Micromirror Control Device Resolving Energy and Interference Contradictions
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Solution Overview
Problem
Micro-mirror control systems in image projection devices require high energy for continuous motion, which is inefficient, especially in portable devices with limited power supplies, and existing methods do not effectively distribute actuation energy between horizontal and vertical tilting axes without mutual interference.
Innovation Solution
A method and device that generate control signals for micro-mirrors at different frequencies, with the second frequency being lower than the first, and use binary modulation to modulate the second control signal, allowing for efficient energy distribution between the axes, reducing energy consumption and enabling larger horizontal deflection angles while minimizing interference between tilting motions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If continuous high-frequency control signals are applied to both tilt axes simultaneously, then image projection function is achieved, but energy consumption increases significantly
Solution Approach 1:
The patent applies periodic action by operating the micro-mirror at its resonant frequency for the fast tilt axis (first tilt axis) while using a lower frequency for the vertical tilt axis (second tilt axis). The control signals are synchronized to the resonant frequency of the micro-mirror, allowing efficient energy transfer and reducing the overall energy required to maintain continuous operation. This periodic resonant excitation enables the micro-mirror to achieve the required scanning motion with minimal energy input.
2Device complexity
If control signals for both tilt axes are applied at the same frequency, then simple synchronization is achieved, but mutual interference between axes occurs
Solution Approach 1:
The patent segments the control signals by assigning different frequencies to the two tilt axes. The first control signal for the fast tilt axis operates at the resonant frequency, while the second control signal for the vertical tilt axis operates at a lower frequency. This frequency segmentation eliminates mutual interference between axes while maintaining precise control independence. The modulator then combines these segmented signals in a way that preserves their individual characteristics without causing cross-axis interference.
3Power
If resonant frequency is used for fast tilt axis, then actuation efficiency increases, but available energy for vertical tilt axis decreases
Solution Approach 1:
The patent merges the control signals for both tilt axes through a modulator that combines the high-frequency resonant signal for the fast tilt axis with the lower-frequency signal for the vertical tilt axis. The modulator integrates these signals in such a way that the resonant actuation of the fast axis and the vertical positioning are achieved simultaneously using a single combined control signal, optimizing energy utilization across both axes.
Solution Approach 2:
The patent resolves the energy allocation problem by introducing a dimensional separation in frequency space. The fast tilt axis operates in the high-frequency resonant domain while the vertical tilt axis operates in the lower-frequency domain. This dimensional separation allows each axis to operate independently in its own frequency domain, eliminating energy competition between axes while maintaining efficient resonant actuation for the fast tilt axis.
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
This approach significantly increases actuation energy, allowing for larger horizontal deflection angles and reducing chip surface area, leading to more efficient energy use and prolonged battery life in portable devices, while maintaining image quality.
Implementation Method 1
a mechanical, electrostatic, magnetic force or a force generated in some other way is selectively exerted on a plurality of actuating elements
Implementation Method 2
modulating the second control signal by binary modulation, for example pulse width modulation, of the second control signal, at the first frequency
Implementation Method 3
laser beams in bundled form strike a biaxially suspended micro-mirror and are deflected by same onto a projection surface
Data Source
AI summary
A method for controlling a micro-mirror, having the following: generating a first control signal which encodes a tilting motion of the micro-mirror about a first tilt axis, at a first frequency; generating a second control signal which encodes a tilting motion of the micro-mirror about a second tilt axis which is perpendicular to the first tilt axis, at a second frequency which is lower than the first frequency; modulating the second control signal by binary modulation of the second control signal, at the first frequency; and controlling force coupling elements of the micro-mirror, using the modulated second control signal and the first control signal.