Passive Stylus Optical Beam Attenuation for Touch Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitive touch systems lack a progressive and consistent response to stylus strokes, requiring additional components like force or pressure sensors and electromagnetic sensors, which increase cost and power consumption, and often necessitate frequent battery replacements, leading to user frustration.
Innovation Solution
An optical touch-sensitive device with emitters and detectors arranged around the periphery, where a passive stylus disturbs optical beams by a variable amount dependent on the force applied, allowing the controller to determine touch strength based on beam attenuation, enabling a more natural user experience without the need for active sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If active sensors (force or pressure sensors, electromagnetic sensors) are added to detect touch strength, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces active mechanical/electromagnetic sensors in the stylus with a passive optical interaction system. The stylus becomes a passive optical element that modulates light from emitters, eliminating the need for force sensors, pressure sensors, or electromagnetic sensors while maintaining touch strength detection capability through optical beam attenuation measurement.
Solution Approach 2:
The patent introduces optical beams as an intermediary between the stylus and the touch detection system. Instead of the stylus actively sensing touch strength, the optical beams serve as a mediator that the stylus passively modulates, allowing the system to infer touch strength from the degree of light attenuation without requiring active sensors in the stylus.
2Measurement precision
If active sensors are added to detect touch strength, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The patent replaces power-consuming active sensors with a passive optical modulation approach. The stylus consumes no power for sensing, as it passively interacts with light from the emitters. The system determines touch strength by measuring optical beam attenuation caused by the stylus, eliminating battery requirements entirely.
3Measurement precision
If electromagnetic sensors are added to detect stylus contact, then measurement precision is improved, but cost increases
Solution Approach 1:
The patent replaces expensive electromagnetic sensors with a passive optical interaction system. The stylus is manufactured as a simple passive optical element without electronic components, significantly reducing manufacturing cost while maintaining accurate contact and touch strength detection through optical beam modulation.
4Measurement precision
If batteries are added to power active sensors in the stylus, then measurement precision is improved, but loss of time increases due to frequent battery replacement
Solution Approach 1:
The patent replaces battery-powered active sensors with a passive optical system. The stylus contains no battery or electronic power source, as it relies on passive interaction with light from the emitters. This eliminates battery replacement entirely, saving users time and eliminating a source of frustration.
5Measurement precision
If multiple emitters and detectors are added to improve resolution, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent segments the optical detection system into multiple emitters and detectors arranged around the periphery of the touch surface. Each emitter-detector pair defines a beam, and by measuring which beams are attenuated and by how much, the system achieves high-resolution touch position and touch strength detection without requiring a dense array of sensors across the entire surface.
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
The solution provides a cost-effective and power-efficient means to detect touch strength and position, offering a consistent and progressive response to stylus interactions, enhancing user experience in applications like drawing and handwriting by visualizing annotations based on force applied.
Implementation Method 1
Each emitter produces optical radiant energy which is received by the detectors
Implementation Method 2
a passive stylus configured to disturb one or more of the optical beams by a variable amount when in contact with the touch sensitive surface. The variable amount is dependent on an amount of force applied to the stylus towards the touch sensitive surface
Data Source
AI summary
A touch sensitive surface has emitters and detectors arranged around a periphery of the touch sensitive surface. The emitters produce optical beams that are received by the detectors. A stylus is configured to disturb one or more of the optical beams by a variable amount when in contact with the touch sensitive surface. The variable amount depends on an amount of force applied to the stylus towards the touch sensitive surface. A controller of the touch sensitive surface is configured to determine the touch strength of a touch event performed by the stylus based on disturbances of one or more of the optical beams. The touch strength provides a measure of the amount of force applied to the stylus.