Touch Device Pressure Sensor Control for Wet Conditions

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Solution Overview

Problem

Conventional touch devices malfunction when in contact with water or when the capacitive touch sensor fails, as they cannot accurately detect touch positions or pressures, leading to inconvenient usage.

Innovation Solution

A control method for touch devices that activates pressure sensors around the periphery of the touch panel to detect pressure values and determine touch positions, using a truth table to confirm the touch location even when the capacitive touch sensor is abnormal, ensuring continuous functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If capacitive touch sensor is used to detect touch input, then touch position detection is accurate under normal conditions, but the system fails when water or liquid contacts the touch device

Engineering Contradiction:

Improvetouch position detection accuracyVSAvoidsystem reliability in wet conditions

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent changes the detection parameter from capacitive sensing to pressure sensing. Pressure sensors detect mechanical pressure applied to the touch panel, which remains effective even when water or liquid contacts the device, thus maintaining reliability in wet conditions while still achieving accurate touch position detection

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces pressure sensors as an intermediary detection mechanism. These sensors are disposed around the periphery of the touch panel and detect pressure applied to the touch area, serving as a mediator that can accurately determine touch position without being affected by water or liquid interference

Inventive Principle:

Principle #24Intermediary (Mediator)

2Force

If pressure detection film is used to detect force magnitude, then pressure detection is possible, but the coordinate position of the force cannot be acquired

Engineering Contradiction:

Improvepressure detection capabilityVSAvoidtouch coordinate position information

Core Design Contradiction:

ForceVSLoss of information

Solution Approach 1:

The patent segments the pressure detection function by placing multiple discrete pressure sensors around the periphery of the touch panel at different positions. Each sensor detects pressure at its specific location, and by analyzing which sensors are activated and their pressure values, the system can determine both the magnitude of applied force and the precise coordinate position of the touch input

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single pressure detection film that only measures force magnitude to a distributed array of pressure sensors positioned at different spatial locations around the periphery. This spatial distribution adds the dimensional information needed to calculate touch coordinate positions based on the pattern and intensity of pressure detected at each sensor location

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Object-affected harmful factors

If capacitive touch sensor is inactivated due to abnormal detection, then false touch inputs are avoided, but the touch device becomes unusable

Engineering Contradiction:

Improvefalse touch input preventionVSAvoiddevice usability

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The patent implements a feedback mechanism where the processor continuously monitors the output of pressure sensors and compares it against expected patterns. When water or liquid contacts the device, the pressure sensor readings will show abnormal patterns (such as uniform pressure distribution or readings inconsistent with actual touch locations), allowing the system to identify and compensate for these conditions while maintaining normal operation

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent creates a universal detection system that can handle both normal touch inputs and abnormal conditions (water contact, liquid exposure). The pressure sensors serve multiple functions: detecting actual user touches, identifying water/liquid presence, and providing backup detection capability when capacitive sensing fails, ensuring the device remains usable across various environmental conditions

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 continuous operation of touch devices by accurately detecting touch positions and pressures, even in wet conditions or when the capacitive sensor is faulty, enhancing user experience and device reliability.

Implementation Method 1

The capacitive touch sensor detects a touch position of an external force applied on the touch panel

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

The plurality of pressure sensors detects a pressure on the touch position

Methodology Applied

Scientific EffectPressure detection: Pressure Gradient

Data Source

PatentUS10969906B2Control method for touch device

Publication Date: 2021.04.06 COMPAL ELECTRONICS INC

AI summary

The present disclosure provides a control method for a touch device. The control method of the touch device allows the plurality of pressure sensors to be activated to detect the pressure on the touch position of the touch panel while the capacitive touch sensor is probably invalid and the touch device is abnormal. Therefore, the touch device works continuously when the capacitive touch sensor is probably invalid.