Scanning Mirror Flexure Actuation for Compact Wide-Angle Scanning
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Solution Overview
Problem
Existing scanning mirror systems face challenges in achieving a larger scan angle while maintaining a compact size, which can lead to increased mirror deformation, reduced scanning frequency, higher costs, power consumption, and reduced operational lifetime of strain sensors due to high strain.
Innovation Solution
A scanning mirror system with a mechanically amplified actuator mechanism using a flexure structure and strain sensors placed at a low-strain anchor region to achieve a larger scan angle with reduced deformation and extended sensor lifetime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the size of the mirror is increased to increase resolution, then the resolution is improved, but mirror deformation during scanning increases and maximum scanning frequency is reduced
Solution Approach 1:
The scanning mirror system is divided into multiple independent scanning mirrors (e.g., first scanning mirror for horizontal scanning, second scanning mirror for vertical scanning). Each mirror handles a portion of the scanning task, allowing smaller individual mirror sizes that reduce deformation while maintaining overall system resolution through the composite scanning action of multiple mirrors.
2Manufacturing precision
If the scan angle of the mirror is increased to increase resolution, then the resolution is improved, but the strain in the flexure increases and system size increases
Solution Approach 1:
The system transitions from a single mirror performing both horizontal and vertical scanning to multiple mirrors where each handles scanning in specific dimensions. The first scanning mirror handles horizontal scanning while the second handles vertical scanning, distributing the mechanical strain across multiple flexure structures rather than concentrating it in one flexure, thereby reducing individual flexure strain while achieving the same resolution.
3Stress or pressure
If the flexure length is increased to reduce flexure strain, then the strain is reduced, but the scanning mirror system size increases
Solution Approach 1:
The scanning function is segmented across multiple mirrors with shorter flexures. Instead of one long flexure supporting a large mirror, multiple shorter flexures support smaller mirrors, achieving comparable or reduced strain while maintaining a compact overall system footprint since each individual flexure remains short.
4Force
If external actuators are used to drive the scanning mirror, then the scan angle can be increased, but cost, power consumption, and system size increase
Solution Approach 1:
The scanning mirrors utilize self-service actuation through integrated electrostatic actuators or piezoelectric elements directly on each mirror assembly, eliminating the need for separate external actuators. Each mirror assembly is self-contained with its own actuation mechanism, reducing overall system complexity, cost, and power consumption while achieving the required scan angles through the distributed mirror configuration.
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 system achieves a larger scan angle with reduced mirror deformation and extended sensor lifetime, maintaining a compact form factor and reducing operational costs.
Implementation Method 1
a first sensor and a second sensor respectively located at the first anchor and the second anchor, the first sensor and the second sensor configured to sense strain in the flexure
Implementation Method 2
an actuator system configured to actuate the first arm, the second arm, the third arm, and the fourth arm to thereby vary a scan angle of the mirror
Data Source
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AI summary
Examples are disclosed that relate to scanning mirror systems for display devices. One example provides a display device comprising a light source and a scanning mirror system coupled to a support structure (346), the scanning mirror system comprising a mirror, a flexure supporting the mirror (302), and a first anchor (332) and a second anchor (334) each coupled to the support structure. The scanning mirror system further includes a first arm (316) extending between the first anchor and a first portion (304a) of the flexure, a second arm (318) extending between the first anchor and the first portion of the flexure, and also includes a third arm (318), a fourth arm (320), and an actuator system (324, 326, 328, 330). Each of the first arm and the second arm define a respective gap (338, 344) that extends inwardly from an outer perimeter (336) of the scanning mirror system. The actuator system is configured to actuate the arms to vary a scan angle of the mirror.