Deflection Device Amplitude Modulation for Projection Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Resonantly operated scanners used in Lissajous projectors often result in excessive intensity at the edges of the projection surface due to minimal speed and soft spring suspension, making them unsuitable for applications requiring robustness against vibrations and homogeneous illumination.
Innovation Solution
A method for activating a deflection device that controls the oscillations of a deflection unit to maintain a predefined turning amplitude outside the maximal amplitude region, allowing for a tailored intensity distribution on the projection surface, reducing undesirable intensity increases at the edges and achieving desired patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If resonant operation of the deflection unit is used to achieve large amplitudes, then the optical resolution is improved, but excessive intensity occurs at the edges of the projection surface
Solution Approach 1:
The activation signal is modulated periodically to vary the turning amplitude of oscillations over time. The amplitude is increased to reach edge points during certain phases, then reduced to minimize dwell time and intensity accumulation at edges, creating a periodic pattern that balances coverage and intensity distribution
Solution Approach 2:
The turning amplitude parameter of the oscillations is dynamically changed by modulating the activation signal. The amplitude varies between a first value (for reaching edges) and a second reduced value (for minimizing edge intensity), allowing control over the intensity distribution pattern on the projection surface
2Area of stationary object
If the turning amplitude of oscillations is increased to reach edge points, then the coverage of the projection surface is improved, but the intensity at edge points increases excessively
Solution Approach 1:
The activation signal applies periodic modulation to the turning amplitude, alternating between higher amplitude phases (for edge coverage) and lower amplitude phases (for intensity reduction). This periodic variation ensures that while edge points are reached, the dwell time at any single location is minimized, reducing excessive intensity accumulation
Solution Approach 2:
The turning amplitude is made dynamic rather than static, continuously varying according to the modulation of the activation signal. This dynamic adjustment allows the system to adapt the amplitude in real-time, increasing it when edge coverage is needed and decreasing it when intensity control is prioritized
3Stability of the object's composition
If a soft spring suspension is used to enable resonant operation, then the amplitude of oscillations is improved, but the robustness against vibrations and shocks deteriorates
Solution Approach 1:
The system exploits mechanical vibration at the resonance frequency of the deflection unit to achieve large oscillation amplitudes. By operating at resonance, the system can maintain high amplitudes with minimal drive force, avoiding the need for soft spring suspensions and enabling the use of more robust hard spring suspensions that provide better vibration and shock resistance
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 enables robustness against vibrations while preventing excessive intensity at the edges, allowing for more uniform illumination and increased robustness, suitable for applications like automobiles, by modulating the activation signal to maintain the turning amplitude below the maximal amplitude, thus reducing flickering effects and enhancing the projection quality.
Implementation Method 1
The deflection unit has a quality factor >3000 and the activation device comprises a control loop that is designed to closed-loop control the first and/or the second activation frequency in a manner dependent on the measured phase position of the oscillations of the deflection unit, such that the maximal amplitude of the oscillations remains in the resonance region of the deflection unit
Implementation Method 2
the activation device comprises a control loop that is designed to closed-loop control the first and/or the second activation frequency in a manner dependent on the measured phase position of the oscillations of the deflection unit
Data Source
AI summary
A method for activating a deflection device comprising at least one deflection unit, for a projection device for projecting trajectories upon a projection surface, wherein the deflection device deflects electromagnetic radiation which is directed upon it, for producing trajectories, and the at least one deflection unit is activated by way of an activation signal delivered from a control device, for producing oscillations in each case with a turning amplitude at a direction change of the oscillation, about at least one deflection axis, wherein in the case of resonance, the oscillations have a maximal amplitude, at which the produced trajectories reach an edge of the projection surface. The activation signal is set in a manner such that the turning amplitude of the oscillations at least temporarily has a predefined value outside a region of the maximal amplitude of the oscillations, and an intensity distribution of the produced trajectories on the projection surface is achieved with a predefined intensity pattern. The document moreover relates to a deflection device as well as to a projection device.