Instantaneous Phase Mapping Deflectometry for Dynamic Surfaces
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Solution Overview
Problem
Existing deflectometry systems are limited in measuring dynamic events and environmental changes due to their reliance on time-multiplexed information, which restricts their ability to capture data in high vibration environments and unstable conditions, and requires multiple images to reconstruct surface slopes.
Innovation Solution
The development of an instantaneous phase mapping deflectometry method that multiplexes phase-shifted fringe patterns with color and uses Fourier techniques to decompose them into X and Y directions, allowing for a single snapshot to capture dynamic events and environmental changes, enabling the measurement of surfaces in high vibration environments and unstable conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If time-multiplexed phase shifting methods are used, then measurement precision is improved, but the system cannot capture dynamic events and is limited to static measurements
Solution Approach 1:
The patent combines multiple phase-shifted fringe patterns (typically 3-5 patterns) into a single composite display pattern that contains all phase information simultaneously. This merged pattern is displayed once and captured in a single camera exposure, eliminating the need for temporal multiplexing while preserving the precision benefits of phase shifting interferometry for dynamic surface measurements
2Measurement precision
If multiple images are captured to reconstruct surface slopes, then measurement accuracy is improved, but acquisition time increases and dynamic events cannot be captured
Solution Approach 1:
The patent encodes multiple phase-shifted patterns in the spatial domain rather than the temporal domain. By displaying all phase patterns simultaneously in a single composite image and using spatial frequency analysis (Fourier transform) to separate them, the system achieves accurate surface slope reconstruction from a single snapshot, eliminating time loss while maintaining measurement precision
3Device complexity
If conventional deflectometry systems are used, then hardware simplicity is maintained, but the system cannot operate in high vibration environments or unstable conditions
Solution Approach 1:
The patent merges multiple phase-shifted fringe patterns into a single composite display pattern that is captured in one camera exposure. This single-shot approach eliminates temporal sequencing requirements, making the system inherently robust against vibrations and environmental instabilities while maintaining the simple hardware configuration of conventional deflectometry systems
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 method enables precise and accurate measurement of dynamic events and environmental changes without the need for multiple images, providing a non-contact, instantaneous measurement of surface slopes with high fidelity, overcoming the limitations of traditional deflectometry systems.
Implementation Method 1
multiplexes phase-shifted fringe patterns with color
Implementation Method 2
uses Fourier techniques to decompose them into X and Y directions
Implementation Method 3
a camera to capture images of the surface (e.g., mirror, lens, etc.) under test, which is illuminated by the screen
Data Source
AI summary
Provided are instantaneous phase mapping deflectometry measurement systems and methods based on multiplexing phase shifted fringe patterns with color, and decomposing them in X and Y using Fourier techniques. The new methods and devices provide accurate measurements, and more robust tools with less uncertainty when reconstructing a surface (e.g., compared to prior art Fourier Transform Profilometry (FTP) methods). The systems and methods revolutionize the applications of deflectometry by enabling measuring dynamic events (e.g., in high vibration environments, and a host of other previously impossible scenarios), and including environmental changes to the bending modes of large optics. Methods of error correction applicable to the new methods and devices are also provided.