Touch Sensor Pseudo Push Determination via Capacitance Thresholds
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Solution Overview
Problem
Existing touch sensors without force sensors face challenges in accurately distinguishing between touch and push operations, often resulting in false detections due to wide-range capacitance changes, such as when a finger is attached.
Innovation Solution
A method using an integrated circuit connected to a touch panel that acquires capacitance level values, detects touches by identifying maximum values, and determines events based on area and sum total data to differentiate between touch and push operations by analyzing the change in capacitance levels and their distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If capacitance change detection is used to detect touch operations, then touch detection sensitivity is improved, but false detection of push operations occurs when capacitance changes in wide range
Solution Approach 1:
The touch panel surface is divided into multiple detection regions (first detection region and second detection region) with different detection thresholds. The first detection region uses a first threshold value while the second detection region uses a second threshold value, allowing different areas to be detected with different sensitivities to prevent false push detections in certain regions
Solution Approach 2:
Different detection thresholds are applied to different regions of the touch panel based on their specific characteristics. The first detection region has a first threshold value while the second detection region has a second threshold value, optimizing detection accuracy for each region's specific usage scenario and reducing false positives
2Reliability
If force sensor is added to distinguish touch and push operations, then push operation detection accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the mechanical force sensor system with an electrical field-based detection system using multiple detection regions and threshold comparisons. By analyzing capacitance changes across different regions and comparing against region-specific thresholds, the system can distinguish push operations without requiring additional mechanical sensors
Solution Approach 2:
The existing capacitance detection system is made multi-functional by implementing region-based threshold comparison logic. The same detection circuitry serves both touch detection and push operation detection functions by analyzing capacitance patterns across multiple regions with different thresholds, eliminating the need for separate force sensing hardware
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 prevents false recognition of push operations by distinguishing between local and wide-range capacitance changes, enhancing the accuracy of touch and push operation detection.
Implementation Method 1
acquiring level values indicating changes in capacitance at positions in a two-dimensional region of the touch panel
Data Source
AI summary
A method performed by an integrated circuit includes determining that a first touch is detected; in response to the determining that the first touch is detected, determining whether a second touch is detected; in response to the determining that the second touch is not detected, determining whether a third touch is detected; in response to determining that the third touch is not detected, determining an event corresponding to a single tap operation is to be output; in response to the determining that the third touch is detected, determining whether a fourth touch is detected; and in response to the determining that the fourth touch is not detected, determining an event corresponding to a double tap operation is to be output.