Projected Capacitive Touch Sensors for Multi-User Anti-Ghosting
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Solution Overview
Problem
Existing touch sensors struggle to accurately differentiate between multiple concurrent touches from different users, leading to ghosting issues that hinder effective multi-user multi-touch functionality.
Innovation Solution
The implementation of a projected capacitive touch sensor that utilizes a sensing array and controller to identify anti-ghosts, associating touches that share anti-ghosts with a common touch entity and those that do not with separate entities, enabling distinct interaction modes for multiple users.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a projected capacitive touch sensor is configured to detect multiple concurrent touches, then multi-touch functionality is enabled, but ghosting issues occur that prevent accurate differentiation between touches from different users
Solution Approach 1:
The patent segments the touch detection problem by introducing anti-ghost detection as a separate analytical layer. The controller divides touches into different touch entities based on anti-ghost relationships, allowing concurrent touches from multiple users to be accurately differentiated. This segmentation enables the system to handle N-touches from multiple users simultaneously while maintaining measurement precision.
Solution Approach 2:
The patent introduces anti-ghost detection as an intermediary mechanism between the sensing array and touch entity association. By detecting anti-ghosts and using them as intermediate indicators, the system can determine whether concurrent touches belong to the same or different touch entities, thereby resolving the ghosting issue and enabling accurate multi-user multi-touch functionality.
2Adaptability or versatility
If the touch sensor associates all concurrent touches with separate touch entities, then multi-user functionality is improved, but touches from the same user may be incorrectly separated
Solution Approach 1:
The patent implements feedback through anti-ghost detection to verify touch entity associations. The controller continuously monitors anti-ghost relationships and uses this feedback to confirm or correct touch entity associations. This feedback mechanism ensures that touches from the same user are not incorrectly separated while still enabling accurate multi-user functionality.
Solution Approach 2:
The patent performs preliminary anti-ghost detection and analysis before finalizing touch entity associations. By pre-processing the touch data to identify anti-ghost relationships, the system establishes accurate touch entity groupings before executing multi-user interaction protocols, thereby improving both reliability and multi-user functionality.
3Speed
If the sensing array detects all touch points concurrently, then multi-touch response speed is improved, but computational complexity increases due to ghosting resolution requirements
Solution Approach 1:
The patent applies partial action by focusing anti-ghost detection only on relevant touch point combinations rather than analyzing all possible touch relationships. The controller identifies and processes only the necessary anti-ghost relationships needed to resolve ghosting for the detected touches, reducing computational complexity while maintaining fast multi-touch response 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
Enables accurate differentiation between touches from different users, allowing for seamless multi-user multi-touch interactions and enhancing the functionality of devices with multi-touch capabilities.
Implementation Method 1
Projected capacitive touch (PCAP) technology uses electric fields from embedded electrodes projected through glass layers that are influenced by finger touches with the result of changes in measured capacitances
Implementation Method 2
uses electric fields from embedded electrodes projected through glass layers
Data Source
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AI summary
Techniques for providing multi-user multi-touch projected capacitive touch sensors are disclosed herein. Some embodiments may include a touch sensor including a touch substrate with a touch surface, a sensing array, and a controller. The sensing array may be configured to provide sense signals indicating a first touch and a second touch occurring concurrently on the touch surface of the touch substrate. The controller may be configured to receive the sense signals from the sensing array and based on the sense signals, determine whether the first touch and the second touch share at least one anti-ghost. In response to determining that the first touch and the second touch share the at least one anti-ghost, the controller may be configured associate the first touch and the second touch with a common touch entity, such as an individual person.