Particulate Matter Sensor Using Dynamic Gain Adjustment
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Solution Overview
Problem
There is a need for a solution to measure the concentration of particulate matter of various sizes using a light sensor in electronic devices, as increasing air pollution from fossil fuel combustion and gas emissions affects human health and requires individual measurement capabilities.
Innovation Solution
An electronic system and method that includes an illuminator, a sensor with a pixel array generating analog signals from scattered light, and a processor converting these signals into digital values to determine particulate matter concentration based on gain values, distinguishing between different size ranges of particulate matter by varying the gain values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a light sensor is used to measure scattered light from particulate matter, then the measurement capability is improved, but the ability to distinguish between different size ranges of particulate matter deteriorates
Solution Approach 1:
The patent applies dynamics by making the gain value adjustable and variable. The processing circuit changes the gain value dynamically based on the detected signal level, allowing the system to adapt to different particulate matter concentrations and size ranges. This enables the same sensor to measure both small particles (PM2.5) and large particles (PM10) by adjusting the amplification factor, thereby resolving the contradiction between measurement precision and size range differentiation capability.
Solution Approach 2:
The patent implements parameter changes by modifying the gain value as a key system parameter. By varying the gain value, the system can enhance the detection sensitivity for different particulate matter sizes. The processing circuit automatically adjusts this parameter based on the scattered light intensity, enabling accurate measurement across multiple size ranges without requiring separate sensors for each particle size category.
2Measurement precision
If multiple sensors are used to measure different size ranges of particulate matter, then the measurement accuracy for each size range is improved, but the device complexity increases
Solution Approach 1:
The patent applies universality by designing a single light sensor that can perform multiple measurement functions. Through the processing circuit's ability to adjust gain values and apply different filtering algorithms, one sensor accomplishes what would traditionally require multiple specialized sensors. This multi-functional approach maintains measurement precision for different particle sizes while avoiding the complexity of implementing a multi-sensor array.
Solution Approach 2:
The patent uses parameter changes to enable a single sensor to function across multiple measurement ranges. By dynamically adjusting the gain value and applying different signal processing algorithms, the same physical sensor can be optimized for detecting different particulate matter sizes. This eliminates the need for multiple sensors with fixed characteristics, thereby reducing device complexity while maintaining measurement accuracy.
3Measurement precision
If the gain value is increased to detect smaller particulate matter, then the detection sensitivity is improved, but the measurement range for larger particulate matter deteriorates
Solution Approach 1:
The patent applies dynamics by implementing automatic gain adjustment in the processing circuit. The system dynamically selects appropriate gain values based on the detected scattered light intensity and the target particulate matter size range. This dynamic adaptation allows the system to use high gain values for detecting small particles while automatically switching to lower gain values when measuring larger particles, thereby maintaining both detection sensitivity and measurement range coverage.
Solution Approach 2:
The patent implements parameter changes by varying the gain value as a controllable parameter. The processing circuit adjusts this parameter based on the measurement requirements, enabling the system to optimize detection sensitivity for small particulate matter when needed while preserving the ability to measure larger particles by reducing the gain. This parameter flexibility resolves the contradiction between enhanced sensitivity and broad measurement range.
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 measurement of particulate matter concentration for specific size ranges, such as PM 10 and PM 2.5, by converting analog signals into digital signals and counting values above a threshold, improving health monitoring and air quality assessment.
Implementation Method 1
a pixel array configured to generate an analog signal based on scattered light according to light output from the light source
Data Source
AI summary
Provided are an electronic system, an image system, and a method for measuring particulate matter. The electronic system includes an illuminator, a sensor and a processor. The illuminator outputs light. The sensor includes a pixel array to generate an analog signal based on scattered light according to the output light, and a converting circuit to convert the analog signal into digital signals respectively corresponding to gain values, based on the gain values. The processor counts the number of values greater than or equal to a threshold value among values of the digital signals, and calculates a concentration of particulate matter having a target size range, based on a variation in the counted number according to a change of the gain values.