Tunable Spectral Illuminator Camera for Compact Hyperspectral Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing digital cameras and optical measurement systems are limited by mechanical filters, which are expensive, large, and often inaccurate, and lack the ability to efficiently capture spectral images across a broad spectrum.
Innovation Solution
A camera system incorporating a tunable optical filter positioned between a spectral illumination source and the scene, allowing dynamic adjustment of active spectral light sub-bands, and a sensor array to measure reflected light in selected sub-bands, enabling efficient multi- or hyper-spectral imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If mechanical filter wheels are used in optical measurement systems, then spectral filtering can be achieved, but the equipment becomes expensive, large-sized and complex
Solution Approach 1:
The patent replaces mechanical filter wheels with a Fabry-Perot interferometer that uses optical interference principles. Instead of mechanically moving filters, the system uses controlled interference of light waves between two parallel reflective surfaces, where the pass band is adjusted by changing the optical path difference through piezoelectric actuators or temperature control, eliminating moving mechanical parts and reducing system complexity.
Solution Approach 2:
The patent changes the physical parameters of the Fabry-Perot interferometer (such as the distance between reflective surfaces or the refractive index of the medium between them) to dynamically adjust the pass band wavelength. This allows continuous spectral filtering without mechanical filter changes, reducing system complexity while maintaining measurement precision.
2Measurement precision
If mechanical filter wheels are used in optical measurement systems, then spectral filtering can be achieved, but the equipment becomes large-sized
Solution Approach 1:
The patent replaces bulky mechanical filter wheels with a compact Fabry-Perot interferometer consisting of two parallel reflective surfaces separated by a small distance (typically micrometers to millimeters). This optical interference-based system achieves spectral filtering in a much smaller volume while maintaining or improving filtering accuracy through precise optical path control.
3Ease of manufacture
If mechanical filter wheels are used in optical measurement systems, then spectral filtering can be achieved, but the equipment is often not sufficiently accurate and stable
Solution Approach 1:
The patent replaces mechanical filter wheels with a Fabry-Perot interferometer that has no moving mechanical parts during operation. The stability is achieved through rigid mounting of the interferometer components and controlled adjustment of the optical path using piezoelectric actuators or temperature control, eliminating mechanical wear, misalignment, and vibration issues that affect filter wheel systems.
4Measurement precision
If a tunable optical filter is positioned between spectral illuminators and the scene, then spectral signal-to-noise ratio is improved, but device complexity increases
Solution Approach 1:
The patent uses a Fabry-Perot interferometer as the tunable optical filter, which achieves high spectral selectivity and signal-to-noise ratio through optical interference. The interferometer's compact design and lack of moving parts during measurement reduce the overall system complexity compared to traditional mechanical filter systems, while providing superior spectral filtering performance.
Solution Approach 2:
The patent dynamically adjusts the pass band of the Fabry-Perot interferometer by changing physical parameters (such as the cavity length or refractive index) to match the spectral characteristics of different illuminators. This parameter tuning approach allows the system to optimize signal-to-noise ratio for each spectral band without adding complex mechanical switching mechanisms.
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 high spectral signal-to-noise ratio and increased field of view by selectively filtering and measuring spectral light, reducing system noise and complexity, and enabling robust spectral image acquisition across a broad spectrum.
Implementation Method 1
a tunable optical filter optically intermediate the one or more spectral illuminators and a scene, and dynamically adjustable to change a selected sub-band of the active spectral light that illuminates the scene
Implementation Method 2
a sensor array including a plurality of sensors each configured to measure spectral light reflected from the scene in the selected sub-band
Data Source
Figure 1A~1C
Figure 2A~2C
Figure 3
AI summary
A camera includes one or more spectral illuminators, a tunable optical filter optically intermediate the one or more spectral illuminators and a scene, and a sensor array. The one or more spectral illuminators are configured to emit active spectral light. The tunable optical filter is dynamically adjustable to change a selected sub-band of the active spectral light that illuminates the scene. The sensor array includes a plurality of sensors each configured to measure spectral light reflected from the scene in the selected sub-band.