Optical Smoke Sensing with Oscillator Timing Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical sensors experience signal decay due to high temperatures, leading to inaccurate sensing and potential false alarms in smoke detectors.
Innovation Solution
An optical sensing system with dual oscillators and processing circuits that compensate for signal decay by calculating a time relation between expected and real oscillating times, allowing for rapid and precise fire detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional optical sensor is used, then the device structure is simple, but the sensing signal decays at high temperature leading to inaccurate detection
Solution Approach 1:
The patent changes the operating parameters of the optical sensor by dynamically adjusting the exposure time based on temperature compensation. The processing circuit calculates a compensation value based on the oscillating signal characteristics and modifies the exposure time parameter to compensate for signal decay caused by high temperature, thereby maintaining sensing accuracy without changing the physical sensor structure.
Solution Approach 2:
The patent implements a feedback mechanism where the processing circuit continuously monitors the oscillating signal from the optical sensor, calculates compensation values based on signal decay characteristics, and adjusts the exposure time accordingly. This closed-loop feedback system ensures that sensing accuracy is maintained despite temperature variations, while the sensor structure remains unchanged.
2Measurement precision
If the exposure time is extended to capture more optical data, then the measurement precision improves, but the response time increases
Solution Approach 1:
The patent applies dynamics by making the exposure time adjustable rather than fixed. The processing circuit dynamically determines the optimal exposure time based on real-time temperature conditions and signal characteristics. This allows the system to extend exposure time when high precision is needed and reduce it when rapid response is required, optimizing the balance between measurement precision and detection speed.
Solution Approach 2:
The patent performs preliminary temperature compensation calculations before the actual optical sensing operation. The processing circuit pre-calculates the compensation value based on temperature conditions and uses this to determine the optimal exposure time in advance, allowing the optical sensor to operate at the best possible settings without delaying the overall detection response.
3Manufacturing precision
If the oscillator frequency is increased to improve time measurement resolution, then the time relation calculation accuracy improves, but the device complexity increases
Solution Approach 1:
The patent segments the time measurement function into two independent oscillators with different frequencies. The first oscillator provides a reference oscillating signal, while the second oscillator generates the actual timing signal. This segmentation allows each oscillator to be optimized for its specific function, with the lower-frequency oscillator providing stable time intervals and the higher-frequency oscillator providing precise measurements, without requiring a single complex high-frequency oscillator.
Solution Approach 2:
The patent introduces an intermediary processing circuit that mediates between the two oscillators and the optical sensor control. This processing circuit calculates the time relation between the oscillating signals and determines the appropriate exposure time, acting as an intermediary that translates the oscillating signals into precise timing control without requiring the oscillators themselves to be overly complex.
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
Compensates for signal decay caused by high temperatures, enabling rapid and accurate fire detection with reduced false alarms.
Implementation Method 1
pixels generate sensing signals corresponding received light
Implementation Method 2
a first oscillator, configured to generate a first oscillating signal with a first oscillating frequency
Data Source
AI summary
A smoke detector comprises a light source, an optical sensor, a first, and a second processing circuit. The optical sensor senses optical data and comprises; a first oscillator, generating a first oscillating signal; and a second oscillator, generating a second oscillating signal. The first processing circuit generates a first command to instruct the first oscillator to oscillate for a first expected oscillating time, and acquires a first real oscillating time, wherein the first processing circuit further computes a time relation between the first expected oscillating time and the first real oscillating time. The first processing circuit generates a second command to instruct the second oscillator to oscillate for a second expected oscillating time according to the time relation. The second processing circuit controls the smoke detector to generate a first alarm according to the time relation. The optical sensor can also be applied to other electronic devices.