Active Stylus Touch Sensor Communication via Modulated Signals
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Solution Overview
Problem
Current touch sensors, particularly capacitive touch screens, face challenges in accurately detecting the presence and location of objects within a touch-sensitive area due to limitations in electrode configurations and communication methods between touch sensors and active styluses, leading to inefficiencies in data transmission and processing.
Innovation Solution
The implementation of an array of drive and sense electrodes on substrates with specific patterns and configurations, coupled with a touch-sensor controller that supplies drive signals and senses charge changes, enables precise detection of touch or proximity inputs. Additionally, active styluses communicate data through modulated signals using techniques like amplitude shift keying, allowing for effective interaction with touch sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional capacitive touch sensors use simple electrode configurations, then the device complexity is reduced, but the measurement precision of touch detection deteriorates
Solution Approach 1:
The touch sensor divides the sensing area into multiple segments with different electrode configurations. Different regions use different electrode patterns optimized for their specific functions (e.g., high-resolution typing area vs. general touch area), allowing high measurement precision in critical areas without uniformly increasing complexity across the entire device.
Solution Approach 2:
The patent applies different electrode configurations to different local areas of the touch sensor. For example, certain regions may use interdigitated electrodes while others use parallel plate configurations, optimizing each local area for its specific detection needs while maintaining overall system manageability.
2Loss of information
If active stylus transmits more data using traditional communication methods, then the information content increases, but the loss of time in data transmission increases
Solution Approach 1:
The active stylus and touch sensor use periodic synchronization signals to establish communication intervals. Data transmission occurs in synchronized bursts rather than continuously, allowing efficient transfer of multiple data types (pressure, tilt, contact state) within defined time windows, reducing overall transmission time while maintaining data completeness.
3Measurement precision
If touch sensors use continuous monitoring to improve detection accuracy, then the measurement precision improves, but the use of energy increases
Solution Approach 1:
The touch sensor system performs monitoring at periodic intervals rather than continuously. The drive signals are applied in alternating periods with sensing periods, allowing the system to maintain detection accuracy through regular sampling while significantly reducing power consumption compared to continuous monitoring.
Solution Approach 2:
The system uses the inherent capacitive properties of the touch sensor and stylus to generate detection signals without requiring constant external power input. The alternating drive and sense electrodes create self-sustaining detection cycles that maintain precision while minimizing energy expenditure.
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 solution enhances the accuracy and efficiency of touch detection and data communication between touch sensors and active styluses, enabling precise tracking of object locations and improved user interactions with touch-sensitive devices.
Implementation Method 1
When an object touches or comes within proximity of the surface of the capacitive touch screen, a change in capacitance may occur within the touch screen at the location of the touch or proximity.
Implementation Method 2
active styluses communicate data through modulated signals using techniques like amplitude shift keying
Data Source
AI summary
In one embodiment, a method includes receiving sensor data from one or more sensors in or on a stylus, the stylus including one or more electrodes and one or more computer-readable non-transitory storage media embodying logic for wirelessly transmitting signals to a device through a touch sensor of the device. The method includes generating a carrier signal and modulating the carrier signal to communicate the sensor data and wirelessly transmitting from the stylus to the device the carrier signal as modulated through the touch sensor of the device.