Optical Sensor with Four Detection Channels for Metamerism Analysis
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Solution Overview
Problem
Current color measurement technologies face challenges in accurately determining the color impression of light sources due to metamerism, where the color appearance can vary under different illuminations, and fail to distinguish between light sources with different spectral compositions, as they rely on tristimulus values that do not account for spectral variations.
Innovation Solution
An optical sensor with multiple detection channels, each equipped with a photodetector and a filter with a unique transmission spectrum, allowing for the representation of CIE color matching functions as linear combinations of these spectra, enabling the determination of tristimulus values and spectral composition analysis, thereby overcoming metamerism and providing more reliable color impression measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If tristimulus values are used for color measurement, then the color impression can be determined, but spectral composition variations cannot be detected
Solution Approach 1:
The optical sensor divides the detection task into multiple spectral channels (at least four), each with a specific filter transmitting different wavelength ranges. This segmentation allows the system to capture spectral composition information while still calculating tristimulus values for color impression measurement, thereby resolving the contradiction between color accuracy and spectral information retention.
Solution Approach 2:
The patent transitions from three-dimensional color space measurement (tristimulus values only) to a higher-dimensional measurement space that includes both color coordinates and spectral parameters. By adding spectral composition analysis as an additional dimension, the system maintains color measurement accuracy while preventing loss of spectral information.
2Measurement precision
If three sensors with CIE color matching functions are used, then color locus can be determined, but metamerism cannot be detected
Solution Approach 1:
The optical sensor employs at least four segmented detection channels with different spectral transmission characteristics, enabling the system to distinguish between metameric samples that appear identical under standard illumination but have different spectral compositions. This segmentation provides the additional spectral information needed to detect metamerism while maintaining accurate color locus determination.
Solution Approach 2:
The system changes the measurement parameters by incorporating spectral composition data alongside traditional colorimetric values. By monitoring spectral parameters in addition to tristimulus values, the system can detect metamerism and provide more reliable color measurements that account for spectral variations.
3Loss of information
If multiple detection channels with different filters are used, then spectral composition can be analyzed, but device complexity increases
Solution Approach 1:
The optical sensor achieves multi-functionality by using the same array of photodetectors and filters to perform both colorimetric measurement (tristimulus values) and spectral composition analysis simultaneously. This universal design allows the system to extract multiple types of information from a single measurement setup, reducing overall device complexity despite the multiple detection channels.
Solution Approach 2:
The patent merges colorimetric and spectrometric measurement functions into a single integrated optical sensor device. By combining the tristimulus value calculation and spectral composition analysis in one instrument with shared optical components, the system reduces complexity compared to using separate devices for each measurement type.
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 optical sensor effectively determines tristimulus values and spectral composition, enhancing the reliability of color impression measurements by accounting for spectral variations, allowing for the detection of metamerism and providing a more comprehensive analysis of electromagnetic radiation.
Implementation Method 1
The at least four photodetectors are capable of detecting electromagnetic radiation
Implementation Method 2
Electromagnetic radiation with a wavelength within the transmission spectrum of a filter is passed by the respective filter. Electromagnetic radiation with a wavelength outside of the transmission spectrum of a filter is attenuated or completely blocked by the respective filter
Data Source
AI summary
An optical sensor comprises at least four detection channels, where each detection channel comprises a photodetector and a filter with a respective transmission spectrum. The transmission spectra of the at least four filters are different from one another, and the transmission spectra are set such that each of the three CIE color matching functions is a linear combination of the transmission spectra of at least two of the filters. Furthermore, a method for detecting electromagnetic radiation is provided.