Light Sensor Infrared Compensation via Weighted Signal Processing
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Solution Overview
Problem
Conventional light sensors inaccurately measure ambient light levels due to the influence of infrared components, particularly in applications involving incandescent light and sunlight, which can impair the accuracy of visible light intensity measurements.
Innovation Solution
A light sensor system calculates the infrared component using weighted color signals from red, green, blue, or alternative color channels and a full spectrum signal, allowing for the correction of these signals to improve accuracy and isolate the infrared component, thereby enhancing the precision of light measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional light sensors are used to measure ambient light levels, then the sensors can detect visible light intensity, but the measurement accuracy is impaired due to infrared component interference
Solution Approach 1:
The patent segments the light spectrum detection by using multiple light sensors with different spectral sensitivity characteristics (first sensor sensitive to visible light, second sensor sensitive to infrared). This segmentation allows the system to separately measure visible light intensity and infrared component intensity, then combine the measurements to achieve accurate ambient light detection while compensating for infrared interference.
2Measurement precision
If infrared blocking filters are used to reduce IR components, then the measurement accuracy may be improved, but the device complexity increases
Solution Approach 1:
The patent replaces the mechanical/optical approach of using infrared blocking filters with an electronic/digital approach. Instead of physically filtering out infrared components, the system uses multiple sensors with known spectral characteristics and applies signal processing algorithms to mathematically separate and compensate for infrared interference, thereby reducing device complexity while maintaining or improving measurement accuracy.
3Measurement precision
If multiple light sensors with different spectral sensitivities are used, then the infrared component can be separated and compensated, but the device complexity increases
Solution Approach 1:
The patent employs light sensors that serve multiple functions: the first light sensor detects both visible light intensity and contributes to infrared component measurement, while the second light sensor primarily detects infrared components but also provides information about overall light levels. This multi-functionality allows the system to achieve accurate color channel signal extraction and infrared compensation without requiring a large number of specialized sensors, thereby controlling device 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
The method improves the accuracy of light sensor signals by isolating and correcting for infrared components, resulting in more reliable measurements of ambient light levels and color characteristics, independent of the light source's conditions.
Implementation Method 1
light sensors to sense red light, green light, blue light and a full spectrum light in order to generate the red channel signal R, the green channel signal G, the blue channel signal B and the clear channel signal C
Data Source
AI summary
Color light sensors are used to sense colored light and a full spectrum light in order to generate at least three color channel signals and a clear channel signal. An infrared component IR is calculated by summing up the color channel signals with individual weighting factors and subtracting a weighted clear channel signal.