Resistive Touch Screen Dual-Touch Detection via Segmented Screens
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Solution Overview
Problem
Current resistive touch screens are unable to detect two simultaneous touches, limiting their capability for input via gestures.
Innovation Solution
A resistive touch screen apparatus comprising a first and second resistive screen separated by a gap, with a reference resistor and voltage source to measure voltage changes across the screens when touched at multiple locations, enabling detection of dual touches by tracing two points of contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single resistive screen is used, then the device structure is simple, but it cannot detect two simultaneous touches
Solution Approach 1:
The single resistive screen is segmented into two separate resistive screens (first and second resistive screens) with different resistance characteristics. This segmentation allows the system to detect multiple touch points by measuring voltage changes across the series combination, resolving the contradiction between maintaining simple structure and achieving enhanced touch detection capability.
2Measurement precision
If voltage is applied across the resistive screen to detect touch location, then touch position can be determined, but the system cannot distinguish between single and dual touches
Solution Approach 1:
A reference resistor is introduced as an intermediary element in series with the resistive screen. This reference resistor serves as a mediator that converts the complex resistance changes caused by multiple touches into measurable voltage changes, enabling the system to distinguish between single and dual touches while maintaining accurate location detection.
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 location and detection of two simultaneous touches, allowing for input via gestures by tracing two points of contact, enhancing user interaction capabilities.
Implementation Method 1
a voltage source configured to apply a voltage across a series combination of the first reference resistor and the first resistive screen
Implementation Method 2
a voltage detector configured to measure a first voltage across the reference resistor, wherein the first voltage increases when a user touches the first resistive screen at two distinct locations
Implementation Method 3
creating two distinct electrical connections between the first resistive screen and the second resistive screen
Data Source
AI summary
An apparatus including: a first resistive screen extending in a first direction and a second direction; a second resistive screen extending in the first direction and the second direction and separated from the first resistive screen; a first reference resistor; a voltage source configured to apply a voltage across a series combination of the first reference resistor and the first resistive screen; and a voltage detector configured to measure a first voltage across the reference resistor.