Multi-Frequency Proximity Detection Circuit for Noise Discrimination
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Solution Overview
Problem
Existing proximity detection technologies face challenges in distinguishing between hand proximity and noise, leading to slower response times and increased false detection probabilities, especially when detection ranges are extended.
Innovation Solution
A detection system that includes a first sensor electrode and a second sensor electrode, with a drive circuit supplying a drive signal of different frequencies in each detection period, and a detection circuit performing proximity detection based on signals received from the second sensor electrode, allowing for more accurate and timely proximity detection by distinguishing between noise and actual object proximity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single frequency is used for proximity detection, then the detection process is simple and fast, but false detection due to noise increases and detection accuracy decreases
Solution Approach 1:
The patent applies periodic action by performing proximity detection multiple times at different frequencies across multiple detection periods. The drive circuit supplies drive signals at different frequencies (e.g., first frequency in first detection period, second frequency in second detection period) to the first sensor electrode, and the detection circuit reads detection signals from the second sensor electrode repeatedly. This periodic multi-frequency detection allows the system to distinguish between noise and actual proximity events, improving detection accuracy while managing complexity through structured periodic operation.
2Reliability
If multiple frequencies are used for proximity detection, then false detection due to noise is reduced, but the detection time increases
Solution Approach 1:
The system performs detection at multiple frequencies through periodic detection periods, where each period uses a different frequency. This structured periodic approach allows the system to gather sufficient data for reliable noise discrimination while controlling the total detection time through defined detection periods.
Solution Approach 2:
The patent implements preliminary action by performing multiple detection operations at different frequencies before making a final proximity determination. The detection circuit accumulates detection results from multiple frequency measurements, and only after this preliminary multi-frequency detection is complete does the system determine whether proximity is detected. This preliminary multi-frequency detection process improves reliability by filtering out noise that would not consistently appear across different frequencies.
3Length of stationary object
If the detection range is extended, then the ability to detect distant objects improves, but the probability of detecting noise increases and response speed decreases
Solution Approach 1:
The patent uses periodic multi-frequency detection to maintain reliability when extending detection range. By performing detection at multiple frequencies over multiple periods, the system can distinguish between actual distant objects and noise signals, even when the detection range is extended to increase susceptibility to noise interference.
Solution Approach 2:
The system changes the frequency parameter of the drive signal across multiple detection periods to improve reliability. The drive circuit varies the frequency of the drive signal supplied to the first sensor electrode in different detection periods, allowing the detection system to identify patterns that indicate true proximity events versus noise, thereby maintaining detection accuracy across extended detection ranges.
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 system reduces false detection due to noise and enhances response speed by using varying frequencies for proximity detection, enabling more accurate detection of objects in a shorter time.
Implementation Method 1
a drive circuit that supplies, to a first sensor electrode, a drive signal of a different frequency in each of multiple detection periods
Implementation Method 2
a detection circuit that performs detection of proximity of an object, based on a detection signal received from a second sensor electrode disposed in the vicinity of the first sensor electrode
Data Source
AI summary
In a detection device, a drive circuit supplies, to a first sensor electrode, a drive signal (second drive signal) of a different frequency in each of multiple detection periods. A detection circuit performs detection of proximity of an object, based on a detection signal (second detection signal) received from a second sensor electrode disposed in the vicinity of the first sensor electrode in each of the multiple detection periods.