Bolometer Retina Gain Table Correction via Resistance Ratios
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Solution Overview
Problem
Bolometric infrared imaging detectors face calibration drift issues due to material resistance variations, leading to ghost images and reduced image quality, especially after intense infrared exposure, and existing correction methods are inadequate for maintaining precision across varying operational conditions.
Innovation Solution
A method for correcting the gain table of bolometric detectors by calculating a new gain table based on the ratio of resistance values and temperature coefficients, using a normalization factor to maintain calibration precision without requiring extensive recalibration procedures or temperature regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional bolometric detectors are used without correction, then the device complexity is low, but measurement precision deteriorates due to calibration drift over time
Solution Approach 1:
The patent applies preliminary action by pre-calculating correction factors based on resistance variations and storing them for later use. The correction methodology is prepared in advance through mathematical modeling of drift behavior, allowing rapid application without complex real-time measurements or interventions.
Solution Approach 2:
The patent replaces mechanical/physical correction systems (such as temperature control mechanisms or hardware recalibration) with a computational approach. By using mathematical models that substitute resistance variation ratios and temperature coefficient calculations, the system achieves precision correction without additional mechanical complexity.
2Measurement precision
If intensive recalibration procedures are performed to maintain precision, then measurement precision improves, but loss of time increases due to prolonged shutdowns
Solution Approach 1:
The patent enables self-service by allowing the detector to automatically apply correction factors derived from its own resistance measurements. The system monitors its own drift characteristics and performs self-correction without requiring external intervention, shutdown, or intensive recalibration procedures.
Solution Approach 2:
Correction factors are pre-calculated based on resistance variation models, enabling immediate application without time-consuming recalibration procedures. The mathematical framework prepares correction strategies in advance based on expected drift patterns.
3Measurement precision
If temperature regulation is implemented to stabilize resistance, then measurement precision improves, but use of energy increases due to active cooling or heating
Solution Approach 1:
The patent replaces physical temperature regulation mechanisms with a computational correction system. Instead of actively controlling temperature to stabilize resistance, the system measures resistance variations and applies mathematical corrections, eliminating the need for energy-consuming thermal control.
Solution Approach 2:
The patent changes the approach from controlling physical parameters (temperature) to correcting electrical parameters (resistance ratios). By working directly with resistance variation ratios and temperature coefficients in the mathematical model, the system avoids energy-intensive temperature control while achieving the same stabilization effect.
4Device complexity
If simple correction methods are used, then device complexity remains low, but measurement precision deteriorates due to residual calibration errors
Solution Approach 1:
The patent uses parameter changes by incorporating temperature coefficients into the correction model. The correction factor is not based solely on resistance ratios but also accounts for temperature-dependent resistance variations through the coefficient α, enabling more precise correction without significantly increasing system complexity.
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 method effectively reduces residual calibration errors and ghost images, maintaining image quality across the detector's lifetime and varying operational conditions, without the need for prolonged shutdowns or specific thermal conditions.
Implementation Method 1
means for absorbing infrared radiation and converting it into heat
Implementation Method 2
In the most widespread case of so-called bolometric detectors, this physical quantity is electrical resistivity
Implementation Method 3
These detectors can be temperature-controlled at their focal plane, typically using a Peltier module (TEC)
Data Source
Figure 1~6
Figure 2
Figure 3
AI summary
A method corrects a gain table of a dispersion correction in response of resistive bolometers of a bolometric detector of a bolometer retina. The method consists of: ■ acquiring (30032, 30033, 30034) retina readout signals corresponding to a scene substantially uniform in temperature; ■ calculating (30034, 30035) a correction table g according to the relation: gij=Rac_shutijRac_refij⋅TCRrefijTCRshutij ■ and correcting (30036) the gain table according to the relation: Gshutij=gij.GrefijN expressions in which: ■ (i, j) represent the coordinates of the bolometers in the retina and the tables; ■ Gref and Gshut are the gain table before and after correction; ■ Rac_shut(i,j) and Rac_ref(i,j) are the resistances of the bolometer (i,j) at the time of signal acquisition and at an earlier time; ■ TCRshut(i,j) and TCRref(i,j) are the coefficients of temperature variation of the bolometer (i,j) at the time of signal acquisition and at the earlier time; ■ N is a scalar normalization factor of the Gshut gain table.