Tap Detection Semiconductor Device Using Dual Threshold Segmentation
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Solution Overview
Problem
Existing portable terminal devices face challenges in accurately distinguishing between intended tap operations and erroneous vibrations, leading to frequent erroneous detection, especially during walking, due to the reliance on single threshold values for acceleration signal detection.
Innovation Solution
A semiconductor device and method that utilize two threshold values and specific pulse width conditions to differentiate between tap operations and other movements by requiring the acceleration signal to exceed both threshold values and adhere to specific time periods, thereby reducing erroneous detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the threshold value is set to be small to discriminate from shaking operations, then the discrimination capability improves, but erroneous detection of walking vibrations increases
Solution Approach 1:
The patent divides the detection process into two distinct phases: a first determination period for detecting tap operations and a second determination period for detecting erroneous vibrations. This segmentation allows the system to use different threshold values and detection criteria for different types of operations, resolving the contradiction between detecting weak taps and filtering walking vibrations.
Solution Approach 2:
The patent performs preliminary detection in the first determination period using a lower threshold to capture potential tap operations, then performs secondary verification in the second determination period. This preliminary action allows the system to sensitively detect weak taps while maintaining reliability through subsequent verification.
2Reliability
If the threshold value is increased to avoid erroneous detection during walking, then the reliability improves, but detection of weak tap operations deteriorates
Solution Approach 1:
The patent segments the detection process into two periods with different threshold values. The first determination period uses a lower threshold to detect weak taps, while the second determination period uses a higher threshold to filter erroneous vibrations, thus resolving the contradiction between sensitivity and reliability.
Solution Approach 2:
The patent implements periodic detection with alternating focus: first period for tap detection with lower threshold, second period for error filtering with higher threshold. This periodic action allows the system to optimize for different detection goals at different times.
3Device complexity
If a single threshold value is used for acceleration signal detection, then the device complexity is reduced, but the ability to distinguish between tap operations and erroneous vibrations deteriorates
Solution Approach 1:
The patent segments the detection process into two determination periods with different threshold values and detection objectives. This segmentation enables the use of multiple threshold values without significantly increasing complexity, as each period has a clear, focused function.
Solution Approach 2:
The patent dynamically adjusts the threshold value based on the detection period: using a lower threshold in the first period for tap detection and a higher threshold in the second period for error filtering. This dynamic adjustment improves discrimination accuracy without requiring a permanently complex system.
4Reliability
If the detection process continuously monitors for erroneous vibrations, then the reliability improves, but the detection speed of tap operations deteriorates
Solution Approach 1:
The patent segments the monitoring process so that the first determination period focuses on rapid tap detection with minimal verification, while the second determination period handles erroneous vibration filtering. This segmentation maintains detection speed by not continuously applying full verification to all signals.
Solution Approach 2:
The patent applies partial verification: not all acceleration signals undergo the full erroneous vibration detection process. Only signals detected in the first determination period proceed to the second period, reducing the overall processing load and maintaining detection speed.
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
This approach effectively suppresses erroneous detection and rapidly identifies tap operations by leveraging the distinct pulse characteristics of tap and walking movements, enhancing the precision and reliability of operation detection in portable terminal devices.
Implementation Method 1
an acceleration sensor installed therein
Implementation Method 2
acceleration signal representing acceleration is input from an acceleration detecting unit
Data Source
AI summary
A semiconductor device including an input unit to which an acceleration signal representing acceleration is input from an acceleration detecting unit installed in a portable terminal device, and a detection unit which detects that a tap operation is performed on the portable terminal device, in a case in which the acceleration signal input to the input unit reaches both of a first threshold value set on the positive side and a second threshold value set on the negative side and a period until the acceleration signal exceeds any one of the first threshold value and the second threshold value and then exceeds the other threshold value is equal to or more than a predetermined first period and is equal to or less than a second period larger than the first period.