Capacitive Touch Sensing With Phase-Based Hover Detection
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Solution Overview
Problem
Current sensors face challenges in detecting touch events with low latency and accuracy, particularly in distinguishing between hover and contact, and in efficiently processing signals for real-world, virtual reality, and augmented reality applications without increasing power consumption.
Innovation Solution
The implementation of frequency-orthogonal signaling techniques, including frequency-division multiplexing, code-division multiplexing, and hybrid modulation, in capacitive sensors that use signal infusion and phase-shifting methods to enhance detection capabilities, allowing for the differentiation of touch events with low latency and improved signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If frequency-orthogonal signaling techniques are implemented, then detection accuracy and latency are improved, but device complexity increases
Solution Approach 1:
The patent segments the signal processing by dividing the sensor array into multiple groups, where each group processes specific frequency-orthogonal signals independently. This segmentation enables parallel processing of complex signals while maintaining detection accuracy, effectively resolving the contradiction between measurement precision and device complexity.
Solution Approach 2:
The patent implements dynamic signal infusion that adapts to detected touch events in real-time. The system dynamically adjusts signal parameters and processing resources based on event detection needs, allowing high detection accuracy only when necessary while reducing complexity during normal operation.
2Measurement precision
If signal infusion and phase-shifting methods are used, then hover and contact differentiation is improved, but power consumption increases
Solution Approach 1:
The patent employs periodic signal infusion at specific frequencies rather than continuous infusion. By using periodic actions with frequency-orthogonal signaling, the system achieves accurate hover and contact differentiation only during necessary measurement intervals, significantly reducing overall power consumption while maintaining detection precision.
Solution Approach 2:
The patent changes signal parameters (frequency, phase) dynamically based on detection needs. By adjusting these parameters periodically and only when hover or contact events are detected, the system maintains high differentiation accuracy while minimizing power consumption during non-event periods.
3Productivity
If frequency-division multiplexing is implemented, then signal processing efficiency is improved, but device complexity increases
Solution Approach 1:
The patent divides the signal processing workload into segmented frequency channels through frequency-division multiplexing. Each channel is processed independently by dedicated sensor groups, enabling parallel processing that improves overall efficiency while managing complexity through modular organization.
Solution Approach 2:
The patent creates a universal signal processing framework where frequency-orthogonal techniques can handle multiple signal types (hover detection, contact detection, pressure sensing) simultaneously. This multi-functional approach improves processing efficiency across different sensor modalities while using a unified complex management system.
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 enables the detection of touch events with very low latency, improved accuracy in distinguishing between hover and contact, and enhanced signal processing, effectively addressing the limitations of existing sensors in real-world and virtual/augmented reality applications without increasing power consumption.
Implementation Method 1
the sensor is a capacitive sensor
Implementation Method 2
phase-shifting methods to enhance detection capabilities
Implementation Method 3
frequency-division multiplexing, code-division multiplexing, and hybrid modulation
Data Source
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AI summary
A person or object is infused with a signal. The infused signal has a phase relationship with the signals that are transmitted from and used by a touch sensor, controller or wearable. The phase relationship of the infused signal is used in order to increase the ability of receivers at or on the touch sensor, controller or wearable to measure and determine touch events, such as hover.