Directional Force Sensing for Stylus Tips
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stylus systems fail to accurately mimic the pressure and angular variations of traditional writing instruments, such as pens and brushes, due to cumbersome and expensive dual sensing mechanisms for pressure and angular sensitivity.
Innovation Solution
A stylus directional force sensing technique employing a directional tip sensor with multiple force sensors to measure the magnitude and direction of force applied to the stylus tip, allowing for control of stylus behavior by determining the total force, angle, and rotation, using configurations like a floating plate setup with sensors to calculate these parameters efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate pressure and angular sensing systems are used, then measurement precision for pressure and angle is improved, but device complexity and cost increase
Solution Approach 1:
The patent combines pressure sensing and angular sensing into a single integrated force sensing system. Multiple force sensors (typically three or more) are arranged in a specific geometric configuration around the stylus axis, allowing simultaneous measurement of both magnitude (pressure) and direction (angle) of applied force through a unified sensing mechanism rather than separate systems.
Solution Approach 2:
The force sensing system serves multiple functions simultaneously: it measures total force magnitude, determines force direction angle, and can calculate rotational components. This multi-functional approach eliminates the need for separate dedicated pressure sensors and angle sensors, reducing overall system complexity while maintaining measurement precision.
2Measurement precision
If multiple force sensors are used to measure directional force, then measurement precision for force direction is improved, but use of energy increases
Solution Approach 1:
The system implements periodic sampling of force sensor data rather than continuous measurement. The directional force sensing is activated at specific intervals or triggered by detected force events, reducing the overall energy consumption while maintaining sufficient measurement precision for the application requirements.
Solution Approach 2:
The force sensing system is designed to be event-driven, where measurements are taken only when force application is detected. The system automatically activates sensing during stylus contact events and enters low-power states during non-contact periods, allowing the stylus to service its own power management needs.
3Measurement precision
If floating plate configuration with multiple sensors is used, then measurement precision for angular forces is improved, but device complexity increases
Solution Approach 1:
The force sensing system is segmented into multiple independent sensor elements arranged in a specific geometric pattern around the stylus axis. Each sensor measures force in a specific direction, and the combined readings from these segmented sensors allow calculation of total force magnitude and directional angle through mathematical processing.
Solution Approach 2:
The floating plate serves as an intermediary mechanical structure that distributes and transmits applied forces to multiple sensors. This intermediate element enables the conversion of complex multi-directional force applications into measurable signals from individual sensors, simplifying the overall measurement architecture.
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 reduces power requirements and computational complexity while enabling accurate emulation of pressure and angular variations, allowing for creative effects like varying line widths and curves, similar to traditional calligraphy, without the need for separate pressure and angular sensing systems.
Implementation Method 1
The sensors can be, for example, elastomeric force sensors, capacitive force sensors, or force sensitive resistors
Implementation Method 2
The sensors can be, for example, elastomeric force sensors, capacitive force sensors, or force sensitive resistors
Implementation Method 3
The sensors can be, for example, elastomeric force sensors, capacitive force sensors, or force sensitive resistors
Data Source
AI summary
The stylus directional force sensing technique described herein employs a directional tip sensor which measures the magnitude and direction of force applied to a stylus tip. This information is then used to control the behavior of the stylus in an application. In one embodiment, this simple design only measures the stylus angle when the tip is actually pressing on the surface. This has the added benefit of reducing power requirements and computational complexity.