Agile IR Scene Projector Using VACN Thermal Emitter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current infrared (IR) scene projectors using resistive heaters struggle to accommodate the performance and oversampling demands of larger and faster focal plane array IR sensors, requiring improved IR emitters and scene projectors for effective testing.
Innovation Solution
Employing a vertically aligned carbon nanotube (VACN) array as a thermal emitter, which absorbs visible light and converts it into IR radiation, enabling faster rise and fall times and broader black-body like IR emission, thus enhancing the capabilities of IR scene projectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If resistive heater elements are used to generate IR radiation, then IR scene projection is achieved, but the rise and fall times are slow and frame refresh rate is limited
Solution Approach 1:
The patent changes the material parameter from conventional resistive heater elements to vertically aligned carbon nanotube (VACN) arrays. This material substitution fundamentally alters the thermal response characteristics, enabling faster heating and cooling rates while maintaining IR radiation capability. The VACN material's superior thermal conductivity and lower heat capacity directly address the slow response time issue of traditional resistive heaters.
Solution Approach 2:
The invention employs a composite structure consisting of vertically aligned carbon nanotubes grown on a substrate. This composite material combines the high thermal conductivity of carbon nanotubes with the mechanical stability of the substrate, achieving both fast thermal response and structural integrity. The composite nature allows for rapid energy dissipation while maintaining the emitter's functional properties.
2Measurement precision
If larger focal plane arrays and faster IR sensors are deployed, then measurement precision and speed improve, but the existing IR emitter technology cannot accommodate the oversampling demands
Solution Approach 1:
The patent implements dynamic control of the VACN-based thermal emitter, enabling real-time modulation of IR radiation output. This dynamic capability allows the emitter to keep pace with fast-reading focal plane arrays and high-speed IR sensors, providing the necessary frame rates and oversampling capabilities that static conventional emitters cannot deliver.
Solution Approach 2:
By changing from conventional resistive heater materials to VACN arrays, the system achieves parameter values (response time, thermal conductivity, emissivity) that are compatible with next-generation fast-reading IR sensors and large-format focal plane arrays, enabling effective testing of advanced sensor systems.
3Productivity
If VACN array is used as thermal emitter, then rise and fall times are faster and IR emission is broader, but device complexity increases
Solution Approach 1:
The patent replaces conventional electrical resistive heating mechanisms with a photothermal conversion system using VACN arrays. This substitution eliminates the need for complex current distribution networks within the heater elements, simplifying the overall device architecture while achieving superior thermal response through optical excitation and rapid thermal conversion in the carbon nanotube material.
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 VACN array provides a fast and agile IR source with high absorptivity and thermal conductivity, allowing for the simulation of various IR environments, suitable for testing advanced IR imaging systems and detectors, with response times controllable by adjusting the length of the carbon nanotubes.
Implementation Method 1
The VACN array may include a plurality of carbon nanotubes disposed proximate to a thermally conductive substrate such that a longitudinal axis of the carbon nanotubes extends substantially perpendicular to a surface of the substrate. The thermal emitter may absorb the visible light from the light emitter and convert the visible light from the light emitter into IR radiation.
Implementation Method 2
produce broad-band black-body like IR emission resulting from absorption and heating of the VACN
Implementation Method 3
The carbon nanotubes may be configured to convert visible light directed thereon into IR radiation such that the IR radiation being emitted by thermal emission array is based on selective provision of the visible light to the VACN.
Data Source
AI summary
An infrared (IR) scene projector device includes a light emitter and a thermal emitter. The light emitter is configured to selectably provide visible light. The thermal emitter includes a vertically aligned carbon nanotube (VACN) array. The VACN array includes a plurality of carbon nanotubes disposed proximate to a thermally conductive substrate, such that a longitudinal axis of the carbon nanotubes extends substantially perpendicular to a surface of the substrate. The thermal emitter absorbs the visible light from the light emitter and converts the visible light from the light emitter into IR radiation.