Asymmetric Flexure for Compact Scanning Mirror Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In display systems, the positioning of the scanning mirror close to the exit window is hindered by symmetrical flexures, leading to a larger scan cone and size penalties, making it difficult to design a compact housing that avoids clipping of the scan cone.
Innovation Solution
The use of an asymmetric flexure allows the scanning mirror to be positioned closer to the exit window by varying the lengths and cross-sectional dimensions of the flexure arms, enabling a more compact arrangement and smaller housing size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a symmetrical flexure is used to support the scanning mirror, then the structure is simple and easy to manufacture, but the scanning mirror cannot be positioned close to the exit window, resulting in a larger housing size
Solution Approach 1:
The patent applies asymmetry by designing a flexure structure with two unequal arms of different lengths. The first arm has a different length than the second arm, allowing the scanning mirror to be positioned at an asymmetric location that enables it to be closer to the exit window. This asymmetric configuration resolves the contradiction by sacrificing structural symmetry to achieve compact housing dimensions.
2Volume of moving object
If the scanning mirror is positioned further from the exit window, then the housing can be larger and accommodate the scan cone, but the overall form factor increases and the device becomes less compact
Solution Approach 1:
The asymmetric flexure positioning allows the scanning mirror to be located closer to the exit window, which reduces the scan cone size at the exit window and enables a smaller exit window area. This directly addresses the contradiction by using asymmetric positioning to minimize both the form factor and the required exit window size simultaneously.
3Device complexity
If a symmetrical flexure is used, then the design is straightforward, but it prevents optimal positioning of the scanning mirror for compact optical path design
Solution Approach 1:
The patent uses asymmetric flexure arm lengths to enable optimal positioning of the scanning mirror within the housing. This asymmetric configuration allows for a more compact optical path design by placing the scanning mirror at a location that minimizes the overall optical path length and housing dimensions, thereby resolving the contradiction between design simplicity and optical path compactness.
Data Source
AI summary
Briefly, in accordance with one or more embodiments, a scanning platform to scan a beam as a projected image comprises a frame and a scanning mirror supported by a flexure coupled to the frame of the scanning platform. The flexure has an asymmetric structure comprising a longer flexure arm and a shorter flexure arm to locate the scanning mirror at a position offset from a center of the frame. The resonant frequency of oscillation of the scanning mirror may be maintained or otherwise determined by selecting an appropriate cross-sectional area of the longer flexure arm or the shorter flexure arm, or combinations thereof.