Scanning Micromirror Structure for Flat Reflectors in Compact Projection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing digital micromirror devices in image projection systems require large and high-intensity light sources, limiting their compactness and efficiency, and often necessitate color wheels or multiple pixel arrays for full-color projection.
Innovation Solution
The use of two-dimensional scanning micromirror systems with two separate uniaxial micromirror devices for orthogonal scanning, combined with hermetic packaging and optical relays, allows for compact and robust image projection systems that utilize electromagnetic actuation and stress relief layers to maintain reflector flatness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If digital micromirror devices use large and high intensity light sources, then image projection quality is improved, but device compactness deteriorates
Solution Approach 1:
The patent replaces traditional mechanical scanning systems with a micromirror device that uses electromagnetic actuation to deflect light beams. This substitution eliminates the need for large mechanical scanning components and high-intensity light sources, achieving compact device volume while maintaining projection quality through precise electronic control of mirror deflection angles
Solution Approach 2:
The patent changes the operating parameters by using low-power light sources in combination with precision electromagnetic actuation. Instead of relying on high light intensity, the system achieves effective projection by precisely controlling the deflection angles and timing of the micromirror, allowing compact device design without sacrificing image projection quality
2Adaptability or versatility
If digital micromirror devices use color wheels or multiple pixel arrays, then full color image projection is achieved, but device complexity increases
Solution Approach 1:
The patent employs periodic modulation of the light source to emit different colors at different time intervals, synchronized with the micromirror deflection sequence. This temporal multiplexing approach enables full-color image projection without requiring physical color wheels or multiple pixel arrays, significantly reducing device complexity while maintaining color versatility
Solution Approach 2:
The system uses dynamic control of the micromirror deflection angles and light source modulation to achieve color projection. By dynamically adjusting the timing and angle of mirror deflection in synchronization with color-coded light emission, the system creates full-color images through temporal sequencing rather than spatial separation, simplifying the overall device architecture
3Manufacturing precision
If micromirror platforms are made thicker, then reflector flatness and stress relief are improved, but device volume increases
Solution Approach 1:
The patent applies local quality enhancement by adding a stress relief layer only at specific locations on the micromirror platform where stress concentration occurs. This localized approach improves reflector flatness and reduces stress without requiring the entire platform to be thicker, thereby maintaining compact device volume while achieving the desired manufacturing precision
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 high-quality image projection with low power consumption, suitable for head-mounted displays, by using thicker platforms and stress relief layers to offset stress, and employing electromagnetic actuation for precise oscillation control.
Implementation Method 1
a first conducting coil positioned on a second side of the first platform opposite to the first side of the first platform, the first conducting coil arranged to apply magnetic forces to the first platform about the first axis
Implementation Method 2
a first magnetic field source arranged to apply a first magnetic field to the first platform
Implementation Method 3
a first platform coupled to a first base by a plurality of first support flexures, such as where the first platform is oscillatable about a first axis
Implementation Method 4
a stress relief layer positioned on a first side of the first platform... the stress relief layer provides a first stress distribution on the first side of the first platform while the first conducting coil provides a second stress distribution on the second side of the first platform
Data Source
AI summary
A scanning micromirror system includes a base having an axis passing therethrough, a plurality of support flexures coupled to the base, and a platform coupled to the base by the plurality of support flexures. The platform has a first side and a second side opposing the first side and is operable to oscillate about the axis. The scanning micromirror system also includes a stress relief layer positioned on the first side of the platform and a reflector positioned on the first side of the platform. The stress relief layer is positioned between the reflector and the platform.