Lens Positioning Unit Using Monolithic Flexure Hinge
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lens positioning systems in optical systems face challenges in achieving precise axial adjustment without causing parasitic motion in directions other than the axial direction, particularly due to backlash and irregularities in screw-type devices.
Innovation Solution
A lens positioning unit incorporating a monolithic flexure hinge structure with a ring-shaped spring and a doughnut-shaped adjustor ring, which converts rotational motion into vertical translational motion, minimizing parasitic motion and ensuring precise axial positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a screw type device is used to adjust lens distance, then the device structure is simple and easy to manufacture, but parasitic motion occurs in directions other than axial direction due to backlash and irregularity
Solution Approach 1:
The patent replaces the traditional screw-type mechanical adjustment device with a flexure hinge-based mechanical system. The flexure hinge uses elastic deformation of a flexible beam structure to achieve rotational motion, eliminating the need for traditional screw threads and associated backlash problems. This substitution maintains mechanical simplicity while achieving precise axial positioning without parasitic motion.
Solution Approach 2:
The patent employs a flexure hinge composed of a flexible beam with controlled thin-walled structure. The hinge utilizes the elastic flexibility of the thin-walled beam to enable smooth rotational motion while maintaining high positioning precision. The flexible structure allows for precise control of lens axial position without the irregularities and backlash inherent in traditional screw mechanisms.
2Ease of operation
If a screw type device is used to adjust lens height, then the adjustment mechanism is simple, but rotation of optical axis occurs causing parasitic motion
Solution Approach 1:
The patent replaces the screw-type rotation mechanism with a flexure hinge system that converts rotational input motion into purely axial translational motion of the lens. The flexure hinge's flexible beam structure ensures that rotation occurs without inducing optical axis rotation or lateral displacement, providing reliable axial motion while maintaining operational simplicity through the adjustment knob.
Solution Approach 2:
The flexure hinge acts as an intermediary mechanism between the adjustment knob (input) and the lens mount (output). It transforms the rotational motion from the knob into precise axial translation of the lens, eliminating the direct coupling that causes optical axis rotation in screw-type systems. This intermediary flexure structure ensures pure axial motion while preserving ease of operation.
3Manufacturing precision
If precise axial adjustment is required, then positioning accuracy must be high, but parasitic motion from traditional mechanisms reduces reliability
Solution Approach 1:
The patent uses a flexure hinge with a precisely engineered flexible beam structure that provides both high positioning accuracy and motion stability. The controlled flexibility of the thin-walled beam allows for micron-level axial positioning while inherently preventing parasitic motions through its designed degrees of freedom, ensuring reliable and stable lens positioning.
Solution Approach 2:
By replacing traditional mechanical connection methods with a flexure hinge system, the patent achieves both high axial positioning accuracy and improved reliability. The flexure hinge eliminates backlash and irregular motion characteristic of traditional mechanisms, providing stable and repeatable positioning while maintaining the ability to achieve precise axial adjustment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables precise micron-level axial adjustment of lenses without parasitic motion in non-axial directions, enhancing the accuracy and reliability of optical systems and facilitating maintenance in applications like LCD and semiconductor exposure apparatuses.
Implementation Method 1
a ring-shaped spring secured to a lower portion of the monolithic flexure hinge structure. The ring-shaped spring may be configured to transmit vertical translational motion of the adjustor ring to the monolithic flexure hinge structure
Implementation Method 2
The upper portion of the monolithic flexure hinge structure may be supported on a wedge formed on an upper surface of the movable part. The wedge may be configured to convert rotational motion of the movable part into vertical translational motion of the upper portion of the monolithic flexure hinge structure
Data Source
AI summary
According to example embodiments, a lens positioning unit includes a fixed structure, a monolithic flexure hinge structure, any one of upper and lower portions of which is provided with a lens mount on which a lens is mounted and the other portion of which is secured to the fixed structure, and an input unit rotatably coupled to the fixed structure, the input unit serving to convert rotational motion into vertical translational motion so as to transmit the vertical translational motion to the upper or lower portion of the monolithic flexure hinge structure provided with the lens mount.