Infrared Detector Array Pixel Segmentation for Drift Correction
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Solution Overview
Problem
Conventional infrared thermometers face challenges in accurately determining surface temperature distributions, especially in scenarios where temperature drift occurs due to aging effects, requiring complex calibration methods and shutter mechanisms for correction.
Innovation Solution
A hand-held thermal imaging camera with an infrared detector array featuring measurement pixels and reference pixels, where the reference pixels are designed to be insensitive to infrared radiation, allowing for the detection of temperature drift and correction without a shutter, using a system with distinct thermal conductivities to differentiate between measurement and reference signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional infrared thermometers use measurement pixels sensitive to infrared radiation, then temperature measurement capability is improved, but temperature drift due to aging effects occurs
Solution Approach 1:
The detector array is segmented into two distinct types of pixels: measurement pixels (sensitive to infrared radiation) and reference pixels (insensitive to infrared radiation). This segmentation allows the system to simultaneously obtain both temperature measurement data and drift reference data, enabling correction of temperature drift while maintaining measurement capability.
Solution Approach 2:
Reference pixels act as an intermediary element that provides a reference signal representing the temperature drift affecting the measurement pixels. By comparing the reference pixel signals with the measurement pixel signals, the system can identify and correct drift effects without compromising the primary measurement function.
2Reliability
If shutter mechanisms are added for drift correction, then temperature drift correction capability is improved, but device complexity increases
Solution Approach 1:
The patent extracts the drift reference function from the measurement function by using reference pixels that are structurally similar to measurement pixels but insensitive to infrared radiation. This eliminates the need for mechanical shutters or other complex correction mechanisms, as the drift information is continuously available from the reference pixels during normal operation.
Solution Approach 2:
The reference pixels continuously provide drift reference information during normal measurement operation, enabling real-time drift correction without requiring external correction mechanisms or additional operational steps. The system corrects its own drift using the inherent reference signals from the reference pixels.
3Measurement precision
If complex calibration methods are used for drift correction, then measurement accuracy is improved, but ease of operation deteriorates
Solution Approach 1:
The reference pixels continuously provide drift reference information during normal measurement operation, enabling continuous drift correction without requiring periodic calibration procedures or interruptions in measurement. This continuous correction process maintains measurement accuracy automatically throughout operation.
Solution Approach 2:
The system uses feedback from the reference pixel signals to automatically adjust and correct the measurement data from measurement pixels. This closed-loop correction process continuously compares reference and measurement signals, identifies drift effects, and applies corrections to maintain measurement accuracy without user intervention.
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
Enables accurate, contact-free temperature distribution measurement and real-time correction of temperature drift, improving measurement precision and eliminating the need for complex calibration and shutter mechanisms.
Implementation Method 1
The temperature measurement using an infrared-sensitive thermometer is based on the detection of thermal radiation, i.e. infrared radiation in particular in a wavelength range between 3 μm and 50 μm, which is emitted by every object with different intensity depending on its temperature
Implementation Method 2
a plurality of reference pixels, each with a second thermal conductivity λBP are connected to the detector array substrate... the second thermal conductivity λBP is greater than the first thermal conductivity λMP
Data Source
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AI summary
The invention relates to a method for determining a temperature of a surface (22) without contact, in particular for determining a temperature distribution of a surface (22) without contact, which method proceeds from an infrared measuring system (10) that at least has: an infrared detector array (36), having a detector array substrate (72) and having a plurality of measuring pixels (62), which are each connected to the detector array substrate (72) with a first thermal conductivity λ MP (120), wherein the measuring pixels (62) are sensitive to infrared radiation and each provide a measurement signal for determining a temperature measurement value T MP (66), which temperature measurement value depends on the intensity of the incident infrared radiation, and having a plurality of reference pixels (64), which are each connected to the detector array substrate (72) with a second thermal conductivity λ BP (122) and which each provide a measurement signal for determining a temperature measurement value T BP (68), and wherein the method comprises at least the following steps: determining the temperature measurement values T BP (68) of a plurality of reference pixels (64); determining the temperature measurement values T MP (66) of a plurality of measuring pixels (62); correcting temperature measurement values T MP (66) by a pixel-associated temperature drift component Tdrift (46). According to the invention, the reference pixels (64) are implemented as blind pixels that are substantially insensitive to infrared radiation, wherein the second thermal conductivity λ BP (122) is greater than the first thermal conductivity λ MP (120) and the temperature drift components Tdrift (46) are determined by using temperature measurement values T BP (68). The invention further relates to an infrared measuring system (10) operated by means of the method.