 100. Through the engagement of the threaded ring 510 with the threaded groove on the inner side of the limiting shell 400, the adjusting ring 500 can drive the transmission ring 220 to move axially a preset distance via the fixing pin 222. At this time, the flexible sealing rings 800 distributed on both sides of the blade 230 are compressed to a certain extent. The compressed flexible sealing rings 800 cause a portion of the lubricating oil in the I-groove 820 to be squeezed out from the through hole 810. Controlling the adjustment ring 500 to reset does not affect the normal aperture adjustment. When the blade 230 is controlled to open and close using the drive component 210, the lubricating oil can be automatically and evenly applied to its surface, realizing automatic lubricating oil replenishment and application.

[0051] In summary, the present invention, through the structural innovation of the integrated blade 230 with groove, flange and protrusion structure 2331, not only improves the accuracy of the coordinated movement of the blade 230, but also has the advantage of strong light blocking of the overlapping blade 230. At the same time, it solves the problem of light leakage caused by long-term wear of the docking blade 230 and the problems of asynchronous movement, offset and jamming of the overlapping blade 230 caused by long-term wear.

[0052] The adjusting ring 500 of the present invention is connected to the transmission ring 220 via the fixing pin 222. When the adjusting ring 500 is rotated, the fixing pin 222 drives the transmission ring 220 to move axially a preset distance, thereby compressing the flexible sealing ring 800 and ensuring the extrusion of lubricant. After the adjusting ring 500 is reset, the transmission ring 220 returns to its original position without affecting the normal aperture adjustment, thus achieving uniform application of lubricating oil on the surface of the blade 230. Lubrication can be replenished without disassembly, making it easy to maintain.

[0053] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0054] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. A cam curve-based automatic adjusting mechanism for zoom lens aperture, comprising a base (100), a cam groove (110) is arranged inside the base (100), the profile of the cam groove (110) is a regular hexagon, characterized in that, Also include: The aperture adjusting module (200) includes a driving piece (210), a transmission ring (220) and a blade (230), the driving piece (210) is used to control transmission ring (220) rotation, the transmission ring (220) surface is provided with linear guide (221), the blade (230) slidingly fits between base (100) and transmission ring (220), the blade (230) surface is fixedly connected with movable pin (231), the movable pin (231) is slidably arranged in cam groove (110) and linear guide (221) inside; The blade (230) both sides are provided with the sunken groove structure (232) and the flanging structure (233) respectively, the sunken groove structure (232) and the flanging structure (233) are located at the side close to transmission ring (220) and close to base (100) respectively, the flanging structure (233) is close to the one end of transmission ring (220) center and is provided with convex structure (2331), the sunken groove structure (232) of adjacent two groups of blade (230) and flanging structure (233) slidingly fit, the convex structure (2331) and sunken groove structure (232) perpendicular to the one side of blade (230) sliding contact; The surface of base (100) and transmission ring (220) is provided with annular groove (700), the annular groove (700) is filled with lubricant and flexible sealing ring (800), the one side of flexible sealing ring (800) protruding from the surface of base (100) and transmission ring (220) can be in sliding contact with blade (230), the one end of flexible sealing ring (800) close to annular groove (700) is provided with the n-shaped groove (820), the other end of flexible sealing ring (800) is provided with a plurality of through holes (810), the lubricant is filled in n-shaped groove (820); Also include limit shell (400), base (100) and limit shell (400) are provided with BOSS column one (120) and BOSS column two (430) respectively, limit shell (400) is fixedly connected with BOSS column one (120), the radial side of transmission ring (220) is in sliding contact with BOSS column one (120), limit shell (400) is provided with fixed ring (410), the axial side of transmission ring (220) is in sliding contact with fixed ring (410); The surface of transmission ring (220) is fixedly provided with a plurality of fixed pins (222) on the one side close to limit shell (400), the outer side of transmission ring (220) is provided with gear ring (240), gear ring (240) is in transmission with driving piece (210), driving piece (210) is fixedly connected with limit shell (400).

2. A cam curve-based automatic aperture adjusting mechanism for a zoom lens according to claim 1, characterized in that, Also include adjusting ring (500), the radial side of adjusting ring (500) is provided with threaded ring (510), threaded ring (510) is threadedly connected in limit shell (400), fixed pin (222) and the axial side of threaded ring (510) contact.

3. A cam curve-based automatic aperture adjusting mechanism for a zoom lens according to claim 2, characterized in that, The limiting shell (400) and the adjusting ring (500) are respectively provided with arc-shaped guide rails one (420) and two (520), the fixed pin (222) penetrates the arc-shaped guide rail one (420), and the BOSS column two (430) penetrates the arc-shaped guide rail two (520).

4. A cam curve-based automatic aperture adjusting mechanism for a zoom lens according to claim 3, characterized in that, A top cover (600) is further included, the adjusting ring (500) is arranged between the limiting shell (400) and the top cover (600), and the top cover (600) is fixedly connected with the BOSS column two (430).

5. A cam curve-based automatic aperture adjusting mechanism for a zoom lens according to claim 4, characterized in that, Rigid sealing rings (530) are arranged on both sides of the adjusting ring (500), and the surfaces of the base (100) and the top cover (600) are provided with sealing grooves (300), and the rigid sealing rings (530) are slidingly arranged in the sealing grooves (300).

6. A cam curve-based automatic aperture adjusting mechanism for a zoom lens according to claim 2, characterized in that, The compression amount of the flexible sealing ring (800) is not greater than 3.5 mm, and the maximum rotation angle of the adjusting ring (500) is 60 degrees.

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