Optical Stops for Infrared Imaging Signal Throughput
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Solution Overview
Problem
Current optical systems face challenges with diffraction effects that lead to increased unwanted background radiation and reduced signal throughput, particularly in small-sized infrared systems, which can result in inaccurate radiometric measurements and false alarms.
Innovation Solution
The implementation of an optical system with two optical stops, one to block unwanted background radiation and the other to capture a larger portion of diffracted scene radiation, along with the use of a shield element to reduce unwanted radiation, enhances radiometric accuracy and increases signal throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of stationary object
If detecting elements and slit apertures are made smaller to reduce system size and mass, then the system becomes more suitable for UAV and man-portable applications, but diffraction effects increase causing unwanted background radiation to leak through and signal radiation to be lost
Solution Approach 1:
The patent divides the optical path into multiple segments by introducing additional optical stops between the slit aperture and detecting elements. These stops segment the diffracted radiation paths, allowing selective blocking of unwanted background radiation while preserving signal radiation. This segmentation resolves the contradiction by enabling small aperture sizes without sacrificing radiometric accuracy.
Solution Approach 2:
The patent introduces intermediary optical stops as mediator elements in the optical path. These stops act as intermediaries that selectively intercept diffracted background radiation before it reaches the detecting elements, while allowing signal radiation to pass through. This intermediary approach enables small system size while maintaining measurement precision.
2Volume of moving object
If detecting elements and slit apertures are made smaller to reduce system size, then the system becomes more compact for portable applications, but signal radiation is diffracted outside the geometric ray bundle and vignette by optical elements, reducing signal throughput
Solution Approach 1:
The patent addresses signal loss in the third dimension by positioning optical stops at strategic locations in the optical path where diffracted signal radiation can be captured. These stops extend the effective collection area beyond the traditional two-dimensional aperture plane, recovering signal radiation that would otherwise be lost to diffraction. This dimensional approach enables compact system size while preserving signal throughput.
3Measurement precision
If unwanted background radiation is blocked to improve radiometric accuracy, then measurement precision improves, but the system complexity increases due to additional optical stops and shield elements
Solution Approach 1:
The patent designs optical stops that serve multiple functions simultaneously: they block unwanted background radiation, preserve signal radiation, and define optical paths. This multi-functionality reduces the need for separate dedicated components, thereby limiting the increase in system complexity while achieving improved radiometric accuracy.
4Loss of energy
If the optical stop is enlarged to capture diffracted scene radiation, then signal throughput increases, but unwanted background radiation from outside the geometric rays also passes through more easily
Solution Approach 1:
The patent applies local quality by positioning multiple optical stops at different locations in the optical path, each with specific properties optimized for its local function. Some stops are positioned to capture diffracted signal radiation while others are positioned to block background radiation. This localized optimization allows the system to simultaneously increase signal throughput and reject background radiation, resolving the contradiction.
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 improves radiometric accuracy by blocking unwanted background radiation and allowing more diffracted scene radiation to reach the detecting element, reducing the impact of diffraction and enhancing the sensitivity of the imaging system.
Implementation Method 1
the effects of the diffraction of light become more significant, leading to the leakage of unwanted background radiation from outside the geometric rays to pass through to the detecting element
Implementation Method 2
leading to the loss of signal radiation that is diffracted outside of the geometric ray bundle and vignette by the optical elements or stop of the system
Data Source
AI summary
Systems and methods for increasing the overall throughput, decreasing the overall background radiation, or a combination thereof for imaging systems.