Infrared Camera Parasitic Heat Compensation via Conversion Matrices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Infrared cameras face challenges in accurately estimating and compensating for parasitic heat, leading to imprecision in temperature readings due to the difficulty in estimating parasitic heat received by pixels, which is not effectively addressed by existing methods such as temperature probes.
Innovation Solution
A method involving parasitic heat sensing pixels and image pixels, where the relative transfer functions and responsivity are determined to create conversion matrices for 2D signal correction, allowing for precise estimation of parasitic heat without a temperature probe, by modeling the interior surface of the camera housing and calculating the etendue of each pixel with respect to different zones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature probe is added to the housing to estimate parasitic heat, then the measurement capability is improved, but the cost increases and the precision remains insufficient
Solution Approach 1:
The patent creates a virtual thermal model that copies and simulates the thermal behavior of the camera housing interior. Instead of using physical temperature probes, the system uses parasitic heat sensing pixels to capture thermal signatures and processes them through conversion matrices to generate a virtual representation of parasitic heat distribution, achieving accurate measurement without additional physical sensors
Solution Approach 2:
The patent replaces the mechanical/physical measurement system (temperature probes) with an optical/electronic system. Parasitic heat sensing pixels capture infrared radiation from the housing interior, and conversion matrices mathematically process these signals to estimate parasitic heat, substituting physical contact measurement with non-contact optical detection and computational analysis
2Measurement precision
If a temperature probe is used to measure parasitic heat, then the measurement function is added, but the cost increases significantly
Solution Approach 1:
The patent makes the pixel array multi-functional by including both image pixels for capturing visual infrared information and parasitic heat sensing pixels for measuring thermal signatures of the housing. This universal approach allows the same detector array to serve dual purposes, eliminating the need for separate temperature probe components and reducing manufacturing costs
Solution Approach 2:
The system uses its own parasitic heat sensing pixels to measure and compensate for parasitic heat effects. The conversion matrices are calibrated using the camera's自身的 thermal characteristics, allowing the system to self-diagnose and self-correct thermal measurement errors without requiring external expensive calibration equipment or temperature probes
3Measurement precision
If existing calibration methods are used, then the manufacturing process is simple, but the thermal image accuracy is insufficient
Solution Approach 1:
The patent performs preliminary calibration by determining conversion matrices that relate parasitic heat sensing pixel readings to actual parasitic heat values. This calibration is done in advance using a black body at known temperatures, creating lookup tables and transfer functions that are stored and applied during normal operation, enabling accurate compensation without complex real-time calculations
Solution Approach 2:
The system implements feedback by continuously monitoring parasitic heat using the parasitic heat sensing pixels and using the conversion matrices to calculate compensation values. These compensation values are applied to correct the thermal measurements from image pixels, creating a closed-loop system that actively compensates for thermal interference and maintains high measurement accuracy
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 enables precise estimation of parasitic heat, achieving thermal image accuracy within a few degrees Celsius, reducing costs by eliminating the need for temperature probes and improving the precision of thermal imaging.
Implementation Method 1
Each pixel of the pixel array converts a measured temperature at the pixel into a corresponding voltage signal
Implementation Method 2
the responsivity of the parasitic heat sensing pixels is determined by placing a black body in the field view of the pixels of said pixel array, and taking readings from said parasitic heat sensing pixels at at least two different temperatures
Data Source
Figure 1~3
Figure 4~5B
Figure 6A~6C
AI summary
The invention concerns a method of calibrating an infrared (IR) camera comprising a pixel array housed in a housing, the pixel array having an image sensor and one or more parasitic heat sensing pixels arranged to receive infrared light from different portions of an interior surface of the housing, the method comprising: receiving, by a processing device (902), one or more readings from each of said parasitic heat sensing pixels (105) and from each pixel (104) of said pixel array; and generating, by the processing device based on said one or more readings, one or more conversion matrices (M -1 Clum and MCpix) for converting readings (Pp) from said parasitic heat sensing pixels into pixel correction values for performing 2D signal correction of said image.