Press Sensor Threshold Switching for Accurate Long-Press Release Detection
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Solution Overview
Problem
Conventional displacement sensors face errors in detecting the end of a long press operation due to threshold settings, either misidentifying the end of press or failing to detect it when the user removes their hand slowly, leading to erroneous operations.
Innovation Solution
A pressing sensor configuration that includes a first sensor element, a press operation determining unit, and a setting unit, where the absolute value of the threshold is reduced after a prescribed time to accurately detect the end of a press operation, even during long presses, by adjusting the threshold difference from the ground voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a small magnitude negative threshold is set for determining the end of press, then the sensor can detect the end of press when the user removes their hand quickly, but the negative voltage from restitutive action may drop below the threshold causing erroneous detection
Solution Approach 1:
The threshold value is changed dynamically based on the elapsed time since press detection started. Initially, a first threshold is used, and after a predetermined time period, it switches to a second threshold with a larger absolute value. This dynamic adjustment allows the system to adapt to different phases of the press operation, resolving the contradiction between fast detection and accurate detection.
Solution Approach 2:
The invention changes the threshold parameter from a fixed value to a time-dependent value. The threshold switches between two different values based on the elapsed time, allowing optimization for different operational phases (initial press detection vs. end of press detection), thereby resolving the contradiction between speed and reliability.
2Reliability
If a large magnitude negative threshold is set for determining the end of press, then erroneous detection from restitutive action is prevented, but the sensor fails to detect the end of press when the user removes their hand slowly
Solution Approach 1:
The threshold value is changed dynamically based on the elapsed time since press detection started. Initially, a first threshold is used, and after a predetermined time period, it switches to a second threshold with a larger absolute value. This dynamic adjustment allows the system to adapt to different phases of the press operation, resolving the contradiction between fast detection and accurate detection.
Solution Approach 2:
The invention changes the threshold parameter from a fixed value to a time-dependent value. The threshold switches between two different values based on the elapsed time, allowing optimization for different operational phases (initial press detection vs. end of press detection), thereby resolving the contradiction between speed and reliability.
3Device complexity
If a fixed threshold is used for determining the end of press, then the device complexity is low, but the sensor cannot accurately detect the end of long press operations
Solution Approach 1:
The threshold value is changed dynamically based on the elapsed time since press detection started. Initially, a first threshold is used, and after a predetermined time period, it switches to a second threshold with a larger absolute value. This dynamic adjustment allows the system to adapt to different phases of the press operation, resolving the contradiction between fast detection and accurate detection.
Solution Approach 2:
The invention changes the threshold parameter from a fixed value to a time-dependent value. The threshold switches between two different values based on the elapsed time, allowing optimization for different operational phases (initial press detection vs. end of press detection), thereby resolving the contradiction between speed and reliability.
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 detection of the end of a long press without erroneous operations, preventing false positives or negatives, even when the user removes their hand slowly, ensuring reliable press operation detection.
Implementation Method 1
the piezoelectric element has electrodes formed respectively on both main surfaces of a piezoelectric sheet. When the piezoelectric sheet is displaced in shape by displacement in shape of the elastic material to cause a piezoelectric effect, by which an output voltage corresponding to the amount of displacement is output from the electrodes
Data Source
AI summary
A pressing sensor is provided that includes a first sensor element that outputs a voltage corresponding to an amount of displacement in shape of a receiving unit that receives a press operation; a press operation determining unit that determines whether the receiving unit is in a state of receiving a press operation; and a setting unit that, after elapse of a first prescribed time from a point of time at which the press operation determining unit determines that the receiving unit has received a press operation, sets an absolute value of a threshold that is smaller than an absolute value of the threshold before elapse of the first prescribed time, the absolute value of the threshold representing a difference from a ground voltage value for determining whether the receiving unit has ended reception of the press operation.