A multi-degree-of-freedom fine adjustment device for lenses of a lens barrel

Abstract

A kind of lens multi-degree-of-freedom fine adjustment device for lens barrel is constituted by mirror frame and adjusting frame assembly, mirror frame is connected with adjusting frame assembly by three groups of uniform adjusting mechanism, each group of mechanism includes cam, fine adjustment screw and counterforce tension spring, cam is hinged to adjusting frame by rotating pin, and the ball head top is contacted with the V-shaped groove of mirror frame eaves;Fine adjustment screw converts horizontal driving force into accurate displacement of mirror frame local or whole by pushing the tail of cam or directly contacting the side of mirror frame;By selectively adjusting fine adjustment screw, lens can be driven to carry out eccentric, tilt and air interval three-degree-of-freedom fine adjustment, without disassembling lens barrel or using glue temporary fixation.The utility model discloses compact structure, and adjusting precision is high, stability is good, effectively solve the difficult problem that compensation lens is difficult to real-time accurate adjustment in optical machine system installation and adjustment, significantly improve installation and adjustment efficiency and system consistency.

Description

Technical Field

[0001] This utility model relates to the field of optomechanical assembly and adjustment technology, specifically to a multi-degree-of-freedom fine-tuning device for lenses in a lens barrel and its assembly and adjustment method. Background Technology

[0002] In an optomechanical system, lenses are the fundamental building blocks of the optical system. To perform correct optical functions and ensure good optical quality, lenses need to be precisely positioned and installed. This precision includes the coaxiality of the lens axis with the optical axis (i.e., lens tilt and eccentricity) and the positional dimensions between lenses (i.e., air gap). Due to limitations in current manufacturing technology and measurement errors, there are unavoidable dimensional errors in the internal precision of the lens barrel structure and the external precision of the lenses themselves. During lens assembly, it is difficult to guarantee the proper fit between the outer diameter of the lens and the inner diameter of the lens barrel, significantly affecting the lens's optical performance. Therefore, an optical system requires a lens element within the lens group as compensation, allowing for fine-tuning in terms of tilt, eccentricity, and air gap.

[0003] Currently, there are two common methods for lens barrel assembly and adjustment in the industry: one is to directly center the lens barrel to ensure the coaxiality and air gap between the lens frame and the lens barrel, and then install the lenses sequentially inside the lens barrel. This method has high precision, but it cannot achieve subsequent fine-tuning of eccentricity and tilt. The other method is to use a center polarimeter to adjust the lenses sequentially inside the lens barrel, and then directly glue and fix them on site with photosensitive adhesive. This method can achieve high precision if it takes a certain amount of time, but it is complicated to operate, time-consuming and labor-intensive, and requires multiple disassembly and assembly during fine-tuning. If an operation error occurs, the adhesive will contaminate other lenses or accidentally touch the already adjusted lens.

[0004] In summary, existing technologies lack a compact, easy-to-operate device capable of real-time, multi-degree-of-freedom fine-tuning of lens eccentricity, tilt, and air gap without disassembling other lenses. Therefore, there is an urgent need to develop a high-precision, reusable, and easy-to-implement lens adjustment device and method suitable for use inside the lens barrel, in order to improve the assembly efficiency, accuracy, and reliability of optical systems. Summary of the Invention

[0005] This invention addresses the aforementioned problems by proposing a lens eccentricity and tilt adjustment device and method for lens barrels. It employs a three-point cam reduction structure, combined with a tension spring and fine-tuning bolts, to fine-tune the lens in three aspects: eccentricity, tilt, and air gap, achieving efficient, stable, and high-precision lens adjustment.

[0006] This utility model is achieved through the following technical solution: On the one hand, this utility model provides a multi-degree-of-freedom fine-tuning device for lenses in a lens barrel, characterized in that it includes: A frame for holding lenses; An adjustment frame assembly coaxially fitted onto the outside of the frame; The mirror frame and the adjustment frame assembly are connected by at least three sets of circumferentially distributed adjustment mechanisms. Each set of adjustment mechanisms includes: A first functional part disposed on the frame; A support unit disposed on the adjustment frame assembly and in contact with the first actuating part, the support unit being configured to convert the received horizontal driving force into a support force perpendicular to the horizontal driving force and act on the first actuating part; And a drive unit disposed on the adjustment frame assembly for providing the horizontal driving force to the support unit; By selectively operating the drive unit, the magnitude and distribution of the supporting force exerted by the support unit on the first action part can be controlled, thereby driving the frame and the lens it carries to move relative to the adjustment frame assembly in at least one of eccentric, tilt, and air gap movements.

[0007] Furthermore, the support unit is a cam, which is rotatably connected to the adjustment frame of the adjustment frame assembly via a pivot pin; the top of the cam constitutes the output end of the support unit and contacts the first action part; the tail of the cam constitutes the receiving end of the support unit and is connected to the drive unit.

[0008] Furthermore, the first functional part is a V-shaped groove formed on the bottom surface of the outer edge of the frame; the top of the cam is spherical and forms line contact with the V-shaped groove.

[0009] Furthermore, the drive unit is a fine-tuning screw, which is helically connected to the side wall of the adjustment frame; the end of the fine-tuning screw contacts the tail of the cam, and the tail of the cam is pushed or pulled by screwing the fine-tuning screw in or out, thereby providing the horizontal driving force.

[0010] Furthermore, the outer wall of the frame is provided with a second working part that directly contacts the end of the fine-tuning screw; the end of the fine-tuning screw is a ball head structure, and the second working part is a plane, so the two form a point contact.

[0011] Furthermore, the cam is configured such that the center of its output end, the axis of the pivot pin, and the contact point of its receiving end are collinear, forming a lever mechanism.

[0012] Furthermore, it also includes a pre-tensioning element; the pre-tensioning element is a reaction spring connected between the mirror frame and the adjustment frame, used to provide a pre-tensioning force to the mirror frame pointing towards the adjustment frame, ensuring that each contact pair in the adjustment mechanism always maintains tight contact.

[0013] On the other hand, this utility model also provides a lens adjustment method using the above-mentioned device, characterized by comprising the following steps: S1: Assemble the adjustment unit, fix the lens inside the frame, and connect the frame to the adjustment frame assembly through the adjustment mechanism; S2: Install the assembled adjustment unit into the predetermined position inside the lens barrel; S3: Through optical measurement, identify the deviations between the current pose of the lens and the target pose in terms of eccentricity, tilt, and air gap; S4: Based on the deviation, select an adjustment strategy and operate the corresponding drive unit: When performing eccentric adjustment, the frame is driven collaboratively by multiple drive units to produce in-plane translation. When tilting is adjusted, at least one of the driving units drives the corresponding support unit to change its support height on a local area of ​​the frame, causing the frame to deflect. When adjusting the air gap, all the drive units work together to drive all the support units, causing the frame to move axially as a whole. S5: After reaching the target pose, lock the drive unit.

[0014] Furthermore, after the eccentric adjustment or air gap adjustment, when locking the drive unit, each drive unit is gradually locked in a cyclical and alternating manner to maintain the stability of the frame posture.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: It can be directly installed inside the lens barrel without disassembling other lens frames. It can be used with other instruments to fine-tune the lens in three aspects: eccentricity, tilt, and air gap, effectively ensuring the efficiency and accuracy of the assembly and adjustment. The device has high adjustment accuracy, low processing cost, stable performance, and can be reused repeatedly, ensuring the consistency and interchangeability of each lens barrel, greatly reducing the adjustment cost and safety risks, and achieving efficient, stable, and high-precision lens barrel adjustment. Attached Figure Description

[0016] Figure 1 This is an exploded view of an embodiment of the multi-degree-of-freedom fine-tuning device for lens barrels of this utility model; Figure 2 This is a schematic diagram of the frame portion of this utility model; Figure 3 This is a schematic diagram of the adjustment frame component in this utility model; Figure 4 This is a cross-sectional view of the adjustment frame assembly of this utility model; Figure 5This is a schematic diagram of the cam part of this utility model; Figure 6 This is a diagram showing the state of the present invention when used inside the lens barrel; Figure 7 This is a schematic diagram of an embodiment of the multi-degree-of-freedom fine-tuning device for lens barrels according to the present invention; The components shown in the diagram are: frame 1, adjustment frame assembly 2, adjustment frame 3, cam 4, reaction spring 5, pivot pin 6, and fine-tuning screw 7. Detailed Implementation

[0017] The preferred embodiments of a lens eccentricity and tilt adjustable device and method for an eyepiece barrel provided by this utility model will be described in detail below with reference to the accompanying drawings and examples. Those skilled in the art should understand that the following description is intended to illustrate the principles and best implementation of this utility model, and not to limit the scope of protection of this utility model.

[0018] like Figures 1 to 4 As shown, the embodiment of the multi-degree-of-freedom fine-tuning device for lens barrels of this utility model comprises a frame 1 and an adjustment frame assembly 2. The frame 1 is a basin-shaped frame with an outer rim. Three V-shaped grooves are evenly distributed at 120° intervals along the bottom surface of the outer rim. These V-shaped grooves serve as the primary actuating part, providing precise guidance and positioning. Each V-shaped groove has hanging holes on both sides for attaching reaction springs. Figure 2 As shown, three planes are evenly distributed on the outer surface of the frame 1 at a position 60° circumferentially offset from the V-groove. These three planes serve as the second working part, providing a stable and repeatable contact interface for horizontal eccentric adjustment, that is, achieving effective contact with the ball head of the adjusting screw during eccentric adjustment. The lens can be fixed to the frame 1 by high-precision optical adhesive bonding or mechanical pressure ring.

[0019] The adjustment frame assembly 2 is coaxially sleeved on the outside of the lens frame 1, and includes: an adjustment frame 3, a cam 4, a reaction spring 5, a pivot pin 6, and a fine-tuning screw 7. The adjustment frame 3 serves as the base of the entire device, and its outer cylindrical surface is precision ground or centered to form a high-precision clearance or transition fit with the inner hole of the lens barrel. Its front and rear end faces ensure strict parallelism and flatness to ensure correct orientation during installation inside the lens barrel.

[0020] See Figure 3 and Figure 4 Three cams 4 are rotatably mounted in corresponding flip grooves on the adjusting frame 3 via pivot pins 6, forming a rotating hinge. The top surface of the cam 4 is ball-head shaped, which forms line contact with the V-groove on the bottom surface of the outer edge of the mirror frame 1, constituting the first contact pair. This "ball-V-groove" fit ensures effective force transmission while allowing relative sliding between the two during adjustment, preventing jamming.

[0021] like Figure 5 As shown, the geometric relationship is designed as follows: the center of the ball head of cam 4 (point A), the axis of pivot pin 6 (point O), and the contact point between the tail of cam 4 and the drive unit (point B) are on the same straight line. The line connecting the center of the ball head of cam 4 and the horizontal push-pull contact point passes through the center of the rotating shaft. These three points are on a straight line, forming a geometric relationship with a fixed proportion. This "three-point collinearity" lever design allows the displacement generated by horizontally pushing and pulling point B to be accurately converted into the vertical lifting displacement of the ball head A with a fixed and calculable transmission ratio. This relationship is the theoretical basis for achieving high-precision and predictable adjustment. Horizontally pushing and pulling the tail of cam 4, through its own rotation, achieves the lifting and lowering of the ball head of cam 4, realizing the adjustment of the corresponding point of the mirror frame 1.

[0022] Three sets of fine-tuning screws 7 serve as driving units, evenly distributed on the side wall of the adjustment frame 3 via threaded joints. They are fixedly installed on the side of the adjustment frame 3, with their installation positions corresponding to the three planes on the outer side of the lens frame 1. The end of the fine-tuning screw 7 has a ball-head structure, which forms a point contact with the plane of the lens frame 1, constituting a second contact pair. This "point-to-plane" contact effectively reduces frictional resistance, making the adjustment more sensitive. The screw portion of the fine-tuning screw 7 should not protrude beyond the outer circle of the adjustment frame 3 to ensure that the device can be smoothly installed into the lens barrel. The ball head of the fine-tuning screw 7 protrudes from the inner side of the adjustment frame 1, contacting the three planes on the side of the lens frame 1, achieving horizontal eccentricity adjustment and locking of the lens frame 1.

[0023] Three sets of reaction springs 5 ​​serve as preload elements, with their upper and lower hooks fixed to the hanging holes at the bottom of the adjusting frame 3 (on both sides of each cam 4) and the hanging holes on the outer edge of the mirror frame 1, respectively. The preload of the springs 5 ​​provides a stable initial state for the entire system, ensuring that the first and second contact pairs are always in close contact in any adjustment direction, completely eliminating gaps, thereby guaranteeing the accuracy, repeatability, and stability of the adjustment after locking.

[0024] The assembly and adjustment method of this utility model, based on the above-mentioned device, specifically includes the following steps: S1. Component Pre-assembly and Lens Fixing: After precision machining or centering, the adjusting frame 3 ensures the fit between the outer circle and the lens barrel, as well as the parallelism and flatness of the front and rear end faces. The cam 4, pivot pin 6, reaction spring 5, and fine-tuning screw 7 are installed onto the adjusting frame 3 to form the adjusting frame assembly 2. Subsequently, the compensating lens is precisely fixed inside the lens frame 1 by bonding or pressing.

[0025] S2. Unit Assembly: Carefully insert the frame 1 with the lens fixed into the adjusting frame assembly 2, ensuring that the ball heads of the three cams 4 fall into the three V-grooves on the outer edge of the frame 1, while the ball heads of the three fine-tuning screws 7 contact the three planes on the outer side of the frame 1. At this time, under the action of the reaction spring 5, the entire device forms a stable pre-tightening system.

[0026] S3. System Integration: The assembled adjustment unit is installed as an independent module into the predetermined position of the microscope tube along the axial direction. The precise fit between the outer circle of the adjustment frame 3 and the inner hole of the microscope tube ensures the initial positioning accuracy of the device.

[0027] S4. Optical Measurement and Deviation Analysis: Using optical measurement equipment such as interferometers and center offset measuring instruments, the imaging quality of the entire optical system, including this compensation lens, is tested, and the required adjustment amount and direction of the compensation lens in the three dimensions of eccentricity, tilt and air gap are quantitatively analyzed.

[0028] S5. Precise fine-tuning of execution: Offset Adjustment: By measuring the quality of the optical system, the adjustment method of the compensating lens is determined. If there is an off-center, the three fine-tuning screws 7 on the side of the adjustment frame 3 are adjusted. Their ball heads directly push the plane on the side of the frame 1, causing the frame 1 and the lens to move as a whole in a plane perpendicular to the optical axis until the mechanical axis of the lens is in the desired position. The three fine-tuning screws 7 are then tightened gradually in a cyclic manner.

[0029] Tilting Adjustment: To correct tilt, selectively adjust one or two fine-tuning screws 7 according to the tilt direction, causing a point on the lens to move up or down until the lens surface is in the desired position. This operation transmits force to the tail of cam 4 through frame 1, driving cam 4 to rotate around pivot pin 6. Utilizing its lever principle, the horizontal thrust is converted into the lifting and lowering motion of the ball joint of cam 4, thereby raising or lowering a part of frame 1 to achieve precise correction of lens tilt.

[0030] Air gap adjustment: If the air gap needs to be adjusted, simultaneously and equally screw in or out the three fine-tuning screws 7 to move the lens axially back and forth as a whole until the distance between the lens and the front and rear lenses is at the desired position. This operation drives the three cams 4 to rotate synchronously, thereby pushing the frame 1 and the lens to move axially as a whole along the optical axis, precisely adjusting the distance between them and the front and rear lenses.

[0031] S6. Final Locking: After repeated measurements and fine-tuning until the optical system reaches optimal performance, gradually tighten the three fine-tuning screws 7 using a crisscross, cyclical method. This step is crucial to prevent frame deformation or positional drift caused by single-point tightening, ensuring the stable maintenance of the adjusted state.

[0032] Based on the geometry of cam 4, the relationship between the horizontal push-pull distance and the ball joint lifting distance can be derived: like Figure 5As shown, let the straight-line distance from the center of the ball head to the pivot point be r, the vertical distance from the center of the ball head to the pivot point be h, the straight-line distance from the horizontal push-pull contact point to the pivot point be R, and the vertical distance from the horizontal push-pull contact point to the pivot point be H. If the horizontal feed is Δd, causing the boss to rotate by θ and the vertical change of the boss by Δh, then the relationship can be derived as follows:

[0033] like Figure 6 The image shows the installation state of this invention during the actual lens barrel adjustment process, as well as its positional relationship with the front and rear sets of lens frames.

[0034] This invention, through the aforementioned specific mechanical structure and operating procedure, transforms the complex optomechanical assembly and adjustment into a controllable and highly repeatable mechanical fine-tuning operation. Its core concepts of "three-point support" and "force-motion conversion," using a three-point cam reduction structure, in conjunction with tension springs and fine-tuning bolts, enable fine-tuning of the lens in three aspects: eccentricity, tilt, and air gap, achieving efficient, stable, and high-precision lens adjustment.

[0035] The above-described specific implementations can be partially adjusted by those skilled in the art in different ways without departing from the principles and purpose of this utility model. The scope of protection of this utility model is determined by the claims and is not limited to the above-described specific implementations. All implementation schemes within its scope are bound by this utility model.

Claims

1. A multi-degree of freedom fine adjustment device for a lens of a lens barrel, characterized by, include: A frame for holding the lens (1); An adjustment frame assembly (2) is coaxially fitted outside the frame (1); The frame (1) and the adjustment frame assembly (2) are connected by at least three sets of circumferentially distributed adjustment mechanisms; Each set of adjustment mechanisms includes: A first functional part disposed on the frame (1); A support unit disposed on the adjustment frame assembly (2) and in contact with the first action part, the support unit being configured to convert the received horizontal driving force into a support force perpendicular to the horizontal driving force and act on the first action part; And a drive unit disposed on the adjustment frame assembly (2) for providing the horizontal driving force to the support unit; By selectively operating the drive unit, the magnitude and distribution of the support force exerted by the support unit on the first action part can be controlled, thereby driving the frame (1) and the lens it carries to move relative to the adjustment frame assembly (2) in at least one of eccentric, tilt and air gap motion.

2. The lens multi-degree-of-freedom fine adjustment device for a lens barrel according to claim 1, characterized by, The support unit is a cam (4), which is rotatably connected to the adjustment frame (3) of the adjustment frame assembly (2) via a pivot pin (6); the top of the cam (4) constitutes the output end of the support unit and contacts the first working part; the tail of the cam (4) constitutes the receiving end of the support unit and is connected to the drive unit.

3. The lens multi-degree-of-freedom fine adjustment device for a lens barrel according to claim 2, characterized by, The first functional part is a V-shaped groove formed on the bottom surface of the outer edge of the frame (1); the top of the cam (4) is a ball head style, which forms a line contact with the V-shaped groove.

4. The lens multi-degree-of-freedom fine adjustment device for a lens barrel according to claim 2, characterized by, The drive unit is a fine-tuning screw (7), which is spirally connected to the side wall of the adjustment frame (3); the end of the fine-tuning screw (7) contacts the tail of the cam (4), and the tail of the cam (4) is pushed and pulled by screwing in or out of the fine-tuning screw (7) to provide the horizontal driving force.

5. The multi-degree of freedom fine adjustment lens for a lens barrel according to claim 4, wherein The outer wall of the frame (1) is provided with a second working part that directly contacts the end of the fine-tuning screw (7); the end of the fine-tuning screw (7) is a ball head structure, and the second working part is a plane, and the two form a point contact.

6. The multi-degree of freedom fine tuning lens for a lens barrel according to claim 2, wherein The cam (4) is configured such that the center of its output end, the axis of the pivot pin (6), and the contact point of its receiving end are collinear, forming a lever mechanism.

7. The multi-degree of freedom fine adjustment lens holder for a lens barrel according to any one of claims 1 to 6, wherein It also includes a pre-tightening element; the pre-tightening element is a reaction spring (5) connected between the mirror frame (1) and the adjustment frame (3), which is used to provide a pre-tightening force to the mirror frame (1) pointing to the adjustment frame (3) to ensure that each contact pair in the adjustment mechanism always maintains close contact.

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