Shortwave Infrared Camera Bandwidth Restriction
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Solution Overview
Problem
Existing shortwave infrared cameras capture the entire 0.9-1.7 micron bandwidth, which is not necessary for night vision systems on commercial vehicles, leading to inefficient image capture and potential non-uniformities due to the full range of wavelengths being detected.
Innovation Solution
A camera design that incorporates a filter or modified image plane to limit the shortwave infrared bandwidth to only capture between 0.9 and 1.5 microns, using a filter or altering the indium arsenide to gallium arsenide ratio in the image plane to exclude wavelengths outside this range, ensuring only the necessary wavelengths reach the detection layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the camera captures the full shortwave infrared bandwidth (0.9-1.7 microns), then the camera can detect all available SWIR wavelengths, but this leads to unnecessary detection of wavelengths not needed for commercial vehicle night vision and potential non-uniformities in the captured images
Solution Approach 1:
The patent extracts and removes unnecessary wavelength ranges from the detected spectrum by implementing a bandpass filter that allows only the required 0.9-1.5 micron range to pass through to the detector. This extraction principle eliminates harmful or unnecessary SWIR wavelengths (1.5-1.7 microns) that cause non-uniformities while preserving the useful bandwidth for night vision applications.
Solution Approach 2:
The patent applies local quality by making the image plane selectively sensitive to specific wavelength ranges through modified semiconductor materials with tailored bandgap energies. Different regions of the detector are engineered to respond only to the desired 0.9-1.5 micron range, creating localized spectral sensitivity that improves image uniformity by excluding wavelengths that would otherwise cause detection non-uniformities.
2Loss of information
If the camera captures the full shortwave infrared bandwidth, then maximum information is available, but this results in inefficient image capture for night vision applications where the full range is not needed
Solution Approach 1:
The patent extracts only the necessary wavelength information (0.9-1.5 microns) required for night vision applications, discarding the excess bandwidth (1.5-1.7 microns) that does not contribute to the application's performance. This extraction improves productivity by reducing the data processing burden and focusing detection resources on the relevant spectral range.
Solution Approach 2:
The patent applies partial action by capturing only the sufficient portion of the SWIR spectrum needed for night vision rather than the complete theoretical bandwidth. The bandpass filter is configured to transmit exactly the wavelength range required for effective night vision, avoiding the excessive capture of additional wavelengths that would increase processing requirements without providing proportional benefit.
3Measurement precision
If a filter is added to limit the bandwidth, then wavelength selection is improved, but the device complexity increases
Solution Approach 1:
The patent merges the filtering function directly into the image plane structure by integrating the bandpass filter with the detector array. This consolidation combines the wavelength selection capability with the detection function in a single integrated component, thereby improving wavelength selection precision while minimizing the increase in device complexity that would result from adding a separate filter assembly.
Solution Approach 2:
The patent employs composite materials in the form of a bandpass filter with specific optical properties that allow precise wavelength selection. The filter is engineered with materials and structures that provide the required spectral transmission characteristics, achieving high measurement precision in wavelength selection while the compact integration keeps the overall device complexity manageable.
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 solution effectively limits the camera's capture to the required bandwidth, preventing unnecessary wavelength detection and maintaining uniformity, thus optimizing image capture for night vision applications without the full range of SWIR bandwidth.
Implementation Method 1
A camera design that incorporates a filter or modified image plane to limit the shortwave infrared bandwidth to only capture between 0.9 and 1.5 microns
Implementation Method 2
altering the indium arsenide to gallium arsenide ratio in the image plane to exclude wavelengths outside this range
Implementation Method 3
altering the indium arsenide to gallium arsenide ratio in the image plane to exclude wavelengths outside this range, ensuring only the necessary wavelengths reach the detection layer
Data Source
AI summary
A camera comprises an image plane for capturing shortwave infrared wavelengths. The image plane captures only a portion of a shortwave infrared wavelength band, and excludes other wavelengths. A method of designing a camera is also disclosed.